HUMAN ANATOMY 
GENERAL AND DESCRIPTIVE  HUMAN ANATOMY 
GENERAL AND DESCRIPTIVE 
FOR THE USE OF STUDENTS 
BY 
JOHN CLELAND, M.D, LL.D, D.Sc., F.R.S. 
PROFESSOR OF ANATOMY IN THE UNIVERSITY OF GLASGOW 
AND 
JOHN YULE MACKAY, M.D., C.M. 
PROFESSOR OF ANATOMY IN UNIVERSITY COLLEGE. DUNDEE’, LATE SENIOR DEMONSTRATOR 
IN THE UNIVERSITY OF GLASGOW 
WITH 630 ILLUSTRATIONS, OF WHICH 257 BY THE AUTHORS ARE NOW 
PRINTED FOR THE FIRST TIME 
jSTciu |9ork 
THE MACMILLAN COMPANY 
LONDON: MACMILLAN & CO., Ltd. 
1896 
All rights reserved Copyright, 1896, 
THE MACMILLAN COMPANY. 
J. S. Cushing & Co. Berwick Sc Smith 
Norwood Mass. U.S.A. 
Norfaooh PREFACE. 
In this work it is sought to provide for students of Medicine and 
of Science a complete compendium of the Anatomy of the Human 
Body, which shall, both in macroscopic and microscopic detail, give 
a clear and full account of universally received facts, while incor- 
porating the results of recent research and indicating the relations 
of structure to function. Development has been gone into, although 
with brevity, yet with the object kept constantly in view of enabling 
the student to understand the morphological import of the adult 
architecture. But there is much morphological speculation which 
would be out of place in a volume like this, not professing to treat 
of the anatomy of any animal form other than the human body. 
As respects topographical relations and other matters of profes- 
sional interest, it has been the aim of the authors to supply the 
wants of both physicians and surgeons. 
When it has seemed expedient, reference has been made to the 
names of authors and even to individual memoirs, but it has been 
left to larger treatises to furnish the investigator with lists of titles 
of books and recent contributions to anatomical literature. 
The sections devoted to the Muscles, the Heart and Bloodvessels, 
the Lymphatics, and also the Distributed Nerves, are the independent 
work of Dr. Mackay, who has also selected the illustrations for them, 
and supplied some from his own pencil. The rest of the book is 
written by Dr. ClMand, who is also responsible for the general 
arrangement. 
To more than half of the illustrations no name is attached; and 
these (with the exception of a few which have already appeared in 
Dr. Cleland’s Animal Physiology in Messrs. Collins’ Advanced Sci- 
entific Series) have been specially prepared for the present work. 
Photography has been largely made use of in the section on the vi 
PREFACE. 
Skeleton, and it is hoped that by this means superior accuracy has 
been gained, while distinctness has been secured by the aid of touch- 
ing, often of an elaborate kind, which had to be taken in hand by 
Dr. Cleland himself. He has likewise provided the original sketches 
of all illustrations whose authorship is not specially indicated. The 
source of every illustration which has been borrowed is acknowledged. 
In some instances photographs taken directly from microscopic 
objects have been secured owing to the kindness and skill of the dis- 
tinguished oculist, Dr. Thomas Reid, and some of those representing 
structures connected with the eye have been taken from Dr. Reid’s 
own preparations. 
In the preparation of the letterpress, valuable assistance has been 
obtained from the works of many writers, among which there are 
specially to be mentioned in Microscopy those of v. Kolliker and 
Toldt, in Embryology those of His and Hertwig, in the Central Ner- 
vous System the Nouvelles Idees sur le Systeme Nerveux of Ramon y 
Cajal, in Surgical Anatomy the work of Treves, and, in many parts, 
Quain’s Anatomy, particularly the tenth edition. 
The Univeesity, 
Glasgow, September, 1896. CONTENTS. 
PAGE 
Introduction, ... 1 
PAGE 
Cerium, - 71 
PAGE 
Epidermis, - 72 
The Living Corpuscle, - 5 
GENERAL ANATOMY. 
Cutaneous Glands, - - 73 
Nails and Hairs, - 75 
The Blood, - - - 8 
Organs of Common Sensation, 78 
The Connective Tissues, - 13 
Retiform Tissue, Fascia, etc., 16 
Ligament and Tendon, - - 17 
Adipose Tissue, - 18 
Mucous Membrane, - - 81 
Embryology or General De- 
velopment, ... 82 
Cartilage, - - - 19 
Maturation of Ovum, - - 83 
Impregnation and Cleavage, 85 
Bone, - - - - - 23 
Layers of Embryo, - 86 
Medullary Folds, - 90 
Periosteum and Marrow, - 30 
Ossification, - 31 
Notochord, - 91 
Enlargement of Bones, - 35 
Articulations, ... 36 
Zones and Segments, - - 92 
Parietes and Mucous Tract, - 91 
Muscle, ----- 40 
Wolffian Bodies and Middle- 
plates, - - - - 96 
Nervous Elements, - - 46 
Supporting Substance, - - 46 
Nerve-fibres, - - - - 48 
Head and Neck, - 97 
Limbs, ----- 99 
Nerve-corpuscles, - - - 50 
Development and Regenera- 
tion, 54 
Vascular System, - - - 101 
Surroundings of Embryo, - 102 
Placenta, ... - 103 
Epithelium, - 54 
Glands, ----- 57 
Bloodvessels, - - - 58 
SYSTEMATIC ANATOMY 
THE SKELETON. 
Development, - 64 
Absorbent System, - - 64 
Lymph and Lymphatics, - 65 
Lymphatic Glands, - - 67 
Closed Follicles, - 68 
I. Axial Skeleton of Trunk. 
Vertebral Column, - 105 
Ribs, - 117 
Sternum, - - - 120 
Saccular Membranes, - - 68 
Integuments, - - - - 70 
Thorax, - - - - 121 
Articulations of Axial 
Subcutaneous Tissue, - - 70 
Skeleton of Trunk, - 122 yiii 
CONTENTS 
Movements, - 127 
PAGE 
Sphenoid, - - - 213 
PAGE 
Development, - - 130 
Temporal, - - - 218 
Ethmoid, - - - 224 
11. Skeleton of Limbs. 
The Upper Limbs, - - 133 
Clavicle, - 133 
Superior Maxillary, - 226 
Palatal, - 229 
Yomer, - 231 
Scapula, - 134 
Humerus, ... 137 
Malar, - 231 
Lachrymal, Inferior Tur- 
Bones of Forearm, - 140 
Bones of Hand, - - 145 
binate, Nasal, - - 233-4 
Articulations of Upper 
Limb 
Mandible, - 234 
Hyoid and Sutural 
Bones, ... 236-7 
Shoulder-girdle, - - 150 
Shoulder-joint, - - 152 
Radio-ulnar and Elbow- 
Fossae, - 237 
Shape of Skull, - - 240 
joints, - 155 
Movable Articulations 
Movements of Elbow 
Development of Skull, - 245 
of Skull, - - - 244 
and Forearm, - - 157 
Joints of Wrist and 
Hand, - 158 
THE MUSCLES AND FASCIAE. 
Movements of Wrist 
and Hand, - - - 161 
Muscles of Upper Limb. 
Connecting Limb with Trunk, 253 
The Lower Limb, - - 162 
Innominate Bone and 
Shoulder, - 260 
Pelvis, ... 162 
Arm, ----- 263 
Actions, - 267 
Femur, - - - - 168 
Patella, 172 
Axilla, ----- 268 
Bones of Leg, - - 173 
Bones of Foot, - - 177 
Deep Fascia, - 269 
Forearm, - 270 
Articulations of Lower 
Limb 
Hand, 281 
Actions and Deep Fascia, - 285 
Muscles of Lower Limb. 
Pelvis, - - - - 184 
Hip-joint, - - - 186 
Hip, ----- 287 
Knee-joint, - - - 189 
Thigh, 292 
Actions, ... - 302 
Joints of Leg and Foot, 194 
Movements of Ankle 
Deep Fascia of Thigh, - - 303 
Leg, 306 
Bones of the Limbs Com- 
pared, . . - 199 
and Foot, - - - 198 
Foot, 318 
Actions, - 323 
Deep Fascia of Leg and 
Foot, ----- 325 
Development of Limb- 
bones, - - - 200 
Muscles of Head and Neck. 
Superficial of Head and 
111. Skull. 
Occipital, ... 206 
Face, ----- 328 
Parietal, - - - 211 
Frontal, - - - - 212 
Orbit, ----- 334 
Suprahyoid, - 338 CONTENTS. 
IX 
Attached to Ramus of Jaw, - 342 
PAGE 
External Iliac, ... 456 
PAGE 
Pharynx, - 345 
Soft Palate, 347 
Surgical Anatomy, - - 457 
Femoral Artery, - 458 
Muscles Proper to Back, - 357 
Muscles of Thorax, - - 365 
Front and Sides of Neck, - 351 
Surgical Anatomy, - - 460 
Popliteal Artery, - 461 
Surgical Anatomy, - - 462 
The Diaphragm, - - - 367 
Muscles of Abdomen, - - 373 
Abdominal Fascia, - - 382 
Veins op the Heart, - - 468 
Vena Cava Superior, - - 468 
Arteries of Leg and Foot, - 462 
Perineum, - - - 387 
Fascia of Perineum and 
Pelvis, ... . 392 
Veins of Head and Neck, - 469 
Spinal Veins, - - - 478 
Veins of the Thorax, - - 479 
Development and Morphology 
OF VOLUNTARY MUSCLES, - 396 
Veins of Abdomen and 
Pelvis, - 480 
Portal System, ... 482 
Veins of the Limbs, - - 483 
THE HEART AND BLOOD- 
VESSELS. 
Development of Heart, - 486 
Heart, ----- 400 
Development op Arteries, - 489 
Development of Veins, - 491 
Pulmonary Vessels, - - 409 
Systemic Arteries, - - 410 
Circulation in Embryo and 
Foetus, - 494 
Ascending Aorta, - - 410 
Transverse Aorta, - - 411 
Coronary Arteries, - - 411 
THE LYMPHATICS. 
Innominate Artery, - - 412 
Lymphatic Ducts, - - - 496 
Lymphatics of Lower Limb, 498 
Common Carotid, - 413 
External Carotid and 
Branches, - 414 
Lymphatics of Abdomen and 
Pelvis, 499 
Lymphatics of Thorax, - 501 
Internal Carotid, - - - 420 
Arteries of Cerebrum, - - 422 
Lymphatics of Upper Limb, - 503 
Surgical Anatomy, - - 425 
Subclavian Artery, - - 427 
Lymphatics of Head and 
Neck, ----- 504 
Surgical Anatomy, - - 433 
Axillary Artery and Branches, 434 
Surgical Anatomy, - - 436 
I. Cerebro-Spinal Nerves. 
Spinal Nerves, - - - 507 
THE NERVES. 
Brachial Artery and Branches, 437 
Surgical Anatomy, - - 439 
Arteries of Forearm and 
Posterior Primary Divi- 
sions, - - - - 509 
Descending Thoracic Aorta 
and Intercostals, - - 445 
Hand, - 440 
Anterior Primary Divi- 
sions, - - - - 511 
Cervical Plexus, - - 511 
Brachial Plexus, - - 514 
Abdominal Aorta, - - 447 
Parietal Branches, - - 447 
Thoracic Nerves, - - 523 
Visceral Branches, - - 448 
Lumbar Plexus, - - 524 
Sacral Plexus, - - 530 
Common Iliac Artery, - - 452 
Internal Iliac, - - - 452 
Coccygeal Plexus, - - 536 X 
CONTENTS 
PAGE 
Cranial Nerves, - - 537 
Olfactory Nerve, - - 537 
Optic Nerve, - - - 538 
Oculo-motor Nerve, - 539 
Trochlear Nerve, - - 539 
Trifacial Nerve, - - 510 
Surgical Anatomy, - 549 
Abducent Ocular Nerve, 549 
Facial Nerve, - - 550 
Auditory Nerve, - - 552 
Glosso-pharyngeal Nerve, 553 
Pneumogastric Nerve, - 555 
Spinal Accessory Nerve, 558 
Hypoglossal Nerve, - 559 
PAGE 
Valve of Vieussens, - 602 
Cerebellum, - - - 603 
Internal Structure, - 605 
IV. Root Part of Cerebrum, 608 
Isthmus Cerebri, - - 608 
Corpora Quadrigemina, 608 
Optic Thalami, - - 609 
Corpora Striata, - - 610 
Floor of Third Ventricle, 610 
Pineal and Pituitary 
bodies, - - - 611 
Optic Tract and Com- 
missure, - - - 612 
Deep Structure of Root 
of Cerebrum, - 613 
V. Walls and Septa of 
Cerebral Ventricles, 615 
Corpus Callosum, - - 615 
Septum Lucidum, - 617 
Fifth Ventricle, - . 617 
Fornix and Corpora Al- 
bicantia, - 043 
Velum Interpositum, - 619 
Third Ventricle, - - 620 
Lateral Ventricle, - 620 
VI. Cerebral Hemispheres, 621 
Convolutions and Fissures, 623 
Internal Structure, - 627 
VII. Olfactory Lobes, - 630 
Weight of Brain, - 632 
Development of Cerebro- 
spinal Axis, - - 633 
11. Sympathetic Nerves. 
Gangliated Cords, - - 561 
Cardiac Plexus, - - 565 
Solar Plexus, - - - 566 
Hypogastric Plexus, - - 567 
Development of the Nerves, 568 
Morphology of the Nerves, 571 
THE CEREBRO-SPINAL AXIS 
AND ITS MEMBRANES. 
Meninges, .... 570 
Dura Mater, - 570 
Arachnoid, - 578 
Pia Mater, - 579 
Spinal Cord, - 580 
Internal Structure, - - 582 
Nerve-roots, - 587 
Brain, ----- 590 
I. General Construction, 590 
Superior Surface, - - 593 
Inferior Surface or base, 593 
ORGANS OF SPECIAL SENSE. 
The Nose, - 039 
Nasal Cartilages, - 039 
Nasal Fossae, - 040 
Jacobson’s Organ, - . 040 
The Eye. 
Tutamina, - 043 
Eyeball, - - - - 646 
Sclerotic, - 047 
Cornea, ----- 047 
Choroid, 650 
11. Medulla Oblongata and 
Pons Varolii, - - 595 
Medulla Oblongata, - 595 
Pons Varolii, - - - 596 
Internal Structure, - 597 
Floor of Fourth Ventricle, 600 
111. Cerebellum and An- 
terior Velum, - - 602 CONTENTS 
XI 
PAGE 
PAGE 
Ciliary Muscle and Processes, 652 
Iris, 653 
Duodenum, - 717 
Jejunum and Ileum, - - 718 
Epithelium of Tunica Vas- 
culosa, - 655 
Mucous Membrane, - - 719 
Retina, ----- 656 
Large Intestine, - 723 
Mucous Membrane, - - 724 
Vitreous Body, - 661 
Caecum, - 724 
Crystalline Lens and Capsule, 663 
Zonule of Zinn, - 664 
Colon, - 726 
Rectum, - - - - 727 
Development of Eye, - - 665 
The Ear, - 667 
Pancreas, - 728 
Liver, 730 
External Ear, ... 667 
Ducts and Gall-Bladder, - 732 
Middle Ear and Ossicles, - 669 
Eustachian Tube, - - - 674 
Development of Stomach, 
Intestine and Liver, 736 
Internal Structure, - - 733 
Internal Ear, - - - 675 
Vestibule, - - - - 676 
Cochlea, - - - - 678 
Development of Ear, - - 682 
RESPIRATORY ORGANS. 
Larynx, - - - - 738 
Cartilages, - 738 
Visceral Cavity, - 683 
THE VISCERA. 
Joints and Ligaments, - 740 
Cavity and Mucous Mem- 
A. Thoracic Cavity, - - 684 
Pericardium, - - - 685 
brane, - - - - 741 
Pleurae, - 686 
Muscles, - - - - 742 
Vessels and Nerves, - - 744 
Mediastina, ... 686 
Trachea, - - - - 745 
B. Abdominal Cavity, - 687 
Peritoneum, - 688 
Lungs, 746 
Internal Structure, - - 748 
Digestive Organs, - - 693 
The Teeth, - 693 
Bronchi and Bronchial Tubes, 751 
Vessels and Nerves, - - 752 
Dentine, - - - 694 
Development of Respiratory 
Organs, - - - 752 
Enamel, - 695 
Crusta Petrosa, - - - 696 
Ductless Glands, - - 753 
Spleen, 753 
Permanent Teeth, - - 696 
Temporary Teeth, - - 698 
Development, - - - 698 
Internal Structure, - - 754 
Thymus and Thyroid Body, 755 
The Mouth, 700 
Thymus, - - - - 755 
Thyroid Body, - - - 756 
Tongue, - - - - 702 
Taste-buds, - - - 704 
Suprarenal Capsules, - - 758 
Tonsils, - - - - 706 
Salivary Glands, - - 708 
Arterial Glomeruli, - - 759 
Pharynx, - - - - 709 
URINARY ORGANS. 
Oesophagus, - 709 
Stomach, - - - 710 
Kidneys, - - - - 759 
Mucous Membrane, - - 713 
Internal Structure, - - 760 
Intestine, - 717 
Small Intestine, - - - 717 
Vessels, - - - - 764 
Development, - - - 765 XII 
CONTENTS, 
PAGE 
Ureters, - - - - 767 
Urinary Bladder, - -* - 767 
11. Female Organs, - - 783 
1. Ovaries, Uterus and 
Muscular Coat, - - - 770 
Mucous Membrane, - - 770 
Vessels and Nerves, - - 770 
' Fallopian Tubes, - 788 
Ovaries, - - - 783 
Ovum, - 785 
Development, - 770 
Uterus, - - - 786 
Structure, - - - 788 
Vessels and Nerves, - 788 
REPRODUCTIVE ORGANS. 
Bicornute, - 788 
Pregnant, - 788 
I. Male Organs, - - - 771 
Fallopian Tubes, - - 780 
1. Testes, Scrotum and Semi- 
2. External Organs of Female, 789 
Parovarium, - - 739 
nal Ducts, - - 771 
Spermatic Cord and 
Superficial Parts, - - 789 
Coverings, - - 771 
Testis, 772 
Nymphae, - 790 
Vestibule and Hymen, 791 
Internal Structure, - 773 
Epididymis, - - - 776 
Urethra, - - - 791 
Clitoris, - - - 791 
Vagina, - - - 793 
Vas Deferens, - - 776 
Vesiculae Seminales, - 777 
Development of Repro- 
ductive Organs, - 794 
2. Prostate, Penis and Urethra, 778 
Prostate Gland, - - 778 
Penis, - - - 779 
Mammary Glands, - - 799 
APPENDIX. 
Urethra, 781 
On Utilization of Rdntgen Rays, 801 
INDEX, --- - 804 
LIST OF ILLUSTRATIONS, xiii LIST OF ILLUSTRATIONS. 
fig. page 
1. Nucleated corpuscles,. ... 6 
PIG. PAGE 
37. Unstriped muscular fibre-cell, coiled 
2h times round in the wall of a 
minute artery, .... 42 
2. Cells with karyokinetic figures, . 7 
3. Monaster and dyaster with achro- 
matin spindle and polar rays, . 7 
38. Striped muscular fibre, . . .43 
4. Blood-corpuscles of man, ... 9 
39. Motorial end-plates of guinea pig, . 44 
40. Organ of Golgi of rabbit, ... 44 
5. Leucocytes escaping from blood- 
vessels, 11 
6. Blood-corpuscles of frog, ... 12 
41. a, Muscular fibres of heart; 6, 
branched muscular fibre from 
tongue, 45 
7. Connective tissue, . . . .13 
8. Deep fascia or aponeurosis, . . 14 
42. Striped fibres in process of develop- 
ment, 45 
9. Yellow-elastic tissue, .... 14 
10. Fibres from ligamentum nuchae of 
horse 15 
43. Neuroglia, corpuscles, ... 47 
11. Subcutaneous connective tissue, . 16 
44. Nerve-fibres, 48 
45. Nodes of Ranvier, . . . .49 
12. Retiform tissue, 16 
13. Tendon, 17 
46. Notches of Lantermann, ... 49 
47. Unipolar nerve-corpuscles, . . 50 
14. Adipose tissue, 18 
15. Portion of fat 10bu1e,.... 19 
48. Bipolar nerve-corpuscles, ... 51 
49. Multipolar nerve-corpuscle, . . 51 
16. Costal cartilage, 20 
17. Cartilage with spindle-shaped cap- 
sules, 21 
50. Minute ganglion from gall-bladder 
of dog, 53 
51. Ganglion from gall-bladder of dog, 
with fine nerve-fibres ending in it, 53 
18. Articular cartilage, .... 22 
52. Medullated nerve-fibres undergoing 
degeneration and regeneration, . 53 
19. Yellow cartilage, .... 22 
20. Embryonic cartilage, .... 23 
53. Varieties of epithelial cells, . . 55 
21. Capsular cartilage, .... 23 
22. Lacunae and canaliculi of bone, . 25 
54. Lobules of parotid gland of embryo 
lamb 58 
23. Section of ox bone 26 
24. Transverse section of compact bone, 26 
55. Elastic tissue from outer and middle 
arterial coats, .... 59 
56. Section of artery, .... 60 
25. Longitudinal sections from shaft of 
femur, adult and at birth, . . 27 
57. Tunica intima, 60 
58. Arteriole and venous radicle, . . 61 
26. Transverse section of tibia of horse, 27 
27. Compact osseous tissue of old age, . 28 
59. Capillaries, 62 
60. Valves of veins, 66 
28. Multinuclear corpuscles, ... 28 
29. Fibrous appearance of bony ma- 
trix, 28 
61. Formation of capillaries, ... 64 
62. Lymphatics, 65 
30. Ossification from periosteum, . . 32 
31. Ossifying extremity of shaft of femur 
at birth, 33 
63. Lymphatic gland of the groin, . . 66 
64. Section of human lymphatic gland . 67 
32. Ossification of astragalus at birth, . 33 
33. First point of calcification, . . 34 
65. Cutaneous ligaments of phalanges of 
finger, 70 
34. Synovial membrane, .... 37 
66. Ridges of integument of thumb, . 71 
67. Vertical section of epidermis and 
cutis vera of front of finger, . 72 
35. Lumbar intervertebral disc, . . 39 
36. Unstriped muscular fibre-cells from 
various situations, ... 42 
68. Epithelium of cornea of ox, . . 73 
69. Sudoriparous glands, .... 74 LIST OF ILLUSTRATIONS 
70. Sebaceous gland of cheek, . . 75 
71. Hair 76 
72. Vertical section of scalp, showing 
two roots of hairs, ... 77 
73. Development of hair, ... 77 
74. Vertical section of skin of sole of 
foot, with ramification of nerves 
in stratum Malpighii, ... 78 
75. Vertical section of skin of sole 
treated with gold, ... 79 
76. Touch-corpuscles very highly mag- 
nified 79 
77. Rounded end-bulbs from human 
conjunctiva, 80 
78. Cylindrical end-bulb from conjunc- 
tiva of calf, 80 
79. Pacinian body, human, ... 80 
80. Ovum of rabbit, .... 83 
81. Changes of germinal vesicle in aste- 
rias glacialis 83 
82. Formation of polar bodies in aste- 
rias glacialis, .... 84 
83. Impregnation, asterias glacialis, . 84 
84. Impregnated ovum of sea-urchin, . 85 
85. Stages of cleavage, .... 85 
86. Amphioxus 86 
87. Two successive stages of area ger- 
miuativa of hen’s egg in the first 
hours of hatching, ... 88 
88. The blastoderm, uterine ovum of 
rabbit, 88 
89. Area embryonalis of rabbit, . . 88 
90. Transverse section through the mid- 
dle of primitive streak of embryo 
chick, 89 
91. Longitudinal sections through ova 
of Triton, 89 
92. Transverse section of ovum of Triton 
passing through the blastopore,. 90 
93. Transverse section through a human 
germinal area with open medul- 
lary groove, 90 
94. Embryo chick and germinal area 
during first day of hatching, . 90 
95. Chick and germinal area of about 
24 hours, 91 
96. Fore-part of chick of 36 hours, . 91 
97. Transverse section of embryo rabbit, 91 
98. Live chick of 48 hours, ... 92 
99. Embryo rabbit of 8 days and 4 hours, 93 
100. Transverse section through dorsal re- 
gion of embryo chick of 45 hours, 93 
101. Human embryo prior to flexion of 
medulla oblongata, ... 94 
102. Transverse section through duck 
embryo with about twenty-four 
primitive segments, ... 95 
103. Human embryo i inch long, . . 97 
104. Anterior wall of mouth and pharynx 
of human embryo about A? inch 
long, 99 
105. Floor of mouth and pharynx of 
human embryo \ inch long, . 99 
106. Embryo rabbit of 8 days and 14 
hours, 100 
FIG. PAGE 
FIG. PAGE 
107. Reconstruction from embryo, Fig. 
101, 101 
108. Embryo rabbit with area vasculosa, 101 
109. Transverse section through embryo 
chick and amnion five days old, . 102 
110. Diagrams of structures outside the 
embryo, 103 
111. Structure of placenta, . . . 104 
112. Vertebral column, front and right 
side, 106 
113. Vertebral column, behind and right 
side, 106 
114. Thoracic vertebra of child, . . 107 
115. Fourth thoracic vertebra, . . 108 
116. First thoracic vertebra, . . . 109 
117. Twelfth thoracic vertebra, . . 109 
118. Second lumbar vertebra, . . . 110 
119. Fifth lumbar vertebra, . . . 110 
120. Third cdrvical vertebra, . . . 11l 
121. Seventh cervical vertebra, . . 11l 
122. Atlas, 112 
123. Axis, 112 
124. Atlas, axis and other vertebra at birth, 113 
125. Sacrum and coccyx, front view, . 114 
126. Sacrum and coccyx, back view, . 114 
127. First and second sacral vertebrae, . 115 
128. Base of sacrum of infant, . . 116 
129. First, second, sixth and twelfth ribs 
of left side, 118 
130. The sternum, 121 
131. Thoracic skeleton 122 
132. Ligamentum nuchae, . . . 124 
133. Articulations of atlas, axis and oc- 
cipital bone from behind, . . 125 
134. Articulations of ribs with vertebrae, 125 
135. Articulations of atlas, axis and oc- 
cipital bone from the front, . 128 
136. Vertebra of embryo one inch long,. 130 
137. Lumbar vertebra of adolescent, . 131 
138. Sterna at different ages, . . . 132 
139. The clavicles, 134 
140. Right scapula from behind, . . 135 
141. Right scapula from above, . . 136 
142. Right scapula from anterior and 
outer side, 136 
143. Right humerus, 138 
144. Supracondylar process on a left 
humerus 140 
145. Sketch to show the mechanism of 
pronation and supination, . . 140 
146. Bones of right forearm from behind, 142 
147. Bones of right forearm from the front, 142 
148. Right hand, palmar view, . . 145 
149. Right hand, dorsal view, . . . 145 
150. Palmar view of right carpal bones, . 146 
151. Dorsal view of right carpal bones, . 147 
152. Left sterno-clavicular and sterno- 
acromial articulations, . • 151 
153. Right shoulder, 153 
154. Extended right elbow-joint from the 
front, 155 LIST OF ILLUSTRATIONS 
XV 
Fr«- PAGE 
FIG. PAGE 
155. Extended right elbow-joint from 
behind, 155 
156. Flexed right elbow-joint, . . . 156 
204. Base of skull, about ten years old, . 219 
205. Right temporal from below, . . 220 
157. Interosseous membrane and carpal 
ligaments, 157 
206. Right temporal from behind, . . 221 
207. Right temporal from before, . . 223 
158. Radio-carpal and common carpal 
articulation, 158 
208. Ethmoid from behind, . . . 224 
209. Ethmoid from front and left, . . 225 
159. Ligaments of back of hand, . . 159 
160. Metacarpo-phalangeal articulation, 160 
210. Right maxillary, . . . .226 
211. Palate of child six years old, . . 227 
161. Right innominate bone about the 
twelfth year, .... 162 
162. Right pelvic bone, outer side, . . 163 
163. Right pelvic bone, deep side, . . 166 
164. Pelvis of male, 167 
212. Vertical section of left side of face, 229 
213. Right palatal bone, .... 230 
214. Vomer, etc., of child, . . . 231 
215. Section displaying septum nasi, . 232 
165. Pelvis of female, .... 167 
216. Right malar, 232 
217. Right inferior turbinated bone, . 234 
166. Right femur, front view, . . . 169 
167. Right femur, hinder view, . . 169 
168. Inferior extremity of right femur, . 171 
218. Lower jaw, 235 
219. Edentulous lower jaw of old age, . 236 
169. Patella, 172 
220. Left nasal fossa, .... 238 
221. Base of cranial cavity of a child, . 239 
170. Right tibia and fibula from the front, 174 
171. Right tibia and fibula from behind, . 174 
222. Temporo-maxillary articulation and 
hyoid bone, 244 
223. Part of base of skull of foetus of 
four months, .... 246 
172. Right foot, dorsal view, . . . 178 
173. Right foot, plantar view, . . . 178 
224. Occipital bone at birth, . , . 247 
174. Right astragalus, .... 179 
175. Right calcaneum and astragalus, . 180 
225. Right temporal at birth, . . . 248 
226. Skull at birth, from above, . . 250 
176. Left scaphoid, 180 
177. The three cuneiforms of left side, . 181 
227. Skull at birth, right side, . . 250 
228. Superficial muscles of the back, . 254 
178. Left cuboid 182 
179. Pelvic and hip-joints, . . . 184 
229. Second layer of muscles of the 
back, 256 
180. Left hip-joint from behind in the 
erect posture, .... 187 
181. Left hip-joint from the front in the 
erect posture, .... 187 
230. Serratus magnus and neighbouring 
muscles, 257 
231. Superficial pectoral muscles, . . 258 
182. Left hip-joint from behind in full 
flexion, 188 
232. Deep pectoral muscles, . . . 259 
183. Right knee from outer side, . . 190 
233. Muscles of shoulder and arm, poste- 
rior view, 260 
234. Muscles of shoulder, posterior view, 262 
184. Right knee from behind, . . . 190 
185. Right knee from the front, . . 191 
235. Muscles of the front of the arm, . 264 
236. Muscles of the front of the arm, 
deep layer, 265 
186. Head of left tibia, .... 191 
187. Left knee-joint laid open and flexed, 192 
237. Triceps muscle, .... 266 
188. Dorsiflexed left ankle, . . . 194 
189. Dorsum of stretched left foot with 
, the outer side depressed, . . 196 
238. Muscles of the front of the forearm, 
superficial layer, .... 271 
190. Plantar view of stretched left foot, 196 
239. Flexor tendons on front of finger, . 272 
240. Muscles of front of forearm, deep 
layer, 274 
191. Young scapula, 201 
192. Young humerus, .... 202 
241. Muscles of back of forearm, deep 
layer, 276 
242. Muscles of back of forearm, super- 
ficial layer, 277 
243. Supinator brevis, .... 279 
244. Muscles of baud, superficial layer,. 282 
245. Muscles of hand, deep layer, . . 283 
246. Palmar interosseous muscles, . . 284 
247. Dorsal interosseous muscles, . . 284 
248. Muscles of the hip, superficial layer, 288 
249. Muscles of hip, deep, . . . 289 
250. Gemelli and obturator muscles, 
from behind, .... 291 
251. Muscles of posterior region of thigh, 293 
252. Posterior muscles of thigh, deep, . 296 
253. Anterior region of thigh, . . . 298 
193. Right innominate bone of twelfth 
year, 203 
194. Right femur approaching the full size, 203 
195. Right tibia and fibula approaching 
the full size, 204 
196. Base of skull, 205 
197. Right side of skull, . . . . 207 
198. Skull from front and right side, . 209 
199. Frontal from be10w,.... 213 
200. Sphenoid at birth, .... 214 
201. Sphenoid from behind, . . . 215 
202. Sphenoid from the front, . . . 215 
203. Vomer, ethmoid, sphenoidal spongy 
bones, palatal and maxillary of 
infant, 216 XVI 
LIST OF ILLUSTRATIONS. 
FIG. PAGE 
254. Inner side of the knee, . . . 299 
255. Ilio-psoas muscle, .... 301 
256. Saphenous opening 305 
257. Outer region of leg, .... 307 
258. Insertions of tendons in the sole, . 308 
259. Anterior region of leg, . . . 310 
260. Posterior region of leg, superficial 
layer, 312 
261. Posterior region of the leg (the gas- 
trocnemius divided), . . . 313 
262. Soleus, 314 
263. Posterior region of leg, deep group 
of muscles, 316 
264. Second layer of muscles of sole, . 318 
265. First layer of muscles of sole, . . 319 
266. Third layer of muscles of sole, . 320 
267. Dorsal interosseous muscles, . . 322 
268. Plantar interosseous muscles, . . 323 
269. Muscle and tendons of dorsum of 
foot, 324 
270. Superficial muscles of the head, . 329 
271. Deeper muscles of the head, . . 331 
272. Orbital muscles of the right side, . 336 
273. Muscles connected with the hyoid 
bone, 339 
274. Extrinsic muscles of the tongue, . 340 
275. Temporal muscle, .... 343 
276. Pterygoid muscles, .... 343 
277. Pterygoid and other muscles, . . 344 
278. Wall of the pharynx, . . . 346 
279. Muscles of the soft palate and phar- 
ynx, from behind, . . . 347 
280. Lateral muscles of the neck, . . 352 
281. Deep muscles of the neck, . . 353 
282. Deep muscles of the back of the neck, 357 
283. Erector spinae, 359 
284. Upper part of the erector spinae and 
the complexus, .... 361 
285. Three bundles of the multifidus 
spinae in the thoracic region, . 362 
286. Semispinalis and multifidus spinae, 363 
287. Posterior short cranio-vertebral 
muscles, 364 
288. Intercostal muscles, .... 366 
289. Levatores costarum,.... 367 
290. Diaphragm, upper surface, . . 368 
291. Diaphragm, under surface, . . 369 
292. Triangularis sterni, .... 371 
293. External oblique muscle,. . . 375 
294. Superficial abdominal ring (dia- 
grammatic), 377 
295. Internal oblique and rectus muscles, 378 
296. Arrangement of the fibres of the qna- 
dratus lumborum (diagram), . 379 
297. Diagram of the crural arch, . . 383 
298. Superficial abdominal ring, . . 385 
299. Conjoined tendon, .... 385 
300. Lower part of the anterior abdomi- 
nal wall, seen from behind, . 386 
301. Levator ani and coccygeus, from 
above, 388 
FIG. PAGE 
302. Superficial perineal muscles of the 
male, 389 
303. Muscles of the perineum in the female, 390 
304. Deep perineal muscles of the male, 391 
305. Diagrammatic section through blad- 
der, rectum, and anus, . . 393 
306. Diagram of section of pelvis, . . 394 
307. Heart, from front and right, . . 400 
308. Heart, from behind, .... 401 
309. Right auricle of child at birth, . 402 
310. Auriculo-ventricular and arterial 
valves, 404 
311. Heart, from before and right side, . 405 
312. Heart, from behind and left side, . 406 
313. Relation of heart and chest wall, . 407 
314. Superficial layer of the muscular 
fibres of the heart, . . . 408 
315. Heart within the pericardium, . 410 
316. Coronary arteries, from in front and 
above, 410 
317. Aorta, thoracic portion, . . . 411 
318. Carotid and subclavian arteries of 
the right side, and their branches, 414 
319. Superficial arteries of the head, . 415 
320. The internal maxillary artery and 
its branches, .... 418 
321. Diagram of the branches of the in- 
ternal maxillary artery, . . 419 
322. Diagram of the branches of the oph- 
thalmic artery, .... 419 
323. External and internal carotid arte- 
ries and their chief relations, . 420 
324. Diagram of the arteries of the base 
of the brain, 421 
325. Autero-lateral group of deep 
branches from the middle cere- 
bral, 421 
326. Superficial branches of the middle 
cerebral artery, .... 428 
327. Diagram of the method of origin of 
the branches of the right sub- 
clavian artery, . . . 428 
328. Arteries of the back of the shoulder, 429 
329. Axillary artery, .... 434 
330. Brachial artery, .... 435 
331. Division of the brachial artery, . 440 
332. Arteries of the forearm, . . . 441 
333. Arteries of the back of the hand, . 442 
334. Superficial palmar arch, . . . 443 
335. Deep arteries of the palm, . . 446 
336. Abdominal aorta, .... 447 
337. Diagram of the branches of the ab- 
dominal aorta, .... 448 
338. Coeliac axis and its branches, . . 448 
339. Superior mesenteric artery and its 
branches, 449 
340. Mesenteric arteries, .... 449 
341. Branches of the iliac arteries. The 
usual arrangement, . . . 452 
342. Branches of the iliac arteries. A 
less frequent arrangement,. . 452 
343. Arteries of the hip and the posterior 
region of the thigh, . , . 453 LIST OF ILLUSTRATIONS. 
XVII 
FIG. PAGE 
344. Arteries of the perineum,, . . 454 
345. Arteries of the thoracic and abdomi- 
nal wall, 455 
346. Femoral artery and its branches, . 458 
347. Anterior tibial artery, . . . 459 
348. Arteries of the dorsum of the foot, 464 
349. Arteries of the hack of the leg, . 465 
350. Arteries of the sole, .... 468 
351. Superior vena cava and its branches, 469 
352. Commencement of the internal jugu- 
lar vein, left side, . . . 469 
353. Superficial veins of the head and 
neck, 472 
354. Veins of the diploe 473 
355. Venous sinuses of the cranium, . 473 
356. Velum interpositum and the veins 
of Galen, 473 
357. Venous sinuses of the base of the 
skull, 478 
358. Sections of the spinal cord in the 
lower dorsal region, . . . 478 
359. Intercostal veins and the azygos 
veins, 479 
360. Inferior vena cava and the abdomi- 
nal aorta, 480 
361. Portal system 481 
362. Superficial veins of the hack of the 
hand 484 
363. Superficial veins of the upper limb, 485 
364. Superficial veins of the leg and foot, 
from the front 486 
365. Superficial veins of the hack of the 
leg, ...... 487 
366. Four successive stages in the de- 
velopment of the heart, . . 487 
367. Development of the larger arteries, 490 
368. Development of the portal system, . 492 
369. Development of the systemic veins, 493 
370. Foetal circulation, .... 495 
371. Superficial veins of the thigh, . 496 
372. Superficial lymphatics of the lower 
limbs, 497 
373. Lymphatics of the small intestine, 502 
374. Lymphatics of the neck and thorax, 502 
375. Lymphatics of the upper limb, . 503 
376. Lymphatics of the head and neck, . 506 
377. Posterior primary divisions of the 
thoracic and lumbar nerves, . 507 
378. Diagram of the cervical plexus, . 512 
379. Superficial nerves of the neck, . 512 
380. Nerves of the axilla, .... 513 
381. Diagram of the brachial plexus, . 514 
382. Deep nerves of front of the arm, . 516 
383. Deep nerves of the forearm, . . 517 
384. Cutaneous nerves of the back of the 
upper limb, 518 
385. Cutaneous nerves of the front of the 
upper limb, 519 
386. Nerves of the palm, .... 520 
387. The posterior interosseous nerve, . 522 
388. Nerves of the dorsum of the hand, . 524 
389. Branches of the lumbar plexus, . 525 
FIG. PAGE 
390. Diagram of the lumbar plexus, . 525 
391. Cutaneous nerves of the back of the 
lower limb, 528 
392. Cutaneous nerves of the front of the 
lower limb 529 
393. Diagram of the sacral and coccygeal 
plexuses, 530 
394. Deep nerves of the front of the 
thigh, 530 
395. Sacral plexus of the right side with 
its branches, .... 531 
396. Deep nerves of the hack of the hip 
and thigh, 532 
397. Deep nerves of the back of the leg, 533 
398. Deep nerves of the sole, . . . 534 
399. Deep nerves of the front of the leg, 535 
400. Nerves of the dorsum of the foot, . 536 
401. Base of the brain, .... 537 
402. Places of exit from the skull of the 
cranial nerves, .... 540 
403. Nerves of the orbit, .... 541 
404. Lenticular or ciliary ganglion from 
the outer side, .... 541 
405. Nerves of the face and scalp, . . 542 
406. Superior maxillary division of the 
fifth nerve, 544 
407. Nerves of the nasal septum, . . 545 
408. Nerves of the outer wall of the nasal 
fossa, 543 
409. Branches of the inferior maxillary 
division of the fifth nerve, . . 546 
410. Spheno-palatine and otic ganglia 
from the deep surface, . . 547 
411. External and internal carotid ar- 
teries and their chief relations, . 554 
412. Pneumogastric and sympathetic 
nerves of the right side, . . 555 
413. Nerves of the tongue, . . . 562 
414. Sympathetic of the lower part of the 
trunk, right side, .... 563 
415. Scheme of complete segmental 
nerve, 573 
416. Cerehro-spinal axis, . . . .576 
417. Tentorium cerebelli and falx cere- 
bri 577 
418. Medulla oblongata, and the spinal 
cord down to Bth thoracic pair of 
nerves, from behind, . . • 581 
419. Lower part of spinal cord and mem- 
branes, from before, . . • 581 
420. Sections of spinal cord, . . • 583 
421. Ependymal or spongioblastic fibres 
of the cord of a seven days’ chick, 583 
422. Diagrammatic transverse section of 
cord in lower dorsal region, . 585 
423. Spinal and sympathetic ganglia from 
neck of chick of 17th day, . . 586 
424. Longitudinal section of posterior 
column, parallel to posterior 
roots, 586 
425. Ascending degeneration in posterior 
column of spinal cord in dogs, . 587 
426. Diagram of relations of different 
elements of spinal cord, . . 588 LIST OF ILLUSTRATIONS. 
FIG. PAGE 
427. Section of spinal cord of dog at 
birth, showing the collaterals, . 589 
428. Brain of human embryo of 12 weeks, 590 
429. Dorsal view of root of brain, . . 591 
430. Cerebral hemispheres from above, . 592 
431. Basal view of root of brain, . . 594 
432. Medulla oblongata of foetus of 8 
months, 598 
433. Pons detached from cerebellum and 
reflected from the fillets and pos- 
terior longitudinal bundles, . 599 
434. Medulla oblongata, corpora quadri- 
gemina and floor of fourth ven- 
tricle, 601 
435. Valve of Yieussens, .... 602 
436. Cerebellum, 604 
437. Frontal section of body and left 
lobe of cerebellum, . . . 605 
438. Sections of cerebellum, . . . 605 
439. Structure of cerebellar laminae, lon- 
gitudinal section, .... 606 
440. Structure of cerebellar lamina of 
mammal, transverse section, . 607 
441. Third ventricle, .... 609 
442. Concretions,, 611 
443. Mesial section of pituitary body, . 612 
444. Pituitary body, 612 
445. Section through corpora quadri- 
gemina and crura cerebri, . . 614 
446. Vertical transverse section, . . 615 
447. Corpus callosum 616 
448. Lateral and fifth ventricles, . . 617 
449. Mesial section of brain, . . . 619 
430. Vertical transverse section, . . 621 
451. Basal surface of the hemispheres, . 622 
452. Relations of convolutions to super- 
ficial parts, 623 
453. Island of Reil, olfactory lobe and de- 
scending cornu of lateral ven- 
tricle, 624 
454. Outer side of right hemisphere, . 625 
455. Right hippocampus major, . . 627 
456. Structure of cortical grey matter, . 628 
457. Elements of cortical grey matter, . 629 
458. Nerve-corpuscles from cortical grey 
matter, 629 
459. Human pyramidal corpuscle, . . 629 
460. Schema of longitudinal section of 
brain 629 
461. Antero-posterior section of olfactory 
bulb of a duck, .... 631 
462. Section of texture of human embryo 
cord, 633 
463. Section of cord of chick of third day 
of incubation, .... 633 
464. Head of embryo chick of third day, 635 
465. Head of embryo chick of four days, 635 
466. From brain of foetus of four months, 636 
467. Brain of human embryo of 4J weeks, 636 
468. Base of brain of foetus of four 
months, 637 
469. Brain of foetus of three months, . 637 
470. Nasal cartilages, .... 639 
FIG. PAGE 
471. Outer wall of right nasal fossa, . 640 
472. Olfactory cells, 641 
473. Jacobson’s organ of goat, . . 642 
474. Accessory lachrymal gland sur- 
mounting Meibomian follicle, . 644 
475. Lymphatics of conjunctiva, . . 644 
476. Free margin of network of capilla- 
ries over margin of cornea, . 645 
477. Lachrymal apparatus, . . . 646 
478. Section of cornea, parallel to surface, 648 
479. Corneal corpuscles of calf, . . 648 
480. Epithelium of human cornea, . . 649 
481. Portion of primary nerve-plexus of 
human cornea, .... 649 
482. Cornea, epithelium and nerves, . 650 
483. Nervous plexus of cornea of sheep, . 650 
484. Pigmented branched corpuscles, . 650 
485. Schema of vessels of the tunica 
vasculosa, 651 
486. Human eyeball from which part of 
the cornea and sclerotic have 
been removed, .... 652 
487. Section of human eye, . . . 652 
488. Injection of human iris, ciliary pro- 
cesses, and fore part of choroid, 653 
489. Schema of vessels at different 
depths, 654 
490. Hexagonal corpuscles of pigmented 
epithelium 655 
491. Schema of elements of retina, . . 656 
492. Diagram of connection between ba- 
cillary elements and ganglionic 
corpuscles, 658 
493. Connections of the horizontal cells 
and the spongioblasts of retina, . 659 
494. Ophthalmoscopic view of centre of 
retina 660 
495. Schema of section through fovea 
centralis and macula lutea, . 661 
496. Four elongated cones from central 
spot 662 
497. Lens breaking up, .... 662 
498. Lens-fibres, 663 
499. Human lens and suspensory appa- 
ratus 663 
500. Portion of suspensory ligament and 
canal of Petit of ox, . . . 663 
501. Section through capsule of lens, sus- 
pensory ligament and canal of 
Petit, 664 
502. Diagram of development of eye, . 665 
503. Section of eye of embryo rat, . . 666 
504. Cartilage and muscles of external 
ear, 668 
505. Internal wall of tympanic cavity, . 670 
506. Tympanic ossicles of right ear, . 671 
507. Diagram of the right ear, . . 672 
508. Right membrana tympani, . . 673 
509. Horizontal section of nasal fossae 
and pharynx, .... 674 
510. Cast of left osseous labyrinth, exter- 
nal aspect, 676 
511. Diagram of membranous labyrinth, 677 LIST OF ILLUSTRATIONS 
XIX 
FI<J. PAGE 
FIG. PAGE 
512. Auditory cells, 677 
513. Transverse section of crista acustica 
of foetal rat, 677 
557. Closed follicles, villi and lacteals, . 722 
558. Intermuscular lymphatics and my- 
enteric plexus of guinea pig, . 723 
514. Section of cochlea of pig at birth, . 678 
515. At the summit of the lamina spiralis, 679 
516. Organ of Corti in vertical section, . 680 
559. Section of small intestine of guinea 
pig 723 
560. Mucous membrane of colon, . . 724 
517. View of surface of organ of Corti in 
child at birth, .... 681 
561. Development of caecum and vermi- 
form appendage, .... 725 
518. Peritoneal membrane denuded of en- 
dothelium, 683 
562. Caecum and ileo-colic valve, . . 726 
563. Mesial section of male pelvis, . . 727 
519. Frontal section of frozen body of 
female of 40 years, . . . 684 
520. Sagittal section of thorax and epi- 
gastrium of frozen body of infant 
Is years old, 685 
521. Abdominal viscera, .... 687 
564. Pancreas from behind, . . . 728 
565. Human pancreas, .... 729 
566. Under surface of liver, . . . 731 
567. Hepatic lobule magnified, . . 733 
522. Liver and its ligaments from behind, 688 
523. Connections of liver and stomach, . 689 
568. Hepatic tissue highly magnified, . 734 
569. Intralobular ducts, .... 734 
524. Diagram of peritoneal folds in mesial 
section, 691 
570. Aberrant ducts with blind glandu- 
lar-looking off-shoots, . . . 735 
571. Diagrams of stomach and intestine 
in third month, .... 736 
525. Incisor tooth, 693 
572. Section from liver of foetus of five 
months, 736 
526. Longitudinal section of pulp and den- 
tine, 694 
527. Sections of human tooth, . . 695 
573. Cartilages of larynx, . . . 738 
528. Section through enamel of elderly 
subject, 696 
574. Mesial section of larynx, . . . 739 
575. Larynx from above, .... 740 
529. Permanent teeth, .... 697 
530. Temporary and permanent teeth, . 698 
531. Development of a temporary and a 
permanent tooth, .... 699 
532. Labial glands, 701 
576. Anterior half of larynx from behind, 741 
577. Muscles of larynx, . . . . 743 
578. Larynx from the left and behind, . 744 
579. Air-tubes from before, . . . 745 
533. Acini of labial gland, . . . 702 
580. Vertical section of epithelium of 
trachea, 746 
534. Transverse section of tongue,. .702 
335. Fauces with the tongue protruded, . 703 
536. Taste-buds, 705 
581. Position of thoracic viscera, . . 747 
582. Lobules of lung, .... 749 
537. Section of an injected tonsil, . . 705 
538. Salivary glands, .... 707 
583. Pulmonary alveoli highly magnified, 749 
584. Finest air-tubes with infundibula 
and alveoli, 749 
539. Section of parotid gland, . . .708 
585. Capillary injection of walls of al- 
vedli, 749 
510. Section of submaxillary gland, . 708 
541. Stomach showing superficial muscu- 
lar fibres, 711 
586. Lungs from behind, .... 750 
587. Embryonic human lungs, . . 752 
542. Stomach everted, .... 712 
588. Deep surface of spleen, . . . 754 
589. Structure of spleen, .... 755 
543. Gastric mucous membrane, . . 713 
544. Opaque injection of mucous mem- 
brane of stomach, . . . 713 
590. Windpipe and thoracic viscera of 
foetus of six months, . . . 756 
545. Section of mucous membrane of 
human stomach, .... 714 
591. Section of lobule of thymus, . . 756 
592. Texture of thyroid body, . . . 757 
516. Mucous membrane of stomachic side 
of pyloric valve, .... 715 
593. Right-suprarenal capsule and solar 
plexus, 758 
594. Female urinary apparatus, . . 760 
547. Mucous membrane immediately 
below oesophageal opening of 
stomach, ." . . . . 715 
595. Frontal section of kidney, . .761 
596. Cortex of kidney, . . • .762 
548. Transverse section of gastric glands, 715 
549. Section of injected mucous mem- 
brane of stomach of cat, . . 716 
550. Abdominal part of digestive tube, . 717 
551. Relations of duodenum, . . . 718 
597. Renal structure highly magnified, . 762 
598. Diagram of tubuli uriniferi . . 763 
599. Suprarenal capsule and lobulated 
kidney of foetus of six months, . 766 
552. Valvulae conniventes, . . . 719 
600. Male bladder, urethra and rec- 
tum, 766 
553. Villi, 719 
554. Section of tip of villus, . . . 720 
601. Base of bladder and the prostatic 
and membranous parts of the 
urethra, from the front, . .769 
555. Two Peyer’s patches, . . . 721 
556. Section of duodenum, . . . 721 
602. Left testicle, 772 
603. Ducts of testis, 773 XX 
LIST OF ILLUSTRATIONS. 
FIG. PAGE 
604. Section of longitudinal lobes of semi- 
nal tubules, 773 
605. Human spermatozoa, . . . 774 
606. Section of tnbulusseminiferusof rat, 775 
607. Ducts of testis, 775 
608. Bladder, prostate and bulb, from 
behind, 777 
609. Body of penis in transverse section, 779 
610. Terminal parts of penis, . . . 780 
611. Uterus, ovaries and Fallopian tubes, 
from the front, .... 783 
612. Section of ovary of child at birth, . 784 
613. Human ovum within Graafian vesi- 
cle 785 
614. Uterus, in vertical transverse sec- 
tion, 786 
615. Uterus, ovaries and Fallopian tubes, 
from behind 787 
616. Female genitalia 790 
FIG. PAGE 
617. Mesial section of female pelvis, . 792 
618. External organs of female, with 
lower part of vagina, . . . 793 
619. Ovaries and Wolffian bodies of em- 
bryo pig, 794 
620. Organs on right side of embryo ram, 794 
621. 622, 623. Diagrams of the develop- 
ment of the sexual organs, . 796, 797 
624. Left testis and gubenaculum in foe- 
tus of fifth month, . . . 798 
625. Dissection of a mamma in active 
condition, 798 
626. Section through centre of mamma, 
parallel to base of nipple, . . 799 
627. Sections of human mamma ready 
for lactation, .... 799 
628,629,630. Rdntgen-ray shadows of the 
wrist extended, flexed inwards 
and over-extended, . . . 801 INTRODUCTION. 
Anatomy and Dissection are two words etymologically equivalent, one 
from the Greek and the other from the Latin. But while the word 
Dissection retains its primitive meaning, namely, the cutting of parts 
asunder, the word Anatomy is applied to the conditions of structure which 
Dissection brings into view, and, widening its signification still further, 
has become the designation of the science which investigates the structure 
of organisms. 
All Anatomy is resolvable into two parts: first, the observation and 
record of structures, and secondly, the consideration of their meaning. 
One mode of considering structure is with reference to function, namely, 
its utility in the organism of which it is a part, and the arrangements 
for its own growth: this is Physiological Anatomy. Another mode is 
with reference to form alone, either in its relation to structures in the 
same animal and in others, or in relation to the series of phases through 
which it has passed in its development, and this is properly termed 
Morphological Anatomy. But physiological and morphological anatomy 
are not unconnected, for structures which appear in one animal or in one 
stage of growth are modified in others in conformity with functional 
requirements. 
The connection of physiological and morphological anatomy is well 
illustrated in the study of development, which as a process of growth 
belongs to the domain of physiology, but as a series of successive forms 
of structure is one of the foundations of morphological anatomy. 
The forms of animals are widely diverse, and are classified in groups 
according to the greater or less degree of their structural resemblance; 
and the same parts can be traced with modifications in animals more or 
less remote one from another, or in the two sexes of one species. So 
also, in the same animal, structures similar one to another may occur 
placed symmetrically like the limbs, or repeated in longitudinal series 
like the ribs. Structures corresponding in any of these ways are said to 
be homologous, and their relationship is called Homology, while an animal 
which has its structures arranged in a chain of homologous parts is said 
to be segmented, and the parts of the chain are called segments, somatomes, 
or metameres. 2 
GENERAL ANATOMY. 
Human anatomy is the study of the structure of the human body, 
and inasmuch as organisms are vegetable and animal, and the human 
body is the highest animal organism, human anatomy has to deal not 
only with shapes special to man, but also with structures found in modi- 
fied form in other animals, and even with elements of texture common to 
animals and vegetables. Human anatomy is therefore only a branch of 
a larger science. The anthropotomist is incompetent, unaided by com- 
parative anatomy, to deal with many questions of morphology of human 
structures, and he must extend his researches into physiology to compre- 
hend their functional significance. 
Human anatomy is important, not only in its relations to science, but 
in the assistance which its facts afford to other pursuits. Thus, artistic 
anatomy, the study of the human frame in relation to its correct delinea- 
tion by sculptors and painters, is a branch which admits of much greater 
attention than it has yet received; it does not, however, come within the 
scope of the present work. More closely bearing on our purposes is the 
assistance which human anatomy renders to medicine and surgery, lying 
as it does at the foundation of the precision with which anatomical details 
are taught in our medical schools ; and, indeed, it is to be noted that many 
details respecting the precise relations of parts, which do not appear to 
have great scientific interest, are most important in surgery. 
The human body presents for consideration textures, and organs com- 
posed of textures. The investigation of the textures is called Histology, 
and includes all microscopic anatomy whether of diffused structures or of 
special organs, while the term General Anatomy excludes the microscopy 
of special organs and embraces the whole consideration of parts distrib- 
uted through different regions of the body. 
The special organs form the subject of Descriptive Anatomy. They 
may be arranged in systems, such as the osseous, muscular, vascular, ner- 
vous and visceral; and when these are taken in series, as will be done in 
this work, the method of instruction is called Systematic Anatomy. But 
the different parts may also be brought under notice in the order in which 
they are laid bare in dissection of the different regions; and this is called 
Regional or Topographical Anatomy. 
Methods, In a text book of this sort, methods do not fall to be con- 
sidered in detail; but some of them may be enumerated. The most 
important method of Anatomy is Dissection, from which the science takes 
its name; and to facilitate dissection, as well as to render preparations 
permanent, preservative substances require to be used. Maceration is 
employed for the clearing of bones from their surroundings, and sometimes 
for the separation and exhibition of other structures. Injection is used 
to dilate the larger bloodvessels and fill them with solid material, and 
also to display microscopic tubes by filling them with coloured fluid. 
Continuous Sections are used both in microscopic and larger anatomy; 
and in microscopic anatomy staining with dyes is largely resorted to. INTRODUCTION. 
B 
Experiment on animals has a certain value as an auxiliary in advancing 
the anatomical knowledge of the nervous centres, but while its physiologi- 
cal results are all-important, the purely anatomical deductions drawn from 
the pursuit of this method are necessarily open to question. 
Descriptive terms. In describing the forms and relative positions of 
structures there are certain terms required which, however simple in 
themselves, have yet a certain conventional use to which it may be con- 
venient to direct the student’s attention at the outset. The words anterior, 
posterior, superior and inferior are used in human anatomy in reference to 
the body in the erect posture. This is rather unfortunate, seeing that the 
same words applied to the lower animals are used in reference to their 
ordinary positions, and become quite ambiguous in descriptions which 
refer indifferently to both the lower animals and man, snch as occur in 
embryology as well as comparative anatomy. In such circumstances it 
is advisable to avoid the words in question altogether. The words dorsal 
and ventral can always be used to express the directions which are in the 
human subject anterior and posterior, and while no convenient words have 
hitherto been found as substitutes for what in human anatomy is ex- 
pressed by superior and inferior, proserial and retroserial may be suggested 
as self-explaining terms completely fitted to supply the want. The mesial 
plane is that in which the right and left half of the body meet; and any 
line which lies in that plane is the middle line of the surface spoken of. 
The words external and internal are held to refer technically to greater 
or less distance from the mesial plane, while the words deep, subjacent, 
and superficial express greater or less distance from the surface. But 
external and internal were often used to signify superficial and deep before 
the modern convention had been arrived at, and relics of former usage sur- 
vive in the particular names given to certain structures, as, for example, 
the expressions external and internal abdominal rings, which would be much 
better spoken of as superficial and deep rings, particularly as it happens 
that the ring called external is in a position nearer the middle line than 
that known as the internal. The word sagittal, introduced by some German 
writers instead of dorso-ventral, and the word frontal or coronal, to express 
a transverse longitudinal plane, have come much into use. Generally, it 
may be laid down that no terms should be used which admit of ambiguity. 
With regard to the naming of individual structures, it may be noted 
that more than one attempt has been made to impose uniformity of nomen- 
clature by the arbitrary authority of an individual or a- committee. It 
may be doubted if any such attempt can possibly be successful.1 But, 
1 A supplemental volume of the Archiv fur Anatomie und Entwiclcelungsgeschichte, 
1895, is devoted to “Nomina Anatomica, Verzeichuiss der von der anatomischeu Gesell- 
schaft auf ihrer ix. Yersammlung in Basel angenommenen Namen. Eingeleitet und im 
Einverstandniss mit dem Redactionsausschuss erliiutert von Wilhelm His.” This work 
is most important for consultation; hut the adoption of its recommendations in this 
country would, in a large number of instances, involve the abandonment of good names 
in general use for others whose advantages are not obvious. 4 
GENERAL ANATOMY. 
manifestly, certain general principles ought to be observed. Names in 
common use ought not to be lightly set aside. When new names have 
to be introduced, they ought to be short, euphonious, and etymologically 
accurate, and ought, as far as possible, to explain themselves; and newly 
discovered structures should be referred to by a descriptive name, whether 
the name of the discoverer be added or not. Names ought always to be 
used in exact accordance with the definition given by the introducer, 
otherwise the same word comes to have two meanings, and its precision 
is lost. Generally, terms are to be preferred which cannot possibly be 
misunderstood, and when a term has unfortunately come to be used with 
different limits from those of its original meaning, it may be well to 
mention the name of the author responsible for the definition followed. GENERAL ANATOMY. 
THE LIVING CORPUSCLE. 
In the simplest living beings, whether animal or vegetable, the functions 
of life are carried on by a single corpuscle, a mass of pulp of microscopic 
dimensions, scarcely begun to be differentiated into parts for different offices. 
One of the earliest complications of such a mass is the distinction of a 
firmer rounded body, the nucleus, within it; and in certain instances, 
notably those of vegetable type, there is added an envelope or cell-wall 
round about. Such corpuscles are not only the simplest form of adult 
organisms, but furnish the embryonic origin of all others; and are the 
most obvious living elements of the adult texture. They are, in fact, units 
of life. They arise, probably in every instance, from pre-existing corpus- 
cles ; and thus the living corpuscles of the textures are comparable with 
separate organisms in possessing parentage, as well as in other respects. 
They are very commonly called nucleated cells. But the term ‘ cell ’ 
had its origin in the importance once attributed to a structure which is now 
known to be really no part of the living corpuscle, the cell-walls formed 
of cellulose in plants being familiar to botanists before their contents were 
well appreciated. Robert Brown first observed and named the nucleus, 
while another botanist, v. Mold, observed that there was within the cell 
a special delicate substance which he called protoplasm. Schwann (1839) 
was the first to realize that organization proceeded by essentially the same 
methods in animals as in plants, and naturally adopted the word ‘cell’ 
from the botanists, though aware that a cell-wall was not in every instance 
present. It was not till much more recent years that histologists generally 
became aware that the protoplasm and nucleus are, as is now conceded, 
the most important elements of living corpuscles in both animals and 
vegetables, and that the cell-wall when present is adventitious. 
Protoplasm is simply a convenient term for the substance surrounding 
the nucleus and constituting the mass of the living corpuscle. Its meaning 
cannot with propriety be extended so as to include the substance of the 
more specialized living elements, such as muscular fibre, which, although 
nearly allied in chemical composition, have peculiarities of their own. 6 
GENERAL ANATOMY. 
It probably, however, always possesses some amount of the contractility 
which is more highly developed in muscle. This property of contractility 
is exhibited very evidently in unwalled corpuscles found in the blood 
and in the connective tissues, and in them takes the form of a power to 
throw out processes and generally to change their shape in every direction, 
like the minute animals called Amoebae; hence such corpuscles are 
called amoeboid or wandering. It is as yet impossible to say if protoplasm 
has for its basis a single definite chemical substance, or what its precise 
composition is in the living state, 
but it is of highly complex nitrogenous 
constitution, coagulable with heat, 
soluble in alkalies, belongs, so far as 
can be ascertained, to the albuminoid 
group, and is easily subjected to 
staining. It may present an almost 
uniform appearance, or may be dis- 
tinctly granular. This granular ap- 
pearance may be due to molecules of 
oil, lecithin, or other substance; and 
the analogy of muscular contraction 
would suggest that there is always 
some other substance besides the main 
Pig. 1. Nucleated Corpuscles from the 
tissue investing the amnion of an embryo lamb. 
The threads of spongioplasm are made evident by 
staining. 
chemical constituent present necessary for the exhibition of contractility. 
Even, however, apart from granules and fluids which may be mixed with 
it, protoplasm is now held by investigators who have given special atten- 
tion to the subject to be resolvable into a network or spongioplasm, and an 
amorphous material or hyaloplasm in the meshes. 
Nuclei are firmer bodies, spherical, flattened or elongated, with a regular 
outline so definite that it must be regarded as a membrane. They often 
occur without apparent protoplasm around them. They are more suscepti- 
ble of staining than is protoplasm, and have been found to exhibit at times 
a close network of threads within them, of specially stainable character, 
and embedded in unstainable substance. Nuclei often contain one or more 
highly refractive bodies in their interior, nucleoli, which may stain more 
deeply still. 
Multiplication of nucleated corpuscles. Nuclei have been long known 
to play an important part in the multiplication of corpuscles. It was seen 
that a nucleus became divided into two nuclei before the surrounding 
protoplasm divided, and that this occurred both in cells surrounded with 
cell-walls and in corpuscles not so surrounded; and the whole process was 
termed fissiparous division, to distinguish it from budding or the separation 
of a small portion of the protoplasm {gemmiparous division). It is now 
known that very complicated changes take place in nuclei prior to their 
dividing, and these processes constitute what is called karyokinesis or 
mitosis. They occur very generally; and it is supposed that direct division THE LIVING CORPUSCLE. 
7 
without their intervention is quite exceptional; but they have been most 
fully observed in certain instances, as in plants and in the cartilage and 
epithelial cells of amphibians. 
The following appear to be the most important stages described: 
(1) The netted appearance of the nucleus is changed to that of coiled 
Fie. 2. Cells with Kaeyokinetic Chromatin Figures, epithelial cells from gills of 
larva of salamander, a, Nucleus at rest; b, a thread formed; o, a dense hall; d, looser 
hall or rosette; e, monaster; f, g, h, i, dyaster and its changes ; k, two independent nuclei 
and hour-glass contraction of the whole cell. (Toldt.) 
and contorted threads of stainable substance or chromatin, while nucleoli 
and nuclear wall disappear. (2) The coiled threads arrange themselves 
into a rosette round a centre. (3) The rosette is converted into an 
equatorial star or monaster of threads arranged in loops with their free 
Fi&. 8. Monaster and Dyastek with Acukomatin Spindle and Polak Kays. Schema. 
(Toldt after C. Kabl.) 
ends at the circumference, while two radiating arrangements of unstain- 
able material, or a,chromatin, at the poles are united by a spindle of delicate 
lines passing through the centre. (4) Each loop of the monaster splits 
longitudinally in its whole length, and each daughter-loop, so formed, 8 
GENERAL ANATOMY. 
parts from its sister-loop in such a manner that the central or curved 
portions travel to opposite poles, and form a double starry figure or dyaster. 
(5) The protoplasm is divided into two masses, one round each new star, 
while the stars give place to the appearance of nuclei at rest.1 
The cell-wall is a structure which in certain instances is formed round 
the nucleated corpuscles. It is seen, for example, distinctly round the 
columnar epithelial cells of the intestine. Many corpuscles used to be 
supposed to have cell-walls round them, which are now definitely known 
to have none. In the case of the adipose vesicle, the wall is formed out 
of the protoplasm by alteration of its substance; but in most instances 
there is not sufficient evidence that it is formed in that way, and not by 
deposit thrown out, like other matrix in which corpuscles lie. It may 
be questioned if, in their young condition, the corpuscles of animals have 
ever any cell-wall round them. 
Nucleated corpuscles in the textures may be 
(1) Massed together with little apparent cement, as in epithelia and 
embryonic textures. 
(2) Embedded in a matrix, as in connective tissue, cartilage and 
bone. 
(3) Elongated into fibres, each derived from (a) one corpuscle, as in 
smooth muscular fibre, or (h) a row of corpuscles as in striped 
muscular fibre, and perhaps, or even probably, in nerve. 
Nucleated corpuscles are also found floating free, as in blood and lymph. 
THE BLOOD. 
Blood consists of two parts, the plasma or liquor sanguinis, and the 
blood-corpuscles. The plasma is broadly divisible into serum and fibrin, 
and the corpuscles into red corpuscles and white. A rough analysis 
showing those constituents may be made by collecting blood from a wound 
into an ice-cold vessel. The cold prevents coagulation taking place; the 
red corpuscles gravitate to the lower part of the vessel, and the plasma 
is left clear and straw-coloured above, while on further standing a slight 
milkiness may be noticed near the surface, caused by the white corpuscles 
rising to the top. On raising the temperature, the plasma forms a trans- 
parent coagulum, and the coagulated fibrin gradually contracts so as to 
separate from the edges of the glass and present a concave surface, while, 
in the concavity and round about, the serum expelled from the contracting 
mass is collected. A similar sequence of events takes place, without the 
precaution of chilling, in various conditions of human blood, as well as 
normally in the blood of the horse. Practitioners, in the days when 
1 For the literature of mitosis and of histology generally the student may he referred to 
the sixth edition of Kdlliker’s Handbuch der Gewebelehre des Menschen, and to the tenth 
edition of Quain’s Elements of Anatomy. THE BLOOD. 
9 
bleeding was generally practised, termed the straw-coloured layer huffing, 
the contraction of the clot cupping, and attached importance in fevers and 
inflammatory complaints to the blood being buffed and cupped. If blood 
be agitated with a bundle of twigs while it is being removed from the 
body, the fibrin at once adheres in a firm contracted coagulum to the 
twigs, while, in the defibrinated blood which remains, the red corpuscles 
rapidly separate from the serum. 
The red corpuscles or discs, in their characteristic condition, as seen, for 
example, in blood from a puncture of the finger, are biconcave circular 
discs, the vast majority of them having exactly one size in any one 
specimen. Their diameter is variously estimated at from oth to 
inch. None of them exceed that size, but a few much smaller are often 
seen in the blood of persons in perfect health. Their colour under the 
microscope is a uniform orange, corresponding in tint to that of a thin 
streak of blood on a white plate. But in dark venous blood this is 
Fig. 4. Bi.ooD-CoKPrsci.ES of Man. a, a, Bed corpuscles of ordinary appearances; 
h, 6, occasional red corpuscles of smaller size; o, c, minute particles of red substance; d, 
red corpuscle crenated by evaporation; e, red corpuscle swollen by addition of water; f, 
finely granular white corpuscle ; ff, similar white corpuscle spread amoeboidly on the glass ; 
h, coarsely granular white corpuscle ; i, small hyaline white corpuscle. 
changed to a dull or purplish crimson, and the form is slightly biconvex. 
Frequently one sees red corpuscles perfectly flat, like a wafer, and without 
any simulation of a bounding membrane. When they are biconcave and 
the edges are completely in focus the central part has a darker shade, not 
unlike a nucleus, but disappearing as the focus is altered. It is only 
very exceptionally that a nucleus is really met with in a red corpuscle 
in a grown mammal. But in the young embryo all the red corpuscles 
are nucleated, and they are larger than those of the adult. On the 
addition of water, the red substance of the corpuscles becomes diffused 
through the fluid, while an amorphous solid remainder is left; and if this 
experiment be performed with defibrinated blood in a test-tube, the solid 
substance will collect in the form of a white sediment at the bottom. 
The soluble red substance consists mainly of haemoglobin, the insoluble 
residuum is called the stroma. 
Haemoglobin is a chemical substance which so far as can be yet ascer- 
tained would appear to be decidedly more complex than even albumin. 10 
GENERAL ANATOMY. 
It takes oxygen freely into its composition when exposed to it, and easily 
parts with it again. The oxygenated haemoglobin is distinguished as oxy- 
haemoglohin, because the bands which it shows with the spectroscope are 
different from those of reduced haemoglobin. In the circulation the hae- 
moglobin, at the same time that the oxygen is expelled from its chemical 
constitution, absorbs carbonic acid, holding it in solution without chemi- 
cally uniting with it. To these properties of haemoglobin the red corpus- 
cles owe their utility, and there can be little doubt that this substance 
exists separately in their composition. Yet the haemoglobin and stroma 
are undoubtedly indistinguishably united in the corpuscles as a homo- 
geneous mass; and the extreme ease with which the corpuscles become 
elongated in passing through narrow channels, to recover their shape on 
emerging, precludes the idea that they have a separate cell-wall. More- 
over, if blood drawn from the finger be heated, short of coagulation, for 
a moment over a flame, the red corpuscles will divide in their whole 
substance in such a manner that, by repeating the experiment, the same 
specimen may be made to show successively a large number of red corpus- 
cles of half, or less than half, the standard diameter and numbers of small 
red granules, or all the discs more or less completely broken up into 
smaller discs or granules, evidently all of the same composition. The 
blood of the guinea-pig treated in the same way gives off worm-like 
threads; but if it be first subjected to freezing, the whole corpuscular 
structure runs into tetrahedral crystals. So also in the rat and squirrel, 
the whole corpuscular substance may be made to crystallize into hexagonal 
plates. These have been described as haemoglobin crystals ; and crystals 
both of haemoglobin and of other kinds, in which the substance of the 
blood is more or less altered, are to be obtained with greater or less ease 
from the blood of different animals. But it is to be noted that in many 
instances, including the blood of man, the crystals do not consist of the 
whole substance of the red corpuscles. 
The white corpuscles or leucocytes of the blood are rounded bodies 
approaching the spherical form, and are much more irregular in size than 
the red corpuscles. The majority are a little larger than the red corpus- 
cles, but some of them are smaller, while others are exceptionally large. 
The average size may be stated at from to of an inch, or 
even less. They have a more or less turbid appearance, but are cleared 
by the addition of water or acetic acid, and then there come distinctly 
into view one or more nuclei, or a multipartite nucleus, in their interior. 
Even outside the body they can, if proper precautions are taken, be 
observed to be capable of great change of shape of an amoeboid kind, 
flattening and sending out branches or pseudopods, and changing their 
position. So also in the web of the frog’s foot, or in the undetached mes- 
entery of a rabbit, the white corpuscles can be seen flattening themselves 
against the walls of capillary bloodvessels and gradually passing through 
them into the tissues around; projecting first a small portion beyond the THE BLOOD. 
11 
outline of the vessel, and then going through a series of hour-glass shapes, 
in which the part external to the vessel becomes larger and the part 
within becomes smaller, until the 
whole corpuscle has passed through. 
This process is called diapedesis. It 
was first discovered by Augustus 
Waller, but remained unverified for 
a number of years, and was sub- 
sequently rediscovered by Cohn- 
heim, who pointed out its great 
pathological importance. The white 
corpuscles originate in the lym- 
phatic glands, in the spleen, in 
retiform or lymphoid tissue distri- 
buted through the body, and in 
the marrow of bones. They have 
their origin in the solid tissues, and 
many of them, as we have seen, 
return to these. 
Several varieties or conditions 
of white corpuscles have been ob- 
served, and appear to indicate 
differences of source, function, age, 
or destination. Sherrington distin- 
Fig. 5.—Leucocytes escaping from a capillary blood- 
vessel in mesentery of rabbit. Elastic and white 
fibres of connective tissue, as well as the structure 
of the vessel, are also seen. 
guishes in the dog (1) the finely granular with the nucleus obscured and 
variable, (2) the coarsely granular of large size, liable, like the first, to 
amoeboid changes of shape, and with granules well-defined, stained yellow 
by osmic acid vapour, (3) the small hyaline with spherical nucleus and small 
amount of clear surrounding protoplasm retaining the spheroidal shape, 
and (4) the large hyaline, with less regular nucleus and larger amount 
of rather clear protoplasm.1 
The corpuscles of non-mammalian vertebrates. There is a broad dis- 
tinction between the blood of mammals and that of all other vertebrates, 
for whereas the red corpuscles are always circular in mammals (save 
only in the camelidae which have them oval), and are in the normal 
adult condition devoid of nucleus, they are, in other vertebrates, always 
oval and always provided with a single distinct oval nucleus occupying 
the centre. The nucleus is devoid of colouring matter, and the coloured 
substance of the disc in which it lies is of the same ductile character as 
the mammalian disc. When, in addition, it is considered that mammalian 
red corpuscles are, in the young embryo, nucleated, and that an occasional 
nucleated corpuscle may be found even in adult mammals, it seems impossible 
to doubt that the mammalian red corpuscle is homologous with the non- 
1 Consult for details and bibliography Sherrington, Royal Society Proceedings, 
February, 1894. 12 
GENERAL ANATOMY. 
mammalian, and that it is the nucleus, not the surrounding disc, which 
is fugitive in mammals. 
The largest red corpuscles are found in the amphibia, the long 
diameter measuring in Proteus anguineus J-yth inch, and in the frog 
TTLTth. In fishes and in reptiles, both of which 
are groups embracing forms widely different in 
structure, it would be difficult to lay down a rule 
according to which the size of the corpuscles varies. 
In birds, which are a compact group, the ostrich 
would appear to have them largest, namely, with a 
long diameter estimated at inch, and the 
humming bird to have them smallest, with a long 
diameter of y^yth. 
Fig. 6. Blood-Corpuscles 
or Frog, viz., four red cor- 
puscles in full view, one in 
profile, and one white cor- 
puscle. 
In mammals the largest diameter is found in 
the elephant, 2 7*4-gth inch; and smallest in the 
smallest ruminant, the napu or tragulus, x 2 \2 sth 
inch. 
Other bodies besides the red and white corpuscles have been described 
as occurring in the blood. The invisible corpuscle of Norris is a body 
of the same size and shape as the red corpuscle, but without the colour. 
Such corpuscles Norris maintains to exist in the circulating blood. 
Undoubtedly, by very slight changes in the blood, some of the red cor- 
puscles lose their colouring matter and become difficult to see, while others 
remain unaffected, or become darker ; and even supposing that the evidence 
is not sufficient to support the contention of Norris that invisible discs 
exist in the circulation, it is of great importance to recognize that the 
red corpuscles are thus dissimilar in nature, as this points to a difference, 
according to age, in their utility as carriers of oxygen. The 
of Bizzozero is a similar structure of smaller size, and is probably the 
result of divided red corpuscles losing their colouring matter. Elementary 
granules of Zimmerman are small particles, some of which have been set 
free by the breaking up of white corpuscles, and are liable to congregate 
as granular masses in blood outside the body, while others are doubtless 
particles separated from red corpuscles after the fashion above pointed 
out. This is probably the nature of those termed haematoblasts by Hayem, 
and looked on by him as origins of the red corpuscles. 
The colourless nuclei of red corpuscles in embryos and non-mammalian 
adults present a strong objection to any theory of the development 
of the red corpuscle which does not derive it from a nucleated cor- 
puscle afterwards losing its nucleus. The theory formerly almost uni- 
versally held, that red corpuscles are formed from certain of the wffiite 
corpuscles, is not open to this grave objection. As shown by the researches 
of Neumann, Bizzozero, and Schafer, another source of red corpuscles in 
the adult is the red marrow of the bones. In the early embryo, red 
blood-corpuscles are produced by the division of nucleated corpuscles THE CONNECTIVE TISSUES. 
13 
within anastomosing cell-walls which are concerned in the first formation 
of bloodvessels in the area vasculosa. 
THE CONNECTIVE TISSUES. 
The connective or binding tissues include a large variety of structures 
differing in appearance and firmness, the firmer varieties forming protective 
sheaths and uniting bands, by means of which the whole body is joined 
together, while the finer descriptions not only surround the elements of 
texture and special structures of 
organs, but are closely associated 
with their nutrition. They all 
consist of corpuscles embedded 
in matrix or deposited substance, 
and to the nature of this the dif- 
ferent varieties owe their physi- 
cal characters. The deposited 
substance is of two kinds, gela- 
tiniferous and yellow-elastic, and 
each of these occurs in fibrous 
and homogeneous forms. 
Gelatiniferous substance, as it 
exists in the body, is of unknown 
chemical nature, but by pro- 
longed boiling is dissolved, being 
converted into gelatine. It is 
often found homogeneous, as in 
structureless membranes and the 
most superficial part of the true 
Fig. 7. Connective Tissue from orbit of ox, exhibit- 
inS corpuscles of various shapes, straight white fibres, 
and curled elastic fibres. 
skin, and this condition passes by gradual transition into the fibrous, 
which is termed white fibrous tissue. White fibres, as seen under the 
microscope, vary from the faintest fibrillation of an otherwise homo- 
geneous substance to distinct threads, presenting a double contour, but 
indefinite in length, which shade away into finer substance. Broader 
bands which at first seem structureless may be resolved by manipulation 
into bundles of finer fibres. White fibres may take irregular courses in 
different directions, felting with one another, or they may be arranged 
in parallel bundles which are sometimes quite straight, as in tendon, 
and sometimes present regular angular undulations reflecting the light 
with satin-like lustre in different directions from different parts of their 
curves. On addition of acetic acid, they swell up and become invisible 
under the microscope, but they resume much of their original appearance 
when the acetic acid is washed away. 
Structures composed of white fibrous tissues, e.g. the ordinary ligaments 14 
GENERAL ANATOMY. 
and tendons, have a definite length and are inextensible; that is to say, 
they cannot be stretched beyond their proper length without damage to 
their tissue. The definite character 
of the movements of joints is depend- 
ent on this property, and were it not 
for the same property in tendons, 
there would be a great waste of power 
by muscular contraction expending its 
energy in lengthening tendons instead 
of moving the bones to which they are 
attached. 
Yellow-elastic substance gets the 
name elastic from having the proper- 
ties of extensibility and resilience like 
india-rubber. In the innermost coat of 
arteries there is a good example of 
a homogeneous membranous arrange- 
ment of this substance, while, in the 
middle and outer coats there are 
laminae exhibiting a transition from 
Fig. 8. Deep Fascia or Aponeurosis oyer 
biceps flexor radialis muscle. Bundles of un- 
dulating white fibres; fusiform and amoeboid 
corpuscles. 
membranes with frequent perforations to firm networks of fibres mem- 
branously arranged. There are two very different dispositions of yellow- 
elastic fibres. In one, the fibres are scattered through white fibrous 
tissue, and each fibre exhibits highly irregular circular curves, totally 
Fig. 9. Yellow-Elastic Tissue, a, Longitudinal section of llgamentum subflavum • 
b, transverse section of llgamentum subflavum; e, independent coiled fibres in the 
pleura. 
distinct in direction from all the others. Such fibres are found in great 
abundance in the cutis vera and subcutaneous tissue, under the serous 
membranes, particularly the pleura, and in other situations. The other dis- 
position of yellow-elastic fibres occurs when they form the main substance THE CONNECTIVE TISSUES. 
15 
of the tissue. The fibres then take a straight course in parallel bundles ; 
and, when it is sought to separate them, they are found to be netted 
together, so that they cannot be thoroughly indi- 
vidualized. Transverse sections bring out the netted 
arrangement, short blocks of thick fibres being seen 
under the microscope, connected by thinner hands, 
which, being pressed out of their original position, 
tend to curl up. So also by teasing out yellow- 
elastic tissue the torn liberated ends curl up; but 
the curling is produced by the manipulation. The 
thick fibres are not of uniform firmness; and in 
yellow-elastic fibrous tissue, which has been kept 
for a length of time and frequently stretched, they 
tend to give way on one side, exhibiting closely 
set transverse cracks, reminding one of india-rubber 
tubes long in use. The ligamenta subflava uniting 
the laminae of the vertebrae consist of yellow-elastic 
fibrous tissue. The only other example of this 
tissue in the human subject is the crico-thyroid mem- 
brane, and even it has a larger amount of white 
fibres intermixed with the yellow. But in quadru- 
peds the largest mass of this substance is the liga- 
Fig. 10.—Fibres from 
Ligamentttm Nuchaf. of 
Horse, from a long-kept 
specimen. They present 
serial transverse cracks on 
one side. 
mentum mediae, and in animals with heavy viscera, like the ox, the sheep, 
and the horse, there is a sheet of it superficial to the muscular wall of the 
abdomen. 
The nucleated corpuscles found in the connective tissues may be broadly 
distinguished into two kinds the migratory or unwalled, and the branched 
or walled. The migratory or amoeboid corpuscles or leucocytes are some of 
them identical with those found in the circulation, which, as has been 
already described, are capable of leaving the vessels and worming their 
way into the tissues; others are flattened out and have irregular forms, 
with a tendency to send out processes, and have the nucleus oval. Every 
stage of gradation exists from the one of these forms to the other, and 
there seems no reason whatever to doubt that the larger and flatter are 
derived from the smaller and rounder, and in turn pass into corpuscles, 
walled and branched. The walled and branched corpuscles are those to 
which the expression connective-tissue corpuscles is usually confined. They 
have a variable number of branches which sometimes anastomose with the 
branches of other corpuscles, but more frequently taper away into linear 
processes or tails. The most common form of all is the spindle-shaped 
corpuscle with two tails elongated in opposite directions, and such corpus- 
cles are seen in all gradations of development from unwalled corpuscles. 
Oval nuclei without protoplasm occur in certain modifications of the con- 
nective tissues. They are found in homogeneous matrix, e.g. in synovial 
membranes and in the fine sheaths of the primitive bundles of nerves. 16 
GENERAL ANATOMY. 
The different varieties of connective tissues composed of corpuscles and 
white substance, with or without admixture of yellow-elastic fibres, are 
retiform tissue, areolar tissue, fascia, aponeurosis, ligament, and tendon. 
Betiform, lymphoid, or adenoid tissue is the variety of connective tissue in 
which, there is the greatest abundance of corpuscular elements. Its matrix 
presents a very delicate gelatiniferous substance, which often appears in 
the lymphatic glands to consist of a network of stellate cell-walls whose 
branches intercommunicate to form the threads bounding the meshes, 
while the interspaces are more or less crowded with leucocytes of different 
sizes which proliferate within it. It is a tissue found in greatest abund- 
ance in the lymphatic glands, and occurs also diffused in thin layers, 
surrounding secreting tubes or lobules. 
Pig. 11. Subcutaneous Connective Tissue 
from embryo duck, showing corpuscles with 
anastomosing- branches, a, A nucleus; b, a 
branch. (Bohm and y. Davldoff.) 
Pig. 12. Retiform Tissue : a, from mes- 
enteric gland of cat; b, from mesenteric gland 
of kitten before birth ; o, from thymus of saia- 
mandra maculata. (Toldt.) 
Areolar tissue consists of delicate gelatiniferous substance exhibiting 
delicate fibres and bundles of fibres taking different directions, so as 
to form a felted arrangement and leave irregular meshes or areae be- 
tween them, which are the cells or spaces to which allusion was made 
when formerly it was termed cellular tissue; it is especially to this variety 
that the expression connective tissue applies. 
Fascia is a firmer variety of felted white fibrous tissue spread out to 
form a sheet or membrane devoid of lustre. All fasciae are continuous 
with looser areolar tissue on one or both sides, and thick sheets are 
often capable of being artificially divided into an indefinite number of 
laminae. Fascia has always a certain admixture of coiled yellow-elastic 
fibres in its substance. 
Aponeurosis is a term properly applied to sheets of white fibrous tissue 
with lustre depending on the regularity of the arrangement of the bundles, THE CONNECTIVE TISSUE. 
17 
often finely undulated, which are either parallel to one another or in two 
or three sets regularly crossing one another. Two kinds are recognized, 
namely, aponeurosis of protection, and aponeurosis of insertion. The same 
protective sheet may be at one part regular and lustrous and at another 
felted and dull, which leads to the words aponeurosis and fascia being 
sometimes used indifferently with reference to one structure. Thus, we 
speak of the aponeurosis of the lower limb or the fascia lata. Aponeurosis 
of insertion differs in being continuous with muscular fibres, and while in 
structure identical with aponeurosis of protection, is on the other hand 
a membranous tendon in general appearance. 
Ligament and Tendon are the two strongest varieties of white fibrous 
tissue, and agree in having the bundles of white fibres running in one 
Fig. 13. Tendon : a, b, c, from boiled flexor tendon of sheep’s trotter, showing quadrate 
scales, a, with the edges slightly folded, b, seen edgeways united by a thread, c, in full 
face with elongated nuclei in continuous thread, one behind each scale; d, e,/, g, normal 
appearances from rat’s tail, d and /, with the scales seen edgeways, e and g, in full face with 
their flat circular nuclei; h, i, abnormal appearances from rat’s tail, the whole chain being 
cylindrical and stained deeply with carmine; k, human, from thick tendon of limb, large 
elongated nuclei deeply stained and united by a thread. 
direction. But ligaments in the human body have not as great lustre as 
tendon, and during life tendons may snap abruptly, as in rupture of the 
tendo Achillis, while ligaments tear in ragged fashion, so that sprains are 
often difficult to heal. 
Tendon has in addition certain structural peculiarities of its own. It is 
surrounded by a sheath of areolar tissue containing nerves, and in trans- 
verse section is seen to consist of separate bundles with finer septa between 
them. The separate bundles of white fibrous tissue exhibit a mass which 
may be easily made to show longitudinal fibrillation, but which is appar- 
ently structureless when its parts are not displaced. Each bundle has 
laid against it and partially surrounding it a linear series of delicate flat 
cells or stainable scales more or less distinctly quadrate in shape with 
circular nuclei. These are the quadrate cells of Ranvier, and may be easily 
B 18 
GENERAL ANATOMY. 
seen in position in the tendons of the tails of small animals, such as rats, 
which do not require sections for their examination. At the back of each 
scale is a longitudinal structure easily stained, described by 801 l as an 
elastic band, alleged by him to have been mistaken sometimes for the 
nucleus, but considered by Banvier as a crest. I find it to consist of elon- 
gated corpuscles consisting chiefly of nucleus, united in linear series by a 
thread of connection. These chains are far more easily distinguished in 
the human subject than the quadrate scales.1 
Medullated nerve-fibres breaking up into branched structures in ten- 
dons near their junction with muscle will be referred to in connection 
with muscular nerve-supply. 
Adipose tissue. The tissue which is commonly known as fat is tech- 
nically termed adipose tissue, the word fat being more properly used to 
signify the solid condition of an oil. Adipose tissue consists of groups of 
microscopic vesicles containing oil and supported by a delicate web of 
connective tissue. Adipose vesicles are mostly from to of an 
Fig. 14.—Adipose Tissue: «, In the unaltered state, the vesicles full of oil and lying 
among fine white fibres; b, stained and cleared from oil, some of the vesicles showing the 
circular flat nucleus, smaller nuclei of leucocytes scattered about, and a capillary with its 
oval nuclei brought into view; c, from foetus of five months, shows a group of germinal 
corpuscles as yet free, from oil, and four converted into vesicles by accumulation of oil; 
d, from emaciated adult, showing withered vesicles, and others in different stages of forma- 
tion from leucocytes. 
inch in diameter and are rounded in form, or sufficiently closely packed 
together to have their sides somewhat flattened one against another. 
They are generally arranged in little clumps or grains separated by loose 
connective tissue from others, and these smaller grains are often collected 
into larger lobules. Though adipose tissue is but poorly vascular, it is 
better supplied with bloodvessels than is connective tissue, and each little 
clump of vesicles has a capillary distribution separated by non-vascular 
1 The nucleated thread appears to me to he the fundamental part of the arrangement 
which is never absent. A specimen is figured from a rat’s tail in which the nuclei were not 
only exaggerated in size, hut united hy a thick protoplasmic thread, while the scales were 
absent. THE CONNECTIVE TISSUE. 
19 
substance from the vessels of the others. If it be carefully stained with 
carmine, and the oil be then removed from it by chloroform or some 
other solvent, a number of nuclei will be seen in every patch of vesicles, 
some of them oval and belonging to the capillary walls, while others are 
circular, with or without adherent protoplasm, and belong one to each 
vesicle. The solidity of adipose tissue depends on the walls of the vesicles, 
together with their surroundings, being saturated with watery fluid, with 
which the oil cannot mix. But if a piece of adipose tissue from the human 
subject be exposed on a plate, the watery fluid evaporates, and the oil 
impregnates the shrivelled tissue and soon gathers in a pool. This does 
not occur with the adipose tissue of the sheep, because in it the oil in 
the vesicles is solidified at the ordinary temperature of the air. 
Adipose vesicles make their appearance early in the fifth month of 
foetal life. Previous to that date glycogen is 
abundant in the tissues, but it subsequently 
diminishes in quantity as adipose tissue becomes 
developed. Originally the adipose vesicles are 
rounded unwalled nucleated corpuscles, leuco- 
cytes, in fact, as may be seen to advantage by 
examining the mesentery of a kitten at birth, 
when little heaps of these corpuscles can be 
seen occupying the positions afterwards occupied 
by collections of adipose vesicles. The oil ap- 
pears in them first in minute molecules, some 
of which get larger, as may be judged from 
other corpuscles containing one or more distinct 
globules, besides minuter particles. The glob- 
ules run together into one, while the protoplasm 
is changed in character, being gradually con- 
verted into the wall of a vesicle, and the nucleus 
is thrown to one side and ultimately flattened. 
This process can be studied with advantage 
not only in the foetus, but in the bodies of 
emaciated adults; and the number of corpuscles 
which may in such circumstances be sometimes 
seen with the nucleus and protoplasm distinct 
Tig. 15.—Portion op Fat Lobitle 
from axilla of a much emaciated 
young man. (Toldt.) 
seems to point to increased activity of the tissues in connection with 
the absorption of oil into the circulation. 
CARTILAGE. 
Cartilage is sometimes classed with the connective tissues and its 
close relation to these is shown in the changes which it undergoes in 
ossification, in the structure of intervertebral discs, and in other ways. 
But typical or hyaline cartilage is a texture with very distinctive features. 20 
GENERAL ANATOMY. 
It is called temporary or permanent according as it is destined to be 
converted into bone or to remain as cartilage till adult life. Among the 
more important masses thus remain- 
ing in the adult may be mentioned 
the costal cartilages, the articular 
cartilages, and those of the larynx, 
trachea, and other air-tubes. 
Hyaline cartilage consists of incap- 
suled corpuscles lying in a clear or 
hyaline matrix which, on boiling, 
yields principally a substance called 
chondrin, resembling gelatin in being 
soluble in hot water and forming a 
jelly on cooling, but differing some- 
what in composition and in respect 
that while, like gelatin, it is precipi- 
tated from solution by tannin, it is 
likewise precipitated by acids, alum 
and sugar-of-lead, which do not pre- 
cipitate gelatin. This chondrinifer- 
ous matrix is the part which gives to 
cartilage its physical characters, mak- 
ing it firm, tough, flexible, springing 
back when bent, and breaking with 
Fig. 16. Costal Cartilage, human. At the 
upper right-hand corner degeneration of corpus- 
cles has set in. 
a somewhat vitreous fracture. It often exhibits under the microscope a 
faint indication of fibres, and more constantly a slightly granular appear- 
ance, most evident in the parts furthest removed from the corpuscles, 
which are also the parts most darkened by osmic acid, probably from a 
certain amount of oily matter being present.1 
The corpuscles lie in capsules of the same substance as the rest of 
the matrix, only firmer and capable of being isolated by softening of the 
matrix by reagents. The corpuscles, when young and active, fill the 
capsules. Their protoplasm is granular, the nucleus distinct; and there 
is often a clear nucleolus, staining very dark with osmic acid. Two, 
three, or more corpuscles may be present in one capsule, while near it 
there may be a similar group, the members of which are each inclosed 
in a distinct capsule separated by bars of matrix from the others; or 
an imperfect bar may be seen partially separating one capsule from another. 
Thus, it is evident that cartilage increases in size by growth throughout, 
the corpuscles multiplying, their capsules dividing, and new matrix being 
afterwards thrown out between them, so that they are forced apart, 
1 Very remarkable complexities of matrix connected with sap-currents and fibrilla- 
tion have been brought into view by special methods. For a full account of these and the 
literature of the subject, see Wolters in Archivfur Mikrosk. Anat., 1891, Vol. xxxvn., 
p. 492. CARTILAGE. 
21 
every such action in the deep part of a block necessitating movements 
in all the parts around. Although in adult fishes, and in certain stages 
of the growth of human bones, cartilage occurs with the capsules uni- 
corpuscular and evenly disseminated, more usually the capsules, whether 
containing one or more corpuscles, are arranged in groups. They may 
be of rounded form, but are more frequently subangular, the individuals 
belonging to one group not being sufficiently separated to swell equally 
in every direction, but presenting flattened 
sides to the other members of the group. 
Another condition is common in the human 
foetus in parts at some distance from an 
ossifying surface, and likewise is found in 
permanent cartilages of various animals, 
namely, capsules linearly elongated and 
spindle-shaped, containing two, three, or 
more corpuscles, and, mixed with these, 
linear spindle-shaped groups of unicorpus- 
cular capsules, the terminal members of 
each group having an elongated triangular 
form. These linear arrangements cross each 
other, pointing in every direction, so that 
together they lead by their growth to in- 
creased size of the block in all diameters. 
Fig. 17. Cartilage with Spindle 
shaped Capsules from lower end of 
femur of child at birth. 
Cartilage is a texture devoid both of ves- 
sels and nerves. It is, however, generally surrounded by a special fibrous 
covering containing bloodvessels, the perichondrium. But where cartilage 
is continuous with bone there is no perichondrium, neither is there any on 
the free surfaces entering into the formation of joints. Large masses of 
cartilage are penetrated by canals containing bloodvessels, but the walls of 
the vessels have always connective tissue between them and the cartilage. 
The costal cartilages are remarkable for the large size of their cor- 
puscles and oval capsules. The corpuscles in one capsule vary in number 
up to six, seven, or more. Both corpuscles and capsules are largest in 
the centre of the cartilage, while at the circumference they are not only 
small, but flattened in a direction parallel to the perichondrium, as if the 
immediate pressure of that inactive membrane interfered with their growth 
more than did the dense mass of matrix penetrated by nutritive currents. 
As age advances, the matrix of costal cartilages becomes granular from 
calcareous deposit, beginning mostly in the heart of the bar, while true 
bone is occasionally developed in the perichondrium. At a much earlier 
period the corpuscles are subject to degeneration,, their protoplasm becom- 
ing coarsely granular and more easily stained with carmine, while dense 
masses form within them, not easily stained, waxy in appearance, but not 
affected by iodine, and these, as thev enlarge, become hollowed into cap- 
sules (Fig. 16). 22 
GENERAL ANATOMY. 
Articular cartilage is the permanent hyaline cartilage which coats the 
opposed surfaces of bones united by synovial articulation. It forms a 
covering which is thickest in the centre when the 
surface is convex, and thinner in the centre than 
at the circumference when the surface is concave. 
It has a more milky appearance than most cartilage, 
and breaks across with a vertically fibrous fracture; 
Fig. 19. Yellow Cartilage, from human epiglottis. 
and this fibrous appearance becomes more notable 
after prolonged maceration, and after certain patho- 
logical changes. It is apparently due to the vertical 
arrangement of the corpuscles in great part of the 
depth, the matrix being firmer in the solid parts be- 
Fig. 18.—Articular 
Cartilage, vertical sec- 
tion, with calcified layer 
beneath. 
tween rows of corpuscles. In the deepest part the capsules are oval; super- 
ficial to this they become elongated, and one finds elongated capsules 
containing linearly placed corpuscles, together with linear rows of shorter 
capsules, up to near the free surface, where the capsules become flat- 
tened out parallel with the surface. A section peeled from the surface 
shows corpuscles grouped together, often a number in one capsule, some- 
thing like costal cartilage, but differing in respect that the corpuscles 
and capsules are fiat. In every joint in the adult, the articular carti- 
lage is separated from the osseous texture beneath, a thin calcified 
layer presenting unbranched cavities in a uniformly calcified matrix. 
It is strange that writers have sometimes been slow to recognize this 
layer, seeing that it persists in the macerated bone, forming-the peculiar 
crust of the articular surfaces, destitute of orifices of the kind which 
pierce the surfaces of true bone. CARTILAGE. 
23 
Yellow or reticular cartilage is seen to most advantage in the epiglottis. 
It differs from hyaline cartilage in having within the matrix a deposit of 
elastic substance arranged more or less distinctly in felted fibres, with 
grannies interspersed. This yellow deposit does not invade the capsules, 
and in preparing sections, an occasional capsule may be rolled out in front 
of the knife, leaving the space which contained it empty. This form of 
cartilage occurs in the human subject in the epiglottis, cornicula laryngis, 
Eustachian tube and the pinna of the ear. 
Fibro-cartilage. Under this name several tissues considerably differing 
one from another are usually described. They will be again referred to 
Fig. 20. Embryonic Cartilage, from 
vertebral column of human embryo two 
months old. Matrix is deposited, but 
there are no capsules. 
Fig. 21.—Capsular Cartilage, from 
ear of bat. The capsules contain clear 
fluid, and are placed close together. 
in connection with the general anatomy of the articulations, under the 
heads of fibro-plates, incomplete joints, and intervertebral discs. 
Embryonic cartilage. In the early embryo, cartilage is at first nearly 
purely corpuscular, there being only sufficient matrix to cement the cor- 
puscles together but no appearance of proper capsules. 
Capsular cartilage. Contrasting with the embryonic there is another 
kind of cartilage found particularly in the pinna of the ear in small mam- 
mals. It consists of empty capsules placed close together and containing 
no vestige of corpuscular substance. No such texture occurs in the human 
subject. 
BONE. 
Bone, or osseous tissue, is so termed from being the principal texture 
entering into the composition of the skeletal structures called bones. A 
bone is an organ in which there are also present other textures. It is 
permeated by bloodvessels; it contains marrow; it is surrounded by a 24 
GENERAL ANATOMY. 
fibrous membrane, the periosteum, in which the arteries ramify before 
entering the osseous tissue; and it may have articular cartilages for 
articulating with other bones. The macerated and dried bones used for 
study are not merely deprived of all these textures, but have likewise lost 
the corpuscular element of the osseous tissue and consist of mere calcified 
matrix. 
General characters. Bone is very generally classified with the connec- 
tive tissues. Like them it consists essentially of branched corpuscles 
embedded in gelatiniferous matrix; but the matrix is impregnated with 
mineral matter to the extent of two thirds of its weight. It has been 
estimated as containing of phosphate of lime 57 per cent., carbonate of 
lime 8 per cent., and phosphate of magnesia and fluoride of calcium at 
the rate on an average of 1 per cent. each. The animal matter may be 
removed by burning in the fire, while the calcined remains preserve the 
original form and apparent structure. So also, if the mineral matter be 
removed by long steeping in dilute hydrochloric acid, the bone will still 
preserve its size, form, and texture, though rendered flexible, shrivelling 
up when dried, and recovering its size when steeped in water. These 
properties, as well as the translucence of the matrix when examined in 
thin sections, show how intimately the mineral and animal constituents 
are commingled. 
Bone is highly elastic, and its elasticity gives strength and spring, 
especially in association with such curves as are exemplified in the ribs, 
the clavicle, the femur, and other parts of the skeleton. It presents two 
principal varieties, the compact and the cancellated. Compact bone is in 
solid mass, while cancellated bone is arranged in spicules and delicate 
plates so as to leave spaces filled with marrow, the whole forming a 
spongy mass easily crushed, and never appearing on the surface, but 
always covered in by at least a thin crust of compact bone. Cancellated 
tissue in the human subject and mammals generally is composed more of 
spicules than of plates, but well-marked plates are often met with on the 
sides of medullary cavities; and a third arrangement is seen in the diploe 
or soft tissues between the outer and inner tables of the skull, produced 
by structure peculiar to compact bone persisting between labyrinths of 
marrow-spaces eaten out by absorption. The spicules of cancellated tissue 
in the larger bones present a distinct tendency to definite arrangement. 
In the upper parts of the femur and humerus, they form lines springing 
from the compact tissue of the shaft and spreading out in interlacing 
arches to end above at considerable angles to the surface. In the vertebrae 
the principal lines of direction are vertical and horizontal; and generally, 
the spicules in different bones may be described as disposed in such a 
manner as to combine strength and lightness, an advantage which is also 
gained in the shafts of the long bones by the compact tissue being in the 
form of a tube round the marrow-cavity. 
The surfaces of dry bones are covered all over with minute orifices, BONE 
25 
just visible to the naked eye, for the entrance of bloodvessels from the 
periosteum; and these, when there is any considerable thickness of com- 
pact tissue, are sloped, and enter from elongated grooves running in one 
direction; but over cancellated tissue they are irregular in size, owing to 
some of them being larger, and they have not such obliquity. 
Near the articular extremities of the long bones of the limbs, on the 
posterior surfaces of the bodies of vertebrae, and in other situations, 
foramina of greater size occur for the exit of veins. Bones possessed of 
a medullary cavity present in addition a foramen in the shaft, constant 
in position, the arterial or nutrient foramen, containing for the supply of 
the marrow and adjacent walls of bone the so-called nutrient artery and a 
small vein. 
Fleshy origins of muscles cause no mark on bone, the muscular fibres 
being attached to the outer layer of the periosteum; but where tendon 
has been attached there is roughness and elevation, because the tendinous 
fibres are continuous with the substance of the bone. The articular 
surfaces of dry bones have a characteristic appearance, being composed of 
calcified cartilage (p. 22). 
Microscopic structure. In thin slices under the microscope, all bone 
exhibits a clear translucent calcified matrix, and in it lacunae and canaliculi. 
Lacunae are small spaces, each of which, in 
the recent state, is occupied by a single 
hone-corpuscle. Canaliculi are fine thread-like 
canals which come off from the lacunae, 
sometimes in numbers fewer than a dozen, 
but in other instances, as in compact tissue 
in the adult, so numerously as to be un- 
countable. They are seen to advantage 
in ground sections of dry bone so mounted 
that the air with which they have become 
filled is not displaced. They then have 
the appearance of closely set fine black 
branching lines continuous with the canali- 
Fig. 22.—Lacunae and Canalicuxi. 
The canaliculi may communicate much 
more freely, but this is not always the 
case. 
culi of neighbouring lacunae, or opening on the surface, or into one of the 
canals about to be described, called Haversian. The lacunae vary in size 
and shape in different situations, but may measure on an average 2 oVo^1 
of an inch in their longest diameter. The bone-corpuscles fill the lacunae 
in which they lie, and send branches into the canaliculi; but the branches 
do not appear to occupy the canaliculi permanently in their whole extent. 
Lacunae and canaliculi can still be brought into view after decalcification; 
and some observers have even been able to isolate them, showing that 
their walls are firmer than the rest of the matrix. 
Compact osseous tissue presents additional arrangements besides those 
which are common to all bone and sufficient for fine spicules or laminae 
embedded in soft tissues. Minute canals entering from the orifices on 26 
GENERAL ANATOMY. 
the surface pervade its whole extent, running nearly parallel with the 
surface, and united by oblique and transverse connecting branches into 
a network occupied throughout with minute bloodvessels. They are 
called Haversian canals, 
after Clopton Havers, who 
noted their existence in 
1689, but was ignorant of 
their contents. They vary 
very considerably in size, 
but the greater number 
of those running longi- 
tudinally are about 
of an inch in diameter, 
while the connecting 
branches are often smaller 
and may even be less 
than YuVoth of an inch. 
In the neighbourhood of 
medullary cavities or can- 
cellated tissue, larger 
Haversian canals are 
formed containing an 
arteriole and a venous 
radicle, but those in thor- 
Fig. 23. Section of Ox Bone, showing nucleated bone- 
corpuscles, also anastomosing canaliculi in the outer rings of a 
Haversian system. Prepared by Mr. Walter Colquhoun. Photo- 
graphed by Dr. Thomas Reid. 
oughly compact tissue contain only one minute vessel belonging to a 
capillary network corresponding with the network of canals. The sub- 
stance of the compact tissue is laminated; 
and in a transverse section of the shaft 
of a long bone the arrangement of the 
lamination is brought into view. The 
lacunae are seen to be arranged in 
concentric layers, and to be flattened 
in the planes of lamination with the 
greater number of their canaliculi 
passing outwards and inwards to com- 
municate with those in the layers 
adjacent; and several lamellae, even as 
many as six, may be counted between 
successive layers. Tour kinds of lami- 
nation are distinguished, viz.: (1) the 
peripheral or primary, surrounding the 
bone and parallel to the periosteum, 
most abundant in young bones: (2) the Haversian systems, forming 
concentric rings round the Haversian canals and composing much the 
larger part of the adult tissue; (3) the internal or perimedullary, lining 
Fig. 24. Transverse Section op Compact 
Tissues of humerus, showing concentric 
arrangement of lacunae and lamellae around 
Haversian canals. (Sharpey.) 27 
BONE 
the medullary cavities; (4) the intermediary or interstitial, filling up 
the spaces between the Haversian systems, and consisting of portions of 
Fig. 25. Longitudinal Sections fkom Shaft of Femuk, showing the arrangement of 
Haversian canals. A, Adult; B, at birth. 
lamellae belonging to the first three kinds, the other parts of which have 
disappeared by absorption. 
Although it has scarcely 
attracted sufficient attention, 
there can be no doubt that 
processes of absorption and 
redeposition of bone are, to 
a greater or less extent, con- 
tinually going on, by which 
old lamellae are eaten into 
and new Haversian systems 
are laid down; for there are 
two kinds of spaces to be dis- 
tinguished scattered through 
compact osseous tissue, one 
kind which may be termed ab- 
sorption-spaces, having ragged 
edges traversing lamellae of 
different systems whose con- 
tinuity they interrupt, and 
others, distinguishable as 
Haversian spaces, in which this ragged outline has begun to be lined by new 
lamellae, the outer rings of systems not yet developed to the extent of 
Fig. 26. Transverse Section of Tibia of Hoksb. a, 
Haversian canal; b, Haversian space ; c, absorption-space. 28 
GENERAL ANATOMY. 
closely surrounding the bloodvessels and thereby completing the 
Haversian canals. In adolescence the alternations of absorption and 
deposition may be studied with special care in horizontal sections of 
the ramus of the lower jaw, where the 
appearances seen completely corroborate 
Humphry’s observations (p. 35). All 
the bones normally become more dense 
for a long time after middle life, the 
arrangement of the lamination at the 
same time becoming more complex. But 
as old age advances absorption gains the 
ascendency, and not only medullary 
cavities are enlarged, but the tables of 
the skull approach one to the other, 
while everywhere compact tissue exhibits 
enormous absorption-spaces or enlarge- 
ments of the Haversian canals, which in 
the recent state contain masses of closely 
set, small, but by no means active 
corpuscles. 
In sections of decalcified bone in which 
Fig, 2T. Compact Osseous Tissue op 
Old Age. Transverse section of macerated 
femur. The dark parts are the absorption- 
spaces. The lacunae are barely visible. 
From photograph by Dr. Reid. 
the soft tissues have been preserved, the Haversian spaces are lined with 
nucleated corpuscles regularly arranged; and similarly on the periosteal 
Fig. 28. Multinuclear Corpuscles from the 
youngest marrow-spaces of the flat bones of the 
human skull. 3ffi. (Kolliker.) 
Fig. 29.— Fibrous Appearance of 
Matrix in wall of Haversian canal 
of decalcified, human femur. 
surface of growing bones a layer of nucleated corpuscles is engaged in 
the formation of the peripheral lamellae. In both situations the corpuscles 
are called osteoblasts, and may sometimes be seen in process of becoming 
embedded, one side fitting into a depression in the bone-substance and BONE 
29 
having prolongations lying in canaliculi, while the other side is free. The 
absorption-spaces are similar in nature to irregular depressions found in 
the walls of growing medullary cavities and known as pits of Howship, but 
are inclosed passages destined, by being concentrically filled up, to be con- 
verted into Haversian spaces, and finally into complete Haversian systems. 
They present within them, like the pits of Howship, multinucleated cor- 
puscular masses, such as were discovered independently by Kolliker and 
Robin in marrow, and called by the one osteoclasts, and by the other 
myeloplaxes. There seems no reason to doubt that these multinucleated 
masses are corpuscles which, proliferating in a confined space, are unable 
to part into separate individuals till they have made room by absorbing 
the bone around, and that then they break up into separate osteoblasts, 
to deposit bone anew. Except by such a process of alternate absorption 
and redeposit, it is impossible to account for the Haversian systems and 
the irregular arrangements of interstitial lamellae. Indeed, all the stages 
of the process can be seen. But such considerable sections are free from 
absorption-spaces, or contain them so very sparsely, that it is evident 
that bone-corpuscles have a very considerable duration. Absorption-spaces 
sometimes begin from a single lacuna in which may be seen a large cor- 
puscle with several nuclei, sometimes by beaded enlargement of canaliculi, 
and sometimes at the sides of Haversian canals, or by pits in the side of 
marrow-cavities. 
The matrix of osseous tissue is far from structureless. The arrange- 
ment in lamellae, already alluded to, becomes much more distinct when 
examined in decalcified specimens, and the lamellae then appear much 
more numerous than the rings of lacunae. Also the tissue between 
the lamellae seems as if arranged in closely set vertical septa, which 
in transverse section may present radiating lines extending from centre 
to circumference of a Haversian system. But when the section is allowed 
to dry, instead of distinct septa with regular spaces between, an appear- 
ance of a network with larger and smaller meshes comes into view. The 
lamellae resist shrivelling much more than the intervening substance. 
It was pointed out by Sharpey that in decalcified bone the lamellae 
exhibit an appearance of fine fibres, which he figured regularly decussat- 
ing. Difficulty seems to be met with in verifying this; but the fibrous 
appearance is easily seen, not only in torn shreds but in vertical sections 
of compact tissue, if a fluid be employed which will make them firmer, 
such as a solution of tannin. They are then seen curving alongside 
of one another, those in one thin sheet decussating with those in another. 
The substance between the lamellae consists of fibres quitting one lamella 
and adhering to the next. The same fibrous appearance can be seen in 
plates of cancellated tissue, sometimes without decalcification. 
Perforating fibres of Sharpey is the name given to fibres springing from 
a superficial lamella, piercing others and capable of being pulled out 
from them. Under the same name both white and elastic fibies have 30 
GENERAL ANATOMY. 
been described; and Kolliker affirms that there is always air present in 
connection with them, showing that they have not been completely cal- 
cified but undergo shrivelling in the dry bone. 
Periosteum, vessels and nerves. Periosteum, the membrane surround- 
ing bone, is a fibrous structure containing bloodvessels and nerves, and 
presenting a layer of osteoblasts on its deep surface. But, at least on the 
shafts of long bones, it is a more regular and complex structure than 
seems yet to have been described by authors. Superficially it presents a 
strong white fibrous layer which sw*ells up with acetic acid. This layer, 
when the bone is free from tendinous attachments, is disposed longi- 
tudinally, but may be strengthened by transverse or felted fibres over it. 
In it small arteries and veins ramify in company. More deeply there are 
thin sheets of firm tissue, not elastic, but not affected by acetic acid, 
exhibiting long fusiform corpuscles disposed in parallel lines. They are 
directed obliquely, those of one layer decussating with those of the other; 
and between the layers is a continuous capillary network with meshes sim- 
ilar to those made in the compact bone by the Haversian canals. Occupy- 
ing the capillary meshes there are numerous irregularly-shaped corpuscles, 
and lastly, on the deep side of the decussating sheets, is the osteoblastic 
layer, which on an adult bone may present an appearance like an epithe- 
lium, while on a growing bone the corpuscles may be two or three deep. 
Schafer has figured a small artery, a large vein, a lymphatic, and a 
nerve in one section of a Haversian canal; but in the shafts and immedi- 
ately beneath the articular cartilages of the great bones of the limbs there 
is only one vessel in each Haversian canal. The vessels form a mesh work 
like the canals in which they lie, and though their walls are strengthened 
by longitudinal fibres, as are those of the deep layer of periosteum from 
which they come, they ought to be regarded as capillaries. A little con- 
sideration will show that any other conclusion is highly improbable. The 
network of Haversian canals is obviously for the nutrition of the osseous 
tissue around, but an artery and vein in company indicate the nutrition 
of a territory beyond. Nerves are easily seen in the superficial structure 
of the periosteum, and have been traced by Kolliker in company with 
the medullary and other arteries into the interior, but there is no 
knowledge of other distribution than to the vascular walls. 
Marrow is of two kinds, the yellow, filling medullary spaces of con- 
siderable -size, and the red, occupying the smaller spaces in cancellated 
tissue. The yellow marrow owes its colour to adipose vesicles, and the 
red marrow owes its redness partly to blood and partly to corpuscles 
outside the bloodvessels. The supporting stroma is exceedingly slight, 
even the part in contact with the osseous walls, where it is sometimes 
distinguished as endosteum or medullary membrane and contains a larger 
number of bloodvessels to nourish the bone. The yellow marrow in 
wasted persons becomes gelatinous in appearance, and presents partially 
emptied fat-vesicles in very delicate stroma. Red marrow contains scattered BONE 
31 
adipose vesicles and a large number of amoeboid corpuscles, most of 
them very similar to white blood-corpuscles, others with larger nuclei, 
some larger in size and some smaller, also red blood-corpuscles and nucle- 
ated corpuscles containing red colouring matter. Near the bone and 
in recesses where absorption is going on, there are multinucleated masses, 
such as have been already alluded to, the osteoclasts of Kolliker, engaged 
in the absorption of osseous matrix. There is no real distinction between 
yellow and red marrow, save that the red contains a smaller number of 
adipose vesicles, and a larger number of other corpuscles. The resem- 
blance of these latter to the corpuscular elements in the lymphatic glands 
and splenic pulp is sufficient to favour the idea now generally held that 
the marrow is a source of development of both white and red corpuscles. 
Capillary bloodvessels form networks in the marrow which can readily 
be exhibited, but at places here and there they present imperfect walls, 
which allow, as I have seen in the rabbit, coloured injection to mingle 
with the corpuscles around. 
Ossification. The greater number of the parts of the skeleton exist 
as cartilage before osseous tissue appears in them. This, however, is not 
a universal arrangement, and bones which do not pass through a cartila- 
ginous condition, but make their first appearance in membrane, are called 
membrane-bones. Membrane-bones may be distinguished into two kinds : 
those which have no connection with cartilage, and those which are 
formed in proximity with it, but separated from it by perichondrium. 
Of the first sort are the roof-bones of the skull, viz., frontal, parietals, 
upper portions of the occipital, and the squamous parts of the temporals. 
But in reference to these it may be remarked that though, in the higher 
animals, the primordial cartilaginous cranium does not extend to their 
neighbourhood, yet, in some animals, as in fishes, it is complete, exhibit- 
ing a roof as well as sides and base. The lower jaw and the vomer 
may be taken as examples of bones which, in the human subject, appear 
on the surface of cartilage, but separated from it by perichondrium. It 
may be questioned if there is any radical difference between membrane- 
bones and others, although authors have given importance to the dis- 
tinction. Not only is there much of the ossification of cartilage-bones 
periosteal in origin, but an osseous centre which has appeared in cartilage 
may extend into the fibrous tissue around, so as to be altogether embedded 
in it. This is the case with the processus gracilis of the human malleus, 
and notably so with the basi-occipital of osseous fishes. There are, how- 
ever, two very distinct modes of ossification, one from membrane the other 
from cartilage. 
Ossification from membrane is exceedingly simple, and the essential 
part of the process has already been described as it is seen in the forma- 
tion of the Haversian systems and peripheral lamellae by the embedding 
of osteoblasts in mineralized matrix clear in appearance from the com- 
mencement, The same embedding of osteoblasts is seen in the ossifi- 32 
GENERAL ANATOMY. 
cation of the roof-bones of the skull. A layer of nucleated corpuscles 
appears in the fibrous membrane in which ossification is about to take 
place, larger and more numerous than those proper to its own substance; 
and the mineralized substance is at first thrown round groups of them 
in radiating bars frequently united so as to make a network of bony 
matter; while the spaces and corpuscles between remain as the primitive 
marrow-spaces and their contents. At the ossifying margins, fibres push 
Fig. 30. Ossification from Periosteum. Sections of femur of kitten before birth, 
A Transverse section ; -5, longitudinal \ci and outer and inner binding strata of perios- 
teum ; c, osteoblastic stratum ; d, bone and marrow-spaces. (Toldt.) 
straight out into the surrounding tissue, and are known as the osteogenic 
fibres. They appear to be connected with the fibrous character of the 
bone-matrix. 
Ossification from cartilage exhibits a certain amount of variation in 
different circumstances. At the growing end of a shaft of bone in which 
ossification has already been proceeding for a length of time, the cartilage 
near the ossifying surface exhibits a series of modifications preparatory 
to undergoing conversion into bone. At a little distance from the ossi- 
fying surface, the cartilage-capsules are isolated, each containing one or 
more cartilage-corpuscles. Nearer the bone, the isolated capsules have 
been broken up into lozenge-shaped groups of small capsules, which, in 
turn, undergo further growth, so as to be converted into vertically placed 
rows of capsules, each of which is transversely elongated and contains 
one large corpuscle. Yet nearer to the ossifying surface the cartilage- 
capsules become rounded out so as to be as deep as they are broad, and 
proliferation of the corpuscles within them begins. Meanwhile changes 
have begun in the matrix between the capsules. It is rendered opaque 
by the deposition of granules of mineralized substance, and, after the BONE 
33 
mineral matter has been removed by acid, it presents a somewhat fibrous 
appearance. This is termed the granular layer, and owing to the small 
amount of matrix in proportion to the bulk of its corpuscular substance, 
it is brittle, and is the part in which the mass of cartilage tends to 
Fig. 31. Ossifying Extremity op Shaft op Femur at Birth, decalcified, a, Fusiform 
cartilage-capsulesh. the corpuscles become rounded and isolated; c, corpuscles large 
and separated by more matrix; d, each such corpuscle converted into a spindle-shaped 
group; e, each such group enlarged and more separated by matrix from others; /’ the 
groups elongating, _ and the capsules enlarging transversely; g, the capsules greatly 
enlarged, the matrix diminished and presenting a pseudo-fibrous appearance this is 
the granular layer, and it is here that the cartilage easily breaks away from the bone; 
h, capsules further enlarged, their corpuscles undergoing proliferation, and two of them 
represented as converted into branched bone-corpuscles by intra-capsular calcification; 
i, bone and two primitive marrow-spaces with two bloodvessels dilated above and lost 
among the marrow-cells. Semi-diagrammatic. 
Fig. 31. 
Fig. 32. 
Fig. 32. Ossification of Astragalus at Birth, decalcified, a, Cartilage ; h, cartilage- 
capsules with numerous minute corpuscles, and one capsule containing a single 
corpuscle which has been surrounded with intra-capsular deposition of mineralized 
matrix; c, primitive marrow-spaces continuous with cartilage-capsules, also group of 
unicellular bone-lobules formed by intra-capsular deposit. 
break asunder from the bone beneath. In the granular layer the capsules 
continue very generally to enlarge, and are filled with corpuscles which 
rapidly increase in number and diminish in size, till the capsules com- 
municate with the marrow-spaces within the new bone, and the corpuscles 
which they contain are indistinguishable from the contents of those spaces; 
those of them which lie close to the mineralized matrix becoming spread 84 
GENERAL ANATOMY. 
out against it and embedded as osteoblasts, while others are converted 
into marrow-cells. 
Deeper down in the marrow-spaces, bloodvessels are found; but I have 
never seen the capillaries nearest to the ossifying edge ending in walled 
loops as sometimes figured, nor is it conceivable that they do so while 
vascularity is advancing. On the contrary, the walls widen out and die 
away so as to make the interiors of the vessels continuous with the cor- 
puscular contents of the marrow-spaces. In some instances the contents 
of the cartilage-capsules, instead of freely proliferating, become branched, 
while mineralized deposit takes place within the capsule, as was originally 
shown by Kolliker in rachitis ; and thus nodules of bone are formed 
corresponding in extent with cartilage-capsules, and having branched 
corpuscles in the interior. 
At one time the view was advanced by Loven, and for a while 
gained support, that the cartilage-corpuscles degenerate and are removed, 
taking no part in the formation of bone. But this is certainly a mistake. 
I have often seen the cartilage-corpuscles taking part in ossification in 
the two ways now mentioned, viz., most frequently proliferating freely 
so as to produce a swarm of osteoblasts and marrow-cells, in other 
instances becoming embedded as branched corpuscles within a clear ball 
of mineralized matrix corresponding in extent with the capsule. The 
preparatory alterations in cartilage about to ossify are by no means 
always so complex as in the shafts of bones 
already considerably ossified. More generally 
the matrix becomes granular round the capsules 
without the capsules being arranged in columns. 
This is the case in the first deposit of mineral- 
ized matter in the shafts of long bones, in the 
vertebrae and other short bones, and in the 
epiphyses of the shafted bones. 
In the first appearance of ossification in 
shafts of bones, the whole thickness of the shaft 
is converted into calcified cartilage, in the form 
of a network of globes containing the corpuscles 
imprisoned within them; and before this has be- 
come converted into true bone, already a sheath 
of bone derived from the periosteum surrounds it. 
Fig. 83. Fikst Point of Cal- 
cification of cartilage in shaft 
of humerus of human embryo of 
two months. (Kolliker.) 
Absorption of the mineralized walls of capsules, with proliferation of their 
contents, forthwith proceeds, and bloodvessels piercing from the periosteum 
enter the primitive marrow-spaces formed by inter-communication of cap- 
sules. In the epiphyses of the long bones and in the carpal and tarsal 
bones, the ossification is at first completely surrounded by cartilage pierced 
by channels containing bloodvessels, one or more of which are enlarged in 
connection with the first appearance of ossification. Thus, in all bone, 
vessels pass in from the outside, and in ossification from cartilage they BONE 
85 
are continued into inter-communicating spaces, primitive areolae, formed by 
the breaking down of the partitions between neighbouring capsules. By 
the enlargement of areolae and concentric deposition of lamellae, Haversian 
systems are formed. 
Enlargement of bones. Owing, no doubt, to its hardness, osseous tissue 
once deposited is incapable of expansion. At least this is the general 
rule in normal circumstances, and contrasts with the power of interstitial 
expansion manifest in cartilage. All extension of the size of an osseous 
mass is by additional substance deposited on its surface. This law of 
osseous growth was demonstrated, so far as the elongation of the shafts 
of bones was concerned, by John Hunter’s experiment of inserting shot 
separated by a measured distance along a shaft of bone in a young animal. 
When, after the lapse of a certain time the bone is examined, the shot are 
found at exactly the original distance one from the other, while the dis- 
tance from each to the extremities of the bone is increased, showing that 
new bone has been added at the extremities of the shaft. Duhamel was 
the first to place a metal ring round the humerus of a young pigeon, and 
to observe that as the animal grows, such a ring becomes covered super- 
ficially, and at last lies loose in the cavity in the interior of the bone; and 
though Duhamel himself believed in the growth of bone by interstitial 
additions expanding the tissue already laid down, the smoothness of the 
layers superficial to the ring in such experiments bear out the fact evident 
from the disposition of the peripheral lamellae, that new bone is added 
peripherally, while the older bone subjacent is absorbed so as to enlarge 
the medullary cavity. 
Besides these main centres of ossification, bones often present supple- 
mentary centres which appear in masses of cartilage subject to pressure 
and strain. These are termed epiphyses, and, in the case of the long bones, 
the centre of ossification of the shaft is called the diaphysis, while there 
are generally epiphyses at the extremities. The epiphyses are late of 
uniting to the diaphysis, a very thin plate of cartilage persisting for a 
length of time between them. The shaft continues to lengthen as long 
as this thin layer of cartilage persists, new cartilage continuing to be 
formed nearly as rapidly as the part adjacent to the shaft is converted 
into bone; but, when by any undue irritation premature union of the shaft 
and epiphysis takes place (synostosis), the elongation at that end ceases. 
So also premature synostosis may take place in any of the sutures of the 
skull, and arrest enlargement along the line of union, the growing edges 
of the bones being obliterated. But probably the most convincing pi oof 
that bone does not increase in size by interstitial expansion is furnished 
by Humphry’s experiments on the lower jaw. By passing wires through 
holes bored in the ramus of the jaw in the young pig, Humphry encircled 
the back part of the ramus with one ring, the fore part with another, and 
found, when the animal was killed after an interval, that the anterioi 
ring was made loose in front by absorption of bone from the edge of GENERAL ANATOMY. 
86 
the ramus, while the hinder edge of the posterior ring was embedded 
by the formation of new bone behind it for a still greater distance than 
the anterior ring stood out loose (Cambridge Philosophical Society Trans- 
actions, xi.). Sections of young lower jaws under the microscope exhibit 
new layers added at the back of the ramus, while absorption is active in 
front. It may, however, be here remarked that there are circumstances 
in the growth of the teeth in both jaws, which point to some mode of 
expansion of those bones requiring further investigation. Thus, it may 
be noted that the permanent canine teeth have their crowns fully formed 
in situations from which they cannot be projected through the gums with- 
out previous separation of the teeth immediately in front and behind. 
It is also the case that the distance between the mental foramina of 
opposite sides increases after ossification of the symphysis of the lower 
jaw. 
ARTICULATIONS. 
The articulations by means of which the different parts of the skeleton 
are united may be divided into complete and incomplete. 
Complete joints are characterized by two cartilaginous surfaces which 
move one on the other, unconnected by intervening substance, but held 
together by ligaments around. The structure of ligament and of articular 
cartilage has already been described. The breach of continuity between 
the articular cartilages is limited round about by synovial membrane, and 
is itself called the synovial cavity, synovia, or synovial fluid being the term 
applied to the substance which lubricates and gives a certain softness to 
the interior of the joint, without being in such quantity that any can be 
gathered. 
The synovial membrane is continued from the margins of the articular 
surfaces to a certain slight extent on the periosteum, before being re- 
flected on the deep aspect of the ligaments and other surrounding parts 
to the margins of the opposed articular surfaces. It is also, in some 
instances, prolonged a certain way on tendons or underneath muscle, 
resembling in such prolongations the separate bursae mucosae provided in 
different places for the gliding of muscles or integument on bone, and 
the thecae or separate synovial sheaths surrounding tendons bound down 
by fibrous bands. But the synovial membrane of a joint differs from 
such other pouches in not forming of itself a continuous shut sac. It is 
not continued over the surfaces of the articular cartilages, save only in 
the foetus, but is rather continuous with them. It is possessed of a 
network of bloodvessels, and these are continued for not more than the 
twentieth of an inch over the margins of the articular cartilages. The 
proper substance of the membrane is homogeneous, and characterized by 
an abundance of oval nuclei with little or no protoplasm round them, and ARTICULATIONS. 
37 
broader than those of the capillaries and the subjacent tissues. Near the 
articular surfaces an apparent continuity can be seen between cartilage- 
corpuscles and a stratum of scattered corpuscles on the surface of the 
membrane, presenting long and dividing branches, as also continuity with 
the oval nuclei mentioned. In many 
joints there are portions of the synovial 
membrane, of variable extent, more spongy 
and vascular than the rest, elevated into 
folds and pads by subjacent adipose tissue, 
and filling up gaps and recesses. These 
were described by Havers as glayidular 
mucilaginosae, and are commonly spoken of 
as Haversian glands. Especially in places 
where the synovial membrane is thrown 
into projecting or receding folds, there 
occur thread-like and clavate projections 
or villi, both simple and branched, just 
visible to the naked eye, and sometimes 
containing encysted corpuscles, important 
as the source of loose cartilages well known 
to surgeons. 
Fibro-plates, usually described under the 
head of fibre-cartilages, occur in certain of 
the complete joints, and are tough, 
generally biconcave structures intervening 
between the opposed articular cartilages, 
intruding free surfaces between them, and 
attached peripherally to the fibrous sur- 
roundings. They may form imperforate 
discs, separating the cartilages completely, 
and thus lie between two distinct synovial 
cavities, as in the temporo-maxillary arti- 
culation; or may have the shape of a 
Fig. 34. Synovial Membrane. A, 
Synovial villi projecting' from free edge of 
semilunar plate of the knee joint. One of 
them presents such a cluster of corpuscles, 
in a clavate extremity, as sometimes is 
inclosed in chondriniferous matrix and 
becomes the commencement of a loose 
cartilage, demanding removal. B, Silver 
preparation of synovial membrane close to 
the head of a metacarpal bone, showing 
flattened corpuscles sending out long 
branching processes and in series with 
cartilage-corpuscles, as well as with the 
oval nuclei represented in the upper border 
of the sketch. 
meniscus, only partially separating them, as in the knee joint; or they may 
be variable, sometimes perforated, sometimes not, as in the sterno-clavicular 
articulation. They consist of closely felted white fibrous tissue with no 
separable synovial membrane, but with oval nuclei discernible towards 
their surfaces, and with fringes of synovial villi at their edges and in 
their vicinity. 
The development of complete joints is noteworthy in connection with 
the relation which incomplete joints bear to them. At an early period 
many parts of the skeleton are more massed together than afterwards, 
being as yet undifferentiated. Thus the bones of each limb form one 
continuous cartilage, and thus also each cartilaginous vertebra is con- 
tinuous at each side with rib and sternum. The articulations which 88 
GENERAL ANATOMY. 
subsequently divide these blocks by means of complete joints appear first, 
in each case, in the form of a fibrous line breaking the continuity of the 
cartilage; a cavity afterwards appears walled completely by synovial mem- 
brane ; and at a later period the membrane disappears from the faces of 
the opposed cartilages. Certain joints, however, are placed between parts 
not originally continuous, but brought into contact by growth. This is 
the case with the joint between the head of a rib and the vertebra above 
it, the sterno-clavicular articulation and that between the sacrum and 
ilium. But probably in all instances there is fibrous continuity before 
formation of the synovial cavity. 
Incomplete joints of two kinds are described—movable and immovable. 
Immovable joints do not differ in any essential particular from the 
temporary separation of the diaphysis and epiphysis of one bone. Thus, 
we have seen that the sutures between bones of the skull remain open 
in connection with the growth of the bones; and if the separation, in early 
life, of the occipital from the sphenoid is to be considered as an articulation, 
there is no reason why the separation of the great wings of the sphenoid 
from the body of that bone should not be regarded in the same light. 
It would, however, be inconvenient to regard the whole cranium with the 
exception of the lower jaw as a single bone, or to distinguish as separate 
bones all its centres of ossification; and therefore the more permanently 
distinct masses justly receive separate names, though it is perfectly under- 
stood that several of the parts so recognized are united by osseous union 
long before adult life is reached, and that all may become united in the 
course of advancing years. The lines of contact of the bones of the skull 
are called sutures, and are distinguished as serrated when the edges are 
jagged and locked together, scaly or squamous when one edge overlaps 
another, and harmonia where there is mere apposition. 
Incomplete joints of the proper or movable description have fibrous tissue 
attached over the whole extent of the exposed surfaces of bone; and 
this fibrous tissue is always mixed with cartilage at its attachment, con- 
stituting one of the varieties of so-called fibro-cartilage. At the symphy- 
sis pubis, this cartilage sometimes becomes calcified as age advances. A 
synovial pouch is also sometimes developed in the ligamentous junction 
of the bones at that joint; but the articulation remains incomplete in 
respect that the membranous wall of the cavity is continuous, and there 
are no opposed surfaces of bare cartilage. 
Intervertebral discs. The most remarkable of the incomplete joints are 
the intervertebral discs uniting the bodies of the vertebrae. These are to 
a certain extent complicated in their development by their connection with 
the notochord (p. 91); but each presents from its surface inwards a gradual 
transition from laminae of white fibrous tissue to the pulpy mass which 
occupies its centre. This pulp, as pointed out by Luschka, exhibits 
grapelike processes about an eighth of an inch in average size, with free 
surfaces and arranged in clusters, filling up the cavity into which they ARTICULATIONS. 
39 
project, and comparable with the villi of a synovial membrane. The pulp 
of the intervertebral discs exhibits in a stroma of connective tissue incap- 
suled corpuscles, single, and in groups, identical with cartilage-corpuscles, 
and is therefore one of the structures long 
described under the name of fibro-cartilage, 
but it is a structure sui generis, with affinities 
to synovial villi as close as to cartilage. It 
presents sometimes corpuscles with laminated 
capsules. 
Movements of joints. In speaking of 
movements of joints it is necessary to distin- 
guish between movements of the articular 
surfaces and the direction of the movement 
given to the part of the body to which the 
moving articular surface belongs. 
Fig. 85.—Lumbar Intervertebral 
Disc, horizontal section, showing the 
grapelike processes of the pulp and 
the laminae of fibres around it. 
The movements of articular surfaces are of two kinds, gliding and rolling; 
and these are very generally combined. Gliding is the shifting movement 
of one surface on another with friction. Rolling is the movement by 
means of which successive portions of surfaces are removed from contact, 
while others in front of them come into contact, without friction, as the 
parts of a carriage-wheel successively touch the ground. For a purely 
gliding movement surfaces must be perfectly conformable and of uniform 
curve; but in many instances opposed articular surfaces are not con- 
formable, they cannot be brought into perfect contact throughout, and 
they are often facetted. In these circumstances, there is an element of 
rolling or coaptation in the movement; the opposed surfaces approaching 
in certain parts, and receding in others, so as to leave a slight gap into 
which Haversian glands are pressed. 
The directions of movement of which a joint may be the centre are of 
three principal kinds angular movement, rotation, and circumduction. 
Angular or hinge movement is movement in one plane, and may 
consist of bending, straightening, and bending in the reverse direction, 
technically termed flexion, extension and over-extension; or of movement 
toward and away from the middle line, adduction and abduction. 
Rotation is revolution round the long axis of the part moved, and 
circumduction is conical movement, in which the distal end of the part set 
in motion circumscribes an area. It is further to be noticed that there 
are joints allowing of but slight motion, which may be useful, not on 
account of the unimportant difference of position of parts which is 
allowed, but by giving elasticity, through causing weight to be borne by 
tense ligaments instead of being conducted through solid bone. This is 
the principal use of the carpo-metacarpal and tarso-metatarsal articulations. 
Nomenclature. The following terms, long applied to joints, though some of 
them falling into deserved desuetude, require explanation. Diarthrosis means a 
complete joint, amphiarthrosis a movable incomplete joint, and synarthrosis an 40 
GENERAL ANATOMY. 
immovable joint. Among the varieties of complete joints have been recognized 
ginglymus, or hinge-joint; enarthrosis, the ball and socket joint; diarthrosis trochoides, 
or pivot joint, and arthrodia, permitting only slight movement. Symphysis is a 
word formerly used as equivalent to amphiarthrosis, but survives as a term applied 
to two mesial structures the symphysis pubis, which is an amphiarthrosis or in- 
complete joint of the movable sort, and the symphysis of the lower jaw, which is 
an immovable union of right and left parts, and undergoes ossification in early 
life. Synchondrosis, signifying union by cartilaginous substance, is a term applicable 
to the union between occipital and sphenoid, and equally so to the union between 
principal centres of ossification and their epiphyses, but has been principally applied 
to the sacro-iliac articulation, which is not really a synchondrosis at all, but a 
complete joint. Schindylesis has been used as a term to indicate the reception of an 
edge of bone into a cleft, the articulation of the vomer with the vaginal processes 
of the sphenoid being the example given; and gomphosis as a word suitable to 
indicate the fitting of the teeth into their sockets; but the vomer articulates edge 
to edge with the vaginal processes, and the teeth, though impacted in the jaws, 
are no part of the skeleton. 
MUSCLE. 
Muscle is a texture consisting of fibres whose special characteristic 
is the property of contractility. By contractility is understood the 
tendency of parts to approach one another temporarily under the in- 
fluence of stimulation; and the exercise of this tendency, as exhibited 
in muscle, is always accompanied by metabolic change; that is to say, 
breaking down of organic compounds by oxidation, or, as it may be 
termed, consumption of fuel. Contractility probably exists in connection 
with the protoplasm of all young living corpuscles ; and in connection 
with amoeboid movements it is exhibited in an unlimited variety of 
directions. But in muscular fibre the contractility, while greatly increased 
in amount, is confined to one direction, namely, the length of the fibre. 
The shortening of the fibre involves a separation of particles laterally, 
there being no total diminution of bulk. The return of the fibre to its 
original shape is effected, not by contractility, but by elasticity, which 
involves no chemical change. 
Muscular fibre exhibits two great varieties distinguished by micro- 
scopic characters as striped and unstriped, and physiologically as voluntary 
and involuntary. The terms voluntary and involuntary are, however, not 
without objection; for in no voluntary movement do we will the con- 
traction of individual muscles; it is the movement to be effected which 
is voluntary, while we remain ignorant of the muscles by which the 
movement is accomplished. Also, it is notable that while the contraction 
and dilatation of the pupil have probably the same relation to volition 
in birds as in mammals, in birds the muscular fibres of the iris are 
striped, and in mammals they are unstriped. Lastly, the pharynx and 
upper parts of the oesophagus, though they are removed from the control 
of the will, have typical striped fibres, and the heart has striped fibres MUSCLE. 
41 
with, peculiarities special to it. But it may be noted that the contrac- 
tions of the heart and the movements of the bird’s iris are more 
sudden than those of unstriped muscular fibre, and that it is in this 
respect that striped muscular fibre differs distinctively in function from 
unstriped; for it both begins to contract more immediately after stimu- 
lation and completes its contraction more quickly. 
Unstriped muscular fibres are generally disposed in continuous sheets, 
as when they surround hollow viscera, or in separate fasciculi, as in the 
erectors of the hair-follicles. Striped muscular fibres are arranged in 
fasciculi or bundles, which are occasionally disposed in sheets, as in the 
upper part of the oesophagus, and in subcutaneous muscles such as the 
platysma myoides in man, or the panniculus carnosus of animals; but are 
generally collected in more distinctly individualized muscles attached to 
bone, and either applied directly to the periosteum or fastened by the 
intervention of tendon. 
A muscle is, therefore, an organ into which other structures enter 
besides muscular fibres. Not only has it got one or more arteries and 
veins, a branch of nerve, and, in most instances, some tendinous arrange- 
ment ; but, in addition, it has its special investment or perimysium of con- 
nective tissue, and has its fibres arranged in fasciculi bound together by 
more delicate connective tissue, the endomysium of authors. 
The actions of muscles are modified by the manner in which their 
muscular fasciculi are disposed, the strength of their contraction depend- 
ing on the number of fasciculi which act together, and the extent of this 
contraction depending on the continuous length over which the fasciculi 
extend, no matter though broken by tendinous intersections. It follows 
that if two muscles have the same length and bulk, but one has its 
fibres running lengthwise, while the other has short fibres arranged 
obliquely between tendons of origin and insertion, so as each to repeat 
the action of the others, the first muscle will be capable of contracting 
to a great extent but with little force, while the second will maintain 
its contraction with great strength, but will be incapable of shortening 
itself to the same extent. Thus, for example, the semitendinosus muscle 
has long fibres, while the semimembranosus, lying beside it, has its fibres 
much shorter and more numerous; both are placed on the stretch when 
the trunk is bent down and the knees kept straight, and the semimem- 
branosus will be the more powerful in helping to raise the trunk; but 
when the origin and insertion of both muscles are approached by throwing 
back the thigh and bending the knee preliminary to delivering a kick 
forwards, plainly the long-fibred muscle, the semitendinosus, can alone 
be effective, the extent of contraction possible for the semimembranosus 
being unequal to shorten it to the extent that the semitendinosus can 
be shortened. Chemically, both striped and unstriped muscular fibres 
consist in greater part of muscle-fibrin, which during life is in the 
form called myosin, and after death is speedily changed in ordinary 42 
GENERAL ANATOMY. 
circumstances to another variety named syntonin, soluble in dilute 
muriatic acid. 
Microscopic structure. Smooth or unstriped muscle consists of separate 
nucleated corpuscles, usually termed fibre-cells. These are flat and elon- 
gated, with pointed extremities more or less drawn out. Their substance 
Fig. 36.— Unstriped Muscular Fibre-Cells from various situations. 
is nearly structureless, but may exhibit a slight indication of longitudinal 
lines. They tear easily across, and, when isolated, tend to fall into zigzag 
folds, with parts lying flat between. They have no cell-wall. The nucleus 
is elongated, often rod-shaped. The fibre-cells are of very different sizes 
in different localities, reaching inch in length in the stomach and 
intestines, and a greater development in the pregnant uterus, while in 
the iris and other places they are very much smaller. Nor are they 
always of the same shape; occasionally they 
show bifidity, and they vary in proportional 
breadth, those of the longitudinal layer of 
the intestine being narrower than the some- 
what shorter fibres of the circular layer. In 
situations where they are well developed they 
tend to adhere in longitudinal bundles bound 
together with cement. In the stomach and 
intestines they are supported by a network of 
fine elastic fibres. 
Fig. 87. Unstriped Muscular 
Fibre-Cell, coiled times round 
in the wall of a minute artery, and 
showing an elongated oval nucleus. 
(Lister.) 
The nerves of smooth muscle form a net- 
work from which branches were traced by Klebs, Frankenhausen and 
J. Arnold, more than twenty-five years ago, to the nucleus of the fibre- 
cell; but others have failed to verify the observation. 
Striped or striated muscle consists of cylindrical or polygonal fibres 
of complex constitution and indefinite length, which present for considera- 
tion contractile substance, nuclei, and a sheath or sarcolemma. The best 
developed striped fibres are those of the limbs and trunk, and may reach 
a breadth of yj-yth inch. Others, as in the face, may be narrower than 
yJyg-th inch. In the tongue there are vertically placed fibres branching 
to the surface with ramifications of much greater tenuity. It has been 
alleged that the length of a fibre generally does not exceed 1}S inches, 
and that rounded ends of fibres may be seen in muscular fasciculi; but 
such statements are to be received with caution. The undoubted ter- 
minations of muscular fibre in tendon are irregular rather than rounded, MUSCLE. 
43 
and although similar appearances are frequent in the course of mus- 
cular bundles, it seems probable that they are the result of accident in 
manipulation. 
The transverse striae from which the fibres are named extend, when 
undisturbed, right across each fibre; they are closely set and at regular 
intervals. The appearance is due to a doubly refracting and dense stripe 
alternating with a singly refracting and less dense substance, in the middle 
of which latter is a faint line, formerly called a membrane by Krause, and 
sometimes presenting the appearance of a single or double row of dots. 
The less dense stripes may be rendered brittle by reagents which fail to 
harden the whole substance, such 
as weak alcohol, and the fibre 
then breaks up transversely so 
as to separate more or less com- 
pletely the discs or sarcomeres, 
as they are called, although in 
point of fact it is only the peri- 
pheral parts of the dense stripes 
that are seen separated. But 
when pressure is applied after 
the whole substance has been 
hardened, the fibre exhibits 
longitudinal striation, and may 
be broken up artificially into a 
number of fibrillae, consisting of 
a linear series of alternating 
denser and less dense parts cor- 
responding with the striae of 
Fig. 88. Striped Muscular Fibre, a, Fibre from 
face, bruised at one part so as to divide the contractile 
substance without injuring the sarcolemma; b, from 
pectoralis major, showing striae with flue line in the 
light spaces, and also tendency to break into flbrillae ; 
c, a similar fibre stained, treated with muriatic acid, and 
washed with carbolic acid, the proper nuclei in the 
interior, broadly oval nuclei in the sarcolemma, two 
nucleated threads, and at the upper part a portion of a 
capillary vessel with its nuclei; d, a fibrilla under a 
higher power, showing Dobie’s lines (dry preparation) ; 
6, fibre with marked inclination to break into discs. 
the fibre. The less dense parts are still traversed in the fibrillae, as in 
the undivided fibre, by a line first noted in the fibrillae by Dobie (1849). 
So much as lies between two such lines is a sarcous element of Bowman. 
The fibrilla can be still further broken up into threads of such tenuity that 
the dense parts of the striae appear as longitudinal lines, while the inter- 
vening spaces are interrupted by a single or double dot. These ultimate 
threads or columns may be seen in transverse sections of muscle as minute 
areae, and are described as separated by a network of sarcoplasma or sar- 
coglia interpenetrating and surrounding the striped mass or rhabdia. 
The sarcolemma or myolemma is a delicate structureless membrane re- 
sembling elastic tissue in not being acted on by acetic acid, but passing 
insensibly at the extremities of the fibres into the substance of the tendon 
or other white fibrous tissue of attachment. It is absent from the muscles 
of the heart and the branching fibres of the tongue. 
The nuclei of striped fibre lie underneath the sarcolemma in more than 
one row, and are of an oval form, with the long diameter about tw ice as 
long as the short, but other much longer nuclei exist in abundance adheiing 44 
GENERAL ANATOMY. 
closely to the surface of the sarcolemma. These are sometimes figured with 
granules beyond their extremities, but I find that they are united in linear 
series by threads which can be separated by carbolic acid from the surface 
of the sarcolemma. They differ widely in appearance from the capillary 
vessels. 
Nerves. Striped muscle is supplied with medullary nerve-fibres which 
after branching come into close contact with them, then suddenly lose 
their medullary sheath and spread into 
branches likened to antlers. These with 
large nuclei between them and a certain 
amount of sarcoplasma are described as 
being beneath the sarcolemma, and con- 
stituting what are called the motorial end- 
plates (Ktihne), and are confined to one 
part of the fibre. Nevertheless, the 
nucleated threads just described are, in 
my opinion, nerve-fibres continued from 
the extremities of the motorial end-plates 
and are never absent. 
An additional nervous terminal organ, 
the organ of Golgi, is found in many in- 
stances in the muscular extremities of 
tendons. It presents the form of a 
spindle-shaped swelling with a sheath 
involving several tendinous bundles and 
supplied with medullated nerve-fibres 
which divide and, losing their medullary 
Fig. 39. Motoeial End-Plates of 
guinea-pig. (Bohm and v. Davicloff.) 
sheaths, penetrate the inclosed tendinous substance, forming extensive 
networks and free terminations. 
Fig. 40. Organ of Golgi of rabbit, treated with very weak acetic acid. Three medul- 
lated nerve-fibres enter it and branch up. (Kolliker.) 
The muscular fibres of the heart, though distinctly presenting striation in 
all its details, are sufficiently peculiar to require separate description. They 
are destitute of sarcolemma, and instead of forming distinct columns or MUSCLE. 
45 
fibres of uniform breadth, are netted, each fibre giving and receiving 
divisions of smaller breadth which unite them with other fibres. They 
also present transverse marks, like partitions, dividing them into short 
lengths, in each of which may be seen a nucleus embedded in the contractile 
Fig. 41. A, Muscular fibres of heart; B, branched muscular fibre from tongue, 
substance. On account of the transverse partitions the cardiac fibres are 
generally said to consist of chains of corpuscles with one nucleus each, but 
the component fibrillae are continuous through the partitions, and the 
partitions in many preparations are not seen. They appear to me to be 
separable by means of carbolic acid, and I regard them as interrupted 
portions of sheath, a ruptured sarcolemma. 
Development of striped muscle. In the embryo, the corpuscles to be 
developed into muscle have the nucleus enlarged and then elongated, and 
become fusiform. Long fibres of uniform 
breadth are subsequently seen, with the 
nuclei at intervals in their interior. In 
opposition to the views of earlier observers, 
who considered that these were formed by 
coalescence of cells, it has more recently 
been taught that they are produced by 
elongation of the fusiform corpuscles and 
multiplication of their nuclei. But in the 
human subject both processes appear to 
occur; for the band between the nuclei is 
at first long and narrow, and afterwards 
when the fibres are of uniform breadth, 
division of nuclei may be seen taking 
place within them. Fibrillated substance 
appears first always at the periphery of 
Fig. 42. Striped Fibres in Process of 
Development, a, 6, o, From human em- 
bryo lj inch long; d, from foetus of sth 
month. 
the fibres, sometimes at one side; and transverse striation of the 
fibrillae can be detected from the first in them. The appearance of a 
sarcolemma also sets in very early. The fibres of the young embryo are 46 
GENERAL ANATOMY. 
at first not a tenth of the breadth attained in the adult; but by the 
time of birth they have become much broader than they were. 
Regeneration. There seems good reason to doubt the existence of 
any power of reproduction in either striped or unstriped muscular fibre. 
After parturition, the unstriped fibres of the uterus undergo fatty de- 
generation; and in pregnancy new fibres can be seen in process of 
formation from the unwalled corpuscles in the connective tissue between 
the bundles. As a consequence of typhoid fever, striped muscular fibre 
may undergo both fatty and colloid degeneration, the striation disappear- 
ing and being replaced in the one case by granules, in the other by masses 
of waxy-looking substance filling the sarcolemma, while new fibres are seen 
passing through the stage of spindle-shaped corpuscles (Zenker). 
NERVOUS ELEMENTS. 
While irritability would appear to be a universal property of the living 
elements of living bodies, it is the special office of the nervous system to 
bring the different parts of the body into relation one with another by 
conveying, through afferent nerves, irritation from different parts to nervous 
centres, and distributing from nervous centres stimulation, through efferent 
nerves, to tissues of different kinds, such as muscles and secreting glands. 
Structurally the two sets of nerve-fibres are indistinguishable, and even 
the functional distinction cannot be demonstrated in many visceral nerves. 
Nervous centres contain, in addition to nerve-fibres, nerve-corpuscles; and 
these two elements, together with supporting substance, constitute the 
nervous system. Nerves form the communications both of one nervous 
centre with another, and of the different nervous centres with the organs 
which they supply. In the latter case they are called peripheral nerves 
or nerves of distribution, and terminate in different modes, which will be 
described with the microscopy of the different organs. 
The special elements of the nervous system, namely, nerve-fibres and 
nerve-corpuscles, are continuous one with the other; and every nerve- 
corpuscle is in itself a centre or, in some sense, a modifier of nervous 
action. Any collection of nerve-corpuscles, together with the nerve-fibres 
in connection with them, constitutes a ganglion. The simpler ganglia are 
distinct from one another, as in the sympathetic system, the branches of 
which are distributed in great part to the viscera; but the brain and 
spinal cord together form one great and complex organ, the cerebro-spinal 
axis, originating as a continuous axial structure, although portions of the 
brain containing nerve-corpuscles, and more or less separable from adjacent 
portions, are sometimes spoken of as cerebral ganglia. 
Supporting substance. In the cerebro-spinal axis, in which enormous 
numbers of nerve-fibres and nerve-corpuscles are closely aggregated, this 
is of a delicate and modified description, giving a soft and distinctive NERVOUS ELEMENTS. 
47 
character to the texture, which is spoken of as nervous substance, and is 
broadly divisible into white substance and grey or cineritious, the grey 
alone containing nerve-corpuscles, and that not in every part. The white 
matter owes its whiteness to the abundance of nerve-fibres furnished with 
medullary sheaths described below. The grey matter lacks that source 
of whiteness, and has a much richer supply of capillary bloodvessels, 
while the nerve-corpuscles embedded in it have also a certain variable 
amount of pigment. The sup- 
porting substance is termed the 
neuroglia (or glia), but where it 
lines the walls of spaces it is 
sometimes, together with the epi- 
thelium, called ependyma. The 
glue-like material, of which it 
apparently consists, has been re- 
solved by later research partly 
into interlacements of fine nerve- 
fibres which are not truly neuro- 
glia, and partly into nucleated 
corpuscles with shaggy masses 
of long delicate threads extend- 
ing far out from them, specially 
numerous around medullated 
nerve-fibres. These corpuscles, 
as will be pointed out in treating 
of the development of the spinal 
cord, are derived, like the ner- 
vous elements, from the primitive 
epiblastic cerebro-spinal axis; 
and from the same source there radiate branching threads continuous 
with the epithelial cells of the central canal; but it would be hazardous 
to maintain the absence of other supportive substance, seeing that we 
must suppose that the bloodvessels are developed in the ordinary way 
from mesenchyma. 
Fig. 43. Neuroglia Corpuscles. A, From cerebral 
convolutions; £, from cerebellum; O, from peripheral 
Part °f white columns of spinal cord, with some medul- 
lated nerves in transverse section faintly seen. Prepared 
by John Morton, M.B. 
The whole cerebro-spinal axis is surrounded by envelopes, and it is 
especially in the passage through the outermost of these, the dura mater, 
that the nerves have added to them the firm connective tissues to which 
they owe their tenacity throughout their distribution, a tenacity so great 
that they may be pulled without injury to their microscopic structure. 
In their distribution the cerebro-spinal nerves are arranged in bundles 
or funiculi, and covered by investments of firm connective tissue, which 
have received names not always applied in the same way by different 
writers. The most characteristic investment, however, is that immediately 
surrounding the funiculi, the perineurium, a firm and distinct membrane 
with oval nuclei, known also as the sheath of Henle. External and internal 48 
GENERAL ANATOMY. 
to the perineurium are lymphatic channels lined with endothelium. The 
delicate connective tissue within the perineurium is sometimes called 
endoneurium, and the denser sheath of white and elastic fibres binding 
the funiculi into larger bundles is termed epineurium. 
Nerve-fibres are distinct threads, originating at one extremity from 
a nerve-corpuscle, and take their course without junction with any other, 
and without branching save within nerve-centres or at their peripheral 
extremities; but bifurcations abound within the cerebro-spinal axis, and 
when nerve-fibres reach the immediate neighbourhood of their peripheral 
termination they habitually branch. In the best developed nerve-fibres 
three distinct structures are found the axis-cylinder, the primitive sheath, 
and the medullary substance between, from the presence of which they are 
called medullated fibres. 
The axis-cylinder may be termed the essential part. If a perfectly 
fresh portion of a spinal nerve be examined, the majority of its fibres 
will be seen as clear structures of a breadth of as much as th inch, 
refracting the light, and 
bounded on each side by 
a double contour; but if 
by manipulation they be 
torn, the semi-fluid medul- 
lary substance will issue 
from them and bring in- 
to view both the sheath 
which contains it and a 
solid thread in the mid- 
dle. This last is the 
axis-cylinder, and is of 
firm albuminoid substance 
deeply stainable with car- 
mine. An appearance of 
fine longitudinal fibrilla- 
tion may be detected in it. 
The primitive sheath, 
sheath of Schwann, or 
neurilemma, is a delicate 
membrane which, like the 
sarcolemma of muscle, re- 
sists the action of acetic 
acid. It presents at inter- 
vals elongated nuclei which 
Fig. 44. Nerve-Fibres. A, Medullated fibres of different sizes, 
fresh, from frog’s leg; B, fibre from frog, treated with absolute 
alcohol; G, two medullated fibres, human—in the lower part of 
one, the axis-cylinder and primitive sheath are shown by removal 
of the medullary substance, and in the other, the axis-cylinder pro- 
jects free from the primitive sheath and medullary substance ; I), 
non-medullated (Remak’s) nerve-fibres from sympathetic chain, 
human. (Toldt.) 
rather dip into the subjacent medullary substance than project on 
the surface; but when the medullary substance disappears, the axis- 
cylinder may continue invested with primitive sheath, or at least the 
nuclei may be continued on the axis-cylinder and project from it, or NERVOUS ELEMENTS. 
49 
even be separable. The nuclei are not found on nerves within the brain 
or spinal cord.1 
The medullary substance, otherwise called white substance of Schwann, 
though homogeneous and clear in the fresh state, escaping freely from cut 
extremities and leaving the axis-cylinder and primitive sheath uninjured, 
becomes turbid and even reticulated, and, when acted on by reagents, 
has been found to exhibit in transverse section radiating dispositions of 
stainable substance embedded in it. When at once hardened in the 
thoroughly fresh state, it remains altogether unstained by carmine; but 
if less fresh it stains considerably. The main constituent of the medullary 
substance escapes from cut or injured fibres in homogeneous masses termed 
myelin, which yields protagon and cerebrin. It may be noted that it 
contains phosphorus and a very small proportion of nitrogen, is probably 
the source of the large amount of cholesterin yielded by decomposition 
of brain-substance both during life and after death, and is blackened by 
osmic acid. The medullary substance can be removed altogether so as to 
show the axis-cylinder in the middle of the primitive sheath.2 
Fig. 45. —Nodes of Ranviee. a, Fresh, in salt 
solution; i, treated with haematoxylin ; c, im- 
pregnated with silver, showing transverse 
striation of axis-cylinder. (Toldt.) 
Fig. 46.—Notches 
op Lantermann. 
Osmic acid prepara- 
tion. (Toldt.) 
The nodes of Ranvier are interruptions of the medullary substance 
1 Although it is customary to describe the nuclei as belonging to the primitive 
sheath, they can in the case of the large medullated nerves he shown to be merely 
applied to it, and may even he separated from it, in the same way as the sarcolemma 
of muscle is distinct from the nuclei adherent to it. 
2 When the medullary substance escapes from the fresh nerve, it leaves adherent to 
axis-cylinder or to sheath none of the structures seen after changes have taken place. 
It seems to he simply an unstable chemical substance. It is worthy of note that 
nervous tissue is prone to decomposition proportionally to the amount of medullary 
substance contained in it. This circumstance, taken into account along with the 
instability of the medullary substance itself, makes it tempting to suggest that 
activity of the axis-cylinder may disturb the equilibrium of the medullary substance, 
and that this in turn may facilitate change in the axis-cylinder, and so promote 
nervous action. 60 
GENERAL ANATOMY. 
caused by constriction of the lumen of the primitive sheath, and have the 
appearance of a transverse septum projecting inwards from it. They are 
sometimes described as occurring one between every pair of successive 
nuclei, but the nuclei are more frequent than the nodes have ever been 
figured. Oblique notches, notches of Lantermann, are often met with divid- 
ing the medullary substance into cones, different series of them facing one 
another; but they result from the effect of reagents and manipulation. 
Of non-medullated fibres more than one vari- 
ety ought to be recognized. Threads already 
alluded to, more or less broad, with elongated 
oval nuclei pressing in from the sides, appear 
to be properly described as axis-cylinders with 
the sheath prolonged on them, in so far as 
the nuclei are obviously the same as those on 
the sheath of medullated nerves. There are 
also naked axis-cylinders near the terminations 
of nerves, without any nuclei disposed on 
them. Lastly, there is to be distinguished 
from these a set of nerve-fibres abundant in 
the sympathetic system, present also in cerebro- 
spinal nerves, called sometimes fibres of Bemak, 
and consisting of threads interrupted by elon- 
gated nuclei. The threads vary in breadth, 
being sometimes granular and as broad as the 
nuclei, but sometimes of the utmost tenuity 
and branching in their course. 
On certain of the smaller nerve-fibres 
ampullae occur of two kinds. One kind, 
abundant on fine fibres in the cortex of the 
brain, is caused by irregular disposition of the 
medullary substance, and is probably always 
an appearance resulting from manipulation. 
The other consists of regular dilatations of an 
axis-cylinder, as in the neuro-fibrous layer of 
the retina, and the artificial origin of this kind 
of ampulla is more questionable. The milky 
white of the cerebro-spinal nerves arises from 
the large amount of medullary substance on 
a number of the fibres, the same cause as gives 
the whiteness to the white brain-substance. 
The less brilliant tint of the sympathetic 
nerves arises from the larger number of non- 
medullated or poorly medullated nerve-fibres. 
Pig. 47. Unipolar Nbrve-Cor- 
pitscles, from jugular ganglion of 
vagus nerves of dog, showing the 
single pole dividing into a large 
fibre, p, and a small fibre, c. The 
abundantly nucleated sheath is also 
shown, which invests the corpuscles 
of the ganglia of nerve-roots and of 
the sympathetic chain. (Kdlliker, 
after Betzius.) 
Nerve-corpuscles are more frequently termed nerve-cells, but have no 
proper cell-wall. They vary in diameter from as much as of an NERVOUS ELEMENTS. 
51 
inch to a very minute size. They always present a granular appearance, 
and very generally contain a heap of yellow granules, also in some 
instances dark brown pigment. They have each a large nucleus, round 
and clear, containing one or two distinct nucleoli capable of being stained 
very deeply with carmine.1 But perhaps the most remarkable character 
of nerve-corpuscles is the possession of one or more poles or branches. 
Corpuscles apparently apolar are often met with, but there is reason 
to believe that these are merely corpuscles which have had their poles 
torn closely off. 
Fig. 48. Bipolar Nerve - Cor- 
puscles, from a sacral ganglion of 
a human embryo at the end of the 
second month. (Kdlliker.) 
Fig. 49. Multipolar Nerve-Corpuscle, from anterior cornu 
of spinal cord of ox; a, axis-cylinder process. (After Belters.) 
Corpuscles apparently unipolar occur in the invertebrata, with the 
pole continued into a single nerve-fibre; but the only known unipolar 
nerve-corpuscles in the mammal, those of the ganglia of the nerve-roots, 
are at an early stage of development bipolar, and subsequently draw their 
1 Nerve-corpuscles have recently been shown to exhibit differences of constitution and 
appearance, according as they have been at rest or in activity; activity being accompanied 
by increased size of cell, nuclei and nucleoli; rest by chromatic material in the cell, and 
fatigue by shrivelling of the whole structure and diffuse chromatic material in the nucleus 
(see Gustav Mann, Journal Anat. and Phys., October, 1894). GENERAL ANATOMY. 
bulk back from the poles so as to give them a common origin, through 
which currents of nervous action must pass in both directions. Also, 
bipolar corpuscles were described thirty years ago by Beale and Julius 
Arnold independently occurring in the sympathetic of the frog, in 
general appearance unipolar, but having one pole originating superficially 
and wound round another of deep origin, afterwards to separate from it 
and take an opposite direction. 
In numbers of multipolar nerve-corpuscles the poles are well made out 
to be of two sorts one remaining as a single stem, the axis-cylinder of a 
nerve, while the others break up repeatedly into smaller branches which 
end in fine extremities. Thus, in the multipolar corpuscles of the anterior 
cornua of the spinal cord, all the poles branch, save one, which is con- 
tinuous with an emerging fibre of an anterior nerve-root, and is distinguished 
as the axis-cylinder pole or pole of Deiters. The arrangement is not univer- 
sal, for the two original poles of the corpuscles of the spinal ganglia are 
certainly both axis-cylinders ; but it is important. 
The branching poles are called protoplasmic, as originating from the 
superficial part of the corpuscle, while the axis-cylinder has been 
supposed to have a deeper origin. The axis-cylinder, though remaining 
a continuous stem, or only once bifurcating, may give off numerous fine 
lateral branches known as collaterals, extending considerable distances 
within nervous substance; and both the main axis-cylinders and the 
collaterals terminate in arborizations or ramifications within a microscopic 
space. 
Such details and much of the recent advances in knowledge of the 
nervous system are due to the methods of metallic staining invented by 
Golgi, principally those in which chromate of silver is deposited. From 
such observations Ramon y Cajal has arrived at the following generaliza- 
tions : “ Nerve-corpuscles are independent unities, and never in continuity 
either by their protoplasmic branches or by their nervous expansions the 
axis-cylinders. Every axis-cylinder ends in arborizations, varicose and 
flexuose, after the fashion of the nervous ramifications of the motor plate 
in muscles. These arborizations apply themselves either to the bodies or 
the protoplasmic expansions of the nerve-corpuscles, establishing connec- 
tions by contiguity or contact, as efficacious as connections by continuity 
of substance would be, for the transmission of the currents.” Some observers 
believe the function of the protoplasmic branches to be purely nutritious; 
but if Cajal’s views are correct, both the protoplasmic poles and the 
axis-cylinder are paths of nervous activity. Also, though we continue to 
speak of commissures, meaning thereby nerve-fibres uniting similar centres, 
it is plain that if nerve-corpuscles are never united there can be no true 
commissure between corresponding corpuscles of opposite sides, and trans- 
verse commissures must resolve themselves into decussations; and, indeed, 
there is other evidence that they are so in the spinal cord, the pons 
Yarolii and the corpus callosum. NERVOUS ELEMENTS. 
It is in harmony with the doctrine of the independent unity of nerve- 
corpuscles, that when nerves are cut across in the living animal the ends 
separated from their centres of origin undergo granular degeneration. 
This is called Waller’s law, and affords a valuable means of tracking the 
continuity of fibres in the cerebro-spinal axis, and of determining, accord- 
ing as the degeneration is ascending or descending, the direction in which 
nerve-corpuscles of origin are to be sought. 
Both the spinal and the sympathetic ganglia differ from the brain and 
spinal cord in having, like the distributed nerves, abundance of white 
Fig. 50.—Minute Ganglion from 
Gall-Bladder of Dog. a, Axis- 
cylinder process; 6, protoplasmic 
processes, which form a plexus at the 
periphery of each ganglion ; c, sympa- 
thetic cells. (Dogiel.) Methylene-blue 
preparation. 
Fig. 52. —Medullated Nerve-Fibres under- 
going Degeneration and Regeneration. Rg, 
Conditions of degeneration the first fibre from 
the rabbit, the second and third from the frog; 
Rg, conditions of regeneration, from the rat. 
(Toldt, after Sigm. Mayer.) 
Fig. 51.— Ganglion from Gall-Bladder op Dog, 
with fine nerve-fibres ending in it. a, a, Non-medul- 
lated fibres ; 6, a medullated fibre. (Dogiel.) 
fibrous tissue entering into their composition. In the larger ganglia, the 
primitive sheath of the nerve-fibre is continued round each nerve-corpuscle, 
and in connection with the sheath there is a layer of flattened nucleated 
corpuscles enveloping each. In all the separate sympathetic ganglia, as 
distinguished from isolated nerve-corpuscles in ultimate diffuse plexuses, 
the corpuscles are made out to be multipolar with one axis-cylinder 
process, which at its far extremity ends in an arborization. 54 
GENERAL ANATOMY. 
Development and regeneration. While it is ascertained that the nerves 
and nerve-corpuscles of the brain, spinal cord and spinal ganglia, and even 
the earliest fibres to the muscles are derived from the medullary epiblast, 
the origin of the nerve-corpuscles of the sympathetic and of the plexuses 
of distribution, such as those within the cornea, heart, diaphragm, and 
intestines, is more problematical. 
The medullary sheath, when present, is always a later formation, and 
within the brain and spinal cord different strands acquire it at different 
periods of development, a circumstance which has been made use of by 
Elechsig to distinguish different continuous tracts of fibres. 
When a nerve is divided, the granular degeneration which sets in 
causes the axis-cylinder of the distal end to waste away, at the same time 
that the nuclei in connection with the primitive sheath become more 
numerous and prominent, but it is not certain that they assist in regener- 
ation. The new axis-cylinders are formed in continuity with those on 
the proximal side of the lesion, and, according to Eanvier, two or three 
may come from the cut end of one, and force their way on in the track 
of the degenerated nerve. 
EPITHELIUM. 
The word epithelium is used to indicate a covering of nucleated cells 
or corpuscles on a free surface; and, with little exception, all free surfaces 
have an epithelium, either consisting of one layer of corpuscles, in which 
case it is simple, or of several layers, and then it is said to be stratified. 
The individual corpuscles may have cell-walls or may have none; they 
may vary in consistence from a delicate pulp, or a film of the utmost 
tenuity, to the densest horn; they are of numerous forms and functions; 
and they are, as a rule, united by a cement more easily soluble than them- 
selves, to constitute a continuous texture. 
Simple epithelia are named according to the characters of their cor- 
puscles, squamous, columnar, cubical, spheroidal, polygonal and ciliated. 
Stratified epithelia are named from the character of the superficial 
stratum of cells, according as these are squamous, cubical or ciliated. 
The cells of their deeper layers present a great variety of appearances, 
requiring separate descriptions in each locality. 
Squamous epithelia exhibit corpuscles having the -form of flat scales of 
considerable size, each with its nucleus. Many simple squamous epithelia are 
of extreme tenuity, and some became known for the first time when weak 
solutions of silver nitrate came into use. The silver has a special tendency 
to deposit on the cement between the scales, chloride being formed, which 
on exposure to light is decomposed, leaving the oxide, and brins^die 
lines of contact into view, even when it is not deposited in their 
so as to show their structure. To this order of epithelia belong the liiSfgs 
of the heart and bloodvessels, lymphatics, serous membranes and the EPITHELIUM. 
55 
walls of spaces associated with the lymphatics in the connective tissues. 
They are usually now distinguished as endothelia, and, while other epi- 
thelial cells are either epiblastic, hypoblastic or genito-nrinary in origin, 
endothelium is mesoblastic, and may be derived from corpuscles in the con- 
nective tissues. Hence the term epitheloid cells is sometimes used instead 
of endothelium.1 Simple squamous epithelium is also found behind the 
Fig. 58. —Vabieties of Epithelial Cells, a, Squamous cells from epithelium of inside 
of cheek; b, simple squamous lining’ or endothelium of serous membrane; c, spiny cell 
from the growing epidermis; d, digitate cells from deepest layer of epidermis of palm ; 
e, columnar cells from intestine ;/, cubical cell from tubule of kidney; g, ciliated spheroidal 
epithelium from choroid plexus ; h, ciliated epithelium from trachea. 
cornea, in the air-cells of the lungs, and in the loops of Henle and 
the Malpighian corpuscles of the kidneys. Stratified squamous epithelium 
is found constituting the epidermis all over the body, and likewise lines 
the mouth, lower part of the pharynx, and the oesophagus, down to 
the stomach; also the vagina, and, we may add, the urinary bladder, 
though its epithelium is sometimes called transitional.2 
Columnar epithelia are those which have their cells vertically elongated. 
Plain columnar epithelium in no case presents more than one distinct 
layer, but the larger air-passages have stratified ciliated columnar 
epithelium. 
Cubical epithelium is a convenient term to indicate epithelial cells 
which have the vertical and transverse diameters nearly equal. They 
are not cubes but short cylinders which present a square appearance in 
vertical section. The tnbnli uriniferi have simple cubical epithelium, the 
ureter stratified cubical. 
1 Although the word epithelium was introduced hy Ruysch to indicate the covering 
of the papillae of the lips, because he deemed the term epidermis inappropriate in that 
situation, and doubtless he had in view d-qK-n, a nipple, subsequent histologists appear, as 
microscopy advanced, to have adopted it as if coined directly from OdAAw, as it might 
have been, to signify a superficial bloom. Only in this way can the modern use of the 
word epithelium be justified. It is the derivation approved of by Allen Thomson 
(Quain’s Elements, 7th ed.), and defends German anatomists from the strictures of 
Sharpey and Hyrtl on the etymology of endothelium. 
2 The term transitional ought to be allowed to drop. Introduced by Henle to indicate 
transition from spheroidal to columnar or scaly (Sharpey, in Quain, sth ed., xeix.), it 
has lately been used to signify transition from simple to stratified (Schafer, in Quain, 
9th and 10th eds.), and, thanks to the introduction of the word cubical, it is not 
required in its original sense. 56 
GENERAL ANATOMY. 
Spheroidal epithelial cells are found in the ventricles of the brain; 
they bear cilia, and constitute a ciliated spheroidal epithelium. The term 
spheroidal is further applied to the secreting corpuscles occupying the 
lobules of a number of glands, such as the salivary; corpuscles whose 
shape is more aptly described as polyhedral. They are often called 
glandidar epithelium, but their shape is not distinctive of glandular 
function, seeing that secreting corpuscles are often of a cubical or 
columnar form. 
Ciliated epithelium presents on its free surface innumerable cilia or 
hair-like processes crowded together on the individual cells. These cilia 
during life are in constant motion, so rapid that individually they are 
invisible, though their presence is made apparent by the movement they 
give to the fluid in which they are lying. The cells on which they are 
placed have always a cell-wall, and the movement continues as long as 
the cell is kept alive in a suitable serum or weak saline solution. Small 
groups of cells scraped from a surface may be rotated rapidly by the 
motion of the cilia. If the movement be watched as it grows slower 
before stopping, it will be seen that the cilia bend over in one direction, 
straightening themselves with a feathery sweep, and move the fluid 
in the direction in which they bend. The movement is always in one 
direction, and is doubtless always towards the outlet of the passage lined, 
thus keeping it microscopically free from solid particles. The cilia have 
been made out to be connected with the protoplasm within the cells, but 
no structure has been demonstrated in them. It is ingeniously suggested 
by Schafer that they may be hollow and moved by the projection of sub- 
stance from within the cell. If the one side be supposed to be hollow 
and expansible while the other is resistant, the theory is compatible with 
the straight position of the cilia after death, and with the bent position 
being that of tension. In mammalia ciliated epithelium may be either 
simple or stratified, and is columnar, except in the four ventricles of 
the brain, where it is simple spheroidal, though in the central canal 
of the cord it is simple ciliated columnar. Ciliated epithelium is found 
throughout the respiratory tract, with certain exceptions, and in the 
Eustachian tubes and lachrymal passages ; also in the epididymis, and 
in the uterus and Fallopian tubes. 
Regarded functionally, epithelium of the squamous sort is generally 
protective, although the sebaceous glands seem to offer an exception to 
this rule ; ciliated epithelium has likewise a mechanical function, keeping 
surfaces clean; polygonal, columnar and cubical epithelium are the forms 
most frequently devoted to secretion. Epithelial cells may also be associ- 
ated with nervous functions. Thus, in the submaxillary gland, secreting 
corpuscles are continuous with efferent nerve-fibres, and in all the organs 
of special sense there are specialized epithelial elements continuous with 
afferent nerve-fibres. GLANDS. 
57 
GLANDS. 
Secretion, generally speaking, consists in the extraction from the blood 
or the elaboration of special substances by epithelial corpuscles, and the 
pouring of them out on a free surface. No doubt the moisture found 
in serous and synovial sacs is not obviously influenced in quantity or 
quality by the endothelium; yet its varieties of character suggest that 
it is more than a transudation from the bloodvessels and textures around. 
As to the structures called ductless glands, while some of them have 
arresting and elaborating powers, they differ from secreting glands in that 
they do not pour their products out on a free surface. Absorption by 
epithelial corpuscles, such as is carried on by the columnar epithelium of 
the intestine, is similar to secretion, in respect that substance is attracted 
into the nucleated corpuscles and passed on by them; but it differs in 
the direction of the current, the current in absorption being directed from 
the surface inwards, and, in secretion, from the bloodvessels to the surface. 
A surface which secretes is a secreting surface, but the free surface 
in connection with secretion is very generally extended by deep recesses; 
and these recesses, with the secreting epithelium within them, and the 
vessels, nerves and supporting texture about them, constitute secreting 
glands. 
Glands are called simple or compound according as they consist of 
one or more recesses, and are called tubular or sacculated according to 
the shapes of the secreting parts. Simple straight tubules are exemplified 
in the tubular follicles of the intestine; the sweat-glands are mostly simple 
convoluted tubules, and compound tubular glands are exemplified by the 
testicle and kidney. The nearest approach to simple saccules is found in 
some of the sebaceous glands of the skin, but even these always show 
a certain tendency to lobation. Compound sacculated glands have the 
saccules forming little dilatations containing polygonal secreting corpus- 
cles, which may be of such considerable size as nearly to fill them. These 
ultimate dilatations are termed acini, and the glands made up of them are 
said to be acinated, and from their arborescent arrangement are also called 
racemose. The salivary and buccal glands and the pancreas are racemose 
glands. 
Only in short simple glands or follicles is the whole recess given to 
the preparation of the special secretion. The tubular passages which 
in other glands lead to the secreting parts are called the ducts, and in 
acinated glands they branch and become smaller, till they end in the 
ultimate secreting acini. 
The wall of the gland or membrane on which the secreting corpuscles 
lie always presents a definite line on section, and is termed membrana 
propria. It may be strengthened in acinated glands by a layer of flattened 
corpuscles united edge to edge so as to form a more or less complete 58 
GENERAL ANATOMY. 
investment, winch has been likened to basketwork. This is sometimes 
spoken of as constituting the membrana propria. The word basement mem- 
brane is also used instead of membrana 
propria, but might with advantage be dis- 
carded. Between the secreting pouches 
there is generally a considerable develop- 
ment of retiform tissue. 
Secreting corpuscles are in some in- 
stances, as the columnar epithelium of 
the intestine, distinctly walled cells; but 
in others the presence of a cell-wall is 
exceedingly questionable, or may be even 
denied. Some, as those of the convoluted 
tubules of the kidney, have the protoplasm 
always turbid; others, as those of the 
straight tubules of the kidney, have it 
always clear. In other situations, as in 
Fig. 54.—Lobules of Parotid Gland 
of embryo lamb, five inches long, illus- 
trating ducts and acini. 
the gastric follicles, the secreting cells vary distinctly in appearance, 
according to the condition of activity, becoming most deeply stainable 
when exhausted. In many parts mucigen is liable to collect in mass 
towards the free surface of the cell, driving the protoplasm and nucleus to 
the deep end; causing in the intestinal epithelium swollen and open cups 
called goblet-cells, and in salivary glands giving rise to the distinction of 
mucous acini from others termed by some authors serous, which have the 
protoplasm uniformly diffused, and the nuclei in the middle. 
BLOODVESSELS. 
The blood, though in the lower forms of animal life it circulates in 
contact with the tissues, is, in all vertebrate animals, contained every- 
where within walled vessels which constitute a closed circulatory system. 
In only one organ is there a probable exception to this, namely, the 
spleen. The bloodvessels are of four kinds, viz., the heart, arteries, 
veins and capillaries. The arteries distribute the blood from the heart 
to the minute capillaries, which permit the flow of substance through 
their walls both to and from the tissues; and the veins bring the blood 
back to the heart. The heart is in the early embryo a simple tube, like 
the other orders of bloodvessels, but becomes developed into a distinct 
and complex structure which is the central organ of two distinct circu- 
lations, the pulmonary and the systemic. The pulmonary arteries carry 
impure blood from the left side of the heart to be aerated in the lungs, 
and the pulmonary veins bring it back purified to the left side of the 
heart, whence it is carried by the systemic arteries, viz., the aorta and 
branches, and, having been distributed throughout the body, is brought 
back by the systemic veins, viz., the superior and inferior vena cava, to 
the right side of the heart. BLOODVESSELS. 
59 
The Arteries have tough thick walls, the walls of the systemic arteries 
being considerably stronger than those of the pulmonary circulation. 
They elongate and expand when fluid is propelled into them, and recover 
their form by their elasticity. The larger arteries, when empty, are 
flattened by the pressure of their surroundings, but their walls are too 
thick to admit of their being in perfect contact; the smaller arteries 
contract circularly. 
Arteries have got three coats, with different properties, each containing 
more than one kind of texture. If an artery be cut across, the greater 
part of the thickness of its walls presents a yellowish tint. This part is 
the tunica media, and the whiter and less dense coat outside it is the 
tunica adventitia, while internally, with the assistance of a lens or a low 
power of the microscope, a thin membrane can be distinguished, the 
tunica intima. 
The tunica adventitia consists principally of dense areolar tissue, the 
felted bundles of which are seen with the naked eye crossing one another 
with every degree of obliquity. In its deeper part it likewise contains 
abundant yellow-elastic tissue so arranged as to be intermediate between 
perforated membrane and a lattice-work of fibres with longitudinal 
inclination. When an artery is ligatured, the tunica adventitia remains 
intact. 
The tunica media consists of two elements yellow-elastic tissue and 
unstriped muscle. The yellow-elastic tissue is less fibrous than in the 
Fig. 55. —Elastic Tissue from Outer and Middle Arterial Coats. A, Fine net- 
work from middle coat of radial artery ; B, elastic lamina from middle coat of subclavian 
artery; G, coarse network from bounding layer between middle and outer coats of 
femoral artery. (Toldt.) 
tunica adventitia, and presents delicate laminae, which intercommunicate 
so as to form a network inclosing the muscular fibres in its meshes. 
The muscular fibres form the principal bulk of the middle coat. They 
are circularly disposed. When an artery is ligatured the thread presses 60 
GENERAL ANATOMY. 
asunder the muscular bundles and ruptures both the middle and internal 
coat; both coats are retracted by elasticity, while, in the living subject, 
the muscular fibres contract, diminishing the calibre of the vessel above 
the ligature, and exposing the ruptured edge to the blood so as to induce 
coagulation. Superficial to the circular muscular fibres there occur in 
some exceptional arteries scattered longitudinal fibres in the deep part of 
the tunica adventitia. This has been specially noticed in the splenic, 
mesenteric, renal, uterine and spermatic arteries, and those of the penis. 
Also, longitudinal fibres are noted by Bardeleben at the inner boundary of 
the tunica media in all the larger arteries. 
The tunica intima is brittle, thin and transparent, and may be torn 
off in shreds. It consists of three layers, viz., (1) a layer of endothelium, 
the cells of which are mostly elongated in the direction of the vessel; 
Fig. 56. Section of Artery, inch 
•wide, showing- the dense muscular tunica 
media, with tunica adventitia around it, 
and the clear crenated tunica intima 
within. 
Fig. 57.—A, fenestrated membrane of tunica intima; B, 
muscular fibres of tunica media adherent to tunica intima; C, 
partially isolated endothelial cells. (Toldt.) 
(2) a very delicate layer of branched corpuscles in homogeneous matrix, 
important to the pathologist as being the seat of the changes which lead 
to aneurism and calcification; (3) an elastic membrane marked with lines 
as of separate fibres, and frequently showing perforations, the fenestrated 
membrane of Henle. 
Arteries, as a general rule, divide dichotomously and give off smaller 
branches in their course. The coeliac and the thyroid axis are examples 
of trunks terminating at once in three. In various animals an artery 
breaks up suddenly into a number of minute trunks which are afterwards 
gathered together again, and this is termed a rete mirabile. Such an 
arrangement is found at the base of the skull of the sheep, in various 
parts of the bodies of ant-eaters, in the legs of running birds, and in 
other animals; but the only thing of the sort in the human subject is on 
a minute scale and common to man and other animals, the glomeruli of 
the kidneys. BLOODVESSELS. 
61 
When two vessels unite, either to form a third vessel receiving its 
blood from both, or a communication in which the direction of the current 
may vary from time to time, they are said to anastomose. Arteries for 
the most part anastomose by means of small twigs only, as in the face and 
neck they do across the middle line, or as do the terminal twigs of 
branches given off at different levels in the limbs; but in the mesentery 
the main branches unite in arches from the convexities of which other 
branches arise to form arches in like manner; and at the base of the 
skull two large trunks, the vertebral arteries, unite to form one mesial 
vessel, the basilar. Arteries generally continue of precisely the same 
calibre as long as they give off no branch, but the spermatic artery 
increases in size. In most instances, when an artery divides, the sum of 
the sectional area of its divisions exceeds the area of the undivided 
trunk; and by the following out of this rule, the total arterial channel 
enlarges and the rate of flow of the blood diminishes from the heart, till 
the capillaries are reached; but an exception to the rule occurs at the 
division of the aorta into the two common iliac arteries. 
In the smallest order of arteries, arterioles, those which lead into the 
capillaries, it is easy to see under the microscope, (1) the oval nuclei of 
the endothelial scales of the tunica 
intima elongated in the direction 
of the vessel, (2) the muscular fibres 
of the tunica media lying in a single 
layer, the individual fibres some- 
times wrapped twice or more round 
the vessel (Fig. 37), their nuclei 
crossing it transversely, and (3) 
spindle-shaped nucleated corpuscles 
lying longitudinally and represent- 
ing the tunica adventitia. 
The larger arteries, as also the 
larger veins, have in their walls 
small vessels for the nourishment 
of their structure, which are termed 
rasa vasorum. Nerves also are 
found in plexuses in the walls of at 
Fig. 58.—Aeteeiole and Venous Radicle, a, 
Artery; b, vein ; c, arteriole passing into capillary. 
Corpuscles of outer coat spindle-shaped, muscular 
fibres transverse, nuclei of endothelium oval. 
least all bloodvessels in whose walls there are muscular fibres 
The capillaries vary from about ?^g7th to of an inch in 
diameter; the smallest appear smaller than blood-corpuscles, but it is to 
be remembered that they are capable of elastic expansion, and that the 
blood-corpuscles change their shape in traversing narrow channels. They 
intercommunicate so as to form a continuous network with meshes which 
vary in different tissues. Thus, the lungs have the widest capillaries 
arranged in the closest meshwork, while poorly vascular tissues have 
narrow capillaries and the meshes large. 62 
GENERAL ANATOMY. 
Capillaries are often described as consisting of endothelium and having 
no other wall proper to them, but this description is misleading, for there 
is a homogeneous membrane quite distinct from the endothelium. The 
endothelium, the lines of con- 
tact of whose scales can be 
brought into view by the 
action of silver nitrate, and 
can also be seen by successful 
carmine staining (Fig. 5), has 
much less prominent nuclei 
than those in the arterioles ; 
but capillaries everywhere 
exhibit, regularly disposed ou 
them, other oval nuclei little 
flattened. These were known 
before the endothelium had 
been detected, and belong to 
Fig. 59. Capillaries. A, Endothelial wall; £, homo- 
geneous wall, with oyal nuclei. 
corpuscles embedded in a homogeneous wall. This may be conveniently 
termed, as it sometimes is, the tunica adventitia, being continuous with 
the tunica adventitia of the arteries. The endothelial scales are pointed 
at the extremities, most of them diamond-shaped; but those placed at a 
bifurcation may have three points, one projecting toward each channel. 
The veins have a total sectional area, for the return of the blood, 
greater for each part than that of the arteries. Arteries are very gener- 
ally accompanied by veins, but there are many subcutaneous veins in the 
neck and limbs without corresponding arteries. In the limbs specially 
there is a notable system of subcutaneous veins, which allows the blood to 
return when the deep veins are pressed on by muscles in contraction. 
The return is facilitated by the frequent anastomoses of veins even of 
considerable size, and in the extremities by the arrangement that in the 
upper limb below the level of the axilla, and in the lower limb below the 
knee, the main arteries are each accompanied by two anastomosing veins 
termed venae comites. There is one exception to the rule that the veins 
beginning in the capillaries are continued into larger and larger trunks, 
namely, the portal vein, which, receiving blood from the intestines, spleen 
and stomach, breaks up in the liver into branches ending in a second 
set of capillaries, through which the blood passes to the hepatic veins. 
The walls of veins are much thinner and greatly more distensible than 
those of arteries, the difference in thickness depending on the circular 
muscular fibres being much less developed, or even, in some veins, absent. 
The tunica intima presents the three elements found in the arteries, 
namely, endothelium, delicate connective tissue and elastic membrane; 
but the latter is very thin and adherent to subjacent connective tissue. 
The tunica adventitia in its deeper part, in a number of veins, presents 
a well-marked development of longitudinal muscular fibres, and longi- BLOODVESSELS. 
63 
tudinal muscular fibres are also found in the deeper part of the middle 
coat. In the middle and outer coats the elastic tissue takes mostly the 
form of longitudinal fibres. 
A remarkable peculiarity of veins consists in the presence of valves in 
most of them. These are thin transparent membranous folds projecting 
into the interior, often not visible when lying against the wall of the 
vein, but nevertheless of great tenacity. 
They are mostly arranged in pairs, which 
form pouches with their mouths directed 
towards the heart, although single folds 
occur, attached to the margins of veins 
opening into larger channels. Their free 
edges are straight, and their attached 
margins deeply curved. When the pouches 
are distended with fluid pushed back from 
the cardiac side, the parts of the folds 
nearest to the free edges are pressed one 
against the other so as completely to block 
the channel; and by this means regurgita- 
Fig. 60.—Valves of Veins. A, vein 
laid open to show the two pouches of a 
valve ; B, unopened vein showings—a, the 
dilatation opposite a valve; b, a closed 
valve seen from distal side. 
tion of blood is prevented, while also all attempts to inject fluid from 
the main trunk into veins furnished with such valves are rendered futile. 
The strength of the valves depends on white fibres regularly arranged as 
in aponeurosis, those nearer the edge coursing parallel to the edge, and 
those further back slanting in different directions so as to decussate. 
Their endothelial scales are elongated longitudinally on the exposed 
side, and transversely within the pouches. Valves are most numerous 
in the veins of the limbs, especially the lower. They are absent from 
the small veins under yLth inch in diameter, and from the pulmonary, 
mesenteric, splenic, portal, hepatic, renal and nterine veins, also from 
the ovarian vein; but they are found in the spermatic. Moreover, they 
are absent from the veins of the head and neck, with the exception 
of the subclavian and external jugular, and the opening of the internal 
jugular into the subclavian. 
Owing to the thinness of their walls, veins when empty are more 
easily completely flattened than arteries, and while the ordinarily con- 
structed arteries require accurate compression against bone to arrest the 
circulation in them, veins are closed against the passage of blood by 
every accidental pressure, such as the swelling of contracted muscles. 
Thus muscular action throws the blood of the limbs into the subcutaneous 
veins, and thus also the valves render the variations of external pressure 
important factors in aiding the return of the blood towards the heart, 
since they are effective to move it in that direction but not in the other. 
The thinness of the walls and the paucity of circular muscular fibres 
cause divided veins to gape much more than arteries, in consequence of 
continuity of the outer coat with loose surrounding tissue. 64 
GENERAL ANATOMY. 
Development of bloodvessels. As all vessels originate from simple 
beginnings, and as the muscular, white-fibrous and yellow-elastic tissues 
are developed in the walls of the larger vessels exactly as in the other 
situations, the question left to consider is the origin of capillaries. The 
first walls of bloodvessels, both in the area vasculosa of the embryo and 
in textures developing later, may be said to be of the nature of a cell- 
wall. In the area vasculosa branched corpuscles undergo proliferation, and 
when the centrally placed progeny are developed into blood-corpuscles those 
round about are flattened against the cell-wall. Other similar corpuscles 
are connected by branches with the wall of the first, and the channel of 
communication enlarges so as to make one continuous hollow. Other 
unwalled corpuscles become connected in series, and flatten out at the same 
time that they throw out a continuous tubular wall, on the interior of 
which the series is arranged. There may be difficulties to explain in con- 
nection with the details of this process, 
but it is impossible to admit the accuracy 
of the descriptions which account for 
the formation of the vessels by the 
coming together of vacuoles or cavities 
hollowed in the interior of the ■ proto- 
plasm of corpuscles. The outer layer of 
the amnion in young mammalian embryos 
admits of easy staining, and is highly 
favourable for the studying of developing 
vessels. In it one may observe that 
new vessels are formed from the unwalled 
corpuscles of the tissue in the way 
described, and that when the form of 
the capillary is completed it exhibits a 
series of distinct flattened corpuscles, 
the first endothelial scales, with spaces 
between them and a perfectly continuous 
homogeneous wall outside, against which 
Fig. 61. Formation or Capillaries from 
connective-tissue-corpuscles round the am- 
nion of an embryo lamb, one inch long. 
other corpuscles may press. The advancing extremity of a vessel in pro- 
gress of formation is sometimes widely open, as for instance in the cases 
of the new vessels underneath surfaces of ossification from cartilage. 
ABSORBENT SYSTEM. 
Under this name are comprehended a system of vessels and spaces by 
means of which substance is poured directly into the great veins to be 
mingled with the blood and, connected with those vessels, solid structures 
called lymphatic glands. 
The absorbent vessels are divisible physiologically into two sets, 
lymphatics and lacteals; but there is no anatomical distinction between the ABSORBENT SYSTEM. 
two save that which is topographical. Lymphatics begin in the textures, 
and bring back from them a clear fluid termed lymph. The lacteals are 
the lymphatics of the mucous membrane of the small intestine, and receive 
substances brought from the intestinal cavity**into the interior of the 
villi, by the absorbent action of living corpuscles. It is principally by 
this means that fatty substances are introduced into the system. These 
substances being in the form of exceedingly small globules or molecules 
give to the watery fluid which conveys them a milky appearance, and on 
that account the fluid is called chyle, and the vessels which contain it are 
termed lacteals. 
Lymph is a clear coagulable fluid, containing nucleated corpuscles. The 
corpuscles are most abundant in lymph which has traversed lymphatic 
glands, and correspond generally in character Avith colourless blood 
corpuscles; but many of them are smaller and with more distinct nucleus. 
Chyle is simply lymph Avith addition of fatty and other substances derived 
from the contents of the intestine. 
Lymphatic vessels, including lacteals, may be divided into three sets, 
viz., capillaries, simple walled tributaries, and trunks. The capillary 
lymphatics are minute vessels, forming 
networks like the capillary bloodvessels, 
but, both as respects the vessels them- 
selves and the size of the meshes, much 
more irregular in size and shape. They 
have no tunica adventitia, but are simply 
spaces lined with endothelium. The 
endothelium itself differs from that of 
blood-capillaries in the scales of which 
it is composed having characteristic 
undulating margins. The simple walled 
tributaries receive the lymph from the 
capillary lymphatics, and differ from 
Fig. 62.—Lymphatics. A, Capillary; B 
simple walled tributary. 
them in being considerably larger, in having endothelial scales more 
elongated and less undulating in outline, and in having valves. The 
stronger walls and the presence of valves indicate the presence of a 
supporting membrane. 
The lymphatic trunks are vessels with three walls, like veins and 
arteries, viz., a tunica intima of endothelium supported by fibrous tissue, 
a tunica media of circular muscular fibres, and a tunica adventitia of white 
and yellow-elastic fibres, in bundles taking all directions. They are all 
supplied with valves, consisting of white fibrous pouches in pairs, like those 
of veins; and they yield opposite the valves, so as to present when 
distended a somewhat beaded appearance, the valves succeeding one another 
with much greater frequency than those of veins. 
In the limbs, head and neck, and walls of the trunk, the lymphatic 
trunks are arranged in deep and superficial sets, the deep sets accompanying 66 
GENERAL ANATOMY. 
bloodvessels, and the superficial arranged on the surface of the body in 
long independent courses. With the exception of the main vessel, the 
thoracic duct, which is the size of a crowquill, they are, all of them, thin, 
white, or transparent threads. Thus the lacteals in the mesentery are with 
difficulty seen against the light when empty, till a dissection is made 
and then by the collapse of their walls they show as whitish threads, like 
the lymphatics elsewhere when dissected out. Lymphatic trunks are 
supplied with bloodvessels which take a longitudinal 
course in their coats. 
Besides the networks of capillary lymphatics, 
lymph spaces lined with endothelium are found in 
various situations, for example, surrounding the 
funiculi of nerves and on the • surfaces of tendons. 
In the frog there are undoubted perivascular spaces 
of this sort round the mesenteric vessels, and in 
the human subject there seems reason to believe 
that similar spaces surround vessels in the substance 
of the brain. 
The most remarkable connection of the lymphatic 
system with spaces is the opening of lymphatic 
vessels into serous membranes. This is found, in 
the case of the peritoneum, on the under surface 
of the diaphragm, and in the case of the pleura, 
opposite the intercostal spaces. A number of endo- 
thelial cells of the serous membrane are arranged 
in a rosette around the opening of the lymphatic, 
and such openings are called stomata. 
Some anatomists still feel difficulty in determining 
whether the lymphatic system is completely closed in 
with endothelium, or is in direct continuity with the 
interstices of the connective tissues. The practical 
point is certain that lymphatics can be injected 
by puncturing with hollow needles, and throwing 
coloured fluids into the tissues; and there seems 
no reason to doubt that while diffusible substances 
pass through the walls of the capillary bloodvessels, 
the lymph is the accumulation of less diffusible 
substances remaining in the interstices of the tissues 
Fig. 63.—Lymphatic Gland 
of the groin. a, Afferent 
duct with* concavities of 
valves turned toward the 
gland; bh, efferent ducts with 
the convexities of their valves 
toward the gland. (After 
Mascagni.) 
to be pressed onwards by every local pressure into the valved lymphatics. 
The walled lymphatics are certainly in continuity with unwalled spaces in 
the lymphatic glands, and there is no radical distinction between lymphatic 
glands and diffuse retiform tissue. Also, by injecting with the puncture- 
syringe, large spaces can be brought into view, surrounding the acini of 
racemose glands and the tubules of the testes and kidneys; from them 
the injection passes on into the walled lymphatics. ABSORBENT , SYSTEM. 
67 
Lymphatic glands. These structures, called , also lymphatic ganglia, 
conglobate glands and lymphatic kernels, are essentially masses of retiform or 
adenoid tissue interpolated in the,course of lymphatic vessels.' They vary 
from the minuteness of a pinhead to three quarters of an inch in length, 
and more than half an inch in greatest breadth, and in an irritated or 
inflamed condition may attain much larger dimensions. They are sur- 
rounded by fibrous capsules, which are aqost separable in young subjects, 
but connected in all both with the connective tissue around and with 
trabeculae passing inwards. They present, on section, a uniform appear- 
ance to the naked eye. They receive afferent lymphatic trunks, which 
travel some distance in 
contact with the capsule 
and divide into smaller 
vessels before dipping in 
at different parts of the 
surface; and at one part 
there is usually a depres- 
sion or hilus where 
arteries enter, and veins 
and efferent lymphatics 
emerge; the efferent lym- 
phatics gathering immedi- 
ately into larger trunks. 
On examination under the 
microscope, two sets of 
structures are seen, trabe- 
cular stroma and cor- 
puscles. The trabeculae 
are white fibrous bundles, 
continued in from the 
capsule, and form a mesh- 
work whose bands get 
finer while the meshes 
get smaller from the sur- 
Pia. 64. Section op Human Lymphatic Gland, highly magni- 
fied, showing the crowded corpuscles of the medullary cylinders 
and the retiform tissue of the lymph-paths with its branched 
corpuscles. 
face towards the centre of the gland. Scattered muscular fibres have 
been found in them, and, in various animals, continuous muscular bands. 
Within the undisturbed meshes of this network the whole space seems 
filled with minute leucocytes, but when a number of them have been 
washed away, or when the section has been stretched, there is left a mass 
of such leucocytes or lymph-corpuscles closely adherent to one another, 
and a reticulum of branched corpuscles separating it from the trabeculae. 
The corpuscles of a lymphatic gland are thus of two kinds, the lymph- 
corpuscles and the branched corpuscles. The coherent mass of lymph- 
corpuscles presents, in the centre of the gland and opposite the 
hilus, the form of a network of cords or cylinders interarching with a 68 
GENERAL ANATOMY. 
network of spaces of similar dimensions to themselves, while at the 
periphery it forms rounded nodules or bulbs, each connected by a neck 
with the cylinders. The peripheral part containing the bulbs is some- 
times termed the cortex, and the deep part the medulla. Around the bulbs 
the reticulum is distinct, and though considerably supported by homo- 
geneous substance investing the branching corpuscles, yet exhibits manifest 
open passages or lymph-paths; and outside the reticulum the main trabeculae 
form alveoli corresponding with the bulbs. In the medulla neither the 
trabeculae, reticulum nor lymph-paths are so distinct; but the spaces 
between the cylinders are crowded with lymph-corpuscles, the protoplasm 
of which is more abundant than in those of the cylinders. Both afferent 
and efferent lymphatics, when followed into the gland, are seen to lose 
their proper walls and to be continuous with the unwalled lymph-paths. 
Closed follicles. It has been customary to class along with the 
lymphatic glands certain minute nodular collections of small unwalled 
corpuscles similar to those of the lymphatic glands, and likewise situated 
in meshes of retiform tissue, namely, the closed follicles of the digestive 
tract. These are rounded bodies like small grains, with definite capsules. 
They are situated in the mucous membrane, and are provided with a 
special distribution of capillary blood-vessels within them, which are 
directed toward the centre and form loops emerging at some distance 
from their entrance. They have an abundance of lymphatics round them; 
but there is no evidence that their corpuscles migrate into either the lym- 
phatics or bloodvessels. They have latterly been described by some as 
lymphatic nodules. Mere nodules of unwalled corpuscles do exist, as, for 
example, in the mucous membrane of the stomach and bladder, but 
differ from closed follicles in having neither special bloodvessels nor 
distinct boundaries. The vague use of the word ‘ lymphatic ’ is, however, 
to be deprecated. From both lymphatic glands and from diffuse retiform 
tissue there can be no doubt that corpuscles travel into lymphatic vessels; 
but the researches of Stohr (1884 and 1891) have shown that a charac- 
teristic feature of the closed follicles of the tonsils and the back of the 
tongue is the passage of leucocytes from them through the epithelium of 
the mucous membrane. Thus the evidence is in favour of closed follicles 
being organs of elimination, and a rational explanation is suggested of their 
importance in disease. 
SACCULAR MEMBRANES. 
Considering the direct communication of serous membranes with lym- 
phatics by stomata, as above described, and the formation, by mere breach 
of continuity of connective tissue, of other sacs comparable to the 
interstices with which the origins of lymphatics are connected, the 
characters which such spaces present may be here considered. SACCULAR MEMBRANES. 
69 
Serous membranes are so named because their lubricating surfaces 
present the appearance of being moistened with a thin watery fluid. 
Under this name are included the membranes derived from the walls of 
the primitive space or coelom separating, in the embryo, the splanchno- 
pleure from the somatopleure, namely, the peritoneum, the pleurae, the 
pericardium and the tunica vaginalis. The cavities inclosed by these four 
membranes are portions of one original space. They all consist of a 
parietal and visceral layer continuous one with the other where the 
parietal layer turns inward to be folded round the surface of the organ, 
or organs, invested by the visceral layer. They are practically shut sacs, 
but in the female the Fallopian tubes open into the peritoneum, and in 
certain fishes and reptiles there are other openings termed the abdominal 
pores. Generally the serous membrane can be stripped with ease from 
the wall or viscus which it clothes, and is seen to consist of homogeneous 
connective tissue, strengthened with curling elastic fibres and lined with 
endothelium; but there is no distinct line of separation between the 
fibrous tissue of the ovary or that of the tunica albuginea testis and their 
serous coverings. Serous membranes are the seat of acute pain when 
inflamed, and minute branches of nerves have been traced to them. 
In addition to the membranes mentioned, the arachnoid used to be 
described as a serous membrane with a parietal and visceral layer; but 
latterly the custom has become general to confine the name arachnoid to 
the transparent membrane over the pia mater, to term the opposed surface 
the deep surface of the dura mater, and to call the intervening cavity the 
subdural space. Nevertheless the subdural space is walled by two sur- 
faces lined with endothelium, and is not without communications with the 
lymphatics. It is not, however, developed from the coelom or any 
primitive cavity, but is hollowed out in previously continuous tissues in 
the same way that synovial membranes are. 
Synovial sacs. The synovial membranes of joints have already been 
considered with the other textures of articulations ; but besides these there 
are sacs differing from them in presenting a membrane of uninterrupted 
continuity round every part of their cavity, while resembling them in 
secreting a similar synovial moisture liable, like theirs, to become glairy 
under inflaming influences. They are of two sorts, bursae mucosae and 
thecae or vaginal membranes. Bursae are thin-walled sacs, intervening most 
frequently between muscle or tendon on the one side, and a bony surface 
on the other. The largest bursae intervene, one of them between the 
gluteus maximus and the great trochanter of the femur, and the other 
between the deltoid muscle and acromial arch on the one hand, and the 
shoulder joint with the immediately surrounding insertions of muscles on 
the other. The bursae beneath the ligamentum patellae, the tendo Achillis 
and the radial insertion of the biceps muscle, are examples of bursae 
between tendon and bone. There are likewise subcutaneous bursae, the 
most constant being that over the patella, the inflammation of which con- 70 
GENERAL ANATOMY. 
stitutes housemaid’s knee, and another at the olecranon, the inflammation 
of which is called miner’s elbow. A theca differs from a bursa in more 
completely investing a tendon or tendons, and in being bound down by 
the strong fibres which complete the canal in which the tendons are made 
to move freely by its aid. A tendon may be completely surrounded by 
the membrane, the investing portion of the theca not being continuous 
with the parietal, save at its extremities, where the one part turns on the 
other like the finger of a glove reflected on itself, or the tendinous and 
parietal layers may be connected by bands of connection, vincula. The 
radical similarity of synovial membranes of joints, bursae and thecae is 
well illustrated by the bursa under the subscapularis muscle and the theca 
of the long head of the biceps flexor radialis, both being prolongations of 
the synovial membrane of the shoulder joint. Bursae and thecae have not 
even the imperfect endothelial lining described in connection with synovial 
membranes of joints. Pacinian corpuscles (p. 8.1) have been found in con- 
nection with bursae and sheaths of tendons. 
INTEGUMENTS. 
The integuments consist of the tough vascular and sensitive corium 
covered superficially with a stratified epithelium, the epidermis, and 
passing on its deep aspect gradually into subcutaneous areolar tissue. 
The subcutaneous areolar tissue or superficial fascia varies in amount and 
density in different parts of the body. In the eyelids, in the penis in 
the male, and in the nymphae in the female, it is free from adipose tissue; 
but in other parts it is pervaded with it, constituting the rete adiposum, 
which reaches its greatest development in the gluteal region. The sub- 
cutaneous tissue in most places permits a gliding movement of the skin 
on the deeper parts; but in the palms of the hands and the soles of the 
feet, vertically placed bundles knit the skin inseparably to the palmar 
and plantar aponeurosis; and the scalp is in like manner bound down 
Fig. 65.—Cutaneous Ligaments of Phalanges of finger, a, The strong parts of the 
sheaths of the flexor tendons ; 66, insertions of ligaments. 
to the aponeurosis of the occipito-frontalis muscle. Also from the sides 
of the phalanges in both hand and foot, as I have pointed out (1867), 
there extend obliquely upwards from the lower ends, and downwards INTEGUMENTS. 
71 
from the proximal ends, strong bands to the skin, so as to fix more or 
less firmly in different individuals the integument on the back of each 
phalanx, and accumulate over the backs of the joints the wrinkles caused 
by extension. The subcutaneous tissue of the scrotum is characterized by 
a continuous layer of unstriped muscular fibres, the dartos, which effects its 
contraction under the influence of cold. 
The corium or cutis vera consists of a stroma of tough gelatiniferous 
substance, apparently uniform toward the surface, but breaking up more 
deeply into thick bands of white fibrous substance, which, followed from 
their origin, are at first closely reticulated and felted, and afterwards 
form meshes of greater size the deeper they are, till ultimately the thick 
bands break up into thin fibres of ordinary connective tissue. The deeper 
meshes are in most places filled with grains of adipose tissue, so that in 
dissecting the skin away from the texture immediately beneath, a honey- 
comb of white fibrous tissue is exposed, with fat or semi-transparent jelly 
in the spaces, according as the subject is well nourished or emaciated. 
The surface is everywhere thrown into minute elevations termed papillae, 
and the superficial part of the corium is therefore indicated as the papillary, 
and the deeper as the reticulated stratum. Especially in the reticulated 
stratum there is a great development of curling yellow-elastic fibres, often 
with highly intricate coils; and it is this tissue which by its resilience 
causes wounds to gape, and the flaps in surgical operations to shrivel to 
a much smaller size than they had when mapped out before being raised. 
There is also a great abundance of connective-tissue-corpuscles in the 
corium, spindle-shaped in the deep parts and with several branches more 
superficially. 
At the very surface, investing the papillae and intervening parts, I find 
a continuous network of small 
stellate corpuscles connected with one 
another by their branches. The papillae 
are little elevations, which, over the 
surface of the body generally, have a 
nodular form not exceeding inch 
in length, and are scattered irregularly. 
In each there is a loop .of bloodvessels, 
and in some there is in addition a 
touch-corpuscle. On the lips they are 
larger and crowded together. Under 
the nails they are likewise crowded, 
much elongated, pointed, and sloped 
in the direction in which the nail 
grows. On the palmar aspect of the 
hand and fingers, and on the sole of the foot, they are finger-like processes 
exceeding inch in length, arranged in ridges each of which presents 
a double row of tufts of papillae, while dotted in single file down the 
pIG- gg.—Bidoes of Integument of Thumb, 
with a single row of orifices of sweat-glands 
in the middle of each. 72 
GENERAL ANATOMY. 
middle of each ridge are the orifices of sweat-ducts at regular distances one 
from another. The pattern of these ridges is seen on the surface of the 
epidermis, and presents differences on the tips of the fingers of different 
individuals, which have been recommended as marks useful for identifica- 
tion of criminals. The regular arrangement of the papillae and sweat-glands, 
together with absence of hairs and sebaceous glands, and great thickening 
of the epidermis, are peculiarities of the palm of the hand and sole of 
the foot. The bloodvessels of the corium distribute their capillaries to 
the papillary stratum, every papilla containing a capillary loop; con- 
sequently superficial scratches and abrasions bleed copiously. By this 
arrangement an abundance of papillae brings a large amount of blood 
within reach of the epidermis; but abundance of blood at the surface is 
not always accompanied with thickness of cuticle: the cuticle of the lips 
is thin. Muscular fibre, although not an essential part of the corium, 
occurs in connection with it. Striped muscular fibres are found where 
striped muscles are inserted into the 
skin, as in the chin; and unstriped 
muscular fibres are much more widely 
distributed in connection with hairs 
and sweat-glands, and are described 
as occurring in the prepuce and 
about the nipple. 
The epidermis, cuticle or scarfskin, 
is a stratified squamous epithelium 
varying much in thickness on different 
parts of the body. It is broadly 
divisible into two great layers, namely, 
the growing part and the part con- 
verted into horn, readily separated 
one from the other by accumulation 
of moisture, whether from over-irrita- 
tion of the deep corpuscles during life, 
which constitutes blistering, or from 
incipient putrefaction after death. 
Fig. 67.—Vertical Section of Epidermis and 
Cdtis Vera of front of finger, a, Horny epider- 
mis ; from b to e, growing epidermis ; b, stratum 
lucidum ; c, stratum granulosum ; d, polyhedral 
strata with prickle-cells; e, columnar stratum 
with striated appearance dependent on elongated 
processes; /, surface of cutis vera squeezed 
separate from the epidermis, and exhibiting in 
this locality interdigitating processes; g, capil- 
lary bloodvessels passing up into two papillae; 
h, orifice of sudoriparous duct which shows the 
spirality of the duct in the horny epidermis; 
i, nerve breaking into fine branches; k, touch- 
corpuscle. 
The growing epidermis, called also 
rete mucosum or layer of Malpighi, is 
soft and easily stained with carmine. 
Its corpuscles arc of different forms at 
different depths. Resting in contact 
with the corium, there is a single 
layer of vertically elongated corpuscles, and superficial to them are those 
of smallest size, which are of similar breadth, but rounded or polyhedral 
in form. Passing still towards the surface, the corpuscles get larger and 
flatter till the deep limit of the horny layer is reached, where they become 
suddenly quite scaly and horny. The elongated or columnar stratum INTEGUMENTS. 
73 
exhibits, where the skin is thick, a vertically striated appearance, and on 
closer examination each of its corpuscles may be seen to consist of a part 
divided into finger-like processes resting on the corium and a distal portion 
in which the nucleus is placed. This layer is the chief seat of pigment 
in the negro and in the dark 
portions of the skin in thewhite 
races. My observations lead me 
to believe that Schneider (re- 
ferred to by Sharpey) was prob- 
ably right in supposing that 
the columnar corpuscles by per- 
petual division of their nuclei 
give rise to more superficial 
corpuscles of the epidermis, 
notwithstanding that, as I 
showed many years ago, the 
corpuscles of the epithelium 
of the cornea arise by pro- 
liferation superficial to the 
elongated layer ; but the sub- 
Fig- 68.—Epithelium of Cornea of Ox. a. Superficial 
scales; h, young cells; c, large cells with digital processes; 
deepest cells j c, deffenercited cells witli nucleus Wcisted 
a;.ay yf> with n’ucieus partially wasted; g, young ceils pro- 
liferatin&- 
ject has not been sufficiently worked out. 
In the polyhedral strata a spiny appearance of the margins of the cor- 
puscles may be detected, whence they have been called prickle-cells. The 
spines of adjacent corpuscles do not fit into one another, but are formed 
by adhesion at intervals, with breaches of continuity between (Martin, 
1875). In the most superficial corpuscles subjacent to the horny layer, 
not only is there considerable flattening, but the protoplasm has become 
altered and granular, imbibing carmine more easity than the subjacent 
younger corpuscles, and constituting a stratum granulosum. 
The horny epidermis consists of scales which are more or less completely 
converted into keratin, the chemical substance which forms the character- 
istic component of horn. It is impervious to ordinary carmine-staining, 
with the exception only of the nuclei of its deepest lamina (stratum lucidum), 
which continue to absorb the dye readily, while the substance round them 
is unaffected. In its other laminae the nuclei are more difficult to detect, 
but by suitable manipulation they can generally be brought more or less 
distinctly into view. This is easiest in situations where the epidermis 
is very thin, the scales being more delicate in such situations. In the 
stratified squamous epithelium of the buccal mucous membrane, which is 
essentially the same structure as epidermis, the superficial scales continue 
to show a distinct nucleus, and granules in the substance round about. 
Even in the negro the horny epidermis is destitute of pigment. 
Cutaneous glands. These are of two kinds, sudoriparous and sebaceous. 
To these might be added the mammary glands, but they are so specialized 
that it is better to consider them with the reproductive organs. 74 
GENERAL ANATOMY. 
The sudoriparous or sweat-glands are found all over the body. They 
are simple tubes, with the secreting part convoluted in the form of a ball 
from which a straight duct proceeds. The convoluted portion and the 
commencement of the duct are lined with simple cubical epithelium. 
Occasionally, e.g. in the heel, the sweat-glands are bifurcated. They lie 
in spaces in the deepest part of the corium, or in the subcutaneous 
tissue, not all at the same depth, but some with shorter ducts than 
others. When the horny epidermis is stripped off and examined on its 
deep surface, hair-like processes are seen projecting from it which are 
tubular prolongations lining the sweat-ducts for some distance. The 
horny scales of these 
prolongations lie edge- 
wise to the surface of 
the skin, toward which 
they are gradually 
pushed, and as they pass 
up among the corpuscles 
of the growing epider- 
mis, the unshrinking 
tube which they form 
is thrown into a spiral 
by the continual flatten- 
ing of the corpuscles 
around, so that, in 
places where the horny 
epidermis is very thick, 
as in the heel, as many 
as four or more turns 
Pig. 69.—Sudoriparous Glands. A, Coiled secreting portions of 
three glands with first parts of their ducts ; B, portion of coiled tube 
more highly magnified. 
like a corkscrew may be seen. The sweat secreted by the sudoriparous 
glands, though mainly a watery fluid with salts in solution, is not destitute 
of oil on the palmar aspect of the hands where there are no other glands; 
and oil appears to be more abundant in the sweat of the armpits, where 
the sudoriparous glands are very large. The ceruminous glands, which 
secrete the wax of the ear, are largely developed convoluted tubes like 
sweat-glands. 
The sebaceous glands are of the racemose type, presenting dilated 
pouches. They are always associated with a hair. Where the hair is 
large, as on the scalp, they open, one or two of them, a short way down 
the neck of its follicle, and are little more than simple saccules, with an 
inclination to lobulation; but the hair may be small, and, especially on 
the lips and nose, may be situated at the opening of a larger sebaceous 
gland, the duct of which may divide more than once before terminating 
in rounded dilatations. The secreting epithelial cells are so flat that they 
may be termed squamous. 
Special epidermal growths of two sorts occur in the human subject, INTEGUMENTS. 
namely, nails and hairs. Both are accompanied with subsidiary arrange- 
ments of the corium and epidermis around. 
Nails. A nail is essentially a thickened shield of horny epidermis 
pushed forwards from within a fold 
contact with the corium for some dis- 
tance. The part of the corium with 
which it is united is called the matrix. 
In the fold of the matrix two papillary 
surfaces covered with epidermis are 
turned toward one another, and the 
closely set pointed papillae, both in 
the fold and on the rest of the matrix, 
are all directed toward the tip of 
the nail. Within the fold one mass 
of horny substance is formed from 
the growing epidermis clothing the 
deep and the reflected surface of 
the fold, so that at this part, the 
root, the nail is hardest in the middle 
depth; but as soon as it escapes from 
the fold, it receives new layers of cor- 
puscles on its deep surface only, and 
hence the exposed part of the nail 
is hard on the surface and softer 
beneath, while it gets thicker gradu- 
ally toward the free extremity. If 
left uncut the nails turn over and 
tend to break into laminae, in conse- 
quence of the continued contraction 
of corpuscles after separation from 
of integument, and remaining in 
Fio. 70.—Sebaceous Gland of Cheek. Op- 
posite B a hair-follicle, containing a small hair, 
opens into the duct. (Toldt.) 
the matrix. The individual scaly corpuscles of which the nails are formed 
are slightly elongated in the direction of growth of the nail. 
Hairs. A hair is an epidermal growth based on a single papilla. It 
projects from a deep invagination of the skin, termed a hair follicle, and 
consists of two parts, viz., the root and the shaft. The root or bulb is a 
dilated and rounded mass of spherical corpuscles surrounding an enlarged 
papilla, and at its upper part showing the different textures found in the 
shaft. The shaft of a fully developed hair presents three textures—the 
cortical substance, the epithelium and the medulla. The cortex or cortical 
substance is badly named; it is no mere bark, but constitutes the main 
structure. It is formed of horny epidermal scales much elongated, and 
incapable for the most part of being fully separated even with the aid of 
liquor potassae. But hairs of the head and beard tend to split at their 
extremities, and it is easy in such a case and in hairs of the armpit to 
exhibit fibres. The epithelium (so called) is a single layer of unelongated 76 
GENEEAL ANATOMY. 
scales on the surface of the cortex so arranged as to have the appearance 
of a network, each scale having its advanced edge convex and free, while 
its lower edge is covered by the next scale. The free edges project very 
slightly in the human subject, but to such 
an extent that when two hairs laid side 
by side pointing in opposite directions are 
rubbed between finger and thumb, they 
move each in the direction of its root. 
To see the epithelium on the shaft properly 
a hair should be cleansed with chloroform 
and examined in air ; but over the root it 
is much thicker, the scales being much more 
closely imbricated. The medulla, in the centre 
of the shaft, is a column of uncompressed 
and unelongated corpuscles having a 
granular appearance and often containing 
minute air-globules. It is not developed 
in the small hairs over the body; and in 
many persons with fine hair is absent even 
from the hairs of the scalp, or occurs in 
interrupted patches. It is easily studied 
in split hairs from the beard. Pigment 
occurs in very variable degree in hair, and 
where present is most abundant in the 
root. In the shaft it is more abundant in 
the cortex than in the medulla, and is 
found both in the granular form and evenly 
diffused. It is granular in black and 
brown hair, and a diffused staining in red 
hair. But hairs of a brilliant shade have 
the additional peculiarity that the medulla 
is well developed and full of minute air- 
globules which reflect the light. A certain 
proportion of such, mixed with a larger 
number of a duller hue and with less- 
developed medulla, are sufficient to warm 
up the apparent effect of the whole. The 
silvery white of old age owes its brilliance 
to the same cause, and one may some- 
Fig. 73.—Hair, a, Papilla covered by 
•cells of the bulb ; h, follicle ; c, d, outer 
and inner cuticuiar sheath, the imbri- 
cated layer not being represented ; e, 
cortex ;/, medulla; g, epithelium ; g', 
■epithelium in optical section ; h, part of 
hair becoming white by disappearance of 
pigment from cortex, and the diameter 
of the hair increased by evolution of air 
in the medulla. 
times see a hair swollen with air and white in one part of its extent, 
while it is slenderer and coloured in a portion above or below. The 
•essential part of the whitening of the hair from age is the disappearance 
of the pigment, which usually takes place simultaneously with the 
development of air in the medulla, and often, in individual hairs, in a 
•single night. The form of the shaft of the hair varies both in different INTEGUMENTS. 
77 
races and in different parts of the body. In straight hair it is cylindrical, 
in curly hair somewhat flattened, and in woolly hair quite strap-shaped. 
The flattest hairs are those of the armpit. 
The hair-follicle is the depression w’hich lodges the root and lower end 
of the shaft of the hair. It is an invagination of the corium, and is 
lined with an invagination of the epidermis, termed the root-sheath. 
The follicle has three distinct layers: (1) the external or peripheral coat 
of closely felted fibres, with the insertion of the erector muscle connected 
with it; (2) a middle dense coat, with nuclei elongated transversely; and 
(3) an internal homogeneous membrane. The sheath presents in contact 
with the follicle a continuation of the deep part of the epidermis, and 
internal to this three distinguishable layers continuous with the horny 
epidermis, viz.: (1) a layer of scales with no perceptible nuclei, named 
after Henle; (2) a layer with distinct nuclei, associated with the name of 
Huxley; (3) an imbricated so-called epithelium of the sheath, with the 
free edges of its scales directed downwards, continuous below with 
the epithelium of the hair itself. The hair-follicles are being 
arranged round various points and lines. Those of the scalp form a whorl 
round the vertex; those of the trunk incline towards the middle line in 
Fig. 72.—Vertical Section of Scalp, showing two 
roots of hairs, a, a, Bloodvessels; b, b, erectores 
pilorum; c, c, sebaceous glands. 
Fig. 73.—Development of 
Hair. A, Downward growth 
of epidermis; JB, form of 
the hair completed. (After 
Kolliker.) 
front and behind; in the male a line, absent in the female, extends 
up from the pubis; in the limbs the slope is downwards. On the side 
toward which the hair is inclined, there is a band of unstriped muscle, 
erector pili, descending from the corium at a little distance obliquely to 
near the lower end of the follicle, and tending to elevate the hair into 
the erect position. The action is well illustrated in the hair of a horse 
when taken ill, the coat losing its gloss and standing up. 78 
GENERAL ANATOMY. 
Hairs begin to appear in the third month of foetal life. A thickening 
■of the epidermis in connection with a papilla dips down into the corium; 
in the lower part of this mass of cells the hair appears with a slender 
shaft and a large bulb into which a papilla projects, and after being so 
elongated as sometimes to be folded on itself, bursts through to the surface. 
The hair which covers the infant at birth, lanugo, falls out and is replaced 
by a new growth. Hairs appear to be reproduced in two ways, namely, 
by a new growth on the same papilla, or by the formation of a new 
papilla near the bottom of the follicle. 
ORGANS OF COMMON SENSATION. 
The skin being the principal seat of common sensation, the organs of 
•common sensation may be conveniently examined now, even although some 
of the most sensitive sur- 
faces, such as the con- 
junctiva and the covering 
of the tongue, have claims 
to be considered as mucous 
membranes; and some of 
the organs to be considered, 
such as Pacinian bodies, 
are not confined to the 
neighbourhood of free sur- 
faces. 
In the integuments, the 
terminal organs of nerves 
become smaller the nearer 
they are to the surface. 
Epidermal endings. Ex- 
ceeclingly fine ramifications 
of nerves can be traced, by 
means of metallic staining, 
O’ 
between the growing cor- 
puscles of the epidermis; 
but with regard to their 
Fig. 74.—Vertical Section of Skin of Sole of Foot, with 
ramification of nerves in stratum Malpighii. The stratum 
corneum is only shown in its deepest parts. Gold preparation. 
(Kolliker.) 
exact mode of termination there is room for further investigation. In 
various situations in the lower animals the ramifications have been 
followed to disc-like expansions or other corpuscular terminations, but 
in the human epidermis it is not clear that they end otherwise than in 
intercellular threads. Branching cells in the epidermis were brought under 
notice by Langerhans, but are generally thought to have no connection 
with nerves. More probably they are wandering corpuscles seeking the 
surface. ORGANS OF COMMON SENSATION. 
79 
Touch-corpuscles of Wagner or of Meissner. These are bodies found 
in papillae of the corium, most abundantly in the hand and foot, especially 
on the flexor aspects of the fingers and toes, and also in the skin of the 
nipple, the red borders of the lips, the tip of the tongue, and the tarsal 
part of the conjunctiva. Each occupies a considerable bulk of the centre 
Fig. 75.—Vertical Section of Skin of Sole treated 
with gold, showing numbers of cells of Langerhans, 
but no nerves. (Kolliker.) 
Pig. 76.—Touch-Corpuscles very highly 
magnified, with two medullated nerve-fibres 
entering it. (Kolliker.) 
of the papilla in which it is contained, and has the appearance of a firm 
oval or pyriform mass, on the surface of which one or two nerve-fibres 
lose their medullary sheaths. Within them there are numbers of nucleated 
corpuscles {touch-cells), transversely elongated, with septa between them; 
and the axis-cylinder of the nerve breaks into branches which pass in 
between the cells. Similar organs, with a small number of more distinct 
transversely-arranged touch-cells, have for a long time been known on 
the edges of the bills of ducks and other birds, corpuscles of Gmndry or 
of Merkel. 
End-bulbs of Krause. These are found in the sclerotic conjunctiva, 
mucous membrane of the cheeks and epiglottis, and the papillae of the 
tongue, glans penis, glans clitoridis and nymphae; also in the synovial 80 
GENERAL ANATOMY. 
membranes of the joints of the fingers. They are rounded bodies, with 
Fig. 77. 
Fig. 78. 
Fig. 79. 
Fig. 77.—Rounded End-Bulbs from human conjunctiva. A, With five nerve-fibres 
entering; B, vertical section through the same end-bulb, showing the touch-cells and 
sections of nerves, and to the right conjunctival epithelial cells ; C, end-bulb with beauti- 
ful winding of the nerve-fibres. (Toldt.) 
Pig. 78-—Cylindrical End-Bulb from conjunctiva of calf. (Toldt.) 
Fig. 79.—Pacinian Body, human, a, Core ; h, c, transverse and longitudinal connec- 
tions between the capsules; d, separated of capsules ;/, nuclei; g, adherent 
connective tissue ; k, nerve-fibre inside the core ; I, its extremity; n, a branch. (Kolliker.) 
a nucleated sheath, containing within them delicate, unwalled, nucleated 
corpuscles, and receiving one or more nerve-fibres which coil round them. ORGANS OF COMMON SENSATION. 
81 
These bulbs are comparable in this respect with Wagner’s touch-corpuscles; 
and there are some of them, called genital corpuscles, on the glans penis 
{pv.), more nearly allied to touch-corpuscles; but there are others, the 
cylindrical bulbs of Krause, which have an axis-cylinder passing up the 
centre, and are in that respect comparable with Pacinian bodies. 
Pacinian bodies. These are bodies which were observed by Yater, 
and distinctly described by Pacini. They may be as much as inch 
in length, but are more frequently considerably smaller. They occur most 
abundantly on the digital nerves on the front of the hand, lying among 
the grains of fat in the subcutaneous tissue. They are found also in the 
walls of joints and bursae, and in other situations, as behind the head of 
the pancreas. They are often seen to great advantage in the mesorectum 
of the cat. They are oval laminated bodies, developed round a single 
nerve-fibre. The successive laminae or capsules are separated by endothelial 
layers, and are closely connected at the base with the primitive sheath of 
the nerve-fibre. The nerve-fibre, piercing into the interior of this system 
of capsules, loses its medullary sheath, and on entering the innermost 
capsule becomes surrounded by a somewhat granular substance, the core, 
and ends towards the further extremity of the core in a single knob, or 
after bifurcation or slight branching. 
MUCOUS MEMBRANE. 
This is the name given to the lining membrane of internal passages 
freely communicating, directly or indirectly, with the outside, and pouring 
out on their surface moisture containing a larger or smaller quantity 
of mucus, a colloid substance whose characteristic constituent, named 
mucin, contains nitrogen, but no sulphur, and is completely soluble in 
lime water. It is liable, especially under the influence of catarrh, to 
be loaded with corpuscles of variable size. These are simply migratory 
corpuscles which have made their way to the surface. There are three 
great tracts of mucous membrane—the alimentary, the respiratory and the 
genito-urinary. Mucous membrane, like integument, presents an epithelium. 
This is of a stratified scpiamous description from the oral aperture to the 
entrance of the stomach, and in some other localities, as the urethra, the 
urinary bladder and the conjuctiva; while it is columnar from the entrance 
of the stomach as far as the deep sphincter ani, ciliated in the respiratory 
tubes, and of various characters in other places. The mucus from which 
the membrane is named is undoubtedly poured out by more than one 
kind of epithelium, and in some places, as in the mouth, the bronchi 
and the biliary passages, there are special glands which have a mucous 
secretion. The mucous membrane proper, subjacent to the epithelium, 
presents, close to the surface, a homogeneous, gelatiniferous matrix, 
rich in bloodvessels, and in its deeper part may pass rapidly into 82 
GENERAL ANATOMY. 
ordinary fine connective tissue with few, if any, capillaries devoted 
specially to its nourishment. But in the case of the stomach and 
intestines there is a distinct definition of the deep limit of the mucous 
membrane afforded by a thin but firm muscular layer, the lamina 
muscularis mucosae, and the whole structure superficial to this is highly 
vascular for the supply of simple tubular follicles supported by retiform 
tissue. 
It may be noted, in comparing mucous membrane with integument, 
that while epidermis is uniformly epiblastic in origin, and the hypoblast 
of the embryo is entirely devoted to the development of epithelium of 
mucous membrane and its glands, the genito-urinary epithelium is in part 
mesoblastic in origin, and that of the conjunctiva, lachrymal duct, nares, 
palate, gums and lining of the cheeks are epiblastic. Nor does the 
tendency to become dry or to pour out mucus on abnormal exposure 
depend on the source of development, seeing that in such circumstances 
the vagina becomes dry, while the urinary bladder pours out mucus ; and 
in the case of the conjunctiva the tarsal part remains moist, while the 
corneal epithelium becomes dry and opaque. 
EMBRYOLOGY 
OR GENERAL DEVELOPMENT. 
The young animal owes its origin to the union of germs or essential 
products of reproduction of the male and female parent. The male germ 
is the spermatozoon, the female germ is the ovum. 
The human spermatozoon is a body with a firm pyriform head comparable 
with a nucleus, and a fine thread-like tail which propels it with an eel-like 
movement, the whole reaching to inch in length. 
Ova, at a certain stage of their development, have a general community 
of structure, being in fact largely developed nucleated corpuscles, provided 
with protoplasm, nucleus, nucleolus and cell-wall. The protoplasm is 
termed the vitellus or yelk, the nucleus the germinal vesicle, the nucleolus 
the germinal spot, and the cell-wall the vitelline membrane (zona pellucida or 
zona radiata). But while this comparatively simple condition is retained 
in the ova of many invertebrate animals and in Amphioxus, there is 
added to the protoplasm or formative yelk in the ova of all vertebrata 
above Amphioxus a greater or less amount of nutrient yelk in globules 
and granules containing the characteristic substance lecithin and more or 
less uniformly diffused in the protoplasm or accumulated in mass. The 
abundance, paucity or absence of nutrient yelk leads to the enormous 
differences of size in the ova of different animals, and also to great 
apparent differences in the process called cleavage which is the first to 
take place after impregnation. In non-mammalian vertebrata, excluding EMBRYOLOGY. 
83 
Amphioxus from the term, the formative yelk accumulates on the upper 
side or animal pole, and the ovum has been termed telolecithal. In osseous 
fishes and amphibians the formative yelk passes round on the surface of 
the nutritive yelk. In ova of the largest sort, such as those of birds, it is 
more distinctly confined 
to a limited area called 
the cicatricula, about |-th 
inch in diameter in the 
hen’s egg, marked by a 
paler colour of the yelk; 
and it is within this area 
that the changes prior to 
and immediately succeed- 
ing impregnation take 
place. These distinctions 
deserve attention even from 
the human anatomist, as 
many details of embryology 
are conveniently studied 
in the ova of amphibians 
and birds. 
Maturation of ovum. 
After attaining its full 
size, the ovum undergoes 
changes preparatory to im- 
Pio. SO.—Ovum of Rabbit, a, Follicular cells; b, zona pellu- 
cida; c, germinal vesicle; d, network within it; e, germinal 
spot; /, yelk. (Hertwig, after Waldeyer.) 
pregnation, which have 
been specially studied in holoblastic invertebrate ova, such as those of the sea- 
urchin and the star fish. The germinal vesicle, which has approached towards 
one side of the ovum, begins to lose its regular form ; and first the germinal 
Pig. 81.—Changes of Germinal Vesicle in Asteeias Glaoialis. A shows a protrusion 
of protoplasm with rays piercing v, the germinal vesicle, while the germinal spot has 
become divided into two substances, viz.,pn, paranuclein, and n, nuclein. B shows v, 
the germinal vesicle shrivelled, its membrane gone ; g, the germinal spot dwindling; and 
sp, a nuclear spindle fully formed. (Hertwig.) 
spot, and then the germinal vesicle disappears. While this is going on, two 
starlike arrangements, united to form the poles of a spindle, make their 
appearance in connection with the germinal vesicle, and one pole of the 
spindle turns round till it comes in contact with the surface of the yelk and 84 
GENEEAL ANATOMY. 
is gradually separated by constriction from the other half, constituting what 
is called the first polar body. The remaining half of the spindle is again 
Pig. 82.—Formation of Polar Bodies in Asterias Glacialis. I. The nuclear spindle, 
sp, approaches the surface. 11. One half the spindle is projected in an elevation. 111. 
The elevation is separated as first polar body, pi, and the inner half of the original 
spindle becomes again a complete spindle. IV. This spindle is protruded in one half its 
extent. V. The protrusion becomes the second polar body, p'2. VI. The deep part of the 
spindle becomes the nucleus, n, of the ovum. (Hertwig.) 
converted into a complete spindle, and a second time one half is pro- 
jected from the surface of the yelk and separated to produce the second 
polar body. From the half of the spindle which remains within the yelk 
Fig. 88.—Impregnation, Asterias Glacialis. A, An elevation occurs opposite the 
nearest spermatozoon ; B, the elevation of the yelk and the head of the spermatozoon are 
pressed together; C, the spermatozoon enters. (Hertwig, after Fol.) 
after the extrusion of the second polar body, a small nucleus is formed 
which retires towards the centre of the yelk, and remains as the nucleus 
of the unimpregnated ovum, the female pronucleus of v. Beneden, a struc- 
ture comparable in size rather to the germinal spot than to the germinal 
vesicle.1 
1 The polar bodies have been made to play an important part in the theories of 
Balfour and Weismann, as so much extruded material carrying with it certain powers 
of growth, whether sexual, hereditary or other. But the polar bodies, are not 
excreted products; they have a structural origin distinctly pointing them out as 85 
EMBRYOLOGY. 
Impregnation, as observed in starfishes and threadworms, is effected 
by a single spermatozoon which outruns the others. The surface of the 
yelk rises to meet the spermatozoon; the spermatozoon pierces into the 
interior, and loses its lash, while its head increases in size. It is now 
called the male pronucleus ; it becomes the centre of a radiate arrangement 
of the yelk, rapidly approaches the female pronucleus and becomes fused 
Fig. 84.—Impregnated Ovum of Sea-Urchin. The male and female pronucleus, m and f., 
approach. (Hertwig.) 
with it, to form the nucleus of the impregnated ovum. In mammals a 
number of spermatozoa pierce the zona pellucida. 
Cleavage, The nucleus of the impregnated ovum becomes the starting- 
point of a series of multiplications of nucleated corpuscles by fissiparous 
division, known as cleavage or segmentation, which may be equal or unequal. In 
unequal segmentation the first cleft extends from one spot, and the process 
goes on most rapidly in that neighbourhood. In amphibia and in certain 
fishes the segmentation, though unequal, involves the whole ovum, which 
Fig. 85.—Stages of Cleavage. Ova of hitch from Fallopian tube. Spermatozoa cling 
to the zona pellucida. 1, Shows division of yelk into two masses, as also the two polar 
bodies; in 4 the morula stage is reached. (Kolliker, after Bischoff.) 
is therefore classified, like ova undergoing equal segmentation, as holohlastic. 
But in the teleosteal and elasmobranch fishes segmentation is partial, not 
including the whole circumference, and the ovum is called meroblastic. The 
organisms. They are aborted ova, as pointed out by Mark, Butschli, Boveri and 
Hertwig (Hertwig, EniwicMungsgeschichte, 4th edition, p. 40). Each spindle is an 
organism dividing into two ; the process is therefore an intervention of two genera- 
tions between the original female germ and that which undergoes impregnation. 
Recognized parthenogenetic ova have only one polar body ; but they are not the only 
ova with this peculiarity, for Amphioxus is found by Sobotta (1895) to have likewise 
only one. 86 
GENERAL ANATOMY. 
extreme of the meroblastic arrangement is exemplified in birds, segmentation 
in them being confined to the small germinal disc or cicatricida. In 
mammals, monotremata excepted, the ovum is holoblastic and segmentation 
is equal. The two nuclei derived by mitosis from the first nucleus seek 
the centres of the masses around them. The process is repeated in each 
of these masses, and again in their progeny, so that the two unwalled 
nucleated corpuscles arising from the first division of the yelk are con 
Fig. 86.—Amphioxus. A, Germinal membrane: c, cleavage cavity; a and v, animal 
and vegetative cells. B, Gastrula: e, epiblast; h, hypoblast; i, primitive intestine ; b, 
blastopore. C, Transverse section of embryo with five mesoblastic somites ;e, epiblast; 
d, medullary plate; m, mesoblast; ch, notochord; I, wall of lateral pouch which is 
converted into half the coelom ; i, intestinal cavity ; **, entrances to coelom afterwards 
obliterated ; h, hypoblast. D, Longitudinal section about same period : msl, mss, first 
and fifth mesoblastic somites; o, hollow of mesoblastic somite ; n, neural canal; cn. 
canalis neurentericus ; other letters as before. (Hertwig, after Hatschek.) 
verted into four, the four into eight, the eight into sixteen, and so on. 
In this manner is formed what is called the morula or mulberry mass. 
Within the morula a cavity is formed by the determination of corpuscles 
to the surface, accompanied in the case of mammals with an absorption 
of fluid leading to considerable enlargement of the ovum. The resulting 
condition is known as the blastoderm or germinal membrane. 
Formation of layers and embryo. In Amphioxus, a development starting 
from this stage takes place, more easily comparable with what has been EMBRYOLOGY. 
87 
seen in the invertebrate form Sagitta than with what is found in the 
vertebrata, but deserving attention from the manifest affinity of Amphioxus 
to vertebrata, and because it throws light on vertebrate development. 
The corpuscles of the blastodermic membrane are arranged one cell deep in 
a complete sphere. One half of the sphere becomes invaginated within 
the other so as to produce the cuplike form known to naturalists as the 
gastrula, the inclosing half constituting the epiblast or ectoderm; and the 
invaginated part the hypoblast or entoderm. The mouth of the gastrula 
becomes contracted into a small aperture, the blastopore. The spinal cord 
is formed from before backwards out of a portion of the ectoderm, which 
is folded into a groove and then into a cylindrical canal with the blasto- 
pore situated at its posterior end, so as to make a continuous passage 
from the central canal of the spinal cord to the cavity of the gastrula, 
the neuventeric canal, destined to be subsequently obliterated. The entoderm 
becomes divided into four parts, viz. : (1) beneath the spinal cord, a 
dorsal strip which is converted into the notochord ; (2) the digestive tube 
running down the middle; and (3 and 4) two lateral pouches given off 
at the fore part or blind end of the elongated gastrula, and expanding as 
they pass backwards, so that they come together on the dorsal and 
ventral aspect of the digestive tube. Each of these lateral pouches 
becomes shut off from the digestive tube and is flattened out so as to 
present two layers, a visceral and a parietal, and also is divided into a 
dorsal and ventral portion, the dorsal part being broken up from before 
backwards into a series of segments, the mesoblastic somites, while the 
ventral part unites with its fellow and bounds the coelom or body-cavity. 
Thus, the whole mass resulting from cleavage is engaged, in Amphioxus, 
in the formation of the embryo. 
All other Vertebrata differ from Amphioxus, in respect that at no time 
does the blastoderm present the simple gastrular form. But in all of 
them, the blastoderm passes into a bilaminar condition, comparable with 
that produced by invagination in Amphioxus; and in all a blastopore 
can be made out, whose correspondence with that of Amphioxus is 
evidenced by its being situate behind the subsequently appearing medullary 
groove or first indication of the cerebro-spinal axis, in such a position that, 
even in mammals, the representative of a neurenteric canal has been traced. 
In the bird’s egg, before hatching, the cicatricula exhibits a clear part, 
area pellucida, which presents an ectoderm of vertically elongated and 
an entoderm of flattened corpuscles, and is bounded peripherally by a 
thickened germinal wall or area opaca. Already also, there is to be seen, 
at the margin toward which the caudal end of the embryo is to be 
directed, a cresentic thickening, the sickle, from the front of which, 
when hatching commences, a knob projects, with a groove appearing 
behind it. In a few hours there is formed from the knob a longer 
thickening, the primitive streak, with a depression, the primitive groove, 
running down the middle. Subsequently the medullary folds, joined GENERAL ANATOMY. 
88 
together in front and bounding the medullary groove, appear in a thickened 
part in the middle of the cicatricula, and grow backwards, pushing hack 
the primitive streak behind them. 
Fig. 87.—Two Successive Stages of Area Germinativa of hen’s egg in the first hours 
of hatching. A. y, Yelk ; ag, area germinativa ; es, embryonal shield ; s, sickle ; sk, 
sickle-knob. B. o, Area opaoa ;p, area pellucida; g, primitive groove ; s, sickle. (Hertwig, 
after Koller.) 
In the mammalian ovum, the blastodermic membrane is spherical, and 
presents a single layer of corpuscles; but, unlike the arrangement described 
in Amphioxus, it has adherent to its deep surface at one part a mass of 
other corpuscles of rounded form, differing from those which form the 
membrane in being granular instead of clear. This granular heap becomes 
flattened out, and, in the part where it adheres, the area embryonalis 
appears as a white thickening. The most deeply placed corpuscles now 
become distinguished as a single layer of flattened cells, the entoderm • 
Fig. 88.—The Blastoderm, uterine 
ovum of rabbit, a, Zona pellucida ; 
h, blastoderm ; c, heap of cleavage- 
corpusoles. (Kolliker, after Biachoff.) 
Fig. 89.—Area Embryonalis 
of rabbit, eight days after im- 
pregnation. ary, Boundary of 
area ; pr, primitive streak and 
groove. (Kolliker.) 
while the remainder, the ectoderm, distinct from the entoderm, consists of 
cubical cells, covered at first with others of flattened form, Bauber’s layer, 
destined soon to disappear in a manner still disputed. The complete 
separation of ectoderm and entoderm gradually extends round the whole 
ovum. The thickening of the area embryonalis belongs entirely to the 
ectoderm. At first circular, it elongates to an ovoid form, and from its 
narrower extremity a primitive streak extends forwards, in connection with 
whose expanded hinder end a minute blastopore has been observed (Heape). 
In front of the primitive streak the medullary folds appear as in the bird. EMBRYOLOGY. 
Subsequently, in all vertebrates, an intermediate layer appears between 
the ectoderm and entoderm, and thus there come to be three layers of 
the embryo, known as epiblast, mesoblast and hypoblast The mesoblast 
makes its apjDearance in cqnnection with the primitive streak, and the 
primitive streak is epiblastic. But epiblast and hypoblast are closely 
united in the middle line, and it is difficult to determine the precise 
source of the rounded corpuscles of which the mesoblast is composed. 
Fig. 90.—Transverse Section through the middle of Primitive Streak of Embryo 
Chick of the stage shown in Fig. 86, B. e, Epiblast; h, hypoblast; to, mesoblast; 
g, primitive groove ; s, primitive streak ; tv, boundary wall of germinal area. (Hertwig, 
after Roller.) 
The theory of Hertwig, according to which the mesoblast represents the 
lateral pouches of the entoderm of Amphioxus, is supported by researches 
on Triton, which show that in that animal the mesoblast, beneath the 
blastopore, originates as a pair of flattened sacs whose walls form a 
visceral and a parietal layer. The speedy separation of the mesoblast 
more or less completely into two layers in all vertebrates is comfirmatory 
Fig. 91.—Longitudinal Sections through Ova op Triton, showing A, the commence- 
ment of gastrular invagination; B, completed gastrulation. e, Epiblast; h, hypoblast; 
m, mesoblast; i, primitive intestine; b, blastopore ; %>, yelk-plug of blastopore; d and v, 
dorsal and ventral lips of blastopore; y, yelk-cells; c, cleavage-cavity or cavity of 
germinal membrane. (Hertwig.) 
of the Hertwig view. Bat not the whole of what is included in the 
term mesoblast, as generally understood, is thus accounted for, according 
to the Hertwig theory. Beyond the outline of the embryo proper, separ- 
ated from it by a clear space, area pellucida, there is, in the germinal wall 
in the chick, and adherent to the entoderm in the mammal, a zone of 
granular corpuscles sending out branches and giving origin to the first 90 
GENERAL ANATOMY 
blood-corpuscles as well as to the walls of bloodvessels; and these extend 
inwards and form the area vasculosa. Hertwig so far adopts a view 
previously put forward by His as to 
consider this growth independent of 
the parietal and visceral layers of the 
mesoblast, and that it is the sole 
source of the blood, connective tissues 
and skeleton; and he gives it the 
name mesenchyma. According to this, 
it is only the epithelia, glands, 
bounding surfaces, nervous system 
and muscles that are developed from 
the three recognized layers, while the 
bloodvessels, connective tissues and 
skeleton have a peripheral origin. 
Certainly it is a fact and worthy of 
note that the blood and structures 
connected with the development of 
Fig. 92.—Transverse Section of Ovum of 
Triton passing through the blastopore 6. 
ml and m 2, Parietal and visceral walls of meso- * 
blastio sac ; e, epiblast; p, yelk-plug; y, yelk- 
cells ; h, hypoblast; i, intestine. (Hertwig.) 
the blood appear in a centripetal manner contrasting with the centri- 
fugal origin of the form and special organs of the embryo 
The medullary folds, as already indicated, are two elevations of epiblast 
united in front, which elongate backwards and turn over to unite one 
Fig. 93.—Transverse Section through a Human Germinal Area 
with open medullary groove, in the vicinity of the neurenteric canal. 
e and h, Epiblast and hypoblast; ml and m 2, parietal and visceral 
-laminae of mesoblast; I, lip of primitive groove, y. (Hertwig, from 
Graf Spee.) 
Pig. 94.—Embryo Chick 
and Germinal Area during 
first day of hatching. Fresh, 
vitelline membrane not re- 
moved. a, Anterior limiting 
sulcus ; m, united medullary 
folds ; pr, primitive streak 
and groove. 
with the other in the middle line and convert the furrow between them, 
the medullary groove, into a closed cylinder, the rudimentary cerebro-spinal 
axis. Immediately after closure, the fore part of the cylinder exhibits three 
dilatations, the first, second and third cerebral vesicles, which go to form the 
brain, while, on the sides of the foremost, two lateral lobes appear, the 
primary optic vesicles, destined to take part in the formation of the eyes. EMBRYOLOGY. 
91 
The remainder of the cylinder is developed into spinal cord. At the edge 
of the medullary groove, as it closes and becomes separated from the rest 
Fig. 95.—Chick and Ger- 
minal Area of about 24 
Hours. Fresh. The medul- 
lary folds more extensively 
united in the head. The four 
first segments of the neck 
distinct, with the medullary 
folds at their level still open. 
Beneath this, the part in 
which succeeding segments 
have to be developed, and, 
still lower, pr, the primitive 
groove. 
Fig. 96.—Forepart of Chick 0f36 Hours. Alive. 
A, Dorsal view : a, front of optic commissure, 
with first cerebral vesicle and primary optic vesi- 
cles above it, and second cerebral vesicle below ; 
6, constriction between second and third cerebral 
vesicle ; c, auditory pit opposite the division be- 
tween the fourth and fifth compartments of the 
third cerebral vesicle ;d, heart; e, first meso- 
blastic somite. B, Ventral view; a, bifurcating 
flexed extremity of first cerebral vesicle ; b, noto- 
chord ; c, auditory pit; d, heart. 
of the epiblast, there is an everted margin whence spring the nerves and 
spinal ganglia. 
The notochord. Beneath the medullary groove, immediately after its 
commencement, a roddike structure makes its appearance in the middle 
line, dimly visible from the surface, but seen in section to be deeply 
placed. This is the notochord or chorda dorsalis, round which the bodies 
Fio. 97.—Transverse Section of Embryo Rabbit, showing—ch, commencing notochord 
continuous opposite * and * with h, the hypoblast, and m 1 and m 2, the parietal and 
visceral layers of the mesoblast. (Hertwig, from E. van Beneden.) 
of the vertebrae are afterwards developed. It is at first continuous on 
each side with both hypoblast and mesoblast; but it becomes rapidly 
separated from the hypoblast and converted into a roddike structure 
between the right and left halves of the mesoblast. Posteriorly, it is 
continuous with the epiblast at the blastopore or neurenteric canal. The 92 
GENERAL ANATOMY. 
notochord becomes surrounded by a sheath, from which are continued the 
membrana reuniens superior round the neural canal, and the membrana 
reunions inferior round the visceral cavity • and thus is formed the mem- 
branous vertebral column. In fishes and amphibians it undergoes further 
development, its texture presenting large membranous vesicles or cell-walls 
in juxtaposition, like the cellulose cell-walls of plants. In the lamprey 
and sturgeon it is developed into a large cylindrical structure in a stout 
sheath of circular and longitudinal fibres. In most fishes it has an in- 
terrupted form in the adult, constituting the jelly between the vertebral 
bodies. In mammals it entirely disappears, except so far as it takes part 
in the formation of the central parts of the invertebral discs. 
Zones and segments. To the sides of the neural axis, and passing 
round it in front, there soon make their appearance two zones, the paraxial 
and the lateral, distinguished by a difference in the development of the 
mesoblast. The mesoblast of the paraxial zone, 
the dorsal plate, is thick and separated by a 
deep and a superficial groove from the lateral 
zone. That of the lateral zone, the lateral 
plaie, splits into a superficial or parietal and a 
deep or visceral layer, between which is the 
space constituting the coelom or body-cavity, 
afterwards divided into the sacs of the pericar- 
dium, pleura and peritoneum. The superficial 
or cutaneous layer forms, with the cuticular 
epiblast and the subsequently intruding muscular 
layer, the somatopleure; while the deep is the 
musculo-intestinal layer, and adhering to the 
hypoblast forms the sptlanchnopleure, from which 
the digestive tube is developed. After the first 
day’s hatching in the chick, and about the eighth 
day after impregnation in the rabbit, there appear 
in the paraxial zones, behind the part destined as 
brain, a pair of dense patches, rapidly followed, 
as development proceeds, by successive pairs 
behind them, till the appearance is given of a 
double range of square blocks on the dorsum of 
the embryo. These are the protovertebrae of older 
writers, more properly termed mesoblastic somites. 
In the newt it is made out very distinctly not only 
that each of these consists of a hollow inclosed 
Fig. 98.—Live Chick of 48 
Houbs. a, In front of second 
primary cerebral vesicle ; b, be- 
tween the second and third ; c, 
auditory pit between the fourth 
and fifth compartments of the 
third cerebral vesicle ; d, heart; 
e, opposite the first mesoblastic 
somite, that of the occipito- 
atlantal segment; /, thalamen- 
cepbalon ; g, hemisphere ; h, 
olfactory pit. At the lower part 
the primitive streak and groove 
are still visible. 
by a single layer of cells, but that the hollows are originally continuous 
with the coelom, and their walls with the two layers of mesoblast bounding 
it. This is not, however, in all vertebrates so apparent. In both birds 
and mammals each somite consists of a dense mass of corpuscles, and in 
mammals the hollows are minute. These somites are specially concerned EMBRYOLOGY 
93 
in the formation of the voluntary muscles. While in some animals this 
takes places in greater part from the lower and inner walls, in birds it is 
principally from the roofs that the muscle-plates are formed. The material 
for the formation of the bodies and arches of 
the vertebrae lies to the inside of the meso- 
blastic somites, and that for the transverse 
processes and costal arches forms a bar beneath 
the fore part of each muscle-plate, while the 
spinal ganglia, though developed, as above 
noted, from epiblast, come to occupy a posi- 
tion beneath the hinder part of each muscle- 
plate ; and thus all these parts were supposed 
by Remak to be developed from the proto- 
vertebrae. Perhaps it were well to include 
them all in such a term as primitive segment, 
and to reserve the expression mesoblastic 
somite for the structure which, so far as per- 
sistent, is converted into muscle. 
It has been found in elasmobranch fishes 
that mesoblastic somites are not only developed 
in series backwards from the first pair, which 
constitutes the first muscular segment of the 
Fig, 99.—Embryo Rabbit op 8 
Days and 4 Hodrs, a, Medul- 
lary groove ; &, remains of primitive 
streak ; c, axial zone with two 
mesoblastic somites ; d, paraxial 
zone ; ee, first indications of heart. 
(Kolliker.) 
neck, but also forwards in the head. As many as nine of these have been 
described, the foremost being alleged to form the rectus superior, rectus 
inferior and obliquus inferior muscles of the eyeball, the second the 
obliquus superior, the third the rectus externus. The fourth, fifth 
Fig. 100.—Transverse Section through Dorsal Region of Embryo Chick op 45 Hours. 
a, Medullary canal; b, mesoblastic somite ; c, Wolffian duct ; d, somatopleure; 
e, pleuroperitoneal cavity ; /, aorta ; g, bloodvessels ; h, splanchnopieure ; k, notochord. 
(Hertwig, from Balfour.) 
and sixth are said to disappear, while the three hindermost go to form 
the muscles uniting the head to the shoulder-girdle (Milnes Marshall). 
Further, in elasmobranchs, the coelom has been traced forwards into the 
head, in the visceral arches hereafter to be described; and the walls of these 
prolongations are supposed to form the muscles of mastication and the 
branchial muscles. But before forming a final judgment with reference 94 
GENERAL ANATOMY. 
to the muscular segments of the head, further information is probably 
required. Thus it would be desirable to know the relation of the 
muscular segments overlying the skulls of the pleuronectid fishes 
to the segments of the skeleton, and to the muscles of the eyes 
and jaws. 
Parietes and mucous tract. It will already have been seen how largely 
the formation of organs is due to the folding of blastodermic layers with 
free surfaces. The freeing of the outline of the embryo from the rest of the 
ovum, as well as the inclosure of 
the viscera, is also due to folding 
of these layers. By local extension 
of superficies, the blastoderm is 
folded in under the margins of the 
cerebral vesicles; and by that means, 
as well as by its own growth, the 
fore part of the embryo is projected 
free into a hemispherical depression, 
the anterior limiting sulcus, long 
before the hinder part has been 
laid down. But gradually the ex- 
tremities of this sulcus are carried 
backwards, and ultimately the coc- 
cygeal end and sides of the embryo 
are surrounded, and the somato- 
pleure gathered together both later- 
ally and longitudinally, so as to 
complete the walls of the body 
and converge to a narrow neck 
at the umbilicus. Meanwhile the 
splanchnopleure, consisting of the 
hypoblast, and deep layer of the 
mesoblast, is folded in, after the 
Pig. 101.—Human Embryo, -t6-, prior to bending 
forward of brain at back of fourth ventricle, a, 
Maxillary lobe, and below it the mouth bounded by 
the first or mandibular arch with the first three 
branchial clefts beyond ; b, heart; c, umbilical vesicle 
torn across ; d, torn edges of amnion ; e, allantois ; 
/, tufts of chorion destined to become placental. 
(After His.) 
same fashion but more closely, and the part in front forms a tube, the 
fore gut, extending forwards and ending blindly beneath the third cerebral 
vesicle, while the part behind forms a similar cul-de-sac, the hind-gut. Thus, 
the digestive-tube is gradually pinched off from the yelk-cavity, of whose 
walls it originally formed part. The neck of communication remains as 
the vitelline duct, and the yelk-sac beyond is in mammals known as the 
umbilical vesicle. The vitelline duct soon becomes elongated and closed, 
being thus converted into a cord by which the omphalo-mesenteric vessels 
are conveyed to and from the walls of the yelk-sac. Neither mouth nor 
anus is a primary opening. There is every reason to believe the blastopore 
or neurenteric canal to be phylogenetically the one communication of the 
digestive cavity with the exterior; but, however that may be, the oral and 
anal apertures are of late appearance and both of them produced by rupture EMBRYOLOGY. 
95 
of epiblast and hypoblast at points somewhat removed from the terminal 
extremity of the gut. The vitelline duct comes off from the digestive tube 
in the course of the small intestine, and the spot is sometimes indicated in the 
adult subject by the occurrence of a diverticulum situated at a distance 
varying from four feet to eighteen inches from the ileo-colic valve. The 
respiratory tubes and the biliary ducts both begin from the fore-gut as mesial 
ventral culs-de-sac, dividing into right and left branches and continuing to- 
ramify. Arising from the ventral aspect of the extremity of the hind-gut is 
Fig. 102.—Transverse Section through Duck Embryo with about Twenty-four 
Primitive Segments, a, Amnion ; b, somatopleure; c, splanchnopleure ; d, muscle-plate; 
e, spinal ganglion ;/, spinal cord ; g, aorta ; h, hypoblast; i, cardinal vein ; wd, Wolffian 
ducts ; st, segmental tube ; ch, notochord. The proto-vertebra of older writers included 
the tissue between d and g in which vertebral elements are found, and through which 
nerve-roots pass. (Hertwig, from Balfour.) 
another hollow projection, the allantois. The allantois forms a vesicular 
expansion which in birds and reptiles continues membranous and extends 
beneath the shell of the egg, carrying with it vessels which perform the 
respiratory function till the animal is hatched. In mammals it is elongated 
and divided by hour-glass contraction into an extra-embryonic and intra- 
embryonic dilatation separated by an elongated cord, the urachus. The intra- 
embryonic dilatation remains as the urinary bladder; the extra-embryonic 
part, projected at the umbilicus, retains for a while its cavity, but owes 
its importance to its mesoblastic layer being spread out in contact with 
the uterine wall, carrying with it bloodvessels from the embryo, and 
rapidly developing the foetal part of the placenta, which furnishes the 
means of intra-uterine respiration and nutrition. GENERAL ANATOMY. 
Wolffian bodies and middle-plates. In the superficial groove between 
the paraxial and lateral mesoblast, when already the split for the coelom 
exists, but before the walls of the embryo are folded in, a cylinder of 
corpuscles which speedily becomes tubular makes its appearance, the 
Wolffian duct, connected with the Wolffian body or temporary renal organ 
discovered by the pioneer in embryology, C. F. Wolff (1759). This 
duct grows backwards with the embryo, and ultimately terminates where 
the allantois springs from the hind-gut. There is difference of opinion 
as to the source whence it is derived, whether mesoblastic or epiblastic, 
but it has been observed as a solid cord in conjunction with the epiblast in 
one section, while, in another further forward it was continuous with the 
mesoblast, and distinct from epiblast; and this condition has been shown 
to me by Mr. J. F. Gemmill. The epiblastic, therefore, is the prior connection. 
On the deep side of the Wolffian duct, the lateral mesoblast projects inwards 
so as to form with its neighbour of the opposite side, underneath the meso- 
blastic somites and notochord a mesial mass, the middle ffiate (Eemak) or 
intermediate cell-mass; while, beneath this, the body-cavity projects inwards 
so as to separate the middle-plate by mesentery from the intestine. 
In this middle-plate, besides the great vessels (which, according to His 
and Hertwig are mesenchymal), there are developed the primitive renal 
organs, occupying nearly the whole length of the embryo, and divided 
into three different organs with very different histories, viz., the head- 
kidneys or fore kidneys, the Wolffian bodies and the hind kidneys. In 
the formation of these organs, two independent sets of structures take part, 
besides the Wolffian duct, viz., glomeruli and tubules. The tubules, some- 
times termed segmental, are transverse, arranged in correspondence with 
the primitive segments, and start from the body-cavity. The glomeruli 
are vascular arrangements of the same sort as the glomeruli of the adult 
kidney, and dip into expansions in the course of the tubules. Three or 
four of the foremost glomeruli dip into hollows or tubes communicating 
with the end of the Wolffian duct, and constitute the head-kidney or 
pronephros. The greater extent of the organ constitutes the Wolffian body 
or mesonephros, and shows at first a series of solid growths of the middle- 
plate, which become hollowed out by extension of tubular prolongations 
from the body-cavity, and ultimately open into the Wolffian duct after 
receiving the glomeruli in their course, the part of each tube between 
glomerulus and abdominal cavity disappearing. At first occupying the 
whole length of the visceral cavity, the Wolffian body retreats towards 
the groin, and disappears in embryonic life, leaving only minute vestiges 
in connection with ovary and testis. The hind kidney or metanephros is 
the permanent kidney of birds and mammals, and takes origin from the 
hinder part of the middle-plate, while the ureter is described as given 
off from the hinder end of the Wolffian duct; but the exact details of 
origin, both of kidney and ureter, are still involved in obscurity. 
Muller’s duct is the name given to a duct which in elasmobranch EMBRYOLOGY. 
97 
fishes and amphibia is formed by longitudinal division of the Wolffian 
duct backwards from a point as far forward as the front of the Wolffian 
body; but in reptiles, birds, and mammals it makes its first appear- 
ance at a later date on the surface of the Wolffian body, as an open 
groove whose edges coming together convert it into a tube. Even in 
birds and mammals, however, it is in part of its course very intimately 
connected with the Wolffian duct. Muller’s duct becomes in the female 
the oviduct, but in the male has a mere temporary development, while 
the epididymis and vas deferens of the male are formed from the Wolffian 
duct. The epithelial boundary of the body-cavity does not, over the 
surface of the Wolffian body, become flattened as it does elsewhere, but 
Cerebellum 
Fourth ventricle 
Mesen- 
cephalon 
Auditory vesicle 
Yelk sac 
External ear 
Mandibular arch 
Maxillary lobe 
Thalamen- 
cephalon 
Pineal body 
Hemisphere 
Olfactory pit 
Heart 
Upper limb 
Allantois 
Lower limb 
Mesoblastic 
somites 
Fig. 103.—Human Bmbeyo, y (adapted mostly from Fraser, partly from Allen Thomson). 
is columnar or cubical, and is termed the germinal epithelium. It is from 
the part of the germinal epithelium on the outer border of the Wolffian 
body that Midler’s duct is developed, while from the part on the inner 
border are developed the essential elements of the testicle in the male, 
and of the ovary in the female. (See Development of Reproductive Organs.) 
The head and neck. The first cerebral vesicle is from its earliest 
development turned down into the fossa which separates it from the 
yelk ; and as growth proceeds, the second vesicle lies over the extremity 
of the fore-gut, while the first vesicle is turned round so as to point back- 
wards beneath it. The heart, when it appears, likewise forms a prominence 
on the ventral aspect of the fore-gut; and between this and the first cerebral 
vesicle is left a depression called the stomodaeum, where epiblast and 
hypoblast are in contact, and afterwards rupture to form the primitive 
mouth. In front of the place of rupture (i.e. proserial to it) the stomodaeal 
epiblast retains contact with the base of the brain, close behind the optic 
commissure, and is gradually shut off from the surface; while another 98 
GENERAL ANATOMY. 
pouch projects from the brain, so as to lie ultimately behind the epiblastic 
pouch; and these two pouches together form the pituitary body. 
The stomodaeum and the heart become separated, and a series of five 
arches of mesoblast, commencing as lateral thickenings and becoming 
completed in the middle line, make their appearance between. These are 
known as the visceral or post-stomal arches, and appear in pairs, the nearest 
to the head being first and largest, and completing before the others the 
arch by union of the right and left process. This first arch is called 
mandibular, and constitutes the part of the face in which the lower jaw 
appears. The second is the hyoid, and to it belong the body and small 
cornu of the hyoid bone. To the third belong the great cornua of the 
hyoid bone, while the fourth and fifth are, in birds and mammals, small 
and unimportant. Between the arches are the four visceral clefts, in which 
the mesoblast is absent, and the epiblast and hypoblast come in contact, 
partly by dipping in of the epiblast, but still more by lateral pouching 
of the hypoblast. In water-breathing animals, the communication of the 
pharynx with the integument is completed by rupture of these layers, 
and the slits so formed remain as gill slits. In some fishes the number 
of visceral arches is greater than five, while the mandibular is always the 
foremost. In the higher vertebrates the number of visceral arches is 
always five, and the clefts are unperforated ; but a congenital fistula-like 
opening into the pharynx from behind the jaw occurs as a rare abnor- 
mality, and is to be accounted for by permanent perforation of the 
second, third, or fourth cleft. The first cleft forms from its hypoblastic 
part the Eustachian tube and tympanic cavity, and by the dorsal end of 
its epiblastic depression the external auditory meatus. In connection with 
the ear, there is already, at a date prior to the appearance of the visceral 
arches, another opening to be seen, the auditory pit, situated at the side 
of the third cerebral vesicle; it becomes shut off from the integument at 
a point opposite the base of the second visceral arch, and forms the 
auditory vesicle destined to be developed into the internal ear. So also the 
olfactory pit is an epiblastic depression on the under surface of the first 
cerebral vesicle, not to be confounded with the nostril; and the crystalline 
lens of the eyeball is formed from a similar invagination converted into a 
closed vesicle. 
Dipping down in front of the first cerebral vesicle and the optic 
vesicles the fronto-nasal process is projected, which has on each side a lobe 
called lateral nasal process, and in front a pair of lobes called middle nasal 
processes, while a notch is left on each side between middle and lateral 
nasal processes for the nostril. The middle nasal processes unite to form 
the columella of the nose, the mesial groove of the lip, and, by a pair 
of globular tubercles at their extremity, the intermaxillary part of the 
palate; while at their united base the septum of the nose, with a free 
inferior margin, projects into the roof of the mouth. Both lateral and 
middle nasal processes are met at the side by another process, the maxillary EMBEYOLOGY. 
99 
lobe, which comes forward below the eye, and not only forms the cheek 
and greater part of the upper lip, but sends inwards from its lower edge 
a lamina to meet, in the long run, both its neighbour of the opposite side 
and the septum of the nose, so forming the palate. Thus the nasal cavity 
takes origin altogether independently of the fore-gut, as do also the walls 
of the mouth, with the exception of the tongue. A communication from 
mouth to nose is left between the middle nasal and the maxillary lobe 
in ruminants and some other mammals, and leads in them into the 
supplementary organ of special sense called Jacobson’s organ; while another 
such passage is left between the maxillary lobe and the lateral nasal 
process, and becomes the lachrymal duct. 
The tongue appears first as a mesial eminence, tuherculum impair, 
opposite the first visceral cleft, separated by a furrow from a horse-shoe 
•elevation opposite the succeeding arches, which is called the furcula and 
Fig. 104.—Anterior Wall of 
Mouth and Pharynx of human 
embryo about inch long, a, 
Tuberculum impar; 6, furcula. 
The visceral arches are numbered. 
(After His.) 
Fig. 105.—Floor of Mouth and Pharynx 
of human embryo J inch long, a, Tuber- 
culum impar; 6, epiglottis; c, ductus 
thyreoglossus. (After His.) 
is the rudiment of the epiglottis and aryteno-epiglottidean folds. The 
second and third visceral arches unite on each side, and intrude a narrow 
elevation between the tuberculum impar and furcula to form the root-part 
of the tongue behind the V-shaped mark, while a pit, ductus thyreoglossus, 
deepens down behind the tuberculum impar. The ductus thyreoglossus 
dilates at its deep extremity to form the mesial portion of the thyroid 
body, becomes obliterated in the middle, and at its entrance remains as 
the foramen caecum of the tongue. The thyroid body has, in addition to 
this mesial origin, two lateral origins from pouches of the fourth visceral 
elefts. The thymus is of similar nature to the thyroid, taking origin, in 
mammals, principally, if not altogether, from pouching of the third clefts; 
in birds, from pouching of the third and fourth ; and in reptiles, from the 
second, third and fourth clefts. 
The limbs. The limbs make their first appearance in the chick in the 
third day, and in the human embryo during the third or fourth week. 
On each side beyond the outer margins of the muscle-plates, there is a 
line or ridge beyond which the mesoblast becomes thinner as it is followed 100 
GENERAL ANATOMY. 
in a ventral direction; and on this line the limbs appear as two lobes 
with dorsal and ventral surfaces, their edges directed towards the cephalic 
and caudal ends of the embryo. The 
division into digits is soon indicated 
by four depressions, the thumb and 
great toe being the digits nearest 
the head. The hand and foot are 
both at first sessile, the elongated 
part of the limb being later of making 
its appearance. I would further 
observe that the elbow is from the 
first directed away from the head, 
while the knee is primarily directed 
outwards and acquires its later posi- 
tion by the rotation which turns the 
sole of the foot towards the ground.1 
Commencement of vascular system. 
In birds and mammals, as shown by 
Kolliker, the earliest condition of the 
heart is in the form of two sym- 
metrically placed tubes at the sides 
of the head, already begun in the 
rabbit to appear while yet there 
are only two mesoblastic somites 
developed. These primitive hearts 
lie in the deeper layer of the meso- 
blast of the lateral zone, their hinder 
ends diverging into the area pellucida. 
By the folding of the layers of the 
embryo, they soon meet together on 
the ventral aspect of the fore-gut to- 
form a single tube, which was long 
Fig. 100.—Embryo Babbit of 8 Days and 14 
Hours, -j-. a, Area pellucida; &, anterior 
bounding fold; c, axial zone; d, peripheral 
zone ; e, medullary fold ; /, mesoblastic 
somites; g, h and i, hinder, mid and fore 
brain; k, primary optic vesicle; I, ventricle of 
heart; in, vena omphalomesenterica ; n, aortic 
extremity of heart; o, parietal space around 
the heart; p, wall of throat dimly visible. 
(Kolliker.) 
supposed to be the primitive condition, and actually is so in elasmobranch 
1 Although, in elasmobranch fishes, Balfour has shown that muscle-plates are pro- 
longed into the oiigin of the pectoral fin, it can scarcely be considered as ascertained 
that the proper limb-muscles are derived from them; and, according to Paterson, 
the limbs of birds and mammals receive no prolongations from the muscle-plates. 
Adult anatomy tells us that the nerves of the limbs are derived from ventral divisions 
and that, while, in the upper limbs, they come from five spinal nerves, they assuredly 
belong to a larger number in the lower limbs. The skeleton of the limb (clavicle- 
excepted) probably always starts from the base of the free part, and extends from, 
this outwards into the free part, and dorsally and ventrally within the wall of the 
trunk to form the limb-girdle. These various considerations, together with the want, 
of correspondence of mesial fin-rays of fishes with vertebral segments, are sufficient 
of themselves to excite suspicion that the doctrine that the limbs are developments, 
belonging to special segments of the trunk is without just foundation. EMBRYOLOGY. 
101 
fishes and amphibians. By the formation of bloodvessels in the area opaca 
and area pellucida, outside the embryo proper, 
and of others within the embryo, continuous 
with the anterior end of the cardiac tube, a 
circulatory system is completed. The area vas- 
culosa is bounded peripherally by a sinus or 
•vena termianlis, whence the blood returns by a 
right and left vitelline vein, and reaches by the 
heart the truncus arteriosus. Thence the blood 
is conveyed by a series of right and left branchial 
arches round the fore-gut to fall into a pair of 
primitive aortae which afterwards unite; while 
lateral branches, the vitelline arteries, a single 
pair in the chick, but numerous and slender in 
the mammal, carry the blood back to the area 
vasculosa. The branchial arches are five in 
number, the foremost being first to appear; but 
in birds and mammals they do not all exist at 
the' same time. The two lateral divisions of the 
Fig. 107. Frontal Recon- 
struction from embryo shown 
in Fig. 101. a, Mesencephalon ; 
b, primary optic vesicle ; c and d, 
ventricle and auricle of heart. 
(After His.) 
coelom turn round to the middle line along with the right and left 
Fig. 108.—Embryo Rabbit with its Area Vasculosa, ventral aspect. a, Sinus ter- 
minalis; b and c, anterior and posterior roots of omphalomesenteric veins, , leai , , 
primitive aortae ; /,/, omphalomesenteric arteries ; g, first cerebral ana pumi ive op 
vesicles. (Kolliker, after Bischoff.) 
tubular hearts, and when the mesial heart is formed, meet in a ventral 102 
GENERAL ANATOMY. 
mesocardium which soon disappears. At the same time they push in 
between the heart and fore-gut so as to make a dorsal mesocardium 
which persists. The venous end of the tubular heart becomes bent with 
a ventral convexity, by the 
arterial end receding from the 
head and the venous end 
being tucked up towards the 
dorsum to assume the posi- 
tion of the auricles into which 
it is developed, while the pro- 
jecting convexity becomes the 
apex. The veins, in their 
change of position, carry with 
them the wall of the coelom, 
and principally by this means 
the pericardium is cut off as 
a separate sac. 
While the heart and vitel- 
line vessels belong to the 
splanchnopleure, the inter- 
costal and lumbar arteries 
pass out in the somatopleure, 
and, in the transparent part 
beyond the limb-ridge, the 
membrana reuniens inferior, are 
continued into a remarkable 
network of vessels, very accur- 
ately represented by Kolliker. 
Fig. 109.—Transverse Section through Embryo Chick 
Five Days Old, and the Amnion around it. a, Sheath of 
notochord; h, epidermis ; c, amnion nearly closed; d, single 
aorta ; e, cardinal veins ; /, muscle-plate; g, spinal gan- 
glion ; h, anterior nerve-root; i, cutaneous layer; k, the 
segmented structures pushing forward into I, the primitive 
abdominal wall; m, the glandular, and n, the musculo- 
intestinal layer, together forming the splanchnopleure. 
(Kolliker, after Remak.) 
The surroundings of the embryo. The somatopleure and splanchnopleure 
continue separated by the body-cavity beyond the embryo, passing quite 
round the yelk, and in fishes and amphibians they continue in contact 
all the way. But in reptiles and birds and mammals, the extra-embryonic 
somatopleure quits the spanchnopleure and rises up over the dorsum of 
the embryo, so as to form a pouch with an orifice which contracts and 
disappears, inclosing the embryo in a transparent sac, the amnion. The part 
of the somatopleure beyond the amnion is called the false amnion, and 
remains adherent by its epiblastic surface to the much thinned and dis- 
appearing zona pellucida, called also prochorion, which in turn adheres to 
the uterus. There is thus an extra-embryonic extension of the coelom 
between the false amnion and the continuation of the sjdanchnopleure round 
the yelk, and it is into this space that the allantois extends. The false 
amnion, with the prochorion, forms an envelope, the chorion, from which 
there soon project multitudes of branching villi embedding themselves in 
the mucous membrane of the uterus. 
The mucous membrane of the uterus undergoes a marked increase of EMBRYOLOGY. 
103 
growth, and becomes in the human subject, and most other mammals, the 
seat of a great thickening destined to be removed with the foetal mem- 
branes in parturition, and therefore named decidua. The part lining the 
cavity of the uterus is called decidua vera. But the ovum becomes em- 
bedded by the part immediately surrounding it rising up and forming a 
continuous covering, the decidua reflexa, which separates it from the free 
surface of the decidua vera, while the part to which the ovum is originally 
adherent is that to which the placenta is afterwards attached and is 
distinguished as decidua serotina. The decidua consists of all but the 
deepest part of the uterine mucous membrane hypertrophied and altered, 
involving the tubular glands and presenting a structure containing blood- 
vessels and largely composed of cells of epithelial character. The villi of 
the chorion were supposed to pass into the mouths of the glands, but 
were shown by Turner to hollow for themselves new depressions between 
Fig. 110.—Diagrams of Structures outside the Embryo. The outer circle represents 
the chorion. A, The amniotic sac, not yet complete, is continuous with the false amnion 
which lines the chorion; the yelk sac is large, and the allantois only a small vesicle; B, 
amnion complete, allantois spreading in contact with chorion ; C, amniotic sac enlarged, 
the yelk sac persisting as a relatively small umbilical vesicle, and the placenta formed 
from the outer layer of the allantois with the chorion. 
them. The columnar ciliated epithelium gives place to flattened cells, and 
the growth of the decidua goes on till the fifth month. The decidua vera 
exhibits two layers : one, a compact layer nearer the surface, in which the 
interglandular elements especially have increased, while the necks of the 
glands take a straight course between; and the other, a spongy layer with 
less interglandular substance, in which the deeper parts of the glands are 
swollen out and contorted so as to give a lacunar structure. The decidua 
reflexa, being formed by folding, has compact substance with orifices of 
glands directed to both its surfaces, and spongy substance in the middle. 
The decidua serotina has likewise compact and spongy substance, and it is 
from the compact substance that the placenta is formed, while the spongy 
substance is the site of the separation of the placenta in parturition. 
The placenta consists of two parts, the maternal and the foetal, which 
are inseparably interlocked. But it is interesting to note that in ruminants 
they remain distinct, the uterus presenting a number of permanent or 
button-like elevations, cotyledons, over which the chorion develops masses 104 
GENERAL ANATOMY. 
of villi corresponding to them and fitting deeply into them; and these 
foetal tufts can be pulled separate from their maternal cotyledons, while 
a considerable amount of milky-looking substance can at the same time 
be squeezed from the recesses which they have occupied. 
The foetal placenta is developed from the allantois. In ruminants the sac 
of the allantois expands so as to fill the cornu of the uterus for a while, till 
the amnion expands and casts it 
to one side, where it can be seen 
shaped like a sausage, as the 
name implies. But in the human 
subject the sac only touches the 
uterine wall, while the outer 
layer, the mesoblastic or mesen- 
chymal covering, is continued as a 
delicate web conveying vessels 
for a time to the whole extent 
of the chorion, and entering its 
villi. In the decidua serotina 
the villi of the chorion are 
exaggerated (chorion frondosum), 
and the compact layer of decidua 
loses all trace of glandular 
structure, while the inter- 
glandular substance is developed 
into blood-sinuses surrounding 
the villi, and into a hasal layer 
of firm tissue containing large 
Pig. 111.— F, Foetal placenta ; M, maternal placenta ; 
a, tortuous artery; v, vein returning Mood from 
maternal sinus d'; d, loop of vessel of foetal villus ;V, 
uterine epithelium ; x, wall of maternal sinus lined with 
endothelium ; t, band stretching across from sinus to 
surface of villus ; ds, decidua serotina. (Hertwig, from 
Turner.) 
multinucleated corpuscles. The basal layer passes out in the form of septa 
between the groups of villi, uniting them in cotyledons, and is prolonged 
round the sinuses as a thin subchorial layer (Kolliker), so as to grasp the 
bases of the foetal tufts. The tufts of foetal bloodvessels are most 
intimately connected with the blood-sinuses which surround them, but are 
nevertheless covered by flattened epithelium. Tortuous arterioles pass 
through the basal layer to dilate at once into the maternal sinuses, 
whence the blood returns by veins, there being no capillaries anywhere 
intervening. The mode of development of the blood-sinuses affords matter 
of dispute as to whether they are truly maternal or clefts between the foetal 
and maternal structure. Hubrecht and other recent writers, observing in 
different animals large epiblastic developments at an early stage, support 
the theory of clefts put forward by Kolliker and others; but it is question- 
able if anything has been seen to upset the view that the deciduate 
placenta of the human subject is fundamentally comparable with the in- 
deciduate placenta of ruminants, and that the epithelium of the foetal 
tufts of the human placenta is representative of both the foetal and 
maternal epithelia in those animals. SYSTEMATIC ANATOMY. 
THE SKELETON. 
The whole osseous and cartilaginous framework of the body constitutes 
what is known as the skeleton.1 
The skeleton may be conveniently considered as consisting of two 
parts, the axial or central, and the appendicular or that pertaining to the 
limbs. Each limb starts from an arch or girdle situated in the trunk; 
the upper limb being supported by the scapula and clavicle, which are 
■easily separable from the structures on which they rest, and the lower 
limb by the os innominatum or pelvic bone, which enters largely into the 
boundary of the lower part of the trunk, and is closely united to the 
vertebral column. The expression ‘ axial skeleton ’ excludes these girdles, 
which in their essential constitution belong altogether to the limbs, and 
refers to the skull, vertebral column, ribs, sternum and costal cartilages, 
parts which lie in a longitudinal range, and exhibit a segmental repetition 
of parts. The skull, however, is so complex that its consideration may 
be delayed till after the limbs are examined. 
I. THE AXIAL SKELETON OF THE TRUNK. 
THE VERTEBRAL COLUMN. 
The vertebral column extends from beneath the skull the whole length 
of the body, and consists of a series of bones called vertebrae, fundamentally 
homologous, but differing greatly in detail. It forms a column of support 
by means of a series of solid structures, the bodies of the vertebrae. From 
the bodies spring the neural arches, which extend backwards and bound 
1 The junior student before proceeding to the study of individual bones and joints, 
ought first to acquaint himself with the general characters of bone, described at 
page 24, and with the nature, varieties, and movements of articulations explained in 
the account at page 36. It may also be noted that although most of the details of 
bones are best studied on dried specimens, the articular surfaces are seen to most 
•advantage in the recent state, covered with fresh articular cartilage. 106 
SYSTEMATIC ANATOMY. 
Fig. 112.—Vertebral Column with its liga- 
ments dried ; view from front and right side. 
Fig. 113.-Vertebral Column • view from 
behind and right side. THE VERTEBRAL COLUMN. 
107 
the neural canal, inclosing the spinal cord and roots of spinal nerves; while,, 
in front of the column is the visceral cavity completely encircled in the 
upper part of the thorax by costal arches, into whose formation there enter 
vertebrae, ribs, costal cartilages and sternum. But the ribs developed in 
the thorax as separate bones are represented more or less distinctly in 
other regions by comparatively minute parts, which are incorporated in 
the structure of the vertebrae. 
Five vertebrae are united to form a bone called the sacrum, to which 
the pelvic bones are attached; and beyond the sacrum there are four 
dwindled vertebrae which tend in the adult to become fused together, 
and are known as the coccyx. Between the skull and the sacrum there 
are twenty-four vertebrae which remain distinct throughout life. There 
are thus thirty-three vertebrae in all. 
Of the twenty-four distinct or movable vertebrae, twelve have ribs 
articulating with them and are called thoracic or dorsal, seven intervene 
between the thoracic vertebrae and the skull and are called cervical, while 
the remaining five, placed below the thoracic, are called lumbar. The 
thorax begins with the first of the vertebrae bearing ribs so prolonged 
as, with the aid of costal cartilages and sternum, to complete a circle- or 
costal arch. The cervical vertebrae have rudimentary ribs or costal elements 
incorporated with them, and the seventh has in exceptional instances a 
pair articulating with it. But even in animals such as the crocodile, in 
which the vertebrae immediately behind the skull are provided with 
separable ribs, the name cervical is given to as many as intervene between 
the skull and the first vertebra bearing a complete costal arch. The first 
and second cervical vertebrae are considerably modified in connection with 
the movements of the head, and are called respectively atlas and axis. 
The vertebrae, with some exceptions at the extremities of the series, 
consist of three main elements which remain separate for some time after 
birth; namely, a solid mesial portion, the centrum, 
and two lateral parts which approach one another 
behind and are afterwards united to complete the 
neural arch, termed sometimes simply the arch. 
During childhood, the centrum and the bases of the 
arch become united into one solid mass, afterwards 
completed by a thin plate above and below, and 
the block so constituted is the body. Thus, though 
it is customary to speak of a vertebra as consisting 
of a body and an arch with processes, the body 
has entering into its composition two lateral elements 
Fig. 114.—Thoracic Ver- 
tebra op Child, with the 
two sides of the arch united 
behind, and entering in front 
along with the centrum into- 
the construction of the body. 
or pon-central parts allied in origin much more closely to the arch than 
to the centrum. 
The body of a vertebra presents, for attachment of the intervertebral 
discs which separate it from the bodies of the vertebrae above and below, 
an upper and an under fine-grained surface of dense tissue, thicker towards- 108 
SYSTEMATIC ANATOMY. 
the circumference, and deficient or membranous toward the centre. Anter- 
iorly the bod}7 is slightly grooved transversely so as to make the upper and 
lower margins prominent, and in the thoracic and lumbar regions it is 
projected well forwards in front of the arch. Posteriorly it is slightly 
.grooved vertically and presents two foramina placed side by side or opening 
into a common depression, which give exit to veins. 
The aperture hounded by the neural arch and the body enters into 
the formation of the spinal canal which contains the spinal cord and the 
roots of the spinal nerves, and it is called the ring. From the arch the 
spinous process or spine projects in the mesial plane, while the transverse 
processes project laterally. The parts of the arch intervening between 
the body and the transverse processes are called the pedicles, and the parts 
between the transverse processes and the spine are the laminae. The 
pedicles have their upper margins on a level with the upper surface of 
the centrum, while the centrum descends further than their lower margins. 
In fact, in all vertebrata the arch corresponds with the proserial and never 
with the retroserial half of the centrum. The laminae at their upper 
margin have a roughness looking backwards, and at their lower margin a 
roughness looking forwards, marking the attachments of the ligamenta sub- 
fiava. Projecting upwards and downwards, close to the transverse processes, 
.are the superior and inferior articular processes, carrying articular surfaces, 
by means of which one vertebra has synovial articulation with another. 
Above and below the pedicles are the superior and inferior notches-, and 
when the vertebrae are articulated, apertures are left between the inferior 
notches of one vertebra and the superior notches of the next, and com- 
pleted in front by the intervertebral 
disc. These are the intervertebral 
foramina, and give passage to the 
spinal nerves. 
It is important to note that the 
transverse processes in the cervical, 
thoracic and lumbar regions are not 
perfectly homologous structures. 
The thoracic vertebrae, twelve in 
number, are specially characterized 
by the presence of articular surfaces 
for ribs. The bodies are flat above 
and below, in the middle of the series 
they measure from behind forwards 
as much as transversely, and, except 
in the first and the three last, they 
Pig. 115.—Fourth Thoracic Vertebra, a, 
Surface for lower facet of head of fourth rib ; 6, 
for tubercle of fourth rib; c, for upper facet of 
head of fifth rib. 
present on the non-central part on each side a small articular facet at 
the upper margin for articulating with the head of the corresponding 
rib, and another at the lower margin for the head of the rib below. 
The ring is small and circular. The spines are elongated, sloping down- THE VERTEBRAL COLUMN. 
109 
wards one over another in the middle of the series, ending in a blunt 
point, and springing gradually from the laminae, whose upper borders 
unite to form a mesial ridge separating a right from a left side, while a 
third is left inferiorly. The transverse processes are cylindrical, inclined 
to a marked degree backwards, and swollen at the extremity, in front 
of which, except on the eleventh and twelfth, there is an articular surface 
looking forwards and upwards for the tubercle of the corresponding rib. 
The transverse processes decrease regularly in length from the first to 
the last, in which they are represented by three tubercles slightly connected 
by a short neck which may be almost absent, and these tubercles are 
homologous with three projections on the swollen ends of the typical 
thoracic transverse processes, One of these projections, external, is a ridge 
for the posterior costo-transverse ligament; a second, internal, gives attach- 
ment to the semispinalis and multifidus spinae muscles; ivhile the third, 
inferior, gives attachment to the inner insertions of the longissimus dorsi 
muscle. The inferior notches are deep, the superior shallow and due 
altogether to the superior articular processes striking up behind them. 
The articular processes project in directions continuous with the margins 
of the laminae, the superior rising above the level of the rest of the ver- 
tebra, while the inferior are mere lateral expansions of the laminae. The 
articular surfaces are almost vertical, the superior looking backwards and 
outwards, the inferior forwards and inwards, and both lying in the arc of 
a circle whose centre is at the front of the body, an arrangement favour- 
able for rotation. 
Special characters of certain thoracic vertebrae. The first has the upper 
of the two pairs of costal surfaces on its body placed some distance down 
Pig. 116.—First Thoracic Vertebra from 
above, a, Facet for head of first rib ; b, for 
tubercle of first rib ; c, for upper part of head of 
second rib. 
Fig. 117.—Twelfth Thoracic Vertebra, a, b, 
Superior and inferior articular processes; c, d, in- 
ternal and inferior tubercles of transverse process 
(corresponding with mammillary, and accessory 
processes of a lumbar vertebra); e, costal facet elevated 
above into an outer tubercle of the transverse process. 
and shaped to receive the whole head of the first rib; also the non-central 
parts of its body project upwards after the fashion of a cervical vertebra, 
deepening the superior notches. The tenth, eleventh and twelfth articulate 110 
SYSTEMATIC ANATOMY. 
•each with only one pair of ribs; the tenth bearing one pair of articular 
■surfaces on its body and another on its transverse processes, while the 
■eleventh and twelfth have no surfaces on their transverse processes, and 
the twelfth has its one pair placed well back on the pedicles. Still more 
distinctive of the twelfth is the eversion of the surfaces of its inferior 
articular processes, and the separation of the three tubercles which together 
represent the transverse process of the typical thoracic vertebra. 
The lumbar vertebrae, five in number, are massive ; their bodies have 
the transverse diameter greater than the mesial; their rings are three- 
sided and large. The spines 
are horizontal and spring 
abruptly from the laminae; 
they are laterally compressed, 
nearly as deep as long, and 
end in a linear extremity. 
The transverse processes have 
only a slightly backward 
inclination. They are com- 
pressed from before backward 
and elongated, evidently in 
series with the ribs. The 
laminae are nearly horizontal, 
S up. Art. 
Fig. 118.—Second Lumbar Vertebra, The superior and 
inferior epiphyses of the body can still be distinguished. 
Inf .Art. 
and the articular processes stand out distinctly from them, the superior 
further separate than the inferior, and -embracing those of the vertebra 
above. The superior articular surfaces are transversly concave, looking 
Ma.Pp 
partly backwards and partly 
inwards, the two parts meet- 
ing rather abruptly, while the 
inferior articular surfaces have 
a corresponding convexity 
lookingforwards and outwards. 
Projecting backwards from the 
superior articular processes are 
two tubercles called mammil- 
lary processes, in series with 
the inner angles of the ex- 
tremities of the thoracic trans- 
Acc.Pr 
Fig. 119.—Fifth Lumbar Vertebra from behind. Note 
the wide separation of the right and left articular processes, 
the decrease in depth of the body behind, and the irregular 
«hape of the transverse and spinous processes. 
verse processes and giving attachment to origins of the multifidus 
spinae. They correspond with the anapophyses (Owen) largely developed 
in the hedgehog and still more prolonged in the armadillo to support its 
armour. At the bases of the transverse processes posteriorly, and pointing 
downwards, are a pair of pointed projections, sometimes indicated by little 
more than roughness; they are called accessory processes, give attachment 
to insertions of the longissimus dorsi, and are in series with the inferior 
■angles of the extremities of the dorsal transverse processes. They are THE VERTEBRAL COLUMN. 
seen in perfection in monkeys, carnivora and other animals, as spikes 
projecting over the following vertebra so as to lock the two vertebrae 
together. They are the met apophyses of Owen. 
The fifth lumbar vertebra has the body very distinctly deeper in front 
than behind, its transverse and spinous processes more massive and less 
shapely than those of the other four, its inferior articular processes wide 
apart, and in connection with this, the inferior margins of its laminae 
thrown backwards and outwards. 
The cervical vertebrae are seven in number, but the first two, the 
atlas and axis, will require separate description. All possess as a distinctive 
character a pair of foramina in connection with the transverse processes. 
These are often named arterio-vertebral, the six upper of them being usually 
threaded by the vertebral artery. But the seventh is never so occupied, 
and as the bars which complete the foramina in front are in series with 
Fig. 120.—Third Cervical Vertebra, a, 
Spine; b, b, superior articular processes; c, 
left inferior articular process ; d, d, posterior 
tubercles of transverse processes; e, e, their 
anterior or costal tubercles; /, right costo- 
vertebral foramen. 
Fig. 121.—Seventh Cervical Vertebra, a, Spine; 
b, b, superior articular processes; c, c, costo-verte- 
brai foramina. 
necks of ribs in the thorax, it is better to distinguish them as costo- 
vertebral. The costal nature of the bars in question is made manifest 
by their springing from the side of the body, in front of the pedicle, 
and by the seventh cervical vertebra not only having a separate centre 
of ossification in each, but showing in childhood the exact extent of the 
costal part marked off by deep lines of separation, where the head of the 
rib meets the body of the vertebra and where its tubercle meets the trans- 
verse process. Outside the foramen the union of the two bars is effected 
by a thin bridge near their lower margins, on a level with the superior 
notch, so that the transverse process presents a groove superiorly for the 
emerging nerve, and at its extremity an anterior and a posterior tubercle. 
The bodies increase in size from the top of the series to the seventh; 
they have a greater diameter from side to side than from before back- 
wards, and their upper surfaces are bevelled at the anterior edge, while 
laterally the non-central parts rise up on each side above the centrum, 
making the body concave from side to side, and the superior notch 
as deep as the inferior. Conversely, the under surface of the body is 
convex from side to side, while in the middle it dips in front over the 112 
SYSTEMATIC ANATOMY. 
body of the vertebra following. The ring is large and triangular. The 
laminae have oblique surfaces, and meet by their upper margins to form 
spines and again diverge. Thus the spines are bifid, and grooved on their 
under surface. The articular surfaces look, the upper pairs upwards and 
backwards, the lower pairs downwards and forwards, and so oblique is 
their inclination that when in position the articular processes on which 
they are placed form together two considerable pillars supplementing the 
bodies in the support of the head. From the third to the seventh the 
cervical vertebrae increase regularly in all dimensions, including length of 
spine and width between the extremities of their transverse processes. 
The seventh cervical vertebra has the spine ending in a subcutaneous 
tubercle like the succeeding vertebrae, and is named on that account 
vertebra prominens. The posterior tubercle of its transverse process is more 
prominent than the anterior, and the inferior surface of the body is not 
prolonged downwards in front. 
The atlas and axis owe their most striking peculiarities to the 
cumstance that in process of development the centrum of the atlas is 
Pig. 122.—Atlas. a, Posterior tubercle; h, 
anterior tubercle; c, c, superior articular surfaces; 
d, d, tips of the vertebral parts of the transverse 
processes ; e, e, tips of the costal parts of the trans- 
verse processes ; /, upper orifice of left arterio-verte- 
bral foramen; g, groove (only partially seen), on 
which bay the vertebral artery and suboccipital 
nerve—i, i, are placed outside the outer edges of the 
inferior articular surfaces. 
Fig. 123.—Axis, a, Odontoid process; 
b, b, superior articular surfaces; c, centrum; 
d, arterio-vertebral foramen ; e, tip of trans- 
verse process ; /, inferior articular process ; 
g, strongly bifid spinous process. 
modified in shape, separated from the rest of that bone, and united to 
the centrum of the axis, forming what is called its odontoid process, 
while the ventral extremities of the arch of the atlas become united by a 
centre of ossification which forms a bar gliding on the front of the 
odontoid process.1 
The atlas incloses within an anterior and a posterior arch a large ring, 
the fore part of which is smaller than the hinder, and separated from it 
in the recent state by a transverse ligament extending between two lateral 
masses so as to lie behind the odontoid process of the axis and form, the 
posterior part of a circle for its reception. On the back of the anterior 
1 It is remarkable that this arrangement exists not only in mammals, but in reptiles 
and birds, though it is generally admitted that mammals are not descended from 
either. THE VERTEBRAL COLUMN. 
113 
arch is a surface covered with cartilage for articulation with the odontoid 
process, and in front of it is a slight prominence, the anterior tubercle, so 
called in opposition to the posterior tubercle, which represents the spinous 
process. The lateral masses are two solid blocks which present on their 
upper surfaces a pair of superior articular surfaces for articulation with the 
condyles of the occipital bone. These surfaces are elongated and concave, 
with their posterior extremities opposite the widest part of the ring and 
their anterior extremities nearer one to the other, their outer margins 
elevated and their inner margins depressed and indented; while internal 
to each is a roughness marking the attachment of the transverse ligament. 
Beneath the lateral masses are two inferior articular surfaces, flat, 
circular, and looking downwards and a little inwards. Outside the 
lateral masses are the transverse processes, perforated by an arterio-ver- 
tebral foramen, like the other cervical vertebrae, but having only one 
extremity, which strikes out so far that the width between it and its 
fellow is not equalled by any succeeding vertebra till the first thoracic 
is reached. The bars uniting to form the posterior arch are cylindrical 
Fig. 124.—Pour Vertebrae of a Child at Birth, a, Cervical; 6, thoracic; c, atlas; 
d, axis. The dotted lines show the parts of the atlas and axis which correspond with the 
non-central part of the body in a dorsal and a typical cervical vertebra. 
except immediately behind the lateral masses, where they are flattened 
superiorly, there being on each side a broad transverse groove over- 
hung in front by the back of the superior articular surface. This is 
occupied by the vertebral artery as it winds round from the arterio- 
vertebral foramen before entering the skull by the foramen magnum; 
and the occipital or first spinal nerve emerges by it. It is really the 
superior notch, while the part which goes to form the lateral mass 
corresponds with the non-central portion of the body in other verte- 
brae. The groove is sometimes arched over and converted into a 
foramen. The ridge behind it corresponds in position with the superior 
articular process of a typical vertebra, and sometimes in old subjects the 
occipital bone rubs so much on the posterior arch as to form a sort of 
articular surface. The laminae of the atlas not unfrequently fail to 
meet in the middle line behind.1 
1 The atlas is occasionally subject to larger defects, both in the anterior and 
posterior arches. Especially worthy of notice is the occurrence of incomplete pos- 
terior arch in conjunction with enlarged ring and throwing forward of the transverse 
processes. It may be also here noted that by following the series of anterior and 
posterior intertransverse muscles till, by means of the rectus capitis anticus minor 
and rectus capitis lateralis, they respectively reach the skull, it can be shown that 114 
THE SKELETON. 
The axis has its body surmounted laterally hy superior articular sur- 
faces homologous with the articular surfaces of the atlas, and in the middle 
by the odontoid process. The superior articular surfaces look upwards and 
outwards, but are slightly raised in their transverse diameter, so as to 
leave gaps in front and behind between them and the opposed surfaces 
of the atlas. The odontoid process is a pillar with a slightly constricted 
neck, smooth behind where it glides on the transverse ligament of the 
atlas, and with an oval surface in front reaching nearly to the summit 
for articulation with the atlas. Its summit is rough and presents two 
lateral slopes which give attachment to the check ligaments. The under 
surface of the body of the axis, the inferior notches and the inferior 
articular processes, are similar to those of the succeeding vertebrae. The 
laminae are continued into a deeply bifid spine, much stronger and also 
larger than those immediately succeeding it, and giving attachment to 
muscles both above and below it. The transverse process is short, and 
has only one tip. 
The sacrum consists of five vertebrae united together, not only by their 
bodies, laminae and articular processes, but also outside the intervertebral 
Fig. 125 
Pig. 126. 
Fig. 125.—Sacrum and Coccyx, front view. The sacrum is turned sufficiently to one 
side to show the right auricular surface descending as far as the middle of the third sacral 
vertebra, and behind it, in shade, the surface of attachment of the dorsal sacro-iliac 
ligament. The epiphysis of the auricular surface, and that over the body of the first 
vertebra, are not yet completely united to the main bone. 
Fig. 126.—Sacrum and Coccyx. View from behind and from the left side. 
foramina, which consequently are converted into bifurcating canals opening 
the tips of the transverse processes of the atlas and axis are in series with the 
posterior tubercles of those of the vertebrae following, while the anterior tubercles or 
tips of ribs are represented by mere roughness at the roots of the transverse pro- 
cesses (Allen, Journal of Anatomy and Physiology, xiv., p. 18). THE VERTEBRAL COLUMN. 
115 
by anterior and posterior sacral foramina, bounded externally by a solid block, 
the lateral mass. The sacral vertebrae diminish rapidly, from the first, 
which is the most massive in the column, to the fifth, which is rudiment- 
ary ; and thus they constitute a wedge-shaped bone, the base of which 
articulates with the last lumbar vertebra by a body and articular processes, 
and is continued laterally into an expansion curving over to the ventral 
surface. 
The ventral surface forms the back of the pelvis, and is concave 
from base to apex and slightly so from side to side. Mesially it is 
separated from the base by an acute angle, and projects forwards into the 
pelvic cavity, forming the sacral 
promontory. Below this, a series 
of four transverse linear eleva- 
tions indicate permanently the 
borders of the five bodies of 
vertebrae, and extend to the 
abrupt internal margins of the 
anterior sacral foramina, whose 
external margins slope outwards 
in the form of deep grooves 
The dorsal surface is convex 
both longitudinally and trans- 
versely. It presents in the 
middle line a series of spines, 
usually three or four in number ; 
Fig. 127.—First and Second Sacral Vertebrae sawn 
separate, seen from above. A, Base of sacrum : a, articu- 
lar process; b, transverse process; c, lateral mass. B, 
Second sacral vertebra : d, portion of arch of first verte- 
bra sawn away with the second; e, f and g have the 
lines proceeding from them lying respectively in the 
intervertebral, the posterior and the anterior sacral fora- 
men, showing ho w the intervertebral foramen is bifurcated 
by the union of the lateral masses of succeeding vertebrae. 
while inferiorly the laminae of 
the fifth vertebra, or of the 
fourth and fifth, failing to meet, leave the lower end of the sacral 
canal imperfect behind. Sometimes the laminae of the third and second 
vertebra have the like imperfection, and in rare instances the sacral canal 
is open in its whole length, without a single spine over it. Separated 
from the middle line by the series of united laminae are two rows of 
tubercles in series with the well-developed mammillary processes of the first 
sacral vertebra, and external to these are the posterior sacral foramina, 
smaller than the anterior, and giving passage to the posterior divisions of 
sacral nerves. External to the posterior sacral foramina is an outer line 
of ridges representing the tips of transverse processes, and separating the 
dorsal from the lateral surfaces. 
The lateral surfaces belong to costal elements additional to trans- 
verse processes, absent from lumbar vertebrae, and exhibited in childhood 
in the three upper sacral vertebrae by additional centres of ossification. 
To this addition is due the stoutness of the lateral masses. On the 116 
THE SKELETON. 
lateral aspect, towards the base, is the auricular surface, a large articu- 
lar surface covered with cartilage for articulating with the iliac 
portion of the pelvic bone, but differing from the generality of articular 
surfaces in being more uneven. It extends over the first two verte- 
brae and a certain way over the third. Its ventral margin keeps 
close to the ventral surface of the bone, while 
the ear-shape from which it is named is due to 
the part on the first vertebra extending dorsally 
considerably further than the rest. The space 
between the auricular surface and the tips of 
transverse processes is occupied with fat, while 
the range of processes gives attachment to the 
strong posterior sacro-iliac ligament. 
Fig. 128.—Base of Sacrum of 
Infant, c, Centrum; m, mam- 
millary process; t, tip of true 
transverse process ; I, main part 
of lateral mass, the costal ele- 
ment. 
which form its imperfect arch turned downwards like inferior articular 
processes. They are called the sacral cornua, and articulate with the first 
coccygeal vertebra, with which also the inferior surface of its dwindled 
body, situated at the apex of the sacrum, articulates. The sacrum 
sometimes consists of six vertebrae, and occasionally is surmounted by a 
vertebra with a thick lateral mass of sacral character on one side and 
a lumbar transverse process on the other. 
The fifth sacral vertebra has the free processes 
11l the erect posture, the sacrum is so placed that the ventral border 
of the auricular surface is horizontal. Toward the base, the dorsal 
surface of the sacrum is therefore superior in position, and the ventral 
surface inferior; and the ventral being the broadest part, the sacrum 
articulates with the pelvic bones, not like the keystone of an arch, but 
with the broad end of its dorso-ventral wedge downmost. 
The coccyx is the name given to the dwindled vertebrae beyond the 
sacrum, which are described as one bone on account of their being usually 
united into one piece before being joined to the sacrum. The first coccygeal 
vertebra has a broad flat body with two transverse processes projecting 
from its sides, and a pair- of cornua striking up from behind it to com- 
plete, with the sacral cornua, a pair of foramina for the fifth pair of sacral 
nerves. The remaining coccygeal vertebrae vary from two to four, but are 
usually three. The second has an upper and a lower flat surface, and 
mere indications of transverse processes. The other two are reduced to 
nodules. The three last are usually united into one bone before being 
united with the first. The period of union of coccyx and sacrum is vari- 
able, but is earlier in the male than in the female, in whom such union 
may cause difficulty in parturition. 
The articulated column presents various curves for consideration. If 
the line of the front of the bodies of the vertebrae be followed, there is 
seen in the neck a marked convexity, which is succeeded by a concavity 
reaching its deepest about the sixth thoracic vertebra. Thence the line 
slopes forwards to the lumbar convexity which projects much further THE VERTEBRAL COLUMN. 
117 
forwards than any other part of the column, and is such that the column 
at this part may sometimes he felt through the abdominal wall in a lean 
patient. The lumbar convexity is succeeded by tbe sacral concavity 
extending far backwards. In addition to these curves, there is also a 
slight deviation to the right in the upper part of the chest, probably 
connected with the fact that the aorta lies at that part on the left side 
■of the column. More important is the circumstance that when the pelvis 
is in an oblique position by only one knee being straightened, which is 
the natural mode of standing, the column is thrown into temporary lateral 
•curves, which, in combination with increase of the mesial curves, produces 
a spirality well adapted to give greater spring and to increase the stability 
of balance. The exaggeration of such natural positions gives rise to the 
lateral curvature known as a pathological condition. 
The great development of mesial curvature is specially characteristic 
■of man, and connected with the maintenance of the erect posture by 
balance. At birth the column is very flexible, and the cervical convexity 
is favoured by the head of the infant being no longer bent upon the 
-chest, but thrown backwards. The lumbar convexity makes its appearance 
somewhat later. To stretch the lower limbs of an infant there is required 
not only the extension of the hip joint, but still more the bending back- 
wards of the lumbar part of the column, so as for the first time to pro- 
duce the convexity, which soon becomes permanent. 
Besides the curves, there are other peculiarities of the human vertebral 
•column connected with the assumption of the erect posture. The lumbar 
vertebrae are massive to support the accumulated weight above them, 
while the cervical vertebrae are light as compared with those of many 
■animals, the head being habitually supported by balance, and not sus- 
pended at the extremity of a column projecting forwards as in quadrupeds. 
Also the pillar of support formed by the bodies of the vertebrae projects 
well forwards into the thoracic and abdominal cavities so as to have the 
weight distributed round it; and, to effect this, the transverse processes 
•at their origins are thrown backwards by the intervention of pedicles 
between them and the bodies, and the thoracic transverse processes have 
a well-marked backward inclination. The imbricated thoracic spines are 
also characteristically human. In many mammals the dorsal projection 
of these processes is such as to form prominent withers affording room for 
muscles at their sides; while in man the mass of muscles straightening 
the back is accumulated most largely in the loins. 
THE RIBS. 
There are twelve pairs of ribs developed as separate bones, and they 
articulate with the twelve thoracic vertebrae. They are prolonged 
forwards by costal cartilages, of which the first seven pairs articulate 
anteriorly with the sternum, while the remaining five are pointed, three 118 
THE SKELETON. 
of them adherent each to the costal cartilage above and the two last 
lying free in the muscular wall. Having regard to these differences, the 
first seven ribs are called sternal or true, and the remaining five are 
distinguished as asternal or false, while the eleventh and twelfth are 
called floating ribs. 
In an early embryonic condition each rib was part of the same 
cartilage as the corresponding vertebra, but in process of development 
the posterior end or head of 
each, with the exception of 
the first and the last three, 
was displaced upwards so as 
to articulate with the body 
of the vertebra above, as 
well as its own; and the 
head presents, therefore, an 
upper and a lower articular 
surface separated by a ridge 
for an interarticular ligament. 
Each rib, with the exception 
of the eleventh and twelfth, 
articulates with the transverse 
process of its own vertebra 
by a part called the tubercle, 
which presents two portions 
—an articular surface looking 
backwards and downwards, 
and, outside the articular 
surface, a ridge for the 
posterior costo-transverse liga- 
ment. The part between the 
head and the tubercle is the 
Fig. 129.—First, Second, Sixth and Twelfth Ribs of 
Left Side, from above, a, Interarticular ridge of head ; b 
single articular facet of head of first and twelfth; c, rough 
elevation of tubercle ; d, opposite articular facet of tubercle 
itself not seen ; e, angle ; J, insertion of scalenus medius; g\ 
tubercle at inner end of line of insertion of scalenus anticus’ 
between the grooves of the subclavian artery and vein ; h, on 
the twelfth corresponds with the tubercle of other ribs. The 
shadows show the vertical curves of the ribs. 
neck, and the remainder of 
the rib is the shaft or body. 
The back of the shaft is 
crossed by an oblique rough- 
ness, called the angle, marking 
the outermost attachments of 
the erector spinae muscle. The neck is longest in the first rib, and 
getting gradually shorter disappears in the eleventh and twelfth. On 
the upper surface the neck has a groove with a ridge in front of it. 
The shaft becomes more compressed as it is followed forwards, and in 
most ribs is somewhat expanded in front. It ends in a shallow depres- 
sion into which the costal cartilage fits, inseparably united to the bone. 
On the inner surface of the shaft interiorly is the subcostal groove; 
extending outwards from the tubercle, best marked at the angle, and THE EIBS. 
119 
dying away gradually beyond, it shelters the intercostal vessels and 
nerve. A supracostal groove is well marked for a variable distance 
forwards from that on the neck. 
The fully developed ribs, when looked at from above, present two 
curves, the part extending from the head to the angle forming an arc 
of a smaller circle than that in whose circumference the part in 
front of the angle lies. When looked at in profile, they present a 
double curve, the slope being diminished at the angle and again increased 
at the anterior end, so that, when laid on a flat surface, the angle and 
the tip touch it while the intervening part does not, and the neck 
strikes upwards. They are also twisted on themselves, so that if at the 
middle they are held with the surfaces looking outwards and inwards, 
the deep surface of the neck and the superficial surface of the fore part 
of the shaft both look upwards as well as forwards. 
The first rib is remarkably short. The head is small, with only one 
articular facet. The neck is long, slender at the head, and thick at the 
prominent tubercle. The body has its superficial and deep surfaces 
looking upwards and downwards, and is broadened out like a scimitar. 
When the neck is held in the horizontal, which is its natural position, 
the body is slightly curved downwards, especially at the outer border 
midway forwards from the tubercle; and this curve is no mere result 
of muscular traction, for it exists even before birth. On the upper 
surface, more than half way forwards, there is a roughness prolonged 
into a small tubercle at the inner margin, marking the insertion of the 
scalenus anticus muscle, and separating two slight depressions, the posterior 
corresponding with the position of the subclavian artery and the anterior 
with the subclavian vein; while the part behind the posterior groove 
is extensively rough, and gives insertion to the scalenus medius. 
The second rib has its superficial surface looking upwards and out- 
wards, and its upper and inner border is about twice as long as the inner 
border of the first rib. In its shaft it is not only narrower than the first 
rib, but narrower than any of the succeeding ribs down to the tenth. 
Superficially, about midway forwards, it has a notable rough thickening 
where the serratus magnus is attached. 
The tenth rib has one articular surface on its head, and one at the 
tubercle. 
The eleventh and twelfth ribs are known by their shortness and very 
slight curvature, and by having only one articular facet, which is on 
the head; while the angle is absent from both, or may be barely 
percej)tible on the eleventh. The twelfth is always considerably the 
shorter of the two, and is usually from two to four inches in length. 
Both have a distinct twist, turning the fore part of the inner surface 
slightly upwards. 
Variations. The ribs are sometimes increased in number on one or 
hoth sides by a small rib attached to the first lumbar vertebra. An 120 
THE SKELETON. 
articulated rib sometimes occurs in connection with the seventh cervical 
vertebra; it may be of considerable length, and in front is usually free, 
but may be united to the rib following. Sometimes, in a thorax other- 
wise normal, one of the ribs bifurcates in front, and is prolonged 
forwards by cartilages which approach or unite at the sternum. 
The costal cartilages take origin from the ribs in an oblique line 
extending from above downwards and outwards. The first seven, and 
not unfrequently the eighth (Cunningham), are prolonged to the sternum. 
Of these the first is the shortest and strongest, and is the only one 
which is united to the sternum by direct continuity in the same way 
as it is united to the rib. The others are united by movable articula- 
tion, usually with the intervention of a small synovial cavity, or, in the 
case of the second, third and fourth, two such cavities, an upper and a 
lower. From the third downwards the cartilages slope upwards with an 
increasing slope to reach the sternum. Those which fail to reach the 
sternum are pointed at the extremity; the eleventh and twelfth being 
short and free, while the others are prolonged forwards, and become 
adherent for a considerable distance by fibrous union, each to the carti- 
lage next above it, sometimes presenting a considerable temporary 
increase in breadth, and even the intervention of an articular cavity. 
Though the costal cartilages are usually invaded, as life advances, by 
calcification in the interior, and may be incrusted with bone on their 
surface, this ossification is irregular, and the positions of the ends of the 
ribs remain constant. 
THE STERNUM 
The sternum consists of segments which unite at different periods one 
with another. Three portions are recognized: the uppermost, the man- 
ubrium, extends down to the second costal cartilage, and only in advanced 
life becomes united by bone to the next portion. The lowest part, the 
ensiform process, projects downwards from the insertion of the last sternal 
costal cartilages, and is seldom united to the part above it till middle age. 
The body, or part intervening between the manubrium and ensiform process, 
presents two obvious segments opposite the second and third intercostal 
spaces, and below these a remaining portion on which the traces of having- 
belonged to more than one segment of the skeleton are more obscure. 
The manubrium, or presternum, is the strongest and broadest part. It 
has a somewhat convex superficial surface, a flat deep surface, and four 
borders. Its upper border is thick and consists of three parts, an inter- 
clavicular depression (incisura semilunaris), and on each side of this an 
articular surface looking upwards, outwards, and a little backwards, for the 
sterno-clavicular articulation, concavo-convex both from behind forwards 
and also from without inwards. The lateral border exhibits superiorly a 
vertically placed rough surface where the first costal cartilage joins it, 
and, beneath this, is concave and smooth as far as the angle separating it THE STERNUM. 
121 
from the comparatively narrow inferior straight border. There a small facet 
intervenes which, together with a similar facet on the body of the sternum, 
makes the notch of insertion of the second costal 
cartilage. 
The body, or mesosternum, increases in breadth 
from its upper end to the insertion of the fifth 
costal cartilage. Two distinct transverse ridges on 
the superficial aspect mark the junction of its first 
and second segments, and of the second and third; 
and opposite these ridges the edges are notched 
to receive the third and fourth cartilages. More 
than half way down on the remaining part are the 
notches for the fifth pair of costal cartilages, with 
an obscure ridge between them, while, still lower, 
are two pairs of notches for the sixth and seventh, 
placed one close above the other, those for the 
seventh marking also the ensiform process. 
The ensiform or xiphoid process, or metasternum, 
is a thin projection with its deep surface continuous 
with that of the mesosternum, while, superficially 
it is depressed at its origin. It often remains 
wholly or in part cartilaginous till a late period of 
life, and is sometimes straight and narrow, sometimes 
Pig. 130, —The Sternum 
from the front. 
expanded, perforated, or bifurcated. Sometimes it projects forwards 
beneath the skin. 
The sternum increases in variability from above downwards, the lower 
half of the mesosternum being in some instances much broader than in 
others, and occasionally perforated. 
A pair of ejnsternal ossifications were first described by Breschet, situated one at 
each side of the interclavicular depression. Luschka described a pair as large as 
pisiform bones ; and a specimen with a pair quite as large was in the Anatomical 
Museum in Galway when I was professor there. 
THE THORAX. 
The thoracic skeleton has its greatest strength behind, its greatest 
height in the plane upwards from the tips of the twelfth ribs, and is short 
in front. Narrow above, it attains its greatest breadth at the level of 
the eighth rib, and its greatest antero-posterior diameter toward the sides, 
at the level of the lower end of the sternum, where the ribs arch back- 
wards, forming the costal fossae to lodge the greatest breadth and depth 
of the lungs, and leave between the angles and the row of spines behind 
a furrow in which lie the muscles of the back. But in the mesial plane, 
the diameter from sternum to vertebral column is much narrower, on 
account of the characteristically human projection of the column into the 122 
THE SKELETON. 
interior, which also increases the proportionate breadth of the cavity. The 
bodies of the vertebrae from about the fifth form a pillar sloping down- 
wards and forwards at an angle of about 15 degrees with the vertical, 
while the average slope of the sternum may be about 25 degrees. Below 
the ninth rib the thorax is slightly narrower, and the eleventh and twelfth 
ribs have their upper margins distinctly everted. 
Fig. 181.—Thoracic Skeleton, with the clavicles, scapulae, and heads of humeri in 
position to show how the apparent shape of the chest is affected by the superposition 
of the shoulders. 
In the female there is little increase of breadth below the fifth or 
sixth rib, but more rapid increase above that level; and this makes the 
heaving of respiration more obvious in the upper part of the chest, it 
being principally in that part that in inspiration small arches are replaced 
by larger at any particular level. In the child the height of the thorax 
is short as compared with its girth. In old age the arches of the ribs are 
liable to be flattened laterally. In the globular chest of emphysema the 
convexity of the sternum is increased. In shoemakers there is often a deep 
depression at the lower end of the sternum caused by pressure of the last. 
The vertebral column is joined together by synovial joints, intervertebral 
discs and ligaments. 
ARTICULATIONS OF THE AXIAL SKELETON. 
The synovial articulations between the articular processes are surrounded 
by fibrous capsules. ARTICULATIONS OF THE AXIAL SKELETON. 
The intervertebral discs are each divisible into a central pulp and a 
laminated white-fibrous structure surrounding it and graduating into it. 
The pulp is soft, yielding, resilient and tough. (For its structure, see p. 38.} 
The laminae consist of thin layers of fibres of tendinous lustre disposed 
obliquely, those of one layer decussating with those of the layers in 
contact with it, and the deep layers more nearly horizontal. When a. 
disc is divided, the cut laminae alternately reflect more or less light to 
the eye, and being relieved from tension, press the cut pulp into a convex 
form. The discs are thickest in the lower lumbar region, reaching to two 
fifths of an inch in depth. In the upper half of the chest they are 
very thin. By inequality of depth in front and behind they take part 
in the formation of the vertebral curves. Between the non-central parts 
of the bodies of the cervical vertebrae there is invariably a synovial space 
left on each side, interrupting the disc, as was pointed out by Luschka. 
The anterior common ligament is a longitudinal band extending in front 
of the vertebrae and the intervertebral discs down to the sacrum. It 
begins above as a narrow fasciculus adherent to the fibrous sheet between 
atlas and occipital bone, and sometimes termed accessory occipito-atlantal 
ligament, and increases in breadth more and more as it descends. It is 
strong in the middle line, its superficial fibres passing over a number of 
vertebrae; but it thins away at the sides, and its deep and lateral fibres 
stretch vertically between the neighbouring margins of vertebrae. 
The posterior common ligament, behind the bodies of the vertebrae, begins 
as a broad band above, at the axis, in continuity with the long occipito-axial 
ligament, and narrows as it descends, till it ends by tapering on the backs 
of the bodies of the sacral vertebrae. It has a dentated appearance; its 
fibres being more gathered together behind each vertebra, where a vein 
emerges on each side from underneath it, while it has a spreading attach- 
ment to each disc and the contiguous margins of vertebrae. 
The ligamenta subflam are strong bands of yellow-elastic tissue which 
extend vertically between the laminae, from the axis to the sacrum; their 
inner edges are in contact, and they are attached to the roughnesses 
on the lower and upper edges of successive laminae. They are so far on 
the stretch in the erect posture, that when the series of laminae is detached 
in one piece kept together by them, it is two or three inches shorter than 
the column from which it has been removed. 
The supraspinous ligament is a continuous band of fibres joining the 
tips of the spines together, from the seventh cervical to the first sacral. 
The ligamentum nuchae is continued up from the spine of the seventh 
cervical vertebra, continuous with the supraspinous ligament, its superficial 
fibres extending to the occipital protuberance, and the deeper fibres 
successively to the occipital crest and the cervical spines from above 
downwards. The superficial part is little more than a raphe between the- 
trapezii and splenii muscles of opposite sides, and the deep part is a 
mere intermuscular septum. It owes its name to being obviously homo- 124 
THE SKELETON. 
logons with the important yellow-elastic ligamentum nuchae by which, 
in the horse and other animals, the head is kept without muscular effort 
from hanging too low down. 
The interspinous ligaments are unimportant 
septa between the spines • and still less im- 
portant are the scattered fibres called intertrans- 
verse ligaments, found in the dorsal and lumbar 
regions. 
The sacro-coccygeal and the coccygeal ligaments 
are dwindled representatives of intervertebral 
discs, anterior and posterior common ligament, 
and joints of articular processes, and require no 
special description. 
The atlas and axis are united to one 
another and to the occipital bone by joints 
and ligaments differing from those of the rest 
of the column. 
The synovial articulations between the atlas 
and occipital condyles, and those between the 
inferior articular surfaces of the atlas and superior 
Fig. 132.—Ligamentum Nuchae, 
with its attachments to the cervi- 
cal vertebrae and occipital bone. 
articular surfaces of the axis arc surrounded by fibrous capsules, and the 
capsule of each of the latter joints is strengthened at the inner part of 
its posterior aspect by a strong accessory ligament. The articulation between 
the odontoid process of the axis and the anterior arch of the atlas has 
no fibrous capsule. 
The long occipito-axial ligament,l already alluded to in connection with 
the posterior common ligament, prolongs that ligament from the back of 
the body of the axis to the basilar process of the occipital bone. 
The transverse ligament of the atlas, in front of the long occipito-axial 
ligament and concealed by it, is attached on each side to the rough 
surface on the inner side of the lateral mass, and separates from the 
proper ring of the atlas an anterior compartment in which the odontoid 
process is grasped. At its attachments its fibres are gathered together, 
while in the middle it is pushed back by the odontoid process and is 
flattened out. From this middle part a short and thin band passes down 
to the body of the axis, and a longer and slenderer band passes up to 
the front of the foramen magnum 3 these are termed the superior and 
inferior appendages, and together with the transverse ligament form the 
cruciform ligament. 
The lateral odontoid or check ligaments are a pair of very strong rounded 
bands, extending from the rough sides of the head of the odontoid process 
outwards to the rough surfaces inside the occipital condyles. Some of 
1 Known also as posterior occipito-axial ligament, apparatus ligamentosus, ligamentum 
latum epistrophei, and catalogued by the German committee among the ligaments of 
the atlanto-epistrophic articulation as membrana tectoria. ARTICULATIONS OF THE AXIAL SKELETON. 
125 
their fibres are continuous from side to side. They are both relaxed 
when the head looks straight forwards, and both of them tightened when 
it is rotated to either side; hence they check too great rotation. 
The middle odontoid (improperly called suspensory) ligament consists of a 
small bundle of loose tissue, containing within it, in the young subject, 
the remains of the notochord, 
as it extends up to the occi- 
pital bone in front of the 
foramen magnum. It has no 
ligamentous function. 
The anterior occipito-atlantal 
and anterior atlanto-axial liga- 
ments or membranes are fibrous 
expansions uniting the anterior 
arch of the atlas with the 
front of the foramen magnum 
and the body of the axis 
respectively, and are strength- 
ened by the narrow mesial 
band by which the anterior 
Fig. 133.—Articulations of Atlas, Axis and Occipital 
Bone seen from within the spinal canal after division of /, /, 
the long occipito-axial ligament, a, Transverse ligament of 
atlas ; b, c, superior and inferior appendages; cl, d, cheek 
ligaments ; e, middle odontoid ligament; g, posterior common 
ligament; h, h, accessory ligaments of atlanto-axial articula- 
tions. The posterior gap is shown between the opposed 
articular surfaces of the atlas and axis. 
common ligament commences. 
The posterior occipito-atlantal 
and posterior atlanto-axial liga- 
ments or membranes are very 
thin white-fibrous expansions 
uniting the posterior arch of the atlas with the back of the foramen 
magnum and the laminae of the axis. They take the place of ligamenta 
subflava. 
Fig. 134.—Articulations of Ribs with Vertebrae. A, View from above. B, View 
from behind. C, View from right side, a, Middle band of stellate or anterior costo- 
vertebral ligament; a', a", superior and inferior bands of the same ; b, interarticular 
ligament; c, ligament of neck of rib or middle costo-transverse; d, costo-transverse 
articular cavity; e, posterior costo-transverse ligament; /, anterior or long costo-trans- 
verse ligament; g, anterior common ligament of the vertebral column. 
The thorax has its most complex arrangement of joints and ligaments 
at the hinder end of the costal arches; and the circumstance that there 
are synovial joints between the bodies ol vertebrae and the heads of ribs, 126 
THE SKELETON. 
and others between transverse processes and the tubercles of ribs, has led 
to the distinction of costo-vertebral and costo-transverse articulations. 
The anterior costo-vertebral ligament or stellate or radiate ligament of the 
head of the rib extends from the front of the head of each typically 
articulated rib three bands—an upper, sloping up to the vertebra 
above, and lying in front of the upper joint; a lower, sloping downwards 
in like manner in front of the lower joint, and a shorter and narrower 
band extending directly inwards to the intervertebral disc. 
The interarticular ligament is a strong, although thin, band stretching 
from the interarticular ridge of the head of the rib into the intervertebral 
disc, and separating the upper articulation of the head of a typical rib 
from the lower.1 
The posterior costo-transverse ligament is a definite and strong flat band 
extending from the ridge of the tubercle of the rib downwards and in- 
wards to the transverse process of its vertebra, behind the costo-transverse 
articular cavity. 
The middle costo-transverse ligament, ligamentum colli costae, or interosseous 
■ligament consists of horizontal fibres uniting the back of the neck of 
the rib to the front of the corresponding transverse process, and filling 
up the interval between the costo-vertebral and costo-transverse articular 
cavities. 
The long (or superior) costo-transverse ligaments consist of two sets of bands 
irregularly developed in different intercostal spaces, and uniting the neck 
of the rib with the vertebra above. The anterior and outer bands extend 
between the ridge on the neck of the rib and the tip of the transverse 
process above; the posterior and inner bands are attached inferiority 
behind the groove of the neck of the rib and superiorly near the root of 
the transverse process. 
The anterior thoracic 'joints are comparatively simple. The junctions of 
ribs with costal cartilages, of pieces of the sternum one Avith another, and 
of the sternum with the first costal cartilage are not properly to be looked 
on as joints, any more than the union of shaft and epiphyses in a young 
bone. But true sterno-chondral articulations occur in connection Avith the 
cartilages of the sternal ribs succeeding the first. Most commonly two 
synovial cavities separated by an interarticular septum are found in connection 
with the second costal cartilage; and descending from this, two cavities 
1 The interarticular ligament derives additional interest from the circumstance that 
in many mammals it is replaced by a ligamentum conjugate costarum, which crosses 
•over between the intervertebral disc and the posterior common ligament, and joins 
the head of the rib to its fellow. In ruminants the conjugal ligament is attached 
by other fibres to the body of the proserial vertebra, but it is not so in carnivora; 
and in both there is a single synovial cavity continued from side to side, repre- 
senting the two pairs of cavities connected with the heads of a pair of ribs in man. 
The transverse ligament of the atlas and the lateral odontoid ligaments belong to 
the same series of transverse fibres, and, in so far, may be regarded as conjugal 
ligaments (Cleland, 1859 and 1861). ARTICULATIONS OF THE AXIAL SKELETON. 
127 
become less frequent; while, in connection with the cartilage of the lowest 
sternal rib, most frequently there is no synovial cavity, and a single cavity 
becomes more frequent as we ascend from this. Interchondral synovial 
■articulations occur variably between successive costal cartilages from the 
fifth to the ninth. On the deep surface the sternum ribs and cartilages 
■are united by continuous periosteum and perichondrium, strong, but not 
otherwise remarkable; and on the superficial aspect of the sternum a 
■decussating arrangement of strong fibres extends across the middle line 
and over the costal cartilages. Also between the costal cartilages, tendinous 
fibres continuous with the external intercostal muscles bind the cartilages 
together, and are stronger and shorter below, where they bind the asternal 
•cartilages. 
MOVEMENTS OF THE AXIAL SKELETON. 
The vertebral column allows mesial and lateral angular movement, 
rotation and circumduction, to different extents in different regions. 
Mesial flexion and extension are allowed most freely in the cervical region, 
and next to it in the lumbar. The neck cannot only be flung backwards 
till the edges of the inferior articular surfaces are caught on depressions, 
often well marked, on the laminae below (Bruce Young), but it can be 
bent forwards so as to throw the fronts of the bodies into a concave curve. 
The lumbar vertebrae can be thrown back considerably, but cannot be bent 
forwards further, as a rule, than is sufficient to bring the fronts of the 
bodies into a straight line by undoing the natural convexity forwards. 
Conversely, in the thorax the column can be straightened so as to undo 
the normal concavity forwards, but cannot be bent further back. Lateral 
flexion is practically allowed in all the three regions of the movable part 
of the column, but while it is of a pure description in the lumbar region, 
and almost if not altogether so in the thoracic region, it is not so in the 
cervical region, because the obliquity of the cervical articular surfaces 
compels an upward gliding of one on another to be accompanied by a 
forward motion and vice versa. Lateral flexion in the cervical region is 
therefore always accompanied with a certain twisting movement. But, 
neither is pure rotation possible in the neck, seeing that the planes of 
■contact of its articular surfaces do not form arcs of circles; the apparent 
rotation is rather a circumduction, produced by oblique twists and com- 
pensatory backward and forward movements. In the lumbar region 
rotation is completely prevented by the locking of the articular processes. 
In the thoracic region alone is pure rotation allowed, the axis of rotation 
corresponding nearly with the fronts of the bodies of the vertebrae. 
The atlanto-axial articulation, although it is distinctly a pivot-joint, 
and that by means of which the head is enabled to be turned from side 
to side on the top of the column, is not so constructed as to allow a per- 
fectly simple rotation round a vertical axis. It has been pointed out that 
the inferior articular surfaces of the atlas do not fit exactly to the 128 
THE SKELETON. 
superior articular surfaces of the axis when placed symmetrically over 
them; hut that on the contrary a gap is left on each side, in front and 
behind, in consequence of the axial surfaces being each divided into an 
anterior and a posterior part, with a slight elevation between. If, how- 
ever, the atlas be rotated, the anterior facet of the axial surface of one 
side and the posterior facet of the other side come into perfect contact 
with the atlas, so that there is much greater stability than when the parts 
are placed symmetrically. The transverse process of the atlas is depressed 
on the side toward which the head is turned, and rises on the other. 
The atlanto-occipital articulation is principally adapted for flexion 
and extension, but admits of a distinct, though often overlooked, oblique 
rotation when the head is midway 
between the extremes of these posi- 
tions. The articular surfaces are 
not spherical, the occipital condyles 
being divided by an oblique ridge 
into two parts, and there cannot, 
therefore, be continuous conforma- 
bility in different positions. They 
are most extensively in contact in 
extreme over-extension, when the 
posterior edges -of the atlantal 
surfaces are locked in depressions 
at the back of the condyles, and 
the posterior tubercle presses against 
the back of the foramen magnum, 
so that no rotation is possible. 
But when the occipital bone is 
flexed forwards, a gap is opened 
between the condyles and the backs 
of the atlantal surfaces, and this 
Fig. 185.—Articulations of Atlas, Axis and 
Occipital Bone from the front, placed as when the 
head is thrown back and twisted to the left, a, a, 
Occipital condyles ; b, b, inferior articular surfaces of 
atlas; c, anterior common ligament; d, narrow 
occipito-atlantal commencement of the same. 
increases until complete flexion is reached, in which the atlas is locked 
against the occipital bone in front of the condyles, and rotation is again 
impossible. 
The ribs move round their heads, the interarticular ligament, where 
present, being the centre of the movement. The plane of movement is 
determined by the plane of contact of the tubercle with the transverse 
process, which from the fourth rib downwards is oblique and compels 
the rib to glide backwards when pulled upwards, and forwards when 
depressed. By this means the shafts are thrown backwards to such an 
extent, when elevated, that the capacity of the chest is greatly increased 
in that direction in inspiration. The anterior extremities of the sternal 
ribs, from the second downwards, revolve round the sterno-chondral 
articulations, and when the muscles are removed a costal arch can be made 
to move upwards and downwards round its two extremities like the MOVEMENTS OF THE AXIAL SKELETON. 
129 
handle of a bucket. Also, in a dissected thorax, it may be noticed that 
when the sternum is moved upwards and downwards, the first costal 
arch, being the shortest of those attached to it, exhibits the greatest 
amount of angular motion. But in respiration, owing to the mode in 
which the elevating force is applied, and the resistance opposed to the 
rise of the first rib, the movements of the chest are quite different. In 
quiet respiration in the healthy chest the first rib and the top of the 
sternum remain unelevated, while the lower end of the sternum is raised 
and slightly advanced; and in forced respiration, although the first rib 
and top of the sternum are raised, their movement is not to the same 
extent as that of the sequent ribs and the lower end of the sternum. 
The body of the sternum in respiration is pushed by the successive costal 
cartilages when these are raised, and offers resistance to them; also, the 
backward sweep given to the hinder parts of the shafts would obviously 
cause their extremities, if free, to retreat from the middle line. By these 
two factors the larger sternal ribs are bent on themselves, and the 
angles above their junctions with their cartilages are forcibly opened in each 
inspiration, so that the parts spring back when the respiratory effort 
ceases. It can easily be seen in healthy respiration that the thorax is 
increased in size in every direction, namely, upwards, downwards, back- 
wards, forwards, and transversely. But when the lower end of the 
sternum is abnormally turned in underneath the manubrium, it can no 
longer be pushed forwards by the costal cartilages. 
The movements of respiration can be demonstrated both on the dead 
subject and on the living to be influenced greatly by the position of the 
vertebrae. When the thoracic part of the column is extended, the ribs 
are raised and the intercostal spaces widened; when it is bent, the reverse 
takes place. In consequence of this, if the body be bent forwards and 
a full breath be taken and the breath held, a considerable amount of 
additional air can be inhaled when the erect attitude is resumed. Con- 
versely, if, with the back well straightened, as deep an expiration as 
possible be made and the breath then held while the body is bent, an 
additional expiration is permitted.1 When the thoracic vertebrae are 
rotated, the ribs of the side toward which the head is turned are 
elevated, and those of the opposite side are depressed, while costal respir- 
ation is interfered with. 
The whole axial skeleton is much more frequently balanced in an 
unsymmetrical than in a symmetrical position. The position termed in 
military drill “ standing at ease ” is much more natural than that which 
is understood by “ attention ”; that is to say, that the natural position 
in standing is with the main weight supported upon one limb, the knee 
of which is straight, while the other limb has the knee bent. In such 
circumstances the pelvis is necessarily thrown into an oblique position, 
1 These facts have been overlooked by physicians in measuring vital capacity, 
and even to some extent in resuscitating the drowned. 130 
THE SKELETON. 
and the lumbar vertebrae with it, and the parts higher up are thrown 
into compensatory curves; the mesial curves are exaggerated, and lateral 
curves are produced, the lumbar vertebrae presenting a concavity toward 
the higher side of the pelvis, and all the joints above being placed in 
oblique positions, including the atlanto axial and atlanto-occipital articu- 
lations. 
DEVELOPMENT OF AXIAL SKELETON OF TRUNK. 
Both in birds and mammals a thickening has been observed on the 
ventral aspect of the sheath of the notochord opposite each pair of muscle- 
plates, but continued outwards with such an obliquity as to lie at the sides 
in the interval between that pair and the next. This is the 'primitive arch, 
and in the atlas persists (A. Froriep). It is followed immediately in the 
sheath itself by a ring of cartilage with whose upper margin, in vertebrae 
other than the atlas, it becomes blended. The notochord is constricted 
and soon obliterated where each ring of cartilage grasps it, but is enlarged 
in the intervals destined for the intervertebral discs. Laterally, the 
vertebrae extend outwards to form the ribs and costal cartilages ; while, 
dorsally, they give off the neural arches which for a time pass only partly 
round the spinal canal. The first primitive arch forms the atlas, while 
the corresponding cartilaginous ring of the notochordal sheath is converted 
into the odontoid process. 
In the human embryo chondrification begins at the commencement of 
the second month, but the neural arches are not closed in with cartilage 
till the fourth month. In an embryo an 
inch long with ossification of the clavicle 
just begun, and probably, therefore, six 
weeks old, I observed that the upper costal 
arches had extended round to the middle 
line in front, that the others had attained 
their full relative length, and that at the 
site of the tubercles the ribs were still 
Fig. 136.—Vertebra of Embryo one 
inch long, with pair of ribs continuous 
with it at the tubercles. 
continuous with the vertebrae, while a complete line of separation between 
rib and vertebra extended inwards from this. The oblique position 
into which the vertebra is thrown as development proceeds is therefore 
effected by rotation round the transverse process, and this accounts for 
the head of the rib being displaced upwards into contact with the body 
of the vertebra above. 
The sternum, there can be no doubt, is at first laid down in the form 
of two lateral strips at right angles to the tips of the costal cartilages. 
It is impossible, however, to refer these strips to prolongations from the 
costal tips. Judging from the appearance in the third month, the manu- 
brium may be originally continuous with the first pair of costal cartilages, 
but the mesosternum takes its origin distinct from costal cartilages, and DEVELOPMENT OF AXIAL SKELETON OF TRUNK. 
131 
the xiphosternum is at first separated from the mesosternum by the sixth 
and seventh costal cartilages meeting in the middle line.1 
Ossification. The vertebrae from the third cervical to the fifth sacral 
have three principal centres of ossification, namely, a pair appearing in 
the seventh or eighth week to form the arch and processes, and a mesial 
ossification, the centrum, appearing immediately after. The osseous laminae 
are united in the first year after birth, and the arches so formed begin 
to be joined to their centra in the third year. The seventh cervical 
vertebra has, in the anterior or costal parts of its transverse processes, an 
additional pair of osseous nuclei appearing in foetal life and detectable for 
a variable period, and similar nuclei have been seen to occur in the sixth, 
fifth and second vertebrae. So also the three upper sacral vertebrae, and 
sometimes the fourth, have each a pair of additional osseous centres, 
eostal in their nature, which make their appearance successively in later 
foetal life and form the bulk of the lateral masses. 
Epiphyses, or supplementary centres of ossification, appearing about the 
eighteenth year, and recognizable till about twenty-five, are found in con- 
nection with both the bodies and processes 
of vertebrae. The bodies have each an upper 
and a lower epiphysial plate extending as 
far as the circumference, near which they 
are best developed; but in the centre, 
unlike the corresponding epiphyses in other 
animals, they are deficient. Two other 
epiphyses are at the tips of the transverse 
processes and spine; and, in the lumbar 
region, two additional surmount the mammil- 
lary processes. The sacrum possesses, besides 
upper and lower epiphyses of the body of 
Fig. 137.—Lumbar Vertebra of Ado- 
lescent, showing epiphyses, u and I, 
Upper and lower epiphyses of the body ; 
s, that of the spine ; t. that of the trans- 
verse process; m, that of the mammillary 
process. 
each vertebra, two pairs of lateral epiphyses peculiar to it. The upper 
and more important of these corresponds in extent with the auricular 
surface, and is united earlier to the first than to the second and third 
vertebrae, thereby allowing the second sacral vertebra to continue to 
increase in breadth {Cleland, 1889). Like the rest of the column, the 
sacrum is not thoroughly complete till the twenty-fifth year or later. 
In the atlas the lateral masses and posterior arch are formed from a 
pair of ossifications corresponding with those of the arch in other vertebrae. 
At birth, these are united by a mere ligamentous band in front of the 
odontoid process; but, during the first year, cartilage appears, and either 
one, two or three osseous nuclei, which normally become blended with the 
1 The origination of the sternum in lateral parts explains the well-known case of 
M. Groux in whom the two halves remained ununited, and could be pulled separate 
by the great pectoral muscles when the hands were clasped. Less complete division 
also occurs. The original distinctness of the lower parts of the sternum from the 
costal arches may well be kept in mind when comparing with the chelonian plastron. 132 
THE SKELETON. 
lateral masses in the fifth or sixth year. The odontoid process of the axis 
is, as has been explained, in reality, part of the first vertebra, being 
developed round the notochord which was continued through it into the 
base of the skull: but it presents in the human subject a pair of centres 
of ossification, which, before the seventh month, unite to form a centrum 
larger than the proper centrum of the axis. This mass bears trace of its 
double origin in presenting a mesial notch above and below, and not only 
forms the odontoid process but extends some distance lower than the level 
of the superior articular surfaces of the axis. The proper centrum of the 
axis has also been recently seen in the form of a pair of separate nodules 
in the sixteenth week, and of a bilobate nucleus in the seventeenth 
(Macalister, 1894). In four instances out of thirty-one, Macalister has found 
in the axis an ossification intervening in the fore part of the interval between 
pedicle and centrum, interesting as apparently homologous with the anterior 
ossifications of the atlas. A separate nodule is sometimes seen at the 
summit of the odontoid process, and in young monkeys a complete cap 
may be found in this situation. The interval between the odontoid cen- 
trum and the centrum proper of the axis becomes limited by smooth 
surfaces before disappearing, and, within it, a certain amount of osseous 
deposit takes place. But the interval disappears altogether, both in front 
and behind, although on section it is often observable in the adult bone 
(Cunningham). In various animals, as in the sheep, a more notable centre 
of ossification forms a wedge ventrally placed between the odontoid process 
and the axis proper; and in a young polar bear I observe both the inferior 
epiphysis of the odontoid process and the superior epiphysis of the centrum 
of the axis distinct. 
In the ribs ossification begins about the same time as in the vertebrae, 
Pig. 138.—Sterna at Different Ages, showing varieties of ossification, a, In third 
month of foetal life, before ossification has set in ; 6, from an older foetus showing a very 
peculiar set of centres of ossification; c, d, e, varieties of osseous centres in three sterna 
of infants ; /, from a child showing the lower part of the mesosternum in two lateral 
parts, with a foramen in the middle. 
from a single centre. A small epiphysis at the head and another at the 
tubercle appear about the eighteenth year, and, like those of the vertebrae, 
are united with the main bone about the twenty-fifth year. DEVELOPMENT OF AXIAL SKELETON OF TRUNK. 
133 
The sternum is very variable in its ossification. The manubrium may 
have one or several nuclei (six have been figured) which, however, soon 
unite. In the remainder of the sternum the nuclei are mesial or in pairs, 
or may even be both lateral and mesial, and most frequently unite to form 
single segments, but sometimes remain distinct for years. The parts opposite 
the second and third intercostal spaces constitute each a temporary segment; 
the remainder of the mesosternum may have a series of one, two or three 
nuclei or pairs of nuclei. Ossification begins in the manubrium about the 
sixth or seventh month of foetal life, and nuclei appear in the mesosternum 
in series from above downwards for a year or more after birth. I observe 
a distinct osseous centre in the xiphoid process of a child of two years, 
but this is unusual. The mesosternum remains in three segments till after 
puberty, and is not usually completed till the twenty-fifth year. 
11. THE SKELETON OF THE LIMBS. 
THE UPPER LIMB. 
The upper or pectoral limb, often called in human anatomy the superior 
extremity, consists of shoulder, arm, forearm and hand. To the shoulder- 
girdle or pectoral arch belong the clavicle and the scapula. In the arm 
there is only one bone, the humerus; in the forearm are the radius and 
ulna; and in the hand there are as many as twenty-seven bones, which 
are arranged in three groups, the carpus, the metacarpus and the 
phalanges. 
The Clavicle. 
The clavicle or collar-bone unites the manubrium of the sternum with 
the acromion process of the scapula. It is the only bone by which the 
upper limb is articulated to the axial skeleton, and it furnishes the ful- 
crum on which the raised arms are stretched outwards from the body 
and approached again to the middle line. 
In its inner three-fourths the clavicle is curved with the convexity 
in front, while the outer fourth is bent forwards so as to produce a con- 
vexity behind. There is also a slight curvature in the vertical plane, 
which, combined with the horizontal curves, gives a spiral twist, often 
well marked in slender specimens, and contributing strength and spring 
in shocks conveyed through the limbs. It is stout at the inner end and 
flattened at the outer, and may be described as having four surfaces, of 
which the anterior and posterior are narrowed towards the outer end to 
margins, while the upper and lower surfaces are broadened at that part. 
The upper surface is superficial, inclined forwards in its inner half, and 
the only muscular mark on it is near the inner end and posterior border, 
where the clavicular origin of the sterno-mastoid muscle is placed. The 
posterior surface is smooth in its inner and concave part, but externally 134 
THE SKELETON. 
where it narrows to a border it is rough and gives insertion to the trapezius 
muscle. The anterior surface, in its narrow external part, gives attach- 
ment to the deltoid muscle, and more internally broadens into an area 
looking forwards and downwards, and affording origin to the upper part 
Pig. 139.—The Clavicles. A, View from above of right clavicle : a, origin of deltoid 
muscle; 6, margin giving insertion to trapezius; c, subcutaneous upper surface ; d, 
smooth deep surface ; e, origin of pectoralis major ; /, clavicular origin of sterno-mastoid 
muscle. B, View from below of left clavicle : g, acromial surface ; h, conoid tubercle ;i, 
trapezoid ridge ; k, arterial foramina ; I, ridge of costo-coracoid membrane, with groove 
of subclavius muscle behind it; m, costo-clavicular impression. 
of the pectoralis major. The inferior surface presents, near the outer end, 
a marked roughness for the two parts of the coraco-clavicnlar ligament. 
Beginning posteriorly in a prominence (the conoid tubercle) projecting back- 
wards and giving attachment to the conoid part of the ligament, it is 
continued obliquely forwards and outwards as a ridge for the trapezoid 
part; near the sternal end the attachment of the costo-clavicular or rhom- 
boid ligament is marked by an irregular and often depressed surface. 
Between these two ligamentous marks runs a longitudinal groove, from 
which the subclavius muscle arises, bounded in front by a ridge for the 
attachment of the costo-coracoid membrane. The sternal end, the stoutest 
part of the bone, is occupied by a large articular surface of somewhat 
variable curve, prolonged on to a prominent angle directed downwards and 
backwards, which is locked against the back of the articular surface of 
the manubrium when the shoulder is thrown backwards. 
The clavicle has no continuous marrow cavity, but the cancellations 
in its centre are large, and on the posterior surface there are usually one 
or two arterial foramina. It is sometimes perforated near its upper and 
hinder border by a cutaneous nerve. 
The Scapula. 
The scapula or shoulder-blade presents (1) an expanded body, with an 
articular head for the humerus at the outer angle; (2) projecting behind 
the body, a spine with a superficial margin prolonged into a flat process, 
the acromion, which articulates with the clavicle ; (3) arising from the upper 
border, close to the head, an important projection, the coracoid process. 
The body or blade is of a nearly triangular form, having three borders 
and an upper, a lower, and an outer angle, the outer supporting the head. 135 
THE SCAPULA. 
The upper border is the shortest, and springing from its outer part is the 
coracoid process, internal to which is the suprascapular notch converted 
by a ligamentous or sometimes a bony band into a foramen transmitting 
the suprascapular nerve, while the remainder of this border is a thin 
edge directed upwards as well as inwards, giving attachment to the 
omo-hyoid muscle. The vertebral border, the base, is the longest, and 
divisible into three parts, a short part opposite the spine, with a second 
part above, and a third 
and longer part below, 
both inclining outwards 
as they recede from the 
first. The uppermost 
part gives attachment 
to the levator anguli 
scapulae muscle, the 
short middle part to the 
rhomboideus minor, and 
the lowest part to the 
rhomboideus major. The 
axillary border is at the 
side of a stout bar 
descending from below 
the articular head; at 
its upper part it presents 
a well marked rough- 
ness about an inch long, 
where the long head of 
the triceps muscle is 
attached, and below this 
it is usually marked by 
one or more grooves, 
where the dorsal branch 
Fig. 140.—Right Scapula from Bhhind. Attachments 'of 
muscles : a, omo-hyoid ; b, levator anguli scapulae ; c, rhomboideus 
minor; d, rhomboideus major; e, teres major; /, teres minor; g, long 
head of triceps ; h, deltoid ; i, trapezius ; k, suprascapular notch. 
of the subscapular artery is in contact with it. The anterior surface 
or venter scapulae is for the greater part slightly hollowed to form the 
subscapidar fossa, from which, as well as from the stout bar outside, 
as far as the axillary border, the subscapularis muscle takes origin, for 
the most part fleshily, hut with tendons within it indicated by converging 
ridges. In front of the upper and lower angles are two small flat surfaces 
beyond the subscapular fossa, which, together with a narrow line running 
between them in front of the base, give attachment to the serratus magnus 
muscle. On the posterior surface or dorsum scapulae, above the spine, is 
the supraspinous fossa, filled by the supraspinatus muscle ; while, below 
the spine the infraspinatus muscle occupies the greatest space, arising 
from what is properly called the infraspinous fossa; while external to it, 
on the thick bar at the axillary margin, is an elongated area with distinct THE SKELETON. 
boundaries indicating the origin of the teres minor, and below this a 
flat surface expanding behind the inferior angle, where the teres major 
takes origin. 
The spine strikes backwards from the dorsum, arising by a line between 
the middle division of the vertebral border and a point separated by a broad 
groove from the back part of the articular head. From the outer end of this 
line a smooth concave border is directed backwards and upwards, while from 
the inner end there slopes a broad superficial border, more elevated as it 
extends outwards, till it arrives over the other, when both spread out and 
Pig. 141,—Right Scapula from Above. 
a, Supraspinal fossa; b, superficial mar- 
gin of spine ; c, acromion ; d, glenoid 
fossa; e, neck; /, angle outside the 
suprascapular notch where the'coracoid 
process changes its direction ; g, rough 
attachment of coraco-clavicularligament; 
h, insertion of pectoralis minor muscle ; 
k, i, origins of coraco-brachialis and short 
head of biceps. 
Fig. 142.—Right Scapula from Anterior 
and Outer Side, a, Notch of the glenoid 
fossa for reception of the small tuberosity of 
the humerus when the arm is raised. 
become respectively the upper and under surfaces of a broad expansion 
called the acromion, which curves upwards and forwards on the top of the 
shoulder and bears on its inner edge, close to the tip, a small oval surface 
for articulation with the outer end of the clavicle. The superficial border 
of the spine begins at the base of the scapula by a smooth triangular area, 
over which glides the flat tendon of the lowest fasciculi of the trapezius 
muscle as it passes outwards to be inserted into a rough mark which lies 
across the border, beyond the triangular area. Outside this the upper 
edge of the superficial border of the spine and, continuous with it, the 
inner edge of the acromion are rough and give attachment all along to THE SCAPULA. 
137 
the trapezius muscle, while the lower border of the spine, together with 
the outer edge of the acromion, gives origin to the deltoid muscle. 
The head is the thickest part and supports a slightly concave articular 
surface called the glenoid cavity. This surface is pyriform, with the upper 
end narrow and inclined forwards so as to leave a notch in front. It fits 
the spherical curve of the head of the humerus, and is bevelled round the 
margin, giving attachment to the glenoid ligament which surrounds it. It 
is surmounted by a little tubercle from which the long head of the biceps 
muscle arises. 
The coracoid process ascends vertically at its base from between the 
head and the suprascapular notch, but soon bends abruptly forwards with 
an outward inclination and a slight downward curve, projecting from under 
the outer end of the clavicle. On the posterior half of its upper surface is 
a thick tuberosity, giving attachment to the conoid and trapezoid ligaments, 
while from the margin of the tip spring the short head of the biceps muscle 
and the coraco-brachialis by a common origin, and more internally the tendon 
of the pectoralis minor muscle. The coracoid process, though only a portion 
of the scapula in the human subject, and reduced to much smaller proportions 
in many mammals, is the representative of a distinct element of the shoulder- 
girdle in monotremata and non-mammalian vertebrata. 
The term neck is sometimes given to the constriction passing beneath the 
head and through the suprascapular notch, separating the head and the 
coracoid process from the rest of the bone. The neck is much more elongated 
and obvious in many mammals than in man. 
The Humerus. 
The humerus or arm-bone is thick and rounded above, slenderer below 
the middle, and flattened out distally into an external and internal epicondyle, 
surmounting the inferior articular extremity which is curved slightly 
forwards. 
The upper extremity presents a head for articulation with the glenoid 
fossa of the scapula. This is large and rounded, forming less than a 
hemisphere, but, when coated with cartilage, accurately spherical in curve, 
except close to the margin below, where a narrow crescentic addition 
would be required. It looks upwards, inwards, and a little backwards, 
when the line joining the epicondyles is placed transversely. Immediately 
outside the head is the great tuberosity, in front the small tuberosity, and 
between the tuberosities the bicipital groove. The circle of depression 
round the head, passing between it and the tuberosities, is distinguished 
as the anatomical neck, while the part below the level of the tuberosities, 
where the upper extremity narrows to the shaft, is called the surgical neck, 
and is a frequent site of fracture. The great tuberosity is continued up from 
the shaft, bulging slightly outwards ; it presents a facet looking upwards 
which gives attachment to the supraspinatus muscle; another, behind it, 138 
THE SKELETON. 
looking upwards and backwards, on which is inserted the infraspinatus 
muscle; and a third, looking directly backwards, on which the teres minor 
is inserted. On the small tuberosity is inserted the subcapularis muscle. 
Great tuberosity 
Small tuberosity 
Supraspinatus 
Infraspinatus 
Teres minor 
Teres major 
Latissimus dorsi 
Pectoralis major 
Coraco-brachiali; 
' Outer border of 
musculo-spiral 
groove 
Base of deltoid' 
roughness 
’ Posterior margin 
of deltoid rough- 
ness 
Outer tip of brach- 
ialis anticus 
Inner border of 
musculo-spiral 
groove 
Apex of deltoid 
roughness 
Arterial foramen 
( Deep fibres of 
'( triceps 
Coronoid fossa! 
Olecranon fossa 
Radial fossa 
Capitellum 
Internal epicondyle 
External epicondyle 
Trochlea for ulna 
Radial groove 
Trochlea 
From the front and inner side. 
From behind. 
Fig. 148.—Right Humerus 
On the shaft, for a fourth of its length, the bicipital groove, so named 
from lodging the long head of the biceps muscle, descends with a slightly 
inward inclination, bounded by an outer ridge which denotes the insertion 
of the pectoralis major muscle, and a less prominent inner ridge to which 
the teres major muscle is inserted, while the tendon of the latissimus dorsi 139 
THE HUMEEUS. 
is attached to the rough lower part of the floor of the groove. Lower down 
and to the outside, looking forwards and outwards, is the deltoid eminence, 
a prominent roughness denoting the insertion of the deltoid muscle, bifurcated 
above and pointed below, reaching below the middle of the shaft, where it 
is sometimes so elevated as to give the bone the appearance of being bent. 
Looking forwards and inwards about the same level there is a slight linear 
roughness where the coraco-brachialis muscle is inserted, and just below 
it the arterial foramen sloping downwards into the bone and conveying 
the principal artery and vein of the marrow-cavity. The posterior border 
of the deltoid eminence is continued upwards towards the facet of the 
teres minor by a line from which the outer head of the triceps muscle arises, 
and it forms the anterior limit of the musculo-spiral groove, which twists from 
behind downwards and forwards and is limited below and behind by the 
external supracondylar ridge. This groove has resting on it the musculo- 
spiral nerve and superior profunda vessels, and is bare of muscular attach- 
ment in the length of its course, as is the inner and posterior surface 
with which it is continuous; but the upper part of the brachialis anticus 
muscle, which grasps the deltoid eminence with a bifid extremity, invades 
the lower and fore part of the groove, and the area so covered may be 
marked off from the rest by a line, and represents the much larger 
groove in many animals, which reaches up the whole length of the shaft, 
and is covered completely with brachialis anticus. The external and internal 
supracondylar ridges extend upwards from the two epicondyles, and separate, 
below the deltoid eminence, a flat posterior surface giving fleshy origin to the 
short head and deep part of the triceps muscle from an anterior surface 
covered by the brachialis anticus and divided into an outer and inner 
portion by a smooth elevation descending in continuity with the deltoid 
muscle. The external supracondylar ridge is the rougher and longer, and 
affords attachment, below the musculo-spiral groove, to the external inter- 
muscular septum, and, in front of the septum, in its upper two-thirds to the- 
supinator longus, and in its lower third to the extensor carpi radialis. 
longior. To the internal supracondylar ridge is attached the internal inter- 
muscular septum. 
The lower extremity, when laid on a flat surface, causes the shaft ta 
incline downwards and inwards by the prominence of the inner border of 
the articular surface. The external epicondyle, which gives attachment to 
extensor muscles of the forearm, descends lower than the internal, while the 
internal epicondijle, which gives attachment to flexor muscles, is more pro- 
minent laterally. The articular surface presents two parts, one for the radius- 
and the other for the ulna. The radial surface is seen only from the front, 
and consists of a spherically curved eminence, the capitellum, and a groove 
separating it from the sharp margin of the ulnar surface. The ulnar surface, 
or trochlea, is in front internal to the radial surface, but is continued round,, 
so as to be equally visible from behind, where it lies midway between the 
condyles and is broader. It is deeply grooved in its whole extent from 140 
THE SKELETON. 
before backwards; its outer margin turns outwards behind the lower border 
of the radial surface, giving the additional breadth behind; and the lower 
part of the inner margin inclines inwards, giving the appearance to the 
trochlea of sloping downwards and inwards both in front and behind, though 
its groove is in the direction of the shaft. In front, above the capitellum, 
there is a depression which receives the head of the radius in flexion, and 
■above the trochlea a larger depression into which, in flexion, the coronoid 
process of the ulna fits; while, behind, there is above the trochlea a deep 
fossa which receives the olecranon in extension. At 
the bottom of this fossa there is sometimes a per- 
foration as in many other mammals; neither, how- 
ever, in man nor in those animals does the olecranon 
fit into this perforation, but it presses against a 
point on the strong inner wall of the fossa where 
usually a mark can be seen indicating the precise 
spot. 
The supracondylar process is an occasional hook- 
like process, not very uncommon, occurring in front 
of the internal supracondylar ridge, having a fibrous 
band extending from it to the internal epicondyle. 
Beneath the arch so formed the median nerve 
passes constantly, while the arterial relations vary 
(Struthers). In some animals, as the cat, a foramen 
occupies the same situation, and is traversed by the 
median nerve and brachial artery. 
Fig. 144.—Supracondylar 
Process on a left humerus. 
The forearm has two bones, the radius and ulna. 
The radius articulates with the humerus outside the 
ulna, and interiorly is in contact with the hand over 
the thenar side, or side supporting the thumb, while 
the ulna lies over the little finger; and as, in ana- 
tomical description, the palm of the hand is said 
to be anterior, and the thumb and little finger are 
said to lie on the outer and inner sides, the radius 
is the outer bone of the forearm, the ulna the inner. 
The palm, however, is capable of pronation and 
supination, which means that it can be turned 
downwards or upwards by the lower end of the 
radius revolving in a semicircle round the ulna 
while the bent elbow is stationary; and the upward 
position of the palm in flexion of the elbow, or its 
BONES OF THE FOREARM. 
Fig. 145.—Sketch to show 
the Mechanism of Prona- 
tion and Supination, a, b, 
Olecranon and coronoid pro- 
cesses of the ulna; c, orbicular 
ligament grasping the head 
of the radius; d, triangular 
fibro-plate permitting the 
lower end of the radius to 
move in a semicircle round 
the ulna. 
anterior position when the forearm is pendent, is the extreme of 
supination. Semi-pronation, though not the position chosen for technical BONES OF THE FOREARM. 
141 
anatomical description, is both the natural and the earliest position. In 
development, the palm looks inwards, with the thumb toward the head, 
and the head of the radius, not only in many mammals, but in all other 
vertebrates in which it exists, articulates with the humerus in front of the 
ulna. The external epicondyle of the humerus is developed overhanging the 
dorsum of the forearm, and the internal overhanging the ventral or flexor 
aspect, as they continue to do in semi-pronation. 
The Radius. 
The radius is much more slender above, where it is in comparatively 
limited contact with the humerus, than at its lower end, which is in extensive 
opposition with the carpus. 
The head, or upper articular extremity, has a nearly circular upper 
surface, with a depression corresponding with the capitellum of the humerus, 
and a convex border which is broadest on the anterior and inner side, and 
fits, especially in semi-pronation, into the groove internal to the capitellum. 
The upper surface is continuous with a vertically-placed articular rim, deepest 
on the anterior and inner side, and rotating in a ring formed by the smaller 
sigmoid cavity of the ulna in conjunction with the orbicular ligament. The 
deepest part of the rim corresponds in semi-pronation with the smaller 
sigmoid cavity of the ulna; and the diameter of the head then thrown into 
the transverse position is slightly longer than the others. 
The shaft is straight and cylindrical for a short distance above, forming 
the neck, then becomes three-sided, and at the same time becomes arched 
in the rest of its extent, with the convexity directed outwards and backwards. 
This arching is important surgically, since in fracture of the lower part of 
the radius it causes the broken ends to be displaced forwards. Opposite to 
where the arch begins is placed the large oval bicipital tuberosity, looking 
inwards and forwards, smooth on its summit, where a bursa is in contact 
with it, and rough along its posterior margin, where the tendon of the biceps 
muscle is inserted. Below this a sharp internal border separates the anterior 
from the posterior surface, and gives attachment to the interosseous mem- 
brane, while both surfaces are continuous on the outer side, by smooth borders 
with the external. The external surface is convex, and about the middle has 
a distinct roughness on it where the pronator radii teres muscle is inserted. 
On the anterior surface a smooth oblique ridge passes downwards and 
outwards from the lower end of the bicipital tuberosity, and separates a 
district extending down from the neck and giving attachment to the 
supinator brevis muscle from a longitudinal groove below and to the inside, 
whence arises the flexor longus pollicis; while from the ridge itself there 
springs the thin radial origin of the flexor sublimis digitorum. Below the 
oblique ridge the arterial foramen for the medullary vessels is situated, 
directed upwards into the bone. The broad lower part of the anterior 
surface is flattened from side to side and made concave by a prominent 142 
THE SKELETON. 
inferior margin, externally distinct from the lower edge of the bone : it 
gives insertion to the pronator quadratus muscle. The posterior surface is 
marked toward the inside by two slight oblique depressions, the upper one 
reaching as high as the upper end of the roughness of the pronator radii 
Limit of subcu-1 
taneous area J 
Small sigmoid 
cavity 
Anconeus 
Coronoid process 
Bicipital tuberosity 
Supinator brev 
I Brachialis anticus 
[ Flexor profundus 
I digitorum 
npital tuberosity 
Extensor ossis 
metacarpi 
pollicis 
Supinator brevis 
' Flexor sublimis 
digitorum j 
Extensor secundi 
internodii pollicis 
Extensor ossis' 
metacarpi 
pollicis 
Pronator terei 
Arterial foramina 
Extensor indicis 
Flexor profundus 
L digitorum 
Extensor carpi 
ulnaris 
Extensor primil 
internodii pollicis ) 
'Pronator quad 
ratus 
Extensor com-' 
munis and exten- 
sor indicis 
Extensor carpi 1 
ulnaris I 
Extensor secundi 
internodii pollicis 
Extensor carpi' 
radialis longior 
and brevior 
[Styloid process 
Fig. 146.—Bones of Right Forearm 
from behind. 
ULNA. 
RADIUS. 
Fig. 147.—Bones of Right Forearm 
from the front. 
RADIUS. 
ULNA. 
teres, and indicating the origin of the extensor ossis metacarpi pollicis, while 
from the other arises the extensor primi internodii pollicis. 
The lower extremity of the radius is thickened from before back- 
wards, and much expanded transversely. At the outside there projects 
downwards a stout projection, called styloid process, not from its shape THE RADIUS. 
143 
but simply from lying on the opposite side of the wrist from the styloid 
process of the ulna. Reaching outwards to near the extremity of this 
process, the inferior articular surface looks downwards and somewhat 
inwards, with an inclination forwards caused by the prolongation down- 
wards of the posterior margin. It is pentagonal in form, and divided 
by a prominent line into an outer triangular part, which articulates with 
the scaphoid bone, and an inner quadrilateral part which articulates 
with the lunar bone. At its inner border it meets at right angles a 
surface looking inwards and concave from before backwards, which re- 
volves on the ulna, and is separated from the radio-carpal joint in the 
recent state by a triangular fibro-plate, which leaves no mark on the 
macerated bone. Behind and on the outside, the lower end of the radius 
is marked by grooves in which tendons are lodged. On the outside of 
the styloid process there is one groove in which lie the extensors of the 
metacarpal bone and first phalanx of the thumb; it is surmounted by a 
roughness to which the supinator longus is attached. Behind there are 
two broad grooves, and between them a narrow groove directed down- 
wards and outwards, with its outer margin always prominent and its 
inner margin variably developed. The narrow groove lodges the tendon 
of the extensor of the second phalanx of the thumb, while the outer 
broad groove is subdivided into an outer and inner part, lodging 
respectively the tendon of the extensor carpi radialis longior and that 
of the extensor carpi radialis brevior; and the other broad groove gives 
passage to the tendons of the extensor communis digitorum and extensor 
indicis muscles. 
The Ulna. 
The ulna is much more slender at its lower than at its upper end. 
It is longer than the radius, and passes up beyond it to fit its olecranon 
process into the corresponding fossa of the humerus. 
The upper extremity presents two articular surfaces termed greater and 
smaller sigmoid cavities, and two projections, the olecranon and coronoid 
processes. The great sigmoid cavity, articulating with the humerus, looks 
forwards and is semicircular from above downwards, with a vertical ridge 
in its whole extent. It is constricted, and sometimes divided, in the middle, 
and above this it forms the front of the olecranon, while below it occupies 
the upper surface of the coronoid process. Internal to the ridge, it is 
transversely concave; while externally it is in its olecranal part bevelled, 
so as to present an elongated outer facet only used in approach to extension, 
and in its coronoid part is limited by the upper margin of the smaller 
sigmoid cavity. The small sigmoid cavity is on the outer side of the coronoid 
process, and is concave from before backwards, fitting against the vertical 
surface on the head of the radius. The olecranon has a rough upper 
surface, giving attachment to the triceps, and behind has a triangular sub- 
cutaneous surface continuous with the border which separates the posterior 144 
THE SKELETON. 
from the inner surface of 'the shaft, while these two surfaces are pro- 
longed up one on each side. The coronoid process presents interiorly a rough 
tuberculated triangular area, into which the brachialis anticus muscle is 
inserted. Both the olecranon and the coronoid process are beaked in front, 
but the coronoid process projects rather further forwards than the olecranon. 
The shaft deviates in its general direction about 10 degrees outwards 
from that of the trochlear ridge of the great sigmoid cavity. It is in the 
greater part of its extent three-sided and slightly curved, with the con- 
vexity backwards; but, for a short distance at the lowmr end, is straight, 
slender and cylindrical. The outer border, separating the anterior from the 
posterior surface and giving attachment to the interosseous membrane, is 
sharp in the greater part of its extent, but at the lower end is reduced to a 
mere line; while above, for about an inch below the smaller sigmoid cavity, 
it is replaced by a triangular area sufficiently depressed to leave room for 
the bicipital tuberosity of the radius passing it in pronation, at the same 
time that it gives origin all over to muscular fibres of the supinator brevis, 
and by the ridge behind it, to tendinous fibres of the same muscle. The 
posterior border, separating the posterior from the inner surface, descends 
from the subcutaneous triangular area of the olecranon, and is itself 
subcutaneous in its whole extent, the aponeurosis of the forearm being 
attached to it; but with regard to its position as seen during life, it 
is to be noted that while in semipronation it is sufficiently prominent 
to be used for leaning on, it is seen, during supination, nearly in the 
middle of the back view of the forearm, as a depressed line between 
the masses of flexor and extensor muscles descending from the two 
epicondyles of the humerus. The internal border is a smooth elevation 
descending from the tuberculated area of the brachialis anticus, and 
separating the anterior from the inner surface. The anterior surface, 
below the tuberculated area, is longitudinally grooved in more than half its 
extent, where it gives origin to muscular fibres of the flexor profundus digit- 
orum muscle, and is perforated towards the upper part of the groove by 
the upwardly directed arterial foramen for the medullary vessels; while on 
its lower part it presents a slight depression, limited internally by a 
line, indicating the origin of the pronator quadratus muscle. The interned 
surface is smooth throughout, and in its upper two-thirds is somewhat 
concave, giving origin in continuity with the grooved part of the anterior 
surface to the flexor profundus digitorum muscle. The posterior surface 
presents above on the outside of the olecranon a triangular area on which 
the anconeus muscle is inserted, separated below by an oblique line from 
a longitudinal groove descending on the inner half of the surface against 
which the extensor carpi ulnaris rests; and external to this are three 
oblique grooves, the uppermost of which, lying below the ridge of the 
supinator brevis, indicates the origin of the extensor ossis metacarpi 
pollicis, while from the second the extensor secundi internodii pollicis 
takes rise, and from the lowest the extensor indicis. THE ULNA. 
145 
The inferior extremity is but slightly expanded, and presents an 
articular surface divided into two parts; one of a circular form looking 
downwards, separated in the recent state from the cuneiform hone by 
the triangular fibro-plate; the other a convex rim looking outwards and 
forwards to articulate with the radius. Behind and internal to the 
articular surface descends the cylindrically-shaped styloid process, which 
gives attachment to the internal lateral ligament of the wrist-joint. 
Between it and the articular surface is the depression to which the 
triangular fibro-plate is attached, and behind there is a groove in which 
lies the extensor carpi ulnaris. 
BONES OF THE HAND. 
The carpus consists of eight small bones arranged in two rows. Those 
of the upper row are named, from without inwards, scaphoid, lunar, 
The Carpus. 
Fig. 148.—Bight Hand, Palmar View. 
Fig. 149.-—Eight Hand, Dorsal View. 
cuneiform and pisiform, and of these, the three first form a block which 
presents superiorly an articular surface convex from side to side as well 
as from before backwards, and looking upwards and backwards; while 
K 146 
THE SKELETON. 
inferiorly it presents another articular surface continuous all the way 
across, but abruptly convex at the radial side, deeply concave in the middle, 
and slightly bevelled internally. The pisiform is articulated in front of 
the cuneiform, and not in range with the other bones of the row. 
The bones of the second row are named trapezium, trapezoid, os magnum 
and unciform; and of these the two inner, namely, the os magnum and 
unciform, fill up the concavity of the upper range, while the two outer, 
the trapezium and trapezoid, articulate with the convexity formed by 
downward projection of the outer part of the scaphoid. 
The scaphoid bone presents superiorly a convex surface looking upwards 
and backwards to articulate with the triangular facet on the radius, and 
inferiorly a deep articular concavity looking downwards and inwards and 
resting on the os magnum. External to both of these surfaces the scaphoid 
Pig. 150.—Palmar View of Bight Carpal Bones, a, Scaphoid ;b, semilunar; c. cunei- 
form ;d, pisiform ;e, trapezium ;/, trapezoid; g, os magnum ;h, unciform, x, x, X, The 
tubercle of the scaphoid, ridge of the trapezium and unciform process of the unciform, 
which, together with the pisiform, give attachment to the anterior annular ligament. 
is thickened and bent forwards as a tuberosity giving attachment to the 
anterior annular ligament. Beneath and behind the tuberosity is a convex 
articular surface continuous with that for the os magnum, and less abruptly 
distinguished from it behind than in front, articulating with the tapezium 
and tapezoid, and most thoroughly in contact with them when the wrist 
is over-extended. The inner side articulates with the lunar and is narrow 
from above downwards and inclined downwards and outwards. The 
anterior and posterior surfaces are non-articular, the anterior concave from 
side to side, the posterior narrow from above downwards and convex from 
side to side.1 
The lunar or semilunar bone is named from its crescentic form as seen 
in profile. Both the outer and inner surface are inclined downwards and 
outwards and are flat. The outer surface is broader from before backwards 
1A little ossicle beneath the inner and back part of the scaphoid was pointed out by 
Gruber as a not unfrequent anomaly, and represents the os centrale found in certain 
mammals. THE CARPUS. 
147 
than the inner, while the inner is the broader from above downwards. 
The upper and under surfaces are quadrilateral, the upper convex, the 
under concave from before backwards. Superiorly it articulates with the 
radius, externally with the scaphoid, internally with the cuneiform, and 
interiorly with the os magnum, while the margin between the inferior 
and internal surfaces is flattened into a narrow surface which comes in 
contact with the unciform bone. The anterior surface is larger both 
transversely and vertically than the posterior. 
The cuneiform or pyramidal bone, presents a flat articular surface 
externally, corresponding with the inner surface of the lunar bone, while 
internally it is rough, rounded and smaller. Its inferior surface is articular 
in its whole extent, resting in contact with the unciform bone, while, on 
the superior surface there is a smaller convex articular surface extending 
inwards a variable distance from the edge of contact with the lunar bone, 
Fig. 151.—Dorsal View of Eight Carpal Bones, a, Scaphoid ;> b, semilunar; c, cunei- 
form ; d, pisiform ; e, trapezium ; /, trapezoid ; g, os magnum ; h, unciform. 
to glide against the triangular fibro-plate. The anterior surface is specially 
distinguished from the posterior by a flat circular articular surface on its 
inner half for the pisiform bone. 
The pisiform bone, as its name implies, is a rounded body like a pea. 
It has only one articular surface, which corresponds with that on the 
front of the cuneiform bone, and from this it droops a little in a downward 
and outward direction. It gives attachment above to the flexor carpi 
ulnaris, below to two ligaments extending to the unciform and fifth meta- 
carpal bones, and externally to the anterior annular ligament. 
The trapezium supports the metacarpal bone of the thumb, and articu- 
lates with it by a large saddle-shaped surface, concave from side to side 
and convex from before backwards, looking downwards and outwards. 
Anteriorly, it presents a prominent ridge for attachment of the anterior 
annular ligament, and, internal to this, a deep groove occupied by the 
tendon of the flexor carpi radialis muscle. The posterior surface is broad, 
and, as well as the anterior and outer surfaces, is non-articular. The inner 148 
THE SKELETON. 
surface is much deeper than the outer, and in its upper half articulates 
from front to back with the trapezoid, while beneath this it has a facet 
posteriorly for the second metacarpal bone, in front of which it is rough 
and curves outwards into the anterior surface. The superior aspect is the 
smallest of all and has a slightly concave articular surface for the scaphoid 
bone. 
The trapezoid is, next to the pisiform, the smallest bone of the carpus. 
Its longest diameter is from its anterior to its posterior free surface; 
and of these the posterior is much the larger, though variable in size. 
The roughness of the anterior surface is prolonged backwards for some 
distance at the lower and outer angle, where it helps to bound the inter- 
val between the bases of the first and second metacarpal bones. The 
inferior articular surface is the broadest, and convex from side to side, 
supporting the second metacarpal bone. The external and internal 
surfaces articulate with the trapezium and os magnum respectively, while 
the superior is narrower and articulates with the scaphoid. Between the 
internal and inferior surfaces, in the posterior part of their extent, an 
angular facet is intercalated, which articulates with the third metacarpal 
bone. 
The os magnum is the largest of the carpal bones. It is surmounted 
by a head, the rounded articular summit of which is prolonged over the 
back of the bone so as to look nearly as much backwards as upwards* 
and is carried still further down on the outer side; and the whole con- 
vexity is divided by a slight line into two parts, articulating with the 
scaphoid and lunar bones respectively. On the inner side is a flat articular 
surface extending from summit to base, interrupted by a rough mark 
for an interosseous ligament, and fitting against the unciform bone. On 
the outside, below the surface for the scaphoid, it articulates by a short 
flat surface with the trapezoid bone. The base, which is horizontal in 
front and looks downwards and outwards behind, corresponds mainly 
with the base of the third metacarpal bone, but posteriorly conies in con- 
tact also with the fourth. The non-articular anterior surface extends from 
summit to base, while the posterior is cut short above by the articular 
head, and is much broader. 
The unciform bone is next in size to the os magnum, and is named 
from a great curved process which, projecting from the inner part of its 
anterior surface, gives attachment to the anterior annular ligament. The 
outer surface of the bone is elongated and flat, corresponding with the 
inner surface of the os magnum, while the base is divided by a line into 
two facets supporting the fourth and fifth metacarpal bones. The inner 
surface is short and rough. The upper surface is articular, looking up- 
wards and inwards, and in more than half its extent from the outer end 
is convex with an inclination backwards, while in the remainder it is con- 
cave and inclined forwards ; it comes mainly in contact with the cuneiform 
bone, but, close to the os magnum, articulates also with the lunar bone. THE METACARPUS. 
149 
The Metacarpus. 
The metacarpal bones are five in number, supporting the digits. Each 
has a base, a slightly curved shaft, and a distal extremity or head 
■convex from side to side as well as from dorsum to palm, and prolonged 
farthest up on the palmar aspect. The first metacarpal bone, that of the 
thumb, requires separate description. The other four decrease regularly in 
size from the second to the fifth, and while differing considerably at 
their bases, have the following characters of shaft and head. 
The shafts of the four inner metacarpals expand gradually from imme- 
diately beyond the base, and present dorsally a flat triangular surface 
Avhich extends up from the head and is prolonged at its apex by a ridge 
separating lateral surfaces. These latter give attachment to muscles, and 
meet on the palmar aspect in a ridge on the distal half of the shaft. 
The head of each of the four inner metacarpals presents an articular 
surface increasing in breadth from behind forwards. It has beneath it, 
in front, a depression to receive the first phalanx in flexion, and on the 
sides of this has prolongations which never come into contact with 
the phalanx. The angles at the base of the triangular area at the 
back of the shaft project laterally as tubercles close to the head, which, 
together with depressions in front of them, give attachment to the lateral 
ligaments. 
The bases of the four inner metacarpal bones have characteristic features 
distinguishing them one from another. The base of the second has its 
upper surface grooved to fit on to the trapezoid, and has two lateral pro- 
jections upwards, the outer of which is seen only behind, and bears a 
lateral facet for articulation with the trapezium, while the inner articulates 
laterally with the third metacarpal bone all the way forwards, and comes 
in contact with the os magnum in front. The base of the third metacarpal 
presents at its posterior and outer angle an upward projection or styloid 
process, ascending beyond the adjacent prominence of the second; it 
articulates above with the os magnum, and at each side with the adjacent 
metacarpals, while on the outer side of the styloid process it has an 
angular facet for the trapezoid. The fourth metacarpal articulates at its 
sides with the third and fifth, while its upper surface inclines very slightly 
inwards and articulates mainly with the unciform bone, but also by a 
small facet behind and to the outer side with the os magnum. The 
fifth metacarpal articulates above with the unciform bone, externally with 
the fourth metacarpal, and has a free rough surface internally, giving 
attachment to the tendon of the extensor carpi ulnaris. 
The first metacarpal bone is shorter and broader than any of the others. 
Its shaft is somewhat flattened from before backwards, presenting posteriorly 
a uniform surface bounded by lateral ridges in front of which is the anterior 
surface, which is divided by a smooth elevation into a broader outer part on 
which the opponens pollicis is inserted, and a narrower inner part giving 150 
THE SKELETON. 
origin to the abductor indicis. The base presents a saddle-shaped surface 
convex from side to side, and concave from before backwards for articulation 
with the trapezium. 
The phalanges are fourteen in number, three for each finger and two 
for the thumb. They are everywhere broader from side to side than 
from before backwards. 
The Phalanges. 
The five proximal or metacarpal phalanges are thickest at their bases,, 
which articulate each by a shallow concave surface with the metacarpal 
bone which supports it. The shaft of each has an anterior surface 
longitudinally concave, flat from side to side, and separated by rough 
lateral ridges for the sheaths of the flexor tendons from the posterior 
surface, which is convex in both directions and smooth. The distal end, 
scarcely wider than the shaft, has a convex articular surface with a trochlear 
groove. 
The intermediate four phalanges, or second row of the fingers, are 
immediately distinguished from proximal phalanges by the presence of 
a little antero-posterior ridge on the basal articular surface, separating two 
slight concavities and fitting into the trochlear groove on the phalanx 
above. 
The distal, ungual or terminal phalanges have basal articular surfaces 
similar to intermediate phalanges of the fingers. Beyond the base they 
suddenly narrow, and they are crowned by a rough ridge at the free end. 
Posteriorly they are smooth, but in front present two roughnesses, one 
continuous with the terminal ridge, the other in front of the base and 
giving attachment to a flexor tendon. 
The phalanges of the middle finger are longer than those of the other 
three; those of the forefinger are shorter than those of the ring finger. 
The distal phalanx of the thumb is the largest of all the distal phalanges, 
and its proximal phalanx is distinguished by its breadth. 
A pair of sesamoid bones is found on the flexor side of the metacarpo- 
phalangeal joint of the thumb, and occasionally others occur in the cor- 
responding joint of one or more of the other digits. 
ARTICULATIONS OF THE UPPER LIMB. 
The Shoulder-Girdle. 
The sterno-clavicular articulation has two synovial cavities separated 
by an interarticular fibro-plate, and is surrounded by a dense capsule 
whose fibres are directed upwards and outwards; those in front and 
behind being termed the anterior and posterior ligaments, while two additional 
bands, the interclavicular and the costo-clavicular, strengthen it on the 
inner and outer aspects. 
The interclavicular ligament consists of fibres associated with the capsule. THE SHOULDER-GIRDLE. 
151 
and extends from one clavicle to the other, uniting their upper borders 
and adherent to the interclavicular notch between. 
The costo-clavicular or rhomboid ligament is very strong, extending out- 
wards for as much as an inch in continuity with the posterior ligament, 
but leaving between it and the anterior ligament a recess opposite which 
the capsule is weak. It is attached interiorly to the first costal cartilage 
and superiorly to the roughness on the under surface of the clavicle. 
Externally its fibres are in series with those of the suhclavius muscle, 
and of the costo-coracoid membrane covering that muscle. In connection 
with it there is often a costo-clavicular synovial bursa. 
The inter articular fibro-plate forms a disc strong at the circumference, 
though sometimes perforated in the middle. It is connected in front and 
Fig. 152.—Left Sterno-Clavicdlar and Sterno-Acromial Articulations, a, Inter- 
clavicular ligament; 6, superior sterno-clavicular ligament; r, fibro-plate; d, costo- 
clavicular ligament; e, first rib ; f, tendon of subclavius muscle; g, coracoid process ; 
h, band of costo-coracoid membrane, sometimes called ligament; i, conoid ligament; 
it, trapezoid ligament. 
behind with the capsule of the joint, while at its upper part it is firmly 
attached to the clavicle, and at its lower to the concavity of the articular 
surface of the sternum. 
The outer synovial cavity, between the fibro-plate and the clavicle, 
extends further down than the inner, so as, at its lower part, especially 
on the deep side, to reach even to the sternum beyond the insertion of 
the fibro-plate. The inner stjnovial cavity stretches higher up than the 
outer, but is less extensive. 
The acromio-clavicular articulation, in which the oval articular surfaces 
of the clavicle and acromion take part, is surrounded by a fibrous capsule, 
forming a strong superior and a thin inferior ligament. The synovial 
membrane is very redundant, invading the surfaces of the articular 
cartilages, and projecting in thick fringes between them. 
The coraco-clavicular articulation is imperfect, consisting of a coraco- 
clavicular ligament divisible into two parts, called conoid and trapezoid. 
The conoid ligament, the posterior and inner part, stretches from the conoid 
tubercle of the clavicle down to the back part of the tuberosity of the 152 
THE SKELETON. 
coracoid process, and, as seen from in front or behind, is broad above 
and narrow below. The trapezoid ligament has its fibres parallel, directed 
from the trapezoid ridge of the clavicle downwards and inwards to the 
tuberosity of the coracoid process, its posterior border in contact with 
the outer border of the conoid ligament; and in the recess between the 
two there is often a synovial bursa. 
Ligaments of the scapula. The coraco-acromial or deltoid ligament is the 
more important of these. Its attachment to the acromion is narrow and 
placed on the inner side of the tip; its other attachment extends along 
the outer edge of the coracoid process. Its anterior and posterior fibres 
are strong, while between them there is a weak part or a gap. It com- 
pletes with the acromion an arch separated by a bursa from the humerus 
and the insertion of the supraspinatus muscle, which are pushed up against 
it when the arm is leaned on. 
The suprascapular ligament is the band of fibres which converts the supra- 
scapular notch into a foramen. 
Movements of the shoulder-girdle. The clavicle admits of movement 
on the sternum in upward, downward, fonvard and backward directions. 
Its elevation is limited by the costo-clavicular ligament, which is tightened 
when the arm is raised. When the arm is depressed, as in lifting a heavy 
weight, the interclavicular ligament and interarticular fibro-plate are 
tightened by the rolling upwards of the inner end of the clavicle round 
the attachments of the anterior and posterior ligaments, while the shaft is 
dragged downward and forward, gliding on the first costal cartilage. Thus 
the greatest depression of the clavicle involves a forward position of the 
shoulder. But when the outer end of the clavicle is raised, it can be moved 
forwards and backwards. The coraco-acromial joint allows movement in 
every direction, so far as its own structure is concerned, but is limited in 
its actual movements by the coraco-clavicular ligament and the wall of 
the thorax. The coraco-clavicular ligament limits movement of the lower 
angle of the scapula outwards, and movement of the base both backwards 
and forwards. In shrugging the shoulder the base of the scapula is 
approached to the clavicle; in letting it fall by its own weight, especially 
when the vertebral column is erect, the angle between scapula and 
clavicle is enlarged. When the arm is raised, the lower angle of the 
scapula is carried outwards, the elevation of the arm being accomplished 
by movement of the shoulder-girdle, as well as of the humerus on the 
scapula, and the movements of the girdle being effected in part at the 
sterno-clavicular articulation, and in part at the acromio-clavicular. 
The Shoulder-Joint. 
This is a true ball-and-socket joint, the surfaces being perfectly spherical, 
with the exception that the head of the humerus requires to be very 
slightly raised close to its margin internally. The large amount of variety 
of movement which it allows is obtained by the small size of the scapular THE SHOULDEE-JOINT. 
153 
articular surface as compared with the humeral, together with looseness of 
capsule, and thus it is more liable than other joints to dislocation. The 
tendon of the long head of the biceps muscle traverses the joint, covered 
by a sheath of synovial membrane. 
The glenoid ligament is a fibrous rim surrounding the glenoid cavity, 
which, taking origin from the bevelled margin all round, has its fibres 
matted and forms a yielding addition to the articular surface. At the 
upper end it is continuous with the tendon of the long head of the biceps 
muscle, which takes origin partly from its fibres and partly from the 
tubercle above the glenoid cavity. 
The fibrous capsule (capsidar ligament) is weak, and is loose to such a 
degree that, when the muscles have been dissected away, the head of the 
Conoid ligament 
Trapezoid ligament 
Suprascapular ligament 
Deltoid ligament 
Acromioclavicular articulation 
Long head of biceps within 
the joint ) 
Humeral end of coraco- \ 
humeral ligament | 
Entrance to bursa opened 
Long head of biceps emerging 
Subsoapularis reflected 
Fig. 153.—Right Shoulder. 
humerus, being allowed to hang, will separate as much as three-quarters 
of an inch from the glenoid surface. The fibres are shortest and strongest 
above, where they are attached close to the tuberosities, and are longest 
below, where they descend on the inner side of the humerus for about half 
an inch below the articular cartilage. They come from the margin ot 
the head of the scapula, with the exception of an accessory band of fibres 
springing beneath the deltoid ligament from the coracoid process, the coraco- 
hurneral ligament. Above and behind, the capsule is strengthened by the 
supraspinatus, infraspinatus and teres minor muscles, while interiorly it has 
no muscular support, and in front it is in peculiar relation to the tendon of 
the subsoapularis muscle, which, instead of supporting it, enters into its 154 
THE SKELETON. 
formation, being separated from the head of the scapula by only a bursal 
prolongation of the synovial membrane, so that it may be said to 
perforate the capsule. Another perforation exists between the greater and 
smaller tuberosity, where the upper part of the bicipital groove is converted 
by short transverse fibres into a canal for the passage of the tendon of 
the long head of the biceps muscle.1 
The synovial membrane lines the capsule, and is reflected to the margins 
of the articular cartilages, covering the periosteum within the capsule on 
the inner side of the humerus. It clothes the glenoid ligament and extends 
as a cylindrical investment over the tendons of the biceps.2 When this 
tendon is pulled on, so as to place the scapula as in elevation of the arm, 
the lower end of this cylinder is drawn down beyond the capsule, and a 
loose continuation of it is reflected up to the opening by which it is pro- 
truded, but incloses an additional extent of the tendon when the humerus 
is depressed. Another complication is found underneath the subscapularis 
muscle where a bursa communicating with the neck by a wide or narrow 
opening lies in front of the neck of the scapula. 
Movements of shoulder-joint. Although the capsule appears to be so 
loose, its lower fibres are stretched in extreme elevation of the humerus, 
the hinder fibres when the arm is flung across the chest, and the anterior 
fibres when the arm is thrown backwards; and in these positions the 
glenoid ligament fits into the margin of the head of the humerus. To 
stretch the upper fibres requires further adduction of the humeral shaft 
than mere contact with the side of the body; but it can be obtained by 
throwing back the vertebral column and folding the arms across the 
chest; but even when the upper part of the capsule is stretched, the 
glenoid ligament is not pressing very closely against the inner part of the 
humeral neck. When the humerus is raised till the glenoid margin is 
locked against it, the shaft lies at right angles to the base of the scapula, 
when the anterior aspect is rotated upward so as to supinate the palm, 
and falls a little short of that amount of elevation, if the palm be pronated. 
When the scapula is made to move on the humerus by pulling on the long 
head of the biceps muscle, the glenoid tubercle is fitted into the upper 
end of the bicipital groove, and special stability of position is obtained. 
This is the position when pushing directly outwards. A position of still 
greater stability is got by pulling on both heads of the biceps muscle so as 
to throw the bones into the position which they occupy when one pushes in 
an outward and forward direction; the top of the smaller tuberosity being 
then fitted exactly into the notch in the front of the glenoid fossa. But 
1 The fibres bounding the opening for the subscapularis above and below, and those 
inserted between the subscapularis and teres minor muscles on the inside of the 
humerus, have been described as three gleno humeral ligaments or folds, but have no 
claim to separate description. 
2ln some mammals the tendon of the biceps is superficial to the joint, e.g. in 
the horse ; in rodents it is in contact with the synovial membrane but not surrounded, 
and in the adult sheep it has a short mesotendon (Welcker, Debierre). THE SHOULDER-JOINT. 
155 
in the positions in which pressure is perhaps most frequently made on 
the humerus, its head is pressed not against the glenoid surface hut against 
the coraco-acromial arch, between which and the muscle clothing the joint 
there is a large sub-acromial bursa. Observation on the living subject 
shows that in raising the arm it is not the case that the elevation at the 
shoulder-joint is completed first, and then followed by movements of the 
shoulder-girdle. The elevation of the shoulder-girdle always begins before 
elevation at the shoulder-joint is completed, but the mode in which the 
two movements are mixed differs in different persons. The amount of 
rotation of the humerus allowed is about quarter of a circle, both in the 
raised and hanging condition. 
The Radio-Ulnar and Elbow-Joints. 
The radius and ulna are articulated one with the other by means of a 
superior and an inferior articulation and ligamentous union between. But 
the superior radio-ulnar articulation is inseparably connected with the 
elbow-joint and may be described along with it. 
The elbow-joint. The orbicular or annular ligament is a strong band 
attached in front of and behind the small sigmoid cavity of the ulna, and 
Fig. 154.—Extended Right 
Elbow-Joint from the front. 
а, Anterior ligament, the inner 
part of the ligament removed so 
as to indicate the coronoid fossa ; 
б, external lateral ligament; c, 
orbicular ligament; d, tendon of 
biceps, with the bursa between 
it and the bicipital tuberosity. 
Fig. 155.—Extended Right 
Elbow-Joint from behind, a, 
External lateral ligament; h, 
orbicular ligament; c, gap be- 
tween humerus and radius ; d, 
oblique radio-ulnar ligament. 
forming together with it a complete ring embracing the head of the radius, 
The external lateral ligament is a flat band attached superiorly below 
the external epicondyle of the humerus and interiorly to the orbicular 
ligament. 156 
THE SKELETON. 
The internal lateral ligament arises from below and from behind the 
internal epicondyle of the humerus and its fibres spread out to be inserted 
along the inner edge of the great sigmoid cavity of the ulna, from its 
olecranal to its coronoid extremity. 
The anterior and posterior ligaments are membranous, and though they 
•complete the fibrous capsule of the elbow-joint, they have no share in 
determining its movements. The anterior 
ligament consists of vertical fibres descend- 
ing from above the coronoid and radial 
depressions of the humerus to the coronoid 
process of the ulna and the orbicular liga- 
ment. The posterior ligament consists of 
fibres which arise from the sides of the 
olecranon fossa of the humerus and are 
attached mostly to the olecranon process; 
but the uppermost of them arch across 
continuously, leaving above them a defi- 
ciency in the fibrous capsule, where the 
olecranon fits into the fossa of the humerus 
in extension. 
Fig. 156.—Flexed Right Elbow-Joint 
from behind. a, Posterior ligament; 
h, internal lateral ligament; c, point of 
contact of capitellum and radius. 
and is prolonged up over the fossae of the humerus, in the neighbour- 
hood of which, especially of the olecranon fossa, it is thickened and 
exhibits pads of fat. It is also prolonged on the inside of the orbicular 
ligament and is loosely reflected below it, so as not to interfere with 
pronation and supination. 
The synovial membrane lines the capsule 
The ligamentous union of the shafts of the radius and ulna is effected 
by two structures : 
The interosseous membrane consists of fibres directed obliquely downwards 
and inwards between the sharp adjacent borders of the radius and ulna, 
beginning a little below the bicipital tuberosity, and inferiorly lying well 
back between the bones as far as the lower articulation. 
The oblique ligament is a little band of fibres, not always present, which 
descends from the outer and lower border of the rough surface beneath the 
coronoid process of the ulna, and is attached to the inner border of the 
radius a little below the bicipital tuberosity. 
The inferior radio-ulnar articulation is a joint in which the lower 
articular surface of the ulna is opposed in its vertical part to the concave 
articular surface on the inside of the lower end of the radius, and in its 
terminal part to a triangular fibro-plate. 
The triangular fibro-plate, or so-called fibro-cartilage, is attached by its base 
to the rectangular border separating the carpal surface of the radius from the 
ulnar surface, and by its apex to the ulna at the base of its styloid process. 
The synovial membrane and fibrous capsule are exceedingly loose, so as not to 
interfere with pronation or supination. THE EADIO-ULNAR AND ELBOW-JOINTS. 
157 
Movements of elbow-joint and forearm. The movement of the ulna on 
the humerus is hinge-like, consisting of flexion and extension in one plane- 
This plane coincides with that in 
which the shaft of the humerus lies, 
as may he proved hy piercing the 
ulna with a pin in such a way that 
its point will slightly project and 
scratch the trochlea of the humerus 
when the joint is flexed and ex- 
tended. The curves of such scratches 
are circular, and there is thus perfect 
conformity of the humeral and ulnar 
surfaces; but the inner part of the 
coronoid portion of the ulnar sur- 
face, and the bevelled part on the 
outside of its olecranal portion, only 
glide into contact with the humerus 
on approach to extension. In ex- 
tension of the arm the shaft of the 
ulna is inclined about 10° outwards 
from the direction of the shaft of 
the humerus, so as to make an angle 
of about 170° with it; and con- 
sequently, when the arm hangs by 
the side, with the palm of the hand 
looking forwards, there is an angle 
pointing inwards at the level of the 
elbow; but pronation brings hum- 
erus and forearm into one straight 
line. The movement of the radius 
on the ulna is such that its shaft 
moves in the surface of a cone, the 
head being rotated within the grasp 
of the orbicular ligament, and the 
lower end circumducted round the 
insertion of the triangular flbro- 
Fig. 157.—Interosseous Membrane and Carpal 
Ligaments from the front, with complete over-exten- 
sion of the wrist, a, Oblique ligament; 6, recess 
formed by the interosseous ligament being attached 
interiorly above the posterior margin of the radial, 
surface for articulation with the ulna; c, styloid pro- 
cess of radius; d, inferior surface of ulna; e, triangu- 
lar fihro-plato ; /, upper surface of semilunar ; g, 
tubercle of scaphoid; h, groove on trapezium for 
flexor carpi radialis ; i, ridge of trapezium ; k, articu- 
lar surface of first metacarpal separated in its palmar 
part from trapezial surface by over-extension of the 
joint; I, in, descending ligaments of the pisiform, 
I, to the unciform process, m, to the fifth meta- 
carpal ; n, insertion of flexor carpi radialis into second 
metacarpal; o, the head of the os magnum. The 
pennate fibres in front of the carpus are the anterior 
radio-carpal and anterior common carpal ligaments. 
plate. The apex of the cone is a little lower than the upper surface of the 
head, a slight shifting of the centre of rotation being caused by the turning 
inwards of the thick part of the convex border in pronation. 
In passing from extreme pronation to extreme supination, or the 
reverse, the lower end of the radius describes a semicircle, as may be seen 
by semiflexing the elbow, when it will be found that either the palm or 
back of the hand can be turned upwards. When the elbow is extended 
and the arm hanging, the hand can be rotated three-quarters of a circle, 
so that the palm can be turned outwards by continuation of rotation inwards ; 158 
THE SKELETON. 
but the additional quarter-circle is obtained from the shoulder-joint.1 Owing 
to the capitellum looking forwards, the head of the radius begins to glide 
away from the humerus as soon as the elbow is extended beyond rectangular 
flexion; and in complete extension only its edge remains in contact, while a 
large angular gap is left behind to be filled with synovial membrane. The 
radius, therefore, is more advantageously placed to resist pressure when the 
elbow is somewhat flexed. It is most thoroughly in contact with the 
humerus when it is partially pronated, and the elbow is bent to a right 
angle. 
The Joints of the Wrist and Hand. 
The radio-carpal articulation, or wrist-joint, presents a superior articular 
surface, concave from side to side and from before backwards, divided into 
three facets, the outer two on the radius, 
and the inner formed by the triangular 
fibro-plate; while inferiorly a corresponding 
convex surface is formed by the upper sur- 
faces of the scaphoid, lunar and cuneiform 
bones, united by an external and an internal 
lunar interosseous ligament. The ligaments 
thus named extend the whole distance from 
behind forwards between the upper lateral 
borders of the lunar bone and the opposed 
borders of the scaphoid and cuneiform bones 
respectively, and are lined above by the 
radio-carpal synovial membrane, and below 
by the synovial membrane of the common 
carpal articulation. Strong internal and ex- 
ternal lateral ligaments descend from the 
styloid processes of the ulna and radius 
respectively to be inserted into the cunei- 
form and scaphoid bones. The posterior 
ligament or back part of the fibrous capsule 
has its fibres directed obliquely downwards 
Fig. 158.—Radio-Carpal and Common 
Carpal Articulation laid open from 
behind, a, Lower end of ulna clothed 
with sacciform capsule as it is seen in 
pronation ; b, ridge on radius outside the 
oblique groove for extensor secundi inter- 
nodii pollicis ; c, triangular fibro-plate; d, 
scaphoid portion of the inferior surface 
of the radius, separated, in this specimen, 
from the lunar surface by a synovial 
fringe ; e, lunar ; /, head of os magnum ; 
g, carpo-metacarpal Joint of thumb. 
and inwards; while the fibres of the anterior ligament or fore part of the 
capsule converge pennately to the lunar bone from the radius and the 
triangular fibro-plate. 
The carpal, carpo-metacarpal and intermetacarpal joints have one 
synovial cavity common to them, with the exception that there is a 
1 In watching natural pronation and supination in the living body, it may be noticed 
that the ulna moves as well as the radius, as if the axis of the revolution were between 
the two ; but careful study shows that this appearance depends on a slight rotation of 
the humerus, and if the humerus be well crushed up to keep it from turning, the lower 
end of the ulna remains stationary in pronation and supination. It is alleged by some 
that a slight lateral movement of the ulna is allowed, but this is certainly a mistake. THE JOINTS OF THE WRIST AND HAND. 
159 
separate synovial sac for the articulation of the first metacarpal bone 
with the trapezium, and that there may be a separate sac for that of the 
cuneiform with the pisiform. 
The articulation of the pisiform with the cuneiform is usually described as 
having a separate synovial 
membrane; but perhaps is as 
often found communicating 
with the cavity of the radio- 
carpal articulation. Two de- 
scending ligaments pass from the 
pisiform bone to the base of 
the fifth metacarpal and the 
unciform process of the unci- 
form bone, and bear the strain 
of the tendon of the flexor 
carpi ulnaris. 
The articulation of the tra- 
pezium with the first metacarpal 
hone is always distinct, and 
surrounded with a fibrous cap- 
sule, in connection with which 
three ligamentous bands may 
be described, two of them, a 
palmar and a dorsal, being 
parts of the capsular wall 
uniting the first metacarpal to 
the trapezium, the dorsal band, 
the stronger and broader of 
the two, while the third is a 
distinct ligament at right 
angles to both of them, ex- 
tending forwards from the 
base of the second metacarpal 
to the inner side of the palmar 
prominence at the base of the 
first metacarpal, and seems to 
have escaped notice. It may 
he termed the internal meta- 
carpal ligament of the thumb. 
Fig. 159.—Ligaments of Back of Hand, a, Posterior 
radio-carpal ligament; b, posterior common carpal ligament, 
extending from the cuneiform partly to the scaphoid and 
partly to the trapezoid and second metacarpal; c, external 
lateral ligament of the common carpal joint; d, internal 
metacarpal ligament of thumb, and, above it, the posterior 
band of the carpo-metacarpal joint of thumb; e, f, insertions 
of tendons of long and short radial extensors of carpus ; g, 
synovial membrane stretched by flexion of third metacarpo- 
phalangeal joint ; h, external lateral ligament of second 
metacarpophalangeal joint; i, space between knuckle and 
extended phalanx. 
The ligaments of the first range of carpal bones, uniting the scaphoid and 
cuneiform to the lunar, are the external and internal lunar interosseous, 
a lea y described with the radio-carpal joint, and dorsal and palmar hands. 
TAe ligaments of the second range are dorsal, palmar and interosseous; but 
16 interosseous differ from those of the first range in being rounded 
urn les which allow the synovial membrane to pass them. There is 160 
THE SKELETON. 
always an interosseous ligament between the os magnum and unciform, 
and another between trapezium and trapezoid, but that between os 
magnum and trapezoid is inconstant. 
The common carpal ligaments uniting the two ranges are dorsal, palmar 
and lateral parts of a fibrous capsule. The dorsal ligament has its fibres 
principally directed with an obliquity downwards and outwards, the 
reverse of that of the dorsal ligament of the joint above, while the palmar 
ligament has its fibres pennate, in continuity with that of the joint above. 
The external lateral fibres unite the scaphoid with the trapezium, the 
internal lateral fibres unite the cuneiform with the unciform. 
The ligaments uniting the lower carpals and four inner metacarpals com- 
prise dorsal and palmar bands, the dorsal much more distinctly separate 
than the palmar. A constant ligament extends directly outwards from 
the bases of the second and third metacarpals to the inner and lower 
angle of the trapezium (Bruce Young). 
The bases of the four inner metacarpals are firmly united by dorsal, 
palmar and interosseous ligaments, the latter not only projecting into the 
synovial cavity, but extending below it. 
The anterior annular ligament is a very strong structure, stretching from 
the tubercle of the scaphoid and front of the trapezium to the pisiform 
bone and the process of the unciform bone. Its attachment to the 
trapezium is j)rincipally connected with the ridge, but it also takes origin 
from near the inner border, so as to convert the groove of the trapezium 
into a tubular passage for the tendon of the flexor carpi radialis. It com- 
pletes the concavity of the carpus into a ring. It is called anterior 
annular ligament, in contradistinction to the posterior, which is described 
with the aponeurosis of the limb. 
The metacarpo-phalangeal articulations are kept together by lateral 
ligaments. Posteriorly they are devoid of ligaments, their synovial mem- 
brane being protected by extensor tendon; 
and anteriorly, though they present a thick 
fibrous wall, it is not attached to the meta- 
carpal bone. 
The lateral ligaments spring from the 
tubercles of the metacarpal bones and the 
depressions in front of them. Their pos- 
terior fibres pass to the sides of the phal- 
anges ; while those further forwards are 
attached more to the palmar aspect, and the 
foremost fibres of each turn forwards over 
the front of the metacarpal head to be 
continuous with corresponding fibres from 
the other side, forming a dense wall ad- 
Pig. 160. Metacarpo - Phalangeal 
Articulation. A, Shows by means of 
two dotted lines, extending from the 
place of attachment of the lateral liga- 
ment, that the ligament has a greater 
distance to pass over in flexion than in 
extension. B, Shows the slackened con- 
dition of the lateral ligament in exten- 
sion, and the fibres arching over the 
front of the head of the metacarpal bone. 
herent to the base of the phalanx and with an edge which fits against 
the metacarpal bone in flexion. THE JOINTS OF THE WEIST AND HAND. 
161 
The interphalangeal articulations have strong lateral ligaments and are 
covered behind by the extensor tendons, in front by the thecae of the flexor 
tendons. 
Movements of wrist and hand. The radio-carpal articulation admits 
principally of flexion and extension, hut also allows a notable amount of 
lateral flexion. Adduction or inward flexion is allowed to a much greater 
extent than abduction or outward flexion, and the total amount of lateral 
movement varies in different persons. In lateral flexion the scaphoid, 
lunar and cuneiform bones so move that each presses only on the facet 
ordinarily opposed to it. In complete over-extension, which is the position 
of the joint when the hand is leaned on, the edge of the radius fits into the 
back of the lunar and scaphoid. In the course of over-extension the radius 
presses the lunar forwards between the scaphoid and cuneiform, and when 
the movement is completed, the joint between the two ranges of carpal 
flones being likewise over-extended, the lunar is kept in its place by tension 
of ligaments. When these ligaments are ruptured dislocation of the lunar 
hone forwards is the result. In the joint between the two ranges of the 
carpus lateral movement can only take place in conjunction with the same 
movement in the radio-carpal joint. In such movements the scaphoid, 
semilunar and cuneiform move one on another, so that in inward 
flexion their transverse curve is flattened, and in outward flexion it is 
increased, and in this way their under surfaces are adapted to the irregular 
transverse curve formed by the upper surfaces of the lower range. The 
flattening of the upper range is effected less by an upward than by a 
backward movement of the scaphoid and cuneiform on the sides of the 
semdunar; and the same movement takes place to a greater extent in 
over-extension of the wrist, when the upper range rests on the less convex 
dorsal part of the surfaces of the os magnum and unciform. The amount 
of movement allowed between the carpals of the second range and between 
the bases of the second and third metacarpals is not sufficient to produce 
obvious changes of form; but when pressure is brought down on the over- 
extended hand the transverse arches of the second carpal range and 
metacarpal bases are flattened sufficiently to make tense the palmar and 
interosseous ligaments, which spring back into their previous condition on 
lemoval of pressure, and by this means great elasticity is secured. 
The opposed surfaces of the trapezium and first metacarpal, being saddle- 
shaped, allow movement of the thumb in every direction. The opposed 
surfaces, however, do not accurately fit but have their convexities narrower 
than the opposed concavities. When the thumb is thrown back, only the 
posterior parts of the opposed surfaces are in contact. When it is bent 
inwards and forwards over the palm there is a slighter gap posteriorly; and 
m abduction with slight flexion the inner half of the metacarpal surface 
18 m accurate contact with the outer half of the trapezial surface. 
The metacarpo-phalangeal and interphalangeal articulations are hinge- 
3°ints; but the metacarpo-phalangeal articulations, with the exception of the 162 
THE SKELETON. 
first, allow lateral movement in the extended position so as to separate the 
fingers and bring them together. The lateral movement is allowed by the 
lateral ligaments being attached far back on the sides of the metacarpals. 
In consequence of this, while both external and internal ligament are 
tight in flexion, they are so slack in extension as to allow the surfaces to 
be separated for about a tenth of an inch. When the hand is open the 
fingers are in one flat plane, and spaces may be seen between them when 
held up to the light; but when the hand is cupped the joints of one 
finger fit against the phalanges of the next, making the cup water-tight, 
and the fourth and fifth metacarpals, whose bases move more freely on 
the carpus than do the second and third, are bent forwards so that the 
bases of the fingers lie in the circumference of a circle and their tips are 
crowded together. In clenching the fist, the fourth and fifth metacarpals 
are still further pulled forwards, so as at once to dig the tips of the inner 
fingers more firmly into the palm and make the knuckle of the third 
finger more prominent. 
THE LOWER LIMB. 
The lower or pelvic limb, called also the inferior extremity, is divisible 
into hip, thigh, leg and foot. To the hips belong the innominate bones, 
which, unlike the shoulder-girdle, are firmly articulated with the vertebral 
column, joining together with the sacrum and coccyx in the construction 
of the pelvis. The thigh has but one bone, the femur; the knee-joint 
is protected in front by a large sesamoid bone, the patella; in the leg are 
the tibia and fibula; and in the foot the bones 
are arranged in groups—the tarsus, meta- 
tarsus and phalanges. 
The innominate, pelvic or hip-bone consists of 
three parts—the ilium, ischium and os pubis— 
distinct in early life, and all taking part in 
the formation of the acetabulum, the articular 
cavity into which the head of the femur fits. 
The ilium expands upwards from the aceta- 
bulum, articulates with the sacrum and forms 
the lateral boundary of the expanded space 
called the false pelvis, at the same time that 
it enters into the formation of the smaller 
space called the true pelvis, the brim or inlet 
of which is formed above and behind by the 
The Innominate Bone and Pelvis. 
Fig. 161.—Right Innominate Bone 
about the Twelfth Year, from the 
deep side. The three elements— 
ilium, ischium, and pubic bone— 
meet opposite the acetabulum, with 
an epiphysis between them. 
base of the sacrum, and forwards from the sacrum to the acetabulum 
by the ilium, and from the acetabulum to the middle line in front by 
the os pubis. The ischium lies posterior to the os pubis and articulates 
with both it and the ilium at the acetabulum. Proceeding from the THE INNOMINATE BONE AND PELVIS. 
163 
acetabulum, the ischium and os pubis inclose between them the large 
thyroid or obturator foramen, filled up in the fresh state by the obturator 
membrane, except at its upper part, where the obturator vessels and 
nerve emerge. Thus, the whole innominate bone consists of two 
expansions meeting at the acetabulum, lying in planes at a considerable 
angle one to the other; the upper expansion formed by the ilium, and 
the lower perforated, and formed by the ischium and os pubis. 
The position which the innominate bone occupies in the erect posture 
18 similar to what is obtained by allowing it to hang from the middle 
the crest of the ilium. The parts named anterior superior spines of 
( Anterior superior iliac 
( spine 
Gluteus medius arises. 
Gluteus minimus arises 
Posterior superior 1 
iliac spine / 
'jiuteus maximus arises 
Inferior curved line 
( Anterior and posterior 
( head of rectus femoris 
Posterior inferior 
iliac spine 
llio-pectineal eminence 
Notch of acetabulum 
Semimembranosus) 
arises ) 
Biceps and semiten- \ 
dinosus arise f 
■yuadratus famoris arises 
Obturator foramen 
Pectineus arises 
Adductor longus 
Adductor brevis 
Adductor magnus arises 
Fig. 162.—Right Pelvic Bone, outer side. 
iliac bones and spines of the pubic bones lie nearly in one vertical 
transverse plane; and the tuberosity of the ischium descends little lower 
than the symphysis pubis.1 
The ilium expands upwards from the acetabulum as a flat blade sur- 
mounted by a convex border, the crest, which rises highest in the middle 
° its course, and, looked at from above, is curved like the letter S, forming 
y h°rinerly many erroneous ideas prevailed on this subject. In the great work of 
to T-IUS> at>rica Humani Corporis, the celebrated figures attributed variously 
itian and to J. Calcar place the pelvis in such a position that the sacrum passes 
w WpWar^S *n a direction from base to apex, like the keystone of an arch of mason- 
' ’ and this error remained prevalent in the first half of the present century, 
Plat1 alth°Ugh in the Anatomia of Bartholinus, and more distinctly in Cheselden’s 
Jack8’ the representation is correct. lam obliged to my former student, Dr, William 
g ’ or directing my attention to the remarkable fact that Leonardo da Vinci has 
rDhfc the P°sition accurately, da Vinci having by his private researches kept himself 
S1 , where Vesalius and either Titian or Titian’s distinguished pupil went astray. 164 
THE SKELETON. 
a concave boundary to the false pelvis, and bending in the opposite direction 
behind. The crest is thick in the fore and back parts of its course, and 
thinner between. The anterior thick part presents two lips separated by 
a ridge, the outer lip giving attachment to the fibres of the external 
oblique muscle of the abdomen, and the inner to the internal oblique 
and the transversalis: the middle thin part gives attachment externally 
to the hinder portions of the oblique muscles and to fibres of the latissimus 
dorsi, and internally to the quadratus lumborum, while the posterior apon- 
eurosis of the transversalis muscle lies between; and the thick back part 
gives attachment to the lumbar fascia and deep muscles of the back, showing 
also on the inner side of the fore part of the surface devoted to them 
the mark of attachment of the ilio-lumbar ligament. The anterior pro- 
jecting extremity of the crest is called the anterior superior spine, and 
affords attachment in front to the sartorius muscle, outside to the tensor 
fasciae femoris, and internally to Poupart’s ligament. Separated from it 
by a short concave edge, the anterior inferior spine projects forwards, and 
gives origin to the anterior head of the rectus femoris muscle and to the 
ilio-femoral ligament; and below this the border of the ilium forms along 
with the pubic bone a convexity in front of the acetabulum, the ilio- 
pectineal eminence. The posterior extremity of the crest is called the 
posterior superior spine, and is separated by a short and sharp concave 
margin from the posterior inferior spine, which supports internally the 
posterior extremity of the articular surface for the sacrum. Beneath this, 
the border is hollowed out, forming the greater part of the great sciatic 
notch. 
The dorsum ilii, or outer surface, presents areae for the attachment 
of the gluteal muscles; namely, posteriorly, for the gluteus maximus, a 
rough surface, extending down to the great sciatic notch; in front of 
this, for the gluteus medius, a space broad behind and narrow in front, 
bounded below by a linear mark, the superior curved line, extending from 
outside and behind the anterior superior spine back to the great sciatic 
notch; and below this line a space for the gluteus minimus, broader in 
front than behind, and extending down to the inferior curved line, which 
curves back to the great sciatic notch from the anterior inferior spine. 
The interval between the inferior curved line and the acetabulum is covered 
by the gluteus minimus, and over the upper edge of the acetabulum there is 
a considerable roughness from which the reflected head of the rectus femoris 
muscle arises. 
The internal surface of the ilium presents an expanded, smooth and 
slightly concave surface, the iliac fossa, giving origin to the iliacus muscle 
and bounding the false pelvis. Below this it also enters into the con- 
struction of the true pelvis, by a part separated from the iliac fossa by a 
smooth border which is continued forwards on the os pubis to its spine, 
and is named in its entirety the ilio-pectineal line. Behind the iliac fossa 
a rougher area extends backwards, on which may' be distinguished, in- THE INNOMINATE BONE AND BELYIS. 
165 
feiiorly, the auricular surface for articulation with the sacrum; superiorly, 
a 10ugh elevated part giving origin to the dorsal sacro-iliac ligament; 
and between the two a sinuous depression free from ligament, and ending 
behind between the two posterior spines. The auricular surface is some- 
v hat crumpled, like the corresponding surface of the sacrum, broader in 
front than behind, with a retreating angle looking upwards and backwards, 
and its lower margin horizontal. 
The ischium is most massive where it forms the back part of the 
acetabulum. On its posterior border, behind the acetabulum, there 
projects backwards and inwards a compressed process, the spine, which 
at its extremity is continued into the small sacro-sciatic ligaments, and 
°n its deep and superficial surfaces respectively gives attachment to the 
coccygeus and gemellus superior muscles, without being marked by them. 
Beneath the spine is the small sciatic notch, with a smoothly grooved surface, 
over which the tendon of the obturator interims muscle turns, and 
bounded inferiorly by the tuberosity. The tuberosity projects downwards 
and backwards, and tapers forwards beneath into the ramus. The main 
surface of the tuberosity is divisible into a close-grained quadrate upper 
part for the hamstring muscles, and a rougher lower part continued 
into the ramus and giving attachment to the adductor magnus muscle. 
The quadrate upper part is divided by a diagonal line into a lower and 
inner portion which gives attachment to the combined origin of the semi- 
ten dinosus muscle and the long head of the biceps, and an upper and 
outer portion from which the semimembranosus tendon arises. Above this 
suiface the gemellus inferior arises, and, from the rough external margin, 
the quadratus femoris; while to its inner margin the great sacro-sciatic 
ligament is attached. 
The ramus of the ischium, narrow and slender, prolonged from the 
lower part of the tuberosity, stretches forwards to meet the inferior 
ramus of the os pubis and complete the obturator foramen. Its lower 
border, continuous with the surface of the tuberosity devoted to the 
adductor magnus, gives origin to the upper fibres of that muscle, while 
fis upper border is continuous with the anterior border of the main 
body of the ischium, and like it enters into the formation of the thin 
ndge of the obturator foramen. On its deep side it gives attachment 
fo the obturator internus muscle, and on its superficial side to the 
obturator externus muscle, whose fibres, as they pass outwards, are gathered 
together and lie in the broad groove between the acetabulum and tuberosity. 
The os pubis forms the fore part of the acetabulum and the anterior 
portion of the brim of the pelvis, and presents an elongated oval surface for 
articulation with its fellow of the opposite side by means of an imperfect 
joint called the symphysis pubis. It joins with the ischium, both externally 
a*id internally, so as to surround with it the obturator foramen; and in 
its whole extent its pelvic or deep aspect is smooth, as is also that of 
tbe ischium. 166 
THE SKELETON. 
The part in front of the obturator foramen is called the superior (or 
ascending) ramus, while the broad part which lies beween the obturator 
foramen and the symphysis is the body, and the narrower portion 
from this to the ramus of the ischium is distinguished as the inferior 
ramus. The superior ramus presents toward the obturator foramen a 
surface obliquely grooved in a forward and inward direction for the passage 
of the obturator vessels and nerves, and on the brim of the pelvis ex- 
hibits the pubic part of the ilio-pectineal line, which limits a smooth 
surface looking forwards, whence the pectineus muscle takes origin. 
The ilio-pectineal line ends about three quarters of an inch or more from 
the symphysis, in a more or less prominent spine to which Poupart’s 
I Dorsal sacro-iliac liga 
t ment attached 
Anterior superior iliac \ 
spine / 
Xon-ligamentous groove 
Auricular surface 
Anterior inferior iliac \ 
spine ) 
Great sciatic notch 
Pubic spine 
Symphysis pubis 
Pubic crest 
Ischial spine 
Small sciatic notch 
Fig. 163.—Eight Pelvic Bone, deep side. 
ligament is attached; while sloping from spine to symphysis is a rough 
crest to which the rectus abdominis and its sheath are attached. The body 
of the pubis decreases in thickness from the superior to the inferior 
ramus, and from near the symphysis to the obturator foramen. Beneath 
the crest it gives attachment to the tendinous origin of the adductor 
longus, and by the greater part of its superficial surface to the adductor 
brevis muscle. Internal to these is a ridge for the adductor gracilis, 
fascia lata and dartos, and between the ridge and the symphysis a space 
for the inter-femoral ligament of the symphysis. 
The acetabidum or cotyloid cavity is deeply cup-shaped, surrounded by a 
prominent margin, except at the fore part of its ischial portion, where 
the margin is absent and a notch is left looking downwards and slightly 
forwards. A non-articular depression continued in from the notch occupies 
the middle of the cavity, and the articular surface curves round this THE INNOMINATE BONE AND BELYIS. 
167 
depression, behind, above and in front of it; its posterior part formed by 
the ischium, its middle part, which is also the largest and looks down- 
wards, formed by the ilium, and its anterior part, the smallest of the 
three, formed by the os pubis. The acetabulum looks forwards, outwards 
and downwards; and, therefore, in the erect posture, embraces the head 
of the femur behind, above and internally, while it leaves it exposed in 
front. 
The pelvis has its inlet or brim extending from the promontory of the 
sacrum, round by the ilio-pectineal lines, to the upper border of the 
symphysis pubis, while its outlet exhibits three prominences, namely, the 
coccyx and the ischial tuberosities, the latter being united, in the recent 
state, to the coccyx by the great sacro-sciatic ligaments. Between the 
ischial tuberosities and the symphysis pubis is the pubic or sub-pubic arch, 
the margins of which give attachment to the corpora cavernosa, the 
triangular ligament and muscles of the perinaeum. The pelvic cavity 
being bounded behind by the sacrum and coccyx, and in front by the 
symphysis pubis, the axis of the pelvis, a line drawn so as to be every- 
where equidistant between those boundaries, is considerably curved. As, 
however, the sacrum and coccyx do not lie in a circular curve, and as the 
sacrum is to a certain extent movable round the retreating angle of its 
auricular surface, and the coccyx movable on the sacrum, the best 
expression of the total curvature of the pelvis is to be found in the facts 
that the tuberosities of the ischia descend, in the erect posture, little 
below the symphysis pubis, and that the brim of the pelvis lies at an 
angle approaching 60 degrees to the horizontal plane. 
The male and female pelvis present a number of differences not any 
of them to be found in every instance, but all of them present in well- 
Fig. lo>4.—Pelvis of Male 
Fig. 165.—Pelvis of Female. 
formed specimens. The diameters of the true pelvis are particularly 
miportant in the female. In the full-grown normal European female the 
average transverse, oblique and antero-posterior (or conjugate) diameters 
may be estimated respectively as 5 and \\ inches at the brim, and 
oach as about 4| inches at the outlet, the transverse diameter slightly 
narrowing from brim to outlet, while the conjugate increases below the 168 
THE SKELETON. 
sacral promontory. In the male these diameters are smaller, and the 
ischial tuberosities less everted, and on both accounts the pelvis is 
deeper and the pubic arch narrower; also the obturator foramen has less 
approach to a triangular form. An additional sexual distinction in the 
pubic arch is occasioned by there being constantly in the adult female 
greater breadth between the lines of origin of the graciles muscles; but 
the growth of this breadth is the last part of the ossification of the 
innominate bone to be completed. 
At different ages the pelvis has different shapes. In early childhood the 
iliac blades diverge at a wide angle one from the other and the pelvic 
outlet is of small proportions; but from about the time of appearance of 
the permanent incisor teeth the angle of iliac divarication as measured by 
the anterior borders of the blades diminishes from as much as 85 degrees 
till, when early adult life is reached, it may vary from 20 to 40 degrees, 
while, in later life it again increases notably, especially in heavy pelvises, 
doubtless in consequence of muscular traction. The conjugate and transverse 
diameters of the pelvic brim are about equal in young children; afterwards 
the conjugate grows more rapidly than the transverse till near puberty, 
and finally the adult proportions are approached by more rapid increase 
in width, apparently due to the transmission of the weight of the body 
through the dorsal sacro-iliac ligaments whose surfaces of attachment 
become much enlarged. In lower races of humanity these later changes 
are more or less completely absent, the pelvis remaining of a form termed 
by Turner dolichopellic, but expressed in connection with its mode of 
development as unhroadened.1 
The Femur. 
The superior extremity of the femur or thigh bone presents a rounded head 
and an elongated neck, separated from the shaft by an outer and an inner 
eminence, the great and the small trochanter, with an anterior rough line and 
a posterior ridge uniting them. The head has a spherically curved surface 
forming more than half a sphere, and encroaching on the neck consider- 
ably further above than below. Below and behind the position of a line 
prolonged up the centre of the neck, its surface is interrupted by a 
depression, which gives attachment to the round ligament of the hip-joint. 
The neck is directed upwards and inwards from the shaft at an angle 
varying from 110 to 140 degrees, more obtuse in the male than the female, 
and in the young than the old. If the posterior extremities of the con- 
dyles at the lower end of the bone be placed in a transverse plane the neck 
is inclined distinctly forwards. It is thicker from above downwards than 
from before backwards, and has three sides separated by a superior, an 
inferior, and a less prominent posterior border. The great trochanter pro- 
jects upwards in a line with the outer part of the shaft. Looked at 
ICleland, Memoirs and Memoranda in Anatomy, Vol. 1., p. 95. THE FEMUR. 
169 
from the outside it presents a square surface limited below by a line to 
which the vastus externus muscle extends, and crossed diagonally from 
Gluteus medius 
( Gluteus 
1 minimus 
Ilio-psoas 
( Lower edge of 
| quadratus 
Pectineal line 
Line of con 
tact of 
gluteus 
maximus 
and 
adductor 
Spiral line 
Magnus 
Arterial ) 
foramen) 
f Upper end of 
( linea aspera 
( Lower end of 
linea aspera 
Anterior orl 
external \ 
crucial | 
ligament 
Inner head of 1 
gastrocnemius J 
(Groove of 
| popliteus 
f External 
( tuberosity 
ig-4[lC6.—Right Femur, front view. 
Spine of adductor magnus. 
■above downwards and forwards by another indicating the inferior border 
°f the insertion of the gluteus medius. Below this diagonal the surface 
Fig. 167.—Right Femur, hinder view. 170 
THE SKELETON. 
is smooth, while above it there is an uneven appearance where bursae 
intervene between tendinous bundles. Continuous with the diagonal line, 
there is a roughness in front of the base of the trochanter, indicating the 
insertion of the gluteus minimus. On the summit the tendon of the 
pyriformis muscle is inserted. Internal to the great trochanter is the 
trochanteric or digital fossa, bounded in front by the upper border of the 
neck, and below by the posterior border. Into this fossa is inserted 
the obturator externus muscle, and on the ridge in front of it is a flat 
impression where the obturator internus is inserted. The small trochanter 
is a spinelike projection inwards from the posterior and inner part of 
the top of the shaft, behind the lower border of the neck, and gives 
attachment to the ilio-psoas muscle. It is connected with the back of the 
great trochanter by means of a thick smooth bar looking upwards, the 
posterior intertrochanteric ridge; while, in front, a rough line called anterior 
intertrochanteric begins at the great trochanter by a tubercle at the upper 
and inner side of the insertion of the gluteus minimus, and extending 
downwards and inwards to the inner border of the shaft, passes thence 
upwards and backwards in front of the small trochanter. The roughness 
of this line is caused by the insertion of the strong anterior fibres of the 
capsule of the hip-joint; the tubercle being the attachment of the outer 
band of Bigelow’s ligament, and the pointed projection downwards at 
its inner part that of the ilio-femoral band. The origin of the vastus 
externus reaches to the tubercle, and the combined crureus and vastus 
internus to the anterior intertrochanteric line, as far inwards as the down- 
ward projection; while below this, the limit of the vastus internus continues 
to be indicated by a much slighter mark, the spiral line. 
The shaft is directed downwards, inwards, and backwards, in standing 
with the knees straight and the feet together. It has a continuous curve, 
with the convexity forwards, and in its lower third gradually increases 
in thickness. In the middle third it presents posteriorly a rough ridge, 
the tinea aspera, continued upwards into a rough surface whose boundaries 
extend toward the two trochanters, and interiorly prolonged into two 
svpracondylar lines which extend to the sides of the back parts of the 
condyles, and inclose a smooth triangular surface looking into the 
popliteal space. The whole surface in front of the linea aspera and 
its prolongations is smooth and clothed by the vasti and crureus muscles, 
and thus the middle third of the shaft shows an anterior surface con- 
tinued into an outer and an inner surface by rounded borders, and the outer 
and inner surfaces separated behind by a prominent ridge. But the 
linea aspera presents throughout two prominent lips, with an intervening 
line which represents a broader surface in lower animals. Into the 
linea aspera are attached from within outwards, between the vasti 
muscles, the adductor longus, part of the adductor magnus, and the 
greater part of the short head of the biceps. The inner supracondylar line 
gives insertion to lower fibres of the adductor magnus, and ends interiorly THE FEMUR 
171 
in a spine marking the insertion of a tendon in which the longest fibres of 
the muscle end; while the upper part of the outer line gives origin 
to the lower fibres of the short head of the biceps. The surface prolonged 
up from the linea aspera is divided by a prominent line into an inner 
and an outer portion. The inner portion is mainly devoted to the 
upper part of the adductor magnus muscle, internal to which are inserted 
the adductor brevis, pectineus and iliacus, while in front of the small 
trochanter the spiral line already mentioned comes down to the linea 
aspera. The outer portion is a rough surface for insertion of the gluteus 
maximus, and is usually rather depressed except at its upper end, a little 
below the base of the great trochanter, where it rises in a prominence 
and receives the pull of the large part of the muscle whose tendinous 
fibres are at first spread out in the fascia lata. Above this, and extending 
up a little on the back of the great trochanter, is the place of attachment 
of the quadratus femoris. About the middle of the linea aspera is 
placed the arterial foramen for the medullary vessels, which slopes upwards 
into the bone. 
The inferior extremity presents a large articular surface divided by 
slight marks into three parts, namely, an anterior surface for the patella 
and two rolling surfaces or 
condyles which articulate 
with the tibia and extend 
backwards, separated by 
a deep intercondylar fossa. 
The patellar surface is 
grooved from above down- 
wards, and the part of it 
outside the groove is trans- 
versely convex and broader 
than the part internal to 
the groove, and is con- 
siderably more prominent, 
throwing the patella in- 
wards when the knee is 
straight. Both the condyles 
Pig. 168.—Inferior Extremity of Right Femdr. a, b, The 
depressions in front of the outer and inner condyles, separating 
them from the patellar surface, and receiving the semilunar 
fihro-plates of the knee-joint in complete extension ; c, d, the 
marks of attachment of the external or anterior, and the internal 
or posterior crucial ligaments. The shaded strip on the outer 
side of the internal condyle is the surface on which the inner 
facet of the patella rests in extreme flexion. 
are convex from side to side, and helicoid in their longitudinal curve. 
The outer condyle is the shorter and broader, and has its outer 
border projecting but slightly further out than the patellar surface. 
The inner condyle lies in greater part parallel with the outer; but 
its outer border being almost directly behind the inner edge of the 
patellar surface, its inner border has in its fore part an outward 
curve. The separation of the outer condyle from the patellar surface 
is marked by a sharp line with a groove behind it commencing 
externally with a notch and directed inwards and slightly backwards 
to the intercondylar fossa; the limit of the inner condyle is marked 172 
THE SKELETON. 
by a similar line and groove beginning internally further forwards and 
directed more backwards, but the groove disappears before reaching the fossa, 
and the line changing its direction cuts off a narrow patellar strip on the 
outside of the condyle from the tibial surface. In the erect posture the two 
condyles rest on the tibia in a horizontal plane while the shaft is oblique; 
but when the knee is bent, the inner condyle projects forwards in the same 
direction as the shaft and pushes the patella to the outside. The posterior 
extremities of the surfaces of the condyles turn upwards to the base 
of the triangular area of the shaft; and here the outer condyle becomes 
narrow and slightly curved inwards, and, when the shaft is held vertically, 
comes a little higher than the inner condyle. Above the back of the 
inner condyle a rough surface indicates where the inner head of the 
gastrocnemius muscle arises; a Aveaker mark similarly placed above the 
outer part of the back of the external condyle gives attachment to the 
plantaris, while a depression outside the extremity of this condyle is 
the place of origin of the outer head of the gastrocnemius. On the 
sides towards the back, about the centre of the helix described by the 
condyles, are the external and internal tuberosities Avhich give attachment 
to the lateral ligaments of the knee-joint; and below and behind the 
external tuberosity is a deep groove, directed dowmvards and forwards, the 
popliteal groove, lodging the popliteus tendon in the flexed position of the 
knee, and at its lower and fore part giving attachment to it. A very 
slight but constant depression in the lower border of the groove marks 
the position of the tendon when the knee is extended (Mackay). Within 
the intercondylar fossa there are two special roughnesses; one for the 
anterior or external crucial ligament is placed well back on its outer 
wall, and the other for the 
internal or posterior crucial 
ligament is at the fore part 
of the fossa. 
The Patella. 
The patella (rotula) or 
knee-pan is of the nature of 
a sesamoid bone, developed 
in the insertion of the quad- 
riceps extensor femoris. It is 
broad above, pointed below, 
Fig. 169.—Patella. A, Superficial view. B, deep view, 
showing the articular surface with its vertical ridge dividing 
superior, middle and inferior facets, and the seventh facet 
on the inner edge. 
flattened superficially, thick at its straight superior margin where the 
rectus femoris and crureus are inserted. Its deep surface is articular, 
■except at the lower part, Avhich is rough and, together Avith the edges 
of the pointed projection below, gives attachment to the ligamentum 
patellae. The articular surface is divided by a vertical elevation 
into a broader external portion transversely concave, and a narroiver THE PATELLA. 
173 
internal portion transversely convex; and both in macerated specimens- 
and in those covered with cartilage two slight transverse elevated 
lines subdivide each of these portions into a broad middle facet and 
narrower facets above and below, while, close to the inner margin, a 
vertically elongated seventh facet is seen, which comes in contact with 
the patellar strip of the inner condyle of the femur when the knee- 
joint is bent to its utmost in sinking down on the hams and balls of 
the toes. 
THE BONES OF THE LEG. 
As in the forearm, so also in the leg there are two bones, the tibia 
and the fibula. The fibula is, however, much more slender than the 
tibia in its whole length. In mammals it does not enter into the knee- 
joint, and it forms little or no part of the pillar of support through which 
the weight of the body is conducted to the foot. At the ankle only one 
bone of the foot, the astragalus, articulates with the leg, and it lies 
underneath the tibia; while the joint is guarded at the sides by two 
projections called malleoli, the inner formed by a process of the tibia, 
and the outer by the lower end of the fibula. 
The Tibia. 
At its upper extremity or head, the tibia or shin bone is expanded, 
especially transversely, and supports an outer and an inner condylar 
surface placed side by side with a narrow interval between. Both of 
these are rather concave in the middle where the condyles of the femur 
principally rest, and toward the circumference of the bone they are bevelled 
where they come in contact with the semilunar fibro-plates, and they turn 
abruptly upwards with a slight twist in the middle of their contiguous 
borders, forming the double summit of an elevation termed the spine. The 
inner articular surface is considerably longer from before backwards than 
the outer. The rough interval between the two is elevated where it takes 
part in forming the spine. Behind this, it sinks into a depression, the 
popliteal notch, from which springs the posterior or internal crucial ligament; 
and in front it is wider, giving origin by its inner two thirds to the 
anterior or external crucial ligament, and in its outer third presenting a 
smoother groove, to lodge the external semilunar fibro-plate when the knee 
is extended. At the sides, the head projects beyond the shaft, forming 
the outer and inner tuberosity. The inner tuberosity presents a horizontal 
groove in which lies one of the insertions of the semimembranosus muscle. 
Towards the back of the external tuberosity there is a small articular 
surface for the fibula, looking outwards, downwards and backwards; and in 
front of this a minute area, giving attachment to the tip of the extensor 
longus digitorum, intervenes between the fibular surface and a line which 
curves forwards limiting the origin of the tibialis anticus from the shaft. THE SKELETON. 
Fig. 170. 
Fig. 171. 
Fig. 170.—Right Tibia and Fibula from the front, a, Groove of tendon of semi- 
membranosus ; ft, 6', anterior tuberosity of tibia, 6, surface for bursa, 6', insertion of 
ligamentum patellae; c, attachment of internal lateral ligament; d, lower end of 
insertion of sartorius, gracilis, and semitendinosus; e, origin of tibialis anticus; /, 
mark of insertion of fibres continuous with tensor fasciae femoris, and below it the 
tibial origin of extensor longus digitorum; g, subcutaneous spot on head of fibula ; 
h, i, origins of peroneus longus and brevis ; Ic, origin of extensor longus digitorum; 
I, peroneus tertius; m, subcutaneous area. 
Fig. 171.—Right Tibia and Fibula from behind, a, Popliteal notch ; b, groove of 
tendon of semimembranosus ; c, muscular attachment of popliteus ; d, oblique line of 
origin of soleus ; e, arterial foramen; /, surface for tibialis posticus ; g, surface for flexor 
longus digitorum ; h, crosses the groove for tendon of tibialis posticus; i, crosses the 
groove for tendon of flexor longus halluois ; k, fibular origin of soleus ; I, fibular origin 
of tibialis posticus; m, origin of flexor longus hallucis; n, groove behind external 
malleolus for tendons of peroneus longus and brevis. THE TIBIA. 
175 
Also, it is worthy of note that in front of the external tuberosity, between 
the tip of the area for the tibialis anticus and the inner condylar surface, 
there is a constant fine-grained impression connected with the insertion 
of the band of fascia lata continued down from the tensor fasciae femoris, 
and running back from this a horizontal groove close to the condylar surface. 
In front, at a lower level than the outer and inner tuberosity, there is a 
thick projection, the tubercle or anterior tuberosity, smooth in its upper part 
where a bursa is placed, and rough below, where it gives attachment to 
the ligamentum patellae. 
The shaft is three-sided and tapering in the greater part of its length, 
but toward the lower end it loses the three-sided form and slightly 
increases in size. An inner border, rounded above and below and more 
distinct in the middle, separates the internal from the posterior surface; 
the sharp anterior border or crest separating the external from the internal 
surface descends from the outer side of the tubercle, and is smoothed 
■away in the lower fourth of the shaft; while the outer border, giving 
attachment to the interosseous membrane between the tibia and fibula 
and separating the external from the posterior surface, passes down from 
the articular surface for the head of the fibula to a rough area looking 
outwards, on which that bone rests at the lower end. Thus, the external 
surface, looking forwards and outwards in its upper three-fourths, is turned 
so as to look forwards below : in its upper two-thirds it is transversely 
concave, and gives origin to the tibialis anticus. The internal surface is 
subcutaneous; at its upper part it presents a rough area outside the 
tubercle, where the tendons of the sartorius, gracilis, and semitendinosus 
muscles are inserted one over another, and behind this a more distinct and 
elongated roughness where the internal lateral ligament of the knee-joint 
is inserted. The posterior surface is crossed above by a strongly marked 
oblique line running downwards and inwards from the articular surface 
for the fibula and marking the attachment of the soleus muscle. The 
triangular area above this line gives origin to the popliteus muscle, and a 
smooth longitudinal ridge descending a short distance below it separates 
an outer area giving origin to the tibialis posticus from a larger area to 
which the extensor longus digitorum is attached. On the outer side of 
this line is situated the arterial foramen for the medullary vessels, sloping 
downwards into the bone, and remarkable as the largest foramen of the 
sort in the body. 
The lower extremity is somewhat broadened out and has projecting 
downwards on its inner side a stout process, the internal malleolus, while 
externally it presents a surface concave from before backwards, against 
which lies the lower end of the shaft of the fibula. The articular surface 
for the astragalus has its principal part directed downwards, quadrilateral 
in shape and broader in front than behind, concave from before backwards, 
slightly bevelled at the outer side, and with the posterior edge projecting 
downwards. On the inner side a continuation of the same articular 176 
THE SKELETON. 
surface is turned down on the internal malleolus, deeper in front than 
behind, and in contact with the inner surface of the astragalus. Posteriorly 
two grooves are seen; one, behind the internal malleolus, is deep and 
has lying on it the tendon of the tibialis posticus, with that of the flexor 
longus digitorum on its surface; the other, slight, sometimes absent, placed 
at some distance outwards, marks the position of the tendon of the flexor 
longus hallucis. 
The transverse diameter of the lower end of the tibia does not lie in 
the same plane as that of the head. If the heads of the two tibiae be placed 
with their backs in one transverse plane, the lower ends will be so directed 
outwards as to leave a right angle between the inner sides of the feet; 
but if the anterior edges of the surfaces for the thigh bones be placed in 
one straight line the feet will be parallel, and the articular surfaces of 
the internal malleoli will look directly outwards. In the erect posture 
the tibia, like the femur, is more advanced at its upper than at its lower 
end. 
The Fibula. 
The fibula or peroneal bone is arched more or less backwards, and at 
its upper end lies behind as well as outside the tibia, while below it is 
more directly external to it. Thus, an amputating knife, if passed 
behind the tibia from inside the leg, is liable to be locked in front 
of the fibula. 
The head presents an oval surface looking upwards, forwards and 
inwards for articulation with the tibia, and superficially is subcutaneous. 
It gives attachment by prominences in front and behind to the ligaments 
uniting it to the tibia, and is surmounted towards the back by a styloid 
process to which the short band of the external lateral ligament of the 
knee-joint is attached; while the long band and the biceps flexor cruris 
muscle are inserted further forwards. 
The inferior extremity, whose projection outwards is the external malleolus, 
descends further than the internal malleolus formed by the tibia, but is 
less prominent. It presents three surfaces. One of these, subcutaneous, 
looks outwards and forwards, is broadest opposite the lower margin of the 
tibia, and is bounded posteriorly by a vertical border, and anteriorly by 
one which curves downwards and backwards to meet it. A second 
surface looks backwards and presents a groove in which the tendon of 
the peroneus brevis descends, with the tendon of the peroneus longus 
muscle over it. The remaining surface looks inwards, and is divided into 
three parts, namely, a triangular articular facet convex from above down- 
wards ; a depressed and uneven part further back, giving attachment to 
ligaments; and an area above, looking toward the concave outer surface 
of the tibia, but rather too flat to fit accurately into it, limited in front 
and behind by two diverging rough lines, of which the hinder is the 
better marked. THE FIBULA. 
177 
The shaft is altogether clothed with muscles, except for a short distance 
above the external malleolus, whose subcutaneous surface is continued 
upwards a short distance and comes to a point, from which the sharp 
cinterior border extends up to the head, giving attachment to the aponeurosis 
of the limb. Outside this border is the external surface continuously grooved 
from the head downwards, giving origin in its upper two-thirds to the 
peroneus longus and brevis muscles, and inferiorly turning backwards 
behind the malleolus. The aider border, behind the peroneal muscles, likewise 
gives attachment to the aponeurosis of the limb. It separates the external 
from the posterior surface, which is convex in its upper three-fourths, and 
twists inwards inferiorly to end at the rough surface for the inferior 
interosseous ligament. The posterior surface is roughened by the fibular 
origin of the soleus muscle for two or three inches downwards from the 
head, and gives attachment in the greater part of the rest of its extent 
to the flexor longus hallucis. It is separated by a sharp internal border 
from the internal surface, which is sometimes described as two, because 
it is diagonally crossed from above downwards and backwards by a ridge 
giving attachment to the interosseous membrane, the partition separating 
the anterior from the posterior muscles of the leg. The portion in front 
of this ridge gives attachment to the extensor longus digitorum and peroneus 
tertius muscles; and the portion behind affords origin to the outer part 
of the tibialis posticus; while a few fibres of the extensor hallucis arise 
from the lower part of the ridge itself. 
THE BONES OF THE FOOT, 
The Tarsus. 
The tarsus consists of seven bones, of which the two largest, the 
astragalus and the calcaneum, are placed behind, the astragalus resting 
on the calcaneum. The astragalus is inclined forwards and inwards, and 
carries in front of it the scaphoid, which supports the three cuneiform 
bones, while these in turn carry in front of them the metatarsals of the 
three inner toes. The calcaneum is inclined forwards and outwards, and 
supports the cuboid bone, which carries in front of it the two outer meta- 
tarsal bones. Thus the cuboid and the three cuneiforms together form 
an anterior row articulating with the five metatarsals. 
The astragalus or talus articulates with the tibia and fibula by means 
of an articular surface which, fitting in between the malleoli, extends over 
its body. Continued forwards in front of the inner two-thirds of the body 
is the neck, supporting an articular head which enters into the astragalo- 
calcaneo-scaphoid articulation and has its surface prolonged backwards 
inferiorly as far as a deep groove directed obliquely underneath the part 
covered by the superior articular surface, and giving attachment to the 
interosseous astragalo-calcaneal ligament. This groove has its outer end in 178 
THE SKELETON. 
front of the body, while its inner end is close to the posterior extremity 
of the bone, and the whole of the space behind the groove is occupied 
Fig. 172.—Right Foot, Dorsal View. 
Fig. 173.—Eight Foot, Plantar View. 
by an articular surface for the posterior astragalo-calcaneal articulation, a 
joint into which the calcaneum and astragalus are the only bones which 
enter. 
The superior articular surface, taking part in the ankle-joint, is divided 
by prominent ridges into a central, an inner and an outer portion. 
The central portion looking upwards is convex from behind forwards, and 
slightly grooved longitudinally; its inner border is straight and nearly 
parallel with the inner side of the foot; its outer border is curved forwards 
and outwards so as to give greater breadth in front than behind, and is on 
the whole more prominent, but is flattened out behind to form an angular 
facet, which fits against a ligament and synovial pad between tibia and 
fibula when the foot is extended. The portion of the superior articular 
surface which looks inwards is a sickle-shaped strip, broadest in front and THE TAESUS. 
179 
narrowing to a point behind, and articulating with the internal malleolus. 
The portion looking outwards for articulation with the fibula is much 
larger, nearly quadrant-shaped, with the centre 
■of the quadrant everted and pointing downwards 
■and forwards. 
The surface for the posterior astragalo-calcaneal 
•articulation, behind the groove for the interosseous 
ligament, has its longer diameter concave and 
directed forwards and outwards from the hinder 
extremity of the bone, to end in front external 
to the neck, while its shorter diameter, at right 
■angles to the longer, is flat. The articular surface 
of the head is clothed with a continuous sheet of 
articular cartilage, but presents as many as four 
facets. The largest of these, occupying more 
than half of the entire surface, looks forwards 
and fits into the concavity of the scaphoid bone. 
Beneath this, and separated from it by a distinct 
prominent line, there is placed externally a small 
facet which articulates with a surface on the 
inner third of the foremost part of the cal- 
naneum, and internally a larger facet which lies 
Pig. 174. —Right Astragalus 
from above. a, b, c, Central, 
internal and fibular divisions 
of superior articular surface; 
d, angular facet which fits in 
between tibia and fibula in ex- 
tension of the ankle-joint; e, 
groove for flexor longus hallucis; 
/, surface of head for articulation 
with the scaphoid. 
m contact with the inferior calcaneo-scaphoid ligament, while, behind 
this, between it and the groove for the interosseous ligament, there 
is another facet for articulation with the sustentaculum tali of the 
■calcaneum. The posterior extremity of the astragalus is non-articular and 
marked by a groove directed downwards and inwards, in which lies the 
tendon of the flexor longus hallucis muscle. At the outer margin of this 
.groove there is a special prominence, the posterior tubercle, giving attachment 
to the posterior band of the external lateral ligament of the ankle-joint, 
■and occasionally presenting a separate ossicle (os trigonum). 
The calcaneum or os calcis is an elongated block directed forwards, 
■outwards and upwards, supporting the astragalus, and articulating in 
front with the cuboid bone. 
The surface for the cuboid is deepest externally, and in its internal 
half is deeply concave from above downwards, having an overhanging 
upper margin. The surfaces for the astragalus are separated by a rough 
groove for the interosseous astragalo-calcaneal ligament. The anterior of 
these surfaces articulates with the head of the astragalus and consists 
of two parts, one situated towards the inner side of the foremost part of 
the upper aspect, the other on a ledge projecting inwards further back, 
called sustentaculum tali; and these two portions, always forming distinct 
facets, are sometimes completely separate, and always move on separate 
areae of the astragalus. The posterior of the two surfaces for the astragalus 
articulates with the body of that bone, and is convex from behind forwards 180 
THE SKELETON. 
and outwards. Placed in front of it, in continuity with the groove for 
the interosseous ligament, and external to the surface for the head of 
the astragalus, is a rough depression which gives attachment to the 
extensor brevis digitorum and to 
the loop of the anterior annular 
ligament, and forms the floor of 
a recess on the dorsum of the foot, 
outside the head of the astragalus. 
Behind the surfaces for articula- 
tion with the astragalus, a stout 
neck projects backwards and ends 
in the tuberosity, which is traversed 
by the rough mark of the inser- 
tion of the tendo-Achillis and is 
smooth and close-grained above for 
a bursa, while below it is sub- 
cutaneous. The subcutaneous part 
is continued round upon the under 
or plantar surface, and ends there 
in an external and internal tubercle, 
the internal the larger, to the fore 
part of which are attached the 
plantar aponeurosis and the super- 
ficial plantar muscles. The rest of 
Fig. 175.—Eight Calcaneum and Astragalus. 
A, Calcaneum from above. B, Astragalus from 
below. a, a', Corresponding articular surfaces of 
posterior calcaneo-astragalar articulation ; 6, 6', cor- 
responding surfaces of calcaneo-astragalo-scaphoid 
articulation ; 6, is situated on the sustentaculum 
tali; c, on the body of the calcaneum is often united 
with the sustentacular surface, and overhangs the 
surface for the cuboid ; e, surface of the head of the 
astragalus for the scaphoid ; and between b' and e, 
the surface which presses on the inferior calcaneo- 
scaphoid ligament. X, Marks where the tendon of 
the flexor longus hallucis passes under the sustenta- 
culum ; x', where it leaves the groove on the 
astragalus. 
the plantar surface is occupied principally by the long plantar ligament, 
and has a depressed rim in front for Haversian glands of the calcaneo- 
cuboid joint. Internally, a broad channel between the tuberosity and 
the sustentaculum tali leads from the back of the leg to the sole of the 
foot; and beneath the sustentaculum tali there is a groove for the flexor 
longus hallucis, continuous with that on the back of the astragalus. 
Externally, the calcaneum is subcutaneous, but crossed by the tendons 
of the peroneus longus and brevis, in connection with whose sheaths 
there are in some instances marks 
toward the fore part, the most 
frequent of which is a ridge or 
spine between them. 
The scaphoid or navicular bone 
is short from behind forwards, and 
has its longest diameter directed 
inwards and downwards. It pre- 
sents a large concave articular 
surface behind for the head of the 
astragalus, and in front has a con- 
vex articular surface divided by lines into three facets for the three 
cuneiform bones, the middle facet shaped and placed like the keystone 
Fig. 176.—Left Scaphoid. A, From behind. B, 
From the front. THE TAESUS. 
181 
of an arch. On the inner side, a tuberosity projects downwards which 
receives the main insertion of the tibialis posticus tendon. On the 
outer side there is sometimes a small facet for articulation with 
the cuboid bone. 
The internal cuneiform bone is, as the name implies, wedge-shaped; 
the base of the wedge being directed downwards, forming a thick tuberosity 
placed in front of the tuberosity of the scaphoid, and curved somewhat 
into the sole, below the sharp apices of the middle and outer cuneiform 
bones. The outer surface, in its hinder two-thirds, lies inside the middle 
cuneiform, with which it articulates above and behind by means of an 
L-shaped surface, while further forwards it fits against the second meta- 
tarsal and articulates with it by a facet at the end of the L-shaped surface. 
Pig. 177.—The Three Cuneiforms of Left Side. A, From the front and outer side. 
B, From the hinder and inner aspect. 
The upper margin is sharp and directed upwards and outwards, as well 
as forwards, where in contact with the middle cuneiform ; but in fiont 
of this is prolonged straight forwards and becomes more rounded. The 
posterior surface, articulating with the scaphoid, is concave and much 
shorter than the flat anterior surface for articulation with the first 
metatarsal. On the inner side there is an oblique depression, leading 
to a distinct mark at the lower and fore part, where the tendon of the 
tibialis anticus is mainly inserted. 
The middle cuneiform bone is the smallest of the three cuneiforms, 
neither reaching so far forwards nor so far down as the others. Its dorsal 
surface is quadrate, little longer than broad. The posterior surface, 
articulating with the scaphoid, is slightly concave, and broader than the 
flat anterior surface for articulation with the second metatarsal. Internally 
it has an L-shaped surface, corresponding with that on the internal 
cuneiform, while externally there is a narrow articular surface along the 
posterior edge to articulate with the external cuneiform. 182 
THE SKELETON. 
The external cuneiform projects forwards beyond the middle cuneiform, 
and is much longer than broad. Its articular surface for the scaphoid 
looks backwards and inwards, and is smaller than the anterior, which 
articulates with the third metatarsal bone. The inner side has an 
articular part in front of the posterior margin to articulate with the 
middle cuneiform, and a narrower articular facet at its anterior margin 
for the second metatarsal, while it is rough in the intermediate extent. 
The outer side looks towards the cuboid, and in its posterior part, 
articulates broadly with it. 
The cuboid is longest on its inner side, which is in large part rough, 
but articulates in the middle of its extent with the external cuneiform 
•by means of a broad articular 
surface descending from the 
upper margin, and has some- 
times a small articular facet 
further back for the scaphoid. 
Posteriorly, it articulates by 
a saddle-shaped surface with 
the calcaneum, and has a 
conical process projecting back 
from its lower and outer 
angle. Anteriorly, it presents 
an articular surface divided 
into two facets corresponding with the bases of the fourth and fifth 
metatarsal bones. Externally, it is short and reduced in height, and 
is grooved for the tendon of the peroneus longus. Interiorly, this 
groove is continued inwards across the fore part, and in front of a 
prominent thick ridge which gives attachment to the long plantar 
ligament and the sheath of the tendon of the peroneus longus. 
Fig. 178.—Left Cuboid. A, Plantar view. B, Dorsal 
view, p, Posterior surface; a, anterior surface ; o, outer 
surface; c, conical process ; g, groove for peroneus longus. 
The Metatarsus. 
The first metatarsal bone, that which belongs to the great toe, is 
shorter but much more massive than any of the four others. The base 
extends the whole height of the inner side of the transverse arch which is 
formed by the bases of the five together; it articulates with the internal 
cuneiform bone by a vertically elongated surface indented on its outer 
side, and presents a tuberosity below, which continues forwards the 
thick ridge formed by those of the scaphoid and internal cuneiform. 
This tuberosity presents on its inner side a smooth impression, com- 
pleting with that on the internal cuneiform the mark of insertion of the 
tendon of the tibialis anticus muscle, and on its outer side a larger 
and rougher impression where the tendon of the peroneus longus is 
inserted. The large rounded head is in height about equal to its breadth; 
on its lower part it presents two grooves for two large sesamoid bones THE METATARSUS. 
183 
situated in the tendons of the flexor brevis hallucis; a prominent ridge 
lies between the grooves, and another less prominent ridge bounds the 
inner groove internally. 
The four outer metatarsal bones differ from metacarpal bones in 
tapering from base to head, and on the dorsal aspects presenting sub- 
cutaneous surfaces broad at the bases and narrowing on the shafts, being 
continued in the second, third and fourth into a ridge between the 
origins of the dorsal interosseous muscles. The second metatarsal bone 
is longer and the fifth shorter than the third and fourth, and, in all, the 
shafts have an appearance of obliquity inwards, which is least marked in 
the second, and most distinct in the fourth and fifth. The heads have 
elongated articular surfaces, convex both longitudinally and from side to 
side, prolonged and bifid below; on each side, behind the head there 
is a lateral projection near the dorsum, where the lateral ligament is 
attached. 
The second metatarsal articulates, at its base, behind with the middle 
cuneiform bone; internally, by only a small facet with the internal 
cuneiform, and sometimes by a less distinct facet with the first meta- 
tarsal : and, externally, it is characterized by a surface, or more generally 
two, an upper and a lower, divided into two facets, one in front of the 
other, to articulate with the external cuneiform and the third metatarsal. 
The third articulates behind with the external cuneiform bone, 
internally with the second metatarsal, and externally with the fourth. 
The fourth articulates behind with the cuboid by a surface narrower 
than the corresponding surface of any other metatarsal bone, and externally 
and internally by large facets with its neighbours; while, behind that for 
the third metatarsal bone, it has usually a small additional facet opposed 
to the outer edge of the external cuneiform bone. 
The fifth articulates behind with the cuboid bone, and internally with 
the fourth metatarsal, and is easily distinguished by a large tuberosity 
projecting outwards and backwards at its base, to give attachment to the 
tendon of the peroneus brevis muscle. 
The Phalanges. 
The phalanges of the foot correspond in number with those of the 
and the distinguishing characteristics of their extremities are 
similar. The phalanges of the great toe are larger than those of the 
thumb. In the four outer toes all the phalanges are smaller than the 
corresponding bones of the fingers; the phalanges of the first row are 
nearly circular at the large base and at the narrowest part of the con- 
stricted shaft; those of the second and third rows are remarkably short, 
only the second phalanx of the second toe being, as a rule, as much 
ns twice as long as it is broad. In the fifth toe the dwindling is so 
extreme that the last two phalanges are frequently united by bony union. 184 
THE SKELETON. 
ARTICULATIONS OF THE LOWER LIMBS. 
The Pelvis. 
The ilio-lumbar and lumbo-sacral ligaments are two strong bands which 
extend from the transverse process of the last lumbar vertebra, the one 
downwards to the sacrum, the other outwards to expand on the inner 
side of the crest of the ilium. 
Fig. 179.—Pelvic and Hip-Joints, a, Two intervertebral discs divided by a section 
through the two last lumbar vertebrae and the base of the sacrum; h, section of dorsal 
sacro-iliac ligament; c, section through the synovial cavity of the sacro-iliac articulation ; 
d, small sacro-sciatic ligament; e, great sacro-sciatic ligament; /, section of symphysis 
pubis; g, round ligament of the hip-joint. (Section by Allen Thomson.) 
The sacro-iliac articulation is a perfect joint, the opposed auricular 
surfaces of the sacrum and ilium being clothed with articular cartilage, 
although the inequalities of their faces, and the adhesions and limitations 
of movement liable to set in with advance of years, misled the older 
anatomists into thinking that there was but one cartilage, and calling the 
joint a synchondrosis, as is still sometimes done. 
The ventral sacro-iliac ligament (anterior of books) is a thin layer of 
short fibres bounding the joint in the whole extent looking towards the 
cavity of the pelvis. THE PELYIS. 
185 
The dorsal sacro-iliac ligament [posterior of books) is an extensive and 
strong mass of fibres descending from the rough and prominent area above 
the auricular surface of the ilium to end on the tubercles outside the 
posterior sacral foramina. Its fibres to the lower sacral vertebrae are 
longer than those to the first and second, and directed backwards. 
A terminal sacro-iliac ligament extends from the posterior inferior 
spine of the ilium to the lateral edge of the third and fourth sacral 
vertebrae. It is not to be confounded, as it usually is, with the dorsal 
ligament, from which it is distinct not only in function but in disposition, 
being separated from it by the space between the upper and lower posterior 
spines of the ilium—a space which is at the end of a channel on the 
dorsal aspect of the joint, in which no ligamentous fibres occur. 
The sacro-sciatic ligaments. These are large flat bands which form 
an important part of the wall of the pelvis. 
The great sacro-sciatic ligament arises broadly from the posterior inferior 
spine of the ilium, the side of the coccyx and the whole lateral border of 
the sacrum between. Its fibres are gathered together at the back of the 
ischial tuberosity and are inserted into its inner margin and that of the 
ramus of the ischium, the lower fibres going further forwards than the 
upper, and forming a projecting edge continuous with the obturator fascia. 
The small sacro-sciatic ligament arises from the greater part of the 
border of the sacrum in front of the great sacro-sciatic ligament and in 
close contact with it, and its fibres converge to be inserted into the tip 
of the spine of the ischium. It divides the space left between the great 
sacro-sciatic ligament and the innominate bone into an upper and a lower, 
called respectively the great and the small sacro-sciatic foramen ; the greater 
giving exit to the pyriformis muscle, with the gluteal artery and nerve 
above it, and the sciatic and pudic arteries and nerves below it; the smaller 
giving exit to the tendon of the obturator internus muscle and re-entrance 
to the pudic artery and nerve. 
The symphysis pubis, or interpubic disc, is an incomplete joint consisting 
of fibrous substance loosely disposed toward the centre, sometimes with 
an irregular space within it, especially in the female. The fibres of the 
disc take origin from the opposed surfaces covered in young adults with 
cartilage, and are arranged concentrically ; but they are inclosed by fibres 
attached to the surfaces around, and these are distinguished as superior, 
inferior, anterior and posterior, names so obviously erroneously applied 
that they cannot be recommended. Those which follow are at least 
more correct. The intrapelvic ligament is the shortest and least distinct 
from those of the disc ; the intercristal ligament is strong, to the 
inner parts of the crests; the pyre-urethral is still thicker and, especia yin 
the female, rounds the front of the subpubic arch; the intern wal ligament 
[anterior of books) occupies the surfaces between the lines of attac ment 
of the fascia lata, and has therefore much longer fibres in the lemaie 
than in the male, as has also the pre-urethral. 186 
THE SKELETON. 
The obturator membrane may be conveniently described in this place; it. 
has, however, no connection with any articulation, but is simply part of the 
pelvic wall. It is a fibrous septum stretching across the obturator foramen 
and leaving, opposite the obturator groove of the anterior ramus of the 
pubic bone, an opening for the passage of the obturator vessels and nerve. 
Movements of pelvis. Only in such positions as sitting on the ground 
or crouching down on the balls of the toes, with the column bent 
forwards, is the sacrum placed with its base upwards so as to press 
downwards in the form of a wedge like the keystone of an arch. In 
the upright position, the ventral borders of the auricular surfaces look 
directly downwards, the weight of the body falls immediately in front 
of them, and the dorsal sacro-iliac ligaments are made tense, as is well 
illustrated in pelvises deformed by rachitis, in which the parts of the 
innominate bones giving attachment to those ligaments are bent in over 
the dorsum of the sacrum. The sacral attachments of these ligaments, 
together with the slight projections of the auricular surfaces of the sacrum, 
furnish the axis round which the sacrum rotates, the base being pressed 
down by the weight of the body, and the apex tilting upwards. The 
upward tilting of the apex of the sacrum tightens the sacro-sciatic and 
terminal sacro-iliac ligaments, and is limited by them. In its second and 
third vertebrae the sacrum is wider at the ventral than at the dorsal margins 
of the auricular surfaces, and the tilting up of the apex slightly separates 
the iliac bones while the symphysis pubis forms the hinge of the movement. 
The same movement takes place to a greater extent in parturition, the 
child’s head pressing directly on the apex of the sacrum before pressing 
the coccyx back. But it is also true that the ligaments of the symphysis 
are liable to elongate before parturition, and thereby allow a certain 
enlargement of the brim of the pelvis. 
The Hip-Joint. 
This is a ball-and-socket joint, the curves of the articular surfaces being 
spherical or nearly so. Besides a capsule surrounding it, the joint presents 
a cotyloid and a round ligament within the capsule. 
The cotyloid ligament is a prominent tough fibrous rim surrounding the 
acetabulum, its fibres taking origin from the prominent margin of the cup 
all round, and bridging over the notch by a part distinguished as the 
transverse ligament, in which three sets of fibres can be distinguished, namely, 
two sets arising from the margins of the notch and decussating, and a 
third set superficial to them and passing straight across. 
The round ligament {ligamentum teres) is a distinct cord of fibres rounded 
at its attachment to the pit of the head of the femur, and extending thence 
down to the margins of the notch and to the deep edge of the trans- 
verse ligament, surrounded by a pillar of synovial membrane. It lies 
in the non-articular part of the acetabulum. THE HIP-JOINT. 
1ST 
The fibrous capsule (capsular ligament) is strong in front and on the outer 
and inner sides, but is weak behind. It does not, when laid bare, allow 
the opposed surfaces to fall separate, as does the capsule of the shoulder- 
joint. It arises from the outer surface of the wall of the acetabulum and 
from the base of the peripheral surface of the cotyloid ligament, as also 
from the transverse ligament, but leaves the notch uncovered for the passage 
of articular vessels. It is inserted in front into the whole length of the 
intertrochanteric line, and externally close to the insertion of the obturator 
externus muscle; but posteriorly, while it clothes the neck of the femur 
in the half nearest the head, it has no femoral insertion. The fibres going 
to the femur from in front of the notch of the acetabulum extend to the: 
Fig. 180.—Left Hip-Joint from behind 
in the erect posture, a, Fibres from 
behind the notch of the acetabulum, 
stretching obliquely upwards and out- 
wards and leaving the neck of the femur 
bare beyond b; c, rectus femoris; d, 
insertion of pyriformis; e, obturator 
intern us ;/, gluteus medius; g, gluteus 
minimus ; 71, psoas magnus. 
Fig. 181.—Left Hip-Joint from the 
front, in the erect posture, a, Rectus 
femoris; 6, pyriformis; c, gluteus medius; 
d, gluteus minimus ; from a to e, ilio- 
femoral ligament ; /, Bigelow’s ligament; 
from g to e, puho-femoral band. 
inner end of the anterior intertrochanteric line, and those from behind 
the notch wind upwards to the trochanteric pit, while in the space 
between there are none but circular fibres; so that the synovial membrane 
is left bare where it is reflected from the capsule to the back of the neck 
of the femur. Several strong bands of fibres strengthening the front of the 
capsule have received special names. The principal of these is the iio 
femoral ligament, arising from the lower part of the anteiior inferior i iac 
spine, directed vertically downwards, so as to cross the neck of the emui 
obliquely, and inserted into the part of the intertrochanteric line on t e 
inner border of the femoral shaft. The ilio-trochanteric fibres from t e 
upper margin of the acetabulum, in close contact with the ilio femora 188 
THE SKELETON. 
ligament, and proceed outwards to the tubercle of the outer end of the 
intertrochanteric line. The Y-shaped ligament of Bigelow is a term in use 
among surgeons to indicate by one name the two bands just mentioned; 
but the important surgical fact is that in dislocation backwards the head 
nf the femur ruptures the capsule behind the outer fibres, and that in 
dislocation forwards it ruptures it internal to the ilio-femoral ligament, 
while in both, the fibres radiating from above the acetabulum remain 
untorn and must be taken into consideration if a dislocation is to be 
reduced without violence. The part of the capsule internal to the ilio- 
femoral ligament is thin and occasionally even perforated ; but a thicker 
pubofemoral band proceeds from the pubic margin of the acetabulum, 
above the notch, and is inserted into the femur behind the ilio-femoral 
ligament. 
The synovial membrane extends from the capsule over the free surfaces 
of the cotyloid ligament. It covers a pad of fat which occupies the non- 
articular portion of the acetabulum. 
From the Haversian gland so formed, 
and from the margin of the transverse 
ligament, it is continued cylindrically 
on the ligamentum teres. In front it 
clothes the whole neck of the femur, 
but at the back part it is reflected 
from the capsule to the periosteum, 
about the middle of the neck. Anteri- 
orly it occasionally communicates in- 
ternal to the ilio-femoral ligament with 
the bursa beneath the ilio-psoas muscle. 
Fig. 182.—Left Hip-Joint from behind in full 
flexion, a, Ramus of ischium sawn across; b, 
superior ramus of pubis, sawn across ; c, notch 
of acetabulum ; d, fibres to the lower end of the 
anterior trochanteric line ; e, fibres inserted into 
the digital fossa; between d and e, circular fibres; 
./, fold of synovial membrane. 
Movements of hip-joint. Being a 
ball-and-socket joint, the hip-joint 
allows movement of the limb in every direction. The limits of the 
different movements are determined partly by the forms of the bones 
and partly by the ligaments. Thus flexion is limited by locking of the 
upper edge of the acetabulum on the front of the femur; and in less 
■extreme flexion, adduction and abduction are respectively limited by 
locking of the anterior and posterior walls of the acetabulum; while over- 
extension is limited by tension of the whole of the strong anterior part 
of the capsule. But other limits are put to movement by the thickness 
■of the soft parts and stretching of muscles. Thus the stretched adductor 
muscles limit abduction of the extended thigh, while, in stout persons, 
stooping is rendered difficult by the obstructing soft parts. 
In the erect posture the fibres of the capsule are stretched by reason 
■of their obliquity, both those in front, against which the femur is 
pushed, and also the ischial fibres behind on which it pulls, and which 
are then twisted in exactly the same direction as the tendon of the 
•obturator externus muscle laid against them and aiding them. In flexion THE HIP-JOINT. 
189 
of the thigh the acetabulo-femoral fibres have their two attachments 
brought opposite one to the other, and are untwisted, while the circular 
fibres behind are placed on the stretch. Abduction with outward rotation 
spreads out the fibres of the front of the capsule; flexion with adduc- 
tion and rotation inwards spreads out the ischial fibres behind. 
The round ligament is placed on the stretch in only one position, 
namely, when a slight degree of flexion is combined with adduction. This 
can be seen by removal of the deep part of the acetabulum without 
injuring the ligaments. The position mentioned is that into which the 
joint is thrown in the extreme of the position called in military drill 
“standing at ease.” In ordinary life the position called “attention” in 
drill, namely, with the weight of the body equally distributed on the two 
lower limbs both kept straight at the knee, is rarely made use of; the 
natural attitude of rest when standing being with the weight principally 
thrown on one straight limb, while the other is used for balance, and 
slightly bent; and it is when the maximum of weight is thrown on one 
limb and the maximum obliquity given to the pelvis that the round 
ligament comes into use. It is sometimes alleged to be a feeble liga- 
ment; but this is never the case in young and healthy joints. 
The margins of the acetabulum and articular cartilage of the femur 
are made parallel in a position combining flexion, abduction and rotation 
outwards, which is that assumed in sitting cross-legged on the floor. In 
ordinary circumstances, and especially when the thigh is behind in running, 
the back of the head of the femur is embedded in the acetabulum, and 
the fore part exposed and pressed against the capsule. Yet dislocations 
backwards are far more common than dislocations forwards. 
To understand the knee-joint properly it must be recognized as con- 
sisting of three joints intercommunicating, namely, a patellar and an 
external and internal tibio-femoral. These three joints are distinct, or 
almost so, in a number of ungulate animals, and are probably always 
distinct in their first appearance. The two originally separate tibio-femoral 
joints are hinge-joints, and have each an external and internal lateral liga- 
ment; but the internal lateral of the outer joint and the external lateral 
of the inner joint are called the crucial ligaments, and the others the 
lateral ligaments of the knee-joint. Further, there is between each con- 
dyle of the femur and the tibia a fibro-plate of semilunar form. 
The Knee-Joint. 
The fibrous capsule of the knee-joint is strong behind and at the sides, 
but weak in front. Above the patella, where the joint is covered b}" 
the extensor muscles, the capsule is absent. On each side of the patella 
it is formed above by spreading aponeurotic insertions of the vasti muscles, 
and, lower down, takes the form of retinacula of the patella. 
The external lateral ligament consists of two parts. Foremost is the 190 
THE SKELETON. 
long external lateral ligament, distinct from the capsule, a rounded cord 
arising from the external tuberosity of the femur, separated from the 
tendon and groove of the popliteus by the bursa of that tendon, and 
inserted below into the head of the fibula, surrounded by the insertion 
of the biceps muscle, and separated from it usually by another bursa. 
The short external lateral ligament is further back and not distinct from the 
capsule. It is attached below to the styloid process of the fibula, which 
also receives other fibres from the back of the capsule. 
The internal lateral ligament is a long, distinct and strong flat band 
descending from the internal tuberosity of the femur to be inserted into 
Pig. 183.—Right Knee from outer side, a, Patellar ligament; h, quadriceps extensor 
cruris ; c, external retinaculum of patella ; d, band of fascia lata pulled on by the tensor 
fasciae femoris ; e, outer bead of gastrocnemius ; /, popliteus ; g, h, short and long bands 
of external lateral ligament; i, insertion of biceps; k, I, m, insertions of sartorius, 
gracilis and semitendinosus. 
Pig. 183. 
Fig. 184. 
Fig. 184.—Right Knee from behind, a, Biceps and, below it, the posterior ligament of 
upper tibio-fibular articulation; 6, semimembranosus; c, its upper band of insertion, 
called Winslow’s ligament; cl, its middle band of insertion ;e, its lower band of insertion 
over popliteus muscle ; /, tendon of popliteus; g, part of the posterior ligament; h, internal 
semilunar disc; i, lc, outer and inner heads of gastrocnemius; I, rectus femoris; m, tendon 
of adductor magnus. 
a rough surface on the shaft of the tibia, further back than the tendon 
of the semitendinosus muscle. It crosses and glides on the anterior 
division of the tendon of the semimembranosus muscle, which lies in 
the groove of the internal tuberosity of the tibia. 
The posterior ligament is the strong back part of the fibrous capsule 
already mentioned, and covers the condyles of the femur. Between the 
condyles it presents a strong oblique band, long known as the ligament 
of Winslow, taking an upward and outward direction, in great part 
continuous with the tendon of the semimembranosus muscle, and con- 
stituting its upper insertion. THE KNEE-JOINT. 
191 
The ligamentum patellae is the tendon of insertion of the quadriceps 
extensor femoris; the patella being a sesamoid bone developed in the 
tendon. It partakes, however, of the toughness of ligament, and is not liable 
to snap. It arises from the borders and deep surface of the lower part of 
the patella, and is inserted into the rough 
part of the tubercle of the tibia. Between 
it and the upper part of the tubercle there 
is an important bursa, liable to inflammation, 
-and more likely to give trouble in diagnosis 
than is inflammation of the superficial bursa 
over the patella. 
The retinacula or lateral ligaments of the 
patella are membranous bands, variously 
described. One, internal, passes from the 
patella to the inner tuberosity of the tibia, 
while another, external, closely connected 
with the strong band of the fascia lata 
pulled on by the tensor fasciae femoris, 
turns downwards to the outer tuberosity of 
the femur. 
Fig. 185.—Right Knee from thefront> 
with the capsule removed and the tibia 
sawn from before backwards between 
the crucial ligaments, a, Tendon of 
popliteus; b, c, external and internal 
lateral ligaments; d, e, external and 
internal semilunar discs; /, g, ex- 
ternal and internal crucial ligaments; 
h, ligamentum patellae reflected with 
portion of patella attached. 
The anterior or external crucial ligament 
is attached above to the inner side of the 
■external condyle of the femur near the 
back, and interiorly to the tibia in front 
7 J 
of the spine. 
The posterior or internal crucial ligament is attached above to the outer side 
■of the inner condyle of the femur, at the fore part of the intercondylar 
fossa, and is inserted interiorly into the popliteal notch. 
The semilunar fibro-plates (cartilages or fibro-cartilages of authors) are 
crescentic felted structures, each with an upper and a lower free surface, a 
free edge turned towards the centre 
of the joint, and a thick peripheral 
border adherent to the fibrous cap- 
sule. They assume the appearance 
of ligamentous bands at their ex- 
tremities. They cover the bevelled 
parts of the tibial surfaces. The 
internal Jihro-plate is the more fixed 
in position, and has its extremities 
widely separate, the posterior being 
attached to the rough surface behind 
the tibial spine, in front of the 
internal crucial ligament, and the 
Fig. 186.—Head of Left Tibia supporting a and b, 
the outer and inner semilunar discs; c, external 
crucial ligament; d, internal or posterior crucial 
ligament; e, accessory band from the external disc 
to join the posterior crucial ligament; /, transverse 
ligament. 
anterior quite in front of the external crucial ligament. The external 
Jihroplate is nearly circular, its extremities being attached near one to 192 
THE SKELETON. 
the other, the posterior on the top of the tibial spine behind the external 
crucial ligament, and the anterior at the outside of the same. At 
its posterior extremity it is joined by an accessory ligament descending 
from the posterior crucial. It is very freely movable in a backward 
and forward direction on the tibia, and, on that account, is capable of 
being dislocated. Anteriorly, the two semilunar fibro-plates are usually 
united by a transverse ligament, a thin bundle of fibres extending 
between the foremost parts of their convex borders. 
The synovial membrane, when artificially distended, bulges out between 
the sides of the patella and the lateral ligaments, and superiorly forms 
a pouch extending a couple of inches upwards, covered by the crureus 
muscle, and kept from falling down between the patella and femur by 
the subcrureus muscle. Beneath the patella, and extending to each side, 
there is a great pad of fat, from the middle of which a thin pillar of 
synovial membrane, called ligamentum mucosum, extends to be attached to 
the front of the intercondylar fossa. It is 
the remains of a septum formed by two 
synovial membranes placed back to back, 
which originally separated the outer from the 
inner tibio-femoral joint. From the sides of 
the base of the ligamentum mucosum, two 
more or less sharp folds, the alar folds or 
ligaments, extend in such a position as to 
fit in under the condyles of the femur. 
Below and behind the ligamentum mucosum 
the membrane is reflected up in front of the 
crucial ligaments, and extends on their sides to 
the posterior wall of the capsule. It covers 
the upper and under surfaces of the semi- 
lunar plates, and is reflected thence to the 
capsule before reaching the margins of the 
tibial surfaces. On the side of the external 
condyle of the femur it is continued over 
Fig. 187.—Left Knee-Joint laid 
open and flexed, a, Ligamentum 
mucosum ; b, h, alar folds ; c, tendon 
of rectus femoris; d, internal fibro- 
plate or disc. 
the popliteal groove and deep surface of the popliteus tendon; and, at 
the back of the inner condyle, it communicates with a bursa between the 
tendon of the semimembranosus muscle and the inner head of the 
gastrocnemius, which sometimes becomes distended with glairy substance. 
Movements of the knee-joint. This is a hinge joint. It also allows 
rotation of the leg when flexed, but not when it is fully extended. 
When the weight of the body falls on the extended knee, extension is 
maintained without muscular aid, as is shown by the patella hanging 
loose; but when the foot is lifted from the ground the patella is involun- 
tarily tightened. In the erect posture the weight of the body falls in 
front of the knee, and so far from muscular action being required to 
prevent flexion, over-extension would take place were it not guarded THE KNEE-JOINT. 
193 
against by the structure of the joint. In the course of the movement 
from flexion towards extension, the femoral condyles revolve on the tibia 
in such a way as to bring successively into contact with the tibia portions 
of their surfaces nearer the front; and until within a short distance of 
complete extension their motion is equal, thus throwing the shaft directly 
forwards. But after the foremost part of the outer condyle has come 
into contact with the semilunar fibro-plate, the revolving of the inner 
condyle is continued on its oblique fore part, and turns the front of the 
shaft inwards. The outer condyle being thus made to rotate on the 
front of the outer condylar portion of the tibial spine, pushes the part 
of the external fibro-plate near its anterior attachment over the anterior 
and inner border of the tibial surface, and is locked firmly against it (Bruce 
Young). Were it not for the locking of the bones one against the other, 
the whole tendency to over-extension would have to be resisted by the 
ligaments and by the flexor muscles; and even with the advantage thus 
gained, the pressure of the weight of the body is so great that when the 
muscles of the calf are paralyzed, convexity of the back of the knee sets 
in. In extension, all the tibio-femoral ligaments are tight, with the 
exception of the internal crucial, which is tightened in flexion and becomes 
the pivot round which the leg can be rotated for about 45 degrees. After 
the knee has been flexed as much as it can be by muscular action, it is 
always possible to flex it further by lifting the leg with the hand; and 
it is into this position of extreme flexion that the knee is brought in 
sinking down on the hams and the balls of the toes. In assuming this 
position the femur is rotated inwards by the backmost part of the outer 
condyle coming into play (Goodsir); and the inner condyle, by a facet 
hitherto unnoticed, presses against the surface of the tibia, twisting up 
behind the spine. 
The patella, in extension, is thrown inwards by the prominence of the 
outer margin of the patellar surface of the femur, and is guarded from 
dislocation inwards by its outer retinaculum, and by fibres descending 
to it from the fascia lata of the outside of the thigh. In flexion it is 
turned outwards by the projection forwards of the inner condyle of the 
femur, and is protected from outward dislocation by the tightening of its 
inner retinaculum over that condyle. The prominence of the knee in 
flexion exhibits a flat surface with three angles, two to the outside formed 
by patella and outer edge of the patellar surface of the femur, and one 
to the inner side formed by the inner condyle. 
The different facets of the patella come into contact with the femur 
in different positions. When the knee is kept extended by the quadriceps 
extensor, the two lower facets of the patella are in contact with the 
uppermost part of the patellar surface of the femur. In semiflexion the 
two middle surfaces only are in contact, while both the upper and lower 
facets are separated from the femur; and thus it is that transverse fracture 
of the patella is of so common occurrence as the result of spasmodic 194 
THE SKELETON. 
contraction of the quadriceps extensor, when the muscle and the liga- 
mentum patellae pull its upper and lower free extremities back, and 
the femur presses it forward in the middle. In extreme muscular flexion 
the upper facets are in contact with the femur; and in complete flexion 
by sinking the weight of the body on the bent knee, the inner facet of 
the patella rests on the surface provided for it on the inner condyle. 
The Joints of the Leg and Foot. 
The superior tihio-fibular articulation is surrounded by a fibrous capsule 
in which anterior and posterior ligaments may be distinguished passing upwards 
and inwards from the fibula. It occasionally communicates with the 
knee-joint. 
The interosseous membrane is a fibrous septum uniting the sharp outer 
edge of the shaft of the tibia with the prominent line on the inner surface 
of the fibula. Its fibres are sloped, downwards and outwards. It leaves a 
considerable opening above, which is traversed by the anterior-tibial vessels. 
The inferior tibio-fibular articulation is closely connected with the 
ankle-joint, and contains within it, prolonged upwards for more than 
half an inch from that joint, a synovial recess 
padded with adipose tissue, but without articular 
cartilage. 
The anterior inferior tibio-fibular ligament is a 
broad band passing upwards and inwards from 
the front of the external malleolus to the front 
of the tibia. 
The posterior inferior tibio-fibular ligament has a 
superficial part disposed similarly to the anterior 
ligament, and a deep part with more nearly 
horizontal fibres stretching inwards from the deep 
surface of the external malleolus, and lined 
inferiorly by the synovial membrane of the 
ankle-joint. 
The inferior interosseous ligament, extending 
downwards from the lower end of the inter- 
osseous membrane, consists of fibres both in 
front and behind the synovial recess, but more 
abundant behind it. 
The transverse ligament of the ankle-joint is a 
tibio-fibular band separated from the deep part 
of the posterior inferior tibio-fibular ligament, as 
seen from within the ankle-joint, by a fold of 
synovial membrane. It arises from the deep surface of the external 
malleolus, and its fibres spread out to be inserted along the posterior 
inferior edge of the tibia. 
Fig. 188.— Dorsiflexed Left 
Ankle from behind, a, Inter- 
osseous membrane ; b, posterior 
ligament of lower tibio-fibular 
articulation ; c, transverse liga- 
ment ; d, e, posterior and middle 
bands of external lateral liga- 
ment of ankle-joint; f, g, h, 
astragalar, calcaneal, and scaph- 
oid portions of internal lateral 
ligament; I, posterior tubercle 
of astragalus, with posterior 
astragalo-calcaneal ligament ex- 
ternal to the dotted line, and 
internal astragalo-calcaneal fibres 
internal to it. THE JOINTS OF THE LEG AND FOOT. 
195 
The ankle-joint is a hinge joint, with lateral ligaments, which also 
help to support the joints between the astragalus, calcaneum and scaphoid. 
The internal lateral ligament is a strong flat band, expanding as it 
descends from the extremity of the internal malleolus, to be inserted 
posteriorly into the inner side of the astragalus near the back, further 
forwards into both astragalus and sustentaculum tali, and in front of 
this into the inferior calcaneo-scaphoid ligament and the inner side of 
the scaphoid bone.1 
The external lateral ligament consists of three round bands, each at 
right angles to both the others. The posterior band extends from the 
pit on the inner side of the external malleolus inwards and slightly 
backwards to the posterior surface of the astragalus, and is lined above 
by the synovial membrane of the ankle-joint, and below by that of the 
posterior astragalo-calcaneal joint. The middle band passes directly down- 
wards from the extremity of the external malleolus to the outer side of 
the calcaneum, and is lined by the synovial membrane of the posterior 
astragalo-calcaneal joint alone. The anterior band extends from the front 
of the external malleolus forwards and inwards to the astragalus in front 
of its upper articular surface, and is lined by the synovial membrane 
of the ankle-joint alone. 
Anterior and posterior ligaments of the ankle-joint are described, but consist 
of mere thin fibrous expansions supporting the synovial membrane. 
The synovial membrane is prolonged up between the tibia and fibula, and 
is cushioned with fat in front and behind, as well as between the bones. 
The tarsal and tarso-metatarsal articulations form a series of closely 
■connected joints with a number of synovial cavities. The posterior astragalo- 
calcaneal articulation is behind the interosseous ligament uniting these 
bones, and has a separate synovial membrane: the astragalo-calcaneo- 
scaphoid articulation has a second, and the calcaneo-cuboid articulation a 
third. Three other synovial cavities are bounded by tarsals and metatarsals, 
viz., one peculiar to the articulation between the internal cuneiform and 
first metatarsal bone, with a distinct fibrous capsule round it; another 
between the cuboid and fourth and fifth metatarsals, extending between 
the bases of those metatarsals; and a third which is common to the 
articulations of the cuneiforms one with another and with the scaphoid, 
cuboid and second and third metatarsal bones, and extending between 
the bases of the second, third and fourth metatarsals. 
Besides the more membranous dispositions of fibrous tissue over synovial 
sacs, the following important ligaments are found in connection with these 
articulations : 
The interosseous astragalo-calcaneal ligament is attached above to the deep 
1 This ligament is often described as if only its posterior fibres were attached to 
the astragalus. But when the joint is cut open they can be seen inserted all along 
the inner side of the joint below the articular surface for the internal malleolus. 
The attachment to the sustentaculum tali is not very strong, and may even be absent. 196 
THE SKELETON. 
groove beneath the astragalus, and below to the corresponding groove- 
on the calcaneum, and consists of a large number of vertical fibres arranged 
in a broad band, to the fore and inner side of the posterior astragalo- 
calcaneal articulation, between it and the astragalo-calcaneo-scaphoid. The 
anterior and outer extremity of this ligament divides in front into two- 
sets of strong fibres, one forming the outer part of the capsule of the 
astragalo-calcaneo-scaphoid joint, and the other the anterior part of the 
Fig. 189.-—Dorsum of Stretched Left Foot with 
the outer side depressed, a, Anterior ligament of 
lower tibiofibular articulation ; b, head of astragalus 
crossed by c, portion of superior astragalo-scaphoid 
ligament; d, scaphoid ; b, internal cuneiform ; r, 
base of second metatarsal; g, external cuneiform ; 
h, i, anterior and middle bands of the external 
lateral ligament of the ankle-joint; k, anterior and 
outer fibres of interosseous astragalo-calcaneal liga- 
ment. They abut against the joint in front, while 
the posterior and outer fibres seen between k and h 
lie against the joint behind; l, cuboid surface of 
calcaneum laid bare by the rotation downwards of 
the cuboid; m, anterior part of cuboid bone, with 
ligaments extending to external cuneiform andfourth 
and fifth metatarsals. 
Fig. 190.—Plantar View of Stretched. 
Left Foot, a, Tendo Achillis; b, groove for 
peroneal tendons; c, short plantar ligament - 
d, long plantar ligament; e, groove for per- 
oneus longus; f, ligament from the fifth to- 
other metatarsal bones ; g, groove for tibialis 
posticus ; h, i, k, the three portions of the- 
internal lateral ligament of the ankle-joint; 
l, groove for the flexor longus hallucis pass- 
ing from astragalus to sustentaculum tali; 
m, scaphoid attachment of inferior calcaneo- 
scaphoid ligament; n, tuberosity of scaphoid 
with tendon of tibialis posticus standing out 
p, band from tuberosity of scaphoid to ex- 
ternal cuneiform ; r, internal cuneiform ; 
s, tendon of peroneus longus. 
capsule of the posterior astragalo-calcaneal joint. The posterior and inner 
extremity of the interosseous ligament is continuous with strong fibres 
placed horizontally between the under surface of the posterior extremity 
of the astragalus and the edge of the calcaneum posterior to the susten- 
taculum, and called the internal ligament of the posterior astragalo-calcaneal 
joint: and this again is continuous with vertical fibres constituting the 
posterior ligament of the same joint and strengthening its capsule; but 
the external part of the capsule is weak. 
The inferior calcaneo-scaphoid ligament is a strong flat ligament supporting' 
the weight falling on the inner three toes. It is covered superiorly with THE JOINTS OF THE LEG AND FOOT. 
197 
synovial membrane, and extends from the anterior margin of the susten- 
taculum tali, beneath the head of the astragalus, to the scaphoid bone, 
to be attached close to its posterior articular surface, between it and the 
tuberosity, and further outwards. It is supported below by the insertion 
■of the tibialis posticus tendon. 
The external calcaneo-scaphoid ligament is continuous with the outer part 
of the preceding. It has very short fibres, being attached posteriorly to 
the superior margin of the anterior extremity of the calcaneum, and lies 
ngainst the inner side of the capsule of the calcaneo-cuboid joint, with 
n.n upper edge exposable from above. 
The inferior calcaneo-cuboid or long and short plantar ligaments resist 
pressure falling on the outer arch of the foot. The long plantar ligament 
■consists of a long and strong band extending back nearly to the tubercles 
of the calcaneum, and inserted in front into the ridge of the cuboid. The 
■short plantar ligament, internal to and continuous with the outer edge of 
the long plantar, is inserted into the inner and back part of the under 
■surface of the cuboid, and especially into its conical process. 
Other plantar ligaments exist further forwards. Four bands start from 
the tuberosity of the scaphoid bone, receiving additional fibres from the 
tendon of the tibialis posticus muscle, and extend to the three cuneiform 
bones and the cuboid; that to the internal cuneiform being much the 
•strongest, and that to the external cuneiform the next strongest. From 
the anterior and outer angle of the internal cuneiform a constant ligament 
passes to the bases of the second and third metatarsals; and from the 
under surface of the base of the fifth metatarsal another extends inwards 
to the bases of the third and fourth ; while, in front of these, the adjacent 
edges of the bases of the four outer metatarsals are united by three bands. 
Interosseous ligaments unite the three cuneiforms and the cuboid, as also 
the four outer metatarsals, one with another, and the second metatarsal 
with the internal cuneiform. 
Dorsal ligaments of capsular character pass, one over the head of the 
■astragalus to the scaphoid, and another so as to cover-in the calcaneo- 
cuboid articulation. Others, in the form of distinct bands, radiate from 
the dorsum of the scaphoid to the three cuneiforms and the cuboid. Smaller 
limited dorsal ligaments, transverse, longitudinal and oblique, unite the 
cuneiforms and cuboid one with another and with the four outer meta- 
tarsals, and the bases of the metatarsals one with another. 
A transverse metatarsal ligament loosely unites the heads of the five 
metatarsal bones together. 
The metatarso-phalangeal and interphalangeal articulations are similar 
to the corresponding joints in the upper limb. The first metatarso-phalangeal 
joint is complicated by two large sesamoid bones in the insertions of the 
short flexor of the great toe; these are faced with cartilage and united by 
transverse fibres which glide on the ridge separating the two grooves on 
the head of the first metatarsal bone. 198 
THE SKELETON. 
Movements of the ankle and foot. At the ankle-joint, movement is 
restricted to one path, and its extent, from extreme dorsiflexion to the 
nearest approach allowed to straightening of the foot into a line with 
the leg, is not more than quarter of a circle. In standing at attention, 
the tibia rests on the middle of the opposed surface of the astragalus; 
and starting from this position, about equal extents of dorsiflexion and 
straightening are allowed. The axis of revolution is oblique, nearly corre- 
sponding with tips of the two malleoli; and the external malleolus being- 
placed lower than the internal, the outer edge of the foot is, to a certain 
extent, turned downwards in straightening, and upwards in dorsiflexion. 
This can be made apparent by placing the feet with the ankles and also 
the balls of the great toes pressed closely together, and rising on tip-toe, 
when the ankles will be found to separate slightly, and the heels to come 
nearer one to the other; while, in sinking on the haunches, the knees 
become parted to a certain extent by compulsion. In straightening the 
ankle, the obliquity of the axis of revolution necessarily causes the back 
part of the outer edge of the upper surface of the astragalus to be pressed 
against the fibula, pushing it away from the tibia and bringing the 
angular facet of the astragalus into contact with the stretched deep part 
of the posterior inferior tibio fibular ligament. In dorsiflexion, the broad 
fore part of the astragalar surface sweeps back into the space between the 
malleoli, tightening the anterior inferior tibio fibular ligament by pushing 
the external malleolus outwards from the front. Thus spring is given to 
the ankle-joint by the mobility of the fibula; and this is the only purpose 
served by the lower tibio-fibular articulation. The fibula is, however, 
more mobile at its head; and this is probably to allow the inward 
movement of the tibia relatively to the femur in incipient flexion of 
the knee. 
Between calcaneum and astragalus there is only one path of movement, 
and it is pivoted round the inner fibres of the interosseous ligament. 
When the weight of the body falls on the foot, whether the heel be on 
the ground or raised, the surfaces of the posterior astragalo-calcaneal joint 
lie in perfect apposition; so also do the surfaces of the astragalo-calcaneo- 
scaphoid articulation, with the exception of the outer part of the facet 
on the fore-end of the calcaneum, which is not in use; and the upper 
margins of the scaphoid and head of the astragalus lie alongside one of the 
other, while the calcaneo-scaphoid ligaments are on the stretch. When 
the foot is straightened as nearly as possible into a line with the leg, 
its outer border is at the same time turned downwards with an inward 
sweep already begun to a slight extent at the ankle-joint, but carried 
out by the calcaneum and scaphoid moving on the astragalus. In this 
movement, the surfaces of the posterior astragalo-calcaneal joint are no 
longer in apposition, but the outer edge of the calcaneal surface moves 
downwards and forwards from beneath the body of the astragalus, and 
only the anterior part of the astragalar surface is in contact with the THE JOINTS OF THE LEG AND FOOT. 
199 
calcaneum, a gap being left behind : a similar want of conformity is 
brought about between the sustentacular facet and the head of the 
astragalus; while the outer part of the facet above the fore-end of the 
calcaneum glides into contact. Also by the same rotation the calcaneum 
pulls on the external calcaneo-scaphoid ligament, and makes the scaphoid 
revolve on the head of the astragalus, so that the latter projects by its 
upper and outer part on the dorsum of the foot, while the tension of 
the inferior calcaneo-scaphoid ligament is relieved. The turning down 
of the outer edge of the foot is continued by the movement of the 
calcaneo-cuboid articulation, which is one of rotation of the cuboid round 
its conical process ; and in front of the cuboid bone, it is carried still 
further by the fourth and fifth metatarsal hones. It is easy to understand 
how in this position arrest of the heel in slipping forwards may lead to 
dislocation of the astragalus. 
The movements of the metatarso-phalangeal joints have been subject to 
much misapprehension., In undeformed feet the great toes lie in contact 
in their whole length when the heels and balls of the great toes are 
placed together on a perfectly flat surface. But the path of movement 
of the toes in over-extension is not upwards, but upwards and outwards 
(Cleland, 1888) round a cone formed by the series of heads of metatarsals. 
In consequence of this the great toes separate when raised; and it is 
in conformity with this that in worn moccasins and in well made shoes 
the inner edge of the sole turns outwards at the great toe. 
In standing, and still more on raising the heel, as in standing on 
tip-toe, or running, the weight of the body tends to flatten both the 
longitudinal and transverse arches, and makes the foot for the moment 
both longer and broader; the ligaments by which these arches are 
supported are made tense, and the relief of this tension on raising the 
foot from the ground gives spring to the step. 
In running, the weight falls first on the ball of the great toe, and is 
then quickly distributed to the others. In walking hare-foot, especially 
if the body be inclined forwards, the same order of events occurs and 
is followed by the heel reaching the ground and receiving part of the 
weight, while conversely the heel is raised from the ground first, and 
the great toe last; but in walking with boots on, the heel is put at once 
to the ground. 
THE BONES OF THE LIMBS COMPARED. 
Though many conflicting theories have been advanced as to the 
relationship of the upper and lower limbs, which cannot be even a uc e 
to in a text-book, and though the subject cannot be fully discussed 
without copious reference to comparative anatomy as well as embryo o^,}, 
there are certain points which may be shortly mentioned for the glut ance 
of inquiry. 200 
THE SKELETON. 
The scapula undoubtedly corresponds with the ilium. It extends 
in a dorsal direction from the shoulder-joint, its blade is covered by 
dorsal muscles, and from the blade there passes to the surface the spine, 
ending at its ventral extremity in the acromion. The ilium, in like 
manner, extends in a dorsal direction from the hip-joint, and its only 
superficial part is the crest, ending ventrally at the anterior superior 
spinous process. The clavicle stretches ventrally from the acromion 
towards the middle line, and, in like manner, Poupart’s ligament stretches 
ventrally towards the middle line from the anterior superior spinous 
process. The coracoid is in monotremata and non-mammalian vertebrates 
a distinct bone extending ventrally from the shoulder-joint, in continuity 
with the blade of the scapula; and in both monotremata and other animals 
another element lies at the same depth, proserial to the coracoid, namely, 
the precoracoid. In the lower limb two deep elements are, in like 
manner, found on the ventral aspect of the hip-joint, namely, the ischium 
and os pubis, the os pubis being proserial to the ischium, and therefore 
corresponding with the precoracoid of monotremata, while the ischium 
is homologous with the coracoid. 
The femur corresponds obviously with the humerus; but no one 
seems to have noted what is nevertheless evident on comparison of early 
stages of development, that the outer epicondyle of the humerus and 
the patellar surface of the femur are similarly situated from their earliest 
development, being placed on the aspect furthest from the mesial plane 
of the body, and continuous with the dorsum of the embryo. 
In the forearm the radius is the proserial element, and the ulna 
the retroserial; while in the leg the tibia is the proserial element, and 
the fibula the retroserial. In the monotremata the head of the fibula 
is prolonged upwards in the same manner as the olecranon of the ulna. 
The thumb and the great toe are the proserial digits of hand and 
foot respectively. The metatarsal articulations of the four anterior tarsal 
bones correspond very closely with the metacarpal articulations of the 
lower range of carpal bones. The pisiform bone is much more developed 
in many animals than in the human subject; and in the bear it presents 
an epiphysis exactly similar to another on the tuberosity of the calcaneum, 
while the bulk of the calcaneum is seen to correspond obviously with 
the combined pisiform and cuneiform bones of the carpus. 
DEVELOPMENT OF THE LIMB BONES. 
The skeleton in both the upper and lower limb makes its first appearance, 
I find, as a single block of cartilage distinct from the axial skeleton; and 
from this all the bones are developed, the clavicle excepted. In the upper 
limb, the scapula, humerus, forearm and hand can all be distinguished, 
forming a continuous mass of embryonic cartilage in which lines after- 
wards appear in the situation of the joints; and similarly, in the lower DEVELOPMENT OF THE LIMB BONES. 
201 
limb, the pelvis, thigh, leg and foot are from one original mass. The 
radius and ulna are at first similar in size at the wrist; they are bent 
forwards at the elbow, the radius in continuity with the front of the 
humerus, and the ulna with the back part. I find also that the tibia and 
fibula are, at the knee, bent similarly forwards towards the head of the 
embryo, and that the heel at an early period projects on the fibular or 
retroserial margin of the foot. 
Among the carpal cartilages at first laid down there has been noted 
one corresponding to the os centrale found in many mammals. It has been 
found to disappear by fusion with the scaphoid, usually before the end of 
the third month (p. 146, footnote). 
Ossification. 
Upper limb. The clavicle is of all the bones in the body that in which 
osseous deposit first appears. This occurs when the embryo is about 
two-thirds of an inch long and is supposed to be about six weeks old. 
I find the clavicle existing as a cartilage prior to the commencement of 
ossification, though it is often described as of purely membranous origin. 
It is allowed to be cartilaginous at its extremities in later development. 
About the eighteenth year or later an epiphysis appears which is incor- 
porated with the shaft by the twenty-fifth year. 
The .scapula begins to ossify about the eighth week from a centre at 
the neck. The coracoid process shows an osseous centre of its own in 
tbe first year, and is joined to the rest of the 
bone about the twelfth or fourteenth. A separate 
little centre, called subcoracoid, begins in contact 
with the ununited coracoid centre immediately 
above the bicipital tubercle, and may extend 
thence over the whole glenoid cavity. Also a 
separable scale may occur on the coracoid at the 
attachment of the coraco-clavicular ligament, and 
a distinct epiphysis at the tip of the process. 
The acromion is in part or altogether ossified 
from one or two separate centres which do not 
appear till near puberty, but soon spread to 
form an epiphysis which retains its independence 
Pig. 191.—Young Scapula. 
a, Acromion with epiphysis ap- 
parent!y formed from two centres 
of ossification ; b, coracoid as yet 
ununited and, below it, the glen- 
oid cavity covered by an extension 
of the subcoracoid centre; c, small 
epiphysis at tip of coracoid; 'I, 
position of occasional small 
centre; c ■ suprascapular strip 
of cartilage. 
-tit,- at .ii r 
lor a considerable time. Along the base ot the 
-i ~ . . 
scapula a narrow cartilaginous strip corre- 
sponding with the suprascapular cartilage of 
"Ur*! i • i iii 
floored mammals continues through adolescence, 
It becomes ossified from two centres, one at the 
inferior angle, and the other commencing opposite 
the inner end of the spine, both of them appearing latei than the 
acromial centres and uniting to form an epiphysis distinguishable till the 
twenty-fifth year. 202 
THE SKELETON. 
The humerus begins to ossify in the shaft about the eighth week. It 
presents in later growth a superior and inferior epiphysis, besides a separate 
epiphysis of the internal epicondyle. The superior 
epiphysis has two or more centres of ossification— 
one in the head, beginning in the first year; one in 
the great tuberosity, beginning in the third, and 
sometimes one in the small tuberosity, appearing 
later. These nuclei join together about the sixth 
year. At the lower end of the bone there are 
four centres of ossification, the largest in the 
trochlea, another in the capitellum, and two others 
in the epicondyles, all appearing from the third to- 
the fifth year. The trochlear, capitellar and ex- 
ternal epicondylar centres unite about the seven- 
teenth year to form the inferior epiphysis, while 
the internal epicondyle remains ununited for a 
little longer. The superior epiphysis is not united 
to the shaft till the twentieth year. 
Fig. 192.—Young Humerus, 
with trochlear, capitellar and 
external epicondylar centres 
united together, while the 
internal epicondylar is sep- 
arate, as is also the superior 
epiphysis. 
The radius and ulna begin to ossify in the middle of the shaft about 
the eighth week, and each has an upper and a lower epiphysis; but these 
are very different in size and in date of appearance. In the radius the 
large lower epiphysis makes its appearance about the end of the second 
year, while that of the head is fully three years later. In the ulna the 
lower epiphysis begins to ossify in the fourth or fifth year, while, at the 
upper end, the diaphysis is continued right up to the elbow, where it is 
tipped by a very small epiphysis which does not appear till the tenth year. 
In both radius and ulna the superior epiphysis is united to the shaft 
about the seventeenth year, and the inferior not till the twentieth year. 
The carpus has one centre of ossification for each bone. Those for the 
os magnum, unciform and cuneiform appear in succession in the first, 
second and third years respectively; those for the trapezium and semi- 
lunar in the fifth year; those of the scaphoid and trapezoid about the 
sixth or seventh year respectively; and lastly the pisiform, so late as the 
twelfth year. 
The metacarpals show ossification in their shafts soon after the radius 
and ulna, and the distal phalanges follow them before the others. The 
four inner metacarpals have manifest epiphyses at their distal ends, appear- 
ing from the third to the fifth year, and remaining distinct till the eighteenth 
or twentieth year. The phalanges have each an epiphysis at the proximal 
end, appearing later and uniting earlier than the metacarpal heads. The 
metacarpal of the thumb resembles the phalanges in having a distinct 
epiphysis at its base, appearing early and remaining long distinct, but it 
often shows evidence of a fugitive epiphysis at its distal end. Conversely, 
traces of proximal epiphysis may be found in some of the other meta- 
carpals. OSSIFICATION. 
203 
Lower limb. The innominate hone presents one principal ossific centre 
ln each of its three elements; that of the ilium appearing about the 
ninth week of foetal life, that of the ischium in the third month, and 
that of the pubic bone in the fourth or fifth 
month, all three radiating from the acetabulum. 
Those of the ischium and pubic bone unite below 
the obturator foramen during the first year after 
birth, while a Y-shaped cartilage continues to 
separate them at their acetabular extremities, one 
from the other and both from the ilium. In 
this cartilage irregular centres of ossification 
appear about the twelfth year, and sometimes 
unite into one piece before uniting with the 
main bones; but more frequently fail to come 
into contact one with another, and are least 
developed between ischium and pubic bone, and 
most extensive between pubic bone and ilium, 
where a large intercalar ossification, which has 
attracted the attention of Albinus and subsequent 
writers, and been distinguished as os acetabuli, 
Fig. 193.—Bight Innominate 
Bone of Twelfth Year, outer 
side, showing the epiphyses in 
the acetabulum. (For the deep 
side see Fig. 161.) 
may completely overlay the pubic bone. The acetabulum is completed 
about the eighteenth year. An epiphysis ossifying from more than 
one nucleus extends along the whole crest of the ilium, and others are 
formed on the anterior inferior iliac spine and the ischial tuberosity. 
They appear after puberty, and disappear before the twenty-fifth year, 
the ischial more slowly than that of the iliac crest. Growth continues 
at the symphysial surface in the female after these epiphyses have become 
fixed, and separate nodules of ossification may be seen in this situation 
while in the male this surface becomes close grained 
and smooth at an earlier date. 
The femur commences to ossify about the end 
of the second month, earlier than the ilium and 
humerus. Ossification extends from the shaft up 
to where the neck joins the head; but for months 
after birth there is continuous cartilage from the 
head to the great trochanter. The epiphysis at the 
lower end appears about the time of birth, and 
its development extends as high as the tuberosities. 
In the first year an epiphysis appears in the head; 
in the fourth year, one in the great trochanter; 
and, about puberty, another in the small trochanter. 
Fig. 194.—Bight Ff.mdr 
APPROACHING THE FULL SIZE, 
with the epiphyses of the 
head, the two trochanters 
and the lower end still dis- 
tinct. 
This last is the first to disappear: the head is 
united about the eighteenth year, and the great trochantei soon aftei 
it, while the lower epiphysis continues separate till about the tvent} 
second year. 204 
THE SKELETON. 
The patella begins to ossify in the third year. 
The tibia begins to ossify about the same time as the femur, and the 
fibula soon after. Each has an upper and a lower epiphysis. The upper 
epiphysis of the tibia is large, including the tuberosities and descending 
in front to include that part of the tubercle covered 
by the bursa, but not the portion on which the 
ligamentum patellae pulls. It makes its first appear- 
ance at the time of birth, and the part for the 
tubercle may have a separate nucleus. The upper 
epiphysis of the fibula does not appear till the 
third or fourth year. The lower epiphyses of these 
bones unite after the eighteenth year, and the upper 
about the twenty-second. 
It will be remarked that while the bones of 
the arm and forearm have those epiphyses first 
united to the shaft which abut on the elbow, it is 
at the ends furthest from the knee-joint that the epiphyses of the 
femur and leg-bones first become united; and it has been noted in con- 
nection with this that the arterial foramina of the bones of the upper and 
lower limbs are in opposite directions, pointing the artery to the seat 
of earlier ossification. 
In the tarsus the only bone with an epiphysis is the calcaneum. This 
bone shows its principal nucleus in the sixth month, and its epiphysis 
about the tenth year. Ossification appears in the astragalus about the 
seventh month, in the cuboid about the time of birth, in the external 
cuneiform in the first year, in the internal cuneiform about the second 
year, in the middle cuneiform about the third year, and in the scaphoid 
about the seventh year. 
The metatarsals and phalanges are similar in development to the 
corresponding bones of the hand; but they are a little later in beginning 
to ossify. 
Pig. 195.—Kight Tibia 
and Fibula approaching 
the full size, with their 
epiphyses still distinct. 
111. THE SKULL. 
The skull is divisible into the cranium, or portion surrounding the brain, 
and the face. The lower jaw or mandible is articulated with the cranium 
by means of a pair of complete or synovial articulations. The rest of 
the skull consists of portions which, even after maceration, are immov- 
ably fitted together, but remain ununited by osseous continuity for very 
different lengths of time. It is very much a question of convenience 
what portions are to be considered as separate bones; but, with some 
exceptions, the parts which are generally so recognized are each united 
into one mass in the young adult, and still separable from others.. The 
cranial bones are counted as eight, viz., the occipital, the two parietals, 
the frontal, the sphenoid, the ethmoid, and the two temporals. The THE SKULL. 
205 
Fig. 196.—Base of Skull, a, Splieno-maxillary fissure, with roof of orbit seen through 
it; b, hamular process of internal pterygoid process ;c, vomer and palatal in contact; d, 
scaphoid fossa; e, foramen lacerum medium ;/, spinous process of great wing of sphenoid; 
g, foramen lacerum posticum; h, attachment of obliquus capitis superior; i, external 
occipital protuberance; k, anterior palatine canal; I, posterior palatine canal; m, foramen 
ovale; n, foramen spinosum ; o, groove for Eustachian tube ; p, carotid canal; q, styloid 
process ;r, stylo-mastoid foramen; s, digastric groove ;t, occipital groove; u, v, attach- 
ments of rectus capitis posticus major and minor; x, attachment of complexus. 206 
THE SKELETON. 
bones belonging wholly to the face are fourteen, of which twelve are in 
pairs, viz., the superior maxillaries, the palatals, the malars, the nasals, 
the lachrymals and the inferior turbinated; while two are mesial, viz., the 
vomer and the mandible. But it may be observed that the ethmoid 
takes only small part in the wall of the cranium, and is mainly developed 
in connection with the nasal fossae. The whole deep surface of the 
cranial wall has a peculiarly close-grained texture which, both from its 
glossy appearance and the way in which it cracks when exposed to 
violence, is termed the vitreous table, in contradistinction to the outer 
table formed of ordinary compact osseous tissue, and to the intervening 
cancellated tissue called the diploe. 
The occipital bone forms the most prominent part of the back of the 
skull, and enters considerably into the base or inferior aspect. It consists, 
at birth, of four pieces corresponding with the permanently distinct 
supra-occipital, basi-occipital and exoccipitals found in fishes and 
reptiles. These are united, and inclose the large oval opening,4 foramen 
magnum, through which the medulla oblongata or lowest part of the brain 
passes, surrounded by its investments, to be continuous with the spinal 
cord. The part in front of the foramen magnum is called the basilar 
process', it increases in thickness from behind forwards, and is so com- 
pletely united with the sphenoid bone, after the twentieth year, that no 
mark is left of the place of union, and the two bones can only be sepa- 
rated by means of the saw, a circumstance which led Sommering to 
describe the sphenoid and occipital as one bone, under the name of 
basilar bone. 
THE OCCIPITAL BONE. 
Borders. The occipital bone is lozenge-shaped, its upper two borders 
being united with the two parietals by means of a deeply serrated suture 
called occipitoparietal or lambcloidal, and its lateral angles fitting in between 
the parietal bone and the mastoid portion of the temporal on each side ; 
while its inferior borders are separated below by the extremity of the 
basilar process, and are each divided into two parts, the upper articulating 
b}7 a not very deeply serrated suture with the mastoid portion of the 
temporal bone, and the lower in contact with the petrous portion of the 
temporal bone by a thin edge running along the side of the basilar pro- 
cess. At the point of union between these two divisions of the lower 
border, a projection, the jugular process, fits by means of a rough summit 
into the retreating angle between the petrous and mastoid portions of the 
temporal, and is bounded in front by a smooth concavity, the jugular 
notch, which, together with an irregular part of the edge internal to it, 
forms the posterior limit of a foramen between the occipital and temporal 
bones, named foramen jugulare or foramen lacerum posticum, transmitting 
by its outer and more regular part the internal jugular vein, and by its THE SKULL. 
Spheno-maxillary fissure 
I Superciliary ridge 
Frontal eminence 
Styloid process | Pterygo-maxillary fissure 
External pterygoid plate 
Fig. 197.—Right Side of Skull, slightly from behind. Young adult female. 
Sagittal suture meeting the \ 
lambdoid ) 
Occipital probole 
External occipital protuberance 208 
THE SKELETON. 
inner part three nerves, the glossopharyngeal, the vagus or pneumogastric, 
and the spinal accessory. 
The deep surface presents, about midway between the lateral angles, 
a prominence, the internal occipital protuberance, to which converge four 
prominent lines from the superior and lateral angles and the back of the 
foramen magnum, separating one from another the two superior and two 
inferior occipital fossae, on which rest the posterior cerebral lobes and the 
lobes of the cerebellum respectively. The inferior line {internal occipital 
crest) is a simple ridge giving attachment to the falx cerebelli, but the 
others are grooved, and correspond in position with two venous sinuses in 
the dura mater, as the fibrous membrane is called which performs the 
office of periosteum and forms the outermost envelope of the brain. The 
upper groove marks the position of the terminal part of the superior longi- 
tudinal sinus, which pours its blood into the lateral sinuses, two channels- 
coursing outwards on the transverse grooves, and destined, after curving 
down on the parietal and temporal bones, each of them to mark the occipital 
with a second and deeper groove, directed inwards behind the jugular pro- 
cess, and forwards to the jugular notch. The basilar process is hollowed 
longitudinally by the basilar groove, on which lies the medulla oblongata, 
and is bevelled at the margin, where the edge of the inferior petrosal 
sinus rests. Passing backwards from the sides of the basilar groove, a 
pair of eminences mark the places of junction of the basi-occipital and 
exoccipital elements, and are continued thence as ridges round to the back 
of the foramen magnum. These supraforaminal ridges form, when clothed 
with the dura mater, the upper limit of the funnel leading down into 
the spinal canal. Inside and behind the ridge, beneath the eminence, there 
is situated on each side the inner orifice of the anterior condyloid foramen, 
through which the hypoglossal nerve passes in a direction downwards, 
forwards and outwards ; while, external to the ridge, there is placed the 
deep orifice of the posterior condyloid foramen, an aperture not always 
present, by which a vein passes upwards, forwards and outwards from 
behind the condyle, to end in the lateral sinus (Fig. 221). 
The superficial surface presents, at a spot nearly opposite the internal 
protuberance, a projection called the external occipital protuberance, the 
mesial point whence curves outwards to the lateral angles the superior curved 
line, corresponding with the more prominent ridge, or transverse crest, 
which in the lower animals separates the cervical aspect from the roof. 
A mesial ridge {external occipital crest) passes from this to the foramen 
magnum and is crossed by an inferior curved line extending outwards 
and forwards to the jugular processes. The part above the superior 
curved line is smooth, and the middle of its convexity is called the 
occipital probole. The superior curved line is itself expanded more or less 
distinctly in young subjects and some adults, into an area giving an 
attachment internally to the trapezius muscle, and externally to the 
splenius and sterno-cleido-mastoid, while its upper limit gives origin to THE SKULL 
Lachrymal depression 
Spheno-maxillary fissure 
■e 
Infraorbital foramen 
Frontal eminence 
Superciliary ridge 
Supraorbital notch 
Nasal spine 
■Ol 
Lachry mo-ethmoidal suture 
Fio, 198.—Skull from front and right side. 
Mental foramen 
Parleto-sphenoidal suture or pterion 
Squamous suture 
Temporo-sphcnoidal suture 
Great wing of sphenoid 
Optic foramen 
Sphenoidal fissure 
Zygomatico-malar suture 
Angle of jaw I 210 
THE SKELETON. 
the occipitales muscles and the thin aponeurosis between them. The part 
between the curved lines presents on each side of the crest a large depres- 
sion for the complexus muscle, rough in its lower part for a deep-seated 
tendon; and further outwards a less distinct longitudinal depression 
marking the insertion of the obliquus capitis superior. Below the in- 
ferior curved line are two other depressions, the inner for the rectus 
capitis posticus minor, and the outer for the rectus capitis posticus major. 
The articular condyles lie to the sides of the anterior half of the foramen 
magnum; behind them are the posterior condyloid foramina already 
mentioned, one or both of which may be absent, and in front, close to 
where the outer margins of the condyles curve inwards, are the exits 
of the anterior condyloid foramina, also already mentioned. Extending 
from condyle to jugular process behind the jugular notch is a rough 
prominence giving attachment to the rectus capitis lateralis; and this pro- 
minence has a certain interest as the representative of the paroccipital 
process which in various animals, as the pig and the sheep, is greatly 
elongated to give attachment to the muscles which in man are inserted 
into the mastoid process. The inferior surface of the basilar process 
presents in the middle the pharyngeal tubercle, giving attachment to the 
occipital ligament of the pharynx, and on each side of this a line in front 
of which the rectus capitis anticus major muscle is inserted, while behind 
and further out is placed the insertion of the rectus capitis posticus 
minor. 
The condyles for articulation with the atlas have their posterior 
extremities opposite the middle of the foramen magnum, and curve in- 
wards as they pass forwards on each side of it. They are convex both 
longitudinally and transversely, with their inner margins prominent, and 
might seem to lie in the circumference of a sphere, but on close inspec- 
tion are seen to be traversed by an oblique line of greatest convexity, 
dividing each into an anterior and posterior facet corresponding with the 
basilar and posterior parts which lie at right angles in a dog or a sheep. 
Internal to them are two rough impressions, the attachments of the 
lateral odontoid ligaments. The fore parts of the condyles are projected 
in the adult on two short wedges of support, beyond the level of the 
foramen magnum. These wedges are absent at birth, and tend to dis- 
appear in old age, and are connected with the balance of the head on the 
column, being developed proportionately to the increase of weight of the 
forehead and face.1 The condyles are much flatter at birth, and often 
flattened in old age. They are comparable with the superior articular 
surfaces of the axis in respect that they are completed in front by the 
mesial element, the basi-occipital, which has within it, in foetal life, the 
notochord. 
1 Gleland, Philosophical Transactions, 1870, and Memoirs and Memoranda in 
Anatomy, 1889. THE PARIETAL BONES. 
THE PARIETAL BONES. 
The parietals are two quadrilateral plates forming the middle region of 
the roof of the skull. 
Borders. Their superior borders are straight and deeply dentated, 
united one with the other in the middle line by the sagittal suture. 
Their posterior borders, similarly dentated, form with the occipital 
the lambdoidal suture. The anterior borders, less deeply serrated, are 
united to the frontal bone by the coronal suture, and have the peculiarity 
that in the lower part the outer table overlaps the frontal bone, 
while in the upper the outer table of the frontal overlaps the parietals. 
The inferior border is in the greater part of its extent concave, with the 
inner table projecting as a sharp edge far beyond the outer, and separated 
from it by a fluted surface which rests against the squamous part of the 
temporal bone, and forms with it the squamous suture. Behind this a 
straight portion joins the squamous edge at a projecting angle, and is 
serrated to articulate with the mastoid portion of the temporal, forming 
with it the parieto-mastoid suture (additamentum suturae squamosae); while 
in front the anterior inferior angle articulates squamously with the great 
wing of the sphenoid. This articulation with the sphenoid (■pterion) is, 
however, sometimes absent on one or both sides, and is variable in extent 
when present. 
The outer surface has its greatest convexity, the parietal eminence, 
rather above and behind the middle. Sweeping upwards from behind, and 
arching forwards below the eminence, is the temporal ridge, dividing the 
superficial upper part from the temporal fossa, and showing more or less 
distinctly'' an upper and lower line with an interval between, the upper 
line marking the superficial limit of attachment of the temporal fascia, 
and the lower the margin of the temporal muscle. Near the middle line, 
and behind the eminence, there is usually an aperture for a vein—the 
parietal foramen. 
The deep surface presents, along by the upper border, a depression which, 
when the right and left bone are fitted together, is completed into a mesial 
groove, marking the course of the, superior longitudinal sinus, and in con- 
tinuity with the superior groove of the occipital. Close to the posterior 
inferior angle there is a small curved portion of the groove for the lateral 
sinus. There are also three sets of hollows which are not peculiar to the 
parietal. The whole surface is covered with shallow digital impressions 
corresponding with the cerebral convolutions, and is traversed by sharp- 
bordered branching grooves, ramifying from the neighbourhood of the 
anterior inferior angle, and marking the course of the branches of the 
middle meningeal artery. Lastly, in adult skulls there are almost always 
seen, near the upper border, some irregular depressions caused by the 
growths called Pacchionian corpuscles eating into and pushing before 
them the vitreous table. 212 
THE SKELETON. 
THE FRONTAL BONE. 
The frontal bone forms the whole of the forehead, and also the roofs of 
the orbits or hollows for the eyeballs, and is divisible into frontal and orbital 
plates. It will be better understood if compared at the outset with the 
frontals of some other animals, such as the dog or the sheep, when it will 
be seen how the borders internal to the orbits have been, throughout the 
vertebrate series, anterior, while the roofs of the orbits are the lower parts 
of walls originally looking outwards; and that the peculiar form of the 
human frontal depends on the large development of the brain and the 
narrowness of the nose. In early childhood it consists, as in most adult 
vertebrates, apes and monkeys excepted, of a pair of bones united in the 
middle line by a frontal suture; and not unfrequently this suture persists 
in the serrated form throughout life. 
Borders. The border forming with the j)arietals the coronal suture is 
serrated and overlaps them above, while on each side the parietal overlaps 
the frontal below; and below the level of the parietal the border expands 
into a triangular surface looking downwards to articulate with the great wing 
of the sphenoid. In front of this triangle is the serrated extremity of the 
external angular process, which articulates with the malar; while, internal to 
the triangle, the posterior border of the orbital plate articulates with the 
orbital wing of the sphenoid. Between these plates, the ethmoidal incisura, 
or notch, extends forwards to the base of the frontal plate; it presents a large 
outer and a smaller inner margin, formed respectively by the outer and 
inner tables of the skull. Between these margins there is on each side of 
the incisura a row of shallow depressions, the roofs of air-cells in the lateral 
mass of the ethmoid bone, and, crossing transversely between them, two 
grooves, completing with that bone the internal orbital canals, the anterior 
of which gives passage to the nasal nerves. The margin internal to the cells 
articulates with the cribriform plate of the ethmoid, while the margin outside 
articulates in greater part with the orbital plate of the same bone, except for 
a short space in front, where it comes in contact with the lachrymal. In front 
of the lachrymal edge is a serrated margin curving forwards and inwards to 
the middle line, and articulating in its outer part with the superior maxil- 
lary, and in its inner with the nasal bone. In the middle line, in front of 
the incisura, the rough nasal spine projects down, articulating in front with 
the nasals, and behind with the central plate of the ethmoid. On each side 
of this is the opening into the fronted sinus, an air-cavity of variable and late 
development extending upwards and outwards over the orbits, lined with 
mucous membrane prolonged from the nose, and most extensive in the 
adult male. 
The surfaces of the frontal bone are the frontal, the orbital, and the cere- 
bral. The most prominent part of the convexity of the frontal surface on 
each side is called the fronted eminence; and above the orbit is an arched 
elevation, the superciliary ridge-, while between the two superciliary ridges THE FRONTAL BONE. 
there is a median elevation over the nose, called the glabella. The inferior 
limit of the frontal surface between it and the orbit is called the orbital arch, 
and presents in its inner half the supra-orbited notch, sometimes converted into 
a foramen, and sometimes 
double, transmitting the 
supra-orbital nerve and 
artery. The inner ex- 
tremity of the arch is 
sometimes called the in- 
ternal angular process, while 
the outer end is the external 
angular process, a stout 
projection already men- 
tioned as articulating with 
the malar. The outer 
margin of this process is 
formed by the temporal 
ridge, which passes upwards and backwards to be continued on the 
parietal bone, and separates the forehead from the temporal fossa. 
The orbital surfaces are triangular, their inner edges parallel, and their 
outer edges at right angles one to the other. Under cover of the 
external angular process lies a depression, fovea lachrymalis, in which 
is lodged the lachrymal gland; and beneath the inner end of the arch 
there is a small indented pit, fovea trochlearis, marking the position of 
the pulley of the tendon of the superior oblique muscle of the eyeball. 
The cerebral surface presents a continuous concavity, into the floor 
of which there project two convexities over the orbits, more dimpled by 
cerebral convolutions than the rest of the surface, and consisting opposite 
these dimples, as also posteriorly, of a single plate of bone without diploe. 
In the middle line, at the base of the frontal spine, is a groove completed 
by the crista galli of the ethmoid into a foramen (/. caecum), containing a 
minute vein opening into the commencement of the superior longitudinal 
sinus, and over this is the fronted crest broadening out into a mesial groove 
continuous above with that formed by the two parietals. Depressions caused 
by Pacchionian bodies may be seen on each side. 
Fig. 199.—Frontal from below, a, Ethmoidal sinuses; b, 
nasal spine ; c, frontal sinus ; d, trochlear depression ; e, supra- 
orbital notch ;/, lachrymal fossa; g, external angular process ; 
h, for malar; i, for sphenoid great wing; k, internal orbital canals; 
I, superior longitudinal sinus ; to, for sphenoid small wing. 
The sphenoid bone, occupying the middle of the base of the skull and 
spreading outwards on the sides, articulates with all the other cranial 
bones, as also with the palatals, malars and vomer. Owing to the 
remarkable manner in which the human cranium is curved on itself to 
make room by extension of the roof for the great size of the cerebral 
hemispheres, the sphenoid is compressed from before backwards; but the 
ordinary mammalian arrangement is that the sphenoid consists of two 
THE SPHENOID BONE. 214 
THE SKELETON. 
mesial bones, one in front of the other, each with a pair of wings spread- 
ing out in the cranial wall, and a pair of descending processes. Besides 
this, the parts called in human anatomy internal pterygoid processes 
remain in other animals separate throughout life as the pterygoid bones. 
Also, the parts called in man sphenoidal turbinated hones are in other 
animals absent altogether, being in fact elements intercalated between 
the lateral masses of the ethmoid and the vomer, bones always in other 
mammalia placed edge to edge, and usually early united to form one 
piece. 
The human sphenoid is described as consisting of a body and three 
pairs of processes, viz., the great alae and the orbital alae (both taking 
part in the wall of the 
cranial cavity), and the 
pterygoid processes, pro- 
jecting downwards, and 
consisting each of an 
external and an internal 
pterygoid plate. But in 
the child the constitu- 
tion of the sphenoid is 
much better seen, and it 
can then be observed that 
interiorly the fore part 
of the body is marked 
off by a transverse notch 
from the hinder part, 
and has a rounded outline filled with cancellated tissue; that the 
internal pterygoid plates, though adherent, are distinguishable in their 
whole original extent, and that a pair of hollow pyramids, the sphenoidal 
turbinated bones, lie on the sides of the fore part of the body, and have a& 
yet no adhesion to the sphenoid. 
The body is indistinguishably united to the basilar process of the 
occipital after the twentieth year. Its upper surface slopes upwards from 
behind, forming along with the basilar process of the occipital a con- 
tinuous plane, the clivus, which terminates in front in a thin plate, the 
dorsum sellae, forming the posterior limit of a deep depression, the sella 
turcica, ephippium or pituitary fossa, which is occupied by the pituitary body. 
In front of the pituitary fossa is the olivary eminence, a transversely 
oval surface separated from it by a line, and in front of the olivary 
eminence the level orbited wings meet in the middle line at a slightly 
higher level. The dorsum sellae is thick and irregular at its summit, 
and has projecting angles called posterior clinoid processes. The olivary 
eminence slopes at each side into a foramen directed forwards and 
outwards into the orbit, the foramen opticum; and on it rests the 
optic commissure, from which the optic nerve on each side passes out- 
Fig. 200.—Sphenoid at Birth, from below. A, Body and orbital 
wings ; B, left great wing not yet united to body, a, Orbital wing 
pierced by optic foramen ; 6, place of union of postsphenoid and pre- 
sphenoid ; c, external pterygoid plate ; d, internal pterygoid plate ; 
e, foramen ovale and foramen spinosum not completed. THE SPHENOID BONE. 
wards through the optic foramen, accompanied by the ophthalmic artery. 
The optic foramen pierces the base of the orbital wing, and, continuous 
with its upper border, a smooth process of that wing projects backwards, 
the anterior clinoid process. On each side three marks indicate the course 
Pituitary fossa 
Olivary process 
Anterior clinoid process 
Anterior ) 
clinoid process ) 
( Posterior clinoid 
( process 
Dorsum sellao 
Carotid groove ’ 
•Foramen rotundum 
Foramen ovale 
Lingula. __ 
Foramen spinosum 
/ Groove of chorda 
I tympani 
Spinous process 
■Scaphoid fossa 
Fig. 201.—Sphenoid from behind. 
of the internal carotid artery, viz., posteriorly, a deep notch separated 
from the posterior border of the great wing by a thin process, the lingula ; 
secondly, a carotid groove running forwards at the side of the sella 
turcica; and thirdly, a concave margin internal to the anterior clinoid 
Sphenoidal sinus 
| Sphenoidal fissure 
Malar margin 
Optic foramen 
Frontal surface 
Sphenoidal turbinate 
Foramen rotundum 
Vaginal process 
Pterygo-palatine groove 
_Vidian canal 
Palatal margin 
. Hamular process 
Fig. 202.—Sphenoid from the front. 
process and behind the foramen opticum. A spicule, the middle clinoid 
process, may be present internal to the groove, and reach up to the 
anterior clinoid process. Inferiorly, opposite the posterior edges of the 
pterygoid process, there is a transverse groove made by a rough ledge 
looking backwards, the attachment of the posterior wall of the pharynx. 216 
THE SKELETON. 
Further forwards, on each side, there is a projection inwards of the sur- 
face continuous with the internal pterygoid plate : it is called the vaginal 
process, and articulates edge to edge with the vomer, while it is partially 
covered in by the sphenoidal process of the palatal bone, and has on it a 
groove, completed anteriorly by the palatal into the pterygopalatine canal, 
a small passage containing the pharyngeal branch of Meckel’s ganglion. 
Extending from between the vaginal processes, the fore part of the body 
projects forwards as a narrowing mesial keel, the rostrum, covered by the 
vomer, and on each side is a triangular plate with its apex pointing 
backwards. This is the portion of the sphenoidal turbinated bones termed 
triangular hone of Berlin, and curves upwards in front so as to look forwards 
and wall-in the sphenoidal sinus, leaving an aperture by which the sinus 
opens into the upper and back part of the nasal fossa. Between the two 
sphenoidal sinuses the bocty is reduced to a thin septum sphenoidale; and 
in front this thin plate has to be broken separate from the central plate 
of the ethmoid, and is named sphenoidal crest. 
The sphenoidal turbinated bones are, however, structures which reach 
the perfection of their development in childhood, and consist at that time 
of four distinct ossicles, of which the largest 
is the bone described by Bertin, while an 
upper and outer and an upper and inner 
plate complete in early years the walls of 
the sphenoidal sinuses, but become soon 
absorbed. The fourth ossicle is a constant 
orbital element, which may become adherent 
to either the sphenoid, the os planum of the 
ethmoid, or the orbital process of the palatal, 
or to all of these, and always completes with 
the palatal bone the sphenopalatine foramen.1 
On this account the sphenoidal turbinated 
bones sometimes are broken away with the 
sphenoid, sometimes with the ethmoid, and 
sometimes with the palatals, along with 
which last they were figured by the first 
Monro. In the lower animals, the sphenoidal 
turbinates being absent, the spheno-palatine 
foramen is completed by the ethmoid, and is ethmo-palatine. 
The orbital, anterior or small alae or wings spread out horizontally 
from where they meet in the middle line in front of the body. At this 
point there is usually a slight projection forwards, the ethmoidal spine, 
and the whole anterior border is serrated, articulating in the middle with 
the ethmoid, and further out with the orbital plate of the frontal. The pos- 
terior border, smooth and free, separates the anterior from the middle fossa 
Fig. 203.—The Vomer, Ethmoid, 
Sphenoidal Spongy Bones, and Left 
Palate and Maxillary Bones, from 
the Skull of an Infant. Seen from 
behind (slightly enlarged), a, Orbital 
plate of the ethmoid ; b, posterior ex- 
tremity of the vomer; c, sphenoidal 
process of the palate bone; d, orbital 
surface of the palate bone, and im- 
mediately above it is the orbital portion 
of the sphenoidalspongybone. Between 
the two processes of the palate bone is 
the spheno-palatine foramen, com- 
pleted above by the inferior portion of 
the sphenoidal spongy bone, e, The 
superior portion of the sphenoidal 
spongy bone. 
1 See Cleland on “Vomer, Ethmoid and Submaxillary Bones” (Philosophical Trans- 
actions, 1862). THE SPHENOID BONE. 
of the base of the cranium, and slopes outwards and forwards to meet the 
anterior at a point which comes almost or quite into contact with the great 
wing. The orbital wing arises, not only internal to the optic foramen, but 
also external to it by a strong bar separating that foramen from the sphenoidal 
fissure; and in front of the exit of the optic foramen a short internal 
orbital plate separates the sphenoidal sinus from the orbit, and articulates 
in front with the os planum of the ethmoid and the orbital plate of the 
sphenoidal turbinated bone. 
The great or posterior ala or wing arises from the body, opposite the 
side of the sella turcica, and rapidly expands backwards and forwards. It is 
separated from the small wing by the foramen lacerum orbitale or sphenoidal 
fissure, a gap rounded internally, and narrowing and ascending as it extends 
outwards,—the aperture of exit of the third, fourth and sixth nerves, and the 
ophthalmic or first division of the fifth, and giving entrance to the ophthalmic 
vein. The great ala may be most conveniently described as divisible by a 
line drawn outwards from the inner end of the sphenoidal fissure into a 
posterior horizontal part and an anterior ascending part. 
The horizontal part of the great ala forms portion of the floor of the middle 
fossa of the base of the cranial cavity, lying oh a lower level than the sella 
turcica, and supporting the middle lobe of the brain. Its outer border 
articulates roughly with the squamous part of the temporal bone, and its 
posterior border, directed backwards as well as outwards, forms a thin edge 
which is barely in contact with the petrous portion of the temporal, com- 
pleting with it interiorly a groove in which lies the Eustachian tube. 
Projecting downwards from the posterior and outer angle, there is a short 
and stout spinous process, giving attachment by its rough edge to fibres of the 
tensor palati, and presenting on its inner side a small groove (Lucas) for the 
chorda tympani nerve; and immediately in front of this is the foramen 
spinosum, through which the middle meningeal artery enters. Anterior and 
internal to the foramen spinosum, and, like it, closed off in development from 
the posterior border, is the large foramen ovale which transmits the inferior 
maxillary nerve, the third division of the fifth. Considerably further for- 
wards and inwards, closed off originally from the anterior border, and lying 
outside and below the inner end of the sphenoidal fissure, is the foramen 
rotundum, which is directed forwards immediately below the level of the 
orbit, and transmits the superior maxillary or second division of the fifth 
nerve. 
The ascending part of the great ala lies altogether in front of the junc- 
tion with the body, and is a three-sided mass projecting upwards and 
outwards. Its summit is rough, articulating principally with the frontal 
bone, but coming in contact also with the parietal outside and behind the 
frontal articulation. By means of its posterior border it articulates with the 
squamous part of the temporal bone, in continuity with the horizontal part of 
the ala; and anteriorly it presents a thin border which articulates with the 
malar, while internally, by means of a free border, it bounds the sphenoidal THE SKELETON. 
218 
fissure. The posterior or cerebral surface is continuous with the upper 
surface of the horizontal part; and another surface, looking downwards in 
continuity with the under surface of the horizontal part, forms with it the- 
reof of the zygomatic fossa, giving origin to the upper head of the external 
pterygoid muscle. The external surface, separated from the lower by a 
temporo-zygomatic ridge, gives attachment to the temporal muscle. The 
remaining surface, looking forwards and inwards, forms portion of the outer 
wall of the orbit, and is bounded below by a free border, which separates it 
from a part looking into the spheno-maxillary fossa, and is the upper border 
of the spheno-maxillary fissure. 
The pterygoid process projects downwards and somewhat forwards. 
It consists of an external and an internal pterygoid plate, united in 
front for more than half their length, but separated below by a rough-edged 
notch, into which the pyramidal process of the palatal fits so as to fill it up. 
The space left between the two plates looks backwards, and is called the 
pterygoid fossa. The external pterygoid plate is slightly everted and broader 
than the internal, and gives attachment by its outer and inner surfaces 
respectively to the external and internal pterygoid muscles. From its border 
a spicule or band sometimes extends back to the spinous process, completing a 
foramen through which the outer branches of the inferior maxillary nerves 
may pass. The internal pterygoid plate, after being continued down as far as 
the external, has a slender prolongation carried downwards and outwards, 
the hamular process ; and at the upper and inner part of the pterygoid fossa 
is a small depression, called scaphoid fossa, indicating the origin of the tensor 
or circumflexus palati muscle, whose tendon winds round the hamular pro- 
cess. The anterior surface of the pterygoid process expands abdve into an 
area reaching up to the orbital surface of the great wing, and forming the 
posterior wall of the spheno-maxillary fossa. In the upper part of this wall 
the front of the foramen rotundum is seen, and internal to this, and below it,, 
the anterior opening of the Vidian canal, which, lying between the originally 
separate ossification of the internal pterygoid plate and the rest of the 
sphenoid, transmits the Vidian nerve and vessels, and passes backwards 
to reach the foramen lacerum medium, a ragged aperture left between the 
sphenoid, the petrous portion of the temporal and the basilar process of the 
occipital. 
THE TEMPORAL BONE. 
The temporal bone possesses considerable complexity, partly owing te 
its connection with the organ of hearing, and partly to its being com- 
posed of heterogeneous parts which happen to be united in the human 
subject by osseous substance. It is usually described as consisting of three 
parts, the squamous, the mastoid and the petrous. But of these the 
squamous is the only part which can claim to be a single distinct element 
in development and comparative anatomy; thus, the mastoid is at no 
period a completed structure separate from the petrous, and it is cus- THE TEMPORAL BONE. 
tomary to include along with the petrous both the styloid process and 
the tympanic plate, which are independent developments. 
The petrous part contains within it the essential organ of hearing 
called the labyrinth or internal ear, which is divisible into portions called the 
cochlea and the vestibule and three semicircular canals, all receiving branches 
from the auditory nerve. The orifice of the ear, external auditory meatus, has 
the squamous part above it, the mastoid behind it, and the rough external 
auditory process of the tympanic plate below and in front of it. It leads 
Supra-orbital notch 
ETHMOID. 
Mesial Plate 
Uncinate process 
Inferior turbinated process. 
External angular process 
Anterior internal orbital) 
foramen j 
Posterior internal orbital \ 
foramen j 
Spheno-palatine foramen 
SPHENOID. 
Turbinate 
External pterygoid process 
Internal pterygoid process 
Vaginal process 
Vidian canal 
Glenoid fossa 
TEMPORAL. 
Foramen spinosum 
Eoramen lacerum medium 
Foramen ovale 
Glaserian fissure 
External auditory process 
Carotid canal 
External auditory meatus 
Eoramen lacerum 1 nerves 
Posticum / veiu 
Styloid process 
Stylo-mastoid foramen 
Digastric groove 
Occipital groove 
Mastoid process 
OCCIPITAL. 
Jugular process 
For rectus capitis lateralis 
Pharyngeal tubercle 
Condyle 
Posterior condyloid foramen* 
Anterior condyloid foramen. 
Inferior curved line 
Parietal bone 
Rectus posticus superior 
Rectus posticus inferior 
Complexus 
Superior curved line 
( External occipital 
\ protuberance 
Fig. 204. Base of Skull, about ten years old, with face bones removed, as also 
right pterygoid process and right uncinate and inferior turbinated processes of 
ethmoid. The occipital is ununited to the sphenoid. 
into the tympanum or middle ear, a chamber transversely narrow, but 
expanded from before backwards, which in the recent state is separated 
from the external ear by the membrana tympani, and communicates with 
the pharynx by means of the Eustachian tube. It may also be mentioned 
that the tympanum contains within it three ossicles, named malleus, incus 
and stapes, minute structures utilized in connection with hearing, but 
integrally connected with the mandibular skeleton, both in the mam- 
malian embryo and in adult non-mammalian vertebrates. 
The squamous part has an extensive free border, which may be traced 
forwards from where it forms the outer wall of a deej) cleft in front ot 220 
THE SKELETON. 
the serrated upper border of the mastoid part: it arches upwards and 
forwards, forming with the parietal the squamous suture, and its outer 
table is prolonged considerably beyond the inner, as a thin scale with a 
fluted surface which looks inwards, so that the two parietals are grasped 
between the two temporals of opposite sides. In front of the parietal 
the free border articulates with 'the great wing of the sphenoid, and. is 
directed downwards, and then obliquely backwards and inwards, becoming 
more distinctly serrated as it proceeds, till it ends by coming in contact 
with the anterior border of the petrous. From this point a fissure, the 
fissure of Glaser, passes outwards to the front of the external auditory 
meatus, and separates the quadrate surface for the temporo-maxillary articu- 
lation from the tympanic plate. The articular surface, in its hinder 
Arterial fissure 
Fissure of Glaser 
External auditory meatus 
Glenoid fossa 
Mastoid foramen 
Articular eminence 
Occipital groove. 
Digastric groove- 
Mastoid process 
Tubercle of external lateral ligament 
Stylo-mastoid) 
foramen ) ” 
Jugular fossa _ 
Aquaeductus \ 
cochleae i ' 
For Jacobson’s nerve. 
Carotid canaL, 
Styloid process,. 
Fig. 205.—Right Temporal from below. 
part, presents a hollow, elongated inwards and a little backwards, the 
glenoid fossa, in which the condyle of the lower jaw lies when the mouth 
is closed, and in front a convex eminence on which it rests when the 
mouth is opened : at the outer end of this eminence there is a tubercle 
marking the attachment of the external lateral ligament; and in front of 
the Glaserian fissure, a postglenoid tubercle separates the glenoid fossa 
from the external auditory meatus. The external and anterior part of the 
-articular surface lies beneath the obliquely folded origin of an elongated 
bar, the zygoma or zygomatic process, which curves outwards and forwards 
to form with the malar bone the zygomatic arch. The lower border of the 
zygoma is rough, giving attachment to the masseter muscle, and is con- 
tinuous with the eminence of the articular surface, sometimes spoken of 
as its anterior root ; the upper border is narrower than the lower, and is THE TEMPORAL BONE. 
much longer, both because it is prolonged further forwards, and because 
it begins further back opposite the postglenoid tubercle. It is continued 
into the posterior root over the external auditory meatus, and still further 
back into a supramastoid crest, and, together with these, gives attachment 
to the temporal aponeurosis. Above and behind the external auditory 
meatus a little pit, the post-auricular depression, is almost constantly 
formed in connection with a slightly projecting squamous attachment of 
the cartilage of the ear. The external surface of the squamous part is 
marked by the attachment of the temporal muscle; the internal surface is 
marked by impressions of cerebral convolutions and branches of the 
middle meningeal artery. 
The mastoid process has two serrated borders, a horizontal and a vertical, 
which articulate respectively with the parietal and occipital. It is named 
Lateral sinus 
.Mastoid foramen 
f Aquaeductus 
\ vestibuli 
Occipital groove 
Digastric groove 
Internal auditory meatus I 
Carotid canal 
For Jacobson’s nerve 
>n s nervel i 1 f 
Jugular fossa For jugular process of occipital 
Pig. 206.—Eight Temporal from behind. 
from the mastoid process, which projects downwards behind the external 
auditory meatus and owes its inflated appearance in the adult to air-cells 
opening into the back of the tympanum. On the deep side of the mastoid 
process, overhung by it, is the deep digastric fossa or cleft, giving origin 
to the posterior belly of the digastric muscle; and from the extremity of 
the process a line passes upwards and backwards, dividing the muscular 
roughnesses into an anterior area, the origin of the sterno-mastoid muscle, 
and a posterior area, which is closer to the digastric groove, and subdivided 
into a part devoted to the splenius capitis, and a smaller and deeper 
part receiving the insertion of the trachelo-mastoid muscle. Internal to 
the digastric cleft, and close to the occipital border, is the occipital 
groove, which lodges the occipital artery. On the cerebral surface, in the 
retreating angle between the mastoid and the petrous parts, there descends 
a deep groove, in which lies the sigmoid part of the lateral sinus, and 222 
THE SKELETON. 
usually a mastoid foramen is found conveying a vein from the outside into 
it, through the hone. A fissure in connection with the mastoid branch of 
the occipital artery, situated, in its most constant part, low on the mastoid 
process, though often figured has failed to be correctly appreciated. It is 
marked arterial fissure in Fig. 205. 
The petrous part, so called from its hardness, is a three-sided pyramid 
directed inwards and forwards from its base at the external auditory meatus 
to its apex at the side of the basilar process of the occipital. Two surfaces, 
an upper and a posterior, look into the cranial cavity, and are separated by 
a long, prominent and free edge, which, extending to the apex from behind 
the cleft at the back of the squamous suture, divides the posterior from the 
middle fossa of the base of the skull, and is grooved by a venous channel, 
the superior petrosal sinus. The posterior surface presents nearer the apex 
than the base, the internal auditory meatus, a large and short canal directed 
transversely outwards, and transmitting the facial and auditory nerves and 
the auditory artery. Within the meatus is seen the lamina cribrosa blocking 
up its extremity, except at the upper and fore part, where is placed the 
inner aperture of the aqueduct of Fallopius, or canal of exit of the facial 
nerve, which, when followed through the bone, will be found passing out- 
wards between and above the cochlea and vestibule, then turning backwards, 
separated from the tympanic cavity by a thin wall, and lastly, directed 
abruptly downwards to the stylo-mastoid foramen. The foramina of the 
lamina cribrosa are arranged in groups, the anterior conveying nerves and 
vessels of the cochlea, and the posterior and upper those of the vestibule. 
External to the internal auditory meatus is the aquaeductus vestibuli, an 
irregular fissure covered by a bony scale of late development; and, on the 
border between the posterior and inferior surfaces, directly below the 
internal auditory meatus, is another small opening similarly formed, called 
aquaeductus cochleae. 
On the superior surface of the petrous part there is a distinct depression 
over the apex, marking the position of the Gasserian ganglion. Further out 
there is a groove leading into the aperture called hiatus Fallopii, directed 
outwards and backwards to open speedily into the aqueduct of Fallopius, 
and transmitting the great superficial petrosal nerve ; more externally, an 
elevation from behind forwards marks the position of the superior semi- 
circular canal; and still further out, a fissure is generally found extending 
backwards a variable distance, and indicating where the petrous part, after 
roofing the tympanum by means of a thin prolongation, called tegmen tympani, 
comes in contact with the squamous part. 
The inferior surface of the petrous part of the temporal is divisible 
into two, one in front of the other; the posterior of these is really a border, 
continuous with the posterior border of the mastoid, and exhibits, from 
without inwards, (1) a recess to receive the jugular process of the occipital 
bone, (2) the jugular fossa in which the internal jugular vein lies as it passes 
through the foramen lacerum posticum between temporal and occipital THE TEMPOEAL BONE. 
bones, (3) a depression bounding the inner or neural part of that foramen 
opposite the aquaeductus cochleae, already mentioned, and (4) a rough area 
articulating with the basilar process. The anterior or free division of the 
inferior surface presents in its outer half the tympanic plate; and this plate 
floors the external auditory meatus and the tympanic cavity; its anterior 
margin bounding the Glaserian fissure; its surface concave and smooth, 
separated by parotid gland from the temporo-maxillary articulation; and its 
posterior margin sheathing with a projecting edge, called vaginal process, the 
.Tegmen tympani 
j Superior semi- 
' \ circular canal 
J Position of internal 
\ auditory meatus 
-Hiatus Fallopii 
External auditory meatus 
Cochleariform process 
j Depression for 
( Gasserian ganglion 
Tympanic plate 
Vaginal process.- 
. Carotid canal 
.Apex 
Styloid process -■ 
For tensor tympani 
For Eustachian tube 
Fig. 207.—Right Temporal from before. The squamous portion and its zygomatic 
process are seen from the deep side. The mastoid process is seen behind the styloid 
process. 
front of the styloid pi'ocess, a cylindrical spike of variable length continued 
into the stylohyoid ligament. Close to the styloid process, and in front of 
the digastric cleft, is the stylo-mastoid foramen by which the facial nerve 
emerges from the aqueduct of Fallopius; and behind the inner end of the 
tympanic plate, internal to the jugular fossa, and in front of it, is the large 
round carotid foremen, the inferior aperture of the carotid canal, a canal 
which, entering vertically, is seen to turn at right angles within the bone 
and to run horizontally forwards and inwards to emerge at the apex into the 
foramen lacerum medium. The thin ridge between the carotid foramen 
and the jugular fossa presents a small foramen by which Jacobsons nerve 
enters to reach the tympanum. In front of the carotid foramen, at the inner 
end of the Glaserian fissure, is an irregular opening in the retreating angle 
between the petrous and squamous parts, the Eustachian orifice; and a closer THE SKELETON. 
inspection shows it to be divided by a scoop-like lamina, the cochleariform 
process, into an upper part which transmits the tendon of the tensor tympani 
muscle, and a lower, which is the osseous part of the Eustachian tube. The 
tegmen tympani projects downwards outside the Eustachian orifice, and 
appears in the inner half of the Glaserian fissure, especially in young- 
subjects ; and the part of the fissure between the tegmen and tympanic plate 
is important as that through which the chorda tympani nerve passes, and 
in which the processus gracilis of the malleus is entangled. 
The foramen lacerum medium is a gap in the base of the skull, best 
named thus, to distinguish it from the foramen lacerum posticum, and 
from the sphenoidal fissure which has sometimes been called foramen 
lacerum anticum. It is bounded in front by the inner part of the pos- 
terior border of the great wing of the sphenoid, internally by the basilar 
process of the occipital, and behind and externally by the apex of the 
petrous part of the temporal. No structure passes directly through it, 
but it is traversed by the internal carotid artery and the continuations 
backwards of the Yidian nerve. 
THE ETHMOID BONE. 
The ethmoid bone consists, fundamentally, of a mesial and a pair of 
lateral elements not united until after birth, and then only by means of 
a cribriform plate growing out from the mesial element. In animals 
other than man the mesial 
part is often united to the 
sphenoid long before it is con- 
nected with the lateral parts ; 
and in mammals generally, 
the lateral parts are united 
by means of the vomer, long- 
before they are joined by the 
cribriform plate. 
The mesial or central plate 
([mesethmoid) forms the upper 
part of the septum separating 
the right and left nasal fossae, 
and grows from above down- 
wards at the expense ot the septal cartilage of the nose. In the 
greater part of its extent it is reduced to a thin lamina; but interiorly 
its border is of the thickness of the septal cartilage, with which it is 
continuous, and in the hinder part of the extent of this border there is 
osseous continuity on one or both sides in the adult with the vomer. The 
posterior border is in osseous continuity with the sphenoidal crest, and the 
anterior border articulates with the nasal spine of the frontal and with 
the nasal bones. The upper border appears in the cranium above the 
ICrista galli 
I Orbital plate 
I ( Superior turbin- 
I 1 ated process 
I Unciform process 
I j Inferior turbin- 
I ( ated process 
I Central plate 
Fig. 208.—Ethmoid from behind. THE ETHMOID BONE. 
cribiform plate as a ridge rising in front into a thick process, the crista 
galli, to which the falx cerebri is attached; and the base of the crista 
galli is broadened out in front, and grooved to complete with the frontal 
bone the minute venous canal called foramen caecum. 
The cribriform plate, extending outwards from the central plate, articu- 
lates with the frontal and fills up its incisura, while immediately below 
this it is united on each side with the lateral mass. The upper surface 
is depressed on each side, and lies beneath the olfactory bulbs; and the 
plate is called cribriform from being pierced by the filaments of the 
olfactory nerves. The larger and more numerous apertures have their 
walls prolonged a certain way on the central plate and lateral masses re- 
spectively, while those between are fewer and smaller, and are simple 
perforations. 
The lateral mass1 (lateral ethmoid) is exceedingly light, consisting of 
walls of air-cells, an orbital plate, two turbinate processes, and an uncinate 
process, all of them thin laminae. 
Above, it presents a row of cells more 
or less opened into by separation 
from the frontal, whose cerebral table 
articulates with the cribriform plate 
internal to the cells, while its super- 
ficial table articulates outside them 
with the orbital plate. The orbital 
plate or os planum is an oblong plate 
forming greater part of the inner 
wall of the orbit, and articulating 
above with the frontal, below with the 
superior maxillary and slightly with the palatal, behind with the orbital 
element of the sphenoidal turbinated bone, and in front with the lachrymal. 
The air-cells are divided into anterior, middle and posterior ethmoidal cells, 
the anterior placed in front of the orbital plate, covered-in externally 
by the lachrymal bone, and opening into the middle meatus of the nose; 
the middle covered-in by the orbital plate, and opening into the middle 
meatus; the posterior covered-in by the orbital plate, but opening into 
the superior meatus of the nose. Descending from the antei’ior cells is 
the uncinate process, which turns backwards below the level of the orbital 
plate, taking part in the formation of the wall between the maxillary 
sinus and nasal cavity, and articulating with the upper edge of the in- 
ferior turbinated bone. The turbinated processes (Fig. 220) are two in number, 
distinguished as superior and inferior (or superior and middle spongy hones), 
and take part in the formation of the inner side of the lateral mass, 
which presents a continuous surface broken only in its posterior half, 
where it presents a cleft, the superior meatus of the nose, leading into the 
posterior ethmoidal cells. The upper margin of this meatus is formed by 
Central plate Crista galli 
I Articulates with lachrymal 
__ Cribrifonn plate 
. Orbital plate 
f Unciform 
j process 
/ Inferior turbin- 
t ated process 
Fig. 209.—Ethmoid from front and left. 
1 Prefrontal of non-mammalian vertebrates. 
P THE SKELETON. 
a lamina curved at its free edge, the superior turbinate process; and a 
similar but more curved lamina, the inferior turbinate process, not only- 
forms the floor of the superior meatus, but extends forwards the whole 
length of the bone, its free edge descending as low as the uncinate pro- 
cess, and roofing the middle meatus of the nose. Between the uncinate 
process and the fore part of the inferior turbinate process, a passage, the 
infundibulum, passes up from the middle meatus, through the anterior 
ethmoidal cells, to open into the frontal sinus. 
The maxilla, maxillary or superior maxillary bone supports the teeth of 
the upper jaw in sockets or alveoli, sunk in a projecting ridge, which com- 
THE SUPERIOR MAXILLARY BONE. 
.. Articulates with frontal 
Articulates with nasal 
Lachrymal groove. 
Limit of articulation with malar 
Crest for inferior turbinated bone 
Articulates with inferior tur- 
binated bone 
Intermaxillary crest 
.Infra-orbital groove 
xMalar process 
Articulates with palatal 
■Tuberosity 
with palatal 
Groove of anterior Groove of posterior 
palatine canal palatine canal 
Pig. 210.—Bight Maxillary, internal and posterior view. 
pletes an arch with its fellow, and is called the alveolar process or dental 
margin. Within this arch the palate plate extends backwards, and more 
externally the bulk of the bone rises up, presenting a facial, a zygomatic, an 
orbital and a nasal surface; while it sends a frontal (or nasal) process 
upwards to the cranium, and a malar process outwards. 
The palate plate falls considerably short of the hinder end of the dental 
margin, and articulates behind with the palatal bone. It is vaulted and 
rough inferiorly, and on its upper or nasal surface is smooth, and thrown 
into a longitudinal furrow by the rising up of the mesial border, which is 
vertically fluted where it unites with its fellow, and in the hinder part of its 
extent makes with it a mesial ridge articulating with the keel of the vomer. 
But in front, above the dental margin, the mesial border is expanded 
upwards, and is separated from the part behind by an interruption which, in THE SUPERIOR MAXILLARY BOXE. 
the disarticulated bone, is interiorly an open groove ascending from the 
palate, and superiorly is converted into a lateral foramen by projection of a 
thin lamina backwards. The open groove completes, with its fellow of the 
opposite side, the incisor foramen or anterior palatine canal of human anatomy, 
and the lateral foramina leading up from it are called foramina of Sten- 
son ; but a fissure passing out transversely, sometimes seen in the adult, 
and always in the young bone, 
indicates that the parts in front 
correspond with the intermaxillary 
bones of the lower animals, and 
that the foramina of Stenson cor- 
respond with the incisor foramina 
largely developed in many mammals, 
and inclosing in some a communi- 
cation between the mucous mem- 
branes of the mouth and nose. 
The laminae which separate them 
are the mesial palatine processes of 
the intermaxillaries. Most fre- 
quently, especially in young sub- 
jects, two small apertures, foramina 
of Scarpa, for the naso-palatine 
nerves, are left in the mesial suture, 
so as to give four small foramina 
inclosed within the mesial incisor foramen; but this arrangement is not 
constant. The upper edges of the heightened parts of the mesial borders 
unite to form the nasal or intermaxillary crest, grooved for the front of 
the vomer and for the septal cartilage of the nose, and projecting forwards 
as the nasal spine. 
The facial surface reaches the middle line below, and presents, higher 
up, an excavation of the inner border, the nasal incisura. Still further up, 
it is continued on the frontal process, up to the frontal bone, and articulates 
internally with the nasal bone, while externally it is separated by a smooth 
border from the inner wall and floor of the orbit. Externally the orbital 
border is limited by the malar process, a stout projection with a ragged 
triangular surface looking upwards and outwards to articulate with the 
malar bone, and with an overhanging smooth border below, beneath 
which the facial is continuous with the zygomatic surface. Eminences are 
seen corresponding with the roots of the teeth, and especially the canine 
fang causes a prominence which separates a slight myrtiform or superior 
incisor fossa from a larger depression external to it, namely, the canine fossa, 
from which the levator anguli oris and compressor naris muscles take origin. 
Above the canine fossa is the infra-orbital foramen, from which the infra-orbital 
nerve and artery emerge ; and above the foramen the levator labii superioris 
muscle arises. 
Fig. 211.—Palate of Skull of Child about Six 
Years Old. a, Anterior palatine canal with its four 
foramina, viz,, Scarpa’s in the middle line, and 
Stenson’s at the sides; the line of suture between 
maxillary and intermaxillary passes outwards below 
a; 6, posterior palatine canal; c, tuberosity of pala- 
tal ; d, external pterygoid plate; e, hamular pro- 
cess ; /’ one of the foramina behind the incisor 
and canine teeth of children, leading to the sacs 
of the permanent teeth. THE SKELETON. 
The zygomatic surface, behind the malar process, is continued round to 
form the tuberosity which looks backwards, forming the anterior wall of the 
zygomatic and spheno-maxillary fossae, and is pierced by some minute 
apertures of posterior dental canals for nerves to the molar teeth. Superiorly 
this surface is separated from the orbital by a free margin, which forms the 
anterior border of the spheno-maxillary fissure, and is interrupted by the 
infra-orbital groove. 
The orbital surface forms the whole floor of the orbit with the excep- 
tion of a minute angle behind, which is completed by the palatal. The 
infra-orbital groove extends forwards in it, and its edges meet to form the 
infra-orbital canal, which terminates at the infra-orbital foramen. It gives 
off minute middle and anterior dental canals, conveying the nerves to the 
bicuspid and incisor teeth. The orbital floor is triangular, its anterior and 
posterior free margins being separated by the articular surface of the malar 
process; its inner margin, followed from behind forwards, articulates with 
the orbital process of the palate bone, the os planum of the ethmoid, and 
the lachrymal. Opposite the fore part of the latter it aids in bounding the 
entrance into the nasal duct, and in front is continued up into the frontal 
process, which forms the fore part of the inner wall of the orbit, and is 
grooved posteriorly to complete with the lachrymal bone the groove for the 
lachrymal sac. 
The nasal surface is surmounted in front by the inner aspect of the 
frontal process, which articulates behind with the lachrymal bone, and 
completes with it some of the anterior ethmoidal cells. Lower down there 
is a projecting line directed backwards and upwards, the crest foi' the inferior 
turbinated bone; and behind this the lachrymal groove descends from the floor 
of the orbit and posterior wall of the nasal process, forming the greater part 
of the wall of the nasal duct, which is completed by the lachrymal and inferior 
turbinated bones. Behind this groove is a large opening leading into a 
cavity extending underneath the orbit forward to the facial wall, and back 
to the tuberosity, and in old subjects projecting even into the malar process. 
This is named the maxillary sinus or antrum of Highmore. The entrance into 
the antrum is greatly diminished by other bones, the inferior turbinated 
articulating edge to edge with the lower margin of the opening, and being 
met by the uncinate process of the ethmoid, while the palate bone overlaps 
from behind. Only the gap left in front of the uncinate process is constant, 
and in the recent state forms the communication between the antrum and 
the middle meatus of the nose. Above the opening of the antrum, close to the 
orbital margin, shallow depressions complete some of the middle ethmoidal 
cells; and the surface behind it, and as far forwards below as the posterior 
edge of the palate plate, is rough for articulation with the palate bone. The 
roughness is interrupted by a groove passing from inside the tuberosity, 
downwards and forwards, to complete with the palate bone the posterior 
palatine caned, and transmit the posterior palatine vessels and nerve, which 
may also groove the palate as they pass forwards. THE SUPERIOR MAXILLARY BONE. 
After loss of a tooth the walls of its socket become absorbed, and when 
all have been lost, the whole dental margin disappears, and even further 
absorption takes place, greatly diminishing the size of the hard palate and 
making it flat. 
, Lachrymal bone 
Supra-orbital notch 
J Ethmoid 
Fronto-nasal suture 
Fronto-maxillary) 
suture ) .* 
Anterior internal orbital canal 
Posterior internal orbital canal 
Sphenoidal turbinate, orbital plate 
Optic foramen 
Orbital process of palatal 
Foramen rotundum 
Lachrymal groove 
Lower process of lachrymal 
Uncinate process of ethmoid. 
Inferior turbinate bone 
Nasal duct 
Palatal 
Vidian canal 
Canine fossa, infra-) 
orbital foramen j 
Incisor fossa— 
Pterygo-palatine canal 
Spheno-palatinc foramen 
| Posterior palatine canal 
Tuberosity of palatal 
Fig. 212.—Vertical Section of Left Side of Face, passing through orbit and 
maxillary sinus. (The orbital plate of the sphenoidal turbinated is very unusually large.) 
THE PALATAL BONE. 
The palatal or palate bone consists of a horizontal or palate plate, a 
vertical plate, and a thick pyramidal process projecting backwards and 
outwards from the back of the line of junction between the two plates. 
The palate plate lies altogether internal to the dental arch of the 
maxilla; it articulates in front with the palate plate of that bone, and, in the 
same manner as that plate, it articulates with its fellow of the opposite 
side and comes in contact with the vomer; while, behind, it has a free 
■concave margin giving attachment to the tensor palati, and forms with 
its fellow a mesial projection, the palatal spine, from which springs the 
agygos uvuli. 
The pyramidal process or tuberosity has two triangular free surfaces— 
■one continued backwards and outwards from the palate, and the other, 
with its base separated from the first by a free margin, and looking back- 
wards to fill the gap between the pterygoid plates and so complete the 
pterygoid fossa. On the sides of this surface are rough borders for 
■articulation with the pterygoid plates, and the oiiter of these is limited 
in front by a projecting line, sometimes scarcely apparent, but sufficient 
to prevent the external pterygoid plate from coming in contact with the 
maxilla below the spheno-maxillary fossa. THE SKELETON. 
The ascending plate becomes very thin as it ascends, and is surmounted 
by two processes, the orbital in front and the sphenoidal behind, separated 
by the spheno-palatine notch. Its smooth internal surface is traversed 
by a projecting crest, higher in front than behind, for articulation with 
the inferior turbinated bone. The outer surface, mostly rough for articu- 
lations, is divided longitudinally by a smooth portion, broadest above 
where it begins on the posterior part of the orbital process and the base of 
the sphenoidal process, and narrowing below to a deep groove sloping 
forwards which goes to form with the corresponding groove on the maxilla 
the posterior palatine canal, while the upper part is the inner wall of the 
spheno-maxillary fossa. In front of this smooth part the outer surface 
Fig. 21B.—Right Palatal Bone. A, from outer side. B, from behind, a, Pterygo- 
palatine groove of sphenoidal process ; h, orbital surface of orbital process ; c, deep wall of 
spheno-maxillary fossa, with spheno-palatine notch above, and groove for posterior 
palatine canal below ; d, crest articulating with inferior turbinated bone ; e, palate plate ; 
/, triangular surface of tuberosity which completes the pterygoid fossa; g, articulates 
with internal pterygoid plate ; h, articulates with maxillary ; i, articulates with external 
pterygoid plate ; k, articulates with maxillary. 
articulates with the maxilla, and also takes part in diminishing the 
entrance into the antrum; behind, it articulates below with the maxilla, 
and inclines backwards above to articulate with the internal pterygoid 
plate. The orbital process has two free surfaces—one, orbital, completing the 
orbital floor, the other, looking back into the spheno-maxillary fossa. It 
articulates in front with the maxilla, and internally with the ethmoid and 
orbital portion of the sphenoidal turbinated, and is hollowed in connection 
with middle ethmoidal cells. The sphenoidal process is a lamina directed 
upwards to the sphenoidal turbinated bone, and bending inwards and back- 
wards below the curved origin of the internal pterygoid plate, grooved 
above to complete with the groove on that plate the pterygopalatine canal, 
and articulating in front of it with the vomer. The sphenopalatine foramen THE PALATAL BONE. 
is the notch of the same name completed into a foramen by the sphenoidal 
turbinated bone; it is the ethmo-palatine foramen of other animals, and 
forms the communication between the spheno-maxillary fossa and the 
posterior nares, giving passage to branches of Meckel’s ganglion and of 
the internal maxillary artery. 
THE VOMER, 
The vomer is a mesial bone entering into the formation of the septum 
between the nasal fossae. It is liable to lose much of its characteristic 
appearance before adult life is reached, partly by anchylosis with the 
central plate of the ethmoid, partly by 
absorption, and ought therefore to be first 
studied in the child. It consists of two 
alae united below and a mesial body 
descending from their line of junction. 
The alae are thick and expanded 
behind, fitting on under the sphenoid; 
and at their tips articulate edge to edge 
with its vaginal processes, and, in front of 
them, wuth the sphenoidal processes of the 
palate bones. In front of this their edges 
descend as they pass forwards, and remain 
in contact with the septal cartilage of the nose, which occupies the interval 
between them. Anteriorly they terminate in a grooved intermaxillary process 
which rests on the intermaxillary crest. 
The body or keel is more and more elongated from above downwards 
as adult age is approached. Its posterior free margin descends from beneath 
the bifid posterior extremity of the alae to the back of the hard palate, 
and its inferior border extends forwards from this to fit in front behind 
the intermaxillary crest. In the young child it presents a flat expansion 
resting on the hard palate, with a mesial ridge and a transverse mark 
corresponding with the lines of junction of the bones beneath; and remains 
of this expansion may be sometimes detected in the adult turned down 
over the ridge which has risen below them.1 A groove on each side below 
the line of origin of the alae indicates the course of the naso-palatine 
nerve. 
In the adult, either one or both alae are united in osseous continuity 
with the central plate of the ethmoid. When the union has taken place 
on both sides, the septum of the nose is straight and a bar of cartilage 
is imprisoned between the two alae and the lower edge of the mesethmoid. 
Pio. 214.—Vomer, etc., of Child. 
a, b, c, The parts of the inferior margin 
of the romer for articulation with the 
palatal, maxillary, and intermaxillary 
bones respectively; d, sphenoidal tur- 
binated bone ; e, orbital plate of the 
ethmoid seen in perspective ; /, inferior 
turbinated process of the ethmoid. 
IVery occasionally a separate little spicule extends down into the suture between 
the maxillae from the point which fits in behind the intermaxillary crest. It nearly 
corresponds with the snout bone in ornithorhynchus and the boar. When I showed 
a specimen of it to Professor Good sir, he recognized it as having been brought under 
his notice by the anatomical attendant. 232 
THE SKELETON. 
But more frequently, especially in civilized nations, osseous union has 
occurred on only one side ; the other ala undergoes absorption to a con- 
siderable extent, and the septum is bulged to the side on which the 
cartilage is left free, so as to narrow the corresponding nasal fossa, more 
frequently the left than the right, and restrict the space for the passing 
of both air and surgical instruments. 
. Crista galli 
Frontal sinus 
Cribriform plate 
.Central ethmoid 
Rostrum of sphenoid 
Frontal spine 
Naso-maxillary suture 
Inferior turbinated bone 
Ala of vomer 
Nasal spine 
Anterior palatine canal 
f Suture between maxillary 
'( and palatal 
Fig. 215.—Vertical Section Displaying Septum Nasi. (The mesial intermaxillary 
surface happens to be marked by two deep grooves, but the crest passes further back, and 
is already united to the maxillary behind Stenson’s foramen.) 
THE MALAR BONE. 
The malar, jugal or cheek bone articulates broadly with the maxilla, 
and projects upwards and outwards, dividing into a stout and long frontal 
process articulating at its extremity with the external angular process of 
the frontal bone, and a compressed and 
shorter zygomatic process passing back to 
articulate with the zygomatic process of 
the temporal bone by a suture, the lower 
end of which projects further back than 
the upper. 
Looked at from the front, the malar 
bone presents a surface bounded by two 
short borders converging to an inferior 
angle, and two longer borders converging 
above. The more internal of the two 
shorter borders is the anterior edge of the 
articulation with the maxilla; the more 
external is thick and uneven, extending back to the zygomatic process of 
the temporal, and giving attachment to the masseter muscle. The anterior 
and more internal of the upper borders is concave throughout, and extends 
Fig. 216.—Right Malar, deep view. 
It articulates at a, with the maxillary; 
at 6, with great wing of sphenoid ; at c, 
with the frontal; at d, with zygomatic 
process of temporal. THE MALAR BONE. 
■downwards and forwards, forming the outer and part of the lower border 
of the orbit; while the posterior and more external extends between the 
frontal and zygomatic processes, and has a double curve, convex above, 
concave below, and gives attachment to the temporal fascia. 
Looked at on the deep side, it presents three surfaces, separated by 
ridges; namely, a surface continued from the inner side of the zygomatic pro- 
cess, longitudinally hollowed so as to complete the temporal and zygomatic 
fossae, and extending as far forwards as a line from the inferior angle 
to the tip of the frontal process; secondly, an orbital surface extending 
back from the orbital margin; and thirdly, a jagged triangular surface for 
articulation with the maxilla, intervening between the two others below, 
and sometimes continuous with an articular margin between them for the 
sphenoid, but more frequently separated from it by a very short free edge 
completing the anterior boundary of the spheno-maxillary fissure. The articu- 
lation with the sphenoid separates the orbit from the temporal fossa, and 
is continuous with the stout serrated articular surface for the frontal bone. 
The malar canal, a small passage for the malar branch of the superior 
maxillary nerve, begins on the orbital surface and ends on the superficial 
surface, a little above its greatest prominence or tuberosity. Another 
aperture, the temporal canal, pierces the orbital plate higher up and gives 
passage to the temporal twig of the superior maxillary nerve. 
The occurrence of a suture dividing the upper and inner part of 
the malar from the lower and outer is rarely met with in European 
skulls, but, in the Japanese, has been seen with unusual frequency, 
extending from the maxillary margin, sometimes upwards to the orbital, 
sometimes backwards to the upper margin of the zygomatic process. 
THE LACHRYMAL BONE. 
The lachrymal bone (os unguis) is a delicate scale on the inner side 
of the orbit, in front of the os planum of the ethmoid. It is grooved 
in its fore part to complete with the nasal process of the maxilla the 
depression which lodges the lachrymal sac, and articulates above with 
the frontal, and below with the orbital plate of the maxilla, while' from 
its grooved part a lower process is prolonged into the canal for the 
nasal duct, and reaches down to the inferior turbinated bone. The groove 
is limited behind by a crest which at its lower end is sometimes more 
or less prolonged round the entrance of the canal for the nasal duct in 
the form of a hamular process. The lachrymal bone is often deficient or 
cribriform. In many mammals it is a more important bone, coming 
forwards on the face. 
The inferior turbinated bone separates the middle from the inferior 
meatus of the nose. It curves inwards and downwards from its attachments, 
THE INFERIOR TURBINATED BONE. THE SKELETON. 
and has a free border running its whole length. Its attached border,, 
in its fore part, is sloped upwards and backwards, articulating with the 
line on the maxilla, and behind this it reaches 
its highest point, articulating with the lach- 
rymal and completing the lower orifice of the 
canal for the nasal duct. From this point a 
line of slope descends more gradually to the 
hinder end; in the first part of this slope 
the margin is folded over to look directly 
downwards and articulate edge to edge with 
the lower boundary of the aperture of the 
maxilla leading into the antrum; in the 
hinder part it articulates with the line on the palate bone. From the 
folded part bounding the antrum a small process projects upwards and 
articulates with the uncinate process of the ethmoid. 
Fig. 217.—The Right Inferior 
Turbinated Bone, from lateral 
side. It articulates at a, with crest 
of palatal; at b, with unciform pro- 
cess of ethmoid; at c, with lachry- 
mal ; at d, with crest on maxillary ; 
at e, with antral wall of maxillary. 
THE NASAL BONE. 
The nasal bone is thickest above, where it articulates by serrated 
suture with the frontal; the mesial border diminishes in breadth as it 
descends; the outer border is longer, and is narrow throughout to articulate 
with the nasal process of the maxilla. These three borders are serrated, 
while the inferior border is a thin irregular margin separated by fibrous- 
tissue from the cartilage below. The deep side is marked in its whole 
length by a groove in which lies the nasal nerve. 
The mandible, inferior maxillary bone or lower jaw consists of right and 
left parts, which become united into one bone in the first or second year 
after birth; and the plane of union, even after it ceases to be indicated 
save by a mere line on the surface, is called the symphysis. The part 
beneath the upper jaw is called the body; from this a ramus ascends on 
each side; and the projection where the thick and strong lower border 
of the body passes into the hinder border of the ramus is called the angle. 
The hinder border of the ramus is continued up to the articular condyler 
and the anterior border, rather concave below and convex above, and 
more nearly vertical than the posterior, terminates in the flat and pointed 
coronoid process which is separated from the condyle by a concavity, the- 
sigmoid notch. The teeth are arranged in sockets whose walls form, like 
those of the upper jaw, a continuous alveolar ridge or process. 
Superficially, at the chin is the mental protuberance, an ornament 
found only in man, and especially in the higher races. Above this, to- 
the side of the symphysis, is a shallow incisor fossa, which gives origin 
to the levator menti. More externally is situated the mental foramenT 
the outlet of the dental canal, giving exit to the mental artery and 
THE MANDIBLE. THE MANDIBLE. 
nerve; and passing beneath this foramen is the external oblique line, 
a distinguishable bar extending from the anterior border of the ramus 
to the mental protuberance. The whole surface of the ramus, including 
the coronoid process, gives attachment to the masseter muscle; and it 
is marked by it most strongly in its lower part, which, with the lower 
border in front of the angle, is ridged and prominent where the tendinous 
parts of the insertion are attached. 
The deep surface presents, near the symphysis, inside the lower 
border, a rough depression to which the anterior belly of the digastric 
muscle is attached; and close to the symphysis, higher up, are two little 
spines, one immediately above the other, the lower giving origin to tho 
Coronoid process 
Left condyle 
, For masseter 
Right condyle 
J Pit for external 
I pterygoid 
Mental foramen 
Inferior dental foramen 
Mylohyoid groove 
Internal pterygoid 
Angle 
Mylohyoid ridgo 
Depression of submaxillary gland 
For genioglossus 
Depression of sublingual gland 
I For digastric 
For geniohyoid 
Fig. 218.—Lower Jaw, from left side and below. 
geniohyoid muscle, and the upper to the genioglossus. From below 
these spines the prominent internal oblique line or mylohyoid ridge passes 
obliquely backwards and ujjwards, giving origin for some distance back 
to the mylohyoid muscle, and at its back part to some fibres of the 
superior constrictor of the pharynx, while it separates the depression 
for the sublingual gland above and in front of it from that for the 
submaxillary gland below and behind it. About the middle of the ramus 
is the inferior dental foramen leading into the dental canal and lodging 
the inferior dental nerve and vessels. Its inner margin is sharp with an 
upward projection, the lingula, giving attachment to the internal lateral 
ligament; and behind this is the commencement of the mylohyoid groove for 
the mylohyoid branches of the inferior dental nerve and vessels. On 
the inner side of the angle, and above it, there is a strongly marked 236 
THE SKELETON. 
range of tubercles where the internal pterygoid muscle is inserted. The 
'deep side of the coronoid process is smooth, giving attachment to the 
deep fleshy fibres of the temporal muscle; but its margins are sharp, 
receiving the fibrous part of the insertion of the same muscle, which in 
front is continued down to a rough depression from which the posterior 
fibres of the buccinator arise. 
The condyle is supported on a constricted neck, on the front of which 
is a depression which receives the greater part of the insertion of the 
external pterygoid muscle. It is convex, and elongated from without 
inwards and backwards, its long axis pointing to the middle of the 
anterior margin of the foramen magnum. 
At birth the ramus rises very slightly above the level of the body, 
and the angle is exceedingly obtuse. When, in consequence of loss of 
the teeth, the alveolar process is absorbed, the arch inclosed by the 
Fig. 219.—Edentulous Lower Jaw of Old Age. 
lower jaw is increased in size; and as loss of the upper teeth diminishes 
the size of the palate, the lower jaw may, in edentulous old age, pass 
-over the palate and approach the nose. But absorption is not confined 
to the alveolar part ; it extends to the muscular surfaces; the angle 
becomes more and more obtuse, and the ramus shorter, reverting to the 
infantile form. 
THE HYOID BONE. 
The hyoid bone, though not accounted in human anatomy as part 
of the skull, is nevertheless related to it in development, remains closely 
connected with it in many mammals, and-belongs to cephalic, not to 
cervical, segments of the organism. It consists of a body and two pairs 
-of cornua, which sometimes, especially the smaller pair, remain separate 
from the body. The body is elongated transversely, and compressed so 
as to lie in an oblique plane from above downwards and forwards; 
superficially, it is marked by two superior impressions which give attach- 
ment to muscles of the tongue, and two inferior depressions which 
receive muscles from below. The great cornua project backwards from 
the extremities of the body, and are rounded at the tips where the 
lateral thyrohyoid ligaments are attached. The small cornua, short and 
pointed, are connected with the tips of the styloid processes of the 
temporal bones by slender bands, the stylohyoid ligaments (Fig. 222). SUTURAL BONES. 
SUTURAL BONES. 
Additional bones are of frequent occurrence in the sutures of the 
cranium, where they are called JVormian hones or ossa triquetra. They 
are most frequent in the lambdoidal suture, where a whole chain of them 
may occur even to the extent of separating the occipital and parietal 
completely, an arrangement which occurs both in this and other sutures 
in chronic hydrocephalus. Sometimes one, three or more large bones 
are developed at the expense of the upper part of the occipital. 
Wormian bones also occur in the sagittal, coronal, parieto-mastoid and 
even the squamous suture; and a single bone of the sort is common 
between the parietal and great wing of the sphenoid, and by becoming 
united with either frontal or squamous may give the appearance of these 
bones coming into contact (Schlocker). Small ossicles of the same descrip- 
tion are said to occur in the face; as, at the outer end of the spheno- 
maxillary fissure, and in connection with the lachrymal bone. 
FOSSAE OF THE SKULL. 
Certain fossae of the skull require further description than could he 
given with that of the individual bones. 
The temporal fossa is the part bounded above by the temporal ridge, 
in front by the malar and external angular process of the frontal, 
behind by the origin of the zygomatic process of the temporal, and below 
by the temporo-zygomatic ridge of the sphenoid ; and it is arched across 
by the zygomatic arch and occupied by the temporal muscle. 
The zygomatic fossa is separated from the temporal by the temporo- 
zygomatic ridge ; it is roofed by the great wing of the sphenoid, and 
bounded internally by the external pterygoid plate. In front of it is the 
tuberosity of the maxilla, separated from the external pterygoid plate 
by a thin edge of the palate bone below, and by the pterygo-maxillary 
fissure higher up, and from the great wing of the sphenoid by the outer 
half of the spheno-maxillary fissure. 
The spheno-maxillary fossa is the narrow space between the pterygoid 
process and the tuberosity of the maxilla, separated from the nasal fossa 
by the palate bone and communicating externally with the zygomatic fossa 
by the pterygo-maxillary fissure, and superiorly with the orbit by the 
inner half of the spheno-maxillary fissure. Into it open five foramina, viz., 
posteriorly, the foramen rotundum and the anterior extremities of the 
Vidian and pterygo-palatine canals ; internally, the spheno-palatine foramen, 
and inferiorly, the posterior palatine canal. 
The pterygoid fossa is the interval between the pterygoid plates; it 
looks backwards, its anterior wall is completed below by the palate bone, 
and in its upper and inner part is the scaphoid fossa. It is occupied by 
the internal pterygoid and tensor palati muscles. 238 
THE SKELETON. 
The nasal fossa is opened into in front and behind by the anterior 
and posterior nares, is roofed by the nasal bone and the cribriform plate 
of the ethmoid, floored by the palate plates of the maxilla and palate 
bone, and separated from its fellow by the osseous septum of the nose 
formed by the vomer and central plate of the ethmoid. The external 
wall has its foremost part formed by the nasal and maxillary bones, and 
its hindermost part by the internal pterygoid plate, and in its intermediate 
extent is complicated by the projection inwards of turbinated bones 
which roof three galleries called meatuses. Of these the inferior meatus is 
the longest; it is roofed by the inferior turbinated bone and walled by 
maxilla and palate bone, and near its fore part has the nasal duct entering 
Inferior turbinated process of ethmoid 
Superior turbinated process of ethmoid | 
Frontal sinus 
Superior meatus 
.Nasal bone 
Spheno-palatine foramen 
Sphenoidal sinus 
.Intermaxillary crest 
Nasal spine 
Inferior turbinated bone. 
Middle meatus 
Inferior meatus 
Palatal - - 
/ Anterior palatal 
\ canal 
Internal pterygoid plate 
Posterior palatine canal /' 
■Groove of posterior palatal artery and nerve 
Fig. 220.—Left Nasal Fossa. (Pterygoid process pulled slightly from palatal.) A 
feather is passed from the frontal sinus to the middle meatus through the infundibulum. 
it from above. The middle meatus is neither prolonged so far forwards 
nor so far back as the inferior; it is roofed by the inferior turbinated 
process of the ethmoid, and has, in the wall between it and the antrum, 
the uncinate process of the ethmoid and parts of the maxilla, lachrymal, 
and palate bone. The antrum opens into it directly, while the infundibulum 
leading up to the frontal sinus opens into the front part of its roof, 
with which the anterior and middle ethmoidal cells also communicate. 
The superior meatus between the superior and inferior turbinated processes 
of the ethmoid is much shorter than the middle meatus, and leads into 
the posterior ethmoidal cells. Behind it in the outer wall is the spheno- 
palatine foramen; and looking forwards towards it, above the posterior 
nares, is an opening into the sphenoidal sinus. FOSSAE OF THE SKULL. 
The orbit is of the form of a four-sided pyramid. Its entrance is 
bounded by the frontal, maxillary and malar bones. Its outer wall is 
■at right angles to that of its neighbour, and is formed by the malar and 
the great wing of the sphenoid. The roof is formed in greater part by 
the frontal, but completed behind by the small wing of the sphenoid. 
Into the construction of the inner wall there enter the nasal process of 
the maxillary, the lachrymal, the os planum of the ethmoid, and the 
sphenoid, including the orbital element of the sphenoidal turbinated bone. 
The floor is formed mostly by the maxillary, and completed behind by 
Foramen caecum 
Cribriform plate 
(Suture between 
- frontal and orbital 
( wing of sphenoid 
Parietal 
Foramen optioum 
Foramen rotundum 
Carotid groove 
Foramen lacerum t 
medium / 
Oepression for Gas- \ 
serian Ganglion / 
Superior semi-? 
circular canal) 
Foramen ovale 
Foramen spinosum 
( Meatus auditorius 
( internus 
I Foramen lacerum 
\ posticum 
1 Foramen condyl- 
f oideum anticum 
Lateral sinus 
Parietal 
Jlnternal occipital 
I protuberance 
Fio. 221.—Base of Cranial Cavity of a Child, showing its anterior, middle and 
posterior fossae. Basilar process of occipital separated by a gap from the sphenoid. 
the orbital surface of the palate bone, which always lies below the orbital 
element of the sphenoidal turbinated, and is often united to it by bony 
union. At the deep end, occupying the apex of the pyramidal cavity 
of the orbit, is placed the optic foramen; and below, and to the outside of 
this, is the wide inner end of the sphenoidal fissure, while the outer 
end of that fissure is prolonged in the angle between the roof and the 
outer surface. The spheno-maxillary fissure lies in the angle between the 
outer wall and the floor, in its posterior two-thirds or more. In the inner 
Wall are the anterior and posterior internal orbital foramina, between 
ethmoid and frontal bone; and near the front is the lachrymal groove 
formed by the lachrymal and the nasal process of the maxilla, and 240 
THE SKELETON. 
leading down into the nasal duct. The foramina in connection with the 
floor are two, the nasal duct and the commencement of the infra-orbital 
canal. 
The three fossae basis cranii correspond with the three main levels of the 
floor of the interior of the cranium. The anterior is formed by the orbital 
plates of the frontal, the ethmoid between them, and the small wings of 
the sphenoid ; and the posterior border of those wings separates it from 
the middle fossa. The middle fossa has a narrow mesial part formed by 
the pituitary fossa, and at each side it widens out and is floored by the 
great wings of the sphenoid and the upper surface of the petrous part of 
the temporal. The superior margin of the petrous separates the middle 
from the posterior fossa, which is walled by the inferior occipital depress- 
ions, the clivus, and the petrous and mastoid. 
THE SHAPE OE THE SKULL. 
The characters of the human skull are divisible into those which dis- 
tinguish it from the skulls of apes, and those which vary according to 
age, sex, nationality and idiosyncrasy. 
Distinctive characters. The most obvious is the huge development of 
the arch of the skull as compared with the base; the arch being expanded 
and the base mesially shortened. If the distance of the root of the nose 
or mesial end of the fronto-nasal suture from the back of the foramen 
magnum be taken to express the length of the base, and the distance 
between the same points as measured with a tape carried over the roof be 
called the arch, then the proportion borne by the arch to the base 
counted as unity varies for the most part in the human skull from 2-45 to 
3, and is most frequently about 270; the general length of the adult male 
base-line being over five inches. The human cranium differs also greatly 
from that of all other animals in having the middle line of the floor of 
the anterior fossa basis cranii parallel to the plane of the foramen 
magnum, so that, regarded as part of the cerebro-spinal cylinder, it may 
be considered as completing in the adult state a semicircular curve. 
The face is elongated downwards from the cranium, so as to give height 
to the nasal fossae, affording space for the reverberation of the voice, 
which is further increased by the maxillary, frontal .and sphenoidal 
sinuses, which are peculiar to man. In the lower animals, on the con- 
trary, the nares are low and the jaws and palate elongated forwards in 
connection with the greater development of the teeth. But a just contrast 
of the size and form of the jaws of apes as compared with those of man 
can only be obtained when adult specimens 'are compared, as the face is 
in all animals later of development than the cranium. This obvious rule 
is too frequently set at nought, with the result of misleading the credulous 
who are willing to be deceived. 
Variations. At different ages the form of the skull differs characteris- THE SHAPE OF THE SKULL. 
tically, passing through a constant series of forms. During the latter half 
of foetal life the proportion borne by the base to the upper part of the 
skull gradually diminishes, till at birth it reaches the smallest proportion ; 
and from that time it goes on increasing both in length and breadth. 
About a month before birth the parietal region reaches its maximum pre- 
ponderance over the frontal and occipital ; and these, but especially the 
frontal, henceforth grow more rapidly, till the adult proportions are 
reached. The roof is at birth, as also in the foetal state, elevated in the 
middle line, and uniformly undergoes in early childhood a flattening due 
to rise of the parietal and frontal eminences; but it again rises in 
adolescence. The angle at which the front of the face lies to the 
anterior fossa of the base (orbito-nasal angle) is greater at birth than after- 
wards, being afterwards diminished both in connection with increased 
growth of the whole lower forehead, and with projection forward of the 
outer table of the frontal when the frontal sinus makes its appearance. 
At birth each roof-bone extends conically from its eminence; and after- 
wards it becomes more uniformly rounded. 
In old age there is a tendency to obliteration of sutures, and to 
absorption of diploe, especially in the parietals, and, next to them, the 
squamous parts of the temporals, and in the frontal and occipital ; and 
also, by means of absorption, to enlargement of air-sinuses. The form also 
tends to change, in a manner to be accounted for by gravitation, and 
most marked when the cranial capacity is large without the bones 
being massive. Thus the base becomes transversely flat or slightly concave, 
the occipital tuberosity descends, the roof and forehead become lower, 
and the sides of the skull project out over the ears. 
In the female special characters are observed less marked than those 
distinguishing the childish from the adult form, yet such as are attributable 
to non-participation in the later stages of male development. Thus the 
face is lighter, the occipital and frontal regions less developed in propor- 
tion to the parietal. Generally, the skull is lower; and the average 
proportion of breadth to length is less. Decidedly the most constant 
character is, as I pointed out, that the clivus forms larger angles than in 
the male with the planes of the foramen magnum and the anterior fossa 
of the base; the base having thus a level as distinguished from a steep 
form. 
In different races the peculiarities of form are less constantly adhered 
to than those dependent on age and sex; but groups of peculiarities 
are to be found in different nationalities, and in individual skulls a 
certain number of these peculiarities are always present. Betzius divided 
races, according to the extent to which the longitudinal diameter of the 
skull surpassed the breadth, into dolichocephali and hrachycephali. The 
Kaffir skull presents an instance of extreme dolichocephalic shape, and 
the Tartar races are examples of the brachycephalic, while in old British 
barrows, and even among stocks surviving in the British Isles, both 
Q THE SKELETON. 
extremes are found. In recent years .a great convention of questionable 
advantage has arisen, according to which the proportion of the greatest 
breadth to the greatest length taken as 100 is called the cephalic index or 
index of breadth, those skulls in which this index is below 75 being 
called dolichocephalic; those in which it is above 80, brachycephalic; 
and the intermediate proportions, mesocephalic. The index of height is, 
in like manner, an expression used to indicate the proportion of height 
from the front of the foramen magnum as compared with the length 
estimated at 100, and by it a classification can be made more closely 
corresponding with racial affinities. But more information is to be gained 
from the positive measurement of length and of height than from either 
of the indices mentioned. 
In British skulls 7 inches is a common length; in the skulls of the 
Incas, who were an exceedingly brachycephalic race, the length may be 
under inches. As to height, 5J inches is about the average, and the 
variations are confined between the limits of 5 and 6 inches. Breadth 
in uncivilized dolichocephalic races may be as small as 5 inches, and in 
Europeans is seldom so little, and may even exceed 6 inches. Retzius 
subdivided each of his great divisions after a method originated by 
Blumenbach, who had compared skulls by looking at them from above 
{norma verticalis) and observing whether the upper jaw projected beyond 
the forehead or not. Those with projecting jaw Retzius called prog- 
nathous, and those not projecting he termed orthognathous. The distinc- 
tion is obvious and important: orthognathism is characteristic of civilized 
races, prognathism of savagery. Precision, however, demands that the 
elements on which the distinction depends be recognized. Prognathous 
dentition is the projection forwards of the teeth; and, in addition to this, 
deficiency of curvature of the base enters importantly into the produc- 
tion of prognathism by causing the floor of the anterior fossa of the 
base to rise in front, instead of being horizontal when the foramen 
magnum looks downwards. But a large angle between the front of the 
face and the floor of the anterior fossa of the base of the cranium (orbito- 
nasal angle) is neither characteristic of savagery nor of civilization; it 
is largest of all in the French, and also large in the Scotch, while the 
Germans and Irish have it remarkably small (Cleland, Phil. Trans., 1869). 
In the lower races, breadth from one zygoma to the other {malar breadth) 
often exceeds the greatest breadth of the cranium, but in civilized races 
never. Also in the lower races the position of greatest cranial breadth 
is liable to be situated not far below the parietal eminences, while in 
civilized races it is nearer the squamous suture, above or a little behind 
the ear. The aperture of the anterior nares varies in shape, being short 
and wide in the negro, long and narrow in the American Indian. In 
markedly prognathous skulls there is usually a subnasal depression beneath 
each nostril. The shortest base line from the back of the foramen 
magnum to the fronto-nasal suture, 5 inches and under, is found in the THE SHAPE OF THE SKULL. 
females of civilized nations, the longest, up to nearly 6 inches, in males 
of savage race.1 
Individual peculiarities or idiosyncrasies tend to affect the roof more 
than the base. Thus individually large skulls differ from others by 
•elongation and broadening of the vault, the former circumstance depress- 
ing the external occipital protuberance in relation to the plane of the 
foramen magnum, and still more in its apparent position during life, in 
■consequence of the increased weight of brain taking place in such a 
manner that the head is more thrown back in balancing it. Sometimes 
an unusual separation of the frontal eminences, with consequent increased 
breadth of forehead at the coronal suture to such an extent as almost to 
■equal the greatest breadth of the whole cranium, occurs in conjunction 
with permanence of the frontal suture, as if increased growth of the 
fore part of the brain had led to that suture remaining open; though it 
is to be noted that there is another set of skulls with open frontal 
suture in which no deviation from the usual form is present. 
Local differences in surface-form (humps of popular phraseology) are 
of infinite variety. The skull is never perfectly symmetrical, and in 
some individuals the want of symmetry is very marked. Other pecu- 
liarities arise from circumstances more or less pathological, especially 
from synostosis, or premature closure of sutures which usually remain 
open. Thus there is a characteristic Cretin skull,2 dependent on pre- 
mature synostosis of the base. In another deformity, called scaphocephalus, 
the arch is low and enormously elongated in the parietal region, which is 
-also low and narrow, the whole peculiarity depending on prenatal oblitera- 
tion of the sagittal suture, and growth at the lambdoidal and coronal 
sutures to compensate; so also trigonocephalus with sharp mesial promin- 
ence of a narrow forehead, results from early obliteration of the frontal 
suture (Welcker). A high form, acrocephalus, with shallow orbits, depends 
in like manner on synostosis of the lateral parts of the coronal suture. 
The cranial capacity owes its interest rather to affording an approx- 
imate indication of the bulk of the encephalon than to its osteological 
importance. Much precaution is necessary for its correct estimation, and 
probably the method first used by Allen Thomson, filling the skull 
with turnip seed, is the most accurate and convenient. The cranial 
lln making racial measurements, a series of words mostly new have come into 
use, among which may be mentioned nasion, the middle of the fronto-nasal suture; 
obdion, the vertex ; ophryon, the glabella; bregma, the middle point of the coronal 
suture; lambda, the apex of the lambdoid suture; inion, the external occipital 
protuberance; hasion, the front of the foramen magnum; opisthion, the back of the 
foramen magnum; pterion, the position of the spheno-parietal suture; stephanion, 
the point where the temporal ridge crosses the coronal suture ; asterion, where the 
occipital fits in between parietal and mastoid, 
2 First described by Virchow, who, however, was completely mistaken as to the 
nature of the deformity, attributing it to increased curvature of the base and calling 
it kyphosis. It presents, as I pointed out, greatly deficient curvature of the base. THE SKELETON. 
capacity has been estimated to vary normally from 60 to 110 cubic 
inches, and to be from 85 to 88 cubic inches in the average European 
male, and in the female about 5 inches less. It varies also according 
to stature, and in the lower racial types is diminished, thus reaching 
a minimum in the slightly-built and dwarfish Bosjes, Andaman Islander 
and Yeddah. It is small in various negro races and in Australians. 
The articulation of the occipital bone with the atlas and axis has been 
already considered (p. 124). 
The temporo-maxillary articulation presents two synovial cavities 
separated by a fibro-plate. 
The inter articular fibro-plate, or so-called fibro-cartilage, is a firm 
structure thicker behind than in front. Its upper surface is concavo- 
convex from before backwards, so as to fit into the concavity as well as 
the convexity of the articular 
surface of the temporal bone. 
Its under surface is concave, 
fitting to the -condyle of the 
lower jaw, and closely con- 
nected with it at the outer 
and the inner edge. 
The synovial membrane above 
the fibro-plate is looser than 
that between the fibro-plate 
and the lower jaw. 
The fibrous capsule has its 
fibres placed vertically behind 
and also on the sides, while 
in front they pass inwards 
to the sphenoidal border of 
the temporal surface and are 
closely connected both with 
the fibro-plate and the ex- 
ternal pterygoid muscle. 
The external lateral liga- 
ment is an oblique band 
strengthening the fibrous capsule and stretching from the tubercle at 
the root of the zygomatic process, downwards and backwards to the 
posterior edge of the outer surface of the neck of the lower jaw. 
The internal lateral ligament is a strong membranous band extending 
from the spinous process of the sphenoid bone to the lingula of the 
inferior dental foramen, and separated from the capsule by the internal 
maxillary vessels and the auriculo-temporal and inferior dental nerves. It 
MOVABLE ARTICULATIONS OF THE SKULL. 
Fig. 222.—Temporo-Maxillaby Articulation and Hyoid 
Bone. A, Joint from the outer side, hyoid appended. B, 
Joint from inner side, a, Interarticular disc ; 0, external 
lateral ligament; c, stylo-hyoid ligament; d, stylo-maxillary 
ligament; e, body of hyoid bone ;/, g, great and small cornu ; 
h, internal lateral ligament; i, internal maxillary artery; Ic, 
middle meningeal artery. MOVABLE ARTICULATIONS OF THE SKULL. 
is a band connected in the foetus with the perichondrium of Meckel’s 
cartilage, but is not without ligamentous function. 
The stylo-maxillary ligament is merely a band of fascia extending from 
the styloid process to the angle of the lower jaw, between the parotid 
and submaxillary glands. 
Movements of the jaw. The principal movements are of a hinge kind, 
opening and shutting the mouth, but differ from those of other hinge- 
joints in that the condyle is moved forwards out of the glenoid cavity on to 
the convexity in front, every time that the mouth is opened, and retreats 
in closing it, as can be felt on placing a finger in front of one’s own ear. 
In accomplishing these movements the upper and lower compartments of 
the joint take different parts, the fibro-plate moving forwards and back- 
wards on the temporal articular surface, while the condyle revolves in 
the concavity of the under surface of the fibro-plate. In opening the 
mouth both the external and internal lateral ligaments are tightened and 
become factors in pushing the condyle of the jaw forwards by limiting 
backward movement at their lower attachments. 
Two other kinds of movement of the jaw are allowed. In one, the 
jaw is pushed forwards and backwards, protracted and retracted by 
movement of the fibro-plate on the temporal bone, while the lower com- 
partment of the joint is passive. In the other, the oblique or grinding 
movement, the condyle of one side is, together with the fibro-plate, drawn 
forwards; and the other condyle remaining in the glenoid cavity, there is 
at the same time a circular movement, the protracted condyle moving 
round the other, and likewise carrying with it the fibro-plate. 
In the early embryo the notochord ends in a pointed extremity curving 
in a ventral direction underneath the first cerebral vesicle, and soon inter- 
fered with and shortened at the point by the cerebral and stomodaeal 
pouches which cohere to make up the pituitary body (p. 98); but it can 
be traced in the posterior sphenoidal region for a considerable time. 
“ The first cartilaginous rudiments appear in the primitively membranous 
skull tube in the form of a pair of rods, the trabeculae cranii. These lie 
along the base of the brain, their posterior part embracing the notochord ; 
and they thus are divisible into prochordal and parachordal regions.” 1 The 
DEVELOPMENT OF THE SKULL. 
1 Wiedersheim, Elements of Comparative Anatomy adapted by W. Newton Parker{ p. 57). 
I have preferred to use these words because they make it clear that admittedly 
there is no radical difference in the nature of the fore part of the mesial bars of 
the skull from that of the hinder part. The intrusion of the fore part of the pituitary 
body from below, however difficult to explain in the present state of our knowledge, 
does not do more than open up a mesial division between the right and left halves of 
longitudinally arranged structures. It may be noted in this connection that in seals 
there is often a mesial perforation of the basilar process of the occipital, and that it is 
frequent when spina bifida involves large portions of the spinal column to find series 
of vertebrae with their bodies in two lateral parts separated one from the other. 246 
THE SKELETON. 
prochordal parts, to which the name trabeculae is more strictly confined, pass 
forwards, one on each side of the pituitary body, to end in the fronto- 
nasal region in cornua turning outwards. The parachordal parts, which 
would appear to be at a certain period distinct from the prochordals,. 
unite around the notochord, and send an extension on each side round the 
foramen magnum and thence forwards round the internal ear. The pro- 
chordal parts unite first in front of the pituitary fossa, and afterwards- 
floor it. The mesial bar thus formed in front of the pituitary fossa is- 
the source of the fore part of the body of the sphenoid and of the whole 
septum of the nose, while the cornua go to the formation of the lateral 
nasal cartilages; and by lateral outspread further back the cartilaginous- 
basis of the great and small sphenoidal wings and of the lateral masses- 
of the ethmoid is laid down. The development of cartilage is confined 
to the lower part of the cranium, but I find it extending a small way 
on the inside of the lower part of the supra-occipital element, and also 
inside the back part of the squamous portion of the temporal. 
Beneath the cranium there are three pairs of cranial bars. The fore- 
most was observed by Kitchen Parker in the pig, developed in the 
maxillary lobe, short and feeble, in the region of the palate and pterygoid 
bones. The others are the mandibular and hyoid arches; and at their base 
there is at first one continuous car- 
tilage which soon becomes divided 
into malleus and incus (and stapes,, 
etc.); while from the malleus a 
bar, Meckel’s cartilage, is continued 
down to meet its neighbour at 
the symphysis, and can be traced 
as late as the fourth and fifth 
months in close connection with 
the mandible, which is formed 
superficial to it, while the upper 
part persists as the processus- 
gracilis of the malleus. The hyoid 
arch at an early period forms, like 
Meckel’s cartilage, a complete car- 
tilaginous bar continuous with its 
fellow of the opposite side. It is developed in the second visceral or 
poststomal lobe of the embryo (p. 98), its lower part forming the body 
and small cornu of the hyoid bone, and remaining continuous, till at 
least the end of the third month, with the upper part, the styloid 
process of the temporal bone.1 
Fig. 223.—Part of Base of Skull of Foetus of 
Four Months, a, Eight squamous ; 6, cartilaginous 
incus with stapes continuous with it; c, malleus 
with Meckel’s cartilage proceeding from it on inner 
side of d, the lower jaw; e, an early and constant 
continuity of the cartilage of the mastoid with the 
short process of the incus and the hyoid arch ; /, 
cartilaginous petrous ; g, fenestra rotunda. 
1 The upper connections of the styloid part of the hyoid cartilage require further 
investigation. Reichert described this cartilage as continuous with the stapes, but 
Fraser has pointed out that this is a mistake. I have verified Fraser’s observations f 
and undoubtedly the connection seen by Reichert is not cartilaginous but only the DEVELOPMENT OF THE SKULL. 
Ossification. The occipital, as already stated, consists at birth of a 
basilar, two lateral and a superior portion. To the basilar part belong 
the basilar process and fore parts of the condyles; the lateral portions 
bound the foramen magnum on its sides, and to them belong the jugular 
processes and greater part of the condyles ; the 
superior or tabular portion reaches to the fora- 
men magnum in the middle line, and forms the 
expanded part of the bone. The basilar and 
lateral portions have each one centre of ossifica- 
tion appearing in cartilage about the end of the 
second month; the superior portion has four 
centres all appearing in membrane prior to the 
others, and becoming soon united, the upper 
pair corresponding with the interparietals, seen 
in many mammals, e.g. the sheep. The superior 
part of the occipital becomes united to the 
lateral in the second year, and the lateral parts 
to the basilar by the sixth year. The anterior condyloid foramen, 
originally in front of the lateral portion, is completed by growth 
forwards of the supraforaminal ridge. 
The parietal probably begins to ossify about the seventh week. It 
soon appears to consist of one centre of ossification radiating from the 
parietal eminence; but, as pointed out by Toldt, there is a second and 
lower centre, the network formed by which can be discerned, forming 
a distinct pattern at the lower and back part for a considerable time. 
This explains the rare anomaly of two parietal bones on one or both 
sides. The parietal foramen is originally a deep gap open towards the 
middle line, and with its fellow of the opposite side has been described, 
unnecessarily enough, as a sagittal fontanelle closed before birth. 
The frontal also probably begins to ossify about the seventh week. It has 
one centre of ossification corresponding with each frontal eminence. The 
two frontals thus formed are separated by the frontal suture which persists 
till the seventh or eighth year, and sometimes throughout life (p. 243). 
Three supplementary centres on each side have been noted (Testut). 
The sphenoid has a pair of osseous centres in the posterior part of the 
body (postsphenoid), a smaller pair in the anterior part (presphenoid), and 
an independent centre in each ala. The centres of the great alae (ali- 
Fig. 224.—Occipital Bone at 
Birth. 
rudiment of the stapedius muscle ; and possibly it may be the same structure which 
Salensky figures as uniting the long process of the incus with the hyoid cartilage. 
But in the third and fourth months the hyoid cartilage, though united to the front 
of the mastoid part of the cartilaginous cranium, can be followed up into continuity 
with the posterior process of the incus ; and in many adult mammals it can be seen 
that this continuity is only broken by articulation. The stapes is generally supposed 
to originate from the wall of the labyrinth. My dissections have satisfied me that 
it is primarily continuous with the incus, and afterwards applied to the petrous. 
(See Cleland, Memoirs and Memoranda in Anatomy, 1889.) 248 
THE SKELETON. 
sphenoids) appear about the eighth week, and from them are ossified the 
great wings and the external pterygoid plates. Soon after, the nuclei of 
the small wings (orhitosphenoids) appear external to the optic nerves, and 
extend inwards embracing them, and these are followed by the nuclei of 
the postsphenoid. The postsphenoid nuclei rapidly unite, while the pre- 
sphenoid nuclei unite not only one with the other, but with the orbito- 
sphenoids. About the seventh month the postsphenoid and presphenoid 
become joined together, leaving for a while a cylindrical column of 
cartilage in the middle, descending from the sella turcica to the back 
part of the septal cartilage of the nose. The alisphenoids remain distinct 
from the body for a considerable time after birth: but already, in the 
fifth month of foetal life, have the separately ossified internal pterygoid 
plates adherent to them below the 
Vidian canals. The lingula has 
been found to have a separate 
centre of ossification (Sutton), and 
sometimes remains distinct through 
life (Debierre). The sphenoidal tur- 
binated bones, as already pointed 
out, constantly present in early life 
four centres each, which combine to 
form a pair of hollow cones. 
The temporal has its petro- 
mastoid and styloid centres origin- 
ating in cartilage, while its squamous 
and tympanic parts are ossified from 
membrane. The petrous begins to 
ossify in the fifth month from an 
elongated centre placed between 
the fenestra ovalis and fenestra 
rotunda, and rapidly extending in 
a twisted form forwards round the 
cochlea and backwards round the 
vestibule. From this main centre 
there are subsequent laminar ex- 
tensions, one set of which forms 
the tegmen tympani, the roof of 
the internal auditory meatus, the 
tympanic wall of the aqueduct of 
Fallopius, and the bony flap cover- 
ing the aqueducts of the vestibule 
and cochlea, while another forms 
the floor of the tympanum and stretches inwards to complete the carotid 
canal. Additional nuclei have been described in connection with the 
superior and posterior semicircular canals, but do not appear to be con- 
Fio. 225.—Right Temporal at Birth, A, 
Squamous portion with adherent tympanic plate in 
the form of a thin ring almost surrounding the ex- 
ternal auditory meatus. B, Petro-mastoid separated 
from the squamous by breaking through the slight 
union, a, The mastoid process scarcely as yet pro- 
jecting ; b, surface for articulating with jugular pro- 
cess of occipital; c, stylomastoid foramen, and the 
groove from which emerged the as yet cartilaginous 
styloid process; d, jugular fossa; e, cochleariform 
process ; /, fenestra rotunda ; g, fenestra ovalis ; h, 
opening in the pyramid for tendon of stapedius ; i, 
edge of contact of the mastoid with the squamous in 
front of the recess in continuity with which the 
mastoid cells are afterwards developed. A bent 
arrow indicates the carotid canal. DEVELOPMENT OF THE SKULL. 
slant as distinct centres.1 The ossification of the root of the styloid process 
is distinct, appearing before birth, and can be traced upwards in various 
mammals at a late date to the point of attachment of the posterior 
process of the incus. The later elongation of the styloid process can 
often be seen in childhood as a separate centre. The squamous centre 
appears, like the other roof-bones, towards the end of the second month. 
The tympanic centre appears in the third month in the form of a delicate 
ring imperfect above. It becomes united before birth to the squamous; 
but its most extensive development is later, and takes place in an out- 
ward direction. This outward extension is completed at first in front 
and behind, leaving for a time, in young skulls, a gap in the floor of the 
external auditory meatus. 
The ethmoid begins to ossify in the lateral masses from scattered and 
irregular nuclei in the fifth month of foetal life. About a year after 
birth ossification commences in the base of the crista galli, and extends 
in the vertical plate and outwards in the cribriform. As a general rule, 
in mammals, the cribriform plate appears to be formed altogether in this 
way; but in the human subject it makes rapid progress while even the 
upper edge of the central plate is imperfectly ossified, and it has separ- 
ate nuclei which may be counted as common to it and the lateral masses. 
The superior maxillary begins early to ossify, being, it is alleged, pre- 
ceded only by the clavicle and lower jaw. The ossific bars radiate from 
a position external to the nasal notch. It has long been a subject of 
dispute whether the intermaxillary part has a separate centre of ossifica- 
tion, and recent observers have exhibited specimens to show it as a 
separate bone up to the fifth month ; but it is granted that the anterior 
wall of the sockets of the incisor teeth is ossified from the superior 
maxillary proper. In connection with this it may be noted that the 
outer incisor teeth lie in front of the palatal cleft which limits the inter- 
maxillary part behind, and have their sockets in other animals wholly 
formed by the intermaxillary bone; and yet, when developed in cases of 
cleft palate, they are external to the cleft. In completely cleft palate 
the intermaxillaries are developed in the mesial process in continuity 
with the vomer.2 
1 Kerckring (Spiciler/ium Anatomicum, 1870, pp. 222, 223), whose description in 
the original Latin is transcribed by Huxley (Lectures on Comparative Anatomy, 1864), 
describes correctly the nucleus of the petrous, and adds that in the fifth month 
three other nuclei appear in the mastoid region. Huxley curiously misinterprets 
Kerckring, alleging the three additional centres to include the petrous, which is 
mentioned and figured by Kerckring as distinct from them when these were seen 
separate. There is no real ground in human anatomy for the expressions pro-otic, 
epiotic, and opisthotic, which took rise in Huxley’s description; but this is not the 
place to discuss how erroneous they are in comparative anatomy. 
2 Comparative anatomy favours the view maintained by some that the intermaxil- 
lary elements have a twofold source, one related to the maxillary lobe, and the other 
to the fronto-nasal. I long ago {Phil. Trans., 1862) pointed out that throughout 
the vertebrata there are to be distinguished the lateral element and mesial palatine THE SKELETON. 
The palatal and nasal bones each ossify from a single centre later 
than the superior maxillary. The vomer, about the same time, is ossified 
from a pair of centres which soon unite. The malar is stated to have 
three centres of origin which speedily unite (Testut). The inferior 
turbinated begins to ossify in the fifth month of foetal life. 
The lower jaw is, next to the clavicle, the earliest bone to show osseous, 
deposit. It is developed round Meckel’s cartilage, mainly outside of it 
but additional centres have been noted at the lingula, at the angle, at 
the coronoid process, and at the condyle. The condyle is laid down in 
cartilage before its ossification begins, but the supposition that' Meckel’s 
cartilage is in any part converted into osseous tissue of the jaw is 
erroneous. 
The fontanelles. The anterior fontanelle (bregma of old writers) is a 
diamond-shaped gap in the osseous roof of the young skull where the 
Fig. 226.—Skull at Birth, from above, 
showing anterior and posterior fontanelles. 
Fig. 227.—5ku1l at Birth, right side, showing a 
considerable postero-lateral fontanelle, and no antero- 
lateral. 
frontal, sagittal, and coronal sutures meet. It remains open till about, 
the end of the second year, and has an obvious pulsation communicated 
to it by the intracranial arteries. The posterior fontanelle, situated where 
the sagittal and lambdoidal sutures meet, presents at birth only a slight 
three-sided space; but the occipital and parietals are at that time suffi- 
ciently loosely connected to allow the tip of the occipital to be pressed 
below the margin of the parietals in the passage of the child’s head 
through the pelvis, so that the spot is easily detected with the fingers 
by the accoucheur. Antero lateral and postero-lateral fontanelles have also- 
been described at the inferior angles of the parietals, but there is no 
constant deficiency in the osseous walls at these parts. 
element found in mammalian intermaxillaries, while birds have a mesial ascending 
element in front of the nostrils; and that in the fish the intermaxillary, so-called, 
is a purely lateral element, while the mesial elements take part in the formation of 
the prevomerine bone (nasal of Owen), closing in the cranium in front and contain- 
ing in addition a nasal element. MUSCLES OF UPPER LIMB. 
251 
THE MUSCLES. 
The tissue of the voluntary muscles forms the red flesh of the body.. 
It is composed of fibres which are collected into bundles surrounded 
by delicate sheaths of connective substance; the bundles of fibres are 
aggregated together into masses which are more or less distinctly 
separated from one another by the investing fibrous tissue, and constitute 
the individual muscles. Among the muscles there is much variety of 
form ; some are broad expanded sheets, others are compact and rounded, 
and there are many varieties of shape. A muscle is an elastic organ 
which possesses the power of contraction, and each individual muscle 
has definite connections or attachments. Certain muscles form ring-like 
bands which surround the margins of openings; they are named sphincters 
by their elasticity they oppose the dilatation of, and by their con- 
tractility they diminish or close the apertures which they encircle. 
Others, entering into the construction of curved walls, by their elasticity 
offer opposition to forces which tend to increase the curvature of the 
surfaces which they cover; contracting, they flatten out the curves and 
remove or produce pressure. The diaphragm, the broad nmscles of 
the abdomen, and possibly also the platysma myoides, offer examples of 
this type of muscle. Most of the muscles are more or less strap-shaped. 
The great majority are attached at both their extremities to portions of 
the bony or cartilaginous framework and cross over joints; contracting, 
they produce movements at the joints; by their elasticity they assist in 
maintaining the bones in apposition, and resist movement. The}?' are 
arranged in groups which oppose and balance one another, and the 
deeper members of a group are usually short, and as a general rule stretch 
over one joint only, while the more superficial are long, and may cross- 
over two or more joints. In the various movements of the body every 
variety of lever is employed, and the same muscle may be used in 
different actions to move different orders of levers, according as a part 
is free to move or is made to serve as a fulcrum. 
The methods of attachment of the muscles to the bones are various. 
Some muscles spring directly by fleshy fibres, others indirectly by means 
of tendons, which may either be compact structures presenting the 
characteristic peculiarities of tendinous texture, or expanded membran- 
ously as aponeuroses. Of the two attachments of a muscle, that which 
in the usual movements which the muscle subserves is the fixed point 
is commonly called the origin, while the other is the insertion', but on 
account of the numerous and varied kinds of bodily movements in which 
any individual muscle may take part, it is impossible to apply the terms 
with scientific accuracy, and they are used, to a large extent, in an 
arbitrary fashion for convenience of description. 
Muscles differ from one another in the number, length and direction. 252 
THE MUSCLES. 
of their fasciculi, or bundles of fibres. Comparing with regard to the 
■extent and power of their contraction muscles of equal bulk, that in which 
the fasciculi are long, and stretch from end to end of the muscle, will 
produce the greater extent of motion; that-in which the bundles are 
shorter, more numerous, and oblique in their direction, will produce a 
smaller amount of motion, but will contract with greater power. The 
action of any individual muscle may be demonstrated in the body by 
approximating its attachments to one another, but it is seldom that a 
muscle acts individually, even in the simplest movements groups of 
muscles being called into play. Muscles which stretch over one joint are 
■comparatively simple in their action; but in the case of those which pass 
over more than one joint, it is necessary before they can exert their 
power on any one particular joint that their actions on the other joints 
over which they pass should be neutralized and balanced by the con- 
traction of opposing muscles. Very many of the muscles cross over more 
than one joint, one of the advantages of the arrangement being that 
muscles, longer and more powerful than those the fibres of which simply 
pass between neighbouring skeletal pieces, are obtained and can exert 
their force upon parts comparatively distant; thus the slender digits are 
under the control of powerful muscles situated in the fleshy parts of the 
limbs. Muscles which pass over more than , one joint play an important 
part as ligaments, and as such, without contracting, bring about during 
movements at the proximal joint simultaneous and opposite movement 
at the distal joint. Taking for the sake of example the muscles of the 
thigh: when the hip is flexed by the action of its special flexor muscles, 
the long muscles behind which pass over the hip and knee, acting simply 
as ligaments, produce a simultaneous flexion at the knee, and conversely, 
when the hip is extended, the long muscles in front extend the knee. 
In the habitual movements and in the maintenance of the sustained 
positions of the body, the ligamentous action of the long muscles is 
specially important. On the other hand, the full contraction of these 
muscles is exhibited in the passage from one extreme of position to 
another, as in the movements associated with throwing a stone or 
kicking a football. In all the movements of the body, except those of 
the very simplest kind, simultaneous or nearly simultaneous action is 
taking place at a number of joints. The student will readily perceive 
that the study of the bodily movements, from the point of view of the 
muscles which produce them, is a very complicated one. 
Fasciae. The connective tissue of the body forms membranous sheets 
wdiich underlie the skin and surround and separate from one another 
the muscles. To the membranous tissue which lies immediately under 
the skin the name superficial fascia is given; it is formed of two layers, 
the more superficial of which contains, in many cases, in its meshes a 
considerable quantity of fat; the deeper, which is comparatively free from 
fat, supports the trunks of the cutaneous vessels and nerves. In the MUSCLES OF UPPER LIMB. 
253 
superficial fascia of the eyelids, the penis and scrotum there is no fat; 
in that of the buttocks and abdominal wall the layer of fat, especially 
in females, is often of considerable thickness. The superficial fascia is 
continuous all over the surface of the body; the details of its arrangement 
in one or two regions, the lower part of abdominal wall, the upper part 
of the thigh, etc., are of surgical importance, and will be specially described 
along with those of the muscles and the deep fascia. 
The deep fascia covers the muscles superficially, and sends processes 
and septa between them; it varies much in strength and consistence in 
the different regions of the body, and often affords a surface of origin 
or insertion to muscular fibres. When mnch strengthened, it becomes 
aponeurotic in its nature. It will be specially described along with the 
muscles in each region. In many places in the body there are in the 
tissue spaces which are lined by synovial membrane; these are termed 
bursae. They usually serve to facilitate the gliding of muscles or tendons 
over prominent surfaces of bone; bursae are also found in the sub- 
cutaneous tissue between the skin and the more prominent structures 
beneath it. Tendons which are passing over pulleys or through narrow 
canals are usually surrounded by delicate connective tissue sheaths, which 
are lined by synovial membrane, and are termed synovial sheaths. 
MUSCLES OF THE UPPER LIMB. 
MUSCLES CONNECTING THE LIMB WITH THE TRUNK. 
These muscles may be arranged in a posterior and an anterior group. 
Those of the posterior group are the trapezius, latissimus dorsi, levator 
anguli scapulae, and the rhomboidei; those of the anterior group are the 
pectoralis major, the pectoralis minor, the serratus magnus, and the 
subclavius. 
The trapezius arises from the tips of the spines and the supraspinous 
ligament of all the dorsal and the seventh cervical vertebrae, the ligamentum 
nuchae, the external occipital protuberance, and the posterior third of the 
superior curved line of the occipital bone. Its fibres converging are inserted 
into the posterior border of the outer third of the clavicle, the inner edge 
of the acromion, and the upper edge of the spine of the scapula. The 
origin and insertion take place for the most part by short tendinous fibres; 
of the fibres of origin those arising from the seventh cervical spine and 
for a little distance above and below that point are slightly longer than 
the others. The connection with the occipital bone is aponeurotic in 
character. The lowest fibres of insertion form a flat tendon which glides 
over the triangular area at the base of the scapular spine, a bursa being 
occasionally interposed. 
The muscle covers portions of the latissimus dorsi, infraspinatus, and 
rhomboideus major muscles, and conceals the rhomboideus minor, levator 254 
THE MUSCLES. 
scapulae, and supraspinatus. On its deep surface lie the superficial 
cervical artery, and the nerves from which it receives its supply, namely, 
•the spinal accessory and some branches of the cervical plexus. 
The trapezius is subject to a number of variations. Above, it sometimes 
Occipitalis 
Trapezius 
Deltoid 
GY3. 
Infraspinatus 
Teres muscles 
Border of I 
concealed part V 
of latissimus J 
Ehomboideus major 
Latissimus dorsi 
DY.U 
...External oblique 
C Space between borders of external 
d oblique and latissimus (triangle 
f of Petit) 
LY_ 
Fig. 228.—The Superficial Muscles of the Back. (L. Testut.) 
falls sliort of the skull, and below, occasionally extends no further than 
the ninth or tenth dorsal spine. In the neck it is sometimes found con- 
nected with or united to the sterno-mastoid muscle. 
The latissimus dorsi has a very broad origin, but its fibres rapidly 
converge as they pass upwards and outwards to the insertion. It springs 
{a) from the spines and supraspinous ligament of the lower five or six dorsal MUSCLES OF UPPER LIMB. 
255 
■vertebrae, (h) from the posterior layer of the lumbar aponeurosis, by means 
of which it is connected with all the lumbar and sacral spines and the 
outer lip of the posterior third of the iliac crest, (c) from a small portion 
of the crest in front of the limit of the attachment of the lumbar aponeurosis, 
(cl) from the lowest three or four ribs by fleshy slips which interdigitate with 
slips of the external oblique muscle, and (e) in many cases by a few fibres 
at its upper border from the fascia covering the lower angle of the scapula. 
It is inserted by a tendon about an inch and a half in breadth into the 
floor of the bicipital groove of the humerus. The muscle crosses behind 
the lower angle of the scapula and covers the teres major at its origin, 
but passing further outwards folds completely round the lower border of 
the teres major and becomes applied to it anteriorly, taking part with it 
in the formation of the posterior wall of the axilla. The muscle becomes 
tendinous two or three inches from the insertion, and the tendon is at first 
in close contact with that of the teres major, but near the bone a bursa 
is interposed between them. The latissimus is covered at its upper part 
posteriorly by the trapezius, but further outwards an angular interval, 
sometimes alluded to as the “auscultatory triangle,” is left between the 
borders of the two muscles and the edge of the rhomboideus major. The 
■outer margin of the part of the muscle which springs from the iliac crest 
frequently overlaps the posterior margin of the external oblique muscle; 
but, on the other hand, in many cases there is left between the borders of 
the two muscles a space in which a portion of the internal oblique is exposed. 
The nerve of supply is the long subscapular from the posterior cord of 
the brachial plexus; it is to be found on the deep surface of the outer 
part of the muscle. Occasionally muscular bands are prolonged from the 
latissimus across the axillary vessels to the muscles of the anterior wall of 
the axilla, or downwards to the muscles and fascia of the inner and back 
part of the arm. 
The rhomboideus major arises by short aponeurotic fibres from the 
spines and interspinous ligaments of the second, third, fourth, and fifth 
dorsal vertebrae; it is inserted into the vertebral border of the scapula 
in the region between the root of the spine and the lower angle of the bone. 
The greater number of the fibres do not directly reach the bone, but pass 
into one or more tendinous bands concealed within the muscular substance 
and lying close to the scapular margin to which at their extremities they 
are attached. 
The rhomboideus minor springs from the lower end of the ligamentum 
nuchae and from the spines of the last cervical and first dorsal vertebrae. 
It is inserted into the vertebral border of the scapula at the root of the 
spine. 
The rhomboidei together form a four-sided fleshy mass directed 
downwards and outwards, covered posteriorly in the greater part of its 
extent by the trapezius, overlapped at the lower and outer angle by the 
latissimus dorsi, but appearing superficially in the narrow area between 256 
THE MUSCLES. 
their borders. They are supplied by a special nerve from the brachial 
plexus. From the upper margin of the rhomboideus minor a muscular slip 
occasionally passes to the atlas or to the occipital bone. 
The levator anguli scapulae, completely covered by the trapezius, arises 
by tendinous slips from the posterior tubercles of the transverse processes 
Occipitalis 
: Stemo-mastoid 
Trapezius 
Complexus 
Splenius... 
Levator anguli scapulae 
Supraspinatus 
1 Infraspinatus 
Serratus posticus superior 
QVE. 
Rhomboideus minor- 
Rhomboideus major 
Triceps 
• Teres minor 
.Teres major 
Erector spinae 
Latissimus dorsi 
Trapeziui 
.Serratus magnus 
Serratus posticus inferior 
Latissimus dorsi 
1)X1 
Internal oblique 
External oblique 
Latissimus dorsi 
Fig. 229.—Second Layer of Muscles of the Back. (L. Testut.) 
of the first four or five cervical vertebrae, and is inserted into the vertebral 
border of the scapula in the region between the upper angle and the root 
of the spine. It is supplied by two or three small branches from the 
cervical and brachial plexuses. Occasionally the muscle is connected by 
a slip with the serratus magnus. 
The serratus magnus (serratus anterior) arises by fleshy slips from the MUSCLES OF UPPER LIMB. 
257 
outer surfaces of the first eight ribs near their anterior extremities. Con- 
verging considerably, the fibres are inserted into an area of the ventral 
surface of the scapula which lies close to the vertebral border of the bone. 
From the first and second ribs a thick slip forming the upper edge of the 
muscle passes backwards and slightly upwards to a rough area near the 
I Upper angle 
\ of scapula 
t Serratus mag- 
. J nus— 
( highest slip 
/ Levator anguli 
\ scapulae 
"") Scalenus posti- 
> cus and scal- 
j enusmedius 
Scalenus anticus 
Omo-hyoid 
Subscapularis 
Subscapularis 
Long head \ 
of biceps ) 
Latissimus ) 
dorsi ) 
Teres major 
■) External and 
V internal 
) intercostals 
Snbscapularis 
Serratus magnus 
15, External 
oblique 
Costal slip of latissimus,. 
Costal slip of latissimus,. 
Fig. 230.—The Serratus Magnus and Neighbouring Muscles. (L. Testut.) 
upper angle; from the second and third ribs two broad thin slips pass 
downwards and backwards to a narrow line which connects the upper and 
lower rough impressions; the remaining slips converge rapidly to form a 
thick mass which is inserted into the large triangular area in front of the 
lower angle. The lower slips interdigitate at their origin with those of the 
external oblique muscle. The inner surface of the muscle is in close con- 
R 258 
THE MUSCLES. 
tact with the ribs, and covers a portion of the serratus posticus superior 
muscle. The outer surface forms the inner wall of the axilla, and upon 
it lies the nerve of supply—the posterior thoracic branch of the brachial 
plexus. 
The pectoralis major arises by short tendinous fibres from the anterior 
surface of the sternum, the cartilages of the first six or seven ribs, and 
Space between pectoralis major and deltoid 
Trapezius | 
Clavicle | | 
Sterno-mastoid 
Deltoid 
Pectoralis major 
Deltoid 
Pectoralis major 
Scrratus 1 
magnus / 
Latissimus 
External oblique 
Fig. 231.—Superficial Pectoral Region. (L. Testut.) 
the upper part of the sheath of the rectus abdominis muscle, and by a 
fleshy slip from the anterior surface of the inner half of the clavicle. 
It is inserted by a strong folded tendon into the outer or anterior lip of 
the bicipital groove of the humerus. The muscular fibres converge as they 
pass outwards, and in crossing the axilla those of the pectoral part 
are folded upwards behind the others to such an extent that the posterior 
lamina of the tendon reaches a little higher on the bone than the anterior. MUSCLES OF UPPER LIMB. 
Aponeurotic fibres are prolonged from the upper edge of the tendon to the 
•capsule of the shoulder-joint, and from the lower edge to the insertion of 
the deltoid muscle. The insertion is slightly overlapped by the anterior 
margin of deltoid. The external anterior thoracic nerve and a branch 
from the internal anterior thoracic enter the muscle on its deep surface. 
A small muscular slip, the sternalis muscle, is occasionally present on 
one or both sides of the body, lying upon the surface of the pectoralis 
major along the edge of the sternum. An additional slip along the lower 
edge of the muscle occasionally descends for some distance in the arm. 
The pectoralis minor arises from the outer surfaces and upper borders 
•of the third, fourth, and fifth ribs near their anterior extremities. It is 
Subclavius 
Pectoralis minor 
Short head of biceps I 
and-coraco-hrachi- V 
alis J 
Suhscapularis 
Pectoralis major 
Pectoralis major 
J Internal 
( intercostals 
■6, Long head of 
triceps 
Pectoralis major 
External intercostals (W f.E 
Fig. 232.—Deep Pectoral Region. (L. Testut.) 
inserted into the inner border and upper surface of the anterior half of 
the coracoid process of the scapula. The insertion takes place by a flat 
tendon continuous at its outer edge with that of the short head of the 
biceps and the coraco-brachialis. The muscle lies under cover of the 
pectoralis major, and forms part of the anterior wall of the axilla. It is 
supplied by the internal anterior thoracic nerve which enters it on its 
deep surface. Occasionally some fibres of the muscle take origin from 
the second rib. 
The subclavius arises by a tendon prolonged for a little distance on 
the under surface of the muscle from the cartilage of the first rib. The 260 
THE MUSCLES. 
narrow muscular belly extends outwards along the groove on the under 
surface of the clavicle, and, becoming pointed at its end, is inserted at 
the extremity of the groove between the conoid and trapezoid ligaments. 
The great vessels and nerves passing between the neck and the axilla 
lie behind the muscle. It is supplied by a special nerve from the front of 
the union of the fifth and sixth cervical nerves in the brachial plexus. 
MUSCLES OF THE SHOULDER. 
These are the deltoid, the supraspinatus, the infraspinatus, the sub- 
scapularis, the teres minor, and the teres major. 
Levator anguli scapulae 
| Supraspinatus 
Rhomboideus minor 
Rhomboideus 1 
major / 
Deltoid 
Infraspinatus [ j 
Teres minor | , 
Teres major ; 
Long head of tricep 
Deltoid 
-Outer head of triceps 
Inner head of triceps. 
...Supinator longus 
Olecranon. 
Extensor carpi 
radialis longior 
■Anconeus 
Aponeurosis of forearm,. 
Pig. 233.—Muscles or Shoulder and Arm, posterior view. (L. Testut.) 
The deltoid arises (a) from the lower border of the spine of the scapula, 
(b) from the outer border of the acromion, and (c) from the anterior MUSCLES OF UPPER LIMB. 
border of the outer third of the clavicle. It is inserted into a rough 
area on the outer surface of the humerus, a little above the middle of 
the bone. It is triangular in outline. The clavicular and spinal portions, 
springing by short tendinous 'fibres, and, passing downwards as the 
anterior and posterior portions respectively of the muscle, are compara- 
tively thin. The central portion of the muscle is thick, and contains 
in its substance some seven or eight tendinous septa which are prolonged 
for some distance downwards from the origin and upwards from the 
insertion, and are arranged in such a manner that those from above 
alternate in position with those from below; the muscular fibres are 
for the most part short, and pass obliquely either from the bony origin 
to the septa, or from the upper to the lower septa, or from the septa to 
the bony insertion. The insertion is partly tendinous, partly muscular ; 
fibres are prolonged from it to the external intermuscular septum of the 
arm. 
The deltoid lies on the upper and outer aspects of the shoulder, and 
covers the joint and the muscles inserted around it. Its anterior border 
is in contact with the pectoralis major. The subacromial bursa projects 
outwards beneath its origin. It is supplied by the circumflex nerve. 
The supraspinatus, occupying the supraspinous fossa of the scapula, 
takes origin by fleshy fibres which spring from the area of the bone 
between the vertebral border and the neck, and from the investing 
aponeurosis. It passes outwards underneath the acromion and narrows 
to a tendon, which, after crossing the shoulder-joint and adhering to its 
capsule, is inserted into the highest of the three facets on the great 
tuberosity of the humerus. It is supplied by the suprascapular nerve. 
The infraspinatus arises (a) from the infraspinous region of the 
scapula, with the exception of the area at the lower angle and outer 
border, from which the teres muscles spring, (6) from the under surface 
of the spine, and (c) from the investing aponeurosis. Narrowing as it 
passes upwards and outwards, it is inserted by a tendon into the middle 
facet of the great tuberosity of the humerus. The tendon is at first 
concealed within the muscular substance, and afterwards, in crossing the 
shoulder-joint, adheres intimately to the capsule. The muscle is to a 
great extent superficial, being only partly covered by the deltoid. It is 
supplied by the suprascapular nerve. 
The subscapularis arises from the whole of the ventral surface of the 
scapula, with the exception of the region of the neck and of the area at 
the vertebral border to which the serratus magnus is attached. Many 
of the fibres spring directly from the bone, but in addition a number 
take origin from two or three tendinous laminae, which are prolonged 
into the substance of the muscle from the ridges of the venter. The 
muscle passes outwards, the lower fibres ascending considerably, the 
upper descending a little; it is inserted by a strong flat tendon into the 
small tuberosity of the humerus. The tendon crosses in front of the 262 
THE MUSCLES. 
capsule of the shoulder-joint, and adheres to it below, but is separated 
from it above by a bursa which usually communicates through an opening 
in the capsule with the cavity of the joint. Another bursa lies upon the 
anterior surface of the tendon, separating it from the common tendon of 
the biceps and coraco-brachialis muscles, which descends in front of it. 
The nerves of supply are the first and third subscapulars from the 
brachial plexus. The subscapularis takes part along with the latissimus 
dorsi and teres major in forming the posterior wall of the axilla. 
The teres minor arises from the narrow area of the dorsal surface and 
the axillary margin of the scapula between the teres major and the long- 
head of the triceps. It is inserted by a tendon into the lowest facet on 
Fig. 234.—Muscles of Shoulder, posterior view. (L. Testut.) 
the great tuberosity of the humerus, and by muscular fibres into the 
shaft for a little distance below. The muscle passes behind the long 
head of the triceps, and crosses the shoulder-joint, its tendon adhering 
to the capsule. It is supplied by the circumflex nerve. 
The teres major arises from the rough area of the dorsal surface of the 
scapula adjacent to the lower third of the axillary border. It passes 
outwards in front of the long head of the triceps, and is inserted by a 
tendon into the posterior lip of the bicipital groove of the humerus. 
The tendon extends a little further down the bone than does that of 
the latissimus dorsi, which is inserted in front of it, and with which it 
is for some distance in close contact. It is supplied by the third sub- 
scapular nerve. MUSCLES OF UPPER LIMB. 
263 
A triangular space is left between the upper border of the teres 
major, the margin of the scapula, and the upper end of the humerus; 
this space the long head of the triceps divides into two portions, the outer 
quadrilateral, the inner triangular. 
THE MUSCLES OF THE ARM. 
These are the coraco-brachialis, the biceps, the brachialis anticus, and 
the triceps. The first three occupy the front of the arm; the triceps 
with which the anconeus muscle is associated covers the posterior surface of 
the humerus. 
The coraco-brachialis arises from the tip of the coracoid process of the 
scapula in association with the short head of the biceps. It is inserted 
into the inner surface of the shaft of the humerus about the middle of 
the bone. From the insertion some tendinous fibres are continued into 
the internal intermuscular septum of the arm. In the upper half of its 
length the muscle is conjoined with the short head of the biceps. It is 
pierced by the musculo-cutaneous nerve which supplies it, and is crossed 
near its insertion by the brachial artery. 
The biceps (biceps brachii) arises from the scapula by two heads—the 
long from the tubercle above the apex of the glenoid fossa, the short from 
the tip of the coracoid process in association with the coraco-brachialis 
muscle. It is inserted into the posterior portion of the bicipital tuberosity 
of the radius, and by a slip into the fascia of the upper and inner part 
of the forearm. 
The long head is a rounded tendon continuous at the margins of its 
origin with the glenoid ligament, and prolonged through the joint, where 
it is invested by the synovial membrane, to the bicipital groove of the 
humerus, down which it is continued for some distance. The short head, 
tendinous at first, soon becomes muscular, and separating from the 
coraco-brachialis in the upper third of the arm, blends a little further 
down with the muscular fibres of the long head to form the belly of 
the muscle, which occupies a prominent position on the front of the arm. 
The tendon of insertion, originating a little above the elbow, passes 
deeply into the hollow below the joint to reach the bone, a bursa inter- 
vening between it and the most prominent portion of the tuberosity. 
From its inner edge about the level of the joint an aponeurotic slip, the 
semilunar fascia, is detached and becomes incorporated with the fascia of 
the inner region of the forearm. 
The pectoralis major crosses the heads of the muscle. The brachialis 
anticus lies behind it in the lower part of the arm. The brachial artery 
lies along its inner edge, and is often overlapped by it. The semilunar 
fascia crosses the artery. The biceps is supplied by the musculo cutaneous 
nerve which lies behind it. Occasionally a third head, springing from 
the humerus close to the insertion of the coraco-brachialis, is met with ; 264 
THE MUSCLES. 
when present, it is usually continued into the semilunar fascia. A fourth 
head has been noted in some instances. 
The brachialis anticus (brachialis) springs by fleshy fibres from the 
lower portion of the anterior surface of the humerus, from the anterior 
surface of the internal intermuscular septum, and from the upper end 
Fig. 235.—Muscles of the Front of the Arm. (L. Testut.) 
of the external septum. It is inserted by a thick tendon into the base 
of the coronoid process of the ulna. At its origin the muscle clasps the 
insertion of the deltoid above, and extends below nearly as far as the place 
of attachment of the capsular membrane of the elbow-joint. From the 
greater part of the external septum it is separated by the supinator 
longus and the extensor carpi radialis longior. The musculo-cutaneous MUSCLES OF UPPER LIMB. 
nerve lies on its surface and supplies it. It receives also a small branch 
from the nmsculo-spiral nerve, which passes down between it and the 
two last-named muscles. The brachial vessels and median nerve lie upon 
the surface of the muscle. 
The triceps (triceps brachii) occupies the back of the arm. It arises 
Fi0.!j236.—Muscles of the Front of the Arm, deep layer. (L. Testut.) 
by three heads—the long, the external, and the internal. The long head 
springs by a short tendon of about an inch or an inch and a half in 
breadth from the axillary border of the scapula immediately below the 
glenoid fossa; the external head springs by short tendinous fibres from 
the posterior surface of the humerus along a narrow line, extending from 
the insertion of the teres minor down to the margin of the musculo- THE MUSCLES. 
spiral groove, and by a few fibres from the upper extremity of the 
external intermuscular septum. The internal head, narrow and pointed 
above, but covering the whole breadth of the bone below, arises by 
fleshy fibres from the posterior surface of the humerus internal to and 
below the musculo-spiral groove, and from the posterior surfaces of both 
the intermuscular septa, the origin extending from the insertion of the 
Fig. 237.—Triceps. (L. Testut.) 
teres major to within a short distance of the olecranon fossa. The 
muscle is inserted into the upper surface of the olecranon process of 
the ulna in two planes, superficial and deep. The fibres descending 
from the long head form a flat superficial tendon, which is joined on 
its outer side by the fibres from the outer head, and on its inner side 
by a few of the most internal fibres of the inner head, and is inserted 
into an area close to the posterior margin of the upper surface of the. MUSCLES OF UPPER LIMB. 
olecranon process; this tendon is continuous at its margins with the 
fascia of the forearm. The remaining fibres of the muscle coming from 
the inner head pass, some to the deep surface of the superficial tendon, 
and some directly to the upper surface of the olecranon, where they are 
inserted close to the place of attachment of the capsular ligament. Some 
of the deepest fibres are attached to the capsule and receive the name of 
subanconeus. The lower fibres of the outer portion of the inner head lie 
from origin to insertion side by side with the higher fibres of the anconeus. 
A narrow area of bone intervenes between the deep and superficial insertion 
into the olecranon, and the space is usually occupied by a small bursa. 
The muscle is supplied by the musculo-spiral nerve, which, along with the 
superior profunda artery, descends between the outer and inner heads in 
the musculo-spiral groove. 
The anconeus, a small triangular muscle, arises by tendinous and 
fibres from the posterior surface of the external epicondyle of the 
humerus. It is inserted into a rough line on the outer surface of the 
olecranon process and into the outer edge of the posterior border of 
the ulna, extending in many cases nearly a third of the length of the 
bone. The uppermost fibres of origin are very short, and lie in serial 
continuity with those of the lower and outer part of the inner head 
of the triceps, from which at times they are not easily distinguished. 
Neither is the muscle distinguishable from the humeral heads of the triceps 
in function. Moreover, it is supplied by a branch of the musculo spiral 
nerve, which arises from the main trunk above the middle of the humerus, 
and traverses the deep part of the triceps. There is therefore much to be 
said for looking on this muscle as a part of the triceps. 
Actions of the Muscles of the Shoulder and Arm. 
In considering the special agencies which produce the various move- 
ments of the arm upon the body, it must be borne in mind that the 
shoulder-girdle is only directly articulated with the trunk at the sterno- 
clavicular joint, and that it receives its chief support from the surround- 
ing muscles, notably the trapezius and the levator anguli scapulae. The 
movements at the scapulo-humeral articulation are very free and are 
permitted in all directions, their limits being set partly by the ligaments 
of the joint, and partly by the tension of the surrounding muscles; but 
all movements at the joint are accompanied to a greater or less extent 
by movements of the scapula upon the chest wall. As an examjfie, when 
the arm is being raised from the side, in addition to the movement at 
the scapulo-humeral articulation, simultaneous movements of both shoulder 
blade and collar bone take place, the scapula rotating in such a manner 
that the lower angle passes forwards and upwards, the upper being corre- 
spondingly depressed and drawn backwards, while the outer end of the 
clavicle is pulled backwards and somewhat tilted so that the anterior edge 
is turned upwards. THE MUSCLES. 
The trapezius rotates the scapula and clavicle in the manner above 
described, and powerfully assists the deltoid in raising the arm. The 
levator anguli scapulae and rhomboidei raise the upper angle of the shoulder 
blade, and draw the base towards the spines, and thus oppose the action 
of the trapezius. The serratus magnus draws the scapula from the spines 
and comes into play in throwing the arm forwards and in pushing. The 
latissimus dorsi depresses the raised arm, draws the humerus backwards, 
and rotates it inwards; its action is well illustrated by the backward 
sweep of the arm in swimming. The pectoralis major draws the arm for- 
wards, and assists in depressing the raised arm. The pectoralis minor 
draws the coracoid process forwards, and opposes the rotating action of 
trapezius. The subclavias, acting upon the outer end of the clavicle, 
also opposes the rotating action of the trapezius. The greater part of 
the deltoid abducts the humerus; but the posterior fibres, those which 
spring from the scapular spine, would rather tend to draw the humerus 
downwards and backwards. The teres major, like the latissimus dorsi, 
draws downwards and backwards and rotates inwards. The subscapularis 
rotates inwards, and may assist in depressing. The teres minor rotates 
outwards, and may also have a slight depressing action. The infraspinatus 
rotates outwards, and the supraspinatus assists the deltoid in abducting. 
The biceps, when acting on the shoulder alone, and the coraco-brachialis assist 
in abducting, and the latter muscle and the short head of the biceps also 
draw the limb slightly forwards. The long head of the triceps, when 
the elbow joint is fixed, assists in depressing the raised arm. 
In addition to the actions already described, many of the muscles 
have an important action upon the trunk if the limb be fixed: thus the 
latissimus dorsi and pectoralis major, and the muscles which in ordinary 
circumstances depress the raised arm draw the body upwards on the arms 
in climbing; and the pectoralis major and minor, the latter especially, 
and perhaps also the lower fibres of the serratus magnus, by elevating 
the ribs take part in the motions of forced inspiration. 
The long head of the triceps depresses the arm, and extends the 
forearm; the rest of the muscle simply extends the forearm; the 
anconeus acts along with the inner head. The biceps supinates and flexes 
the forearm, and assists to raise the arm. The short head of the muscle, 
along with the coraco-brachialis, while assisting to raise the arm, also draws 
it forward. The brachialis anticus flexes the forearm. 
The Axilla. 
The axilla is the pyramidal space which lies between the upper end 
of the humerus and the chest wall, and is bounded in front and behind 
by the muscles which pass from the trunk to the upper limb. The 
anterior wall is formed by the pectoralis major, on the deep surface of 
which lie the costo-coracoid membrane and the pectoralis minor. The 
posterior wall is formed by the subscapularis, teres major, and latissimus dorsi. MUSCLES OF UPPEE LIMB. 
The anterior and posterior walls come nearly into contact at the bicipital 
groove of the humerus, but have lying between them the biceps and coraco- 
brachialis, which may be considered as forming a narrow outer wall, against 
which rest the axillary vessels, with the trunks of the brachial plexus of 
nerves. The inner wall is covered by the serratus magnus. The apex is 
bounded by the clavicle, the upper margin of the scapula, and the outer 
margin of the first rib. The base is covered by the axillary fascia. 
Fascia of the front of the shoulder. A somewhat thin layer of fascia 
covers the anterior surface of the pectoralis major. It is attached above 
to the clavicle and internally to the sternum ; below, it is continuous with 
the abdominal fascia; externally it passes into the fascia covering the 
deltoid and into the axillary fascia. 
Deep Fascia of the Shoulder and Arm. 
Fascia of the back of the shoulder. A strong layer of aponeurosis 
covers the infraspinatus and teres minor, where they are left uncovered 
by the deltoid. It has attachments to the spine and the vertebral and 
axillary margins of the scapula, and is continuous posteriorly with the 
fascia covering the trapezius, rhomboidei and latissimus dorsi. At the 
hinder margin of the deltoid it splits; one portion passes superficial to 
the muscle, and becomes continuous with the fascia covering the pectoralis 
major; the other invests the muscles on the deep surface of the deltoid. 
The fascia is continuous in front and below with the axillary fascia and 
the fascia of the arm. Muscular fibres of the suspraspinatus and infra- 
spinatus muscles spring from its deep surface, and the deltoid tendon at 
its posterior border is partially blended with it. 
The axillary fascia is the name given to the strong layer which, 
stretching between the anterior and posterior borders, forms the floor of 
the axillary space. It is continuous below with the fascia of the arm, 
in front with that covering the pectoralis major, and behind with that 
of the latissimus dorsi and teres muscles. On the deep aspect of the 
pectoralis major a strong layer of fascia, the costo-coracoid membrane, stretches 
from the first rib at its sternal end to the coracoid process (Fig. 152, h); 
at its upper border it embraces the subclavian muscle, and is fixed to 
the clavicle; below, it surrounds the pectoralis minor and joins the fascia 
stretched across the base of the axilla, binding it down, so that when the 
arm is raised the axilla has its greatest depression towards the front. The 
costo-coracoid membrane is pierced by the cephalic vein and by branches 
of artery and nerve supplying the pectoralis major. 
The deep fascia of the arm, for the most part thin, but becoming 
stronger in the neighbourhood of the epicondyles, completely surrounds 
the muscles. At the inner edge of the biceps, near the middle of the 
arm, an opening transmits the basilic vein aud internal cutaneous nerve. 
Two well-maTked intermuscular septa separate the muscles of the front from 
the triceps behind, and afford origin from both surfaces to muscular fibres. THE MUSCLES. 
The internal intermuscular septum extends from the insertion of the 
■coraco-brachialis muscle, from which it receives fibres, to the internal 
epicondyle. It is pierced by the inferior profunda and anastomotic 
arteries, and by the ulnar nerve and a branch of the musculo-spiral 
nerve. 
The external septum, not so strong as the internal, stretches from the 
insertion of the deltoid, from which it receives fibres, along the outer 
ridge to the external epicondyle. It is pierced by the anterior division 
of the superior profunda artery and by the musculo-spiral nerve. 
MUSCLES OF THE FOREARM. 
The muscles of the forearm are arranged in four groups, two of them 
superficial in position, the other two deeply placed. Of the superficial 
groups the inner springs from the internal epicondyle of the humerus and 
spreads downwards and outwards over the front of the forearm, and the 
muscles belonging to it, which enter the hand, pass in front of the anterior 
surface of the wrist; the outer springs from the external epicondyle, and 
the muscles belonging to it, which reach the hand, cross the posterior 
surface of the wrist joint. The hollow of the elbow is a triangular space 
of variable size placed in front of the elbow-joint; its apex is directed 
downwards and slightly outwards; it is bounded on each side by the 
marginal muscle of the inner and outer groups respectively. The deep 
groups of muscles belong respectively to the anterior and posterior surfaces 
of the forearm. 
Anterior and Inner Superficial Group. 
This group is formed of five muscles. From without inwards they are 
the- pronator radii teres, flexor carpi radialis, palmaris longus, flexor digi- 
torum sublimis, and flexor carpi ulnaris. They are very closely associated 
together at their origin from the internal epicondyle from which they 
spring in the order named, and in addition each receives fibres from the 
investing fascia of the forearm and from intermuscular septa which pass 
between and separate from one another the individual muscles at their 
upper ends. Besides the origins already mentioned three of the five 
muscles present additional slips or heads. The pronator teres receives a 
slip from the coronoid process, the flexor carpi ulnaris is connected with 
the olecranon process, and the flexor digitorum sublimis has its main 
head of origin from the humerus, continued downwards upon the internal 
lateral ligament and the coronoid process, and receives in addition a thin 
broad slip from the oblique line and anterior border of the radius. 
The pronator radii teres (pronator teres) springs from the internal epi- 
condyle, the fascia of the forearm and an intermuscular septum on its 
inner side; and it receives an additional slip from the inner side of the 
coronoid process. The muscle is somewhat rounded in outline, and is MUSCLES OF UPPEE LIMB, 
directed downwards and outwards. It is inserted under cover of the 
supinator longus into a rough impression on the outer surface of the 
radius at the lower extremity of the oblique line. The median nerve 
Fig. 238.—Muscles of the Front or the Forearm, superficial layer. (L. Testut.) 
descends between the heads of origin, and the ulnar artery passes downwards 
and inwards behind the deep head. 
The flexor carpi radialis springs from the internal epicondyle, the 
fascia of the forearm and the intermuscular septa on both sides. It is 
inserted into the anterior surfaces of the second and third metacarpal THE MUSCLES. 
bones at their bases. The muscular belly narrows about the middle of 
the forearm, and gives place to a long tendon which, in its passage 
downwards, occupies a special compartment in the outer part of the 
anterior annular ligament and passes in front of the scaphoid and along 
the groove of the trapezium. A synovial sheath surrounds the lower part 
of the tendon. 
The palmaris longus springs from the internal epicondyle, the fascia 
of the forearm and the intermuscular septa on both sides. It narrows 
in the upper third of the arm to a slender tendon which passes in front 
of the anterior annular ligament to end in the palmar aponeurosis. 
The flexor carpi ulnaris springs from the internal epicondyle, the 
fascia of the forearm and the intermuscular septum on its outer side; 
fibres also spring from the inner side of the olecranon process, and 
continuously therewith in the upper three-fourths of the forearm from the' 
strong layer of fascia attached to the posterior border of the ulna. It is 
inserted into the pisiform bone from which, however, the tendon is 
continued onwards in the form of slips which attach themselves to the 
anterior annular ligament, the unciform process and the bases of the 
fourth and fifth metacarpal bones. The muscular fibres give place to 
tendon in the lower fourth of the forearm. The ulnar nerve enters the 
forearm between the heads of the muscle. 
The flexor, digitorum sublimis springs from the internal epicondyle,. 
the fascia of the forearm and the intermuscular septa on both sides ; and 
j Ligamentum 
( breve 
Tendon of deep 
flexor 
Tendon of deep 
flexor 
- Tendon of 
superficial 
flexor 
Third phalanx 
■Tendon of deep flexor 
I', Tendon of superficial 
flexor 
Second phalanx 
3, Vaginal sheath (cut) 
4, Ligamentuxn longum 
.Metacarpal bone 
Ligamentum breve | Vaginalsheath (cut) 
First phalanx 
Fig. 239.—Flexor Tendons on Front of Finger. (L. Testut.) 
more deeply placed fibres continuous with the humeral head spring from 
the internal lateral ligament of the elbow and from the side of the 
coronoid process ; a second head, broad and thin, springs from the radius, 
extending in its origin downwards along the oblique line and a small 
part of the anterior border of the bone. It is inserted by four tendons 
into the anterior surfaces of the second phalanges of the four inner 
digits. The muscle breaks up about the middle of the forearm, and the 
tendons pass in pairs behind the anterior annular ligament, those for the MUSCLES OF UPPER LIMB. 
middle and ring fingers lying in front of those for the index and little 
fingers. Opposite the first phalanx each tendon splits into two portions, 
which embrace the tendon of the deep flexor, bending round it till the 
original borders meet and effect a junction behind it. Immediately before 
the insertion, which takes place into the borders of the anterior surface 
of the second phalanx, the tendon again splits into two portions. The 
tendons, along with those of the deep flexor, are surrounded by a synovial 
sheath as they pass behind the annular ligament. 
Passing along the anterior surface of the phalanges the pair of tendons 
belonging to each finger is covered by an arch of strong fibrous tissue 
{the vaginal ligament) springing from the margins of the bones; opposite 
the joints the sheath is much reduced in thickness to allow of flexion, 
and is formed of a delicate membrane with diagonally-crossing fibres 
attached behind to the interphalangeal ligaments. At the third phalanx 
the sheath is much reduced and forms a thin covering to the tendon of 
the deep flexor. 
This long canal is lined by a synovial membrane which is reflected 
over the tendons so as to surround each, but little bands of membrane 
{vincula tendinum) pass from one tendon to another, and from the tendons 
to the bones. The vincula are of two kinds; each tendon close to its 
termination is attached to the phalanx above that into which it is 
inserted by a considerable band, the ligamentum breve; other more delicate 
and less constant connections are termed ligamenta longa. 
The muscles of this group are three in number—the flexor digitorum 
profundus, flexor pollicis longus, and pronator quadratus. They are closely 
applied to the anterior surface of the bones of the forearm. 
Deep Anterior Group. 
The pronator quadratus, a flat four-sided muscle, arises from the anterior 
surface of the lower fourth of the ulna, and is inserted into the anterior 
surface and inner border of the corresponding portion of the radius. The 
other two deep muscles descend in front of it. 
The flexor digitorum profundus, embracing the coronoid process above 
and extending in its origin as far as the margin of the pronator quadratus 
below, arises from the anterior and inner surfaces of the upper three- 
fourths of the shaft of the ulna, the ulnar half of the corresponding 
region of the interosseous membrane, and, on the inner side, from the 
aponeurosis attached to the posterior border of the ulna. It passes to the 
four inner fingers, and is inserted in each case into the anterior surface of 
the terminal phalanx at its base. The tendons lie side by side as they 
pass behind the anterior annular ligament, and only become distinctly 
separate from one another when they reach the palm. Along with those 
of the superficial flexor which lie in front of them, they are at the 
wrist surrounded by a synovial sheath. In the palm they give origin 
s THE MUSCLES. 
to the lumbricales muscles. In each finger the tendon is invested by 
the fibrous and synovial sheaths already described, and pierces opposite 
the first phalanx the tendon of the superficial flexor. The ligamentum 
breve, which unites the tendon to the second phalanx, is specially 
strengthened by elastic tissue. 
Brachialis anticus 
Pronator radii teres 
Flexors of caipus 
Biceps 
Flexor digitorum sublimis 
Supinator brevis 
Pronator radii teres 
Flexor digitorum profundus 
Plexor pollicis longus 
..Pronator quadratus 
Plexor carpi ulnaris 
Pig. 240. Muscles of Front of Forearm, deep layer. (L. Testut.) 
Plexor digitorum sublimis 
The lumbricales (Fig. 244), four small rounded muscular bellies tapering 
to delicate tendons, spring, a little below the annular ligament, from the 
surfaces and the outer edges of the tendons of the deep flexor; the two 
inner muscles, however, spring likewise from the inner edges of the 
adjacent tendons. They pass to the four inner fingers, where each is 
inserted into the fibrous expansion of the extensor tendons on the back 
of the first phalanx. The tendons cross the outer surfaces of the heads 
of the metacarpal bones. MUSCLES OF UPPER LIMB. 
The flexor pollicis longus, extending in its origin from the bicipital 
tuberosity to the margin of the pronator quadratus, and narrow and 
pointed above where it is limited by the oblique line, springs from the 
anterior surface of the radius and the radial half of the adjacent 
interosseous membrane ; in many cases a delicate slip from the coronoid 
process joins the inner edge of the muscle. It is inserted into the 
anterior surface of the terminal phalanx of the thumb at its base. The 
tendon passes behind the anterior annular ligament and between the 
outer and inner portions of the short flexor of the thumb to gain the 
anterior surface of the phalanges, to which it is bound down by a vaginal 
sheath similar to those of the other digits. From the wrist to the 
insertion it is surrounded by a synovial sheath. 
Nerve supply of the muscles of the front of the forearm. These 
muscles are supplied by the median and ulnar nerves, the ulnar con- 
tributing branches to the flexor carpi ulnaris and the inner half of the 
flexor profundus digitorum, the median to the others. The two outer 
lumbricales are supplied by the median, the two inner by the ulnar. 
Synovial sheaths. A large synovial sheath surrounds the tendons of 
the superficial and deep flexors of the fingers, and the median nerve, as 
they pass behind the annular ligament. It extends upwards for a little 
distance above the ligament and downwards into the metacarpal region 
of the hand, where it terminates by four blind extremities. It is subject 
to considerable variations. Frequently in the case of the little finger and 
occasionally in the others, it passes downwards on the tendons to join 
the digital sheaths. It often communicates with the sheath of the flexor 
pollicis longus. On the other hand it is sometimes found completely or 
partially divided by a partition into lateral portions. The tendon of the 
flexor pollicis longus is inclosed in a special sheath, which is nearly 
always continuous with its digital sheath. The tendon of the flexor carpi 
radialis is likewise inclosed in a special sheath. 
Posterior and Outer Superficial Group. 
The muscles of this group in order from before backwards are—the 
supinator longus, extensor carpi radialis longior, extensor carpi radialis 
brevior, extensor digitorum communis, extensor minimi digiti, and extensor 
carpi ulnaris. The first two spring from the external supracondylar ridge 
of the humerus and from the anterior surface of the external intermuscular 
septum of the arm; the others, in the order named, arise from the 
external epicondyle by a common tendon, and receive fibres from the 
fascia of the forearm and the intermuscular septa derived from it. 
The supinator longus (brachio-radialis) arises from the upper two-thirds 
of the external supracondylar ridge of the humerus and the corresponding 
area of the external intermuscular septum of the arm. It is inserted into 
the outer border of the radius immediately above the styloid process. 276 
THE MUSCLES. 
The fleshy belly of the muscle narrows to a tendon in the lower half of 
the forearm. 
The extensor carpi radialis longior arises from the lower third of the 
Tendons of origin of extensor digi- 
torum communis,extensor minimi 
digiti, and extensor carpi ulnaris 
Supinator brevis 
Supinator longui 
Anconeus 
Extensor carpi radialis longior 
Extensor carpi radialis brevier 
Extensor ossis metacarpi pollicis 
Extensor primi internodii pollicis 
Extensor secundi internodii pollicis 
Extensor indicis 
Extensor carpi ulnaris 
Tendons of extensor j 
digitomm communis | 
10, 1 st dorsal interosseous muscle 
(abductor indicis) 
9, Tendons of extensor digitomm 
communis 
Fig. 241.—Muscles or Back of Forearm, deep layer. (L. Testut.) 
external supracondylar ridge of the humerus and the corresponding area of 
the external intermuscular septum of the arm. It is inserted into the 
posterior surface of the base of the second metacarpal bone. MUSCLES OF UPPER LIMB, 
The extensor carpi radialis brevior springs from the external epi- 
condyle by the common tendon, and receives fibres from the fascia of the 
forearm and the intermuscular septa. It is inserted into the posterior 
Supinator longus 
Triceps 
.Extensor carpi radialis longior 
■Anconeus 
Extensor carpi radialis brevior 
Plexor carpi ulnaris 
Extensor digitorum communis 
Extensor carpi ulnaris 
Extensor ossis metacarpi pollicis 
Extensor primi internodii pollicis 
Extensor digitorum communis 
Extensor minimi digiti 
Posterior annular ligament 
Extenspr primi internodii pollicis 
Extensor carpi radialis longior 
Extensor carpi radialis brevior 
Extensor secundi internodii pollicis 
Extensor indicis 
Abductor minimi digiti 
14 
Flexor pollicis longus 
Ist dorsal interosseous 
surface of the base of the third metacarpal bone. The two radial extensors 
become tendinous about the middle of the forearm, and their tendons 
are, a little lower down, crossed superficially by the tendons of the extensors 
of the metacarpal bone and first phalanx respectively of the thumb, a 
Fig. 242.—Muscles of Back of Forearm, superficial layer. (L. Testut.) 278 
THE MUSCLES. 
bursa being interposed at the point of crossing. Thereafter the two tendons, 
under cover of the posterior annular ligament, pass along the outermost 
broad groove on the back of the radius, where each is surrounded by a 
synovial sheath. At the insertion a small bursa is interposed between 
each tendon and the bone. 
The extensor digitorum communis springs by the common tendon from 
the external epicondyle, and receives fibres from the fascia of the forearm 
and the intermuscular septa. It is inserted into the posterior surfaces of 
the second and third phalanges of the four inner digits. The tendons 
separate from one another a little above the annular ligament, and pass 
side by side along the inner broad groove on the back of the radius, 
receiving a synovial investment. On the dorsum of the hand the 
diverging tendons present two connections of different kinds with one 
another; the more obvious consists of two slips given off' from the 
tendon of the ring finger to join the tendons of the middle and little 
finger, and is well known to musicians; the other consists of a transparent 
transverse band between the tendons of the middle finger and forefinger. 
On the back of the first phalanx of each finger the tendon spreads out into 
a fibrous expansion, which covers the bone posteriorly. The expansion is 
continued below into three thin slips, the median of which is attached 
to the base of the second phalanx, while the two lateral, after joining 
with one another, reach the base of the third phalanx. The tendinous 
expansions on the backs of the first phalanges are joined by the tendons 
of the lumbricales and interosseous muscles, and detach from their 
margins fibres to the metacarpo-phalangeal and interphalangeal ligaments. 
In the case of the index, and in that of the little finger, the expansion 
receives in addition an accession from the tendon of the special extensor 
of the digit. 
The extensor minimi digiti (extensor digiti quinti proprius), a long 
slender muscle, springs by the common tendon from the external epi- 
condyle, and receives fibres from the fascia of the forearm and the inter- 
muscular septa. The tendon passes along a groove between the lower 
ends of the radius and ulna, and on the back of the hand divides into 
two, one portion joining the innermost tendon of the common extensor, 
the other passing directly to the fibrous expansion on the back of the 
first phalanx of the little finger. 
The extensor carpi ulnaris springs by the common tendon from the 
external epicondyle of the humerus, and receives fibres from the fascia of 
the forearm and the intermuscular septa. It is inserted into the tuberosity 
at the base of the fifth metacarpal bone. The muscle descends along the 
inner portion of the posterior surface of the ulna, and the tendon, surrounded 
by a synovial sheath which is continued almost to the insertion, passes 
along a special groove on the posterior surface of the lower extremity of 
the bone. MUSCLES OF UPPER LIMB. 
279 
The Deep Posterior (Troup. 
There are five muscles in this layer: the supinator brevis, extensor 
ossis metacarpi pollicis, extensor primi internodii pollicis, extensor secundi 
internodii pollicis, and extensor indicis. They lie close to the bones and 
the interosseous membrane, and are placed from above downwards in the 
order in which they are named above. The inner limit of their origin is 
marked by a line upon the ulna, which begins above on the outer surface 
of the head at the hinder edge of the lesser sigmoid cavity, and is 
continued down the middle of the posterior surface of the shaft, dividing 
it into inner and outer portions. The upper fifth of this line marks the 
limit of the ulnar origin of the supinator brevis, the second fifth that of 
the extensor of the metacarpal bone of the thumb; the third and fourth 
fifths correspond to the position of the extensors of the second phalanx 
of the thumb and of the index finger. From the lower fifth no muscular 
fibres spring. The extensor of the first phalanx of the thumb lies at 
its origin from the interosseous membrane between the extensor of the 
metacarpal bone and that of the second phalanx and does not extend 
so far inwards as the ulna. The muscles are directed downwards and 
outwards. 
The supinator brevis (musculus supinator) arises from the orbicular 
ligament of the radius, the external lateral ligament of the elbow, the 
depression beneath the lesser sigmoid cavity of the ulna and the ridge 
limiting the depression behind. It is inserted into the outer surface of 
} External epicondyle (attachment of 
external lateral ligament) 
Olecranon 
Radius 
.'Supinator brevis 
Ulna Radius 
Fig. 248.—Supinator Brevis. (L. Testut.) 
the radius, extending as far forwards as the oblique line. The muscle is 
flat and four-sided, narrow above and at its origin, broad below and at 
its insertion. The posterior interosseous nerve runs in its substance. 
The extensor ossis metacarpi pollicis (abductor pollicis longus) arises 
from the outer part of the posterior surface of the ulna below the 280 
THE MUSCLES. 
supinator brevis and above the middle of the bone, from the adjacent 
interosseous membrane, and from a small area of the posterior surface 
of the radius behind and below the insertion of the pronator teres. It is 
inserted into the base of the metacarpal bone of the thumb on its outer 
side. Its tendon along with that of the extensor of the first phalanx 
crosses the tendons of the radial extensors of the carpus, a bursa being 
interposed, and passes along the groove on the outer surface of the lower 
end of the radius. A common synovial sheath surrounds both tendons in 
the groove. 
The extensor primi internodii pollicis (extensor pollicis brevis) arises 
below the extensor of the metacarpal bone, from the interosseous membrane 
and the posterior surface of the radius. It is inserted into the posterior 
surface of the base of the first phalanx of the thumb. Its tendon accom- 
panies that of the extensor of the metacarpal bone. 
The extensor secundi internodii pollicis (extensor pollicis longus) arises 
from the outer portion of the posterior surface of the ulna occupying an 
area placed about the middle of the bone, and from the adjacent inter- 
osseous membrane. It is inserted into the posterior surface of the base 
of the terminal phalanx of the thumb. Its tendon passes along the narrow 
oblique groove on the back of the radius and crosses the radial artery on 
the back of the carpus. In the groove the tendon is surrounded by a 
synovial bursa. 
The extensor indicis (extensor indicis proprius) arises from the outer 
portion of the posterior surface of the ulna below the middle of the bone, 
and by a few fibres from the adjacent interosseous membrane. Its tendon 
passes with those of the common extensor, and terminates in the expansion 
on the back of the first phalanx of the index finger. 
Nerve supply of the posterior and outer group of muscles. These 
muscles are, with the exception of the supinator longus and the extensor 
carpi radialis longior, which receive their twigs from the musculo-spiral, 
supplied by the posterior interosseous nerve. 
Synovial sheaths of the extensor tendons. As they pass along the 
bony grooves into which they are bound by the posterior annular liga- 
ment these tendons are all surrounded by synovial sheaths. As a rule 
one common sheath surrounds all the tendons of each groove, but the 
radial extensors of the carpus are each inclosed in a separate synovial 
sheath. 
Variations in the Forearm. 
Many of the muscles are at times absent altogether, and, in the case of 
the larger muscles, individual tendons or heads of origin are often wanting. 
On the other hand, muscles are sometimes found double, or may have 
additional heads of origin or tendons of insertion. Frequently slips pass 
from one to another, and in some cases distinct additional muscles are 
found. As the number of recorded variations is very large, only the more MUSCLES OF UPPEE LIMB. 
important need be briefly noticed. The humeral head of the pronator 
teres sometimes extends upwards along the supracondylar ridge for some 
distance, and when a supracondylar process is present the muscle is 
usually connected with it. The palmaris longus is absent in one out of 
-every ten cases ; it is often double ; sometimes its muscular belly is found 
in the lower part of the forearm, the muscle springing by a narrow 
tendon. The flexor digitorum sublimis is sometimes absent, its place 
being taken by a short muscle which springs in the hand from the 
annular ligament and palmar aponeurosis; less important is the absence of 
its radial head, or the division of the muscle into four fleshy bellies. 
In connection with the deep flexor an accessory slip from the coronoid 
process to one or other of the tendons has been frequently observed. To 
the lower extremities of the radius and ulna respectively two small 
muscles, the radio-carpal and cubito-carpal, have occasionally been found 
attached; the first passes towards the trapezium and os magnum, the 
second to the unciform. 
The radial extensors of the carpus frequently send a slip to the 
metacarpal bone or to one of the special muscles of the thumb. The 
tendon of insertion of the ulnar extensor of the carpus often sends on an 
expansion which reaches the back of the first phalanx of the little finger. 
From the upper part of the supinator brevis two small slips have been 
observed to pass to the orbicular ligament, reaching it, the one in front 
and the other behind, and acting as tensors of the ligament. 
MUSCLES OF THE HAND. 
The palmaris brevis consists of a few fleshy fibres springing from the 
inner edge of the palmar fascia and inserted into the skin on the inner 
border of the palm. It is very variable in size, and is sometimes absent 
altogether. It crosses superficially the ulnar artery and nerve. 
Muscles connected with the Thumb. 
The short muscles of the thumb form the thenar eminence of the hand. 
The abductor pollicis (abductor pollicis brevis) arises from the outer 
part of the annular ligament and from the ridge of the trapezium. It is 
inserted into the outer border of the first phalanx of the thumb at its 
base. 
The opponens pollicis springs from the outer part of the anterior 
annular ligament and the surface of the trapezium. It is inserted into 
the metacarpal bone of the thumb along the whole length of its outer 
border and the adjacent part of its anterior surface. The muscle lies 
behind the abductor. 
The flexor pollicis brevis is formed of two portions—an outer which 
is also superficial at its origin, and an inner or deep portion. The outer THE MUSCLES. 
portion arises from the lower edge of the outer part of the anterior 
annular ligament, and is inserted by a short tendon which contains a 
sesamoid bone into the outer border of the first phalanx at its base. 
The inner portion arises by a broad origin from the ligaments and fibrous 
structures, covering the three outer bones of the second row of the 
carpus, and from the bases of the three outer metacarpals. Its most 
Fia. 244.—Muscles of Hand, superficial layer. (L. Testut.) 
superficial fibres, forming a rounded slip, pass obliquely behind the 
tendon of the long flexor to join the tendon of insertion of the outer 
head of the muscle. The deeper fibres are inserted along with the 
adductor into the inner border of the first phalanx at its base by a 
tendon which, like that of the outer portion of the muscle, contains 
a sesamoid bone. 
The adductor pollicis, triangular in outline, arises from the anterior MUSCLES OF UPPER LIMB. 
ridge of the metacarpal bone of the middle finger. It is inserted along 
with the deep portion of the flexor brevis. 
Muscles connected with the Little Finger 
The short muscles of the little finger form the hypothenar eminence. 
The abductor minimi digiti springs from the pisiform bone. It is 
Pig. 245.—Muscles of Hand, deep layer. (L. Testut.) 
inserted into the inner border of the first phalanx of the little finger 
at its base. 
The flexor brevis minimi digiti springs from the unciform process 
and the anterior annular ligament. It is inserted along with the abductor. 
The opponens minimi digiti arises in common with the flexor brevis. 
It is inserted into the anterior border and inner surface of the meta- 
carpal bone of the little finger. THE MUSCLES. 
The Interosseous Muscles. 
They occupy the spaces between the metacarpal bones, and are seven 
in number. Three of them, regarded as palmar, adduct the fingers towards 
the middle line of the hand; four, more dorsal in position, are abductors. 
The palmar muscles are placed in the three inner interspaces. Each 
lies along the side of one finger, springing from the metacarpal bone, 
and being inserted by tendon partly into the first phalanx at the lateral 
aspect of the base and partly behind into the extensor tendons. The 
first belongs to the inner side of the index finger, the second and third 
to the outer sides of the ring and little fingers respectively. 
Fig. 246.—The Palmar Interosseous 
Muscles. (L. Testut.) 
Pig. 247.—The Dorsal Interosseous 
Muscles. (L. Testut.) 
The dorsal muscles. One occupies each interspace. Each takes origin 
by two heads, one from each of the two bones between which it is placed, 
and except in the case of the first or abductor indicis, the larger head is 
derived from the bone belonging to the finger on which the muscle acts. 
Each tendon is inserted into the first phalanx in a manner similar to 
the method of insertion of the palmar muscles. The first muscle belongs 
to the outer side of the index finger, the second and third to the outer 
and inner sides respectively of the middle finger, the last to the inner 
side of the ring finger. 
Nerve supply of the muscles of the hand. These muscles are supplied 
by the median and ulnar nerves. The median supplies the abductor pollicis, MUSCLES OF UPPER LIMB. 
the opponens pollicis, the outer head of the flexor pollicis brevis, and 
the two outer lumbricales. The ulnar supplies all the others. 
The actions are in most cases indicated by the names of the muscles, 
and it is only requisite to give a special description in the case of one 
or two. Pronation is effected by the pronator quadratus and the pronator 
radii teres; the latter muscle also, when pronation has been completed 
or is prevented by the action of opposing muscles, assists in flexing the 
elbow. When the forearm is vigorously pronated, a rotatory movement 
of the humerus in the outward direction takes place, and this also is 
probably partly at least the result of the contraction of the pronator teres. 
Supination is brought about by the biceps and supinator brevis. The supinator 
longus assists in flexion of the elbow after that movement has been com- 
menced by the other flexors, and is adequate of itself to maintain flexion; 
it has but little supinating action upon the radius. 
Actions of the Muscles of the Forearm and Hand 
The ulnar and radial flexors and extensors of the carpus oppose one 
another in flexion and extension of the wrist. When the flexors and 
extensors of the same side act together, lateral movement is produced 
at the joint. In addition, the long radial extensor may have in certain 
circumstances a slight flexing action upon the elbow. The superficial 
and deep flexors of the fingers act respectively upon the second and third 
phalanges, and are opposed by the common extensor; these muscles also 
act upon the wrist. The connections which pass between the tendons 
of the common extensor interfere, particularly in the case of the ring 
finger, with the independent extension of the separate digits. The index 
and little fingers, however, have each a special muscle, and can be 
individually extended with more freedom than either the ring or 
the middle finger. The lumbricales produce flexion at the metacarpo- 
phalangeal articulations and extension at the interphalangeal joints, as is 
exemplified in making the hair stroke in writing. The interosseous muscles, 
in addition to their own special action, assist the lumbricales; the dorsal 
set abduct the fingers from the middle line of the hand, while the palmar 
muscles adduct. The palmaris longus makes tense the fascia of the palm; 
the palmaris brevis dimples the skin at the inner side of the hand, and 
helps to deepen the hollow of the palmar cup. 
Deep Fascia of the Forearm and Hand. 
The fascia forms a moderately strong layer which closely invests all the 
superficial muscles, and, sending septa between them at their upper ends,, 
affords origin to many of their fibres. It is attached to the internal and 
external epicondyles and the posterior border of the ulna, and receives 
fibres from the tendons of the biceps and triceps. At the bend of the 
elbow it is pierced by a vein of considerable size. At the lower and 
back part of the forearm it is considerably thickened to form the posterior 286 
THE MUSCLES. 
annular ligament; in front of the wrist the anterior annular ligament, 
much stronger than the posterior, is continuous superficially with 
the fascia. 
The anterior annular ligament, a thick broad band, is fixed to the 
trapezium and scaphoid on the outer side, and to the pisiform bone and 
unciform process on the inner side. At its lower edge it is continuous 
with the palmar aponeurosis, and gives origin to some of the muscles of 
the thumb. The ulnar artery and nerve pass in front of the main body 
of the ligament, but are frequently covered by a few of the most superficial 
fibres. The median nerve and the tendons of the long flexors of the 
fingers and that of the thumb pass behind it. The tendon of the radial 
flexor of the carpus descends in a special canal at the outer attachment 
of the ligament. 
The posterior annular ligament is not nearly so strong as the anterior 
ligament. It is fixed on the inner side to the pisiform bone, and on the 
outer side to the outer margin of the radius, but at both extremities it is 
further continued to blend with the fascia of the front of the limb. It is 
fixed on its deep surface to the ridges on the back of the radius and 
ulna and to the back of the capsule of the wrist-joint, and thus completed, 
a number of osteo-fibrous canals are formed, along which the extensor 
tendons pass. 
Two layers of the deep fascia are found in the palm. One is more 
superficial, and covers the tendons of the long flexor muscles and the 
vessels and nerves, and spreads laterally as thin expansions over the 
thenar and hypothenar eminences; the other is more deeply placed, and 
invests the interosseous muscles and blends on either side, among the muscles 
of the thumb and little finger, with the lateral expansions of the superficial 
layer. Two vertical septa pass between the superficial and deep layers, 
and separate the regions occupied by the short muscles of the thumb and 
little finger respectively from the central space of the hand. 
Deep Fascia of the Hand. 
The palmar aponeurosis is the strong central portion of the superficial 
layer. It is triangular in outline, with its apex at .the annular ligament. 
The fibres are chiefly longitudinal in direction, but towards the base a 
number of transversely running fibres, forming the superficial transverse 
ligament, are added. A little above the clefts of the fingers the longi- 
tudinally directed fibres of the aponeurosis are collected into four slips, 
one corresponding to each of the inner digits. Each slip, after detaching 
first a superficial bundle which passes downwards in front of the superficial 
transverse ligament to be attached to the skin at the base of a finger, is 
continued onwards on the deep surface of the superficial transverse ligament, 
and splits into two portions to give passage to the flexor tendons which 
descend upon the front of the digit; the portions into which each slip 
splits are attached to the metacarpo-phalangeal ligaments, and blend with MUSCLES OF UPPER LIMB. 
the deep transverse ligament. The superficial transverse ligament is formed 
of a few transversely running fibres, and is placed in front of the digital 
slips, from each of which it receives a small accession. 
The lateral expansions of the palmar aponeurosis cover and invest the 
muscles of the thumb and little finger, and are continuous at the borders 
of the hand with the fascia of the dorsum. 
In the central part of the palm lie the tendons of the flexor muscles 
of the digits, the lumbricales muscles and a number of the palmar digital 
vessels and nerves; these structures lie behind the strong central part of 
the palmar aponeurosis and in front of the interosseous fascia. The flexor 
tendons which descend upon the anterior surfaces of the fingers pass through 
the digital slips of the palmar aponeurosis; the vessels and nerves and the 
lumbricales’ tendons, which descend upon the sides of the fingers, pass 
between the slips and behind the superficial and in front of the deep 
transverse ligament; the tendons of the interosseous muscles descend 
behind the deep transverse ligament. 
The interosseous fascia forms a delicate layer, which covers in front 
the interosseous muscles, and laterally blends with the fascia which invests 
the short muscles of the thumb and little finger. At its lower extremity 
it is continuous with the deep transverse ligament, a strong band which 
crosses in front of the lower extremities of the four inner metacarpal 
bones, and is blended with the metacarpo-phalangeal ligaments and the 
digital slips of the palmar aponeurosis. 
The septa which pass between the palmar aponeurosis and the inter- 
osseous fascia are of a delicate nature. The inner of the two separates 
the muscles of the little finger from the central part of the palm, and is 
pierced by the superficial palmar arch of artery and a digital branch of 
the ulnar nerve; the outer separates the muscles of the thenar eminence 
from the central part of the palm—it is pierced by the palmar digital 
nerves for the outer side of the index finger and for the thumb. 
The deep fascia of the dorsum is found in two comparatively thin layers. 
The more superficial is continuous with the lower edge of the posterior 
annular ligament and the lateral expansions of the palmar fascia, and covers 
and is closely associated with the extensor tendons. The deeper invests 
the surface of the interosseous muscles, and is attached to the metacarpal 
bones. 
THE LOWER LIMB. 
MUSCLES OF THE HIP. 
The muscles of this region are the gluteus maximus, gluteus medius, 
gluteus minimus, pyriformis, gemellus superior, obturator internus, gemellus 
inferior, quadratus femoris, and obturator externus. With the gluteus 
medius and gluteus minimus the tensor vaginae femoris is closely 
associated. With the exception of the last they are inserted into the 288 
THE MUSCLES. 
great trochanter or in its immediate neighbourhood. The gluteus maximus 
and tensor vaginae femoris are entirely superficial ; the gluteus medius is 
partially so; the others are deeply placed. 
The gluteus maximus, a large four-sided muscle, extending downwards 
and outwards, arises from the posterior fifth of the iliac crest and the small 
adjoining area of the dorsum ilii, from the lower part of the posterior 
layer of the lumbar aponeurosis, from the margin of the posterior surface 
of the lower half of the sacrum and upper half of the coccyx, and from 
the posterior surface of the great sacro-sciatic ligament; fibres also spring 
Fig. 248,—Muscles op the Hip, superficial layer. (L. Testut.) 
from the fascia on the deep surface of the muscle. The deeper fibres ol 
the lower part of the muscle are inserted into the rough gluteal ridge 
of the femur, extending from the outer lip of the linea aspera towards 
the great trochanter. The remainder, forming the larger part, passes into 
the fascia lata of the upper and outer part of the thigh. 
At the insertion into the fascia the tendinous fibres cover the great 
trochanter, a large bursa being interposed; the lower margin of the 
muscle in sweeping outwards crosses the upper part of the ischial tuber- 
osity. On its deep aspect lie the upper part of the adductor magnus, 
the origins of the hamstrings, the quadratus femoris, and gemelli, and MUSCLES OF LOWER LIMB. 
portions of the obturator internus, pyriformis, and gluteus medius muscles, 
and the vessels and nerves which escape by the great sacro-sciatic foramen. 
It is supplied by the inferior gluteal nerve from the sacral plexus. 
The gluteus medius, fan-shaped, arises from the large area of the 
dorsum ilii, limited above by the middle three-fifths of the crest and the 
superior curved line, and below by the middle curved line; fibres also spring 
from the strong fascia which overlies the surface of the muscle, where it 
is uncovered by the gluteus maximus. It is inserted by a short tendon 
into the oblique line running downwards and forwards upon the outer 
Gluteus maximus 
Gluteus medius 
Pyriformis 
Great trochanter 
Gemellus superior 
Obturator internus 
Gemellus inferior 
Obturator internus 
Great sacro-sciatic ligament 
Quadratus femoris 
14, Tuberosity of ischium 
Adductor magnus 
Gracilis.. 
■ Gluteus maximus 
f Vastus externus 
( covered by the fascia 
Semimembranosus | Long head of biceps 
Semitendinosus 
Pig. 249.—Muscles of Hip, deep layer. (L. Testut.) 
surface of the great trochanter, a bursa being interposed close to the 
insertion between the tendon and the bone. The anterior fibres are 
directed downwards and slightly backwards, the posterior downwards and 
forwards. The muscle is partially concealed by the gluteus maximus and 
nearly completely covers the gluteus minimus. It is supplied by the 
superior gluteal nerve from the sacral plexus. 
The gluteus minimus, very similar in shape to the gluteus medius, 
arises from the area of the dorsum ilii between the middle and inferior 
curved lines. It is inserted by a tendon into the anterior border of the 
great trochanter, a small bursa being interposed close to the insertion. 290 
THE MUSCLES. 
The deep surface of the tendon is united by a strong band of aponeurotic 
fibres, which is closely associated with a band from the portion of the 
fascia lata connected with the tensor vaginae femoris, to the capsule of 
the hip-joint and the acetabular margin, in close proximity to the 
reflected tendon of the rectus femoris. The anterior borders of the two 
smaller gluteal muscles are closely associated with one another and with 
the posterior surface of the tensor vaginae femoris. The pyriformis 
behind overlaps the minimus and is often partially incorporated with 
the medius. The gluteus minimus is supplied by the superior gluteal 
nerve. 
The tensor vaginae femoris (tensor fasciae latae) arises from a narrow 
area of the dorsum ilii immediately behind, and extending for a short 
distance above and below, the anterior superior spine. It is directed 
downwards and slightly backwards as a somewhat narrow band on the 
outer aspect of the upper third of the thigh and ends in the fascia lata. 
On the deep surface of the muscle a strong slip of fascia extends up- 
wards to the capsule of the hip-joint, which it joins in connection with 
the fibres from the gluteus minimus tendon. The portion of fascia lata in 
direct continuity with the muscular insertion passes downwards as the 
ilio-tibial band to the external lateral patellar ligament and the outer 
tuberosity of the tibia. Like the two smaller gluteal muscles with which 
it is so closely associated at its origin, it is supplied by the superior 
gluteal nerve. 
The pyriformis arises within the pelvis from the anterior surface of the 
second, third and fourth pieces of the sacrum. It passes as a fleshy mass 
outwards through the great sacro-sciatic foramen, and narrows near its 
insertion to a rounded tendon which is attached to the upper border of 
the great trochanter, and is usually firmly bound to the subjacent tendon 
of the obturator internus. The muscle is supplied by special branches 
from the sacral plexus. The great sciatic nerve emerges from the pelvis 
at the lower border of the pyriformis and descends behind the gemelli, 
the obturator internus, and the quadratus femoris. 
The obturator internus arises within the pelvis. Its deeper fibres spring 
from the anterior three-fourths of the obturator membrane, the more super 
ficial from the edges of the foramen arising in a semicircular line, which 
begins below at the lower and passes round the anterior and upper margins, 
and extends backwards into the angle between the ilio-pectineal line and 
the sacro-sciatic notch. The line of origin from the bone is interrupted 
opposite the groove on the upper margin of the foramen; fibres also spring 
from the fascia on the inner surface of the muscle. The fibres converge 
rapidly and form a narrow band, tendinous and partially divided into four in 
front and muscular behind, which turns over the smooth fibro-cartilaginous 
surface between the ischial spine and tuberosity. It is inserted, along with 
the gemelli and in close contact with the pyriformis, by a rounded tendon 
into the anterior region of the inner surface of the great trochanter. A MUSCLES OF LOWEE LIMB. 
large bursa lies between the tendon and the fibro-cartilaginous surface, 
and is sometimes continued on to the back of the capsule of the hip-joint. 
The muscle is supplied by a special branch from the sacral plexus. 
The gemelli, narrow fleshy bundles, are placed one above and the other 
below the extra-pelvic portion of the obturator internus and overlap it, the 
superior and smaller chiefly on the posterior aspect, the inferior chiefly in 
front. The superior arises from the base of the ischial spine, the inferior 
from the tuberosity and the outer lip of the trochlear surface. They are 
inserted with the tendon of the obturator internus. The three muscles 
Pig. 250.—Gemelli and Obturator Muscles, from behind. (L. Tostut.) 
cross the posterior surface of the capsule of the joint, and are attached to 
it by fascia The superior is supplied by a special branch from the sacral 
plexus, the inferior by a nerve from the same source, common to it and 
the quadratus femoris. 
The quadratus femoris, small, four-sided, and fleshy, springs from the 
outer margin of the ischial tuberosity. It is inserted into the posterior 
margin and outer surface of the great trochanter, extending as far down 
as the level of the upper border of the small trochanter. The muscle 
conceals the tendon of the obturator externus. Its lower border is in 
contact with the upper edge of the adductor magnus. It is supplied from 
the sacral plexus. 
The obturator externus takes origin from the outer surface of the wall 
of the pelvis. It springs from the bony margin of the anterior half of the 
obturator foramen, and from the anterior half of the obturator membrane. 
Narrowing rapidly to a flattened band, it passes outwards beneath the 
acetabulum, then outwards and upwards across the posterior surface of the 292 
THE MUSCLES. 
capsule of the joint, a bursa being interposed. It is inserted by tendon 
into the digital fossa of the trochanter. It is supplied by the obturator 
nerve from the lumbar plexus. 
Variations of the muscles of the hip. Some of the smaller muscles 
are sometimes entirely absent, most frequently the superior gemellus; but 
absence of the inferior gemellus, of the quadratus femoris, and of the 
pyriformis has occasionally been observed. Contiguous muscles are some- 
times united with one another thus—the quadratus femoris with the 
adductor magnus, and the pyriformis with the gluteus medius, minimus, 
or gemellus superior. The gluteus maximus is sometimes divided into 
two layers, and its lowest sacro-coccygeal fibres are sometimes distinct 
from the others, representing the agitator caudae of the lower animals. 
The gluteus medius is sometimes double at its insertion, and the minimus 
is occasionally almost completely divided into two parts. The pyriformis 
is very frequently divided into two by one of the roots of the great 
sciatic nerve. An accessory gluteal muscle has been found between the 
maximus and medius. 
POSTERIOR FEMORAL REGION. 
The hamstring muscles,—biceps, semitendinosus and semimembranosus, 
—passing from the tuberosity of the ischium to the outer and inner sides 
of the knee, occupy the back of the thigh. They spring from two triangular 
impressions on the upper and posterior region of the tuberosity, the biceps 
and semitendinosus by a common tendon from the internal and lower of 
the two, the semimembranosus from the upper and outer. The biceps has 
an additional head from the linea aspera. 
They lie behind the quadratus femoris and adductor magnus, and are 
themselves covered posteriorly in the upper part of the thigh by the gluteus 
maximus. As they separate above the knee, the biceps to the outside, 
the other two inwards, they form the upper walls of the diamond-shaped 
popliteal space completed below by the heads of the gastrocnemius. They 
are supplied by the great sciatic nerve which descends in front of them. 
The biceps (biceps femoris). The tendon of the long head, arising from 
the ischial tuberosity in common with the semitendinosus, separates from 
that muscle in the upper fifth of the thigh. Almost immediately after- 
wards it enlarges into a rounded muscular belly, which above the knee 
is joined by the short head, a broad fasciculus of muscular fibres springing 
from the outer margin of the linea aspera, the upper part of the external 
supracondylar line and the external intermuscular septum. The muscle 
terminates in a short divided tendon which is inserted into the outer 
surface of the head of the fibula on either side of the long part of the 
external lateral ligament of the knee-joint, a bursa intervening. Fibres 
from the tendon pass forwards to the outer side of the head of the tibia 
and to the fascia of the leg. MUSCLES OE LOWER LIMB. 
293 
The semitendinosus springs by muscular fibres from the inner surface 
of the tendon common to it and the long head of the biceps. The 
muscular belly consists of longitudinal fibres interrupted about the middle 
hy an oblique tendinous intersection, and narrows in the lower third of 
thigh to a slender rounded tendon which, becoming expanded, is 
*nserted behind that of the sartorius, and below, but in the same plane 
with that of the gracilis, into the inner surface of the shaft of the tibia 
Fig. 251.—Muscles of the Posterior Region of the Thigh. (L. Testut.) 294 
THE MUSCLES. 
at its upper end. Some fibres are detached from the tendon to the fascia 
of the leg. A bursa lies between the tendons and the internal lateral 
ligament of the knee-joint. 
The semimembranosus, springing from the upper and outer facet upon 
the ischial tuberosity by a broad tendon, membranous in the greater 
part of its breadth and several inches in length, terminates below in a 
tendon which divides into three portions—one detached to the fascia 
covering the popliteus muscle, another to the posterior surface of the 
capsule of the knee, the third passing forwards under cover of the internal 
lateral ligament of the joint to the extremity of the groove on the inner 
surface of the head of the tibia. The muscular belly is formed of short 
oblique fibres running between the tendon of origin which is continued 
downwards for some distance on its outer side and the tendon of inser- 
tion continued upwards on the inner side, and thus possesses greater force 
and smaller extent of contraction than the other hamstring muscles. Close 
to its origin it passes in front of the outer part of the common tendon of 
the other hamstrings, and thereafter is continued down the thigh along the 
anterior edge of the semitendinosus. A bursa separates the tendon of 
insertion from the inner head of the gastrocnemius. The groove in which 
a portion of the tendon lies is lined by firm fibrous tissue and lubricated 
by a synovial membrane. 
Variations of the posterior femoral muscles. The short head of the 
biceps may be absent, and sometimes, though very rarely, the semi- 
membranosus is absent. On the other hand, an additional head of the 
biceps is occasionally found springing from the internal supracondylar 
line, the linea aspera, or the ischium. An additional head of the semi- 
membranosus may be present, springing from the linea aspera. 
INNER FEMORAL REGION. 
The muscles of this group are the gracilis, pectineus, adductor longus, 
adductor brevis, and adductor rnagnus. At their origins they occupy 
the anterior surface of the pubis and ischium, above, to the inner side of, 
and below the obturator externus. The gracilis passes downwards to 
the inner side of the knee. The others pass outwards, downwards 
and slightly backwards towards the linea aspera and the lines continued 
from it. At the insertion the pectineus, adductor brevis, and adductor 
longus lie in order from above downwards in front of the adductor 
rnagnus, but the adductor brevis is overlapped by the lower edge of the 
pectineus. The upper part of the inner edge of the adductor longus 
forms on the front of the upper third of thigh, the inner boundary of a 
triangular area, Scarpa’s triangle, the outer margin of which is formed by the 
upper part of the sartorius and the floor by the pectineus and portions of the 
iliacus, psoas, adductor brevis, and adductor longus. From base to apex of 
this space the femoral artery passes downwards in the thigh. After traversing MUSCLES OF LOWER LIMB. 
295 
the space the artery crosses the insertion of the adductor longus, and 
still further down passes backwards through the adductor magnus to the 
popliteal space. From the anterior surface of the insertions of the adductor 
longus and adductor magnus in the middle third of the thigh, membranous 
fibres crossing the femoral vessels pass outwards to the vastus internus 
and form the anterior wall of a three-sided passage called Hunter's canal. 
The deep femoral branch of the main arterial stem courses behind the 
adductor longus and gives off a number of perforating branches which 
pass backwards through the adductor magnus to the posterior region of 
the thigh. 
The muscles, with the exception of the pectineus, are supplied by the 
obturator nerve. The pectineus receives its supply from the anterior 
crural but has an occasional twig from the obturator. The adductor 
magnus receives an additional twig from the great sciatic. 
The gracilis springs by a short, thin tendon from the rough line close 
to the symphysis on the lower part of the body of the pubis, and from 
the anterior margin of the pubic portion of the ischio-pubic ramus. The 
body of the muscle, flattened and slender, passes down superficially on the 
inner aspect of the thigh, and narrows in the lower third to a tendon 
which, somewhat expanded at its termination, is inserted behind the 
sartorius and above the semitendinosus into the inner surface of the shaft 
of the tibia at the upper end. 
The pectineus arises from the ilio-pectineal line and the smooth surface 
m front of it in the region between the spine of the pubis and the ilio- 
pectineal eminence. It is inserted into the upper part of the line leading 
from the linea aspera to the back of the small trochanter. Superficial at 
its origin it rapidly passes backwards in the floor of Scarpa’s triangle. 
The ilio-psoas muscle is in contact with it externally. 
The adductor longus, triangular in outline, springs by a short, narrow 
tendon from the body of the pubis at the anterior and inner angle. It 
is inserted by aponeurotic fibres closely associated with the insertion of 
the adductor magnus into the inner edge of the linea aspera. In its 
greater part it is superficial, but near its insertion it is crossed by the 
femoral vessels and the sartorius. The pectineus lies at its outer edge, 
the gracilis internally, the adductor brevis is posterior to it at its origin, 
and the adductor magnus is behind it lower down. 
The adductor brevis, deeply placed, springs from the body of the 
pubis below the adductor longus and between the gracilis and obturator 
externus. It is inserted into the line leading from the linea aspera to 
fhe back of the small trochanter, lying behind the lower portion of the 
Pectineus above and reaching to the adductor longus below. The muscle 
is frequently split into two portions at its insertion by the first perforating 
branch of the deep femoral artery. 
The adductor magnus springs from the surface of the ischio-pubic ramus, 
and in addition spreads in its origin backwards on the tuberosity as far as the 296 
THE MUSCLES. 
margin of the quadratus femoris and forwards upon the body of the pubis 
into the angle between the origins of the adductor brevis and obturator 
externus. The anterior part of the origin is overlapped by the gracilis, the 
Glutens minimus 
Small sacro-seiatic ligament 
28, Great sacro-sciatic 
foramen 
Pyriformis 
29, Small sacro-sciatic 
foramen 
.Obturator externus 
.Gluteus maximus 
.Quadratus femoris 
Great sacro-sciatic ligament 
Long head of biceps 
Gracilis 
.Adductor magnus 
Adductor magnus, 
Adductor magnus 
Semimembranosus. 
.Vastus externus 
-.Opening for popliteal vessels 
...Short head of biceps 
Semimembranosus, 
Sartorius 
Long head of biceps 
Gracilis 
Semimembranosus 
.Tendon of biceps 
Popliteus 
Soleus 
Fig. 252.—Posterior Region of Thigh, deep dissection (compare Fig, 
251). (L. Testut.) 
posterior part is subcutaneous. It is inserted into the back of the femur, 
behind the other muscles of the group, along a line which extends from the 
upper extremity of the gluteal ridge to the adductor tubercle. The fibres MUSCLES OE LOWER LIMB. 
most anterior at their origin pass almost directly outwards to the inner 
margin of the gluteal ridge; those succeeding are oblique in direction and 
are inserted by short tendinous fibres into the inner margin of the linea 
aspera and the upper third of the supracondylar line; the most posterior 
fibres descend almost vertically behind the others to the adductor tubercle, 
where they are inserted by a rounded cord-like tendon. Through the break 
in the insertion opposite the greater part of the supracondylar line the 
femoral vessels pass. Three or four smaller openings at intervals along the 
line of insertion transmit the perforating arteries. The posterior part of 
the muscle is superficial above, below it is covered by the gracilis and 
semimembranosus. 
Variations of the internal muscles of the thigh. Contiguous muscles 
are frequently found more or less united with one another—thus, the 
adductor longus with the pectineus, and the adductor magnus with the 
longus, brevis, or quadratus femoris. The adductor brevis and pectineus 
are occasionally found in two portions, and in the case of the adductor 
magnus the upper and lower fibres are sometimes quite separate from 
the rest of the muscle. Variations in extent of attachment are not very 
frequent in this group, but the pectineus is sometimes found connected 
with the capsule of the hip-joint. 
ANTERIOR FEMORAL REGION. 
The muscles of this group are the sartorius, quadriceps extensor 
femoris, and the ilio-psoas. The sartorius and a portion of the quadriceps 
cross both hip- and knee-joints; of the others, the ilio-psoas acts upon 
the hip, the remainder of the quadriceps upon the knee. They are, with 
the exception of the psoas, supplied by the anterior crural nerve. The 
psoas is supplied by special branches from the lumbar plexus. 
The sartorius, long, narrow and superficial, and formed of longitudinal 
bundles which run the whole length of the muscle, arises from the anterior 
margin of the ilium, the origin extending for a short distance downwards 
from the anterior superior spine. It is inserted by a thin expanded 
tendon which detaches fibres to the fascia of the leg and the capsule of 
the knee-joint into the inner surface of the shaft of the tibia at its upper 
end in front of the tendons of the gracilis and semitendinosus. In the 
tipper portion of the thigh the muscle is directed downwards and inwards; 
afterwards nearly directly downwards, near its insertion, the tendon bends 
forwards. It crosses the rectus femoris, ilio-psoas, pectineus, adductor 
longus, the femoral vessels, and vastus internus, and forms in the upper 
part of the thigh the outer boundary of Scarpa’s triangle. 
The quadriceps extensor cruris is formed of four parts—the rectus 
femoris, vastus externus, vastus internus, and crureus, which have a 
common insertion into the patella. The rectus femoris, the most super- 
ficial, and distinct almost to its insertion, springs from the hip bone and THE MUSCLES. 
occupies the middle of the front of the thigh. The others, very closely 
associated with one another in their whole extent, take origin from the 
Iliacus Psoas magnus 
Fig. 253.—Anterior Region of Thigh, superficial. (L. Teatut.) 
femur, the crureus between the other two, and closely cover the surface 
of the bone. The common insertion is centred round the strong tendon 
of the rectus femoris, which passes to the middle of the upper border MUSCLES OF LOWER LIMB. 
and the anterior surface of the patella, and is joined on its deep surface 
by the crureus tendon and on its margins above the bone by fleshy fibres 
from the vasti, and a little lower by their tendons which reach the lateral 
portions of the upper border of the patella and the lateral patellar 
regions of the knee capsule. A large bursa communicating with the 
joint lies underneath the common insertion. From the lower margin of 
the patella the ligamentum patellae passes to the anterior tubercle of the 
tibia. 
Fig. 254.—Inner Side of the Knee. (L. Testut.) 
The rectus femoris arises by two very short, strong, tendinous heads— 
one, the reflected tendon from the rough mark on the upper and outer 
border of the acetabulum, the other, the straight tendon from the anterior 
inferior iliac spine. These unite with one another at an angle of about 
45 degrees, and form a rounded tendon. The muscular belly occupies the 
middle three-fifths of the thigh, but consists of short oblique fibres stretching 
from the tendon of origin which passes downwards for some distance in the 
muscular substance to the tendon of insertion, which is prolonged upwards 
on the deep surface. The origin is deeply placed, being covered by the 
iliacus and gluteus minimus and crossed by the sartorius; the rest of the 
muscle is superficial. THE MUSCLES. 
The vastus externus, a thick muscular sheet occupying the outer 
region of the thigh, and presenting an anterior border free from the 
crureus in its whole extent, springs partly by an aponeurosis which 
extends for some distance on the surface of the muscle and partly by 
fleshy fibres from the upper part of the anterior intertrochanteric line, the 
line limiting the great trochanter in front and to the outside, the outer 
margin of the gluteal ridge, and the upper portion of the linea aspera; 
fibres also spring from the external intermuscular septum. The fibres pass 
downwards and inwards to the tendon, which forms on the deep surface 
of the muscle in its lower part and joins the outer part of the common 
insertion. The muscle is superficial in the greater part of its extent, 
being only slightly overlapped by the rectus and tensor vaginae femoris. 
It lies upon the crureus. 
The vastus internus arises partly by aponeurotic and partly by fleshy 
fibres from the lower extremity of the anterior intertrochanteric line, 
from the line leading thence to the linea aspera, and from the inner lip 
of the linea aspera. The origin is closely connected behind with the 
insertions of the adductor longus and adductor magnus. The fibres pass 
outwards and downwards, and the muscle lies close upon the bone. Its 
most anterior fibres pass into the superficial aponeurosis of the crureus, and 
the muscle therefore contrasts with the vastus externus in having no free 
border in front. If the muscular mass be divided from below upwards, 
however, it will be found that there is no continuity between the crureus 
and vastus internus at their origins, and that there is a continuous tract 
along the whole inner surface of the femur from which no muscular fibres 
spring. The remainder of the fibres pass to a tendon which forms on the 
deep surface of the muscle, and joins the inner part of the common insertion. 
The muscular fibres of the vastus internus are continued further downwards 
towards the patella than are those of the vastus externus. The muscle is 
overlapped by the rectus and crossed by the sartorius, but in the space 
between these two it is superficial. The femoral vessels are for some distance 
in contact with its surface. 
The crureus springs from the outer portion of the shaft of the femur 
and extends in its origin from the anterior intertrochanteric line to within 
a few inches of the lower end of the bone ; some of the lower fibres spring 
from the external supracondylar line and external intermuscular septum. 
It is largely overlapped by the vastus externus, with the origin of which 
it is at its posterior margin continuous. Its aponeurosis of insertion joins 
the deep part of the common tendon, and is continued upwards over the 
anterior surface of the muscle, presenting to the posterior surface of the 
rectus, which is similarly covered, an aponeurotic expansion which allows 
gliding. 
A few of the lower fibres of the muscle receive the name of subcrureus. 
They are attached to the wall of the synovial bursa which lies behind the 
common tendon of insertion. MUSCLES OF LOWER LIMB. 
301 
The ilio-psoas, arising and chiefly contained within the abdomen, is 
formed of two parts which, distinct above, are united and inserted together 
below. 
The iliacus occupies the iliac fossa and springs from the broad 
marginal area, extending from the region of the anterior inferior spine 
Fia. 255.—The Ilio-Psoas Muscle. (L. Testut.) 
upwards and backwards to the sacro-iliac ligaments and edge of the 
Sacrum. It crosses the capsule of the hip, from which sometimes a few of 
e lower fibres take origin, and is inserted partly into the outer edge of 
e psoas tendon and partly into the triangular area in front of and 
elow the small trochanter. THE MUSCLES. 
The psoas magnus occupies the angle between the anterior surfaces of 
the tranverse processes and the lateral regions of the bodies of the lower 
movable vertebrae, its origin extending from the last dorsal to the fifth 
lumbar. The fibres spring partly from the transverse processes, on which 
they reach outwards nearly to the tips, partly from the intervertebral 
discs and the contiguous bony vertebral margins, and partly from a series 
of tendinous arches which, crossing the lumbar vessels, stretch from the 
upper to the lower edges of the bodies of the vertebrae. Narrowing as it 
passes downwards it first partly overlaps and then becomes united with 
the inner edge of the iliacus, crosses the capsule of the hip, and is 
inserted by tendon into the small trochanter. 
In the abdomen both muscles are covered by the iliac fascia. The 
psoas is crossed by the external iliac artery which, while still on its 
surface, passes behind Poupart’s ligament. At its origin the lumbar 
plexus of nerves lies deeply embedded in it and the branches leave it at 
various points. In the thigh the conjoined muscles form part of the floor 
of Scarpa’s triangle. Between the deep surface of the psoas and the 
capsule of the hip lies a large bursa which often communicates with the 
cavity of the joint. 
The psoas parvus, inconstant and variable, lies, when present, upon 
the surface of the larger psoas muscle. It usually springs from the 
intervertebral disc which unites the last dorsal to the first lumbar vertebra 
and from the contiguous edges of the bones. Rapidly narrowing, it ends 
in a long tendon which, passing downwards and becoming partly blended 
with the iliac fascia, is inserted into the ilio-pectineal eminence. The 
muscle though well developed and constant in many animals is absent in 
the human subject, on one or both sides, in about fifty per cent, of cases. 
Variations of the anterior femoral muscles. These are not frequent. 
Absence of the sartorius has been noted. Additional attachments of the 
sartorius, psoas and iliacus have been described. The two last mentioned 
muscles are sometimes completely separated down to their attachments. 
Actions or the Muscles of the Hip and Thigh. 
The gluteus maximus is the chief extensor of the hip-joint, and may 
act from the thigh or from the trunk. Acting from the trunk the upper 
fibres tend to abduct the thigh while the lower fibres adduct and rotate 
outwards. The whole muscle comes into play in walking, running, leaping, 
and in rising from the sitting to the erect posture. Through its connection 
with the fascia lata the muscle acts along with the tensor vaginae femoris 
upon the knee-joint. The gluteus medius and minimus are abductors of the 
thigh, or, acting from the thigh, tilt the pelvis over the femur, as happens 
in walking in the case of the supporting limb. The anterior fibres of both 
muscles tend to rotate the limb inwards, more particularly in the flexed 
position of the joint. The posterior fibres of the gluteus medius act as MUSCLES OF LOWER LIMB. 
extensors and, to a slight extent, as rotators outwards. The tensor 
vaginae femoris acts upon the tibia through the ilio-tibial band, and on the 
femur through the external intermuscular septum; it is a rotator inwards, 
and an abductor of the thigh, and is an extensor of the knee-joint and 
a rotator outwards of the tibia. In the completion of the extension of 
the knee it both rotates the femur directly and holds the tibia firm, and in 
the flexed position of the knee it acts with the biceps in rotating the leg 
outwards opposing the sartorius, gracilis, semitendinosus, and semimem- 
branosus, which all rotate the leg inwards. The pyriformis is an abductor 
and to a slight extent an extensor and rotator outwards of the thigh; 
the obturator internus and gemelli are rotators outwards; like the other 
muscles at the back of the joint they act upon the trunk in walking, 
assisting to tilt the pelvis over the supporting limb. The quadratus 
femoris and obturator externus are outward rotators and have in addition 
a slight adducting action upon the limb. 
The adductor muscles may act either from the trunk or from the 
femur. They oppose the gluteus medius and minimus and thus come into 
play in walking, in balancing the trunk upon the limb. The pectineus, 
adductor longus and adductor brevis assist in flexing the thigh. The 
gracilis flexes the knee and rotates the tibia inwards. The posterior fibres 
of the adductor magnus would assist in extension of the hip. The ham- 
string muscles extend the hip and flex the knee. With bent knee they 
rotate the leg—the biceps outwards, the other two inwards. The rectus 
femoris flexes the hip and extends the knee; the vasti and crureus 
muscles extend the knee. The anterior origin of the rectus is the only one 
tightened when the thigh is extended, and the jmsterior the only one 
tightened when the thigh is flexed. The sartorius flexes both hip and knee, 
everts the thigh and rotates the leg inwards. The ilio-psoas flexes the thigh, 
and may act either from the trunk or from the femur; acting from below 
the psoas can produce lateral flexion of the lumbar portion of the column. 
In walking while the swinging limb is passing forwards, chiefly from 
the action of gravity after the knee has been bent, the weight of the body 
is supported by the trunk being drawn over the other limb. The gluteus 
maximus acts as the chief extensor; the gluteus medius, gluteus minimus 
and the external rotators bring about the lateral tilting of the pelvis, their 
action being opposed and modified by the adductor muscles which assist in 
maintaining the balance of the body. When the stride taken is longer 
than the natural step the action of the ilio-psoas is required to carry the 
femur forwards. 
DEEP FASCIA OF THE THIGH. 
The deep fascia of the thigh, or fascia lata, is attached above to Poupart’s 
ligament, the body and inferior ramus of the os pubis, the ischium, the 
great sacro-sciatic ligament, the lower part of the lumbar aponeurosis 
and the crest of the ilium. Below, it sweeps on the inner side and behind 304 
THE MUSCLES. 
into the fascia of the leg; at the outer side it is fixed to the head of the' 
fibula and the external tuberosity of the tibia; and in front, becoming 
blended with the insertions of the quadriceps muscle, it is attached to tho 
patella, assisting to form the lateral patellar ligaments and the capsule of 
the knee. A thin layer, sweeping over the patella, incloses the large 
prepatellar bursa which, when inflamed and swollen, is the seat of the 
affection known as “ housemaid’s knee.” The fascia, which is generally 
strong, is specially strengthened on the outer aspect of the thigh, where 
it receives the attachment of the greater part of the gluteus maximum 
muscle and of the tensor vaginae femoris. From the insertion of the 
latter muscle at the junction of the upper and middle thirds of the 
thigh, a strong portion of the fascia, described as the ilio-tibial band, passes 
downwards and is attached partly to the external tuberosity of the tibia 
and partly to the patella, assisting to form the external lateral patellar 
ligament. The external intermuscular septum of the thigh is closely con- 
nected with the deep surface of the ilio-tibial band; it passes to the linea 
aspera between the biceps and vastus externus muscles, affording origin 
to both, and is specially strong at its lower end where it reaches the 
back of the external condyle of the femur. On the deep aspect of the 
tensor vaginae femoris a strong process of the fascia passes upwards and 
is attached, in association with a band of tendinous fibres from the tendon 
of the gluteus minimus, into the capsule of the hip-joint and the acetabular 
margin at the place of origin of the reflected tendon of the rectus femoris. 
On the posterior aspect of the limb a strong layer passes on the deep 
surface of the gluteus maximus, assisting to inclose the muscle and 
affording origin to many of its fibres. A delicate posterior intermuscular 
septum is sometimes described as passing to the linea aspera behind the 
adductor muscles. The fascia is weakest over the inner region of the thigh. 
The internal intermuscular septum, much weaker than the outer, 
passes to the linea aspera between the vastus internus and the adductor 
muscles, and becomes blended with the sheath of the femoral vessels. 
Closely associated with the femoral sheath and the internal intermuscular 
septum is the short passage in the middle third of the thigh, known as 
Hunter’s canal. The canal is formed in the angle between the attachment 
of the vastus internus in front, and those of the adductor magnus and 
adductor longus behind, by strong tendinous fibres which pass between 
the muscles and limit a passage, three-sided, in cross section, which trans- 
mits the femoral artery and vein and the long saphenous nerve. The 
canal extends upwards from the margin of the lowest perforation in the 
insertion of the adductor magnus for two or three inches, but its upper 
extremity is not well defined, as the tendinous fibres which complete its 
walls gradually become weaker and are continuous with the femoral sheath. 
The saphenous opening is a large perforation of the fascia on the 
anterior aspect of the thigh for the transmission of the saphenous vein 
and a number of smaller vessels. It is placed below the inner part of MUSCLES OF LOWEE LIMB. 
305 
Poupart’s ligament, and is formed by a splitting of the fascia into two 
portions, an inner and an outer. The inner or pubic portion passes 
upwards and is attached to the first half-inch of the ilio-pectineal line, 
along the line of attachment of Gimbernat’s ligament; traced outwards 
it is deflected behind the femoral vessels, becoming continuous with the 
posterior wall of their sheath, and covers the pectineus muscle. The 
outer or iliac portion of the fascia passes upwards to Poupart’s ligament; 
its inner margin is sickle-shaped and forms the outer boundary of the 
saphenous opening. The sickle-shaped or falciform margin is divided into 
three regions—an upper and a lower falciform process, both well marked, 
Pig. 256.—The Saphenous Opening. 
and an intermediate portion, not so distinctly outlined, where there is 
a close connection between the fascia lata and the cribriform fascia, the 
layer of superficial fascia which immediately overlies the opening. The 
femoral sheath is formed, in its upper part, of a prolongation of the fascia 
transversalis and fascia iliaca of the abdominal walls. The artery and 
vein are contained in different compartments, separated from one another 
by a delicate septum, the vein being the more internal. Immediately 
internal to the vein, however, a third compartment, short, and ending 
in a blind pointed extremity, about half an inch below Poupart’s ligament, 
contains a small lymphatic gland and some fatty tissue. A femoral hernia 
descends in this compartment and, stretching the walls of the sheath, 
Passes to the surface through the saphenous opening. 306 
THE MUSCLES. 
The muscles of this region are the peroneus longus and the peroneus 
brevis. Their origins occupy the whole outer surface of the fibula with 
the exception of the lower fourth, and, for a little distance about the 
middle of the bone, overlap, the upper part of the brevis stretching 
upwards in front of the lower part of the longus. The origin of the 
longus is pierced by the external popliteal nerve. Intermuscular septa 
separate the two muscles from the extensor digitorum longus and 
peroneus tertius in front and the soleus and flexor hallucis longus behind. 
Above the ankle the muscles are continued into tendons which pass in 
company behind the external malleolus, then forwards under cover of the 
external annular ligament along the outer surface of the heel. The tendon 
of the brevis, which lies above the other, reaches the base of the fifth 
metatarsal, that of the longus is continued across the sole to the first 
metatarsal bone. A common synovial membrane invests both tendons 
behind the malleolus and under cover of the annular ligament, but splits 
into two where the tendons begin to separate. A second synovial 
membrane surrounds the tendon of the longus in the sole. The muscles 
are supplied by the musculo-cutaneous nerve. 
EXTERNAL REGION OF THE LEG. 
The peroneus longus arises from the external surface of the head and 
the upper two-thirds of the outer surface of the shaft of the fibula; 
additional fibres spring from the intermuscular septa in front and behind, 
and from the external tuberosity of the tibia above. In the lower part 
of the leg it narrows to a tendon which passes behind the outer malleolus 
and forwards, first under cover of the external annular ligament, then along 
the outer surface of the calcaneum to the cuboid, in the groove of which 
bone it sweeps forwards and inwards into the sole. It is inserted into 
the tuberosity of the first metatarsal bone and the adjoining part of the 
internal cuneiform bone. In crossing the sole the tendon lies in contact 
with the bones, and is covered by a fibrous investment from the long 
plantar ligament. A sesamoid bone is sometimes found in the portion 
of the tendon which lies in the groove of the cuboid. 
The peroneus brevis arises from the middle two-fourths of the outer 
surface of the shaft of the fibula; additional fibres spring from the intermus- 
cular septa in front and behind. Above the ankle it narrows to a tendon 
which passes behind the external malleolus, and is continued forwards, 
along the outer surface of the calcaneum and cuboid to the tuberosity 
of the fifth metatarsal bone, where it is inserted. Frequently the tendon 
sends a slip to the extensor tendon of the little toe. In passing round 
the malleolus the tendon lies in front of and afterwards above that of 
the peroneus longus. 
Variations of the muscles of the external region of the leg. The 
two peronei are sometimes partly united with one another, An additional 
muscle, the peroneus quartus, is sometimes found springing from the MUSCLES OF LOWEE LIMB 
307 
fibula, behind the peroneus brevis, and passing to insertion on the 
calcaneum or cuboid. Another accessory slip, the peroneus quinti digiti, 
Fig. 257.—Outer Region of Leg. (L. Testut.) 
occasionally found passing from the fibula, below the peroneus brevis, 
the extensor tendon of the little toe; when present it takes the place 
°f the slip detached from the tendon of the peroneus brevis. 308 
THE MUSCLES. 
ANTERIOR REGION OP THE LEG. 
The muscles of the anterior region of the leg are the tibialis anticus, 
the extensor hallucis longus, the extensor cligitorum pedis longus, and 
the peroneus tertius ; but the last-mentioned is small, and is regarded as 
a portion of the extensor digitorum longus. In the upper fourth of the 
Tibialis posticus Tibia Fibula 
3, Flexor hallucis longus 
Flexor digitorum longus 
Peroneus brevis 
Internal malleolus. 
.External malleolus 
Peroneus longus 
Calcaneum 
Tibialis posticus 
Communicating slip) 
between tendons f 
.Peroneus longus 
Peroneus brevis 
Peroneus longus 
.Flexor digitorum longus 
Flexor hallucis longus. 
5, Flexor digitorum longus 
Fig. 258.—Insertions of Tendons in the Sole, semi-diagrammatic. (L. Testut.) 
leg the tibialis anticus, the most internal of the group, lies in contact 
with the extensor digitorum longus, their fibres being separated only by 
an intermuscular septum. Lower down, the extensor hallucis longus 
intervenes between them; but this muscle, smaller than those between 
which it is placed, is at first overlapped and concealed by them, and only 
becomes apparent on the surface, between their tendons, in the lower 
third of the leg. An intermuscular septum on the outer side of the group MUSCLES OF LOWEE LIMB. 
309 
separates the extensor digitorum longus and peroneus tertius from the 
peroneus longus and peroneus brevis. 
Above the ankle the different muscles of the group narrow to tendons, 
that of the long extensor of the toes subdividing into four, which pass 
behind the anterior annular ligament to reach the dorsum of the foot. 
In passing behind the ligament the tendons maintain their relative 
positions to one another, and the two more internal are contained each 
in a special compartment, and those of the long extensor of the toes and 
peroneus tertius in a fibrous loop which forms the outer part of the 
ligament. The fibrous sheaths are lined by synovial membranes which 
are reflected upwards and downwards for a little distance upon the 
tendons. On the dorsum of the foot the tendons lie in a plane superficial 
to the short extensor of the toes; the tibialis anticus and peroneus tertius 
pass to the inner and outer sides respectively, the others are continued 
forwards to the extremities of the toes. 
The anterior tibial artery is covered by the fleshy part of the tibialis 
anticus, and is crossed in the vicinity of the ankle by the tendon of the 
extensor hallucis longus. The anterior tibial nerve, which accompanies 
the artery, supplies all the muscles of the group. 
The tibialis anticus (tibialis anterior) arises from the upper two-thirds 
of the outer surface of the shaft of the tibia extending to the base of the 
outer tuberosity, and from a narrow area of the adjoining interosseous mem- 
brane ; fibres also spring from the investing fascia and the short septum on 
the outer side of the muscle. The area of origin from the bone is much 
broader above than below, where it narrows to a line close to the inter- 
osseous membrane. It is inserted into the anterior and inner part of the 
base of the internal cuneiform bone and the adjoining ridge of the first 
uietatarsal bone. Its tendon becomes free from muscular fibres in the 
lower third of the leg; near its insertion it is somewhat expanded, and 
a small bursa lies beneath it. 
The extensor hallucis longus, a very narrow muscle, is somewhat 
obliquely placed at its origin. It springs from the middle third of the 
anterior portion of the inner surface of the fibula and the adjacent inter- 
osseous membrane, and below in the upper part of the lower third of the 
leg from the interosseous membrane alone. Its tendon forms on its anterior 
margin, and becomes free about the level of the ankle. It is inserted after 
giving off lateral expansions which cover the first metatarso phalangeal joint 
into the dorsal surface of the terminal phalanx of the great toe at its base. 
The extensor digitorum pedis longus has an exceedingly narrow origin 
which extends along the upper two-thirds of the anterior portion of the 
mner surface of the fibula, and reaches upwards in front of the head of 
Ihe bone to the external tuberosity of the tibia; in addition, many of its 
fibres spring from the intermuscular septum on its outer side, and a few 
fr°m the short septum on its inner side; others spring from the upper 
part of the interosseous membrane. The tendon forms on the anterior 310 
THE MUSCLES. 
edge of the muscle, becomes free above the ankle, and almost immediately 
divides into four portions, which proceed towards the four outer toes. 
Each tendon, on reaching the dorsum of the first phalanx, spreads after 
the manner of the tendons of insertion of the common extensor of the 
Gastrocnemius 
.Gastrocnemius 
Tibialis anticus. 
Extensor digitorum longus,.,. 
Peroneus longus... 
Soleus 
Plexor digitorum longus 
Extensor hallucis longus 
Peroneus brevis, 
Peroneus longus 
, Imier'surface of tibia 
Peroneus tertius 
Extensor digitorum longus 
Extensor digitorum brevisi 
Peroneus tertius 
.Tibialis anticus 
Extensor hallucis longus 
Pig. 259.—Anterior Region of Leg. (L. Testut.) 
fingers into an expansion from which three slips are continued, the 
median to the base of the second phalanx, the two lateral, after re- 
uniting, to the base of the third. The tendinous expansions are joined 
by the tendons of the lumbricales and interosseous muscles, and those 
of the three inner of the toes into which the muscle is inserted by 
the tendons of the short extensor muscle. MUSCLES OF LOWER LIMB. 
311 
The peroneus tertius, taking origin in the upper part of the lower 
third of the leg, springs from the anterior portion of the inner surface 
of the fibula, the adjacent interosseous membrane, and the intermuscular 
septum on its outer side. Its tendon, broadening near its extremity, is 
inserted into the upper surface of the base of the fifth metatarsal bone 
and gives a slip to the base of the fourth. 
Variations of the muscles of the anterior region of the leg. The 
peroneus tertius is often wanting. In connection with the others additional 
slips of insertion are frequently found. The tibialis anticus may be partly 
inserted into the fascia of the dorsum of the foot, the synovial mem- 
brane of the ankle, or the neck of the astragalus. The extensor hallucis 
longus occasionally detaches a tendinous slip to the first metatarsal bone, 
and a small accessory muscle, an extensor primi internodii hallucis has 
been observed. The tendons of the extensor digitorum longus occasionally 
detach slips to the corresponding metatarsal bones. 
POSTERIOR REGION OF THE LEG. 
The muscles of this region are arranged in two groups, superficial and 
deep, between which the posterior tibial artery and nerve descend towards 
the foot. 
The superficial group is formed by the gastrocnemius, soleus, and 
plantaris, all of which are inserted into the basal portion of the os calcis. 
The gastrocnemius and soleus, large muscles, the first taking origin above 
and the other below the knee-joint, descend in company, the one behind 
the other, and together form the prominence of the calf of the leg. Their 
tendons of insertion are incorporated together to form the tendo Achillis, 
The plantaris, a small muscular belly with a long slender tendon, lies 
between the other two. 
Another muscle, the popliteus, although, from its position in front of 
the vessels and nerves, entitled to be ranked with the deep group, is 
Riore conveniently treated along with those of the superficial group. It 
is small and confined to the upper part of the leg. 
The internal popliteal nerve supplies the gastrocnemius, plantaris, and 
popliteus muscles. The soleus is partly supplied by the internal popliteal 
and partly by the posterior tibial nerve. 
The gastrocnemius is formed of two fleshy bellies which spring separ- 
ately from the back of the femur, and are united about the middle of the 
eg in a common tendon. The inner head, tendinous internally, fleshy 
externally, takes origin along an oblique line, of about an inch in length, 
ndiich lies close above the posterior extremity of the articular surface of 
the internal condyle. The outer head, tendinous, arises along a somewhat 
shorter line at the posterior margin of the outer surface of the external 
condyle, extending almost vertically upwards from a depression above the 
Popliteal groove. The fleshy bellies on the posterior surface of which THE MUSCLES. 
the tendons of origin are prolonged for a little distance approach one 
another in the upper third of the leg, limiting the popliteal space, and 
Fig. 260. Posterior Region of Leo, superficial layer. (L. Testut.) 
their edges thereafter, although separated superficially by a groove, are 
united more deeply by a tendinous raphe. The tendon of insertion, thin 
and membranous, clothes the greater part of the deep surface, and after MUSCLES OF LOWER LIMB. 
313 
receiving all the muscular fibres becomes incorporated with the tendon of 
the soleus to form the tendo Achillis. The inner belly is broader and 
extends a little further down than the outer. Underneath the inner head 
lies a bursa which communicates frequently with the cavity of the joint, and 
Fig. 261.—Posterioe Region of the Leg (the gastrocnemius divided). (L. Testut.) 
between it and the semimembranosus tendon another bursa is usually found. 
The outer head frequently contains a sesamoid bone. 
The soleus, not so conspicuously divided into lateral portions as the 
gastrocnemius, forms a large but short-fibred muscle. It is attached above, 
externally to the posterior surface of the head and upper third of the 314 
THE MUSCLES. 
shaft of the fibula, and internally to the popliteal line, and below it to 
the inner margin of the tibia for two or three inches; between the upper 
ends of the bony attachments fibres, intermediate in position, spring from 
a fibrous arch which crosses the large vessels and nerve. The muscular 
belly descends on the tendo Achillis to within a short distance of 
the heel. 
The fibres of the muscle which are short and oblique pass between 
three tendinous structures—one a median vertical raphe, the other two 
broad sheets of longitudinally running fibres, one almost entirely 
concealed in the substance of the muscle with its edges appearing on 
the deep surface, the other covering the superficial surface. 
The median raphe is continued up from the tendo Achillis ; 
it is strong and complete below, but above it narrows and 
is confined to the deep part of the thickness of the muscle. 
The posterior broad or superficial tendon is likewise con- 
tinued from the tendo Achillis, and becomes finer near the 
upper end of the muscle. The anterior broad or concealed 
tendon is stronger above than below, and splits into two as 
it descends into the region where the median raphe is com- 
plete ; from both its surfaces muscular fibres spring, so that 
it is to a large extent hidden within the muscular substance. 
Those from its posterior surface, forming the great mass, 
and the edges of the muscle pass chiefly into the posterior 
broad tendon; those from its anterior surface, much fewer 
in number, and not occupying the whole extent of the 
surface, but leaving a marginal area bare on each side, 
are directed downwards and forwards towards the central raphe. 
The tendo Achillis (tendo calcaneus), the strongest tendon in the body, 
extends through the lower half of the leg. It is formed by the broad 
but thin tendon of the gastrocnemius becoming incorporated with the 
posterior surface of the soleus tendon. It becomes narrower and thicker 
as it descends, and then, expanding slightly, is inserted into the lower 
part of the posterior surface of the os calcis. A bursa intervenes 
between the upper part of the surface and the tendon. 
The plantaris, a small muscular belly of about three inches in length, 
continued into a long slender tendon, is, at its origin, almost completely 
covered by the outer head of the gastrocnemius. It springs by fleshy 
fibres from the lower extremity of the external supracondylar ridge of 
the femur, and from the adjacent portion of the capsular ligament of 
the knee. The tendon, passing downwards and inwards in front of 
the gastrocnemius, reaches the inner margin of the tendo Achillis, 
and in close contact therewith is inserted into the basal portion of the 
os calcis. 
Fig. 262.—The 
Soleus, deep sur- 
face. 
The popliteus, small, thin, and triangular, is closely applied to the 
bones and ligaments at the back of the knee. It springs from the femur MUSCLES OF LOWER LIMB. 
within the capsule of the joint and under cover of the external lateral 
ligament, from the anterior extremity and upper margin of the popliteal 
groove, by a narrow tendon which, descending with an inward direction, 
grooves the external semilunar cartilage and pierces the posterior ligament. 
The muscular fibres, reinforced by a few from the posterior part of the 
capsule, spread out and are inserted into the whole of the triangular 
area of the shaft of the tibia above the popliteal line. 
The deep group. The muscles of the deep group, with the exception 
of the popliteus, which has been already described, are the tibialis 
posticus, the flexor hallucis longus, and the flexor digitorum pedis longus. 
They are continued by tendons which pass round the internal malleolus, 
under cover of the internal annular ligament, into the sole. At the 
origin the tibialis posticus lies between the other two, springing from the 
tibia and fibula and the interosseous membrane ; the flexor hallucis longus 
on the outer side springs from the fibula, and the flexor digitorum 
longus on the inner side takes origin chiefly from the tibia. A horizon- 
tally stretched intermuscular septum separates the muscles of this group 
from the soleus and detaches partitions which separate the tibialis 
posticus from its neighbouring muscles, A vertical septum at the outer 
side intervenes between the flexor hallucis longus and the peroneus longus 
and brevis. The posterior tibial vessels lie upon the surface of the 
tibialis posticus, and the accompanying posterior tibial nerve supplies the 
muscles. 
A little distance above the ankle a change takes place in the relative 
position of the muscles. The tendon of the tibialis posticus passes for- 
wards and inwards in front of the flexor digitorum longus. In passing- 
round the internal malleolus, under cover of the internal annular liga- 
ment, the tendons are confined by septa in osteo-fibrous canals which 
are lined by synovial membrane; the tendon of the tibialis posticus is 
anterior in position, that of the flexor digitorum longus immediately 
behind it, while that of the flexor hallucis longus is the most posterior; 
the vessels and nerve lie between the two last-mentioned tendons, but 
in a plane slightly superficial to them. 
In the sole the tendons are covered by the superficial layer of muscles. 
That of the tibialis posticus, close to the bones, passes forwards on the 
inner side to the scaphoid. The tendon of the flexor hallucis longus is 
directed forwards to the great toe, on its way crossing above the tendon 
of the long flexor of the toes and detaching a slip to it. The tendon of 
the flexor longus digitorum, passing forwards and outwards, to be inserted 
into the four outer toes, receives from behind, about the middle of the 
foot, the insertion of the flexor accessorius, and divides immediately 
thereafter into four portions, from which, close to the point of division, 
the lumbricales muscles spring. 
The tibialis posticus (tibialis posterior) springs from the upper three- 
fourths of the shaft of the fibula, occupying at its origin the whole of 316 
THE MUSCLES. 
the posterior area of the inner surface, from the upper half of the 
outer part of the posterior surface of the tibia, and from the inter- 
osseous membrane. Fibres also take origin from the intermuscular 
Fig. 263. Posterior Region of Leg, deep group of muscles. (L. Testut.) 
septum on the surface of the muscle. The tendon forms on the inner 
border of the muscle and becomes free from muscular fibres a little above 
the ankle. It is inserted into the tuberosity of the scaphoid bone, but 
detaches slips to the internal cuneiform bone, the sustentaculum tali, MUSCLES OF LOWEE LIMB. 
and the ligaments of the sole. Near the insertion a sesamoid bone lies 
in the tendon. 
The flexor hallucis longus takes origin from the lower two-thirds of 
the posterior surface of the fibula; fibres also spring from the layer of 
deep fascia which covers the muscle. The tendon forms on the inner- 
edge of the muscle, becomes free at the level of the ankle, and in passing 
round the malleolus grooves the back of the astragalus, and the susten- 
taculum tali. On its way forwards in the sole it crosses above and 
detaches a slip to the tendon of the long flexor of the toes. It enters 
a fibrous sheath on the first phalanx of the great toe, and is finally 
inserted into the base of the second phalanx on its plantar surface. 
The flexor digitorum pedis longus arises from the inner part of the 
posterior surface of the tibia, and occupies at its origin a region corre- 
sponding to the middle two-fourths of the shaft; fibres also spring at its 
outer border from the intermuscular septum, which covers the tibialis 
posticus, and which, arching over the tendon of that muscle, is connected 
below with the interosseous membrane and the fibula. The tendon becomes 
free from muscular fibres at the upper border of the internal annular 
ligament; in passing forwards and outwards in the sole it is connected 
with that of the flexor longus hallucis, and receives the insertion of the 
flexor accessorius. Immediately thereafter it divides into four portions, 
which, after giving origin to the lumbricales, are continued to the four 
outer toes, where they are inserted into the terminal phalanges. Each 
tendon as it passes forwards in the toe pierces a tendon of the superficial 
flexor, and the tendons in each toe are surrounded by a fibrous and 
synovial sheath similar in all respects to that which in the finger 
surrounds the flexor tendons. 
The flexor accessorius is closely associated with the tendon of the 
flexor digitorum longus, and like it is covered by the superficial muscles 
of the sole. It arises from the lower part of the calcaneum by two 
heads, the inner broad and fleshy from the anterior tubercle and a portion 
of the area behind it, the outer narrow and tendinous from the base of 
the external tubercle. The muscular belly is inserted, about half-way 
forwards in the sole, into the outer margin and the upper surface of the 
tendon of the long flexor of the toes. 
The lumbricales, four fleshy slips, take origin from the tendons of the 
flexor digitorum longus, close to their point of separation. The most 
internal springs from the inner side of the tendon for the second toe, 
each of the others from the two tendons between which it is placed. 
They are inserted tendinously into the four outer toes, each tendon passing 
along the inner side and reaching the tendinous expansion on the dorsal 
surface of the first phalanx. 
Variations of the muscles of the posterior region of the leg. The 
plantaris is frequently absent. As a rare occurrence, absence of the gastroc- 
nemius has been noted. An accessory head of the gastrocnemius has been 318 
THE MUSCLES. 
found either on the inner or outer side arising from the fascia, the tendons 
round the joint, or the lower part of the femur; the soleus and plantaris 
in like manner occasionally receive additional slips of origin. The soleus 
has been found partially or wholly inserted separately into the calcaneum. 
In connection with the popliteus an additional slip is frequently noticed 
passing from the head of the fibula to the oblique line of the tibia (the 
peroneo-tibial muscle of Gruber). Among the deep group two small 
Fig. 264.—Second Layer of the Muscles of the Sole. (L. Testut.) 
occasional muscles have been described—a tensor of the capsule of the 
ankle-joint springing from the lower part of the tibia, and a peroneo- 
calcanean from the posterior surface of the external malleolus to the 
calcaneum. 
THE SOLE. 
The special muscles of the sole, along with the tendons of those of 
the deep group of the back of the leg and their associated muscles, form 
altogether four layers covered superficially, or on the plantar aspect, by MUSCLES OF LOWER LIMB. 
the plantar fascia. Two sets of vessels and nerves, the external and 
internal plantar, derived from the posterior tibial trunks which divide on 
entering the sole, pass forwards among the muscles supplying them and 
reaching the toes. 
The muscles of the first layer, three in number, from within outwards 
the abductor hallucis, the flexor digitorum brevis, and the abductor minimi 
digiti, occupy the whole length of the sole, and are intimately connected 
Fio. 265.—First Layer of the Muscles of the Sole. (L, Testut.) 
with the plantar fascia. Two vertical septa of fascia, one on each side 
of the central muscle, separate the muscles of this layer from one another; 
and between the abductor hallucis and the short flexor of the toes the 
internal plantar nerve and artery pass forwards. 
In the second layer are found the tendons of the long flexors of the 
toes and the associated muscles, the accessorius and lumbricales, all of 
which have been already described. Between this layer and the first the 320 
THE MUSCLES. 
external plantar artery and nerve pass forwards and outwards as far as 
the base of the fifth metatarsal bone. 
The third layer is formed of short muscles specially connected with 
the great and small toes. They are confined to the anterior part of the 
foot. Those passing to the great toe, three in number, are in order from 
within outwards, the flexor hallucis brevis, the adductor hallucis, and the 
transversus pedis. At some little distance from these, underlying the 
fifth metatarsal bone, is the flexor minimi digiti brevis. 
Fig. 266.—Third Layer op the Muscles of the Sole; (L. Testut.) 
The interosseous muscles form the fourth layer. They occupy the 
spaces between the metatarsal bones and are seven in number, as in the 
hand, four dorsal and three plantar in position. Between the interosseous 
muscles and the short muscles of the great toe, the external plantar 
artery and the accompanying deep branch of nerve bend inwards in the 
sole, passing from the base of the fifth metatarsal bone towards the first 
interosseous space. Further back in the sole the tendons of the peroneus 
longus and tibialis posticus lie close to the bones. 
The supply of the muscles of the foot is divided between the external MUSCLES OF LOWER LIMB. 
321 
and internal plantar nerves. The internal plantar supplies the flexor 
digitorum brevis, the abductor hallucis, the flexor hallucis brevis, and the 
innermost lumbricalis. All the other muscles in the sole are supplied by 
the external plantar. 
The flexor brevis digitorum occupies the middle of the sole. It is 
very narrow behind, but broadens considerably as it passes forwards. It 
springs from the internal calcaneal tubercle, and receives many fibres 
from the plantar fascia, which covers it and detaches a septum on either 
side. Opposite the bases of the metatarsal bones it divides into two 
portions, each of which almost immediately gives origin to two tendons. 
The tendons pass to the four outer toes. Each, after entering a sheath, 
is perforated by a tendon of the long flexor, and is inserted into the 
second phalanx, the whole arrangement being similar to that already 
described in connection with the flexor muscles of the fingers. 
The abductor hallucis springs from the inner calcaneal tubercle, the 
internal annular ligament, and the investing plantar fascia, and receives 
in addition, in most cases, fibres from the scaphoid and internal cuneiform 
bones. Becoming tendinous behind the ball of the great toe, it is 
inserted in conjunction with the inner portion of the flexor brevis 
hallucis into the tuberosity at the inner side of the base of the 
first phalanx. 
The flexor hallucis brevis springs from the calcaneo-cuboid and naviculo- 
cuneiform ligaments in close connection with the insertion of the tibialis 
posticus. The muscular belly divides into two portions, each of which is 
continued forwards into a tendon. The inner tendon conjoined with that 
of the abductor is inserted into the internal basal tuberosity of the first 
phalanx; the outer tendon, along with the adductor and transversus pedis, 
into the external tuberosity. A large sesamoid bone lies in each tendon 
of insertion. 
The adductor hallucis (adductor obliquus) arises from the long plantar 
ligament and the basal extremities of the second and third metatarsal 
bones. It is inserted with the outer portion of the flexor brevis. 
The transversus pedis (adductor transversus), very small, passing almost 
directly inwards, and placed close to the bones, springs by slips from the 
metatarso-phalangeal ligaments of the second, third, and fourth toes. It 
is inserted with the adductor hallucis. The muscle is covered by the 
flexor tendons, and crossed superficially by the digital nerves, but the 
digital arteries of the second and third interspaces pass forward on its 
dorsal surface. 
The abductor minimi digiti, very broad behind, arises from the under 
surface of the os calcis, immediately in front of the external and internal 
tubercles, and from the investing plantar fascia. Becoming narrow and 
tendinous as it passes forwards, it is inserted into the outer side of the 
base of the first phalanx of the fifth toe. 
The flexor minimi digiti brevis, a small fleshy slip, arises from the 322 
THE MUSCLES. 
under surface of the base of the fifth metatarsal bone, and the sheath of 
the peroneus longus. It is inserted with the abductor minimi digiti. 
The interosseous muscles. The arrangement of these muscles is very 
similar to that of the corresponding muscles in the hand, but differs 
from it in this respect that in the foot the muscles are grouped round 
the second digit instead of the third, as in the hand. Springing from 
the metatarsal bones they are inserted by tendons, which cross the 
metatarso-phalangeal joints, partly into the basal portions of the phalanges 
of the first row, partly into the expansions of the extensor tendons. 
Fig. 267.—The Dorsal Interosseous Muscles. (L. Testut.) 
The four dorsal muscles. Each springs from the sides of both the bones 
between which it is placed; but while in most cases the origins extend 
along nearly the whole length of the metatarsal bones, the inner head of 
the first muscle is connected with the base only of the first metatarsal 
bone. The first two are inserted into the second digit. The third 
and fourth belong to the outer sides respectively of the third and 
fourth digits. 
The three plantar muscles act cn the three outer toes, and each is 
placed on the inner side of the digit to which it belongs. Each arises 
from but one metatarsal bone, that of the digit upon which the muscle 
acts, but all derive additional fibres from the sheath of the peroneus 
longus muscle. MUSCLES OF LOWER LIMB. 
323 
DORSUM OF THE FOOT. 
In addition to the tendons of the long muscles already described, one 
special muscle is found upon the dorsum of the foot. 
The extensor brevis digitorum takes origin from the anterior part of the 
upper and outer surfaces of the os calcis, and from the anterior annular 
ligament. It divides into four tendons, which pass to the four inner toes. 
The tendon belonging to the great toe is inserted into the dorsal surface 
of the first phalanx. Those of the second, third, and fourth digits join 
from the outer side the corresponding tendons of the long extensor. The 
Fio. 268.—The Plantar Interosseous Muscles. (L. Testut.) 
muscle is crossed by the tendons of the long extensor and peroneus 
tertius. Its innermost tendon crosses the dorsal artery of the foot. It 
is supplied by the external branch of the anterior tibial nerve. 
Actions of the Muscles of the Leg and Foot. 
The popliteus acts upon the knee-joint alone. In full extension of the 
joint the muscle acts as a rotator outwards of the femur, or inwards of 
the tibia, its tendon occupying a groove which crosses the lower lip of 
the popliteal groove of the femur. In this action the muscle assists to 
initiate flexion by undoing the lock between the articular surfaces of the 
joint. In addition, it is probable, on the other hand, as was held by 
doodsir, and as may be observed during manipulation of the joint in the 
‘dead body, that in the later stages of flexion the muscular fibres are again 
fully stretched, owing to the upward rotation of the anterior part of the 324 
THE MUSCLES. 
external condyle during the movement. Acting in this position the muscle 
would assist in the initial stages of extension, its tendon occupying the 
popliteal groove of the femur.1 
Fig. 269.—Muscle and Tendons of the Dorsum of the Foot. (L. Testut.) 
The gastrocnemius acts Upon both knee and ankle, producing flexion 
of the former or extension of the latter, according as the one or other 
extremity of the muscle is maintained in a fixed position. It under- 
goes no change of length in the passage from standing erect on tip-too 
to extreme flexion of the knee and flexion of the ankle-joint, and may 
be held as acting ligamentously in all ordinary movements of flexion 
and extension of the limb. The soleus acts upon the ankle alone, assisted 
1 Goodsir taught that this was the special action of the popliteus, and that it 
undid the inward twist given to the outer condyle of the femur in extreme flexion 
(page 193). I prepared for him, at his desire, a dissection of the leg of the cat, 
showing that in that animal the popliteus extended the flexed joint to a very con- 
siderable extent.—J. C. MUSCLES OF LOWER LIMB. 
325 
by the gastrocnemius, causing extension and raising the heel from the 
ground. On account of its great strength and the shortness and obliquity 
•of its fibres, the muscle serves the purpose of a strong elastic ligament 
behind the ankle-joint, and plays an important part in supporting the 
joint in the erect position of the body. The form of club-foot known 
■as talipes, equinus, in which the heel is raised arid the patient walks upon 
the toes, is due to the abnormal contraction of the muscles inserted by 
the tendo Achillis. 
The tibialis anticus and peroneus tertius flex the ankle; the former also 
■assists in inversion, the latter in eversion of the sole. The extensor 
digitorum longus and the extensor hallucis longus, after full extension 
of the digits, also take part in flexion of the ankle. Talipes calcaneus, 
in which the toes are extended and the ankle flexed, the patient walking 
upon the heel, is dependent on the muscles of the anterior region 
of the leg. The tibialis posticus inverts the sole and slightly extends 
the ankle. Talipes varus, in which the inner side of the foot is raised 
and the heel drawn up, is dependent on this muscle, with the frequent 
association of the tibialis anticus; the variety known as equino-varus, in 
which the heel is still further raised, depends upon the implication of the 
muscles inserted by the tendo Achillis. The peroneus longus and brevis 
extend the ankle and evert the sole. Talipes valgus, in which the outer side 
of the foot is raised, is dependent on these muscles, and when those of the 
anterior region are likewise involved, the variety calcaneo-valgus is jmoduced. 
The flexor digitorum longus, after full flexion of the digits, or when the toes 
are fixed, assists in extension of the ankle; its action upon the toes is 
brought into the line of the foot by the flexor accessorius. The action 
of the other muscles of the foot is sufficiently indicated by the names 
which are applied to them. 
FASCIA OF THE LEG AND FOOT. 
The deep fascia of the leg, strong and resistant, is continuous over 
the popliteal space and on the inner side of the limb with the fascia 
lata. In the upper part of the leg it is strengthened by fibres from the 
tendons of the biceps, sartorius, gracilis, semitendinosus, and semimem- 
branosus muscles. It is firmly fixed over the prominent parts of the 
bones, being thus attached to the head of the fibula, the external 
tuberosity of the tibia, the anterior border, the whole inner surface, and 
the posterior border of that bone, and the internal and external malleoli. 
From its deep surface fibrous septa pass to the anterior and external 
borders of the fibula, separating the peroneus longus and brevis muscles 
from those in front and behind. Among the anterior muscles a short 
vertical septum, confined to the upper part of the leg, passes between 
fhe tibialis anticus and extensor digitorum longus; and among the 
posterior muscles a transverse septum, attached to the outer border of 326 
THE MUSCLES. 
the fibula and the posterior border of the tibia, separates the deep from 
the superficial group, and covers the vessels and nerve. The fascia 
affords attachment on its deep surface and its septa to many of the 
muscles of the leg. 
The anterior annular ligament is formed by a thickening of the fascia 
at the level of the ankle-joint. It is shaped like the letter Y laid upon 
its side, the outer part representing the base of the letter, the inner 
portions the limbs. The outer part of the ligament forms a strong loop 
through which, wrapped in a common synovial sheath, the tendons of 
the long extensor of the toes and that of the peroneus tertius pass. The 
loop is attached externally to the upper surface of the os calcis, in front 
of the interosseous ligament, but some of its fibres are continuous with 
the lower part of the external annular ligament. From the inner 
extremity of the loop the limbs of the Y pass inwards. The upper, which 
is the stronger, is attached to the internal malleolus; the lower, passing 
over the border of the dorsum of the foot, becomes continuous with the 
lower part of the internal annular ligament. The tendons of the extensor 
of the great toe and the tibialis anticus pass, each surrounded by its 
own synovial sheath, in separate compartments, the former behind both 
bands, the latter through the upper and behind the lower. The anterior 
tibial artery and nerve sometimes accompany the tendon of the extensor 
of the great toe, but occasionally occupy a special fibrous and synovial 
sheath. A somewhat thickened band of fascia in the lower part of the 
leg, lying immediately above the anterior annular ligament, is sometimes 
described along with it. The synovial sheath of the tibialis anticus 
extends upwards behind this band. 
The internal annular ligament is a thickened band of fascia, with ill- 
defined edges, stretching downwards and backwards from the internal 
malleolus to the inner margin of the tuberosity of the os calcis. Its 
lower part is continuous with the lower band of the anterior annular 
ligament, and gives origin to a large portion of the abductor hallucis 
muscle. On its deep surface pass, in separate sheaths, each lined by 
synovial membrane, the tendons of the tibialis posticus, flexor digitorum 
longus, and flexor hallucis longus. The sheaths of the two first men- 
tioned lie close together, and occasionally communicate; the posterior 
tibial vessels and nerve occupy a sheath between the second and third, 
but lie in a plane slightly more superficial than that of the tendons. 
The external annular ligament, from the point of the external malleolus,, 
extends downwards and backwards to the lower portion of the outer 
surface of the calcaneum. The ligament covers the tendons of the peroneus 
longus and brevis, which, as they pass forwards on its deep surface, occupy 
a common synovial sheath. Continuous with the anterior margin of the 
ligament and with the outer extremity of the anterior annular ligament a. 
couple of fibrous loops surround and separate from one another the two 
tendons. MUSCLES OF LOWEE LIMB, 
327 
Deep fascia of the sole. As in the hand, two layers of fascia are 
found—one, the plantar aponeurosis, superficial to the muscles; the other 
more deeply placed, covering and investing the interosseous muscles. 
The plantar aponeurosis is divided into three regions—a central and 
two lateral, and along the lines of union between these intermuscular 
septa pass deeply into the sole. It is connected with the skin by 
numerous fibrous bands, and is perforated in many places for the passage 
of cutaneous vessels and nerves. The central portion, triangular in outline, 
is attached behind to the internal tubercle of the calcaneum. It is ex- 
ceedingly strong and dense, and affords origin to many of the fibres of the 
superficial flexor of the toes. Posteriorly the fibres of the aponeurosis are 
parallel and directed forwards, but in the anterior part of the foot trans- 
verse fibres are added, and the whole structure spreading out becomes 
somewhat thinner. A little behind the digital clefts it divides into five 
slips which, passing towards the toes, divide and sink deeply to join the 
metatarso-phalangeal and vaginal ligaments, the whole arrangement being 
similar to that of the central portion of the palmar aponeurosis, with the 
exception that in the foot there are five digital slips, while in the hand 
there are only four. A superficial transverse ligament binds the slips 
together, and offsets are detached to the skin. The external lateral portion 
forms an exceedingly strong band stretched between the external calcaneal 
tubercle and the tuberosity of the fifth metatarsal bone. It invests the 
abductor minimi digiti, and is continuous round the border of the foot 
with the fascia of the dorsum. The internal lateral portion, thin and un- 
important, is continuous with the internal annular ligament of the ankle. 
It invests the abductor hallucis, and is continuous round the margin of 
the sole with the fascia of the dorsum. The intermuscular septa separate 
the internal plantar vessels and nerves and the abductor and short flexor 
muscles of the great toe on the one hand, and the abductor minimi digiti 
on the other hand, from the central space of the foot which is occupied 
by the short flexor of the toes, the tendons of the long flexor with the 
lumbricales and accessorius, the tendon of the long flexor of the great 
foe, and the external plantar vessels and nerves. The septa are well 
marked behind, but much weaker in front. 
The interosseous fascia is weak and unimportant, but its anterior edge 
is strengthened into a firm band, the transverse metatarsal ligament, which 
binds together the heads of the five metatarsal bones. 
Deep fascia of the dorsum of the foot. The fascia of the dorsum is 
relatively unimportant. A thin layer, continued from the anterior annular 
ligament, surrounds the tendons and covers the short extensor muscle; 
more deeply, a thin layer covers the interosseous muscles and the 
metatarsal bones. 328 
THE MUSCLES. 
MUSCLES AND FASCIA OF THE HEAD AND NECK. 
The superficial fascia of the head and neck presents little of import- 
ance. It forms a somewhat dense layer in the region of the scalp and 
the nape of the neck. In the lateral part of the neck the platysma 
myoides, a thin muscular sheet, lies in its substance. 
The platysma myoides is a thin subcutaneous muscular sheet extend- 
ing over the side and front of the- neck. The fibres spring from the fascia 
over the clavicle and pass upwards and inwards towards the lower jaw 
into the fascia over which most of them are inserted, between the attach- 
ment of the masseter and the symphysis. A few of the most internal 
cross the middle line, those of the rigfit side being generally in front. 
The most posterior fibres sweep over the inferior maxilla and reach the 
angle of the mouth, where they become blended with other muscles. The 
size of the muscle is very variable, and it frequently receives accessory 
slips which have been noted as springing in different cases from the upper 
costal cartilages, the thyroid cartilage, the mastoid process, and the cartilage 
of the ear. On the deep surface of the muscle lie the trunks of the 
superficial veins and nerves of the neck. It is supplied by the infra- 
maxillary branch of the facial nerve, which effects a junction with the 
superficial cervical of the cervical plexus. It raises the skin of the neck 
and breast, draws down the angle of the mouth, and can also depress the 
lower jaw; it has been conjectured that in its contraction, by drawing 
apart the walls of the external jugular vein, it may assist, in laboured 
respiration, the return of the venous blood from the head. The platsyma 
is the representative in man of a subcutaneous muscular sheet much more 
largely developed in many of the lower animals. 
SUPERFICIAL MUSCLES OF THE HEAD. 
A number of small muscles which act upon the soft parts of the face 
and scalp are included in this group. For convenience of description they 
are usually subdivided into smaller groups according to their more im- 
mediate action upon the scalp, ear, eyebrows and eyelids, nose, and mouth; 
but it will be seen that many act at the same time on more than one of the 
parts named. In the expression of emotions, in which these muscles play 
an important part, muscles which belong to the different subsidiary groups 
are often called into action at once. For a detailed scientific examina- 
tion of the action of the facial muscles in this respect the student is 
referred to the work of Duchenne (Paris, 1862), as the subject is too 
large to be treated of in a manual of this scope. As to the simple action 
of each individual muscle it will, in the great majority of cases, be 
recognized as evident from the description, and need not entail a separate 
statement. All the muscles of this group are supplied by the seventh 
or facial nerve. MUSCLES AND FASCIA OF HEAD AND NECK. 
The epicranial aponeurosis is a thin tendinous expansion which covers 
the greater part of the surface of the cranium, and is closely connected 
with the two thin muscular sheets which on each side constitute the 
occipito-frontalis muscle. Anteriorly it is attached to the frontal portions 
Attrahens auriculam 
Attollens auriculam | Masseter Zygomaticus major 
Fig. 270.—Superficial Muscles of the Head. (L. Testut.) 
of the muscles, posteriorly to the superior curved line of the occipital bone 
and to the occipital portions of the muscles. At the sides it degenerates 
into a thin tissue which overlies the temporal aponeurosis and gives origin 
to two of the auricular muscles. It is closely connected with the skin by 
firm tissue, containing fat in its meshes, and it lies upon the epicranial 330 
THE MUSCLES. 
periosteum, being separated only by a delicate tissue devoid of fat and' 
allowing free gliding movement. 
The occipito-frontalis muscle is formed of two portions, an anterior 
and posterior, connected with one another by the intervening epicranial 
aponeurosis. 
The occipital portion (occipitalis) arises from the outer two-thirds of 
the superior curved line of the occipital bone, and occasionally to a small 
extent from the adjoining portion of the temporal bone. Its fibres, between 
one and two inches in length, pass into the epicranial aponeurosis. 
The frontal portion (frontalis), larger and paler than the occipitalis,, 
rises in a convex line from the epicranial aponeurosis some distance in 
front of the coronal suture. The fibres terminate in the subcutaneous tissue 
of the root of the nose and of the eyebrows. The muscles of opposite 
sides converge as they descend, and finally come into contact with one 
another. By the action of these muscles the scalp is drawn forwards and 
backwards, the eyebrows elevated, and the skin of the forehead thrown 
into transverse lines. In most cases they are only partially under the 
control of the will. They present frequent variations in the extent of 
their development. 
The attollens auriculam (auricularis superior), a thin fan-shaped sheet 
of fibres, rises from the lateral portion of the epicranial aponeurosis. It 
is inserted into the upper part of the auricle in the region of the anterior 
part of the helix and antihelix. 
The attrahens auriculam (auricularis anterior), a small thin bundle 
hardly separate from the anterior edge of the attollens, passes from the 
epicranial aponeurosis to the auricle in the region of the anterior part of 
the helix. 
The retrahens auriculam (auricularis posterior) consists of two or three 
small bundles of fibres passing from the mastoid process to the auricle in 
the region of the posterior part of the concha. 
In most cases the auricular muscles are not under the direct control 
of the will. 
The orbicularis palpebrarum is a thin sheet of muscular fibres covering 
the surface of and surrounding the eyelids. The central or palpebral 
portion takes origin from the tendo palpebrarum or internal tarsal liga- 
ment, a narrow band about one-sixth of an inch in length, springing from 
the nasal process of the superior maxilla, and extending outwards in front 
of the lachrymal groove. The fibres, which are pale and thin, lie upon 
the surface of the tarsal membranes in the lids, and are connected exter- 
nally with the external tarsal ligament, a less defined band than the internal, 
attached to the malar bone. 
The peripheral portion of the muscle, much broader than the central 
and formed of coarser bundles of fibres, is variable in size and largely 
blended at its margins with other muscles. It springs from the basal 
portion of the internal tarsal ligament, the internal orbital process of the MUSCLES AND FASCIA OF HEAD AND NECK. 
frontal, and the nasal process of the superior maxillary bone. The fibres 
form a set of loops between the upper and lower attachments. 
The tensor tarsi, or muscle of Horner, is a deep slip of the orbicularis, 
lying behind the lachrymal sac. It springs from the ridge of the lach- 
Temporal muscle Temporal ridge 
Fig. 271.—The Deeper Muscles of the Heau. (L. Testut.) 
rymal bone, and passes outwards to the marginal bundles of the palpebral 
portion of the muscle, dividing into two slips as it goes. 
The corrugator supercilii. From the inner end of the superciliary 
ridge, and from the nasal process of the superior maxilla, a number of 
fibres spread upwards and outwards. They are closely associated with 
the frontalis muscle, on the deep surface of which they can be dis- THE MUSCLES. 
played when it is reflected with the skin. The upper and inner fibres 
are directed towards the frontal eminence; the lower and outer fibres 
pass outwards to the middle of the margin of the orbit. 
The orbicularis closes the lids, draws down and smooths the skin of 
the forehead, and elevates that of the cheek. The palpebral portion, while 
closing the lids, probably presses against the wall of the lachrymal sac and 
canaliculi, causing the tears to enter when pressure ceases. The tensor 
tarsi assists in the compression of the sac and forces the tears along the 
duct. The whole set of fibres described as corrugator supercilii draws 
the eyebrows and the skin of the region beneath the frontal eminence 
downwards and inwards. When the corrugator and frontalis act together 
rectangular farrows are produced, the inner portion of the eyebrow is 
raised while the outer portion is depressed, and the transverse furrows 
of the outer part of the forehead which the occipitalis acting alone would 
produce are obliterated. 
The compressor naris, thin and triangular, arises under cover of the 
■elevator of the upper lip, from the superior maxillary bone between the 
canine fossa and the nasal margin. It spreads over the bridge of the nose 
into a subcutaneous aponeurosis common to it and its fellow of the oppo- 
site side. 
The pyramidalis nasi consists of a few fibres prolonged downwards 
from the inner part of the frontalis, to terminate in the aponeurotic ex- 
pansion of the compressor naris. 
The levator labii superioris alaeque nasi, pointed at its origin and 
broadening below, springs from the nasal process of the superior maxilla, 
and is partly inserted into the ala of the nose, and partly blended with the 
orbicular muscle of the lips. In its descent it crosses the compressor naris. 
The depressor alae nasi is a small irregular bundle of fibres closely 
connected with the compressor naris, passing from the incisor fossa of the 
superior maxilla and the skin of the lip, partly to the ala and partly to 
the septum of the nose. 
The dilatatores naris, anterior and posterior, are two small indistinct 
slips passing from the cartilage of the nose to the skin at the lateral 
margin of the nostril. 
Muscles of the lips. A number of muscles radiate towards the margins 
•of the mouth, where their fibres becoming blended form an elliptical sheet, 
the orbicularis oris, which surrounds the aperture. 
The levator labii superioris, four-sided in outline, arises immediately 
below the margin of the orbit and above the infra-orbital foramen. Its 
fibres, passing among those of the orbicularis oris, are inserted into the 
skin of the upper lip. 
The zygomaticus minor, a small variable slip, passes from the anterior 
part of the malar bone to the skin of the lip. At its upper end it is 
closely associated with the orbicularis muscle of the eyelids, at its lower 
with the elevator of the upper lip. MUSCLES AND FASCIA OF HEAD AND NECK. 
The zygomaticus major springs from the outer part of the malar bone. 
Below it blends with the orbicularis, and is inserted into the skin at the 
angle of the mouth. 
The levator anguli oris arises under cover of the elevator of the upper 
lip, from the canine fossa of the superior maxilla. It passes downwards 
to the angle of the mouth, its fibres being partly attached to the skin 
and partly continued into the lower part of the orbicularis. 
The risorius of Santorini consists of a number of thin scattered bundles 
of fibres from the fascia over the parotid gland and the angle of the jaw, 
which reach the skin at the angle of the mouth. It is a detached upper 
portion of the platysma myoides. By its action it draws the angle of 
the mouth outwards and even a little downwards; hence it does not come 
into play in laughter, as its name would imply, but rather in grinning. 
The depressor anguli oris (triangularis menti) arises from the lower 
border of the inferior maxilla, between the mental foramen and the attach- 
ment of the masseter. Narrowing, it passes to the angle of the mouth, 
its fibres being partly attached to the skin, and partly continued into 
the upper part of the orbicularis. 
The depressor labii inferioris (quaclratus menti) arises from the lower 
jaw, along a line passing from below the mental foramen nearly to the 
symphysis. Its fibres, passing among those of the orbicularis, are inserted 
into the skin of the lower lip. A quantity of fatty tissue is interspersed 
among the fibres of the muscle. 
The levator menti (miisculus superbus) springing compactly from the 
incisor fossa of the lower jaw, spreads downwards and forwards to be 
inserted into the skin of the chin, its inner fibres decussating with those 
of its fellow of the opposite side. 
The buccinator arises behind from the pterygo-maxillary ligament, and 
by its margins from the alveolar ridges of the maxillary bones opposite 
the molar teeth. Becoming narrower and thicker as it passes forwards, 
it reaches the angle of the mouth and is continued into the orbicularis of 
both lips, the central fibres decussating with one another, the marginal 
ones being continued onwards without decussation. It is pierced oppo- 
site the second molar tooth of the upper jaw by the duct of the parotid 
gland (Stenson’s duct). 
The musculi incisivi, superior and inferior, are deep accessory slips of 
the orbicularis oris. The superior arises from the incisor fossa of the 
superior maxilla, and from the nasal septum (naso-labialis), and passes out- 
wards to the angle of the mouth among the fibres of the orbicularis. 
The inferior, arising from the incisor fossa of the lower jaw, likewise 
passes outwards to the angle. 
The orbicularis oris appears as an elliptical muscle of a breadth 
nearly uniform all round, and corresponding to the depth of the free lip 
in the middle line. It is closely connected with the skin on the surface, 
and especially at the margin of the lips, but is separated from the mucous THE MUSCLES. 
membrane by the labial glands and the coronary arterial arches. The 
more superficial fibres are derived from the elevators and depressors of 
the angles of the mouth. Deeper than those are found the fibres of the 
buccinator muscles, and deepest of all lie those of the musculi incisivi. 
The bundle of fibres running in the margin of the lips is somewhat 
distinct from the rest of the muscle, and is derived from the buccinators. 
The fibres of the elevators and depressors of the lips pass obliquely amongst 
the transverse fibres to reach the skin, and, in addition to these, a special 
set of oblique fibres has been described as being peculiarly well developed 
in the child, passing between the mucous membrane and the skin near the 
margin of the lips. At the angle of the mouth the fibres of the 
major, the risorius, and the upper part of the platysma are partially 
blended with the orbicularis. 
The movements of the lips depend on the combined and antagonistic 
actions of the muscles which pass to the orbicularis. The aperture of the 
open mouth is widened by the action of the buccinators in combination 
with the elevator and depressor muscles of the lips. By the combined 
actions of the elevators and depressors of the angles of the mouth the 
oral aperture is narrowed. The buccinators draw outwards the angles 
and press the lips against the teeth, and in this way play an important 
part in the process of mastication. When the aperture of the lips is 
narrowed by the other muscles, the graduated contraction of the buccinators 
governs the expulsion of air from the buccal cavity. 
THE MUSCLES AND FASCIA OF THE ORBIT. 
The cavity of the orbit contains the globe of the eye, which is placed 
in the fore part, and, in addition, six muscles which act upon the eyeball. 
Another muscle, the elevator of the upper lid, is also, in its greater 
part, ''contained within the orbit. The rest of the cavity is filled, even 
in the most emaciated subjects, with soft fat, which, along with the fascia 
which divides it into lobes, and sheaths the muscles and surrounds the pos- 
terior part of the globe, plays an important part in maintaining the position 
■of the eyeball and in modifying the actions of the muscles upon it. 
The muscles which act upon the eyeball are the four straight and the 
•two oblique muscles. 
The four recti or straight muscles—the superior, inferior, external, 
and internal—take origin at the back of the orbit from a common tendon, 
somewhat aponeurotic in its nature, which is partially divided into two 
portions, an upper and lower. The common tendon is attached to the 
upper, inner, and lower margins of the optic foramen, thence it crosses the 
sphenoidal fissure to a prominent point on the posterior margin of the 
orbital surface of the great wing of the sphenoid bone; a tendinous band 
connected with the origin of the external rectus muscle crosses the fissure 
somewhat higher up, and connects the outer ends of the upper and lower MUSCLES AND FASCIA OF HEAD AND NECK. 
335 
portions of the tendon. The recti muscles are inserted tendinously into 
the anterior part of the sclerotic coat of the eyeball, at distances varying 
from a third to a fourth of an inch from the margin of the cornea or 
transparent portion of the wall of the globe. The direction of the muscles 
as they pass forwards is of importance in connection with their actions. 
The superior and inferior muscles pass outwards as well as forwards, 
the external rectus markedly outwards, the internal almost directly 
forwards. The external rectus rises partly from the upper and partly 
from the lower portion of the common tendon; between its heads the 
upper and lower divisions of the third, the ophthalmic division of the fifth, 
and the sixth nerves enter the orbit, and the ophthalmic vein emerges. 
The oblique muscles are two in number, the superior and inferior. 
The superior arises in close proximity to the upper and internal recti 
immediately in front of the optic foramen, and is continued forwards 
■close to the inner angle of the orbital roof as far as a cartilaginous pulley, 
which is attached to a depression on the orbital surface of the frontal 
Bone, close to the margin of the cavity. The rounded tendon of the 
muscle, lubricated by a synovial sheath, turns over the pulley, and is 
■continued backwards, outwards, and downwards, passing underneath the 
tendon of the superior rectus, by the outer margin of which it is inserted 
into the sclerotic, a little behind the middle of the globe. The inferior 
or smaller oblique arises from the floor of the fore part of the orbit, from 
a depression in close proximity to the margin of the bony canal which 
gives passage to the nasal duct. It passes outwards and backwards 
underneath the inferior rectus, and turns upwards to be inserted under 
cover of the external rectus into the posterior part of the globe, in line 
with the attachment of the superior oblique. 
The levator palpebrae superioris arises by a narrow pointed tendon 
from the small wing of the sphenoid bone, immediately above the optic 
foramen. Broadening as it passes forwards, the muscle lies immediately 
above the superior rectus. Close behind the anterior margin of the orbit, 
it ends in a fibrous expansion, which is inserted into the tarsal membrane 
of the upper lid, and into the outer and inner tarsal ligaments. A few 
fibres are detached to the conjunctiva, and a few are given to the pulley 
■of the superior oblique muscle. 
The external rectus is supplied by the sixth nerve, the superior 
oblique by the fourth, all the others by the third nerve. 
The fascia of the orbit presents a somewhat complicated arrangement; 
to special portions of it the names external capsule and internal capsule 
have been given. 
The external capsule forms sheaths for the four straight muscles, and 
gives offsets which inclose the levator palpebrae and superior oblique. It 
is weak in the posterior part of the orbit, but stronger in front. Traced 
forwards from the optic foramen upon the straight muscles, it is found 
'as a thin layer stretching between the margins, and splitting to inclose 336 
THE MUSCLES. 
each muscle. The muscles are ensheathed, however, only for about four- 
fifths of their length, for before reaching the tendons of insertion the 
external capsule splits into two portions. The posterior portion, continuous 
with the layer on the surfaces of the muscles directed towards the optic 
nerve, is reflected backwards behind the eyeball, embraces the optic nerve, 
and is continued backwards on it posteriorly as an outer sheath. The 
anterior portion sweeping off the orbital surfaces of the muscles is con- 
tinued forwards to the margins of the orbit, where it is partly attached, 
to the bone and partly continued into the tissue of the eyelids. This 
layer of fascia as it passes forwards forms sheaths for portions of the 
inferior and superior oblique muscles. Four specially strengthened bands 
are described as connected with it, passing forwards to the bony margin 
of the orbit, one from each of the sheaths of the recti muscles. The 
external band is the strongest; it stretches from the sheath of the external 
Fig. 272.—Orbital Muscles of the Right Side. The eyelids have been turned over 
to the inner side, and are viewed from their deep surface. 
rectus to the orbital process of the malar bone, where it is connected with 
the outer tarsal ligament. The band from the internal rectus is connected 
with the lachrymal crest. The superior and inferior bands are not so 
well marked as the other two. 
The internal capsule, the capsule of Tenon, is a very delicate layer 
which covers the posterior part of the globe, and is continued back as 
an inner sheath to the optic nerve. It passes forwards on the globe 
nearly to the cornea, and in front is attached to the ocular conjunctiva. 
It likewise sends a delicate reflexion for a short distance upon each of 
the tendons inserted into the globe. Between the internal capsule and 
the sclerotic lies a narrow space, which is traversed by delicate trabe- 
culae of connective tissue, and by vessels and nerves; it is regarded as a 
lymph space, and it acts to a certain extent as a synovial socket, within 
which the eyeball glides. In extirpating the eye the surgeon, 
in separating its attachments, seeks to avoid injuring the capsule. The MUSCLES AND FASCIA OF HEAD AND NECK. ' 
337 
space extends for a short distance upon the orbital or free surface of 
each of the tendons, but does not pass round to the ocular surface or 
surface of pressure, the capsule'being closely adherent to the margins of 
the tendons. 
Actions of the muscles of the orbit. The eyeball does not appreciably 
change its form nor its position as a whole under the actions of the 
muscles; the motions imparted to it are those of rotation round a point 
placed immediately behind the centre of its antero-posterior axis. The 
maintenance of position probably depends partly on the antagonistic 
actions of the straight and oblique muscles, and partly on the support 
afforded by the orbital fascia, and the influence which it exercises in 
modifying the actions of the muscles. The four straight muscles are 
intimately connected with the fascia, more especially with the bands 
which pass to be attached to the orbital margins, and it is probable 
that these bands, by their gradual extension during muscular action, 
act as agents, moderating to a certain extent the direction in which 
the force is applied to the globe, and finally, by their complete 
tension, play the part of tendons of arrest. When the eyeball is in the 
position from which its movements are calculated, the pupil being directed 
forwards, its antero-posterior axis is parallel to the antero-posterior axis 
of the body. The axis of the orbit, however, is directed outwards as 
well as forwards; this fact requires to be borne in mind in the study of 
the actions of the individual muscles. There are three primary axes 
round which a globular body may rotate, but the movements of the 
eye are limited, and they are most conveniently described in terms 
which refer to the manner in which they affect the position of the cornea. 
Rotation of the eyeball round its vertical axis turns the cornea outwards 
or inwards according to the direction in which it takes place ; the move- 
ments are spoken of as abduction and adduction of the cornea. In a 
similar manner rotation round the transverse axis results in elevation or 
depression of the cornea. Rotation round the antero-posterior axis would 
produce a rotation of the cornea. A simple movement of rotation of the 
cornea does not occur in the case of the eye, but a very slight inclination of 
the vertical meridian of the globe takes place in the oblique movements of 
the cornea, in which vertical and transverse displacement are combined. 
Movements of elevation or depression of the cornea take place in the 
two eyes simultaneously; when the gaze is fixed on a near object both 
eyes are turned inwards ; when the gaze is directed laterally there is 
abduction in one case and adduction in the other. Movements in which 
the cornea is turned outwards or inwards are effected by the external 
and internal recti muscles. Upward movement of the cornea is caused 
principally by the superior rectus, but as the muscle passes somewhat 
outwards to its insertion, in the line of the orbital axis, a certain amount 
of oblique rotation is communicated to the ball by its contraction. The 
inferior oblique muscle, acting in concert with the superior rectus, corrects 338 
THE MUSCLES. 
the obliquity of the movement, with the result that by the simultaneous 
actions of the two muscles a direct upward movement of the cornea takes 
place. The levator palpebrae is closely associated by direct connection 
through the fascia, and in its - nerve supply, with the superior rectus, and 
the upper eyelid is raised as the pupil is turned upwards. The inferior 
rectus, like the superior, is directed somewhat outwards, and the obliquity 
of its action is corrected by the superior oblique muscle. Pulled on in the 
dead subject the oblique muscles would produce an oblique movement of 
rotation of the eyeball, the superior depressing and abducting the cornea, 
the inferior elevating and abducting. By the combination of different 
muscles various degrees of oblique movement of the cornea may be pro- 
duced. The amount of upward movement which actually takes place has 
been calculated as about 34 degrees, downward 57 degrees, outward 42 
degrees, inward 45 degrees. 
Three subsidiary groups of muscles are treated together under this 
heading—(a) a set connecting the hyoid bone with the lower jaw and with 
the styloid and mastoid processes; (h) a set passing from the hyoid bone 
and styloid process to the tongue, the extrinsic muscles of the tongue ; 
(c) a muscle from the styloid process to the pharynx and larynx. They 
present relations to the vessels and nerves of the upper part of the neck, 
which can be conveniently studied together. 
SUPRA-HYOil) MUSCLES. 
The digastric muscle is formed of two fleshy bellies and an intervening 
tendon. The posterior belly, longer than the anterior, arises from the digastric 
fossa of the mastoid process, and is directed forwards and downwards to 
the tendon. The anterior belly, broader than the posterior, springs from 
an oval area on the lower margin of the inferior maxilla, close to the 
symphysis, and is directed downwards and slightly backwards. The 
intervening tendon, nearly two inches in length, is placed immediately 
above the hyoid bone, to which, at the junction of the body with the great 
cornu, it is bound by aponeurotic fibres. At its origin from the digastric 
fossa the muscle is deeply placed under the other muscles connected with 
the mastoid process; the intervening tendon is crossed by a portion of 
the fibres of the stylo-hyoid muscle; in the rest of its area the muscle is 
superficial. Absence of one or other of the bellies has been noted ; the 
anterior belly is occasionally double, and in rare cases the posterior belly 
is double. 
The mylo-hyoid, a thin, four-sided muscle, rises from the mylo-hyoid 
ridge of the lower jaw. The more posterior fibres are inserted into the 
anterior surface of the body of the hyoid bone, the more anterior into a 
median fibrous raphe, which extends from the hyoid bone to the sym- 
physis. The most anterior fibres are very short. The anterior belly of 
the digastric partly covers the under or superficial surface of the muscle. MUSCLES AND FASCIA OF HEAD AND NECK. 
The muscles of opposite sides together form a muscular floor for the 
buccal cavity. 
The genio-hyoid springs from the lower genial tubercle of the inferior 
maxilla, and is inserted into the anterior surface of the body of the hyoid 
bone. It is a small rounded bundle, and lies on the upper or deep surface 
of the mylo-hyoid, close to the middle line. 
Trachea 
The stylo-hyoid, a slender band, springs by a short tendon from the 
posterior and external part of the base of the styloid process. It passes 
downwards and forwards and is inserted into the anterior surface of the 
lateral part of the body of the hyoid bone. It is at first deeply placed, 
but afterwards becomes superficial, as it lies above the upper border of 
the posterior belly of the digastric, and its fibres passing to insertion 
embrace the intervening tendon of that muscle. The stylo-luyoideus alter 
Pig. 273.—The Muscles connected with the Hyoid Bone. (L. Testut.) 340 
THE MUSCLES. 
is the name given to an occasional muscle passing from the styloid 
process either to the great or small cornu of the hyoid bone. 
Nerves. The stylo-hyoid and the posterior belly of the digastric are 
supplied by the seventh nerve, the mylo-hyoid and the anterior belly of 
the digastric by a branch from the inferior maxillary division of the 
fifth. The genio-hyoid receives its supply from the twelfth or hypoglossal 
nerve. 
Actions. The muscles act both on the hyoid bone and the lower jaw. 
When the jaw is fixed the hyoid bone, and with it the larynx, is drawn 
upwards by the digastric, upwards and forwards by the mylo-hyoid and 
genio hyoid, and upwards and backwards by the stylo-hyoid. The hyoid 
bone is drawn upwards in the action of swallowing. The mylo-hyoid 
in contracting raises the floor of the mouth and pushes the tongue up- 
wards. The digastric depresses the lower jaw and opens the mouth. 
The stylo-glossus, a narrow band, springs from the styloid process 
near its extremity, and from the stylo-hyoid ligament. It passes forwards 
and downwards, and is applied to the lower surface of the tongue at its 
border, its fibres becoming blended with those of the hyo-glossus and of 
the intrinsic muscles. 
The hyo-glossus, thin and four-sided, springs from the upper border 
of the lateral part of the body, and from the great cornu of the hyoid 
bone. It passes upwards to the under surface of the posterior part 
of the tongue at its border, where its fibres, along with those of the 
Pig. 274.—The Extrinsic Muscles of the Tongue. 
stylo-glossus, to the inner side of which they are at first placed, become 
interlaced with those of the intrinsic muscles. A small muscular slip 
(chondro-glossus) occasionally arises from the smaller cornu, and passes on 
the surface of the hyo-glossus to the tongue. An accessory slip sometimes 
springs from the thyro-hyoid ligament. MUSCLES AND FASCIA OF HEAD AND NECK. 
The genio-glossus, fan-shaped, springs from the upper genial tubercle 
of the inferior maxilla; the fibres pass into almost the whole length of the 
under surface of the tongue from near the tip backwards into the glosso- 
epiglottic fraenum, and into the body of the hyoid bone. It lies close to 
the middle line, and its inner surface is in contact with that of its fellow 
of the opposite side; the genio-hyoid lies along its lower border, and the 
hyo-glossus and stylo-glossus are in contact with its outer surface. 
Nerves. The stylo glossus, hyo-glossus, and genio-glossus are supplied 
by the hypoglossal nerve. 
Actions. The stylo glossus draws the tongue backwards and upwards, 
the hyo-glossus backwards and downwards. The genio-glossus depresses 
the tongue, and its anterior fibres retract, while its posterior fibres protrude 
the organ. The genio-glossus and stylo-glossus muscles of the two sides 
acting together and along with the palato-glossi turn up the edges and 
depress the centre of the tongue, and the hyo-glossus muscles oppose this 
action. 
The stylo-pharyngeus springs by a short tendon from the inner part 
of the base of the styloid process. Passing downwards and inwards, it 
becomes flattened and enters the wall of the pharynx, passing between 
the superior and middle constrictors. It is inserted Avith the palato- 
pharyngeus muscle chiefly into the upper and posterior edges of the 
thyroid cartilage, and partly into tbe Avail of the pharynx and the side 
of the epiglottis. It is supplied by the glosso-pbaryngeal nerve, and acts 
as an elevator of the pharynx and larynx. 
Relations of the supra-hyoid group of muscles. This group of muscles 
presents important relations to the large vessels and nerves of the upper 
part of the neck. The external and internal carotid arteries pass upwards 
to the head from the point of division of the common carotid opposite the 
upper border of the thyroid cartilage. The external, the more superficial, 
reaches to a spot behind the neck of the lower jaw, crossing in its course 
over the styloid process; the internal passes on the deep surface of the 
process to the carotid foramen. Along Avith the internal carotid artery are 
closely associated the internal jugular vein and the vagus or pneumogastric 
nerve. The stylo-hyoid muscle, springing from the base of the process, 
crosses along Avith the posterior belly of the digastric superficially to 
the external carotid artery ; and the stylo-pharyngeus, also from the base 
of the process, passes between the external and internal vessels; the stylo- 
glossus, from the tip of the process, does not come into actual relation Avith 
either vessel. The internal carotid artery, Avith its accompanying struc- 
tures, passes upwards in close contact with the Avail of the pharynx. 
Three nerves pass downwards and inwards to the tongue; they are the 
hypoglossal, the glosso-pharyngeal, and the lingual branch of the fifth. 
The hypoglossal nerve crosses superficially to the external carotid artery, 
and in its curved course passes slightly further down in the neck 
than the lower margins of the stylo-hyoid and the posterior belly of the 342 
THE MUSCLES. 
digastric muscles. The glossopharyngeal nerve, lying along the lower 
border of the stylo-pharyngeus muscle, lies between the external and internal 
arteries. The lingual nerve is placed further forwards on the deep 
surface of the ramus; it does not come into relation with either vessel, 
but crosses the stylo-glossus muscle. Further forwards, in the region 
underneath the body of the lower jaw, the submaxillary salivary gland 
lies on the surface of the mylo-hyoid muscle in the submaxillary triangle, 
the region marked off by the anterior belly of the digastric, the stylo.- 
hyoid, and the border of the inferior maxilla; its duct turns round the 
posterior border of the mylo-hyoid and passes across the muscles of the 
tongue to reach the floor of the mouth. Besides the duct and the three 
nerves already mentioned, the lingual artery and veins cross the sublingual 
muscles. On the deep surface of the mylo-hyoid and upon the hyo-glossus 
lie, in order from below upwards, the ranine vein, the hypoglossal nerve, 
the duct of the gland (Wharton’s duct), and the lingual nerve; on the 
deep surface of the hyo-glossus and upon the genio-glossus lie, in the 
same order, the lingual artery and its venae comites and the glosso- 
pharyngeal nerve. The sublingual salivary gland lies upon the anterior 
part of the genio-glossus, under cover of the mucous membrane of the 
mouth, and rests below on the mylo-hyoid. 
MUSCLES ATTACHED TO THE RAMUS OF THE JAW. 
Four muscles are on each side attached to the ramus of the jaw or 
its processes, and play an important part in the process of mastication, 
in which they are assisted by the muscles of the tongue, lips, and cheeks. 
The masseter, strong and four-sided, springs from the zygomatic 
arch, and is inserted into the outer surface of the ramus and coronoid 
process of the lower jaw. It is formed of three sets of fibres, differing 
from one another in direction. The largest and most superficial portion 
passes downwards and backwards. It springs from the lower border of 
the anterior two-thirds of the arch by a strong tendon which sends septa 
among the muscular fibres ; it is inserted into the lower half of the ramus. 
The second portion, the fibres of which pass directly downwards, springs 
from the inner surface of the anterior two-thirds and the lower border of 
the posterior third of the arch, and is inserted into the upper portion of 
the ramus; except at its posterior and upper angle, it is overlapped by 
the first part. The third portion, the fibres of which are directed down- 
wards and forwards, springs from the inner surface of the posterior third 
of the arch, and is inserted into the outer surface of the coronoid process; 
it is completely overlapped by the second part. The third portion is easily 
separable from the second, but has usually been described along with it. 
The temporal muscle, flat and fan-shaped, springs from the whole 
surface of the temporal fossa, with the exception of the portion formed 
by the malar bone, and from the overlying temporal fascia, except at its 
lower part. The muscular fibres converge, the anterior descending almost MUSCLES AND FASCIA OF HEAD AND NECK. 
343 
vertically, the posterior passing forwards almost horizontally. It is inserted 
by tendon into the upper and anterior borders of the coronoid process, 
and partly by tendon and partly by fleshy fibres into the whole inner 
surface of the process and into the anterior area of the inner surface of 
the ramus. 
The external pterygoid muscle arises from the walls of the zygomatic 
fossa by two fleshy heads—the upper from the zygomatic surface of the 
great wing of the sphenoid, the lower and larger from the outer surface 
of the external pterygoid plate. The fibres, converging, pass backwards 
and a little outwards, and are inserted partly into the depression on the 
front of the head of the lower maxilla, and partly into the inter-articular 
fibro-plate of the temporo-maxillary articulation. 
Fig. 275.—The Temporal Muscle. The fibres 
at a are reflected forwards ; they arise from the 
temporal fascia, and are inserted into the anterior 
border of the coronoid process: b, the temporo- 
maxillary articulation represented as when the 
mouth is shut. 
Fig. 276.—The Pterygoid Muscles, from 
the outer side after removal of part of the 
lower jaw. a, External pterygoid; h, inter- 
nal pterygoid ; c, buccinator; d, temporo- 
maxillary articulation represented as when 
the mouth is open. 
The internal pterygoid muscle arises in the pterygoid fossa from the 
inner surface of the external pterygoid plate, partly by fleshy fibres, and 
partly by a flattened tendon which is continued within the substance of 
the muscle. Additional fibres take origin, external to the lower fibres 
of the external pterygoid, from the outer surface of the tuberosity of the 
palate, and the neighbouring area of the superior maxilla. It is directed 
downwards, backwards, and outwards, and is inserted into a rough impres- 
sion on the inner surface of the ramus of the jaw at the angle. 
Relations. The masseter is entirely superficial, and the temporal 
almost entirely so. The other two are deeply placed in the zygomatic 
fossa. The heads of the external pterygoid are placed one on each 
side of the pterygo-maxillary fissure, and the muscle, in reaching to its 
insertion, passes between the internal lateral ligament of the articulation 
(spheno-maxillary ligament) and the inner surface of the lower maxilla. 
The internal pterygoid arises, for the greater part, on the deep surface of 
the external pterygoid, and has the tensor palati on its internal aspect. THE MUSCLES. 
The parotid gland, which lies behind the ramus, sends its duct forwards 
across the masseter, and a small accessory portion of the gland usually lies 
beside the duct on the surface of the muscle. A deep prolongation of the 
gland passes on the deep surface of the ramus into contact with the 
internal and external pterygoid muscles. The facial nerve and the external 
carotid artery lie in the substance of the gland; the nerve sends branches 
forwards over the masseter, and the internal maxillary branch of the 
artery runs forwards on the deep surface of the ramus and usually 
crosses the outer surface of the external pterygoid to enter, between its heads, 
the pterygo-maxillary fissure. The inferior maxillary division of the fifth 
nerve, which escapes from the skull by the foramen ovale, breaks up into 
its branches on the deep surface of the external pterygoid; of these the 
Fig. 277.—Pterygoid and other Muscles, displayed by reflecting the tongue downwards. 
deep temporal and masseteric pass over the upper border of the muscle, 
the buccal emerges between its heads, and the lingual and dental descend 
beneath its lower border. 
Nerves. All the muscles of the group are supplied by the inferior 
maxillary division of the fifth nerve. 
Actions. The masseter, temporal, and internal pterygoid muscles of 
opposite sides usually act together and draw the lower jaw upwards against 
the upper maxilla. The external pterygoid draws the head of the jaw 
forwards, and thus comes into play along with other muscles in opening 
the mouth. Its chief use is in grinding the food between the teeth, the 
muscles of opposite sides acting alternately. The posterior fibres of the 
temporals are opponents of the external pterygoids. 
The temporal fascia, a strong, firm layer, is attached to the posterior 
margin of the malar bone, the temporal ridge of the frontal and parietal MUSCLES AND FASCIA OF HEAD AND NECK. 
345 
bones, the supra-mastoid ridge of the temporal bone, and the zygomatic 
arch. It is a single sheet above, but splits into two about two inches 
from its lower margin, and a little fat lies between the layers as they 
descend to the outer and inner surfaces of the zygoma. On the deep 
surface of the lower part of the fascia a quantity of soft fatty tissue lies 
between it and the temporal muscle. 
The masseteric fascia is a moderately strong layer which covers the 
masseter muscle, and is continued forwards from the fascia of the parotid 
gland. Anteriorly it passes into a more delicate layer which overlies 
the buccinator. On the surface of the buccinator a quantity of soft fatty 
tissue, “the buccal pad,” peculiarly well developed in children, lies under- 
neath the fascia, and is continuous on the deep surface of the ramus with 
the fat under the temporal fascia. 
MUSCLES OF THE PHARYNX. 
General description and relations. The pharynx, the dilated upper 
extremity of the digestive tube, is open in front to the nose, mouth, and 
larynx, and is attached to the base of the skull above. At the sides 
and behind, its walls are formed by aponeurotic tissue, covered internally 
by a mucous membrane and externally by a layer of muscles, the chief 
of which are the three constrictors, superior, middle, and inferior. Each 
is formed of lateral portions, which meet in the middle line behind in 
a central raphe continued down from the basilar process. They partially 
overlap one another from below upwards. The lower margin of the 
inferior constrictor embraces the oesophagus; its upper margin slopes 
upwards and backwards on the surface of the middle constrictor to reach 
the middle line above the level of the hyoid bone. The lower fibres 
of the middle constrictor descend under cover of the inferior muscle for 
some distance; its upper fibres ascending as far as the base of the skull 
cover in turn a portion of the superior muscle. The fibres of the 
superior constrictor are chiefly horizontal in direction; it reaches to the 
base of the skull in the middle line only, and in the interval between 
its upper margin and the skull the pharyngeal aponeurosis is stronger than 
elsewhere. The Eustachian tube and the levator palati pass over the upper 
border of the superior constrictor to enter the pharynx, the stylo-pharyngeus 
passes between the superior and middle constrictors, and the inferior 
laryngeal nerve ascends below the lower border of the inferior constrictor. 
The back of the pharynx lies upon the vertebral bodies and prevertebral 
muscles; the great vessels and nerves of the upper part of the neck lie 
by its sides. Supernumerary muscular slips passing to the wall of the 
pharynx are frequently found; they may arise from the spine of the 
sphenoid, the internal pterygoid plate, the under surface of the petrous 
bone, the basilar process, or the mastoid process. 
The inferior constrictor arises from the side ot the cricoid cartilage, 
and from the ala and upper border of the thyroid cartilage in the region 346 
THE MUSCLES. 
behind the oblique line. On their way to the central raphe the lower 
fibres are almost horizontal, while the more superior ascend with increasing 
degrees of obliquity. 
The middle constrictor arises from the upper border of the great 
cornu of the hyoid bone and the extremity of the stylo-hyoid ligament. 
The middle fibres are horizontal; the superior ascend, and the inferior 
descend, with considerable obliquity. 
The superior constrictor arises by slips attached in series from below 
upwards to the side of the tongue and mucous membrane of the mouth, 
the extremity of the mylo-hyoid ridge of the inferior maxilla, the pterygo- 
Fig. 278.—The Wall of the Pharynx. (L. Testut.) 
maxillary ligament, and the lower part of the posterior border of the 
internal pterygoid plate. The fibres are mostly horizontal, but the upper 
and lower slightly diverge. The tonsil lies on its inner surface. It is 
united to the buccinator by the pterygo-maxillary ligament. 
Nerves. The constrictors are supplied through the pharyngeal plexus, 
probably from the bulbar portion of the spinal accessory nerve; the inferior 
constrictor, in addition, receives branches from the superior and inferior 
laryngeal nerves. 
Actions. The muscles contract from above downwards. In deglutition 
the lower part of the pharynx is raised ; the superior constrictor and the 
upper part of the middle constrictor assist in shutting off the nasal 
passages; the lower part of the middle constrictor and the inferior con- 
strictor narrow the lateral diameter of the pharynx. MUSCLES AND FASCIA OF HEAD AND NECK. 
347 
THE MUSCLES OF THE SOFT PALATE. 
The soft palate or velum, attached in front to the posterior margin of 
the hard palate, is a movable curtain, with a free pendulous posterior 
border projecting into the pharynx and prolonged in the middle line into 
small process, the uvula. It is formed by a somewhat ill-defined 
a, Basilar process 
B, Posterior nares 
Membranous wall of pharynx 
Levator palati 
C, Eustachian tube. 
Q, Aperture of Eustachian 
Pharyngeal recess 
Superior constrictor 
Salpingo-pharyngeus 
3, Levator uvulae. 
1 6, 8, 9, Palato- 
pharyngeus. 
>, Tongue 
Tonsil 
Pal ato-phary n geus 
o, Epiglottis 
Posterior pillar of fauces 
, Stylo-phary ngeus 
Anterior pillar of fauces 
Aperture of larynx 
Palato - ph ary n ge us 
Pharyngo-laryngeal recess 
f, Inter-arytenoid region 
Thyicid cartilage 
(posterior border) 
Thyroid body 
Thyroid body 
Oesophagus' 
Trachea 
Fig. 279.—Muscles op the Soft Palate and Pharynx, from behind. (L. Testut.) 
fibrous layer, which gives origin and attachment to various muscles, and 
is covered by mucous membrane, continuous on the upper surface with that 
of the nasal cavities, on the under with that of the mouth. At its lateral 
niargins it is attached to the internal pterygoid plates and to the wall 
of the pharynx by the muscles which enter and pass from it. Its muscles 
reach it from above, pass from it downwards, or are confined entirely 
within its substance. To the last group belong the elevators of the 
uvula, one on each side of the middle line, passing backwards along the 348 
THE MUSCLES. 
upper surface to reach the uvula, where they become blended. The 
muscles which pass downwards from it are on each side, the palato-glossus 
and palato-pharyngeus forming respectively the anterior and posterior 
pillars of the fauces between which lies the tonsil. The muscles which 
reach it from above are likewise two on each side, the tensor palati and 
levator palati, the former, anterior in position, springing from the sphenoid, 
the latter from the petrous bone. In the soft palate the muscular fibres 
of the levator uvulae lie above those of the levator palati, and both 
are embraced above and below by those of the palato-pharyngeus, while the 
palato-glossus forms the lowest stratum. The tendinous fibres of the 
tensor palati enter the aponeurosis of the palate beneath the insertion 
of the levator palati. 
The levator uvulae (azygos uvulae) arises from the posterior nasal 
spine and the aponeurosis of the soft palate. In the uvula it blends with 
its fellow of the opposite side, and is inserted into the sub-mucous tissue. 
The palato-glossus arises on the under surface of the palatal aponeurosis, 
its fibres decussating across the middle line with those of the muscle of the 
opposite side. It descends in the anterior pillar of the fauces to the side 
of the posterior part of the tongue, where it becomes blended with the 
transverse lingual fibres. At its posterior border a few fibres spread over 
the surface of the tonsil (amygdalo-glossus). 
The palato-pharyngeus arises in two layers, the smaller from the 
upper surface of the soft palate above the levator uvulae, the fibres 
decussating across the middle line with those of the opposite side, 
the lower from the margin of the hard palate and from the palatal 
aponeurosis. A small slip [salpingo-pharyngeus) descends to it from the 
lower margin of the cartilage of the Eustachian tube. The muscle passes 
backwards and downwards in the posterior pillar of the fauces to the wall 
of the pharynx, and, spreading, blends with the stylo-pharyngeus to be 
inserted partly into the upper and posterior borders of the thyroid cartilage, 
and partly into the wall of the lower part of the pharynx, where some 
of its fibres reach the middle line. 
The tensor palati [circumflexus palati) has a broad origin from the 
sphenoid bone behind and internal to the foramen ovale, stretching from 
the spine to the scaphoid fossa at the root of the internal pterygoid jfiate. 
It also receives fibres from the outer side of the cartilage of the Eustachian 
tube. The muscle forms a flattened band, which, descending, becomes 
tendinous, and turns round the hamular process, a small bursa intervening. 
The tendinous fibres spread out into the aponeurosis of the velum, and 
in addition are partly inserted into the transverse ridge of the under surface 
of the horizontal plate of the palate bone. 
The levator palati, rounded in outline, springs by a narrow tendon 
from the under surface of the petrous bone in front of the carotid canal, and 
by some fibres from the lower edge of the hinder part of the cartilage of 
the Eustachian tube. The muscle passes downwards, forwards, and inwards, MUSCLES AND FASCIA OF HEAD AND NECK. 
349 
over the border of the superior constrictor of the pharynx, and lies in 
close contact with the membranous portion of the wall of the Eustachian 
tube. It is inserted into the aponeurosis of the soft palate, many of its 
posterior fibres decussating with those of the opposite side. 
Nerve supply. The nerve supply of the muscles of the soft palate is 
not yet, in all the cases, satisfactorily determined. The palato-glossus, 
palato-pharyngeus, and levator uvulae receive their nerves from the 
pharyngeal plexus, and it is probable, from the records of clinical experi- 
ence and physiological experiment, that these branches reach the plexus 
from the bulbar portion of the spinal accessory nerve through the vagus 
and glosso-pharyngeal trunks. The levator palati is supposed, by many 
anatomists, to receive branches through Meckel’s ganglion from the facial 
nerve, but it is more probable that its supply comes from the plexus in 
the way indicated above. The tensor palati receives a branch from the otic 
ganglion, presumably from the motor portion of the fifth, but it is possible 
that this twig may be derived from the glosso-pharyngeal nerve by of 
the nerve of Jacobson, and the lesser superficial petrosal (W. A. Turner, 
Journal of Anatomy ami Physiology, xxm. 523). 
Actions. The levator and tensor palati act together, raising and making 
tense the velum. The palato-glossus and palato-pharyngeus depress the 
soft palate on the one hand, or on the other raise the tongue and pharynx 
when the velum has been raised and made tense by its superior muscles. 
Along with a number of other muscles they all come into play in the act 
of swallowing. The food, after mastication, lies upon the surface of the 
tongue, which is then raised and drawn backwards by the action of the 
stylo-glossi muscles, together with the stylo-hyoidei and stylo-pharyngei, 
the mass being pressed against the under surface of the soft palate. The 
next stage, spasmodic in its nature, is characterized by the shutting off 
of the nasal, laryngeal, and anterior part of the buccal passages and the 
propulsion of the bolus into the grasp of the constrictors of the pharynx. 
The palato-glossi muscles contracting assist the tongue in shutting off 
the anterior part of the buccal cavity. The elevator muscles of the hyoid 
bone and larynx, the thyro-hyoid, genio-hyoid, mylo-hyoid, and stylo-hyoid, 
assisted by the palato-pharyngeus and stylo-pharyngeus, draw the larynx 
upwards under the tongue, which, by its pressure upon the epiglottis, com- 
pletely closes the laryngeal orifice. The levator and tensor palati raise and 
make tense the palate. The stylo-pharyngei muscles contracting meet in the 
middle line and, assisted by the upper part of the superior and middle con- 
strictors, prevent the food entering the nasal passages and, at the same time, 
draw upwards the lower part of the pharynx. The next stage of the 
process is involuntary, and consists in the contraction from above down- 
wards of the constrictors of the lower part of the wall of the pharynx, 
by which the bolus is propelled onwards into the oesophagus. In 
vocalization the palate is raised and made tense by the levator and 
tensor muscles. 350 
THE MUSCLES. 
THE INFRA-HYOID GROUP. 
This group comprises the sterno-hyoid, sterno-thyroid, thyro-hyoid, and 
omo-hyoid muscles. 
The sterno-hyoid arises, along a narrow line, from the posterior surface 
of the inner extremity of the clavicle, the sterno-clavicular capsule, and, 
to a small extent, the manubrium sterni. It is inserted close to the 
middle line into the inner part of the lower border of the body of the 
hyoid bone. The muscle is ribbon-shaped, and varies in breadth from 
about one inch to one inch and a half. 
The sterno-thyroid arises, close to the middle line, from the posterior 
surface of the manubrium, and from the cartilage of the first rib. It is 
inserted into the oblique line of the ala of the thyroid cartilage. It lies 
behind the sterno-hyoid, and is usually a little broader than that muscle. 
The thyro-hyoid arises from the oblique line of the ala of the thyroid 
cartilage, and is inserted into the lower margin of the outer part of the 
body and the basal portion of the great cornu of the hyoid bone. It 
continues the line of the sterno-thyroid, and at its insertion is, to a great 
extent, covered by the omo-hyoid and sterno-hyoid muscles. 
The omo-hyoid is formed of two ribbon-shaped bellies and an intervening 
tendon. The posterior belly rises from the upper margin of the scapula 
in the vicinity of the notch, and passes forwards and slightly upwards in 
the neck to the tendon, which lies beneath the sterno-mastoid muscle. The 
anterior belly ascends from the tendon with a slight inclination inwards 
to its insertion into the lower border of the outer part of the body of 
the hyoid bone. 
Relations. The sterno-hyoid muscles of opposite sides converge as they 
ascend, the sterno-thyroids, close together below, diverge as they pass 
upwards. The muscles lie in front of the trachea and thyroid body, but 
a little above the sternum a narrow interval is left in the middle line, 
in which the windpipe is exposed, having, however, on its surface some fatty 
tissue, in which lie the inferior thyroid veins. At their origin the sterno- 
thyroid muscles lie in front of the innominate and left carotid arteries and 
the left innominate vein. The posterior belly of the omo-hyoid forms the 
upper boundary of a space, the other margins of which are formed 
by the clavicle and the sterno-mastoid, the subclavian triangle, in which 
the third part of the subclavian artery, surrounded by the cords of 
the brachial plexus, is sought for by the surgeon in the operation 
for ligature. A double layer of the deep cervical fascia binds down 
the posterior belly and intervening tendon of the muscle to the clavicle 
and the first rib and passes in front of the artery. The anterior belly 
of the omo-hyoid, in escaping from the cover of the sterno-mastoid at 
the level of the cricoid cartilage, crosses over the common carotid artery, 
and the angle between the two muscles is the spot where the ligature is 
usually applied to the vessel. Between the thyro-hyoid membrane and MUSCLES AND FASCIA OF HEAD AND NECK. 
351 
the insertions of the muscles into the lower border of the hyoid bone a 
bursa usually intervenes. Variations among the infra-hyoid muscles are 
by no means infrequent. One or other of them, or one of the bellies of 
the omo-hyoid, is occasionally absent, and accessory bands are often present, 
more particularly in the case of the omo-hyoid. 
Nerves. The thyro-hyoid receives a special branch from the hypoglossal. 
The others are supplied from the loop formed by the junction of a branch 
from the second and third spinal nerves with the descending branch of the 
hypoglossal. In all probability all the fibres of supply, even those from the 
hypoglossal, are derived from the first three spinal nerves through the 
connections which pass between the cervical plexus and the hypoglossal. 
Actions. The sterno-hyoid and omo-hyoid depress the hyoid bone, the 
sterno-thyroid depresses the larnyx, while the thyro-hyoid either depresses 
the hyoid bone or elevates the larynx according to circumstances. The 
thyro-hyoid comes into play in raising the larynx in deglutition and in 
the production of the high notes of the voice; the others are called into 
action to depress the hyoid bone and larynx after deglutition, and in the 
production of the low notes. 
THE LATERAL MUSCLES. 
The sterno-mastoid (sterno-cleido mastoid) arises in two portions, sternal 
and clavicular, separated below by a narrow interval, and joining together 
in the lower third of the neck. The sternal portion springs by a short 
tendon from the anterior surface of the manubrium, the clavicular portion 
by mixed fleshy and tendinous fibres from the upper border of the inner 
third of the clavicle. The clavicular portion passes almost vertically 
upwards on the deep surface of the common mass, and, narrowing, is 
inserted by tendon into the tip of the mastoid process. The sternal 
portion, passing upwards and backwards on the surface of the muscle, 
and broadening, is inserted into the rough area on the outer surface of the 
process and into the outer third or half of the superior curved line of the 
occipital bone. Frequently a bundle of fibres (cleido-occipitalis) belonging to 
the clavicular portion passes upwards along the posterior border of the 
muscle to the superior curved line. Occasionally a muscular slip connects 
the anterior border of the trapezius with the posterior border of the sterno- 
mastoid. 
The muscle is supplied by the spinal accessory nerve, and by branches 
from the second cervical nerve. It is inclosed in a strong sheath 
of the cervical fascia. The external jugular vein, descending, crosses 
it, and in the lower third of the neck lies along its posterior border; 
the anterior jugular vein passing outwards to join the external jugular 
crosses the deep surface immediately above the origin. The sterno-mastoid 
covers the lower portions of the sterno-hyoid and sterno-thyroid muscles, 
crosses the omo-hyoid, and at its insertion overlies the splenius, trachelo- 352 
THE MUSCLES. 
mastoid, and digastric muscles. The first and second parts of the subclavian 
artery lie behind it in the lower part of the neck. The common carotid 
artery is under its cover as far as the level of the cricoid cartilage of the 
larynx; above that level in the natural body with the fascia uncut the artery 
is overlapped by the anterior border of the muscle. The names anterior and 
Pectoralis major 
Pig. 2SO.—Lateral Muscles or the Neck. 
(L. Testut.) 
posterior triangle are often used to designate the regions of the neck in front of 
and behind the muscle. Acting from the head the sterno-mastoid muscles 
raise the upper part of the chest wall, and come into play in forced 
inspiration. Acting from below the two muscles bend the neck and draw 
the head forwards; one acting alone produces an oblique movement of MUSCLES AND FASCIA OF HEAD AND NECK. 
353 
rotation of the head, in which the ear is approached to the sternum and 
the face turned to the opposite side. In the operation for the relief of 
“ wry-neck,” the surgeon divides the muscle of the side from which the 
face is averted from a quarter to half an inch above its origin, taking care 
of the anterior and external jugular veins. 
The scalenus anticus arises from the anterior tubercles of the transverse 
processes of the cervical vertebrae from the third to the sixth. It is 
inserted into the scalene tubercle of the first rib in front of the groove 
for the subclavian artery. 
Fig. 281.—Deep Muscles of the Neck. (L. Testut.) 
The scalenus mtedius arises from the posterior tubercles of the transverse 
processes of the cervical vertebrae from the second to the sixth. It is 
inserted into the first rib behind the groove for the subclavian artery. THE MUSCLES. 
The scalenus posticus, smaller than the other two, is somewhat variable, 
being occasionally absent altogether. It arises from the posterior tubercles 
of a few of the lower cervical vertebrae, and is inserted into the upper 
border of the second rib, in close proximity to the place of insertion of 
the first slip of the serratus posticus superior muscle. 
The scalene muscles all take origin by tendinous slips. The subclavian 
vein crosses the lower end of the anterior muscle, and the common carotid 
artery, with its accompanying structures, lying upon the transverse processes, 
is in front of the origins of the muscle; the phrenic nerve, descending, crosses 
the muscle from without inwards. The subclavian artery passes outwards 
over the first rib, between the attachments of the anterior and middle 
muscles, and the tubercle to which the former is attached is recognized 
by surgeons as the guide to the vessel in the operation for ligature. The 
nerves of the brachial plexus pass outwards between the two muscles, and lie 
in close proximity to the artery. Two of the branches of the plexus, the 
nerve to the rhomboids and the posterior thoracic, pass backwards through 
the middle scalene muscle. The scalene muscles elevate the upper ribs and 
come into play in forced inspiration; acting from below they produce 
flexion of the cervical portion of the column. They receive small branches 
from the anterior divisions of the cervical nerves as they emerge from the 
intervertebral foramina. 
The longus colli muscle is divided into three portions, a vertical, and 
an upper and a loAver oblique portion. The vertical portion springs by 
musculo-tendinous slips from the bodies of the three upper dorsal and 
two lower cervical vertebrae, and is inserted by similar slips into the 
bodies of the second, third, and fourth vertebrae of the neck. The lower 
oblique portion arises in common with the lower part of the vertical 
portion, and is inserted into the anterior tubercles of the transverse 
processes of the fifth and sixth cervical vertebrae. The upper oblique 
portion, larger than the lower, and sometimes separately described as 
the “atlantal” muscle, passes from the anterior tubercles of the transverse 
processes of the third, fourth, and fifth cervical vertebrae, and is inserted 
into the anterior surface of the atlas. 
THE PREYERTEBRAL MUSCLES. 
The rectus capitis anticus major arises by tendinous slips from the 
anterior tubercles of the transverse processes of the third and the succeeding 
cervical vertebrae. The slips unite to form a flattened fleshy band which 
is inserted into the basilar process of the occipital bone along an oblique 
line extending outwards and forwards from the pharyngeal spine for about 
half an inch. 
The rectus capitis anticus minor arises from the anterior part of the 
base of the transverse process of the atlas, and is inserted into the 
basilar process of the occipital bone under cover of the outer margin of 
the larger rectus. MUSCLES AND FASCIA OF HEAD AND NECK. 
355 
The rectus capitis lateralis, a small four-sided muscle, springs from 
the upper surface of the extremity of the transverse process of the atlas, 
and is inserted into the jugular process of the occipital bone. 
The longus colli lies immediately on the vertebral bodies and the roots of 
the transverse processes ; its upper part is covered by the rectus capitis 
anticus major. The rectus lateralis is in series with the posterior inter- 
transverse muscles of the neck, small rounded bundles which pass between 
the posterior tubercles of the transverse processes of the successive cervical 
vertebrae. Between the rectus lateralis and the posterior belly of the 
digastric the occipital artery passes backwards. The oesophagus, con- 
tinued up into the pharynx, lies upon the muscles of this group, and by 
its sides the common carotid arteries, continued into the internal carotids, 
ascend in front of the transverse processes. The two smaller muscles are 
supplied by the first cervical nerve, the larger rectus by the first and 
second, and the longus colli by special twigs from the cervical nerve 
trunks. The longus colli flexes the cervical portion of the column, the 
rectus major and minor flex the head upon the column, the rectus 
lateralis produces a lateral movement of the head. 
The deep cervical fascia, though nowhere very strong, is of importance 
surgically, and because in certain diseased conditions it is liable to undergo 
thickening and serves to determine the directions in which abscesses 
spread. It forms an exceedingly complicated structure, investing all 
the different muscles, the viscera and the larger bloodvessels and 
nerves of the neck. 
Followed from the back of the neck, where it invests all the muscles, 
it may be traced from the border of the trapezius to the posterior edge 
of the sterno-mastoid, covering the splenius, levator anguli scapulae, and 
posterior belly of the omo hyoid. Above, it is attached to the superior 
curved line of the occipital bone and to the mastoid process; below, where 
it is strongest, it is attached to the clavicle, and is pierced immediately 
behind the sterno-mastoid by the external jugular vein. Of its deeper 
septa in the posterior triangle the most important is a layer which 
invests and binds down the posterior belly of the omo-hyoid, retaining 
it in a much more horizontal position than the anterior belly; it is 
partly attached below to the first rib, and partly continued into the 
costo-coracoid membrane, and it covers and invests the scalenus anticus, 
at the outer border of which it has to be divided in the operation for 
ligature of the subclavian artery. 
Traced forwards from the posterior triangle the fascia splits to inclose 
the sterno-mastoid, and the enveloping layers meet again at the anterior 
border of the muscle to be continued toward the middle line. Above, it 
is attached to the zygoma and to the lower jaw; below, it is attached to 
the clavicle and sternum. In the middle line above the level of the 
thyroid body it meets the layer of the opposite side as a single sheet, 
and is fixed to the hyoid bone. Below the level of the thyroid body, THE MUSCLES. 
the layers of fascia approaching one another from the opposite sides 
of the neck split into two just before reaching the middle line, and a 
double junction is effected, with the result that an interfascial space is 
formed in the front of the lower part of the neck, its walls being attached 
below to the anterior and posterior margins of the sternum. At its 
lower angles this space is prolonged for a short distance outwards on 
each side on the deep surface of the sternal head of the sterno-mastoid; 
the anterior jugular veins lie for a portion of their course in the space, 
and each passes outwards in the lateral recess of its own side. 
From the deep surface of the sterno-mastoid muscle an important deep 
process of the fascia passes forwards and inwards. This process surrounds 
the common carotid arteries and their accompanying structures, forming a 
sheath for them with distinct compartments for the artery, the vein and 
the vagus nerve. Beyond the vessels the process divides into two, a visceral 
and a prevertebral layer. The visceral layer reaches the windpipe and 
gullet, enveloping them in front and behind, and is continued down upon 
them into the thorax, where it joins the fibrous layer of the pericardium. 
The prevertebral layer passes in front of the longus colli and the bodies of 
the vertebrae, and is likewise continued down into the thorax. Delicate 
septa, passing between the anterior portion of the visceral layer and the 
more superficial layer, complete the investment of the sterno-hyoid and 
sterno-thyroid muscles. Behind the visceral layer, between it and the 
prevertebral layer, is the retro-oesophageal space, which, however, is not 
entirely uninterrupted, but is bridged across by delicate bands of con- 
nective tissue which pass between the layers of fascia which form its walls. 
Another important deep process passes from the fascia in the upper 
part of the neck in the region where, stretching to the .zygoma, it covers 
the parotid gland. The deep process passes upwards on the deep surface 
of the parotid, completing a sheath for the gland, and investing the posterior 
belly of the digastric, the styloid and the pterygoid muscles. The parotid 
capsule is dense, and in swelling of the gland, such as occurs in the affection 
known as “mumps/’ the pressure which it exercises upon the nerves 
contained within the gland is frequently so great as to give rise to severe 
pain. The submaxillary gland is also encapsuled. In connection with 
the deep process which passes to the skull on the deep surface of the 
parotid, a number of stronger bands or ligaments are developed. The 
stylo-maxillary ligament stretches from the styloid process to the angle of 
the jaw, and is the strongest portion of the layer intervening between 
the parotid and submaxillary glands. The spheno-maxillary ligament, or 
internal lateral ligament of the lower jaw (p. 244), is similarly continuous 
with the fascia at its anterior and posterior borders. Two other bands, 
which are partly connected with the fascia, may be mentioned here. The 
first, the pterygo-maxillary ligament from the hamular process to the extremity 
of the mylo-hyoid ridge of the lower jaw, gives origin to the buccinator 
in front and a portion of the superior constrictor of the pharynx behind; MUSCLES AND FASCIA OF HEAD AND NECK. 
357 
the other, the ptery go-spinous ligament, a hand passing from the external 
pterygoid plate to the spine of the sphenoid, is occasionally ossified. 
A thin layer of fascia in the lower part of the neck on each side 
forms a cervico-thoracic septum. It is attached to the first dorsal transverse 
process and the concave margin of the first rib, and forms a dome-like roof 
to the pleural cavity. Occasionally a few muscular fibres from one of the 
scalene muscles spread over it. 
THE DEEP MUSCLES OF THE BACK. 
Under this term may be included the whole of the muscles covered 
by the two posterior serrati and the vertebral and lumbar aponeurosis. 
The group stretches from the back of the sacrum to the skull, and the 
Epicranial aponeurosis 
Occipitalis, 
Complexus. 
Splenius capitis 
Splenius colli 
Ligamentum nuchae 
Levator anguli scapulae. 
Serratus posticus superior 
..Second rib 
Rhornboideus minor 
Serratus posticus ’ 
superior 
Rhornboideus major 
Rhornboideus major 
Longissimus dorsi 
Fig. 252.—Deep Muscles of the Back of the Neck. (L. Testut.) 
individual members of it are characterized by a larger number of origins 
and insertions, and a greater amount of normal variation, and exhibit a 
less perfect differentiation than most muscles. Most superficial among 
them are the splenius, occupying the cervical and upper thoracic regions, 358 
THE MUSCLES. 
and the erector spinae which extends the whole length of the trunk. 
Only a small slip of the erector spinae—viz., that termed trachelo-mastoid 
—is covered by the splenius; apart from this the splenius and erector 
spinae exhibit parallel borders in contact with one another. The splenius 
arises from cervical and upper thoracic spines, and is inserted into the skull 
and upper cervical transverse processes. The erector spinae, occupying 
the whole breadth of the space covered by the lumbar aponeurosis,, 
arises largely from spines up to the level of the seventh thoracic, 
and is inserted into accessory and transverse processes and ribs and not 
into spines, save only to a small extent in the upper thoracic region. 
On the deep surface of the splenius and erector spinae are three long 
muscles, the fibres of which are directed upwards and inwards, taking 
origin from mammillary processes and their homologues, and passing to- 
insertion on spines. The individual muscles are distinguished from 
one another by the length of their fibres, and the longer fibred are the more 
superficial. The first, the complexus, passes from the higher thoracic trans- 
verse processes and cervical articular processes to the skull. The second, 
the semispinalis, from the higher ten thoracic transverse processes to spines 
from that of the axis to the fourth thoracic. The third, the multifidus spinae,. 
made up of short bundles, passes from the back of the sacrum, the lumbar 
mammillary processes, the thoracic transverse processes, and the cervical 
articular processes, to the spines of all the movable vertebrae from the 
axis downwards. Besides the long muscles there are also numerous short 
muscles which pass between contiguous spines and between contiguous 
transverse processes in the region below the atlas vertebra. In the 
region between the axis and the skull there is a special group of four 
small muscles. 
The splenius arises from the spines of five or six of the higher thoracic 
vertebrae, from that of the seventh cervical and from the ligamentum 
nuchae, extending in its origin as high as the third cervical spine. The 
upper and larger portion receives the name of splenius capitis, and is 
inserted into the mastoid process and the outer part of the superior curved 
line. The lower portion, the splenius colli, is inserted by tendons into 
the posterior tubercles of the transverse processes of the first three or 
four cervical vertebrae. 
The erector spinae arises from the lower thoracic and all the lumbar 
and sacral spines, from the posterior sacro-coccygeal ligaments, from the 
posterior fourth of the iliac crest, and from the adjacent triangular area 
of the ventral surface of the ilium behind the attachment of the posterior 
sacro-iliac ligament. The greater part of the origin is formed by a strong; 
flat tendon attached internally to the spines and externally to the iliac 
crest, and giving origin on its deep surface to fibres of the multifidus- 
spinae; but the outermost portion of the origin from the crest and the 
whole of that from the ventral surface of the ilium are muscular. The 
muscle is composed almost entirely of two columns, each consisting of a DEEP MUSCLES OF THE BACK. 
359 
principal or basal part, and two successive prolongations. The basal part 
of the inner column is the longissimus dorsi, and its prolongations are the 
transversalis cervicis and the trachelo-mastoid. The basal portion of the 
.Com plexus 
Splenitis 
Trachelo-mastoid 
Cervicalis ascendeus 
Longissimus dorsi 
Transversalis cervicis 
.Complexus 
Levator costae 
Musculus accessorius 
Longissimus dorsi 
Ilio-cos tails 
Ilio-costalis 
External oblique 
Erector spinae (tendon of origin) 
Pio. 283.—Erector Spinae. (L. Testut.) 
outer column is the ilio-costalis, and its prolongations are the musculus 
accessorius and the cervicalis ascendens. At the inner margin of the 
longissimus dorsi there is a small additional portion, the spinalis dorsi, 
which extends upwards to the higher thoracic spines. 360 
THE MUSCLES. 
The ilio-costalis (sacro-lumbalis—ilio-costalis lumborum), the basal muscle 
of the outer column, is inserted by tendons into the angles of the six 
lower ribs, and gives a slip to the musculus accessorius. 
The musculus accessorius (ilio-costalis dorsi), the second portion of the 
column, springs by tendons from the angles of the six lower ribs, and 
is inserted in like manner into the angles of the six upper ribs and the 
transverse process of the seventh cervical vertebra. Its tendons of origin 
are internal to those of insertion of the ilio-costalis. 
The cervicalis ascendens (ilio-costalis cervicis), the highest portion of the 
outer column, receives a slip from the musculus accessorius, and springs by 
tendons from the angles of the sixth and three or four of the higher ribs. 
It is inserted by short tendons into the posterior tubercles of the trans- 
verse processes of the fourth, fifth, and sixth cervical vertebrae. Its tendons 
of origin are internal to those of insertion of the musculus accessorius. 
The spinalis dorsi is a narrow set of musculo-tendinous bundles attached 
to the sides of the spines of the thoracic vertebrae, and passing from the 
lower to the higher of these. It is freely connected at its edge with the 
longissimus dorsi, and on its deep surface with the semispinalis muscle. 
The longissimus dorsi, the basal muscle of the inner column, thick 
and fleshy, is inserted along the whole length of its outer and inner 
margins. Externally it is attached in the lumbar region by muscular 
slips to the transverse processes of the vertebrae and the intervening 
portions of the middle layer of the lumbar aponeurosis, and in the thoracic 
region by a series of delicate musculo-tendinous slips to the eight or nine 
lower ribs between their tubercles and their angles. Internally it is 
attached by a set of rounded tendons, which in the lumbar region pass 
to the accessory processes and in the thoracic region to the tranverse 
processes of all the vertebrae. Some of its fibres are continued above 
into the upper muscles of the column. 
The transversalis cervicis (longissimus cervicis) springs by delicate tendons, 
placed internally to those of the longissimus dorsi, from the transverse 
processes of the four or five upper thoracic vertebrae and that of the last 
cervical. It is inserted by tendons into the posterior tubercles of the 
transverse processes of the cervical vertebrae from the second to the sixth. 
The trachelo-mastoid (longissimus capitis), in close connection with the 
inner surface of the transversalis cervicis, takes origin by tendons from 
the transverse processes of the two or three upper thoracic vertebrae, and 
from the roughnesses on the sides of the articular processes of the two 
or three lower cervical vertebrae. It forms a thin muscular sheet, and 
is inserted into the posterior region of the outer surface of the mastoid 
process, under cover of the splenius capitis. A tendinous intersection crosses 
the upper part of the muscle. 
The complexus, a strong fleshy mass, arises from the articular processes 
of the lower four or five cervical vertebrae, and from the transverse 
processes of the upper six or seven thoracic vertebrae, and at its inner DEEP MUSCLES OF THE BACK. 
361 
edge it usually receives a slip from one or two of the higher thoracic or 
lower cervical spines. It is inserted into the inner area between the two 
curved lines of the occipital bone. A tendinous intersection is usually 
Obliquus superior 
Occipitalis | 
Occipital protuberance 
Occipitalis 
Splenius capitis 
Mastoid process 
Right and left complexus 
Splenius colli 
3rd cervical articular process 
Splenius colli 
Complexus (tendinous 
intersection) 
Trachelo-mastoid 
Biventer cervicis 
Levator anguli scapulae 
Ist thoracic transverse 1 
process I 
.Tendon of biventer 
Scalenus posticus 
.Complexus 
Serratus posticus superior 
Transversalis cervicis 
Complexus 
Splenius 
Longissimus dorsi 
Fig. 284.—The Upper Part of the Erector Sphstab and the Complexes. (L. Testut.) 
found about the middle of the inner edge of the muscle, and, in con- 
sequence, the name biventer cervicis is sometimes given to the portion of 
the muscle which lies next the spines. 
The semispinalis springs from the transverse processes of the thoracic 
vertebrae from the first to the tenth, and is inserted into ten spines from 
that of the axis downwards. The upper four or five slips show large 
muscular bundles springing from short tendons of origin, and, collectively, 
receive the name of semispinalis colli. The lower portion of the muscle, 
semispinalis dorsi, is made up of five or six slender muscular slips lying 
between long tendons of origin and insertion. 
The multifidus spinae is formed of a large number of generally fan- 
shaped muscular bundles, and extends from the sacrum to the axis. In 
the neck the bundles arise from the articular processes of the third and 
succeeding vertebrae, in the thoracic region from the transverse processes, 
in the loins from the mammillary processes, and in the sacral region, where 
the bundles are blended together at their origin, the muscular fibres spring 362 
THE MUSCLES. 
from the hollow on the back of the sacrum extending as far as the fourth 
foramen, from the posterior sacro-iliac ligament, and from the overlying 
tendon of the erector spinae. The fibres pass to the spines of all the 
movable vertebrae from the axis down- 
wards, and on each spine the insertion 
spreads from the base almost to the tip. 
The more superficial fibres of each fan- 
shaped bundle cross over three or four 
vertebrae; the deeper are successively 
shorter, and the deepest of all, most 
constant in the thoracic region, but 
occasionally present in the neck and 
loins, pass between contiguous bones. In 
the neck and thoracic region the bundles 
may be separated from one another with 
tolerable accuracy; but in the loins, where 
the muscle is thickest, the fibres of succes- 
sive bundles are considerably intermixed. 
The more superficial or longer fibres of 
any one bundle overlie the deeper or 
c 
Fig. 285.—Three Bundles of the Multi- 
tudes Spinae in the Thoracic Region. 
a, Multifidus spinae; h, levator costae; 
c, posterior costo-transverse ligament. 
shorter fibres of the neighbouring higher bundles. The deepest or shortest 
fibres which pass between contiguous bones are sometimes separately 
described under the names rotatores dorsi or rotatores spinae. The highest 
one or two bundles of the muscle are necessarily short. 
The interspinales muscles form in the neck and loins a single set on 
each side of the middle line; in the thoracic region they are usually absent 
altogether. In the neck the muscles are rounded bundles, the highest 
of which is placed between the second and third vertebrae. In the 
lumbar regions they are thin and flattened from side to side. 
The intertransversales muscles form in the neck and loins a double 
set on each side; in the thoracic region they are usually absent. The 
cervical muscles, anterior and posterior in position, pass respectively 
between successive anterior tubercles and successive posterior tubercles of 
transverse processes, the highest pair stretching between the atlas and the 
axis. The lumbar muscles are, relatively to one another, external and 
internal in position. The external muscles (intertransversales laterales) pass 
between successive transverse processes; the internal muscles (intertransversales 
mediales) in each case extend from the accessory process of one vertebra 
to the mammillary process of that immediately beneath it. 
The rectus capitis posticus major, a fan-shaped muscle, passes from 
the side of the spine of the axis upwards and outwards to the outer 
part of the inferior curved line of the occipital bone and the under- 
lying rough area. 
The rectus capitis posticus minor, fan-shaped, and smaller than the 
last, springs from the tubercle of the posterior arch of the atlas, and DEEP MUSCLES OF THE BACK 
passes upwards to its insertion into the inner part of the inferior curved 
line and the underlying depression. 
Complexus 
Rectus capitis posticus minor 
.Obliquus superior 
Rectus capitis posticus major 
Obliquus inferior. 
/ Tendons of splenius colli and levator 
I anguli scapulae 
Multifidus spinae 
Transversalis cervicis 
Cervical interspinales, 
.Semispinalis colli 
I) 1. 
.Semispinalis dorsi 
Interspinous ligament 
j Longissimus dorsi (inner 
| insertions) 
Multifidus spinae 
f Longissimus dorsi (inner 
( insertions) 
Lumbar interspinales 
Multifidus spinae 
The obliquus capitis inferior springs from the spine of the axis. It 
passes outwards and upwards to its insertion into the lower and back part 
°f the transverse process of the atlas. 
Fxo. 286.—The Semispinalis and Multifidus Spinae. (L. Testut.) 
The obliquus capitis superior arises from the upper surface of tho 364 
THE MUSCLES. 
transverse process of the atlas. It broadens as it passes upwards and 
inwards to its insertion into the outer area between the curved lines of 
the occipital bone. 
Actions. A number of the muscles act upon the skull. By the com- 
bined action of the complexus, splenius, trachelo-mastoid, superior oblique 
and recti, of opposite sides, the skull is drawn backwards upon the column, 
and when the muscles of only one side act an oblique movement is pro- 
duced ; the principal elevator of the cranium is the complexus, and the 
principal agent in producing oblique movement the splenius. The inferior 
oblique of one or other side acting without its fellow produces a movement 
-of rotation at the atlanto-axial joint, and is assisted by the splenius, trachelo- 
Rectus capitis posticus major 
Rectus capitis posticus minor 
Obliquus capitis superior 
Obliquus capitis superior. 
Mastoid process 
1, Spine of atlas 
•Rectus capitis postiousmajor 
.Obliquus capitis superior 
Transverse process 
of atlas 
Obliquus capitis inferior 
Spine of axis, 
Interspinales, 
Fig. 287.—The Posterior Short Cranio-Vertebral Muscles. (L. Testut.) 
mastoid, and the larger rectus of its own side. The rest of the muscles 
.act upon the column, producing lateral curvature or extension according 
as those of one side only or of both sides together are brought into play. 
Relations and nerve supply. The suboccipital triangle is the space bounded 
by the margins of the two oblique and the larger recti muscles; the 
vertebral artery, in a portion of its course, lies in it, and the suboccipital 
nerve, which supplies the four short posterior cranio-vertebral muscles, 
emerges between the artery and the atlas. The deep cervical artery 
lies on the deep surface of the cervical portion of the complexus, and upon 
the origins of the multifidus spinae muscle. Further down in the back 
the dorsal branches of intercostal and lumbar arteries ramify among the 
muscles of the group. The posterior primary divisions of the spinal nerves, 
dividing into external and internal branches, likewise ramify among the 
muscles. The external branches pass to the splenius and erector spinae; the 
internal branches supply the deeper muscles of the back with the exception 
of the cervical intertransverse and the lateral lumbar intertransverse muscles 
which are supjdied by the anterior divisions of the nerves. DEEP MUSCLES OF THE BACK. 
The external intertransverse muscles in the loins lie in morphological 
series with the levatores costarum and the external intercostal muscles in 
the thoracic region, and with the posterior intertransverse muscles and 
the rectus capitis lateralis in the neck. The anterior intertransverse 
muscles in the neck are in series below with the internal intercostal 
muscles of the thorax, and above with the rectus capitis anticus minor 
muscle. The internal intertransverse muscles (intertransversales mediates) 
of the loins are represented in the thoracic region probably by the inter- 
transverse ligaments, and are not represented in the neck. 
Deep fascia of the back. In the thoracic region the deep muscles of 
the back are covered posteriorly by a delicate layer of fascia, the vertebral 
fascia, which extends outwards from the spines to the ribs beyond the 
angles and blends with the intercostal fascia. Above, it passes on the 
deep surface of the superior serratus and becomes blended with the deep 
fascia of the neck; below, it is continuous with the posterior layer of the 
lumbar aponeurosis. 
The turn,bar aponeurosis. Under this name three layers of fascia are 
described. The posterior layer, a strong aponeurotic sheet, is attached to 
the lumbar and sacral spines and to the posterior third of the iliac crest. 
In its lower part it becomes blended with the tendon of the erector 
spinae. At its outer margin it joins the middle layer and forms with it 
a single sheet from which a portion of the transversalis abdominis muscle 
is continued. In crossing outwards it covers posteriorly the deep muscles 
of the back and gives origin to the serratus inferior and a portion of the 
latissimus dorsi. The middle layer springs from the tips of the lumbar 
transverse processes and is attached above to the lower border of the last 
rib, and below to the ilio-lumbar ligament and the iliac crest. It passes 
outwards in front of the deep muscles of the back, and at the outer 
border of the erector spinae is joined by the posterior layer. The anterior 
layer is a more delicate sheet of fascia wdiich covers the quadratus lum- 
borum, and is partly blended at the outer margin of the muscle with the 
conjoined middle and posterior layers and partly continued into the fascia 
transversalis. 
The intercostal muscles. In each interspace are found two layers of 
muscular fibres, oblique in direction, forming the external and internal 
intercostal muscles. Neither layer extends from end to end of the space, 
the external being deficient in front, the internal behind. For some 
distance in each space the intercostal vessels and nerves run forwards 
between the muscles, but near the front they sink into the substance of 
the inner layer. 
THE MUSCLES OF THE THORAX. 
The external intercostals are formed of fibres which pass from above 
downwards and forwards. Each muscle springs from the lower margin of 
a rib and is inserted into the upper margin of the rib below. The 366 
THE MUSCLES. 
posterior edges of the muscles reach backwards to the line of the tubercles. 
The anterior edges, in most cases, extend as far forwards as the line of 
junction of the bony ribs with the cartilages, but in the case of the first 
two or three fall a little short of, and in the case of a few of the lower 
reach a little further than this line. Continuous with the anterior edges, 
thin sheets of aponeurotic fibres, the anterior intercostal aponeuroses, extend 
to the extremities of the spaces. 
The internal intercostals are not so strong as the externals, and are 
formed of somewhat shorter fibres, the direction of which is downwards 
.and backwards. Each muscle springs from the cartilage and osseous rib, 
Internal intercostal 
Fig. 288.—The Intercostal Muscles. (L. Testut.) 
along the line of the upper margin of the subcostal groove, and is inserted 
into the rib below, on the inner surface close to the upper edge. The 
anterior edges of the muscles extend to the extremities of the spaces, 
and the last two are continuous in front with the internal oblique muscle. 
The posterior edges do not reach further backwards than the line of the 
angles, and, beyond this, thin sheets of fascia, the posterior intercostal 
aponeuroses line the external muscles. 
Additional slips are frequently found in connection with the intercostal 
muscles. The name “ supra-costalis ” has been given to an occasional slip 
connected with the external muscles descending from the anterior extremity 
of the first rib over two or three interspaces. The “sub-costal muscles” 
are small variable muscular sheets placed on the inner surface of the MUSCLES OF THE THORAX. 
367 
thoracic wall in the vicinity of the angles of the ribs; they are associated 
with the internal muscles and usually cross over more than one inter- 
space. The intercostal muscles are supplied by the intercostal nerves. 
The levatores costarum, twelve in number on each side, are small 
triangular muscles placed on the hinder aspect of the posterior extremities 
of the ribs. Each springs from the posterior surface and lower edge of 
the extremity of a transverse process, and passing downwards and out- 
wards parallel to the line of an external intercostal muscle, is inserted 
into the upper margin and posterior surface of the rib, immediately 
below, in the region between the tubercle and the angle. The first springs 
from the transverse process of the last cervical, and the last from that of 
Levator costae 
External intercostal 
.Internal intercostal 
Posterior intercostal aponeurosis 
Fio. 289.—The Levatores Costarum. (L. Testut.) 
Levatores costarum 
the eleventh thoracic vertebra. Near the lower end of the series a few of 
the muscles present additional slips which, under the name of levatores 
costarum longiores, cross over two interspaces. 
The diaphragm, or midriff, is a vaulted musculo-tendinous partition which 
separates the thorax from the abdomen, and is pierced by the structures 
which pass from the one cavity to the other. The fibres arise from the 
front of the lumbar portion of the column, from the fascia covering the 
psoas and quadratus lumborum muscles, from the cartilages of the six 
lower ribs, and from the ensiform process of the sternum; they con 
verge to a central tendon which forms the dome of the vault. 
The central or trefoil tendon is formed of interwoven fibres continuous 
with the fleshy fibres of the muscle. It is concave posteriorly, convex 
and partially divided into three leaflets anteriorly—the left leaflet being 
the smallest, the right the largest of the three. The upper surface of the 
central leaflet is firmly attached to the pericardium, and rises as high as 
the level of the xipho-sternal articulation. The left leaflet rises to about 368 
THE MUSCLES. 
half an inch above the central portion, and the right, which is the highest 
of all, to a little more than an inch. Near the posterior margin of the 
tendon, in the line between the central and right leaflets, is a large some- 
what four-sided aperture for the passage of the inferior vena cava. 
Pig. 290.—The Diaphragm, upper surface. (L. Testut.) 
The vertebral portion of the muscle springs from two strong tendinous 
pillars or crura. The right crus, larger and broader than the other, takes 
origin from the anterior surface of the bodies of the first three lumbar 
vertebrae and the intervening discs; the left is confined to the first two 
lumbar bodies and the disc between them. The fibres from the crura MUSCLES OF THE THOEAX. 
369 
converge and partially decussate with one another, and finally reach the 
median portion of the posterior margin of the central tendon. Opposite 
Pig. 291.—The Diaphragm, under surface. (L. Testut.) 
the disc between the last dorsal and first lumbar vertebrae, the vertebral 
portion of the muscle presents an opening which transmits tie aorta, and, in 
addition, the thoracic duct and, usually, the great azygos vein. The lateral THE MUSCLES. 
margins of the opening are formed by the tendinous fibres of each crus, 
and posteriorly a few fibres cross between the crura behind the aorta. A 
little above, and somewhat to the left of the aortic opening, is an aperture 
for the passage of the oesophagus and the pneumogastric nerves. The 
aperture is elongated from before backwards, and is usually entirely 
pounded by the decussating fleshy fibres from the pillars, those from the 
right passing generally in front of those from the left. In addition, the 
vertebral portions of the diaphragm are generally pierced by the splanchnic 
nerves, the lesser azygos vein, and, occasionally, by the main cords of the 
sympathetic. 
The ligamenta arcuata are thickened bands of the fascia lining the 
abdominal wall. The internal stretches from the body to the tranverse 
process of the first lumbar vertebra arching over the psoas muscle; the 
external extends from the first lumbar transverse process to the last rib, 
near its point, arching over the quadratus lumboruxn muscle. The fibres 
from these bands, forming on each side a broad thin portion of the muscle, 
pass to the posterior margins of the lateral leaflets of the tendon. The 
sympathetic cord usually passes under the internal, and the last dorsal 
nerve under the external arched ligament. 
The costal portion of the muscle springs on each side by six fleshy 
slips from the inner surfaces of the six lower ribs, chiefly from the 
cartilages, but to a slight extent also from the bones. The slips inter 
digitate with the slips of the transversalis abdominis muscle. The muscular 
fibres arch upwards to the lateral and anterior margins of the central 
tendon, those from the eighth and ninth ribs being the longest. 
The sternal portion is formed by a slender fasciculus, sometimes divided 
into two, the fibres of which are the shortest of the whole muscle. It 
passes from the back of the ensiform process to the anterior margin of 
the central leaflet. Between the sternal and costal portions an interval 
is left on each side, through which the superior epigastric artery passes 
from the thoracic to the abdominal wall, and at which the lining mem- 
branes of the two cavities come into contact. 
The diaphragm is supplied by the phrenic nerves from the cervical 
plexus. 
The triangularis sterni (transversus thoracis) is formed of a number of 
delicate slips in series with those of the transversalis abdominis muscle. It 
arises on each side from the back of the lower part of the sternum, extending 
upwards in its origin as far as the level of the third costal cartilage. 
The slips are inserted into the lower edges and posterior surfaces of the 
costal cartilages from the second to the sixth, the highest, however, 
having a partial attachment to the bony rib. The upper slips are almost 
vertical in direction, the lower transverse. The muscle lies behind the 
internal mammary artery in a portion of its course. It is very variable 
in size and is sometimes absent altogether. The triangularis receives its 
supply from intercostal nerves. MUSCLES OF THE THORAX. 
371 
The serratus posticus superior (Fig. 282) arises by a thin flat tendon 
from the lower part of the ligamentum the last cervical and the 
first two or three thoracic spines. It passes downwards and outwards as a 
thin sheet, and immediately beyond the lateral margin of the erector 
spinae is inserted into the outer surfaces and upper borders of four 
ribs from the second to the fifth, and into the fascia covering the corre- 
sponding intercostal spaces. The muscle lies on the deep surface of the 
Fig. 292.—The Triangularis Sterni. (L. Testut.) 
vhomboidei, and is completely covered by them, except at the upper part 
of the origin where it comes into contact with the deep surface of the 
trapezius. 
The serratus posticus inferior (Fig. 229) arises, under cover of the 
latissiraus dorsi, from the posterior layer of the lumbar aponeurosis in 
the region betiveen the tenth thoracic and fourth lumbar spines. It is 
inserted by four slips into the lower borders of the last four ribs. The 
sbps of insertion extend outwards from the border of the erector spinae 372 
THE MUSCLES. 
muscle as far as the margins of the costal slips of the latissimus dorsi. 
The first slightly overlaps the second, the third is considerably overlapped 
by the second, and in many cases the last is almost completely concealed 
by the third. 
The two posterior serrati muscles are supplied by intercostal nerves. 
Actions of the muscles of the thorax. Air is drawn into the lungs by 
the enlargement of the cavity of the thorax consequent upon the action 
of the muscles attached to and forming its walls. The enlargement is pro- 
duced by the descent of the diaphragm and by the movements of the costal 
arches. The movements of the ribs have already been described (p. 128). 
The central portion of the tendon of the diaphragm is attached to the 
pericardium, and, undergoing little or no alteration in position, leaves the 
heart undisturbed; but the muscular fibres are straightened by contraction, 
and their peripheral parts are thereby separated from the thoracic wall. 
In this way the costo-phrenic space is opened up, and into it the bases 
of the lungs are drawn, while the abdominal viscera are displaced down- 
wards. The serratus posticus inferior draws backwards the four lower ribs, 
and, along with other muscles, affords resistance to the costal portion of 
the diaphragm, and thus enables it in contracting to concentrate its 
action upon the thoracic floor. The serratus posticus superior and the 
levatores costarum elevate the ribs and take part in inspiration. The 
triangularis sterni depresses the ribs and takes part in forced expiration. 
The action of the intercostal muscles has been the subject of much 
controversy. According to Haller the external and internal muscles have 
a common action. It is nevertheless geometrically true that if two rods, 
maintained parallel to one another, are attached at one end to a vertical 
bar (representing the vertebral column), so as to be capable of upward 
and downward movement, and if points be marked on each to represent 
the attachments of the fibres of the external and internal intercostals, the 
fibres of the external muscles will be seen to be shortened by the elevation 
and those of the internal by the depression of the rods. This is the 
foundation of the view originated by Hamberger, that the external inter- 
costals are muscles of inspiration and the internal muscles of expiration. 
Hutchinson (Cyclopaedia of Anatomy and Physiology, 1852) pointed out, that 
in as far as the region of the costal cartilages is concerned, the sternum 
must be considered the upright bar on which the movement takes place. 
He regarded therefore the anterior portions of the internal intercostals 
as elevators of the ribs, and inspiratory in function, and in this saw an 
explanation of the absence of the external intercostal muscles in front, and 
of the internal muscles posteriorly, muscular effort being specially required 
in inspiration. The geometrical arguments of Hamberger and Hutchinson 
necessitate the supposition that the successive ribs remain parallel to one 
another in all phases of movements, but in the dead body it may be 
seen that two contiguous ribs may be forced apart or drawn together 
without the simultaneous elevation or depression of both. MUSCLES OF THE THORAX. 
373 
The two layers of muscles acting together would tend to approximate 
the x'ibs in series to the more fixed extremity of the thorax. In ordinary 
inspiration an actual approximation takes place in the case of the first 
and second spaces, the first rib remaining practically stationary, the 
second and third being elevated; and in the succeeding spaces it seems 
probable that, in the altered conditions brought about by the elevation 
of the upper ribs, the contraction of both layers of muscles would be 
required to maintain the parallelism of the ribs and support the thoracic 
wall. As the successive ribs are being elevated together the fibres of the 
internal intercostals will, from their direction, tend to be stretched, but 
the slight eversion of the lower border of the greater part of the rib 
which takes place during the movement will have a counterbalancing 
effect. In forced expiration, when the lower ribs are fixed by the con- 
traction of the muscles of the abdominal wall, contraction of the inter- 
costal muscles of the lower spaces will tend to diminish the size of the 
thoracic cavity. 
In full inspiration a number of additional muscles are called into 
action. The vertebral column is extended; the sternum and the first 
and following ribs are elevated by the sterno-mastoid and scaleni muscles. 
In forced inspiration, with the arms fixed, the pectoralis minor and 
parts of the pectoralis major and serratus magnus, give powerful assist- 
ance. In ordinary expiration little or no muscular effort is required, the 
natural elasticity of parts bringing about recoil. In forced expiration the 
vertebral column is flexed, and the muscles which act upon the lower ribs, 
particularly those of the abdominal wall, are called into play: the tri- 
angularis sterni and possibly also the lower intercostals assist. 
MUSCLES AND FASCIA OF THE ABDOMEN. 
The cavity is separated from the thorax by the diaphragm, below it 
passes into the pelvis. The wall is partly formed by ribs, vertebral column, 
and pelvic bones, and is completed by various muscles and fasciae. The 
anterior and lateral portions of the wall are chiefly formed by three broad 
muscles on each side superimposed upon one another, named, from without 
inwards, respectively the external oblique, the internal oblique, and the 
transversalis. Over the lateral area of the wall they are fleshy, but in front 
they pass into thin expanded tendons, which meet in the middle line with 
one another, and with the similarly united tendons of the opposite side in 
a raphe which extends from the ensiform process to the upper margin of the 
symphysis pubis, and is named the linea alba. A cicatricial depression a 
little below the middle of this line is named the umbilicus. A long, vertically 
placed muscle, the rectus abdominis, lies by the side of the linea alba, and is 
inclosed in a sheath which is formed by the separation into two layers of 
the tendon of the internal oblique, one portion strengthened by junction THE MUSCLES. 
with the tendon of the external oblique passing in front of the muscle, 
the other incorporated with that of the transversalis passing behind. In 
the lower part of the anterior wall of the sheath lies a small muscle, the 
pyramidalis. The lineae semilunares are two indistinct lines seen from 
the front when the fascia has been removed, marking the outer edges of 
the recti muscles. The lineae tranversae, three or four in number on each 
side, cross from each linea semilunaris to the linea alba; they mark the 
position of tendinous intersections in the substance of the recti muscles. 
The posterior border of the external oblique is sometimes overlapped 
by the outer edge of the latissimus dorsi muscle, but frequently a narrow 
interval is left between them in which a few of the posterior fibres of the 
internal oblique are exposed, and through which there occasionally occurs 
a protrusion of abdominal viscera, a “ lumbar hernia.” The posterior 
edges of the broad muscles reach as far back as a line drawn from the last 
rib near its point to the iliac crest at the junction of the posterior third 
with the anterior two-thirds, and behind this line the posterior wall of the 
abdominal cavity is formed by a thin muscle, the quadratus lumborum, 
which stretches between the last rib above and the ilio lumbar ligament and 
the iliac crest below, and reaches as far inwards as the extremities of the 
transverse processes. On the anterior surfaces of the transverse processes 
and sides of the vertebral bodies lies the psoas magnus, along with which the 
psoas parvus, an occasional muscle, is sometimes found. The venter of 
the ilium is clothed by the iliacus muscle. A strong layer of aponeurosis, 
the middle layer of the lumbar aponeurosis, attached to the tips of the 
transverse processes, stretches outwards behind the quadratus lumborum. 
At the outer border of the erector spinae muscle it is united with the 
posterior layer of the lumbar aponeurosis which sweeps outwards from 
the spines, and the incorporated layers of fascia are continued into the 
transversalis muscle, affording it a portion of its origin. 
The inner surface of the abdominal wall is everywhere lined by a con- 
tinuous sheet of fascia, for the most part delicate, but strengthened at 
places, and receiving different names in the different regions which it covers. 
On the deep surface of the anterior and lateral part of the wall it is called 
transversalis fascia; on the quadratus lumborum it is known as the 
anterior layer of the lumbar aponeurosis. On the iliacus muscle and upon 
the psoas and the vertebral bodies it is named iliac fascia. Above, the 
fascia forms a thin layer which lines the diaphragm; below, it is fixed to 
the margin of the true pelvis, and is continued downwards as the pelvic 
fascia. 
The lower margin of the anterior abdominal wall corresponds to a 
line drawn inwards and downwards from the anterior superior spine of 
the ilium to the extremity of the first half inch of the ilio-pectineal line, 
and continued inwards and forwards along the first half-inch of the ilio- 
pectineal line and the spine and crest of the pubis to the symphysis. 
The lower border of the aponeurosis of insertion of the external oblique MUSCLES AND FASCIA OF THE ABDOMEN. 
375 
muscle stretches between the anterior superior spine and the extremity 
of the first half-inch of the ilio-pectineal line, and further inwards is 
attached to the spine and crest of the pubis. With the lower margin 
of the aponeurosis are incorporated the other constituents of the anterior 
abdominal wall. When the thigh is extended, the fascia lata being uncut, 
some of the lower fibres of the aponeurosis of the muscle are brought 
into special prominence and give the appearance of a band stretching 
from the anterior superior spine to the spine of the pubis. The band 
thus made prominent is Poupart’s ligament; it forms an important surgical 
Pectoralis major 
Latissimus dorsi 
Serratus magnus 
External oblique 
Sheath of rectus 
Umbilicus 
Tendon of external oblique 
Superflcial’abdominal ring 
Fig. 293.—The External Oblique Muscle. (L. Testut.) 
landmark. The great vessels which pass between the abdomen and the 
thigh lie behind Poupart’s ligament, and by their inner side there is a 
small blind pouch into which a protrusion known as a “femoral hernia 
occasionally occurs. 
The lower part of the anterior abdominal wall is traversed by an 
oblique passage, the inguinal canal, which transmits in the male the 
spermatic cord and in the female the round ligament of the uterus. The 
inner opening of the canal is known as the internal or deep abdominal 
ring, and is placed about half an inch above the middle of Poupart’s 376 
THE MUSCLES. 
ligament. The external or superficial ring lies immediately above the 
spine of the pubis. A hernial protrusion along this canal is called an 
“ inguinal hernia.” 
The external oblique has a broad origin from the outer surfaces of 
the eight lower ribs, by fleshy slips which interdigitate, the higher with 
those of the serratus magnus, the lower with those of the latissimus dorsi. 
The muscular fibres from the last two ribs pass almost directly down- 
wards to the outer lip of the anterior half of the iliac crest, the others 
are directed inwards and downwards to a broad aponeurosis which forms 
the tendon of insertion. 
The aponeurosis of the external oblique covers the anterior part of 
the abdominal wall. It consists for the most part of parallel, obliquely 
descending, fibres passing inwards in front of the rectus muscle to the linea 
alba. Its lower edge is stretched from the anterior superior iliac spine to 
the first half-inch of the ilio-pectineal line and the spine and crest of the 
pubis, where it is attached along a continuous line. It is described under 
the names of “Poupart’s ligament” and “ Gimbernat’s ligament.” 
Fouparfs ligament, or the superficial crural arch, is the band of fibres 
brought into prominence when the thigh with the fascia lata intact is 
extended and rotated outwards. It stretches from the anterior superior 
spine to the spine of the pubis. In its outer three-fourths it contains all 
the fibres of the lower edge of the aponeurosis of insertion of the external 
oblique, but in its inner fourth only the more superficial, those which 
form the band attached to the pubic spine. Gimbernat’s ligament is formed 
by the deeper fibres which pass from the inner fourth of Poupart’s ligament 
to insertion into the first half-inch of the ilio-pectineal line. Muscular fibres 
of the internal oblique and transversalis muscles spring from the outer 
part of Poupart’s ligament, and, more internally, the conjoined tendon of 
the two muscles is attached to the deep surface of the ligament, and is 
continued along with Gimbernat’s ligament to the ilio-pectineal line. 
Deeper still, the fascia transversalis is fixed to the back of Poupart’s 
ligament, and at its inner part is closely associated with Gimbernat’s 
ligament and the conjoined tendon. The fascia iliaca blends with the 
fascia transversalis on the deep surface of the outer half of Poupart’s 
ligament; further inwards the two fasciae are separated from one another 
by the great vessels, but still further inwards they again meet at the 
outer edge of Gimbernat’s ligament. The iliac portion of the fascia lata 
is attached to the lower edge of Poupart’s ligament, and the pubic 
portion of the same fascia is fixed to the ilio-pectineal line along the 
line of attachment of Gimbernat’s ligament. To the anterior surface of 
Poupart’s ligament is attached the fascia of Scarpa, the deep layer of 
the superficial fascia of the lower part of the anterior abdominal wall. 
The external or superficial abdominal ring is an opening in the lower part 
of the tendon of the external oblique for the passage of the spermatic cord 
and its associated structures in the male, or the round ligament of the MUSCLES AND FASCIA OF THE ABDOMEN. 
377 
uterus in the female. The opening is a narrow space left between the fibres 
■attached to the crest of the pubis and those which are attached to the spine. 
The margins of the aperture are called the columns or pillars of the ring. 
Some of the fibres of the inner pillar decussate on the front of the 
symphysis, with corresponding fibres from the opposite side. The opening 
is triangular in shape, the base being on the crest of the pubis, and the 
apex half an inch distant, a little above and a little external to the spine. 
The pillars are bound to one another by a delicate sheet of transverse 
■or intercolumnar fibres which is prolonged, under the name of the inter- 
columnar or spermatic fascia, as a covering to the structures which pass 
through the ring. The cord or round ligament, in passing through, lies 
upon the lower or outer pillar, in immediate proximity to the outer edge 
•of the spine. Some fibres which pass inwards from Grimbernat’s ligament 
Inter-columnar fibres 
External oblique 
Symphysis pubis _ 
| Inner pillar of left ring 
'3, Tendon of ex- 
ternal oblique 
1, Poupart’s liga- 
ment 
Inner pillar of right ring 
4, Outer pillar of 
ring 
7, Superficial 
abdominal ring 
Triangular 
fascia 
Pig. 294.—The Superficial Abdominal Ring (diagrammatic). (L. Testut.) 
•cross the floor of the ring, passing behind the inner pillar to reach the 
front of the sheath of the rectus, where they are associated with the 
fibres of the inner pillar of the opposite side. They are very variable in 
the extent of their development and are named the triangular fascia. 
The internal oblique arises by fleshy fibres, which are directed imvards, 
the upper passing, in addition, obliquely upwards, the lowest having a 
slight direction downwards. They spring from the middle area of the 
anterior two-thirds of the iliac crest, and from the outer half of Poupart’s 
ligament. At the upper and posterior border a few fibres take origin 
from the lumbar aponeurosis. The upper fibres are attached to the lower 
borders of the cartilages of the last four ribs, and lie at their insertion 
in the same plane as the internal intercostal muscles. Those next in 
order pass into a broad aponeurosis which begins about an inch from the 378 
THE MUSCLES. 
margin of the rectus muscle, and sweeps inwards to the linea alba, splitting 
as it reaches the muscle to assist in forming its sheath; the anterior layer 
blends with the tendon of the external oblique, the posterior with that 
of the transversalis. The lowest fibres, joining with the lowest of the 
Internal intercostal 
External intercostal. 
Serratus magnus. 
Rectus 
Sheath of rectus (anterior wall) 
Umbilicus 
Internal oblique 
External oblique. 
Rectus 
Pyramidalis 
10, Tendon of external oblique 
Fig. 295.—The Internal Oblique and Rectus Muscles, (L. Testut.) 
transversalis muscle, are inserted along with them by the conjoined tendon 
into the first half-inch of the ilio-pectineal line, and into G-imbernat’s 
and a portion of Poupart’s ligament. The lower border of the muscle 
crosses in front of the inguinal canal. 
The cremaster represents a continuation downwards of a few of the 
lower fibres of the internal oblique, and is much better developed in 
the male than in the female. It springs from Poupart’s ligament at 
the lower margin of the internal oblique, and in the male its fibres 
descend in front of the cord; many of them form loops, and pass 
backwards to an inner insertion on the spine of the pubis, but others 
reaching further down are lost in a fascia, the cremasteric fascia, which 
invests the cord and the testicle. In the female a few fibres representing; 
the muscle are usually found descending in front of the round ligament. 
The transversalis has a broad origin, and its fibres are directed MUSCLES AND FASCIA OF THE ABDOMEN. 
379 
inwards, the lowest however, having, in addition, an inclination downwards. 
It springs (a) from the inner surfaces of the cartilages of the six lower ribs 
by fleshy slips which interdigitate with those of the diaphragm, (h) in the 
region between the last rib and the iliac crest, from the lumbar aponeurosis, 
(c) from the inner lip of the anterior half of the iliac crest, and (cl) from the 
outer third of Poupart’s ligament. All, except the lowest fibres, pass into 
a broad aponeurosis, which, joining the posterior layer of the aponeurosis 
of the internal oblique, sweeps towards the linea alba, and assists in 
forming the sheath of the rectus. Along the greater part of its length 
the aponeurosis begins about an inch from the margin of the rectus, but 
above it is narrow, and there the muscular fibres extend inwards for a 
little distance behind the sheath. The lowest fibres, closely associated 
with those of the internal oblique, pass into the conjoined tendon. 
Between the internal oblique and transversalis muscles run some of the 
lower dorsal and upper lumbar nerves, the lumbar arteries, and a branch 
of the deep circumflex iliac artery. 
The conjoined tendon, which receives the lowest fibres of the internal 
oblique and transversalis muscles, begins close to the inner and upper 
margin of the deep abdominal ring, and in passing downwards to its 
insertion is crossed in front, obliquely from without inwards, by the cord 
or round ligament. It is blended below with the deep surface of 
Poupart’s and Gimbernat’s ligament, and along with the latter is 
attached to the first half-inch of the ilio-pectineal line; its outer margin 
reaches as far outwards as the middle of Poupart’s ligament. Its 
outer border circumscribes the inner 
and lower margins of the deep ring, 
and is chiefly composed of fibres 
derived from the transversalis muscle. 
The middle portion of the tendon is 
the weakest, while the inner portion, 
descending to the ilio-pectineal line, 
is the strongest and best marked. The 
fascia transversalis is closely united to 
the deep surface of the tendon, but 
may, in a well-developed subject, be 
separated from it by careful dissection. 
The outer margin of the tendon, which 
surrounds the lower and inner sides of 
the deep ring, has sometimes been 
described under the name of the 
“reflected tendon of Sir Astley 
Cooper.” Occasionally muscular fibres 
belonging to the two muscles descend 
Anterior oblique 
fibres 
Vertical fibres 
Posterior 
oblique fibres- 
llio-lumbar 
ligament 
Fig. 296.—Arrangement or the Fibres of the 
Quadrates Lumborum (diagram.) (L. Testut.) 
upon the whole breadth of the tendon to the insertion. (Mackay, 1889.) 
The quadratus lumborum arises from the ilio-lumbar ligament and THE MUSCLES. 
the inner lip of the iliac crest for about an inch beyond the attachment 
•of the ligament. The outermost fibres are directed upwards and slightly 
inwards to the lower edge of the last rib, and those more internal, passing 
with more and more obliquity, are inserted into the transverse processes 
of the first four lumbar vertebrae. An additional set of fibres at the 
inner edge and on the anterior surface of the muscle springs from the 
transverse processes of the three lower lumbar vertebrae, and is inserted 
with the outer part of the muscle into the last rib and first lumbar 
transverse process. 
The rectus abdominis, strap-shaped, springs from the anterior surface 
and the upper border of the body of the pubic bone by a strong tendon 
partially divided into two. The inner portion of the tendon arises from 
the whole anterior surface of the symphysis, and is at its inner edge 
continuous with the corresponding tendon of the muscle of the opposite 
■side; the outer portion is attached to the crest. At the upper end the 
muscle is inserted by three slij)s, the outermost to the lower border of the 
fifth rib immediately external to the cartilage, the other two to the anterior 
■surfaces of the cartilages of the sixth and seventh ribs respectively. In 
the course of the muscle three tendinous intersections are commonly found; 
the first is usually placed opposite the articulation between the ninth and 
tenth costal cartilages, the second about an inch above the umbilicus, and 
the third about half an inch below the umbilicus. These do not as a rule 
penetrate the whole thickness of the muscular substance, but are confined 
to the anterior surface, and are intimately adherent to the anterior wall 
of the sheath. They may extend beyond the rectus into the substance 
of the internal oblique, and they occasionally appear to be continued from 
the extremities of some of the lower ribs. Additional ones are sometimes 
present. 
The pyramidalis is a small triangular muscle, of an inch to two inches 
in length, contained in the anterior wall of the sheath of the rectus. It 
arises from the anterior surface of the pubis, and, becoming narrower as 
it ascends, is inserted into the linea alba. The muscle is frequently absent 
■on one or both sides. 
The sheath of the rectus. Close to the margin of the rectus the 
.aponeurosis of insertion of the internal oblique splits into two layers, 
the anterior of which blends with the aponeurosis of the external oblique, 
the posterior with that of the transversalis. These pass to the linea alba, 
inclosing the rectus between them. The anterior wall of the sheath, 
moderately strong in the greater part of its extent, becomes thinner 
above where it is continued into the deep fascia of the chest wall; some 
fibres of the pectoralis major spring from it. At its lower end the 
pyramidalis is embedded in it. On its posterior aspect it is closely 
united to the tendinous intersections of the rectus muscle. 
The posterior wall of the sheath is strong in its upper two-thirds, 
and is fixed above to the margins of the cartilages of the sixth, seventh, MUSCLES AND FASCIA OF THE ABDOMEN. 
381 
and eighth ribs. In its lower part, below a line drawn between the most- 
prominent parts of the iliac crests of the opposite sides, it is very weak,, 
most of the fibres of the internal oblique and many of those of the trans- 
versals passing to the anterior wall of the sheath. The lower edge of 
the strong upper portion, lying a little below the umbilicus, is often 
marked as a distinct curved line, the semilunar fold of Douglas. A second 
semilunar fold, a little nearer the pubis, is often present, marking the spot 
where the deep epigastric artery enters the sheath; it has been named 
the hand of Henle. 
The linea alba is formed by the decussation of the tendinous fibres 
of the aponeuroses of the three broad muscles of the abdominal wall. It 
extends from the xiphoid process of the sternum to the pubis. It is 
somewhat broader above than below, and is pierced by numerous apertures 
for the passage of small vessels. The superficial fascia is adherent to it 
in front, the fascia transversalis behind. 
The umbilicus or navel is the mark left by the withering of the umbilical 
cord after birth. It is placed a little below the middle of the linea alba. 
From the front it appears as a somewhat rounded hollow, behind as a 
much smaller transversely elongated depression. It is occupied by some 
cicatricial and fatty tissue, by the urachus with the obliterated hypogastric 
arteries, and by the umbilical vein. The lower part of the space contains 
the urachus and the remains of the arteries, and is filled up by cicatricial 
tissue. The upper part of the space, much weaker, contains the remains 
of the vein surrounded by fatty tissue, which is continuous with the 
subcutaneous fat. Through the weak upper portion a hernial protrusion 
may take place. 
Actions of the abdominal muscles. Acting from below they flex the 
vertebral column, depress the lower ribs, and exercise pressure upon the 
abdominal viscera. They assist powerfully in producing the evacuation 
of the contents of hollow viscera, and play an important part in the 
movements of forced expiration. The muscles of one side, acting alone, 
can bring about lateral flexion of the column. The quadratus lumborum 
has but little direct action upon the viscera, but assists in producing 
lateral flexure of the column; it draws downwards the last rib, and, on 
account of its antagonism to the diaphragm, has been regarded by some 
as an agent in inspiration. When the thorax and upper part of the 
column are fixed the abdominal muscles of one or both sides may, by 
acting upon the lower part of the column, raise the pelvis. 
Nerves. The muscles are supplied by the lower dorsal nerves, and 
by the upper branches of the lumbar plexus. The muscles which receive 
supply from lumbar nerves are the pyramidalis and the lower parts of 
the internal oblique and transversalis, which receive branches from the 
ilio-hypogastric and ilio-inguinal nerves, and the cremaster which is- 
supplied by the genital branch of the genito-crural. 382 
THE MUSCLES. 
ABDOMINAL FASCIA. 
The deeper layer of the superficial fasciaat the lower part of the anterior 
wall, goes by the name of the fascia of Scarpa. Scarpa’s fascia is firmly fixed 
to Poupart’s ligament, extending as far inwards as the superficial abdominal 
ring. On account of this attachment, fluid which has been effused under 
the superficial fascia of the abdomen is prevented access into the thigh. 
At the ring the fascia passes downwards over the cord, or in the female 
the round ligament, and becomes continuous with the superficial tissue of 
the scrotum or labium, according to the sex. The superficial tissue of the 
scrotum is named the dartos tunic or fascia; it has a reddish colour, and 
contains a number of involuntary muscular fibres. It is continuous behind 
with Colles’ fascia, the superficial fascia of the anterior part of the perineum. 
Along the middle line of the abdomen the superficial fascia is fixed to the 
linea alba, and is continued below into the superficial fascia of the penis, 
which, like the dartos, contains a few involuntary muscular fibres, but 
is devoid of fat. A strengthened portion from the lower part of the 
linea alba and the symphysis attached to the dorsum of the penis near 
the root constitutes the suspensory ligament of the penis. 
A very thin deep layer of fascia lies close on the surface of the 
external oblique muscle, and becomes blended with its tendon at the 
lower part of the anterior abdominal wall, taking part in the formation 
of the intercolumnar fascia. 
The lining fascia of the abdomen. The anterior surface of the 
quadratus lumborum muscle is covered by a moderately strong layer of 
fascia, which goes by the name of the anterior layer of the lumbar aponeurosis. 
At its inner margin it is attached to the transverse processes of the 
lumbar vertebrae, and blends with the upward prolongation of the iliac fascia, 
which covers the psoas muscle; at its outer edge it is partly continued 
into the transversalis fascia on the deep surface of the transversalis muscle, 
and partly into the aponeurotic sheet formed by the union of the posterior 
and middle layers of the lumbar aponeurosis which forms the posterior 
tendon of the transversalis muscle. Below, it is fixed to the iliac crest; 
above, it passes as a very thin layer on to the diaphragm. A strengthened 
band, the ligamentum arcuatum externum, arches from the transverse process 
of the first or second lumbar vertebra to the inner surface of the last 
rib near its point, crossing the quadratus muscle and giving origin to a 
number of the fibres of the diaphragm. 
The iliac fascia, which below covers the iliacus muscle, is continued 
upwards as a fine layer over the surface of the psoas muscle, and spreads 
thence to the diaphragm, and is attached externally to the transverse 
processes, and internally to the vertebral bodies and intervertebral discs. 
Between the body and the transverse process of the first lumbar vertebra 
the fascia is strengthened in the form of a fibrous band, the ligamentum 
arcuatum internum, which gives origin to a number of the fibres of the MUSCLES AND FASCIA OF THE ABDOMEN. 
383 
diaphragm. The ligament has an occasional additional attachment to the 
transverse process of the second lumbar vertebra. At the lower part of 
the abdomen the fascia is stronger where it spreads over the iliacus muscle, 
and is attached externally to the iliac crest and internally to the ilio- 
pectineal line. It furnishes a delicate investment to the external iliac 
vessels, and behind them is continued into the thigh, forming the posterior 
Avail of the femoral sheath and blending with the deep prolongation of 
the pubic portion of the fascia lata on the ilio-psoas and pectineus muscles. 
The lower border of the fascia in the region external to the vessels is 
attached to the deep surface of Poupart’s ligament, where it meets the 
fascia transversalis. Abscesses connected Avith carious vertebrae, even 
Avhen the disease is limited to the dorsal region, may pass downwards 
in the substance of the psoas muscle and reach the thigh under cover 
of the prolongation of the iliac fascia. 
The fascia transversalis is a thin sheet which lines the deep surface 
of the transversalis muscle, and is continuous with the fascia covering the 
quadratus lumborum and the delicate layer on the under surface of the 
diaphragm. Anteriorly it is attached to the linea alba. Below, in the 
middle line, it passes behind the symphysis into the pelvis; further out- 
wards it is attached to the deep surface of the conjoined tendon and 
Gimbernat’s ligament, and still more externally to Poupart’s ligament 
and the iliac crest. In the region immediately external to Gimbernat’s 
ligament it is arched over the vessels, and is prolonged into the thigh as 
the main part of the anterior Avail of the femoral sheath. Beyond the 
artery it meets, on the deep surface of Poupart’s ligament, the fascia iliaca. 
Fig. 297.—Diagram of the Crural Arch. (L. Testut.) 
The crural canal and femoral hernia. The vessels which pass between 
the abdomen and the thigh receive in the abdominal portion of their course 
from the fascia iliaca upon which they lie, a delicate investment surrounding 
and separating them; but as they pass into the thigh there is added to this 
a moderately strong sheath, prolonged from the fascia transversalis in front 
and the fascia iliaca behind. At the place of exit of the vessels the sheath 384 
THE MUSCLES. 
is somewhat larger than is necessary to contain them, and a space, sufficient 
in size to admit the little finger, is left between the vein, which is the 
inner of the two vessels, and the edge of G-imbernat’s ligament. The 
sheath rapidly narrows, and the space is continued downwards for but a 
short distance—about half an inch—into the thigh, and terminates in a 
pointed blind extremity. The space is the crural canal; it occasionally 
gives passage to a protrusion of abdominal viscera known as a “femoral 
hernia.” In the normal state it is occupied by one or two small 
lymphatic glands and some subperitoneal tissue which constitute the 
septum crurale. The abdominal opening of the canal is bounded internally 
and anteriorly by Gimbernat’s ligament, to which the fascia transversalis 
is attached, externally by the vein, a delicate septum intervening, and 
posteriorly by the pectineus muscle clothed by the prolongation of the fascia 
iliaca into the deep portion of the fascia lata of the thigh. Immediately 
above the anterior margin the spermatic cord or round ligament passes 
obliquely downwards. In very rare cases an aberrant obturator artery from 
the deep epigastric passes downwards by the edge of Gimbernat’s ligament 
in such close proximity to the inner margin of the opening that it would 
be in danger of being cut in the operation for relief of a strangulated 
hernia. More frequently, however, when the aberrant vessel is present it 
passes downwards by the outer edge of the aperture of the crural canal. 
The crural canal terminates opposite the upper part of the saphenous 
opening, and a hernial protrusion which has passed through the canal 
receives, therefore, no covering from the fascia lata. The coverings of a 
femoral hernia are—the peritoneum of the abdominal wall forming the 
sac, the remains of the septum crurale, the anterior wall of the sheath of 
the vessels, and the cribriform fascia which covers the sajffienous opening. 
The name, deep crural arch, is sometimes given to the arch formed 
by Gimbernat’s ligament and the fascia transversalis over the crural canal 
and the vessels as they pass between the abdomen and the thigh. 
The deep abdominal ring—the inguincd canal—inguinal hernia. At 
the lower part of the anterior abdominal wall, about half an inch above 
the middle of Poupart’s ligament, the fascia transversalis is pierced by the 
spermatic cord in the male and the round ligament of the uterus in 
the female, and the opening thus formed in the fascia is called the 
internal or deep abdominal ring. From its margins a delicate continuation, 
the infundibuliform fascia, is prolonged onwards as an investment of the 
structures which pass through the ring. The upper and outer margins 
of the ring are somewhat weak, but the inner and lower margins are 
considerably strengthened by an intimate connection of the fascia trans- 
versalis with the outer edge of the conjoined tendon of the internal 
oblique and transversalis muscles. Close to the inner margin of the ring 
the deep epigastric artery passes upwards and inwards behind the inguinal 
canal in a sheath derived from the fascia transversalis. 
The inguinal canal, about one and a half inches in length, is the MUSCLES AND FASCIA OF THE ABDOMEN. 
385 
oblique passage between the deep and the superficial abdominal rings, 
and runs immediately above and almost parallel to the inner half of 
Poupart’s ligament. It is lined by the infundibuliform fascia. Above, it 
is crossed in front by the lower border of the internal oblique muscle, 
continuous with which in front of the canal lie the fibres of the cremaster 
muscle, much better developed in the male than in the female. More 
superficially in front lies the tendon of the external oblique muscle. Be- 
hind the canal lies the conjoined tendon, closely adherent to which, on 
the deep surface, is the lower part of the fascia transversalis. The deep 
epigastric artery crosses behind the canal in close proximity to the inner 
edge of the deep ring. 
An inguinal hernia may enter the canal by the deep ring, in which 
case its neck lies external to the deep epigastric artery, and it is called 
an oblique or external hernia. On the other hand, it may pass through 
the abdominal wall in the line of the canal at any spot between the artery 
Pig. 299.—The Conjoined Tendon. a, In- 
ternal oblique muscle (cut through and reflected); 
b, transversalis muscle; c, cremaster; d, testicle; 
e, tendon of external oblique (reflected) ; /, con- 
joined tendon ; g, deep epigastric artery. 
Fig. 298.—The Superficial Abdominal Ring. 
a, Fascia of Scarpa; b, intercolumnar fascia; 
c, spermatic cord. 
and the position of the superficial ring, and in this case receives the name 
of internal or direct hernia. Either form of hernia may remain inclosed 
within the wall, or may pass on through the superficial ring to the scrotum 
or labium. The ordinary contents of the canal usually lie behind the 
hernia in each case. 
In both forms the protrusion receives a covering from the peritoneum 
of the anterior abdominal wall, which is called the sac of the hernia, in 
association with which there is usually a delicate layer of subperitoneal 
tissue. The coverings of an oblique inguinal hernia, retained within the 
abdominal wall, are, in addition to the sac, simply those which have 
already been enumerated as forming the immediate surroundings of the 
2 B 386 
THE MUSCLES. 
inguinal canal, namely—the infunclibuliform fascia surrounding the sac, 
muscular fibres of the internal oblique and cremaster, and the tendon of the 
external oblique in front; the conjoined tendon with the fascia transversalis 
lying behind. In the scrotum this form of hernia, in addition to the 
dartos tissue, is surrounded by the intercolumnar fascia from the margins 
of the superficial ring, the cremasteric fascia, into which the cremaster 
muscle is continued, and the infundibuliform fascia. 
Umbilical vein 
a, Umbilicus 
2, Obliterated 
hypogastric 
artery 
i,T, Posterior sur- 
face of rectus 
abdominis 
;4, Deep 
: epigastric 
artery. 
1, Urachus 
Deep ’ 
abdominal 
ring. 
b, External in- 
guinal fossa 
Spermatic artery 
Spermatic artery 
5, Vas deferens 
5, Vas deferens 
c, Posterior surface 
of pubis 
Fig. 300.—The Lower Part of the Anterior Abdominal Wall, seen from behind. (L. Testut.) 
Bladder 
A direct hernia, in addition to the sac and the subperitoneal tissue, 
carries before it a portion of the fascia transversalis and conjoined tendon, 
usually associated as a single covering, and, if retained within the wall, 
lies behind the lower part of the external oblique tendon. In the scrotum 
its coverings are similar to those of the oblique form, with the exception 
that the investment from the fascia transversalis and conjoined tendon 
replaces the infundibuliform fascia. 
When the anterior abdominal wall is viewed from the deep surface, 
the deep epigastric artery passing towards the outer margin of the rectus 
abdominis muscle makes with it the sides of a triangle of which the inner MUSCLES AND FASCIA OF THE ABDOMEN. 
387 
part of Poupart’s ligament is the base; this is called the triangle of 
Hesselhach. Within this triangle a direct hernia pierces the wall; external 
to it an oblique hernia enters the deep abdominal ring. A much more 
prominent fold of peritoneum, however, than that formed by the deep 
epigastric artery is caused by the obliterated hypogastric artery, which, 
passing from the side of the bladder to the umbilicus, crosses behind 
the inguinal canal a little internal to the deep epigastric artery. The 
depressions on either side of this prominent fold are sometimes called the 
external and internal inguinal fossae. These names are somewhat con- 
fusing, for while a hernia piercing the wall in the internal fossa is always 
of the direct or internal order, one piercing in the external fossa is direct 
or internal on the one hand or oblique or external on the other, according 
as- it passes to the inner or to the outer side of the deep epigastric artery. 
MUSCLES AND FASCIA OF THE PERINEUM. 
In the posterior part of the perineum or pelvic outlet the anus is 
surrounded by the external sphincter muscle, so named to distinguish it 
from a somewhat deeper band of fibres, the internal sphincter, which, how- 
ever, is to be regarded merely as a thickened portion of the proper 
musculature of the bowel. From the pelvic wall on either side the levator 
ani muscle sweeps downwards and inwards to blend with the wall of the 
lower part of the rectum, the terminal part of the bowel, and to form 
with its fellow a median raphe behind and, for a short distance, in front of 
the anal aperture. In the male the bladder and prostate gland lie immedi- 
ately in front of the rectum, and are partially supported by the anterior 
portions of the levatores ani muscles, and the urethra passes through the 
prostate, and is directed forwards under the arch of the pubis to enter 
the penis. Upon the upper surface of the levatores ani muscles the recto- 
vesical fascia sweeps inwards and downwards from the pelvic wall to the 
bladder and rectum, and forms a complete floor of fascia to the pelvic 
cavity. The lower part of the obturator internus muscle, beneath the line 
of reflection of the recto-vesical fascia, is lined by the obturator fascia, 
and the space on each side of the lower part of the rectum, between the 
obturator fascia and the under surface of the levator ani muscle, is named 
the ischio-rectal fossa. In the anterior part of the perineum, in front 
of the ischial tuberosities, a double layer of fascia, the triangular liga- 
ment of the urethra, stretches from side' to side between the opposite 
margins of the ischio-pubic arch. The posterior or upper of the two layers 
is at its margins closely connected along the line of its bony attachment 
with the obturator fascia, and in its central part is blended on the under 
surface of the prostate with the recto-vesical fascia. In the male the 
triangular ligament is pierced by the membranous portion of the urethra, 
and between its layers lies the constrictor urethrae muscle. Upon the 
superficial aspect of the under or anterior layer of the ligament lies the 388 
THE MUSCLES. 
root of the penis formed of the bulb in the middle line, and the crura 
of the corpora cavernosa at the sides. The crura are covered by the 
erectores penis muscles, and the bulb by the accelerator urinae. In the 
female the vagina intervenes between the bladder and rectum, and passes 
through the triangular ligament; the accelerator urinae is represented by 
the sphincter vaginae and the erectores penis by the erectores clitoridis 
muscles. 
The central point of the 'perineum in the male is a spot about an 
inch in front of the anal aperture; it marks the posterior extremity 
of the bulb. To this point the anterior extremity of the sphincter ani 
reaches, becoming confluent with the posterior part of the accelerator 
urinae, and the superficial transverse muscles from the ischial tuberosities 
join in the interlacement. In the female the corresponding muscles 
meet a point between the vaginal and anal orifices. A somewhat firm 
mass of the superficial connective tissue at the central point of the 
perineum is sometimes spoken of as the perineal body. 
Symphysis pubis 
Obturator vessels and nerve 
Linea 
albuginea 
f Obturator 
[ interims 
.Levator ani 
.Gluteal artery 
Edge of small sacro-1 
sciatic ligament / 
Pyriformis. 
4, Coccyx 
5, Ischial spine 
6, Prostate gland 
and urethra 
7, Rectum 
10, Oocoygeus 
14.15, Median 
raphe of levator 
ani 
Fig. 301.—The Levator Ani and Coccygexjs, from above. (L. Testut.) 
The levator ani muscle lies on the deep surface of the pelvic and 
its continuation the recto-vesical fascia. It arises in front by a few fibres 
from the body of the pubis near the lower margin of the symphysis, 
behind from the margin of the ischial spine, and between these points from 
the pelvic fascia. The anterior fibres of the muscle pass backwards, MUSCLES AND FASCIA OF THE PEEINEUM. 
389 
downwards, and inwards, embracing the neck and base of the bladder, and 
in the female the vagina, and meet the corresponding fibres from the opposite 
side in the middle line in front of the anus, and are connected there with 
the deeper fibres of the superficial sphincter; in the male the anterior 
fibres of the muscles embrace the sides of the prostate and meet below the 
gland. The fibres next in origin pass to the rectum and blend with its wall, 
which they enter between the deep and superficial sphincters. The posterior 
fibres, forming the greater part of the muscle, pass over the sides of the 
rectum, and are inserted into a median raphe prolonged backwards to 
the point of the coccyx. A few of the most posterior fibres are attached 
to the sides of the coccyx. 
a, Inferior ramus of 
pubis 
b, Tuberosity of 
ischium 
c, Anus 
e, Corpus 
cavernosum 
/ Bulbo- 
\ cavernosus 
Erector penis 
I', Anterior fibres 
of the bulbo- 
cavernosus 
4, Anterior layer of 
triangular liga- 
ment 
( Superficial 
( transverse 
<3, Coccygeus 
10, Ano-bulbar 
raphe 
11, Ano-coccygeal 
raphe 
12, Levator ani 
! Superficial 
■-! sphincter of 
( anus 
Great sacro-sciatic ligament | Coccyx Gluteus maximus 
Adipose tissue of ischio-rectal fossa 
Fig. 302.—Superficial Perineal Muscles of the Male. (L. Testut.) 
The coccygeus, triangular in outline, is continuous with the posterior 
edge of the levator ani. Narrow at the origin it springs from the spine 
of the ischium. Broad at its insertion it is attached chiefly to the side 
of the coccyx and partly also to the side of the sacrum. 
The sphincter ani externus, or superficial sphincter muscle, three-quarters 
of an inch to an inch in depth, surrounds the lower part of the rectum and 
encircles the anal aperture. Posteriorly the fibres are continued backwards 
along the ano-coccygeal raphe to the point of the coccyx; anteriorly they 
pass forwards to the central point of the perineum, where they are con- 
nected with the bulbo-cavernosus or sphincter vaginae muscle, according 390 
THE MUSCLES. 
to the sex. Many are inserted into the skin. The fibres of the levator 
ani which enter the rectal wall become intimately associated with those 
of the external sphincter. 
The superficial transverse muscle is a small muscular slip, very vari- 
able in size, and sometimes absent altogether, arising from the inner surface 
of the ischial tuberosity, and inserted into the central point of the perineum, 
where it is connected with the superficial sphincter ani and with the bulbo- 
cavernosus, or in the female sphincter vaginae. 
The bulbo-cavernosus, ejaculator or accelerator urinae muscle, of the 
male, invests the bulb and the posterior part of the corpus spongiosum. 
A, Vagina 
B, Urethra 
c, Anus 
b, Inferior ramus 
of pubis 
I, I', 1", Sphincter 
vaginae 
5, Sphincter ani 
externus 
6, Levator ani 
10, Clitoris 
f Anterior layer of 
triangular ligament 
Ischio-cavernosus 
f Superficial transverse 
\ muscle 
Adipose tissue of' 
ischio-rectal fossa J 
Gluteus maximus 
Coccyx 
Coccygeus 
Pig. 303.—Muscles of the Perineum in the Female. (L. Testut.) 
A median tendinous raphe belonging to the muscle and dividing it into 
lateral portions is continued from the central point of the perineum 
forwards on the under surface of the bulb, and from it the fibres spring, 
the posterior being connected behind with the sphincter ani externus. 
The fibres of each side diverge from one another. The posterior, which 
embrace the bulb, are inserted into the under surface of the triangular 
ligament; the anterior, which embrace the hinder part of the corpus 
spongiosum, pass to a tendinous expansion on the upper or dorsal surface of 
that body. At the extreme anterior border of the muscle a few fibres 
are directed forwards on each side to the crus penis, which they join 
in front of the ischio-cavernosus muscle. MUSCLES AND FASCIA OF THE PERINEUM. 
391 
The sphincter vaginae muscle of the female corresponds to the bulbo- 
cavernosus of the male. It is attached behind to the central point of the 
perineum, where it is continuous with the sphincter ani externus. Its 
fibres pass forwards, surrounding the vaginal orifice, and covering the 
outer surfaces of the bulbi vestibuli. They are attached in front partly 
to the vestibular wall, and partly to the corpora cavernosa clitoridis. 
The ischio-cavernosus muscle in the male, or erector penis, invests the 
crus penis. Its fibres arise from the inner surface of the tuberosity and 
ramus of the ischium behind and on both sides of the crus, and converge 
to a tendinous expansion which passes forwards on the under surface of 
the crus, and gradually unites with its wall. 
Symphysis pubis 
Veins passing to 
prostatic plexus 
Anterior layer of I 
triangular ligament \ 
b, Base of bladder 
c, Prostate 
D,Vesicula seminalis 
and vas deferens 
e, Urethra 
1, Colies’ fascia 
3, Constrictor 
urethrae 
4, Posterior layer of 
triangular ligament 
5, Cowper’s gland 
Fig. 304.—Deep Perineal Muscles of the Male. The anterior layer of the triangular 
ligament of the left side has been reflected; the lower and hinder portions of the 
levatores ani and the recto-vesical fascia have been removed ; the anus has been drawn 
backwards. (L. Testut.) 
The ischio-cavernosus or erector clitoridis of the female is similar in 
arrangement to but smaller in size than the erector penis. 
The constrictor or compressor urethrae muscle of the male, or muscle 
of Guthrie, is constituted by a set of fibres lying between the layers of the 
triangular • ligament. The greater number pass across the middle line 
between the inferior pubic and ischial rami of opposite sides, some in front 
of and some behind the urethra, and associated with these are some circular 
fibres surrounding the canal. The most posterior fibres have a direction 
slightly backwards towards the central point of the perineum and are 
sometimes separately described under the name of deep transverse muscle. 392 
THE MUSCLES. 
A set of fibres passing obliquely backwards from the fore part of the sub- 
pubic arch on each side to the urethra and anterior part of the prostate has 
been described as the muscle of Wilson; its presence is denied by many 
anatomists. 
The constrictor urethrae, or deep transverse muscle, of the female con- 
sists of fibres partly transverse and partly oblique in direction, arising 
from the inferior pubic and ischial rami on each side, and passing inwards 
between the layers of the triangular ligament to blend with the vaginal 
wall and surround the urethra. 
Nerves. All the muscles of the perineum, with the exception of the 
coccygeus, are supplied by the pudic nerve. The coccygeus receives its 
supply from the coccygeal plexus; the fourth sacral nerve sends an addi- 
tional branch to the levator ani. 
Actions. The sphincter ani firmly closes the anal aperture. The fibres 
of the levatores ani which are attached to the wall of the bowel raise the 
lower part of the rectum and oppose the action of the sphincter; those 
fibres which pass across the side of the bowel to the ano-coccygeal raphe 
raise and compress the lower part of the rectum, and assist in the evacuation 
of its contents. The erectores penis, by compressing the crura, bring about 
erection of the penis. The bulbo-cavernosus and constrictor urethrae com- 
press the urethral canal, and assist in expelling its contents. 
FASCIA OF THE PERINEUM AND PELVIS. 
The superficial fascia of the posterior part of the perineum sinks very 
deeply into the ischio-rectal fossa, and is heavily loaded with fat. In 
the anterior part of the perineum the deeper layer of the superficial fascia 
is known as Cones’ fascia. In front it is continuous with the dartos; at 
the sides it is bound down to the margins of the ischio-pubic arch ex- 
tending as far backwards as the ischial tuberosity; behind it bends deeply 
round the superficial transverse muscle and joins the posterior edge of 
the triangular ligament. Between it and the triangular ligament lie the 
crura and bulb; the superficial perineal vessels and nerves pierce it in 
their passage forwards to the scrotum. An incomplete vertical septum in 
the middle line separates the space into lateral portions. From the attach- 
ments of the fascia it follows that fluid effused between it and the anterior 
layer of the triangular ligament cannot pass backwards to the posterior 
part of the perineal space or outwards into the thighs, but may pass for- 
wards to the anterior abdominal wall. 
The pelvic fascia is continued downwards from the abdominal walls, 
and is therefore continuous with the iliac and transversalis fascia. It is 
attached firmly to the ilio-pectineal line. In the posterior part of the 
pelvis it forms a thin layer which covers the pyriformis muscle and the 
nerves of the sacral plexus, and is pierced by the branches of the internal 
iliac vessels which pass through the great sacro-sciatic notch. In front of MUSCLES AND FASCIA OF THE PERINEUM. 
393 
the notch it lines the upper part of the obturator internus only, and, along 
a line drawn from the spine of the ischium to the symphysis, near its 
lower margin, it leaves the muscle and sweeps downwards and inwards 
to the middle line of the pelvic outlet, and there the layers of opposite 
sides meeting form for the pelvic cavity a floor of fascia which supports 
and forms a sheath for the bladder, and in the male the prostate gland, 
and is pierced by the rectum, and in the female by the vagina also. 
The portion of the fascia which sweeps inwards from the wall, and which, 
as above described, is continuous with the pelvic fascia, is, from its con- 
nection with the viscera, specially named the recto-vesical fascia. The lower 
part of the obturator internus is covered by a layer which is named the 
obturator fascia, and the under surface of the levator ani is clothed by the 
anal fascia; these layers line the walls of the ischio-rectal fossa, and are 
continuous with one another at the apex of that space. 
Pelvic fascia 
Brim of pelvis 
Obturator membrane 
. 
. 
Union of obturator 
and anal fascia 
Obturator fascia,. 
Obturator internus 
Obturator externus 
Recto-vesical fascia 
Levator ani 
Ischio-rectalfossa 
Anal fascia 
Ischial tuberosity 
Fig. 305.—Diagrammatic Section through Bladder, Rectum, and Anus, to show 
the relations of the pelvic fascia. 
The levator ani muscle lies close on the deep surface of the recto- 
vesical fascia; its anterior portion springs from the pelvic surface of the 
pubic bone, but in the greater part of its extent it arises from the 
deep surface of the pelvic fascia. Most of its fibres take origin along a 
specially strengthened line, the white line, or linea albuginea, which marks 
the place where the pelvic fascia leaves the surface of the obturator internus, 
and is continued into the recto-vesical fascia; a few, however, spring from 
the fascia above the level of the white line. The obturator fascia reaches 
up to the white line, and becomes there continuous with the anal fascia. 
At the upper margin of the obturator foramen the pelvic fascia is pierced 
by the obturator vessels and nerve. 
The recto-vesical fascia sweeps backwards from the anterior, and 
inwards from the lateral walls of the pelvis to the bladder, which it 
reaches near the base and immediately splits into two layers. One 
passes upwards over the bladder, blending with its wall and forming 
its sheath; the other passes downwards sheathing the base and, in 
the male, inclosing the prostate. The attachments to the bladder 
constitute the true ligaments of that organ. The anterior true ligament on 394 
THE MUSCLES. 
each side is a strong band of fibres, with which some involuntary muscular 
fibres are mixed, passing from the body of the pubis to the anterior 
part of the base of the bladder; the lateral true ligament, sweeping from 
the wall along the line of reflection, is continued backwards from the 
anterior, than which it is, however, much weaker in structure. Between the 
anterior ligaments of opposite sides the fascia is thin, and, viewed from 
above, depressed into a hollow. The portion of fascia which passes down- 
wards under the base of the bladder in the male surrounds very closely the 
prostate gland, forming a sheath for it, and gives off a layer which incloses 
the vesiculae seminales. The sheath of the prostate is very strong, and is 
mainly derived from the fibres of the under surface of the anterior true 
vesical ligaments. In front the weak fibres, passing back to the prostate from 
Fig. 306.—Diagram of Section of Pelvis, dividing longitudinally the prostatic portion 
of the urethra. 
the symphysis, are pierced by the dorsal vein of the penis, which enters 
a plexus of veins lying between the proper capsule of the gland and its 
sheath from the recto-vesical fascia; the veins lie at the base and the 
lower part of the sides of the organ, but over the rest of the area 
the sheath and the capsule are closely adherent. Behind the bladder, 
between it and the rectum, the layers of recto-vesical fascia of opposite 
sides in the male subject meet in the middle line, but in the female they 
pass on to the vaginal wall. Further back, on the side of the rectum, 
the fascia splits, about three inches from the anus, one portion passing 
upwards and the other downwards, both blending with the coats of the 
bowel. The attachment to the rectum is sometimes named ligament of 
the rectum. 
The obturator fascia is attached below to the bone along the lower margin 
of the obturator internus muscle; behind, it is attached to the great and MUSCLES AND FASCIA OF THE PERINEUM. 
395 
small sacro-sciatic ligaments; above, it reaches to the white line, where it 
becomes continuous with the anal fascia. It lines the outer wall of the 
ischio-rectal fossa, and in a special canal in its substance the pudic vessels 
and nerves run forwards in a portion of their course. 
The anal fascia is a delicate layer which covers the under surface of 
the levator ani, and lines the inner wall of the ischio-rectal fossa. 
The subpubic fascia or triangular ligament of the urethra. Two layers 
of fascia, constituting together the triangular ligament of the urethra, 
stretch from side to side in the anterior part of the perineum. They are 
pierced by the membranous part of the urethra in the male, and by the 
urethra and vagina in the female, and between the two lie the constrictor 
urethrae muscle, the pudic vessels and nerves in a portion of their course, 
and Cowper’s or Bartholin’s gland, according to the sex. 
The anterior or under layer of the triangular ligament, moderately 
strong, is attached in front to the subpubic ligament, and at the sides to 
the inner lips of the rami, extending as far back as the tuberosity. At 
its posterior edge it is united with the posterior layer of the ligament, 
and with Colies’ fascia, which to join it turns round the superficial 
transverse muscle. In the male it is pierced in the middle line, about 
an inch from the symphysis, by the urethra, which almost immediately 
after enters the penis. The posterior part of the spongy body ter- 
minating in the bulb, and the crura of the penis, lie upon its anterior 
surface. The vessels of the corpora cavernosa and those of the bulb 
pass through it as do also, close to the symphysis, the dorsal vessels 
and nerves of the penis. 
The posterior or upper layer of the triangular ligament lies upon the upper 
surface of the constrictor urethrae muscle, and separates it from the anterior 
part of the levator ani. Traced from either side it passes inwards from 
the inner margin of the ramus, where, at its attachment to the bone, it 
is continuous with the anterior part of the obturator fascia. In the male 
it reaches the middle line at the base of the prostate, and is there continuous 
with the recto-vesical fascia which forms the sheath of the gland. The 
urethra as it is leaving the prostate passes through it. At its posterior 
border it is blended with the anterior layer of the ligament, and is pierced 
by the pudic vessels and nerves as they pass forwards. In the female 
the lateral portions traced inwards reach the vaginal wall where they 
blend with the recto-vesical fascia. 
The ischio-rectal fossa. At the posterior part of the perineum there 
lies on each side, between the wall of the bowel and the tuberosity of 
the ischium, a considerable space named the ischio-rectal fossa, which is 
filled with fat and traversed by branches of the pudic vessels and nerves. 
In cross section the space is triangular in outline, having the skin and 
fascia stretching between the anal opening and the tuberosity as its base. 
The outer wall is formed by the obturator fascia clothing the lower part 
of the obturator internus muscle, the inner wall by the levator ani 396 
THE MUSCLES. 
muscle covered by the anal fascia. The apex is above at the white line. 
In front, the space, much narrowed, extends forwards almost to the 
symphysis on the upper or posterior surface of the triangular ligament. 
Surgical anatomy of the pelvic fascia. The relations of the fascia to the 
viscera are of considerable surgical importance. Rupture of the male 
urethra, with subsequent extravasation of urine, takes place most fre- 
quently in front of the anterior layer of the triangular ligament, and the 
attachment of Colles’ fascia to the posterior edge of the triangular liga- 
ment and to the rami prevents the extravasated fluid from reaching the 
posterior part of the perineal space or the thighs; but, on the other hand, 
directs it forwards to the abdominal wall, where it ascends under Scarpa’s 
fascia. Less common is the rupture of the urethra between the layers 
of the triangular ligament, and when it happens the fascia for a con- 
siderable time resists the passage of the extravasated fluid. The recto- 
vesical fascia, forming the anterior and lateral true ligaments of the 
bladder, reaches that organ at the upper margin of the base, consequently 
the whole base of the bladder, with the vesiculae seminales and the 
prostate gland, is excluded from the pelvic cavity and projects into the 
perineum. The prostate, however, receives an exceedingly strong sheath 
from the downward continuation of the fascia. Between the base of the 
bladder and the prostate on the one hand, and the anterior wall of the 
lower part of the rectum on the other, a comparatively thin septum of 
fascia intervenes. The base of the bladder immediately above the prostate 
may be punctured from the rectum without opening the pelvic cavity. 
Prostatic abscesses open usually into the urethra, but extravasation of 
urine or pus has in rare cases taken place into the cavity round about 
the base of the bladder, and in such cases the extravasated fluid may 
pass downwards upon the rectum. The portion of the fascia which passes 
to the side of the rectum is weaker than that which is attached to the 
bladder; it reaches the side of the bowel about three inches from the 
lower end. A portion of the fascia, with the levator ani on its deep 
surface, is prolonged downwards on the lower part of the bowel, strength- 
ening its wall. The rectal opening of a fistula in ano is rarely found 
higher up than an inch from the margin of the anus, and in the majority 
of cases is placed even lower than that. 
DEVELOPMENT AND MORPHOLOGY OF THE VOLUNTARY 
MUSCLES. 
The voluntary muscles of the trunk are derived from the muscle plates 
formed from the outer regions of the mesoblastic somites. Some of the 
muscles of the head are derived from the lateral mesoblast, others from 
dorsally placed masses of mesoblast which correspond to the somites of 
the trunk. The muscles of the limbs appear in the higher forms to arise DEVELOPMENT AND MOEPHOLOGY. 
397 
independently of the muscle plates from the mesohlastic tissue of the limb 
outgrowths; but in the lower forms, for instance in elasmobranch fishes, 
the limb muscles are formed, to a large extent at least, from processes 
which are budded from the muscle plates of the segments to which, in each 
case, the limb corresponds. 
The mesohlastic somites present at an early date a central cavity which, 
in certain cases, as for instance in those of the anterior somites of the 
embryo duck, can be seen to be continuous for a short time with the 
general body cavity. The outer and inner walls of the somites are at 
first of equal thickness, but at an early stage the inner wall undergoes 
a rapid growth, with the result that in each case the originally centrally- 
placed cavity comes to occupy a lateral position. The greater part of the 
thickened inner wall, formed of irregular or stellate cells, gives rise to the 
tissue out of which the vertebral column is formed; the remainder of each 
somite presenting in its interior the original cavity forms a muscle plate. 
The outer wall of the muscle plate is formed of elongated columnar cells, 
the inner wall of two or three layers of flattened cells. The muscle plates 
grow rapidly, extending ventrally into the somatopleure and dorsally 
towards the vertebral column, the growth taking place at the dorsal and 
ventral angles of the plates where the outer walls become continuous Avith 
the inner Avails. The cells of the inner Avails of the muscle plates give 
rise to a system of muscular fibres; the changes Avhich take place in those 
of the outer Avails have not been clearly folloAved. 
The original muscular fibres have at first a longitudinal direction, and 
those of the successive segments are separated from one another by inter- 
segmental septa along which the nerves run, and in which, in the thoracic 
region, the ribs are formed. Subsequently, by the complete or partial 
obliteration of the septa, and by the groAvth and the increase in 
numbers of the fibres, there is formed a complicated system of 
muscles, the individual members of which are separated from one 
another and collected into groups by ucav connectiATe-tissue septa deriAred 
from the mesenchyme. 
The fascia Avhich surrounds the muscles forms a general superficial 
investment and four great septa. One of the septa, dorsal in position, 
extends from the spines of the vertebrae to the surface and separates the 
dorsal muscles of opposite sides from one another; it is represented in the 
adult by the ligamentum nuchae and by the interspinous and supraspinous 
ligaments. Another, the haemal septum, passes ventrahvards; it is present 
in the caudal region of lower forms, but in the rest of the trunk it is 
split into lateral portions between Avhich the visceral cavity is interposed; 
it is represented by the lining fascia of the Adsceral cavity. The tAvo 
others, one on each side of the body, lateral in position, divide the mus- 
culature of each lateral half into a dorsal and a ventro-lateral portion; 
the remains of these septa persist as the middle layers of the lumbar 
aponeurosis. Each of the tAvo great groups of muscles is further 398 
THE MUSCLES. 
subdivided, and in the planes of division the main branches of the 
nerves run. 
The dorsal group of muscles is supplied by the posterior primary divisions 
of the nerves; the fibres which compose it are chiefly longitudinal in 
direction and many of the more deeply placed are confined to one 
segment. It is divided by a longitudinal partition into an outer and an 
inner portion ; to the outer portion belong the splenius and erector spinae 
muscles; to the inner portion, on the other hand, the complexus, semispinalis, 
multifidus spinae, the median lumbar intertransverse, the interspinales, and 
the posterior short cranio-vertebral muscles. 
The ventro-lateral group is supplied by the anterior primary divisions 
of the nerves; it is more complicated than the dorsal group and presents 
a greater modification from the original segmental type; many of its fibres 
have an oblique or transverse direction. It is subdivided into two layers 
between which the nerves course in the body wall, and the more superficial 
of the two is again subdivided into different strata. The deeper of the 
two main layers forms three sets of muscles which may, from their relative 
positions, be termed (a) hyposkeletal, (b) lateral, and (c) ventral. The 
hyposkeletal muscles are regarded by some observers as arising independ- 
ently of the muscle plates from the general mesoblast, but it is probable 
that they are formed, as indicated above, from the deeper layer of the 
lateral musculature ; they lie upon the under or, from the point of view 
of human anatomy, anterior surface of the vertebral column, and are 
represented in man by the rectus capitis anticus major, the longus colli, 
and probably by the vertebral portion of the diaphragm. The lateral 
muscles of the deeper layer are the transversalis abdominis, and probably 
also the coccygeus, levator ani, deep transversus perinei, internal inter- 
costals, scalenus anticus, and anterior cervical intertransverse muscles. The 
ventral muscles are represented by the rectus abdominis, triangularis sterni, 
omo-hyoid, sterno-thyroid, and sterno-hyoid muscles. 
The more superficial layer of the lateral group is represented in the 
thorax, abdomen, and pelvis by the external intercostals, the levatores 
costarum, the internal and external oblique muscles of the abdomen, the 
quadratus luraborum, the lateral lumbar intertransverse, and the superficial 
perinaeal muscles, and in the neck by the posterior and middle scaleni, 
and by the posterior intertransverse muscles. As more superficial strata 
belonging to this layer there may be reckoned the three serrati muscles, 
the rhomboidei, the latissimus dorsi, the levator anguli scapulae, the 
pectoralis major and minor, and probably jmrtions at least of the sterno- 
mastoid and trapezius. 
The muscles of the head. In the region of the head the mesoblast 
extends forwards on each side as a lateral plate; mesoblastic somites are 
not formed, but the formation of the successive branchial arches affords 
evidence of a segmentation. In the lower forms, for instance in elasmo- 
branch fishes, each lateral plate of head mesoblast is cleft into a somatic DEVELOPMENT AND MOEPHOLOGY. 
399 
and splanchnic layer which form the walls of a cavity continuous behind 
with the body cavity; on the formation of the branchial arches this cavity 
is broken up into a number of segments, the first of which is pre- 
mandibular, the second occupies the mandibular, the third the hyoid arch, 
while the others correspond to the succeeding branchial arches. Each of 
the first three sections of the head cavity is formed of a dilated dorsal 
portion and a narrow ventral portion. The dorsal portions are regarded 
as corresponding to the mesoblastic somites in the trunk; from their 
walls the muscles of the orbit are formed. From the inner or splanchnic 
walls of the narrow ventral portions contained within the mandibular, 
hyoid, and the succeeding arches, the mandibular, hyoid, and branchial 
muscles are developed. Among higher forms, in reptiles and birds, traces 
of the formation of a head cavity and its division into successive segments 
have been observed. A number of segments have been counted, the 
dorsal portions of which, corresponding to somites, are said to be formed 
in order from behind forwards. The most anterior head-somite gives 
origin to the muscles of the orbit supplied by the third nerve; the 
second to the superior oblique muscle, supplied by the fourth nerve; 
the third to the external rectus muscle, supplied by the sixth nerve; 
behind this two or three somites seem to disappear entirely ; from the 
hinder head-somites, according to some observers, the muscles which 
pass from the head to the shoulder-girdle are developed. From the walls 
of the ventral or visceral portion of the section of the head cavity 
belonging to the mandibular arch there are developed the muscles of 
the jaws and the tensor palati, supplied by the motor branch of the 
fifth nerve; and from the corresponding regions of the hyoid arch there 
arise the stapedius and the muscles connected with the hyoid bone, 
supplied by the facial nerve; the superficial muscles of the face and neck 
supplied by the seventh nerve have probably spread from the region of 
the hyoid arch. In the splanchnic wall of the pharynx corresponding 
in position to the first branchial arch there are developed the pharyngeal 
muscles supplied by the glosso-pharyngeal and its associated nerves, and 
with these, judging from its nerve supply, the levator palati must prob- 
ably be reckoned, although its position immediately behind the Eustachian 
tube would seem to warrant the supposition that it was developed from 
the hyoid arch. The intrinsic muscles of the tongue and those supplied 
by the true hypoglossal branches probably also spring from the 
splanchnic mesoblast in the neighbourhood of the ventral extremities of 
the anterior branchial arches. 400 
THE YASCULAE SYSTEM. 
THE YASCULAE SYSTEM. 
THE HEART. 
The heart is a hollow organ with muscular walls. The blood enters it 
through six large channels and one smaller one,—the four pulmonary veins 
from the lungs, the superior vena cava and the inferior vena cava from 
the body generally, and the coronary sinus from the walls of the heart 
itself. It distributes the blood through the aorta and the pulmonary 
artery. It is inclosed in a membranous sac, the pericardium, which 
also completely or partially invests for a little distance the great vessels 
connected with it. 
It has the shape of a somewhat flattened cone, with anterior and 
posterior surfaces and right and left borders. Its base lies on the 
vertebral column in the region corresponding to the bodies of the sixth, 
seventh, and eighth dorsal vertebrae, the structures in the posterior 
mediastinum intervening; the apex projects downwards, forwards, and to 
the left, and is found opposite a spot in the fifth left intercostal space 
three and a half inches from the middle line of the sternum. The anterior 
surface looks upwards as well as forwards, the posterior downwards and 
backwards. 
It is divided by a longitudinal septum into right and left portions, each 
of which is again subdivided by a transverse constriction into two chambers, 
auricle and ventricle, the former being superior and dorsal in position, 
the latter inferior and ventral. A deeply marked groove, the auriculo- 
Vena cava superior- 
.Aorta 
Ductus arteriosus 
.Pulmonary artery 
.Left auricular appendix 
Apex 
Fig. 307.—The Heart, from the front and slightly from above and from the right 
(C. Gegenbaur.) 
ventricular sulcus, marks externally the place of separation between auricles 
and ventricles, and in the ventricular region two shallow longitudinal 
depressions anterior and posterior in position, the interventricular grooves, 
mark on the surface the line of division between the ventricles. The septum. THE HEART. 
401 
which separates the right and left divisions of the heart from one another, 
is so placed that the right division occupies the greater part of the anterior 
surface, the left division the greater part of the posterior surface of the 
organ. The anterior and posterior interventricular furrows meet one 
another a little to the right of the apex, which is formed from the left 
ventricle only. Of the borders of the heart, the right, or margo acutus, 
is narrower and longer than the left, or margo dbtusus. 
The auricular portion of the heart has the form of an irregularly- 
shaped crescent, embracing from behind and from the right side the base 
of the aorta, and having its horns or extremities prolonged, as the auri- 
cular appendices, towards the sides of the pulmonary artery. The auricular 
portion rests behind on the column, the pericardium and the structures in 
the posterior mediastinum intervening. The septum is directed from 
behind forwards and to the left, so that the right auricle, which lies 
Left pulmonary artery 
Aorta. 
Superior vena cava 
Eight pulmonary artery 
Left pulmonary veins 
Eight pulmonary veins 
Inferior vena cava 
Fig. 308.—The Heart, from behind. The coronary sinus is seen in the aurieulo- 
ventricular furrow; the left coronary vein with a posterior cardiac tributary and the 
posterior interventricular vein are also shown. (C. Gegenbaur.) 
to the right side of and in front of the aorta, is narrow behind, and 
broad and expanded in front, while the left is somewhat flattened out 
behind the aorta and pulmonary artery. 
The right auricle, viewed from the front and the outer side, presents a 
broad, prominent, somewhat four-sided surface, prolonged anteriorly into the 
appendix, which projects towards the left. The superior and inferior 
venae cavae enter respectively at the upper and lower posterior angles. 
When the auricle is opened, the inner and posterior parts of its wall are 
found to be smooth, but the anterior part and the wall of the appendix 
are made rough by the presence of vertical muscular bands, standing out 
as strong ridges, the musculi pectinati, under the endocardial lining. The 
posterior limit of the roughened area is marked on the external surface by a 
groove which runs from in front of the entrance of the vena cava superior 
to the right of the opening of the inferior cava, and which has received 
2 C 402 
THE VASCULAR SYSTEM. 
the name of sulcus terminalis. On the right surface of the interauricular 
septum is situated an oval depression, the fossa ovalis, which is bounded, 
except at its lower part, by a prominent margin, the annulus ovalis. The 
fossa ovalis is the remains of what was, in foetal life, the foramen ovale, 
an open passage between the auricles, which afterwards became closed by 
the application of a valvular fold. The communication between the 
auricles sometimes persists in the adult as a narrow oblique passage. 
In front of the opening of the inferior vena cava, a fold of endocardium 
passes across the posterior part of the auricle to the lower extremity of the 
annulus ovalis • it is of very variable size, and frequently shows numerous 
small perforations. It is the remains of the Eustachian valve, a fold which, 
in foetal life, directed the blood of the inferior vena cava through the 
foramen ovale to the left auricle. There is no valve at the opening of 
the superior vena cava. Between the Eustachian valve and the auriculo- 
ventricular opening, which occupies the floor of the auricle, is the orifice 
Vena cava superior 
Right auricular appendix 
Foramen ovale. 
Eustachian valve 
Vena cava inferior 
Valve of Thebesius 
Fig. 309.—Right Auricle of Child at Birth, showing the foramen ovale. The 
anterior wall has been removed. (C. Gegenbaur.) 
of the coronary sinus, into which the veins of the heart pour their blood. 
It is guarded by a thin imperfect valvular fold, the valve of Thebesius. 
Numerous small pits open upon the wall of the auricle; many of 
them are blind, but some contain the openings of small veins from the 
wall oi the heart; they are known collectively as the foramina of Thebesius. 
The left auricle, four-sided and somewhat flattened, is, to a large extent, 
hidden behind the aorta and pulmonary artery. Its appendix, which is 
the most superficial part, projects forward by the left side of the pulmonary 
artery. Internally it presents a smooth surface, except in the appendix, 
the walls of which are marked by prominent muscular ridges. Posteriorly 
the four pulmonary veins, two upon each side, open into it, the orifices 
being destitute of valves. On the septum the position of the foetal 
foramen ovale is marked by an irregularity of the surface, the most con- 
stant feature of which is a small depression with a slender limiting ridge 
below it, at the upper border of the original foramen. The auriculo- 
ventricular aperture lies in the anterior part of the floor. THE HEART. 
403 
The ventricular portion of the heart. Each of the two chambers into 
which it is divided presents two hasally placed orifices, the auriculo- 
ventricular and the arterial, both of which are guarded by valves. The 
auriculo-ventricular valve, in each case, is formed of fibrous cusps or segments, 
pointed and free at their extremities, which project into the cavity, and 
confluent at their bases, where they form an annular membrane attached 
to the margin of the opening. The arterial valve, in each case, is made up 
of three semicircular segments (semilunar or sigmoid) formed of fibrous 
tissue, and attached by their convex borders to the wall of the artery at 
the place where it springs from the ventricle, while their free borders, 
which are nearly straight, project into the cavity. The free border of each 
segment is strengthened by a delicate fibrous band, and immediately below 
the middle of the margin there is a small thickening, the nodulus or corpus 
Arantii; the thinnest portions of each segment lie immediately below the 
lateral portions of the free border, and are named the lunulae. Opposite 
each segment there is a pouch or sinus of the wall of the vessel, which 
completes, with the corresponding segment of the valve, the wall of a cup; 
the pouches are termed the sinuses of Vcdsalva. When the ventricles are con- 
tracting and the blood is passing through the arterial orifices, the segments 
are applied to the walls of the sinuses; during the ventricular diastole 
regurgitation of blood from the arteries is prevented by the closure of the 
valves, the nodules coming into contact, and the lunulae of neighbouring 
segments overlapping. 
The ventricular wall attains its maximum diameter, except in the case 
of the septum, about the junction of the basal and middle thirds. The 
wall of the left ventricle is two or three times thicker than that of the 
right. The septum, in its greater part, has almost the same diameter as 
the wall of the left ventricle, but is thickest in the region of the apex. 
It is somewhat curved, its right side being convex, while its left is concave, 
and, as a result, the outline of the right ventricle, in section, is crescentic, 
while that of the left is oval or circular. At its upper or basal portion 
the septum is in line, dorsally, with the inter-auricular septum, and 
intervenes between the auriculo-ventricular openings; further forwards it 
separates the right auriculo-ventricular from the aortic orifice; and still 
more ventrally, it passes between the posterior margin of the pulmonary 
and the anterior margin of the aortic orifice. As the septal cusp of the 
right auriculo-ventricular opening is placed a little lower than the anterior 
cusp of the left orifice, the septum intervenes for a short distance near its 
posterior part between the right auricle and the left ventricle. Immediately 
in front of the area last described, and close to the hinder margin of the 
right segment of the aortic valve, there is a small portion of the septum, 
fhe pars membranacea, which is very thin, and contains no muscular fibres; 
ift abnormal circumstances it is occasionally deficient, permitting a com- 
munication between the ventricles. 
The inner surface of the ventricular wall presents, in its greater part, 404 
THE VASCULAR SYSTEM. 
a complex arrangement of muscular elevations, which project into the 
cavities, and are termed columnae carneae. Some of these are simply pro- 
jecting muscular ridges; others are attached to the wall at their extremities, 
and are free in their intermediate portions ; others again, specially named 
the musculi papillares, are definitely arranged muscular projections attached 
basally to the wall in the region of the apex, and giving origin at their free 
extremities to a number of delicate tendons, the chordae tendineae, which pass 
to the margins and ventricular surfaces of the segments of the auriculo-ven- 
tricular valves. During the ventricular systole, the musculi papillares contract 
along with the walls of the ventricles, and the tightened chordae tendineae 
prevent the retroflexion into the auricles of the segments of the valves, which, 
applied to one another, and thus maintained in position, close the orifices. 
The right ventricle occupies the greater part of the anterior surface 
and right border of the heart, and only a small portion of the posterior 
surface. Behind and below it rests upon the diaphragm, the central 
tendon of which is united with the fibrous layer of the pericardium. 
Viewed from the front it presents a triangular surface prolonged at the 
upper angle, the conus arteriosus or infundibulum, into the pulmonary 
artery. Except in the region of the infundibulum the inner surface of the 
wall presents a close reticulation of columnae carneae. The musculi 
papillares form two groups, respectively anterior and posterior in position. 
A fleshy band which is frequently found stretching across the cavity of 
the ventricle, from the septum downwards to the base of the anterior 
papillary muscles, is named the moderator hand. The auriculo-ventricular 
orifice is placed a little below and to the right of that of the pulmonary 
Pulmonary artery 
Aorta, 
Pig. 310.—The Auriculo-Ventricular and Arterial Valves, seen from above and 
behind after section through the auricles and arteries. (C. Gegenbaur.) 
Valve of Thebesius 
artery. The auriculo-ventricular orifice admits three fingers placed side by 
side. The valve which guards it, the tricuspid valve, is formed of three 
cusps, of which two are lateral and one is mesial in position; they may be 
named the anterior and posterior lateral, and the septal. From the anterior 
papillary muscles chordae tendineae pass to the angle between the two THE HEART. 
405 
lateral cusps ; from the posterior muscles they are directed to the angle 
between the septal and posterior cusps; to the angle between the septal 
and anterior cusps there pass tendinous hands which spring from the septum 
either directly or by small muscular points. Sometimes one or other of the 
cusps is partially divided into two, and there are to be found in some 
cases small, intermediate cusps in the angles between the larger ones. 
The valve at the root of the pulmonary artery is not so strong as that 
at the base of the aorta. 
The left ventricle, which rests below and behind on the diaphragm, 
occupies the greater part of the posterior surface of the ventricular portion 
of the heart, only a comparatively small portion of it appearing in front. 
It forms the whole apex. In the interior of the ventricle the columnae 
carneae present a complicated arrangement, especially at the apex. They 
are absent from the upper part of the septum and anterior wall, so that 
Left common carotid artery 
Left subclavian artery 
Innominate artery 
Transverse portion of aorta 
Ligamentum arteriosum 
Superior vena cava. 
Pulmonary artery 
Aorta 
Pulmonary valve 
Auricular appendix, 
Annulus ovalis 
Fossa ovalis. 
Moderator band 
Opening of coronary sinus. 
Eustachian valve 
Anterior wall of right auricle \ 
showing musculi pectinati/ 
Inferior vena cava 
Posterior lateral cusp of tricuspid valve | Septal cusp 
Anterior lateral cusp 
Fig. 311.—The Heart, from before and the right side. The cavities of the right 
auricle and ventricle have been exposed by the removal of a portion of the wall. 
the region of the cavity which is immediately below the aortic orifice, and 
has been named the aortic vestibule, presents a smooth surface. The musculi 
papillares form two large groups, one left or anterior in position, the other 
right or posterior. The orifices of the ventricle are situated very close 
together in the upper part of the ventricle, the aortic being higher than the 
other, and to the right of it. The auriculo-ventricular orifice, admitting only 
two fingers in normal circumstances, is smaller than that of the right side, 
and the valve which guards it, though similar in general construction to 
the tricuspid valve, is much stronger. It presents two cusps only, and 
has been named, in consequence, the bicuspid or mitral valve. The 
cusps are placed obliquely, and are of unequal size, the larger being 
anterior to the other, and to the right of it. The ventricular suiface of 406 
THE VASCULAR SYSTEM. 
this cusp forms a portion of the aortic vestibule, and its base separates 
the aortic and auriculo-ventricular orifices from one another. The chordae 
tendineae are numerous and strong, and pass, like those of the right side, 
to the angles between the valves, and are attached to the free margins and 
ventricular surfaces. Occasionally small subsidiary cusps are found in the 
angles between the larger ones. The aortic orifice, circular in outline, is some- 
what smaller than that of the pulmonary artery; the segments of its valve 
are much stronger than those of the right side. The sinuses of Valsalva 
are relatively to one another, right, left, and posterior in position; from 
the right and left the corresponding coronary arteries of the heart spring. 
Position of the heart with reference to the chest wall. The base of 
the heart lies opposite the bodies of the sixth, seventh, and eighth dorsal 
vertebrae. The apex approaches the surface at a spot, in the fifth left inter- 
Ligamentum arteriosum. 
Aorta 
a, Back of left auricle 
c, Left pulmonary veins 
d, Auricular appendix 
Pulmonary artery 
Aortic valve 
a Right pulmonary veins 
Left cusp of mitral valve 
Right cusp of mitral valve 
Anterior musculus papillaris 
• Posterior musculus papillaris 
Fig. 312.—The Heart, from behind and the left side after removal of the outer wall of 
the left ventricle. 
costal space, three and a half inches from the middle line, and one and a 
half inches below the nipple. The area occupied by the heart may be 
marked out on the surface by three lines : (1) on the right side, a curved 
line with the convexity to the right, and reaching at the farthest about 
an inch and a half from the middle line, drawn from the sternal end 
of the third right costal cartilage to that of the seventh right costal 
cartilage; (2) a line drawn across, from the sternal end of the seventh 
right costal cartilage to the apex; (3) a slightly curved line, from the 
apex to the left edge of the sternum between the second and third 
costal cartilages. The whole of that part of the heart which lies to the 
right of the middle line is overlapped by pleura ; on the left side, while 
a large portion of the heart is overlapped, a small area of jjericardium is 
left uncovered by the pleura. This area may be marked out on the THE HEART. 
surface by three lines, one drawn down the middle of the sternum, from 
the level of the fourth costal cartilages to the upper end of the ensiform 
process, the other two connecting the extremities of the first with the site 
Superior vena cava 
Pulmonary orifice 
Aortic orifice 
Right auriculo-ventricular \ 
orifice f 
Fig. 313.—The Position of the Heart with reference to the Chest Wall 
(C. Gegenbaur.) 
of the apex. This area lies under the inner extremities of the fourth, 
fifth, and sixth intercostal spaces of the left side. 
The aortic opening lies behind the left border of the sternum at the 
lower edge of the third left costal cartilage; the pulmonary orifice is 
above and to the left of the aortic, at the left border of the sternum, at 
the level of the upper edge of the third left costal cartilage. The left 
auriculo-ventricular opening lies behind the fourth left costal cartilage and 
the adjacent portion of the sternum ; the right auriculo-ventricular orifice 
is placed behind the left half of the sternum at the level of the fifth 
costal cartilage. 
The structure of the heart wall. The wall of the heart is chiefly 
formed of muscular tissue, but in the region surrounding the auriculo- 
ventricular and arterial openings there is a quantity of fibrous tissue, which 
encircles the orifices and becomes continuous with the tissue of the 
valves, sends a process downwards into the septum, and gives attachment to 
most of the muscular fibres. Superficially the heart is covered by the 
visceral pericardium or epicardium, while internally the cavities are lined 
by a smooth delicate membrane, the endocardium, which is continuous 
with the tunica intima of the vessels. A variable and, in some cases, 
a considerable amount of fat is found lodged under the pericardium, chiefly 
at the base of the heart, and in the course of the different furrows. 
The walls of the auricles are much thinner than those of the ventricles. 
A superficial set of fibres, common to both auricles, runs transversely 
in front and behind, but is better marked in front; some of the fibres 
of this layer pass into the septum. Of the deeper fibres, which are proper 408 
THE VASCULAR SYSTEM. 
to each auricle, some form vertical loops attached below to the fibrous 
tissue which surrounds the great orifices, 
others, running transversely, encircle each 
cavity and take part in forming the partition ; 
of this group a special band surrounds the 
fossa ovalis. Circular fibres are likewise 
found in the walls of the appendices and 
surrounding the openings of the veins. 
The arrangement of the muscular tissue 
of the walls of the ventricles is exceedingly 
complicated, and, as yet, is far from being 
thoroughly understood. «The muscular 
bundles are quite distinct from those of the 
auricles; all of them probably take origin'from 
the centrally placed fibrous tissue. Passing 
from the base, they descend towards the 
apex of the ventricles, and, forming twisted 
loops, ascend again towards the base, to be 
attached there, either directly, or indirectly 
through the chordae tendineae. Many of 
the bundles in the centre of the substance 
of the wall seem to have an almost trans- 
verse course, and, on careful dissection, 
the wall may appear to be made up of 
Fig. 314.—Superficial Layer of the 
Muscular Fibres of the Heart. A, 
From before. B, From the apex. (C. 
Gegenbaur.) 
an almost indefinite number of layers, so gradual is the change in the 
direction of the sheets of fibres. While the wall of the left ventricle 
contains many fibres which are confined to itself, the great majority 
of the fibres of the right ventricle are continuous with fibres which 
belong also to the left ventricle. The superficial layer over the whole 
surface of both ventricles descends towards the apex of the heart, where 
its fibres twist upon themselves, forming a whorl, and ascend as the 
musculi papillares and the deepest layer of the left ventricle; the super- 
ficial descending fibres of the front of the heart ascend in the posterior 
wall of the left ventricle, those of the back in the anterior wall. An 
intermediate stratum of fibres descends from the base towards the apex 
of the left ventricle; many of the fibres of this set, twisting upon them- 
selves, ascend again in the septum or in the wall of the left ventricle; 
others, however, cross in the septum and ascend in the wall of the right 
ventricle, forming its deeper layers and its musculi papillares. Some of 
the fibres of this intermediate layer have an exceedingly oblique, indeed, 
almost a transverse course. Speaking generally, the wall of the left ventricle 
may conveniently be divided into two layers descending from right to left, 
superficial to a transverse set, and two with an opposite obliquity, deeper 
than the transverse; while on the right side, it may be sufficient to recog- 
nize two oblique layers, and an intermediate transverse layer. THE HEART. 
409 
Vessels and nerves. The heart is supplied by the coronary arteries, 
the branches of which penetrate the muscular substance in all directions. 
The fibrous tissue of the valves, and the whole endocardial lining layer 
are non-vascular. The lymphatics are very numerous, and pass to the 
glands on the deep surface of the aorta. The nerves come from the 
superficial and deep cardiac plexuses; the ventricular branches have 
numerous minute ganglia beneath the pericardium. 
Size and weight. In a state of moderate distension the heart measures 
about 5| inches in length, 3| in breadth, 2| in thickness. In an adult 
man it weighs about 11 oz., in the female about 9 oz. At birth it is about 
of the body wTeight, in adult life from ylyth to yyyth. 
Pericardial connections (Fig. 315). The visceral layer of the pericardium, 
as it leaves the vessels and is continued into the parietal layer, forms 
a mesocardial fold, made up of two portions, an anterior or arterial, and a 
posterior or venous, which were primitively connected with one another 
by a fold which afterwards became obliterated, leaving a passage termed 
the transverse sinus of the pericardium. 
The arterial part surrounds the aorta and pulmonary artery, for the 
distance of about two inches, with a complete pericardial tube. 
The venous part is formed of two limbs continuous with one another, 
the one ascending and the other transverse in direction, and at the angle 
between the two the superior vena cava lies, surrounded except for a 
narrow strip behind. The ascending limb runs along the posterior margin 
of the right auricle, beginning below at the inferior vena cava, which is 
partially covered by the membrane, below and in front, for about half an 
inch, and inclosing higher up the right pulmonary veins, which are covered, 
except posteriorly, for about of an inch. The transverse limb passes 
to the left, along the upper border of the left auricle. It broadens out 
at the extremity, and presents three folds, the two lower for the left 
pulmonary veins, which, except posteriorly, are inclosed for about of an 
inch; the highest, the vestigial fold of Marshall, contains a vestige of the 
left superior vena cava. 
THE ARTERIES AND VEINS. 
THE PULMONARY ARTERIES AND VEINS. 
The pulmonary artery springs from the heart at a spot opposite the 
upper margin of the third left costal cartilage at the border of the sternum. 
About two inches in length, it is directed upwards and backwards, and, 
dividing into right and left branches, terminates beneath the 
arch of the aorta, under cover of the second left costal cartilage, and 
opposite the body of fifth dorsal vertebra. It is separated from the 
chest wall by the pericardium and by the left pleura. It lies at first 
in front of the ascending portion of the aorta, and then to the left 410 
THE VASCULAR SYSTEM. 
side of it and, in company with it, is surrounded in its whole length 
by a complete pericardial sheath. The left auricle is placed behind it, 
and the coronary arteries and the auricular appendices lie on its sides, 
at its commencement. 
The branch for the right lung, longer and somewhat larger than that 
for the left, passes transversely behind the aorta and superior cava, and in 
front of the oesophagus, and divides in the root of the lung into two 
branches, the lower and larger of which is distributed to the middle and 
lower lobes. The branch for the left lung passes outwards and backwards, 
iu front of the descending aorta, and divides in the root into two branches 
for the upper and lower lobes respectively. From its commencement there 
passes upwards to join the under side of the aortic arch a short fibrous 
cord, the ligamentum arteriosvm, the remains of the ductus arteriosus, which 
in foetal life formed the main continuation of the pulmonary artery. 
In the roots of the lungs the arteries lie behind the upper veins, and iu 
front of the bronchi; but the left artery, somewhat higher than the right, 
lies in a plane above the bronchus; the right branch lies below the 
bronchus, between it and the vein. 
The pulmonary veins are four short trunks, each about half an inch in 
length, an upper and a lower on each side. Those of the right side pass 
behind the superior vena cava and the right auricle, those of the left in 
front of the descending aorta. In the root of the lung on each side the 
veins are placed lower than the other structures, and the higher of the 
two is likewise the most anterior of the different constituents. 
SYSTEMIC ARTERIES. 
The Aorta. 
The aorta (Fig. 317) passes at first upwards and to the right, then 
transversely to the left and backwards, and finally descends along the 
vertebral column as far as the middle of the body of the fourth lumbar 
vertebra, opposite which it terminates by dividing into the common iliac 
arteries. The descending portion is partly thoracic, partly abdominal. 
The vessel at its commencement is, in normal circumstances, slightly smaller 
in calibre than the pulmonary artery, and in its course it gradually 
diminishes, numerous branches being given off. 
The ascending portion of the aorta springs from the heart opposite the 
left border of the sternum, at the level of the lower edge of the third left 
costal cartilage; it is directed, with a slight curve, upwards, forwards, and 
to the right, and at the right border of the sternum at the attachment of 
the second right costal cartilage, the spot at which it most nearly approaches 
the surface, passes into the transverse portion. It is a trifle over two inches 
in length. It presents, at its base, three dilatations corresponding to the 
sinuses of Valsalva; there may also be a certain enlargement, the great sinus 
of the aorta, running along the whole length of its right or convex border. Fio. 315.- The Heart within the Pericardium. The parietal layer of the pericardium 
cut through in front. (L. Testut.) 
Fig. 316.—Coronary Arteries, from in front and above. (C. Gegenbaur.) 
To face p. 410. Right common carotid artery 
Left common carotid artery 
Right subclavian artery 
.Left subclavian artery 
4, Innominate artery 
1, Ascending, passing 
into transverse portion 
10, Superior vena cava 
3, Coronary arteries 
Left bronchus 
Great azygos vein 
} Oesophageal branches 
2, Descending portion 
Intercostal artery 
Intercostal artery 
Fig. 317.—The Aorta, thoracic portion. (L. Testut.) 
To face p. 411 THE AORTA. 
411 
The pulmonary artery lies at first in front, but afterwards to the left of 
it, and both are enveloped in a common tubular pericardial sheath. The 
left auricle and the right pulmonary artery lie behind it, the superior vena 
cava is placed to its right side, and the right auricular appendix lies 
in front near its commencement. It is separated from the sternum by 
the pericardium and by the right pleural sac. The branches of this 
portion of the aorta are the arteries of the heart. 
The right coronary artery (Fig. 316) springs from the right sinus of 
Valsalva. Emerging between the pulmonary artery and the right auricular 
appendix it passes along the auriculo-ventricular furrow until it reaches, on 
the posterior aspect of the heart, the posterior interventricular groove. 
It then divides into two, one division descending in the interventricular 
groove towards the apex, the other passing transversely still further 
onwards in the auriculo-ventricular furrow. Of the numerous branches 
given off previous to the division, the largest descends towards the apex 
along the margo acutus; others ramify upon the surface of the auricles and 
ventricles, and the basal portions of the great arteries. 
The left coronary artery springs from the left sinus of Valsalva. 
It passes between the pulmonary artery and the left auricular appendix, 
and divides into two branches, one descending, the other transverse. The 
former passes downwards in the anterior interventricular groove towards 
the apex; the latter passes along the auriculo-ventricular furrow towards 
the transverse branch of the right artery. Numerous branches are supplied 
to the surface of the ventricles and auricles and the basal portions of the 
great arteries; one of considerable size descends towards the apex along 
the margo obtusus. 
The transverse portion of the aorta passes backwards and to the left, 
and is curved with the convexity upwards. It commences opposite the 
right border of the sternum at the place of attachment of the second 
costal cartilage, and passes at first upwards and to the left behind the 
lower half of the manubrium. As it crosses, it gradually recedes from the 
breast bone, and reaches the left side of the body of the fourth 
dorsal vertebra, to the lower border of which it descends. It therefore 
forms an arch obliquely placed from right to left and from before back- 
wards. The upper border of the arch corresponds with the line between 
the upper and lower halves of the manubrium. Some fatty tissue, remains 
of the thymus gland, lies in front of it, and it is overlapped, slightly 
on the right side and to a considerable extent on the left, by the 
corresponding pleural sacs. Behind it lie the trachea, oesophagus, and 
thoracic duct. The left bronchus passes outwards beneath it. It over- 
hangs the bifurcation of the pulmonary artery, with the left branch of 
which it is connected by the ligamentum arteriosum. The left innominate 
vein lies along its upper edge at its anterior part, and the left superior 
intercostal vein crosses it anteriorly. It is also crossed in front by the left 
phrenic and pneumogastric nerves and by the superficial cardiac nerves ; the 412 
THE VASCULAR SYSTEM. 
recurrent laryngeal branch of the left pneumogastric turns round beneath it 
and passes upwards towards the neck behind it. The deep cardiac plexus 
lies behind it, between it and the trachea; the superficial cardiac plexus 
lies beneath it, between it and the pulmonary artery. Many lymphatic 
glands lie behind and beneath it. 
Three large branches—the innominate, left carotid, and left subclavian— 
are given off from its convexity. The ligamentum arteriosum is attached 
to its lower border immediately beyond the place of origin of the left sub- 
clavian artery. 
Varieties of the aorta are very numerous, but most of them are to be 
explained by slight variations in the growth of different parts of the 
vessel; thus, neighbouring branches may be approximated to or even con- 
nected basally with one another, or, on the other hand, they may be unduly 
separated from one another. In the same manner some of the nearer 
derivatives of the main branches are sometimes transferred to the aorta 
itself, the most common case being that of the left vertebral artery. 
Occasionally it is the right vertebral which is so transposed, and among 
other arteries the internal and external carotids (the common carotid being 
absent), the thyroidea ima, the inferior thyroid, and the internal mammary 
have been, in special cases, noted as springing from the aorta. Slight 
variations in the exact position of the arch are not infrequent, and it may 
be placed either higher or lower than usual. 
Among the more important malformations are some which depend on 
very early developmental changes, and will be best understood by the 
student after reference to the chapter on the development of the primary 
vessels. Sometimes the trunk arches to the right instead of to the left 
side, a variation which is occasionally accompanied by a transposition of 
the viscera generally, and depends on the survival of the right aortic root 
of the embryo instead of the left. In very rare cases both right and left 
arches have been found present. The right subclavian is occasionally the 
last of the great branches arising from the arch, and in this case the 
fourth right arch, which forms the usual root of the right subclavian, has 
■disappeared, but, on the other hand, the right aortic root has remained 
patent and forms the basal portion of the vessel; with this malformation 
it has been noticed that frequently the thoracic duct opens into the great 
veins of the right side instead of into those of the left. A number of mal- 
formations of such a very serious nature as to be inconsistent with life 
have been found in foetuses. They are chiefly interesting from the light 
which they throw on early developmental processes. 
The Innominate Artery. 
The innominate artery arises from the aorta opposite the middle point 
of the manubrium. It passes upwards and to the right, and terminates 
immediately behind the right sterno-clavicular articulation by dividing THE COMMON CAROTID ARTERY. 
413 
into the right subclavian and right common carotid arteries. Some remains 
of the thymus gland lie in front of it. It lies behind the sternum and 
the origins of the sterno-hyoid and muscles. It is placed 
at its commencement in front of the trachea, and higher up by the 
side of the trachea; at its right side it is in contact with the right pleura. 
The left innominate vein crosses it, and the right innominate vein and 
the right pneumogastric nerve lie by its right side. Occasionally a small 
branch, the thyrodea ima artery, passing upwards in front of the trachea 
to the thyroid body, springs from it. 
The Common Carotid Arteries. 
The left common carotid artery (Fig. 317) arises from the arch of the 
aorta, behind the middle of the manubrium, being placed at its origin 
immediately to the left of the innominate artery. It passes upwards 
and to the left, and enters the neck behind the left sterno-clavicular 
articulation. It lies behind the first piece of the sternum and the origins 
of the sterno-hyoid and sterno-thyroid muscles; remains of the thymus 
gland lie upon it, and it is crossed in front by the left innominate vein. 
It rests at first upon the anterior surface of the trachea, and afterwards, 
by the side of the trachea, upon the oesophagus, which deviates at the 
root of the neck a little to the left side. The thoracic duct lies behind 
it. The thoracic part of the left subclavian artery lies further back and 
to the left of this portion of the vessel, and the left pneumogastric nerve 
is a little external to it. 
The common carotid arteries in the neck (Fig. 318) ascend, without 
branching, in front of the cervical transverse processes, as far as the fourth 
vertebra, where, on a level with the upper border of the thyroid cartilage, 
they divide into the external and internal carotid arteries. The course 
may be marked on the surface by a line drawn upwards from the sterno- 
clavicular articulation towards a point midway between the mastoid pro- 
cess and the angle of the jaw. The artery is crossed a little above its 
middle, at the level of the cricoid cartilage, by the anterior belly of the 
omo-hyoid muscle; the part of the vessel below the crossing, lying by 
the side of the trachea, is deeply placed; the part above, by the side of 
the larynx, is comparatively superficial. In its whole course the artery, 
accompanied by the internal jugular vein and the pneumogastric nerve, is 
surrounded by a sheath derived from the cervical fascia. Each structure 
occupies a separate compartment in the sheath; the vein lies external to 
the artery, close to it, with a tendency below to separate a little from it 
on the right side, and to overlap it slightly on the left; the nerve lies 
behind and between the vessels. The sheath rests behind on the origins 
of the longus colli and scalenus anticus muscles; the sympathetic nerve 
lies behind it along its whole length, and the inferior thyroid artery and 
the recurrent laryngeal nerve cross obliquely behind it in the lower part 414 
THE VASCULAR SYSTEM. 
of the neck. In front of the sheath, in immediate contact with it, the 
descending branch of the hypoglossal nerve passes downwards. In the 
region beneath the level of the cricoid cartilage, the sterno-hyoid, sterno- 
thyroid, and sterno-mastoid muscles cover the sheath; immediately above 
the level of clavicle the anterior jugular vein crosses outwards in front of 
the sheath, separated from it by the sterno-thyroid and sterno-hyoid muscles ; 
a little higher up a middle thyroid vein, in many cases, crosses in front of the 
artery. At the level of the cricoid cartilage the sheath lies immediately 
under cover of the anterior border of the sterno-mastoid muscle, and is 
crossed by the omo-hyoid muscle. Above the cricoid cartilage the artery 
is, in normal circumstances, slightly overlapped by the anterior edge of 
the sterno-mastoid muscle. In this region a slender arterial twig (the 
sterno-mastoid branch of the superior thyroid) descends in front of the 
sheath, and one or more superior thyroid veins also cross it superficially. 
The place of division of the common carotid artery is sometimes 
found a little higher than usual. Occasionally one or more of the earlier 
branches of the external carotid artery spring from the upper end of the 
common carotid. Important variations of the vessel are not common. Its 
absence has been noted, the external and internal carotid arteries springing 
directly from the aorta. 
The External Carotid Artery. 
The external carotid artery (Figs. 318, 319) passes upwards from the place 
of division of the common carotid, at the level of the upper border of the 
thyroid cartilage, to a spot immediately below and behind the neck of the 
lower jaw, where it divides into its terminal branches, the internal maxillary 
and temporal. At its upper extremity it is lodged in the parotid gland, and 
lies upon the surface of the styloid process. It has no companion vein. It 
first lies internal to the internal carotid artery but afterwards becomes super- 
ficial to it, and, while it is in contact with it below, it is separated from it 
above by the styloid process. Below the styloid process, the stylo-pharyngeus 
muscle and the glosso-pharyngeal nerve pass downwards and forwards on the 
deep surface of the external carotid, between it and the internal carotid. 
Below the angle of the lower jaw it is crossed superficially from above 
downwards and behind forwards by the stylo hyoid and the posterior 
belly of digastric; below the crossing it is comparatively superficial, being 
only slightly overlapped by the anterior edge of the sterno-mastoid muscle; 
above it is deeply placed in the substance of the parotid gland. Below the 
digastric muscle it is crossed by the hypoglossal nerve and the lingual and 
facial veins. Above the crossing, in the substance of the gland, the facial 
nerve and temporo-maxillary veins are superficial to the artery. The 
external carotid gives off numerous branches, and rapidly diminishes in size. 
The branches of the external carotid artery are the superior thyroid, 
the lingual, the ascending pharyngeal, the facial, the occipital, the posterior 
-auricular, the temporal, and the internal maxillary. Internal carotid 
Basilar 
auricular 
Ascending pharyngeal 
Occipital. 
.. Facial 
.. Lingual 
2, Internal carotid 
3, External carotid 
Superior thyroid 
1, Common carotid 
Vertebral .. 
Deep cervical 
Thyroid axis 
Suprascapular 
10, Subclavian 
Superior intercostal Internal mammary' 
Fig. 318. Carotid and Subclavian Arteries of the Right Side, and their Branches. 
(L. Testut.) 
To face p. 414. j Frontal branch of 
( ophthalmic 
{Nasal branch of 
ophthalmic 
/ Angular branch 
\ of facial 
Occipital 
.Facial 
ior dental branch 
internal maxillary 
Internal carotid | 
Common carotid 
Fig. 319.—Superficial Arteries of the Head. 3, External carotid; 4, superior 
thyroid; 5, lingual; 6, facial; 6", coronary branches of facial; 9, temporal; 10, trans- 
verse facial branch of temporal; 11, anterior auricular branch of temporal; 12, 
middle deep temporal branch of temporal; 13, orbital branch of temporal; 14, frontal 
branch of temporal; 15, parietal branch of temporal; 16, posterior auricular; 17, 
occipital. (L. Testut.) 
To face p. 415. THE EXTERNAL CAROTID ARTERY. 
415 
The superior thyroid artery (Figs. 318, 323) assists in supplying the 
thyroid body. It springs from the anterior border of the external carotid, 
close to its commencement, and arches at first forwards and downwards, 
and then descends under cover of the omo-hyoid, sterno hyoid, and sterno- 
thyroid muscles. Its terminal branches ramify in the gland, anastomosing 
with the inferior thyroid branches of the same side, and to a slight extent 
also across the middle line with the arteries of the opposite side. In its 
course the superior thyroid artery furnishes the following branches: (1) 
the hyoid, a slender twig directed inwards on the thyro-hyoid membrane, 
immediately beneath the hyoid bone; (2) the sterno-mastoid, a small vessel, 
descending for a little distance in front of the carotid sheath; (3) the 
superior laryngeal, piercing the thyro-hyoid membrane along with the superior 
laryngeal nerve, and ramifying on the inner wall of the larynx; (4) the crico- 
thyroid, a very slender twig, but of importance on account of its position, 
as it may give rise to haemorrhage in the operation of laryngotomy, 
passing, as it does, towards the middle line on the crico-thyroid mem- 
brane, close to the lower border of the thyroid cartilage. 
The lingual artery (Figs. 318, 323) springs from the anterior border of 
the external carotid, opposite the great cornu of the hyoid bone, and passes 
forwards on the deep surface of the hyo-glossus muscle to the tongue, but 
does not pursue a straight course. Close to its origin, it forms a small 
arch with the convexity upwards, and is crossed by the hypoglossal nerve; 
thereafter, directed forwards, it runs above the great cornu of the hyoid 
bone at a lower level than the nerve; then, at the anterior border of the 
hyo-glossus, it bends sharply upwards to reach the tongue, along the under 
surface of which, under the name of ranine artery, it is continued forwards. 
It rests successively upon the middle constrictor of the pharynx and the 
genio-glossus. It is crossed, near its origin, by the posterior belly of the 
digastric, and it is covered, further forwards, by the hyo-glossus muscle. 
Its named branches are: (1) the hyoid, a small twig which runs along 
the upper border of the hyoid bone; (2) the dorsal artery or arteries 
of the tongue, arising under cover of the hyo-glossus and piercing the 
posterior part of the tongue; (3) the sublingual, a branch of moderate size, 
supplying the sublingual gland and the surrounding parts. The ranine 
artery, giving off numerous branches, runs forwards with a tortuous course 
along the under surface of the tongue towards the tip ; near its termina- 
tion, by the side of the fraenum, it is very superficial. There is but little 
anastomosis between the vessels of opposite sides. 
The ascending pharyngeal artery (Fig. 318), a long slender vessel, 
arises from the deep surface of the external carotid, about the level of the 
place of origin of the lingual artery. It passes upwards, to the base of 
the skull, upon the wall of the pharynx, crossing the deep surface of the 
stylo-pharyngeus muscle. It supplies delicate offsets to the prevertebral 
muscles, the wall of the pharynx, the tonsil, the Eustachian tube, and the 
palatal muscles. Its terminal branches enter the skull by the foramen 416 
THE VASCULAR SYSTEM. 
lacerum medium, the jugular foramen, and the anterior condylar foramen, 
and supply the dura mater. 
The facial artery (Fig. 319) takes origin from the anterior border of 
the external carotid trunk, immediately above the lingual; it passes forwards 
and upwards, crosses the ramus of the lower jaw, and reaches the face. 
In the neck it rests, successively, upon the middle constrictor of the pharynx, 
the stylo-glossus, and the mylo-hyoid muscles; it is crossed superficially by 
the posterior belly of the digastric and the stylo-hyoid; and it passes along 
a groove on the deep surface of the submaxillary gland. Emerging from under 
cover of the gland, it crosses the jaw immediately in front of the anterior 
border of the masseter muscle. On the face it takes an exceedingly 
tortuous course, towards the inner canthus of the eye, crossing superficially 
the buccinator, levator anguli oris, and levator labii superioris muscles, 
and lying under cover of the platysma and zygomatici. Near its termination 
it usually passes through the substance of the common elevator of the lip 
and nose. On the face, branches of the facial nerve cross it superficially, 
and the infraorbital nerve emerges on its deep surface. The companion vein 
lies, on the face, external to and at some little distance from it; in the 
neck, the vein descends behind the artery and is more superficially placed. 
(a) Cervical branches. The tonsillar branch, a long slender twig, ascends, 
crossing the outer surface of the stylo-glossus muscle, pierces the superior 
constrictor, and supplies small branches to the tonsil and the side of the 
tongue. The palatine branch, arising close to the tonsillar, ascends between 
the stylo-glossus and stylo-pharyngeus muscles, turns over the border of 
the superior constrictor, and descends with the levator palati to the soft 
palate. It gives numerous branches to the superior constrictor, the Eus- 
tachian tube, and the palate, and anastomoses with its fellow of the opposite 
side and with the descending palatine branches of the internal maxillary. 
Glandular arteries supply the submaxillary gland. The submental artery, a 
branch of some size, is given off by the facial immediately before crossing 
the jaw, and runs forwards on the surface of the mylo-hyoid muscle. It 
supplies the submaxillary gland, and detaches branches which, piercing the 
mylo-hyoid, reach the sublingual gland. Its terminal branches cross the 
ramus near the symphysis, and supply the muscles of the lower lip. It 
anastomoses with its fellow of the opposite side, the lingual, the inferior 
labial of the facial, and the mental branch of the internal maxillary. 
(b) Facial branches. A number of muscular branches of small size 
anastomose with the buccal, transverse facial, and infra-orbital arteries. 
The other branches, which are specially named, are all given off from the 
anterior border of the parent trunk. The inferior labial artery runs 
forwards on the deep surface of the depressor anguli oris muscle, and 
supplies the lower lip and anastomoses with the sub-mental, mental, and 
inferior coronary vessels. The coronary artery of the lower lip arises below 
the angle of the mouth; the coronary artery of the upper lip arises above 
the angle of the mouth; each runs inwards near the margin of the lip, THE OCCIPITAL AETEEY. 
417 
between the muscle and the mucous membrane, to meet its fellow of the 
opposite side ; the artery of the upper lip detaches a branch to the nasal 
septum. The lateral nasal artery ramifies upon the side of the nose, anasto- 
mosing with a branch of the ophthalmic artery. The angular artery is the 
terminal part of the facial at the inner canthus; it anastomoses with the 
nasal branch of the ophthalmic artery. 
The occipital artery (Figs. 319, 323), arising opposite the facial, is 
directed upwards and backwards, and passes under cover of the posterior 
belly of the digastric muscle, on the deep surface of which it reaches the 
inner side of the mastoid process; continuing its course it runs back- 
wards in the occipital groove, and crosses the lateral rectus and the 
superior oblique muscles; finally, at the posterior border of the splenius, 
becoming superficial, it turns upwards on the back of the head. The 
internal carotid artery, the internal jugular vein, the pneumogastric, 
spinal accessory, and hypoglossal nerves are crossed by the vessel on its 
way backwards, but the last named nerve loops round the artery from 
below, and, passing forwards, crosses it superficially close to its origin. 
The occipital artery gives off a number of muscular branches, the most 
important of which enters the sterno-mastoid. The mastoid branch enters 
a foramen in the mastoid and anastomoses with a branch from the pos- 
terior auricular. The ramus cervicalis princeps, or descending cervical artery, 
is given off under cover of the splenius; it divides into two branches, 
one of which ramifies on the deep surface of the splenius, while 
the other, passing under cover of the complexus, anastomoses with 
the deep cervical and vertebral arteries. The terminal branches, spreading 
over the back of the head, anastomose with one another, and with the 
posterior auricular and temporal arteries. 
The posterior auricular artery (Fig. 319) takes origin from the external 
carotid a little above the occipital. It is directed upwards under cover of 
the parotid gland, crosses the styloid process, and, in the groove between 
the cartilage of the ear and the mastoid process, divides into its terminal 
branches, auricular and mastoid. It is crossed by the facial nerve. Some 
small branches pass to the parotid gland. The stylo-mastoid branch enters 
the stylo-mastoid foramen, and supplies twigs to the mastoid cells and to 
the tympanic walls, anastomosing with the tympanic branch of the internal 
maxillary artery. • The auricular branch supplies both surfaces of the pinna 
of the ear. The mastoid branch bends backwards above the sterno-mastoid, 
and anastomoses with the occipital artery. 
The temporal artery (Fig. 319) springs from the termination of the 
external carotid artery a little below the neck of the lower jaw. From its 
origin, where it is embedded in the parotid gland, it is directed upwards over 
the posterior root of the zygoma; about two inches above the zygoma, it 
divides into two branches, anterior and posterior, which ramify subcutan- 
eously over the side of the head. The auriculo-temporal nerve, which, 
in its course through the gland, is placed internally to the artery, ascends 418 
THE VASCULAR SYSTEM. 
with it in front of the ear. The common temporal vein is behind and 
superficial to the artery as it crosses the zygoma. 
Branches. The transverse facial artery arises in the substance of the 
parotid gland, and runs horizontally forwards above the duct of Stenson. 
It anastomoses with the facial, infraorbital, and buccal arteries. The 
middle temporal pierces the temporal fascia and the temporal muscle 
immediately above the zygoma, and ascends upon the surface of the hone, 
supplying the muscle and anastomosing with the deep temporal arteries. 
Auricular arteries, two or three in number, supply the fore part of the 
cartilage of the ear, anastomosing with the posterior auricular artery. The 
anterior temporal branch, directed upwards and forwards, ramifies over 
the anterior part of the lateral region of the scalp, anastomosing with 
branches of the ophthalmic artery; this is the branch usually chosen for 
temporal blooddetting. The posterior temporal branch, larger than the 
anterior, is directed upwards and backwards, and anastomoses with its 
fellow of the opposite side, and with the occipital and posterior auricular 
arteries. 
The internal maxillary artery (Figs. 320, 321) springs from the 
termination of the external carotid artery immediately below the neck of 
the lower jaw. From its origin, where it is concealed in the substance of 
the parotid gland, it passes forwards, upwards, and inwards. In the first 
part of its course, accompanied by the internal maxillary vein, it passes 
on the deep surface of the ramus of the jaw, along the lower border of 
the external pterygoid muscle, crossing superficially the internal lateral 
ligament of the temporo-maxillary articulation and the inferior dental 
nerve. In the second part of its course it passes through the zygomatic 
fossa to the space between the heads of the external pterygoid muscle, 
crossing sometimes on the superficial and sometimes on the deep surface 
of the lower of the two heads of the muscle; in the former case it lies 
on the deep aspect of the temporal muscle at its insertion; in the latter 
it crosses the lingual nerve, and the internal pterygoid muscle, and emerges 
below the buccal nerve. In the third part of its course it passes through 
the pterygo-maxillary fissure to the spheno-maxillary fossa, where it breaks 
up into a number of branches. Numerous veins surround the second and 
third parts of the artery. 
The branches of the first part of the artery enter bony foramina. The 
tympanic passes through the fissure of Glaser, ramifies on the walls of the 
tympanum, and anastomoses with the stylo-mastoid branch of the posterior 
auricular artery. The middle meningeal, a branch of considerable size, runs 
upwards on the deep surface of the external pterygoid muscle, passes be- 
tween the heads of the auriculo-temporal nerve, and enters the skull by the 
foramen spinosum. Within the cranium, after detaching some small offsets 
which supply the Gasserian ganglion and enter the petrous bone, it con- 
tinues upwards towards the anterior and lower angle of the parietal bone, 
where it divides into two branches which ramify upon the inner surface of f Supraorbital 
-J branch of 
I. ophthalmic 
Fig. 320.—The Internal Maxillary Artery and its Branches 1 External carotid 
artery; 2 internal maxillary artery; 3, tympanic; 4, 4', middle meninS6small 
0 pT”' \r anter?F dcep temporal; 8, B', inferior dental; 
iAfrao?b?taIg- lr,’v’il! ?’ \ ’ desceildl"g Palatine; 13, posterior superior dental; 14, 
9 mMdbrtinW ’ 10, pterygo-palatme ; 17, spheno-palatine ; 18, temporal artery 
(L. Testut )d P t p l branch > 20> posterior auricular artery; 21, facial artery. 
To face p. 418. Fig. 321.—Diagram of the Branches of the Internal Maxillary Artery. 1, Tym- 
panic ; 2, middle meningeal; 3, small meningeal; 4, posterior deep temporal; 5, anterior 
deep temporal; 6, inferior dental; 7, 8, pterygoid ;9, buccal; 10, descending palatine ; 
11, posterior superior dental; 12, infraorbital; 13, pterygo-palatine; 14, Vidian; 15, 
spheno-palatine. (L. Testut.) 
Fig. 322.—Diagram of the Branches of the Ophthalmic Artery, a, Ophthalmic 
artery; 6, optic nerve ; c, globe of the eye ; 1, lachrymal; 2, central artery of the retina ; 
3, posterior or short ciliary ; 4, middle or long ciliary; 5, superior muscular; 6, inferior 
muscular ;7, supraorbital; 8, posterior ethmoidal; 9, anterior ethmoidal; 10, superior 
palpebral; 11, inferior palpebral; 12, frontal; 13, nasal. (L. Testut.) 
To face p. 419. THE INTERNAL MAXILLARY ARTERY. 
419 
the skull, extending forwards to the frontal, backwards to the occipital bone, 
and upwards to the vertex. The small meningeal branch enters the skull 
by the foramen ovale, on the deep surface of the emerging nerve, supplies 
the dura mater of the middle fossa, and gives twigs to the Gasserian 
ganglion. The inferior dental branch descends, with the inferior dental 
nerve in the dental canal, supplying all the teeth of the lower jaw, and 
detaches a branch which, emerging by the mental foramen, terminates on 
the face in anastomosis with branches of the facial artery. Before entering 
the canal the detaches a mylo-hyoid branch, which runs along the 
mylo-hyoid groove and supplies the surrounding muscles; a small branch 
frequently descends for some distance with the lingual nerve. 
The branches of the second part of the artery are distributed to the 
muscles of mastication, and are named in accordance with the individual 
muscles which they mainly supply. The pterygoid branches are irregular in 
number and size. The deep temporal are generally two, posterior and anterior; 
they pass upwards close to the bone in the substance of the temporal muscle, 
and anastomose with branches of the middle temporal artery, and, through 
the outer wall of the orbit, with derivatives of the ophthalmic artery. The 
masseteric branch usually springs from the posterior deep temporal artery; 
passing outwards through the sigmoid notch it enters the masseter muscle. 
The buccal artery ramifies on the buccinator muscle, and anastomoses with 
branches of the facial artery. 
The branches of the third part of the artery, like those of the first, enter 
bony foramina. The posterior superior dental descends upon the surface of 
the superior maxillary bone, and detaches twigs which, entering the 
posterior dental canals, supply the molar and bicuspid teeth. The infra- 
orbital artery runs forwards in the infraorbital canal and, emerging by the 
infraorbital foramen, terminates on the face in branches which supply the 
surrounding parts, and anastomose with the facial and ophthalmic arteries; 
on its way forwards the artery detaches twigs to the orbit, and gives off 
an anterior superior dental branch, which descends in the anterior dental 
canal to complete the supply of the teeth, and gives, on its way, twigs to 
the membrane lining the maxillary antrum. The superior or descending 
palatine artery runs downwards, with the descending branches of Meckel’s 
ganglion, in the posterior palatine canal, and is continued forwards along 
the hard palate towards the incisor foramen, through which its terminal 
branch ascends to anastomose with the naso-palatine artery; it detaches 
branches to the gums and the hard palate, and in addition gives off twigs 
which, descending through the smaller palatine canals, ramify in the soft 
palate, and anastomose with the ascending palatine branch of the facial 
artery. The spheno-palatine artery passes through the spheno-palatine 
foramen into the nasal fossa; its branches ramify in the nasal mucous 
membrane, and reach the frontal and maxillary sinuses; one, the naso- 
palatine, descends on the septum to anastomose with the terminal branch 
of the descending palatine artery. The Vidian branch passes backwards 420 
THE VASCULAR SYSTEM. 
along the Vidian canal, and gives branches to the pharynx, the Eustachian 
tube, and the levator palati muscle. The pterygo-palatine, a minute twig, 
passes backwards in the pterygo-palatine canal towards the upper part 
of the pharynx. 
The Internal Carotid Artery. 
The internal carotid artery (Fig. 323) stretches directly upwards from 
the termination of the common carotid artery to the carotid canal of the 
temporal bone, along which it passes to enter the skull. Within the skull 
it is distributed in branches to the brain and to the structures within the 
orbit. In the neck it lies at first behind and external to, but afterwards on 
the deep surface of the external carotid trunk. It is overlapped at first by 
the sterno-mastoid, then crossed by the digastric and stylo-hyoid muscles, and 
finally is very deeply placed on the inner aspect of the stylo-pharyngeus 
muscle, the styloid process, and the parotid gland. It ascends by the side 
of the pharynx, and rests behind upon the rectus capitis anticus major. 
The internal jugular vein is external and posterior to the artery, and the 
pneumogastric nerve lies behind the artery, between it and the vein, en- 
veloped along with them in a common sheath. At the base of the skull, 
in addition to the pneumogastric nerve, the glosso-pharyngeal, spinal 
accessory, and hypoglossal nerves emerge between the artery and vein. 
The spinal accessory is soon directed backwards across the vein, the 
glosso-pharyngeal passes forwards superficially to the artery, and a little 
lower down, near the lower edge of the digastric muscle, the hypoglossal 
nerve, passing forwards, likewise crosses the artery superficially. On the 
deep surface of the artery the superior laryngeal branch of the pneumo- 
gastric crosses forwards. The superior cervical ganglion of the sympathetic 
lies behind the sheath. The occipital and posterior auricular arteries pass 
backwards superficially to the artery, the former below and the latter above 
the digastric muscle. 
Within the carotid canal the artery is accompanied by the ascending 
branch of the superior cervical ganglion of the sympathetic, and is surrounded 
by a plexus of small veins. It passes at first upwards, then bends forwards 
and inwards. In the first portion of its course it is separated from the 
tympanum by the thin anterior part of the inner wall of the cavity. 
At the bend the bony portion of the Eustachian tube crosses it externally. 
Further forwards, where it is leaving the canal, it underlies the outer edge 
of the Gasserian ganglion, being separated from it by fibrous membrane only. 
Within the cranium the artery at first, in continuation of its course on 
leaving the carotid canal, is directed forwards and inwards across the 
foramen lacerum medium- it then turns upwards in the groove on the side 
of the sphenoid, between the lingula and the petrosal process; it next 
passes forwards on the side of the body of the sphenoid, lying in the 
cavernous sinus, and invested by its lining membrane; and it finally turns 
upwards by the inner side of the anterior clinoid process, perforates the Fig. 323.—The External and Internal Carotid Arteries and their Chief 
Relations. 11. to VI., Cervical nerves (anterior divisions), a, Gasserian ganglion; 
h, Meckel’s ganglion ; c, internal jugular vein; d, middle meningeal artery; e, sterno- 
mastoid muscle. 1, 2, Lingual nerve; 3, connecting branch between lingual and 
inferior dental; 4, chorda tympani; 5, submaxillary ganglion; 6, glosso-pharyngeal 
nerve ; 7, hypoglossal nerve ; 8, descendens hypoglossi ; 9, thyro-hyoid branch ; 10, con- 
nections between lingual and hypoglossal; 11, terminal branches of hypoglossal; 
12, communicating branches from cervical plexus; 13, ansa hypoglossi; 14, spinal 
accessory; 15, pneumogastrio; 15', ganglion of the trunk of the pneumogastric; 
16, superior laryngeal nerve. (L. Testut.) 
To face p 420. Fio. 324.—Diagram of the Arteries of the Base of the Brain. 1, Internal carotid ; 
2, middle cerebral; 3, anterior cerebral; 4, anterior communicating ;5, posterior com- 
municating ;6, vertebral; 7, basilar ;8, posterior cerebral; 9, posterior spinal; 10, anterior 
spinal; 11, posterior inferior cerebellar; 12, anterior inferior cerebellar; 13, superior 
cerebellar ; 14, transverse branches. (L. Testut.) 
Frontal lobe 
Anterior communi-) 
eating artery ( 
Anterior cerebral \ 
artery / 
Superficial branches 
Internal carotid artery 
Middle cerebral artery 
4, Superficial branches 
4', Deep branches 
Optic nerve 
Basilar vein 
c, Temporal lobe 
Pig. 325.—The Antero-Lateral Group of Deep Branches from the Middle 
Cerebral, (L. Testut.) 
To face p. 421*. THE OPHTHALMIC AETEEY. 
421 
roof of the sinus, and reaches the base of the brain in the neighbourhood 
of the anterior perforated spot. As it passes forwards in the sinus it is 
surrounded by filaments of the sympathetic, and is in contact externally 
with the third, fourth, ophthalmic division of the fifth, and sixth nerves. 
There are no branches in the neck. Very minute twigs are detached 
in the carotid canal, and within the skull, to the tympanum and to the 
walls of the sinus. Immediately after perforating the roof of the sinus 
it detaches the ophthalmic artery, and at the base of the brain, before 
dividing into its terminal branches, the anterior and middle cerebral arteries, 
it gives off the posterior communicating and anterior choroid arteries. 
The ophthalmic artery (Fig. 322), arising from the internal carotid as 
it ascends by the inner side of the anterior clinoid process, passes through 
the optic foramen below, and by the outer side of the optic nerve. Within 
the orbit it passes obliquely forwards and inwards with a slightly tortuous 
course, crossing in the posterior part of the cavity usually over, but some- 
times under, the optic nerve. At the level of the pulley of the superior 
oblique muscle it divides into its terminal branches—the frontal and nasal. 
The branches are very numerous. A number of muscular twigs are given 
off irregularly from the main trunk and from its more important 
derivatives. The branches which are specially named may be divided 
into three groups, according as they are given off—(a) as the main trunk 
lies by the outer side of the optic nerve; (6) as it crosses the nerve; 
(c) as it is passing forwards along the inner wall of the cavity. 
(a) The lachrymal artery runs forwards along the upper margin of the 
external rectus muscle to the lachrymal gland which it supplies. It 
detaches temporal and malar twigs, which pass through bony foramina to 
the exterior of the skull, in company with the similarly named branches 
of the superior maxillary division of the fifth nerve; and it likewise gives 
off slender palpebral branches to the upper and lower eyelids. The central 
artery of the retina, a slender vessel, leaves the ophthalmic artery at the back 
of the orbit, penetrates into the interior of the optic nerve, and, passing 
forwards within it, ramifies upon the retina. 
(h) The ciliary arteries are divided into three groups—posterior, middle, 
and anterior. The posterior or short ciliary arteries, usually two in number 
at the origin, divide into ten or twelve branches, which pass forwards, sur- 
rounding the optic nerve, and pierce the sclerotic posteriorly ; they ramify in 
the choroid coat. The middle or long ciliary arteries, two in number, arising 
either separately or with the posterior vessels, pierce the sclerotic 
posteriorly, one on either side of the optic nerve, a little in front of 
the short ciliary arteries, and are continued forwards to the iris. The 
anterior ciliary arteries, six or seven in number, may arise either directly 
or in conjunction with some of the muscular branches; they pierce the 
sclerotic anteriorly close to its corneal margin, and supply the ciliary 
processes of the choroid. The supraorbital artery passes forwards by the 
inner side of the levator palpebrae muscle, leaves the orbit by the supra- 422 
THE VASCULAR SYSTEM. 
orbital notch, in company with the supraorbital nerve, and ramifies upon 
the forehead, anastomosing with the temporal and frontal arteries. 
(c) The ethmoidal arteries are two in number, anterior and posterior; 
they leave the orbit by the internal orbital canals. The posterior vessel, 
usually the smaller, is distributed to the upper and posterior part of the nasal 
mucous membrane. The anterior vessel, accompanying the nasal branch of 
the ophthalmic division of the fifth nerve, first detaches some small twigs to 
the dura mater of the anterior cranial fossa and then descends, supplying the 
fore part of the nasal mucous membrane. Its terminal twig appears ex- 
ternally on the side of the nose, having passed outwards between the lower 
edge of the nasal bone and the nasal cartilage. The palpebral arteries, two 
slender vessels, are distributed to the upper and lower eyelids respectively, 
and anastomose with branches of the lachrymal artery. The frontal artery 
(Fig. 319), one of the terminal branches, is directed upwards for a little 
distance on the forehead, anastomosing with its fellow of the opposite side 
and with the supraorbital artery. The nasal artery, the other terminal 
branch, ramifies over the root of the nose and anastomoses with the angular 
branch of the facial artery. 
Arteries oe the Cerebrum. 
The arterial supply of the cerebrum is most conveniently described in 
sequence, although only the anterior and middle cerebral arteries are 
derived from the internal carotids, while the posterior cerebral arteries are 
right and left derivatives of the basilar, a mesial vessel formed by the 
union of the right and left vertebral arteries. An anastomotic connection 
between the main trunks at the base of the brain is called the circle of 
Willis : it is completed by the anterior communicating artery in front 
and the posterior communicating arteries at the sides posteriorly. Besides 
the anterior and middle cerebral arteries, the internal carotid usually 
gives off directly a slender vessel—the anterior choroid artery. 
The circle of Willis (Fig. 324) is formed by the anastomosis of the 
branches of the basilar and internal carotid arteries at the base of the 
brain. The larger vessels which take part in its formation are the posterior 
cerebrals, internal carotids, and anterior cerebrals of opposite sides, and it 
is completed by the posterior communicating arteries stretching between 
the internal carotids and posterior cerebrals, and by the anterior communi- 
cating artery joining together the anterior cerebrals. It is heptagonal in 
form and within its area are placed from before backwards the optic com- 
missure, infundibulum, corpora albicantia, and posterior perforated spot. It 
serves the purpose of equalizing the blood-pressure in the arteries distributed 
to the brain, and also maintains the supply to every part of the organ in 
cases of obstruction of one or other of the larger stems. 
General distribution of the arteries of the cerebrum. The arterial 
branches which are distributed to the brain may be divided into super- 
ficial and deep groups. The superficial branches ramify in the pia mater THE ARTERIES OF THE BRAIN. 
423 
and finally give off very slender twigs which enter the surface of the 
brain. The neighbouring branches anastomose with one another in the 
pia mater, but the twigs which ramify in the brain substance have no 
anastomotic connection with one another. The superficial branches of the 
anterior cerebral artery supply the anterior and inner part of the orbital 
surface, the whole inner surface of the frontal lobe, the anterior and 
upper part of the outer surface of the frontal lobe, the whole inner 
surface of the parietal lobe, and the corpus callosum. The superficial 
branches of the middle celebral supply the posterior and outer part of 
the orbital surface, the posterior and lower part of the outer surface of 
the frontal lobe, the island of Reil, the whole of the outer surface of the 
parietal lobe, and the two upper convolutions of the outer surface of 
the temporal lobe. Those of the posterior cerebral supply the remaining 
part of the temporal lobe and the whole of the occipital lobe. A 
very small branch from the posterior communicating artery is given to 
the uncinate convolution of the temporal lobe. The choroid arteries 
belong to the superficial group; the largest of them, the anterior choroid, 
detaches numerous small branches to the optic thalamus and to the hippo- 
campus major. 
The deep branches are slender vessels which pierce the base of the brain 
and ramify chiefly in the basal ganglia, which they largely supply. Like the 
branches of the superficial arteries which enter the brain substance, they do 
not anastomose with one another. They are divided into six groups, an 
antero-mesial and a postero-mesial, and, on each side, an antero-lateral and 
a postero-lateral. The antero-mesial group is formed by a few branches from 
the anterior communicating and anterior cerebral arteries; they pass through 
the lamina cinerea and. reach the anterior end of the caudate nucleus. The 
antero-lateral group (Fig. 325) springs from the middle cerebral artery; it 
is formed of numerous vessels which pierce the anterior perforated spot: 
they complete the supply of the caudate nucleus, and likewise pass to the 
lenticular nucleus, the external and internal capsules, and the anterior part 
of the optic thalamus. One of these vessels, somewhat larger than the 
others, and placed externally to them, has frequently been found ruptured, 
and has, in consequence, been named by Charcot, “the artery of cerebral 
haemorrhage.” The postero-lateral group is formed of two or three small 
vessels which spring from the posterior cerebral artery on the outer side 
of the crus, and pass to the posterior part of the optic thalamus and to 
the corpora quadrigemina. The postero-mesial group is composed of five or 
six vessels which arise from the posterior cerebral arteries close to their 
origin, and pass upwards through the posterior perforated spot to the 
inner part of the crus and to the optic thalamus. 
The anterior choroid artery, a small vessel, arises from the internal 
carotid trunk close to its extremity. It passes backwards, and, under 
cover of the uncinate convolution, to which it detaches some small branches, 
enters the extremity of the descending cornu; it ramifies in the choroid 424 
THE VASCULAR SYSTEM. 
plexus and detaches twigs to the optic thalamus and to the hippocampus 
major. 
The posterior communicating artery, usually a slender trunk, hut of 
very variable size and commonly unequal on opposite sides of the body, 
springs from the internal carotid immediately before its terminal division. 
It passes backwards, crossing the optic tract and crus cerebri, and joins the 
posterior cerebral artery. It gives off one or two slender branches to the 
crus and to the optic thalamus. 
The anterior cerebral artery, from the termination of the internal 
carotid, runs forwards and inwards between the olfactory tracts and optic 
nerves to the great longitudinal fissure, where it approaches very closely 
its fellow of the opposite side with which it is put into communication 
by a short transverse trunk, the anterior communicating artery. There- 
after, in company with its neighbour, it courses in the longitudinal fissure, 
turning over the genu and runnning backwards upon the surface of the 
corpus callosum to anastomose with the posterior cerebral artery. Its 
branches are—(a) a few slender deep branches which, along with those 
of the anterior communicating artery, constitute the antero-mesial group; 
they pierce the lamina cinerea and supply the anterior end of the 
caudate nucleus; (b) a number of superficial branches of which (1) two or three 
inferior frontal vessels supply the anterior and inner part of the orbital surface 
of the frontal lobe; (2) two or three internal frontal vessels supply the mesial 
surface, and sweep over the margin of the hemisphere to supply the 
anterior and upper part of the outer surface of the frontal lobe; (3) a 
parietal branch supplies the inner surface of the parietal lobe; (4) an artery 
to the corpus callosum. 
The anterior communicating artery, a transverse communication between 
the two anterior cerebral arteries, sometimes double, lies upon the lamina 
cinerea in front of the optic commissure and usually gives off two or 
three slender deep branches, which assist in supplying the fore part of 
the caudate nucleus. 
The middle cerebral artery (Figs. 325, 326), the larger of the terminal 
divisions of the internal carotid artery, passes upwards and outwards in 
the fissure of Sylvius for a little distance, and then divides into its 
terminal branches which are superficial in their distribution. From the 
main trunk a number of deep branches are given off, constituting the 
antero-lateral group. These vessels supply the anterior part of the optic 
thalamus and the greater part of the can date nucleus, with the exception 
of the extreme fore part; they also supply the le.nticular nucleus and the 
external and internal capsules. They pass through the anterior perforated 
spot. The terminal or superficial branches are four in number; they pass 
upwards between the convolutions of the island of Reil: (1) the inferior 
frontal supplies the posterior part of the orbital surface of the frontal lobe 
and the adjacent part of the third frontal convolution ; (2) the ascending 
frontal supplies the lower and posterior part of the outer surface of the THE ARTERIES OF THE BRAIN. 
425 
frontal lobe; (3) the parietal supplies the anterior and upper parts of 
the parietal lobe; (4) the parieto-temporal, often double, the largest and 
most posterior, supplies the lower and posterior parts of the parietal 
lobe and sends branches downwards upon the first and second temporal 
convolutions. 
The posterior cerebral artery, arising from the termination of the basilar 
artery at the anterior border of the pons, passes at first outwards across the 
crus in front of the third nerve, then turns upwards and backwards, round 
the crus, and terminates on the under and inner surface of the hemisphere. 
As it is turning backwards it receives the posterior communicating artery. 
Its deep branches form (a) the postero-median and postero-lateral groups: the 
vessels belonging to the former, five or six in number, pass through the 
posterior perforated spot to supply the optic thalamus and the inner part of 
the crus; those belonging to the latter, two or three in number, pass up- 
wards by the outer side of the crus to the optic thalamus and to the corpora 
quadrigemina; (b) some slender branches to the crus are detached as the main 
trunk lies on it. The superficial branches are—(1) the posterior' choroid arteries, 
which supply the choroid plexuses and velum interposition; (2) the 
anterior temporal which supplies the anterior part of the inner surface 
of the temporal lobe; (3) the posterior temporal which supplies the lower 
part of the outer surface, and the posterior part of the inner surface of 
the temporal lobe; (4) the occipital which supplies both surfaces of the 
occipital lobe. 
Surgical anatomy of the common carotid artery and its branches. 
The course of the common carotid in the neck may be marked on the 
surface, by a line drawn from the sterno-clavicular articulation to a point 
midway between the angle of the jaw and the mastoid process. The 
vessel bifurcates opposite the upper border of the thyroid cartilage. It 
is crossed by the omo-hyoid muscle at the level of the sixth cervical 
vertebra, opjiosite the cricoid cartilage; below the crossing it is deeply 
placed, being covered by the sterno-mastoid muscle; above, it is com- 
paratively superficial, being only overlapped by the anterior border of 
the muscle. The artery is reached through an incision made along 
its course, the centre being on a level with the cricoid cartilage. 
The head must be supported and the chin drawn upwards, and, in 
order to prevent the edge of the sterno-mastoid from being drawn com- 
pletely over the vessel, only slightly turned to the opposite side from 
that on which the operation is to be performed. A descending branch 
from the facial vein may be met with at the anterior border of the 
sterno mastoid. The sterno-mastoid and omo-hyoid are to be clearly 
defined and drawn apart, and the sheath of the vessels exposed. On 
the surface of the sheath the superior thyroid veins, the sterno-mastoid 
branch of the superior thyroid artery, and the descendens hypoglossi nerve 
will probably be encountered. The sheath is to be opened over the artery, 
which is to be carefully separated from the walls. The hook is passed 426 
THE YASCULAE SYSTEM. 
from the outer side to avoid the vein, and care must be taken to prevent 
the inclusion of the pneumogastric nerve. A prominence of the costal 
process of the sixth cervical vertebra, the “ carotid tubercle,” is immediately 
behind the artery at the place of operation. 
The course of the internal carotid artery is marked on the surface by 
the upper part of the carotid line already described. The incision, which 
is made along the anterior border of the sterno-mastoid muscle, extends 
upwards from the middle of the thyroid cartilage, as it is only the lower 
and comparatively superficial portion of the vessel which can be reached 
by the surgeon. The anterior border of the sterno-mastoid is drawn back- 
wards, the posterior belly of the digastric and the hypoglossal nerve 
immediately below it are identified, and the position of the great cornu 
of the hyoid bone is recognized. The facial, lingual, and superior thyroid 
veins may cross the artery. The external carotid lies in close proximity, 
a little in front and a little internal; it must be drawn inwards. The needle 
is passed from without inwards, and care must be taken of the pneumogastric 
nerve; the superior laryngeal branch of the pneumogastric, and the 
sympathetic nerve lie on the deep surface of the sheath. 
The external carotid, like the internal carotid, is deeply placed above, 
and is usually ligatured below the level of the digastric muscle, the portion 
of the vessel usually chosen being that which intervenes between the origins 
of the superior thyroid and lingual arteries. The line of the vessel 
in this region is practically the same as that of the internal carotid, 
and the steps in the operation for ligature are identical with those 
already described. The superior thyroid, lingual, facial, and occipital 
arteries may also be reached, at their places of origin, through the same 
incision. 
The lingual artery is generally sought for in the second part of its 
course, under cover of the hyo-glossus muscle and immediately above 
the great cornu of the hyoid bone, the variability of the origin of the vessel 
and the difficulty of the operation rendering the ligature of the first part of 
the artery in most cases unadvisable. A curved incision is made from a 
point a little below and external to the symphysis, to a spot a little 
below the place where the facial artery crosses the lower jaw, the con- 
vexity reaching downwards as far as the upper margin of the great cornu 
of the hyoid bone. Some superficial veins may be met with; the sub- 
maxillary gland is exposed and carefully drawn upwards, the edge of the 
mylo-hyoid muscle is defined, and the intervening tendon of the digastric 
is drawn outwards. The hypoglossal nerve, with the ranine vein immed- 
iately below it, coursing upon the surface of the hyo-glossus is exposed. 
An incision through the muscle, a little below the nerve, between it and 
the great cornu, will expose the artery which is accompanied by two 
small venae comites. 
The facial artery is usually ligatured at the place where it crosses the 
lower margin of the jaw, immediately in front of the masseter muscle. A THE SUBCLAVIAN ARTERY. 
427 
transverse incision is made across the line of the vessel. The vein lies 
behind the artery and in close proximity to it. 
The temporal artery may be secured immediately above the zygoma; 
the companion vein lies behind and overlaps it. 
The Subclavian Artery. 
The subclavian arteries (Figs. 317, 318, 327) of the opposite sides differ 
from one another in their origin. The left artery arises within the thorax 
from the transverse portion of the aorta and, passing upwards, enters the 
neck behind the left sterno-clavicular articulation; the vessel of the right side 
springs from the extremity of the innominate stem, opposite the right sterno- 
clavicular articulation. Each vessel passes outwards in the neck with an 
upward arch over the apex of the lung, and, crossing under the clavicle and 
over the first rib, enters the axilla. The arch formed by the subclavian 
artery in the neck is placed above the inner half of the clavicle, and its 
summit reaches about an inch above the upper border of the collar bone, the 
arm hanging by the side. In its passage outwards the artery passes behind 
the scalenus anticus muscle; for convenience of description it is divided 
into three parts, the first internal to the muscle, the second behind it, and the 
third between the outer border of the muscle and the outer margin of the 
first rib. The first part of the left subclavian, including, as it does, the 
thoracic portion of the vessel, is about an inch longer than that of the 
right side. 
The first part of the left subclavian artery. At its origin it lies a little 
behind and slightly to the left of the left common carotid artery, and the 
two vessels maintain their relative positions in their passage upwards to the 
neck. It lies behind but at some little distance from the left margin of the 
manubrium; the trachea lies to its right side; the oesophagus and the thoracic 
duct are behind it; and, on the left side and behind, it is covered by the pleura. 
In the neck it passes from behind the upper part of the sterno-clavicular joint 
outwards and upwards to the margin of the scalenus anticus muscle. The 
trachea, the oesophagus, the recurrent laryngeal nerve, and, at first, the 
thoracic duct, lie to its right side, but the duct, bending downwards and out- 
wards to reach the innominate vein, afterwards crosses in front of it; the 
trunk of the sympathetic nerve and the longus colli muscle lie behind; 
the pleura is in contact with it below. It is covered in front by the 
sterno-mastoid, sterno-hyoid, and sterno-thyroid muscles. The subclavian 
and internal jugular veins unite in front of it to form the left innominate 
vein, and the vertebral vein descends to the innominate in front of it. 
The phrenic and some branches of the sympathetic nerves pass downwards 
into the thorax in front of it, and the pneumogastric nerve descends in 
front and a little to the right side. 
The first part of the right subclavian artery arches upwards and outwards 
from the extremity of the innominate stem, behind the upper part of the 
right sterno-clavicular articulation, to the margin of the scalenus anticus 428 
THE VASCULAR SYSTEM. 
muscle. The sterno-mastoid, sterno-hyoid, and sterno-thyroid muscles cover 
it superficially; behind, it rests on the longus colli; the pleura is in contact 
with it below. The right subclavian and internal jugular veins unite in front 
of it to form the right innominate vein, and the vertebral vein descends in 
front of it. The pneumogastric and some loops of sympathetic nerve cross it 
superficially, and the recurrent laryngeal nerve, turning round it, passes 
upwards and inwards behind it; the main trunk of the sympathetic descends 
behind it. 
The second part of the subclavian artery forms the highest part of the arch. 
It is covered in front by the scalenus anticus and sterno-mastoid muscles, and 
is in contact with the pleura below and behind; the brachial plexus lies 
above it. The subclavian vein is placed a little lower than the artery, and 
in front of it, being separated from it by the scalenus anticus. The 
phrenic nerve descends, on the right side, in front of the inner part of the 
second portion of the artery; on the left side, as already described, it 
runs downwards in front of the outer part of the first portion of the artery. 
The third part of the subclavian artery extends downwards and outwards 
from the outer margin of the scalenus anticus to the outer margin of the first 
rib. It is the most superficial portion of the vessel and is likewise the longest 
of the three parts; it lies, under cover of the deep cervical fascia, in a 
triangular space, the sides of which are formed by the margins of the sterno- 
mastoid and omo-hyoid muscles, and the clavicle. Behind, it is in contact 
with the scalenus medius, and below, it rests upon the first rib. The sub- 
clavian vein is lower than, and in front of, the artery; and the external 
jugular vein, descending to the subclavian, crosses it superficially, receiving 
as it passes in front of the artery, the suprascapular and transverse 
cervical veins from the shoulder. The suprascapular artery running 
behind the clavicle crosses the third part of the subclavian, and the 
transverse cervical artery, passing outwards in the neck, lies above it. 
The brachial plexus lies above and behind it, the lowest cord being in 
close contact with it. The slender nerve to the subclavian muscle crosses 
it in front, and the supraclavicular branches of the cervical plexus descend 
in the superficial tissue in front of it. 
The branches of the subclavian artery are—(1) the vertebral, (2) the 
internal mammary, (3) the thyroid axis, and (4) the superior intercostal 
artery. The three first mentioned spring from the first part of the artery, 
the last usually takes origin from the second portion; the third part, save 
in abnormal circumstances, gives off no branch. 
(1) The vertebral artery (Fig. 318) arises from the upper border of the 
first part of the subclavian artery, a little distance from the margin of the 
scalenus anticus muscle. It is at first directed upwards and a little out- 
wards to reach the foramen in the transverse process of the sixth cervical 
vertebra; it then passes almost directly upwards through the successive 
higher foramina, save that in passing from that of the second to that of 
the first vertebra it bends considerably outwards. After threading the trans- Ascending frontal branch Sulcus circularis Parietal branch 
'* * YX 
Parieto-temporal branches 
Ascending frontall 
branch / 
( Parieto- 
temporal 
( branches 
Middle 
cerebral > 
artery j 
“Temporal lobe 
Fig. 326.-—The Superficial Branches of the Middle Cerebral Artery, a, Anterior 
portion of island of Reil; b, posterior portion of island of Reil; c, sulcus centralis ; e 
parieto-temporal convolution ; 2, inferior frontal branch ; 5, ascending frontal branch • 
S, temporal branches. (L, Testut.) 
Fig. 327.—Diagram of the Method of Origin of the Branches of the Right 
Subclavian Artery, a, Ist part of subclavian ; b, 2nd part of subclavian; c, 3rd part of 
subclavian ; 1, vertebral artery ; 2, thyroid axis ; 3, suprascapular artery ; 4, transverse 
cervical artery: 5, Inferior thyroid artery ; sascending cervical branch; 6, internal 
mammary artery; 7, superior intercostal artery arising, unusually, from the first part; 8, 
deep cervical artery. (L. Testut.) 
To face p. 428, ( Transverse cervical 
\ artery 
i Suprascapular artery 
Posterior circumflex artery 
Dorsal branch of suhscapular artery 
Fro. 328.—Arteries of the Back op the Shoulder. (C. Gegenbaur.) 
To face p. 429. THE VERTEBRAL ARTERY. 
429 
verse process of the atlas, it turns backwards and inwards behind the 
superior articular process of that bone, occupying the groove on the posterior 
arch; then piercing the occipito-atlantal ligament, dura mater, and arachnoid, 
it reaches the side of the spinal cord. It then ascends through the 
foramen magnum, and runs forwards along the basilar process of the 
occipital bone, gradually approaching its fellow of the opposite side, with 
which, at the posterior border of the pons, it unites to form the basilar 
artery. Before entering the foramen of the sixth cervical vertebra, the 
artery lies between the origins of the scalenus anticus and longus colli 
muscles, and is covered in front by the internal jugular and vertebral 
veins. Ascending through the foramina, it passes in front of the issuing 
cervical nerve trunks, and is surrounded by filaments of the sympathetic 
nerve, and by a venous plexus. As it turns backwards, before entering 
the spinal canal, it lies in the occipital triangle, and the posterior 
primary division of the suhoccipital nerve passes out beneath it. Within 
the subarachnoid space, it crosses the side of the medulla immediately 
below the roots of the hypoglossal nerve. 
The branches of the vertebral artery in the neck are all of small size. 
The spinal branches pass towards the spinal canal, where they divide, 
supplying the bony walls, the membranes, and the cord. Numerous 
muscular branches ramify among the deeper muscles of the neck, and 
anastomose with branches of the ascending cervical, deep cervical, and 
occipital arteries. When piercing the dura mater the artery gives off a small 
meningeal branch, which ramifies in the posterior fossa of the skull. The 
posterior spinal branch is detached as the vertebral artery enters the cranium. 
It runs downwards upon the side of the cord, and divides into two slender 
vessels which form the commencement of lateral anastomotic chains of 
arteries. The anterior spinal artery arises near the extremity of the vertebral. 
It passes backwards upon the medulla, and unites with its fellow of the 
opposite side to form a median anastomotic arterial vessel, which runs down- 
wards upon the cord. The posterior inferior cerebellar artery arises between the 
spinal arteries. It passes over the restiform body and reaches the 
vallecula, where it breaks up into branches, some of which supply the 
inferior surface of the cerebellum, while others ramify in the choroid plexus 
of the fourth ventricle. 
The arteries of the spinal canal and spinal cord. Lateral arteries 
running along the issuing nerves enter the canal. They are derived from 
the vertebral, deep cervical, intercostal, lumbar, ilio-lumbar, and lateral 
sacral arteries. Each artery on reaching the canal divides into two branches, 
one of which ramifies on the bony wall, while the other, piercing the mem- 
branes, is continued towards the cord. The successive branches which ramify 
upon the bony walls communicate with one another and with the corre- 
sponding vessels of the opposite side, with the result that three longitudinal 
arterial anastomotic chains, one median and two lateral, communicating 
freely with one another by transverse branches, are formed on the posterior 430 
THE VASCULAR SYSTEM. 
surface of the vertebral bodies. The branches which pass' towards the cord 
are in most cases small, and lose themselves upon the membranes and 
nerve roots, but a few, larger than the others, are continued into the longi- 
tudinal anastomotic vessels. The anterior anastomotic vessel, formed above 
by the junction with one another of the anterior spinal branches of the 
vertebrals, runs the whole length of the cord in front of the anterior 
median fissure, and is reinforced by seven or eight lateral branches. The 
lateral anastomotic chains, arising above from the posterior spinals of the 
vertebrals, are double on each side, one vessel lying in front of and the other 
behind the posterior nerve roots. They are smaller and more irregular 
than the anterior, but run the whole length of the cord, and are reinforced 
by occasional lateral branches. 
The basilar artery (Fig. 324) extends forwards and upwards from the 
posterior to the anterior border of the pons, occupying a median groove on 
its under surface, and ends by dividing into the posterior cerebral arteries, 
which have been already described (p. 425). It gives off—(1) the transverse 
arteries, numerous small vessels, which pass outwards on either side, supply- 
ing the pons and adjacent parts of the brain ; (2) the internal auditory arteries, 
one on each side, accompanying, in each case, the auditory nerve to the 
internal ear ; (3) the anterior inferior cerebellar arteries, which ramify on the 
under surface of the cerebellum and anastomose with the posterior inferior 
cerebellars of the vertebral; (4) the superior cerebellar arteries, which arise at 
the extremity of the basilar, immediately behind the posterior cerebrals, 
and turning outwards behind the third nerves, wind round the crura, and 
are distributed in branches, some forwards to the isthmus cerebri and 
velum interposition, and others backwards to the upper surface of the 
cerebellum, anastomosing with the inferior cerebellar arteries. 
The arteries of the cerebellum, pons, medulla, and spinal cord ramify 
and anastomose with one another in the pia mater, and finally detach 
small twigs which pass into the nervous substance within which, like 
the ultimate derivatives of the cerebral arteries, their branches have no 
anastomotic connections with one another. 
(2) The thyroid axis (Fig. 318) springs from the front of the first part 
of the subclavian, a little external to the place of origin of the vertebral 
artery. It is about a fourth of an inch in length, and divides into three 
diverging branches—the inferior thyroid, the transverse cervical, and 
the suprascapular. 
The inferior or ascending thyroid artery passes from the thyroid axis 
upwards and inwards, in front of the vertebral artery, and behind the 
carotid sheath and the middle cervical ganglion of the sympathetic, to 
the lower and hinder part of the thyroid body, where its terminal branches 
ramify, anastomosing with those of the superior thyroid artery, and, to a 
certain extent, with those of the thyroid arteries of the opposite side. On 
its course the artery supplies muscular, oesophageal, and tracheal branches. An 
inferior laryngeal branch accompanies the recurrent laryngeal nerve to the THE THYROID AXIS. 
431 
larynx. The ascending cervical artery is a long slender branch which is given 
off as the parent vessel is crossing behind the carotid sheath. It runs 
upwards, for a variable distance, in front of the transverse processes, and 
gives off small twigs which anastomose with branches of the vertebral 
and occipital arteries. The ascending cervical is somewhat variable 
in its origin, and may spring directly from the thyroid axis or from 
the transverse cervical artery. Occasionally it is of large size, and com- 
pensates, through its anastomosing branches, for deficiency in either the 
occipital or vertebral artery. 
The transverse cervical artery (Fig. 328) passes outwards and a little 
upwards across the lower part of the neck as far as the anterior border of the 
levator anguli scapulae muscle, where it divides into the superficial cervical, 
and posterior scapular arteries. It crosses in front of the scalenus anticus 
and the brachial plexus, sometimes, however, threading its way between the 
nerve cords, and, passing behind the omo-hyoid, divides under cover of the 
anterior border of the trapezius. The superficial cervical branch ramifies on 
the deep surface of the trapezius. The posterior scapular branch crosses the 
deep surface of the levator anguli scapulae, and descends along the posterior 
border of the scapula, on the deep surface of the rhomboidei muscles, 
distributing numerous branches to both surfaces of the scapula and to the 
surrounding muscles. It anastomoses with the suprascapular and subscapular 
arteries, the intercostals, and the superficial cervical artery; a very constant 
branch passing between the rhomboidei muscles reaches the deep surface of 
the trapezius. The transverse cervical artery is very irregular; it frequently 
springs from the third part of the subclavian, or its posterior scapular 
branch may spring from the third part, while the superficial cervical has 
the course of the usual trunk. 
The suprascapular artery (Fig. 328) descends towards the clavicle, 
and passes outwards along the posterior surface of that bone to the upper 
margin of the scapula; continuing its course, it crosses over the ligament 
which completes the suprascajmlar notch, and descends on the dorsal 
surface of the scapula, beneath the acromion, to the infraspinous fossa, 
where its terminal branches ramify. Its chief branches are muscular tivigs, 
the medullary artery of the clavicle, and a subscapular branch, which, given 
off as the vessel crosses over the notch, descends on the ventral surface 
of the scapula. The suprascapular artery anastomoses with the other 
scapular arteries and with the acromio-thoracic. 
(3) The internal mammary artery (Figs. 31.8, 345) arises from the lower 
border of the first part of the subclavian, usually opposite the place of origin 
of the thyroid axis. It descends, at first with an inclination forwards and 
inwards, and reaches the back of the cartilage of the first rib; afterwards 
it is continued directly downwards, about half an inch from the margin of 
the sternum, behind the successive rib cartilages, as far as the lower margin 
of the sixth interspace, where it divides into its terminal branches, the 
musculo-phrenic and the superior epigastric. In passing from the neck to the the Vascular system. 
thorax it crosses behind the subclavian vein, and is crossed in front, from 
without inwards, by the phrenic nerve. Within the thorax it lies on the 
deep surface of the internal intercostal muscles, and is at first in contact with 
the pleura behind, but lower down it is separated from the pleura by 
the triangularis sterni muscle. Two veins accompany it in the greater 
part of its course, but join with one another above to form a single 
vessel which lies by its inner side. 
The branches of the artery are numerous, but small. The comes nervi 
phrenici, a long slender vessel, accompanies the phrenic nerve to the dia- 
phragm, giving off slender twigs to the pericardium and pleura. The 
mediastinal, pericardial, and sternal branches form three sets of minute 
anastomosing vessels. The anterior intercostals, two in each of the first six 
intercostal spaces, run backwards, first on the deep surface of the internal 
intercostal muscles, and afterwards between the internal and external 
layers, to anastomose with the main intercostals and their collateral 
branches. The perforating branches, one in each of the first six intercostal 
spaces, become subcutaneous by the side of the sternum; the middle two 
or three of them supply the mammary gland, and are often much 
enlarged. The musculo-phrenic, one of the terminal branches, inclines out- 
wards, downwards, and backwards behind the cartilages of the seventh, 
eighth, and ninth ribs, and, becoming much reduced in size, perforates the 
attachment of the diaphragm about the level of the tenth rib; it gives 
off anterior intercostals for two or three spaces, and, to the diaphragm, 
a number of muscular branches which anastomose with branches of the 
inferior phrenic artery. The superior epigastric, the other terminal division, 
enters the abdominal wall by the side of the ensiform process, descends 
behind the rectus muscle, within its sheath, and finally enters the substance 
of the muscle to anastomose with the deep epigastric artery. It gives off 
numerous small branches, muscular, cutaneous, and peritoneal in their dis- 
tribution, and some which pass backwards within the fold of the falciform 
ligament to the liver. As a not infrequent abnormality, a branch of mod- 
erate size has been found springing from the upper part of the internal 
mammary, and descending on the inner aspect of the chest wall at some 
little distance from the main trunk; it has been named the infracostal artery. 
(4) The superior intercostal artery arises, usually, from the back of the 
second part of the subclavian, close to the inner margin of the anterior scalene 
muscle, but frequently, however, especially on the left side, it springs from the 
first part of the main vessel. It passes at first backwards and gives off its deep 
cervical branch; it then descends over the neck of the first rib, lying internal 
to the sympathetic nerve, and supplies the first two intercostal spaces after 
the manner of an aortic intercostal. The deep cervical branch passes back- 
wards, between the transverse process of the last cervical vertebra and the 
neck of the first rib, and, ascending behind the transverse processes, between 
the origins of the complexus and multifidus spinae, terminates by anasto- 
mosing with the ramus cervicalis princeps of the occipital artery. It gives THE SUBCLAVIAN ARTERY. 
433 
off numerous muscular branches which anastomose with twigs of the 
vertebral artery. 
Surgical anatomy of the subclavian artery. The first and second parts 
of the artery are so deeply placed, and have such important connections, that, 
save in very exceptional circumstances, an operation upon them would hardly 
be considered justifiable. The third part of the vessel may, however, be 
easily reached. A horizontal incision is made across the lower part of 
the posterior triangle, about half an inch above the clavicle, from the 
posterior border of the sterno-mastoid to the anterior edge of the trapezius. 
In making this incision the surgeon usually draws downwards the skin of 
the neck and cuts through it against the clavicle. In the superficial fascia, 
the platysma and a number of the descending branches from the cervical 
plexus are met with, and, occasionally, a vein from the arm, a branch 
from or a continuation of the cephalic. At the posterior border of the sterno- 
mastoid the external jugular vein passes through the deep fascia, and receives 
on its outer side its suprascapular and transverse cervical tributaries which 
sometimes form a small plexus in front of the artery. They must be drawn 
aside or divided between ligatures. The posterior belly of the omo-hyoid 
muscle, with the transverse cervical artery coursing outwards immediately 
below it, is placed a little above the line of the subclavian; the suprascapular 
artery lies behind the clavicle; if necessary, these structures must be drawn 
aside. The edge of the scalenus anticus muscle is to be defined and the 
finger passed downwards along it to the scalene tubercle of the first rib. 
The artery emerges from behind the muscle and may, as a rule, be easity 
recognized. The cords of the brachial plexus lie above the artery and on a 
plane posterior to it, the lowest cord being in close proximity to it. The 
vein lies in front and below. The needle is passed from above down- 
wards and behind forwards, between the lowest nerve-cord and the artery, 
and should be handled with great care, as there is danger of wounding the 
pleura. During the operation the clavicle should be kept depressed as 
much as possible. 
The vertebral artery may be ligatured through an incision extend- 
ing upwards from the clavicle for about three inches along the posterior 
border of the sterno-mastoid muscle. The external jugular vein and the 
sterno-mastoid are drawn inwards. The line between the longus colli and 
the scalenus anticus can be appreciated by the finger, and the carotid tubercle 
of the sixth vertebra can be easily recognized. The artery lies a little below 
the tubercle. Its vein lies immediately in front of it and must be pushed 
aside. The branches of the sympathetic nerve are to be separated as far as 
possible. 
The inferior thyroid artery may be reached through an incision made 
along the anterior border of the lower part of the sterno-mastoid. The 
carotid sheath is to be drawn outwards. The artery passes inwards from 
behind the sheath, a little below the carotid tubercle. THE YASCULAR SYSTEM. 
The Axillary Artery. 
The axillary artery (Fig. 329) is the continuation of the subclavian 
and extends through the axilla from the outer margin of the first 
rib to the lower border of the teres major muscle. It enters the axilla at 
the apex and is continued downwards along the outer wall in contact with 
the coraco-brachialis and biceps, and rests behind successively upon the first 
and second digitations of the serratus magnus, the subscapularis, the latissimus 
dorsi, and the teres major. In front it is covered, in the greater part 
of its extent, by the pectoralis major, and behind that muscle, in order 
from below upwards, by the pectoralis minor, and costo-coracoid membrane, 
and, when the shoulder is depressed, the subclavius muscle. It extends 
below the lower border of the pectoralis major for about an inch and a 
half and is there comparatively superficial. It is in close relationship 
with the axillary vein and the nerve-cords of the brachial plexus. For 
convenience of description it is divided into three parts : the first, about 
an inch in length, above the pectoralis minor; the second, a trifle longer, 
behind that muscle; and the third, about three inches in length, below its 
lower border. 
The axillary vein lies internal to the artery in its whole length; the 
cephalic vein crosses in front of the first part of the artery; and one of 
the brachial venae comites frequently crosses in front of the third part. 
The three cords of the brachial plexus lie by the outer side of the first 
portion of the artery, but as they pass onwards they change their 
positions in relation to the vessel; the inner cord passes behind the artery 
and gains its inner side, where it lies between the artery and the vein; the 
posterior cord passes inwards and descends behind the artery; the outer 
cord approaches the artery and comes into contact with it externally. In 
the upper part of the axilla the nerve-cords detach one or two branches, 
and a little below the lower margin of the pectoralis minor they break 
up into their terminal divisions. The external anterior thoracic branch 
crosses in front of the first part of the artery, and the internal anterior 
thoracic passes forwards by the inner side of the second part, and the 
two nerves are connected with one another, forming a loop in front 
of the artery. The third part of the artery is crossed in front by the 
inner head of the median nerve; in contact with its outer side is the 
outer head of the median above and the completed trunk of that nerve 
below; with its inner side the internal cutaneous and ulnar nerves are in 
contact; the musculo-spiral nerve descends behind it. In addition to these, 
the posterior thoracic nerve (the nerve to the serratus magnus), which 
arises in the neck and passes into the axilla through the apex, lies for a 
little distance behind the first part of the artery. A number of lymphatic 
glands are in contact with the artery and its main branches. The branches 
of the axillary artery are inconstant both in number and size ; the more Posterior circumflex artery 
Anterior circumflex artery | Acromio-thoracic artery 
Dorsal branch of 1 
subsoapular f 
Subscapular artery 
Long thoracic artery 
Fig. 329.—The Axillary Artery. (C. Gegenbaur.) 
To face p. 434. Superior profunda branch 
Brachial artery 
Inferior profunda branch 
Muscular branches -^ 
Anastomotic branch 
Radial artery 
Ulnar artery 
Pig, 330.—The Brachial Artery. (L. Testut.) 
To face p. 435. THE AXILLARY ARTERY. 
435 
important are the acromio-thoracic, the long thoracic, the subscapular, and 
the posterior and anterior circumflex arteries. 
(1) The acromio-thoracic artery, a short stem, arises from the front of the 
first part of the artery. Its branches, passing forwards, pierce the costo- 
coracoid membrane and supply the two pectoral muscles and the surrounding 
parts, and are divided, from their distribution, into four sets, the thoracic, 
clavicular, acromial, and humeral; one of the last named, a vessel of mod- 
erate size, descends for some distance between the deltoid and the 
pectoralis major, by the side of the cephalic vein. 
(2) The long thoracic or external mammary artery arises from the second 
part of the main trunk, and is directed downwards and inwards along the 
lower border of the pectoralis minor muscle. Its branches supply the 
muscles of the anterior wall of the axilla, the mamma, and the axillary 
connective tissue and glands. 
(3) The subscapular artery, usually the largest branch, arises from the 
third part of the axillary trunk, and is directed downwards and backwards, 
along the outer border of the scapula towards the lower angle; its 
branches ramify in the axilla, supply the muscles of the posterior 
wall, and take part in an anastomosis on both surfaces of the scapula 
with those of the suprascapular and posterior scapular arteries. The most 
important is the dorsal branch, which is usually larger than the continua- 
tion of the vessel. It arises near the commencement of the parent trunk, 
and is directed backwards through the triangular space bounded by the long 
head of the triceps, the teres major, and the margin of the scapula; it 
passes across the axillary border of the bone in a groove, and, under 
cover of the teres minor, gains the dorsum; some of its branches reach 
the lower angle. 
(4) The posterior circumflex artery, a considerable branch, arises im- 
mediately below the subscapular artery, and is directed backwards, with the 
circumflex nerve, through the quadrilateral space bounded by the humerus, 
the long head of the triceps, and the teres muscles. Continuing its course 
it winds round the back of the humerus, and breaks up into numerous 
branches which supply the deltoid and teres muscles and the shoulder- 
joint, and anastomose with those of the anterior circumflex, acromio- 
thoracic, and superior profunda arteries. 
(5) The anterior circumflex artery, a small vessel, arises a little below the 
posterior branch, and winds round the front of the humerus on the deep 
surface of the biceps and coraco-brachialls muscles; a slender branch runs 
upwards in the bicipital groove to the joint, and others ramify in the 
muscles and anastomose with the branches of the posterior circumflex 
artery. 
Anastomoses of the branches of the axillary artery. The different 
branches anastomose very freely with one another and with the upper 
intercostal arteries. From above the suprascapular anastomoses with the 
acromio-thoracic, from below the superior profunda forms free connections 436 
THE VASCULAR SYSTEM. 
Avith the posterior circumflex. On both surfaces of the scapula the branches 
of the suprascapular, posterior scapular, and subscapular arteries anastomose 
freely with one another. The branches of the long thoracic which reach 
the mamma anastomose there with derivatives of the intercostal and 
internal mammary arteries. 
Varieties of the axillary artery and its branches. In addition to 
the branches which have been described others are frequently met with; 
among these the superior thoracic running upwards and inwards from the 
first part, and the alar thoracic descending from the second part to supply 
the connective tissue and glands, may be specially mentioned. Occasionally 
(in the proportion of one in every ten cases) a large branch, continued 
into one of the arteries of the forearm, comes off the third part of the 
axillary trunk; this abnormality is one of the varieties of “ high division ” 
of the main artery of the limb. Frequently the dorsal branch of the 
subscapular artery comes off as a separate trunk, and, on the other hand, 
the subscapular and posterior circumflex often spring as a common vessel. 
The posterior circumflex is in many cases absent from the axillary alto- 
gether, its place being taken by a large branch which ascends behind the 
teres major muscle from the superior profunda of the brachial. The long 
thoracic artery is often double. 
Surgical anatomy of the axillary artery. When the arm is hanging 
by the side the artery is bent with the convexity upwards, but Avhen the 
limb is abducted to a position at right angles with the trunk the vessel 
holds a straight course, which may be marked by a line drawn from the 
middle of the clavicle to the inner border of the prominence of the coraco- 
brachialis and biceps muscles. The upper part of the artery is seldom 
interfered with by the surgeon, as the operation upon the third part of 
the sAibclavian is judged safer. In this portion of its course the vessel is 
deeply placed, and, along with the vein, is surrounded by a sheath con- 
tinued downwards from the neck. The vein, when the arm is abducted, 
overlies the first part of the artery, and its Avails are so closely connected 
with the costo-coracoid membrane that a wound is liable to lead to great 
bleeding, and to the further danger of entrance of air into the heart. 
The first part of the artery has sometimes been torn in cases of disloca- 
tion or fracture. The lower half of the third part of the artery is usually 
selected for ligature; the vessel here lies by the inner side of the coraco- 
brachialis, immediately under the deep fascia. An incision, about three 
inches in length, is made along the line of the artery; the inner margin 
of the coraco-brachialis is exposed, and the musculo-cutaneous and median 
nerves are drawn outwards, the internal cutaneous nerve is drawn in- 
wards, and the hook passed from Avithin outwards. The axillary vein 
is sometimes replaced in the loAver part of the axilla by a continuation 
of the venae comites of the brachial; sometimes also an irregular band 
of muscular fibres from the latissimus dorsi crosses in front of the lower 
part of the artery. The current in the lower part of the artery may be THE BRACHIAL ARTERY, 
437 
controlled by pressure directed outwards against the humerus. In opening 
an axillary abscess the surgeon should direct the point of the knife away 
from the axillary artery and avoid the subscapular behind, and the long 
thoracic in front, making his incision in the middle of the armpit. 
The Brachial Artery. 
The brachial or humeral artery (Fig. 330), the continuation of the axillary, 
extends from the lower margin of the teres major to the hollow in front 
of the elbow, where, opposite the neck of the radius, it divides into the 
radial and ulnar arteries. It lies immediately under the deep fascia, and is 
placed at first by the inner side of the humerus, and afterwards in front 
of the bone; close to its termination it sinks deeply between the pronator 
teres and supinator longus muscles. It rests behind successively upon the 
long head of the triceps, the inner head of the same muscle, the insertion 
of the coraco-brachialis, and the brachialis anticus; to its outer side lie 
the coraco-brachialis and, afterwards, the biceps, the latter muscle over- 
lapping it in well developed subjects; in front it is crossed, near its 
termination, by the semilunar fascia from the biceps. Two venae comites, 
the inner being usually the larger, accompany it, and frequent though 
variable transverse branches, uniting them, cross in front of and behind 
the artery. The basilic vein, in the lower half of the arm, lies by its inner 
side, the deep fascia intervening; the median basilic vein crosses super- 
ficially at the bend of the elbow, the semilunar fascia being placed 
between it and the artery. The median nerve crosses in front of the 
artery, about the middle of the arm, being placed externally to it above, 
and internally to it below. The internal cutaneous nerve lies in contact 
with it internally, in the upper half of the arm; the ulnar nerve, in the 
same region, is internal and somewhat posterior to it; and the musculo- 
spiral nerve is behind it for a short distance at its upper end. 
(1) A number of muscular branches are given off irregularly from the 
brachial trunk; the most important of them constitute a set of arteries 
which supply the biceps, and anastomose with one another. 
(2) The superior profunda artery, the largest branch, springs from the 
inner side of the main trunk near its commencement, and passes down- 
wards and backwards to reach the musculo-spiral groove, in which, accom- 
panied by the musculo-spiral nerve, it winds round the back of the 
humerus. At the outer margin of the bone it divides into two branches, 
posterior and anterior; the posterity)' descends in the substance of the 
triceps muscle, behind the external intermuscular septum, and anastomoses 
below with the recurrent branch of the posterior interosseous artery; the 
anterioi' pierces the septum, along with the musculo-spiral nerve, and 
descends, under cover of the supinator longus. to anastomose with the 
recurrent branch of the radial artery. Numerous muscular branches to 
the triceps are detached by the superior profunda; a branch passes up- 438 
THE YASCULAE SYSTEM. 
wards to anastomose with the posterior circumflex of the axillary; and 
a slender nutrient artery enters a foramen on the back of the humerus. 
(3) The inferior profunda artery arises from the brachial, a little above 
the middle of the arm, and descends behind the internal intermuscular 
septum, in company with the ulnar nerve, to the space between the 
internal epicondyle and the olecranon, where it anastomoses with the pos- 
terior recurrent branch of the ulnar and with the anastomotic artery. 
(4) The nutrient artery of the humerus is variable in its origin, 
springing either directly from the main stem or from one of the branches. 
It is directed downwards and enters a canal near the insertion of the 
coraco-brachialis muscle. 
(5) The anastomotic artery springs from the inner margin of the brachial, 
about two inches above the elbow. It anastomoses, under cover of the 
pronator teres muscle, with the anterior recurrent branch of the ulnar, 
and a branch pierces the internal intermuscular septum and winds round 
the back of the humerus, anastomosing with the posterior recurrent of 
the ulnar, the inferior profunda, and the superior profunda arteries. 
Varieties of the brachial artery. Sometimes the brachial artery is 
found to deviate inwards from its usual course, passing, in company with 
the median nerve, round a supracondyloid process, and only regaining its 
normal position at the elbow; and even when no such process, or at best 
but a rudimentary bony elevation, is present, the vessel has been found 
with a considerable inward deflection, being bound down by fibres of the 
pronator teres or brachialis anticus. Frequently this variation in the 
course of the brachial artery co-exists with another abnormality, namely, 
the presence of another large arterial stem in the arm. The additional 
vessel springs from the axillary or from the upper part of the brachial, 
and descends along the usual line by the inner edge of the biceps to join 
the lower part of the brachial, or be continued into one of its main branches. 
It is in all probability derived from an enlargement of anastomotic connections 
between branches of the brachial ramifying in the biceps muscle and in the 
deep fascia, and similar branches of the main arteries of the forearm. At 
other times, even though the true brachial artery is not deflected from its 
usual course, it is reduced in calibre, and is accompanied, side by side, 
by an additional artery. In these circumstances the abnormal vessel is 
always placed in front of the median nerve, while the true brachial lies 
behind the nerve. The abnormal stem is variable in diameter; it may be 
of greater calibre than the true brachial, and. may be continued below into 
one or more of the branches usually arising from the brachial artery. 
Further, it frequently happens that, when only one artery descends in the 
limb, occupying apparently the usual line, it is found in front of instead 
of behind the median nerve; in such a case it is probable that the true 
brachial has entirely disappeared, a more superficial stem replacing it. 
The presence of more than one artery in the arm is frequent, the 
average being about one in every five cases. Sometimes, but rarely, the THE BRACHIAL ARTERY. 
439 
brachial artery splits above into two trunks of equal size, uniting with 
one another below to form a single vessel, which divides in the usual 
manner into the radial and ulnar arteries. At other times, when there are 
two vessels, one is long and slender, springing from the brachial above and 
joining below either the brachial itself or one of its main divisions; 
such a slender vessel is called a vas aberrans. More frequently, when there 
are two arteries in the arm, they pass into the forearm as separate vessels, 
or at most are only connected with one another there by a slender 
transverse branch; the condition is known as high division, or high separation 
of one of the branches of the brachial artery. The student will under- 
stand, from what has been already said, that, of the two, the artery 
which has the proper relation to the median nerve is the true brachial, but, 
in the usual nomenclature of the different forms of high division, it is 
generally the larger of the two vessels which receives the name of brachial, 
the other being considered as a branch arising abnormally. In naming 
the different varieties, the interosseous artery of the forearm, in normal 
circumstances a branch from the upper part of the ulnar artery, is reckoned 
of equal importance with the ulnar and radial vessels. The most common 
variety is that which is termed a high radial, one of the stems being 
continued into the ulnar and interosseous, the other into the radial alone. 
Next in frequency comes the high ulnar, one stem being continued into 
the radial and interosseous, the other into the ulnar alone. Yery rare is 
the high interosseous, one stem being continued into the radial and ulnar, 
the other into the interosseous alone. The point at which the high divi- 
sion takes place is most commonly in the upper part of the arm, frequently 
indeed in the axilla, less commonly in the lower part of the arm, and 
rarely in the middle. 
The superior and inferior profunda arteries often spring by a common 
stem. Sometimes the superior profunda is absent, its place being taken 
by a branch from the posterior circumflex artery. 
Surgical anatomy of the brachial artery. The course of the artery 
may be indicated by a line drawn from the axilla, a little behind the 
anterior fold, to the middle of the hollow in front of the elbow. The 
vessel may be compressed by pressure directed in the upper two-thirds of 
the course outwards and slightly backwards, in the lower third directly 
backwards. The artery may be ligatured at any point, the more usual 
places being the bend of the elbow and the middle of the arm. When 
the operation is performed at the elbow, an incision of about two inches 
in length is made along the inner edge of the biceps tendon. The median 
basilic vein is to be avoided, the semilunar fascia cut through, the venae 
comites separated, and the needle introduced from within outwards. When 
the operation is performed at the middle of the arm, the presence of the 
basilic vein in the superficial fascia is to be remembered. The arm is 
abducted and extended, and an incision about two and a half inches in 
length is made along the line of the artery. The inner edge of the biceps 440 
THE VASCULAR SYSTEM. 
must be defined, and with this object the limb is usually not supported 
from behind, as the pressure is apt to push forward the triceps muscle, 
which may confuse the operator. The median nerve here lies in front 
of the vessel, and is to be drawn outwards, and to aid this procedure 
the limb should be temporarily flexed; the needle is passed from the side 
on which the nerve lies, care being taken to avoid the venae comites. 
When the brachial artery is tied, the circulation is maintained chiefly 
through the anastomotic connections between the branches which ramify 
in the muscles and in the fascia. 
The Ulnar Artery. 
The ulnar artery (Figs. 331-335) is the larger of the two vessels 
into which the brachial divides. It is directed downwards through the 
forearm, at first with a slight arch inwards, and afterwards almost vertically, 
then crosses in front of the anterior annular ligament, by the outer side 
of the pisiform bone and the inner side of the unciform process, to end 
in the superficial palmar arch. It is at first deeply placed, and passes 
behind the superficial muscles from the internal epicondyle; further down 
it is comparatively superficial, being only overlapped by the edge of the 
flexor carpi ulnaris; at the lower end of the forearm it is uncovered by 
the muscle, lying by the outer edge of its tendon under the deep fascia; at 
the wrist it is crossed by some fibres from the tendon of the flexor carpi 
ulnaris. It rests behind at first upon the tendon of the brachialis anticus, 
afterwards upon the flexor digitorum profundus, and finally upon the 
anterior annular ligament. Two venae comites accompany it. The median 
nerve crosses it superficially close to its origin, the deep head of the 
pronator teres intervening. The ulnar nerve lies by its inner side in the 
lower half of the forearm and at the wrist. 
Of the branches given off in the forearm the most important is the 
interosseous artery; in the upper part two recurrent branches are detached, 
and in the lower part two carpal branches are given off; in addition 
there are numerous muscular branches. At the lower border of the anterior 
annular ligament the ulnar detaches a deep branch which completes the 
deep palmar arch of the hand. 
(1) The recurrent branches. The anterior recurrent artery, a small vessel, 
passes upwards under cover of the pronator teres to anastomose with the 
anastomotic branch of the brachial. The posterior recurrent artery, a little 
larger than the anterior, arises along with it, or immediately below it, 
and passes upwards between the heads of the flexor carpi ulnaris to 
anastomose with the inferior profunda and anastomotic arteries. 
(2) The interosseous artery, a short stem of considerable thickness, 
arises from the ulnar about an inch from its commencement, and passes 
backwards and downwards to the upper margin of the interosseous mem- 
brane, where it divides into anterior and posterior branches. The Brachial 
Anastomotic 
Radial recurrent 
Posterior ulnar recurrent 
, Anterior ulnar recurrent 
Ulnar 
Radial. 
Muscular | 
( Ulnar recurrent 
I (common stem) 
Common interosseous 
Posterior interosseous 
Anterior interosseous 
Fig. 331.—The Division of the Brachial Artery. (L. Testut.) 
To face p. 44°- Brachial artery 
Median nerve 
Anastomotic 
Radial recurrent 
.Ulnar 
Radial 
Muscular branch 
Muscular branch 
.Muscular branch 
Superficial volar 
-Deep branch of ulnar 
Palmar digital artery 
Fig. 332.—The Arteries of the Forearm, superficial dissection. (L. Testut.) 
To face p. 441. THE ULNAR ARTERY. 
441 
anterior interosseous branch descends in front of the interosseous mem- 
brane, in company with a branch of the median nerve, as far as the upper 
border of the pronator quadratus muscle; it then pierces the membrane 
and is continued to the back of the wrist, where it terminates in 
anastomosis with the posterior carpal vessels. On its way it gives off, in 
addition to a number of muscular branches—(a) a slender median artery 
which accompanies the median nerve in the forearm, and is sometimes 
much enlarged to take part in the supply of the hand; (b) nutrient 
arteries to the radius and ulna; (c) anterior communicating branches which, 
in front of the wrist, anastomose with the anterior carpal arteries. The 
posterior interosseous branch passes backwards over the upper part of the 
interosseous membrane, and descends between the superficial and deep 
layers of the posterior muscles ; much reduced in size below, it terminates 
in anastomosis with the arteries on the back of the wrist. Besides 
numerous muscular branches, it gives off a recurrent branch which passes 
upwards, under cover of the anconeus, to anastomose with the posterior 
terminal division of the superior profunda artery. 
(3) The carpal branches. The posterior carpal artery is given off a little 
above the pisiform bone, and passes backwards under cover of the tendon 
of the flexor carpi ulnaris; it detaches a dorsal digital branch for the ulnar 
side of the little finger, and inosculates on the back of the wrist with the 
posterior carpal branch of the radial to form the posterior carpal arch. 
The anterior carped artery is a very slender twig which reaches the front 
of the carpus and assists to form the anterior carpal arch. 
(4) The deep branch is given off at the lower border of the anterior 
annular ligament. It passes backwards between the abductor and flexor 
minimi digiti brevis to inosculate with the deep palmar arch. 
Varieties of the ulnar artery. High origin of the ulnar is said to 
occur in one in thirteen cases; when it takes place the vessel, instead of 
passing behind the muscles from the inner epicondyle, generally takes 
a superficial course and only gains its normal situation in the lower fourth 
of the forearm. In such cases the recurrent and interosseous branches 
spring from one of the two trunks into which the other artery in the arm 
divides. An enlarged median artery may spring from the anterior inter- 
osseous or directly from the ulnar. It generally joins the superficial palmar 
arch, and, in entering the hand, may pass in front of or behind the 
anterior annular ligament. 
The Radial Artery. 
The radial artery (Figs. 331-335), continuing the line of the brachial, 
passes almost directly downwards as far as the lower end of the radius; it 
then bends backwards and downwards to reach the back of the wrist, and 
finally enters the palm between the first and second metacarpal bones and is 
continued into the deep palmar arch. In the forearm it lies at first in the 442 
THE VASCULAR SYSTEM. 
hollow of the elbow, separated by some fatty tissue from the supinator 
brevis; afterwards it rests in succession upon the insertion of the pronator 
teres, the radial slip of the flexor sublimis, the flexor pollicis longus, the 
pronator quadratus, and the lower end of the radius. The supinator longus 
is external to it, overlapping it in the upper half of the forearm; to its 
inner side lie the pronator teres, and, lower down, the flexor carpi radialis; 
the radial nerve is in contact with it externally in the middle third of 
the forearm. 
At the wrist it first bends backwards below the styloid process, resting 
upon the external lateral ligament, and afterwards descends upon the back 
of the scaphoid and trapezium to the interval between the heads of the 
first and second metacarpal bones; in this part of its course it is crossed 
superficially, first by the tendons of the extensors of the metacarpal bone 
and first phalanx of the thumb, and afterwards by that of the second 
phalanx of the thumb. As it passes forwards into the hand it is placed 
between the heads of the first dorsal interosseous muscle. 
In the palm the radial artery turns inwards under cover of the short 
flexor muscle of the thumb, and is continued into the deep palmar arch. 
Two venae comites accompany the radial artery in its whole course. 
In the forearm, in addition to numerous muscular branches, the radial 
detaches a recurrent branch, an anterior carpal branch, and the superficial 
volar branch. At the wrist it gives off a posterior carpal branch, the first 
dorsal interosseous, the dorsalis indicis, and the dorsalis pollicis arteries. 
In the palm, before passing into the deep arch, it gives off the arteria 
princeps pollicis and the radialis indicis. 
(1) The recurrent branch passes upwards under cover of the supinator 
longus to anastomose with the anterior division of the superior profunda 
artery. 
(2) The anterior carpal artery, a very slender vessel, arising near the 
wrist, reaches the front of the carpus and takes part, along with the 
anterior carpal branch of the ulnar, in forming the anterior carpal arch. 
The anterior carpal arch is of small size, and distributes minute branches 
which supply the carpal bones and anastomose with offsets from the 
anterior interosseous artery of the forearm and from the deep palmar arch. 
(3) The superficial volar artery, of very variable size, arising near 
the wrist, passes among the short muscles of the thumb, and, when well 
developed, inosculates with the termination of the superficial palmar arch. 
(4) The posterior carpal branch takes origin under cover of the 
extensor tendons of the thumb, and runs inwards upon the back of the 
carpus to anastomose with the posterior carpal branch of the ulnar. The 
posterior carpal arch, formed by the inosculation of the two posterior carpal 
arteries, is of small size. It gives off—(a) recurrent branches which ramify 
upon the carpus and anastomose with the terminal twigs of the anterior 
and posterior interosseous arteries of the forearm; and (h) the dorsal inter- 
osseous arteries of the two inner spaces. Posterior interosseous 
Posterior carpal of ulnar 
3, Radial 
Posterior carpal arch 
i Dorsalis indicis 
and inner branch 
< of dorsalis pollicis 
arising by a 
I. common stem 
Dorsal interosseous 
Superior perforating 
Dorsal interosseous 
8, Dorsalis indicis 
9, Dorsalis pollicis (inner branch) 
10, Dorsal collateral digital 
branches 
Fig. 333.—Arteries of the Back of the Hand. (L. Testut.) 
To face p. 442. Radial 
Ulnar 
Superficial volar- 
Deep branch of ulnar 
Superficial arch 
Palmar digital arteries 
:ternal branch 'j 
jf arteria prin- r 
ceps pollicis J 
Arteria radialis indicia... 
9, Palmar digital artery 
11, Palmar collateral 
digital branches 
Fig. 334.—The Superficial Palmar Arch. (L. Testut.) 
To face p. 443* THE ARTERIES OF THE HAND. 
443 
(5) The first dorsal interosseous artery springs from the radial as it 
descends on the back of the carpus. 
The three dorsal interosseous arteries descend, one in each of the three 
inner intermetacarpal spaces; they lie upon the dorsal interosseous muscles, 
on the deep surface of the extensor tendons. Each artery gives off—(a), 
at the upper extremity of its space a superior perforating branch which 
joins the deep palmar arch, and (h) at the lower extremity of the space 
an inferior perforating branch which joins the palmar digital artery from the 
superficial palmar arch. At the digital cleft each vessel divides into two 
dorsal collateral branches which descend upon the contiguous sides of the 
fingers and anastomose, about the level of the base of the second phalanx,, 
with the dorsal branches of the palmar collateral arteries. 
(6) The dorsalis indicis artery springs from the radial before it passes 
between the heads of the first interosseous muscle. It descends upon the 
radial border of the index finger. 
(7) The dorsalis pollicis artery arises in close proximity to the last 
mentioned branch and, after descending upon the back of the metacarpal 
bone of the thumb, divides into outer and inner branches. Frequently 
the outer and inner branches for the thumb rise se]3arately from the radial 
artery. 
(8) The arteria princeps pollicis passes downwards upon the anterior 
surface of the metacarpal bone of the thumb, and in the interval between 
the insertions of the two portions of the flexor pollicis brevis muscle 
divides into two branches which anastomose and pulsate on the front of 
the second phalanx of the thumb. 
(9) The arteria radialis indicis passes downwards under cover of 
the adductor pollicis and runs along the radial side of the index 
finger. 
Varieties of the radial artery. High origin is said to occur about 
once in eight cases; an origin below the usual point is comparatively 
rare. The vessel seldom deviates from its usual course through the 
forearm, but it is sometimes much reduced in size, and its entire absence 
has been recorded. Its recurrent branch may be reduced in size, or trans- 
ferred altogether to the ulnar or interosseous stem, or, on the other hand, 
it may be much enlarged. The branches which are distributed to the hand 
are very variable in size. 
The anastomoses around the elbow-joint. The arteries from above are 
the anterior and posterior divisions of the superior profunda, the inferior 
profunda, and the anastomotic; those from below are the radial recurrent, 
the posterior interosseous recurrent, and the posterior and anterior ulnar recur- 
rents. The anastomotic, besides anastomosing with the anterior ulnar 
recurrent, pierces the internal intermuscular septum, forms connections 
with the inferior profunda and posterior ulnar recurrent, and sends a 
branch over the olecranon fossa to anastomose with the posterior branch 
of the superior profunda. 444 
THE VASCULAR SYSTEM. 
Surgical anatomy of the arteries of the forearm. The radial and 
ulnar arteries are seldom ligatured except in cases of wound. The course 
of the radial artery in the forearm may be marked by a line drawn from 
the middle of the hollow of the elbow to the anterior border of the tendon 
of the extensor ossis metacarpi pollicis at the wrist. The vessel may be 
tied in any portion of this course, but the operation is most easily per- 
formed in the lower third of the forearm, where the artery lies between 
the tendons of the supinator longus and flexor carpi radialis. The position 
of the ulnar artery in the lower half of the forearm may be marked on 
the surface by the lower part of a line drawn from the internal epi- 
condyle to the outer side of the pisiform bone. Above the wrist the 
artery lies by the radial side of the tendon of the flexor carpi ulnaris. 
The operation is only performed in the lower part of the forearm. 
The Superficial Palmar Arch. 
The superficial palmar arch (Fig. 334), the continuation of the ulnar 
artery, turns outwards, forming a bend with the convexity reaching down- 
wards as far as the line between the upper and middle thirds of the palm. 
It passes behind the palmaris brevis and the palmar aponeurosis, and rests 
upon the short muscles of the little finger, the digital branches of the 
median nerve, and the tendons of the superficial flexor of the fingers. 
It terminates, much reduced in size, opposite the metacarpal bone of the 
index finger, by inosculating with either the superficial volar artery or 
the arteria radialis indicis. It is accompanied by two small venae comites. 
In addition to a number of small superficial branches, it gives off the 
palmar digital arteries which supply the three inner fingers and the ulnar 
side of the index finger. 
The digital arteries are four in number. The first descends to run 
along the ulnar border of the little finger. The other three descend, one 
in each of the three inner intermetacarpal spaces; each artery lies, between 
the flexor tendons, in front of the nerve and the lumbricalis muscle, and 
divides, about a fourth of an inch behind the cleft, into two branches, the 
collateral digitals, which run along the contiguous sides of the fingers. 
Immediately before dividing, each of the three arteries is joined by a 
palmar interosseous branch from the deep palmar arch, and by an inferior 
perforating branch from the dorsal interosseous artery of its space. Each 
■collateral branch descends upon the side of a finger between the palmar 
and dorsal nerves, and terminates, in anastomosis with its fellow, in front 
of the third phalanx; it supplies both surfaces of the finger, and its dorsal 
branches anastomose about the base of the second phalanx with the dorsal 
digital artery. THE THORACIC AORTA. 
445 
The Deep Palmar Arch. 
The deep arch (Fig. 335), the continuation of the radial artery, is 
completed internally by inosculation with the deep branch of the ulnar 
artery. It is placed about half an inch nearer the wrist than the super- 
ficial arch and lies upon the bases of the metacarpal bones, behind the 
flexor tendons; it gives off three palmar interosseous arteries, and some 
small recurrent vessels, and receives the superior perforating arteries. 
The palmar interosseous arteries, three in number, descend, one in 
each of the three inner interspaces, to join, near the clefts of the fingers, 
the digital branches of the superficial arch. The recurrent branches, small 
and irregular, pass backwards from the deep arch to anastomose with 
the anterior carpal arteries. The superior perforating arteries may join 
the palmar interosseous arteries instead of the deep arch. 
Varieties of the arteries of the hand. Very frequently the arrange- 
ment of the branches of the chief arterial arches departs from the normal 
type; but as the connections between the different sets of vessels are so 
free, deficiency in one arch is made up for by excess in another. The deep 
arch may largely take the place of the superficial, or the superficial may 
supply the digital vessels to the index finger and thumb. An enlarged 
superficial volar or a median artery may assist or take the place of the 
ulnar in the hand, and by an increase in the size of perforating branches 
defective interosseous vessels may be compensated for. 
The descending portion of the thoracic aorta (Fig. 317) passes down- 
wards in the posterior mediastinal space from the left side of the fourth 
dorsal vertebra, gradually inclining towards the middle line, and pierces the 
diaphragm opposite the twelfth dorsal vertebra. It rests closely upon the 
vertebral column, and lies behind the pericardium above and the vertebral 
portion of the diaphragm below. At its commencement it is crossed in 
front by the root of the left lung, and the pleura is in contact with it on 
the left side. The oesophagus lies at first by its right side, lower down 
it is directly in front of the aorta, and still lower it is placed somewhat 
to the left. The thoracic duct and the larger azygos vein lie by its right 
side; the smaller azygos vein ascends by its left side as far as the seventh 
dorsal vertebra, where it passes to the right behind it. 
It detaches numerous small offsets to the pericardium, the oesophagus, 
the diaphragm, and the glands of the posterior mediastinum; its more 
important branches are the bronchial and intercostal arteries. 
The bronchial arteries supply the bronchi, the lungs, and the bronchial 
glands. They are variable in number and in their mode of origin. The 
right bronchial artery, usually single, arises in some cases from the first 
aortic intercostal of the right side, in others from the aorta, by a common 
THE DESCENDING THORACIC AORTA. 446 
THE VASCULAR SYSTEM. 
stem, with the upper of the two bronchial arteries of the left side. The 
left bronchial arteries, generally two in number, spring from the upper part 
of the aortic trunk. The arteries pass outwards in the roots of the lungs 
behind the bronchi, and ramify with the air tubes. 
The intercostal arteries are usually nine in number on each side, the 
first two spaces being supplied by the superior intercostal branch of the 
subclavian arterjr. They spring from the posterior part of the aorta, and 
pass outwards crossing the vertebral bodies, the first two or three with an 
inclination upwards, the others almost transversely. On account of the position 
of the parent trunk the higher branches of the right side are longer than the 
•corresponding vessels of the left. In crossing the vertebral bodies the 
arteries of the right side pass behind the greater azygos vein and the 
thoracic duct, those of the left behind the smaller azygos veins, or the 
left superior intercostal vein. Opposite the necks of the ribs the vessels 
of each side are crossed in front by the gangliated cord of the sympathetic. 
At the posterior extremities of the spaces they lie upon the external inter- 
costal muscles, and are covered in front by the pleura, hut further forwards 
they pass behind the internal intercostals, and afterwards continue their 
course between the two muscular layers. In each space the artery runs 
in the subcostal groove, along the lower margin of the upper of the two 
ribs, its companion vein lying above it, and the intercostal nerve below : 
near the anterior extremity it terminates in anastomosis with an anterior 
intercostal branch of the internal mammary, the musculo-phrenic, or the 
superior epigastric, according to the region. In addition to numerous small 
offsets, the intercostal arteries detach dorsal, collateral, and lateral branches. 
The successive intercostal arteries anastomose with one another by slender 
vessels which form two chains, one in front of the rib necks, the other 
between the rib necks and the transverse processes; in addition, the dorsal 
branches are connected with one another by slender twigs which lie behind 
the transverse processes. The first artery anastomoses with the superior 
intercostal branch of the subclavian. 
The dorsal branch passes backwards between the transverse processes, 
by the inner edge of the superior costo-transverse ligament. It detaches 
offsets to the spinal canal (see p. 429), and afterwards divides among the 
muscles of the back into two vessels, internal and external in position, 
which accompany the branches of the posterior primary division of the 
corresponding spinal nerve. The collateral branch arises in the intercostal 
space, in the neighbourhood of the angles of the ribs. It descends at 
first, crossing the space obliquely, and afterwards runs forwards between 
the muscular layers, along the upper margin of the lower of the two 
ribs. It terminates like the parent trunk in anastomosis with an anterior 
intercostal branch of the internal mammary or musculo-phrenic. The lateral 
branch passes outwards along with the lateral branch of the intercostal 
nerve of the space, supplying the muscles and the skin. Besides the 
branches specially described, the intercostal arteries give off a number of Anterior interosseous 
Radial.. 
- Ulnar 
Anterior carpal arch. 
Anterior carpal arch 
Superficial volar „ 
I', Deep palmar arch 
Deep branch of ulnar 
7, Artcria prinecps pollicis and 
arteria radialis indicia arising 
by a common stem 
8, Palmar interosseous artery 
Superior perforating branch 
Palmar interosseous arteries 
Palmar digital artery 
11, Palmar digital artery 
13, 14, Outer and inner 
branches of arteria 
prineeps pollicis 
16, Palmar collateral 
digital branches 
Fig. 335.—The Deep Arteries of the Palm. (L. Testut.) 
To face p. 446. Oesophagus 
6, 6", Suprarenal 
arteries 
.Inferior phrenic arteries 
17, Inferior vena 
cava 
C, Suprarenal 
capsule 
..Coeliac axis 
.-Suprarenal artery 
4, Superior mesen- 
teric artery 
5, Renal artery 
b, Kidney 
3, Aorta 
7, Spermatic artery 
Lumbar artery. 
8 Inferior mesen- 
teric artery 
Lumbar artery. 
r Lumbar branch 
-! of middle 
t sacral artery 
f Common iliac 
\ artery 
15, Middle sacral 
artery 
External iliac artery 
/ Deep circumflex 
\ iliac artery 
Deep epigastric artery 
e, Rectum 
11, Internal iliac 
artery 
f, Bladder 
Gr, Yas deferens 
Fig. 836.—Abdominal Aorta. (L. Testut.) 
To face p. 447. THE ABDOMINAL AORTA. 
447 
small twigs which supply the vertebral bodies, the pleura, the ribs, and 
the intercostal muscles; some of the latter enter the mammary gland 
and during lactation may increase to a considerable size. 
THE ABDOMINAL AORTA. 
The abdominal aorta (Figs. 336, 337) descends upon the front of the 
column, from the opening in the diaphragm, opposite the twelfth dorsal 
vertebra, to the middle of the bod}’ of the fourth lumbar vertebra, where, a 
little to the left of the middle line, it terminates by dividing into the common 
iliac arteries. The place of division is on a level with a line drawn across 
the abdominal wall between the highest points of the iliac crests. The 
vessel is placed at first between the crura of the diaphragm, and between 
it and the right crus the greater azygos vein and the thoracic duct are inter- 
posed. The inferior vena cava lies in contact with its right side below, but 
higher up is separated from it by the crus. The left lumbar veins pass 
behind it. Its anterior surface is successively in contact with the solar 
plexus, the splenic vein and pancreas, the left renal vein, the third part 
of the duodenum, and the aortic plexuses and the peritoneum ; a number 
of lymphatic glands surround and overlie it. Its branches, which are 
numerous and large, are divided into two groups, parietal and visceral. 
The parietal branches are the inferior phrenic, the lumbar, and the 
middle sacral. The visceral branches are the coeliac axis, the superior 
mesenteric, the inferior mesenteric, the suprarenal, the renal, and the 
spermatic or ovarian. 
Parietal Branches op the Abdominal Aorta. 
The inferior phrenic arteries ramify on the under surface of the 
diaphragm. They spring either by a common stem, or separately, from 
the front of the aorta immediately after it has entered the abdomen. 
Each artery inclines upwards and outwards on the corresponding crus, 
the vessel of the right side passing behind the vena cava, that of the left 
behind the oesophagus. At the posterior margin of the central leaflet of 
the trefoil tendon each artery divides into an anterior and posterior 
branch. The anterior branch passes forwards to anastomose with the 
branches of the internal mammary artery, and with its fellow of the 
opposite side; the 'posterior branch passes outwards and enters into 
anastomosis with the lower intercostal arteries. In addition to the 
terminal branches, each artery supplies a small branch to the suprarenal 
capsule, the superior suprarenal. The artery of the right side supplies offsets 
to the vena cava, that of the left side gives twigs to the oesophagus. 
Occasionally there is but one inferior phrenic artery, and sometimes one 
or both vessels arise from the coeliac axis. 
The lumbar arteries are comparable in their distribution to the inter- 448 
THE VASCULAR SYSTEM. 
costal vessels. They are usually five in number on each side. The first 
passes outwards upon the body of the last dorsal vertebra, the others, in 
succession, upon the bodies of the first four lumbar vertebrae. The 
first and second pass behind the crura of the diaphragm, and those 
of the right side cross behind the vena cava. They pass behind the 
sympathetic nerve trunk and the psoas muscle, and the first artery, which 
accompanies the last dorsal nerve, usually crosses in front of the quad- 
ratics lumborum, while the others as a rule pass behind that muscle. In 
the abdominal wall they course at first between the transversalis and 
internal oblique muscles, and finally enter the sheath of the rectus. They 
give off dorsal, lateral, and terminal branches which are similar in their 
distribution to the corresponding offsets of the intercostal arteries. They 
form anastomotic connections with one another, with the lower intercostal 
arteries, the circumflex iliac, middle sacral, and ilio-lumbar arteries, and by 
their terminal branches with the superior and deep epigastric arteries. 
The middle sacral artery arises from the back of the aorta about a 
fourth of an inch above its bifurcation, and is continued downwards in 
front of the last lumbar vertebra and the sacrum to the coccygeal gland, 
in which, much reduced in size, it terminates. It gives off on each side— 
(l) a lowest lumbar artery, which is sometimes of considerable size, and runs 
outwards upon the body of the fifth lumbar vertebra; (2) lateral branches, 
which ramify upon the front of the sacrum. In front it detaches some 
anterior branches, which enter the mesorectum. The middle sacral artery 
represents the sacral portion of the aorta of the lower animals. 
Visceral Branches of the Abdominal Aorta. 
The coeliac axis (Fig. 338), a very short trunk, springs from the front 
of the aorta, immediately above the pancreas. It is about a third of an 
inch in length, and divides at its extremity into the hepatic, gastric, and 
splenic arteries. The solar plexus surrounds it at its origin, and the 
semilunar ganglia are placed by its sides. 
(a) The hepatic artery passes at first forwards and to the right, along 
the upper border of the pancreas as far as the upper margin of the first 
part of the duodenum. It then turns upwards in front of the foramen of 
Winslow, between the layers of the small omentum, in company with 
the common bile duct, which lies by its right side, and the portal vein 
which lies behind it. Close to the liver it divides into right and left 
terminal branches. On its way it gives off—(1) two or three small pancreatic 
branches; (2) as it is entering the small omentum, the pyloric artery which 
descends to the neighbourhood of the pylorus, and runs from right to left 
along the small curvature of the stomach, inosculating with the gastric artery; 
(3) immediately above the pyloric, the gastro-duodenal artery which descends 
behind the first part of the duodenum and divides into two branches; 
one of these, the right gastro-epiploic, courses along the greater curvature Vasa brevia 
r 
Left gastro- 
epiploic 
' Inferior phrenic 
Gastric 
Fig. 338.—The Coeliac Axis and its Branches, (C. Gegenbaur.) 
Pyloric 
Common bile ductA 
Gastro-duodenal - 
Superior i 
pancreatico- [■ 
duodenal j 
Right gastro- 
epiploic 
Fig. 337.—Diagram of the Branches of the 
Abdominal Aorta. 1, Aorta; 2, inferior phrenic; 
3, coeliac axis ; 4, superior mesenteric ; 5, renal; 
6, 6', 6", suprarenal; 7, spermatic; 8, inferior 
mesenteric ; 9, lumbar ; 10, common iliac ; 11, 
internal iliac; 12, external iliac; 15, middle 
sacral. (L. Testut.) 
To face p. Middle colic 
/ Superior 
\ mesenteric 
/ Inferior 
( mesenteric 
{Left colic 
(ascending 
branch) 
f Left colic 
(descending 
branch) 
Sigmoid 
j Superior 
| haemorrhoidal 
Fig. 340.—The Mesenteric Arteries. (C. Gegenbaur.) 
Fig. 339.—The Superior Mesenteric Artery and its Branches. (0. Gegenbaur.) 
Vermiform appendix 
Inferior'j 
pancreatico- >■ 
duodenal J 
Middle colic, 
Bight colic 
Ileo-colic. 
To face p. 449’ COE LI A C AXIS. 
449 
of the stom „ch from right to left between the layers of the great 
omentum, supplying both gastric and omental branches, and terminates 
by anastomosing with the left gastro-epiploic branch from the splenic 
artery; the other, the superior pancreatico-duodenal artery, descends between 
the head of the pancreas and the duodenum, supplying both, and anas- 
tomoses with the inferior pancreatico-duodenal branch from the superior 
mesenteric artery. The right terminal branch of the hepatic artery passes 
behind or between the hepatic and cystic ducts, and after giving olf the 
cystic branch to the gall bladder reaches the right end of the portal fissure, 
where it divides into a number of branches which supply the greater 
part of the right lobe. The left terminal branch passes towards the left 
end of the transverse fissure to enter the left lobe, which it supplies. It 
gives off in addition a branch to the Spigelian lobe, and it partly supplies 
the quadrate lobe. 
The hepatic artery may spring directly from the aorta. One or other 
of the terminal divisions is sometimes assisted or replaced by branches of 
the superior mesenteric or of the gastric. The whole artery may be 
wanting, its place being taken by branches from one or both of the above- 
mentioned trunks. 
(b) The gastric artery (coronary artery of the stomach) (Fig. 338), the 
smallest branch of the. coeliac axis, runs at first upwards and to the left 
behind the posterior wall of the lesser sac of the peritoneum to the cardiac 
end of the stomach, where it detaches some oesophageal branches. It then 
bends sharply downwards and to the right, and courses along the lesser 
curvature of the stomach towards the pylorus. It terminates by inosculating 
with the pyloric branch of the hepatic artery. Its chief branches are 
oesophageal and gastric; the former anastomose with the thoracic oesophageal 
arteries; the latter descend on both surfaces of the stomach, and anastomose 
with the branches of the arteries of the greater curvature. A small hepatic 
branch passes to the left lobe of the liver and anastomoses with the left 
branch of the hepatic artery; occasioually this branch is much enlarged, 
and it may assist or even replace the left hepatic artery. 
(c) The splenic artery (Fig. 338), the largest branch of the coeliac axis, 
passes to the left and courses, often in a tortuous manner, along the upper 
border of the pancreas and across the anterior surface of the left kidney. 
It lies behind the posterior wall of the smaller sac of the peritoneum, and 
approaches the spleen between the layers of the splenio-phrenic ligament. 
It supplies branches to the pancreas, spleen, and stomach. The pancreatic 
branches are small and numerous; one of them larger than the others runs 
from left to right in the gland along with the duct. The left gastro-epiploic 
artery arises near the termination of the parent trunk, and passes from left 
to right along the greater curvature of the stomach; it terminates by 
inosculating with the right gastro-epiploic branch of the hepatic artery; 
its branches, gastric and omental, in their distribution anastomose with 
offsets of the other gastric and the colic arteries. The vasa brevia of the 
2 F 450 
THE VASCULAR SYSTEM. 
stomach, four or five in number, pass between the layers of the gastro- 
splenic omentum to the left extremity of the stomach, and anastomose 
with the other gastric arteries. The splenic branches, six or seven in number, 
enter the hilum of the spleen. 
The superior mesenteric artery (Fig. 339), a little smaller than the 
coeliac axis, arises below it from the front of the aorta, under cover of the 
pancreas. It emerges between the pancreas and duodenum and, entering 
the mesentery, passes between its folds downwards and to the right towards 
the caecum. Its branches supply the lower part of the duodenum, the 
rest of the small intestine, the ascending colon, and half of the transverse 
colon. The inferior pancreatico-duodenal branch springs from the right side 
of the parent trunk and, after passing to the right, ascends between the 
pancreas and duodenum to anastomose with the superior pancreatico- 
duodenal branch of the gastro-duodenal of the hepatic artery. The middle 
colic artery springs from the right side of the parent trunk and passes for- 
wards in the meso-colon to supply the right half of the transverse colon. 
It inosculates with the ascending branch of the left colic of the inferior 
mesenteric artery. The right colic, arising from the right side of the main 
vessel, passes outwards to the ascending colon. The ileo-colic, also springing 
from the right side, passes downwards and to the right and supplies the 
caecum and the neighbouring portions of the tube. The small intestinal 
branches (rasa intestini tenuis), twelve to sixteen in number, pass from the 
front of the parent stem to the small intestine. The successive branches of 
the superior mesenteric artery inosculate with one another, forming loops, the 
branches from which, again inosculating, form secondary loops; and between 
the arteries which pass to the jejunum and ileum, tertiary and even quaternary 
loops may thus be formed. From the ultimate loops branches pass to 
both sides of the intestine, communicating in the wall freely with one 
another. 
Yariations in the superior mesenteric artery are by no means uncommon. 
The number of branches is often reduced by the conjunction, at their bases, 
of neighbouring colic arteries; on the other hand, additional branches 
are frequently detached to viscera other than those usually supplied by 
the vessel. 
The inferior mesenteric artery (Fig. 340), smaller than the superior, 
arises from the front of the aorta about an inch and a half above the 
bifurcation. It descends with an inclination to the left, giving off the left 
colic and sigmoid branches, and is continued as the superior haemorrhoidal 
artery into the pelvis, crossing in its course the left common iliac artery. 
The left colic branch passes to the left and divides into an ascending 
and descending branch, the former of which anastomoses with the 
middle colic artery, the latter with the sigmoid artery. The sigmoid 
branch runs downwards and to the left and breaks up for the supply 
of the sigmoid flexure ; it anastomoses below with the superior haemor- 
rhoidal artery. The branches of the left colic and sigmoid arteries form THE EENAL AETEEIES. 
451 
loops similar to those which are formed by the branches of the other 
colic arteries. The superior haemorrhoidal artery courses between the layers 
of the raesorectum and divides into two branches which descend, one 
on each side of the rectum. Four or five inches from the anus these 
branches pierce the muscular coat and break up into a number of slender 
descending vessels which reach as far as the internal sphincter and anas- 
tomose with one another and with branches of the middle haemorrhoidal 
arteries from the internal iliac stems. 
The suprarenal arteries (capsular arteries or middle suprarenal arteries) 
(Fig. 336) are two slender vessels which arise from the aorta about the 
level of the place of origin of the coeliac axis. Each passes outwards 
across the crus of the diaphragm to the suprarenal capsule of its own 
side. Each capsule receives in addition a superior artery from the 
inferior phrenic and an inferior branch from the renal artery. 
The renal arteries (Fig. 336), vessels of considerable size, spring from 
the aorta a little below the place of origin of the superior mesenteric artery 
and pass outwards, one on each side, to the kidney. The right vessel is 
a little lower in position and is also slightly longer than the left; on its 
way outwards it passes behind the inferior vena cava. Both arteries lie 
behind their companion veins, and their four or five terminal branches 
at the hilum of the kidney are placed in front of the pelvis of the 
ureter. Besides the terminal branches each artery furnishes a small 
inferior capsular artery to the suprarenal capsule, and some twigs to 
the ureter and to the glands and connective tissue which lie around 
the kidney. 
Variations in the renal arteries are very common. Accessory renal 
arteries are often present, in rare cases reaching in number five or six. 
The terminal branches which in normal circumstances pass in at the 
hilum may enter the kidney at any spot. 
The spermatic arteries (Fig. 336), of the male, spring close together 
from the front of the aorta a little below the place of origin of the renal 
arteries. Each artery descends with an outward inclination, crossing the 
ureter and the distal extremity of the external iliac artery, and at the deep 
abdominal ring enters the inguinal canal in company with the vas deferens, 
in front of which it descends in a somewhat tortuous manner to the testicle. 
Its terminal branches supply the epididymis and the body of the testicle; 
it anastomoses with the artery to the vas deferens, and gives off 
cremasteric twigs which anastomose with offsets of the cremasteric branch of 
the deep epigastric artery. The spermatic arteries sometimes spring by a 
common stem; one or both may arise from the renal. 
The ovarian arteries, of the female, are similar in origin and in the first 
part of their course to the spermatic arteries of the male. Each vessel 
crosses the common iliac artery of its own side, inclines inwards at the 
margin of the pelvis, and runs somewhat tortuously between the layers 
°f the broad ligament of the uterus, beneath the Fallopian tube, to the 452 
THE VASCULAR SYSTEM. 
ovarjr. Besides its terminal branches to the ovary, each artery gives off 
twigs to the Fallopian tube and the round ligament of the uterus, and 
sends to the uterus a considerable branch which enters into anastomosis 
with the uterine artery. During pregnancy the ovarian arteries are much 
enlarged. 
THE COMMON ILIAC ARTERIES. 
The common iliac arteries (Fig. 336), arising at the extremity of the 
aorta opposite the middle of the fourth lumbar vertebra, descend with an 
outward inclination, forming with one another an angle, which is greater 
in the female than in the male. Each vessel is about two inches in length, 
and divides at the level of the disc between the fifth lumbar vertebra and the 
sacrum into the external and internal iliac arteries. The artery of the right 
side has the lower extremity of the vena cava in contact with it externally 
and posteriorly, crosses the termination of the left common iliac vein, and 
lies in front of its own companion vein; the artery of the left side lies in 
front and to the outer side of the left common iliac vein. The sympathetic 
nerve-cords descend behind the arteries. Each of the arteries is crossed 
in front by the sympathetic branches to the hypogastric plexus and by 
the ureter, and, in the female, usually by the ovarian artery. The artery 
of the left side is crossed, in addition, by the superior haemorrhoidal 
artery. Both vessels are covered by peritoneum and overlaid by the 
intestines, the lower part of the ileum lying in front of that of the right 
side, the sigmoid flexure in front of that of the left. The lateral branches 
of the arteries are very minute; they ramify in the subperitoneal tissue, 
the ureter, and the psoas muscle. 
The Internal Iliac Artery. 
The internal iliac artery (Figs, 341, 342), from an inch to an inch 
and a half in length, descends into the pelvis from the bifurcation of the 
common iliac artery opposite the lumbo-sacral articulation, and divides near 
the margin of the great sacro-sciatic foramen into an anterior and posterior 
division. It lies in front of the lateral mass of the sacrum. It crosses 
in front of the external iliac vein, and its own companion vein lies 
behind and somewhat internal to it; the lumbo-sacral nerve-cord and the 
obturator nerve are also behind it. The ureter descends by its inner 
side; in front it is covered by the peritoneum. 
The anterior division breaks up in an irregular manner into a number of 
visceral and parietal branches. The visceral branches are the superior and 
inferior vesical, the middle haemorrhoidal, and in the female the uterine 
and the vaginal. The pai’ietal branches are the obturator, sciatic, and 
pudic. The branches of the posterior division of the artery are the gluteal, 
ilio-lumbar, and lateral sacral. Common iliac 
Tlio-lumbar 
Deep circumflex iliac . 
sacral 
_Gluteal 
-Sciatic 
_Pudic 
.Vesical 
Deep epigastric \ 
.Obturator 
Fig, 341. The Branches of the Iliac Arteries. The usual arrangement. (C. Gegenbaur.) 
Sciatic 
_ Gluteal 
Deep epigastric 
Aberrant obturator^ 
-.Superior vesical 
-Pudlc 
Fig. 342.—The Branches of the Iliac Arteries. A less frequent arrangement than 
that represented in Fig. 341. (C. Gegenbaur.) 
To face p. 452. .Gluteal 
Pudic j 
Ascending branch 
of internal 
circumflex 
Sciatic 
Transverse branch 
of internal 
circumflex 
Comes ncrvi ischiadici 
Perforating 
• branches of 
deep femoral 
Popliteal 
Fig. 343.—Arteries of the Hip and the Posterior Region of the Thigh. (L. Testut.) 
To face p. 453. THE SCIATIC ARTERY. 
453 
The superior vesical artery (Fig. 342) is in the foetus the main 
continuation of the internal iliac artery. It passes forwards and upwards 
to the side of the bladder, and is thence continued upwards as an 
impervious cord, the obliterated hypogastric artery, to the umbilicus. The 
hypogastric arteries are in foetal life important vessels, carrying the blood 
to the placenta. Besides its branches to the bladder, the superior vesical 
artery usually furnishes the slender artery of the vas deferens which accom- 
panies the spermatic duct to the testicle and anastomoses with the spermatic 
artery. 
The inferior vesical artery descends to the lower part of the bladder, 
and in the male to the prostate gland. Its terminal branches anastomose 
with offsets of the superior vesical artery. 
The vaginal artery, of the female, takes the place of the prostatic 
portion of the inferior vesical artery of the male. It supplies the lower 
part of the vagina, and anastomoses with its fellow of the opposite side 
and with the pudic and uterine arteries. 
The middle haemorrhoidal artery passes to the lower part of the rectum, 
and anastomoses with the superior and inferior haemorrhoidal arteries. 
The uterine artery, in the female, runs inwards and upwards in a 
tortuous manner between the layers of the broad ligament. It distributes 
many branches to the uterus, and anastomoses with the ovarian and vaginal 
arteries. 
The obturator artery (Fig. 341) runs forwards and downwards on 
the pelvic wall, passes through the obturator notch in the thyroid 
foramen, and, under cover of the obturator externus muscle, divides 
into internal and external terminal branches. It is placed a little 
below the ilio-pectineal line, beneath the obturator nerve, and above the 
companion vein. Within the pelvis it detaches iliac and pubic branches 
which anastomose with offsets of the ilio-lumbar and deep epigastric 
arteries. The internal terminal branch passes downwards, supplies the 
upper ends of the adductor muscles, and anastomoses with the internal 
circumflex artery. The external terminal branch passes outwards below 
the acetabulum and, after furnishing a branch which enters the hip-joint 
through the cotyloid notch, supplies the muscles upon the back of the 
capsule and anastomoses with the sciatic and internal circumflex arteries. 
The obturator artery is very frequently absent from the internal iliac, its 
place being taken by an aberrant obturator artery (Fig. 342) from the 
deep epigastric; the aberrant artery is formed by the enlargement of the 
anastomosing branches on the back of the pubis (p. 457). 
The sciatic artery (Figs. 341, 343), one of the terminal branches of the 
anterior division of the internal iliac, descends upon the nerves of the sacral 
plexus and the pyriformis muscle, and, at the lower border of the muscle, 
escapes through the great sacro-sciatic notch to divide immediately into a 
number of branches. Most of these are muscular in their distribution and 
supply the lower part of the gluteus maximus and the adjacent muscles; 454 
THE VASCULAR SYSTEM. 
some reach the skin. The coccygeal branch perforates the great sacro-sciatic 
ligament and ramifies upon the back of the coccyx. The comes nervi 
ischiadici, a slender vessel, accompanies, for a variable distance, the great 
sciatic nerve. The terminal offsets of the sciatic artery anastomose with 
branches of the pudic, gluteal, obturator, internal circumflex, and first 
perforating arteries. 
The pudic artery (internal pudic artery) (Figs. 341, 344), the smaller of 
the terminal branches of the anterior division of the internal iliac artery, 
descends by the anterior and inner side of the sciatic artery and escapes 
with it through the lower part of the great sacro-sciatic notch. Con- 
tinuing its course it turns over the spine of the ischium to re-enter 
the pelvis by the lesser sacro-sciatic notch, having, as it lies upon the 
bone, a vein placed on each side of it, the pudic nerve internally, and the 
nerve to the obturator interims externally. From the lower margin of 
the ischial spine it runs forwards along the outer wall of the ischio-rectal 
fossa as far as the anterior extremity of the tuberosity, occupying in this part 
of its course a special canal formed by the obturator fascia, and having the 
dorsal nerve of the penis above it, and the perineal branches of the pudic nerve 
below it. In the anterior part of the perineum it pierces the base of the 
triangular ligament and ascends between its layers, lying close to the bone, 
in the substance of the compressor urethrae muscle. Immediately below 
the symphysis it perforates the anterior layer of the ligament and descends 
along the dorsum of the penis under the name of the dorsal artery of 
the penis. 
Branches of the pudic artery. Small muscular offsets are given to the 
obturator interims and the neighbouring muscles; they anastomose with 
branches of the sciatic artery. The inferior haemorrhoidal artery or arteries 
arise in the posterior part of the perineal space and pass forwards and 
inwards to the anus supplying the integument, the external sphincter, and 
the levator ani, and anastomosing with the middle haemorrhoidal artery. 
The superficial perineal arteries, one or two in number, arising about the 
middle of the perineum, pass forwards, generally superficially to the super- 
ficial transverse muscle and, perforating Colies’s fascia, are continued to the 
scrotum where they supply the integument and the subcutaneous tissue 
and anastomose with the superficial pudic branches from the femoral artery. 
The transverse perineal artery, a small vessel, is given off in close connection 
with the superficial perineal; it passes inwards to the central point of 
the perineum, supplying the muscular and subcutaneous tissue. The artery 
of the bulb arises immediately after the parent trunk has entered the space 
between the layers of the triangular ligament. It runs forwards and inwards 
and, by the side of the urethra, pierces the anterior layer of the ligament to 
supply the bulb. The artery of the corpus cavernosum, given off a little 
above the artery of the bulb, perforates the anterior layer of the ligament 
and immediately enters the crus; it runs forwards to the anterior ex- 
tremity of the cavernous body. The dorsal artery of the penis pierces the Scrotum 
6, Scrotal 
branches 
g, Bulb 
4, Artery to 
the bulb 
Erector penis 
Bulbo-caveruosus 
Pudic artery 
I Muscular 
\ branches 
Superficial 
perineal 
artery 
Pudic artery | | 
Levator ani [ 
External sphincter 
| | Muscular branches 
1 Inferior haemorrhoidal branches 
Superficial transverse muscle 
Fig. 344.—The Arteries of the Perineum. On the left side a superficial dissection, on 
the right a deep dissection. (L. Testut.) 
To face p. 454. Subclavian vessels 
Internal mammary artery 
Anterior intercostal branch 
Cutaneous branches 
Anterior intercostal branch 
| Superior epigastric artery 
Transversalis 
Umbilicus 
Tendon of external oblique - 
Sartorius ( 
Deep epigastric artery 
3External iliac artery 
3, Femoral artery 
2, Femoral vein 
Spermatic cord 
Fig. 345. Arteries of the Thoracic and Abdominal Wall. (L. Testut.) 
To face p. 455. THE GLUTEAL AETERY. 
455 
anterior layer of the triangular ligament close to the symphysis, courses 
through the suspensory ligament, and runs along the penis by the side 
of the single dorsal vein. Behind the glans the vessels of the opposite 
sides form an anastomotic circle. Many of the branches enter the 
corpus cavernosum and anastomose with its special artery. 
The pudic artery of the female is similar to but smaller than the 
corresponding artery of the male; the superficial perineal branches ramify 
in the labia; the artery to the bulb enters the bulb of the vestibule, and 
the artery to the corpus cavernosum and the dorsal artery supply the 
clitoris. 
Varieties of the pudic artery. All or any of the branches usually given off by 
the pudic after it has passed between the layers of the triangular ligament 
may be transferred to an accessory pudic artery, a vessel which arises within 
the pelvis from the stem of the pudic itself, or from one of the other 
branches of the internal iliac artery, and descends by the of the prostate 
to perforate the triangular ligament, in front of the urethra. The artery 
of the bulb is very variable in size; it sometimes arises further back than 
usual and occupies a position which renders it liable to be wounded in 
the lateral operation for lithotomy. 
The gluteal artery (Fig. 343), the largest branch of the internal iliac, passes 
backwards between the lumbo-sacral cord and the first sacral nerve; it emerges 
through the great sacro-sciatic foramen at the upper border of the pyriformis 
muscle, in company with the superior gluteal nerve, and immediately after- 
wards divides into a deep and a superficial branch. The superficial branch, the 
smaller of the two, ramifies on the deep surface of the gluteus maximus 
and anastomoses with offsets of the sciatic and lateral sacral arteries; one 
of its twigs, which is sometimes much enlarged, arches downwards across 
the back of the pyriformis muscle. The deep branch, subdividing into 
upper and lower branches, ramifies with the superior gluteal nerve between 
the gluteus medius and minimus muscles. The upper branch runs along 
the upper border of the gluteus minimus and anastomoses with the deep 
circumflex iliac and the external circumflex arteries; the lower branch 
crosses about the middle of the muscle and anastomoses with the external 
circumflex and sciatic arteries. 
The ilio-lumbar artery (Fig. 341), similar in distribution to a lumbar 
artery, passes upwards and outwards, crossing behind the common iliac 
artery, the obturator nerve, and the psoas muscle. Under cover of 
the psoas it divides into a lumbar and an iliac branch. The lumbar branch 
ascends beneath the psoas to the quadratus lumborum muscle, supplies a 
spinal twig, and anastomoses with the lower lumbar arteries. The iliac 
branch passes outwards beneath the psoas, pierces the iliacus, and, on the 
surface of the bone, divides into numerous branches which supply the 
nauscles, furnish nutrient vessels to the ilium, and anastomose with offsets 
°f the obturator, external circumflex, and circumflex iliac arteries. 
The lateral sacral arteries (Fig. 341) are usually two in number, a superior 456 
THE VASCULAR SYSTEM. 
and an inferior. The superior descends to the first sacral foramen, through 
which it passes backwards to supply the muscles and integument 
posteriorly. The inferior descends by the inner edges of the lower anterior 
foramina as far as the coccyx. It furnishes branches which pass back- 
wards through the foramina, supplying the walls of the spinal canal and 
emerging behind, where they distribute twigs to the muscles and to the 
integument, and anastomose with branches of the gluteal and sciatic arteries. 
The lateral sacral arteries also furnish some small branches to the rectum 
and others which anastomose on the front of the sacrum with offsets of 
the middle sacral artery. 
The External Iliac Artery. 
The external iliac artery (Fig. 341) continues the line of the common 
iliac, and stretches from the level of the lumbo-sacral articulation to 
the lower border of Poupart’s ligament, where it is continued into the 
femoral artery. It is from three and a half to four inches in length, 
and lies behind the lower two-thirds of a line drawn upon the surface 
from a point about half an inch below and to the left of the umbilicus to 
Poupart’s ligament midway between the anterior superior spine and the 
pubic symphysis. It rests behind upon the iliac fascia and is placed 
above the margin of the true pelvis, at first to the inner side of and 
afterwards in front of the psoas muscle. Its companion vein lies at first 
behind and afterwards by its inner side. The ureter frequently crosses 
in front of it at its upper end; the spermatic vessels and the genital 
branch of the genito-crural nerve descend in front of it, crossing it 
obliquely from without inwards. At the lower end the deep circumflex 
vein passes inwards in front of it. It is surrounded by numerous lymphatic 
glands, is’ covered by the peritoneum, and is crossed on the right side by the 
lower part of the ileum, on the left by the sigmoid flexure. A very delicate 
sheath of subperitoneal areolar tissue envelops the artery and vein as they 
descend upon the iliac fascia. Its branches are the deep epigastric and the 
deep circumflex iliac: in addition a number of very minute twigs are 
supplied to the surrounding lymphatic glands. 
The deep epigastric artery (Fig 345) takes origin about a fourth of an 
inch above Poupart’s ligament, and, coursing in the fascia transversalis, 
passes at first inwards and then turns upwards, by the inner margin of the 
deep abdominal ring, towards the sheath of the rectus muscle, which it enters 
some little distance below the semilunar fold of Douglas. In its subsequent 
course it passes up behind the muscle and finally enters its substance, a little 
above the umbilicus, to anastomose with the superior epigastric of the in- 
ternal mammary. Its branches are numerous but small. Pubic twigs descend 
behind the pubis and anastomose with branches of the obturator artery. 
The cremasteric, a slender branch, descends upon the cord or round ligament, 
anastomosing with branches of the spermatic or ovarian artery. Numerous THE EXTERNAL ILIAC ARTERY. 
457 
muscular branches ramify in the abdominal wall and anastomose with offsets 
of the circumflex iliac, ilio-lumbar, lumbar, and lower intercostal arteries. 
An aberrant obturator artery springs from the commencement of the deep 
epigastric trunk in about 30 per cent, of the cases. It is due to an 
enlargement of one of the pubic branches : it descends to the obturator 
notch usually by the outer side of the crural canal; in rare cases, how- 
ever, it passes by the inner margin of the crural ring, a position in which 
it is in danger of being wounded in the operation for the relief of a 
strangulated femoral hernia. 
The deep circumflex iliac artery (Fig. 341) springs from the outer side 
of the main stem in close proximity to the origin of the deep epigastric. 
It passes outwards and upwards behind Poupart’s ligament to the anterior 
superior spine, and is then continued backwards along the iliac crest. It lies 
in the deep layer of fascia of the abdominal wall and furnishes numerous 
branches to the muscles of the upper part of the thigh and the lower part of 
the abdomen; it anastomoses with the deep epigastric, gluteal, ilio-lumbar, 
and lumbar arteries. One branch, frequently of some size, ascends im- 
mediately above Poupart’s ligament, between the transversalis and internal 
oblique muscles. 
Surgical anatomy of the abdominal arteries. Ligature of the abdominal 
aorta has been performed, but hitherto without success. The spot most 
suitable for the operation is about an inch above the bifurcation, and could 
be reached by an incision made along the linea alba, having the umbilicus 
as its centre. The descending branches from the aortic to the hypogastric 
plexus of sympathetic nerves which lie upon the sides of the vessel should 
be carefully avoided. The vena cava lies to the right side. The common 
iliac artery has been successfully tied. It may be easily reached through a 
median incision from the symphysis pubis to the umbilicus, and in this 
way also the internal iliac may be secured. Surgeons, however, in tying 
either of the two vessels, have usually adopted a method which, if properly 
carried out, saves the peritoneum from injury. A curved incision is 
carefully made through the abdominal wall down to, but not including, 
the peritoneum, and the serous membrane is stripped from the iliac fascia 
and pushed upwards until the artery is reached. The incision commences 
near the inner end of and a little above Poupart’s ligament, passes upwards 
and outwards for a little distance parallel to the ligament, and then bends 
upwards and inwards. The incision must not, at its lower end, be carried 
so far inwards as to wound the superficial abdominal ring or the cord; if it 
come too near Poupart’s ligament the deep circumflex iliac vessels would 
be endangered ; if it be placed too far above Poupart’s ligament the deep 
abdominal ring might be injured; the deep epigastric artery may be 
exposed at the inner part of the wound. The veins which accompany the 
diac arteries are very large, and numerous sympathetic branches are in 
close proximity and should be carefully cleared aside. In the case of the 
internal iliac artery the ureter must be avoided. The external iliac artery 458 
THE VASCULAR SYSTEM. 
is secured through an incision very similar to, but not so extensive as 
that required for either of the other two vessels. It is made a little 
above Poupart’s ligament and is slightly bent upwards at its outer end. 
On account of the presence of the large branches below, the ligature is 
applied about an inch and a quarter above Poupart’s ligament. 
The spot at which the gluteal artery escapes from the pelvis is opposite 
the lower end of the upper third of a line drawn from the posterior 
superior iliac spine to the top of the great trochanter, the thigh being 
rotated inwards. The sciatic and pudic arteries escape from the pelvis 
at a spot which is opposite the upper end of the lower third of a line 
drawn from the posterior superior spine of the ilium to the tuberosity of 
the ischium. These vessels may be ligatured at the spots indicated, but, as 
they lie very deeply, the operation in each case is difficult and demands a 
free incision. The left pudic artery, in the wall of the ischio-rectal fossa, 
may be injured by the knife, should the point be turned too much back- 
wards, at the close of the first incision in the operation of lateral lithotomy. 
The artery of the bulb, when arising further back than usual, will probably 
be cut in the same incision, and may require ligature. 
The Femoral Artery. 
The femoral artery (Fig. 346), the continuation of the external iliac, 
enters the thigh, from under Poupart’s ligament, midway between the anterior 
superior spine and the symphysis pubis. It descends through the upper two- 
thirds of the thigh as far as the margin of the opening in the insertion of 
the adductor magnus muscle, through which, as the popliteal artery, the 
trunk is continued to the back of the limb. It is at first placed in front of 
the head of the femur, then, owing to the inclination of the neck, lies 
at some little distance from the bone; still lower it descends by the inner 
side of the shaft. In the upper third of the thigh it lies in Scarpa’s triangle; 
in the remainder of its course it occupies Hunter’s canal. In Scarpa's triangle 
it rests successively upon the psoas, pectineus, adductor brevis, and adductor 
longus muscles and is comparatively superficial, being covered only by the 
fascia. At first the vein is internal to it, but lower down gradually passes 
behind it; the deep femoral vein is likewise at the lower part placed 
behind it; occasionally a large tributary of the internal saphenous vein 
ascends in the superficial fascia in front of the lower part of this portion 
of the artery. The anterior crural nerve lies external to it in its upper 
part, and, a little below Poupart’s ligament, breaks up into its terminal 
branches, of which the internal cutaneous nerve descends in front of the 
artery, gradually crossing it, while the internal saphenous and the nerve to 
the vastus internus pass downwards by its outer side. At the apex of 
Scarpa’s triangle the artery passes under cover of the sartorius muscle and 
enters Hunter's caned; in this portion of its course it is covered in front and 
internally by the sartorius and, bound down by aponeurotic fibres, rests in  circumflex iliac 
Superficial epigastric 
Superficial pudic 
Deep femoral 
Internal circumflex 
External circumflex 
' [-Perforating arteries 
Anastomotica magna 
.Patellar branches 
Fig. 346.—The Femoral Artery and its Branches. The femoral artery is repre- 
sented as drawn outwards a little in its upper part to show the origin of the deep 
femoral from its posterior surface. (C. Gegenbaur.) 
To face p. 458. Anterior recurrent branch 
Anterior tibial artery 
Anterior tibial nerve 
Muscular branch 
Muscular branch 
Muscular branch 
Anterior tibial artery 
Anterior terminal branch of peroneal artery 
Internal malleolar branch 
External malleolar branch 
Anterior tibial nerve 
Dorsal artery of foot 
Fig. 347.—The Anterior Tibial Artery. (L. Testut.) 
To face p. 459. THE FEMORAL ARTERY. 
the angle between the insertions of the adductors longus and magnus behind,, 
and the vastus interims muscle externally. Within the canal the vein lies 
behind it, gradually passing to the outer side below, and the long or 
internal saphenous nerve is placed in front of it; the nerve to the vastus 
internus descends in front of the canal, a little external to and in front of 
the line of the artery. 
In the neighbourhood of the saphenous opening the femoral artery gives 
off a number of small superficial branches which supply the lymphatic glands 
of the groin and the skin and superficial fascia in the vicinity ; they are— 
the superficial circumflex iliac, passing upwards and outwards; the superficial 
epigastric, passing upwards; and the upper and lower superficial pudic arteries, 
directed towards the pubic region and the scrotum—each of these vessels- 
anastomoses with the superficial branches of the correspondingly named 
deep trunk. A number of irregular muscular branches are given off at 
intervals. The most important branch is the deep femoral artery. Near 
the lower end of the stem the anastomotica magna is detached. 
The deep femoral artery (Fig. 346) springs from the femoral about an 
inch and a half below Poupart’s ligament; it is of considerable size and the 
portion of the femoral artery above its origin is, on that account, frequently 
named the “common femoral,” and the portion below the “superficial 
femoral.” It descends at first by the outer side of, and afterwards behind 
the parent trunk, from which it is separated by the femoral and deep 
femoral veins and the adductor longus muscle, and it rests successively 
upon the iliacus, pectineus, adductor brevis, and adductor magnus muscles, 
through the last mentioned of which it finally passes in the lower part 
of the middle third of the thigh, much reduced in size, as the last perfor- 
ating artery. It gives off the external and internal circumflex and the 
perforating branches. 
The external circumflex artery usually springs from the deep femoral artery 
near its commencement, but very frequently from the femoral itself. It 
passes outwards under cover of the rectus and sartorius muscles and breaks 
up into three sets of branches—(l) the ascending, which pass upwards under 
cover of the tensor vaginae femoris muscle to anastomose with branches 
of the gluteal artery; (2) the transverse, which sink into the substance of 
the crureus and vastus externus muscles and anastomose with the upper 
perforating arteries; and (3) the descending, which pass downwards upon 
the quadriceps muscle, supplying it, and anastomose with the lower per- 
forating arteries and the external articular branches of the popliteal. 
The internal circumflex artery usually springs from the commencement 
of the deep femoral, but, like its neighbour, it is frequently transferred 
fo the main trunk. It passes backwards between the psoas and pectineus 
muscles, supplying the adductor muscles, anastomosing with the obturator 
artery, and giving off an articular branch which enters the joint through the 
cotyloid notch. It then divides into two branches (Fig 343), one of which, the 
ascending, passes upwards behind the hip-joint to anastomose at the upper 460 
THE VASCULAR SYSTEM. 
border of the quadratics femoris with the sciatic artery, while the other, 
the transverse, passes backwards between the lower border of the quadratics 
femoris and the upper border of the adductor magnus muscles to assist 
in the supply of the muscles of the back of the limb and anastomose 
with the sciatic and upper perforating arteries. 
The perforating arteries (Fig. 343), four in number, including the terminal 
part of the deep femoral, pass backwards through the adductor magnus, 
elose to its insertion, to supply the back of the limb ; they anastomose with 
the sciatic, with the internal and external circumflex arteries, with one 
another, and with the muscular and articular branches of the popliteal 
artery. They are very variable in size and number, being frequently reduced 
to two or three. The first, commonly the largest, pierces the adductor brevis 
before passing through the adductor magnus, and breaks up into its terminal 
branches under cover of the gluteus maximus; the second usually pierces 
the adductor brevis but may pass backwards by its lower border. 
The anastomotica magna artery (Fig. 346) springs from the femoral 
near the lower end of Flunter’s canal, and almost immediately divides into 
two branches, superficial and deep. The superficial branch descends on the 
deep surface of the sartorius, with the internal saphenous nerve, to the 
upper and inner part of the leg, where it supplies the superficial parts, 
and anastomoses with the internal articular arteries; the deep branch descends 
in front of the tendon of the adductor magnus on the surface of the 
vastus interims muscle, or within its substance, and anastomoses with the 
upper internal articular branches of the popliteal artery. 
Varieties of the femoral artery. Sometimes, but very rarely, the femoral 
artery is absent or much reduced in size, its place being taken by an 
enlarged comes nervi ischiadici of the sciatic; this is the course of the 
main artery of the limb in birds. 
Surgical anatomy of the femoral artery. The course of the artery may 
be marked on the surface by the upper two-thirds of a line drawn 
from a point on Poupart’s ligament, midway between the anterior superior 
spine and the symphysis, to the adductor tubercle of the inner condyle of 
the femur. The ligature is usually applied at the apex of Scarpa’s triangle. 
There is frequently found in the superficial fascia a large tributary of the 
internal saphenous vein ascending along the line of operation. The sartorius 
muscle is exposed, and its inner border forms the guide to the vessel. The 
internal cutaneous nerve descends here in front of the vessel, the femoral 
vein is behind, and the long saphenous nerve and nerve to the vastus 
internus are external; the vein and the internal saphenous nerve lie very 
elose to the artery. The femoral artery may be secured in Hunter’s canal. 
An incision is made along the line of the artery in the middle third of 
the limb; the long saphenous vein lies in the subcutaneous tissue to 
the inner side of the incision ; the fascia is cut through along the outer 
■edge of the sartorius and the muscle is drawn inwards. If the limb 
be abducted the tendon of the adductor magnus will be made tense, THE POPLITEAL ARTERY. 
461 
and will serve as a guide to the position of the vessel. When the canal 
has been opened the long saphenous nerve is found in front of the 
artery, and the femoral vein lies behind; the nerve to the vastus 
internus may be seen before the canal is opened. The upper part of 
the femoral, above the origin of the deep femoral, is unfavourable for 
ligature on account of the proximity of the large branches; the circula- 
tion through it may be controlled by pressure directed backwards. 
The Popliteal Artery. 
The popliteal artery, the continuation of the femoral trunk, extends 
through the lower third of the thigh and the upper sixth of the leg, from 
the opening in the insertion of the adductor magnus to the lower border 
of the popliteus muscle, where it divides into the anterior and posterior 
tibial arteries. It is directed at first downwards and inwards to gain, 
opposite the back of the knee-joint, the middle line of the popliteal space, 
and then descends vertically, resting first on the capsule of the joint and 
afterwards on the popliteus muscle. At the upper end it is covered by the 
semimembranosus, below it passes under cover of the gastrocnemius, and is 
crossed by the plantaris. The companion vein is at first external to the 
artery, but crosses it gradually, resting closely upon its posterior surface 
about the middle of the space, and gains its inner side below; the short 
saphenous vein ascends superficially behind the lower part of the artery 
to join the popliteal vein. The internal popliteal nerve lies behind the 
artery and vein in the middle of the space, but below is placed by their 
inner side. The branches of the artery are divided into two groups, muscular 
and articular. 
The muscular branches are arranged in two sets, upper and lower in 
position. The upper set is formed of three or four vessels, which supply 
the lower ends of the hamstring muscles and anastomose with the lower 
perforating and upper articular arteries. The lower set includes two 
branches, the outer and inner sural arteries, which supply the gastrocnemius, 
the plantaris, and the upper part of the soleus, and detach slender twigs 
to descend subcutaneously upon the calf. 
The articular branches are five in number, the two upper encircling 
the bone above the joint, the two lower coursing round the bones below 
the joint, and the middle or azygos artery piercing the posterior ligament 
to enter the joint. The upper articular arteries, external and internal, the 
external being the larger, are directed, above the heads of the gastrocnemius, 
and under cover of the hamstring muscles, to the front of the lower end of 
the femur, where they anastomose with one another, and with the upper 
muscular branches, the external circumflex, and the anastomotica magna 
from above, and with the lower articular arteries from below. The lower 
articular arteries, internal and external, the internal being the larger, are 
directed transversely upon the surface of the popliteus muscle, and pass 462 
THE VASCULAR SYSTEM. 
respectively under cover of the internal and external lateral ligaments to 
ramify over the front of the joint, anastomosing with one another, with the 
upper articular arteries from above, and with the recurrent branches of 
the anterior tibial artery from below. The articular arteries supply small 
branches to the capsular ligament and to the surrounding muscles. The 
■azygos articular artery, arising opposite the middle of the joint, pierces 
the posterior part of the capsular ligament to supply the crucial ligaments 
and the ligarnentum mucosum. 
Varieties of the popliteal artery are not frequent; it sometimes divides 
into its terminal branches a little higher than usual. The vein is 
frequently found double in the lower part of the popliteal space and occa- 
sionally even in the upper part of the space. 
Surgical anatomy of the popliteal artery. The popliteal artery is seldom 
ligatured, as in most cases the surgeon would prefer to deal with the 
femoral. The artery is so deeply placed in the fat of the space and is so 
very closely associated with the vein, especially in the middle of the space, 
that the operation would be specially difficult and dangerous. The vessel 
has been secured near its lower end between the heads of the gastrocnemius 
by a median incision. In this operation the short saphenous vein and 
the sural arteries are to be avoided. The internal popliteal nerve is first 
met with; the vein lies on the deep surface of the nerve, and both are 
internal to the artery and somewhat superficial to it. The artery has 
also been ligatured in the lower part of the thigh, as it lies between the 
adductor magnus and semimembranosus muscles. The incision is made 
behind the tendon of the adductor magnus, the sartorius is drawn back- 
wards, and the semimembranosus exposed; the artery here lies close to 
the bone with the vein on its deep surface. 
The Anterior Tibiae Artery. 
The anterior tibial artery (Fig. 347) springs from the termination of 
the popliteal stem at the lower border of the popliteus muscle, and almost 
immediately passes forwards, between the heads of the tibialis posticus 
muscle, through the interosseous membrane. It then passes downwards 
as far as the level of the ankle-joint, beyond which it is continued as 
the dorsal artery of the foot. As it descends it rests in the upper two- 
thirds of its course upon the interosseous membrane, in the lower third, 
upon the tibia. In the upper part it is deeply placed, being covered by the 
muscles between which it lies; internally the tibialis anticus, externally the 
extensor digitorum longus in the upper third of the leg, and the extensor 
hallucis longus below; but near the ankle, as the muscular fibres give place 
to tendon, the artery becomes comparatively superficial. About, or a little 
above the level of the ankle it is obliquely crossed from without inwards by 
the tendon of the extensor of the great toe. Two venae comites accompany 
it, one lying in front, the other behind. The anterior tibial nerve, which THE ANTERIOR TIBIAE ARTERY. 
463 
gradually approaches it from the outer side in the upper fourth of the leg, 
descends for a little distance in front of it, hut at the ankle again falls 
back to its outer side. The branches are small and numerous, and are 
divided into three sets—recurrent, muscular, and malleolar. 
The posterior recurrent branch, often absent, is given off before the 
artery pierces the interosseous membrane, and ascends on the deep surface 
of the popliteus muscle to anastomose with the lower articular branches 
of the popliteal. The anterior recurrent branch takes origin immediately 
after the artery has pierced the membrane, and passes upwards through 
the tibialis anticus to end, like the posterior branch, in anastomosis with 
the lower articular arteries. The muscular branches, very numerous, 
supply the muscles of the front of the leg. Before the artery pierces the 
membrane, a slender branch is distributed to the upper part of the soleus. 
The malleolar branches pass from the main stem transversely behind the 
tendons immediately above the ankle-joint; the internal, the smaller, ramifies 
upon the inner malleolus and anastomoses with the internal malleolar branch 
of the posterior tibial artery and with the internal branches of the dorsal 
artery of the foot; the external, usually a little lower in position than the 
internal, is distributed around the outer malleolus and anastomoses with the 
anterior and posterior terminal divisions of the peroneal artery. 
The Dorsal Artery of the Foot. 
The dorsal artery of the foot (Fig. 348), the continuation of the anterior 
tibial artery, passes forwards from a spot opposite the middle of the ankle- 
joint to the posterior extremity of the interspace between the metatarsal 
bones of the first and second toes, where it sinks into the sole to inosculate 
with the termination of the external plantar artery lies upon the sur- 
face of the tarsal bones, being bound down by a strong layer of connective 
tissue; the tendon of the long extensor of the great toe lies to its inner 
side, and before it dips into the sole it is crossed by the first tendon of 
the extensor digitorum brevis. It is accompanied by two venae comites 
and by the inner terminal branch of the anterior tibial nerve, which is 
usually placed along its outer side. As it passes forwards on the dorsum of 
the foot it gives off one or two small branches from its inner side, and 
from the outer side the tarsal and metatarsal branches. Before it sinks 
into the sole it detaches the first dorsal interosseous artery; in the sole 
it gives off the arteria princeps hallucis. 
The internal branches, small and irregular, ramify over the inner side 
of the tarsus and anastomose with branches of the internal plantar and 
the internal malleolar arteries. The tarsal artery passes outwards under 
cover of the extensor brevis muscle in company with the outer terminal 
branch of the anterior tibial nerve, and breaks up into twigs which supply 
the surrounding parts and anastomose with branches of the external 
ttialleolar,- the external plantar, and the metatarsal arteries. 464 
THE VASCULAR SYSTEM. 
The metatarsal artery passes outwards upon the bases of the metatarsal 
bones, underneath the extensor tendons. It detaches the dorsal interosseous 
arteries of the three outer spaces. The dorsal interosseous branches pass for- 
wards upon the interosseous muscles and at the clefts of the toes divide, like 
the corresponding arteries of the hand, into dorsal collateral branches, which 
run forwards upon the digits, anastomosing on the sides of the toes with 
the branches of the plantar digital vessels. Each interosseous trunk is 
connected with the external plantar artery by a posterior perforating branch, 
and with the plantar digital artery of its space by an anterior 'perforating 
branch; the most external trunk gives off a branch for the outer side of the 
little toe. The dorsal arteries of the foot are comparatively larger than 
those of the hand. Recurrent branches pass from the metatarsal artery to 
anastomose with offsets of the tarsal artery. The first dorsal interosseous 
artery, given off before the main stem enters the sole, passes forward and 
supplies digital branches to both sides of the great toe and the inner side 
of the second toe. and is connected by an anterior perforating branch with 
the plantar digital artery of its space. 
The arteria princeps hallucis (Fig. 350), the innermost plantar digital 
artery, springs from the termination of the dorsal artery of the foot; it 
passes forwards in the first interosseous space, detaches a branch to the 
inner side of the great toe, aud divides to supply the contiguous sides of 
the great and the second toes. Its innermost branch inosculates with the 
termination of the internal plantar artery. 
The Posterior Tibiae Artery. 
The posterior tibial artery (Fig. 349), arising from the termination of 
the popliteal trunk, at the lower border of the popliteus muscle, descends 
upon the back of the leg with a slight inclination inwards, resting in suc- 
cession upon the tibialis posticus, the flexor longus digitorum, the lower end 
of the tibia, and the capsule of the ankle-joint; it terminates midway between 
the internal malleolus and the centre of the prominence of the heel, by 
dividing into the internal and external plantar arteries. In the upper two- 
thirds of its course it is deeply placed in front of the gastrocnemius and 
soleus muscles and a deep layer of the fascia. Lower down, by the inner 
margin of the tendo Achillis, it is comparatively superficial, being covered 
only by the fascia. It terminates under cover of the internal annular 
ligament and the origin of the abductor hallucis muscle. As it descends 
behind the malleolus it lies between the tendons of the flexor digitorum 
longus internally and the flexor hallucis longus externally, and occupies 
a special fibrous sheath placed between those of the tendons, and slightly 
superficial to them. It is accompanied through its whole course by two 
venae comites and by the posterior tibial nerve, which crosses it pos- 
teriorly from the inner to the outer side, about an inch and a half below 
the popliteus muscle. It gives off numerous small muscular branches, Anterior tibial 
Anterior terminal branch)_ 
of peroneal 
I nternal malleolar branch 
External malleolar branch 
Dorsal artery of foot 
Internal branch 
Tarsal branch 
Metatarsal branch 
Dorsal artery of foot 
(Dorsal interosseous 
arteries 
Posterior perforating artery 
Dorsal interosseous f 
arteries \ 
14, Dorsal digital branches 
Fig. 3iB.—Arteries of the Dorsum of the Foot. (L. Testut.) 
To face p. 464. Popliteal- 
Anterior tibial 
Posterior tibial 
Medullary artery 
Peroneal 
Posterior tibial.. 
I 
i 
i 
i 
\ 
i 
Muscular branches 
Muscular branch 
I Anterior terminal branch of 
( peroneal 
f Posterior terminal branch of 
\ peroneal 
Communicating branches 
Posterior tibial 
Fig. 349.—Arteries of the Back of the Leg 
(L. Testut.) 
To face p. 465. THE POSTERIOR TIBIAE ARTERY. 
465 
the medullary artery of the tibia, one or two communicating branches, the 
internal malleolar branches, and one branch of considerable size, the 
peroneal. 
The medullary branch, the largest of its kind, arises near the upper 
end of the trunk, and enters the tibia. The communicating branches, 
one or two in number, pass outwards, in front of the tendons, about an 
inch or two inches above the heel, and communicate with similar branches 
from the peroneal artery. The internal malleolar branches, one or two 
in number, ramify upon the malleolus and anastomose with offsets of the 
anterior tibial and of the dorsal artery of the foot. 
The peroneal artery (Fig. 349), springing about an inch and a half below 
the commencement of the parent trunk, passes downwards and outwards 
towards the fibula, and then descends by the inner border of that bone, 
under cover of, or sometimes in the substance of the flexor hallucis longus 
muscle. About an inch and a half above the ankle it terminates by 
dividing into anterior and posterior branches. It is accompanied by two 
venae comites. In its course it gives off a number of muscular branches, 
the medullary artery of the fibula, and, near the ankle, one or more com- 
municating branches which join the corresponding branches of the posterior 
tibial. The anterior terminal branch, or anterior peroneal artery, passes 
forwards through the interosseous membrane, and descends in front of the 
lower tibio-fibular articulation; it forms connections with the external 
malleolar branch of the anterior tibial, and ramifies in front of the mal- 
leolus. The posterior terminal branch descends behind the lower tibio-fibular 
articulation, ramifies round the point of the external malleolus, and 
anastomoses with the arteries in front of the malleolus and with branches 
of the tarsal and external plantar arteries. 
The External Plantar Artery. 
The external plantar artery (Fig. 350), the larger terminal division of 
the posterior tibial, takes origin midway between the point of the internal 
malleolus and the prominence of the heel, under cover of the internal 
annular ligament and the origin of the abductor hallucis. It passes at 
first obliquely forwards and outwards towards the tuberosity of the fifth 
metatarsal bone; then, changing its direction, it bends inwards and forwards 
arching across the sole. It terminates at the proximal end of the first 
intermetatarsal space by inosculating with the extremity of the dorsal 
_artery of the foot. As it passes forwards and outwards it is placed at 
first between the abductor hallucis and the calcaneum, and afterwards 
between the flexor digitorum brevis and the flexor accessorius. As it 
turns inwards, it lies in the space between the flexor digitorum brevis 
and the abductor minimi digiti and is thus comparatively superficial. In 
ffie last portion of its course it crosses the proximal extremities of the 
fourth, third, and second metatarsal bones, and is covered superficially 466 
THE VASCULAK SYSTEM. 
by the flexor tendons and the lumbricales, and, at its termination, by the 
adductor hallucis. It is accompanied by two venae comites, and has in 
the first part of its course the external plantar nerve on its inner side. 
Its branches are numerous, the most important being the plantar digital 
arteries. 
Some calcaneal branches ramify upon the under surface of the os calcis, 
anastomosing with offsets of the posterior branch of the peroneal artery. 
Muscular branches supply the surrounding muscles, and detach cutaneous 
twigs which appear along the line between the middle and outer portions 
of the plantar fascia. These branches form anastomotic connections at 
the outer border of the foot with offsets of the tarsal and metatarsal 
branches of the dorsal artery. Articular branches run backwards from the 
arch. The posterior perforating arteries, three in number, ascend through 
the proximal extremities of the three outer intermetatarsal spaces and join 
the dorsal interosseous arteries. 
The plantar digital arteries are four in number. The outermost passes 
forwards upon the flexor minimi digiti brevis and reaches the outer side 
of the fifth toe. The others, deeply placed, pass forwards upon the 
interosseous muscles of the three outer spaces, crossing above the trans- 
versus pedis muscle. Becoming superficial at the clefts of the toes, they 
communicate by means of the anterior perforating arteries with the dorsal 
interosseous arteries, and divide into collateral digital branches, the inner- 
most of which supplies the outer side of the second toe. The collateral 
digital branches pass forwards upon the sides of the toes, anastomosing 
freely with one another and with the dorsal digital arteries. 
The Internal Plantar Artery. 
The internal plantar artery (Fig. 350), much smaller than the external, 
takes origin with it from the termination of the posterior tibial. It passes 
forwards between the abductor hallucis and the flexor digitorum brevis. 
At the base of the great toe it terminates by inosculating with the arteria 
princeps hallucis, the innermost plantar digital artery. It gives off a 
number of muscular and cutaneous branches, the more important of which 
anastomose at the inner border of the foot with branches of the dorsal 
artery. One or two articular branches pass deeply into the sole, and two 
or three slender digital branches accompany the digital branches derived 
from the internal plantar nerve, and inosculate at the three inner clefts 
with the plantar digital arteries. 
Varieties of the arteries of the leg and foot. The anterior tibial artery 
is occasionally much reduced in size, and when this is the case it is usually 
reinforced or entirely replaced below by an enlarged anterior peroneal 
trunk. The posterior tibial artery is in like manner frequently much 
reduced or may be entirely deficient except in its lower part, and the THE ARTERIES OF THE LEG. 
467 
current of blood in these cases passes through an enlarged peroneal artery, 
and one or more of the communicating branches. The dorsal artery of the 
foot may be partly or wholly derived from the anterior peroneal artery. 
It may be reduced in size, some of its ultimate digital branches being 
transferred to the external plantar artery by an enlargement of the per- 
forating vessels ; on the other hand, it may be larger than usual, forming 
the greater part or even the whole of the plantar arch. The external plantar 
artery varies inversely with the dorsal artery of the foot. The internal 
plantar artery is very variable; it may extend no further than the muscles 
at the base of the great toe or, much enlarged, may give the chief supply 
to that digit. 
Surgical anatomy of the arteries of the leg. The course of the anterior 
tibial artery may be marked on the surface by a line drawn from a point 
midway between the outer tuberosity of the tibia and the head of the 
fibula to a spot opposite the centre of the front of the ankle-joint. The 
vessel may be reached in any part of its course through an incision made 
along this line. It is most superficial in the lower third of the leg, and 
in this situation it is being gradually crossed from without inwards by the 
tendon of the extensor hallucis longus; its venae comites are in close 
apposition, and the anterior tibial nerve lies by its outer and anterior 
border. The dorsal artery of the foot continues the line of the anterior 
tibial from the middle of the ankle-joint to the posterior extremity of the 
first intermetatarsal space. It lies very close to the bone, and is enveloped 
in a firm layer of connective tissue. Two venae comites accompany it, and 
the nerve lies usually to the outer side. The posterior tibial artery is deeply 
placed in the upper two-thirds of the leg, but is comparatively superficial 
below. The lower part of a line drawn from the centre of the popliteal 
space to a spot midway between the point of the internal malleolus and 
the most prominent part of the heel would indicate the course of the 
vessel. It may be ligatured in the lowTer third of the leg through an 
incision made midway between the margin of the tendo Achillis and the 
inner border of the tibia ; or it may be tied at the inner side of the ankle 
through a curved incision half an inch below the point of the malleolus. 
The venae comites are in close apposition to it, and the nerve is placed 
externally. It may be reached in the middle third of the leg through 
an incision about a quarter of an inch behind the inner border of the tibia; 
in this operation part of the origin of the soleus muscle must be divided. 468 
THE VASCULAR SYSTEM. 
THE VENOUS SYSTEM. 
THE VEINS OF THE HEART. 
The veins of the heart terminate in a common trunk, the coronary 
sinus. 
The coronary sinus (Fig. 308), about an inch in length, lies in the 
posterior part of the auriculo-ventricular furrow, between the left auricle 
and ventricle, and opens into the right auricle, the orifice, which is guarded 
by the valve of Thebesius, being placed between the Eustachian valve and 
the auriculo-ventricular opening. The tributaries of the sinus are the left 
and right coronary veins, the posterior interventricular vein, and the 
oblique vein. 
The left or great coronary vein (Fig. 308) runs in the auriculo-ventricular 
furrow, beginning in front and terminating behind in the left extremity of 
the sinus. Its chief tributary is the anterior interventricular vein, a vessel 
which, much larger than the anterior part of the coronary vein into which it 
falls, ascends in the anterior interventricular groove, receiving branches from 
the surface of both ventricles. The left coronary also receives from the 
surface of the left ventricle a number of posterior cardiac veins, one among 
which, sometimes larger than the others, is named the left marginal vein. 
Some of the posterior cardiac veins fall directly into the sinus. 
The right or small coronary vein (Fig. 308) runs in the auriculo-ventricular 
furrow, beginning in front and terminating behind by falling into the right 
extremity of the sinus. It receives from the surface of the right ventricle a 
number of anterior cardiac veins, one among which is sometimes named the 
right marginal vein. The posterior interventricular vein ascends in the posterior 
interventricular furrow, and falls into the right extremity of the sinus, 
generally by a separate orifice, but in very close proximity to the opening 
of the right coronary vein. Both coronary veins receive, in addition to 
the tributaries from the ventricular walls, some small irregular vessels 
from the surface of the auricles. 
The oblique vein, the remains of the left duct of Cuvier, descends 
in the vestigial fold of Marshall, and enters the left extremity of the 
coronary sinus. It is very slender and is frequently impervious. The 
orifices of all the veins which open into the sinus, with the exception of 
that of the oblique vein, are guarded by valves. 
In addition to the large veins which open into the sinus, a number of 
very small veins, venae minimae cordis, run in the substance of the cardiac 
wall, and open into some of the pits of Thebesius in the right auricle. 
The Vena Cava Superior. 
The superior vena cava (Figs. 351, 359) is formed by the junction of 
the right and left innominate veins, and descends from behind the first Calcaneal branch 
Posterior tibial 
3, Internal plantar 
External plantar artery 
Posterior perforating branch 
{External plantar artery 
(plantar arch) 
Plantar digital arteries- 
-Plantar digital arteries 
Outermost plantar digital branch 
Arteria princeps hallucis ) 
(innermost branch) ) 
9, Plantar collateral digital 
branches 
Fig. 350.—Arteries of the Sole. (L. Testut.) 
To face p. 468. Facial 
Right internal jugular 
Left internal jugular 
Left external jugular 
Right external jugular 
Right anterior jugular 
Left subclavian 
2, Right innominate 
Right internal mammary 
2', Left innominate 
Superior vena cava 
3, Right subclavian 
9, Left internal mammary 
Pig, 351.—The Superior Vena Cava and its Branches. (L. Testut.) 
Foramen for mastoid vein 
Superior petrosal sinus 
Auditory nerve 
1 Facial nerve 
I | Pars intermedia 
j | | Inferior petrosal sinus 
Posterior condylar vein 
I Connecting branch through anterior 
I condylar foramen 
Process of dura mater separating glosso-pharyn- 
geal and pneumogastrio nerves 
Internal jugular 
Pig. 352.—The Commencement of the Internal Jugular Vein, left side, a, Spinal 
accessory nerve ;b, pneumogastric nerve; c, glosso-pharyngeal nerve ; 1, lateral sinus; 
2, dilated portion or bulb of the internal jugular. (L. Testut.) 
To face p. 469. THE VEINS OF THE HEART. 
469 
right costal cartilage to the level of the third right costal cartilage, where 
it enters the right auricle. It is about three inches in length, and 
receives about half-way down the great azygos vein. Above the entrance 
of the azygos vein it is overlapped by the right pleura, and the right 
pneumogastric nerve lies behind it; below, it is enveloped except for a 
narrow line posteriorly, by the pericardium, and rests behind on the right 
bronchus and the right pulmonary artery and veins. On its left side it is 
in contact with the ascending portion of the aorta; the phrenic nerve 
descends on its right side. In addition to the larger tributaries, it receives 
some minute veins from the anterior mediastinum. 
Right innominate vein (Fig. 351). This vessel is formed by the junction 
of the right internal jugular and subclavian veins. It is a little over an inch 
in length, and descends, with a slight inclination inwards, on the right side 
of the innominate artery, from behind the sternal end of the clavicle to 
the level of the first costal cartilage. It is in contact with the pleura 
externally and posteriorly; the phrenic nerve descends by its outer border, 
and the pneumogastric is placed behind it. In front of it lie some remains 
of the thymus gland and, on the deep surface of the clavicle, the origin of 
the sterno-hyoid muscle. Its lateral tributaries are the vertebral, the inferior 
thyroid, and the internal mammary veins; and it receives at its commence- 
ment the right lymphatic duct. 
Left innominate vein (Fig. 351). The left innominate, formed by the 
junction of the left internal jugular and subclavian veins, is about three 
inches in length. Commencing behind the sternal end of the left clavicle, 
it passes to the right, descending slightly as it goes, and crosses behind 
the upper part of the manubrium and in front of the three great 
branches of the transverse portion of the aorta, to terminate behind 
the first right costal cartilage. It is placed above the arch of the 
aorta, and in front of it lie the remains of the thymus gland and 
the origins of the sterno-hyoid and sterno-thyroid muscles. Its lateral 
tributaries are the vertebral, inferior thyroid, internal mammary, left superior 
intercostal, and some small pericardial and thymic veins; and it receives 
at its commencement the thoracic duct. The innominate veins have no 
valves. 
VEINS OF THE HEAD AND NECK. 
The vertebral vein commences in the suboccipital triangle as a 
plexus of small vessels communicating with the occipital, deep cervical, 
and spinal veins. The plexus is continued downwards through the 
successive foramina, receiving as it descends some small spinal and muscular 
branches. Lower down the plexus gives place to a single vessel which 
emerges in front of the vertebral artery, crosses the subclavian artery, 
aud terminates in the innominate vein. Close to its termination the 
Vertebral vein is joined by the deep cervical vein, the anterior vertebral 
Vein (a muscular branch from the front of the column), and as a rule 470 
THE VASCULAR SYSTEM. 
the first intercostal vein. One or two valves guard the termination of the 
vertebral vein. 
The deep cervical vein commences in the suboccipital plexus, through 
which it is continuous with the occipital veins. Below the plexus, the vein, 
continued downwards, accompanies the deep cervical artery. It terminates 
in the vertebral vein. 
The inferior thyroid vein (Big. 351) descends in front of the trachea in 
company with its fellow of the opposite side, with which it is frequently 
united by transverse branches. The left vein terminates below in the left 
innominate vein, the orifice being guarded by a valve; the right vein either 
joins its fellow of the left side, or terminates separately in the angle 
of junction between the innominate veins or in the right innominate. 
Internal Jugular Vein (Figs, 351, 352). This great vein, continuous 
with the lateral sinus, descends from the posterior part of the jugular fora- 
men, and on its way lies by the outer side, first of the internal carotid and 
afterwards of the common carotid artery. It terminates behind the sternal 
end of the clavicle in the innominate vein. At its commencement in the 
jugular foramen it is somewhat dilated, and receives the inferior petrosal 
sinus. About an inch above its termination a couple of valves are found. 
Its lateral tributaries are the middle and superior thyroid, the lingual, 
facial, and pharyngeal veins ; and in many cases it receives a communi- 
cating branch from the external jugular vein. 
The middle thyroid vein, from the side of the thyroid body, crosses the 
common carotid artery a little below the level of the cricoid cartilage, 
and falls into the internal jugular. The superior thyroid vein (Fig. 353), 
accompanying the superior thyroid artery, passes outwards to the internal 
jugular, crossing the upper part of the common carotid artery. 
The lingual veins (Fig. 353). Two small venae comites accompany 
the lingual artery, and eventually join with one another to form a 
stem which receives the much larger ranine vein, a vessel which, passing 
backwards from the tip of the tongue, crosses the outer surface of the 
hyo-glossus muscle immediately below the hypoglossal nerve, and receives 
on its way the sublingual and dorsal branches. The common lingual vein 
crosses the external and internal carotid arteries, and either falls directly 
into the internal jugular or unites with the terminal part of the facial 
vein. Occasionally the branches which make up the lingual vein enter 
the internal jugular separately. 
The facial vein (Fig. 353) collects the blood from the anterior part of the 
scalp and from the face. It commences near the vertex of the head in a net- 
work which anteriorly is continued into the frontal vein. The frontal vein 
passes towards the root of the nose, communicating across the middle line 
with its fellow of the opposite side, and above the inner canthus unites with 
the supraorbital vein, a vessel which draws its supply from the lateral part of 
the forehead. The common trunk thus formed, the angular vein, is directed 
backwards and downwards, passing the inner canthus, and, below the orbit, is VEINS OF THE HEAD AND NECK. 
471 
continued into the facial vein. The angular vein receives numerous palpebral 
and nasal branches, and through its larger tributaries communicates freely 
with the veins of the orbit, and through them with the cavernous sinus. 
The facial vein passes backwards and downwards over the face, holding 
a straight course behind the facial artery, crossing on the deep surface of 
the zygomatici and the platysma. It receives from the front nasal 
and labial branches, and from behind palpebral, glandular, and muscular twigs, 
and a somewhat large branch of communication which comes forwards, upon 
the buccinator muscle, from the pterygoid plexus. In the neck the facial 
vein descends superficially over the digastric and stylo-hyoid muscles, 
crosses the external and internal carotid arteries, and falls into the internal 
jugular vein opposite the hyoid bone. In this part of its course it receives 
(a) from the front, submental and glandular branches, through which it com- 
municates with the anterior jugular vein; (b) on its deep surface, the inferiai' 
palatine vein which accompanies the ascending palatine branch of the artery ; 
and (c) from behind, the anterior division of the temporo-maxillary vein, 
through which it is brought into communication with the external jugular 
vein. A communicating branch frequently passes from the lower end of 
the facial, along the margin of the sterno-mastoid muscle, to the anterior 
jugular vein. At its lower end the facial occasionally receives the pharyn- 
geal, lingual, and superior thyroid veins. It sometimes falls into the external 
jugular and occasionally into the anterior jugular vein. 
The pharyngeal veins form, on the outer surface of the pharynx, a 
plexus which communicates above with the pterygoid plexus and, through 
the foramen lacerum medium, with the cavernous sinus. They open as 
one or two trunks into the facial or internal jugular. 
Subclavian Vein (Fig. 351). This trunk is the continuation of the 
axillary vein. It commences at the outer border of the first rib, and 
terminates in the innominate vein behind the sternal end of the clavicle. It 
is placed in front of and a little lower than the subclavian artery, from 
"which it is separated by the scalenus anticus muscle. The phrenic nerve, 
which crosses in front of the artery, passes behind the vein. Near the outer 
border of the sterno-mastoid it receives the external jugular vein. A 
couple of valves are found immediately external to the orifice of the 
tributary. 
The external jugular vein (Fig. 351) is formed immediately behind the 
angle of the jaw by the union of the posterior auricular vein with the 
posterior division of the temporo-maxillary vein. It descends, lying in the 
superficial fascia, under cover of the platysma, and crosses the sterno mastoid 
uiuscle, the posterior border of which it gains two or three inches above 
the clavicle. Close to the clavicle, a little behind the sterno-mastoid, 
it pierces the deep fascia and falls into the subclavian vein. Its lateral 
tributaries are the anterior jugular, the suprascapular, the transverse 
cervical, and the posterior jugular veins. It is very variable in size, and 472 
THE VASCULAR SYSTEM. 
is sometimes absent when the anterior jugular is large. It contains a 
valve a little above its lower extremity. 
The anterior jugular vein (Fig. 351) takes origin in the inframaxillary 
region from a number of small vessels, which communicate laterally with the 
submental veins. It descends in the superficial fascia in front of the larynx 
and trachea, and near the clavicle perforates the deep fascia and is con- 
tinued backwards, immediately above the bone, on the deep surface of the 
sterno-mastoid muscle, to terminate in the lower part of the external 
jugular vein. It is connected above the sternum with its fellow of the 
opposite side by a transverse branch, which crosses the lower part of the 
trachea. It is of very variable size. It frequently receives a communi- 
cating branch from the facial vein. In many cases it ends in the sub- 
clavian or innominate vein. 
The suprascapular and transverse cervical veins accompany the corre- 
sponding arteries, and terminate in the external jugular, sometimes in a 
plexiform manner, a little above the clavicle, in front of the third portion 
of the subclavian artery. 
The posterior jugular vein is of very variable size, and when well 
developed usually communicates above with the occipital vein. Descending 
behind the sterno-mastoid it falls into the external jugular vein some little 
distance above the clavicle. 
The posterior auricular vein descends from the lateral part of the scalp 
where its radicles communicate with those of the temporal and occipital veins. 
It receives branches from the pinna and passes downwards, crossing the 
sterno-mastoid muscle, to the upper extremity of the external jugular vein. 
The temporo-maxillary vein, a short trunk, lies in the lower part of the 
parotid gland. It is formed above, opposite the neck of the jaw, by the 
junction of the temporal and internal maxillary veins, and divides below, 
opposite the angle, into two divisions, the anterior of which descends 
to the facial, while the posterior, joining with the posterior auricular, forms 
the external jugular. Occasionally it passes entirely to the external 
jugular, which then usually, at its upper end, either gives to or receives 
from the lower end of the facial a communicating branch. 
The temporal vein is formed immediately above the zygoma by the junction 
of a trunk formed by the union with one another of anterior and posterior 
superficial branches with a deep or middle temporal. The radicles of the 
superficial branches ramify over the lateral part of the scalp and com- 
municate with the vessels in front and behind, and those of the other 
side; those of the deep branch, which pierces the temporal fascia, 
communicate with the deep temporal and orbital veins. The temporal 
vein crosses the zygoma behind and superficial to the arter}*-, and 
unites opposite the neck of the jaw with the internal maxillary vein. It 
receives anterior auricular, glandular, articular, and transverse facial branches. 
The internal maxillary vein, a short trunk, passes backwards, under cover of 
the ramus of the jaw, from the pterygoid plexus, and joins the temporal vein. Superior thyroid 
Anterior jugular 
Fia. 353. Superficial Veins of the Head and Keck. 1, Frontal; 2, superficial 
parietal veins communicating with frontal, temporal, and occipital; 3, occipital; 4, 
superficial temporal; G, posterior auricular; 7, angular; 8, facial; B', 10, connections 
between facial and temporal veins ; 9, external jugular; 11, lingual; 14, external carotid 
artery ; 15, internal jugular ; IG, pneumogastric nerve. (L. Testut.) 
To face p. 472. Fia. 351,—Veins of the Diplok. The outer table of the cranial wall has been removed, 
(L. Testut.) 
Falx cerebri 
Superior longitudinal sinus 
Crista galli 
( Torcular 
( Herophili 
Lateral sinus 
Internal jugular vein 
Fig. 355.—The Venous Sinuses of the Cranium. 3, Tentorium; 5, inferior longi- 
tudinal sinus; 6, straight sinus: 7, vena magna Galeni ; 10, superior petrosal sinus ; 
10', place of junction of superior petrosal with lateral sinus; 11, cavernous sinus; 12, 
circular sinus ; 15, Gasserian ganglion. (L. Testut.) 
To face p. 473. VEINS OF THE HEAD AND NECK. 
473 
The pterygoid plexus surrounds the pterygoid muscles. It is formed of 
vessels which correspond to the branches of the internal maxillary artery, 
viz., middle meningeal, inferior dental, tympanic, pterygoid, deep 
temporal, superior dental, palatine, spheno-palatine, and infraorbital 
veins. It communicates above with the ophthalmic veins and the 
cavernous sinus, anteriorly with the facial vein, and below with the 
pharyngeal plexus. 
The Veins of the Cerebrum. 
The veins of the cerebrum are divided into superficial and deep sets. 
Some of the superficial veins of the inner surface of the hemisphere 
enter the trunks of the deep veins. 
The superficial veins. Those from the superior part of the hemispheres, 
ten to twelve in number on each side, pass to the superior longitudinal 
f Septum 
1 lucidum and 
I fifth ventricle 
f Nucleus 
\ caudatus 
f Anterior 
-[ pillars of 
( the fornix 
Vein of theh 
corpus J- 
striatum J 
Vein of Galen 
Choroid plexus 
(Velum inter- 
( positum 
Corpus callosum 
f Posterior 
--! pillars of 
I fornix 
Fig. 356.—The Velum Interpositum and the Veins of Galen. (Beaunis.) 
sinus; those from the inferior regions pass to the cavernous, superior petrosal, 
and lateral sinuses. Among the superficial veins, one, the superficial Sylvian 
°r middle cerebral vein, of comparatively large size, overlying the Sylvian 474 
THE VASCULAE SYSTEM. 
fissure, enters the cavernous sinus anteriorly, and is connected posteriorly, 
through superior and posterior anastomotic veins, with the superior longitudinal 
and lateral sinuses respectively. The superficial cerebral veins anastomose 
freely with one another. 
The deep cerebral veins enter the veins of Galen, two trunks which run 
backwards side by side between the layers of the velum interpositum, and 
eventually join with one another to form the vena magna Galeni, a short stem 
which enters the straight sinus. Each vein of Galen (Fig. 356) is formed 
in the neighbourhood of the foramen of Monro by the junction of two 
vessels, namely, (a) the choroid vein, a vessel which ascends and passes 
forwards in the choroid plexus of the lateral ventricle, and (h) the vein 
of the corpus striatum, which runs forwards in the groove between the optic 
thalamus and corpus striatum, receiving branches from both. Passing 
backwards the veins of Galen are joined by branches from the optic 
thalamus, the choroid plexus of the third ventricle, the corpus callosum, 
and the corpora quadrigemina. Near its termination each vein receives 
a large branch, the basilar vein, which, commencing in front near the 
anterior perforated space by the junction of some anterior cerebral veins, 
from the under surface of the orbital region, with the deep Sylvian 
vein, from the island of Red, runs backwards, receiving on its way inferior 
veins of the corpus striatum, emerging from the anterior perforated spot, 
and a number of tributaries from the region of the tuber cinereum, from 
the inner surface of the parietal and occipital lobes, and from the mid-brain. 
Some superior cerebellar veins join the vena magna Galeni. 
Cerebellar veins. From the upper surface of the cerebellum branches 
pass to the great vein of Galen, and to the straight, lateral, and superior 
petrosal sinuses; the branches from the under surface pass to the lateral, 
inferior petrosal, and occipital sinuses. 
The Veins of the Orbit. 
The common ophthalmic vein (Fig. 357) is a short trunk which commences 
in the posterior part of the orbit, being formed by the union of the superior 
and inferior ophthalmic veins ; it passes backwards between the heads of 
the external rectus muscle, below the entering nerves, and through the 
inner part of the sphenoidal fissure, to terminate in the anterior extremity 
of the cavernous sinus. 
The superior ophthalmic vein commences in front in connection with 
the supraorbital, frontal, and angular veins, and passes backwards, 
crossing above the optic nerve in front of the ophthalmic artery, 
receiving as it goes the upper muscular, anterior and posterior ethmoidal, 
lachrymal, anterior ciliary, upper posterior ciliary veins, and the central 
vein of the retina. 
The inferior ophthalmic vein, taking origin from the union of some of 
the lower muscular veins with the lower posterior ciliary veins, passes VEINS OF THE HEAD AND NECK. 
475 
backwards along the floor of the orbit, and communicates freely with the 
pterygoid plexus, in which it sometimes ends. 
The tributaries of the ophthalmic veins correspond to the branches of 
the artery. The veins from the eyeball are the anterior and posterior 
ciliary veins. The anterior ciliary veins correspond to and accompany the 
anterior ciliary arteries. The posterior ciliary veins are four in number, 
and emerge from the sclerotic, a little behind the middle of the globe. 
The Veins of the Diploe. 
The veins of the diploe (Fig. 354) run in the cancellated bony tissue 
which lies between the outer and inner tables of the skull. They may 
be divided into frontal, parietal, and occipital sets. The frontal veins open 
partly into the supraorbital vein, and partly into the cavernous sinus. The 
'parietal veins partly end in the deep temporal veins, and partly in the 
superior petrosal and lateral sinuses. The occipital veins terminate in the 
lateral sinus, and in the veins which ramify externally on the surface of 
the occipital region of the skull. 
The Venous Sinuses of the Cranium. 
The venous sinuses are channels within the substance of the dura 
mater, possessing a delicate lining membrane continuous with that of the 
veins. ' They communicate at certain spots with the external veins by 
small perforating vessels which are sometimes called “the emissary veins 
of Santorini.” They receive the blood from the cerebrum and cerebellum, 
the orbit and eye-ball, and to a small extent from the meninges and 
diploe. They terminate in the internal jugular vein. 
The superior longitudinal sinus (Fig. 355), triangular in section with the 
apex downwards, commences at the crista galli, and, gradually increasing in 
size, extends backwards along the middle line to the internal occipital 
protuberance, where, turning sharply to the right, it becomes continuous 
with the right lateral sinus. Its lumen is at many places interrupted 
by transverse fibrous bands (the cords of Willis), and Pacchionian bodies 
here and there project into it. It receives the superior cerebral veins, 
most of which pass into it from behind forwards, a direction opposed to 
that of the current of blood within it. Some meningeal branches from 
the falx likewise enter it. In many cases it communicates through the 
parietal foramen with the veins of the scalp, and in early life constantly 
through the foramen caecum with those of the nose. Occasionally it 
terminates in the left lateral sinus. 
The inferior longitudinal sinus or vein (Fig. 355), a slender channel, 
receiving usually some branches from the falx, runs backwards in the 
free margin of the falx and terminates in the straight sinus. 
The straight sinus (Fig. 355), triangular in section with the apex upwards, 476 
THE VASCULAR SYSTEM. 
runs backwards and downwards on the surface of the tentorium along the 
line of attachment of the falx. It commences in front at the junction 
of the inferior longitudinal sinus with the vena magna Galeni from the 
velum interpositum, and terminates behind, usually in the left lateral 
sinus, occasionally in that of the right side. It receives lateral branches 
from the upper surface of the cerebellum and from the tentorium. 
The lateral sinuses (Figs. 352, 357) commence at the internal occipital pro- 
tuberance, where they are connected transversely across the middle line, a 
confluence, the torcular Herophili, being formed between them and the termina- 
tions of the superior longitudinal and straight sinuses. Each passes outwards 
on the occipital bone as far as the inferior angle of the parietal, crossing 
which it is slightly arched upwards; it then bends sharply, and is directed 
downwards and inwards on the inner surface of the mastoid ; it finally 
turns forward on the jugular process of the occipital bone to the jugular 
foramen, in the posterior part of which it becomes continuous with the 
internal jugular vein. It receives, just as it is bending downwards, the 
superior petrosal sinus; a little lower, the mastoid perforating vein which 
connects it with the occipital vein enters it; near its termination it is usually 
connected with the occipital sinus, and occasionally through the posterior 
condylar foramen with the suboccipital plexus. Lateral branches pass to it 
from the temporal lobe of the brain, the cerebellum, the medulla and pons, 
and from the posterior veins of the diploe. The transverse portion of each 
sinus runs along the attachment of the tentorium. The sinus of the right 
side, continued, usually, from the superior longitudinal sinus, is commonly 
larger than that of the left, which in most cases carries the blood of the 
straight sinus. The position of the sinus may be marked externally by a 
line drawn from the external occipital protuberance to the base 
of the mastoid process, and then bent downwards towards the tip of the 
process. In some cases a small sinus, the petrosquamous sinus, passes 
forwards from the lateral sinus along the line between the petrous and 
squamous portions of the temporal bone. It represents the terminal 
portion of the lateral sinus of the very early embryo, in which the blood 
from the cranial cavity passed through a foramen in front of the ear to 
the primitive jugular (external jugular) vein. 
The occipital sinus (Fig. 357), a small channel, ascends to the torcular 
Herophili along the line of attachment of the falx cerebelli. It commences 
at the sides of the foramen magnum and is usually connected with one 
or both lateral sinuses. It communicates with the posterior intraspinal 
veins, and frequently, through the anterior condylar foramen, with the 
vertebral and anterior spinal veins. 
The cavernous sinuses (Fig. 357) lie on each side of the body of the 
sphenoid bone, extending backwards from the sphenoidal fissure to the 
apex of the petrous bone. Their cavities are broken up into a number of 
intercommunicating spaces by delicate interlacing bands. They communi- 
cate, across the middle line, with one another by branches in front of, VEINS OF THE HEAD AND NECK. 
477 
behind, and occasionally also below the pituitary body, which together are 
named the circular sinus-, and a small lateral projection of each, outwards 
beneath the small wing of the sphenoid, is sometimes named the spheno- 
parietal sinus. They receive the ophthalmic veins, some lateral tributaries 
from the frontal lobes, the superficial Sylvian veins, and some anterior 
meningeal veins, and their blood passes backwards in the superior and 
inferior petrosal sinuses. Each cavernous sinus communicates with the 
pterygoid plexus of its own side through the ophthalmic vein and through 
the slender Yesalian vein, which passes through a small foramen in the 
great wing of the sphenoid. Communicating branches also pass through 
the foramen lacerum medium and the carotid foramen to the pharyngeal 
plexus and the internal jugular vein. In the outer wall of the sinus the 
third and fourth nerves, and the ophthalmic division of the fifth nerve 
run forwards; and through the sinus, covered only by the thin lining 
membrane, the internal carotid and the sixth nerve pass. 
The superior petrosal sinuses (Fig. 357), narrow channels, run backwards 
from the posterior extremities of the cavernous sinuses to the lateral 
sinuses. Each sinus lies on the upper border of the petrous bone, along 
the attachment of the tentorium, and receives veins from the tympanum, 
the temporal lobe of the brain, and the cerebellum. 
The inferior petrosal sinuses (Fig. 357), shorter but of greater diameter 
than the superior, pass backwards from the extremities of the cavernous 
sinuses. Each runs along the posterior margin of the petrous bone, 
and passes through the anterior compartment of the jugular foramen to 
end in the bulb of the internal jugular vein. Between the sinuses of 
opposite sides there stretches a plexus of intercommunicating veins which 
lies upon the basilar process, and is connected with the anterior intra- 
spinal veins; it receives the name of basilar or transverse sinus. The 
inferior petrosal sinus receives veins from the internal ear, the medulla 
and pons, and the cerebellum. 
The communications between the intracranial and extracranial venous 
channels. The cavernous sinus is placed in communication by the upper 
division of the ophthalmic vein with the frontal, nasal, and angular veins, 
and by the lower division of the ophthalmic vein, the Yesalian vein, 
and one or two small veins traversing the foramen ovale, with the 
pterygoid plexus. It is further connected with the pharyngeal plexus by 
branches which pass through the foramen lacerum medium, and with 
the internal jugular vein by a minute plexus surrounding the internal 
carotid artery. The lateral sinus communicates, by means of the mastoid 
vein, with the occipital or posterior auricular vein, and occasionally also 
a vein which occupies the posterior condylar foramen it is con- 
nected with the vertebral veins. The basilar sinus communicates with 
the anterior intraspinal veins; the occipital sinus is connected with the 
posterior intraspinal veins, and through the anterior condylar foramen with 
the vertebral and extraspinal veins. Occasionally a minute vein passes 478 
THE VASCULAR SYSTEM. 
from the torcular Herophili to one of the tributaries of the occipital vein. 
The superior longitudinal sinus communicates in many cases through the 
parietal foramen with the radicles of the temporal vein, and in the child 
through the foramen caecum with the veins of the nose. 
THE SPINAL VEINS. 
The spinal veins form a complicated plexus of vessels which may be 
subdivided into separate groups as follows, viz., the veins of the spinal 
cord, the veins of the vertebral bodies, the anterior and posterior extra 
spinal veins, and the anterior and posterior intraspinal veins. 
The veins of the spinal cord ramify in the pia mater, and are disposed 
as anterior, lateral, and posterior longitudinal trunks, and a network of 
branches communicating above with the veins of the medulla. Laterally 
branches pass outwards on the nerve roots, and are connected with offsets 
of the intraspinal veins. 
The veins of the vertebral bodies (Fig. 358) are accompanied by minute 
arteries, and ramify in the cancellous tissue of the bones; they communi- 
cate in front with the anterior extraspinal veins, and behind empty them- 
selves into the anterior intraspinal veins. 
The anterior extraspinal veins (Fig. 358), best developed in the neck, 
form a plexus of small branches on the anterior surface of the spinal 
column. They communicate below with the plexus in front of the sacrum, 
and laterally are connected, according to the region, with the vertebral, 
dorsal, or lumbar veins. 
The posterior extraspinal veins form a plexus which rests upon the 
laminae and the articular and spinous processes, and receives deep and 
superficial tributaries from the back. Frequently the superficial veins of 
the back are connected with one another by a slender median anastomosing 
vessel. The plexus communicates anteriorly, by branches which pierce the 
ligamenta subflava, with the intraspinal plexus, and laterally, according to 
the region, Avith the vertebral, dorsal, lumbar, or lateral sacral veins. 
The anterior intraspinal veins (Fig. 358) are lavo long trunks running the 
Avhole length of the canal, placed one on each side of the posterior common 
ligament of the bodies. Opposite the bodies of the vertebrae each trunk 
is somewhat dilated, and communicates Avith its felloAV by a transverse 
branch Avhich crosses in front of the posterior common ligament, and 
receives the veins of the vertebral body. Above, they are connected with 
the basilar plexus of veins ; lateral offsets accompany the nerves in the 
intervertebral foramina. 
The posterior intraspinal veins, one on each side of the middle 
line, lie in front of the laminae, and are connected Avith one another by 
numerous transverse branches. From behind they receive the perforating 
branches of the posterior extraspinal plexus. Above they communicate 
Avith the occipital sinuses, and, along with the anterior intraspinal veins Fig. 358.—A, Horizontal section of the spinal cord in the lower dorsal region, showing 
the spinal veins ; B, vertical antero-posterior section, a, Spinous process ; b, transverse 
process; c, vertebral body; d, spinal canal: 1, anterior extraspinal veins; 2, posterior 
extraspinal veins ; 2', connecting branch between intraspinal and extraspinal veins ; 
3, anterior intraspinal veins; 4, posterior intraspinal veins ; 5, veins of the vertebral 
bodies ; 6, intercostal vein. (L. Testut.) 
Fig. 357.—The Venous Sinuses of the Base of the Skull. 1, Ophthalmic 
vein; 2, cavernous sinus; 3, circular sinus; 4, transverse or basilar sinus; 5, 
superior petrosal sinus; 6, occipital sinus; 7, lateral sinus; 8, straight sinus; 
9, inferior petrosal sinus; 10, superior longitudinal sinus ; 11, anterior condylar 
veins; 12, middle meningeal vein; 13, internal carotid artery; 14, vertebral 
arteries. (L. Testut.) 
10 
To face p. 478. External jugular vein Internal jugular vein 
Right lymphatic duct 
Thoracic duct 
1, Aorta 
2, Superior vena cava 
3, Left innominate vein 
3', Right innominate vein 
Right superior inter- 
costal vein 
/ Left superior intor- 
\ costal vein 
Great azygos vein 
Thoracic duct 
Great azygos vein 
Left lower azygos vein 
10, Right ascending 
lumbar vein 
10', Left ascending 
lumbar vein 
Receptaculum chyli 
Fig. 359.—The Intercostal Veins and the Azygos Veins. (L. Testut.) 
To face p. 479. VEINS OF THE THORAX. 
479 
and the basilar plexus, take part in forming a venous ring at the foramen 
magnum. Laterally they are connected by their branches with the veins of 
the cord and with offsets from the anterior intraspinal vessels. The intra- 
spinal veins lie between the dura mater and the walls of the spinal canal. 
THE VEINS OF THE THORAX. 
The internal mammary veins (Fig. 351) are two trunks which lie one 
on each side of the artery. In the first or second intercostal space they 
join with one another to form a single vessel, which is placed by the 
inner side of the artery, and falls into the innominate vein of its own side. 
The intercostal veins (Fig. 359) are eleven in number on each side. 
Each vein lies above its companion artery, and receives tributaries corre- 
sponding to its branches. With the exception of one or two of the higher 
vessels on each side, the intercostal veins, in their passage inwards, 
cross behind the cords of the sympathetic. On the right side the first 
intercostal vein ascends by the side of the superior intercostal artery, and 
terminates in the vertebral vein. The veins of the second, third, and 
fourth spaces usually join with one another to form a descending trunk, 
the right superior intercostal vein, which falls into the vena azygos major 
as it is arching over the root of the lung. The lower veins terminate 
separately in the great azygos vein. On the left side the first intercostal 
vein, like that of the right side, ascends to the vertebral vein. The 
second, third, fourth, and frequently one or two more, fall into an 
ascending trunk, the left superior intercostal vein which crosses the arch 
of the aorta, and joins the left innominate vein. Still lower, two or 
three veins cross the middle line and enter the great azygos vein either 
separately or by a common trunk, the left upper or third azygos vein, which 
is frequently connected with the lower end of- the left superior intercostal 
vein. The lowest three or four veins of the left side open into the left 
lower or smaller azygos vein. 
The azygos veins (Fig. 359). The great or right azygos vein commences 
ln the abdomen, as the ascending lumbar vein, a vessel which ascends in 
front of the transverse processes and connects the successive lumbar 
veins with one another, and which, in addition, is usually connected 
with the common iliac vein, the inferior cava, and the renal vein by 
tranches, any one of which may become enlarged and appear as the root 
of the azygos vein. The great azygos vein ascends through the aortic 
°pening, and continues its course upwards on the vertebral column lying 
to the right of the aorta and the thoracic duct. About the level of the 
fifth dorsal vertebra it leaves the spine and arches over the root of the right 
11llllng to fall into the superior vena cava. It receives the first lumbar vein 
of the right side and all the right intercostal veins except the first, the right 
bronchial vein and some oesophageal branches, and, in addition, through 
the left 
azygos veins, a number of the intercostal veins of the left side. 480 
THE VASCULAR SYSTEM. 
The left lower or smaller azygos vein takes origin in the abdomen in 
a manner similar to that of the great azygos. It passes through the left 
crus, and ascends upon the spine as far as the seventh or eighth dorsal 
vertebra, where it crosses behind the aorta and thoracic duct to fall into 
the great azygos vein. It receives some oesophageal branches, the first 
left lumbar, and three or four of the lower intercostal veins of its own side. 
The left upper azygos vein is formed by the junction of two or three 
of the left intercostal veins belonging to the middle of the series, and 
frequently communicates above with the left superior intercostal vein. 
It falls into the great azygos or, sometimes, into the left lower azygos vein, 
but is very variable, and is often absent altogether. 
The bronchial veins accompany the corresponding arteries; that of the 
right side terminates in the great azygos vein, that of the left falls into 
the left upper azygos, or the left superior intercostal vein. 
THE VEINS OF THE ABDOMEN AND PELVIS. 
The inferior vena cava (Figs. 336, 360) commences under cover of the 
right common iliac artery at the level of the upper margin of the body of the 
last lumbar vertebra; it ascends with a slight inclination forwards, pierces 
the diaphragm, entering at the same time the pericardial cavity, and 
immediately afterwards terminates, opposite the lower border of the eighth 
dorsal vertebra, in the right auricle of the heart. Before passing through 
the diaphragm it lies in a deep groove on the under surface of the liver, 
lower down it rests upon the right crus, still lower it lies by the right 
side of the aorta upon the vertebral column. On its deep surface the 
right lumbar, renal, suprarenal, and inferior phrenic arteries pass outwards; 
the solar plexus lies behind it; it is crossed superficially by the right 
spermatic artery, the mesentery, the duodenum and pancreas, and the 
portal vein. It is formed by the confluence of the two common iliac 
veins, and it receives as tributaries the lumbar, renal, inferior phrenic, and 
hepatic veins, and the right spermatic or ovarian, and right suprarenal. 
The lumbar veins accompany the lumbar arteries. The highest vein 
on each side usually falls into the azygos vein, the lower ones into the 
inferior cava, those of the left side crossing behind the aorta. On the 
deep surface of the psoas muscle, in front of the transverse processes, a 
vertically running vessel, the ascending lumbar vein, connects the successive 
trunks, and is continued above into the azygos vein; it communicates 
frequently with the renal vein, the common iliac, and the inferior 
cava. 
The renal veins (Fig. 360) fall into the inferior vena cava, and are placed 
in front of the renal arteries; that of the right side is a short trunk; that of 
the left, considerably longer, crosses in front of the aorta, and receives 
the left suprarenal and left spermatic veins, and occasionally the left 
inferior phrenic vein. Imperfect valves are found in the renal veins. Hepatic veins 
Inferior phrenic vein 
Oesophageal opening 
Inferior vena cava 
-Inferior phrenic artery 
Suprarenal vein 
Coeliac axis 
Renal vein 
Superior mesenteric artery 
Spermatic or ovarian vein 
Lumbar vein 
-Aorta 
Right common iliac vein 
■Psoas muscle 
Left common iliac vein 
Middle sacral artery 
External iliac vein 
Fig. 360.—The Inferior Vena Cava and the Abdominal Aorta. (0. Gegenbaur.) 
To face p. 480. Liver 
Gall bladder 
Stomach 
Splenic vein 
Spleen 
Left gastro-epiploic vein 
Small 
intestine 
Middle haemorrhoidal vein 
Inferior haemorrhoidal vein 
Fig. 361. The Portal System. 1, Portal vein ; 2, superior mesenteric vein ; 3, inferior 
mesenteric vein; 4, superior haemorrhoidal vein ; 6, right gastro-epiploic vein ;9, coron- 
ary vein of stomach ; 10. pyloric vein ; 11, cystic vein. (L. Testut.) 
To face p. 481. VEINS OF THE ABDOMEN AND PELVIS. 
481 
The spermatic veins ascend from the testicle, and are placed in front 
of the spermatic artery and vas deferens. They exhibit at first a plexi- 
form arrangement {pampiniform plexus). Within the inguinal canal the 
plexus is reduced to two or three vessels which, higher up, join with one 
another and form a single vein. The vein of the right side enters the 
inferior cava; that of the left falls into the left renal vein. 
The ovarian veins form a plexus {ovarian or pampiniform plexus) 
between the layers of the broad ligament, and communicate freely with the 
uterine veins. Higher up they behave like the spermatic veins. Valves 
are usually found at the terminations of the spermatic or ovarian veins, 
and imperfect valves are found in their branches. 
The suprarenal veins, one on each side, terminate on the right side 
in the inferior cava, and on the left side in the left renal vein. 
The inferior phrenic veins accompany the inferior phrenic arteries; the 
vein of the right side enters the inferior cava, that of the left falls 
into either the left renal or the inferior cava. 
The hepatic veins open directly into the inferior vena cava, as two or 
three large trunks and a number of smaller ones. They have no valves, 
but, as they enter the inferior cava obliquely, the lower margin of each 
forms a semilunar projection. 
The common iliac veins (Figs. 336, 360) are formed by the confluence 
of the external and internal iliac veins. Each vessel passes upwards and 
inwards from a point opposite the upper margin of the sacro-iliac articulation, 
and at the upper border of the fifth lumbar vertebra, a little to the right 
°f the middle line, unites with its fellow. The vein of the right side ascends 
behind the right common iliac artery, that of the left side is placed to the 
tight of the left common iliac artery, and at its termination lies behind 
the upper part of the right common iliac artery. The common iliac veins 
Usually contain no valves. They receive as tributaries the ilio-lumbar veins 
which accompany the ilio-lumbar arteries, and that of the left side also 
receives the middle sacral vein, a vessel which is formed by the union with 
one another of the two venae comites of the middle sacral artery. 
The internal iliac vein lies behind and to the inner side of the internal 
artery, and extends from the neighbourhood of the upper margin 
the great sacro-sciatic notch to the level of the upper part of the sacro- 
*bac articulation, where it unites with the external iliac vein. It contains 
rio valves. It receives tributaries corresponding to all the branches of the 
internal iliac artery, except the ilio-lumbar, the vein accompanying which, 
111 ordinary circumstances, terminates in the common iliac vein. By the 
free communication of the venous radicles which unite to form the tribu- 
taries of the internal iliac veins, several intercommunicating plexuses are 
formed in the pelvis. 
The anterior sacral plexus is formed upon the front of the sacrum by 
fbe tributaries of the middle sacral and lateral sacral veins. It communicates 
With the spinal veins and with the haemorrhoidal plexus. 482 
THE VASCULAR SYSTEM. 
The haemorrhoidal plexus lies immediately under the mucous membrane 
of the lower part of the rectum, and communicates in front with the 
vaginal or prostatic plexus. The veins which pass from it are the 
superior haemorrhoidals of the portal system, the middle haemorrhoidals 
passing to the internal iliacs, and the inferior haemorrhoidals joining 
the pudics. 
The vaginal plexus surrounds the lower part of the vagina; it receives 
branches from the vagina and from the uterus, but the latter veins have 
also a free connection with the pampiniform plexus, formed between the 
layers of the broad ligament by the ovarian veins. 
The vesical plexus surrounds the whole bladder, lying under cover of the 
peritoneal coat. Vesical veins pass from it to the internal iliac veins; and 
it communicates below with the vaginal or prostatic plexus. 
The prostatic plexus surrounds the base and sides of the prostate gland, 
and is covered by the sheath from the recto-vesical fascia; it communicates 
above with the vesical plexus, and receives from the front the dorsal vein 
of the penis. 
The dorsal vein of the penis, a single median vessel, commences in a set 
of veins which form a circle round the base of the glans. It passes back- 
wards along the dorsum of the organ, receiving both superficial and deep 
branches. At the base of the penis it gives off on each side a slender 
branch of communication to the pudic veins, and is then continued back- 
wards through the triangular ligament to the prostatic plexus. 
The internal pudic veins. Two small venae comites accompany the pudic 
artery and terminate in the internal iliac vein. They receive veins from the 
corpus cavernosum and the bulb, and the perineal and inferior haemorrhoidal 
veins. 
The obturator, sciatic, and. gluteal veins fall into the internal iliac vein. 
The external iliac vein (Fig. 360) extends from the level of Poupart’s 
ligament to a spot opposite the sacro-iliac articulation, where it unites with 
the internal iliac vein. Below it is internal to the artery; higher up it 
is internal and posterior to it. It usually contains one or two valves. It 
receives as tributaries the deep epigastric and deep circumflex iliac veins, vessels 
which accompany the similarly named arteries. 
THE PORTAL SYSTEM OF VEINS. 
The veins from the abdominal and pelvic portions of the intestinal 
canal and those from the spleen, pancreas, and gall bladder carry their 
blood to the portal vein, a vessel which enters the liver, and there ramifies 
like an artery, its capillaries, along with those of the hepatic artery, 
eventually opening into the hepatic veins. In the adult there are no 
valves in the portal vein nor in any of its tributaries. 
The portal vein (Fig. 361), about three inches in length, commences at 
the confluence of the superior mesenteric and splenic veins, behind the THE FOETAL SYSTEM OF VEINS. 
483 
pancreas and immediately in front of the vena cava inferior, a little to the 
right of the middle line. It ascends behind the first part of the duodenum 
and enters the small omentum, between the folds of which, lying behind 
the hepatic artery and bile duct, it passes towards the transverse fissure 
of the liver. At its termination it becomes somewhat swollen, and divides 
into right and left branches, which pass to the respective lobes, that 
for the right being shorter and thicker than that destined for the 
left ; the left branch, in addition, partly supplies the quadrate and 
Spigelian lobes. The left branch of the portal vein is connected posteriorly 
with a solid cord, the remains of the ductus venosus, and anteriorly with 
the round ligament of the liver, the remains of the umbilical vein. The right 
branch is joined by the cystic vein. The trunk of the portal vein receives the 
coronary vein of the stomach and, a little lower, the pyloric vein, both of which 
correspond to the similarly named arteries. 
The superior mesenteric vein is the companion of the superior mesenteric 
artery, to the right and in front of which it is placed. In addition to 
branches wTiich correspond to those of the artery it receives near its upper 
extremity the right gastro-epiploic vein. It crosses in front of the third part 
of the duodenum, and terminates behind the pancreas in the portal vein. 
The splenic vein lies immediately below the splenic artery, and receives, 
in addition to branches which correspond to those of the artery, the 
inferior mesenteric vein, which, ascending from below, joins it near its 
termination in the portal vein. 
The inferior mesenteric vein passes upwards, at first, on the left side 
of the inferior mesenteric artery; afterwards, ascending beyond the level 
of the place of origin of the artery, it is continued with an inward 
inclination behind the pancreas, and terminates in the splenic vein. Its 
branches correspond to those of the artery; those which are lowest in 
position, the superior haemorrhoidal, take origin in the haemorrhoidal plexus, 
where they freely communicate with the middle and inferior haemorrhoidal 
veins. The plexus lies immediately under the mucous membrane of the 
lower part of the rectum. 
The veins of the limbs are divided into two groups, deep and super- 
ficial in position, freely communicating with one another. They are all 
provided with valves, but these are more numerous in the deep than in 
the superficial veins, and in those of the lower than in those of the 
upper limb. The deep veins accompany the arteries, and, as a rule, 
need no detailed description; but the superficial veins have mostly no 
arteries corresponding to them, and form plexuses on the surface of the 
fascia, more particularly at the distal extremities of the limbs. 
THE VEINS OF THE LIMBS. 484 
THE VASCULAR SYSTEM. 
Veins of the Upper Limb. 
The superficial veins of the hand (Fig. 362). Although in each finger a 
couple of minute venae comites accompany each digital artery, the 
greater part of the returning blood passes through the meshes of a sub- 
cutaneous plexus to a couple of superficial dorsal veins. Above the clefts of 
the fingers the dorsal vessels from the contiguous sides of the neighbouring 
digits unite with one another, and the resulting trunks, passing upwards, 
enter on the back of the hand a large irregularly disposed plexus. From 
the outer border of the plexus the radial vein is prolonged, and from 
the inner border the posterior nlnar vein takes origin, and to a slight 
extent also the anterior ulnar. A number of small veins from the 
palm of the hand and the thenar eminence converge to form the median 
vein; a few branches from the inner side of the palm join the 
anterior ulnar vein. Numerous small communicating branches connect 
the deep and superficial veins of the palm. 
The superficial radial vein commences in the outer part of the dorsal 
plexus, and courses upwards along the outer border of the forearm, 
receiving numerous superficial tributaries. A little above the elbow, on 
the outer side of the biceps muscle, it unites with the median cephalic to 
form the cephalic vein. It communicates below with the deep veins of 
the palm, and higher up with the deep radial veins. 
The posterior superficial ulnar vein, arising from the inner extremity 
of the dorsal plexus, passes upwards on the posterior aspect of the fore- 
arm, receiving numerous tributaries which communicate with those of the 
radial and anterior ulnar veins. Below the elbow it is joined by the 
anterior ulnar vein, and a little above the level of the joint it unites, on 
the inner side of the biceps muscle, with the median basilic to form the 
basilic vein. A considerable communicating branch passes between the 
lower part of the vein and the deep ulnar veins. 
The anterior superficial ulnar vein, smaller than the posterior, which it 
joins a little below the elbow, commences near the wrist, and ascends 
along the ulnar border of the forearm. Its tributaries communicate freely 
with those of the veins on either side of it. 
The superficial median vein (Fig. 363) ascends along the front of the 
forearm. At the hollow of the elbow it is joined by the deep median vein> 
a large communicating branch from the ulnar and radial venae comites. 
The resulting trunk immediately divides into the median cephalic and 
median basilic veins. The tributaries of the median vein are derived from 
the palm of the hand and the front of the forearm, and communicate 
freely with those of the neighbouring superficial trunks. 
The median cephalic vein passes upwards and outwards to join the 
superficial radial vein. The median basilic vein passes upwards and 
inwards to join the posterior superficial ulnar vein; it rests behind on 
the semilunar fascia of the biceps, which separates it from the brachial Posterior superficial) 
ulnar vein ) 
. Superficial radial vein 
Branch to anterior ) 
superficial ulnar vein ( 
Commencement of ) 
posterior ulnar vein ) 
j Commencement of 
\ superficial radial vein 
Dorsal plexus i 
3, 
Dorsal plexus 
1, Superficial digital veins 
■Digital plexus 
Fig. 362.—The Superficial Veins of the Back of the Hand. (L. Testut.) 
To face p. 484. Cephalic vein 
.Inner brachial vena comes 
iasilic vein 
Median basilic vein 
.Deep median vein 
Median vein 
Fig. 363.—The Superficial Veins of the Upper Limb. (C. Gegenbanr.) 
To face p. 485. THE VEINS OF THE LIMBS. 
485 
artery. Although the superficial trunks of the arm, on account of the 
free anastomoses between their tributaries, are subject to many variations, 
yet a considerable vein will almost constantly be found in the position of 
the median basilic. For this reason, despite its proximity to the main 
artery, the median basilic vein was in the past, when blood-letting was 
a more fashionable procedure than it is now, usually selected for the 
operation of venesection. 
The basilic vein (Fig. 363) ascends on the inner side of the biceps; 
about the middle of the arm, after passing through the deep fascia, it 
terminates by joining the inner of the two brachial venae comites. 
The cephalic vein (Fig. 363) ascends at first on the outer side of the 
biceps, and afterwards in the groove between the deltoid and pectoralis 
major muscles to a spot a little below the clavicle, where, passing deeply, 
it crosses the first part of the axillary artery, pierces the costo-coracoid 
membrane, and terminates in the axillary vein. Occasionally the cephalic 
vein is prolonged over the clavicle to terminate in the external jugular or 
subclavian vein, and even when the termination is normal, a considerable 
branch is sometimes found passing upwards in front of the collar bone. 
A vessel in this position might be divided by the surgeon in making the 
cutaneous incision in the operation for ligature of the third part of the 
subclavian artery. Both basilic and cephalic veins receive small tributaries 
from the arm. 
The deep veins of the upper limb. Each artery below the axillary 
18 accompanied by two venae comites. The axillary vein ascends by the 
inner side of the axillary artery; in addition to the tributaries, which 
correspond to the branches of the artery, it receives the cephalic vein ; 
it is frequently double in the lower part of the axilla, and occasionally 
m its whole course. 
Veins of the Lower Limb. 
The superficial digital veins pass backwards to a venous arch on 
the dorsum of the foot, those of the plantar surface ascending behind 
the clefts of the toes to join the larger dorsal vessels. The superficial veins 
°f the sole are small but numerous; the anterior vessels reach the 
dorsum along with the plantar digital veins, the posterior turn round the 
sides of the foot to join the dorsal arch. The dorsal venous arch, of con- 
siderable size but very irregular in disposition, lies upon the instep; it 
receives digital, dorsal, and plantar tributaries, and posteriorly is continued 
into the external and internal saphenous veins. Between the clefts of the 
foes, on the dorsum, and at the sides of the foot there are numerous 
communications between the deep and superficial veins. 
The external saphenous vein (Fig. 365), from the outer side of the dorsal 
fr°hj passes behind the external malleolus and ascends with an inward 
inclination upon the back of the leg to the lower part of the popliteal 
space, where, after perforating the deep fascia, it enters the popliteal vein. 486 
THE VASCULAR SYSTEM. 
It receives numerous superficial tributaries from the outer side of the foot, 
and from the outer and posterior region of the leg, and a number of 
communicating branches from the deep veins. Near its termination a 
communicating branch, sometimes so enlarged as to form the main con- 
tinuation of the vein, ascends on the back of the thigh to join the internal 
saphenous vein. 
The internal saphenous vein (Figs. 364, 371), from the inner extremity 
of the dorsal arch, passes in front of the internal malleolus, and ascends 
along the inner side of the leg; it bends backwards behind the inner 
condyle of the femur, and, finally, passes upwards upon the front of 
the thigh as far as the lower part of the saphenous opening where, about 
an inch and a half from Poupart’s ligament, it falls into the femoral 
vein. It receives communicating branches from the plantar veins, the 
anterior and posterior tibial veins, and the deep veins of the thigh. 
Its tributaries are derived from the inner side of the foot, the inner and 
anterior region of the leg, the thigh, and the lower part of the abdominal 
Avail. Very frequently a vessel of considerable size joins it near its 
termination, ascending for some distance in front of the femoral artery in 
the lower part of Scarpa’s triangle. 
Deep veins of the lower limb. With the exception of the femoral, the 
deep femoral, and the popliteal, all the arteries of the lower limb are accom- 
panied by two companion veins. The popliteal vein is formed at the 
lower border of the popliteus muscle by the union with one another of the 
venae comites of the anterior and posterior tibial arteries. At the lower 
part of the space the \rein is internal to the artery, but as it ascends it 
crosses the artery posteriorly and becomes a little external to it above. 
Frequently the popliteal vein is double in the loAver part of the space, 
and occasionally in its whole course. 
The femoral vein, in Hunter’s canal, lies behind and a little external 
to the artery; at the apex of Scarpa’s triangle it is posterior to the 
artery; higher up it gains the inner side of the artery, and in this 
position passes behind Poupart’s ligament to be continued into the external 
iliac vein. In addition to tributaries which correspond to the branches of 
the artery, it receives the internal saphenous vein. The superficial circum- 
flex iliac, superficial epigastric, and superficial pudic veins join the internal 
saphenous vein. The deep femoral vein ascends in front of the deep 
femoral artery, and falls into the femoral vein in the upper part of 
Scarpa’s triangle. 
The Development of the Heart, 
The heart in man, and in mammals generally, makes its first appearance 
in the form of two tubes hollowed out of the splanchnic mesoblast on 
the ventral aspect of the alimentary canal, in the region of the head. 
Each tube is formed of a somewhat thickened outer wall of mesoblastic 
tissue, which becomes the muscular wall of the heart, and a delicate endo- Patella _ 
Internal saphenous vein 
Jnternal saphenous vein 
External malleolus 
Internal malleolus 
Internal saphenous vein 
Dorsal venous arch 
Fig. 364.—The Superficial Veins of the Leg and Foot, from the front. 
To face p. 486. Connecting branch between internal 
saphenous and external saphenous^ 
Y- 
Biceps 
Semitendinosus 
Popliteal vein 
External saphenous vein, 
External saphenous vein, 
Internal malleolus 
External malleolus 
Fio. 365.—The Superficial Veins of the Back of the Leg. (L. Testut.) 
To face p. 487. THE DEVELOPMENT OF THE HEART. 
487 
thelial layer. When the ventral closure of the alimentary canal takes place, 
the tubes of opposite sides are brought into contact, and coalesce to form a 
mesial tube. The upper end of the tube is continuous with two arterial 
vessels which, forming the first pair of arterial arches, take a dorsal direction 
on the sides of the alimentary canal, and are continued downwards as the 
primitive aortae. The lower end of the tube is continuous with the two 
vitelline veins which bring back the blood from the surface of the yelk sac. 
In elasmobranch fishes and amphibia, the heart does not begin to develop 
until after the splanchnic walls have met ventrally, and makes its appear- 
ance from the first as a single tube; in birds the tube is at first single 
Fig. 366.—Four Successive Stages in the Development op the Heart. 1, Arterial 
bulb ; 2, ventricle; 5, auricular portion ; G, veins entering the sinus venosus. (L. Testut.) 
ln front, but double behind. After the fusion has taken place the tube 
becomes divided by slight constrictions into four portions; of these the 
°ne nearest the head, the iulbus arteriosus, becomes the basal portion of 
the pulmonary artery and aorta, the next is the ventricular portion of 
the heart, the next the auricular, and the last forms the sinus venosus, 
a dilatation which at first receives all the veins, and afterwards becomes 
absorbed into the right auricle. While the successive portions are becoming 
differentiated from one another, the whole organ, growing more rapidly 
than the upper part of the body, and its arterial end being pushed 
away from the head, becomes bent upon itself. The curvature is at first 
S-shaped, the cephalic portion being bent to the right, the succeeding 488 
THE VASCULAR SYSTEM. 
portion to the left. Later, the curve is increased to a loop with the 
venous end dorsal to the arterial bulb, while the whole loop, projecting at the 
apex, is devoted to the ventricular part. 
By the subsequent changes the cavity of the heart is divided into right 
and left portions, and the orifices become guarded by A7alves. Although 
in passing from the lower to the higher forms of vertebrate life it is the 
auricular portion which is first subdivided, yet in the course of the develop- 
ment of the mammalian heart it is the ventricular septum which first 
makes its appearance. The ventricular septum commences at the apex and 
extends both towards the auricle and the arterial bulb; afterwards it 
becomes continuous with the septa which divide the bulb and the auricle 
into right and left portions; but the junction does not take place at once, 
and for some time during foetal life, and occasionally as an abnormality 
in the adult, there is left a passage over the border of the ventricular 
septum from one side of the heart to the other. The walls of the ventricle 
early become muscular, and the cavity is at first comparatively small, 
being encroached upon by projecting muscular bands which have a 
reticulated arrangement, a condition which continues to a much greater 
extent through life in forms lower than birds. 
The sinus venosus receives, in addition to the vitelline veins, the 
umbilical veins and the right and left ducts of Cuvier; and a little later 
the inferior vena cava joins the common orifice of the vitelline and 
umbilical veins. The opening of the sinus becomes shifted to the right 
portion of the common cavity, and is narrowed to a slit-like aperture 
guarded by prominent valvular folds. Eventually the sinus itself becomes 
absorbed into the right auricle, its anterior limit in the adult being 
marked by the sulcus terminalis of His. The right valvular fold of its 
orifice becomes the Eustachian valve at the opening of the inferior vena 
cava; the right duct of Cuvier persists as the superior cava, while the left 
undergoes atrophy, the portion of the sinus venosus into which it opened 
forming the coronary sinus. 
The common auriculo-ventricular aperture, at first transversely elongated, 
becomes divided into two by endocardial thickenings which, projecting 
from its anterior and posterior lips, eventually join one another, and 
fuse likewise with the ventricular septum. The connective tissue of 
these thickenings forms the greater part of the membranous portion 
of the ventricular septum. From these thickenings the septal valves 
of the orifices are also formed. The lateral valves take origin by a 
slight folding in of the wall of the heart in the region between auricles 
and ventricles, and are at first largely formed of muscular tissue, which, 
however, afterwards almost entirely disappears. The exact method of 
the development of the auricular septum is still a subject of controversy. 
It grows from the upper part of the cavity, and descends to the left of 
the venous openings to become connected with the endocardial thickenings 
which subdivide the auriculo-ventricular orifice, and through them with THE DEVELOPMENT OF THE HEART. 
489 
the ventricular septum. In the back part of the septum, an aperture, 
which forms the foramen ovale, is at first left, hut becomes subsequently- 
closed by a second septum. The left auricle becomes connected with the 
pulmonary veins in a manner which has not jmt been accurately determined. 
The auricular appendices appear very early as ventral projections from each 
side of the common auricle. 
The arterial bulb is divided into two stems by a septum which starts 
between the fourth and fifth arterial arches as two folds, one from each 
side of the vessel; these gradually meet one another, and are continued 
backwards in a spiral manner to join the ventricular septum. The 
channels which result from this division are ultimately completely 
separated and become the basal portions of the aorta and pulmonary artery. 
At the ventricular orifice of the bulb the segments of the valves are formed 
by endocardial projections. Before the common arterial orifice is subdivided 
there are four endocardial projections or cushions at its base; the right 
and left cushions increasing in size meet one another and, becoming con- 
tinuous with the septum, subdivide the orifice into two, each of which 
presents three endocardial projections. 
The heart is at first situated in the region of the head, but during 
development it is gradually shifted downwards until it assumes its per- 
manent position in the thorax. 
The Development of the Artepjes. 
In early embryonic life the bulbus arteriosus divides into two vessels 
which pass towards the head on the ventral aspect of the alimentary 
canal; springing from these the branchial arteries, forming a system of 
arterial arches, lie in series on the right and left sides of the alimentary 
canal, and fall into a couple of dorsal trunks which at first separately run 
the whole length of the body, but afterwards join with one another in the 
region below the heart and form there a single mesial vessel, the dorsal 
aorta. In fishes and amphibia, the arterial arches are connected with the 
gills; but in the higher forms, in which gills are never developed, the 
arterial arches pass dorsally at first in the successive branchial processes, 
and eventually partly disappear and partly give rise to the permanent 
vessels. There are five arches on each side in the embryos of all forms 
higher in the scale than the amphibia; but of these the first two, 
counting from the head, the mandibular and the hyoid arches, have 
°nly a transitory existence and disappear very early. 
In man the following changes take place: The portion of the dorsal 
longitudinal vessel, on each side, in the region between the third and 
fourth arches disappears. The portion above the third arch in which the 
current is directed towards the head forms part of the carotid system. 
Below the fourth arch two portions of the vessel may be recognized, viz., 
file aortic root and the mesial aorta, the latter being a common stem 490 
THE VASCULAR SYSTEM. 
formed by the union of the vessels of the opposite sides. The right aortic 
root disappears, the left forms a portion of the permanent aorta. 
The fifth arch of the right side disappears entirely; that of the left 
side gives off from its ventral extremity a branch to each lung, and its 
continuation towards the root of the dorsal aorta becomes the ductus 
arteriosus, a vessel which is patent during foetal life, but becomes in the 
adult a solid cord. When the bulbus arteriosus is divided by a septum 
into two channels, that which is connected with the right ventricle becomes 
continuous with the fifth left arch and forms the base of the pulmonary 
artery, while the other, connected with the left ventricle, becomes the 
ascending aorta 
Ventral longitudinal vessels 
Dorsal longitudinal vessel 
carotid portion 
Internal carotid 
Internal carotid 
Dorsal longitudinal vessel 
(portion which disappears) 
Subclavian, 
Dorsal longitudinal vessel 
aortic root 
Subclavian 
Right aortic root 
Intercostal artery 
Dorsal longitudinal vessel, mesial aorta 
Pie. 367.—Diagram to Illustrate the Development of the Larger Arteries. 
Ito 5, The primitive arterial arches. EC, External carotid; C'C, common carotid ; In, 
innominate; P, pulmonary; A, aorta ; DA, ductus arteriosus. (After Rathke.) (J. Y. M.) 
The fourth arch of the left side forms a portion of the arch of the aorta, 
and is continued by the left aortic root into the dorsal aorta. The left 
subclavian artery springs from the left aortic root near the place where 
the ductus arteriosus or fifth left arch enters. The ventral vessel of 
the right side, in the region below the fourth arch, becomes the innominate 
artery of the adult. The fourth arch of the right side persists as far 
as the place from which the right subclavian, corresponding in position 
to the left subclavian, springs, but its continuation beyond this as the 
right aortic root disappears. The fourth right arch is therefore represented 
in the adult by the basal portion of the right subclavian artery passing 
outwards from the innominate. THE DEVELOPMENT OE THE ARTERIES. 
491 
It is generally held, in accordance with Rathke, that in mammals the 
portions of the ventral vessels, which stretch from, the extremities of the 
fourth arches to the third, form the common carotid arteries, that the 
further continuations of these vessels towards the ventral extremities of the 
higher early disappearing arches form the external carotid arteries, and 
that the third arches themselves and the highest portions of the dorsal 
vessels continued from them form the internal carotid arteries. 
The fourth and fifth arterial arches, originally developed in the neck,, 
descend with the heart into the thorax. The inferior laryngeal nerves turn 
round the lowest arch on each side, and on account of the descent of the 
heart and vessels take, in the adult, a recurrent course. Most of the varieties 
in the arrangement of the branches of the aorta are to he explained simply 
by variations in the growth of the aortic arch, branches being either 
approximated to or conjoined with one another or unduly separated from 
one another. One variety, however, that in which the innominate artery is 
absent, and the right subclavian comes off as the last branch of the arch, 
is specially interesting from a developmental point of view. In this case the 
fourth arch of the right side, which normally persists as the basal portion 
of the right subclavian, has disappeared; while, on the other hand, the right 
aortic root, a portion of the dorsal longitudinal vessel which, in normal 
circumstances entirely disappears, has persisted as the basal portion of 
the subclavian artery. 
The Development of the Veins. 
The heart, in the earliest stage, is joined at its venous extremity by the 
right and left vitelline veins, which bring the blood from the vascular area of 
the yelk sac; they open separately into the sinus venosus. A little later, on 
the establishment of the placental circulation, the right and left umbilical veins 
enter the sinus in close proximity to the vitelline veins. From an early 
period also there enter the sinus the right and left ducts of Cuvier, each 
of which, a short transverse vessel, is formed by the junction of the 
primitive jugular vein from the upper part of the trunk with the cardinal 
vein which returns the blood from the Wolffian body and the lower part 
of the trunk. 
The portal system (Fig. 368). On the development of the liver the 
vitelline veins join with one another a little below the heart to form for 
a short distance a single vessel; between the single portion and the 
heart they break up into branches which, ramifying in the substance of 
the liver, become the venae advehentes and revehentes of the portal system. 
The veins from the intestinal canal join the single portion of the vitelline 
veins, which thus becomes the portal vein, and the original terminations 
of the veins in the sinus, continued from the venae revehentes, persist for 
a time as right and left hepatic veins. 
In the substance of the umbilical cord the umbilical veins join with 
one another very early to form a single vessel, but within the trunk they 492 
THE VASCULAR SYSTEM. 
remain distinct from one another. They soon lose their direct connection 
with the sinus and join the right and left branches, respectively, of the 
portal vein, and their blood passes to the heart through the liver. A 
little later the right umbilical vein disappears, and from the left, at the 
place of its connection with the left portal vein, a new trunk, the ductus 
venosus, passing upwards to the right hepatic vein, is developed, and 
carries the most of the blood from the placenta to the heart. The left 
hepatic vein, in turn, loses its connection with the heart and falls into 
Right duct of Cuvier __ 
Sinus 
venosus 
Left duct of Cuvier 
Right umbilical vein 
~ Left umbilical vein 
Vena cava inferior 
Left vitelline vein 
Right vitelline vein _ 
Venae revelientes (hepatic veins) 
Venae revehentes (hepatic veins) 
Ductus venosus 
Venae advehentes 
Venae advehentes 
Right umbilical vein 
/ Left umbilical vein 
\ (round ligament of liver) 
Jntestinal veins 
Right vitelline vein_ 
Portal vein 
Left vitelline vein 
Intestinal veins 
Pig. 368.—Diagram to Illustrate the Development of the Portal System of 
Veins. The original veins which remain permanent are represented in black, those 
which disappear in outline. Veins later in appearing are shaded. Veins which remain 
as impervious cords are dotted. (After His.) (J. Y. M.) 
the ductus venosus. With the development of the lower limbs the 
inferior vena cava appears, and joins the cardiac end of the ductus 
venosus. After birth, the left umbilical vein becomes a solid cord, the 
round ligament of the liver, passing to the left branch of the portal vein; 
from the posterior part of the left portal vein, the ductus venosus, which 
likewise becomes impervious, stretches to the inferior vena cava. 
The systemic veins (Fig. 369). The primitive jugular veins which receive 
the blood from the cranial cavity and form the upper branches £>f the ducts 
of Cuvier, represent in the adult the external jugular veins; they are joined 
near their cardiac extremities by the subclavian and internal jugular THE DEVELOPMENT OF THE VEINS. 
veins which are later of being formed. Between the primitive jugular 
veins of opposite sides, below the place of entry of the subclavian and 
internal jugular veins, there appears a transverse connecting branch. 
This transverse branch becomes the left innominate vein. The portion 
of the right primitive jugular on the distal side of the junction becomes 
the right innominate, the portion on the cardiac side and the right 
duct of Cuvier becomes the superior vena cava. Concomitantly with 
Left innominate 
Eight external jugular (primitive jugular) 
Internal jugular Internal jugular 
Left external jugular (primitive jugular). 
Right subclavian 
Left subclavian 
Right cardinal vein ) 
(great azygos vein) ) 
Right duct of Cuvier 1 
(superior vena cava)) 
Left duct of Cuvier 
Coronary sinus 
J Left cardinal vein 
( (left superior intercostal) 
Inferior vena cava 
f Left cardinal vein 
( (smaller azygos) 
Right renal vein 
Left renal vein 
Left spermatic 
Right spermatic 
Lumbar vein 
Right external iliac 
Left external iliac 
Right internal iliac 
Left internal iliac 
Fig. 369.—Diagram to Illustrate the Development of the Systemic Veins. The 
original veins which become permanent are represented in black. The portions which 
disappear are shown in outline. The veins which are developed later are shaded. The 
portions which remain as impervious cords are dotted. (After Hochstetter.) (J. Y. M.) 
the development of the left innominate vein, which carries the blood of 
the left side to the right duct of Cuvier, the left duct of Cuvier 
undergoes atrophy; its basal portion however remains as the coronary 
sinus and the oblique vein of the heart, and the remainder of it is 
represented partly by the delicate fibrous cord which lies in the vestigial 
fold of Marshall, and, probably, in part by the uppermost portion of the 
left superior intercostal vein. 494 
THE VASCULAE SYSTEM. 
The cardinal veins receive at first the blood from the Wolffian bodies 
and the lower part of the trunk. In their distal portions they remain 
as the internal iliac veins, and receive as branches the external iliac 
veins from the limbs. In the abdominal portion of their course the 
-cardinals at first receive the lumbar, spermatic, and renal veins, and, in 
the thoracic portion of their course, the intercostal veins. The inferior 
vena cava, developing from the heart, divides into two branches which 
unite with the right and left cardinal veins at the places of entry of the 
renal veins, and the new vessel to a large extent takes the place of the 
original trunks. The right branch of the two into which the inferior 
vena cava divides, with the portion of the right cardinal vein immediately 
below the place of junction, becomes the lower part of the main trunk of 
the permanent vena cava, namely, that portion which receives the right 
renal, right spermatic, and the lumbar veins; the portion of the right 
■cardinal vein beyond the lower extremity of the inferior vena cava, 
between it and the lowest portion of all, which becomes the internal iliac 
vein, is represented in the adult by the right common iliac vein. Above 
the right renal vein a small portion of the right cardinal either dis- 
appears altogether, or remains as a slender connection between the renal 
vein or the vena cava, on the one hand, and the great azygos vein on 
the other. The thoracic portion of the right cardinal vein becomes the 
great azygos vein. 
On the left side, a transverse branch passes from the upper ex- 
tremity of the left internal iliac vein to the right cardinal, and becomes 
the left common iliac vein. Above this, the abdominal portion of the 
left cardinal disappears, save probably for a small part at the origin 
of the left spermatic vein. The left branch of the vena cava becomes 
the basal portion of the left renal vein. Above this the left cardinal 
is again interrupted. The lower part of the thoracic portion of the left 
cardinal vein becomes the left ayzgos vein and, by the development 
of a transverse branch, passes its blood into the right cardinal vein. 
Above the position of the transverse branch a portion of the left cardinal 
vein is usually atrophied. The highest portion remains as the greater 
part of the left superior intercostal vein. 
The Circulation in the Embryo and Foetus. 
The vitelline or omphalo-mesenteric circulation. The earliest vessels 
which are developed in connection with the embryo are those of the 
vascular area; they are formed in the mesoblast of the splanchnic 
wall of the yelk sac. From the vascular area the blood is carried to the 
venous end of the heart by two vitelline veins, and, after passing through the 
heart and the primitive arterial arches, reaches the dorsal aorta. From 
the abdominal portion of the dorsal aorta two vitelline arteries, at first 
very large in comparison with the other branches, carry the blood to the CIRCULATION IN THE EARLY EMBRYO AND FOETUS. 
495 
vascular area. Within the area the arteries ramify and become connected 
peripherally with a circular vessel or sinus which, though venous in the 
bird, is arterial in the mammal. The capillaries of the vascular area 
absorb the nutritive material from the yelk sac. 
The placental circulation (Fig. 370) becomes established in man about 
the fourth week. The blood returned from the placenta passes through 
the umbilical vein, from which it is carried through the ductus venosus 
into the hepatic veins, where it is mixed with the blood from the liver. 
Fig. 370.—Diagram of the Foetal, Circulation, a, b, Umbilical vein: c, ductus 
arteriosus ; d, hypogastric arteries ; e, omphalo-mesenteric vessels; f, ductus venosus. 
From the hepatic veins it enters the termination of the inferior vena cava, 
becoming mixed there with the blood from the lower limbs. Entering 
the heart by the orifice of the inferior cava, it is directed by the 
Eustachian valve through the foramen ovale into the left auricle. From the 
left auricle, where it becomes mixed with a small quantity of blood 
returning from the lungs, it falls into the left ventricle. From the left 
ventricle it enters the commencement of the aorta, and is carried thence, 
owing to the position and direction of the carotid and subclavian 
branches, almost entirely to the head and neck and upper limbs, from 496 
THE VASCULAR SYSTEM. 
which it returns to the right auricle of the heart by the superior vena 
cava. The blood from the superior vena cava passes through the right 
auricle into the right ventricle, and from thence is carried by the pul- 
monary arteries in small quantity to the unexpanded lungs, but in much 
greater quantity through the ductus arteriosus, the still patent fifth left 
arterial arch, to the dorsal aorta. A part of the blood within the dorsal 
aorta supplies the lower part of the trunk and the lower limbs, returning 
by the cardinal veins and the inferior cava; but the larger part, entering 
the internal iliac arteries, is carried by the right and left hypogastric arteries, 
to the placenta. 
When the lungs become expanded, after the first few resjDirations, the 
pulmonary arteries rapidly dilate and draw off a large portion of the blood 
which, returning by the pulmonary veins to the left auricle, tends to close 
the valve of the foramen ovale. Subsequently the valve becomes completely 
closed. Instances of incomplete closure are, however, not uncommon, but 
the resulting passage between the auricles is usually small; when a con- 
siderable opening remains, the venous blood mixing with the arterial 
blood produces a cyanotic condition. The ductus arteriosus and the 
hypogastric arteries rapidly shrink and become, in two or three days, 
obliterated, and the ductus venosus and umbilical vein, a few days later, 
likewise become impervious. During foetal life there is not the same 
disproportion in thickness between the walls of the right and left ventricles, 
as is the case in the adult, owing, doubtless, to the fact that the resistance 
which each chamber has to overcome is, while the ductus arteriosus is still 
patent, about the same. 
THE LYMPHATICS. 
The lymphatic vessels or absorbents take up the lymph from the tissues; 
those of the intestine also take up the chyle and receive the special name 
of lacteals. The majority open into lymphatic glands; from the glands 
others pass onwards, and ultimately the contents of all are discharged 
into the venous system by the thoracic duct and the right lymphatic 
duct. The thoracic duct opens into the commencement of the left 
innominate vein; it carries the chyle, and the lymph from both lower 
limbs, the whole of the abdomen with the exception of a small portion 
of the upper surface of the liver, the whole of the left side and a portion 
of the right side of the thorax, the left upper limb, and the left side 
of the head and neck. The right lymphatic duct opens into the com- 
mencement of the right innominate vein; it carries the lymph from a 
small portion of the upper surface of the liver, the greater part of the 
right side of the thorax, the right upper limb, and the right side of the 
head and neck. Anterior superior spine \ 
of the ilium / 
Spermatic cord 
Femoral artery 
Pubis 
Femoral vein 
Internal saphenous vein 
Patella 
.Internal saphenous vein 
Fig. 371.—The Superficial Veins of the Thigh. (L. Testut.) 
To face p. 496. Superficial lymphatics of loins. 
Superficial lymphatics), 
of gluteal region ) 
Superficial inguinal glands 
(oblique) 
( Superficial lymphatics of 
J. lower part of anterior 
( abdominal wall 
Femoral vein.. 
J Superficial lymphatics 
\ of perineum 
■Superficial lymphatics of penis 
Superficial inguinal glands, 
(vertical) 
.Superficial lymphatics of scrotum 
Superficial lymphatics of thigh 
Internal saphenous vein 
Superficial lymphatics of thigh. 
Superficial lymphatics accom 
h panying the internal 
saphenous vein 
Internal saphenous vein 
Superficial lymphatics of leg J 
Dorsal veins of foot 
.Superficial lymphatics of dorsum 
( Lymphatic plexus of 
\ inner side of foot 
Fig. 372.—Superficial Lymphatics of the Lower Limbs. (L. Testut.) 
To face p. 497. THE LYMPHATICS. 
497 
The thoracic duct (Fig. 359), about eighteen inches in length, com- 
mences in the upper part of the abdominal cavity, and ascends through 
the thorax to the neck, where it terminates by falling into the distal 
extremity of the left innominate vein. Its lower extremity is somewhat 
dilated and forms a thin walled sac, the receptaculum chyli, about an 
inch and a half in length, and a quarter of an inch in breadth, which 
lies upon the body of the second lumbar vertebra under cover of the right 
crus of the diaphragm, and to the right of and behind the aorta. As 
it ascends, the duct at first diminishes in breadth, but in the upper part 
of the thorax and in the neck its diameter gradually increases. A 
couple of valves prevent regurgitation at the venous orifice, and a large 
number are found in the course of the vessel. In the thorax the duct is 
placed, at first, to the right side of the aorta, between it and the great 
azygos vein, and rests upon the vertebral column and the right intercostal 
arteries. About the level of the fourth dorsal vertebra it crosses behind 
the arch of the aorta; thereafter it ascends upon the left side of the 
column behind the left subclavian artery, and on the left edge of the 
oesophagus. In the neck it runs upwards for a short distance behind 
and between the left carotid and subclavian arteries and then with a 
crook-shaped bend passes forwards, outwards, downwards, and eventually 
a little inwards, in front of the vertebral vein and the left subclavian 
artery, and terminates in the angle of union of the subclavian and 
internal jugular veins of the left side. The thoracic duct is subject to 
numerous variations. It may begin higher or lower than usual; the place 
at which it crosses behind the aorta is not constant; it is sometimes 
double in a part of its course, or even throughout; it may terminate partly, 
or entirely, in the veins of the right side of the neck; it sometimes passes 
behind the vertebral vein; finally, instead of falling into the extremity 
of the innominate vein, it may end wholly or partly in one of the neigh- 
bouring large veins at the root of the neck or the upper part of the 
thorax. 
The receptaculum chyli receives the right and left lumbar trunks, and 
the mesenteric trunk; with the mesenteric trunk those of the coeliac glands 
are commonly associated. To the thoracic duct pass the efferent vessels 
from the whole of the left side of the thorax and a few of those from the 
lower part of the right side of that cavity; in the neck it is joined by the 
vessels from the left side of the head and neck and the left upper limb. 
The right lymphatic duct (Fig. 374), about half an inch in length, is 
formed by the union of trunks bringing the lymph from the right side of 
the head and neck with those coming up from the right axillary glands, 
and terminates in the angle of junction of the right internal jugular and 
iight subclavian veins. In addition, it receives the lymphatic vessels from 
the greater part of the right wall of the thorax, and those of the right 
llng and the right side of the heart. 498 
THE LYMPHATICS. 
LYMPHATICS OP THE LOWER LIMB. 
Glands. One or two small glands are sometimes found by the side of 
the anterior tibial artery in front of the interosseous membrane of the 
leg. 
The popliteal glands, four or five in number, are usually small, and 
lie among the fat of the popliteal space, by the side of the artery. 
They receive the deep vessels of the leg and, in addition, the few 
superficial vessels which pass deeply with the external saphenous vein. 
The superficial inguinal glands (Fig. 372) form two groups; one, superior 
in position, forms an obliquely placed chain, parallel to Poupart’s ligament; 
the other, inferior in position, is arranged in a vertical chain placed by the 
sides of the upper extremity of the internal saphenous vein. The individual 
glands are usually of considerable size. The inferior group, formed of four 
or five glands, receives all the superficial vessels of the lower limb with the 
exception of those of the gluteal region and the few which pass with the 
external saphenous vein into the popliteal space. The superior group is made 
up of a variable number of glands, usually eight or nine, which receive 
from above the superficial vessels of the lower part of the abdomen and 
back, and from below, internally, those from the penis, scrotum and 
perineum, and externally those from the gluteal region. The efferent vessels 
of the superficial inguinal glands pass through the saphenous opening, or 
pierce the fascia lata, and terminate, partly, in the deep inguinal and, 
partly, in the external iliac glands. 
The deep inguinal glands, three or four in number, lie by the side of 
the upper extremity of the femoral vein. They receive the great majority 
of the deep vessels of the lower limb and many of the efferent vessels 
from the superficial glands. Their own efferent vessels pass to the 
external iliac glands. 
Vessels. The superficial lymphatics (Fig. 372). A few from the back of 
the leg, ascending with the external saphenous vein, pass into the popliteal 
space and join the popliteal glands; by far the greater number are directed 
towards the internal saphenous vein, and ascend by its side to the inferior 
superficial inguinal glands. The superficial vessels of the gluteal region enter 
the outer part of the superior inguinal chain. The deep lymphatics accompany 
the arteries. Those by the side of the anterior tibial artery occasionally 
enter one or two glands which are sometimes found in front of the 
interosseous membrane. All those of the foot and leg pass to the popliteal 
glands, from which the efferent ducts ascend by the side of the femoral 
artery to the deep inguinal glands; the great majority of those from the 
thigh enter the deep inguinal glands, but one or two small vessels accompany 
the obturator artery and end in the internal iliac glands. The deep lym- 
phatics of the gluteal region pass with the gluteal and sciatic arteries to the 
internal iliac glands, one or more small extrapelvic glands being sometimes 
found in their course. LYMPHATICS OF THE ABDOMEN AND PELVIS. 
499 
LYMPHATICS OF THE ABDOMEN AND PELVIS. 
Glands. The external iliac glands, three to five in number, surround 
the external iliac artery; they are of variable size, the lower ones being 
generally larger than the upper. They receive the efferent vessels of the 
deep inguinal glands and some of those of the superficial inguinal glands, 
and also the deep lymphatic vessels which, coming from the lower part of 
the abdominal wall, accompany the deep circumflex iliac and epigastric 
arteries. They discharge into the lumbar glands. 
The internal iliac glands, usually twelve or thirteen, but variable 
in number, lie by the side of the internal iliac artery and its chief 
branches. They receive the deep lymphatic vessels of the gluteal 
region and the perineum, and a few which accompany the obturator 
artery from the adductor region of the thigh. They also receive the 
greater number of the lymphatic vessels from the bladder and prostate, 
those from the vesiculae seminales, and those from the vagina and the 
lower part of the uterus. Their efferent vessels pass to the lumbar glands. 
The sacral glands are four or five in number. They lie in front of 
the sacrum along the line of attachment of the mesorectum. They are 
connected anteriorly with five or six rectal glands which lie between the 
folds of the mesorectum. The sacral glands receive the lymphatics of the 
sacral part of the pelvic wall, those of the rectum, and a few of the 
posterior vessels of the bladder and prostate. Their efferent vessels join 
the lumbar glands. 
The lumbar glands are divided into three groups, two of them 
lateral, the third mesial in position. The mesial glands, six or seven in 
number, are of considerable size, and surround the aorta, extending 
upwards as far as the place of origin of the superior mesenteric artery. 
They receive the efferent vessels of the external iliac, internal iliac, and 
sacral glands, and some of those of the lateral lumbar glands. They 
receive, in addition, in the male, the lymphatics from the testicle, and, in the 
female, those from the upper part of the uterus and the ovary, and to them 
are also directed the vessels from the kidneys and suprarenal capsules, and 
from the vertebral portions of the diaphragm. They discharge themselves 
fry right and left vessels into the receptaculum chyli. Into the left vessel 
the lymphatics from the sigmoid flexure and the lower part of the descending 
°olon usually open. The lateral groups are made up of numerous small 
glands which lie behind the psoas muscles, between the successive trans- 
verse processes. They receive the deep lymphatic vessels of the posterior 
abdominal wall, and their efferent vessels pass partly to the mesial glands 
and partly to the receptaculum chyli. 
The mesenteric glands. Several glands of considerable size surround 
tfre base of the superior mesenteric artery, and are connected distally 
Wlth a very large number of small glands which lie between the layers 
°f the mesentery. The small glands are arranged in an irregular 500 
THE LYMPHATICS. 
manner, and are scattered through the mesentery, most numerously, how- 
ever, in the upper half, from the base to within two inches of the margin of 
the bowel; a special group near the termination of the artery receives the 
name of ileo-colic. The mesenteric glands receive the lacteals from the 
lower part of the duodenum, the jejunum, ileum, and a part of the 
ascending colon, and discharge themselves into the receptaculum chyli 
by a trunk which receives the efferent vessels of the mesocolic and coeliac 
glands. The mesocolic glands, twenty to thirty in number, and of small 
size, lie between the layers of the mesocolon, and receive the vessels from 
the transverse colon and the upper portions of the ascending and descending- 
colon. Their efferent vessels pass to the duct of the mesenteric glands. 
The coeliac glands, sixteen to twenty in number, lie in front of the aorta 
and surround the coeliac axis. They receive the lymphatic vessels of the 
greater part of the liver, the stomach, the upper part of the duodenum, 
the spleen, and the pancreas. Their efferent vessels, joining that of the 
mesenteric glands, enter the receptaculum chyli. Many of the lymphatics 
of the liver on their way to the coeliac glands pass through a number of 
small glands, the hepatic glands, which lie in front of the portal vein, 
between the layers of the small omentum. The vessels from the stomach 
are connected with small superior and inferiw gastric glands which form 
chains upon the smaller and greater curvatures respectively. A few small 
splenic glands are found at the hilum of the spleen. 
Vessels. Parietal lymphatics. The superficial vessels of the perineum, 
along with those of the penis, pass to the inner end of the superior super- 
ficial inguinal chain. The deep vessels of the perineum pass with the pudic 
arteries, and those of the penis, partly, with the pudic arteries and, partly, 
with the dorsal vein, to the internal iliac glands. The superficial vessels of the 
abdominal wall pass downwards to the superior superficial inguinal glands, 
and upwards to the axillary glands. The deep vessels of the pelvic wall pass to 
the internal iliac and sacral glands; those of the abdominal wall terminate 
in the external iliac, lateral lumbar, and mesial lumbar glands, and in the 
glands which lie by the sides of the internal mammary arteries. 
Visceral lymphatics. The vessels from the testicle ascend in the cord to 
the lumbar glands, and those of the ovary and the upper part of the uterus 
have a similar termination. The vessels of the lower part of the uterus and 
the vagina end chiefly in the internal iliac glands, but a few accompanying 
the round ligament end in the superficial inguinal glands. Those of the 
bladder, vesiculae seminales, and prostate gland pass, in great part, to the internal 
iliac glands, but a few from the back of the bladder, in the male, join the 
rectal lymphatics, and with them reach the sacral glands. The lymphatics 
from the kidneys and suprarenal capsules pass to the lumbar glands. 
Lymphatics of the intestine. The vessels from the rectum pass to the 
rectal glands, and thence to the sacral glands; those from the sigmoid 
flexure and the lower half of the descending colon join the duct of the left 
lumbar glands; those from the upper portion of the descending, the LYMPHATICS OF THE ABDOMEN AND PELYIS. 
501 
whole of the transverse, and the upper portion of the ascending colon 
join the mesocolic glands; from the lower part of the ascending colon 
and from the whole small intestine, with the exception of the upper part 
of the duodenum, the vessels pass to the mesenteric glands. The 
lymphatics of the stomach and the upper part of the duodenum pass with 
the coronary and right gastro-epiploic arteries to the coeliac glands, and 
with the left gastro-epiploic to the splenic lymphatic vessels; they are 
connected with the superior and inferior gastric glands. 
The lymphatics from the spleen are connected with the splenic glands, 
and are continued onwards to the coeliac glands, receiving as they go a 
few of the vessels from the stomach and those of the pancreas. 
The deep lymphatics of the liver pass, partly, with the portal vein to the 
hepatic glands, and thence to the coeliac glands, and, partly, with the hepatic 
veins through the diaphragm, to terminate in a few glands which 
lie beside the thoracic portion of the inferior vena cava; the efferent ducts 
of these glands pass backwards to the lower end of the thoracic duct. 
The superficial lymphatics of the liver pass in several directions—(a) those 
from the mesial portions of the upper surface ascend between the layers 
of the falciform ligament, pierce the diaphragm behind the ensiform 
process, and join the anterior mediastinal glands, the efferent ducts from 
which pass partly to the right lymphatic duct and partly to the thoracic 
duct; (b) those from the lateral portions of the upper surface descend to 
the coeliac glands; (c) those from the posterior border pierce the diaphragm, 
and reach the glands in contact with the thoracic portion of the inferior 
vena cava; (d) those from the under surface join the deep lymphatics 
which accompany the portal vein, and like them are connected with the 
hepatic glands before reaching the coeliac glands. 
THE LYMPHATICS OF THE THORAX. 
Glands. The anterior intercostal or sternal glands, seven or eight 
in number on each side, are placed at the sternal extremities of the 
intercostal spaces by the sides of the internal mammary arteries. They 
receive a few of the lymphatics from the inner side of the mammary 
gland, the deep vessels of the anterior part of the chest wall, and those 
which accompany the superior epigastric and musculo-phrenic arteries. 
They are connected with the anterior mediastinal glands, and their 
efferent vessels pass upwards, on the right side, to the right lymphatic 
duct, and, on the left, to the thoracic duct. 
The posterior intercostal glands form a group on each side of the 
spine at the vertebral extremities of the intercostal spaces. The in- 
dividual glands are of very small size, and there are usually two or 
three in each interspace. They receive the deep lymphatics of the posterior 
part of the thoracic wall, and the hinder part of the parietal pleura, 
and those of the deep muscles of the back, and of the spine. The efferent 502 
THE LYMPHATICS. 
vessels pass mainly to the thoracic duct, but those from the higher glands 
on the right side join the right lymphatic duct. 
The anterior mediastinal glands, three or four in number, lie behind 
the lower part of the sternum. They receive the lymphatics from the 
mesial portion of the upper surface of the liver, and some of the vessels 
of the diaphragm and pericardium : they are connected with the anterior 
intercostal glands, and discharge themselves into the right lymphatic and 
thoracic ducts. 
The superior mediastinal glands surround the basal portion of the 
aorta. They form a large ill-defined group which is continuous, below, 
with the posterior mediastinal glands, and, on each side, with the bronchial 
glands. They receive lymphatic vessels from the heart, pericardium, 
and thymus gland. Their efferent ducts pass upwards on the sides of 
the trachea to the right lymphatic and thoracic ducts. 
The bronchial glands (Fig. 374), very numerous, and in the adult of a 
very dark colour, surround the main bronchi and their primary subdivisions 
in the roots of the lungs. They receive the lymphatics of the lungs and 
some of those of the pleural membranes, and their efferent ducts pass 
upwards with those of the superior mediastinal glands. 
The posterior mediastinal glands, ten to twelve in number, form a 
chain by the sides of the descending aorta. They receive some lymphatic 
vessels from the diaphragm, those of the oesophagus, and those of the 
posterior portion of the pericardium. Their efferent vessels pass chiefly 
to the thoracic duct, but a few of the higher on each side join those 
from the bronchial glands. Some small glands lie in contact with the 
thoracic portion of the inferior vena cava. They receive the superficial 
lymphatics of the posterior border of the liver and some of the deep 
lymphatics of the liver. Their efferent ducts pass backwards on the 
diaphragm to the thoracic duct. 
Vessels. The superficial vessels of the thoracic wall pass to the axillary 
glands. The greater number of those from the mammary gland reach the 
group of axillary glands which is placed along the lower border of the 
pectoralis major, hut a few from the inner side are directed to the anterior 
intercostal glands. The deep parietal vessels pass to the anterior and posterior 
intercostal glands, as do also those of the parietal pleura. The lymphatics 
of the diaphragm pass to the anterior and posterior mediastinal and inter- 
costal glands. The vessels from the lungs and from the visceral layer of 
the pleura are directed to the bronchial glands. The oesophageal lymphatics 
end in the posterior mediastinal glands. Those of the pericardium pass 
to the anterior, superior, and posterior mediastinal glands. The cardiac 
lymphatics form a plexus on the surface of the heart and terminate in 
two trunks, that of the right side passing in front of the aorta, that of 
the left keeping to the left of the pulmonary artery, and both terminating 
in the superior mediastinal glands. Tributary of superior mesenteric vein Efferent trunk from glands 
Efferent trunk from glands I I Mesentery 
One of the smaller glands of the mesentery | | i | Gland 
Lacteal vessel Lacteal vessel 
Fig. 373.—Lymphatics of the Small Intestine. (L. Testut.) 
Deep cervical glands j 
External jugular vein 
Fig. 374.—Lymphatics of the Neck and Thorax, b, Superior vena cava ;c, sub- 
clavian vein ; d, internal jugular vein. I', Thoracic duct; 2, 2', right lymphatic duct; 3,4, 
submaxillary lymphatic glands ; 0, axillary glands; 7, S, bronchial glands. (L. Testut.) 
Thoracic duct Aorta 
To face p. 502. One of the deep cervical glands 
Lymphatics accompanying) 
cephalic vein f 
Lymphatics of the shoulder 
Axillary vein 
Axillary glands 
Cephalic vein 
.Superficial lymphatics of arm 
Basilic vein 
Epicondylar gland 
Superficial lymphatics) 
of forearm) 
{Superficial lymphatics 
of forearm 
Palmar lymphatic plexus 
Superficial lymphatics ) 
of thumb ( 
Fig. 375.—Lymphatics of the Upper Limb. (L. Testut.) 
To face p. 503. LYMPHATICS OF THE UPPER LIMB. 
503 
LYMPHATICS OF THE UPPER LIMB. 
Glands. The axillary glands (Fig. 375), about twelve in number, 
are placed beneath the deep fascia of the axilla; they are arranged in 
four groups. The main group, formed of five or six glands, lies by the 
side of the axillary vessels; it receives the deep and most of the superficial 
lymphatic vessels of the limb. The pectoral group is placed at the lower 
border of the pectoralis major by the side of the long thoracic artery; 
it contains two or three glands, and receives the superficial vessels of 
the anterior region of the trunk from the level of the umbilicus to the 
clavicle, with the exception of a few from the inner side of the mammary 
gland. The subscapular group lies upon the subscapular artery at the 
posterior border of the axilla; it is formed of two or three glands, and 
receives the superficial vessels of the posterior surface of the trunk from 
the shoulder to the level of the iliac crest; many of these, crossing the 
middle line without communicating with the vessels which they pass, come 
from the opposite side of the body. The infraclavicular group is formed 
of one or two small glands which lie upon the costo-coracoid membrane; 
it receives a few of the outermost of the superficial lymphatics of the arm 
and some of those from the shoulder. The different groups of glands are 
freely connected with one another. Their efferent ducts, joining to form a 
single trunk, or remaining as three or four distinct vessels, pass upwards 
along the subclavian vein and fall, on the right side, into the right 
lymphatic duct, and on the left into the thoracic duct. 
There are occasionally one or two small glands to be found in the 
course of the deep lymphatics by the side of the brachial artery, and in rare 
instances in the course of those which accompany one or other of the arteries 
of the forearm. In connection with the superficial lymphatics, one or two small 
epicondijlar glands are very frequently met with a little above the internal 
epicondyle, close to the commencement of the basilic vein; and sometimes 
a small gland is found at the bend of the elbow. 
Vessels (Fig. 375). The superficial lymphatic vessels form a very 
close meshwork on the palmar surfaces and on the sides of the fingers, and 
°n the palm of the hand; from the greater part of this meshwork the 
collecting vessels pass to the dorsum of the hand, but at the wrist a number 
pass to the front of the forearm. In the forearm the ascending trunks tend 
fo accompany the superficial veins; they are very numerous and com- 
municate freely with one another. In the arm most of the vessels accompany 
the basilic vein, and a few of them usually terminate in the epicondylar 
glands. At the axilla the greater number pierce the fascia and terminate 
m the main group of the axillary glands, but a few from the outer side of 
tFe arm ascend with the cephalic vein, and end in the infraclavicular group 
°f glands. In the course of the last mentioned vessels a small super- 
ficial gland is sometimes found (Sappey). The deep lymphatic vessels 504 
THE LYMPHATICS. 
accompany the arteries of the hand, forearm, and arm, and terminate 
in the main group of the axillary glands. Some of them, occasionally 
pass through a few small glands which lie by the side of the brachial 
artery. 
Glands (Fig. 376). In most cases one or two occipital glands of small 
size overlie the occipital origin of the trapezius muscle ; when present 
they receive the vessels from the posterior region of the scalp, and dis- 
charge themselves into the superficial cervical glands. 
LYMPHATICS OF THE HEAD AND NECK. 
The mastoid glands, one or two in number and of small size, lie 
behind the ear above the line of insertion of the sterno-mastoid muscle. 
They receive some of the vessels from the lateral and posterior region of 
the scalp and those from the back of the pinna. According to Sappey 
there are a number of mastoid glands on the deep surface of the sterno- 
mastoid close to the insertion, receiving there the efferent ducts of the 
more superficially placed glands, and some of the vessels from the scalp. 
The mastoid glands are generally regarded as sending their efferent ducts 
to the superficial cervical glands, and the glands of Sappey are probably 
connected with the deep cervical glands. 
The parotid lymphatic glands, ten to twelve in number (Sappey), are 
placed under the fascia which covers the parotid gland, some of them 
being imbedded in the glandular tissue. They receive vessels from the 
parotid gland, and from the anterior and lateral regions of the scalp, the 
lateral parts of the face, and the front of the pinna of the ear. Their 
efferent ducts pass, partly, to the submaxillary and, partly, to the super- 
ficial cervical glands. 
The submaxillary lymphatic glands, ten to twelve in number, occupy 
the digastric triangle; one or two of the most anterior of them receive the 
name of suprahyoid glands. The vessels which reach them come from the 
anterior part of the face, the floor of the mouth, the anterior part of the 
tongue, the submaxillary and sublingual salivary glands, and from the more 
anteriorly placed of the parotid lymphatic glands. Their efferent ducts 
pass partly to the superficial cervical glands and partly to the superior 
deep cervical glands. 
The superficial cervical glands lie in the superficial fascia of the neck, 
the majority forming a chain at the posterior border of the sterno-mastoid 
muscle. They receive all the superficial vessels of the neck, and the 
efferent ducts of the occipital glands, some of those of the parotid and 
submaxillary groups, and probably some of those of the mastoid glands. 
They discharge themselves into the inferior deep cervical glands. 
The internal maxillary glands, five or six in number, are placed 
in the zygomatic fossa. They receive vessels from the temporal and 
zygomatic regions, the orbit, the roof of the mouth, the soft palate, the 
nasal cavity, and the upper part of the pharynx, and their efferent ducts LYMPHATICS OF THE HEAD AND NECK. 
505 
pass to the superior deep cervical glands. A small postpharyngeal gland 
lies upon the vertebral column; it receives vessels from the pharynx and 
the prevertebral muscles. 
The superior deep cervical glands form a chain which lies by the 
side of the internal jugular vein, in the region between the base of 
the skull and the thyroid cartilage. They receive the lymphatics of the 
cranial cavity, the efferent ducts of the internal maxillary glands, and 
some of those of the parotid and submaxillary groups, the vessels from 
the posterior part of the tongue, the lower part of the pharynx, the 
upper part of the larynx, the upper part of the thyroid body, and those 
from the deep muscles of the upper part of the neck. In connection 
with the lymphatics from the posterior part of the tongue one or two 
small lingual glands are found on the outer surface of the hyo-glossus 
muscle. The efferent ducts from the superior deep cervical glands are 
continued to the inferior deep cervical glands. 
The inferior deep cervical glands are found by the side of the lower 
part of the internal jugular vein. They receive the efferent ducts of the 
superior deep cervical glands and those of the superficial cervical glands, 
and the vessels from the lower j)art of the larynx, the lower part of the 
thyroid body, the cervical portions of the trachea and oesophagus, and the 
deep muscles of the lower part of the neck. The vessels from the lower part 
of the larynx pass through one or two small laryngeal glands which lie 
by the side of the upper part of the trachea. The efferent ducts from 
the deep cervical glands unite to form the jugular lymphatic trunk which 
opens, on the right side, into the right lymphatic duct, on the left, into 
the thoracic duct, or, occasionally, on one or both sides, into one of the 
great veins at the root of the neck. 
Vessels. The superficial lymphatics (Fig. 376). The lymphatics of the 
scalp pass to the occipital or, when these are absent, to the superficial 
cervical glands, and to the mastoid and parotid glands; from the eyelids 
and the upper lateral region of the face the lymphatics pass to the parotid 
glands; from the nose, lips, and lower lateral region of the face they pass to 
the submaxillary glands. From the external ear the lymphatics are 
directed to the parotid and mastoid glands. The superficial lymphatics of 
the neck are received by the superficial cervical glands. 
The deep lymphatics. The lymphatics of the brain form plexuses in the 
pia mater, and are afterwards collected into larger trunks which escape 
from the cranium by the sides of the carotid and vertebral arteries and 
the internal jugular veins, and terminate in the superior deep cervical 
glands. The meningeal lymphatics accompany the meningeal arteries to 
the internal maxillary and superior deep cervical glands. The lymphatics 
°f the spinal cord pass outwards through the intervertebral foramina by 
the sides of the entering arteries, and terminate, according to the region, 
ln the deep cervical, posterior intercostal, and lateral lumbar glands. The 
lymphatics from the orbit enter the internal maxillary glands, as do also 506 
THE LYMPHATICS. 
those of the nasal cavities, the roof of the mouth, and the temporal and 
zygomatic fossae. 
The lymphatics of the floor of the mouth and the anterior part of the 
tongue pass to the suhmaxillary glands; those of the posterior part of the 
tongue pass through the lingual glands to the superior deep cervical glands. 
The lymphatics from the pharynx pass partly to the internal maxillary and 
partly to the superior deep cervical glands. The lymphatic vessels from the 
parotid salivary gland end in the internal maxillary and parotid groups 
of glands; those from the suhmaxillary and sublingual salivary glands enter 
the suhmaxillary lymphatic glands. The lymphatics of the larynx form two 
sets ; those above the glottis pass upwards through the thyro-hyoid mem- 
brane to the superior deep cervical glands; those below the glottis, piercing 
the crico-thyroid membrane, end in the inferior deep cervical glands. 
The lymphatics of the thyroid body accompany the upper and lower thyroid 
arteries to the superior and inferior deep cervical glands. Those of the 
cervical portions of the trachea and oesophagus enter the inferior deep cervical 
glands. 
THE NERVES. 
I. CEREBRO SPINAL NERVES. 
From the central organ of the nervous system, the brain and spinal 
cord, there spring on each side forty-three nerve-trunks, the branches of 
which are distributed throughout the body. Thirty-one pairs, taking origin 
from the cord, are termed spinal nerves; twelve spring from the brain and 
are called cranial nerves-, one of the cranial nerves, however, the eleventh, 
receives many of its fibres from the cervical region of the cord. 
Physiologists have divided nerve fibres into two classes according as 
they conduct impulses to or from the central organ : those which carry 
impulses to the centre are afferent or centripetal fibres; those which con- 
duct from the centre and towards the periphery are efferent or centrifugal 
fibres. The dorsal roots of the spinal nerves contain only afferent fibres; 
the ventral roots on the other hand are formed of efferent fibres; beyond 
the place of junction of the roots with one another the trunk of each 
spinal nerve contains both kinds of fibres, and is termed a mixed trunk. 
Certain of the cranial nerves contain only one kind of fibre, others are 
mixed nerves. As the nerve-trunks approach the areae of their peripheral 
distribution the different kinds of fibres of which they are composed 
separate from one another. Thus, mixed trunks break up ultimately into 
branches, each of which is either afferent or efferent, and has its own 
special distribution. It may further be remarked concerning cutaneous 
nerves, that allied nerves are supplied to contiguous areae. Thus, the 
posterior divisions of the spinal nerves supply one contiguous area of in- Lymphatics of scalp 
Lymphatics 
of scalp 
Lym-'J 
phatics V 
of scalp J 
Mastoid 
glands 
( Lym- 
•l phatics 
( of nose 
Occipital glands 
Parotid lymphatic ) 
elands ( 
Lymphatics 
of lips 
External jugular \ 
vein f 
Deep cervical gland 
f Lymphatics 
\ of chin 
Facial vein 
Submaxillary lymphatic glands 
n, Internal jugular vein 
B, 4, Parotid lymphatic glands 
carotid artery 
Subclavian artery. 
> Right lymphatic duct 
Fig. 376.—Lymphatics of the Head and Neck. (L. Testut.) 
To face p. 506. External branch (first dorsal nerve) 
Last cervical | 
First dorsal nerve 
Internal branch 
Cutaneous branch 
Upper dorsal nerve 
Internal branch 
External branch 
(External branch of 
( lower dorsal nerve 
Muscular twigs 
0, Cutaneous branches 
( External branch of 
( lower dorsal nerve 
Muscular twigs 
Cutaneous twigs of 
primary posterior I 
divisions of sacral I 
nerves 
Fig 377.—The Posterior Primary Divisions oe the Thoracic and Lumbar Nerves. 
(L. Testut.) 
To face p. 507. SPINAL NERVES. 
507 
tegument from the crown of the head to the gluteal region; the three 
branches of the fifth cranial, though reaching the face by different routes,, 
together supply the whole face, and the head in front of the ear; and the 
cutaneous branches of the musculo-spiral in the upper limb, and those of 
the small sciatic, the great sciatic, and the anterior crural in the lower 
limb, all follow the same law. 
SPINAL NERVES. 
There are thirty-one pairs of spinal nerves, as follows ; eight cervical, 
twelve thoracic, five lumbar, five sacral, and one coccygeal. The first nerve, 
the suboccipital, passes outwards between the occipital bone and the atlas; 
the next seven appear in order below the successive cervical vertebrae. 
The remaining nerves of the series are named from the vertebrae below 
which they escape. The coccygeal nerve issues from the lower extremity 
of the spinal canal, and passes outwards beneath the first piece of the coccyx. 
Each nerve springs from the sides of the cord by two roots, an anterior 
and a posterior. The posterior roots are formed of afferent fibres; each of 
them presents a ganglion, involving most of its fibres, situated close to the 
place of junction with the anterior root. The anterior roots contain efferent 
fibres, and have no ganglia. With the exception of the case of the sub- 
occipital nerve, in which the motor root is the larger, the posterior roots 
exceed the anterior in size, the discrepancy being most marked in the 
cervical region, and least apparent among the dorsal nerves. The roots, 
invested by the pia mater, traverse the subarachnoid and arachnoid spaces, 
and pass towards the intervertebral foramina, on a level with which they 
separately pierce the sac of the dura mater. In each foramen, surrounded 
by a common sheath, the anterior and posterior roots join with one an- 
other to form the nerve; at the outer extremity of the foramen the nerve 
breaks up into anterior and posterior primary divisions, each consisting of 
mixed fibres from the two roots. The ganglia are placed in the intervertebral 
foramina, and lie outside the common sac, but within the tubular prolonga- 
tions of the dura mater. The arachnoid membrane is reflected upon the 
roots, but the investments from the dura mater and pia mater become 
continuous with the sheaths of the nerves. The last sacral and coccygeal 
nerves are formed, by the junction of the roots, within the common sac of 
the dura mater at some distance from their places of exit. In the case 
of the other sacral nerves, the primary divisions of which escape through 
the anterior and posterior sacral foramina, the junction of the roots, 
although taking place outside the sac of the dura mater, is effected within 
the spinal canal. The first and second nerves are formed opposite the 
posterior arches of the atlas and axis respectively. 
Each posterior root springs from the postero-lateral groove of the cord 
% some six or eight fasciculi, which form a linear series. The ganglion 
18 usually bilobate at its inner extremity, and the bundles of the root are 508 
THE NERVES. 
gathered into two before reaching it. Each anterior root takes origin by 
some four or five sets of bundles which do not form a linear series, but are 
scattered in an irregular manner over a certain breadth in front of the lateral 
column of the cord. The roots of the successive nerves arise from the cord 
at intervals. Those of the first nerves ascend slightly to the place of exit;. 
those of the second and third pass outwards almost horizontally; the others, 
in order from above downwards, descend with increasing degrees of obliquity. 
In the case of each nerve there is considerable variation, but, as a 
general rule, among the upper dorsal nerves the roots take origin from 
the cord opposite the vertebra immediately above the one beneath which 
the nerve which they give rise to emerges, while, among the lower dorsal 
and upper lumbar nerves, the roots arise opposite the second vertebra 
above that beneath which the nerve which they form makes its exit 
from the spinal canal. The lower lumbar, the sacral, and the coccygeal 
nerve roots arise from the terminal portion of the cord opposite the first 
lumbar vertebra, and, descending in the subarachnoid space, form the 
cauda equina. The splitting of each nerve trunk into anterior and posterior 
divisions takes place immediately after its exit from the intervertebral 
foramen. 
The posterior primary divisions of the nerves are, with the exception of 
those of the first and second nerves, smaller than their corresponding 
anterior divisions. Their distribution is limited to the muscles which 
occupy the furrows by the sides of the spines, and to the integument of 
the back. The anterior divisions supply the limbs and the anterior and 
lateral regions of the trunk. They communicate directly with the 
sympathetic chain. In the cervical, lumbar, and sacral regions they form 
plexuses. 
Deep connections of the roots of the spinal nerves. The posterior 
roots are formed of afferent fibres, which are connected with the cells of 
the spinal ganglia. Passing inwards from the ganglia, the fibres of 
the root reach the spinal cord, within which each divides into an 
ascending and a descending branch; from the fibre before its division, and 
from each of its two branches, numerous slender collaterals are 
detached. The fibres terminate in the grey matter of the posterior horn, 
and probably also in that of the intermediate region of the cord, by break- 
ing up into numerous delicate arborizations, which in their ramification 
come into close contact with the nerve cells or with their processes, but never 
communicate directly with them. The collaterals terminate, as do the 
main branches of the fibres, in ramifications, which surround nerve cells. 
Some of them pass into the anterior horn of the grey matter of the same and 
the opposite side of the cord, and surround the cells which give origin 
to the anterior or efferent roots. 
The anterior roots are formed of fibres which are the continuations of 
the axis-cylinders of cells in the anterior, and probably also in the inter- 
mediate regions of the grey matter. These cells are surrounded by SPINAL NERVES. 
509 
the arborizations of the collaterals of posterior root fibres, and in addition 
by the lateral or terminal branches of fibres which descend from cells of 
the anterior cornua at a higher level, from the cerebellum, and from the 
cerebral cortex. 
From their places of origin they are at once directed backwards, passing 
behind a line of muscles by which, in the neighbourhood of the openings 
of the intervertebral foramina, they are separated from the anterior divisions. 
This line is represented in the neck by the rectus capitis lateralis and 
the posterior intertransverse muscles, in the thoracic region by the levatores 
costarum and the external intercostals, in the loins by the external intertrans- 
verse and quadratus lumborum muscles. With the exception of the first 
cervical, the last two sacral, and the coccygeal, each member of the series 
divides into an external and an internal branch. These branches immediately 
on their origin diverge from one another, the line of separation being marked 
in the neck by the line of the origins of the complexus muscle, in the 
thoracic region by the intertransverse ligaments, and in the loins by the 
internal or median intertransverse muscles. Both external and internal 
branches give off muscular twigs. The special muscles in the different 
regions which are supplied by them are the short posterior cranio-vertebral 
muscles, the interspinales, the internal lumbar intertransverse muscles, the 
multifidus spinae, semispinalis, erector spinae, and splenius. The cutaneous 
supply is furnished by the internal branches in the cervical and upper 
dorsal regions, and by the external branches in the lower dorsal, lumbar, 
and upper sacral regions. 
THE POSTERIOR PRIMARY DIVISIONS. 
The Posterior Divisions of the Cervical Nerves. 
The posterior division of the first cervical or suboccipital nerve does not 
divide into an internal and an external branch. It is a short trunk which 
passes backwards over the posterior arch of the atlas, beneath the vertebral 
artery, and breaks up into a number of twigs which supply the four 
short posterior cranio-vertebral muscles. It likewise gives a twig to the 
complexus, and occasionally furnishes a cutaneous branch which ramifies 
over the back of the occiput. 
The external branches of the cervical nerves, from the second to the 
eighth, are small and entirely muscular in their distribution; they are 
directed outwards to the cervical portion of the erector spinae and to the 
splenius. 
The internal branches, from the second to the fifth, pass inwards under 
cover of the complexus muscle. They give off muscular twigs to the 
multifidus spinae, semispinalis, complexus, and interspinales, and, in 
mldition, furnish cutaneous branches, which pierce the trapezius close to 
the middle line. 510 
THE NERYES. 
The cutaneous branch of the second nerve is of large size, and is known 
as the great occipital (Fig. 379). It is directed upwards behind the obliquus 
capitis inferior muscle, and pierces the complexus below the outer margin of 
the occipital origin of the trapezius. Its branches ramifying with those of 
the occipital artery supply the integument covering the upper part of the 
occipital and the posterior part of the parietal bone, and form connections 
externally with those of the small occipital nerve from the cervical plexus. 
The cutaneous branch of the third nerve, under the name of third or 
smallest occipital nerve, is directed upwards towards the occiput by the inner 
side of the great occipital nerve. On the deep surface of the complexus, 
small connecting twigs pass between the suboccipital nerve and the internal 
divisions of the second and third cervical nerves. The cutaneous branches 
of the fourth and fifth nerves are distributed to the integument of the 
back of the neck. The internal branches of the sixth, seventh, and eighth nerves 
are very small; they are distributed to the multifidus, semispinalis, com- 
plexus, and interspinales, and furnish, as a rule, no cutaneous twigs. 
The Posterior Divisions oe the Thoracic Nerves. 
The internal branches (Fig. 377) supply the deeper muscles; the upper 
six or seven, in addition, furnish cutaneous offsets, which pierce the trapezius 
close to the spines and ramify outwards , over the back, that of the second, 
the largest of the series, reaching almost to the back of the shoulder. 
The external branches supply the erector spinae muscle. From the 
lower five or six, cutaneous twigs are detached; these pierce the latis- 
simus dorsi at a little distance from the middle line, and are chiefly 
directed outwards and downwards. 
The Posterior Divisions of the Lumbar Nerves. 
The interned branches are small, and supply the multifidus, the inter- 
spinales, and the internal intertransverse muscles. 
The external branches of the first three supply the erector spinae, and 
furnish cutaneous offsets which pierce the aponeurosis of the latissimus 
dorsi at the outer border of the erector spinae, immediately above the iliac 
crest, and are continued downwards in the subcutaneous tissue of the gluteal 
region, the lowest reaching as far as the level of the great trochanter. 
The external branch of the fourth is small and does not, as a rule, reach 
the surface, but terminates in the erector spinae. 
The external branch of the fifth descends to join that of the first sacral. 
The Posterior Divisions of the Sacral Nerves and the 
Coccygeal Nerve. 
The first four escape by the posterior sacral foramina; the fifth and the 
coccygeal make their exit from the lower extremity of the spinal canal. THE POSTERIOR PRIMARY DIVISIONS. 
511 
The internal divisions of the first three are small and end in the multifidus 
spinae. 
The external branches of the first three form with one another, and with 
that of the last lumbar nerve, a series of loops on the back of the sacrum; 
from the loops branches proceed to a second series of loops in the substance 
or on the posterior surface of the great sacro-sciatic ligament; from the 
secondary loops two or three branches pass to the surface, perforating 
the gluteus maximus and supplying the skin over its lower and inner part. 
The fourth and fifth sacral and the coccygeal nerves. The posterior 
divisions of these nerves are of small size, and do not divide into external 
and internal branches; they form with one another, and with a small 
branch from the third sacral, a series of delicate loops, from which slender 
twigs pass to the skin in the neighbourhood of the coccyx. 
THE ANTERIOR PRIMARY DIVISIONS. 
The Cervical Plexus. 
The cervical plexus is formed from the anterior primary divisions of 
the first four cervical nerves. Those of the third and fourth are the 
largest of the series, that of the first is a comparatively slender trunk. 
The first nerve of the plexus passes forwards between the rectus capitis 
lateralis muscle and the rectus capitis anticus minor, and descends in front 
of the base of the transverse process of the atlas to join the ascending 
branch of the second; the others emerge between the anterior and posterior 
intertransverse muscles, and lie in a plane immediately in front of the 
origins of the scalenus medius. The second and third nerves divide into 
ascending and descending branches which, uniting with one another, with 
the first nerve above, and with the fourth nerve below, form a series of 
three loops. The branches of the plexus are divided into superficial and 
deep groups. 
superficial branches 
The superficial branches, passing backwards and outwards from their 
origins, emerge from under cover of the sterno-mastoid opposite the 
middle third of its posterior border. They are arranged in ascending 
and descending groups :in the former are the small occipital, the great 
auricular, and the superficial cervical; in the latter are the supra-acromial, 
the supraclavicular, and the suprasternal. 
The small occipital nerve (Fig. 379) is derived from the loop formed 
hy the second and third nerves. It ascends along the posterior border of the 
sterno-mastoid, and divides into mastoid and occipital branches, which supply 
the integument covering the mastoid, the outer part of the occipital, and the 
lower part of the parietal region of the skull; a slender auricular branch is 
directed forwards to the skin of the upper part of the inner surface of the 
Pmna. The small occipital nerve is of variable size, and occasionally is THE NERVES. 
512 
double; its branches form connections with those of the great occipital, 
great auricular, and posterior auricular nerves. 
The great auricular nerve springs trom the second and third nerves, 
and emerges from the cover of the sterno-mastoid immediately below the 
small occipital nerve. Crossing the muscle obliquely it passes upwards 
and a little forwards, under cover of the platysma, towards the region of 
the ear, beneath which it divides into mastoid, facial, and auricular branches. 
j Communicating branch 
\ to sympathetic 
To rectus capitis lateralis 
I Communicating branch 
\ to pneumogastric 
J Communicating branch 
( to hypoglossal 
/ Communicating branch 
\ to sympathetic 
To rectus capitis antious minor 
Small occipital 
/ Communicating branch 
\ to sympathetic 
Great auricular 
Superficial cervical 
J Communicating branch 
( to sympathetic 
, J. Cornmunicantes 
( hypoglossi 
To sterno-mastoid 
Supra-acromial 
Supraclavicular 
To trapezius Phrenic 
\ Suprasternal 
Fig. 378.—Diagram of the Cervical Plexus, a, b, c, To rectus capitis anticus major, 
longus colli, and intertransversales; d, e, to scalenus medius, and levator anguli scapulae. 
(J. Y. M.) 
These supply the integument covering the mastoid process, the parotid 
region of the face, the inner surface of the pinna, and partly also, by 
means of slender perforating twigs, the outer surface of the pinna. The 
branches form connections with those of the small occipital and facial nerves. 
The superficial cervical nerve, from the second and third nerves, 
emerges below the great auricular, and, passing forwards under cover of the 
platysma, breaks up into numerous branches, which supply the skin of 
the front of the whole length of the neck. Two or three of the upper 
branches are connected with those of the inframaxillary branch of the 
facial nerve, forming loops of considerable size. 
The descending branches, variable in number, spring from the third 
and fourth nerves, and descend under cover of the platysma; near the 
clavicle they break up into suprasternal, supraclavicular, and supra-acromial 
terminal twigs. They supply the lower and lateral regions of the neck, Connections'! h 
between great I .1: 
occipital and j \ 
small occipital J 
Great occipital.. 
Small occipital-' 
Groat auricular - 
Mastoid branches of great) 
auricular and small 
occipital (conjoined)) 
Spinal accessory 
Branches to trapezius - 
Fig. 379.—The Superficial Nerves of the Neck. 2', 2", Branches of groat auricular ; 
3, connecting twig with inframaxillary of facial; 5, s', 5", 6, superficial cervical; 7. 8, 
descending superficial branches of cervical plexus ; 13, facial. (1.. Testut.) 
To face p. 512. Fia. 380. —Nerves of the Axilla. 1, Nerve to the rhomboids; 2, suprascapular; 3, 
nerve to subolavius; 3', connections with phrenic nerve ; 4, phrenic ; 5, external anterior 
thoracic; 6, internal anterior thoracic; 6', connection between external and internal 
anterior thoracic; 7, posterior thoracic ; 8, short subscapular; 9, 10, lowest subscapular; 
11, long subscapular; 12, external cutaneous; 13, median; 14, ulnar; 15, internal 
cutaneous; 16, lesser internal cutaneous; 16', 16", connections between lesser internal 
cutaneous and intercostal branches ; 17, intercosto-humeral; 18, 19, 20, 21, lateral 
branches of 3rd, 4th, sth, and 6th intercostal nerves. I. to V., The nerve trunks which 
form the brachial plexus; the primary cords of the plexus have been dissected up in 
order to show the formation of the outer and inner cords; the nerve to the subclavius 
is represented as receiving an unusual root from the seventh cervical nerve. (L. 
Testut.) 
To face p. 513. THE CERVICAL PLEXUS. 
513 
and their terminal branches reach the pectoral region and the shoulder. 
The suprasternal branches are slender, and pass forwards across the 
sterno-mastoid to the integument in front of the manubrium. The supra- 
clavicular branches cross the clavicle and supply the skin covering the 
upper part of the pectoralis major. The supra acromial branches ramify 
over the upper part of the deltoid. 
DEEP BRANCHES. 
Connecting branches pass from each of the main trunks to the first 
ganglion of the sympathetic, and from the first loop to the pneumogastric 
and hypoglossal nerves. 
The muscular branches are divided, according to the direction in which 
they pass, into an outer and an inner group. 
Those of the outer group supply the sterno-mastoid, trapezius, scalenus 
medius, and levator anguli scapulae. The nerve to the sterno-mastoid 
springs from the second nerve; entering the deep surface of the muscle 
it forms connections with the spinal accessory nerve. The nerves to the 
trapezius are generally two in number, and are of considerable size; they 
spring from the third and fourth nerves, in association with the descending 
superficial nerves; under cover of the trapezius they are freely connected 
with the spinal accessory nerve. The branches to the scalenus medius and 
levator anguli scapulae are of small size, and spring from the third and 
fourth nerves. 
The branches belonging to the inner group supply the rectus capitis 
anticus minor, the rectus capitis lateralis, the upper cervical intertrans- 
verse and prevertebral muscles, and the diaphragm, and assist in the 
supply of the infrahyoid muscles; the majority are slender twigs which 
pass at once into the muscles from the neighbouring nerve trunks. 
The branches to the infrahyoid muscles (rami communicantes hypoglossi), two 
m number, spring separately from the second and third nerves. They 
usually join with one another to form a single trunk, which passes inwards 
and downwards, crossing the carotid sheath superficially, and unites with 
the descending branch of the hypoglossal nerve to form a loop, the ansa 
hypoglossi, from which twigs proceed to the sterno-hyoid and sterno thyroid 
niuscles, and the posterior belly of the omo-hyoid. 
The phrenic nerve, along with its fellow of the opposite side, supplies 
the diaphragm. It springs mainly from the fourth cervical nerve, but 
receives usually a slender twig from the third nerve, and, as a rule, is 
eonnected with the fifth nerve, the first of the brachial plexus. It 
descends in the neck, crossing anteriorly, from above downwards, the 
scalenus anticus muscle. In the lower part of the neck and upper part of 
the thorax, the relations of the nerves of the opposite sides are not quite 
the same. Each nerve crosses in front of the internal mammary artery 
°f its own side, passing from its outer to its inner margin, and is crossed 514 
THE NERVES. 
by the subclavian vein. The nerve of the right side crosses the second 
part of the subclavian artery, the scalenus anticus intervening, and after- 
wards descends by the outer side of the right innominate vein. That of 
the left side is placed in front of the first portion of the left subclavian 
artery, and lower down crosses the arch of the aorta. Within the thorax 
both nerves descend on the sides of the pericardium, passing in front 
of the pulmonary roots. They then pierce the diaphragm, and on its 
under surface spread out into branches, which supply the muscle and 
form connections with twigs from the diaphragmatic plexus of the 
sympathetic nerves. In the upper part of the thorax the phrenic is 
usually joined by a twig from the sympathetic nerve, and sometimes 
receives filaments from the nerve to the subclavius muscle; less commonly 
it receives a communicating twig from the descending branch of the 
hypoglossal. On its way it detaches small twigs to the pericardium and 
pleura. 
THE BRACHIAL PLEXUS. 
The brachial plexus (Figs. 380, 381) is formed by the anterior divisions 
of the fifth, sixth, seventh, and eighth cervical nerves, and the larger part 
Pig. 381.—Diagram of the Brachial Plexus. A, First primary cord; B, second 
primary cord ; C, third primary cord ; E, external cord; P, posterior cord ; /, inner cord. 
1, Communicating branches to sympathetic; 2, branches to intertransverse and longus 
colli muscles; 3, branches to scalene muscles; 4, posterior thoracic nerve ; 5, nerve to the 
rhomboids ; 6, nerve to subclavius ; 7, suprascapular nerve ; 8, external anterior thoracic ; 
9, internal anterior thoracic; 10, external cutaneous; 11, internal cutaneous; 12, lesser 
internal cutaneous ; 13, ulnar; 14, outer head of median ; 15, inner head of median ; 16, 
median ; 17, musculo-spiral; 18, 19, 20, the three subscapular nerves; 21, circumflex. 
(J. Y. M.) 
of that of the first dorsal nerve. The fifth cervical nerve usually receives 
a slender connection from the fourth. Each of the constituent trunks is 
connected with the gangliated cord of the sympathetic nerve by a com- THE BRACHIAL PLEXUS. 
515 
municating branch. The cervical nerves emerge between the intertransverse 
muscles and pass outwards in the plane between the scalenus anticus and 
scalenus medius; the portion of the first dorsal which joins the plexus 
ascends over the inner border and upper surface of the first rib. A little 
beyond the outer margin of the anterior scalene muscle the fifth and sixth 
nerves unite with one another to form an upper or first cord; the seventh 
nerve forms by itself a middle or second cord; the eighth cervical and first 
dorsal join with one another on the deep surface of the anterior scalene 
muscle to form a lower or third cord. The three primary cords, 
thus formed, pass outwards and downwards towards the apex of the 
axilla in company with the third part of the subclavian artery, 
the lower cord being placed behind the upper margin of the vessel, 
and the other two in close proximity. 
As the nerve-cords are passing from the neck into the axilla, a re- 
arrangement of their fibres takes place. Each of the three primary cords 
divides into an anterior and posterior branch, and these branches unite 
with one another in such a way as to give rise to three new or secondary 
cords, which are named respectively the outer, inner, and posterior cord 
of the brachial plexus. The outer cord is formed by the anterior branches 
of the first and second primary cords. The inner cord is formed by the 
anterior branch of the third cord. The posterior cord is formed by the 
posterior branches of all of the three primary cords. Variations, for 
the most part of little consequence, occur in the formation of the 
secondary cords, the most usual being the contribution of a portion of 
the anterior division of the second primary cord to the formation of the 
inner cord. 
The nerve-cords enter the axilla, and descend through its first part by 
the outer side of the axillary artery, but a little farther down a change 
in the relative positions of the structures takes place. The inner cord 
sweeping behind the artery gains its inner side, the posterior cord reaches 
the posterior surface of the artery, while the outer cord, approaching the 
vessel more closely, comes into contact with its outer side. In these 
positions the three cords descend for a little distance; but while still high 
111 the axilla they break up into their terminal divisions. Some of the 
branches of the plexus take origin in the neck, most of them arise below 
fhe clavicle. 
Branches of the Brachial Plexus in the Neck. 
As the nerves emerge from the intervertebral foramina, they detach 
s>nall muscular branches for the supply of the intertransverse, scalene, and 
l°ngus colli muscles. The fifth cervical nerve is connected by a communi- 
catvng branch with the phrenic nerve. 
The nerve to the rhomboids, a long slender cord, takes origin from the 
Wk of the fifth cervical nerve; it pierces the middle scalene muscle and 516 
THE NERVES. 
passes downwards and outwards on the deep surface of the levator anguli 
scapulae to reach the posterior margin of the scapula, along which it 
descends on the deep surface of the rhomboid muscles : it supplies both 
rhomboid muscles, and detaches twigs to the levator anguli scapulae. 
The posterior thoracic nerve (external respiratory nerve of Sir Charles 
Bell) arises by three roots which spring from the fifth, sixth, and 
seventh cervical nerves respectively; the roots separately pierce the middle 
scalene muscle and unite with one another on its posterior surface. The 
nerve descends through the apex of the axilla, behind the large structures 
which pass to and from the arm, and, continuing its course, passes down- 
wards on the axillary surface of the serratus magnus, to which muscle it 
is entirely distributed. 
The nerve to the subclavius, a slender thread, arises from the front 
of the first primary cord of the plexus and passes downwards, crossing in 
front of the third part of the subclavian artery, to enter the deep surface 
of the muscle; it frequently communicates by a small twig with the 
phrenic nerve. 
The suprascapular nerve, a considerable offset, arises from the back of 
the first primary cord ; it courses downwards and outwards to the upper 
border of the scapula, and passes through the suprascapular notch (beneath 
the ligament). It detaches a twig to the shoulder-joint, and supplies the 
supraspinatus and infraspinatus muscles, descending through the great 
scapular notch to reach the latter muscle. 
Branches of the Brachial Plexus given off Below the Clavicle. 
The outer cord gives off the external anterior thoracic nerve, and the 
external cutaneous or musculo-cutaneous nerve, and is continued as the outer 
head of the median nerve. The inner cord gives off the internal anterior 
thoracic nerve, the lesser internal cutaneous nerve, the internal cutaneous nerve, 
and the ulnar nerve, and is continued as the inner head of the median 
nerve. The posterior cord gives off three subscapular nerves and the cir- 
cumflex nerve, and is continued as the rnusculo-spiral nerve. The branches 
of the posterior cord supply the integument and the muscles of the posterior 
aspect of the limb. 
The external anterior thoracic nerve arises from the outer cord about 
the level of the clavicle. It passes forwards and inwards in front of 
the first part of the axillary artery, and breaks up into branches which 
pierce the costo-coracoid membrane, and supply the pectoralis major,, 
entering the muscle on its deep surface; one branch crosses inwards and 
downwards in front of the artery and forms a connection with the in- 
ternal anterior thoracic nerve. 
The internal anterior thoracic nerve takes origin from the inner cord 
in the upper part of the axilla and passes forwards between the axillary 
artery and vein to gain the deep surface of the pectoralis minor,- to- .Internal cutaneous 
Lessor internal cutaneous 
Branch to coraco-brachialis 
Ulnar 
4', Outer head of median 
Inner head of median 
Circumflex, 
Median 
Musculo-cutaneous 
Cutaneous branch of circumflex 
Muscular branches of 
musculo-cutaneous 
Branch to brachialis anticus 
External cutaneous branch) 
of musculo-spiral ( 
Musculo-spiral 
Muscular branches of ( 
musculo-spiral\ 
.Muscular branches of 
median 
Fig. 382.—The Deep Nerves of the Front of the Arm. 
a 
Testut.) 
To face p. 516 Median 
..Ulnar 
Branch to extensor carpi radialis longior 
Musculo-spiral 
.Branch to pronator teres 
Posterior interosseous.' 
Muscular branches | 
Radial 
( Branch to flexor carpi radialis 
( and palmaris longus 
Anterior interosseous. 
Branch to flexor sublimis 
A branch to the flexor profundus 
Branch to the flexor carpi ulnaris 
/ Branch to flexor 
I profundus 
Branch to flexor pollicis longus 
Dorsal branch 
I Communicating branch with 
| internal cutaneous 
Palmar cutaneous branch of median. 
Communicating branch between 1 
radial and musculo-cutaneous ) 
Deep palmar branch 
•Superficial palmar branch 
-Digital branches 
Fig. 383.—Deep Nerves of the Forearm. (L. Testut.) 
To facd p. 517. THE ULNAR NERVE. 
517 
which muscle it is chiefly distributed; one or two branches, however, 
pass through the pectoralis minor and terminate in the pectoralis major. 
Near its origin the trunk of the nerve is joined by a considerable 
communicating branch from the external anterior thoracic nerve. 
The musculo-cutaneous (external cutaneous) nerve (Fig. 382) arises 
from the outer cord in the upper part of the axilla. It is directed down- 
wards and outwards, pierces the coraco-brachialis, and descends in the 
upper arm between the biceps and the brachialis anticus; in this portion 
of its course it supplies the coraco-brachialis, biceps, and brachialis anticus 
muscles. It becomes subcutaneous a little above the level of the bend 
of the elbow at the outer edge of the biceps tendon, and immediately 
afterwards divides into an anterior and a posterior branch, both of which 
are entirely sensory in their distribution. They supply the integument 
of the anterior and posterior surfaces of the radial side of the fore- 
arm. The posterior, the smaller, reaches as far as the wrist; the anterior 
communicates above the wrist with the radial nerve, and distributes its 
terminal filaments to the skin over the thenar eminence. 
The lesser internal cutaneous nerve (nerve of Wrisberg) arises 
from the inner cord at about the same level as the internal anterior 
thoracic nerve; it passes downwards and inwards, crossing at first behind 
the axillary vein, to pierce the fascia in the upper third of the arm. It 
supplies the integument of the inner and posterior region of the arm, 
reaching as far as the elbow, and gradually passing backwards as it 
descends. It is of variable size and ramifies in front of the intercosto- 
humeral nerve, with which it is closely associated in its distribution, the 
two stems being usually connected in the axilla by communicating branches. 
The internal cutaneous nerve takes origin from the inner cord, 
immediately below the nerve of Wrisberg, and descends by the inner and 
anterior margin of the artery to about the middle of the upper arm, 
where it pierces the fascia and divides into an anterior and posterior 
branch. In the axilla it detaches one or two small branches which supply 
the integument of the inner region of the upper part of the arm. The 
anterior and posterior terminal branches descend along the anterior and 
posterior, borders respectively of the inner side of the forearm, supplying 
the skin as far as the level of the wrist. The anterior branch frequently 
communicates, a little above the wrist, with a cutaneous twig of the 
ulnar nerve. 
The ulnar nerve (Figs. 382-386), a trunk of large size, takes origin 
from the inner cord, immediately below the internal cutaneous nerve. It 
descends at first by the inner side of the main artery between it and the 
vein. In the upper third of the arm it gradually separates from the artery 
and passes backwards to pierce the internal intermuscular septum. Con- 
tinuing its course it descends behind the septum, passes between the inner 
cpicondyle and the olecranon, and enters the forearm between the heads of 
the flexor carpi ulnaris. It then descends in a straight line upon the sur- 518 
THE NERVES. 
face of the flexor digitorum profundus to the wrist, being deeply placed 
at first behind the flexor carpi ulnaris, but afterwards lying, with the 
ulnar artery, at the outer edge of the tendon of that muscle. It crosses 
the wrist, passing on the outer side of the pisiform bone, in front of the 
anterior annular .ligament, and terminates on entering the hand by dividing 
into a superficial and a deep branch. 
Supra-acromial - 
Circumflex— 
J Internal cutaneous of 
( muscnlo-spiral 
-Intercosto-humeral 
Upper and lower external 
cutaneous branches of- 
musculo-spiral 
Lesser internal cutaneous 
-Internal cutaneous 
External cutaneous 
Radial 
>orsal branch of ulnar 
Fig. 384.—Diagram of the Cutaneous Nerves of the Posterior Surface of the 
Upper Limb. (J. Y. M.) 
No branches are given off in the arm; hut as the nerve passes the 
elbow-joint one or two articular filaments are detached. 
Branches in the forearm. Muscular branches are supplied to the flexor 
carpi ulnaris and the inner half of the flexor digitorum profundus. Two THE ULNAR NERVE. 
519 
anterior cutaneous offsets are detached to the skin of the lower part of the front 
of the forearm and the inner part of the palm ; the higher of the two, forms 
a communication with the internal cutaneous nerve, the other accompanies 
the ulnar artery to the hand. The dorsal branch leaves the parent trunk 
about two inches above the elbow-joint, and, passing backwards on the 
_Supra-acromial 
Circumflex 
Axillary twig of internal ( 
cutaneous f’ 
Internal cutaneous of ) 
musculo-spiral ) 
Intercosto-humeral 
Lesser internal cutaneous 
Internal cutaneous 
{Upper external cutaneous of 
musculo-spiral 
cutaneous 
Cutaneous twig of ulnar. 
Palmar cutaneous of ulnar 
j Palmar cutaneous of 
( median 
Pig. 385.—Diagram of the Cutaneous Nerves of the Anterior Surface of the 
Upper Limb. (J. Y. M.) 
deep surface of the tendon of the flexor carpi ulnaris, pierces the fascia 
and breaks up into branches which supply the inner area of the back of 
the hand and furnish the dorsal digital nerves for both sides of the little 
finger and the inner side of the ring finger; its terminal twigs form con- 520 
THE NERVES. 
nections with branches of the radial nerve and assist in the supply of the 
outer side of the ring and the inner side of the middle fingers. 
Branches in the hand. The superficial division furnishes a twig to the 
palmaris brevis and some small cutaneous offsets, and then divides into two 
branches, the inner of which becomes the palmar digital nerve for the inner 
side of the little finger, while the outer forms a connection with the median 
nerve and divides into branches for the contiguous sides of the little and 
ring fingers. The deep division, muscular in its distribution, passes back- 
wards among the muscles of the little finger and crosses outwards in 
the palm in company with the deep palmar arch; it supplies the muscles 
of the little finger, the two inner lumbricales, all the interossei, the 
adductor pollicis, and the inner head of the flexor pollicis brevis. 
The median nerve (Figs. 382, 386), continued from the outer and inner 
cords of the plexus, is formed in the third part of the axilla, the inner 
head crossing in front of the artery to join the outer head. In the arm the 
nerve, descending with the artery, is placed at first by the outer side 
of the vessel, but afterwards passes in front of it, and finally gains its inner 
side. In the forearm it passes between the heads of the pronator teres, 
and descends on the deep surface of the flexor digitorum sublimis. At the 
wrist it lies at the outer edge of the tendons of the superficial flexor. In 
entering the hand, it passes in front of the tendons and behind the anterior 
annular ligament, at the lower border of which it splits into an external 
and internal division. No branches are given off in the arm, but at the 
level of the elbow some articular filaments are detached. 
Branches in the forearm. Separate muscular branches are supplied 
to the pronator teres, flexor carpi radialis, palmaris longus, and flexor 
digitorum sublimis. The anterior interosseous nerve descends with the 
anterior interosseous artery, supplies the inner half of the tiexor pro- 
fundus, the flexor pollicis longus, and the pronator quadratus, and furnishes 
an articular filament to the wrist. A small palmar cutaneous branch arises 
a little above the wrist, and passes in front of the annular ligament to 
supply the outer portion of the palm. 
Branches in the hand. The outer terminal division first detaches a 
muscular branch which supplies those short muscles of the thumb, which 
are placed externally to the tendon of the flexor pollicis longus, viz. the 
abductor, the opponens, and the outer head of the flexor pollicis brevis; 
it then divides into two branches, the outer of which furnishes the palmar 
digital nerves for both sides of the thumb, while the inner, after furnishing 
a muscular twig to the outer lumbricalis, becomes the palmar digital nerve for 
the outer side of the index finger. The inner terminal division divides into 
two branches; the outer gives a muscular twig to the second lumbricalis and 
divides into palmar digitcd branches for the contiguous sides of the index and 
middle fingers; the inner branch forms a connection with the ulnar nerve 
and splits to form the digitcd branches for the contiguous sides of the middle 
and ring fingers.  Anterior interosseous 
4, Palmar cutaneous of median 
‘•Ulnar 
Radial < 
Anterior interosseous 
Deep branch of ulnar 
Dorsal branch of ulnar 
Superficial branch of ulnar 
j Branch to muscles 
\ of little finger 
Muscular branch-. 
Cutaneous branch 
8,9, Digital branches 
of median 
Branch to 
adductor pollicis ) 
Branch to fourth 
lumbricalis 
Digital branch 
Branch to inner 
side of little 
finger 
Branch to outer side of \ 
index finger ) 
6, 6', Branches to thumb 
10, Branch to first 
lumbricalis 
11, Branch to second 
lumbricalis 
16, Communication between 
ulnar and median digital 
branches 
20, Branch to third 
lumbricalis 
22, Branch to interosseous 
muscles of second inter- 
space 
Fio. 386.—Nerves of the Palm. (L. Testut.) Musculo-spiral 
Branch to anconeus 
.Branch to brachialis anticus 
,Branch to supinator longus 
t j Branch to extensor carpi radialis 
' ( longior 
Ulnar. 
) Branches to superficial layer 
)’ of extensor muscles 
Branch to extensor carpi ulnaris, 
Posterior interosseous 
) Branches to deep layer of 
| extensor muscles 
Branch to extensor indicis 
Dorsal branch of ulnar 
Posterior interosseous 
Dorsal branch of ulnar 
Fig. 387.—The Posterior Interosseous Nerve. (L. Testut.) 
Dorsal branch of ulnar 
To face p. 521. THE MUSCULO-SPIRAL NERYE. 
521 
The palmar digital nerves, the series of which is completed by the 
branches of the ulnar nerve, descend farther on the fingers than do the 
dorsal nerves. They lie in front of the arteries and reach almost to the 
tips. They supply the palmar surfaces of the digits, and give branches 
posteriorly, which assist in the supply of the dorsal surfaces. In each 
finger the offsets of the palmar nerves ramify in the matrix of the nail; 
in the index and middle fingers, and the outer side of the ring finger, 
branches of the palmar nerves form the chief supply of the integument 
covering the dorsal surfaces of the second and third phalanges. 
The three subscapular nerves (Fig. 380) are derivatives of the posterior 
cord, and take origin in the axilla. They supply the muscles of the posterior 
wall of the axilla. The first or short subscapular supplies the subscapularis; 
the second, middle, or long subscapular ramifies on the deep surface of the 
latissimus dorsi; the third or lowest subscapular detaches a twig to the 
lower border of the subscapularis, and is distributed to the teres major. 
The circumflex nerve arises from the posterior cord, immediately below 
the lowest subscapular. It accompanies the posterior circumflex artery, 
and breaks up into its branches on the deep surface of the deltoid 
muscle. A slender articular filament passes upwards to the shoulder-joint; 
muscular branches supply the deltoid and teres minor, that for the tei’es 
minor being remarkable for the presence of a gangliform swelling. A 
number of cutaneous branches pierce the deltoid and ramify over its lower 
part; one, larger than the others, descends along the posterior border of 
the deltoid, detaches some recurrent branches which ramify over the 
muscle, and supplies the skin of the outer and posterior region of the 
arm for a little distance below the deltoid insertion. 
The musculo-spiral nerve (Figs. 382, 387), the continuation of the posterior 
cord of the plexus, is the largest nerve of the limb. In the axilla it descends 
behind the main artery, but in the upper third of the arm it inclines 
inwards, and, with the superior profunda artery, passes between the outer 
and inner heads of the triceps. It then follows the course of the musculo- 
spiral groove, pierces the external intermuscular septum, and descends 
under cover of the supinator longus and extensor carpi radialis longior, 
between them and the brachialis anticus, to the level of the external 
epicondyle, where it splits into its terminal divisions, the radial and 
posterior interosseous nerves. It detaches cutaneous and muscular branches. 
The internal cutaneous branch, a slender twig, arises from the upper part of 
the main trunk; extending nearly to the elbow, it is distributed to the integu- 
ment of the inner area of the posterior surface of the arm, behind the 
region supplied by the intercosto-humeral nerve. The upper external cutaneous 
branch, detached as the main trunk sweeps round the outer border of the 
humerus, pierces the fascia in the line of the external intermuscular septum, 
aml extends as far as the elbow, supplying the skin of the outer and anterior 
region of the lower part of the arm. The loiver external cutaneous branch, 
considerably larger than the upper, and arising in company with it, or 522 
THE NERVES. 
immediately below it, passes downwards to gain the posterior surface of 
the forearm. Reaching as far as the wrist, it supplies the skin of the 
lower part of the outer region of the arm, and of the back of the forearm. 
The muscular branches supply the triceps, anconeus, supinator longus, and 
extensor carpi radialis longior muscles, and a small twig enters the brachialis 
anticus. One of the branches for the lower part of the inner head of the 
triceps (the ulnar collateral nerve of Krause) springs from the upper part 
of the trunk and descends through the internal intermuscular septum 
within the sheath of the ulnar nerve; the nerve to the anconeus, also 
given off high up, is a long slender trunk which descends through the 
substance of the inner head of the triceps. The nerves to the supinator 
longus and extensor carpi radialis longior and the twig to the brachialis 
anticus spring from the lower part of the main trunk. 
The radial nerve (Figs. 383, 388), the smaller of the terminal branches of 
the musculo-spiral, descends in the forearm at first under cover of the fleshy 
belly of the supinator longus and afterwards along the posterior edge of its 
tendon. It pierces the fascia a little above the wrist and passes on to the 
back of the hand, where it detaches a number of branches to the integument 
of the dorsal surface and breaks up into digital branches. The branches to 
the dorsum of the hand supply the skin of the outer area, and some of them 
sweeping round the radial border are distributed to the outer part of the 
thenar eminence. The dorsal digital nerves supply both sides of the thumb, 
the index and middle fingers, and in most cases the outer side of the ring 
finger. The series of dorsal digital nerves is completed by the offsets of 
the dorsal branch of the ulnar nerve. Communications between the branches 
of the two main trunks take place at the bases of the middle and ring 
fingers, and the number of the digital branches from each source is subject to 
variation. Although the radial nerve is in most cases entirely cutaneous 
in its distribution, occasionally a branch is detached to the abductor 
pollicis muscle. 
The dorsal digital nerves descend on the fingers behind the arteries. 
In the case of the thumb, the little finger, and the inner side of the 
ring finger, they supply the integument as far as the base of the nail; in 
the other cases they do not as a rule pass beyond the distal extremities 
of the first phalanges, the supply of the integument being completed by 
the palmar digital branches. 
The posterior interosseous nerve (Fig. 387), the larger terminal division 
of the musculo-spiral, passes backwards round the neck of the radius, in 
the substance of the supinator brevis, to gain the dorsal surface of the 
forearm, where it descends at first between the superficial and deep layers 
of muscles, and afterwards on the posterior surface of the interosseous 
membrane. At the wrist, much reduced in size, it passes with the tendons 
of the extensor digitorum communis and extensor indicis along the broad 
groove on the back of the radius; on the back of the carpus it terminates 
in a gangliform swelling, from which branches pass to the wrist and to the THE THORACIC NERVES. 
523 
articulations of the hand. The branches which it detaches on its course 
are entirely muscular, and supply all the muscles, superficial and deep, of 
the back of the forearm, with the exception of the supinator longusy 
the extensor carpi radialis longior, and the anconeus. The muscles to 
which it is distributed are—the supinator brevis and the extensores carpi 
radialis brevier, digitorum communis, minimi digiti, carpi ulnaris, ossis 
metacarpi pollicis, primi internodii pollicis, secundi internodii pollicis, and 
indicis. 
THE THOEACIC NERVES. 
The thoracic nerves are twelve in number. The first eleven are usually 
called intercostal nerves, the twelfth is named the last dorsal. They do not 
unite with one another to form plexuses, but course independently round 
the body wall and terminate as the anterior cutaneous nerves of the thorax 
and abdomen. On their way they supply the muscles, and give off lateral 
cutaneous branches. Each nerve is connected to a corresponding ganglion 
of the sympathetic chain by two branches, one of which has the character- 
istic appearance of a spinal nerve, the other that of a sympathetic nerve. 
The upper six trunks course in the wall of the thorax; the lower six, in 
an increasing degree in succession from above downwards, traverse the 
abdominal wall before terminating in their anterior cutaneous twigs. 
The upper six intercostal nerves. The first nerve is of large size,, 
but its greater part immediately passes upwards in front of the hinder 
part of the first rib to join the brachial plexus; the remainder of the 
nerve passes onwards as an intercostal trunk. Each nerve passes behind 
the sympathetic chain, and in front of the external intercostal muscle, and 
at first, in the region where the internal intercostal muscle is deficient,, 
lies immediately behind the pleura. Further outwards it passes between 
the two layers of the intercostal muscles, and occupies the subcostal 
groove, lying, except in the case of the first two or three, below the 
companion artery. More anteriorly it sinks into the substance of the 
internal intercostal muscle, and finally gains its deep surface, crossing in 
front of the triangularis sterni muscle and the internal mammary artery. 
The anterior cutaneous branches are of small size. They pierce the 
thoracic wall by the side of the sternum, and are chiefly directed outwards 
to supply the integument over the great pectoral muscle. That of the first 
nerve is frequently absent. 
The lateral cutaneous branches arise between the intercostal muscles, and 
run forwards for a little distance with the main trunks. Passing outwards 
they pierce in succession the wall of the thorax along a line drawn 
vertically downwards immediately behind the anterior wall of the axilla,. 
and reach the surface between the digitations of the serratus magnus. 
The first nerve usually gives off no lateral branch. The lateral branch of 
the second nerve is known as the intercosto-humeral nerve (Fig. 380); it is of 
large size, is directed outwards and backwards through the axilla, where it 
forms communications with the nerve of Wrisberg, and is distributed to the 524 
THE NERVES. 
integument of the inner and posterior part of the arm, reaching nearly 
to the elbow. The remaining lateral branches divide, before reaching the 
surface, into anterior and posterior twigs, which ramify subcutaneously, and 
form connections in front with the supraclavicular and anterior cutaneous 
nerves, and behind with the cutaneous offsets of the posterior primary 
divisions. The posterior cutaneous twig of the third nerve is large, and 
supplies the integument of the base of the axilla, forming connections 
with the intercostodiumeral nerve. 
The muscular branches supply the levatores costarum, the external and 
internal intercostal muscles, the serratus posticus superior, and the tri- 
angularis sterni. 
The lower five intercostal nerves. These are at first similar in course 
to the upper nerves; eventually, however, they enter the abdominal wall 
and run forwards between the internal oblique and transversalis muscles. 
The anterior cutaneous branches, somewhat irregular, reach the surface in a 
double row by the outer and inner borders of the rectus. The lateral 
cutaneous branches appear between the digitations of the external oblique 
muscle, and divide like the majority of those of the higher nerves into 
anterior and posterior twigs. The muscular branches supply the levatores 
costarum, the external and internal intercostal muscles, the serratus 
posticus inferior, the transversalis, the rectus, the internal oblique, and the 
external oblique. 
The last dorsal nerve passes outwards in company with the first 
lumbar artery, escaping below the ligamentum arcuatum externum, crossing 
anteriorly the quadratus lumborum muscle, and piercing the posterior tendon 
of the transversalis muscle. Its subsequent course is similar to that of 
one of the lower intercostal nerves. The lateral branch does not divide 
into two, but, piercing the external oblique some little distance above 
its insertion, is continued downwards over the iliac crest, a little behind the 
anterior superior spine, and supplies the integument of the anterior part 
of the gluteal region. The other branches are similar to those of one of 
the lower intercostal nerves. 
THE LUMBAR PLEXUS. 
The lumbar plexus (Figs. 389, 390) is formed in front of the transverse 
processes, in the substance of the psoas muscle, from the anterior divisions 
of the first four lumbar nerves. The first receives a slender branch from 
the last dorsal nerve, and detaches a connecting branch to the second 
lumbar; the second, third, and fourth break up into branches which form 
the roots of the chief derivatives of the plexus ; the fourth gives off a 
connecting branch, which descends to the fifth and assists in forming 
the lumbo-sacral cord. Each of the nerves is joined by communicating 
branches from the lumbar ganglia of the sympathetic chain. The branches 
of the plexus are the ilio-hypogastric, the ilio-inguinal, the genito crural, 
the external cutaneous, the anterior crural, the obturator, and, in occasional 1, External cutaneous of musculo-spiral 
Radial 
Musculocutaneous 
5, Communications between 
ulnar and radial 
Dorsal branch of ulnar- 
| External dorsal branch 
"I to thumb 
Inner dorsal branch 1 
to little finger f 
8, Twigs from palmar 
digital branches of 
ulnar 
9, Twigs from palmar digital 
bi'anches of median 
Pig. 388.-- Nerves of the Dorsdm of the Hand. (L. Testut.) 
To face p. 524. Internal oblique 
External oblique 
Transversalis 
1 lio -h y pogastric 
Ilio-inguinal 
llio-hy pogastric 
Ilio-hypogastric_ 
Iliac branch of)’ 
ilio-hypogastric j 
Ilio-hypogastric 
External cutaneous 
Ilio-inguinal 
.Genito-crural 
J Genital branch of 
( genito-crural 
j Crural branch of 
< genito-crural 
Anterior crural 
External 
cutaneous 
Fig. 389.—The Branches op the Lumbar Plexus. The psoas has been removed on 
the right side, d. Tendon of external oblique ; e, internal saphenous vein ; /, rectum ; 
g, bladder ; h, crura of diaphragm ; i, spermatic cord ; 4, genito-crural; 4', genital branch 
of genito-crural; 4", crural branch of genito-crural; 5, anterior crural; 6, obturator ; 7, 
lumbo-sacral cord ; 8, branch from last dorsal to first lumbar nerve; 9, branches to 
quadratus lumborum ; 10, branch to iliacus ; 11, accessory obturator ; 12, dorsal nerve of 
penis; 13, gangliated cord of sympathetic ; 14, communicating branches with sympa- 
thetic. (L. Testut.) 
To face p. 525. THE LUMBAR PLEXUS. 
525 
circumstances, the accessory obturator; in addition, from the first three 
trunks small twigs are detached to the psoas and quadratus muscles. 
The ilio-hypogastric and the ilio-inguinal arise by a common trunk from 
the first lumbar nerve; the genito-crural takes origin by separate roots 
from the second and third; the obturator springs from the anterior parts 
of the second, third, and fourth nerves; the external cutaneous arises 
from the posterior parts of the second and third nerves; the anterior crural 
is derived from the posterior parts of the second, third, and fourth; the 
accessory obturator, when present, springs by one or more roots from the 
obturator nerve or from the lower part of the plexus. 
Connecting branch from last dorsal 
Ilio-hypogastric. 
Ilio-inguinal- 
Genito-crural 
External cutaneous' 
Anterior crural 
Obturator Connecting branch to fifth lumbar 
Fig. 390.—Diagram of the Lumbar Plexus, a, Communicating branches to synr 
pathetic; b, to psoas and quadratus muscles. (J. Y. M.) 
The ilio-hypogastric nerve emerges from the outer border of the psoas, 
and, descending obliquely towards the iliac crest, crosses in front of the 
quadratus lumborum; it then pierces the transversalis and detaches its 
iliac or lateral branch. The remainder of the nerve courses forwards 
and downwards, passing through the internal oblique, and finally emerges 
as an anterior cutaneous nerve, about an inch above the superficial ab- 
dominal ring. Muscular branches are supplied to the three broad muscles 
of the abdominal wall, and to the rectus and the pyramidalis; connecting 
twigs pass to the ilio-inguinal and occasionally to the last dorsal. The 
iliac branch, after piercing the internal and external oblique muscles, crosses 
the crest of the ilium about two inches behind the anterior superior spine. 
Its branches, which all pass to the integument, descend as far as the 
level of the great trochanter, forming connections with those of the lateral 
branch of the last dorsal nerve in front, and the posterior divisions of the 
lumbar nerves behind. 
The ilio-inguinal nerve is more slender than the ilio-hypogastric, beneath 526 
THE NERVES. 
and in close proximity to which it emerges from the psoas, crosses the 
quadratus lumborum, and courses through the abdominal wall. It becomes 
subcutaneous by passing through the superficial abdominal ring. Muscular 
branches are detached to the three broad muscles. The terminal twigs are 
distributed to the scrotum or labium, and to the upper and inner part of 
the thigh. Occasionally the ilio-hypogastric and ilio-inguinal nerves are 
united for a considerable distance into one trunk. 
The genito-crural nerve emerges on the anterior surface of the psoas, 
either as a single trunk or already divided. It descends in front of 
the muscle, and splits at a variable spot into its terminal divisions. 
The genital division accompanies the spermatic vessels along the inguinal 
canal, and supplies the cremaster muscle. The crural division descends in 
front of the external iliac vessels, enters the thigh, and finally, by the 
outer margin of the femoral artery, about two inches below Poupart’s 
ligament, pierces the fascia lata; its terminal twigs supply the integument 
of the upper and anterior part of the thigh, and form connections with 
those of the middle and internal cutaneous branches of the anterior crural 
nerve. 
The external cutaneous nerve emerges at the outer border of the 
psoas, a little below the level of the ilio-inguinal nerve. It crosses in 
front of the iliacus and, in close proximity to the anterior superior spine, 
passes behind Poupart’s ligament; in the thigh it immediately breaks up 
into anterior and posterior branches. The posterior branch, the smaller, 
passes backwards, pierces the fascia near the outer margin of the gluteus 
maximus, and distributes its offsets to the integument of the posterior and 
outer part of the upper two-thirds of the thigh. The anterior branch, passing 
downwards, pierces the deep fascia three or four inches below Poupart’s 
ligament, and ramifies over the outer part of the thigh, supplying the skin 
as far at the level of the knee, some of the terminal twigs reaching the 
patellar plexus. 
The obturator nerve emerges from the inner border of the psoas, 
and courses forwards along the wall of the true pelvis to the obturator 
eanal, lying immediately above the obturator vessels. Near the place of 
exit from the pelvis it divides into anterior and posterior branches. The 
■anterior branch passes through or over the obturator externus, and descends 
in the thigh on the anterior surface of the adductor brevis, and behind the 
pectineus and adductor longus. At the lower border of the adductor 
longus it forms communications with the long saphenous and internal 
cutaneous nerves; it usually terminates as a cutaneous twig, piercing the 
fascia at the anterior border of the gracilis, about half-way down the 
thigh. It supplies muscular branches to the adductor longus and gracilis, 
and occasionally to the adductor brevis and pectineus. 
The posterior branch pierces the obturator externus and descends in the 
thigh behind the adductor brevis. It supplies muscular offsets to the 
obturator externus, adductor brevis, and adductor magnus, and furnishes THE ANTERIOR CRURAL NERVE. 
527 
a small branch which enters the hip-joint through the cotyloid notch. It 
terminates in a long slender nerve, which descends to the knee-joint, 
coursing first in the substance of the adductor magnus, then lying by 
the inner side of the artery in the popliteal space, and finally piercing 
the posterior ligament. 
The accessory obturator nerve, when present, descends along the inner 
margin of the psoas, crosses in front of the superior ramus of the pubis, 
and joins the anterior division of the main nerve or terminates in the 
pectineus. 
The anterior crural nerve (Figs. 389, 394), the largest offset of the plexus, 
emerges from the outer border of the psoas, a little below the level at which 
the external cutaneous nerve escapes. It descends in the groove between the 
psoas and iliacus, passes behind Poupart’s ligament, and, immediately after 
entering the thigh, breaks up, by the outer side of the femoral artery, 
into its terminal branches. Within the abdomen it furnishes a number of 
twigs to the iliacus. The terminal branches are divided into two groups, 
one of which is mainly cutaneous in its distribution, the other chiefly 
muscular. The first or more superficial group comprises the internal and 
middle cutaneous nerves and the nerves to the sartorius. The deeper 
group is formed of the nerves to the pectineus and quadriceps, and one 
cutaneous nerve, the long saphenous. 
The nerve to the pectineus, a slender twig, is directed inwards behind 
the femoral artery and enters the anterior surface of the muscle. The 
nerves to the sartorius, usually two or three in number, are at first incor- 
porated with the middle cutaneous trunk; they enter the upper part of 
the muscle. The nerves to the rectus femoris, one or two in number, pass 
directly to the deep surface of the muscle in its upper part; from one of 
them a branch is usually directed backwards to the hip-joint. The nerves 
to the vasti and crureus muscles form a number of large branches which 
descend for a considerable distance on the surface of the muscles which 
they supply; terminally they furnish twigs to the knee-joint. 
The middle cutaneous nerve divides, close to its origin, into two branches 
which usually pierce the fascia lata separately, about four inches below 
Poupart’s ligament; the outer generally traverses the sartorius muscle, 
while the inner crosses in front of it. They supply the integument of the 
lower two-thirds of the front of the thigh, their terminal branches reaching 
the patellar plexus. 
The internal cutaneous nerve, in its descent, gradually crosses the femoral 
artery in front. In the upper part of the thigh it detaches a number of 
twigs which reach the surface by the side of the internal saphenous vein. 
About the middle of the thigh it divides into an anterior and a posterior 
branch. The anterior branch, the larger, descends by the anterior 
border of the sartorius, pierces the fascia in the lower third of the thigh, 
supplies the integument in the vicinity of the inner side of the knee, 
and furnishes branches to the patellar plexus. The posterior branch, 528 
THE NERYES. 
after forming connections with the internal saphenous and obturator 
nerves, descends by the posterior border of the sartorius, perforates the 
fascia about the level of the knee-joint, and distributes its branches to 
the upper part of the inner side of the leg. 
Last dorsal 
Ilio-hypogastric _ 
Posterior divisions of upper 
lumbar nerves 
External cutaneous. 
Posterior divisions of 
sacral nerves 
C Cutaneous branch from 
[ anterior division of 
t fourth sacral 
Small sciatic. 
Pudendal branch of small sciatic 
/■Small sciatic 
Small sciatic _ 
Posterior branch of 
internal cutaneous 
External saphenous i 
(peroneal communicating) / 
I External saphenous (tibial 
[ communicating) 
-Twigs of internal saphenous 
I Plantar cutaneous branch of 
\ posterior tibial 
Pig. 391.—Diagram of the Distribution of the Cutaneous Nerves upon the 
Posterior Surface of the Lower Limb. (J. Y. M.) 
The internal saphenous nerve, in its descent, gradually approaches the 
femoral artery ; in the middle third of the thigh the nerve accompanies 
the artery in Hunter’s canal, lying in front of it and a little to its outer 
side. When the artery passes backwards into the popliteal space, the 
nerve, continuing its straight course, descends on the deep surface of 
the sartorius, and finally pierces the fascia below the level of the knee, THE ANTERIOR CRURAL NERVE. 
529 
emerging between the tendons of the sartorius and gracilis. In the thigh 
the nerve furnishes twigs which, uniting with branches of the obturator and 
the posterior division of the internal cutaneous nerve, constitute the 
subsartorial plexus. A little above the level of the knee a considerable 
Ilio-inguinal 
Genito-crural (crural branch) 
r External cutaneous 
Twig from internal cutaneous- 
Obturator (occasional) 
cutaneous branch) f 
.Middle cutaneous 
Anterior branch of internal) 
cutaneous ) 
Patellar branch of internal \ 
saphenous j 
Internal saphenous 
Cutaneous branches of external 
' popliteal 
Musculo-cutaneous _ 
Musculo-cutaneous 
External saphenous 
Internal saphenous 
Anterior tibial 
Fig. 392.—Diagram of the Distribution of the Cutaneous Nerves upon the 
Anterior Surface of the Lower Limb. (J. Y. M.) 
branch is detached which, piercing the sartorius, turns outwards and 
1 amities in front of and below the patella, forming along with branches of 
the external, middle, and internal cutaneous nerves, the patellar plexus. In 
the leg the internal sajxhenous nerve descends in the superficial fascia, by 
tile side of the internal saphenous vein, and supplies the skin of the inner 530 
THE NERVES. 
region. At the ankle it passes in front of the internal malleolus. Its 
terminal branches communicate with offsets of the musculo-cutaneous nerve, 
and ramify upon the inner side of the metatarsal region of the foot. 
The sacral plexus (Fig. 395) is formed by the union with one another of the 
lumbo-sacral cord (which results from the junction of the descending branch 
of the fourth with the fifth lumbar nerve), and the first, second, third, 
and a portion of the fourth sacral trunks. These are chiefly continued 
THE SACRAL PLEXUS. 
f Connecting branch from 
( fourth lumbar 
9 Lv 
Superior gluteal 
Inferior gluteal. 
External popliteal! 
portion of great > 
sciatic J 
■?Sni 
Small sciatic 
Internal popliteal portion ) 
of great sciatic ( 
9 SIV 
i Sv 
Pudic^ 
C 
Fig. 393.—Diagram of the Sacral and Coccygeal Plexuses. 1, To pyriformis; 2, 
to quadratus femoris ; 3, to obturator internus ; 4, cutaneous branch of fourth sacral; 5, 
muscular branch of fourth sacral; 6, 7, muscular and cutaneous branches of coccygeal 
plexus; 8, visceral branches ; 9, communicating branches with sympathetic. The great 
sciatic is represented as split up into its terminal branches. (J. Y. M.) 
into two nerves, the great sciatic above and the pudic below, but several 
subsidiary branches are also given off. The great sciatic, the largest nerve 
of the body, is formed from the larger parts of the lumbo-sacral cord, and 
the first, second, and third sacral trunks; in it may be distinguished two 
portions, one more anterior which eventually becomes the internal popliteal 
nerve, the other more posterior destined to become the external popliteal nerve. 
The pudic nerve, much smaller than the great sciatic, is formed from portions 
of the third and fourth trunks, and frequently receives a fasciculus from 
the second. The subsidiary nerves are—the superior gluteal which springs 
from the back of the lumbo-sacral cord and the first sacral trunk; the 
inferior gluteal from the back of the first and second sacral trunks; the 
small sciatic from the back of the second and third sacral trunks; the 
nerve to the pyriformis from the second or third sacral trunk; the nerve External cutaneous 
Anterior crural 
6, Nerve to vastus externus 
Middle cutaneous 
4, Internal cutaneous 
4', Branch to peotineus 
b, Femoral vein 
Spermatic cord 
.Branch to pectineus 
9, Obturator 
a, Femoral artery 
Nerve to rectus femoris 
Internal saphenous 
Nerve to vastus internus 
) Patellar branch of 
( internal saphenous 
Internal saphenous 
Fig. 394.—Deep Nerves of the Front of the Thigh. (L. Testut.) 
To face p. 530. Aorta 
External cutaneous nerve 
.Sympathetic 
SH 
. Ramus communicans 
..Slll 
.SIV 
.Coccygeal plexus 
Crural branch of ) 
genito-crural \ 
Inferior haemorrhoidal nerve 
I Perineal nerve 
f 
.Small sciatic nerve 
Symphysis^' 
1 Superficial branches 
/ of perineal 
Dorsal nerve of left side 
Dorsal nerve of penis 
1 Pudendal branch of small sciatic 
Transversus perinei 
Fm 395 —The Sacral Plexus of the Right Side with its Branches, h, Common 
iliac artery; c, internal iliac artery ; d, external iliac artery ; f, bulb; 1, great sciatic 
nerve ; 2, lumbo-sacral cord ; 3, a branch to levator ani; 4, nerve to obturator mternus ; 
5 visceral branches ; 8, dorsal nerve of penis ; 9"', deep branches of perineal; 13, genito- 
crural nerve ; 13', genital branch of genito-crural; 14, obturator nerve; 15, superior 
gluteal nerve j 18, rami communicantes. (L. Testut.) 
To face p. 531- THE SACEAL PLEXUS. 
531 
to the obturator interims from the second and third sacral trunks; the 
nerve to the quadratus femoris from the third sacral trunk ; and some 
visceral branches from the second, third, and fourth sacral trunks. 
The lumbo-sacral cord descends over the base of the sacrum; the other 
trunks escape by the anterior sacral foramina. Uniting with one another, 
they rest upon the pyriformis muscle, and all the branches, with the 
exception of the visceral nerves and the nerve to the pyriformis, escape fz’om 
the pelvis by the great sacro-sciatic foramen. The lumbo-sacral cord and 
the first two sacral trunks are of large size, the third and fourth sacral 
are comparatively small. Each of the trunks is connected with the sym- 
pathetic by a short branch of communication. 
The superior gluteal nerve (Fig. 396), from the lumbo-sacral cord and the 
first sacral trunk, escapes through the great sacro-sciatic foramen, above the 
pyriformis muscle, in company with the gluteal artery. It ramifies between 
the gluteus medius and minimus, supplying them both, and sends its terminal 
branch forwards through their conjoined anterior margins to the tensor 
vaginae femoris. 
The inferior gluteal nerve, from the first and second sacral trunks, 
escapes with the sciatic artery below the pyriformis muscle; it breaks 
up into numerous branches which supply the gluteus maximus, entering 
it on its deep surface. It is frequently partially incorporated with the 
small sciatic nerve. 
The small sciatic nerve, from the second and third sacral trunks, 
is cutaneous in its distribution. It leaves the pelvis below the pyri- 
formis, and descends along the middle line of the posterior surface of 
the limb, as far as the calf of the leg. After escaping from the cover of 
the gluteus maximus it descends in the thigh beneath the fascia lata, and 
becomes subcutaneous at the level of the knee. It distributes from both 
sides numerous branches to the integument, and near its termination com- 
municates with the short saphenous nerve. Four or five branches of 
considerable size turn backwards at the inferior border of the gluteus 
maximus muscle and end in the skin of the lower part of the gluteal region. 
One offset, the pudendal branch, courses inwards and forwards below the 
tuberosity of the ischium to the scrotum or labium. 
The nerve to the obturator internus, from the second and third sacral 
trunks, escapes below the pyriformis along with the pudic artery, and 
bending round the ischial spine re-enters the pelvis by the small sacro- 
sciatic foramen to reach the inner surface of the muscle. On its way it 
supplies a twig to the gemellus superior. 
The nerve to the quadratus femoris, from the third sacral trunk, 
escaping below the pyriformis, passes downwards on the deep surface of 
the gemelli muscles, the lower of which it supplies on its way. It enters 
the quadratus on the deep surface. 
The pudic nerve (Fig. 395), derived from the third and fourth sacral 
trunks, and occasionally from the second, escapes below the pyriformis, 532 
THE NERVES. 
and, in company with the pudic artery, by the inner side of which it 
is placed, bends round the small sacro-sciatic ligament to reach the ischio- 
rectal fossa, at the posterior extremity of which it breaks up into three 
branches. The three branches, along with the artery, continue their course 
forwards for some distance on the outer wall of the fossa in a canal formed, 
by the obturator fascia. 
The most posterior of the three, the inferior haemorrhoidal, separates 
itself from its neighbours in the hinder part of the fossa; it is directed 
downwards, forwards, and inwards, and breaks up into numerous twigs, 
which, travelling through the fatty tissue, reach the external sphincter 
muscle and the integument around the anus. 
The second branch, the perineal nerve, pierces the wall of the canal a 
little further forwards, and breaks up into superficial and deep branches, 
respectively cutaneous and muscular in their distribution. The superficial 
branches, two in number, the external and internal superficial 'perineal nerves, 
run forwards, passing through or beneath the superficial transverse muscle. 
They break up, as they traverse Colies’s fascia, into numerous long slender 
twigs, the branches of which form communications with those of the 
pudendal and inferior haemorrhoidal nerves; they supply the skin of the 
anterior part of the perineal space and the scrotum or labium. The deep 
branch of the perineal nerve, or deep perineal nerve, supplies the levator ani, 
transversus perinei, compressor urethrae, bulbo-cavernosus or sphincter 
vaginae, and the ischio-cavernosus, and furnishes a twig to the bulb. 
The third main branch, the dorsal nerve of the penis or clitoris, accom- 
panies the artery to its termination, lying above it in the anterior part of 
the fossa, by its outer side between the layers of the triangular ligament, 
and below and external to it in the terminal portion of its course. It 
supplies, in passing, a branch to the corpus cavernosum, and ramifies freely 
on the integument of the penis; in the female it is much smaller than in 
the male, and ramifies on the clitoris. 
THE GREAT SCIATIC NERVE. 
The great sciatic nerve (Fig. 396) escapes from the pelvis through the great 
sacro-sciatic foramen, below the lower border of the pyriformis muscle, and 
passes downwards, resting in succession upon the gemellus superior, ob- 
turator interims, gemellus inferior, quadratus femoris, and adductor magnus, 
to a little beyond the middle of the thigh, where it divides into the 
internal and external popliteal nerves. In the upper part of its course, 
on the deep surface of the gluteus maximus, it lies between the ischial 
tuberosity and the great trochanter, being placed a little nearer to the 
former than the latter prominence; further on it is covered posteriorly 
by the long head of the biceps muscle. The place of division is variable, 
and may be found at any spot in the upper two-thirds of the thigh ; and 
occasionally the internal and external popliteal nerves spring directly from Superior gluteal nerve 
Superior gluteal nerve 
Inferior gluteal nerve 
Pudic nerve and artery | 
Inferior gluteal nerve 
Small sciatic nerve 
Sciatic artery 
Inferior gluteal nerve 
Great sciatic nerve 
4', Pudendal branch 
Small sciatic nerve 
Nerve to short head of biceps 
Nerve to semitendinosus 
Nerve to semimembranosus 
Nerve to long head of biceps 
Internal popliteal nerve 
Branches to gastrocnemius 
External popliteal nerve 
( Peroneal communicating 
( nerve 
Tibial communicating nerve 
Cutaneous branch of 
( external popliteal 
Fig. 396.—Deep Nerves of the Back of the Hip and Thigh. (L. Testut.) 
To face p. 532. Great sciatic 
4, Branches to gastrocnemius \ 
5, Tiblal communicating i 5 
Popliteal artery. \ 
External popliteal 
Branches to gastrocnemius 
Internal popliteal 
Nerve to plantaris 
Nerve to popliteus 
Peroneal communicating 
Branch to soleus 
( Cutaneous branch of external 
( popliteal 
Branch to soleus 
Posterior tibial artery 
Peroneal artery 
Posterior tibial 
Nerve to tibialis posticus 
Nerve to flexor digitorum longus 
Nerve to flexor pollicis longus 
Plantar cutaneous branch 
Posterior tibial artery 
Fig, 397.—Beep Nerves of the Back of the Leg. (L. Testut.) 
To face p. 533, THE GREAT SCIATIC NERVE. 
533 
the plexus. The great sciatic nerve, or, when it is. split at or near its 
origin, the inner of the two divisions, furnishes muscular branches to the 
semimembranosus, semitendinosus, and both heads of the biceps, and gives 
an additional twig to the adductor magnus. 
THE INTERNAL POPLITEAL (THE TIBIAL) NERVE. 
The internal popliteal nerve (Fig. 396), the larger of the two divisions, 
continuing the straight course of the parent trunk, descends along the 
middle line of the popliteal space, at the lower end of which, passing 
under cover of the soleus, it becomes the posterior tibial nerve. It is the 
most superficial of the large structures contained in the space, and is at 
first external to the main artery; but afterwards, crossing it superficially, it 
is placed by its inner side. It detaches one cutaneous, three articular, 
and several muscular branches. 
The cutaneous branch, the tibial communicating nerve, is one of the 
roots of the external saphenous nerve; it descends on the surface of the 
gastrocnemius and underneath the fascia to the lower third of the leg, 
where, becoming subcutaneous, it is joined by the peroneal communicating 
branch from the external popliteal nerve. The resulting trunk, the 
external or short saphenous nerve, passes behind and below the outer malleolus 
and runs forwards on the outer side of the foot, forming communications 
with the musculo cutaneous nerve, and supplying terminally the outer side 
of the little toe. Occasionally its area of supply is extended to the 
dorsum of the foot and to the third and fourth toes; the peroneal com- 
municating branch is sometimes very small, the external saphenous nerve 
being in these circumstances mainly continued from the tibial communicating 
trunk. 
The articular branches, three in number, and of small size, accompany the 
superior and inferior internal, and the azygos articular arteries respectively. 
Their terminal twigs pierce the capsular ligament of the knee. 
The muscular branches supply both heads of the gastrocnemius, the plan- 
iaris, the soleus, and the popliteus. The branch to the last-named muscle 
descends on its posterior surface, and turns round its lower border to enter 
it anteriorly. 
The posterior tibial nerve (Fig. 397) accompanies the posterior tibial 
artery, and divides terminally, between the internal malleolus and the 
heel, into the internal and external plantar nerves. It is at first internal 
to the vessels, but afterwards crossing behind them, descends by their 
outer border. It supplies muscular branches to the soleus, tibialis posticus, 
flexor digitorum longus, and flexor pollicis longus. A cutaneous twig, the 
calcameo-plantar nerve, is detached from the lower part of the trunk ; it pierces 
the internal annular ligament and ramifies in the skin of the heel and ot 
the inner side of the posterior part of the sole. One or two small articular 
filaments are described as passing from the posterior tibial nerve to the 
ankle-joint. 534 
THE NERVES. 
The internal plantar nerve (Fig. 398), the larger of the divisions of the 
posterior tibial, is comparable in its distribution to the median nerve in 
the hand. Concealed at first by the abductor hallucis, it afterwards runs 
forwards between that muscle and the flexor digitorum brevis, furnishing 
branches to both, and detaching a number of cutaneous twigs, which appear 
superficially along the line of the internal intermusmlar septum. Opposite 
the base of the first metatarsal bone it gives off the plantar cutaneous branch 
for the inner side of the great toe, which nerve on its way forwards 
detaches a twig to the flexor hallucis brevis muscle. 
About the middle of the foot the internal plantar nerve breaks up 
into three digital branches. The first furnishes a twig to the first 
lumbricalis muscle, and divides into plantar branches for the contiguous 
sides of the first and second toes. The second divides into branches 
for the contiguous sides of the second and third toes; it occasionally 
supplies the second lumbricalis muscle. The third, after receiving a 
communicating branch from the external plantar nerve, supplies the con- 
tiguous sides of the third and fourth toes. The plantar digital nerves 
supply the plantar surfaces of the toes, and each detaches a dorsal branch 
which ramifies under the nail. 
To sum up, the internal plantar nerve supplies muscular branches to 
the flexor digitorum brevis, the abductor hallucis, the flexor hallucis brevis, 
the first lumbricalis, and, occasionally, the second lumbricalis. Its cutaneous 
branches (a) ramify on the inner portion of the sole, and {b) form the 
plantar digital nerves of the first, second, and third toes, and the inner 
side of the fourth. 
The external plantar nerve (Fig. 398), comparable to the ulnar in the 
hand, is directed obliquely outwards in the sole between the flexor brevis 
digitorum and the flexor accessorius, in company with the external plantar 
artery. It supplies on its way muscular branches to the flexor accessorius 
and abductor minimi digit! muscles, and furnishes one or two cutaneous 
twigs, which reach the surface along the line of the external intermuscular 
septum. Opposite the base of the fifth metatarsal bone it divides into 
a superficial and a deep branch. 
The superficial branch divides into outer and inner portions. The outer 
portion detaches offsets to the flexor minimi digiti brevis, and, as a rule, 
to the interosseous muscles of the fourth space, and is afterwards continued 
as the plantar cutaneous nerve of the outer side of the little toe. The inner 
branch, after giving off a slender twig to join the outermost digital branch 
of the internal plantar nerve, divides to supply the contiguous sides of 
the fourth and fifth toes. 
The deep branch of the external plantar nerve bends forwards and 
inwards, in company with the plantar arterial arch, on the deep surface 
of the flexor tendons. It is entirely muscular in its distribution, supplying 
the three outer lumbricales, the interosseous muscles of the three inner 
spaces, the adductor hallucis, and the transversus pedis. Posterior tibial nerve 
Posterior tibial artery 
Branch to accessorius 
Branch to flexor 
digitorum brevis 
Internal plantar 
12, Branch to abductor minimi 
digiti 
Branch to abductor hallucis. 
Branch to flexor 
digitorum brevis 
External plantar 
Branch to abductor hallucis.' 
Deep branch 
Superficial branch 
Branch to flexor minimi 
digiti brevis 
Nerve of inner side of 1 
great toe j 
Internal plantar 
Connection with internal plantar 
Branch to flexor 
hallucis brevis 
Branches to lumbricales 
15, Digital branches 
Fig. 398.—Deep Nerves of the Sole. (L. Tcstut.) 
To face p. 534 Patellar branch of internal saphenous 
External popliteal 
Musculo-cutaneous 
Internal saphenous 
Branch to peroneus longus 
Branch to extensor 
digitorum longus 
Branch to tibialis anticus 
Anterior tibial nerve 
Branch to extensor 1 
hallucis longus J 
Musculo-cutaneous 
Anterior tibial artery 
External branch of anterior 
tibial 
Extensor digitorum brevis 
Extensor digitorum brevis 
Dorsal digital nerve 
Digital branch of anterior tibial 
Dorsal digital nerve 
Pig. 399.—Deep Nerves of the Front of the Leg. (L. Testut.) 
Dorsal digital nerves 
To face p. 535. THE EXTERNAL PLANTAR NERVE. 
535 
The muscular branches of the external plantar supply the following 
muscles: flexor accessorius, abductor minimi digiti, flexor minimi digiti 
brevis, transversus pedis, adductor hallucis, all the interosseous muscles, 
and the two or three outer lumbricales. The cutaneous branches (a) ramify 
on the outer region of the sole, and (b) form the plantar digital nerves 
of the little toe and the outer side of the fourth. 
THE EXTERNAL POPLITEAL (THE PERONEAL) NERVE. 
The external popliteal (Fig. 396) descends along the outer margin 
of the popliteal space, at first under cover of the biceps muscle and after- 
wards along the inner edge of its tendon. Immediately below the head of 
the fibula, it bends forwards, pierces the origin of the peroneus longus, 
and divides into its terminal branches, the musculo-cutaneous and anterior 
tibial nerves. On its way it detaches two cutaneous and three articular 
offsets. 
Of the cutaneous branches one, the smaller, supplies the skin of the outer 
and posterior region of the upper part of the leg; the other, the peroneal 
communicating, joins the tibial communicating in the lower third of the 
leg to form the external saphenous nerve. 
The articular branches are small: two of them accompany the external 
articular arteries to the knee; the third, the recurrent articular branch, 
arising near the termination of the parent trunk, is directed upwards, 
through the tibialis anticus, to the joint. 
The musculo-cutaneous nerve (Fig. 399), one of the terminal divisions 
of the external popliteal, descends between the peronei and extensor 
digitorum longus, supplying on its way the peroneus longus and brevis, 
and furnishing some slender cutaneous offsets. A little below the middle 
of the leg it pierces the fascia and divides into an outer and an inner 
branch. 
The outer branch detaches filaments to the skin of the front of the lee, 
O* 
ramifies over the outer side of the dorsum of the foot, forming communi- 
cations with the internal branch on the one side and the external 
saphenous nerve on the other, and terminates in dorsal digital branches 
for the contiguous sides of the fifth and fourth and the fourth and third 
toes; its area of supply is occasionally diminished in extent by the 
encroachment, from the outer side, of the external saphenous nerve. 
The inner branch detaches filaments to the front of the leg and ramifies 
over the inner side of the dorsum, communicating on the one side with 
the outer branch and on the other with the internal saphenous nerve; it 
terminates usually in three branches. The inner of these supplies the inner 
side of the great toe, the second joins the terminal twig of the anterior 
tibial nerve which supplies the contiguous sides of the first and second 
toes, the third supplies the contiguous sides of the second and third toes. 
The dorsal digital nerves (Fig. 400) supply the integument in each case as 
far as the base of the nail; they are very variable in their mode of origin. 536 
THE NERVES. 
The anterior tibial nerve (Fig. 399) passes forwards and downwards 
from the place of division of the external popliteal, and traverses the 
origin of the extensor digitorum longus muscle to gain the anterior surface 
of the interosseous membrane. Continuing its course it descends at first by 
the outer side of the anterior tibial artery, and afterwards in front of it, and 
in company with the vessel reaches the dorsum, of the foot, passing behind 
the anterior annular ligament; a little below the ligament it divides into 
external and internal branches. On its way it detaches muscular offsets to 
the tibialis anticus, extensor digitorum longus, extensor hallucis longus, 
and peroneus tertius, and gives one or two articular filaments to the 
ankle-joint. 
The external branch bends outwards over the tarsus on the deep surface 
of the extensor digitorum brevis; it supplies the short extensor muscle, 
and, after becoming swollen like the posterior interosseous nerve of the 
upper limb, terminates in filaments which are distributed to the articula- 
tions of the foot. 
The internal branch, continuing the course of the parent trunk, passes 
onwards under cover of the innermost division of the short extensor muscle, 
and along the first interosseous space, at the extremity of which, after receiving 
a communicating branch from the inner division of the musculo-cutaneous 
nerve, it divides into the dorsal branches for the contiguous sides of the 
first and second toes. 
THE FOURTH SACRAL NERVE. 
A small portion of the anterior division of this nerve enters, as already 
described, into the formation of the sacral plexus. Another small portion 
passes downwards to join the coccygeal plexus. The remainder of the 
nerve breaks up into visceral, muscular, and cutaneous branches. The 
visceral branches are small, and pass to the pelvic plexus of the sym- 
pathetic ; they are associated with a few similar branches from the second 
and third sacral nerves. The muscular branch passes between the coccygeus 
and levator ani, detaching twigs to both, and reaches the external sphincter 
of the anus, in the supply of which it assists. The perforating or cutaneous 
branch pierces the great sacro-sciatic ligament, turns round the lower border 
of the gluteus maximus, and supplies the integument at the margin of the 
coccyx. 
The coccygeal plexus (Fig. 393) is formed of two small loops, the 
anterior division of the fifth sacral nerve being joined from above by 
the descending branch from the fourth, and from below by the anterior 
division of the coccygeal nerve. The fifth sacral and the coccygeal before 
becoming connected with one another traverse the substance of the sacro- 
sciatic ligaments, and pierce the coccygeus muscle. From the plexus some 
minute visceral branches are detached; a slender muscular twig enters the 
coccygeus. A cutaneous branch pierces the coccygeus and ramifies in the 
skin over the back of the coccyx. External branch of musoulo-cutaneous 
Internal branch of musculo-cutaneous 
Anterior tibial 
Internal saphenous nerve 
Internal saphenous vein 
External branch of anterior tibial 
Internal branch of anterior tibial 
External saphenous 
Communication between anterior 
tibial and musculo-cutaneous 
Twigs from digital branches of 
external plantar 
Twigs from digital branches of internal plantar 
Pig. 400.—Nerves of the Dorsum of the Foot. (L. Testut.) 
To face p. 536. Olfactory tract 
Genu of corpus callosum 
Optic nerve •< 
Fissure of Sylvius 
Anterior 
perforated spot 
..Infundibulum 
Oculo-motor 
Patheticus 
f Posterior 
[ perforated spot 
Trifacial 
f Space between 
J crus and 
V hemisphere 
Abducens oculi 
Auditory 
Glosso-pharyngeal 
Pn eumogastric 
i Middle peduncle 
t of cerebellum 
Spinal accessory 
Hypoglossal 
f Anterior median 
■ fissure of 
L medulla 
Spinal accessory 
1, Anterior 
extremity of 
longitudinal 
fissure 
2, Posterior 
extremity of 
longitudinal 
fissure 
5, Optic commissure 
sOptic tract 
7, Tuber cinereum 
9, Left crus 
10, Left corpus 
albicans 
13, Pons 
Cerebellum 
Fig. 401.—The Base of the Brain, showing the origins of the Cranial Nerves. (L. Testut.) 
To face p. 537. THE CRANIAL NERVES. 
537 
THE CRANIAL NERVES. 
The cranial nerves are numbered, from before backwards, and each is, in 
addition, distinguished by a special name. According to the system of 
According to the system of 
Names.1 
System of Willis. 
System of Soemmerring. 
Olfactory, 
a 
First. 
First. 
Optic, 
a 
Second. 
Second. 
Oculo-motor, 
e 
Third. 
Third. 
Pathetic or trochlear, 
e 
Fourth. 
Fourth. 
Trifacial or trigeminal, a 
e 
Fifth. 
Fifth. 
Abducent ocular, 
e 
Sixth. 
Sixth. 
Facial, 
e 
( Portio dura. 
Seventh. 
■J Seventh. 
Auditory, 
a 
1 Portio mollis. 
Eighth. 
Glosso-pharyngeal, - a 
e 
] [ 
Ninth. 
Pneumogastric or vagus,a 
e 
| Eighth. 
Tenth. 
Spinal accessory, 
e 
J ( 
Eleventh. 
Hypoglossal, 
e 
Ninth. 
Twelfth. 
1 In this table a stands for afferent, and e for efferent. 
Soemmerring, which is now usually adopted, twelve pairs are enumerated ; 
in the older system of Willis they were arranged in nine pairs. In com- 
paring the two systems, the first six nerves in each correspond; the 
seventh nerve of Willis forms the seventh and eighth of Soemmerring. The 
eighth nerve of Willis corresponds in the more modern system to three 
trunks, the ninth, tenth, and eleventh; and the ninth nerve of Willis becomes 
in the classification of Soemmerring the twelfth. In speaking of the nerves 
behind the sixth, it is advisable to employ the descriptive names of the 
trunks, as the use of the numbers may lead to confusion 
THE FIRST OR OLFACTORY NERVE. 
The first or olfactory nerve (Figs. 407, 408) consists of a brush of 
filaments arising from the olfactory lobe of the brain. This lobe in many 
mammals projects forwards from the under surface of the frontal region of 
the hemisphere and contains in its interior a ventricle, but in man and 
the ape it is much reduced in size. It is rudimentary in the seal, and 
absent in the cetacean. In man the lobe presents an olfactory bulb and tract. 
The olfactory nerve-filaments number from twenty to thirty; they are 538 
THE NERVES. 
non-medullated. They descend through the foramina of the cribriform plate 
of the ethmoid, receiving, as they pass through the bone, sheaths from the 
dura mater. They are grouped into an outer and an inner set, and in 
their distribution are confined to the upper or ethmoidal region of the nasal 
fossa. The outer set ramifies on the surface of the upper and middle 
turbinate bones, the inner set is distributed upon the upper part of the septum. 
THE SECOND OR OPTIC NERVE. 
The optic nerve is, like the olfactory lobe, in reality a portion of the 
brain. It is continued from the optic commissure or chiasma, and terminates 
in the retina; from the chiasma two flattened white bands, the optic tracts, 
are continued backwards, one on each side, and pass round the crura to 
the region of the corpora quadrigemina and the posterior part of the 
optic thalamus. 
The optic chiasma lies immediately in front of the infundibulum, and 
between the anterior perforated spots, on the under surface of the floor 
of the third ventricle; interiorly it rests on the olivary process of the 
sphenoid bone. It is formed of nerve fibres, the majority of which 
pass from the retinae. These fibres undergo a partial decussation in 
the chiasma. The posterior part of the chiasma is formed of very fine 
fibres, which are not continued into the optic nerves; they constitute the 
commissures of Gudden and Meynert. 
The optic nerves pass forwards on each side from the chiasma. Each 
traverses the optic foramen, lying internal to and above the ophthalmic 
artery, and is continued within the orbit to the eyeball, which it enters at 
a spot a little internal to and a little below the middle point of its 
posterior surface. The nerve is surrounded by a strong sheath from the 
dura mater, and its fibres are divided into separate bundles by fibrous 
septa. The central artery of the retina passes into it from below and is 
continued forwards in its substance. 
In the chiasma the nerve fibres which come from the outer or temporal 
side of each retina pass backwards to the tract of their own side without 
decussation. The fibres from the nasal or inner side of the retina cross 
in the chiasma to the opposite tract. Each tract therefore contains the 
temporal or outer fibres of its own side and the inner or nasal fibres of 
the opposite side. 
The optic nerve and retina of each side are developed as a vesicular 
outgrowth from the region of the fore brain. The outgrowth is formed 
of a hollow stalk and a terminal dilatation. By the approximation of 
the walls of the stalk to one another and their subsequent thickening 
the optic nerve is formed. Nerve fibres, growing from the retina, pass 
backwards along the stalk, which becomes solid. The fibres of opposite 
sides partially decussating, give rise to the chiasma, and, continued back- 
wards, form the greater part of the tracts. In many of the mammalia, 
and in all vertebrates below mammals, the decussation of the fibres is complete. THE THIRD OR OCULO-MOTOR NERVE. 
THE THIRD OR OCULO-MOTOR NERVE. 
The third nerve (Fig. 403) is distributed to all the muscles of the orbit 
with the exception of the external rectus and the superior oblique, and 
through its connection with the lenticular ganglion supplies the ciliary 
muscle and the sphincter of the pupil. The nerve springs by several 
bundles from the inner side of the crus cerebri, immediately in front of 
the pons. It passes forwards, crossing below the posterior cerebral artery, 
and pierces the dura mater between the anterior and posterior clinoid 
processes. It then runs forwards in the outer wall of the cavernous sinus, 
and, on gaining the sphenoidal fissure, breaks up into an upper and 
a lower division; these, passing between the heads of the external rectus 
muscle, enter the orbit separately, the nasal branch of the ophthalmic 
division of the fifth intervening between them The upper division 
supplies the levator palpebrae and the superior rectus. The lower division 
furnishes, near the back of the orbit, the short root of the lenticular 
ganglion, and afterwards divides into three branches distributed respectively 
to the inferior rectus, the internal rectus, and the inferior oblique. In 
passing along the wall of the cavernous sinus the third nerve forms com- 
munications with the cavernous plexus of the sympathetic, and occasionally 
with the sixth nerve and the ophthalmic division of the fifth. 
The nucleus of origin of the third nerve lies immediately ventral to the 
aqueduct of Sylvius, and extends from the level of the posterior margin 
of the anterior quadrigeminal body forwards into the region of the hinder 
part of the third ventricle. The great majority of the root-fibres from 
the nucleus pass to the nerve of the same side, but a few of the most 
posterior undergo decussation. 
THE FOURTH, THE PATHETIC, OR TROCHLEAR NERVE. 
The fourth (Fig. 402), the smallest of the cranial nerves, supplies the 
superior oblique muscle of the orbit. It springs from the anterior and outer 
part of the valve of Vieussens, and passes outwards across the superior cere- 
bellar peduncle, and then bends forwards, outwards, and downwards round 
the outer side of the crus cerebri, between the posterior cerebral and superior 
cerebellar arteries. It pierces the dura mater at the free edge of the 
tentorium, immediately behind the posterior clinoid process, and continues 
its course along the outer wall of the cavernous sinus, between the third 
nerve and the ophthalmic division of the fifth. In this part of its course 
it receives a communicating branch from the cavernous plexus of the 
sympathetic, and from the ophthalmic division of the fifth. Bending 
upwards and crossing the outer side of the third nerve it reaches the 
sphenoidal fissure, through which it passes. It enters the orbit above and 
internal to the other nerves, runs forwards and inwards above the levator 
palpebrae, and terminates by entering the upper surface of the superior 
oblique muscle. 540 
THE NERVES. 
The nucleus of origin of the fourth nerve is situated in the grey matter of 
the floor of the aqueduct of Sylvius, at the level of the posterior quadri- 
geminal body and immediately behind the oculo-motor nucleus. The fibres 
from the nucleus curve outwards on the surface of the posterior longitudinal 
bundle, and turning upwards by the inner side of the nucleus of the fifth 
nerve, enter the anterior medullary velum, or valve of Yieussens, in which 
they pass across the middle line, decussating with those of the opposite side. 
The decussation is apparently complete, and the fourth nerve is peculiar in 
this respect. 
THE FIFTH, THE TRIFACIAL, OR TRIGEMINAL NERVE. 
The fifth (Figs. 401, 402), much the largest of the cranial nerves, springs 
in two portions, a sensory and a much smaller motor, from the side of the 
pons, a little behind the anterior curved border. The sensory fibres pass 
through a great ganglion (the Gasserian ganglion), and break up into three 
divisions, the ophthalmic, superior maxillary, and inferior maxillary. The 
motor portion joins the inferior maxillary division. The nerve has the 
peculiarity, that branches from all its three divisions furnish roots of small 
ganglia which have likewise roots from the sympathetic. The ophthalmic 
division furnishes a root to the ciliary ganglion; the superior maxillary 
division is connected with the spheno-palatine ganglion; the inferior maxillary 
gives branches to the otic ganglion, and to the submaxillary ganglion. 
Either directly or through its associated ganglia the fifth nerve distri- 
butes sensory branches to the eyeball, to the skin of the face and the 
frontal and temporal regions of the head, to the mucous membrane of the 
nose, the roof of the mouth, the anterior part of the tongue and the 
floor of the mouth, and to both upper and lower teeth. The muscular 
branches supply the muscles of mastication. From the otic ganglion 
branches pass to the tensor tympani and tensor palati. 
The nuclei of origin. From the place of emergence on the side of the 
pons the fibres may be traced for a little distance in a dorsal direction and 
slightly backwards; and many of them are found to terminate in two 
nuclei which lie side by side, ventral to the lateral part of the floor of the 
anterior portion of the fourth ventricle. These nuclei, of which the outer 
is sensory, the inner motor, receive, however, only a portion of the fibres; 
the remainder form two roots, named respectively retroserial and pro- 
serial in position. The retroserial root, formed of sensory fibres, 
descends in the medulla and the upper part of the spinal cord, 
gradually decreasing in size, as far as the level of the origin of the second 
or third cervical nerve. The cells among which its fibres terminate may 
be regarded as continuing the line of the sensory nucleus of the fifth 
downwards to the substantia gelatinosa of Rolando in the cord. The 
proserial root, gradually diminishing in size, passes forwards in the isthmus 
cerebri as far as the level of the anterior quadrigeminal bodies. The cells 
among which its fibres terminate are situated in the lateral part of the grey Levator palpcbrae 
j- Supraorbital 
Lachrymal nerve 
-Superior oblique muscle 
Recurrent meningeal branches 
of superior maxillary 
Olfactory filaments 
Middle meningeal artery( 
Recurrent meningeal 
branches of inferior 
maxillary 
.Supratrochlear 
.Optic nerve 
-Oculo-motor 
-Internal carotid artery 
’athoticus 
-Abducens oculi 
-Trifacial 
-Tentorial branches 
Facial and auditory 
-Glosso-pharyngeal 
Pneumogastric 
Hypoglossal 
Vertebral artery 
Spinal accessory 
Pig. 402.—The Places of Exit from the Skull of the Cranial Nerves. (C. Gegenbaur.) 
To face p. 540. Infratrochlear 
Nasal branch 
Oculo-motor 
Patheticus 
Trifacial 
Inferior maxillary 
division of trifacial 1 
Superior maxillary division 
of trifacial 
Infraorbital branches of superior maxillary 
Fig. 403.—The Nerves of the Orbit. 11., Optic nerve: 1, ophthalmic division of 
trifacial; 2, nasal branch ; 3, supratrochlear ; 4, lachrymal; 5, upper division of oculo- 
motor ; s', lower division of oculo motor ; 6, lenticular ganglion ; 7, short ciliary nerves ; 
0, Meckel’s ganglion ; 10, posterior superior dental nerves ; 11, orbital branch of superior 
maxillary. (L. Testut.) 
Fig. 404.—The Lenticular or Ciliary Ganglion from the outer side, a, Globe of the 
right eye; 6, inferior oblique muscle; c, optic nerve; d, 7, internal carotid artery: 1, 
lenticular ganglion ; 2, short root; 3, inferior division of oculo-motor ; 4, long root; 6,10, 
nasal branch of ophthalmic ; 6, sympathetic root; 8, short ciliary nerves ; S', one of the 
long ciliary nerves; 9, ciliary nerves within the eyeball; 11, sclerotic. (L. Testut.) 
To face p. 541 THE FIFTH, THE TRIFACIAL, OR TRIGEMINAL NERVE. 
541 
matter of the aqueduct. The function of the proserial root is still the 
subject of controversy; but while many regard it as motor, it seems most 
probable that it is sensory, and that the two roots are to be compared 
to the ascending and descending fibres of the posterior root of a spinal 
nerve. 
The trunk of the nerve passes from the side of the pons forwards and 
outwards, to enter an aperture in the dura mater above and immediately 
external to the apex of the petrous part of the temporal bone, where the 
sensory part, becoming expanded and somewhat plexiform, is continued into 
the ganglion. The Gasserian ganglion occupies a recess in the dura mater, and 
rests on a depression near the apex of the superior surface of the petrous 
bone. In its longest diameter, from before backwards and outwards, it 
measures about five-eighths of an inch. It is of a soft texture and reddish 
colour. Internally it is in contact with the cavernous sinus; anteriorly it 
rests upon the internal carotid artery, separated from the vessel by the 
fibrous tissue which crosses the foramen lacerum medium. From its 
anterior or convex border the three great divisions of the nerve are 
directed to the sphenoidal fissure, the foramen rotundum, and the foramen 
ovale. Small branches are described as passing from it to the carotid 
plexus of the sympathetic and to the dura mater. The motor portion 
(portio minor) arises a little in front of but in close proximity to the sensory 
portion, and passes forwards and outwards beneath it to join in its entirety 
the inferior maxillary division. 
The ophthalmic division, the smallest of the three, passes forwards 
in the outer wall of the cavernous sinus towards the sphenoidal fissure,, 
lying, in its course, below and to the outer side of the fourth nerve. It 
detaches a small twig to the dura mater, and is connected with the cavernous 
plexus of the sympathetic, and with the third, fourth, and sixth nerves. 
Before reaching the sphenoidal fissure it gives off the nasal branch, and 
divides into the frontal and lachrymal branches. The nasal nerve enters 
the orbit between the upper and lower divisions of the third nerve, and 
passes between the heads of the external rectus muscle. The frontal and 
lachrymal, keeping to the outer side of the third nerve, enter the orbit 
above the upper head of the external rectus muscle. 
The First Division or Ophthalmic Nerve. 
The frontal nerve, the largest of the three, runs forwards above 
the levator palpebrae muscle, and about the middle of the orbit 
divides into the supraorbital and supratrochlear branches. The supra- 
orbital nerve, the main continuation of the frontal, emerges along with 
the supraorbital artery by the supraorbital notch, detaches filaments 
to the skin and conjunctiva of the upper eyelid, and divides into two 
branches which ramify in the integument of the front of the head, the 
outer and larger reaching backwards beyond the vertex. The supra- 
trochlear nerve, much smaller than the supraorbital, emerges above the 542 
THE NERVES; 
pulley of the superior oblique muscle; it is connected with the infratrochlear 
nerve, detaches filaments to the upper eyelid, and ramifies with the frontal 
artery over the root of the nose and the anterior part of the forehead. 
The lachrymal nerve (Fig. 402) passes forwards along the angle between 
the roof and the outer wall of the orbit, in company with the lachrymal 
branch of the artery. It detaches a slender twig which joins the tem- 
poral branch of the temporo-malar nerve, and terminates in filaments 
which are distributed to the lachrymal gland, to the integument at the 
■outer canthus, and to the skin and conjunctiva of the outer part of the 
upper eyelid 
Supraorbital 
Supratrochlear 
jachrymal 
-Infratrochlear 
-Temporal 
Great occipital 
-Malar 
-External nasal 
.Infraorbital 
Auriculo- ) 
temporal) 
Third occipital 
Buccal 
_Mental 
Small occipital.. 
Great auricular. 
Superficial cervical 
Fig. 405.—Diagram of the Nerves of the Face and Scalp. Ito 7, Branches of 
facial nerve: 1, temporal; 2, malar ; 3, infraorbital; 4, buccal; 5, supramaxillary ; 6, 
inframaxillary; 7, posterior auricular. Immediately above the posterior auricular the 
auricular branch of the pneumogastric is figured. (J. Y. M.) 
The nasal nerve (Figs. 403, 407, 408), entering the orbit between the 
heads of the external rectus muscle, passes forwards and inwards over the 
optic nerve. It then enters the anterior internal orbital foramen, and along 
with the anterior ethmoidal artery crosses the upper surface of the horizontal 
plate of the ethmoid bone, lying immediately underneath the dura mater of the 
anterior cranial fossa. Through the aperture by the side of the crista galli it 
descends into the nose, where it at once breaks up into an outer and an inner 
terminal division. As it is entering the orbit it detaches the long root of 
the lenticular ganglion, a slender twig which reaches the posterior and upper THE OPHTHALMIC NEJRVE. 
543 
angle of the ganglion. Crossing the optic nerve the nasal detaches the long 
ciliary nerves, two in number, which run forward by the inner side of 
the optic nerve, and pierce the back of the sclerotic coat of the eyeball 
along with the short ciliary nerves from the ganglion. Before leaving 
the orbit it gives off the infratrochlear branch, a slender twig which, 
passing forwards, emerges below the pulley of the superior oblique muscle, 
sends upwards a connecting filament to the supratrochlear nerve, and 
terminates in branches which ramify in the skin and conjunctiva at the 
inner canthus. The inner terminal branch of the nasal nerve ramifies 
on the anterior and upper part of the septum of the nose. The older 
terminal branch descends on the deep surface of the nasal bone, furnishing 
filaments which ramify in front of the upper and middle turbinate processes; 
it then emerges between the lower edge of the nasal bone and the upper 
lateral cartilage, and descends on the deep surface of the compressor 
naris to the point of the nose, supplying the integument of the bridge. 
The lenticular or ciliary ganglion (Fig. 404) is usually described along 
with the fifth nerve, although it is probable from its development that it 
is to be regarded as more closely related to the oculo-motor trunk. 
It is a small four-sided body of a reddish colour, and measures from before 
backwards about a twelfth of an inch; it is to be found in the posterior 
part of the orbit, and lies on the outer side of the optic nerve. It 
receives posteriorly three roots: the long root, sensory, conies from the 
nasal branch of the ophthalmic and joins the upper and posterior angle 
of the ganglion; the short root, motor, from the lower division of the third, 
joins the lower and posterior angle; the middle root, from the cavernous 
plexus of the sympathetic, very slender, either reaches the ganglion between 
the other two or is incorporated for a longer or shorter distance with one 
or other. From the anterior extremity of the ganglion the short ciliary 
nerves are given off; they are at first six or eight in number, but dividing 
they form from fifteen to twenty filaments which, encircling the optic nerve, 
and forming two groups, an upper and a lower, reach the back of the eyeball. 
The long ciliary nerves from the nasal nerve form connections with and 
accompany the branches of the ganglion. The ciliary nerves pierce the 
sclerotic in a ring round the entrance of the optic nerve. They distribute 
sensory filaments to the eyeball from the fifth nerve, motor fibres to the 
ciliary muscle and sphincter of the pupil from the third nerve, and, from 
the cavernous plexus of the sympathetic, fibres which, on stimulation, 
produce dilatation of the pupil. 
The Second Division or Superior Maxillary Nerve. 
The superior maxillary nerve (Fig. 406), directed forwards and a little 
outwards, emerges from the cranium by the foramen rotundum, crosses the 
upper part of the spheno-maxillary fossa, passes along the infraorbital groove 
and canal, and appears on the face at the infraorbital foramen, on emerging 
from which it breaks up, on the deep surface of the levator labii superioris 544 
THE NERVES 
muscle, into its terminal branches. Within the cranium it detaches some 
small recurrent meningeal branches. Crossing the spheno-maxillary fossa it 
gives off from its upper margin an orbital branch, and, from below, the two 
spheno-palatine branches to Meckel’s ganglion. As it passes forwards upon 
the superior maxillary bone it detaches the posterior, middle and anterior 
superior dental nerves. The terminal part, sometimes named the infra- 
orbital nerve, breaks up into inferior palpebral, lateral nasal, and superior 
labial branches, which form with the branches of the facial nerve free 
communications to which the name infraorbital plexus has been given. 
The orbital or temporo-malar branch (Fig. 403) enters the orbit by the 
spheno-maxillary fissure and divides into two slender nerves, the temporal 
and malar branches. The temporal branch ascends on the outer wall, is con- 
nected by one or two slender filaments with the lachrymal nerve, and 
pierces the bone at the level of the outer canthus; it is then directed 
outwards and backwards over the anterior part of the temporal muscle,, 
and pierces the temporal fascia about an inch above the zygoma and a 
little behind the malar bone; it is connected with the facial nerve, 
and supplies the skin of the anterior part of the temporal region. The 
malar branch is directed forwards to the malar foramen, through which it 
passes, to appear upon the surface at the most prominent part of the 
cheek; it is connected with the facial nerve and ramifies in the skin 
covering the malar bone. 
The spheno-palatine nerves are two short stems which descend to the 
anterior part of the spheno-palatine ganglion; some of their fibres terminate 
in the ganglion, of which they form the sensory roots; many, however, are 
prolonged beyond the ganglion into its palatine and nasal branches. 
The superior dental nerves supply the teeth of the. upper jaw, and 
detach filaments to the mucous membrane of the outer side of the gum 
and the adjacent area, and the lining membrane of the antrum of 
Highmore. They communicate with one another in a plexus within 
the substance of the alveolar ridge. The posterior nerve arises either as 
one branch which rapidly subdivides or as two separate branches from 
the main trunk as it is entering the infraorbital groove; the branches 
descend upon the posterior surface of the superior maxillary bone and enter 
bony canals, within which they break up into twigs which supply the molar 
teeth. The middle nerve, often absent altogether, arises in the infraorbital 
groove, is directed forwards and inwards, and descends in a special canal 
in the outer wall of the antrum; it supplies the bicuspid teeth. The 
anterior nerve arises in the infraorbital canal and descends in the anterior 
wall of the antrum ; it detaches a filament to the mucous membrane of 
the anterior part of the inferior turbinate bone and the lower meatus of 
the nose, and breaks up into branches which supply the incisor, canine, 
and, in the absence of the middle nerve, the bicuspid teeth. 
The infraorbital or terminal branches. The inferior palpebral branchesf 
usually two in number, are the smallest of the terminal offsets; they are Superior maxillary division of fifth 
Posterior superior dental 
Orbital branch 
Meckel’s ganglion 
Oculo-motor nerve 
Great superficial petrosal 
Facial 
Anterior' 
superior 
dental 
(Nerve of 
1 Jacobson 
Great deep 
petrosal 
Glosso-pharyngeal 
Vidian 
Connections between superior dental branches 
First cervical ganglion 
r gympathetic 
Internal jugular vein 
Fro. 406.—The Superior Maxillary Division of the Fifth Nerve. (L. Testut.) 
To face p 544* Olfactory filaments 
Nasal branch of ophthalmic 
(inner terminal division) 
3, Naso-palatine 
3', 4, Anterior or great 
palatine 
Fia. 407. Nerves of the Nasal Septum. (L. Testut.) 
Olfactory bulb 
i Olfactory filaments 
| | Olfactory tract 
Nasal branch of 
ophthalmic (outer 
terminal division) 
Superior maxillary division 
of trifacial 
Vidian 
Ptery go- palat in e 
Posterior palatine 
External palatine 
Orifice of Eustachian tube 
Nasal branch of anterior 
palatine 
Anterior palatine 
5, Meckel’s ganglion 
8, 9, Nasal branches of 
Meckel’s ganglion 
Soft palate 
Anterior palatine 
Fio. 408.—Nerves of the Outer Wall of the Nasal Fossa. (L. Testut. 
To face p. 545- THE SUPERIOR MAXILLARY NERYE. 
545 
directed upwards and supply the skin and conjunctiva of the lower lid. 
The lateral nasal branches, three or four in number, supply the integument 
of the side of the nose. The superior labial branches, usually four in 
number, descend to ramify in the skin and mucous membrane of the 
upper lip. 
The spheno-palatine ganglion (Meckel’s ganglion) (Figs. 406, 408), lies in 
the spheno maxillary fossa ; it is triangular in outline, and measures from 
before backwards, its longest diameter, about a fifth of an inch. Its sensory 
root comes from the superior maxillary of the fifth and is formed by the 
two spheno-palatine nerves already described. The motor and sympathetic 
roots are conjoined for some distance, and form the Vidian nerve which 
enters the ganglion from behind. The motor root, the great superficial petrosal 
nerve, takes origin from the geniculate ganglion of the facial nerve; it is 
directed forwards in the hiatus Fallopii, and is joined on the outer side 
of the internal carotid artery, in the foramen lacerum medium, by the 
sympathetic root, the great deep petrosal nerve, which is derived from the 
carotid plexus of the sympathetic. The Vidian nerve, thus formed, passes 
forwards in the Vidian canal to the posterior angle of the ganglion. It 
detaches one or two small branches which pierce the floor of the canal 
and ramify in the lining membrane of the upper and posterior part of the 
nasal fossa; their fibres probably run backwards in the trunk of the Vidian 
from the ganglion. The branches of the ganglion are superior, posterior, 
internal, and inferior. 
The orbital or superior branches, two or three slender twigs, enter the 
orbit, pierce its inner wall, and ramify in the lining membrane of the 
posterior ethmoidal cells. 
The pharyngeal or posterior branch, a very slender twig, courses in the 
pterygo-palatine canal, detaches some twigs to the lining membrane of the 
sphenoidal sinus, and is distributed to the mucous membrane of the upper 
part of the pharynx in the neighbourhood of the Eustachian lube. 
The nasal branches, partly prolonged directly from the spheno-palatine 
roots, are directed inwards through the spheno-palatine foramen; they are 
eight or nine in number, and are mostly of small size. They ramify upon 
the roof, the posterior and lower part of the septum, and the lateral wall of 
the nose, extending as far down as the middle meatus. One of them, much 
larger than the others, the nasopalatine nerve (nerve of Cotunnius), descends 
upon the septum and enters the palate through the anterior palatine fossa, 
to terminate in branches which supply the mucous membrane of the anterior 
region of the hard palate and gum, and form communications with those 
of the great palatine nerve. The left naso-palatine branch descends through 
the anterior of the foramina of Scarpa, while the right occupies the posterior, 
and communications pass between the two nerves. 
The palatine branches, three in number, descend in the palato-maxillary 
canal; like the nasal branches, they are partly prolonged directly from the 
spheno-palatine roots. They are named respectively from the bony apertures 546 
THE NEEVES. 
from which they emerge—the large or anterior, the small or posterior, and 
the smallest or external. The large palatine nerve (palato-nasal) detaches, 
as it descends, two branches which ramify on the posterior part of the 
lateral wall of the nose in the region of the middle and lower meatus. 
Afterwards, it bends forwards on the under surface of the hard palate, and 
breaks up into branches which supply the mucous membrane of the hard 
palate and gum in nearly the whole extent, and communicate with the 
branches of the naso-palatine nerve. The small palatine nerve ramifies in 
the mucous membrane of the soft palate. By many it is regarded as giving 
to the levator palati and azygos uvulae muscles branches of supply, the fibres 
of which are supposed to be derived from the facial through the great 
superficial petrosal nerve; others hold that these muscles are supplied by 
the spinal accessory nerve through the pharyngeal plexus. The smallest 
palatine nerve is directed outwards and downwards, and ramifies over the 
outer part of the soft palate and the tonsil. 
The Third Division or Inferior Maxillary Nerve. 
The inferior maxillary nerve (Figs. 409, 410), the largest of the three 
divisions, escapes from the skull by the foramen ovale, and enters the 
zygomatic fossa; it is formed of two roots which join with one another 
immediately bejmnd the foramen; the larger of the two is sensory, and 
comes from the Gasserian ganglion; the smaller is the motor root of the 
fifth. The trunk thus formed is very short, and lies on the deep aspect 
of the external pterygoid muscle. It detaches a recurrent branch and the 
nerve to the internal pterygoid muscle, and immediately afterwards breaks 
up into an anterior and a posterior portion, which, close to their origin, 
are frequently separated from one another by a ligamentous band or bony 
spicule stretched from the external pterygoid plate to the great wing of 
the sphenoid bone in the neighbourhood of the spine. The recurrent 
branch (Fig. 402) passes upwards through the foramen spinosum and divides 
into two slender twigs, one of which ramifies in the dura mater, while 
the other, passing through the petro-squamous fissure, ramifies in the 
lining membrane of the mastoid cells. The nerve to the internal pterygoid 
springs from the deep surface of the parent trunk, and passes down- 
wards under the cover of the pterygo-spinous ligament to reach the deep 
surface of the internal pterygoid muscle. Near its origin it is connected 
with the otic ganglion. 
The anterior portion, chiefly motor in function, immediately breaks up 
into the masseteric, buccal, external pterygoid, and deep temporal branches. 
The masseteric nerve, a considerable branch, passes upwards under 
cover of the upper head of the external pterygoid muscle, detaches a 
posterior deep temporal twig, and bends outwards in the sigmoid 
notch to enter the deep surface of the masseter muscle. The buccal 
nerve (long buccal) is directed outwards between the heads of the Fig. 409.—Branches of the Inferior Maxillary Division of the Fifth Nerve. 
1, Auriculo-temporal ; 2, connecting1 branch with facial; 3, masseteric ; 4, posterior deep 
temporal; 5, middle deep temporal; 6, buccal; 7, anterior deep temporal; 8, lingual; 
9, inferior dental; 10, branch to mylo-hyoid and anterior belly of digastric ; 11, mental; 
12, infraorbital branches of superior maxillary ; 13, malar branch of superior maxillary ; 
14, facial nerve. (L. Testut.) 
To face £>.- 546; Nasal branches 
Meckel’s ganglion 
Vidian 
Nerve to tensor palati 
Otic ganglion 
Nerve to tensor tympani 
Great superficial petrosal 
Nasal branch 
of ophthalmic 
of fifth 
'Chorda tympani 
Great palatinc- 
Auriculo-temporal 
Internal maxillary 
artery 
.Middle meningeal artery 
Nerve to internal pterygoid 
i Inferior dental artery 
Inferior dental 
Lingual 
Nerve to mylo-hyoid and anterior belly of 
digastric 
Fig 410.—The Spheno-Palatine and Otic Ganglia from the Deep Surface. (C. Gegenbaur.) 
To face p. 547. THE INFERIOR MAXILLARY NERVE. 
547 
external pterygoid muscle, and then bends forwards on the deep 
surface of the insertion of the temporal muscle, which it sometimes 
pierces. Escaping from under cover of the ramus it ramifies in the fat 
of the cheek, forming communications with the facial nerve ; its terminal 
branches, which are sensory, supply the mucous membrane of the cheek, 
and the skin at the angle of the mouth. Near its origin it detaches the 
external pterygoid nerve and the anterior deep temporal nerve. The 
external pterygoid nerve arises with the buccal branch and enters the deep 
surface of the external pterygoid muscle. The deep temporal nerves are 
commonly three in number. The anterior usually springs from the buccal 
nerve, and ascends on the outer surface of the upper head of the external 
pterygoid muscle; the middle springs directly from the parent trunk and 
ascends on the deep surface of the external pterygoid muscle; the pos- 
terior arises in common with the masseteric branch. They all enter the 
temporal muscle from its deep surface. 
The posterior portion, which is chiefly sensory, breaks up into three 
important trunks—the auriculo-temporal, the inferior dental, and the lingual. 
The auriculo-temporal nerve (Fig. 409) arises by two roots which 
pass backwards and join with one another, embracing between them the 
middle meningeal artery; the nerve then bends upwards on the deep 
surface of the temporo-maxillary articulation, passes through the parotid 
gland, and crosses the zygoma, lying behind the temporal artery and on 
its deep surface. Continuing its course it ascends in front of the ear and 
breaks up into long slender terminal branches. Near its origin it detaches 
(a) communicating twigs to the otic ganglion, (5) two communicating branches to 
the temporo-maxillary division of the facial nerve, (c) some branches to the parotid 
gland, and (d) a nerve to the temporo-maxillary articulation. As it is crossing the 
zygoma it detaches (e) two nerves to the meatus-, these branches, very slender 
and lying close to the bone, enter the external auditory canal, and are 
distributed to the integument lining it, the upper of the two furnishing a 
branch to the tympanic membrane. As the nerve passes in front of the 
external ear (/) two auricular branches are given off; these nerves supply the 
skin of the tragus and the anterior part of the helix. The terminal or 
temporal branches ascend with the branches of the temporal artery superficial 
to which they lie; they supply the integument of the region above and in 
front of the ear, and form communications with branches of the facial 
nerve. 
The inferior dental nerve (Fig. 409) is the largest branch of the inferior 
maxillary trunk; it is not entirely sensory as it detaches a muscular twig to 
the mylo-hyoid and the anterior belly of the digastric. It passes downwards 
and outwards behind the lingual nerve to reach the inferior dental canal, 
descending at first under cover of the external pterygoid muscle, and after- 
wards resting upon the internal pterygoid, on the deep surface of the ramus. 
Within the canal it is continued forwards almost to the middle line, detach- 
ing branches which, after communicating with one another and furnishing 548 
THE NEE YES. 
filaments to the gums, supply the teeth of the lower jaw. The mylo- 
hyoid nerve is given oft’ by the main trunk before it enters the inferior 
dental canal• it runs forwards on the under surface of the mylo-hyoid, 
supplying twigs to it, and terminates in the anterior belly of the digastric. 
The mental branch, of considerable size, leaves the main trunk as it is 
passing forwards in the canal; it escapes by the mental foramen, and 
breaks up into branches which supply the integument of the chin and the 
skin and mucous membrane of the lower lip, and form connections with 
branches of the facial nerve. The mental branch is larger than the terminal 
part of the main trunk, which latter sometimes receives the name of 
incisor branch. 
The lingual or gustatory nerve (Figs. 411, 413) descends in front of 
the inferior dental nerve, to which a bundle of its fibres may for a short 
distance adhere. On the deep surface of the external pterygoid muscle 
it is, near its origin, joined from behind by the chorda tympani nerve 
from the facial. On emerging from the cover of the external pterygoid 
it passes between the internal pterygoid and the ramus, and, crossing 
the anterior border of the superior constrictor of the pharynx, reaches 
the floor of the mouth immediately below the last molar tooth 
of the lower jaw. Continuing its course, it runs forwards on the hyo- 
glossus, forming a bend with the convexity downwards, passes under 
cover of the mylodryoid muscle, and, crossing Wharton’s duct, gains the 
margin of the under surface of the tongue, along which it is continued 
to the tip. Near the posterior border of the mylo-hyoid it detaches one 
or two branches to the submaxillary ganglion, and gives off the sublingual 
branch which supplies the sublingual gland and furnishes filaments to the 
gums and to the floor of the mouth. The branches to the ganglion may 
easily be dissected back to the chorda tympani. A little further forwards 
the lingual receives a branch from the ganglion and two or three connecting 
filaments from the hypoglossal nerve. Its terminal branches are distributed to 
the gums, to the floor of the mouth, and to the surface of the tongue in 
the region in front of the circumvallate papillae. The lingual is the nerve 
of tactile sensibility and of taste of the anterior two-thirds of the tongue; 
the fibres which subserve the sense of taste are supposed by some to come 
through the chorda tympani, and to be ultimately derived not from the 
facial but from the glosso-pharyngeal through its connecting branches with 
the seventh nerve. 
The submaxillary ganglion (Fig. 413) is about an eighth of an inch in 
length. It rests upon the hyo-glossus muscle, immediately below the lingual 
nerve, near the posterior border of the mylo-hyoid muscle. It receives 
from the lingual nerve one or two roots, and it also receives a sympathetic 
root from the plexus on the facial artery. It detaches a number of 
branches to the submaxillary gland and to Wharton’s duct, and one which, 
joining the trunk of the lingual, passes to the tongue. 
The otic ganglion (Fig. 410) measures about a fifth of an inch from THE INFERIOR MAXILLARY NERYE. 
549 
before backwards. It is placed immediately below the foramen ovale and 
in front of the middle meningeal artery. It lies on the deep surface of 
the inferior maxillary trunk, at the place of origin of the nerve to the 
internal pterygoid, with which it is usually very closely connected. It 
receives root fibres from the following sources—(a) from the nerve to the 
internal pterygoid; (b) from the small superficial petrosal nerve, which 
comes from the tympanic branch of the glosso-pharyngeal and receives a 
communicating filament from the geniculate ganglion of the facial, and 
afterwards pierces the spheno-petrous suture to reach the ganglion from 
behind; and (c) from the sympathetic on the middle meningeal artery. 
It is also connected by delicate filaments with the auricula-temporal and 
chorda tympani nerves. It detaches muscular branches to the tensor tympani 
and tensor palati muscles. 
Surgical anatomy of the fifth nerve. The branches of the fifth trunk 
are frequently the seat of severe and obstinate neuralgia, for the relief 
of which the surgeon is often compelled to excise portions of the nerve. 
In very severe cases, in which the pain has been referred to all or a consider- 
able proportion of the branches, the Gasserian ganglion itself has been the 
subject of operation. To reach the ganglion, the zygoma and the coronoid 
process are divided, the external pterygoid muscle is cut through, and the 
portion of bone immediately surrounding the foramen ovale is removed; 
the ganglion is then pulled outwards, and as far as possible removed. 
This operation is a very serious one. The supraorbital branch of the 
ophthalmic division is easily exposed by a transverse incision immediately 
above the supraorbital notch. The infraorbital nerve is also easily 
reached as it appears upon the face. A great part of the trunk of the 
superior maxillary division, and Meckel’s ganglion, may be removed by 
first opening the antrum of Highmore through its anterior wall, then 
perforating the posterior wall of the space, and finally with great care 
breaking through the thin plate of bone which forms the floor of the 
infraorbital canal and groove. Exposed in this manner the nerve may be 
cut through almost as far back as the foramen rotundum. This operation 
has been practised for the relief of obstinate neuralgia affecting the teeth 
of the upper jaw. The trunk of the inferior maxillary division has been 
reached, as it escapes from the skull, by an operation similar to the first 
stages of that for the removal of the Gasserian ganglion. The inferior 
dental branch can be exposed from the inside of the mouth, the guide 
to the nerve being the prominent margin of the inferior dental foramen, 
Avhich may be felt through the mucous membrane. The lingual nerve 
can also be reached from the inside of the mouth through an incision 
made about half an inch below the last molar tooth of the lower jaw. 
THE SIXTH, THE ABDUCENT OCULAR NERVE. 
The sixth nerve supplies the external rectus muscle. It emerges 
from the brain at the inferior border of the pons, above and toward the 550 
THE NERVES. 
outer edge of the anterior pyramid. It is directed forwards and pierces 
the dura mater immediately internal to the apex of the petrous bone, after 
which it runs through the cavernous sinus below and by the inner side 
of the ophthalmic division of the fifth nerve. It enters the orbit by the 
sphenoidal fissure, passing between the heads of the external rectus muscle, 
and lying below the lower division of the third nerve. About half-way 
forwards in the orbit it pierces the inner surface of the external rectus,. 
On its way it receives communicating fibres from the carotid plexus and 
from the ophthalmic division of the fifth nerve. 
The nucleus of origin lies close to the surface of the floor of the fourth 
ventricle, near the middle line, and above the striae acusticae. 
THE SEVENTH OR FACIAL NERVE. 
The facial nerve (Fig. 410) takes origin from the surface of the brain 
in two portions : the larger portion, the portio dura, arises from the side 
of the medulla, between the olivary and restiform bodies, immediately below 
the pons; the smaller portion, the pars intermedia, takes origin immediately 
external to the portio dura, between it and the auditory nerve. 
The nucleus of origin of the portio dura lies in the reticular formation 
some distance below the surface of the fourth ventricle, about the level of 
the striae acusticae. The fibres which pass from the nucleus have a tortuous 
course within the substance of the brain, before they reach the surface; they 
take first of all a dorsal direction, and approach the floor of the fourth 
ventricle; they are then continued forwards, running in the eminentia teres; 
finally, bending at a right angle, they arch outwards over the nucleus of 
the sixth nerve, and are continued downwards and outwards to the sur- 
face. The fibres of the pars intermedia arise from the upper end of the 
glosso-pharyngeal nucleus. 
From its superficial origin the facial nerve passes outwards to the 
internal auditory meatus, resting in its course upon the upper and anterior 
surface of the auditory nerve. At the bottom of the meatus it separates 
from the companion trunk and enters the aqueduct of Fallopius, within which 
it passes through the temporal bone. Within the aqueduct it first passes out- 
wards above and between the cochlea and vestibule as far as the hiatus 
Fallopii; it then bends sharply backwards in the substance of the inner wall 
of the tympanum, above the fenestra ovalis; it finally descends, with a 
slight arch backwards, behind the tympanic cavity to the stylo-mastoid 
foramen. The bend which the nerve makes above the fenestra ovalis 
is known as the “genu,” and at its anterior border is a small reddish 
coloured triangular swelling, the apex of which is directed forwards, the 
geniculate ganglion. The pars intermedia, which from the first is closely 
applied to the under surface of the portio dura, partly becomes incorporated 
with the portio dura in the internal auditory meatus, and partly terminates 
in the ganglion. Below the stylo-mastoid foramen the facial nerve is directed THE FACIAL NERVE. 
551 
downwards, outwards, and forwards, and enters the parotid gland, within 
which it divides into two terminal branches, the temporo-facial and the 
cervico-facial. 
Within the aqueduct of Fallopius a number of branches are detached, 
(1) The great superficial petrosal arises from the apex of the geniculate 
ganglion, passes forwards in the hiatus Fallopii, crosses below the Gasserian 
ganglion, and, on the outer side of the internal carotid artery, joins with 
the great deep petrosal from the carotid plexus of the sympathetic to form 
the Vidian nerve, which passes to Meckel’s ganglion. (2) A communicating 
branch, passes from the ganglion to the small superficial petrosal which, con- 
tinued from the tympanic branch of the glosso-pharyngeal, pierces the petrous 
bone a little external to the hiatus Fallopii, and descends, usually through 
the spheno-petrous suture, to the otic ganglion. (3) The nerve to the 
stapedius muscle, a small branch, arises as the main trunk descends behind 
the tympanum. (4) The chorda tympani, a branch of some size, arises near 
the lower end of the aqueduct; it is directed at first upwards and forwards, 
then pierces the posterior wall of the tympanum, and courses forwards on 
the inner surface of the tympanic membrane near its upper margin, passing 
between the long process of the incus and the handle of the malleus. It 
leaves the tympanum by the canal of Huguier at the inner part of the 
fissure of Glaser and, after forming connections with the otic ganglion, 
joins the lingual nerve with which it is distributed to the submaxillary 
and sublingual glands, and to the anterior two-thirds of the tongue. (5) 
Occasionally a small branch, the external superficial petrosal, passes from 
the geniculate ganglion to the sympathetic on the middle meningeal artery 
above the foramen spinosum; and (6) there is frequently a communicating 
branch given off from below the ganglion to the auricular branch of the 
pneumogastric. 
Immediately below the stylo-mastoid foramen the facial nerve detaches 
two branches : (1) The auricular branch runs upwards in the fissure between 
the vaginal and mastoid processes, passes under cover of the retrahens auram, 
and breaks up into branches which supply the retrahens auram, the small 
muscles on the inner surface of the auricle, and the occipitalis; it forms 
connections with branches of the great auricular and small occipital nerves 
and with the auricular branch of the pneumogastric; (2) the nerve to the 
stylo-hyoid and the posterior belly of the digastric divides and gives a 
branch to each of these muscles. A communicating filament from the glosso- 
pharyngeal nerve joins the nerve to the stylo-hyoid, or passes directly to the 
facial in the neighbourhood of the stylo-mastoid foramen. 
The terminal branches of the facial are the temporo-facial and cervico- 
facial. In passing through the parotid gland these nerves cross superficially 
the external carotid artery and the temporo-maxillary vein; the temporo- 
facial is connected by two communicating branches with the auriculo- 
temporal nerve; the cervico-facial forms connections with the branches 
of the great auricular nerve. Before leaving the gland each of the two 552 
THE NERYES. 
divisions breaks up into three branches. The branches pass forwards 
over the face and upper part of the neck, ramifying and forming, by their 
repeated connections with one another, a plexus to which the name “pes 
anserinus ” has been given; they likewise form communications with the 
various branches of the fifth nerve which appear upon the face. 
The temporo-facial branches are the temporal, malar, and infraorbital. 
The temporal branches cross the zygoma a little in front of the temporal 
artery, and pass chiefly towards the upper margin of the orbit. They 
supply the atollens and attrahens auram, the small muscles of the outer 
surface of the auricle, the orbicularis palpebrarum, the corrugator supercilii, 
and the frontalis, and they form connections with the auriculo-temporal, 
temporal, and supraorbital branches of the fifth. The malar branches pass 
towards the outer angle of the orbit, supply the orbicularis palpebrarum, 
and form connections with the malar, lachrymal, and infraorbital branches 
of the fifth nerve. The infraorbital branches run forwards above Stenson’s 
duct; they are the largest of the series, and supply the orbicularis 
palpebrarum, the muscles of the nose, the elevators of the upper lip, 
the orbicularis oris, and the buccinator; they form connections with terminal 
twigs of the infraorbital and nasal branches of the fifth. 
The cervico-facial branches are the buccal, supramaxillary, and infra- 
maxillary. The buccal branches run towards the angle of the mouth, 
supply the buccinator and orbicularis oris, and form connections with the 
buccal branch of the fifth (long buccal). The supramaxillary branches run 
towards the chin ; they supply the orbicularis oris, the muscles of the lower 
lip, and the levator menti, and form connections with the mental nerve. 
The inframaxillary branches pass out from the lower border of the parotid 
gland, and ramify under the upper part of the platysma, which they 
supply; they form connections with the great auricular and superficial 
cervical nerves. 
THE EIGHTH OR AUDITORY NERVE. 
The eighth nerve (the portio mollis of the seventh pair of Willis) arises 
from the side of the medulla oblongata close to the hinder border of the 
pons, immediately external (dorsal) to the place of origin of the seventh 
nerve. It passes outwards behind and below the facial nerve, and in close 
contact with it, and at the bottom of the internal auditory meatus divides into 
two terminal branches; these, the vestibular and cochlear nerves respectively, 
are described along with the organ of hearing. 
Nuclei of origin. Traced into the medulla, the fibres form two bundles, 
the lateral and mesial roots, which embrace the restiform body. The lateral 
root is mainly continuous with the cochlear, and the mesial with the 
vestibular nerve. The fibres end in three separate collections of nerve 
cells. The ventral nucleus is a collection of nerve cells which lies in the 
medulla in the angle between the two roots, and extends in a dorsal THE AUDITORY NERVE. 
553 
direction in the substance of the lateral root; this nucleus receives the 
fibres of the lateral or cochlear root. The dorsal nucleus, sometimes called 
the chief nucleus, is a collection of nerve cells placed beneath the floor of 
the fourth ventricle; it is broadest at its middle part which lies beneath 
the striae acusticae, and there it reaches inwards to the median line; 
it extends upwards as far as the level of the nucleus of the sixth nerve. 
The nucleus of Deiters lies by the outer side of the dorsal nucleus and 
by the inner side of the restiform body; it hardly reaches so far down- 
wards as the dorsal nucleus, and is broadest at its upper end. The 
fibres of the mesial or vestibular root have been traced to the vicinity of 
the dorsal nucleus and the nucleus of Deiters. 
THE NINTH OR GLOSSO PHARYNGEAL NERVE. 
The glosso-pharyngeal nerve (Figs. 411, 413) is formed from the two 
anterior of a series of fasciculi which spring separately from the side of 
the medulla in the line between the olivary and restiform bodies; the two 
bundles pass outwards and unite with one another to form the trunk of 
the nerve. The nerve contains both afferent and efferent fibres. 
Nuclei of origin. The afferent fibres partly terminate in the anterior or 
cerebral extremity of the nucleus of the ala cinerea, and partly pass into the 
funiculus solitarius. The nucleus of the ala cinerea is placed beneath the floor 
of the lower part of the fourth ventricle in the region of the inferior fovea 
and ala cinerea; at its anterior part it is covered by the dorsal nucleus of 
the eighth nerve, and is more deeply placed and a little further from the 
middle line than behind. The funiculus solitarius passes downwards by the 
outer side of the nucleus, but its inferior extremity has not yet been 
satisfactorily determined; it may be compared to the retroserial root of 
the fifth nerve. The efferent fibres of the nerve take origin from the 
anterior or cerebral extremity of the nucleus ambiguus, a mass of grey 
matter which lies in the reticular formation of the fourth ventricle ; it is 
co-extensive with the nucleus of the ala cinerea, but is more deeply placed 
in the medulla. 
The nerve passes outwards to the jugular foramen, through which, in a 
separate tube of dura mater in front and to the outer side of that which 
contains the vagus and spinal accessory trunks, it leaves the skull. As it 
is passing through the foramen, it presents two ganglionic enlargements, 
the jugular and petrous ganglia. The jugular ganglion is situated in the 
upper part of the foramen; it is very small and embraces only a few of 
the fibres of the nerve ; it gives off no branches, and is sometimes absent 
altogether. The petrous ganglion lies in a groove of the petrous bone, and 
measures about a fourth of an inch in length; it gives off three or four 
small connecting branches and the tympanic branch. 
On emerging from the foramen, the nerve appears between the internal 
jugular vein and the internal carotid artery, and passes downwards and 554 
THE NERVES. 
forwards on the deep surface of the stylo-pharyngeus muscle, crossing 
between the external and internal carotid arteries; it then turns over the 
lower border of the stylo-pharyngeus and passes forwards on its surface, 
and on the deep surface of the hyo-glossus, to the back of the tongue, 
where it divides into its terminal branches. On its way it supplies the 
stylo-pharyngeus muscle, and detaches some pharyngeal branches and a 
tonsillar branch. 
Connecting branches. From the petrous ganglion three slender com- 
municating branches are given off; one of these passes to the superior 
cervical ganglion of the sympathetic, another joins the auricular branch of the 
vagus-, the third passes to the ganglion of the root of the vagus. From the 
trunk of the nerve a little below the ganglion a communicating twig is 
given to the facial or to its stylo-hyoid branch. 
The tympanic branch or nerve of Jacobson springs from the petrous 
ganglion; it enters a minute canal which opens between the jugular foramen 
and carotid canal, and is conducted to the tympanic cavity, on the inner 
wall of which it ascends, grooving the surface of the promontory, and 
breaking up into a number of branches which form the tympanic plexus. 
The branches of the plexus ramify in the mucous membrane, passing 
forwards to the posterior portion of the Eustachian tube and backwards to 
the mastoid cells. From the plexus, a branch, the small superficial petrosal 
nerve, which may be regarded as the continuation of the nerve of Jacobson, 
passes forwards and, receiving a communicating branch from the geniculate 
ganglion of the facial, pierces the superior surface of the petrous bone, 
courses beneath the dura mater, external to the hiatus Fallopii, and 
passes through the petro-sphenoidal fissure to join the otic ganglion. 
Another branch, the small deep petrosal nerve, passes forwards from the 
plexus along a canal beneath the tensor tympani muscle to join the carotid 
plexus of the sympathetic and the great deep petrosal nerve, which passes 
to Meckel’s ganglion. In addition, one or two small branches pierce the 
anterior tympanic wall and join the carotid plexus. 
Pharyngeal branches. These are given off a little below the ganglion; 
they are three or four in number. One or two of them, of small size, 
pass directly to the mucous membrane of the upper part of the pharynx, 
piercing the superior constrictor. The largest branch descends a little to 
join the pharyngeal branch of the vagus, along with which and one or 
two branches from the superior cervical ganglion of the sympathetic, it 
ramifies over the middle constrictor, forming the pharyngeal plexus. From 
the plexus branches proceed to the mucous membrane of the pharynx, 
and to the constrictor muscles, the palato-glossus muscle, and the palato- 
pharyngeus muscle. In addition the levator palati and azygos uvulae 
muscles probably receive their supply through the pharyngeal plexus 
(see p. 546). One or two branches usually pass from the plexus to the 
superior laryngeal branch of the vagus, and a communicating twig joins 
the hypoglossal nerve. Flo. 411.—The External and Internal Carotid Arteries and their Chief 
Relations. 11. to VI., Cervical nerves (anterior divisions), a, Gasserian ganglion ; 
l>, Meckel's ganglion ; c, internal jugular vein; d, middle meningeal artery ; e, sterno- 
mastoid muscle. 1, 2, Lingual nerve; 3, connecting branch between lingual and 
inferior dental; 4, chorda tympani; 5, submaxillary ganglion; 6, glosso-pharyngeal 
nerve ; 7, hypoglossal nerve ; 3, descendens hypoglossi: 9, thyro-hyoid branch; 10, con- 
nections between lingual and hypoglossal; 11, terminal branches of hypoglossal; 
12, communicating branches from cervical plexus; 13, ansa hypoglossi; 14, spinal 
accessory; 15, pneumogastric; 15', ganglion of the trunk of the pneumogastric; 
16, superior laryngeal nerve. (L. Testut.) 
To face p. 554. Facial 
Spinal accessory 
Superior cervical 
ganglion 
Hypoglossal 
■ Sympathetic 
plexus on 
carotid 
arteries 
Cervical portion of 
pneumogastric 
Branches to trapezius 
Cardiac branch 
Larynx 
Common carotid artery 
Trachea 
Superior laryngeal (external 
branch) 
Inferior cervical [ 
ganglion ( 
Brachial plexus 
Subclavian artery 
Recurrent laryngeal 
Cardiac branch 
Bronchus 
Thoracic 
sympathetic 
cord 
Thoracic 
sympathetic cord 
Small splanchnic 
nerve 
f Stomach (cut 
I across, showing 
| anterior and pos- 
terior surfaces) 
Abdominal aorta 
Renal artery 
Solar plexus 
Superior mesenteric artery 
Fig. 412.—The Pneumogastric and Sympathetic Nerves of the Right Side, a, 
Parotid gland, turned upwards ; e, oesophagus ; i, thoracic aorta ; k, coeliac axis ; n, vena 
cava superior ; o, great azygos vein ; p, thoracic duct: 2, thoracic portion of pneumo- 
gastric ; 3, semilunar ganglion ; 6, superior laryngeal (internal branch) ; 9, posterior 
pulmonary plexus ; 12, glosso-pharyngeal; 15, branches to sterno-mastoid ; 17, phrenic ; 
18, cervical sympathetic cord ; 20, middle cervical ganglion ; 23, great splanchnic nerve. 
(L. Testut.) 
To face p. 555. THE GLOSSO-PHARYNGEAL NERVE. 
555 
A little below the place of origin of the pharyngeal nerves one or 
more slender muscular branches are detached to the stylo-pharyngeus. 
Near the tongue one or two tonsillar branches are given off; these 
ramify over the tonsil and the anterior pillar of the fauces. 
Glossal branches. Of the terminal branches one, the dorsal branch, is 
distributed to the circumvallate papillae, and the posterior third of the 
tongue extending backwards to the epiglottis; the other, the lateral branch, 
ramifies over the side of the posterior half of the tongue. 
THE TENTH NERVE, THE VAGUS OR PNEUMOGASTRIC. 
The pneumogastric nerve (Fig. 412) arises immediately behind the 
glosso-pharyngeal nerve from the groove on the side of the medulla between 
the olivary and restiform bodies, by several fasciculi which unite with one 
another to form a single stem. 
Nuclei of origin. Within the substance of the medulla the fibres are 
connected with the nucleus of the ala cinerea and the nucleus ambiguus 
already described in connection with the ninth nerve; a few join the 
funiculus solitarius. 
From its place of origin the vagus is directed outwards to the foramen 
jugulare through which, in company with the spinal accessory nerve, it 
leaves the cranium. In the foramen it presents a small ganglion about a 
sixth of an inch in diameter, the ganglion of the root. As it emerges from the 
foramen it appears between the internal carotid artery and internal jugular 
vein; the glosso-pharyngeal nerve is in front of it; the spinal accessory is 
behind; and the hypoglossal nerve, at first on its deep surface, winds 
round its posterior border, and is closely connected with it. In this situation 
the nerve swells into a second and larger ganglion, the ganglion of the 
trunk (plexus nodosus). Descending in the neck the vagus occupies a 
special compartment in the carotid sheath and lies on the deep surface 
of and between the artery and vein. From the root of the neck, 
on account of the want of symmetry of the parts in the upper region 
of the thorax, the course and relations of the nerves of the opposite 
sides must be separately traced. The nerve of the right side descends in 
front of the first part of the subclavian artery, and detaches its recurrent 
branch, which passes upwards behind the artery. It then enters the 
thorax behind the innominate vein and descends to the posterior surface 
of the root of the lung. Behind the root it forms a flattened cord from 
which numerous branches, forming the posterior pulmonary plexus of 
the right side, pass outwards to the lung. Below the root, the 
nerve divides into two branches which descend upon the side of the 
oesophagus, detaching to one another and to the corresponding cords 
of the opposite side communicating branches which form the oesophageal 
plexus. Near the diaphragm the two cords reunite and form a single 
trunk which passes through the oesophageal opening and ramifies on THE NEE YES. 
the posterior surface of the stomach. The left nerve enters the thorax 
between the carotid and subclavian arteries, crosses in front of the arch 
■of the aorta, and gives off its recurrent branch, which passes upwards 
behind the arch. It then gains the back of the root of the left lung 
and detaches branches which form the left posterior pulmonary plexus. 
Afterwards it descends as two cords upon the left side of the oesophagus 
and takes part in forming the oesophageal plexus. It passes through the 
oesophageal opening of the diaphragm as a single trunk and ramifies over 
the front of the stomach. 
Communicating branches. The most important communicating branch 
which the vagus receives is the accessory portion of the spinal accessory nerve; 
this cord gives one or two filaments to the ganglion of the root and then 
joins the ganglion of the trunk ; most of its fibres pass into the pharyngeal 
and superior laryngeal nerves, but some descend in the trunk of the vagus. 
The glosso-pharyngeal nerve is connected with the vagus by a twig which 
joins the ganglion of the root. The hypoglossal nerve exchanges some fibres 
with the ganglion of the trunk. The first cervical ganglion of the sym- 
pathetic and the first loop of the cervical plexus also communicate with the 
ganglion of the trunk. 
The meningeal branch, a slender twig, arises from the ganglion of the 
root, and is distributed to the dura mater in the vicinity of the jugular 
foramen. 
The auricular branch, the nerve of Arnold, a delicate nerve, arises from 
the ganglion of the root; it passes in front of the upper end of the 
internal jugular vein, enters a small canal in the jugular fossa, traverses 
the temporal bone, crossing the inner surface of the aqueduct of Fallopius, 
and appears at an opening on the surface of the mastoid, behind the ex- 
ternal auditory meatus. It is connected by communicating branches with 
the glosso-pharyngeal and facial nerves. Terminally, it divides into two 
branches, one of which supplies the back of the pinna and the meatus, 
while the other joins the auricular branch of the facial nerve. 
The pharyngeal branches, one or two in number, arise from the ganglion 
■of the trunk; their fibres are chiefly continued from the accessory portion 
of the spinal accessory nerve. They join the pharyngeal branches of the 
glosso-pharyngeal and sympathetic nerves to form the pharyngeal plexus 
(p. 554). 
The superior laryngeal nerve springs from the ganglion of the trunk, and 
contains a number of fibres from the accessory portion of the spinal accessory 
nerve. It is the sensory nerve of the greater part of the larynx, and it 
supplies the crico-thyroid muscle, and gives a twig to the inferior con- 
strictor. It passes downwards and forwards on the deep surface of the 
internal carotid artery, communicates with the sympathetic and the pharyn- 
geal plexus, and divides into an internal and an external branch. The 
internal branch, the internal laryngeal nerve, accompanies the laryngeal branch 
of the superior thyroid artery, pierces the thyro-hyoid membrane, and is THE YAGUS OE PNEUMOGASTEIC. 
557 
distributed to the mucous membrane from the base of the tongue and the 
epiglottis downwards as far as the true vocal cord, and also to that 
covering the back of the cricoid cartilage : on the deep surface of the ala 
of the thyroid cartilage it communicates with the inferior laryngeal nerve. 
The external branch, the external laryngeal nerve, a slender twig, descends on 
the deep surface of the infrahyoid muscles, and is distributed to the crico- 
thyroid muscle and the inferior constrictor of the pharynx; it also gives 
off' one or two slender branches to the mucous membrane of the larynx, 
and it usually detaches a branch which joins one of the cardiac branches 
of the sympathetic. 
The recurrent or inferior laryngeal nerve is the chief motor nerve of 
the larynx, but also supplies sensory filaments to the region below the 
vocal cord; in addition it furnishes branches to the cervical portions of the 
trachea and oesophagus. The nerve of the right side arises in the lower part 
of the neck; it bends round and ascends behind the first part of the 
subclavian artery, then passes upwards and inwards behind the common 
carotid and inferior thyroid arteries to gain the angle between the 
oesophagus and trachea in which it continues its ascent. It is con- 
nected with the inferior cervical ganglion of the sympathetic nerve, and 
supplies oesophageal and tracheal branches, and gives some twigs to the 
inferior constrictor. It enters the larynx beneath the edge of the inferior 
constrictor muscle, supplies all the muscles of the larynx except the crico- 
thyroid, ramifies in the mucous membrane of the region below the true vocal 
vord, and forms a communication with the superior laryngeal nerve. The 
nerve of the left side arises in the thorax, arches round the aorta, and then 
ascends into the neck behind the subclavian artery. It gives off a cardiac 
branch as it is passing beneath the aorta; its subsequent course in the 
neck and its distribution are similar to those of the nerve of the right side. 
The cardiac branches are three or four in number, and are subject to 
considerable variation. One or two arise in the upper part of the neck 
from the main stem and from the external laryngeal branch; descending 
they join with the cardiac nerves from the cervical sympathetic. Ono 
arises in the lower part of the neck, and one takes origin in the thorax 
from the main trunk on the right side and from the recurrent nerve on 
the left side. They all join the deep cardiac plexus, with the exception 
of the lowest cervical branch of the left side, which crosses in front of the 
arch of the aorta to end in the superficial cardiac plexus. 
Two or three anterior pulmonary branches of slender size arise in the 
upper part of the thorax; they pass to the front of the root of the lung,, 
and join with branches of the sympathetic nerves to form the delicate 
anterior pulmonary plexus which ramifies upon the front of the root. 
The posterior pulmonary branches are numerous and of large size. 
They are given off behind the root of the lung, and, communicating with 
one another and with a few delicate sjunpathetic branches from the higher 
thoracic ganglia, form the posterior pulmonary plexus, the branches of which 558 
THE NERVES. 
ramify with the bronchi in the lungs. The plexuses of opposite sides 
communicate with one another. 
The oesophageal branches communicate with one another and with 
those of the nerve of the opposite side forming the oesophageal plexus from 
which branches pass to the muscular wall and mucous membrane of the 
thoracic portion of the oesophagus. 
The terminal or gastric branches ramify upon the stomach, and form 
communications with the sympathetic. The nerve of the left side is chiefly 
distributed to the front of the stomach. In the neighbourhood of the small 
curvature it forms communications with the nerves of the posterior surface, 
and furnishes branches to the hepatic plexus of the sympathetic. The 
nerve of the right side is chiefly distributed to the posterior surface of the 
stomach, and gives communicating branches to the coeliac plexus of the 
sympathetic. 
Development. The recurrent course of the inferior larjmgeal branch can be 
accounted for on developmental grounds. At an early stage in the embryo the 
nerve passed inwards to the larynx below the lowest of the primary vascular 
arches; by the descent of the heart and the great vessels from the neck 
into the thorax the nerve was drawn downwards. The distribution of 
the nerves of the right and left sides respectively to the posterior and 
anterior surface of the stomach was brought about in the course of 
development by a change in position of the stomach, which originally 
projected forwards in the middle line, but afterwards became turned over 
on to its right side. 
THE ELEVENTH OR SPINAL ACCESSORY NERVE. 
The spinal accessory nerve (Fig. 412) is formed of two distinct portions, 
respectively bulbar and spinal in origin. The bulbar portion, the smaller of 
the two, springs by five or six roots, which are in continued series with those 
of the vagus. The spinal portion arises by a number of fasciculi, which spring 
from the side of the upper part of the spinal cord between the anterior and 
posterior nerve roots, in the region above the level of origin of the sixth 
cervical nerve; the lower of the fasciculi emerge from the cord immediately 
behind the line of attachment of the ligamentum denticulatum; the higher 
ones, more posteriorly placed, are close to the posterior roots. Gradually 
increasing in size the nerve ascends behind the ligamentum denticulatum, 
and enters the cranium through the foramen magnum. It is then joined 
by the bulbar portion, and the common trunk passes outwards behind 
the vagus to the jugular foramen. Immediately beneath the jugular 
foramen the component parts of the nerve separate from one another. 
Nuclei of origin. The fibres of the bulbar portion are in the medulla 
oblongata connected with the posterior extremity of the nucleus ambiguus, 
from which the efferent fibres of the vagus spring; those of the spinal 
portion take origin from a group of cells, which in the lower cervical THE SPINAL ACCESSORY NERVE. 
559 
region lies at the base of the anterior horn, hut which, when followed 
upwards, gradually assumes a more ventral position. 
The bulbar or accessory portion joins the ganglion of the trunk of the 
vagus : and most of the fibres pass into the cardiac, inferior and superior 
laryngeal, and pharyngeal branches. The fibres which it conveys to the 
vagus are believed to be partly cardiac inhibitory and partly motor for 
the muscles of the larynx and pharynx and some of those of the palate. 
The spinal portion (Fig. 379) assists in the supply of the sterno-mastoid 
and trapezius muscles. It passes backwards and downwards, crossing, as a 
rule, the deep surface of the internal jugular vein, and lying between the 
posterior belly of the digastric muscle and the transverse process of the 
atlas. Continuing its course it passes through the sterno-mastoid muscle, 
crosses obliquely the posterior triangle of the neck, and gains the deep 
surface of the trapezius, upon which it descends, gradually diminishing 
in size as its branches enter the muscle. On the deep surface of the 
sterno-mastoid it is joined by a branch of the second cervical nerve, and 
on the deep surface of the trapezius by two or three branches from the 
third and fourth cervical nerves. 
THE TWELFTH OR HYPOGLOSSAL NERVE. 
The hypoglossal nerve (Fig. 413) takes origin by ten or twelve root 
bundles which spring from the side of the medulla oblongata in the furrow 
between the anterior pyramid and the olivary body. 
Nucleus of origin. The fibres spring from a large nucleus which lies 
close to the middle line, beneath the floor of the hinder part of the fourth 
ventricle, and extends backwards through the closed portion of the medulla, 
along the ventro lateral margin of the central canal, to become continuous 
with the anterior cornu of the spinal cord. 
The several fasciculi of origin are directed outwards from the surface, 
and become gathered into two bundles; these separately pierce the dura 
mater and enter the anterior condylar foramen, within which they unite 
with one another. After emerging from the foramen the nerve becomes 
adherent for a short distance to the posterior border of the lower ganglion 
of the vagus. It then passes between the internal carotid artery and the 
internal jugular vein. In its subsequent course the nerve forms a bend 
with the convexity downwards. It passes at first downwards and forwards 
to within a short distance of the great cornu of the hyoid bone, crossing 
the internal carotid artery, escaping from the cover of the posterior belly 
of the digastric, looping round the occipital artery, and crossing the 
external carotid artery. It then runs forwards above the great cornu, 
passing on the deep surface of the tendon of the digastric, and resting on 
the hyo-glossus muscle. Its terminal branches ascend upon the hyo-glossus 
and the genio-glossus to the tongue. 
As it is leaving the skull the nerve detaches a small meningeal branch. 560 
THE NERVES. 
Immediately below the foramen of exit the hypoglossal is joined by 
communicating branches from the first loop of the cervical plexus, and from 
the superior cervical ganglion of the sympathetic-, there is also an interchange 
of fibres between it and the ganglion of the trunk of the vagus as they 
adhere to one another below the base of the skull. A little lower down 
a branch from the vagus or from the pharyngeal plexus joins the trunk 
of the nerve. As it rests upon the hyo-glossus, before it breaks up into 
its terminal branches, two or three filaments pass between it and the 
lingual branch of the fifth nerve. 
The branches of distribution supply the intrinsic muscles of the tongue 
and the stylo-glossus, hyo-glossus, genio-glossus, genio-hyoid, and thyro- 
hyoid, and the anterior belly of the omo-hyoid; in addition they furnish 
part of the supply of the posterior belly of the omo-hyoid, the sterno hyoid, 
and the sterno-thyroid. It is usual among mammals for all the muscles 
below the hyoid bone to be supplied altogether by the spinal nerves, 
and it is quite probable that in man the nerve fibres to these muscles 
have a similar origin, those detached from the hypoglossal possibly reaching 
it through the connecting branches with the cervical plexus. 
The descending branch (descendens hypoglossi, descendens noni in the 
system of Willis) arises as the main trunk is looping round the occipital 
artery ; it passes downwards and forwards upon the surface of the carotid 
sheath, and detaches a twig to the anterior belly of the omo-hyoid. It is 
then joined by a branch (the communicans hypoglossi) which springs by 
two roots from the second and third cervical nerves respectively; from 
the loop which is thus formed (the ansa hypoglossi) branches pass to the 
sterno-hyoid, sterno thyroid, and the posterior belly of the omo-hyoid; 
occasionally a branch from the loop extends into the thorax, and com- 
municates with the phrenic nerve. The descending branch sometimes 
springs from the vagus instead of the hypoglossal, and it may run for 
some distance within the carotid sheath. The nerve to the tlujro-hyoid, a 
slender twig, is detached from the hypoglossal as it bends forwards below 
the posterior belly of the digastric. 
The nerves to the stylo-glossus, hyo-glossus, genio-glossus, and genio-hyoid 
are slender branches, which are given off as the main stem rests on the 
hyo-glossus muscle. The terminal or glossed branches pierce the under 
surface of the tongue. 
THE SYMPATHETIC NERVES. 
The central part of the sympathetic system is formed of two gangliated 
cords, one on each side of the body, which run through the whole length of 
the trunk by the side of the vertebral column, and are sometimes called 
the prevertebral chains. In the thoracic region there are usually twelve 
ganglia on each side, one corresponding to each segment, but the number is. 
liable to diminution on account of the occasional conjunction of neighbouring THE SYMPATHETIC NEEYES. 
561 
ganglia; in the cervical region the number of ganglia is reduced to three; 
there are four or five lumbar and four sacral ganglia, and the chains of 
opposite sides terminate in a median ganglion impar on the front of the 
coccyx. The ganglia of the great sympathetic cords may be termed 
the proximal ganglia, and they are to be distinguished from other more 
distally placed secondary or distal ganglia which are found scattered among 
the branches of the cords. 
The proximal ganglia are connected with the anterior divisions of the 
spinal nerves by branches which are styled the rami communicantes. These 
communicating branches are of two kinds, which are named respectively 
white and grey branches of communication. The white rami are formed 
of medullated fibres of small diameter; they may be regarded as 
the sole roots of the sympathetic system. They contain both efferent 
and afferent fibres, and are probabty limited to the thoracic and the 
upper part of the lumbar region ; their fibres, running in the anterior 
and posterior roots of the spinal nerves, pass between the thoracic and 
upper lumbar proximal ganglia and the spinal cord. It is to be added, 
however, that from the second, third, and fourth sacral nerves fibres 
similar to those which form the white roots pass outwards and, instead 
of joining the proximal ganglia of the main cord, run directly to the 
distal ganglia of the pelvic plexus of the sympathetic. Many of the 
cranial nerves contain fibres which are to be compared to those of the 
sympathetic system. The grey rami are branches of distribution from the 
sympathetic ganglia ; they are ■ formed chiefly of non-medullated fibres; 
one passes to each of the spinal nerves. On reaching the spinal nerve 
the grey fibres of the ramus break up into two divisions; one of these, 
the smaller, passes backwards and ramifies on the sheaths of the spinal 
cord, the other turns outwards with the spinal nerve, and is distributed 
peripherally. The very few white fibres which are found in the grey 
rami are probably afferent sympathetic fibres, and enter the cord by the 
white roots. 
The longitudinal cord of the sympathetic of each side is formed from 
a series of commissures which pass between the successive ganglia; from 
the ganglia of the thorax and upper lumbar region, which receive the 
white roots, the fibres stream upwards into the neck and downwards 
into the pelvis. 
Branches. In addition to the grey rami, which are distributed to the 
body wall, there are given off in the neck, thorax, and upper part of 
the abdomen, numerous visceral branches, the most important of which 
are the cardiac and splanchnic nerves; they form large plexuses con- 
taining ganglia; from the plexuses smaller plexuses are prolonged to 
the viscera and visceral bloodvessels, and these in their turn frequently 
contain ganglia. The efferent fibres of the sympathetic have various 
functions. To the heart and bloodvessels there pass fibres which are 
termed vaso-motor; their stimulation causes acceleration of the heart 562 
THE SYMPATHETIC NERVES. 
beat, and contraction of the bloodvessels. Another set of fibres, which 
are termed vaso-inhibitory, are distributed to the heart and vessels; the 
inhibitory fibres for the heart, however, run in the vagus nerve ; and 
those for some of the vessels of the head, e.g. those of the salivary 
glands, are found in certain of the cranial nerves ; the nervi erigentes, 
the stimulation of which dilates the vessels of the genital organs, are 
known to arise from the second and third sacral nerves, and to join 
the pelvic plexuses of the sympathetic; the course of the inhibitory 
fibres for the other vessels is not known. To the muscular layers 
of the viscera there pass fibres, stimulation of which induces con- 
traction, they may be called viscero-motor ; the viscero-motor fibres, for 
nearly the whole length of the alimentary canal, run in the vagus 
and its associated nerves, but those for the pelvic portion of the 
tube and the other pelvic viscera probably run partly in the splanchnic 
trunks, and partly along with the nervi erigentes from the sacral nerves 
to the pelvic plexus. Most physiologists agree that there are also viscero- 
inhibitory fibres, stimulation of which inhibits the contraction of the 
muscular tissue of the viscera; the course of these fibres is not 
known, but it is probable that those for the abdominal portion of 
the alimentary canal run in the splanchnic nerves. Glandular fibres pass 
from the sympathetic to the salivary and sweat glands, and possibly 
to other glandular organs. Those for the salivary glands ascend in the 
cervical sympathetic and pass out from the superior cervical ganglion; 
they carry impulses which affect the processes which take place in 
the glands. The fibres for the sweat glands probably pass through 
the grey rami, and are distributed with the nerves which run in the 
body wall; their stimulation produces an increase in the secretion of 
sweat. Filo-motor fibres pass to the muscles of the hair follicles; their 
course is probably similar to that of the fibres for the sweat glands. 
Dilator fibres for the pupil ascend in the cervical sympathetic and the 
cavernous plexus to the ciliary ganglion. The afferent fibres of the sym- 
pathetic probably come chiefly from the abdominal and pelvic viscera 
through the splanchnic nerves. 
The Cervical Portion of the Cangliated Cord. 
The cervical portion of the sympathetic cord (Fig. 412) lies upon the 
rectus capitis anticus major and longus colli muscles, in front of the trans- 
verse processes of the vertebrae, and on the deep surface of the carotid 
sheath. At the root of the neck, on the right side, it descends behind the 
subclavian artery, but one or two offsets (ansa Yieussenii) usually cross 
in front of the vessel to rejoin the main stem below it. It presents 
three ganglia. 
The superior cervical ganglion, the largest of the series, is somewhat 
spindle-shaped, measures about an inch in length, and probably repre- . Auriculo-teniporal 
.Chorda tympani 
pTrifacial 
-Lingual 
- Stylo-glossus 
- Glosso-pharyngeal 
-Stylo-pbaryngeus 
_Hypoglossal 
Submaxillary ganglion 
Descendens hypoglossi 
Nerve to thyro-hyoid 
Mylo-hyoid 
Gciiio-hyoid 
External carotid artery 
Ansa hypoglossi 
Superior thyroid artery 
Vagus 
- Sterno-hyoid 
- Omo-hyoid 
Fia. 413.—The Nebvbs of the Tongue. (C. Gegenhaur.) 
To face p. 562. First lumbar ganglion 
..Solar plexus 
( Superior 
( mesenteric plexus 
Renal plexus 
Ilio-hypogastric. 
Aorta» 
-Small intestine 
Lumbar sympathetic chain 
Lumbar plexus. 
Branches from aortic to 
Inferior mesenteric 
plexus 
hypogastric plexus 
Sacral 
sympathetic chain 
.Great intestine 
Rectum 
Vas deferens 
RlnHHpr 
Sacral plexus 
Uretor 
Vcsicula serninalis 
Spermatic plexus 
Prostate 
Fig. 414.—The Sympathetic or the Lower Part of the Trunk, right side. 
3, Semilunar ganglion ; 8, aortic plexus ; 9, pelvic plexus. (Testut, after Hirschfeld.) 
To face p. 563 THE SUPERIOR CERVICAL GANGLION, 
563 
sents four ganglia, which have become united into a single mass; it is 
placed in front of the transverse processes of the second and third vertebrae. 
Its branches are the communicating, the vascular, the ascending, the 
pharyngeal, and the superior cardiac. 
The communicating branches are numerous: one passes to each of the 
anterior divisions of the first four cervical nerves, one passes to the 
hypoglossal nerve, one to each of the ganglia of the vagus, and one to 
the petrous ganglion of the glosso-pharyngeal. 
The vascular branches pass to the external carotid artery and ramify with 
its branches; some of them reach the thyroid body, others terminate in 
the intercarotid body; the sympathetic roots of the otic and submaxillary 
ganglia are detached from the vascular branches. 
The ascending branch accompanies the internal carotid artery; it enters 
the carotid canal, and divides into an external and an internal branch. 
The external branch breaks up within the canal and on the outer side 
of the artery, into numerous subdivisions, which, interlacing and com- 
municating with one another, form the carotid plexus. From the carotid 
plexus a number of communicating branches are given off: (a) one or two 
tympanic branches pierce the wall of the canal and pass between the carotid 
plexus and the tympanic plexus; one of these, generally regarded as 
passing from the tympanic plexus to the carotid plexus and the great 
deep petrosal nerve, is named the small deep petrosal nerve (p. 554); (b) 
the great deep petrosal crosses the foramen lacerum medium and joins the 
great superficial petrosal of the facial to form the Vidian nerve; (c) a 
branch joins the sixth nerve; and (cl) a branch joins the Gasserian 
ganglion. The internal branch breaks up into the cavernous plexus, which 
lies on the under surface of the artery as it is passing forwards through 
the cavernous sinus; from the plexus (a) vascular branches accompany the 
branches of the internal carotid artery; (b) communicating branches join the 
third and fourth nerves, and the ophthalmic division of the fifth ; (c) the 
sympathetic root of the lenticular ganglion passes into the orbit either separately 
or in conjunction with the nasal branch of the ophthalmic division of 
the fifth; and (d) small filaments pass to the pituitary body. 
The pharyngeal branches of the superior ganglion are two or three in 
number; they join with the pharyngeal branches of the vagus and 
glosso-pharyngeal nerves to form the pharyngeal plexus (p. 554). 
The superior cardiac branch descends by the side of the main trunk 
and communicates with the external and recurrent laryngeal nerves, and 
with the other cervical cardiac nerves; on the right side it passes in 
front of or behind the subclavian artery and joins the deep cardiac 
plexus; on the left it crosses in front of the aortic arch, and terminates 
in the superficial cardiac plexus. 
The middle cervical ganglion is much smaller than the superior, 
and is sometimes absent altogether; it is probably formed from two 
originally separate ganglia. It is placed opposite the sixth cervical 564 
THE SYMPATHETIC NERVES. 
vertebra, and generally rests upon the inferior thyroid artery. It detaches 
(a) communicating branches to the anterior divisions of the fifth and sixth 
cervical nerves, (b) vascular branches with the inferior thyroid artery to the 
thyroid body, and (c) the middle cardiac branch, which on each side descends 
to the deep cardiac plexus; the left nerve enters the thorax behind and to 
the inner side of the subclavian artery; the nerve of the right side crosses 
the subclavian either on its superficial or its deep aspect. 
The inferior cervical ganglion, intermediate in size between the 
superior and middle, lies between the last cervical transverse process and 
the neck of the first rib; it probably represents two originally separate 
ganglia. It detaches (a) communicating branches to the seventh and eighth 
cervical nerves; (b) vascular branches which ascend with the vertebral 
artery, forming a plexus surrounding its stem and accompanying its 
branches; and (c) the inferior cardiac nerve, which on each side joins the 
deep cardiac plexus. 
This portion (Fig. 412) descends by the side of the vertebral column, 
lying behind the pleura, and crossing anteriorly the intercostal vessels. 
It presents twelve ganglia, but the first (the ganglion stellatum) is fre- 
quently conjoined with the inferior cervical ganglion. The upper ten 
ganglia lie upon the heads of the corresponding ribs; the lower two 
rest upon the vertebral bodies. Entering the abdomen the sympathetic 
trunk either passes behind the internal arched ligament or pierces the 
crus of the diaphragm. The branches are the communicating, the vascular, 
the pulmonary, and the three splanchnic nerves. 
The Thoracic Portion of the Gangliated Cord. 
Two communicating branches, respectively white and grey, pass from 
each ganglion to the corresponding spinal nerve. Vascular branches of 
small size pass from the first five or six ganglia to the aorta. A few 
pulmonary branches from the upper ganglia enter the posterior pulmonary 
plexus. 
The great splanchnic nerve arises by separate branches from the ganglia 
from the fifth to the ninth or tenth; these roots bend forwards upon 
the column and, joining with one another, form a considerable trunk 
which, piercing the crus of the diaphragm, enters the abdomen and 
terminates in the semilunar ganglion. Before entering the abdomen the 
nerve of the right side frequently presents a small ganglion upon its 
trunk; a similar ganglion is occasionally found on the left nerve. 
The middle splanchnic nerve of small size springs from the tenth and 
eleventh ganglia; it passes behind the internal arched ligament and 
ends in the solar plexus. The smallest splanchnic nerve springs from the 
twelfth ganglion; it descends with the middle splanchnic and usually ends in 
the renal plexus. The splanchnic nerves contain many medullated fibres 
which, emerging by the white roots from the cord, pass over the ganglia 
of the main chain without being connected with their cells. THE GANGLIATED CORD. 
565 
The lumbar portion (Fig. 414) descends upon the surface of the column 
by the inner margin of the psoas muscle. It crosses anteriorly the lumbar 
vessels, and on the right side lies behind the vena cava inferior. It 
presents four or five ganglia. 
The Lumbar Portion of the G-angliated Cord. 
Communicating branches pass from the ganglia to the anterior divisions 
of the lumbar nerves ; they are longer than the corresponding 
branches in the dorsal region, and are less regular in their arrangement. 
A few branches, very irregular as to number and place of origin, pass to 
the aortic and hypogastric plexuses. 
The Sacral Portion of the Gangliated Cord. 
This portion (Fig. 414) descends in front of the sacrum by the inner 
margins of the anterior foramina; it presents usually four small ganglia, and 
the cords of the opposite sides terminate in a median ganglion impar, which 
lies upon the last piece of the sacrum or on the coccyx. Irregular com- 
municating branches pass to the anterior divisions of the sacral nerves. A few 
small twigs reach the pelvic plexus, and from the ganglion impar branches 
proceed to the coccygeal gland. 
The Cardiac Plexus. 
The cardiac plexus lies below and behind the arch of the aorta. It 
is formed by the interlacement of the cardiac branches of the vagus and 
sympathetic nerves. From the trunk of the vagus on each side three 
cardiac branches are given off in the neck; and a cardiac branch is 
detached in the thorax usually from the main trunk upon the right side 
and from the recurrent laryngeal nerve upon the left. The cervical 
sympathetic cord on each side gives off three cardiac nerves. The various 
branches, however, are subject to considerable irregularity. The plexus 
is usually described as being formed of two portions—the superficial and 
the deep—which are, however, continuous with one another. 
The superficial cardiac plexus lies below the arch of the aorta, immediately 
to the right side of the ductus arteriosus. It receives the superior cardiac 
branch of the sympathetic cord of the left side, and the lowest cervical 
branch of the pneumogastric of the same side, and at the point of junction 
of the nerves a small ganglion, the ganglion of Wrisberg, is frequently 
found. The plexus gives off some slender branches to the left anterior 
pulmonary plexus, and is continued into the right coronary plexus. 
■ The deep cardiac plexus lies in front of the trachea, and behind the arch 
of the aorta. It receives all the cardiac branches already enumerated, with 
the exception of the two which pass to the superficial plexus. It gives 
branches to both anterior pulmonary plexuses, and to the right coronary 
plexus, and is continued inferiorly into the left coronary plexus. The 566 
THE SYMPATHETIC NERVES. 
right and left coronary plexuses accompany the right and left coronary 
arteries respectively; the branches, which are numerous, pierce the muscular 
substance of the heart, and present many microscopic ganglia. The right 
plexus is formed'by branches from the deep and superficial cardiac plexuses; 
the left is continued from the deep plexus. 
The Solar Plexus (Epigastric Plexus). 
The solar plexus (Fig. 414), the largest of the sympathetic plexuses, 
rests upon the abdominal aorta at the place of origin of the coeliac axis, 
and stretches outwards towards the suprarenal bodies. It contains on 
each side a large ganglionic mass, the semilunar ganglion. The solar 
plexus is continued downwards on each side into the aortic plexus, and 
from the main plexus and its continuations there radiate a number of 
secondary plexuses which accompany the phrenic and visceral branches of 
the abdominal aorta. 
The semilunar ganglion (see figure in description of suprarenal capsule) 
lies upon the crus and consists of a flattened collection of smaller ganglia 
closely united with one another. It measures between an inch and an 
inch and a half in transverse and vertical diameter, but its size varies, 
and some of its component smaller ganglia are frequently distinct from 
the main mass. It receives the great splanchnic nerve of its own side. 
The phrenic or diaphragmatic plexuses ascend with the inferior phrenic 
arteries, and ramify on the diaphragm, forming connections with the 
branches of the phrenic nerves. On the right side there is usually a small 
ganglion in the phrenic plexus. 
The suprarenal plexuses consist of a number of branches which pass 
into the suprarenal capsules. 
The renal plexuses accompany the renal arteries to the kidneys. They 
are formed of numerous large nerves, and receive the smallest splanchnic 
nerves. 
The coeliac plexus is continuous with the anterior surface of the solar 
plexus ; it surrounds the coeliac axis, and receives communicating 
branches from the right pneumogastric nerve. It breaks up into smaller 
plexuses, which accompany the branches of the coeliac axis. Of these 
the hepatic plexus is the largest; it is joined by a branch of the left pneumo- 
gastric nerve and detaches pyloric, pancreatico-duodenal, and cystic plexuses, 
and bifurcates terminally with the right and left divisions of the hepatic 
artery. The coronary plexus descends with the artery upon the small 
curvature, and forms connections with the pneumogastric nerves and with 
the pyloric plexus. The splenic plexus passes to the spleen and detaches 
pancreatic and gastro-epiploic offsets with the branches of the splenic 
artery. 
The superior mesenteric plexus is continued from the lower part of the 
solar plexus: the nerves which form it are remarkable for their white colour; THE SOLAR PLEXUS. 
567 
they surround the superior mesenteric artery and pass between the layers of 
the mesentery to the intestines. 
The aortic plexuses, one on each side, are continued downwards from 
the lower lateral portions of the solar plexus. They descend upon the 
sides of the aorta, communicating with one another across the middle line in 
front of the vessel; they receive branches from the lumbar ganglia; and 
below, forming on each side a number of large cords, they cross the common 
iliac arteries and terminate in the hypogastric plexus. From the aortic 
plexuses the spermatic or ovarian plexuses are given oft’; they accompany the 
similarly named arteries. 
The inferior mesenteric plexus is detached from the left aortic plexus; 
it is somewhat similar to the superior mesenteric plexus though of smaller 
size. The inferior mesenteric ganglion lies on the aorta immediately below 
the inferior mesenteric artery ; it communicates with the aortic plexuses. 
The Hypogastric Plexus. 
This plexus is formed in front of the last lumbar vertebra by the union 
with one another of the cords continued from the right and left aortic 
plexuses; it also receives branches from the lower lumbar ganglia. It 
forms a flattened reticulated band, and usually contains no ganglia ; it 
divides below into the right and left pelvic plexuses. 
The pelvic plexuses (Fig. 414) lie by the sides of the rectum, and, 
in the female, of the vagina. They receive a few slender branches 
from the sacral ganglia, and are joined by twigs from the second, third, 
and fourth sacral nerves. Each plexus forms a considerable inter- 
lacement with a number of small ganglia. From the pelvic plexuses 
there are detached a number of subsidiary plexuses which pass with the 
branches of the internal iliac arteries to the pelvic viscera. 
The haemorrlwidal plexus accompanies the middle haemorrhoidal artery 
to the rectum and communicates with the inferior mesenteric plexus and 
with the haemorrhoidal branches of the pudic nerve. 
The vesical plexus passes forwards to the sides of the bladder. Con- 
nected with the vesical plexus there is in the male the prostatic plexus, and 
smaller collections of nerves ramify over the vesicula seminalis and 
accompany the vas deferens. From the prostatic plexus the cavernous 
nerves {nervi erigentes) pass forwards by the side of the membranous portion 
of the urethra to supply the cavernous tissue of the penis; the small 
cavernous nerves enter the hinder part of the cavernous bodies, the large 
cavernous nerves run forwards on the dorsum and join the dorsal nerves of the 
penis. 
In the female, vaginal plexuses surround the lower part of the vaginal 
wall, supply its erectile tissue, and furnish branches to the clitoris. The 
uterine plexus ascends with the uterine artery and ramifies in the muscular 
substance of the uterus. 568 
THE NERVES. 
THE DEVELOPMENT OF THE NERVES. 
The development of the nerves has not as yet been thoroughly worked 
out, and there is much discrepancy between the opinions of different 
observers. It is, however, generally conceded that the essential parts of 
the nerves are epiblastic in their origin. They appear to grow outwards 
towards the periphery, partly from the ganglia and partly directly from 
the brain or spinal cord. The ganglia are formed from a thickened 
longitudinal strip of the deep layer of the epiblast, which is formed on each 
side of the mid-dorsal line in the angle of junction between the epiblast 
of the neural groove and that of the general surface. The thickened 
strip is usually formed before the closure of the neural groove takes place, 
and it extends from the region of the fore-brain backwards to or nearly 
to the hinder extremity of the spinal cord. When the closure of the 
tube takes place, the thickened strips of the two sides lose their con- 
nection with the general epiblast, but remain for a time in continuity 
with the dorsal margin of the neural tube, and by their mesial margins 
in contact with one another. The name “neural crest” has been given 
to the continuous ridge thus formed, overlying the dorsal border of the 
medullary cylinder. The ganglia are formed as thickenings of the crest, 
each corresponding in position to a mesoblastic somite; and the unaltered 
portions of the crest continue for a while uniting the successive ganglia. 
The ganglia are at first connected with the dorsal margin of the neural 
tube, but the original continuity is soon broken through, and each comes 
to form an isolated mass of epiblastic cells lying by the side of the 
neural tube. Eventually, however, a secondary connection is established 
between the ganglion and the side of the cerebro-spinal cylinder. Some 
of the hinder ganglia in the chick are said to arise as independent 
swellings of the epiblast, the continuous neural crest not extending back- 
wards over the whole length of the cord. 
Development of the spinal nerves. When the separate ganglia have been 
established they sink in a ventral direction for a little distance between 
the mesoblastic somites and the side of the cord. They may be 
named the primitive ganglia; not only do they form the spinal ganglia 
of the posterior roots of the adult, but, according to most observers, 
a separated portion of each gives rise to a sympathetic ganglion. From 
the inner and outer extremities of the somewhat spindle-shaped spinal 
ganglion growth takes place. From the inner extremity of the ganglion 
the growing process attaches itself to the side of the spinal cord at a 
spot which corresponds with what will afterwards be the position of the 
tip of the posterior horn of the grey matter, and thus the secondary 
connection of the ganglion with the cord is established. The out- 
growth from the outer extremity of the ganglion forms the afferent 
portion of the segmental nerve. The anterior roots of the nerves 
grow directly from the cord, from the side of which they emerge close DEVELOPMENT OF THE NERVES. 
569 
to the ventral margin. Extending outwards, they reach the developing 
posterior roots, and complete the nerves. The original nerve-fibres 
are delicate processes prolonged from the nerve cells ; become 
the axis-cylinders of distribution, and acquire medullary sheaths and 
connective-tissue coverings from the general mesoblast through which 
they run. According to His, the growth towards the periphery is slow. 
He describes the spinal nerves as beginning to develop in the human 
foetus in the fourth week, and as not having completed their growth to 
the tips of the extremities by the end of the eighth week. 
It will be seen that this leaves much in the arrangement and distribution 
of the nerves which still requires explanation. The mode of growth of the 
immensely long axis-cylinder processes, the regular formation of plexuses, 
and the regularity of the supply of definite muscles or areae of skin from 
definite segments of the cord, have not been adequately explained. Hensen 
has put forward the theoretical suggestion that all nerves take their origin 
from a network of intercellular protoplasmic processes; and Hertwig 
has attempted to explain the regularity of the distribution of the trunks, 
by suggesting that the cutaneous nerves have arisen from a subepithelial 
protoplasmic network, and that the motor nerves are formed by the 
drawing out and subsequent growth of very delicate protoplasmic con- 
nections which, at an early date, stretched between the cells of the 
embryonic cord and those of the closely contiguous muscle plates. The 
nerve-trunks are formed, according to these theories, during the process 
of growth by the binding together of neighbouring protoplasmic threads 
in a common sheath. 
The sympathetic system. Very little is known of the details of the 
development of the sympathetic system. The ganglia appear to originate 
in common with the spinal ganglia, and the longitudinal commissural 
bands are described as uniting the ganglia at a later period. The method 
of origin of the roots, the branches of distribution, and the secondary ganglia 
has not yet been investigated. It may be suggested, however, from a 
consideration of the anatomical details that (1) the efferent fibres of the 
white roots grow to the ganglia from the cord, inasmuch as they break up 
into arborizations within the ganglia ; (2) that the secondary ganglia are 
derived from the chief ganglia, as many of the fibres of the white roots 
pass through the chief ganglia and terminate in the secondary ganglia; 
and (3) that the efferent branches of distribution grow from the ganglia 
as do the outgrowing afferent fibres from the spinal ganglia. 
The cranial nerves. With the exception of the optic nerve, which 
is derived from a special lobe of the brain, the cranial nerves develop, 
in the majority of cases, either from the neural crest, or as direct out- 
growths from the brain. 
As in the case of those which are associated with the cord, the 
cranial ganglia lose their original connections with the dorsal border and 
become attached to the side of the neural axis. At their outer extremities, 570 
THE NERVES. 
however, they remain for a time close to the surface, and become 
attached to epiblastic thickenings, which lie at the dorsal extremities of 
the gill clefts. In the opinion of many observers these epiblastic 
thickenings detach cells which assist in forming the ganglia. The 
epiblastic thickenings just mentioned have been called the “rudimentary 
branchial sense-organs of Beard ”; they appear to represent the branchial 
sense organs of fishes, and to be in series with the organs developed 
in that group along the lateral line. The development of the nerves 
which grow directly from the brain has not been satisfactorily studied. 
The development of the olfactory and optic nerves is described along 
with that of the brain. 
The oculo-motor nerve seems to develop chiefly as a direct outgrowth 
from the basal surface of the central organ, but evidences of embryonic 
ganglionic substance found in its root suggest the probability of its having 
been formed partly from the neural crest. The development of the 
fourth nerve has not been satisfactorily studied, but like the third it 
probably arises partly from the neural crest and partly directly from the 
brain. The sixth nerve probably grows directly from the ventral surface 
of the hind-brain. 
The fifth nerve takes origin from a primitive cranial ganglion, and 
becomes connected with the side of the hind-brain. The ganglion becomes 
continuous externally with a lateral epiblastic thickening, and is in all 
probability partly formed from it. From the ganglion the ophthalmic 
branch grows forwards in front of the eye, and the inferior maxillary 
branch grows downwards into the mandibular arch; with the formation 
of the maxillary process the superior maxillary branch groAvs forwards. 
The development of the motor branch of the fifth is not satisfactorily 
determined, but according to Gaskell there are evidences in its root of a 
primitive ganglionic origin. 
The seventh and eighth nerves are formed from one primitive ganglion. 
The epiblastic depression which forms the ear may be compared to 
a lateral sense organ, and the deeper layers of its Avail probably assist in 
forming the ganglia of the auditory nerve, from AAdiich the nerve-fibres 
grow to the surface. The facial nerve descends along the anterior border 
of the hyoid arch, and detaches a branch, the chorda tympani, AAdiich 
runs along the posterior border of the mandibular arch, and joins the 
inferior maxillary trunk. 
The glosso-pharyngeal and vagus nerves develop from primitive ganglia. 
The glosso-pharyngeal descends along the anterior border of the first 
branchial arch, and gives a small branch to the posterior border of the 
hyoid arch. The \ragus is the nerve of the second and third branchial 
arches; in the tadpole it gives off the nerA'e of the lateral line. The 
bidhar portion of the spina,l accessory is to be regarded as a portion of the 
vagus nerve; the development of the spinal portion has not yet been 
ascertained. The hypoglossal nerve is regarded by many as arising entirely DEVELOPMENT OF THE NERVES. 
571 
as a direct outgrowth from the ventral surface of the brain ; but, on 
the other hand, the presence of a small ganglion in connection with its. 
root, which has been discovered in the mammalian embryo by Froriep, 
would suggest that the nerve may partly be formed from the neural 
crest. 
Morphology of the Nerves. 
Various attempts have been made to classify the different nerve-fibres 
from a morphological point of view, the most interesting being that 
of G-askell. This observer recognizes two great groups, “somatic” and 
“ splanchnic,” differing from one another in the size, the central connections, 
and the distribution of their constituent fibres. In a typical spinal nerve 
he finds five subsidiary groups of fibres, two of which fall into the 
somatic, while three appertain to the splanchnic division. The somatic 
groups are afferent and efferent; the afferent somatic fibres come from the 
epiblastic surface of the body, pass through the spinal ganglia, and are- 
connected centrally with the extremity of the dorsal horn of the grey 
matter of the cord; the efferent somatic fibres take origin from the ex- 
tremity of the ventral horn of the grey matter, and are distributed to all 
the voluntary muscles, with the exception of those which he includes in 
the respiratory group. The splanchnic groups he terms respectively the 
“sensory splanchnic,” the “gangliated splanchnic,” and the “non-gangliated 
splanchnic.” The first of these is composed of afferent fibres, which belong 
to the sympathetic system; they pass through the spinal ganglia, and 
are supposed to be connected centrally with the basal portion of the 
dorsal horn. The “ gangliated splanchnic ” group he regards as arising 
from the cells of Clarke’s column; the fibres are efferent, and pass to the 
sympathetic ganglia, from which in turn the various sympathetic efferent 
fibres emerge. The “ non-gangliated splanchnic ” fibres are supposed to 
take origin from the cells of the lateral column of grey matter; they are 
distributed to certain of the voluntary muscles, namely, those which 
belong to Sir Charles Bell’s respiratory group. The dorsal roots of the 
spinal nerves contain the somatic and splanchnic afferent fibres; the ventral 
roots carry the somatic and the two forms of splanchnic efferent fibres. 
To the views of Gaskell it has to be pointed out in objection that the 
respiratory muscles of the trunk cannot be separated developmentally 
from the other voluntary muscles, and that it is only in the region of 
the head that a separation of the voluntary muscles into two groups 
can be effected. It may also be suggested that the term “ splanchnic ” 
is not properly applicable either to sympathetic nerve-fibres, which run 
in the somatic wall, as for instance those which supply the sweat glands 
and the muscles of the hair follicles, or to fibres which supply voluntary 
muscles, such as some of those of the respiratory group, which form a. 
constituent part of the body wall. 572 
THE NERVES. 
While it is evident that the details of the development of the nervous 
system are not sufficiently well known to enable us to formulate a 
definite morphological classification of the nerves, yet an analysis of 
the various fibres which go to make up a typical segmental nerve of the 
trunk, and the collection of these fibres into groups dependent on the 
tissues to which they are distributed, may prove of use to the student 
in assisting him to remember the anatomical details. Each typical nerve 
springing from the cord is formed by the union of a posterior or 
dorsal and an anterior or ventral root, the former containing afferent and 
the latter efferent fibres. Connected with each nerve trunk there is 
found in the earty embryo a ganglion which, in the course of development, 
becomes subdivided into a dorsal or afferent and a ventral or efferent 
portion. The dorsal portion becomes the spinal ganglion, the ventral 
portion the sympathetic ganglion. The spinal ganglion is connected to the 
cord by the posterior root. The sympathetic ganglion is connected to the 
cord by efferent fibres which run in the anterior root. Besides the efferent 
fibres which pass to the sympathetic ganglion, another set of efferent fibres is 
found in the anterior root. These fibres spring from the ventral extremity 
of the anterior horn of the cord, and pass to the voluntary muscles. The 
fibres which make up the roots of a segmental nerve may therefore be 
divided into three groups: (1) an afferent group forming the posterior root, 
and connected with the spinal ganglion• (2) an efferent group, forming 
part of the anterior root, and connected with the sympathetic ganglion ; 
(3) an efferent group, non-gangliated, forming part of the anterior root, 
passing to the voluntary muscles. Following, but somewhat modifying 
the terminology of Gaskell, these groups may be named respectively: 
(1) the dorsal ganglia,ted afferent, (2) the ventral gangliated efferent, (3) the 
ventral non-gangliated efferent. 
Tracing now to their distribution the various fibres which a complete 
segmental nerve might be conceived to contain, they may be arranged 
with reference to the special groups, as follows : 
1. Fibres of the dorsal gangliated group (afferent). 
(a) To epiblastic and hypoblastic surfaces (nerves of general and 
special sense). 
(h) To general mesoblast (afferent fibres from heart, genito-urinary 
(c) To organs derived from the muscle plates, the voluntary muscles 
organs, etc.). 
(the nerves of muscular sensibility). 
2. The fibres of the ventral gangliated group (efferent). 
(a) To epiblastic and hypoblastic surfaces (glandular nerves). 
(b) To general mesoblast (vaso-motor, viscero-motor nerves, etc.). 
3. The fibres of the ventral non-gangliated group (efferent) 
(c) To organs derived from the muscle plates (the motor nerves of MORPHOLOGY OF THE NERVES. 
573 
the voluntary muscles of trunk). The limb muscles in the 
lower forms are, like the muscles of the trunk, derived from 
the muscle plates. This has not been made out for the higher 
forms, but the nerves of the limb muscles in the higher 
classes seem to belong to the same group as those of the trunk 
The segmental nerve divides almost immediately on its formation into 
two portions, to which the names “spinal” and “sympathetic” have been 
given. The spinal portion contains the afferent epiblastic fibres, the afferent 
fibres of the voluntary muscles, and the efferent fibres of the voluntary 
muscles; the sympathetic portion, known as the white root, or white 
ramus communicans, of the sympathetic ganglion, probably contains all 
the other fibres, namely, those of the ventral gangliated group and the 
afferent fibres of the hypoblast and the general mesoblast. Immediately 
after the formation of the spinal and sympathetic portions, a rearrange- 
ment of fibres takes place, which results in the formation of the nerve 
trunks of distribution, which may be called “ somatic ” and “ splanchnic.” 
The rearrangement is brought about by the passage of fibres, the so-called 
grey root or grey ramus communicans, from the sympathetic ganglion to 
the spinal nerve. The resulting somatic nerve trunk runs in the somato- 
pleuric wall, and contains all the afferent and efferent somatopleuric fibres; 
the remaining splanchnic trunk ramifies in the visceral wall, and contains 
all the splanchnic fibres. The following diagram shows the arrangement 
described above. In connection with the diagram, it has to be noted 
muscles). 
Dorsal 
root 
Somatic 
Ventral 
root 
Splanchnic 
Fig. 415.—Diagram representing the jirobable course of the various kinds of fibres in a 
hypothetically complete Segmental Nerve (spinal region). 1, Bpiblast afferent fibre ; 
2, 3, mesoblast afferent fibres ; 4, hypoblast afferent fibre ; 5, muscle plate afferent fibre ; 
6 epiblast efferent fibre ; 7, 8, mesoblast efferent fibres ; 9, hypoblast efferent fibre ; 10, 
muscle plate efferent fibre. Sp.G., Spinal ganglion; S.N., segmental nerve; Sp., spinal 
portion of the segmental nerve (what is usually called the spinal nerve); Sy., sympathetic 
portion (white ramus communicans with sympathetic); g.r., gray ramus communicans ; 
Som., somatic trunk running in body wall ; SpL, splanchnic trunk running in splanchno- 
pleur ; Sy.G., Sympathetic ganglion. (J.Y.M.) 
that the efferent fibres which pass to the sympathetic have been 
represented as if they all terminated in the ganglion of the main 
chain of the sympathetic. Actually, however, a number of them pass. THE NERVES. 
through the ganglion of the sympathetic chain, and terminate in arborizations 
within one or other of the secondary ganglia. While the description above 
given deals with the arrangement of fibres in a hypothetically complete 
segmental nerve it is to be noted that probably the cervical, and the 
lower lumbar, and some of the sacral nerve roots, do not contain any 
sympathetic portion. 
The somatic branches show in their origin and distribution a regular 
segmental type. The splanchnic or visceral branches, on the other hand, 
■exhibit but little evidence of a segmental arrangement. On the one side 
of the sympathetic ganglia the branches of connection with the cord or 
white rami have been found in a number of mammals experimentally 
investigated, particularly in the dog, cat, and rabbit, to occur oidy in the 
thoracic and upper lumbar regions; on the other side of the ganglia, 
the somatic branches of distribution or grey rami are regular and seg- 
mental in their arrangement. 
The nerves which spring from the brain cannot, like those which 
take origin from the cord, be clearly arranged in correspondence with 
■a series of consecutive segments; their fibres, however, may be classified 
as belonging to groups which are to be compared to the dorsal gangliated 
afferent, the ventral gangliated efferent, and the ventral non-gangliated 
efferent groups of a typical segmental nerve. In studying the arrangement 
and distribution of the fibres it is to be remembered that the only 
muscles of the head which are formed from structures homologous 
to the mesoblastic somites are those of the orbits. The muscles of 
mastication and the facial muscles are formed in the lateral mesoblast. 
Certain of the cranial efferent nerves, the fibres of which, from their 
distribution to glandular structures, and to muscles developed from the 
general mesoblast, seem to correspond to those of the ventral gangliated 
group of a spinal nerve, have, in the adult, no ganglia in connection 
with their roots; but in each of these instances traces of ganglionic 
substance have been found in the embryo, suggesting an origin from a 
primitive ganglion, and in connection with the branches of distribution 
■one or more distal ganglia are found in the adult. 
The following classification of the cranial nerves must be regarded as 
purely a hypothetical one; it differs in a number of points from that put 
forward by Graskell. The third, or oculo-motor, nerve is chiefly made up 
of fibres which correspond to those of the non-gangliated efferent group of 
a typical segmental nerve. It supplies muscles which are formed from the 
first mesoblastic somite of the head. Its fibres to the ciliary ganglion and 
from thence to the ciliary muscle probably correspond to those of the 
gangliated efferent group of fibres of a segmental nerve. Gaskell has 
discovered in its trunk traces of embryonic ganglionic substance. In com- 
paring the third to a typical segmental nerve, it is to be noted that afferent 
fibres are wanting, those corresponding to gangliated efferent are few in 
number, and that those corresponding to the non-gangliated efferent form MORPHOLOGY OF THE NERVES. 
575 
the bulk of the nerve. The fourth nerve supplies the superior oblique 
muscle, which is formed from the second mesoblastic somite of the head. 
Its fibres are to be compared to those of the ventral non-gangliated group 
of a segmental trunk. As in the case of the third, Gaskell has dis- 
covered in the fourth nerve traces of ganglionic substance, which may 
perhaps represent an original dorsal afferent portion. The fifth nerve is 
formed of two portions; the fibres of the larger afferent portion correspond 
to those of the dorsal group, while those of the smaller efferent portion 
are to be compared to those of the ventral gangliated group of a seg- 
mental nerve trunk. The motor portion of the nerve is distributed to 
muscles which are formed in the general mesoblast; its fibres form connec- 
tions with the otic ganglion; and it is interesting to note that Gaskell 
has discovered in its trunk, as in that of the third nerve, the remains of 
ganglionic substance. 
The fibres of the sixth nerve seem to be comparable to those of the 
ventral non-gangliated group; they supply the external rectus muscle, 
which is formed from the third mesoblastic somite of the head. The 
seventh or facial nerve is formed of fibres which belong in all probability 
to the ventral gangliated group. It supplies muscles which are formed 
in the lateral mesoblast; it is connected with the geniculate ganglion 
and with the submaxillary ganglion; and Gaskell has discovered in its 
trunk, as in those of the third and the motor portion of the fifth, 
remains of ganglionic structure. The fibres of the eighth or auditory 
nerve correspond to those of the dorsal gangliated group which are 
specially connected with the epiblast, and its ganglia correspond to an 
afferent ganglion. The ninth, or glosso-pharyngeal, and the tenth, or vagus, 
may be taken together; each consists of two portions, one correspond- 
ing to the dorsal group and the other to the ventral gangliated group. 
The two ganglia of each nerve may possibly represent the afferent 
and the efferent ganglia of a typical segmental nerve-trunk. The eleventh, 
or spinal accessory nerve, is made up of two portions, one of which, 
the accessory portion, is probably to be regarded as a portion of the 
vagus trunk, the other, the spinal portion, as a set of fibres be- 
longing to the anterior roots of the cervical segmental nerves. The 
twelfth, or hypoglossal, is usually regarded on account of its super- 
ficial origin and central connections as comparable to the ventral non- 
gangliated portion of the root of a segmental nerve, but from their 
distribution the glossal fibres would seem to belong more naturally to 
the ventral gangliated group. It is interesting to notice that Froriep 
has discovered in the embryo a small ganglion associated with the 
hypoglossal trunk. If the foregoing conceptions of the arrangement 
and distribution of the cranial nerves are true, it follows that no 
cranial nerve in the adult has all the parts represented in a typical seg- 
mental nerve, namely, three groups of fibres, a dorsal afferent gangliated, 
a ventral efferent gangliated, and a ventral efferent non-gangliated. The 576 
THE NERVES. 
fourth, the sixth, and, according to most, the twelfth trunk seem to be 
formed purely of fibres belonging to the ventral non-gangliated group. 
The motor of the fifth and the seventh seem to be formed of fibres 
belonging entirely to the ventral gangliated group. The sensory of the 
fifth and the eighth nerve would be formed purely of fibres belonging 
to the dorsal gangliated group. Of mixed trunks the third nerve seems 
to be formed of fibres belonging to the ventral non-gangliated and the 
ventral gangliated efferent groups; while the ninth and tenth would be 
made up of fibres belonging to the dorsal afferent and the ventral efferent 
gangliated groups. 
THE CEREBRO-SPINAL AXIS AND ITS MEMBRANES. 
Cerebro-spinal axis is the name given to the whole of the great 
continuous centre of the cerebro-spinal nervous system. Though obviously 
consisting of two parts, the brain and the 
spinal cord, and though the cord is com- 
paratively simple in structure and similar 
in appearance in different parts of its length, 
while the brain is so complex and so dissimilar 
in its successive parts as to be even now 
incapable of being fully compared with the 
cord in its details, yet the cerebro-spinal axis 
is single in its origin, and indivisible in the 
adult condition save by arbitrary section. 
It is a symmetrical organ, and the nerves 
arise from it in pairs, both the cerebral nerves, 
as those are called which come from the brain, 
and the spinal nerves, or those belonging to 
the cord. The brain or encephalon occupies 
the cranial cavity, and fills it, as it does also 
in all birds and mammals; but the spinal 
cord is far from filling up either the length 
or the width of the spinal canal in which it 
lies, and floats in a watery cerebro-spinal fluid. 
Both brain and spinal cord are surrounded by 
three coverings called meninges, namely, the 
Fig. 416.—Cebebeo-Spinal Axis. 
dura mater, the arachnoid, and the pia mater 
The dura mater is a tough fibrous membrane, the deep surface of which 
is smooth and free,1 coated with fine endothelium, and lies in contact, for 
1 This description is given in deference to the prevalent fashion. Nevertheless it 
is the case that, at least in the foetus, there is a layer which is easily filled in 
patches with injection, exhibiting a close network of vessels, with a delicate trans- 
parent layer over, them, and uninjected fibrous tissue beneath. This I have seen DURA MATER. 
577 
the most part continuously, with the opposed free surface of the arachnoid, 
which has likewise an endothelium. The space between dura mater and 
arachnoid, formerly known as the arachnoid space, is now usually termed 
subdural. The dura mater of the cord forms a loose sheath, which extends 
some way into the sacrum. It is separated by loose connective and 
adipose tissue, as well as by veins, from the periosteal and ligamentous 
walls of the canal, but is kept in position by bands of fibres which pass 
downwards from its anterior surface to be attached to the posterior common 
ligament over the bodies of lumbar and sacral vertebrae. The anterior 
and posterior roots of the spinal nerves pierce it near the intervertebral 
foramina by’ which they respectively emerge, and its fibres are continued 
on them and mingle with their bundles; but on its deep side the anterior 
and posterior roots of each nerve disappear by two openings, separated 
one from the other by a fibrous band. 
The dura mater within the cranium differs from that in the spinal canal 
in being adherent to the bone, and performing at once the offices of 
fibrous covering to the brain and of periosteum to the inner table of the 
skull. It sends inwards three septa—the tentorium cerebelli, the falx 
cerebri and the falx cerebelli. 
The tentorium cerebelli is projected between the cerebellum and the 
posterior lobes of the cerebral hemispheres. Its attachment extends from 
Fig. 417.—Tentorium Cerebelli and Falx Cerebri. 1, Entrance of great vein of Galen 
into the straight sinus; 2, free margin of tentorium : 3, falx cerebri; 4, left side of 
tentorium. (Luschka.) 
the internal occipital protuberance, along by the groove for the lateral 
sinus, and thence by the posterior and upper border of the petrous part 
both in the spinal part and on the sides of the falx cerebri. It is also to be remembered 
that it has long been recognised that in the neighbourhood of the base of the falx 
very small accumulations of delicate tissue can be seen beneath the deep surface. 
These circumstances, together with the early condition found by me in cases of com- 
plete open spinal bifida [Jour. Anat. and Phys., 1883), favour the old view that a 
parietal arachnoid adheres to the dura mater. 578 
CEREBROSPINAL MEMBRANES. 
of the temporal bone, with the superior petrosal sinus in the groove 
along its line of attachment, and stretches from the tip of the petrous 
to the tip of the anterior clinoid process. Its free margin is of a horse- 
shoe form, reaching from one anterior clinoid process to the other, in- 
cluding in its curve a space through which passes a constricted part of 
the brain, termed isthmus cerebri; and its surface is arched, being most 
elevated in the middle of its free edge. The falx cerebri is a mesial septum 
named from being sickle-shaped. It is attached to the crista galli of the 
ethmoid, and along by the whole length of the groove marking the course 
of the superior longitudinal sinus, and to the tentorium cerebelli forwards 
as far as the free margin of the latter. The free margin of the falx 
cerebri is not always very definite throughout; and running in connection 
with it there is a small venous channel, the inferior longitudinal sinus. 
This and a trunk formed by the veins of Galen, enter from the interior of 
the brain at the junction of the margins of the falx cerebri and tentorium, 
while the straight sinus is hollowed out in the line of contact of these two 
septa.1 The falx cerebelli is a slight mesial projection of dura mater 
beneath the tentorium, and in its line of attachment the occipital sinus 
is placed. 
The arachnoid is a thin transparent membrane which loosely invests 
the cerebro-spinal axis, superficial to the pia mater, resting on it in many 
places and connected with it by loose tissue, while in others it is com- 
pletely separated by a considerable distance; the whole interval, both 
where fibres are absent and where they are present, constituting the 
subarachnoid space. The arachnoid is a water-tight membrane, presenting 
to the subdural space a smooth surface covered with endothelium, and 
consists mainly of laminated straight white fibres, which near the surface 
are stretched out in a sheet without perforation, but more deeply form 
trabeculae. Immediately under the endothelium, and also more deeply, 
there is also homogeneous membrane, alleged to be composed of flattened 
cells. Large oval nuclei, like those of synovial membranes, are abundant 
in the trabeculated part, and leucocytes occur in great numbers in the 
meshes. 
In the spinal canal the arachnoid surrounds not only the spinal cord, 
but the collection of roots of nerves proceeding downwards from it called 
cauda equina, enveloping it in one large loose sheath, which extends down 
to the extremity of the tube of dura mater; and it is within this extensive 
part of the subarachnoid space, together with its continuation upwards 
on the spinal cord, that the cerebrospinal fluid is principally situated, 
while the surfaces of the subdural space are more closely in contact, 
1 Bearing on the irregularity of the free margin of the falx, I have made the 
observation that in the foetus the falx extends down to the corpus callosum, and 
is inferiorly quite continuous with the arachnoid, and that before birth the lower 
part begins to disappear, leaving the fold of arachnoid from one hemisphere to the 
other free or nearly so. ARACHNOID AND PIA MATER. 
579 
resembling in this respect other opposed endothelial surfaces. On each 
side the arachnoid has a series of attachments to the dura mater of two 
sorts : it embraces the roots of each spinal nerve where they pierce the 
dura mater, and between the successive roots of nerves it surrounds the 
attachments of the ligamentum denticulatum to be hereafter described. 
Within the cranium the arachnoid passes smoothly over the convolu- 
tions of the cerebral hemispheres and the laminae of the cerebellum, 
being loosely attached to the pia mater, but not dipping into the sulci. 
Between the hemispheres it reaches so far down as barely to touch the 
pia mater of the corpus callosum; and from the hinder end of that 
structure it passes directly to the upper surface of the cerebellum. 
There are two spots (cisternae) at which it is removed a considerable 
distance from the pia mater—one below the cerebellum, where it passes 
directly down behind the fourth ventricle to the lower part of the 
medulla oblongata; the other at the base of the brain, stretching over 
the rhomboid space between and in front of the crura cerebri, and 
extending laterally to the Sylvian fissure, and between each crus and the 
overlapping hemisphere. The arachnoid within the cranium is in con- 
tinuity with the dura mater where’the different cranial nerves leave the 
subdural space, also where the veins quit the pia mater and stretch across 
to the superior longitudinal cavernous and other sinuses. 
The Pacchionian bodies (described by Pacchioni, 1721) are round 
semi-transparent structures, irregular in number and situation, but 
principally occurring near the mesial plane, beneath the roof of the 
skull, and almost constantly present in the adult; some of them generally 
pushing their way partially through the dura mater and causing absorp- 
tion of the inner table of the skull, while others may find their way 
through the wall of the superior longitudinal sinus. They were shown 
by Luschka (1852) to be clavate enlargements of villi of the arachnoid, 
and they may be fairly compared, like the grapelike growths of the 
nucleus pulposus of an intervertebral disc, with villi of synovial mem- 
branes. They do not all arise from the surface to which latterly the 
term arachnoid has been restricted. Luschka, like anatomists of the 
time when he wrote, looked on the deep surface of the dura mater as 
covered with a parietal arachnoid, and he carefully described parietal as 
well as other Pacchionian bodies. I had occasion to confirm his obser- 
vations (1863). Though acknowledged to be coated with endothelium, 
Pacchionian bodies often form adhesions which mask the pedicle. 
The pia mater is the vascular covering of the cerebro-spinal axis. 
Only very small bloodvessels are admitted within the nerve-substance of 
the brain and cord; the largest veins showing in sections of the brain as 
mere dark spots, while the arteries are still smaller. The arteries, after 
piercing the dura mater, pass into the pia mater and branch out into 
large numbers of small twigs, from which smaller arterioles plunge 
vertically into the brain-substance; and in like manner the emerging 580 
CEREBRO-SPINAL MEMBRANES. 
venous radicles are gathered together in the pia mater into large trunks. 
The pia mater consists of these arteries and veins, together with a small 
amount of white fibrous tissue, partly in the form of bands with elastic 
fibres wound round them. It adheres closely to the surface of the 
nerve-substance, being folded in so as to be applied to the' walls of the 
anterior longitudinal fissure of the cord and of the sulci of the cerebral 
hemispheres and the cerebellum, and mingles with every nerve-root. It 
also dips into the interior of the brain at two places, namely, the 
transverse fissure and the fourth ventricle, forming vascular fringes, 
called choroid plexuses, to be described with the details of the brain. 
The pia mater of the spinal cord has its fibrous tissue strengthened at 
certain places to form longitudinal bands. One of these is a shining 
thread in the middle line in front (tinea splendens); another, broader, 
called ligamentum denticulatum, runs down on each side between the 
anterior and posterior roots of nerves, and gets its name from being 
attached to the dura mater between the roots of each nerve and those 
of the nerve below by a slender but firm thread clothed with the 
arachnoid, which is thus thrown into a denticulated line. There are 
about twenty-one such denticulations—the first placed above the sub- 
occipital nerve and in front of the vertebral artery; the last about the 
level of the first lumbar vertebra. Interiorly the fibres of both liga- 
mentum denticulatum and linea splendens are continued into a thread 
called filum terminate, extending downwards from the extremity of the 
cord. In the middle line, behind the cord, a network of trabeculae, 
partly single, partly double, extends from between the posterior nerve- 
roots of opposite sides, across the subarachnoid space, back to the 
arachnoid membrane, and is described as the septum posticum of the 
subarachnoid space. 
THE SPINAL CORD. 
The spinal cord (medulla spinalis) is continuous above with the part 
of the brain called medulla oblongata, which passes into it without any 
line of separation. It extends very constantly from the foramen magnum 
to the lower border of the body of the first lumbar vertebra, varying 
usually between 16 and 18 inches in actual length. It is of generally 
cylindrical form, but with differences of size and shape at different 
levels. It is circular in section in the greater part of the thoracic 
region, and |th inch or more in diameter, while it is of slightly greater 
transverse breadth at its commencement. But it has two enlargements 
—the cervical and the lumbar. The cervical enlargement extends from 
near the commencement, as far as the emergence of the first thoracic nerve, 
and is characterized by increase in transverse breadth. It is the part 
which furnishes the roots of the nerves from which the large trunks 
(brachial plexus) for the supply of the upper limb arise. The lumbar 
enlargement is less noticeable, being caused by expansion all round, but to SPINAL CORD. 
581 
less extent in any one diameter. It begins more than two inches above 
the lower end, and tapers inferiorly into a conical extremity, in ivhich 
Fig. 419.—Lower Part of Spinal Cord and Membranes, from before, a, a, a, Edge of dura mater; 6, edge of arachnoid: c, line of divided anterior 
nerve-roots; d, d, distal ends of divided anterior nerve-roots; e, threads of ligamentum denticulatum stripped of their arachnoid covering; /, ex- 
tremity of spinal cord ; g, fllum terminate lifted out from the nerve-roots of the cauda equina and seen through the arachnoid ; h, linea splendens. 
Pig. 4IB.—MKDtrLLA Oblongata, and the Spinal Cord down to Bth Thoracic Pair of Nerves, from behind. The range of spinal ganglia 
of the right side is seen beyond the divided dura mater, a, a, Other edge of divided dura mater; 6, edge of arachnoid, below which the sub- 
arachnoid space is unopened; c, c, posterior roots leaving the subdural space; d, d, lino of posterior roots emerging from spinal cord; e, e, e, 
attachments of ligamentum denticulatum ; f, posterior fissure; g, groove between columns of Burdach and Goll; h, clava; i, spinal accessory 
nerve ; k, ligula ; I, striae acusticae ; m, divided crura cerebelli. 
Fig. 417. 
Fig. 418. 582 
CEREBRO-SPINAL AXIS. 
the cord terminates. Both this enlargement and the sides of the 
conically-tapering extremity afford origin to closely-crowded roots of 
lumbar and sacral nerves, including those which supply the lower limbs. 
These roots of nerves, from above downwards, extend for regularly- 
increasing distances within the dura mater to reach the successive inter- 
vertebral foramina, and the whole bundle of them lying beyond the cord, 
within a loose sheath of arachnoid, is called the cauda equina. Hid in the 
centre of the cauda equina is the silvery thread, filum terminale, continuous 
with the pia mater, which stretches down to the extremity of the dura 
mater, to be fixed with it to the lower end of the sacrum. 
In the mesial plane the cord exhibits in its whole length, continued 
down from the medulla oblongata, a deep anterior fissure into which a 
mesial process of pia mater dips, and posteriorly a depressed line, 
descending from the calamus scriptorius of the medulla oblongata, 
indicating the edge of a posterior fissure closed in its whole length by a 
reticulum of supporting material proper to the cord, the posterior septum. 
On each side the roots of the spinal nerves are connected with the 
cord in two series—the anterior roots (also called motor) distributed to 
the voluntary muscles; and the posterior roots (or sensory), distributed to 
the integument. Each root, whether anterior or posterior, consists of 
separate bundles, and, save in the upper part of the neck, the nearest 
bundles of successive roots are not further separate than the successive 
bundles of one root; but the bundles of each root approach one another 
as they pass outwards, the lowest bundles of the uppermost roots being 
horizontal, and those of succeeding roots more and more directed down- 
wards. The bundles of the anterior roots lie four or more abreast, the 
innermost emerging gently from the cord and concealing those external 
to them; and there is no depression where they appear, the antero-lateral 
furrow, sometimes described, having no existence in nature. The bundles 
of the posterior roots, on the contrary, lie in a single longitudinal series, 
standing out abruptly in a distinct postero-lateral furrow further removed 
from the middle line than the inner bundles of the anterior roots. Each 
posterior root, after emerging from the dura mater, has a spinal ganglion 
placed on it before being joined by the anterior root to form the nerve- 
trunk ; and the spinal ganglia are so intimately connected with the micro- 
scopic structure of the cord itself that neither can be understood apart 
from the other. 
Internal structure. On transverse section of the cord the posterior 
septum is seen to be deeper than the anterior fissure, and the distance 
between the two is not more than an eighth of the antero-posterior diameter 
on each side. At the bottom of the anterior fissure, white substance, con- 
sisting of fibres crossing the mesial plane, constitutes the anterior or white 
commissure, and the rest of the distance back to the posterior septum is 
occupied by the grey commissure, in the middle of which, dividing it into 
anterior and posterior grey commissure, there is a small canal, the central canal SPINAL CORD. 
583 
of the spinal cord. • The canal is invisible to the naked eye in the unprepared 
human subject, and just visible in hardened sections; but is a structure of 
much morphological significance, inasmuch as the spinal cord in its earliest 
embryonic condition was a grooved superficial ribbon whose sides were 
folded backwards so as to complete a tube which persists in this form, 
Fig. 420.—Sections of Spinal Cord. A, Mid-cervical; B, mid-thoracic; C, mid- 
lumbar ; D, near the pointed extremity. Below, in the middle of each, is the open 
anterior fissure ; above is seen the posterior fissure, and on each side of it, in A and B, 
a septum which lies between the columns of Burdach and Goll. 
and of whose walls the spinal cord is the developed condition. The 
central canal is continued above into the medulla oblongata to open into 
the calamus scriptorius, the mesial groove of the floor of the fourth ventricle; 
and it is prolonged down a long way into the filum terminale, which is 
thus, at least in its upper part, a continuation of the cord without develop- 
Fig. 421.—Ependymal or Spongioblastic Fibres of the Cord of a Seven Days* 
Chick. Golgi method, (v. Kolliker.) 
ment of nervous elements. The central canal is lined with elongated 
columnar ciliated epithelium, whose cells exhibit by the Golgi method a 
continuity with spougioblastic or neuroglial elements. The grey commis- 
sure is prolonged on each side into an expanded mass of grey matter, 
prolonged forwards and backwards so as to form what are called the 
anterior and posterior cornua, the anterior cornu clavately expanded and 
giving off’ the anterior roots of nerves, while the posterior cornu is con- 584 
CEREBRO-SRINAL AXIS. 
tinuous with the posterior roots. The whole surrounding texture consists 
of white substance. 
The white substance is arranged in three columns, anterior, lateral and 
posterior; the lateral column consisting of as much as lies between the anterior 
and posterior roots, and having the anterior and posterior columns respec- 
tively in front and behind it. The 'posterior column is perfectly separate, being 
situated internal to the posterior cornu; but in consequence of the bundles 
of the anterior roots being transversely scattered, the anterior column is not 
so definitely distinguished from the lateral column, and therefore it often 
becomes necessary to speak of the two together as the antero-lateral column. 
When the anterior and lateral columns are spoken of separately, the outer- 
most bundles of the anterior are taken as marking their plane of separation. 
Save at the white commissure, the white substance consists of longitudinally 
directed medullary nerve-fibres closely packed in supporting substance. 
Fibres of different diameters are intermingled; but those of largest size are 
most abundant toward the circumference of the antero-lateral column. A 
number of imperfect longitudinal septa, similar in substance to the posterior 
septum, extend from a superficial circumferent layer of neuroglia inwards 
through the white substance, breaking up and disappearing at different 
distances from the surface. It is principally in these septa that the arterioles 
pass inwards, giving off a sparse capillary network to the white matter, 
and ending in a more copious network in the grey matter; but a pair of 
longitudinal vessels formed by anastomosis of branches of the anterior spinal 
artery run in the grey commissure, one on each side. The septa are 
continuous with substance between the nerve-fibres, and contain, as well 
as it, neuroglia-corpuscles with large numbers of threadlike branches. 
No such septa are found above the medulla oblongata. 
Tracts in the white substance are recognised, not indeed in most instances 
to be distinguished one from another in sections, but having different con- 
nections, as evidenced by degenerations following lesions, according to 
Waller’s law (p. 53), or by aid of the fact that in development different 
strands receive their medullary sheaths at different periods (Flechsig’s 
method), or by direct anatomical observation, especially in early develop- 
ment. They are termed ascending or descending according as experiment 
or other evidence shows that their fibres run upwards or downwards from 
the corpuscles from which they start. 
In the anterior column, on each side of the anterior fissure, is a descending 
tract, the direct pyramidal tract, or column of Turck, continued down from 
the outer fibres of the anterior pyramid of the medulla oblongata, and 
diminishing steadily from above downwards. The remaining larger part 
of the anterior column, the anterior ground part, appears to consist of mixed 
ascending and descending fibres, emerging from the grey substance and 
re-entering it after short courses. 
In the lateral column there are distinguished three cerebellar tracts 
on the surface. The largest known is the hindermost; it is the direct SPINAL COED. 
ascending cerebellar tract, and was pointed out by Flechsig. In front of 
it is the indirect ascending cerebellar tract, or tract of Gowers, whose fibres 
pass lip into the pons before reaching the cerebellum by the superior 
peduncle; and still further forwards is the descending cerebellar tract, tract 
of Lowenthal or Marchi, whose fibres undergo degeneration from above 
downwards after removal of the cerebellum. Beneath the direct ascending 
cerebellar tract there runs the important crossed pyramidal tract, continuous 
with the inner or decussating fibres of the anterior pyramid of the medulla 
oblongata. Still deeper, between the anterior and posterior cornua, is the 
lateral ground part, consisting of fine fibres in bundles separated by grey 
reticulations, and taking very short courses outside the grey substance. 
Lastly, at the back of the lateral column, and invading the posterior 
column, there is a group of fine fibres, the marginal tract of Lissauer, connected 
with the posterior nerve-roots. 
Gelatinous substance 
Central canal 
Column of Gull 
Tract of Burdacb 
Tract of Lissauer 
Small nerve-cells 
Crossed pyramidal tract 
Lateral ground-tract 
Posterior vesicular ‘ 
column of Clarke 
Comma, 
Direct ascending 
cerebellar tract 
Reticular process 
' Indirect ascending 
cerebellar tract 
of Gowers 
Anterior commissure 
Lateral cornu 
Outer cells of \ 
anterior cornu f 
'Descending cerebellar 
tract of Lowenthal 
„ and of Marchi 
Inner cells of 1 
anterior cornu f 
Fig. 422.—Diagrammatic Transverse Section of Cord in Lower Dorsal Region. 
On one side the ascending tracts are left white, the descending tracts marked with 
horizontal lines, and mixed fibres marked with oblique lines. 
Direct pyramidal tract 
Anterior ground-tract 
In the posterior column a longitudinal septum, continued down from 
the furrow between clava and cuneate fasciculus in the medulla oblongata, 
separates, to a certain extent, an inner portion, the column of Goll, from the 
larger outer part or tract of Burdach. Both of these columns are partly 
continuous with the posterior nerve-roots, but in neither do the root- 
fibres continue for more than a limited extent. The only fibres of the 
posterior column known to undergo descending degeneration after injury 
to the cord are deeply placed on the inner side of the posterior cornu, 
and are known as the comma. Further observation, however, appears 
necessary before they can be identified with the descending divisions of 
the bifurcating fibres of the posterior nerve-roots described below. 
The grey substance of the cord varies in amount at different levels. 586 
CEEEBRO-SPINAL AXIS. 
It is most developed in the cervical and lumbar enlargements, and smallest 
below the middle of the thoracic region, where both anterior and posterior 
cornu are very narrow, while in the conus medullaris the white matter 
disappears more rapidly than the grey, leaving a ring of unsurrounded 
grey matter at the upper end of the filum terminale. 
The anterior cornu has an outline running from its foremost part 
in a direction outwards and backwards; and more or less continuous 
Fig. 423.—Spinai, and Sympathetic Ganglia from Neck of Chick of 17th Day. 
a, Spinal cord ;b, anterior root; c, posterior root; d, spinal ganglion ; r,, spinal nerve ; 
r, sympathetic ganglion. a, a, Sympathetic axis-cylinders of the communicating 
branches directed to the spinal nerve ; 6, protoplasmic branches of sympathetic nerve- 
corpuscles ; d, nerve-corpuscle of anterior or motor-root; e, e, sympathetic axis-cylinders 
becoming vertical; /, artery cut across ; g, body of vertebra; h, fusiform corpuscle of 
spinal ganglion ; i, i, transition from bipolar to unipolar corpuscle ; j, completely uni- 
polar corpuscle. (Cajal.) 
Fig. 424.—Semi - Diagrammatic Longitudinal Section of Posterior Column, 
parallel to Posterior Boots, s, White substance; o, grey substance; a, posterior 
root; al, collateral from its ascending branch; h', collateral from its stem; b, collateral 
from its inferior branch ending in arborization (above the letter); c, corpuscle with 
axis-cylinder which turns upwards in the white substance ; d, corpuscle with bifurcating 
axis-cylinder; e, corpuscle with axis-cylinder turned downwards ; f, g, arborizations of 
axis-cylinders. (Cajal.) 
Fig. 423. 
Fig. 424. 
with this outward extension, but most distinct from it in the region 
supplying the thoracic nerves, there is a projection which has been 
called the lateral horn (intermedio-lateral tract of Lockhart Clarke); while 
in the concavity between this and the posterior cornu the grey matter 
has a particular tendency to form a reticulation round longitudinal white 
bundles, the reticular process. The anterior cornu has the most abundant 
cells, and those which appear the largest in transverse sections of the 
cord; they are multipolar, and have their axis-cylinder-processes con- SPINAL COED. 
587 
tinned into anterior roots of nerves. They are arranged in groups, 
especially toward the extremity of the cornu, and those of the lateral 
cornu form a similar group adjacent to them. 
The posterior cornu, less swollen and, save in the lumbar enlargement, 
more elongated than the anterior, is less marked by nerve-cells. It 
presents in transverse section a slight bulbous swelling, supported by a 
neck, and extending to the postero-lateral groove, where it receives the 
posterior nerve-roots. Toward the tip it presents in the fresh state 
a semi-transparent portion, the substantia gelatinosa of Rolando, in which 
there is a transverse band of very small roundish corpuscles. The other 
nerve-corpuscles of the posterior cornu are mostly toward its margins, 
and are sparse, larger than those of the substantia gelatinosa, though 
much smaller than those of the anterior cornu. But along with the 
posterior cornu there is to be noticed a very definite collection of nerve- 
corpuscles, the posterior vesicular column of Lockhart Clarke, lying close to 
the inner side of its neck, with fine fibres curving round it. This column 
is almost confined to the region of the cord connected with the thoracic 
roots. Its cells are multipolar, normally smaller in transverse section 
than those of the anterior cornu, but considerably longer vertically. 
Flechsig pointed it out as the source of the direct ascending cerebellar 
tract, and Cajal has traced some of its axis-cylinders into that part of 
the lateral column, while he has followed others into the anterior com- 
missure. Gaskell considers it as probably the source of the splanchnic 
efferent nerves. 
Fig. 425.—Ascending Degeneration in Posterior Column of Spinal Cord in Dogs, 
after division of posterior nerve-roots. I. After division, by Singer, from 2nd sacral to 
6th lumbar ; a, at level of 6th lumbar; 6, of 3rd thoracic ; c. of middle of neck. 11. After 
division, by Singer, of 11th and 12th thoracic : a, at level of 12th thoracic ; 6, of 3rd 
thoracic; c, of middle of the neck. 111. After division, by Kahler, from sth cervical to 
2nd thoracic : a, at level of Ist thoracic ; 6, of 6th cervical; c, of Ist cervical. (Toldt.) 
The nerve-roots. The anterior nerve-roots consist of fibres mostly, if 
not all of them, from the axis-cylinders of the multipolar corpuscles of 588 
CEREBROSPINAL AXIS. 
the anterior cornu of the same side, and devoid of collaterals. It is open 
to question if any can be traced to the opposite side, or if the fibres of 
the white commissure are not rather derived from special corpuscles in 
the anterior cornu, and continued into the antero-lateral cord of the other 
side. Such commissural fibres have been seen, after crossing, to divide 
into an ascending and a descending fibre. 
The posterior nerve-roots contain some centrifugal fibres from the 
anterior cornu (Lenhossek and Cajal), but consist principally of centri- 
petal fibres from the spinal ganglion. The nerve-corpuscles of these 
f g ti i 
Fig. 426.—Diagram of Relations of Different Elements, a, Collaterals from column 
of Goll, forming larger part of posterior commissure; h, collaterals from column of Goll 
to posterior cornu; c, collaterals, some of which reach forward to the anterior cornu ; d, 
posterior nerve-root and its collaterals ; e, collaterals from antero-lateral column to 
anterior cornu; /, g, collaterals crossing in anterior commissure; h, axis-cylinder 
arising from corpuscle in anterior cornu, and crossing to anterior column of opposite side 
by anterior commissure at i; j, motor nerve-root arising from motor corpuscle k ; I, 
bifurcating axis-cylinder of anterior column arising from corpuscle of same side ; in, 
another arising from opposite side ; n, corpuscle with axis-cylinder giving off collateral 
in the grey substance ; o, axis-cylinder from column of Clarke ; p, axis-cylinder from s; 
q, transverse section of axis-cylinder; r, bifurcation of posterior nerve-root; s, marginal 
corpuscle of substance of Rolando; t, small corpuscle of the same; u, corpuscle of 
Clarke’s column. (Cajal.) 
ganglia are unipolar in the adult condition (p. 51), but the one pole 
divides into a centrifugal and a centripetal branch ; and within the cord 
the centripetal branch is found to bifurcate into an ascending and a 
descending fibre, both ending by arborization in the posterior cornu. 
As the fibres enter the cord they are distinguishable, according to Cajal, 
into an outer and an inner fasciculus, the outer consisting of fine fibres 
bifurcating in the marginal zone of Lissauer, and ending wholly in the 
posterior cornu, the internal consisting of larger fibres which bifurcate 
in the columns of Goll and Burdach. 
Sections, in living animals, of posterior roots before entering the cord 
show that the continuations upwards of their fibres, after ascending a SPINAL CORD. 
589 
certain distance, quit the white substance, and in their course they are 
pushed toward the mesial plane by others entering above them (Fig. 425). 
The collaterals given off from axis-cylinders in the white substance 
add to the structure of the spinal cord a remarkable complication, our 
knowledge of which is due to Golgi’s methods and dates no earlier than 
from 1880. These delicate fibres are given off at right angles from axis- 
cylinders, and pass horizontally into the grey substance to end in arboriza- 
tions. They arise very abundantly from the posterior columns, springing 
there in greater number from fibres of posterior roots. Of these one 
important group extends directly forwards into the anterior cornu, and 
Fig. 427.—Section of Spinal Coed of Dog at Birth, showing Disposition of 
Collaterals, a, Bundles crossing the substance of Rolando ; b, bundles crossing from 
outer side of cornu to opposite side ; c, dense plexus ; d, from posterior column to 
posterior cornu of opposite side ; e, f, middle and anterior bundles in grey commissure ; 
o, sensivito-motor bundles ; h, i, from anterior and lateral columns ; l, point of origin of 
numbers of sen sitivo-motor bundles; m, fasciculus going to Clarke’s column ;n, situation 
of anterior corpuscles. (Cajal.) 
surrounds with its arborizations the corpuscles of the motor nerve-roots, 
constituting the sensitivo-motor or reflexo-motor fibres, and furnishing an 
explanation of reflex actions. Others form a dense plexus in front of 
the substance of Rolando. A third set crosses the middle line, many of 
its fibres springing from the column of Goll; while a fourth small set, 
coming from the column of Goll, ends by embracing the corpuscles of 
the posterior reticular column of Lockhart Clarke. A number of the 
collaterals springing from the antero-lateral columns cross the middle 
line, those of the anterior column passing in front of the central canal, 
and those of the lateral columns passing behind it. 
The researches of Brown-Sequard first showed that sensory impressions 590 
CEREBRO-SPINAL AXIS. 
were conveyed from the hind limbs of animals after division of the posterior 
columns on both sides nearer the head, and that a mesial section of the cord 
made opposite the origins of the nerves to the fore limbs paralysed sensation 
in both those limbs without affecting the hind limbs. These observations, 
as also more recent researches of Edinger and the disposition of the 
collaterals, all point to a decussation of sensory tracts in a forward 
direction, and not far from the entrance of the posterior nerve-roots, in 
the length of the cord. 
THE BRAIN. 
I. GENERAL CONSTRUCTION 
The brain, or encephalon, presents below, resting on the basilar process 
of the occipital bone, a short extension upwards from the spinal cord, 
namely, the medulla oblongata, increasing in breadth, and rapidly changing 
both in the disposition of its parts and the mode of 
origin of nerve-roots. The medulla oblongata is crossed 
superiorly by the pons Varolii, a body having the 
appearance of a great band of transverse fibres, forming 
a prominence, which rests on the upper part of the 
clivus as far as the summit of the dorsum sellae, and 
is gathered together at each side to enter the cere- 
bellum. The cerebellum is a large brain-mass presenting 
a laminated surface of grey substance, and, together 
with the medulla oblongata and pons, fills the part of 
the cranial cavity beneath the tentorium. The whole 
of the rest of the brain, occupying all the cranial cavity 
above the tentorium, constitutes the cerebrum. The 
cerebrum is continuous with the parts below the ten- 
torium by the part traversing the constricted aperture 
bounded by the dorsum sellae and the free margin 
Fig. 428.-Bra.ik of 
Human Embryo of 12 
Weeks, with the pia 
mater removed, and the 
hemisphere spread out. 
a, Medulla oblongata ; b, 
fourth ventricle ; c, cere- 
bellum ; d, flocculus ; e, 
corpora quadrigemina; 
f, optic thalamis; g, 
hemisphere-vesicle laid 
open; h, corpus striatum 
within it. (After Tiede- 
mann.) 
of the tentorium and termed the isthmus cerebri, which would be divided 
by a section made close above the pons and the cerebellum. The parts 
of the cerebrum in contact with almost the whole wall of the cavity above 
the tentorium are the right and left cerebral hemispheres, much the largest 
masses of the brain, and presenting convoluted surfaces of grey substance. 
The body of the sphenoid, however, from the summit of the dorsum sellae 
forward to the united orbital wings, is not invaded by the hemispheres, 
and the cribriform plate of the ethmoid has the olfactory lobes immediately 
overlying it. 
Emerging from the pons Varolii are two diverging pillars of white 
substance, the crura cerebri, speedily overlapped by the hemispheres; 
and, when followed round the side, the crura cerebri are seen to be in 
continuity dorsally with structures emerging from the cerebellum, invested GENERAL CONSTRUCTION. 
591 
like them with pia mater • and the pia mater is also seen passing onwards 
into the interior of the cerebrum by what is called the transverse fissure, 
separating the root part of the cerebrum from the hemispheres above 
and on the sides. 
If the student will now, at the commencement of the study of the brain, 
glance at one, early stage of development, he will be aided in forming a 
general conception which will materially assist the comprehension of 
the adult structure. The medulla oblongata, pons Yarolii and cerebellum 
are developed in the wall of one expansion of the cerebro-spinal cylinder, 
Optic thalamus 
Corpora quadrigemina 
Quadrangular lobe 
Pineal body 
.Valve of Vieussens 
Depression where raphe 
of pons approaches 
the ventricle 
Superior crus cerebelli cut 
-Middle crus cerebelli cut 
..Superior fovea 
-Inferior crus cerebelli cut 
.Stria acustica 
. -Inferior fovea 
-Ligula 
Clava 
Restiform body 
Superior semilunar lobe : 
Horizontal fissure 
Inferior semilunar lobe : 
Fasciculus gracilis 
Primitive pouch 
Fasciculus cuneatus 
Fig. 429.—Dorsal View of Root of Brain, after removal of hemispheres by a cut at * 
separating the optic thalami from the corpora striata. The right half of the cerebellum 
is removed and the valve of Vieussens divided rnesially to show the floor of the fourth 
ventricle. 
namely, the third primary cerebral vesicle. They constitute the metenecphalon, 
(or metencephalon and myelencephalon), in the interior of which is left a dilated 
space, the fourth ventricle, continued up from the central canal of the spinal 
cord, but devoid of nervous wall in the part behind the upper half of the 
medulla oblongata. Above the metencephalon the nervous walls are again 
complete, and on the dorsum an elevation presenting a mesial and a 
transverse furrow, and on that account called corpora quadrigemina, is 
superimposed, while the canal is again constricted, and is called the aqueduct 
of Sylvius. This is the mesencephalon, derived from the second primary 
cerebral vesicle. Forwards from the mesencephalon there is another 592 
THE BRAIN. 
expansion, the thalamencephalon, presenting dorsally a pair of bodies, the 
optic thalami, covered, like the corpora quadrigemina, with pia mater, and 
joined by a thin roof in the middle line, but with a larger space between 
them, and ultimately with the nervous roof thrown open. From the front 
of the thalamencephalon a pair of hollow outgrowths, also covered with 
pia mater, grow and expand so as to extend backwards and outwards and 
inwards over both optic thalami and corpora quadrigemina. These are the 
hemisphere-vesicles, their cavities are the future lateral ventricles, and they 
present each, projecting into the cavity from the floor close to the thalamen- 
cephalon, a solid part which constitutes the corpus striatum. At an early 
date the nervous walls of the hemisphere-vesicles become grooved and 
Big. 430.—Brain from above, showing the two hemispheres. On the right the fissure 
of Rolando is marked, and on the left the principal convolutions. 
imperfect close to the lines from which the roofs of the vesicles turn back 
over the optic thalami, and the pia mater at this part, reflected on itself, 
projects a hypervascular fringe, a choroid plexus, into the interior, extending 
from side to side of what is called the transverse fissure of the brain. 
Even in the adult, as pointed out by Reichert, a section can easily be made, 
dividing the optic thalami from the corpora striata, and passing closely in 
front of the optic tracts, and thereby separating the comparatively simple 
root of the brain from the hemisphere-vesicles, which owe their complexity 
to their magnitude, the convolution of their pia-matral surface, the forma- 
tion of commissures crossing the mesial plane, and the unequal thickening 
of their walls. GENERAL CONSTRUCTION. 
593 
Superior surface. The part of the brain in contact with the cranial 
vault is formed by the two hemispheres, separated by the great longitudinal 
fissure, into which the falx cerebri descends; and at the bottom of this 
fissure, in the extent corresponding with the free margin between the 
tentorial and ethmoidal attachments of the falx, the hemispheres are united 
one with the other by a great transverse commissure, the corpus callosum. 
Inferior surface or base. The medulla oblongata is continuous with the 
spinal cord, and abruptly crossed at its other extremity by the pons Varolii, 
whose fibres gather together on each side and plunge into the cerebellum. 
The cerebellum spreads its lateral lobes on each side of the medulla 
oblongata and pons, and occupies the whole of the rest of the posterior 
fossa basis cranii behind them ; it roofs over a space, the fourth ventricle, 
of which they form the floor. 
The hemispheres extend backwards over the cerebellum and forwards 
to fill the frontal part of the cranium; and its projections in these directions 
are termed the posterior and anterior lobes, while a third projection of each 
hemisphere, distinguished as the middle lobef fills the middle fossa basis 
cranii external to the free edge of the tentorium, and is separated from 
the anterior lobe by the fissure of Sylvius, hidden within which there is a 
limited group of convolutions, the gyri operti or Island of Beil, the surface 
of the root-part of the hemisphere. 
Emerging in mutual contact at the border of the pons, the crura cerebri 
diverge as they enter the optic thalami from below, and become concealed 
by the middle lobes of the hemispheres, while the transverse fissure of 
the brain, the middle part of which is placed above, between the corpus 
callosum and the corpora cpiadrigemina, enters on each side between the 
crus cerebri and the middle lobe. Crossing each crus, a white band, the 
optic tract, is directed forwards and inwards to the middle line, where it 
meets its neighbour and forms, in conjunction with it, the optic commissure, 
from which the optic nerves are continued. The optic nerves strike out 
free, being surrounded by a prolongation of the pia mater; but the optic 
tracts present only one free surface, and enter into the construction of the 
wall of the brain. A little external to the optic commissure, at the inner 
end of the Sylvian fissure, on each side, there is an area pierced by a large 
number of small arteries, the anterior perforated spot. Between the crura 
1 The expressions, anterior, posterior and middle lobe have been dismissed by 
some writers, but are still useful in their original sense as applied to projections in 
three different directions. The more modern expressions, frontal, parietal, occipital, 
temporal, orbital, central, limbic and falciform lobe, are neither applicable to pro- 
jections nor to masses of the whole substance of the hemisphere, but properly refer to 
definite groups of convolutions. Professor Macalister has clearly and correctly stated 
the nature of these latter: ‘ ‘ Certain infoldings are early and constant, and form 
important landmarks dividing the surface into areas called lobes. It must be borne in 
mind that these are only surface markings.” Much confusion has resulted from neglect 
of this distinction. The anterior, middle and posterior lobes are lobes of projection ; 
the groups of convolutions are surface-lobes. 594 
THE BRAIN. 
and the optic tracts there is left a rhomboid space. In the posterior angle 
of this space, between the crura and in front of the pons, there is a 
depression where a number of small arteries, placed closely together, enter 
the cerebral substance, the posterior perforated spot. In front of this a pair 
of rounded white elevations like small peas lie together, the corpora albicantia, 
structures connected with the fornix ; and in front of them the rhomboid 
space is filled by the tuber cinereum, a thin grey lamina whose deep surface 
looks into the third ventricle. The tuber cinereum is attached to the 
corpora albicantia, the inner edges of the optic tracts and the posterior 
edge of the optic commissure, and is prolonged into a hollow projection, 
infundibulum, which narrows rapidly, and is continuous by its slender 
extremity with the solid structure, pituitary body, occupying the sella 
turcica. 
Infundibulum 
Corpora albicantia 
Posterior perforated spot 
Crus cerebri 
V, Motor root 
V, Sensory root 
Pons Varolii 
Middle crus of cerebellum 
Flocculus 
' Restiform body 
Olivary body 
Anterior pyramid 
Decussation of pyramids 
l^ceroh 
Anterior longitudinal fissure 
Fig. 481.—Basal View of Root of Brain after removal of hemispheres by a cut 
separating optic thalami from corpora striata, and passing along the anterior borders of 
the optic tracts. The lower border of the pons is slightly pressed upwards to show the 
descent of the fibres of the anterior pyramid and sixth nerve. 
From the anterior border of the optic commissure there passes upwards 
another grey membrane, lamina cinerea (Fig. 446). When the anterior lobes 
of the hemispheres are separated from below, the fore part of the corpus 
callosum is brought into view, bending round from above, and prolonged 
back nearly as far as the front of the optic commissure, but at a higher 
level; and there it comes to an edge continued on each side into a crus GENERAL CONSTRUCTION. 
595 
directed to the anterior perforated spot, while the lamina cinerea fills up 
the interval and forms the anterior wall of a cnl-de-sac of the floor of the 
third ventricle, bounded below and behind by the optic commissure. 
The optic nerves are, strictly speaking, portions of the brain, as are 
also parts of the contents of the eyeballs, both being derived from the 
primary optic vesicles of the embryo. In like manner, underneath the 
anterior lobes of the hemispheres, and resting on the cribriform plate of 
the ethmoid, there is a pair of structures, the olfactory lobes, each consisting 
of a narrow tract and broader bulb, formerly known as nerves, but now 
universally acknowledged to be lobes of the brain, giving off the olfactory 
nerves from the under surface of the bulbs (Fig. 453). 
It may be well also at this stage to indicate shortly the superficial 
origins of the other cranial nerves. They appear: the oculo-motor (3rd) 
on the inner side of the crus cerebri, just above the pons, and passing 
between the posterior cerebral and the superior cerebellar artery; the 
nervus patheticus (4th) on the outside of the crus, close to the pons, and 
below the superior cerebellar artery; the trigeminal (sth) from between 
the fibres of the pons, towards its outer extremity; the abducens oculi (6th), 
near the mesial plane, between the pons and what is called the anterior 
pyramid of the medulla oblongata; the facial and the auditory nerve, between 
the pons and the side of the medulla oblongata, in the angle between them 
and the cerebellum, the auditory to the outside; the glosso-pharyngeal, 
from the medulla oblongata just below the facial, in a furrow behind 
what will be described as the olivary body; the vagus or pneumogastric in 
the same furrow; the spinal accessory in a line continuous with the vagus; 
and the hypoglossal in the furrow internal to the olivary body. 
11. THE MEDULLA OBLONGATA AND PONS VAROLII. 
The medulla oblongata ('myelencephalon) is about an inch long. Its 
ventral surface is bounded above by the lower border of the pons Varolii, 
and its dorsal surface is continued into the floor of the fourth ventricle. 
The anterior fissure of the spinal cord is continued up to the border of 
the pons, beneath which it has an abrupt end (foramen caecum); but about 
two-thirds of an inch lower down it becomes shallow for a third of an 
inch, and, when it is opened out, four or five bundles of white substance 
on each side are laid bare as they slope downwards and cross the mesial 
plane, decussating with their neighbours of the opposite side, and dis- 
appearing by dipping into the interior. This is the decussation of the anterior 
pyramids, already referred to in connection with the tracts of the spinal 
cord, and its lower border may be taken as the limit of the medulla oblongata. 
The anterior pyramid is an elongated elevation alongside of the middle line, 
becoming narrower and less prominent below; external to it is another 
elevation limited interiorly, the olivary body j and external to the olivary 
body a thick rounded column, named restiform body on account of shallow 596 
THE BRAIN. 
oblique marks giving it a ropelike appearance, passes upwards and outwards 
to enter the cerebellum, and forms the lateral wall and great part of the 
posterior wall of the medulla oblongata. Between the restiform bodies 
behind, lying together below, separated by the continuation of the posterior 
fissure of the spinal cord, are two slender columns, funiculi graciles, con- 
tinuous with the columns of Goll. Superiorly the restiform bodies diverge, 
and the funiculi graciles between them first widen out so as to continue 
in contact one with the other, getting the name of clavae or posterior pyramids, 
then separate and taper each to a point still in contact with the restiform 
body, while between them is exposed the floor of the fourth ventricle. 
So far as we have gone, the surface of the medulla oblongata is of white 
matter, and clothed with pia mater like the spinal cord; but here the 
parts behind the central canal fail any longer to meet, and grey matter, 
continuous with that of the spinal cord, is exposed; an open furrow, calamus 
scriptorius, being the consequence, continuous with the inlet to the 
central canal, between the clavae. Rudiments, however, of a posterior 
wall exist; namely, the obex, a minute ridge of white matter behind the 
orifice of the canal, and the ligulae, two attenuated bands attached internal 
to the clavae, and turned over like the lapels of a coat. The part of the 
medulla oblongata, in which the central canal is complete, is called the 
closed part, while that into whose construction the floor of the fourth 
ventricle enters is called the open part. The groove between the anterior 
pyramid and the olivary body dies away below, but is pretty much in a 
line with the anterior roots of the spinal nerves, and has lying in it a 
row of nerve-bundles, the root of the hypoglossal nerve. A group of superficial 
arched fibres, emerging from the anterior fissure, slope over the pyramid 
and the lower part of the olivary body, and join the restiform body. The 
groove between the olivary body and the restiform body is further forwards 
than the posterior roots of the spinal nerves, and in it is another row of 
nerve-bundles, forming the roots of three nerves; the few uppermost 
gathering together to form the glosso-pharyngeal nerve, a number of succeeding 
bundles becoming grouped in like manner to form the vagus or pneumogastric 
nerve, and the remainder, more sparsely scattered, the lowermost of them 
ascending between the anterior and posterior roots of several of the highest 
spinal nerves, all gathering together to make a third trunk, the spinal 
accessory nerve. 
The pons Varolii is the structure which crosses the front and sides of 
the upper end of the medulla oblongata, and the name indicates a bridge 
extending from one half of the cerebellum to the other. But this bridge 
is too intimately connected with the prolongations of both white and grey 
matter from the medulla oblongata, and with the floor of the fourth ventricle, 
to be described separately from them, and thus the term pons Varolii has 
come to be extended to the whole depth of structure grasped on the front 
and sides by transverse fibres, and bounded by the fourth ventricle behind. 
It is broader in the human subject than in other mammals. Its lower border THE MEDULLA OBLONGATA AND PONS YAEOLII. 
597 
is transverse, while its upper border sweeps downwards as it curves out. 
A shallow groove marks its surface in the middle line, corresponding with 
the position of the basilar artery. Its fibres are gathered together on each 
side to enter the cerebellum, and are termed the middle peduncles of the 
cerebellum where they enter its substance, each in contact with an inferior 
peduncle continuous with the restiform body below, and with a superior 
peduncle above, passing up from the cerebellum to the corpora quadrigemina. 
In gathering together to form the middle peduncle of the cerebellum, 
the superficial fibres, starting from the upper half in the middle line, turn 
down so as to overlay those of the lower half, and are distinguished as the 
oblique band, and directed particularly to the under half of the cerebellum. 
Internal structure. In the lower part of the medulla oblongata the grey 
matter continued from the spinal cord is first displaced by the decussation 
of the anterior pyramids, so as to separate, as seen in transverse section, 
the inner tips of the anterior cornua from the rest, and finally cause them to 
disappear. At the same time, each anterior pyramid forms a white mass in 
front; behind and outside it the white substance of the olivary body 
surrounds the lower end of its own special nucleus; and behind this there 
is a lateral nucleus continuous with the so-called lateral cornu of the cord 
or outer angle of the clavate enlargement of the anterior cornu. Immediately 
behind the lateral nucleus there is found the continuation upwards of the 
gelatinous cornu of Rolando, expanded and termed tubercle of Eolando, 
and having on its surface white nerve-fibres belonging to the root of the 
fifth nerve; and behind the tubercle of Rolando there are two lobes of 
grey matter lying under the fasciculus cuneatus and fasciculus gracilis, and 
named nucleus cuneatus and nucleus gracilis. Thus the grey matter con- 
tinuous with that of the cord is thrown greatly backwards and to the sides. 
But the distance between the central canal and the anterior median fissure is 
much increased, and is occupied by a decussation of fibres distinct from that 
of the anterior pyramids, and continuous with the anterior white commissure 
of the cord, the decussation of the fillets {superior pyramidal decussation); and 
the space between this and the series of grey lobes mentioned is occupied 
b7 a reticular formation, in which vertical bundles occupy meshes between 
bundles taking transverse and oblique courses. 
In the upper or open part of the medulla oblongata a transverse section 
shows a raphe running back in the mesial plane to the grey matter 
lining the floor of the fourth ventricle in uninterrupted continuity with 
the grey matter of the cord; and on each side are three areae, anterior, 
middle and posterior, separated by nerve-roots coursing between the 
ventricular floor and the grooves behind and in front of the olivary body. 
At the pia-matral surfaces of the anterior and posterior areae, the fibres 
of the anterior pyramid and the restiform body respectively stand out 
compactly, while in the olivary body is seen the olivary nucleus, about 
to be described, and throughout the deep part there extends a peculiar 
netted appearance, the reticular formation already alluded to, which is caused 598 
THE BEAIN. 
by the decussation of fibres taking a more or less nearly horizontal course, 
with others more nearly vertical, and is continued up through the posterior 
part of the pons Varolii. In the lateral area the reticular formation has 
small nerve-corpuscles scattered through it, and is distinguished as grey, 
while that in the anterior area is called white. 
Pig. 432.—Medulla Oblongata of Foetus of 8 Months. P, Pyramid as yet devoid of 
white substance; 0, olive with accessory olives ; OC, olivary cerebellar fibres ; Ft (ponti- 
culus), ligula; IX, X, roots of glosso-pharyngeal and vagus; Xl, sensory vago-glosso- 
pharyngeal root; Fs, funiculus solitarius ; Im, motor vago-glosso-pharyngeal root bending 
round ; X' 2, motor vago-glosso-pharyngeal nucleus (nucleus ambiguus); V, sensory root of 
fifth ; Villa, principal auditory root; Fid, posterior longitudinal bundle ; S, Sl, median 
and lateral divisions of fillet; S'2, interolivary part of fillet; PC, RC, inferior peduncle of 
cerebellum, (v. Kblliker.) 
The olivary nucleus (inferior olive or corpus dentatum) is a thin corrugated 
capsule or pouch of grey matter occupying the length and breadth of 
the olivary body, with white matter round about it and in its interior, 
and wifch a hilum or opening of the pouch directed inwards. It is 
characterized throughout by numerous multipolar corpuscles of small size. 
An outer and an inner accessory olivary nucleus are described behind 
and in front of it, and may be seen in transverse section. A superior 
olive, not much developed in man, consists of similar corpuscles above the 
principal nucleus, placed in the pons Varolii, behind the transverse fibres. THE MEDULLA OBLONGATA AND PONS YAEOLII. 
599 
Transverse pcaiions of fibres. The transverse fibres of the pons Varolii 
are seen in transverse sections to be platted somewhat in the mesial 
plane, so as to take a deeper course on one side than the other. The 
same arrangement is manifest to a much greater extent in ordinary 
dissection at the upper and lower borders. The strands also decussate 
in an upward and downward direction, the oblique band already 
noticed having others parallel to it placed more deeply. Thus it is 
certain that the fibres do not unite corresponding portions of the cere- 
bellum. Some of the deepest fibres lie on one side behind the fibres 
from the anterior pyramids, and on the other in front of them; and 
their decussation gives in transverse section the appearance of a pro- 
jecting point, while, in the same way, others pass on one side behind, 
and, on the other, in front of a deeper longitudinal band, the fillet, causing 
by their decussation a projection backwards. Transverse fibres are abundant 
Posterior quadrigeminal bodies 
Aqueduct of Sylvius 
Posterior longitudinal bundles 
-Fillet dividing 
Reticular formation 
Pyramidal bundles. 
Raphe of pons 
Superior crus cerebelli 
Olivary fasciculus 
Upper border of pons 
Inferior crus cerebelli 
Olivary body 
Anterior pyramid 
Fig. 433.—Pons Detached from Cerebellum and Reflected from the Fillets and 
Posterior Longitudinal Bundles. 
in the medulla oblongata also. They form, along with neuroglia, the raphe, 
as they course backwards or forwards in the mesial plane; and they are 
distinguished as the superficial and deep arched fibres. The superficial 
set escape from the raphe in front, and cross the anterior pyramid and 
the olivary body, or the olivary body only, as they pass back to join the 
restiform body. Of the deep arched fibres a number pass through the 
hilum into the capsule of the olivary nucleus, and some of these, 
together with others, run, like the superficial set, to the restiform body, 
and so to the cerebellum, while their inferior connections are undeter- 
mined. A large number more of the deep fibres pass backwards and 
downwards to the nucleus cuneatus and nucleus gracilis, while, traced in 
the other direction, they are found to be continued upwards on the 
opposite side in the band called the fillet, going to the corpora quadri- 
gemina, and form, as they cross the mesial plane, the already mentioned 
decussation of the fillets. 
Longitudinal fibres. The anterior pyramids have their fibres continued 
up into the pons Yarolii, first as a pair of round bundles and afterwards 600 
THE BRAIN. 
in more flattened form, to be still more flattened in the crusta or 
inferior part of the crura cerebri. Followed downwards, the internal 
half of their fibres divide into several strands, which decussate with their 
fellows of the opposite side; while, at the same time, they become deep, 
and are continued into the lateral columns of the spinal cord. The 
outer fibres are thus approached to the anterior longitudinal fissure, and 
extend down on its sides as the direct pyramidal tracts (columns of 
Turck). A distinct strand from the anterior column of the cord, outside 
these latter, passing obliquel}' backwards and upwards over the lower 
part of the olivary body to join the restiform body, constitutes the 
arciform fibres of Solly. The remaining fibres of the anterior column of 
the cord and the anterior half of the superficial fibres of the lateral 
column pass up into the olivary body, the reticular formation and 
a band called the posterior longitudinal bundle; while the remainder of 
the lateral column of the cord—namely, the direct cerebellar tract— 
joins with the cuneate fasciculus or tract of Burdach to form the resti- 
form body. The tract of Goll is continued into the funiculus gracilis or 
clava. The fibres, however, of the clava do not enter the cerebellum, 
but would appear to end in the nucleus gracilis; and probably those of 
the cuneate fasciculus end mostly in the nucleus cuneatus. Among the 
longitudinal fibres passing up through the deep part of the pons may be 
mentioned the posterior longitudinal bundles and the fillets. The 
posterior longitudinal bundle lies side by side with its fellow, only some 
fibres from the raphe intervening beneath the floor of the fourth ventricle. 
The fillet (lemniscus), already alluded to, passes upwards and outwards, and 
divides into two parts, mesial and lateral, one for the corpora quadri- 
gemina, and the other to join the crusta. 
The floor of the fourth ventricle and the roots of nerves connected 
with it. The floor of the fourth ventricle is a lozenge-shaped surface 
of grey matter flooring a space communicating with the third, and 
through it with the lateral ventricles, and lined, as are also these others, 
with ciliated epithelium, which is not, however, columnar like that of 
the central canal of the cord, but more or less flattened. The inferior 
angle is at the termination of the central canal, between the clavae; the 
superior angle, situate behind the corpora quadrigemina, opens into the 
aqueduct of Sylvius; and the lateral angles are formed by a lateral recess 
at each side, continued into the peduncle of the flocculus, in the angle 
between the restiform body and the cerebellum, so that the lower half 
of the lozenge belongs to the medulla oblongata and the upper half to 
the pons. From the lateral recess there extend directly inwards two 
small bundles of white lines—striae acusticae; and below this level, on 
each side, there is a depression, inferior fovea, bifurcating downwards; 
while above it there is a superior fovea. The part internal to the inferior 
fovea contains the upper part of the nucleus of cells from which springs 
the hypoglossal nerve, and whence its fibres strike forwards between THE MEDULLA OBLONGATA AND PONS YAEOLII. 
601 
the posterior longitudinal bundles. The hypoglossal nucleus runs into the 
anterior cornu of the cord; and close to it externally, but scarcely 
reaching to the fourth ventricle, is the upper end of the nucleus of the 
spinal accessory nerve, the 
lower fibres of which come 
also from the cord, from the 
outer part of the anterior 
cornu. Opposite the inferior 
fovea the glosso-pharyngeal 
nerve takes origin, while the 
vagus takes origin continu- 
ously with it, from the 
elevation (ala cinerea) inclosed 
by the bifurcation of the 
inferior fovea; but a rounded 
bundle placed more deeply 
{funiculus solitarius) adds fibres 
from a lower level to both 
these nerves. The auditory 
nerve can be easily seen at 
its superficial origin to come 
partly round by the outside 
of the restiform body and 
partly through the texture 
internal to it. It arises from 
the transverse district between 
the fovea superior and fovea 
inferior. Its principal cells of 
origin, constituting the dorsal 
Fig. 434.—Medulla Oblongata, Corpora Quadrigemina 
and Floor of Fourth Ventricle, with diagram of nuclei of 
origin of nerves (5 to 12); those near the surface white, those 
more deeply placed dotted, cl, Clava ;/, mesial furrow ; e, 
eminentia teres; a, ala oinerea; fa, fovea anterior; sir, in- 
ferior cerebellar crus; br, middle crus; 6, superior crus. 
(Toldt.) 
nucleus, are dorsal and internal to the restiform body; but there is a 
nucleus of the external root, which is closely connected with the peduncle 
of the flocculus, and also an accessory nucleus between the two roots. 
A number of the fibres cross the middle line. The nucleus of the 
facial nerve is external to the fovea superior, and that of the sixth 
nerve internal to it. Further up, near the upper margin of the pons, 
and to the side of the upper end of the fourth ventricle, lie the motor 
nucleus of the fifth nerve and a large collection of nerve-cells external 
to it, the sensory nucleus, both of them on a level Avith the emergence 
of the nerve, the fibres of the sensory part passing through the pons 
in a direct line, and those of the motor part arching with an upward 
convexity. Beyond these nuclei additional roots can be followed both 
upwards and downwards. The inferior or retroserial root has been alluded 
to as clothing the tip of the prolongation of the gelatinous substance of 
Rolando \ the superior or proserial root is traced to underneath the corpora 
quadrigemina, and at all levels a certain number of fibres cross the 602 
THE BRAIN. 
mesial plane. Internal to the superior root of the fifth nerve, beneath 
the aqueduct of Sylvius, are placed the nuclei of the third and fourth 
nerves. A few of the fibres of the third nerve cross the middle line 
from the nucleus of the opposite side. All the fibres of the fourth nerve, 
after passing up round the aqueduct of Sylvius, decussate in the middle line 
of the valve of Yieussens, close to its attachment to the corpora quadri- 
gemina. 
The cerebellum is united to the rest of the brain by three pairs of 
peduncles and the valve of Yieussens, all in immediate contiguity, so as 
to be cut across in one continuous section. The superior peduncles are 
somewhat flattened bands passing upwards to the posterior quadrigeminal 
bodies, and are joined together across the middle line by a thin lamina, 
111. THE CEREBELLUM AND ANTERIOR VELUM. 
■Stria terminalis 
Pineal crus 
Pineal body, 
(Section of corpus 
( striatum 
Optic thalamus 
Anterior brachium 
Anterior quadrigeminal body. 
Posterior quadrigeminal body. 
Inner geniculate body 
, Outer geniculate body 
f Posterior tubercle of 
[ thalamus 
Fraenulum veli^ 
Velum anticum 
Superior crus cerebelli- 
Fillet- 
-Optic tract 
•Crus cerebri 
Lingula - 
Pons Varolii 
Middle crura of cere- 
bellum decussating 
Fig. 435.—Valve of Vieussens, or anterior velum, with the corpora quadrigemina, 
optic thalami and pineal body. The laminae of the cerebellum are removed. 
the valve of Yieussens. The middle peduncles are continuous with the 
pons Yarolii, and the inferior peduncles are apparently continuous with 
the restiform bodies; but it is to be noted that the restiform bodies 
include the funiculi cuneati, whose fibres are not directly continued into 
the cerebellum, while the inferior peduncle includes fibres from the olivary 
body of the opposite side which are not part of the restiform body. 
The valve of Vieussens (anterior medullary velum) may be at once 
described, though not counted a part of the cerebellum. It is a thin 
but strong lamina about an inch in length, easily split in the middle, 
and consisting mainly of longitudinal fibres. It passes posteriorly into the 
cerebellum, and anteriorly into the corpora quadrigemina, while it is 
attached on each side to the inner edge of the superior peduncle of the 
cerebellum. It is clothed with pia mater on its upper surface ; its under 
surface forms the fore part of the roof of the fourth ventricle. On its 
fore part, close behind the corpora quadrigemina, the roots of the fourth THE CEREBELLUM AND ANTERIOR VELUM. 
pair of nerves, coming up from beneath the floor of the aqueduct of Sylvius, 
decussate in the middle line, and proceed transversely outwards, adherent 
to its surface, to reach the crura cerebri, and turn round them. On the 
posterior half or more of its upper surface, it is overlaid by a series of 
about six simple grey laminae like those of the cerebellum and serial with 
them, but growing from the valve and adherent to it, termed the lingula. 
The cerebellum consists mainly of two lateral lobes or hemispheres, 
between which there is the posterior cerebellar notch behind, and concealed 
in a vallecula below is a distinct mesial part, the inferior vermiform 
process; while superiorly there is a mesial elevation sloping gently back- 
wards and to the sides, in no way marked off from the lateral lobes, 
which has been called the superior vermiform process, and, together with 
the inferior vermiform process and the intervening district, has come to 
be termed the body of the cerebellum, in consequence of a division into a 
more distinct body and smaller lateral lobes being common among mammals. 
Nevertheless one original embryonic pouch is the source of the whole 
cerebellum, and this pouch does not throw out lateral offshoots but only 
becomes laterally expanded, the vermiform processes appearing late, and 
the whole human cerebellum corresponding with the undivided form of 
the organ found in the non-mammalian vertebrates. The vestige of this 
primitive pouch furnishes to the cerebellum its small amount of ventricular 
surface, which, together with the valve of Yieussens, forms the medullary 
roof of the fourth ventricle, and is placed between the peduncles of opposite 
sides, between that valve in front and the free margin of a delicate membrane 
behind, to be presently described, called the posterior medullary velum. 
The whole pia-matral surface is composed of grey matter, and is thrown 
into folia or laminae, which, when divided vertically, either in the mesial 
plain or in directions radiating from the peduncles, give the appearance of 
a branching leafy stem called arbor vitae, caused by simple laminae, grey 
on the surface, being separated by sulci into which the pia-mater dips, 
these simple laminae being grouped to form larger laminae, and these again 
being mostly collected into larger lobules with deep sulci or fissures between, 
the most important of which is the great horizontal fissure, continued un- 
interruptedly round, so as to separate the upper from the under surface, 
and extending from one middle peduncle to the other. 
Lobides. On the upper surface, the foremost lobule forms part of the 
superior vermiform process and is continuous with the lingula in front, 
looking forwards and projecting over it. It is called the central lobe, and 
is prolonged into two alae on the anterior margins of the hemispheres. 
Behind it there is a large collection of laminae, consisting of a mesial 
monticxdus divided into the culmen and the declivus, and a great quadrangular 
lobe on each side, correspondingly divided into anterior and posterior lunate 
lobe. Behind this there are laterally the superior semilunar lobes, which 
are joined in the middle by a narrower part, the tuber vermis. On the 
under surface in each hemisphere, posteriorly, is placed the inferior semi- 604 
THE BRAIN. 
lunar lobe, and in front of it the lobus gracilis. These both curve forwards 
externally as far as the anterior margin of the hemispheres; and, circum- 
scribed by them to the outside and behind, the anterior and inner part 
of the hemisphere is formed by two more compact lobules consisting of 
shorter laminae taking a direction more backwards and upwards, namely, 
the biventral, or cuneate lobe; and, internal to it, looking into the vallecula, 
the amygdala. The inferior vermiform process presents three groups of 
laminae in front of the tuber vermis. Hindermost the pyramid is its 
broadest part, and, together with the narrower part in front of it, the 
uvula, it dips farthest down into the fourth ventricle, while in front of 
the uvula the nodule or laminated tubercle projects forwards, underlying 
the primitive ventricle, and has its base continued on each side into the 
Tuber vermis 
Pyramid 
-Amygdala 
Biventral lobe 
Slender lobe 
Uvula 
Nodule 
.Inferior semilunar lobe 
Superior semilunar lobe 
Flocculus 
Olivary nucleus 
Reticular formation 
Anterior pyramid 
Pio. 43(3. Cerebellum from below, with pons Varolii and section through medulla oblongata. 
posterior medullary velum already mentioned, a thin translucent membrane 
of white substance, with a free edge looking forwards. Externally the 
free edge of the posterior velum is continued on to the stem or peduncle 
of a minute lobe deserving further attention, the flocculus. 
The flocculus (subpedunculated lobe) is in its development no mere 
lobule of the cerebellum similar to the others, but is a lateral outgrowth 
of the floor of the cerebro-spinal cylinder, while the rest of the cerebellum 
is a mesial extension of the roof further forwards.1 It lies beneath the 
cerebellar peduncles and in front of the cuneate lobe, the peduncle of 
the flocculus being close to the origin of the auditory nerve. The peduncle 
of the flocculus has a groove which extends its whole length, and on 
into the flocculus itself from the lateral recess of the fourth ventricle, 
one margin of the groove being continuous with that of the ligula and 
1 In the rabbit and some other animals it is lodged in a deep hollow in the pars 
petrosa of the temporal bone. THE CEREBELLUM AND ANTERIOR YELUM. 
605 
the other with that of the posterior medullary velum. The groove is 
thus a ventricular epithelial surface, to be distinguished from the pia-matral 
surface round about, and so turned round by the redundant bulk of the 
cerebellum that its cerebellar edge lies lower than the ligulae. 
Internal structure. Deeply placed centres of grey matter are found in 
the cerebellum independent of the grey matter of the surface, and consist 
principally of a pair of corrugated purselike sheets, similar in appearance 
to the olivary bodies of the medulla oblongata. They are called corpora 
clentata, and are situated one on each side, not far from the ventricular aspect. 
Between them, above the roof of the fourth ventricle, Stilling describes some 
nodular patches of gi'ey matter in pairs, namely, the nucleus fastigii, nucleus 
emboliforrnis, and nucleus globosus. There seems room for some doubt of 
their independence of the laminae 
Fig. 437.—Frontal Section of Body and Left Lobe 
of Cerebellum. The left corpus dentatum is seen in 
the centre of the lobe. A section of the uvula over- 
hangs the medulla oblongata, and between the two 
the cruciate form of the choroid plexus of the fourth 
ventricle is displaced. 
Fig. 438.—Sections of Cerebellum. A, Trans- 
verse section of lamina or folium, showing the 
pinnate arrangement of leaflets, ;B, leaflet more 
highly magnified : a, pia mater; b, molecular layer 
with thinly scattered granules; c, granular layer 
d, central white matter; e, corpuscles of Purkinje. 
The superficial or cortical grey matter clothing the laminae has a complicated 
structure peculiar to it. It is divided abruptly into two strata, the super- 
ficial of which, somewhat the thicker of the two, is called the molecular 
layer, while the deeper is called the granular and is of a slightly redder 
grey. The granular layer gets its name from presenting, even under 
a low power, granules scattered thickly through all its substance. These 
granules have now been demonstrated by Golgi’s method to be minute 
nerve-corpuscles averaging -s(jVd’tli inch in diameter, each with three or four 
short branching protoplasmic processes and a very fine axis-cylinder-process 
which passes up through a variable depth of the molecular substance, there 
to divide into two branches taking their courses in opposite directions parallel THE BRAIN. 
to the surface and along the length of the lamina, and ending in bulbous 
extremities. Also the granular layer presents a certain number of large 
stellate nerve-corpuscles, and it has the whole of the nerve-fibres of the 
underlying white matter coursing on through it to reach the molecular 
layer. The molecular layer contrasts with the granular in presenting a 
much smoother appearance under the microscope. On its floor there is a 
single stratum of large nerve-corpuscles, corpuscles of Purkinje, pretty 
closely set, each having at its base or deep part continuity with a medul- 
lated nerve-fibre direct from the white brain-matter of the centre of the 
lamina, and, at its superficial extremity, a single protoplasmic pole at once 
breaking up dichotomously into a number of processes which make for the 
surface. The main branches can be easily seen with the usual modes of 
staining, but a much more extensive arborization is brought into view by 
means of the Golgi method; and this arborization is spread out in a plane 
Fig. 439.—Semi-diagrammatic Longitudinal Section of Cerebellar Laminae, a, b, c, 
Molecular, granular and white layers : a, ascending axis-cylinder of grain-like corpuscle ; 
h, bifurcation of the same, and formation of a parallel fibre ; d, profile view of corpuscles 
of Purkinje ; e, thickened free extremities of parallel fibres ; /, axis-cylinder of corpuscle 
of Purkenje. (Cajal.) 
transversely crossing the lamina, so that in longitudinal sections of laminae 
the arborizations of the corpuscles of Purkinje are seen as hedgelike septa, 
while the intervening spaces are, as it were, ruled with the lines of the 
divisions of the axis-cylinder-processes of the corpuscles of the granular 
layer. There are likewise in the molecular layer, placed at different levels, 
small stellate nerve-corpuscles transversely flattened, and having the axis- 
cylinder-process much elongated in the transverse plane and parallel to the 
surface of the lamina, with terminations and collaterals descending and 
breaking into copious ramifications, the terminal baskets of Kblliker, surrounding 
each corpuscle of Purkinje and curving inwardly round its axis-cylinder. 
Cajal recognises three kinds of nerve-fibres in the central white matter, 
namely, (1) descending fibres coming from the corpuscles of Purkinje and 
giving off a certain number of ascending or recurrent collaterals; (2) thick 
nerve-fibres ascending and ramifying in the granular layer in “mossy” 
branches; (3) other thick fibres ascending to ramify in the molecular layer, 
and these he terms clambering fibres. THE CEREBELLUM AND ANTERIOR VELUM. 
607 
Disposition of fibres within the cerebellum. If the horizontal fissure, in a 
conveniently prepared cerebellum, be torn open, it will be found that the 
corpus dentatum is embedded in fibres below that fissure, and appears to 
receive into its interior the fibres of the superior peduncle ; the fibres of 
the middle peduncle are arranged in interdigitating fasciculi, those from 
the upper half of the pons passing to the lower part of the cerebellum, and 
those from the lower part of the pons going to the upper part of the 
cerebellum, some of them crossing the middle line (Fig. 435); and the 
fibres of the inferior peduncle pass up between the two sets of fibres spread 
Fig. 440.—Semi-diagrammatic Transverse Section of Cerebellar Lamina of Mammal, 
a, Molecular layer; b, granular layer; c, white substance: a, corpuscle of Purkinje in 
front view; b, small stellate corpuscles of molecular layer; d, terminal descending 
arborizations surrounding Purkinje’s corpuscles; e, superficial stellate corpuscles; f, 
large stellate corpuscles of the granular layer; g, grain-like corpuscles with ascending 
axis-cyfinders bifurcating at i; h, mossy fibres ; j, neurogliar corpuscle with plume; 
m, neurogliar corpuscle of the granular layer; n, clambering fibres; o, ascending 
collaterals from the axis-cylinder of Purkinje’s corpuscles. (Cajal.) 
out below the horizontal fissure, namely, those of the superior peduncle 
internally and the lower fibres of the middle peduncle externally, and mingle 
with the ascending fibres of the middle peduncle. The fibres belonging 
to the inferior vermiform process pass outwards above the fibres of the 
superior peduncle. 
Roof and choroid plexus of fourth ventricle. The ventricular surface 
of the valve of Yieussens and of the cerebellum, back to the posterior 
medullary velum, constitutes the roof of the fourth ventricle, so far as that 
ventricle is roofed by brain-matter coated with epithelium. But the free 608 
THE BRAIN. 
edge of the posterior velum is the upper margin of a gap in the roof of the 
cerebro-spinal cylinder, and the remaining boundary of the gap passes 
round by the groove of the floccular peduncle and the free edge of the 
ligula on each side. Over the gap the pia mater is spread, sending in a 
fringe of choroid plexus which follows the course of its boundaries, com- 
pleting a ring bent in so as to give it the shape of a cross or of the letter 
T, the lateral parts extending outwards to the flocculi, the lower parts lying 
internal to the ligulae, and the upper part being sometimes carried forwards 
in the middle line on the nodule, but sometimes running straight across. 
In the undisturbed condition it wreathes round the pendent uvula, which 
has its own covering of pia mater, like the other folia of the cerebellum. 
The fourth ventricle cannot be opened by separation of the medulla ob- 
longata from the cerebellum without injury to the pia mater. It is a 
mesial tear made in this way below the extremity of the choroid plexus, 
which is described by Luschka under the name of foramen of Magenclie and 
is figured by the most recent writers and supposed by them to be natural. 
It can easily be demonstrated to be artificial, if the dissector be on his 
guard; but it is not easy to make certain if there is within the circuit of 
the choroid plexus a layer independent of the proper investment of the 
uvula and nodule.1 
IV. THE ROOT PART OF THE CEREBRUM. 
The isthmus cerebri is a somewhat irregularly shaped cylinder, rendered 
ventrally bilobate b}r the outward and upward direction of the two crura 
cerebri, which, issuing from the pons Yarolii, form its greater bulk, while 
it is completed dorsally by two comparatively small bands, the superior 
peduncles of the cerebellum, with the valve of Vieussens between them 
roofing the upper part of the fourth ventricle. Between the crus cerebri 
and the superior peduncle of the cerebellum, in the fore part of the distance 
from cerebellum to corpora quadrigemina, there is an elevation on 'each 
side caused by the fillet (its lateral division) passing up to the corpora 
quadrigemina. 
The corpora quadrigemina is the name given to a body about half an 
inch long, and three-eighths broad, composed principally of grey matter, 
but having a white surface, covered with pia mater, looking backwards 
1 The utility of the foramen of Magendie is supposed to be to allow passage of fluid 
from the brain to the spinal canal; but Reid and Sherrington have shown that the 
capacity of the spinal canal is diminished by bending, and it is hard to believe that 
in stooping it is an advantage to the brain to have fluid propelled into its ventricles. 
Besides, even if an opening exists, it is obvious that it must be effectually occluded 
by the choroid plexus when the parts are in situ. A supposed ventricular opening is 
figured at the floccular extremity of the choroid plexus of the fourth ventricle and 
called foramen of Luschka. A similar opening has been alleged to exist at the ex- 
tremity of the descending cornu of the lateral ventricle. Such openings may be 
produced by very trifling pressure. THE BOOT PART OF THE CEREBRUM. 
609 
and upwards, and divided by a crucial depression, into a superior larger 
pair of elevations {nates) and a posterior inferior smaller pair (testes) 
with a slight mesial bridle, fraenulum veil, behind it. Beneath them is a 
narrow canal, the aqueduct of Sylvius {iter a tertio ad quartum ventriculum), 
continuous with the fourth ventricle and opening in front into the third 
ventricle between the optic thalami, with grey matter surrounding it 
continuous with that of the floor of the fourth ventricle, and containing, 
as already noted, the nuclei of origin of the third and fourth nerves. 
Fifth ventricle 
• Corpus striatum 
r Anterior 
pillars of 
„ formix, cut 
i Anterior 
' commissure 
Anterior' 
tubercle of 
optic 
thalamus. 
Stria terminalis. 
Grey 
commissure 
Optic thalamus. 
Floor of third 
ventricle 
...Pineal body 
Posterior 
pillar of fornix 
Hippocampus ] 
minor | 
Fornix cut 
across 
' Posterior 
cornu of 
lateral 
ventricle 
Fig. 441.—Third Ventricle opened by division of fornix and removal of velum inter- 
positum. (Bouchard.) 
The optic thalami are two large oval bodies looking upwards in front of 
the corpora quadrigemina, having the free surface white, and in great part, like 
the corpora quadrigemina, clothed with pia mater; but they have not, like 
them, continuity of the pia-matral surface across the middle line. Beneath 
them are the crura cerebri, while from the front and outer sides emerge 
the fibres continuous with the crura, spreading toward the whole surface 
of the hemispheres and known as corona radiafa. The posterior extremity 
of the optic thalamus projects free, external to the front of the corpora 610 
THE BRAIN. 
quadrigemina, and is called the posterior tubercle, while the anterior part 
presents an elevation, the anterior tubercle, distinguished by a slight depression 
running internal to and behind it, so as to indicate the free margin of a 
superimposed brain-structure, the fornix, which is separated from it by a 
fold of pia mater, velum interpositum, whose redundant vascular margin, 
the choroid plexus of the lateral ventricles, more or less overlies the anterior 
tubercle. The upper surface of each optic thalamus is separated by a 
furrow in front and on the outer side from the corpus striatum. 
The corpora striata present each a large pyriform elevation of grey matter, 
the caudate nucleus, in front and outside of the optic thalamus; its fore 
part being broad and rounded, and separated from its fellow by the anterior 
pillars of the fornix and by the septum lucidum, while posteriorly it tapers 
to a point outside the hinder end of the optic thalamus. There are two 
other nuclei of the corpus striatum placed deeply, namely, the lenticular 
nucleus and the claustrum, and all three lie back to back with the island 
of Eeil, forming with it the root part of the hemisphere, while the rest 
of the hemisphere, distinguished as the mantle (Reichert), has no grey 
matter except on the convoluted surface. 
The taenia semicircularis or stria terminalis is a narrow band in the furrrow 
between the optic thalamus and corpus striatum. It is a gelatinous-looking 
structure, containing a vein and some white nerve-fibres, but is principally 
interesting as an embryological landmark. 
The floor of the third ventricle. The mesial surfaces of the optic thalami 
are nearly in contact one with the other, forming the lateral walls of the 
third ventricle, and covered like other ventricular surfaces with ependyma 
and ciliated epithelium. They are very usually united across the middle 
line by a little bridge of grey matter, the middle, soft or grey com- 
missure of the third ventricle, but this is often absent. The floor of the 
ventricle slopes downwards and forwards, supported at first by the 
tegmentum of the crura cerebri; and in front of this it is simply the 
thin grey lamina constituting the tuber cinereum, and exhibits the mouth 
of the infundibulum leading to the pituitary body, while, still further 
forwards, it forms a pointed cul-de-sac, the optic recess, on the upper surface 
of the optic commissure, and bounded anteriorly by the lamina cinerea. 
At the back of the third ventricle the opening of the aqueduct of Sylvius 
is seen, and over it a transverse band, the posterior white commissure of 
the third ventricle with the pineal body attached to it. At the front of 
the ventricle, just above the optic recess, two cylindrical white cords, the 
anterior crura of the fornix, descend to disappear in the grey matter on 
each side ; and immediately in front of them there is a transverse white 
cord, the anterior commissure of the third ventricle (Figs. 446 and 449). 
The pineal body or conarium is a small structure like a currant, of a slightly 
flattened and conical shape and deep reddish colour, attached by a narrow 
neck to the posterior white commissure, and surrounded with pia mater, or, 
rather, embedded in it, resting on the front of the corpora quadrigemina. In THE ROOT PART OP THE CEREBRUM. 
611 
its structure it presents a number of crypts containing epithelium, and sup- 
ported by connective tissue. The crypts are the seat of numerous nodulated 
concretions of lime salts, which can be felt like sand when the substance is 
laid hold of with the forceps, and are 
known as acervulus cerebri. The pineal 
body is better developed in young 
subjects and in at least some mammals 
than in the human adult.1 
The posterior white commissure of 
the third ventricle is not a cylindrical 
band as at first sight it appears, but 
a thin sheet of white substance pro- 
longed forwards from the corpora 
quadrigemina, and folded back on 
itself. Its free edge is again turned 
slightly forwards, and where so turned 
has the pineal body attached to it 
mesially, while on each side it is pro- 
longed forwards on the optic thalamus 
Fig. 442.—Concretions of acervulus cerebri in 
tissue of pineal body. Three show their nodu- 
lated surfaces, while the fourth is focussed for 
its centre, to display the lamination round a 
shrivelled corpuscle. 
at the margin where the white upper surface of that body meets the 
grey surface opposed to its neighbour. The prolongations are called pineal 
crura or striae, and the recess between these, the pineal recess. The whole 
arrangement gives the appearance as if the posterior commissure had 
formed a primordial roof to the third ventricle, with the pineal body at 
its fore end, and as if the vascular connections of the latter or some other 
cause had held it back while the optic thalami grew in a forward direction. 
The anterior white commissure is a small round fasciculus of white 
nerve-fibres visible in the anterior wall of the third ventricle, close in 
front of the anterior pillars of the fornix, as these descend and turn back- 
wards to the corpora albicantia. Its fibres pass into the part of the corpora 
striata known as the internal capsule. It is distinct even in birds, though 
they have no other commissure of the hemisphere-vesicles. 
The pituitary body is a tough reddish structure, occupying the sella 
turcica, in a special recess of the dura mater, the opening of which is 
contracted and surrounded by the circular venous sinus. It consists of an 
anterior and a posterior lobe. The anterior lobe, much the larger and some- 
what embracing the posterior, is a prolongation upwards of the roof of the 
stomodaeal epiblast, and exhibits throughout life columns of closely-set cor- 
1 Descartes imagined the pineal body to be the seat of the soul. Geoffrey St. 
Hilaire looked on it as a vestigial structure indicating a primeval entrance to the 
alimentary canal between the lateral halves of the central nervous system, such as 
occurs among invertebrata; and his view was afterwards favoured by Goodsir, and 
still later by Owen (1881). In recent years it has been noted that in elasmobranch 
fishes and various reptilian forms the pineal body actually is connected tubularly 
with a vesicle beneath the skin, which is spoken of as a vestige of a mesial parietal eye. 612 
THE BRAIN 
puscles with trabeculae between, like the columnar part of the cortex of the 
suprarenal body; the posterior part, truly cerebral in origin, is a prolongation 
downwards from the infundibulum, but like the pineal body fails to exhibit 
in mammals any nervous structure, and is composed of a variety of connective 
tissue, which may be looked on as thickened neuroglia.1 (See also pp. 97 
and 245.) 
Fig. 444.—Pituitary Body. A, mesial 
section ; a, anterior or glandular part 
projecting up into infundibulum; b, 
posterior or cerebral part, 4. b, Portion 
of anterior part more highly magnified. 
Fig. 443.—Mesial Section of Pituitary Body and Sur- 
roundings. Rabbit 4 inch long, a, b, Presphenoidal and 
postsphenoidal cartilage; c, dorsum sellae; d, notochord; 
e, infundibulum ; f, hypophyseal pouch ; g, duct of the 
same ; h, process filled with rounded cells, while the pouch 
is lined with columnar cells. (Mihalkovics.) 
The optic tracts and commissure. A retreating angle is left between the 
posterior tubercle of the optic thalamus and the side of the corpora quadri- 
gemina, and in this angle are seen two small elevations, the outer and 
the inner geniculate body, connected with the optic tract. The optic tracts 
traced backwards divide into a larger outer and a smaller inner root, the 
outer entering the outer geniculate body, which is also the larger, and 
the inner passing to the inner geniculate body. The outer root continues 
from the outer geniculate body to the superior corpus quadrigeminum, 
partly directly along a ridge called anterior hrachium, partly by turning 
over the posterior tubercle of the optic thalamus; a strand also of its 
fibres passes by the posterior tubercle to the corona radiata, and forms 
a direct cortical tract (Gudden). The inner root is continued by the posterior 
hrachium to the inferior corpus quadrigeminum. 
The optic tracts, united to the crura close to the line along which they 
1 The pituitary body presents a puzzle not only in development but in function ; and 
it can only be pointed out as remarkable that great enlargement of this body has been 
observed as a very frequent accompaniment of a curious hypertrophic disease affecting 
many parts of the body and named Acromegaly by its discoverer, Dr. Pierre Marie. 
Perhaps the mental symptoms in cases of Acromegaly make it not improper in this place 
also to note that “ naso-pharyngeal adenoids,” hypertrophic growths of the region from 
which the larger part of the pituitary body took origin, are notably liable to affect the 
mental pow'ers. THE ROOT PART OF THE CEREBRUM. 
613 
become covered by the hemispheres, extend onwards to the optic commissure 
or chiasma, where the fibres of each divide into two parts, one travelling 
to the retina of the same side, and the other decussating with its fellow 
of the opposite side and going to the other eye. Fibres also pass from 
one tract to the other in the inferior and hinder part of the chiasma 
{commissure of Gudden), and are said to join together the two internal 
geniculate bodies. It is to be noted that the arrangement of a chiasma 
with partial decussation occurs only in mammals. In fishes and reptiles 
the one optic stem may cross the middle line free from the other, without 
division into tract and nerve at that point. 
Deep structure of root of cerebrum. The crura cerebri are divided 
into two parts—the crusta or ventral part, and the tegmentum or dorsal. 
It is only the crusta which is completely divided into two pillars. A 
transverse vertical section through the corpora quadrigemina and crura 
shows grey matter of the corpora quadrigemina separated by a white 
streak from that which surrounds the aqueduct of Sylvius in continuity 
with the floor of the third and fourth ventricles, and beneath and 
around this the tegmentum, separated by a definite outline from the 
crusta below. The crusta consists of the continuation upwards of the 
anterior pyramid of the medulla oblongata, greatly added to by other 
fibres from sources not easy to determine, though some of their fasciculi 
are distinctly traceable by dissection from the middle peduncle of the 
cerebellum. It passes on beneath the optic thalamus into a broad white 
tract, called the interned capsule, beneath the nucleus caudatus of the 
corpus striatum, and spreading out toward every part of the cortex of 
the hemisphere, under the name of corona radiata. In the plane of 
contact of crusta and tegmentum there is a broad sheet of blackish hue 
extending outwards from the middle line where overlapped by the pons 
Yarolii; it is called the substantia nigra, and owes its darkness to pig- 
mented nerve-cells. It may be said to occupy an angular recess con- 
tinuous with the tuber cinereum and crushed together dorso-ventrally by 
the unusual thickness of the crusta and the pons Yarolii in the human 
subject. Another very distinct, but much smaller, patch of pigmented 
cells is likewise placed in a retreating angle, being situated between the 
superior peduncles of the cerebellum and the posterior longitudinal 
bundles, where the aqueduct of Sylvius meets the fourth ventricle. 
It is called locus caeruleus, and is in transverse diameter no larger than a 
pellet of small shot. 
The posterior longitudinal bundle, already traced up from the neigh- 
bourhood of the outer part of the anterior column of the spinal cord, 
after passing up under the grey matter of the floor of the fourth ventricle, 
becomes closely connected beneath the aqueduct of Sylvius with the 
nuclei of the motor nerves to the orbit (3rd, 4th, and 6th), and is 
prolonged beneath the grey matter of the optic thalamus (as stratum 
dorsale of Forel). The formatio reticularis, much diminished in extent 614 
THE BEAIN. 
as it ascends in the tegmentum, has a number of nerve-corpuscles scattered 
through it; it presents a reddish-grey appearance termed the red nucleus, and, 
more in front, under the optic thalamus, in contact with the crusta, a 
group of nerve-corpuscles, described as corpus subthalamicum by Luys. The 
fillets, travelling up with an outward inclination, divide each into a 
lateral and a mesial part. The lateral fillet appears for a short distance 
on the surface, and then crosses over the superior peduncle of the cere- 
bellum to enter the inferior corpora quadrigemina. The mesial fillet 
spreads out and sweeps round to join the crusta. The superior peduncles 
of the cerebellum, on reaching the corpora quadrigemina, turn down by 
the outside of the posterior longitudinal bundles, cross the mesial plane, 
decussating one with the other, and reach the red nucleus, whence they 
pass on to the optic thalami along with other fibres. 
Section of anterior tubercle of corpora quadrigemina 
2, Aquaeductus Sylvii 
The red nucleus of tegmentum 
Oculo-motor nucleus 
Crusta 
Locus niger. 
1, Interpeduncular space 
Crusta 
Deep roots of oculo-motor nerve 
Fig. 445.—Section through Corpora Quadrigemina and Crura Cerebri 
(Bouchard, after Stilling.) 
The optic thalamus consists of a continuous mass of grey matter with 
only a thin layer of white matter, stratum zonale, on its surface, and thin 
and partial septa dividing it into mesial, lateral and anterior nuclei, 
besides a small collection of large corpuscles beneath the pineal crus, 
ganglion habenulae, whence a band {fasciculus retroflexus of Meinert) descends 
through the tegmentum to the region of the posterior perforated spot. The 
optic thalamus has the back part of the caudate nucleus of the corpus 
striatum external to it above, and the internal capsule beneath and 
external to it, and sends out fibres to radiate with those of the internal 
capsule to different parts of the cortex of the hemisphere {crura and 
ansae of authors). 
The corpora striata have three very distinguishable nuclei—nucleus 
caudatus, nucleus lenticularis and claustrum. The nucleus caudatus is the 
part which looks into the lateral ventricle, and is separated from the 
nucleus lenticularis by white matter called internal capsule. The internal 
capsule is seen in horizontal section to change its direction opposite the THE ROOT PART OF THE CEREBRUM. 
615 
front of the optic thalamus so as to form an angle {genu), with the 
posterior limb directed forwards and inwards, and the anterior forwards 
and outwards. The nucleus lenticularis fills up the retreating angle opposite 
the genu of the internal capsule, and is connected in its whole length 
with the nucleus caudatus by streaks of grey matter, from which the 
corpus striatum takes its name; but it is connected with it most closely 
in front, where indeed the two nuclei become continuous. The nucleus 
lenticularis in frontal section is wedge-shaped, divided by two white lines 
into an outer, a middle and an inner stratum—the first (putamen) of a 
redder colour than the other two {globus pallidus). Outside the nucleus 
lenticularis there ascends a layer of white matter narrower than the internal 
capsule ; it is called the external capsule, and contains fibres from the optic 
.Lateral ventricle 
Corpus callosum. 
Fornix 
Choroid plexus of 
lateral ventricle 
Nucleus caudatus 
.Optic thalamus 
Choroid plexus of I 
third ventricle ( 
Internal capsule 
Bundle of Vicq-d’Azyr. 
Insula 
External capsule 
Nucleus lenticularis 
Anterior crus of fornix. 
Mouth of infundibulum. 
Claustrum 
Lamina cinerea cut open 
Chiasma 
Optic nerve 
Fig. 446.—Vertical Transverse Section in front of the lamina cinerea. 
thalamus and the anterior white commissure. It is rounded externally 
by the claustrum. The claustrum is a very thin sheet of grey matter 
intermediate in position between the nucleus lenticularis and the convolu- 
tions of the island of Reil, and broadening out in its lower and fore part 
so as to present a triangular form in frontal section. It has spindle- 
shaped corpuscles with yellow pigment, as has also the globus pallidus. 
Both nucleus lenticularis and claustrum are connected below with the 
superficial grey matter at the anterior perforated spot. 
V. WALLS AND SEPTA OF THE CEREBRAL VENTRICLES. 
The corpus callosum, or great commissure of the brain, is an arched 
structure consisting mainly of transversely-arranged white fibres, which 
join the two hemispheres together in the space left by the circuit of the 
falx cerebri for more than half their total length. It forms in this extent 
the floor of the great longitudinal fissure; it ends posteriorly in a thick- 616 
THE BRAIN. 
ened extremity, while anteriorly it presents a stout genu, prolonged 
backwards into a completely retroverted part, the rostrum; and the 
rostrum rapidly thins, and ends in a pair of crura descending on 
each side of the lamina cinerea to the anterior perforated spot. The 
superficial aspect is in contact in its whole extent with a convolution 
(gyrus fornicatus) of each hemisphere, and is from two-thirds to three- 
fourths of an inch broad. It has a transverse striation indicating the 
direction of its bundles, and has a few longitudinal marks, viz., in the 
.Genu of corpus callosum 
Centrum ovale 1 
of Vieussens J 
Mesial raphe 
Nerves of 
Lancisi 
Transverse 
fibres 
Splenium or bourrelet 
Fig. 447.—Corpus Callosum from above. (Bouchard.) 
middle, a longitudinal furrow, divided by a mesial elevation, the raphe, 
best seen in front; to the sides of this, a pair of slightly wavy distinct 
white threads, nerves of Lancisi; and considerably further out, where the 
overhanging convolutions cease to be in quite close contact, a pair of 
grey lettered hands or striae. A grey coat or indusium, containing scattered 
multipolar corpuscles, a vestigial continuation of the cortex of the 
cerebral convolutions, though not very evident, covers the whole surface. 
The deep surface completes the roof and anterior limit of the lateral WALLS AND SEPTA OF THE CEREBRAL YENTRICLES. 
617 
ventricles; in the concavity of the genu it is concealed laterally by the 
corpora striata, and between them gives attachment to the two laminae 
of the septum lucidum, with the fifth ventricle between; while further 
back it is directly united to the two lateral halves of the fornix, whose 
lines of continuity with it recede from the mesial plane as they pass 
backwards. At its posterior extremity the corpus callosum is about 
twice as thick as it is further forwards; it may be about a third of an 
inch in depth, and looked at from below presents behind the fornix a 
limited projection, broader in the middle, the splenium. In front of 
this a triangular portion, transversely striated, the lyra, is seen. At the 
genu the corpus callosum is again greatly thickened before thinning away 
in the rostrum. The fibres traced into the hemispheres spread out in every 
direction, and those in front and behind curve forwards and backwards 
respectively, constituting the so-called foixeps minor and major. The 
corpus callosum is occasionally altogether absent. The recorded cases 
of total absence have usually been accompanied with other deficiency of 
cerebral development, sufficient of itself to account for the idiocy which 
in most cases, but not all, has been observed during life. 
The septum lucidum is the name given to a pair of vertically-placed 
laminae considered as one structure, but really quite distinct, with their 
inner surfaces separated by a small mesial 
space, the fifth ventricle, and their outer 
surfaces looking into the lateral ventricles. 
It bridges the distance between the fore 
half of the corpus callosum and the fornix, 
being attached to the fornix by an edge 
looking downwards and backwards, and 
to the corpus callosum in the rest of 
its extent, and being of a shape rounded 
and deep in front but tapering to a point 
behind. Each lamina is a portion of the 
wall of the corresponding hemisphere, 
which has become separated, by the 
development of the corpus callosum, from 
the part whose surface looks into the 
great longitudinal fissure; and although 
it is flat and only about inch in 
thickness, it consists of white matter 
coated with grey on the surface looking 
towards its fellow and originally con- 
tinuous with the cortex of the convolu- 
tions. 
Fig. 448.—The Lateral and Fifth Ven- 
tricles. a, Posterior fibres of corpus callo- 
sum ; b, genu of corpus callosum, with fifth 
ventricle below; c, fornix and, external to it, 
choroid plexus; d, corpus striatum and, be- 
tween it and the choroid plexus, part of optic 
thalamus with stria terminalis in the furrow; 
e, section of corpus striatum ; /, descending- 
cornu of lateral ventricle with hippocampus 
major occupying its floor, and fimbria be- 
tween it and the choroid plexus; g, hippo- 
campus minor in the posterior cornu. 
The fifth ventricle, the mesial space between the two laminae of the 
septum lucidum, is as much as a tenth of an inch in breadth in front, 
while its lateral walls come in contact behind. Though originating as a 618 
THE BRAIN. 
recess from a pia-matral surface, it has not been followed by the pia mater, 
and its walls present only a delicate network of vessels embedded in brain- 
substance, presenting on the surface a scattered layer of corpuscles which may 
be looked on as epithelioid. 
The fornix, when looked at from above, with its adhesion to the corpus 
callosum unbroken, presents the appearance of an arched triangular lamina 
of white substance, the body resting on a deep projection of pia mater of 
corresponding extent, the velum interpositum. The margins of this 
triangular body are concave, the lateral being free, with the hypervascular 
fringe of the velum interpositum, the choroid plexus of the lateral ventricles, 
projecting beyond them, and the posterior being attached to the corpus 
callosum, as is also the mesial part of the dorsum, while the anterior angle is 
prolonged into two round pillars or anterior crura, and the two posterior 
angles form a pair of posterior crura prolonged each into a flat ribbon, the 
fimbria or taenia hippocampi. 
The posterior crura of the fornix lie in front of the splenium of the 
corpus callosum, one on each side, separated by the velum interpositum 
from the upper surface of the posterior tubercle of the optic thalamus. 
The taenia hippocampi, extending outwards beyond the optic thalamus 
and corpus callosum, turns forwards round the crus cerebri to lie in the 
floor of what is called the descending cornu of the lateral ventricle, with 
the choroid plexus entering from the exterior between it and the crus 
cerebri, while its attached border is continuous superiorly with a convexity 
of the floor of the descending cornu named hippocampus major, and in- 
teriorly with the grey convoluted surface of the hemisphere. Its fibres in 
a fresh brain can often be seen spreading obliquely on the hippocampus 
major, and apparently they make for the cortex of the temporal lobe. 
The pillars or anterior crura of the fornix descend side by side between 
the corpora striata in front of the taenia semicircularis and behind the 
anterior white commissure, separating as they descend, so that the com- 
missure is seen between them from behind; then turning backwards each 
becomes covered with the grejr lining of the third ventricle on its own 
side and dips to the corresponding corpus albicans, whose main bulk it 
seems, as seen in dissection, to form by twisting abruptly inwards, forwards 
and upwards, before it is continued upwards and backwards as the bundle 
of Ficq-d’Azyr to the optic thalamus, in the deep part of which it spreads 
outwards horizontally. Thus, the fornix unites the optic thalamus and 
temporal lobe of the same side. 
But the corpora albicantia (mammillaria) are not mere twistings of the 
pillars of the fornix; they contain grey matter, and experiment would 
appear to show that the bundle of Yicq-d’Azyr is not directly continuous 
with the fibres of the pillars of the fornix. Also, there is a bundle passing 
backwards from each of the corpora albicantia to the inner part of the 
crusta; and these bodies not only represent a more developed mesial body in 
lower vertebrates, but are comparatively large in the foetus. WALLS AND SEPTA OF THE CEREBRAL VENTRICLES. 
619 
The velum interpositum (Fig. 356) is the fold of pia mater corresponding 
in form and extent with the fornix, beneath which it rests on the optic 
thalami, continuous behind with the pia mater of the corpora quadrigemina 
below and with that of the splenium above. Beyond the margin of the 
fornix it swells out into a stronger and thicker fringe rich in redundant 
loops of bloodvessels, the choroid plexus of the lateral ventricle; and at the side, 
where the posterior crus of the fornix runs into the taenia hippocampi 
or fimbria, the pia mater still enters the descending cornu of the lateral 
ventricle, and the choroid plexus is continued without intervention of a 
velum interpositum. The continuous fissure by which the velum inter- 
positum enters mesially beneath the fornix, and the pia mater enters the 
descending cornua of the lateral ventricles, is horseshoe-shaped and is 
Corpus albicans 
Marginal 
convolution 
Paracentral lobule 
Mesial precen- 
tral fissure 
Intramarginal 
sulcus 
Precuneus 
Calloso-marginal 1 
fissure J 
. Callosal gyrus 
■ Corpus callosum 
Fifth ventricle 
Fornix 
Parieto-occipital 
fissure 
Genu corporis callosi 
Rostrum 
■Cuneus 
• Splenium 
■ Hippocampal gyrus 
Lamina cinerea 
Optic nerve 
.Calcarine fissure 
| Anterior cal- 
{ carine fissure 
Pituitary body. 
Pineal body.- 
.Monticulus 
Corpora quadrigemina. 
Aqueduct of Sylvius, 
• Tuber vermis 
■Horizontal fissure 
Central lobe. 
Lingula 
Pyramid 
Laminated tubercle 
Fig. 449.—Mesial Section of Bhain, with the anterior crura of the fornix and the bundle 
of Vicq-d’Azyr dissected. 
called the transverse fissure of the hrain. The velum interpositum supplies 
minute vessels upwards to the fornix, and the under surface near the sides 
sends down branches to the optic thalami. Its principal artery is the 
anterior choroidal from the internal carotid, which enters at the extremity 
of the transverse fissure and runs in the whole length of the choroid 
plexus, receiving anastomotic branches from posterior choroidal branches 
of the posterior cerebral artery. The blood is returned by a pair of veins 
running forwards in the choroid plexus, which are joined below the anterior 
pillars of the fornix by a vein from the surface of the corpus striatum 
and another from the septum lucidum to form the two veins of Galen; 
and these pass backwards in the middle to join before opening into the 
straight sinus. 620 
THE BRAIN. 
A pair of small vascular fringes, the choroid plexuses of the third ventricle, 
dip down from the velum interpositum near the middle line, and the 
ciliated epithelial lining of the third ventricle is reflected over them and 
extends downwards on the inner surfaces of the optic thalami. The 
ciliated epithelium is in like manner continued from the upper or ven- 
tricular surface of the fornix and taenia hippocampi over the choroid plexuses 
of the lateral ventricles on to the exposed parts of the upper surface of 
the optic thalami and the walls of the descending cornua of the lateral 
ventricles. There is, however, left at one place a communication between 
the third and the two lateral ventricles, the foramen of Monro. This 
aperture is formed by the anterior angle of the body of the fornix, with 
the front of the velum interpositum adherent to it, arching over and 
between the anterior extremities of the furrows of the right and left taenia 
semicircularis before it dips down in the form of two pillars. Thus, the 
foramen of Monro is a Y-shaped communication, single below and double 
above, between the third ventricle and the two lateral ventricles. 
The third ventricle is limited behind by the pineal recess, the posterior 
white commissure and the anterior opening of the aqueduct of Sylvius. 
Its lateral walls are formed by the opposed grey surfaces of the optic 
thalami, which are most frequently united to a certain extent in the form 
of a grey commissure. The floor deepens from behind forwards and 
presents pretty well forwards an opening leading into the infundibulum, 
and, quite in front, the optic recess. The anterior wall prevents the pillars 
of the fornix descending with the anterior white commissure between and 
in front of them. The roof is formed by velum interpositum and choroid 
plexuses of the third ventricle, and its communication with the lateral 
ventricles by means of the foramen of Monro, is in front. 
The lateral ventricles are the adult condition of the original hollows 
of the hemisphere-vesicles. They differ from the other ventricles in being 
surrounded by white substance save where the caudate nuclei of the corpora 
striata are exposed, From before backwards and inwards there are seen, 
in the floor of each, corpus striatum, stria terminalis, anterior tubercle of 
optic thalamus, choroid plexus, and half of the body of the fornix. Each 
has three cornua. The anterior cornu is a short and rounded cul-de-sac 
projecting into the anterior lobe of the hemisphere, in front of the corpus 
striatum. The posterior cornu is a longer cul-de-sac stretching backwards 
in the posterior lobe, curved and pointed, the convexity outwards and the 
point inclined inwards. It presents a convexity of its floor to the inner 
side, which is named hippocampus minor, and is the obverse convexity 
corresponding to a sulcus (named calcarine) on the mesial surface of the 
hemisphere. The remaining cornu, the lateral or •descending, is longest of 
all, and is not a cul-de-sac like the others, inasmuch as its nervous walls 
present in the whole length a breach of continuity, the lateral part of 
the transverse fissure. It takes a downward spiral direction round the crus 
cerebri, being at first directed backwards, then outwards and forwards, WALLS AND SEPTA OF THE CEREBRAL VENTRICLES. 
621 
and terminating with an inclination inwards. Its floor presents a convex 
elevation, hippocampus major (cornu Ammonis), extending its whole length. 
This is the obverse of the sulcus termed hippocampal, and is separated by 
a groove from the posterior crus of the fornix and from the fimbria, 
which in turn has the choroid plexus entering at its free edge into the 
cornu. At its extremity the hippocampus is expanded somewhat, and has 
Nucleus caudatus 
Optic thalamus 
Corpus callosum 
Front of pineal body 
Pineal crus 
Descending cornu 
Fornix 
Posterior white commissure 
Corpora geniculata 
Posterior longitudinal 
bundle 
Nucleus of Luys 
From superior crus 
of cerebellum 
Hippocampus major 
Gyrus dentatus 
Pyramidal bundle 
Transverse fibres of pons 
Fimbria 
Hippocampal lobe 
Uncus 
Reticular substance of pons 
Substantia nigra 
Fig. 450.—Vertical Transverse Section, cutting the superficial part of the pons, but 
clear of the medulla oblongata. Looking forwards. 
three or four shallow notches on its convex edge, giving it a digitate 
appearance, whence it has received the name of pcs hippocampi. The 
hippocampus major amd minor are united at their commencements; and 
the angle left between them as they separate is called eminentia collateralis 
or pcs accessorius. 
VI. THE CEREBRAL HEMISPHERES. 
The hemisphere-vesicle of the embryo becomes developed into two 
parts, the stem-part and the mantle (Reichert); the former a solid mass 
consisting of the corpus striatum and island of Reil, and the latter all 
the remainder of the hemisphere.1 The corpus striatum and hemisphere 
1 The olfactory lobe of the encephalon is not here mentioned. It is considered as 
part of the hemisphere by Schwalbe (1881) and Turner (1890), who include with it 
under the name rhinencephalon the bulbus hippocampi. Schafer follows the course 
of including under that name the combined olfactory and limbic lobes; and undoubtedly 
if the bulbus hippocampi is to be included in the term, he is perfectly right in 622 
THE BEAIN. 
are thus, as respects development, one division of the brain, the hemisphere- 
vesicle ; and indeed the division into stem-part and mantle is so far 
secondary that while in reptiles, as in mammals, the corpora striata are 
but limited bodies at the base of a large ventricle roofed by this mantle, 
in birds the mantle has scarcely a separate existence, there being only a 
thin membrane roofing the lateral ventricle into which the corpus striatum 
looks; and to such an extreme is this carried that it is impossible to 
escape the conclusion that work done by the mantle in mammals and 
reptiles is done by the stem-part in birds. 
External olfactory fissure 
Internal orbital gyrus 
Posterior orbital gyrus 
Orbital gyrus 
-Triradiate fissure 
Olfactory tract 
Bulbus hippocampi- 
-Fissure of Sylvius 
Uncus. 
Anterior perfor- 
ated spot 
Temporo-oocipital 
fissure 
■Cut surface 
Hippocampal gyrus. 
■Lateral ventricle 
Middle temporal 
gyrus 
Inferior temporal 
■Fornix 
•Lyra 
gyrus| 
-Splenium 
Calcarine fissure 
Pig. 451.—The basal surface of the hemispheres as seen after removal of the root of the 
brain by Reichert’s section, namely, a cut carried along the outer side of the optic tract 
and along the furrow between the optic thalamus and nucleus caudatus. 
The hemisphere, as distinguished from the hemisphere-vesicle, does not 
include the corpus striatum. Its grey matter is of peculiar construction, 
considering that “there is no sufficient reason for excluding the remainder of the 
limbic lobe.” Owen, who introduced the term rhinencephalon, used it to designate 
what he considered as one of four primary divisions of the brain, and counted as 
another the prosencephalon, in which he included both the hemispheres and optic 
thalami. The term mantle was introduced by Reichert, and is meant by Schwalbe to 
be used in the sense originally given to it. The whole limbic lobe, including the bulbus 
hippocampi, belongs to the mantle as defined by Reichert. As for the olfactory lobe, 
Schwalbe is right in comparing it with the retina and optic nerve, the primary optic 
vesicle of the embryo brain; and it might be said that in development the rhinencephalon 
is related to the front of the first cerebral vesicle, as the primary optic vesicle is to its 
back part. The rhinal fissure described by Turner in mammals is not homologous with 
the fissure limiting the rhinencephalon in fishes. THE CEREBRAL HEMISPHERES. 
623 
arranged on the surface, and is termed the cortical substance-, and the 
surface is thrown into convolutions (gyri) and fissures (sulci), by which 
its superficies is enormously increased. The increase of surface brings the 
cortical substance in all its depth nearer to the supply of blood from the 
pia mater than would be otherwise possible, and is probably necessary 
for other reasons, inasmuch as there is a definite arrangement of nervous 
elements at different depths, just as there is in the cortical substance 
of the cerebellum. In no brain are the fissures and convolutions perfectly 
symmetrical, and in no two brains is the arrangement perfectly similar. 
The fissures appear in a regular order, and those which appear first are 
constant and symmetrical, while complication takes place by the formation 
of secondary and shallower fissures, and by frilling of the convolutions 
between. Interest attaches to the details of the arrangement, first, on 
account of the complexity being greater in civilized races than in savages, 
and greater in persons of much intelligence than in persons of little; 
secondly, on account of the same convolutions being found in simpler form 
in apes and monkeys; and, thirdly, on account of definite local paralyses or 
alterations of function being associated with lesions of certain definite 
parts of the convoluted surface, whether produced in monkeys by experi- 
ment or in men by disease. 
Pio. 452.—From a Preparation in Spirit, showing the relations of the superficial 
convolutions to the middle meningeal artery and their positions in the head. 
Convolutions and fissures. The fissure of Sylvius. This is no mere 
sulcus, but owes its existence partly to the form of the cranial cavity, 
partly to the fundamental division of the hemisphere into a solid part and 
a mantle. It begins on the base, at the anterior perforated spot, by a 
broad and deep part (vallecula or fossa of Sylvius), and is so situated that 
the free border of the orbital wing of the sphenoid fits into it. Outside the 624 
THE BRAIN. 
anterior perforated spot, it contains the island of Reil, beyond which it is 
continued into two principal limbs or branches, viz., the posterior, running 
about two inches backwards before turning upwards a little way, and the 
anterior ascending, which is shorter and is directed upwards and a little 
forwards after giving off at its commencement a less important and short 
anterior horizontal branch. According to Horsley the anterior ascending 
limb starts opposite the upper end of the spheno-squamous suture and 
runs upwards along by or just in front of the coronal suture, while the 
anterior horizontal corresponds in position with the spheno-parietal suture, 
and the posterior limb, starting from opposite the highest point in the 
squamous suture, ends close to the parietal eminence. 
The island of Reil (insula, lobus centralis, gyri operti) is a triangular mass 
isolated from the rest of the hemisphere by a depression, sulcus circularis 
v. limitans, and broken externally into gyri breves, typically five in number, 
Olfactory bulb 
Genu 
Triradiate fissure 
Olfactory tract 
Left crus of corpus callosum 
Inner olfactory root 
Outer olfactory root 
Optic nerve, 
Ghiasma 
Island of Roil 
Corpora albicantia. 
.Anterior perforated spot 
Divided crus cerebri. 
Optic tract 
' Roof of descending cornu 
of lateral ventricle 
Corpora genieulata 
Fornix 
Optic thalamus 
Fimbria 
Splenium 
Pes hippocampi 
Fig. 453.—Left Island of Beil and Olfactory Lobe, with Descending Cornu of 
Lateral Ventricle laid open by a cut through the wall between it and the posterior 
branch of the fissure of Sylvius, and reflecting the floor containing the hippocampus major. 
the three foremost separated by a complete sulcus from the two behind 
(anterior and posterior insula of Eberstaller), and all converging toward 
the inner angle or pole. The portions immediately surrounding the circular 
sulcus are spoken of as opercula. Cunningham counts four of these: (1) 
the external, known as fronto-parietal-, (2) the posterior or temporal-, (3) 
the orbital, lying internal to the anterior horizontal branch of the Sylvian 
fissure; and (4) the part which sometimes intervenes between the fronto- THE CEEEBEAL HEMISPHEEES. 
625 
parietal and the orbital, the frontal operculum; the frontal being the pars 
triangularis of the third frontal convolution, called le cap by Broca. 
Superficial aspect. The fissure of Rolando (sulcus centralis) begins at the 
mesial border of the hemisphere a little behind the mid point of its 
upward arch, and runs downwards and forwards towards the Sylvian fissure. 
Its upper end shows more frequently than not on the mesial surface, to at 
least a slight extent and with a backward inclination. Its lower end 
usually falls short of the fissure of Sylvius, but points to the middle of 
the island of Eeil. In its course, which is never direct, a backward upper 
genu and a forward lower genu have received attention. 
The convolutions bounding the Eolandic fissure are best named anterior' 
and posterior Rolandic gyri (Pansch), but are also known as ascending frontal 
and parietal, and anterior and posterior* ascending or central. In front of the 
anterior Eolandic gyrus, the precentral sulcus (transverse frontal fissure so 
Pig. 454. —Outer Side of Right Hemisphere. Op. 1, 2, 3, 4 are the four opercula of 
the island of Reil, numbered as they are numbered in the text. 
called) is placed, distinct below from the anterior ascending Sylvian limb, 
and falling short of the mesial border above. In front of this, a superior 
and an inferior frontal sulcus separate the superior, middle and inferior 
fronted gyri. The superior frontal is more or less continued into the 
anterior Eolandic gyrus, and the inferior frontal ends posteriorly in a 
dilated pars triangularis, le cap of Broca, already alluded to in connection 
with the opercula, remarkable as being, especially on the left side, the seat 
of lesion in aphasia. The three frontal convolutions constitute the fronted 
lobe of Gratiolet; but more usually the term frontal lobe is used to designate 
the whole surface in front of the Eolandic fissure, as recommended by 
Turner; and though this is topographically less appropriate, it is to be 
remembered that all divisions of the mantle into lobes are quite artificial 
and open to objection. 
Behind the posterior Eolandic gyrus the postcentral sulcus is situated, 
which, like the precentral, falls short both of the mesial edge and of the 
Sylvian fissure; but toward’ the upper end it has its main continuation 
2 R 626 
THE BRAIN. 
turned backwards, and thus presents an ascending and a horizontal part. 
Above the horizontal part the superior parietal gyrus is placed, extending 
back to where the parieto-occipital, a sulcus of the mesial surface, cuts the 
superior edge of the hemisphere opposite the lambda, while two gyri lie 
below it—one in front of the other—the supra-marginal (or, better, pre- 
angular) and the angidar. The convolutions further back constitute the 
occipital lobe, and are called superior, middle and inferior occipital gyri, and 
are separated by superior and inferior occipital sulci; while, in like 
manner, the surface below the posterior limb of the Sylvian fissure is 
called temporal lobe, and is divided by a superior and an inferior temporal 
sulcus into superior, middle and inferior temporal gyri. 
The mesial and inferior surfaces. The earliest of the mere sulci of the 
mantle to appear is the calloso-marginal sulcus which, beginning below and in 
front of the rostrum of the corpus callosum, turns round that body and 
divides the mesial surface into a marginal and a callosal part. When it 
reaches opposite the splenium, it turns upwards and ends by cutting the 
superior margin just behind the fissure of Rolando. Further back, opposite 
the tip of the occipital bone, another, the parieto-occipital sulcus, begins by 
deeply cutting the superior margin, and is directed downwards and forwards 
to meet a second, the calcarine sulcus, named from corresponding in position 
with the hippocampus minor, which is its obverse; and from the point of 
meeting of these two a third, the anterior calcarine sulcus, sweeps forwards 
and downwards beneath the splenium. On the tentorial and sphenoidal parts 
of the under surface there runs forwards, parallel to the inferior temporal 
and occipital sulci, a line of occipito-temporal sulci; and between these and 
the anterior calcarine sulcus there may be another line, the collateral sidcus. 
The district between the calloso-marginal sulcus and the margin of the 
great longitudinal sidcus is termed the marginal convolution, and has a 
tendency to be more or less doubled by a longitudinal sulcus within it, a 
doubling which is alleged to be absent when the first frontal convolution 
is doubled, and present when the first frontal is single (Manouvrier). The 
wedge between the calcarine and parieto-occipital sulci is called the cuneus, 
the space in front of it, extending from margin to splenium, and forwards 
to the turning up of the calloso-marginal fissure, is the praecuneus or quadrate 
lobule, and the portion of the marginal convolution immediately in front 
of this has been called the paracentral lobule. The convolution traceable 
round the corpus callosum from front to back of the anterior perforated 
spot is the long known gyrus fornicatus or gyrus cinguli (limbic lobe of Broca). 
The name callosal gyrus is best confined to the part over and in front of 
the corpus callosum, and to this part the term gyrus fornicatus also is by 
some recent authors restricted, while the posterior part turning round the 
crus cerebri is the gyrus hippocampi, slightly dilated at its extremity in 
man, but much more so in animals with well developed smell, to form 
the bulbus hippocampi. The dilatation presents an inward fold, the uncus; 
also a thickening of the cortex, sometimes called nucleus amygdalae. The THE CEREBRAL HEMISPHERES. 
627 
fissure between the main gyrus and the uncus corresponds with the 
pes hippocampi, and is continuous with the sulcus hippocampi, the obverse 
of the hippocampus major. The sulcus hippocampi separates the inner 
margin of the gyrus hippocampi from the gyrus dentatus (fascia dentata), 
a thin streak of grey matter indented by small bloodvessels, and intervening 
between the gyrus hippocampi and the fimbria. 
Superior temporal gyrus 
Torn surface 
Hippocampal lobe. 
Uncus. 
Gyrus dentatus. 
Hippocampus major 
Fimbria- 
Pig. 455,—Right Hippocampus Major removed with temporo-sphenoidal lobe, 
Resting on the anterior fossa basis cranii are the orbital convolutions 
and sulci, constituting the orbital lobe (Gratiolet). Parallel to the great 
longitudinal fissure there is a constant sulcus against which the olfactory 
tract and bulb lie, the olfactory sulcus, with the gyms rectus on its inner 
side; and in the middle of the surface external to it there is a sulcus 
with three ramifying branches, triradiate sulcus (Turner). The convolu- 
tions separated by the three branches have been variously described and 
are subject to much variation, but may be best distinguished as the 
external and internal orbital, more or less sagittal, and the posterior orbital, 
transverse in direction. 
Structure, A vertical section through the cortical substance of the 
hemisphere in the unaltered condition shows everywhere a division into 
a superficial reddish-grey stratum and a deeper stratum of colder grey tint, 
separated from the other by a thin whiter line, the primary pale band. 
In some parts of the hemisphere a deeper pale band can be easily seen, 
which does not, however, arise from additional complexity, but rather the 
reverse; and it is noteworthy that in the occipital lobe, where the deeper 
or second pale band is best seen, the total depth of cortical substance 
is least. 
Beginning at the pia-matral surface, there is found most superficially, 
in some parts, a certain number of medullated fibres; and these are so 
numerous on the gyrus hippocampi as to give a visible milky covering called 
reticulated white substance, while in other places they are altogether absent. 
They may be counted as belonging to the most superficial layer everywhere 
present, the superficial molecular layer, in which there are numerous neuroglial 
spider-cells, and great numbers of exceedingly fine nerve-fibres of two sets, one 628 
THE BRAIN. 
lying horizontally with minute nerve-corpuscles of more than one shape con- 
nected with them, and the other branching toward the surface from deeper 
strata. In the deeper part of this stratum there is great abundance of 
nuclei, or small corpuscles with little or no proper corpuscular substance 
round them, and from them we pass to what are usually counted the 
second and third layers, namely, those 
characterized respectively by small and 
large pyramidal corpuscles, which, however, 
graduate regularly one into the other, the 
smallest pyramids being most superficial, 
and the largest the deepest. Then comes 
the primary pale band, and beneath it 
the fourth layer, or layer of polymorphous 
nerve-corpuscles of various authors. The 
primary pale band presents a second 
stratum rich in nuclei (Cleland, 1870), and 
beneath it a stratum of horizontally placed 
medullated fibres. The layer of poly- 
morphous corpuscles has in it both nuclei 
and pyramidal corpuscles, though more 
irregularly arranged than in the more 
superficial strata, and among other kinds a 
larger number of fusiform nerve-corpuscles, 
both vertical to the surface and parallel to 
it, and also corpuscles with an ascending 
axis-cylinder. 
Superficial 
molecular 
Small pyramidal 
corpuscles 
Large pyramidal 
corpuscles 
Primary pale 
band 
Polymorphous nerve-corpuscles 
The pyramidal corpuscles are those 
which are typical of the cerebral con- 
volution. Their characteristic feature is 
that they are broadest at their deep end, 
and taper to a point like a church-spire, 
the point being directed toward the sur- 
face and prolonged into a long thread, 
the ascending or apical pole, which runs 
straight on, giving off in its course 
fine lateral branches, till it reaches the 
Deep pale 
band 
Fig. 456.—Semidiagrammatic Section of 
Grey Matter. (J. C., 1870.) 
molecular layer, where it breaks 
interlacing with its neighbours 
into a crowd of diverging ramifications 
Other protoplasmic poles, which immedi- 
ately break up into branches, come off round the base; and an axis- 
cylinder-process directed downwards and continued into the white 
substance in the interior of the hemisphere, springs directly from the 
base or in connnection with one of the protoplasmic branches, and gives 
off while in the grey substance from six to ten ramifying collaterals. 
The medullated fibres of the white centre of the hemisphere, traced 
into the grey substance, are at first in bundles, but soon become scattered THE CEREBRAL HEMISPHERES. 
629 
more uniformly, and get individually smaller, by diminution of medullary 
sheath. The large medullated fibres, parallel to the surface, arciform fibres 
Fig. 457.—Elements in Section of 
Cortical Grey Matter, a, Molecular 
layer; b, white substance; a, corpuscle 
with short axis-cylinder forming an ex- 
tensive arborization; 6, corpuscle with 
ascending axis-cylinder falling short of 
the molecular layer; c, corpuscles with 
ascending axis-cylinder ramifying in the 
molecular layer; d, small pyramidal 
corpuscle. (Cajal.) 
Fig. 459.—Diagram of Human Pyra- 
midal Corpuscle, showing collaterals 
of axis-cylinder and branches of the 
corpuscle and apical pole. (Cajal.) 
Fig.4sB. Nerve-Corpuscles from 
the Convoluted Grey Substance. 
One typical pyramidal corpuscle with 
apical pole making for the surface, 
central axis-cylinder and lateral 
basal poles; and two other nerve- 
corpuscles of a polymorphous type 
with more than one axis-cylinder. 
Fig. 460.—Schema of Longitudinal Section of Brain, 
showing disposition of the fibres of association between 
anterior and posterior lobes, ft, 5, c, Pyramidal cor- 
puscles ; d, terminal nervous arborization ; e, ascending 
arborizations of collaterals of fibre of association ; /, 
corpus callosum divided. (Cajal.) 
of Lockhart Clarke, form a distinct layer at the deep surface of the primary 
white band and occur scattered more superficially, but are disposed in a 630 
THE BRAIN. 
dense stratum on the deep surface of the cortical substance. They belong 
to the order of association fibres, a name used to include all bundles 
serving to bring into communication different parts of the hemispheres. 
“Fibres come from all regions of the cortex, converging as they traverse 
the corpora striata to penetrate the crura cerebri. In small mammals these 
fibres, on arriving at the level of the corpus striatum, send out to that 
body a large collateral, and then descend in little bundles separated by septa 
of grey substance, which they provide with very fine collaterals” (Cajal). 
In the grey matter bounding the sulcus hippocampi, namely, the gyms 
dentatus and grey matter of the hippocampus major, there are naturally 
special peculiarities, as these are the parts bounding the transverse fissure, 
a communication with the interior caused by total suppression of the nervous 
wall of the hemisphere-vesicle. The pyramidal corpuscles are here gathered 
together into one stratum, superficial to which their ascending poles form a 
stratum radiatum, succeeded by another, the stratum laciniosum, distinguished 
by their interlacing crowds of branches; and over this the densely nucleated 
zone of the molecular layer is greatly developed, getting the name of 
stratum granulosum. 
The olfactory lobes, sometimes regarded as portions of the hemispheres 
(p. 621, footnote), are but feebly developed in the human subject in com- 
parison with their size in vertebrata generally and in most mammals, 
although it is true that in cetacea they are absent, while in the seal and 
in monkeys they are of smaller proportions than in man. They originate 
as hollow structures coming off, in elasmobranch fishes, from the sides 
of the hemispheres, but in other vertebrata rather from their fore and 
under surfaces. In most mammals they continue hollow, and in some 
the communication with the ventricle persists. It may further be stated 
here from personal observation, as indicating the place of primary union 
with the hemisphere, though not generally noticed, that in the human 
foetus so late as in the sixth month, the olfactory bulb has its sole base 
in front of the island of Reil, and at an earlier period is completely 
separated from the anterior perforated spot by a very deep sulcus filled 
with pia mater. 
VII. THE OLFACTORY LOBES 
The olfactory lobe lies against the straight sulcus of the orbital 
surface of the hemispheres, and consists of the bulb and the peduncle or 
tract, with its roots. 
The olfactory bulb is of oval form and grey colour; it rests on the 
cribriform plate of the ethmoid, into whose surface it fits, and the minute 
and easily torn bundles of the olfactory nerve enter its under surface. 
It is continued behind into a slender and white stalk, the peduncle or tract; 
and tract and bulb together form a structure about 1| inches long, 
surrounded with pia mater. The attachment of the peduncle is at the 
hinder end of the sulcus olfactorius, and from it two obvious white THE OLFACTORY LOBES. 
631 
roots extend—an outer root directed outwards in front of the outer part 
of the locus perforatus anticus, and an inner root which curves inwards and 
turns forwards in the longitudinal fissure to join the gyrus fornicatus and 
peduncle of the corpus callosum. Between these two roots the grey 
matter continuous with the peduncle is sometimes described as the middle 
or grey root. In this grey matter fibres are sometimes found which 
apparently are developed in lower animals in a remarkable manner backwards 
(Rorie, Natural History Review, 1863). Schwalbe rightly points out that 
this grey surface (trigonum olfactorium) “is only the basal surface of a 
small ball-shaped lobule, tuber olfactorium, which occupies a deep three- 
sided depression at the hinder border of the under side of the frontal 
lobe, continuous at its base with the lamina perforata anterior, from which 
it is separated by a shallow groove.” 
In its finer structure the peduncle consists principally of white 
longitudinal fibres; and superficial to them a column of grey matter is 
prolonged from the hemisphere 
on the dorsal side, while in 
the interior a flat streak of 
neuroglia replaces the original 
hollow. The bulb presents 
likewise longitudinal white 
fibres round a central neur- 
oglia, the white fibres gathered 
in small bundles with their 
medullary sheaths united or 
very closely placed. Outside 
the longitudinal fibres it pre- 
sents dorsally only a little 
gelatinous grey substance, but 
on the ventral side it has a 
complex structure arranged in 
strata of which the deepest 
is characterized by angular 
nerve - corpuscles known as 
Fig. 461.—Anteeo-Postbeioe Section of Olfactoey Biji.b 
of a Duck, a, Arborization of the olfactory fibres within 
the glomeruli ; b, descending trunks of the large cuplike 
corpuscles in granular fringes within the glomeruli; c, the 
large cuplike or mitral corpuscles ; n, superficial zone of 
mitral cells, and the next by 
’ J 
copious granules or nuclei 
fibres : ,E> superficial member of a deep zone of grainlike 
corpuscles. (Cajal.) 
like those of the granular layers of the cortex of the convolutions, while 
superficial to these is a stratum thickly strewed with globular arrange- 
ments termed glomeruli, and on the surface is a thick plexus of nerve- 
fibres continued up from the mucous membrane of the nose. These latter 
end in the glomernli, each of which consists of a convoluted and branched 
termination of an olfactory nerve-fibre and of a complicated arborization 
of a protoplasmic fibre from a mitral cell. Each mitral cell has in 
addition other protoplasmic poles branching in the granular layer, and 
an axis-cylinder continued into the layer of medullated fibres. 632 
THE BEAIN. 
THE WEIGHT OF THE BRAIN. 
Considerable attention has been devoted to the weight of the brain, 
for the same reasons that it has been given to the cranial capacity, namely, 
with a view to obtaining racial characteristics, and to ascertaining what 
ratio exists between mass and capability of work. So far as difference of 
race is concerned, cranial capacity is the easiest mode of estimating 
the size of the brain, since skulls can be obtained in numbers when 
brains cannot. On the other hand, it is weight, and not mere bulk 
which indicates mass. The average weight of the brain in adult males 
in this country has been estimated at 49| ounces, and in women at 
five ounces less. The conclusion has also been arrived at that no brain 
under 30 ounces is sufficient for the exercise of the normal functions. 
On the other hand, there are instances of remarkable men having had 
great weight of brain. Thus Cuvier’s brain, the heaviest on authentic 
record, weighed 65 ounces; but it is beyond doubt that neither do large 
brains belong exclusively to great men, nor have all great men had 
particularly large brains; and, apart from the sources of greatness being 
very various, it is to be remembered how many different parts go to 
make up brain-mass, that the amount of cerebral cortex does not vary 
pari passu with the brain-weight, and that, even if it did, we do not 
know how much depends on perfection of the systems of association-fibres.1 
The weight of the brain varies more regularly in proportion to stature 
than to weight of body. The brain in the female bears a smaller pro- 
portion to the stature than it does in the male, but a greater pro- 
portion than in the male to the weight of the body. Also the ratio of 
the cerebrum to the cerebellum is smaller in the female than in the 
male, being as 7'84 to 1, instead of 8-02 to 1 (Marshall). It is a well- 
known law that the smaller the animal the greater the proportion, 
ceteris paribus, of the weight of the brain to that of the body ; this has 
been found to hold good in the human subject in both sexes, and 
accounts for the greater proportion of brain-weight to body-weight in 
the female. In accordance with another law, the proportion of the brain 
to the rest of the body is greatest in early development. The average 
brain-weight of the male child at birth is about 13 ounces, and that of 
the female child about 12 ounces. The greatest absolute weight of brain 
is reached in early adult life, and appears to diminish till extreme old age. 
1 Since this account of current statements was written, there have appeared two 
communications in the Lancet on Bth and 15th June, 1895. In the first, Dr. Middlemass 
describes a brain weighing Gof: oz. ; and in the second, Dr J. A. Campbell gives a list of 
15 brains over 60 oz. from among 1146 autopsies during a number of years in the 
Cumberland and Westmoreland Counties Asylum. The 15 brains included one female, 
62J oz. ; the other 14 were male. The heaviest weighed oz., the next weighed 
65 oz., and the next 63| oz., while four weighed each 62J oz. This appears to be one 
of the most important contributions to statistics of heavy brains yet made, and makes 
one wish for further results of the 1146 autopsies, as well as for records of similar sort 
from other institutions. DEVELOPMENT OF THE CEREBROSPINAL AXIS. 
633 
DEVELOPMENT OF THE CEREBRO SPINAL AXIS. 
The cerebro-spinal axis, as already stated (p. 90), makes its first appear- 
ance as the epiblast of the medullary groove, and is soon converted into 
a cylinder by turning inwards of the margins. In the cord, while yet 
those margins are still in continuity with the epidermis beyond, there is 
a separate thickening formed in the fold of eversion on each side, and 
these thickenings remain in connection with the cord as ridges projecting 
outwards in each segment to form a pair of spinal ganglia, the sources 
of the sensory nerve-fibres, while the motor roots project from the cylinder 
Fig. 462.—Section of Texture of Human 
Embryo Cord, a, Germinal cells between inner 
ends of spongioblasts; 6, columnar part of the 
spongioblasts; c, reticular or marginal zone 
formed by them ; cl, neuroblast. (Cajal, after 
His.) 
Fig. 463.—Section of Cord of Chick of Third Day 
of Incubation, a, Anterior root; b, posterior root; 
a, a, very young neuroblasts ; V, a more developed 
neuroblast, probably commissural; c, c, neuroblasts 
of anterior roots ; d, growth-cone of a commisural 
axis-cylinder; e, e', corpuscles of anterior nerve- 
roots, already with rudimentary dendrites; h, i, 
growth-cones of anterior roots; o, corpuscles of spinal 
ganglion. (Cajal.) 
in a more ventral position corresponding with their subsequent site of 
origin. The epiblast in the open medullary groove already consists of 
columnar epithelial cells whose deep extremities alternate with others; and 
after closure of the cylinder it thickens on each side, leaving the central 
canal linear in transverse section and bounded ventrally and dorsally by 
short cells. The lateral thickening is effected by elongation of the columnar 
cells or spongioblasts, and prolongation of each into branches which unite 
with similar branches of others to make a reticulum extending to the 
mesoblastic surface. This is the myelospongium of His, destined to form at 
least the foundation of the neuroglia. Between the columnar cells, close 
to the central canal, there are germinal cells in different stages of karyo- 
kinesis, giving rise, according to His, to the neuroblasts, cells with a large 
oval nucleus and an elongated process directed towards the place of 
emergence of the anterior root. By means of the chromate of silver method THE BRAIN. 
the axis-cylinders of the motor nerves have been seen in embryonic 
animals pushing their way through the tissues with a little growth-cone at 
their extremity, and the sensory nerves have been seen growing outwards 
and inwards from their spinal ganglia. Within the cord the most ventral 
neuroblasts send their growth-cone into the anterior root of the same 
side, the most dorsally situate push theirs across the middle line at the 
anterior commissure, while others intervening insinuate theirs into the 
periphery of the cord, the region of the future white columns. By the 
sixth week, in the human subject, the central canal projects dorsally con- 
siderably beyond the posterior roots, and laterally opposite them; the 
posterior columns are distinctly seen on each side, and the anterior columns 
project ventrally on each side of the middle line, separated by the first 
indication of the anterior longitudinal fissure. 
Till the foetus is four inches long from crown to nates, the cord and 
vertebral column grow equally, the nerves being given off opposite the 
intervertebral foramina by which they emerge, and the length of the canal 
being occupied. After that period the cord lengthens more slowly than 
the column, and by the time of birth it terminates opposite the third 
lumbar vertebra. Obviously this entails more rapid and greater growth 
of the lower nerve-roots to form the cauda equina; but it is interesting to 
note that other nerve-roots have been found equal to effecting a similar 
elongation without the aid of heredity, when it has been forced on them 
by displacement of the brain in hernia cerebri.1 
The development of the brain has been already to some extent referred 
to (pp. 90 and 97). It originates in the part of the medullary groove first 
laid down, and soon takes the form of a series of three primary cerebral 
vesicles, the third or hindermost of which elongates and tapers to the cord, 
while the second is at first of oval form, and the first or foremost expands 
in a trilobate fashion. The lateral lobes of this trilobate expansion each 
become quickly marked off in the shape of a globular part and a pedicle, 
the primary optic vesicle and the optic nerve; and in the chick in the first 
half of the second day of hatching, the grooves bounding the inner margins 
of the pedicles meet in the middle line exactly in the constriction between 
the first and second cerebral vesicles, which is therefore the precise site 
of the anterior edge of the optic commissure, a fact too little taken into 
account in judging of the morphological relation of the eyeball to the second 
cerebral vesicle (Fig. 96 a). Immediately afterwards the first cerebral vesicle 
of the chick becomes bifid at its extremity, this bifidity being the earliest 
indication of hemisphere-vesicles (Fig. 96 b). While these changes have 
been taking place, the brain has become more and more bent on itself by 
the greater growth on the dorsal than on the ventral side, so that the 
direction of the first cerebral vesicle is reversed and has its distal end 
pointing downwards. 
The third primary cerebral vesicle, the after-brain, early shows a division 
1 Cleland, Journal of Anatomy and Physiology, April, 1883. DEVELOPMENT OF THE CEEEBEO-SPINAL AXIS. 
635 
laterally into compartments, more or less vaguely delineated in old works, 
beginning with those of Malpighi. These compartments in the chick are 
of a very constant description (J. C., Nature, 1875), being at first distinctly 
five in number, with the auditory pit appearing opposite the constriction 
between the fourth and the fifth (Fig. 98). In the fourth day they 
assume the form of deep recesses, which soon after become filled up, and 
their future history remains to be worked out. Very soon there becomes 
apparent in the roof of the third vesicle a deficiency in the neural cylinders, 
free edges being visible along the sides. But from the foremost (proserial) 
extremity a backward growth sets in, with a free edge directed backwards, 
and this is the commencement of the cerebellum, which afterwards becomes 
prominent and has its dorsal substance so redundant that the free edge 
is turned round by it, remaining through life as the posterior velum. On 
Pie. 464.—Head of Embryo Chick of 
Third Day. 1, 2, 3, 4, 5, Visceral lobes ; 
11, 111, second and third primary cerebral 
vesicles ; a, auditory pit, between fourth 
and fifth lateral compartments of third 
vesicle; opl, primary optic vesicle ; op' 2, 
secondary optic vesicle ; opn, optic tract 
and nerve; pin, pineal body; th, thala- 
mencephalon ; hv, hemisphere-vesicle ; 
olf, olfactory pit. 
Pig. 463.—Head of Embryo Chick of 
Four Days. chi, cerebellum; other 
letters as in last figure. 
each side behind the cerebellum there is a deep lateral cleft, in front of the 
first of the original five compartments. This is seen to advantage in the 
human foetus of about four months, and round its edges a membranous 
growth rises up, which is the commencement of the flocculus. While 
therefore the cerebellum is a mesial dorsal growth, the flocculus is ventro- 
lateral and starts from a more retroserial position. The ligula is also 
seen to advantage in the young foetus, and easily recognized as an imperfect 
dorsal wall of the lower half of the fourth ventricle. Two antero-posterior 
curves are early seen in the third vesicle, namely, a ventral convexity, on 
the sides of which the floccular clefts and growths are placed, and a 
dorsal convexity corresponding in position with the point where the clavae 
separate and the medulla oblongata becomes open. 
The second cerebral vesicle, or middle brain, is the source of the corpora 
quadrigemina and other parts around the aqueduct of Sylvius. In the 
embryo cbick it becomes greatly distended, remaining for a considerable 
time the most elevated part of the brain. In the mammal it takes the form 636 
THE BRAIN. 
of a narrower tube bent over on itself. In the process of bending, 
however, in this region, the optic commissure is carried with the optic 
thalami downwards, which gives a seeming justification to the generally 
received view that optic tracts, optic commissure, and primary optic 
vesicles belong to quite a different part of the brain from the corpora 
quadrigemina. However, it will be noted, both in the chick and in His’s 
figure of the human brain of four and a half weeks, that the anterior or 
upper border of the optic tract is marked out by a deep depression. 
Fig. 467.—Brain of Human Em- 
bryo of 4J Weeks. Profile view, a, 
Peduncle of flocculus ; 6, cerebellum ; 
c, corpora quadrigemina ; d, optic 
thalamus ; e, pineal body ; f, hemi- 
sphere ; g, h, anterior and posterior 
olfactory lobes; i, optic nerve; k, 
hypophyseal pouch. (After His.) 
Pig. 466.—From Foetus of Four 
Months, a, Corpus striatum; b, optic 
thalamus ; c, corpora quadrigemina; d, 
cerebellum; e, stria terminalis; /, ex- 
ternal geniculate body ; g, flocculus ; h, 
ligule ; i, olivary body ; k, cuneus. 
The first cerebral vesicle, apart from the primary optic vesicles, is the 
source of the region of the third ventricle, thalamencephalon and hemisphere- 
vesicles, together called fore brain or prosencephalon, and of the olfactory 
bulbs or rhineucephalon. The hemisphere-vesicles, beginning as a pair 
of projections from the extremity of the undivided thalamencephalon, sprout 
forwards, and are then directed upwards and backwards over it, so that 
in a foetus of twelve weeks (Fig. 428) they not only cover it dorsally 
and laterally, but overhang the corpora quadrigemina. The corpus striatum, 
together with the insula, is a development of the ventral root-part of the 
hemisphere-vesicle. The original neck of communication between the 
hemisphere-vesicle and the thalamencephalon is called primitive foramen of 
Monro, and is identical with the foramen of Monro in the adult. Back- 
wards from it, in consequence of the great growth of communicating 
substance between optic thalamus and corpus striatum, there is a change 
of form which ultimately simulates adhesion of the two structures, but 
it may be noted that in a foetus of four months there is a very deep cleft 
between optic thalamus and corpus striatum. Above this, on a line back 
from the foramen of Monro, there is a tract of non-development of neural 
elements on the dorsal and posterior aspects of the neck of the hemisphere- DEVELOPMENT OF THE CEEEBEO-SPINAL AXIS. 
637 
vesicle, while in the same position there is hypertrophy of the folded 
pia mater. Thus the hypertrophied pia mater occupies a groove in the 
inner wall of the hemisphere-vesicle, and being separated from the cavity 
by nothing but a layer of epithelium, becomes the choroid plexus of the 
lateral ventricle. 
The olfactory lobe springs early, as a hollow outgrowth, from the anterior 
inferior part of the hemisphere, and in a human embryo of four and a half 
weeks has been figured by His as already showing indication of an anterior 
and a posterior part. In the third and subsequent months, it can easily be 
seen, as figured by Tiedemann, on the inner and back part of the orbital 
lobe of the hemisphere and extending forwards free to form peduncle 
and bulb, while from the base, which contains the original communication 
with the interior of the hemisphere, a thick elevation strikes directly 
outwards in front of the island of Reil, 
Olfactory bulb 
Insula 
Optic nerve and ohiasma 
.Corpus albicantia 
■ Crus cerebri 
■Floccular cleft 
Anterior pyramid 
Fia. 468.—Base of Brain of Foetus of Four Months, f. 
Fig. 469.—Brain of Foetus of Three Months, f. a, Olfactory 
bulb; b, insula; c, corpora albicantia ; d, pons ; e, corpora quadri- 
gemina ; /, cerebellum ; g, floccular notch ; h, anterior pyramids; i, 
cervical enlai-gment. Transitory fissures are seen on hemispheres. 
The thalamencephalon is originally completely roofed, and in the 
chick of the fourth day presents a pointed mesial dorsal projection 
apparently attached to the roof of the containing parietes. This is the 
pineal body, whose connections no doubt turn it back at the same time 
that the falx cerebri, which was originally vertical and in front of the 
corpora quadrigemina, is flung backwards by the enlargement of the 
hemispheres. The development of the pituitary body has been already 
referred to in connection with its structure (p. 612), and with the 
development of the base of the skull (p. 245). The corpora albicantia 
are remarkable in being very largely developed in the fourth and fifth 
month of foetal life, so as to form a great rounded eminence not altogether 
behind the chiasma, but extending beyond its anterior edge. 
Fig. 469. 638 
THE BEAIN. 
The surface of the hemispheres in the third month exhibits a number 
of transitory fissures; and in the fourth and fifth months a certain number 
of these are still seen lying transversely in the neighbourhood of the 
upper and inner border, especially about the middle. It is especially 
noticeable that there are in the interior of the lateral ventricles of the 
young foetal brain elevations, the obverses of fissures, which do not occur 
later. The fornix owes its origin to a pair of choroidal fissures, which 
at first are of the nature of other sulci; and although the nervous wall 
gives way, and the pia mater plunges into the ventricular space, it is to 
be recollected that the lining epithelium is not interrupted. Higher up 
than the choroidal fissure, while as yet there is no corpus callosum, an 
extensive longitudinal sulcus, fissura arcuata, begins in front of the olfactory 
bulb, its obverse appearing as a great convexity on the mesial wall of 
the fore part of the lateral ventricle, and arching backwards. Its fore 
part persists as the callosal fissure, and its hinder part as the hippocampal 
and calcarine fissures, the latter being one of a series of radiating offsets, 
the rest of which are transitory, with the exception of the occipito-parietal. • 
The corpus callosum seems to begin in close connection with the 
anterior white commissure, but becomes separated from it and the adherent 
lateral halves of the fornix by a depression deepening backwards to form 
the fifth ventricle, which is ultimately closed off from the peripheral surface. 
ORGANS OF SPECIAL SENSE. 
The organs of common sensation, scattered over the body, and con- 
sisting of mere nerve-extremities and minute structures connected with 
o 
them, have been relegated to General Anatomy (p. 78). 
The organs of special sense are of two very different kinds, the organ 
of taste being in no respect homologous with the others. 
Taste is dependent on nerve-terminations scattered over a portion of 
mucous membrane supplied with sensation by two pairs of cranial nerves, 
both of them distributed to other parts as well, and is only a function 
of the tongue, an organ belonging anatomically to the digestive system. 
But the organs of smell, sight, and hearing are in many respects 
serially homologous structures. They are closely connected with three 
pairs of outgrowths of the brain, viz., the olfactory bulbs, the primary 
optic vesicles and the flocculi. They each present an invagination of the 
cutaneous surface. Each has, closely connected with it, a communication 
between the mucous membrane and the surface of the body ; and, lastly, 
it may be added, though only as an opinion, that there is proof from 
comparative anatomy that their nerves emerge through openings in serially 
homologous elements of the cranium. 
The sense of smell, however, is in respect of simplicity, comparable 
with taste; while the appreciation of variations of light and sound 
necessitates much complexity in the eye and ear. THE NOSE. 
639 
THE NOSE. 
Under this name is included the whole extent of the nasal fossae, 
which open in front by the nostrils, and behind into the pharynx, bounded 
in front by the nasal cartilages, and having air sinuses in connection with 
them. In fishes, the myxinoids excepted, the olfactory organ is distinct 
from the alimentary canal, and devoid of communication therewith. But 
in all air-breathing vertebrata, posterior nares exist, and odours are con- 
veyed to the termination of the olfactory nerve by inspiration. Thus, 
the lower part of the nasal fossae are subservient to the sense of smell, 
but belong also to the respiratory tract; and, in vocalization, which is 
equally dependent on respiration, the voice is modified by vibration 
throughout the nasal fossae and the air-cavities connected with them. 
The nasal cartilages complete the septum between the nasal fossae, and 
shut them in anteriorly: they are mesial and lateral. The mesial or 
septal cartilage is the persistent extremity 
of the cartilaginous primordial cranium, 
which was continued forwards in early 
life from the front of the body of the 
sphenoid bone, invaded above by the 
central plate of the ethmoid, and sheathed 
below by the vomer and the crista nasalis. 
Owing to the irregular development of 
the vomer, its posterior connections vary 
somewhat in the adult, vestiges being 
still traceable in many instances back to 
the sphenoid, with a vomerine ala on one 
side or on both; but it fits edge to edge, 
in direct continuity with the central 
plate of the ethmoid forward to the 
nasals, while from nasals, vomer and 
maxillaries it is separated by fibrous 
tissue, and its inferior border is pro- 
longed forwards between the nostrils, 
where it can be felt turning upwards 
Fio. 470.—Nasal Cartilages. 1, Maxillary; 
2, nasal bone; 3, septal cartilage; 4, tri- 
angular cartilage; 6, alar cartilage; 6, 
accessory cartilage; 7, adipose tissue. 
(Luschka.) 
near the tip of the nose. The anterior border of the septal cartilage is 
continuous at one part with the mesial edges of the triangular (upper lateral) 
cartilages, two plates which, united in the middle line, extend outwards and 
adhere by their upper edges to the margins of the nasal bones, while their 
lower edges are slightly separated from the alar cartilages. The alar (lower 
lateral) cartilages present each an expansion limiting the nostril in front, 
and giving shape to the extremity of the nose. From the inner side of 
this expansion a linear band passes backwards in the columella or strip of 
integument between the nostrils, and may end in a prominence inside 
the nostril; and on the outer side the expanded part may be prolonged 640 
OEGANS OF SPECIAL SENSE. 
back in a thinner and narrower form for some distance on the lateral 
dilatation of the wall of the nostril, called the ala. Sometimes portions 
of this prolongation are completely detached. Other little detached accessory 
cartilages occur between the alar and the septal cartilage. The greater 
part of the ala of the nose contains no cartilage. 
The nasal fossae, so far as their extent and the form of their walls 
are concerned, require no further description than has been already given 
at p. 238; for they are lined in their whole extent with mucous membrane 
closely adherent to the periosteum and extending round the cavities of 
all the various air-sinuses. This used to be called the pituitary or the 
Schneiderian membrane. It is thick and spongy over the turbinations of 
the ethmoid (superior and middle concha) and on the septum nasi, still 
more so on the inferior turbinated bones (inferior concha), but comparatively 
thin and firm on the floor and other boundaries, and reduced to tenuity 
within the air-sinuses. It is divisible into three districts, namely, the 
vestibule and the respiratory and olfactory tracts. 
Superior concha 
Superior meatus- 
Agger nasi - 
Middle concha 
Middle meatus 
Inferior concha 
(Mouth of Eusta- 
| chian tube 
Inferior meatus 
Vestibule 
Position of levator 
palati 
Fig. 471.—Outer Wall of Right Nasal Fossa. 
The vestibule is the part in front, where the cavity is roofed in by the 
nasal cartilages, and is lined with stratified squamous epithelium. Close 
to the apertures of the nostrils it presents large sebaceous glands and hairs 
projecting into the passage. 
The respiratory tract includes the whole nasal fossa, with the exception 
of the olfactory tract to be described over the vestibule. It has stratified 
ciliated columnar epithelium, as have also the air-sinuses, and is studded 
over with the racemose glands. It abounds in lymphoid tissue more or 
less diffuse, and in leucocytes which make their way even to the surface. 
The part in front of the inferior turbinated bone and inferior turbination 
of the ethmoid is called the agger nasi. THE NOSE. 
641 
Ihe olfactory tract has usually been described as coextensive with the 
turbinations and mesial plate of the ethmoid, but Max Schultze declared 
it to be limited to the level of the upper turbination, and the researches 
of v. Brunn have now made it certain that both the olfactory nerve and 
the olfactory part of the mucous membrane are confined to one continuous 
district, situated on the upper ethmoidal turbination without reaching 
either its lower edge or posterior extremity, and extending across the 
roof down over a similar area on the septum, the whole olfactory tract 
of both fossae being little more than a square inch in size. It has a non- 
ciliated columnar epithelium, which presents, besides deep cells, two sets 
of elongated cells stretching down through it ; one, the proper columnar 
epithelial cells, are prolonged deeply in long dividing branches con- 
tinuous with the stroma beneath; the other, the olfactory cells, are 
attenuated rod-like structures 
between the larger columnar 
cells, with their nuclei mostly 
placed more deeply, and receive 
their name from their deep 
extremities being supposed to 
be continuous with olfactory 
nerve-fibres, as has now been 
finally demonstrated to be 
really the case. Y. Brunn has 
distinctly made out in the 
human subject, what had been 
seen in the frog and other 
animals, numbers of hair-like 
processes surrmounting the 
olfactory cells. He demon- 
strates also the existence of 
a delicate membrane, with 
apertures through which the 
hair-like processes project [external limiting membrane). The glands of the 
olfactory region (glands of Bowman) are tubes with dilated extremities 
and a tendency to convolution. In the human subject several are gathered 
to one outlet (Toldt), and the epithelium is cylindrical. The branches of 
the olfactory nerve, after piercing the cribriform plate of the ethmoid, 
are arranged in a close network of branches. The nerve-fibres are non- 
medullated axis-cylinders, with nucleated primitive sheaths. As they 
approach the surface they break up into minute fibrils. 
Pig. 472.—Olfactory Cells, a, Three epithelial cells, an 
olfactory cell and the peripheral process of another. A mem- 
brana limitans unites the free extremities of the cells; the 
olfactory cells are surmounted by olfactory hairs, and the 
middle epithelial cell by a structureless cap; b, olfactory cell 
with deep process followed further; c, an olfactory cell 
prepared by the Golgi method, (v. Brunn.) 
The nasal fossae are supplied with blood, in the upper part by 
anterior and posterior ethmoidal branches of the nasal artery, and lower down 
by branches of the internal maxillary artery. They receive branches from 
Meckel’s ganglion and, anteriorly, offsets from the nasal branch of the 
ophthalmic division of the fifth nerve. 642 
ORGANS OF SPECIAL SENSE. 
Development. The first appearance of the olfactory organ is an epiblastic 
depression, which is afterwards inclosed by the development of the face, 
and complicated by the ethmoidal turbinations. 
Jacobson’s organ, a structure developed in most mammals, and traced 
in other vertebrates, exists in vestigial form in the human subject, but 
will be best understood by referring first to the ruminant form which 
Jacobson described. If a probe be passed through the patent incisor 
foramen in the palate of a sheep or goat, and a vertical section be made 
on the same side, the probe will not be visible in the nasal cavity, 
because it will have entered a compressed pouch whose mouth is close 
to the incisor foramen, and which extends backwards within a cartilag- 
inous sheath derived from the septal cartilage, and concealed by the 
Fig. 4t3.—Jacobson’s Organ of right side of nose of goat, a, Right side of palate; 
b, septal cartilage; c, central plate of ethmoid; d, deep side of mucous membrane of 
mesial wall of right nasal fossa ; e, cartilaginous capsule containing the mucous membrane 
of Jacobson’s organ ; f, mouth of capsule in the incisor foramen ; g, olfactory branch to 
Jacobson’s organ; h, the branch from Meckel’s ganglion. 
mucous membrane of the septum. Passing forwards to it are two long and 
distinct nerves, one from the olfactory and the other from Meckel’s 
ganglion; and the mucous membrane has been found to present olfactory 
cells continuous with nerve-fibres, like those of the nasal cavity (v. 
Brunn). This organ first found in the human subject in the foetus 
(Dursy), was discovered by Kolliker to be generally present in the adult 
as a minute pouch, about an eighth of an inch long, lined with ciliated 
epithelium. The cartilage is also faintly represented. 
THE EYE. 
The essential part of the eye is the eyeball, containing within it the 
nerve-terminations sensitive to light, the refractive apparatus by which the 
landscape is repeated on the sensitive surface, and arrangements for regulat- 
ing focus ; while it is bounded in greater part by a fibrous capsule, the 
sclerotic, and completed in front by a transparent structure, the cornea. THE EYE. 
The eyeballs are surrounded by muscles already described (p. 334), which 
come into use by turning the antero-posterior diameters or axes of vision 
of the two eyeballs on one object, either directly in front, or above, below 
or toward one side. In addition to all these structures there are others 
in front of the eyeballs, viz., the eyebrows, eyelids, conjunctiva and 
lachrymal apparatus, collectively termed tutamina oculi, as affording protec- 
tion from glare and from violence, and preserving the necessary transparency 
of the surface which admits the light. 
Tutamina. 
The eyebrows can scarcely be considered important for the protection 
of the eyes, but they are present in all races of men and represented 
among animals, and peculiarities presented by them are frequently trans- 
mitted hereditarily. It may be noted that they consist each of an outer 
and an inner portion, which do not always exactly meet, end to end. 
The eyelids have the integument thin, and the subcutaneous connective 
tissue loose and devoid of fat, enabling them to be separated easily. 
Beneath the subcutaneous connective tissue is a thin sheet of muscular 
fibres belonging to the orbicularis palpebrarum; and between this and the 
mucous membrane or conjunctiva of each lid, the margin is made stiff by 
the tarsus. The tarsi, or tarsal plates, have a cartilaginous density, but 
are really two fibro-plates composed of felted tissue; that of the lower 
eyelid is a narrow linear strip, while that of the upper lid is crescentic, 
fully quarter of an inch deep in the middle, and can easily be brought 
into view in outline in the living subject, as by its stiffness and definite 
upper margin it enables the lid to be everted by the surgeon. To its 
upper margin is attached the tendon of the levator palpebrae muscle. 
Both tarsi are attached at the inner extremity to the tendo palpebrarum 
(p. 330). In both eyelids unstriped muscular fibres extend in a thin 
sheet towards the orbit from the deep margin of the tarsus (H. Midler’s 
muscle). The extremities of the aperture between the eyelids are termed 
the outer and inner canthi. The outer canthus is a simple angular junction 
of the lids, but the inner canthus is a rounded recess floored by a pink 
and spongy caruncula, and with margins each of which joins the margin 
of the corresponding lid at a projecting angle. These projections are 
the upper and lower papilla lachrymalis; and each of them presents an 
orifice, punctum lachrymals, directed backwards towards the eye. Along 
their free margins, external to the puncta lachrymalia, the eyelids are 
furnished with eyelashes. The eyelashes (cilia) are in healthy individuals 
curved, with their convexities toward the opposed range, and are larger 
in the upper than in the lower ■ lid, and twice as numerous. Tubular 
modified sweat glands lie in a row behind the roots of the lashes and open 
in connection with their follicles. But much larger and obvious to the 
naked eye are the Meibomian follicles whose orifices lie in a single row 644 
ORGANS OF SPECIAL SENSE. 
close to the inner edge of the margin of each lid. These glands can be 
detected through the conjunctiva, close beneath which they lie, embedded 
in the tarsus (Fig. 272). Each consists of a long duct with saccules, 
simple and divided, ranged along each side, filled with sebaceous secretion, 
and presenting flat secreting cells like those of ordinary sebaceous glands. 
They are about thirty or forty in number, and afford a certain protection 
against overflow of tears. The Meibomian follicles are surmounted by 
accessory lachrymal glands, consisting of convoluted masses of tubules pouring 
their secretion out on the conjunctiva 
Fig. 474.—A, Accessory Lachrymal 
Gland surmounting B, the extremity 
of a Meibomian Follicle. (Dr. Keid.) 
Fig. 475.—Lymphatics of Conjunctiva. A, 
Fine network with free edge on margin of 
cornea; B, over the sclerotic. (Teichmann.) 
The conjunctiva is the mucous membrane within the aperture of the 
eyelids, developed by reflection of the integuments, and presenting a pal- 
pebral and an ocular part. The conjunctiva palpebralis is so vascular as to 
have a pink colour; it is firmly adherent to the tarsal cartilages, but beyond 
these is loose and easily separated. At the inner canthus it forms the caruncle, 
in which are to be found modified sudoriparous and sebaceous glands; and 
outside this it is thrown into a vertical fold, plica semilunaris, a vestigial 
third eyelid, better developed in various mammals, in some of which it 
contains tough structure, and even, as in the seal, a considerable cartilage, 
and also corresponding with the large membrana nictitans of birds. The 
conjunctiva bulbi is reflected on the sclerotic, and in the healthy state is 
transparent, displaying the course of only a few vessels, while its capillaries 
are insufficient to modify the whiteness of the sclerotic beneath it. Its THE EYE. 
645 
vessels are independent of those of the sclerotic, and form a capillary net- 
work which only slightly incroaches over the margin of the cornea, but 
does so by a marginal fringe of small meshes accompanied by nerves; 
and in the same situation the lynqfliatics also cease, after forming a 
close meshwork of finer capillaries than those of the sclerotic conjunctiva. 
Beyond this, the dermal elements are lost, and only the epithelium is 
continued over the surface of the cornea in health, although, under in- 
flammatory irritation, conjunctival bloodvessels may spread freely on it. 
Fig. 476.—Free Margin of Network op Capillaries over Margin of Cornea, photo- 
graphed from stained specimen, a, Shows the breadth of the closely meshed zone, -p-; 
b, a portion of the same, -7r®, shows the nervous plexus. 
The lachrymal apparatus consists of the lachrymal gland, which secretes 
the tears and pours them out on the surface of the conjunctiva to keep 
it moist and the corneal epithelium transparent, and of an arrangement 
of passages, the lachrymal canals, which take up the tears from the surface 
of the eye, and in ordinary circumstances convey into the nose the whole 
amount secreted. The lachrymal gland occupies the fovea lachrymalis of 
the frontal bone, at the upper, outer and fore part of the orbit. Its 
length transversely is about three quarters of an inch, its breadth from 
before backwards about quarter of an inch, and its depth about an eighth 
of an inch, and it has in addition a thin outlying part in front. It pours 
out its secretion by about a dozen ducts, which open into the line of 
reflection from the palpebral to the ocular conjunctiva. It is a racemose 
gland, with structure similar to a serous salivary gland. It has a special 
lachrymal branch from the ophthalmic artery and from the ophthalmic 
division of the fifth nerve. Branching nerve-fibres have recently been seen 
in the guinea pig piercing the membrana propria and forming fine plexuses 
surrounding each secreting cell (Dogiel). The lachrymal canals or passages 
begin at the pundum lachrymale on the margin of each eyelid. From the 646 
ORGANS OF SPECIAL SENSE. 
punctum of each lid a canaliculus is directed vertically for about a twelfth 
of an inch. The canaliculi abruptly turn to run inwards above and below 
the canthus, and open close together or by a single opening into the 
lachrymal sac, behind the attachment of the tendo palpebrarum. 
Lachrymal gland 
Orifice of frontal simis 
J Canaliculi opening into lacli- 
\ rymal sac 
.Anterior ethmoidal sinus 
Carunculus 
Plica semilunaris 
.Inferior turbination of ethmoid 
Orifice of nasal duct 
.Inferior turbinated hone 
Infraorbital nerve 
Fig. 477. —Lachrymal Apparatus. The nasal fossa and the frontal and maxillary 
sinuses are laid open. 
The lachrymal sac occupies the groove formed by the lachrymal bone 
and nasal process of the maxilla, and its fine mucous membrane is supported 
internally by periosteum, and externally by fibres continued from the 
periosteum of the margin of the groove. It is supported also by the tensor 
tarsi muscle passing forwards across it. It is continued inferiorly into 
the nasal duct, in which the mucous membrane adheres to the periosteum 
till it reaches the nasal fossa at the fore part of the inferior meatus. There 
the mucous membrane is slightly redundant and may offer resistance to 
catheterization, if not lightly handled. In the canaliculi and the lower 
end of the nasal duct the epithelium is stratified squamous; in the 
intervening sac and greater part of the nasal duct it is simple columnar 
ciliated. 
The Eyeball. 
The eyeball is a nearly spherical structure, the surroundings of which, 
including its muscles and movements, have been already considered (p. 334). 
The diameter perpendicular to the centre of the cornea or transparent 
part in front is called the axis of vision-, and the vertical plane passing 
through the centre, at right angles to the axis, is called the equator. The 
equator is circular and about an inch in diameter; the axis of vision 
is somewhat shorter; and the fore part of the circumference, formed by 
the cornea, has the curve of a smaller sphere than the remainder formed 
by the sclerotic. Within the sclerotic and cornea, which together con- 
stitute the outer coat, is the middle coat or tunica vasculosa, consisting of 
choroid, ciliary muscle, ciliary processes and iris, and inside this the nervous THE EYEBALL. 
647 
coat or retina; while the cavity of the globe is filled with transparent 
media, the more consistent of them, viz., the crystalline lens and the vitreous 
humour, occupying the greater part, but leaving in front a space called the 
anterior chamber, containing a watery fluid, the aqueous humour. 
The sclerotic is a dense and tough white fibrous coat forming the outer 
wall of the eyeball in its whole extent, except for an area in front, half 
an inch in diameter, where it is replaced by the cornea. Its fibres are 
closely matted, neither confined to one direction nor one plane; and among 
the white fibrous bundles yellow-elastic fibres are scattered. It is incap- 
able of stretching by sudden distension, but yields perceptibly to continued 
pathological pressure from within. It is thickest behind where it is about 
•jo-th inch thick, and diminishes gradually to half this thickness about a 
tenth of an inch from the corneal margin, becoming perceptibly thicker 
close to the cornea. Posteriorly it is pierced by the optic nerve, the 
bundles of which enter separately, so as to give to a section across them 
a sieve-like appearance named lamina cribrosa; and the sheaths of the 
bundles join the sclerotic texture in such a way that the tract of the 
nerve diminishes in its passage, through the nerve-fibres being collected 
to a point which is situated one-tenth of an inch internal to the centre 
of the back of the sclerotic, and slightly below it. In the centre of the 
optic nerve the central artery of the retina passes in, and the numerous 
posterior ciliary arteries enter round about the nerve, with two long ciliary 
arteries—one on each side. The ciliary nerves, about eighteen in number, 
pierce the sclerotic in a wider circle, and mark its interior surface with 
grooves for some distance forwards. Adherent to the deep suface of the 
sclerotic there is a layer of pigmented connective tissue, membrana fusca, 
consisting mainly of flat, pigmented lobate and branched corpuscles with 
clear nuclei uncovered with pigment. It forms in man a distinct mem- 
brane, separated from the choroid coat by one or more lymph-spaces with 
endothelial lining, which communicate with the interior of the capsule of 
Tenon by the apertures of emergence of the venae vorticosae. It is also 
distinct from the sclerotic, and binds down to the sclerotic the ciliary nerves 
as they course forwards to divide behind the ciliary muscle into branches 
to supply that muscle and the iris and cornea. Neither ox nor sheep 
have any separate membrana fusca. In them the sclerotic and choroid 
are united by densely pigmented connective tissue, which cannot be separated 
from either. 
The cornea. The transparent fore part of the outer coat is slightly 
thicker at the periphery than in the rest of its extent; and its curvature, 
which normally is the same in the transverse and vertical directions, is 
a little more prominent than that of the sclerotic. The plane of continuity 
with the sclerotic passes obliquely through the thickness of the coat, parallel 
to the axis of the eye. 
The proper corneal substance is a modification of white fibrous tissue, 
arranged in laminae about sixty in number, closely united in the natural 648 
ORGANS OF SPECIAL SENSE. 
condition, but capable of being swollen by the action of re-agents (e.g. 
weak bichromate of potash), so as to show that the fibres uniting the 
laminae are less firm than the laminae themselves. The fibres are delicate 
and straight, those of adjacent laminae decussating; and at the edge of 
the cornea they are continuous with those of the sclerotic. Nucleated 
corpuscles are abundant, and in vertical sections appear spindle-shaped, 
Fig. 478.-t-Section of Cornea, parallel to surface ; showing corneal corpuscles lying in 
branched space. (Beaunis.) 
tying between the lamellae; but in horizontal sections are seen to be 
spread out flat, and to give off slender branches which, when undisturbed, 
take straight courses, mostly in two decussating lines of direction such 
as might correspond with the courses of fibres of adjacent laminae, uniting 
Fig. 479.—Corneal Corpuscles of Calf, macerated in vinegar and stained with haema- 
toxylin; photographed. The stained threads of protoplasm are seen in unstained sur- 
roundings. In b the corpuscles are multiplying. (Dr. Reid.) 
the corpuscles in a network, and also giving off threads parallel to the 
branches in the other direction. These corpuscles occupy spaces or laminae 
which intercommunicate, and would appear to correspond pretty closely 
with them in size and shape, but to be capable of distension. Beaded 
channels, decussating in like direction with the corpuscular branches, first 
described by Bowman, have in later years been passed over as artificial 
structures, but the appearance can be brought into view without injection, THE EYEBALL. 
649 
and is a beaded condition of the branches of corpuscles. The laminae 
nearest the front are more firmly bound together by fibres which extend 
obliquely inwards from the surface. 
In front and behind, the proper substance of the cornea is bounded 
by elastic substance. The anterior elastic lamina (Bowman) is very thin 
and inseparable, but can be displayed by producing cracks in it by 
Pig. 480.—Epithelium of Human Cornea. The part to the right is in the neighbour- 
hood of a lesion, which has led to alteration of the tissue and wandering of corpuscles 
up into the epithelium. (Dr. Reid.) 
alternate swelling and shrivelling of the underlying substance. The posterior 
elastic lamina (membrane of Descemet or of Demours) is much thicker than 
the anterior and is easily separated; in the horse it can be removed 
complete. Portions detached curl up, with the anterior surface turned in; 
it is brittle and structureless. At 
the circumference it is continuous 
with the ligamentum pectinatum 
iridis, which can be removed with 
it. On its deep surface there is a 
single layer of squamous epithelium, 
separating it from the aqueous 
humour. 
The superficial epithelium of the 
cornea is in apparently immediate 
contact with the anterior elastic 
lamina, and consists in the human 
subject of elements not very dis- 
similar from those of the general epidermis. The deepest cells are broad 
and not greatly elongated, and the strata are not very numerous. But in 
some animals, as the horse and the ox (Fig. 68), the deepest cells are of 
a highly elongated columnar form, their pointed extremities striking up 
between digitations of cells superficial to them; and I was able to make 
out, superficial to both these strata, a stratum of proliferation (1868). 
Fig. 481.—Portion of Primary Nerve-Plexus of 
Human Cornea, highly magnified, showing ganglionic 
corpuscles and nuclei of nerve-fibres. (Dr. Reid.) 
The nerves of the cornea enter its substance from the sclerotic, near 
the front. They are branches of the ciliary nerves, over forty in number, 650 
ORGANS OF SPECIAL SENSE. 
which pierce the sclerotic opposite the ciliary muscle and enter the cornea 
at a little distance from the surface, to form in it at that depth an open 
meshwork, the primary plexus. From this plexus numerous fine branches 
pass toward the surface and form a subepithelial plexus on the anterior 
elastic lamina, whence minute fibres extend to form an intra-epithelial 
plexus, and end in free and dilated extremities close to the surface. 
There are no vessels in the cornea; the conjunctival capillaries cease after 
overlapping its border, as already described (p. 645). 
Fig. 482.—Cornea, Epithelium and Nerves, a. Corneal cor- 
puscles ; h, anterior elastic lamina; c, deep epithelial cells ; d, 
primary nerve-plexus; e, branch to surface; /, subepithelial 
plexus ; g, g, branches to intra-epithelial plexus, h. (Kolliker.) 
Fig. 483.—Nervous Plexus of 
Cornea op Sheep under a low mag- 
nifying power. The nerves enter the 
cornea from the periphery at the 
lower edge of the figure. 
Fig. 484.—Pigmented Branched Cor- 
puscles. a, From membrana fusca; b, from 
between the arteries of the choroid. 
The choroid is essentially a vascular membrane, and has the peculiarity 
that its arteries and veins are spread out in a membranous sheet, and are 
connected by means of the smallest order of branches with a membranous 
sheet of capillaries underneath them. The arteries are the short ciliary 
branches, about twenty in number, of the ophthalmic artery, and, piercing 
the sclerotic at the back, divide within the membrane; the divisions 
running directly forwards alongside one of another with narrow intervals 
between, so that the choroid tears easily in a longitudinal direction. 
They extend forwards into the ciliary processes, and communicate with the 
anterior ciliary arteries. The veins, venae vorticosae, lie on the sclerotic 
aspect of the arteries, inseparably united to them, and form a close net- 
work ending abruptly in front, opposite the ora serrata of the retina, a 
little outside the bases of the ciliary processes. They converge to four or 
five points round the widest part of the globe, and from each of these a THE EYEBALL. 
651 
trunk springs, which at once proceeds to pierce the sclerotic backwards. 
The connective tissue binding the arteries and veins together, the stroma 
proper of the choroid, is made brown by the presence of numerous flat 
pigmented corpuscles branched like those of the membrana fusca, only to 
a greater degree. But this stroma is not prolonged on the central or con- 
cave surface of the arterial layer. In contact with that surface there is 
extended the membrane of Ruysch or membrana chorio-capillaris, a continuous 
close network of capillaries, with fine meshes, especially at the back of 
the eyeball, and continued forwards to the ora serrata of the retina, 
Fig. 485.—Schema of Vessels op the Tunica Vascdlosa. On the right side the ciliary 
muscle is supposed to he removed to bring the ciliary processes into view, o, Optic 
nerve ; A a and Va, anterior ciliary artery and vein ; Vv, vena vorticosa ; Al, long ciliary 
artery ; dm, circulus iridis major; Ah, Ah, short ciliary arteries. (Leber.) 
about an eighth of an inch from the margin of the cornea. It com- 
municates with the arteries and veins by numbers of minute arterioles 
and venous radicles, not, however, so numerous as in animals provided 
with a tapetum,1 such as the ox. In them the capillaries are arranged in 
a series of stellules, exhibiting in the centre the extremities of short 
vertical vessels, which traverse the tapetum and give passage to and from 
the capillaries. The membrane of Ruysch has on its deep or retinal 
surface a very thin structureless elastic lamina, the membrane of Bruch, 
IThe tapetum is a structure altogether absent in man, but present in the majority 
of vertebrates, and most abundant in nocturnal animals and those which require to 
see below the surface of water. It intervenes between the arterial layer and the 
membrane of Ruysch, and consists of connective tissue in hoofed animals, of granular 
matter in carnivora, and of vesicles filled with rods in fishes. In the horse and 
the ox it is developed in the upper part of the back of the eye so as to catch 
the images of objects on the ground. 652 
ORGANS OF SPECIAL SENSE. 
closely but not inseparably adherent to it. The membrane of Bruch rests 
on the pigmented epithelium described further on. 
The ciliary muscle forms a white ring, a tenth of an inch in breadth, 
extending backwards from the attachment of the iris to the sclerotic. It 
consists of two sets of unstriped muscular fibres, the radiating and the 
circular. The radiating fibres arise in the immediate neighbourhood of a 
groove on the deep aspect of the sclerotic, at the border of the cornea, the 
svlcus sclerae. This groove is the outer border of a lymphatic canal, the 
circular sinus; and while some of the radiating fibres of the ciliary muscle 
arise from the iris internal to this canal, others arise from the posterior 
margin of the sulcus. Diverging from this origin the fibres are inserted 
on the choroid and into the ring of origin of the ciliary processes. Among 
the foremost radiating fibres, more or less mixed with them, are the circular 
fibres first described by Heinrich Muller. The radiating fibres are largely 
developed in man as compared with the ox and horse, but the circular 
fibres are not so well developed. In the seals the circular fibres are 
enormously developed. 
Fia. 487.—Section of Human Eye, 
a, Sclerotic; 6, cornea ; c, con- 
junctiva ; d, iris; e, lens; /, ciliary 
muscle ; g, retina ; h, optic nerve. 
The dentated margin of the white 
retina is the ora serrata; and be- 
tween the ora serrata and lens is the 
ciliary zone, with the most promin- 
ent parts of the ciliary processes 
seen as white rays. Above and 
below the lens, the canal of Petit 
exhibits a triangular section. 
Pia. 486.—Human Eyeball from which part 
of the Cornea and Sclerotic have been 
Removed, a, Ciliary nerves piercing the sclerotic 
around the optic nerve; 6, ciliary muscle; c, 
canal of Schlemm or, more properly, of Fontana ; 
d, pupil; e, iris ;/, ciliary nerves dividing toward 
the front of the choroid in which are seen venae 
vortioosae and arteries. 
The ciliary processes are a series of projections forming a circle of rays 
projecting on the deep side of the tunica vasculosa, separated by an interval 
called orbiculus ciliaris from the ora serrata of the retina and edge of the 
membrane of Euysch, their bases being opposite the union of the iris 
with the ciliary muscle, and each presenting a free extremity which points 
inwards behind the periphery of the iris. They are erectile structures 
consisting of a rich vascular network supported by connective tissue con- 
tinuous with the stroma of the choroid, but without pigment. The arteries 
of the choroid bejmnd the edge of the membrane of Euysch run onwards 
across the orbiculus ciliaris, dilating as they reach the processes, and are THE EYEBALL. 
653 
continued along their free or posterior edges, while the deep parts receive, 
with the iris, blood from the anterior ciliary arteries. The veins pass hack 
to the choroid, and the capillary network has its vessels enlarged and tortuous. 
The iris,1 the fore part of the tunica vasculosa, is the contractile curtain 
which gives colour to the eye; it presents in the middle a circular aperture, 
the pupil. But dissectors, supplementing their knowledge by dissection of 
eyes of other animals, must recollect that the pupil is elongated horizontally 
in the horse and the ox, while it is elongated vertically in the cat. The iris 
is connected peripherally with the ciliary muscle and ciliary processes, 
and, by means of a structure termed ligamentum pectinatum iridis, with the 
membrane of Descemet. It has a stroma of connective tissue presenting 
_ Pupillary margin 
.Ciliary processes 
' Long ciliary artery 
entering circulus 
1. major 
Choroidal arteries 
passing on to ciliary- 
processes 
Venae vorticosae with the chorio- 
capillary network more faintly 
seen 
Fig. 488.—Injection of Human Iris, Ciliary Processes, and Fore Part of Choroid. 
(Injection by A. Stirling.) 
stellate corpuscles with prominent nuclei and long anastomosing branches. 
Its muscular fibres are unstriped in mammals, striped in birds, and are 
arranged in two sets. The more distinct set is circularly arranged round 
the pupil and called the sphincter; it is nearer the back than the front. 
The others, constituting the dilatator, are still closer to the back, consider- 
ably more scattered and radiate in direction, and stronger peripherally. 
At the back of the iris there is a continuation of the membrane ot Bruch 
resting on the thick pigmented epithelium behind. In front, at the cir- 
cumference, the membrane of Descemet, becoming fibrous at the margin of 
the cornea, turns in to join the fore part of the stroma of the iris, and it 
is this which is called ligamentum pectinatum iridis j but the name is not 
as descriptive of the appearance in the human subject as it is of the 
1 Uvea of old anatomists, who included under the term the pigmented epithelium 
behind it. The terms pars uvealis iridis for the iris proper and pars retinalis iridis 
for the pigmented epithelium are inaccurate. 654 
ORGANS OF SPECIAL SENSE. 
arrangement in the ox and in the horse, in which the membrane of Descemet, 
with tooth-like projections from the iris, is more easily seen to be the sole 
anterior wall of the sinus circularis. The epithelium lining the hack of 
the membrane of Descemet can be traced round on the front of the iris. 
The arteries of the iris are derived from the long ciliary and the anterior 
ciliary arteries. The long ciliary arteries piercing the sclerotic with the 
posterior ciliaries, pass forwards, one on each side in the choroid, and 
divide in the periphery of the iris, each into an upper and a lower branch 
which unite to complete a ring, the circulus major. This is joined by 
branches from the anterior ciliary arteries, five or six vessels which pierce 
the sclerotic not far from its anterior margin and end also in the supply 
of the ciliary processes. From the circulus major numerous branches take a 
convergent course in the depth of the stroma and anastomose so as to form 
another ring of communication near the pupillary margin, the circulus minor. 
Fig. 489.—Schema of Vessels at Different Depths, a, Vessels of the iris; b, of 
ciliary processes ; c, chorio-capillary vessels ; d, vena vorticosa ; e, long ciliary artery; f, f, 
anterior ciliary vessels and their communication through the sclerotic with the ciliary 
processes ; g, the cornea ; m, one of the recti muscles ; n, optic nerves and, in it, central 
artery of retina communicating with others ; s, episcleral anastomosis. (After Leber.) 
The nerves of the iris are the terminal branches of the ciliary nerves 
continued forwards after the giving off of the branches to the ciliary 
muscle and cornea. These nerves, after piercing the sclerotic, run forwards 
between the membrana fusca and the choroid, forming a circular series of 
about fifteen straight trunks which begin to break-up about a tenth of 
an inch from the ciliary muscle. They enter the iris at the periphery 
and form a copious plexus in its substance. 
Spaces connected, with the iris. The space between the cornea and 
the iris is named the anterior chamber. It owes its name to its having 
been formerly supposed that the iris hung free, with aqueous humour not THE EYEBALL. 
655 
only in front but also behind it in a space which was distinguished as 
the posterior chamber-, but such an arrangement only occurs as an unusual 
abnormality detectable by quivering of the iris from want of support. 
The pigmented epithelium on the posterior surface of the iris rests peri- 
pherally on the free tips of the ciliary processes which fit into the plications 
of the zonule of Zinn, while in its remaining extent it presses on the 
front of the capsule of the lens. The circular space bounded superficially 
by the sclerotic groove, and on the deep side by origins of the ciliary 
muscle and iris, is now generally termed the canal of Schlemm, but is 
undoubtedly the same as the broader canal seen in the ox and other 
animals, and long known as the canal of Fontana or sinus circularis iridis. 
The term spaces of Fontana has come into use to indicate a range of 
intervals between the fibres continued into the iris from the membrane 
of Descemet, which may be safely described as communicating with other 
intervals situated between the bundles of the ciliary muscle and giving 
a netted appearance to radial sections. 
The epithelium of the tunica media, named by Max Schultze the 
'pigmented layer of the retina, extends to the margin of the pupil. It is 
developed in connection with the tunica media, 
and not, as has been erroneously alleged, with 
the retina; for the retina is the invaginated 
part of the primary optic vesicle of the embryo, 
the choroid the uninvaginated part; and the 
pigmented epithelium, in contact from the first 
with the choroid, only comes into apposition 
with the retina at a period later than the 
appearance of the pigment. In its greater 
part, behind the ora serrata of the retina, the 
pigmented epithelium is a single layer, and 
the cells are hexagonal, each showing a clear 
nucleus and separated by a clear line from its neighbours. In the perfectly 
preserved condition present an outer part or base free 
from pigment, and a pigmented deep part prolonged into a multitude of 
fine thread-like processes dipping between the outer ends of the elements 
of the bacillary layer of the retina, especially when it has been exposed 
to bright light. In the choroidal part of its extent the pigment of the 
epithelium is most abundant at the back of the eye. In the lower animals it 
is absent from the epithelium over those places where the tapetum is present. 
In front of the ora serrata—namely, at the back of the orbiculus ciliaris, 
ciliary processes and iris—the epithelial cells are densely pigmented, close 
together, of lenticular form, and several layers deep; but the prominent 
ridges of the ciliary processes are usually left uncovered, and, in a bisected 
eyeball, shine through the vitreous humour as white rays. In some 
instances the orbiculus ciliaris is devoid of pigment, while pigment is present 
both in front of it and behind it. 
Fig. 490.—Hexagonal Corpuscles 
of Pigmented Epithelium, a, as 
seen from the surface; b, showing 
the contractile processes ; c, as seen 
completely in profile. 656 
ORGANS OF SPECIAL SENSE. 
Colour of the eye. In those individuals and families occasionally met 
with, called albinos, there is absence of pigment, not only from the hair, 
but also from the interior of the eyeball; and the iris is made pink by 
the colour of the blood circulating within it, while a pinkish light 
shines through the pupil from the blood in the membrane of Ruysch. In 
blue and grey eyes the colour is due to the pigmented epithelium forming 
a dark background to the unpigmented iris proper. The more delicate 
the tissue of the iris, the purer is the blue colour; and thus, as the iris 
gets thicker, the blue eye of the child is liable to become grey in after 
years. Whatever be the exact optical explanation of this, a similar pheno- 
menon is seen in the blue appearance of the sclerotic in many children, 
lost as the sclerotic becomes more dense. The different shades of hazel 
and brown eyes depend on the amount of pigment present in the stroma 
of the iris. This pigment is deposited in branched corpuscles and loose 
granules, and its special seat is in the fore parts of the stroma. 
The retina is an exceed- 
ingly delicate membrane, but 
is originally part of the em- 
bryonic brain, and remains in 
its full development a nerve- 
centre containing both nerve- 
fibres and nerve - corpuscles. 
It separates very easily from 
the coats superficial to it, 
save only at the optic pore or 
papilla, a slightly elevated 
spot situated one-tenth of an 
inch internal to the axis of 
the eye, where the fibres of 
the optic nerve pierce its outer 
strata and spread out on the 
surface turned toward the 
vitreous humour. It is trans- 
parent in the perfectly fresh 
condition, and of a pale pink 
colour, except in the central 
spot, the macula lutea, to be 
separately described. But 
when eyes are kept in the 
dark, and removed and exam- 
ined in sodium or magnesium 
lights, they exhibit a deep 
Fig. 491.—Schema of Elements or Retina. A, Special 
element: 1, bacillary layer, rods and cones; 2, outer 
nuclear layer; 3, outer molecular layer; 4, inner nuclear 
layer; 5, inner molecular layer; 6, ganglionic layer; 7, 
nerve-fibrous layer. B, Supportive elements : 1 and 7, ex- 
ternal and internal limiting membranes ; other numbers as 
in A ; the vertical structures between 1 and 7 are Muller’s 
fibres. (After Max Schultze.) 
purple colour owing to the presence of a substance called rhodopsin in 
the structures termed the rods. The rhodopsin, or visual purple, is rapidly 
destroyed by exposure to most kinds of light. More gradually the trans- THE EYE. 
657 
parent condition gives place after death to a milky white. The retina 
comes to an apparent margin in front, called ora sermta, placed about a 
tenth of an inch from the ciliary processes, and bounding the orbiculus 
ciliaris between. The ora serrata is in a continuous line in the ox, but 
in the human subject it is divided into numerous concavities separated 
by teeth. Beyond the ora serrata, a cubical unpigmented epithelium, 
continuous with the bacillary layer described below, lies behind the 
pigmented epithelium on the ciliary processes, and is called the ciliary part 
of the retina. Dr. Reid has displayed and photographed this layer behind 
the iris also. 
Excluding the pigmented epithelium, seven layers may be distinguished 
in the retina. The outermost forms in its development the lining of that 
part of the primary optic vesicle which is not lined by the pigmented 
epithelium, and it is called the bacillary layer. The other six are included 
between structureless external and internal limiting membranes, and consist 
of an outer nuclear layer, an outer molecular layer, an inner nuclear layer, 
an inner molecular layer, a ganglionic and a neuro-fibrous layer. These 
are held together by a considerable amount of delicate substance, con- 
stituting a connective framework between the external and internal limit- 
ing membranes, and giving, in vertical sections, an appearance of fibres, 
still known as Muller's fibres (Heinrich Muller), broadening out at their 
attachments to the limiting membranes. 
The bacillary layer, or visual epithelium, consists of vertically placed 
elements called rods and cones, both presenting an outer and an inner 
part: the outer part consisting of a highly refractive but perishable structure 
stained black by hyperosmic acid and resolvable into thin discs piled one 
on another; the inner part finely granular, of protoplasmic character, con- 
taining at its outer end an elliptical lens-like body, also said by some 
observers to contain a central thread. The inner part was found by Max 
Schultze to present fine grooves round about, separating apparent fibres 
which he traced on to the outer part, while, near the base, they were 
connected with a crown of fine threads coming up from the external 
limiting membrane. The rods are much the more numerous, and mostly 
about ■gjjo'tli inch long. Their outer or laminated portion is about half 
their total length and cylindrical, and their inner or basal portion is much 
the same shape. Their outer portion is the sole seat of the visual purple. 
The cones are shorter than the rods, the shortness depending principally 
on the outer portion, which is also narrower, especially at the apex, and 
is devoid of visual purple. But the inner or basal portion of the cone is 
considerably broader than that of the rod. Consequently, looked at from 
the surface, the ends of the rods are seen lying close together, while the 
broad bases of the cones appear as larger circles with the tip of the outer 
portion in their middle. In birds, reptiles and amphibians, the cones 
present at the outer end of the basal portion oily-looking globules of red 
and green colour. In amphibians the bacillary structures are of gigantic size. 
2 T 658 
ORGANS OF SPECIAL SENSE. 
The mode of action of the rods and cones is to a certain extent 
deducible from their structure. The discs of the laminated portions are 
suited for reflecting, from different depths, light striking at all obliquely, 
and such obliquity will result from passing through any other than the 
central point of the lens-like body. The rays, when reflected, will return 
by other courses than those by which they entered, and thus be diffused 
over different portions of the nerve-endings, whether these be in the 
centre of the basal elements or lodged in the grooves around. Vertical 
rays will, in the human eye, be absorbed by the pigmented epithelium 
behind, as will also such oblique rays as come in contact with the pig- 
mented threads around; but when a tapetum is present there is no pigment 
to absorb completely penetrating rays, nor to confine rays, either in pene- 
tration or reflection, to one rod or cone. 
No rod or cone can produce more than 
one sensation or spot of appreciated 
landscape, and therefore the greater the 
number in a given area the greater will 
be the fineness of vision. As all light 
has to traverse the thickness of the 
retina to reach the bacillary layer, it is 
obvious that the nerve-fibres are insensible 
to the direct action of light; and this is in 
accordance with the easily demonstrated 
blindness of the optic pore, the spot situ- 
ated one-tenth of an inch internal to the 
axis, where the nerve-fibres enter the 
retina, and where there is necessarily 
absence of visual epithelium. 
Fig. 492.—Diagram of connection be- 
tween Bacillary Elements and Ganglionic 
Corpuscles, a, Bacillary layer ; b, external 
granular layer; c, external plexiform; e, 
internal granular; f, internal plexiform ; g, 
ganglionic ; h, optic nerve layer; a, rods ; 
b, cones; c, granule of cone; d, granule of 
rod; e, bipolar corpuscle of rods; /, f, bi- 
polar corpuscles of cones; g, h, i, j, k, gang- 
lionic corpuscles ramifying in different 
strata of internal plexiform layer; r, r, 
inferior arborizations of bipolar corpuscles; 
s, centrifugal nerve-fibre; t, nucleus of 
Muller’s fibre (the latter looked on as epi- 
thelial) ; x, terminations of rod-fibres among 
ascending arborizations of bipolar corpuscles; 
2, contact of arborizations of cones and bi- 
polar corpuscles. (Cajal.) 
7 „ . ■■ , , 
Layer presents at first Sight little blit a 
The external nuclear or external granular 
close aggregation of oval bodies. On 
closer examination these are found to be 
placed on the course of perpendicular 
nerve-fibres, each continuous with a rod 
or cone, those going to the rods being 
particularly fine and liable to varicosity. The bodies attached to the cones 
are the larger, they are distinctly nucleated, and, save within the macula 
lutea, they are pressed up against them, immediately beneath the external 
limiting membrane. The bodies connected with the rods interrupt the fibres 
at a variable part of their course; they are oval, and, when fresh, show 
transverse striation, two or more less refractive lines forming bands in a 
denser substance. It is noticeable that near the ora serrata this layer 
diminishes gradually in thickness, while the rods appear to remain as 
numerous as elsewhere. 
The outer molecular or external plexiform or reticular layer is that in THE EYE 
659 
which the termination of fibres from the external and internal granular 
layers come into relation. In its superficial part, the rod-fibres are held 
by Cajal, in opposition to older statements and to Tartuferi and Dogiel, 
to end each in a spherule, several of which he represents surrounded by 
the arborization of a single bipolar corpuscle of the internal granular layer. 
In the deeper part, the cone-fibres give off branches which commingle 
each with the flattened arborization of a corresponding bipolar corpuscle. 
The internal nuclear or internal granular layer takes its most obvious 
character from the bipolar corpuscles just mentioned, whose superficial and 
deep poles pass respectively into the outer and inner plexiform layers. It 
contains also horizontal or subreticular cells, whose ramifications pass out 
into the external plexiform layer, mingling with the superficial arborizations 
of the bipolar corpuscles. Cajal divides them into large and small, both 
of them with peripheral branches, and with an axis-cylinder ending in an 
arborization. In like manner at its deeper part this layer presents spongio- 
blasts or ramifying cells devoid of axis-cylinders, whose branches descend 
into the internal plexiform layer. 
Fig. 493.—Connections ok the Horizontal Cells and the Spongioblasts of the 
Internal Nuclear Layer, a, b, Prolongations in (3) external nuclear layer from rods 
and cones; a, b, small and large horizontal cells ; c, horizontal cell with descending 
protoplasmic processes; d, e, flattened arborizations ; /, g, h, i, I, spongioblasts ramifying 
at different depths in (2) the internal plexiform layer; in, n, diffuse spongioblasts; o, 
bistratified ganglionic corpuscles. (Cajal.) 
The inner molecular or internal plexiform layer, like the external plexiform, 
is a stratum in which terminal ramifications of different corpuscles come 
into contiguity. Here the deep terminations from the bipolar corpuscles 
of the deep granular layer meet at five different levels expansions from 
ganglionic corpuscles of the following layer, and the spongioblasts also 
ramify in as many strata. 
The ganglionic layer presents large nerve-corpuscles, and is most largely 
developed at the back of the eye, where the corpuscles lie two or three 
deep, while in other places they are in one plane and, toward the ora 
serrata, are scattered. The corpuscles present each an axis-cylinder-pole 
continuous with a fibre of the neuro-fibrous layer, and usually several 660 
ORGANS OF SPECIAL SENSE. 
branching superficial poles coining off separately or from a common stem, 
and directed into the inner molecular layer to end at different depths. 
The neuro-fibrous layer lies between the nerve-corpuscles and the internal 
limiting membrane. The fibres of the optic nerve, before entering the 
retina, lose their medullary and primitive sheaths, and the naked ampullated 
axis-cylinders spread out in bundles radiating from the optic pore. Those 
passing outwards arch so as to avoid the macula lutea, which thus receives 
its nerve-fibres from its whole periphery. 
Fig. 494.—Ophthalmoscopic View of Centre of Retina, a, Optic papilla ; b, e, veins ; 
c, d, arteries; /, limit of apparent area of papilla; m, fovea centralis. (Beaunis after 
Galezowski.) 
The central artery of the retina, entering it in the centre of the fibres of 
the optic nerve, divides at once into branches, usually an upper and a 
lower, which, avoiding the macula lutea, spread out in the neuro-fibrous 
layer, and together with the nearly corresponding veins can be seen for 
some distance during life by means of the ophthalmoscope. They are 
alleged to be surrounded by perivascular lymphatic spaces (His). The 
capillaries reach no further outwards than the external molecular layer, 
the external nuclear being non-vascular. 
The macula lutea, or yellow spot of Soemmering, is situated in the axis 
of the eye, and is a transversely oval depression about T-th inch in 
diameter, rendered yellow by a diffuse staining in the vascular layers. 
In the centre there is an appearance of a perforation, fovea centralis, caused 
by the absence of those layers. In the macula lutea the cones are greatly 
increased in number, and in the fovea centralis they replace the rods 
altogether, at the same time that they attain the elongation of rods and 
become greatly narrower than elsewhere. The optic nerve-fibres, as already 
explained, consist only of those required for the macula itself, and even 
they are absent from the fovea centralis, as the nerve-fibres of the nuclear THE EYE. 
661 
layers slope obliquely to that spot. The ganglionic layer in the macula 
lutea has its corpuscles greatly increased in number, lying five or six 
deep, and with the protoplasmic poles reduced to one each; but in the 
fovea centralis the nerve-corpuscles are altogether absent. Also the inner 
nuclear layer is absent in the fovea centralis, and the outer nuclear layer 
shows one corpuscle for each cone, separated by a certain distance from 
the external limiting membrane. 
The fovea centralis receives images from an area of about quarter 
of an inch at ten inches from the eye, and it is easy to observe by fixing 
the eye on one letter in a line of print at that distance that this is the 
full extent of the most distinct vision. The accumulation of cones in the 
fovea centralis appears, therefore, to prove that they are more perfect 
structures than rods, while their smaller size here than elsewhere gives a 
greater number of separately recognizable points within a limited space.1 
Pig. 495.—Schema of Section* through Fovea Centralis and Macula Lutea. 1, 
Pigmented epithelium; 2, cones; 3, external limiting membrane; 4, external nuclear 
layer; 5, fibres of cones ;6, external plexiform layer ;7, internal nuclear layer ;8, internal 
plexiform layer; 9, ganglionic layer; 10, nerve-fibrous layer and internal limiting mem- 
brane. (After Max Schultze.) 
The transparent structures within the eyeball consist of the vitreous 
body, the crystalline lens and membranes which surround them so that 
they can be removed from the globe in one coherent mass. 
The vitreous body or vitreous humour fills up, together with the crystalline 
lens, the space surrounded by the three coats of the eye. It is a transparent 
substance, bright and colourless, which, when unsupported, alters its shape 
like a delicate jelly. It is surrounded by a closely adherent transparent 
and structureless hyaloid membrane, more tenacious than its internal sub- 
stance; and this is inseparably united in front with the capsule investing 
1 Obviously there is no separate communication between the brain and each rod 
or cone, and the brain cannot receive separate impressions from each. See Cleland, 
“Physical Relations of Consciousness,” Journal of Anatomy and Physiology, November, 
1870. Recent researches make the truth then put forward more abundantly evident. 662 
ORGANS OF SPECIAL SENSE. 
the lens, so that when the coats of the eye are removed three transparent 
structures remain in one connected mass. The posterior wall of this capsule 
is sunk in the vitreous humour so as to hollow it in front into a fossa 
patellar is. The vitreous body consists of solid and fluid 
constituents which can be distinguished by draining. 
It can be made opaque by hardening reagents, and can 
be kept nearly transparent in spirit by careful previous 
treatment with weak bichromate of potash. When 
hardened it tends, towards the circumference, to tear 
in concentric laminae, and it also tears easily in 
directions radiating from the axis of the eye. But 
only two definite structures have been found in it, 
namely, first, sparsely scattered amoeboid corpuscles 
with distinct clear nuclei, and the canal of Cloquet 
(verified by Stilling and Schwalbe), a straight channel 
about inch in breadth, extending from the optic 
pore to the back of the capsule of the lens, in the 
position of an ante-natal artery and communicating with 
the lymphatics of the optic nerve. 
Fig.496.—Four Elong- 
ated Cones from Cen- 
tral Spot, a, Pile of 
refractive discs ; b, basal 
parts of cone ; c, exter- 
nal limiting membrane ; 
d, corpuscle situated in 
the course of the fibre 
from the cone, (Schnltze.) 
The crystalline lens is a firm transparent structure, 
with a circular outline placed on edge, about one-third 
of an inch in diameter; and with an anterior and a 
posterior convex surface, the posterior the more pro- 
minent, and an axial thickness from before backwards 
of about a fifth of an inch. Neither surface is spherical; but in both the 
curve increases as it approaches the circumference. The lens is closely 
surrounded by a capsule, and on removal from this, soon begins to 
exhibit a concentrically laminated structure, each lamina breaking up into 
segments. The lines of fracture 
extend from the centres of the 
two surfaces, three on each. Those 
in front are directed, one upwards 
and the others at equal angles from 
it and from one another; while of 
those behind, one extends down- 
wards, and the others diverge in 
upward directions in the intervals 
between those in front. When by 
the weight of the lens resting on it 
one surface is kept from breaking 
Fig. 497.—Lens breaking up. A, Three lines ex 
tending from the central point in front, and the 
extremities of three alternating lines from the cen- 
tral point behind ; B, six segments separating in 
front and exposing the nucleus, in the case of a lens 
exposed on a flat surface. 
up, the other breaks into six. The outer laminae are less firm than 
those which they surround, and the density increases gradually till the 
centi’al part is reached, which is very firm and called the nucleus. Both 
laminae and nucleus consist of altogether peculiar fibres directed from 
before backwards, and each presenting in the young condition a nucleus THE EYE. 
663 
in front of the equator of the lens, which, however, in the adult 
lens has disappeared, except in the most superficial fibres. The fibres, 
broad in the middle, are attenuated in part of their extent. They are 
bound together by a cement which is specially abundant and granular 
in the lines where the laminae break up (though, indeed, this has been 
denied). Those in the heart present hexagons in tranverse sections, while 
those at the circumference are flattened. But the most characteristic 
feature is that the edges present each a single row of what are usually 
described as serrations, which are in reality (as I find both in the horse 
Fig. 498.—Lens-Fibres, a, Portion of 
fibre from lens of horse, completely iso- 
lated, and showing three of the rows of 
knobs; b, portions of fibres of lens of 
horse less completely isolated; c, separ- 
ated knobs as seen both in horse and in 
human subject; d, transverse section of 
fibres of human lens. 
Fig. 500.—Portion of Sus- 
pensory Ligament and 
Canal of Petit op Ox, f-, 
from specimen displayed in 
spirit, ab, Smooth hyaloid 
membrane ; be, attachment 
of zonular fibres; cd, plica- 
tions of hyaloid membrane 
with secondary plications to 
fit into secondary recesses 
between ridges of ciliary 
processes; de, suspensory 
ligament with crowded 
hollow processes; ef, hair- 
like passages injected from 
canal of Petit; g, anterior 
wall of capsule ; h, posterior 
wall of capsule ; i, section of 
canal of Petit. 
Fig. 499.—Human Lens and Suspensory Apparatus, 
■j. From preparation displayed in spirit, a, Canal of 
Petit; b, canal opened into ; c, suspensory fibres of its 
anterior wall; d, plicated hyaloid membrane with ad- 
herent pigmentary corpuscles. 
and the human subject) pedunculated knobs, the peduncles being often 
the only parts seen on account of the extremities being broken off and 
lying about. The uncompressed fibres have six rows of knobs. Steeping 
in muriatic acid is good for their display. The fibres rest behind in contact 
with the capsule; and in this situation fluid, “liquor Morgagniis liable 
to collect in drops after death. In front a single layer of squamous 
epithelium intervenes between the lens and the capsule; and at the 
circumference of the lens the cells of this epithelium are in series with 
short fibres, the latest additions to the structure of the lens itself. 
The capsule of the lens closely surrounds it and presents an anterior and 664 
OEGANS OF SPECIAL SENSE. 
a posterior wall, which, though both of them structureless, differ considerably 
in consistence. The anterior wall is thicker than the posterior and elastic 
to such an extent that when ruptured it causes, by its pressure, the lens 
to escape, while the ruptured edges turn inwards. The posterior wall 
when separated from the vitreous humour and ruptured does not curl 
inwards, being less distinctly elastic. It has the hyaloid membrane 
closely united with it. 
Suspensory apparatus and zonule of Zinn. When the vitreous body and 
the lens are removed together from the parts which inclose them, a circle 
of radiating plications is seen beyond the circumference of the lens, and 
to this circle it is usual to give the name zonule of Zinn. The plications 
fit in closely between and behind the ciliary processes, and there adheres to 
them a greater or smaller amount of the intervening pigmented epithelium. 
From the prominent margin of the fossa patellaris a structure exhibiting 
Homogeneous hyaloido-capsular membrane Fibrous suspensory ligament 
Corneal epithelium 
Anterior elastic lamina 
Cornea 
Membrane of Descemet 
J Simple squamous 
( epithelium 
Ligamentum pectinatum iridis 
Canal of Schlemm or Fontana | 
Ciliary muscle 
Iris 
j" Anterior wall of 
1 capsule of lens with 
( epithelium 
Ciliary process 
Conjunctiva 
Canal of Petit 
Sclerotic 
Choroid 
Retina 
Hyaloid ) 
membrane \ 
J Posterior wall of 
\ capsule of lens 
Fig. 501.—Section through Capsule of Lens, Suspensory Ligament and Canal of Petit. 
Vitreous body 
radiating fibres extends inwards to the circumference of the anterior wall 
of the capsule of the lens, and this is what is properly termed the 
suspensory ligament of the lens. If it be punctured, coloured injection can 
with the slightest pressure be made to fill a three-sided space behind it, 
which is limited centrally by the peripheral part of the posterior wall of 
the capsule of the lens, and posteriorly by the hyaloid membrane. This 
is the canal of Petit. This canal has not been alleged to have an 
endothelial lining; and, in point of fact, it is traversed by a certain 
amount of tissue allowed to be so delicate as to be easily destroyed in 
removal of the ciliary processes from the plications of the zonule. This 
delicate tissue is the so-called prismatic ligament, and has even been figured 
under the name of ligamentum suspensorium lentis, but is not comparable 
in tenacity with any of the three walls of the canal of Petit. 
The suspensory ligament proper, the anterior wall of the canal of Petit, 
has a much more complex structure than it has been credited with. 
Thick sections of the human eye, made by the writer, show distinctly THE EYE. 
665 
under the microscope a homogeneous hyaloido-capsular membrane behind 
the recognised suspensory or zonular fibres. But neither the suspensory 
ligament nor the canal of Petit can be completely studied by means of 
sections, especially very thin sections. If perfectly fresh eyes are treated 
with exceedingly weak bichromate of potash, to which spirit is afterwards 
added, the pigmented corpuscles and those of the ciliary part of the 
retina have their cement dissolved and allow the transparent structures, 
including the middle part of the zonular fibres, to separate easily from 
the recesses peripheral to the iris. It is then seen that the zonular fibres 
take rise from the hyaloid membrane beyond the fossa patellaris, and are 
inserted into the front of the capsule of the lens by flattened attachments. 
Successful injections display converging straight thread-like passages ex- 
tending from the canal of Petit a little way on the front of the capsule. 
The part of the suspensory ligament fastened in the fresh state to the 
recesses round the iris exhibits hollow prominences; and these have 
unpigmented corpuscles adherent to them which are probably the structures 
described as ciliary glands. 
Development of the Eye. 
The eye is developed partly from the brain and partly from the 
surface of the embyo; the retina and choroid being in fact portions of the 
brain and pia mater, while the lens is of cuticular origin, and the sclerotic, 
cornea, iris and vitreous body are derived from intervening mesoblast. 
Fig. 502.—Diagram of Development of Bye. a, Conjunctival epithelium; b, lens- 
fibres continuous with deepest epithelial layer; c, neck of primary optic vesicle; d, 
secondary optic vesicle; e, e, pia mater;/, g, choroid coat and the retinal artery both 
continued from the pia mater ; h, nervous substance continued into retina ; i, epithelium 
of ventricle continuous with pigmented epithelium ; k, epithelium of ventricle continuous 
with bacillary layer. 
The cerebral part of the eye is the earliest to appear, and begins in 
the chick at the end of the first day of hatching, in connection with the 
first cerebral vesicle, as a rounded lateral portion, the primary optic vesicle, 
nearly as large as the mesial portion or first vesicle proper, and separated 
from it by a partition which rises up from the ventral aspect and reaches 
back to the middle line at the constriction between the first and second 
cerebral vesicles, where it meets its fellows to form the anterior edge of 
the future optic commissure. Thus the vesicle becomes pedunculated, and 606 
ORGANS OF SPECIAL SENSE. 
the peduncle is the future optic nerve. Soon the primary optic vesicle and 
fore part of its peduncle become folded in, the lower and fore part of the 
vesicle being invaginated so as to come in contact with the upper and back 
part, and the edge of invagination becomes divided into a circular fore 
part and two retreating lower edges, which approach one to the other, 
so as to complete a cup, the secondary optic vesicle. At the same time 
that the primary optic vesicle is invaginated to form the cup of the 
secondary vesicle, a superficial depression appears opposite the mouth of the 
and 
Lens-epithelium. 
Lens-fibres. 
continuous at the 
\ J Continuous with 
( vitreous body 
Zone of proliferation 
Optic nerve 
Circle of invagination. 
Vitreous body. 
( Choroid and choroidal 
( epithelium 
Epidermis 
Retina 
Outicular and subcutaneous 
Pig. 503.—Section of Eye of Embryo Rat. The place of continuity of the retina 
and choroid at the invagination of the primary optic vesicle is seen. ("Preparation bv 
I)r. Mackay.) 
cup, and deepens to a pit which becomes constricted at the neck and 
closed off as a shut sac embedded in mesenchyma and lined with epithelium, 
to be converted into the lens; while from the mesenchyma are derived the 
vitreous humour, iris and outer coat of the eyeball. The pigmented 
epithelium appears in the chick toward the fourth day, and it then 
becomes evident that the non-invaginated portion of the wall of the primary 
optic vesicle is converted into choroid and pigmented epithelium, while the 
invaginated part is converted into retina. There is no development of 
brain-matter from the non-invaginated wall, and therefore the vessels and 
epithelium come in contact exactly as they do at the choroid plexuses of 
the brain; while the retina, being formed from the invaginated wall, has 
its originally superficial surface turned to the centre of the eyeball, has 
its vascular supply on that surface, and has the surface originally looking DEVELOPMENT OF THE EYE. 
667 
into the brain-cavity applied to the pigmented epithelium. The bacillary 
layer is late in developing, and is thought to proceed from the outer nuclear 
layer, which perfectly accords with the view that each rod or cone is part 
of the same corpuscle as the structure connected with it below the external 
limiting membrane. 
The lens becomes solid by the elongation of the cells lining the hinder 
half of its capsule, till they press against those of the anterior half, which 
remain permanently as epithelium. For a considerable time it occupies a large 
part of the cavity of the eye, is nearly spherical, and in close contact with 
the cornea which has intruded between it and the superficial epithelium. 
At the same time the retina is proportionally thick and the vitreous body 
small in amount. The fibres in the centre are long, and the new fibres 
are added at the circumference; and in antero-posterior sections the nuclei 
of the fibres form a broad belt with a convexity forwards, which is at first 
near the back, but afterwards toward the front. The capsule of the 
lens receives an artery, the hyaloid branch of the central artery of the 
retina, which extends from the optic pore to the middle of the posterior 
surface, and is connected with the tunica vasculosa at the circumference, 
whence vessels converge in front. In later development the whole eye 
expands, increasing the cavity behind the lens and forming the anterior 
chamber in front, while the connection between capsule of lens and tunica 
vasculosa stretches out as the iris. In the centre of the iris, the fore part 
of the vascular capsule of the lens, being continuous with it, occludes the 
future pupil, and is often called membrana pupillaris. These vascular arrange- 
ments disappear in the human foetus before birth, but in some animals—as 
in the kitten—persist for a short time after. 
The eyelids make their first appearance in the third month of foetal 
life. They afterwards become united together by cohesion of the epithelium 
on their edges, which continues till shortly before birth. The lachrymal 
ducts correspond in position with the lines of junction of the maxillary lobes 
and lateral nasal processes. They are originally superficial, and become 
deeper by the growth forwards of surrounding parts. 
THE EAR. 
The ear consists of three parts, called the external, middle and internal 
ear ; the external and middle ear being separated one from the other by 
the membrana tympani and both of them filled with air, while the internal 
ear, which contains the whole distribution of the auditory nerve, is filled 
with fluid. 
The External Ear. 
The external ear consists of the expanded part or pinna, and the tube 
leading down to the membrana tympani, the external auditory meatus. 
The cup of the pinna is called the concha, the pendent part is the lobule, 668 
ORGANS OF SPECIAL SENSE. 
and the incurved prominent margin starting in front of the concha and 
carried round from above to end behind at the base of the lobule is the 
helix. Between the hack of the concha and the helix there is a prominence 
called the antihelix, formed by folding of the supporting cartilage and 
bifurcated above. The depression between helix and antihelix is called 
the fossa of the helix, and that lying in the bifurcation of the antihelix 
is the fossa of the antihelix. In front of the meatus a prominence, often 
hairy, called tragus, projects backwards, while, behind it, another prominence, 
the antitragus, points forwards and upwards. The lobule consists of 
adipose tissue, in a firm stroma of white fibres, and is liable to considerable 
variation in form and size. The rest of the pinna is supported by cartilage. 
Pig. 504.—Cartilage and Muscles of External Ear. A, Outer aspect; B, cranial 
aspect; a, b, c, attrahens, attollens and retrahens auriculam muscles; d, concha; e, 
antihelix ;fr g, large and small muscle of helix; h, tragus and tragic muscle; i, anti- 
tragus and antitragic muscle ; k, the edge of the cartilage which is attached by fibrous 
tissue to the external auditory meatus of the temporal bone ; I, tragus from behind ; m, 
transverse muscle crossing the sulcus at the back of the antihelix; n, oblique muscle 
crossing sulcus at the back of the inferior branch of the antihelix. The lobule is repre- 
sented in dotted outline. 
The cartilage of the pinna presents in its texture an abundance of hyaline 
matrix threaded with networks of fibres mostly of yellow elastic character. 
It not only enters into the construction of the pinna, but also bounds 
the part of the meatus superficial to the external auditory process of the 
temporal bone, to which it is attached by fibrous tissue. It is a continuous 
sheet folded round the meatus, with one border at the anterior end of 
the helix, and the other looking upwards above the tragus, which is a 
projection of the free margin, as is also the antitragus. The cartilage 
presents in its unexpanded part two or three gaps, fissures of Santorini, 
placed transversely to the direction of the meatus. On the upper and 
back part of the edge of the helix there is often a small point or tubercle 
(Fig. 504, a) to which Darwin attracted attention, adopting the view sug- THE EXTERNAL EAR. 
669 
gested by Woolner the sculptor that it represented the tip of the ear in the 
lower animals. The inferior extremity of the cartilage of the helix is 
separated by a deep cleft from the upper edge of the antitragus. An 
anterior ligament extends from a tubercle on the front of the helix to the 
root of the zygoma; and a posterior ligament passes from a thickening 
at the back of the concha to the mastoid process; while the attrahens, 
retrahens and attollens auriculam muscles likewise attach the cartilage to 
the skull (p. 330). More minute collections of muscular fibres pass from 
one part of the cartilage to another, but are not constantly developed. 
They are; (1) the greater muscle of the helix, on the anterior convexity; 
(2) the smaller muscle of the helix, below the greater, and attaching the helix 
to the concha; (3 and 4) the tragic and antitragic, on the outer sides of 
the tragus and antitragus; (5) the transverse muscle, consisting of fibres 
bridging the concavity of the fold forming the antihelix ; and (6) the oblique, 
a smaller set of fibres bridging the concavity of the inferior division of 
the antihelix. 
The external auditory meatus or canal extends from the concha to the 
membrana tympani. It is walled in by the cartilage of the pinna in 
its superficial part and by the temporal bone more deeply. Its entrance as 
it leaves the concha under cover of the tragus has a forward inclination ; 
and immediately internal to the concha it turns transversely inwards, but 
immediately resumes a forward inclination, which it preserves in the rest 
of its extent. It is also sloped somewhat upwards from its commencement 
till within the bony canal, where it inclines downwards. Thus, the whole 
passage is straightened by pulling the pinna upwards and backwards; 
and when a speculum is introduced a certain distance, its outer end has 
to be raised to bring the membrana tympani into view. The integument 
lining the meatus becomes thinner and more sensitive in the osseous part. 
The cartilaginous part has few and ill-marked papillae. It is furnished 
with hairs which have an outward slope and are provided with sebaceous 
glands. But much more remarkable are the ceruminous glands which secrete 
the wax; they are of similar structure to the sudoriparous glands elsewhere,, 
but much larger. In the deep parts the hairs and glands disappear, and 
papillae are well marked and numerous. 
Arteries and nerves. The external ear receives branches from the 
posterior auricular, superficial temporal and internal maxillary arteries, 
and is supplied with nerves by the posterior auricular branch of the facial, 
the auriculo-temporal branch of the third division of the fifth, and the 
great auricular and small occipital nerves from the cervical plexus. 
The Middle Ear. 
The middle ear, the tympanum, presents principally for consideration 
the tympanic cavity, the ossicles with their muscles, and a mucous mem- 
brane ; and connected with it are the membrana tympani and the Eustachian 670 
ORGANS OF SPECIAL SENSE. 
tube. The tympanic cavity is a space measuring approximately one-eighth 
of an inch from without inwards, half an inch from above downwards, and 
three quarters of an inch in its longest diameter, which extends forwards and 
inwards. It is bounded internally by the pars petrosa of the temporal, is 
roofed mostly by the lamina of the pars petrosa called legmen tympani, and is 
floored by the tympanic plate. It communicates behind with the mastoid 
cellsand into the formation of its outer wall there enter the membrana 
tympani, the pars squamosa and the tympanic plate; while, in front, it 
narrows to the Eustachian orifice. The walls exhibit various points of 
interest. On the margin of the deep end of the external auditory meatus 
there is a distinct sharp-edged groove, absent only from the part above 
and in front, where there is a notch, the notch of Eivini, and the meatus 
is completed by the pars squamosa. In the inner tympanic wall there 
are two foramina. One of them, fenestra ovalis, is elongated transversely 
and is occluded in the recent state by the base of the stapes; the other, 
Mastoid 
antrum Fenestra ovalis 
Section through roof 
Processus cochleariformis 
Canal of tensor tympani 
of 
Eustachian tube 
Meatus auditorius 1 
externus J 
■Section of tympanic plate 
| Carotid canal 
Mastoid process \ 
N 
| Promontory 
Fenestra rotunda 
Groove of tympanic nerve 
Fig. 505.—Internal Wall of Tympanic Cavity. (Pansch.) 
Pyramid 
fenestra rotunda, placed below the fenestra ovalis and looking backwards 
and outwards, is occluded by membrane, the secondary membrane of the 
tympanum. Above and in front of the fenestra rotunda there is a con- 
vexity, the promontory, corresponding with the commencement of the cochlea. 
Above the fenestra ovalis the wall of the aqueduct of Fallopius projects 
as it passes backwards, after having crossed transversely outwards above 
and between the cochlea and vestibule. In the posterior wall of the 
tympanum the same tube turns outwards before descending to the stylo- 
mastoid foramen by a course in which it is no longer seen from the 
tympanic cavity of the dry bone. Above the aqueduct of Fallopius a 
large irregular recess, the mastoid antrum, leads back into the mastoid 
cells. This antrum exists before birth, though the mastoid process beneath 
it only becomes gradually swollen out in future years by cells lined with 
mucous membrane prolonged from the tympanum. On a level with the 
fenestra ovalis the posterior wall presents an elevation, the pyramid, with 
a perforation in its summit for the passage of the tendon of the stapedius THE MIDDLE EAR. 
671 
muscle; and when the bone at this part is laid open, the perforation is seen 
to lead into a more dilated space for the stapedius muscle, passing down 
in front of the aqueduct of Fallopius and communicating with it below. 
Immediately in front of this, in the young subject the root of the styloid 
process may be made out sheathed by a lamina derived from the pars 
petrosa, and superficial to the pyramid is a foramen leading from the 
aqueduct of Fallopius and giving passage to the chorda tympani nerve. 
The ossicles of the ear, three in number—the malleus, the incus and 
the stapes—are joined together so as to connect the memhrana tympani 
with the fenestra ovalis; and by swinging movements 
round a line joining two fixed points, one in front 
and the other behind, they regulate pressure on the 
internal ear, in harmony with the tension of the 
membrane. 
The malleus presents at its upper end a thick 
rounded head with an obliquely saddle shaped surface 
behind for synovial articulation with the incus, and 
is connected with the roof by a fold of mucous 
membrane which may contain fibres (ligamentum 
mallei superius). The head is supported on a neck 
(or body) connected by an external ligament to the 
outer wall above the membrana tyrapani • and from 
the front of the neck a long processus gracilis extends 
forwards to end in a thin flattened extremity em- 
bedded in fibrous tissue (ligamentum anterius) in the fissure of Glaser. 
Immediately below the processus gracilis, the malleus is thickened by 
a sudden projection outwards, the processus brevis, whose summit is the 
uppermost point of attachment to the membrana tympani; and thence it 
descends as a stout prolongation, the manubrium or handle, compressed 
from before backwards and ending in a knob which furnishes a centre of 
radiation for fibres of the membrana tympani. 
Fig. 506.—Tympanic Ossi- 
cles of Right Ear. a, Pro- 
cessus gracilis of malleus; 
b, posterior process of incus; 
the line ab is the axis of 
rotation. When c, the 
handle of the malleus, with 
fibres of the membrana tym- 
pani radiating from its ex- 
tremity, is pulled inwards 
by e, the tendon of the 
tensor tympani, the incus 
likewise rotates and pushes 
d, the stapes, in at the fenes- 
tra ovalis; /, tendon of 
stapedius. 
The incus, placed behind the malleus, presents on the front of its 
thickest part or body a saddle-shaped surface fitting to that of the malleus. 
It sends out two processes. One, the posterior process, is conical, and 
passes backwards to be attached at its extremity by ligamentous union in 
front of the descending part of the aqueduct of Fallopius. The other, 
the descending process, longer and cylindrical, is turned inwards abruptly 
at its extremity to end in an orbicular articular surface. This is the 
os orbiculare of some older anatomists, and articulates synovially with the 
head of the stapes. 
The stapes lies horizontally between the fenestra ovalis and the orbicu- 
lar extremity of the descending process of the incus. Its base is a plate 
fitting against the vestibular aspect of the margin of the fenestra ovalis, 
united to it by membrane or annular ligament, so that when the stapes 
is pushed by the incus the ligament is tightened and the contents of the 672 
ORGANS OF SPECIAL SENSE. 
internal ear pressed upon. The lower edge of the base is distinguished 
from the upper by a slight concavity. Two arched crura spring from the 
base, the hindermost somewhat more curved than the other, and then join 
to form a short neck supporting a disc-like head which articulates synovially 
with the incus. 
There are two distinct muscles in connection with the ossicles. The 
more important is the tensor tympani. It has a muscular belly fully half 
an inch long, lying beneath the adjacent margins of the sphenoid and pars 
petrosa, and resting on the cartilaginous part of the Eustachian tube, from 
which it principally arises. Its tendon enters the tympanum above the 
cochleariform process, and is held by that shelf of bone until opposite 
Fig. 507.—Diagram of the Right Ear. a, Osseous part of the canal of the external 
ear; 6, membrana tympani with the upper part removed ; c, malleus ; d, incus ; e, stapes 
with its base filling up the fenestra ovalis (the fenestra rotunda is seen a little lower); /, 
Eustachian tube ; g, tensor tympani muscle ; h, stapedius muscle ; i, i, the facial nerve 
divided ; k, mastoid cells ; I, to, vestibular and cochlear divisions of the auditory nerve ; 
n, vestibule ; o, cochlea. 
the malleus, when it turns abruptly outwards over the end of the bony 
shelf, and crosses the tympanic cavity to be inserted into the handle of 
the malleus near its root. It thus pulls the handle inwards, and makes 
tense the membrana tympani; but it ought to be noticed that its insertion 
so high up on the handle, while it diminishes its leverage to rotate, gives 
it an inward pull on the whole bar round which rotation takes place, 
extending from the tip of the posterior process of the incus to that of the 
processus gracilis. The other muscle, the stapedius, lies in the space already 
indicated within the pars mastoidea, and, passing upwards, ends in a 
tendon, which emerges at the foramen of the pyramid and passes forwards 
to be inserted into the neck of the stapes. It is calculated, by contracting 
when the action of the tensor tympani is extreme, to relieve pressure on THE MIDDLE EAR. 
673 
the internal ear by producing an oblique position in which only the posterior 
fibres of the annular ligament will be tightened, while anteriorly the base 
of the stapes is pressed against the vestibular side of the wall of the fenestra. 
The mucous membrane of the tympanum is prolonged from the pharynx 
through the Eustachian tube, and extends back to line the mastoid cells. 
Its folds are not quite constant in their arrangement. It surrounds 
cylindrically the stapes and lower end of the descending process of the 
incus. Above the incus it is prolonged from behind on the outer wall 
of the tympanum to the malleus, forming the boundary of a posterior 
fossa. It also connects the posterior or short process of the incus, 
together with the chorda tympani nerve, to the outer wall. In front of 
the head of the malleus the chorda tympani and processus gracilis of the 
malleus are connected by a fold to the outer wall; and above this is the 
anterior fossa, separated from the posterior by the superior and external 
ligaments of the malleus. A small recess between the external ligament 
and the short process of the malleus is called Eussac’s space, and lies 
opposite the portion of the membrana tympani in the notch of Rivini. 
In structure the mucous membrane is very thin, and for the most part it 
is closely connected with the periosteum. It is lined with columnar 
ciliated epithelium on the floor and internal wall; but this is changed for 
a single layer of squamous cells on the tympanic membrane. The mucous 
membrane of the middle ear is supplied by Jacobson’s nerve, the tympanic 
branch of the glosso-pharyngeal. 
-Mastoid antrum 
Notch of Rivini 
-Head of malleus 
-Short process of incus 
Umbo 
Chorda tympani 
-Surface for stapes 
Fig. 508.—Bight Membbana Tympani. -f. A, From outside. B, From within, with 
malleus and incus in situ. 
The membrana tympani separates the middle from the external ear. It 
is attached to the inner extremity of the meatus auditorius externus, and 
lies obliquety to it, its inferior edge being nearer the mesial plane than 
the superior, and the anterior nearer than the posterior; so that the lower 
and anterior part forms an acute angle with the floor of the meatus, and 
the upper and posterior part an obtuse angle with its roof. Below the 
middle, it presents an umbo or apex of a shallow cone, directed inwards, 
corresponding in position with the tip of the handle of the malleus, 
and sometimes in the living subject permitting indications of the form of 
that structure to be, seen. Above, in the notch of Rivini, there is a little 674 
ORGANS OF SPECIAL SENSE. 
depressed and slack portion, the membrana flaccida of Shrapnell. The 
membrana tympani consists of three layers—namely, the proper fibrous 
membrane, an outer covering from the integument, and an inner covering 
of mucous membrane. The fibrous layer consists principally of fibres 
radiating from the tip of the handle of the malleus; but toward the cir- 
cumference these have been found to be crossed on their tympanic side 
by thin annular fibres. Attention does not seem to have been directed 
to the fact that the circular groove of the tympanic plate is mainly occupied 
by a strong ring of fibres, and that it is this ring which is continued across 
the notch of Eivini and separates the membrana flaccida from the rest of 
the membrane. The tegumentary covering is thin and destitute of papillae. 
The handle of the malleus, from the processus brevis to near the tip, is 
between the mucous layer and the fibrous, its periosteum being closely 
united to the latter; and close to the sides of this line of union there is 
greater vascularity of the mucous membrane than elsewhere. 
Cut surface of septum nasi 
Middle meatus 
-Middle concha 
.Maxillary sinus 
Temporal muscle 
Mouth of left Eustachian ) 
tube (" 
.External pterygoid 
.Lower jaw 
Inner wall of right") 
Eustachian tube V 
laid open J 
.Tensor palati 
internal pterygoid 
j Internal maxillary 
' 1 artery 
.Levator palati 
.Pharyngeal recess 
Rectus capitis » 
anticus major j 
External carotid 
Internal carotid 
Atlas 
. Odontoid process 
Fig. 509.—Horizontal Section of Nasal Fossae and Pharynx showing relations of 
Eustachian tube. 
The Eustachian tube is an inch or more long, and leads from the 
tympanum to the pharynx. It begins in the lower division of the 
Eustachian orifice of the temporal bone, which is lined with thin raucous 
membrane, and is known as the osseous part of the tube. The whole 
of the rest is called the cartilaginous part, and is walled above and internally 
by cartilage, which is also folded for a short distance down on the outer 
side, while the floor and the greater part of the outer wall are formed of THE MIDDLE EAR 
675 
fibrous membrane. Occupying the petro-sphenoidal groove, the roof of 
the tube, as it passes forwards, dips downwards from the base of the skull, 
and in its whole course the cartilaginous inner or posterior wall lies 
alongside of the outer wall of the pharynx, so as to permit of a horizontal 
section being made showing the recessus pharyngeus and Eustachian tube 
(which are the persistent hypoblastic portions of the first and second 
visceral clefts of the embryo) lying one close behind the other. The tube 
rapidly increases in depth and ends in the pharynx by an expanded opening, 
whence the old name salpinx. The expanded opening lies above the soft 
palate and behind the inferior meatus of the nose; it has a prominent 
internal or posterior margin and an angular roof, both stiffened by the 
thickened and elongated edge of the cartilage, which is here from a third 
to half an inch in height. Anteriorly the opening is smoothly continuous 
with the inferior meatus of the nose, and interiorly it presents a convex 
floor continuous with the upper surface of the velum (Eig. 471). Con- 
sequently, a sound or catheter curved at the end, when introduced into 
the nose with the point downwards, has only to be carried back till it 
ceases to be supported by the hard palate, then turned so as to direct 
the point outwards, when it will slip into the Eustachian tube, avoiding 
with certainty the pharyngeal recess (fossa of Rosenm filler). The convexity 
of the floor of the opening is caused by the levator palati muscle, which, 
arising tendinously from the process between the Eustachian orifice, of the 
temporal bone and the carotid canal, occupies a gradually widening groove 
formed by the floor of the tube all the way forwards (Fig. 277). The 
tensor palati is another muscle closely connected with the tube, inasmuch 
as it has fibres of origin from the whole length of the edge of the cartilage 
in the outer wall. Also, the salpingo-pharnygeus, when present, descends 
from the lower end of the edge of cartilage forming the inner lip of the 
pharyngeal opening. It is certain that all three muscles are contracted in 
the act of swallowing, and that the levator palati by increase of thickness 
during contraction raises the floor of the tube, while the tensor palati and 
salpingo-pharyngeus pull the edges of the cartilage downwards. Thus the 
shape of the tube is certainly altered in swallowing, but there is difference 
of opinion as to whether the alteration has a dosing or opening effect, 
though the anatomical facts make it evident that any dilating influence of 
the tensor palati is exercised on the hinder and smaller part of the tube, 
while the levator closes the anterior orifice (Cleland, 1868). The lining 
epithelium of the mucous membrane is stratified columnar ciliated, which 
indicates that in ordinary circumstances the walls are sufficiently separate 
to allow of ciliary currents. 
The Internal Ear. 
The internal ear or labyrinth consists of a complex cavity situated within 
the petrous part of the temporal bone, and of membranous structures within 
it. The cavitv is called the osseous, the continued structures the mem- 676 
ORGANS OF SPECIAL SENSE. 
branous labyrinth ; and each is divided into two parts, the vestibule and 
the cochlea, the division being situated opposite the internal auditory 
meatus, whose cribriform plate abuts against the vestibule posteriorly, and 
against the cochlea in front. The osseous labyrinth is lined with periosteum, 
and the fluid between the periosteum and the membranous labyrinth is 
called perilymph. The membranous labyrinth is lined with epithelium, and 
the fluid contained within it is distinguished topographically as endolymph. 
Fenestra ovalis Superior semicircular canal 
\ Ampulla of external semicircular 
( canal 
Fenestra rotunda Ampulla Posterior semicircular canal 
The vestibule. The osseous vestibule consists of a cavity and three semi- 
circular canals. The vestibular cavity has the fenestra ovalis in its outer 
wall, and communicates with the cochlea below and in front; the lower 
part of the communication being hollowed into a depression, recessus 
cochleae, internal to the fenestra rotunda. On its inner side in front 
is a depression, fovea hemispherica, corresponding with the cribriform plate 
of the internal meatus and separated by a crest (crista vestibuli) from 
a more elongated concavity, fovea hemielliptica, which involves the roof 
and internally receives the aqueductus vestibuli. Posteriorly it com- 
municates with the semicircular canals. The three semicircular canals are 
one superior, another posterior, and the third external. The superior canal 
is an upright arch at right angles to the length of the petrous portion 
of the temporal, and the top of this arch is indicated on the upper surface 
of the bone by an elevation. The posterior canal lies close to the posterior 
surface of the bone, beneath which it can be seen in the young subject; 
and at its upper end it is joined to the superior canal by a short part 
common to both. The external canal is free at both ends from the others, 
is shorter than either of them, and is horizontal and deeply placed. Each 
canal has a bulbous swelling, the ampulla, at one end, and this, in the 
superior and external canals, is situated at their outer ends, and in the 
posterior at the lower end. 
Fig. 510.—Cast of Left Osseous Labyrinth, External Aspect. (Pansch.) 
The membranous vestibule differs from the osseous in respect that, con- 
tained within the vestibular cavity there are two membranous vesicles, the 
utricle and the saccule. The utricle is the posterior and larger of the two 
vesicles, is broad from side to side and flattened from before backwards, 
and lies beneath the fovea hemielliptica. It receives the fine extremities 
of three membranous semicircular canals corresponding with the osseous 
semicircular canals in disposition and in each having an ampulla at one end. THE INTERNAL EAR. 
677 
The saccule, in front of the utricle, and smaller than it, is flattened from 
above downwards, and is circular as seen from above. It is separated 
from the utricle by a simple septum of small extent, and it communicates 
Fig. 511.—Diagram of Membranous Labyrinth, a, Canalis cochlearis; 6, ampulla; 
c, sacculus; d, canalis reunions ; e, utriculus ;/, sacculus endolymphaticus. (Pansch.) 
with the canalis cochleae by a small duct, canalis reuniens. From saccule 
and utricle two other minute ducts pass back and unite at the commence- 
Fig. 513.—Transverse Section of Crista 
Acustica of Foetal Rat. a, Semicircular 
canal; b, crista ; o, nervous bundle continued 
by bipolar cells ; d, small nervous bundle 
ending in the upper part of the semi- 
circular canal; a, bipolar epithelial cell; 6, 
c, other epithelial cells. (Cajal.) 
Fig. 512.—Auditory Cells, elongated epithelial cells and 
nerve-endings from macula acustica utriculi of child at hirth. 
(After Retzius.) 
ment of the aquaeductus vestibuli, to form a single ductus endolymphhaticus, 
which dilates beneath the periosteum into a small vesicle, sacculus 
endolymphaticus (Bottcher), interesting as, together with the canalis 
reuniens, completing the continuity of the whole cavity of the membranous ORGANS OF SPECIAL SENSE. 
labyrinth. The membranous vestibule presents, throughout, three walls, 
an outer or fibrous which is notably vascular, a structureless membrana 
propria, and an epithelium which is simple squamous except in the parts 
in which the auditory nerve terminates. The parts of the vestibule to 
which the nerve is distributed are five, namely, the macula acustica of 
the utricle, a smaller macula acustica of the saccule, and a crista acustica 
in the ampulla of each semicircular canal; and to each of these a separate 
bundle of nerve-fibres proceeds. The maculae acusticae are two patches 
marked by thickening on the lower parts of their respective vesicles, while 
the cristae acusticae are semilunar folds, one projecting inwards transversely 
in each ampulla. In all the five spots the epithelium is cylindrical, and 
presents auditory cells with hair-like processes projecting from the free 
extremity, while intermingled with them are elongated epithelial cells 
Pig. 514.—Section of Cochlea of Pig at Birth, a, Canalis cochleae; h, scala tym- 
pani; c, scala vestibuli; d, basilar membrane and organ of Corti; e, membrane of 
Reissner ;/, spiral ganglion. (Reichert.) 
branched at their deep extremities and without hair-like processes. The 
auditory or hair-cells receive fine branches from nerve-fibres which lose 
their medullary sheaths as they pierce the membrana propria and spread 
out in other fine branches between them. On the surface of the auditory 
epithelium there is in each of the five patches a number of minute 
crystals of carbonate of lime (otoconia), and, superficial to the jelly in 
which these lie, an appearance of a membrane. The utricle and saccule 
lie nearer to the inner than the outer wall of the vestibule, and the 
membranous semicircular canals adhere to the convex sides of the arches 
of the osseous tubes containing them. 
The cochlea. The osseous cochlea is a tube starting from the lower and 
fore part of the vestibule, and coiled spirally in the form of a snailVshelb 
It begins at the fenestra rotunda and has the centre of the base of its 
spiral opposite the anterior part of the cribriform plate of the internal 
auditory meatus, while its apex or cupola abuts against the tympanum at THE INTERNAL EAR 
679 
the commencement of the Eustachian tube, and the carotid canal is 
beneath it. The tube is about inch wide at its commencement and 
about half that width at the apex. The pillar of bone in the centre of 
the spiral is termed the modiolus-, and from this there projects at right 
angles a spiral flange, lamina spiralis, extending into the tube along its 
whole length, but diminishing in breadth more rapidly than does the 
tube. It begins at the inner margin of the recessus cochleae in the floor 
of the vestibule, and ends at the cupola in a hook-like process, the hamulus. 
The modiolus is hollowed by canals containing the cochlear branches of 
the auditory nerve and internal auditory artery. The nerve-canals are 
united opposite the attachment of the lamina spiralis by a spiral canal for 
a spiral ganglion, and the branches of both vessels and nerves escape by 
a range of openings beneath the edge of the lamina spiralis. 
Within the osseous tube there is a lining of periosteum continuous with 
that of the vestibule, and attached to it centrally and peripherally is the 
cochlear part of the membranous labyrinth, commonly called the canalis cochleae. 
The canalis cochleae is attached centrally to the lamina spiralis, and 
peripherally to a strip of the circumferent wall, and between these attached 
parts it is bounded by two membranes, called respectively the basilar 
membrane and the membrane of Meissner. The basilar membrane (together 
with the limbus to be afterwards described) separates it from a passage 
containing perilymph, the scala tympani; and the membrane of Reissner 
separates it from a similar passage, the scala vestibuli. At the base of the 
cochlea it presents a round cul-de-sac beyond the point where it receives 
the narrow canalis reunions, and it is attached to the margin of the recessus 
cochleae so as to cut off the commencement of the scala tympani, and with it 
the fenestra rotunda, from the vestibule; but at the cupola there is a small 
space, helicotrema, inch across, between the end of the osseous tube, 
the hamulus and the blind end of the canalis cochleae ; and here the scala 
tympani is continuous with the scala vestibuli which at the other end 
opens into the cavity of the vestibule 
above the canalis cochleae. Thus, the 
secondary membrana tympani closing 
the fenestra rotunda looks into a 
passage, the scala tympani, which 
only communicates with the vestibule 
circuitously by the helicotrema and 
scala vestibuli. 
The osseous lamina spiralis is pro- 
longed outwards by a thickening of 
non-calcified substance, the limbus, 
which on the side next the scala tympani extends in a direct plane 
into the basilar membrane, but on the other rises into a convexity, 
the crista spiralis, covered with tooth-like processes, the outermost of 
which project as a lip, the labium vestibulare, overhanging a groove, sulcus 
Fig. 515.—At the Summit of the Lamina 
Spiralis, a, Helicotrema; b, hamulus ; c, crista 
spiralis; d, papilla spiralis; e, outer edge of 
basilar membrane. 680 
ORGANS OF SPECIAL SENSE. 
spiralis, which separates it from the labium tympanicum or part continuous 
with the basilar membrane. At the inner edge of the crista Reissner’s 
membrane is attached, which is a delicate structure consisting of a 
fine layer of connective tissue and a simple squamous epithelium. 
The basilar membrane is stronger than the membrane of Reissner, and 
is transversely striated, being formed of fibres passing outwards to be 
attached to a structure lining the wall in a considerable breadth of both 
scalae, and usually called the spiral ligament, though described originally 
by Bowman as muscular, and admitted to be rich in spindle-shaped nucleated 
corpuscles. In consequence of the rapid diminution of breadth of the lamina 
spiralis, the basilar membrane is somewhat wider at the cupola than at 
the base. On the surface of the basilar membrane the epithelium of the 
canalis cochleae is modified to form a highly complicated structure, named 
from its discoverer organ of Corti. In the description of this I shall be 
guided to a great extent by Schwalbe. 
Pig. 51G.—Organ of Cokti in Vf.etioal Section, a, Cells of Claudius over cochlear 
ligament (Bowman’s muscle); 6, basilar membrane; c, outer support-cells (cells of 
Deiters); d, outer auditory hairs ; e, lining of scala tympani; f, outer rods ; g, membrana 
tectoria (Corti’s membrane); h, inner support-cells; i, sulcus spiralis; k, labium 
vestibulare ; m, outer auditory cells ; n, nerve-fibres passing to them ; o, inner rod ; p, 
simple epithelium of sulcus spiralis; q, medullated nerves. (Bohm and v. Davidoff, 
after Betzius.) 
The most prominent part of the organ of Corti is a strip of uniform 
breadth, the papilla spiralis-, and between this and the free edge of the 
labium vestibulare of the limbus there is a strip, likewise of uniform 
breadth, in which the nerves pass obliquely up and enter the canal by 
a range of foramina counted by Kolliker as lying on the basilar membrane, 
but considered by Henle and more recent observers as belonging to the 
limbus. The foundation of the papilla spiralis is an outer and an inner 
row of strap-like structures called rods of Corti, which are specially developed 
epithelial elements of the deepest layer, and are of such breadth that three 
of the inner row are rather narrower than two of the outer. These are 
attached by thicker footplates to the basilar membrane, and, rising up, incline 
one to the other so as to include a roofed space or tunnel, and are then 
folded over and continued into headplates directed outwards, so that those 
of the inner rods bend over those of the outer rods and those of the outer 
rods fit into the hollow of the heads of the inner rods. On the inner or THE INTEENAL EAR 
681 
modiolar side of the rods of Corti a simple epithelium lines the sulcus 
spiralis, and is prolonged outwards. Where it abuts against the inner rods 
the cells become elongated and arranged in more than one stratum. The 
outermost row of those placed superficially have free extremities lying 
close to the headplates of the rods, and each carry a row of short, straight 
hair-like processes. They are called the inner auditory cells. External to 
the outer rods the epithelial structures are more elongated, presenting in 
the basal turn three, and in the others four rows of outer auditory cells, 
separated and supported by other cells of elongated form, cells of Deiters, which 
are broad beneath them, and prolonged between them as narrow pillars. 
The outer auditory cells have straight hair-like processes arranged on the 
summit of each in a single curved line. Between the summits of the inner- 
most row, elongated squamous processes extend from the headplates of the 
Pig. 517.—View of Surface of Organ of Corti in Child at Birth, a, Epithelium of 
membrane of Reissner turned over ;b, its attachment; c, epithelium of limbus :d, labium 
vestibulare : /, sulcus spiralis ; g, inner support-cells ; h, inner auditory cells ; i, k, ends of 
rods; I, outer auditory cells ; m, phalanges ; n, outer cells of membrana reticularis; o, 
cells of Hensen ;p, cells of Claudius. (Bohm and v. Davidoff, after Retzius.) 
outer rods; and other squamous plates, phalanges, fit in between the 
extremities of these processes, and are interposed between the auditory 
cells of the second row, while another row similarly fits in between the 
ends of the first phalanges and separates the third row of auditory cells 
one from another. These phalanges are connected with the summits of 
the cells of Deiters, but are separable from them at the same time that 
they retain their connection one with another so as to form the membrana 
reticularis, w'hich is continued out into an unbroken layer of cells {of Hensen) 
composing the outer limit of the papilla spiralis. Beyond this the part 
of the basilar membrane uncovered by the papilla spiralis has a simple 
epithelium of large cubical cells (of Claudius). 
The whole papilla spiralis is covered over by a remarkable membrane 
called membrane of Corti (membrana tectoria), which lies free in the canalis 
cochleae. It is attached to the crista spiralis close to the membrane of 
Reissner, and is free externally, arching over the organ of Corti, but slightly 
curled upwards at the margin, and presents no structure save a distinct 
oblique striation. 
The nerves of the cochlea are arranged in the canals of the modiolus in 682 
ORGANS OF SPECIAL SENSE. 
a roll whose turnings correspond with those of the tube, those for the cupola 
being in the centre; and, reaching the spiral canal, they enter at the spiral 
ganglion. This ganglion consists of bipolar cells interrupting the nerve- 
fibres. Emerging from this, the nerve-bundles pass obliquely through the 
limbus, flattened at first, but becoming cylindrical where they perforate. 
There they lose their medullary sheaths, and, as varicose axis-cylinders, 
are prolonged both to the inner and outer parts of the papilla, and in 
longitudinal directions beneath the rods of Corti; but further observation 
is desirable as to their precise method of distribution to the auditory cells. 
The arteries are branches of the internal auditory, and while in the 
modiolus form a spiral row of convolutions, glomeruli arteriosi of Schwalbe, 
and supply also the spiral ganglion. The returning blood is gathered to 
a spiral vein opposite the scala tympani. A network of vessels surrounds 
the whole tube, but is much closer than elsewhere on the outer wall of the 
canalis cochleae, internal to the spiral ligament, and in this a vessel has 
been described as running spirally, the vas prominens. Also vessels pass 
out into the limbus and the basilar membrane, and one running along 
beneath the papilla spiralis has been described as vas spirale. But the 
outer part of the basilar membrane is non-vascular. 
Development of the Ear. 
The external, middle and internal ear are in great measure developed 
independently. The internal ear takes origin from the pit 
(p. 98), which, after closure, is called the otic vesicle, whose place of entrance 
into the cranium becomes lost to view, save in elasmobranch fishes, 
where in the adult it pierces the roof. The vesicle presents a neck and a 
sac. The lower part of the sac is converted into cochlea and the upper 
part into vestibule and semicircular canals, while it is alleged that the 
neck remains as the endolymphatic sac and duct, though further investiga- 
tion is desirable both on this subject and on the origin of the semicircular 
canals. The formation of the canalis cochleae by retreat of the basilar 
membrane and membrane of Reissner from the osseous wall was pointed 
out many years ago by Huschke. W. His, Jun., finds at an early date a 
ganglion not confined to the formation of the spiral ganglion of the cochlea, 
but going to all the parts of the labyrinth which afterwards receive nerve- 
terminations, and including cells in connection with the facial nerve to form 
the geniculate ganglion. 
The tympanic cavity has been already stated (p. 98) to be the hypo- 
blastic part of the first branchial cleft, while the external meatus is the 
epiblastic part of the same, and the membrana tympani is in the position 
where epiblast and hypoblast meet in this cleft in the embryo. The 
origin of the ossicles has been already mentioned (p. 246). The expanded 
part of the pinna makes its appearance before the closure of the vertebral 
end of the first branchial cleft, in the form of a series of definite prominences 
behind, above and in front of the cleft. THE VISCERAL CAVITY. 
683 
VISCERA. 
THE VISCERAL CAVITY. 
Having regard to the skeleton, the body may be said to present two 
great cavities, the neural and the visceral. 
The neural cavity contains the great centre of the nervous system, 
the cerebro-spinal axis, and is divisible into two parts, namely, first, the 
cranial cavity, expanded and irregular in form, containing the likewise 
expanded and irregular encephalon, and, secondly, the regularly segmented 
spinal canal containing the regularly constructed spinal cord. The neural 
cavity originates in the early embryo from the medullary groove, which 
becomes closed in by the meeting of the medullary folds in the middle line 
(p. 90), and is specially characteristic of the vertebrata. 
Pig. 518.—Peritoneal Membrane denuded of Endothelium, showing capillaries, 
nucleated single nerve-fibres and amoeboid corpuscles. The capillaries contain blood. 
Photographed from carmine preparation. 
The visceral cavity, in the widest sense of the term, is the space 
occupied by viscera, and bounded more or less completely by skeletal and 
muscular walls, and exists not only in the thorax, abdomen and pelvis, 
but also in the head and neck as well; the pharynx, oesophagus, tongue, 
larynx, trachea and thyroid body being all developed in connection with 
the same mucous membrane as lines the abdominal part of the alimentary 
canal. The term visceral cavity is, however, more frequently used in a 
more restricted sense, and applied to the thorax, abdomen and pelvis, 
the regions characterized by containing large serous membranes. Not 
only are these membranes embryologically derived from a single pleuro- 
peritoneal sac or coelom, corresponding with the coelom or body-cavity of 
invertebrate animals, but the coelom is, in early embryonic life, found 
even in the head, in at least elasmobranch fishes (p. 93). In further 
development the common sac undergoes subdivision, the pericardium and 
the two pleural sacs being completely separated from the peritoneum, 684 
VISCERA. 
and, in the male of the human species, two other small portions being 
likewise closed off, namely, the tunicae vaginales which cover the testes. 
All the divisions are transparent membranes with delicate simple squamous 
covering. They have a vascular network proper to them, are supplied 
with nerves (Fig. 518), and become painful when inflamed. In man, as in 
all mammals, the visceral cavity is completely divided by the diaphragm 
into a thoracic cavity containing the heart and lungs covered respectively 
with pericardium and pleurae, and the abdominal cavity lined with peri- 
toneum and extending into the pelvis. 
(A) The Thoracic Cavity 
The thoracic cavity is mainly occupied by the heart and lungs, each 
with its own serous sac. Those of the lungs are termed the pleurae, and 
Fig. 519.—Frontal Section of Frozen Body of Female of 40 Years. 1, 2, Lungs ;3, 4, 
costo-phrenic spaces ; 5, left ventricle ; 6, aortic cusp of mitral valve; 7, right auricle; 8, 
aorta; 9, innominate artery; 10, left common carotid; 11, vena cava inferior; 12, vena 
cava superior; 13, pulmonary artery ; 14, trachea ; 15, diaphragm ; 16, liver ; 17, stomach ; 
18, spleen; 19, pancreas ; 20, loops of small intestine ; 21, descending colon. (Luschka.) 
that of the heart is, together with an investing fibrous pouch, called the 
pericardium. To the interval between the two pleurae the name mediastinum 
is given, and it is occupied in its principal part (the middle mediastinum) 
by the pericardium and its contents, as well as great bloodvessels and the 
bifurcating trachea, while superficial to it the anterior mediastinum is dis- THE THORACIC CAVITY. 
685 
tinguished, and behind is the posterior mediastinum, in which the oesophagus 
is placed. 
The pericardium consists of two membranes, a fibrous and a serous. 
The fibrous pericardium is a strong white fibrous bag, widest below, where 
it is attached to the central tendon of the diaphragm, in front and behind 
to its margin, and on the right side external to the opening for the vena 
cava inferior, while on the left side it encroaches on the muscular fibres. 
Superiorly it is connected with the outlets of the pulmonary veins, and 
Fig. 520.—Sagittal Section of Thorax and Epigastrium of Frozen Body of Infant 
1J years old. 1, 2, 3, Sternum ; 4, 5, diaphragm ; 6, its central tendon ; 7, right lung 
crossing the mesial plane ;8, thymus ; 9,10, trachea and left bronchus ; 11, 12, oesophagus 
and aorta in posterior mediastinum ; 13, pericardium ; 14, right auricular appendix ; 15, 
left auricular cavity ; 16, right ventricle ; 17, ascending aorta; 18, right pulmonary artery; 
19, left innominate vein; 20, innominate artery; 21, liver; 22, pancreas ; 23, stomach. 
(Luschka.) 
also with the vena cava superior and the pulmonary artery, but its strongest 
fibres are prolonged high on the front of the ascending aorta. The serous 
pericardium presents a parietal and a cardiac part. The parietal part clothes 
the tendinous surface of the diaphragm, and lines the fibrous pericardium. 
The cardiac part is continuous with the parietal by two distinct folds, one 
of which invests the ascending aorta and the pulmonary artery in a tubular 
sheath, while the other, behind, separated from the arterial sheath by a 
passage called the transverse sinus, is connected with the great veins and 
with the auricles, namely, with the right edge of the right auricle between 
the superior and the inferior vena cava, and with the upper edge of the 
left auricle between the right and left superior pulmonary veins, as has 
been more particularly described at p. 409. 686 
VISCERA. 
The pleurae present each a parietal and a pulmonary part. The pul- 
monary part closely invests the lung, and dips in between the principal 
lobes, the three of the right, the two of the left. It surrounds the root 
of the lung, lying in contact with it above, behind and in front, but 
forming below it a fold with an anterior and posterior layer, ligamentum 
latum pulmonis, reaching down towards the diaphragm, and attaching the 
inner surface of the lung to the pericardium. Although thin, the pleura is 
capable of being separated continuously from the surface of the lung. It 
has a large number of elastic fibres in its substance, and has independent 
branches of vessels ramifying through it from the neighbourhood of the 
root. It is subject also, especially along the sharp lines separating the 
surfaces, to pigmentary deposits such as are found in the pulmonary 
substance. 
The parietal part is applied to the costal walls, the diaphragm and the 
pericardium, and is arched above the level of the first rib, so as to come 
in contact with the subclavian artery and vein behind the clavicle; the 
right pleura usually reaching slightly further up than the left. The 
diaphragmatic floor is placed very decidedly on a higher level on the 
right side than on the left, but it may be mentioned, as a point which 
in former years often came under my notice in giving clinical instruction, 
that the left floor is more easily raised by pathological diminution of the 
lung above it than the right, owing to the stomach being raised more 
easily than the liver. The diaphragmatic and costal pleura are continued 
down as far as the attachments of the diaphragm allow, and are in contact 
one with the other below the level of the edge of, the lung for a distance 
which increases in expiration, and decreases in inspiration, and is known 
as the costo-diaphragmatic or costo-phrenic space. 
The posterior mediastinum, or the space between the pericardium and 
the vertebral column, is bounded on each side by pleura, the right pleura 
coming further forwards on the bodies of the vertebrae than the left, 
which leaves the column sooner, and, passing forwards, clothes the side of 
the descending aorta. Beneath the pleura the azygos veins lie on the 
bodies of the vertebrae, and on the right side the great vena azygos passes 
forwards above the root of the lung to open into the superior vena cava. 
The oesophagus lies in the middle of the posterior mediastinum, with the 
aorta descending at first on its left, and afterwards behind it; and the 
thoracic duct lies between the oesophagus and the right vena azygos till, 
near the upper part of the thorax, it crosses the middle line obliquely. 
The anterior mediastinum is bounded on each side by the reflection of 
the pleura from the costal wall to the pericardium. The line of reflection 
on each side comes nearly into contact with its neighbour in the mesial 
plane opposite the second intercostal space; but from this level that of 
the right pleura is continued downwards vertically while that of the left 
pleura slopes downwards and outwards in such a direction as to leave the 
pericardium at the apex of the heart in contact with the thoracic wall to THE ABDOMINAL CAVITY. 
687 
the left of the sternum. The part behind the manubrium of the sternum 
preserves in the young subject vestiges of the thymus gland, which in the 
adult are reduced to a small quantity of rather deep yellow fat. 
(B) The Abdominal Cavity. 
The abdominal cavity contains the digestive tract from the stomach 
onwards, and two large glands connected with it, namely, the liver and 
Eight lobe of liver 
Sternum 
Left lobe of liver Mamilla 
Stomach 
Liver_ 
Spleen 
( Cul-de-sac of 
( stomach 
Gall bladder. 
J Splenic flexure 
( of colon 
Hepatic flexure \ 
of colon J 
Transverse colon 
Umbilicus 
One of the taeniae \ 
of the colon J 
Small intestine 
Promontorium 
Poupart’s ligament 
Sigmoid flexure 
Urinary' 
bladder 
Pubic spine 
Fig. 521.—Abdominal Viscera. The great omentum has been removed. (Pansch.) 
pancreas; the spleen and the suprarenal capsules which are structures 
belonging to the group called ductless glands; and also the kidneys, the 
urinary bladder and the reproductive organs. It is divisible into abdomen 
proper and pelvis; but the pelvis, or region below the level of the brim of 
the true pelvis of the skeleton, is only the lower part of the cavity of the 
abdomen, undistinguished from it by any partition, and lined by a continua- 
tion of the same serous membrane, the peritoneum, lo enable the regions 
of the abdomen proper to be explicitly expressed, three zones are recognized. 688 
YISCEKA. 
The middle one is the interval between the levels of the lower ribs and 
the crests of the iliac bones, and its lateral parts are called the lumbar 
regions, while its mesial part is termed umbilical. The lateral parts of the 
zone above are called hypochondriac, and its mesial part is the epigastric 
region. In the inferior zone the mesial part is called hypogastric, and the 
lateral parts iliac. Any particular spot in the abdomen can always be 
explicitly registered by reference to one or more definite points in the 
skeleton. 
The peritoneum, the serous membrane lining the abdomen, is thrown into 
a number of complicated folds, partly owing to the number of viscera to 
which it is applied, and partly to the great elongation and consequent 
winding of the digestive tube. Those folds which unite the small intestine, 
colon and rectum to the parietes are termed mesentery, mesocolon and meso- 
rectum; those which unite other viscera with the parietes are called 
ligaments-, and those which unite one viscus with another are called omenta. 
Suspensory ligament Ductus venosus Vena cava inferior 
Round ligament- 
Upper layer of coronary ligament 
Spigelian lobes 
Left triangular ligament 
J Right triangular 
1 ligament 
J Lower layer of 
( coronary ligament 
■Renal depression 
Stomachic depression 
.Foramen of Winslow 
Fissure of round ligament 
Quadrate lobe 
Gall bladder Colic depression 
Fig. 622.—Liver and its Ligaments from Behind. 
The part which lines the anterior wall of the abdomen is thrown at 
the lower part, above the brim of the pelvis, into three depressions by 
two cords which run upwards to the umbilicus, one from either side of the 
urinary bladder, namely, the obliterated hypogastric arteries; and in those 
instances in which the deep epigastric artery happens to lie distinctly 
external to the obliterated hypogastric artery an additional small depression 
is formed on each side between the two vessels. Oblique inguinal hernia 
pushes its wmy by deepening the depression external to the deep epigastric 
artery, while direct inguinal hernia passes down internal to the deep 
epigastric, and either internal or external to the obliterated hypogastric 
according as that cord corresponds with the deep epigastric artery, or is 
separated from it by a peritoneal depression above the umbilicus. A single THE ABDOMINAL CAVITY. 
689 
cord, the obliterated umbilical vein, ascends to the under surface of the 
liver, which it reaches at the notch dividing the right from the left lobe; 
and the peritoneum reflected from the abdominal wall round this cord is 
thrown into a fold called the suspensory or falciform ligament of the liver, 
while the obliterated vein is sometimes called the round ligament of the 
liver. On each side of the suspensory ligament the peritoneum passes 
backwards, clothing the diaphragm and the dorsum of the liver as far 
back as the posterior border of the liver; and it likewise turns round the 
anterior edge of the liver and closely invests its under surface, extending 
on the right and left side so far back that the reflection below comes in 
contact with the reflection above, so as to form a pair of folds between 
liver and diaphragm called the right and left triangular ligaments. Between 
these the layers of peritoneum above and below the liver are separated by 
the thick posterior border of the liver lying in direct contact with the 
diaphragm, and together constitute the coronary ligament. 
Falciform and round ligament 
Left triangular ligament of liver 
Colic impression 
Spleen 
Kidney, 
Hepatic flexure 
Transverse colon 
Splenic flexure 
Fig. 523. Connections of Liver and Stomach. A broad arrow is placed in the 
foramen of Winslow, behind the gastro-hepatic or small omentum. To the right of the 
oesophageal opening of the stomach the gastro-phrenic ligament is seen. (Alexander 
Macphail, M.8.) B 
But, while at each side the peritoneum extends back under the liver 
to its posterior border, it is reflected in the middle at the portal fissure 
away from the liver to the duodenum and stomach, and opposite the right 
end of the portal fissure turns in behind the structures entering and leaving 
that fissure, so as to form a constricted aperture, the foramen of Winslow, 
which, followed to the left, expands into the smaller sac of the peritoneum. 
The foramen of Winslow is usually just large enough to admit a finger. 
It has above it the only lobe of the liver invested by the smaller sac of 690 
VISCERA. 
peritoneum, namely, the lobulus Spigelii; behind it the inferior vena cava ; 
beneath it the duodenum, and in front of it the gastro-hepatic omentum. 
The gastro-hepatic or small omentum is the peritoneal fold connecting the 
pylorus and commencement of the duodenum with the portal fissure of the 
liver, and contains within it the bile duct to the right, the hepatic artery to 
the left, and the portal vein between and behind these, besides nerves and 
lymphatics. From the liver and diaphragm the peritoneum extends down- 
wards over the stomach as far as the inferior border or great curvature, and 
beyond this it is continued onwards as the superficial layer of a pendulous 
fold, sometimes disposed over the surface of the small intestines, and 
sometimes crumpled along the lower border of the transverse colon, the 
gastro-colic or great omerUum. When this is cut a little below the stomach, 
the interior of the smaller sac of the peritoneum is laid bare, and the gastro- 
colic and gastro-splenic omenta, the splenic ligament and the transverse 
mesocolon can be studied. 
The smaller sac of the peritoneum (sac of the great omentum), commencing 
at the foramen of Winslow, and passing towards the left between the 
Spigelian lobe of the liver and the origin of the hepatic artery, expands 
behind the stomach. It extends up to the diaphragm, and, lying above 
the stomach in contact with the general peritoneum, forms with it the 
gastro-phrenic ligament which, on the right is continuous with the gastro- 
hepatic or small omentum. Anteriorly the small sac covers the posterior 
surface of the stomach and commencement of the duodenum ; posteriorly 
it invests the anterior surface of the body of the pancreas, reaching, on 
the left, even to the spleen, a small portion of which, as much as half an 
inch in diameter, it may invest in front of the hilus. Below the pancreas 
it leaves the posterior wall of the abdomen, and descends to the anterior 
surface of the transverse colon, and between this and the stomach it is laid 
in contact back to back with the pendulous fold of the general peritoneum 
already traced. 
The gastro-colic or great omentum is, therefore, a greatly elongated fold 
formed by a layer of the greater and a layer of the smaller sac of peri- 
toneum placed back to back; but, as it lies in its natural and pendulous 
position it presents four layers, the anterior and posterior belonging to 
the general peritoneum, while the intervening two are the anterior and 
posterior walls of the smaller sac gliding one on the other. The layers 
belonging to the greater and smaller sacs are not only applied very firmly to 
one another, but are in many places so attenuated and perforated as to 
present the appearance of a net; while, in the bars between the perforations, 
adipose tissue is often very considerably developed. 
The gastro-splenic omentum is formed by the peritoneum extending 
from the front of the stomach to the front of the hilus of the spleen, and 
the smaller sac extending from the posterior surface of the stomach to 
touch the spleen. The spleen is not only attached thus to the stomach, 
but also to the diaphragm, the latter connection forming the spleno-phrenic THE ABDOMINAL CAVITY. 
691 
ligament. This consists of two layers, one of them belonging to the smaller 
sac, and reflected from the surface of the pancreas and upper part of the 
surface of the left kidney, the other belonging to the greater sac or general 
peritoneum, and continuous at the posterior margin of the hilus with 
the peritoneal investment of the spleen. The spleno-phrenic ligament 
contains the splenic vessels between its layers, and superiorly is continued to 
the left side of the oesophageal opening of the stomach by what may be called 
a left gastrophrenic ligament. 
Gastro-hepatic omentum 
Coronary ligament of liver 
Suspensory ligament of liver 
Liver 
Stomach 
-Foramen of Winslow 
Aorta 
Round ligament 
Pancreas 
Mesocolon 
Small sac 
Transverse colon 
Greater sac 
Termination of duodenum 
Oastro-colic omentum - 
Divided mesentery 
Mesorectum 
Ileum— 
Urachus- 
Rectum 
Uterus 
Bladder. 
Pouch of Douglas 
Fig. 524.—Diagram of Peritoneal Folds in mesial section. 
The transverse mesocolon, in the greater part of its extent, is the con- 
tinuation backwards of the layers of the greater and smaller sacs of the 
peritoneum which form the great omentum. The layer from the smaller 
sac invests the front, and that from the greater sac the back of the transverse 
colon, and the two layers meeting again extend back to the abdominal 
wall at the lower border of the pancreas. But beyond the left border of 
the smaller sac a certain extent of the transverse colon may be separated 
from the posterior wall by mesocolon formed altogether by the general 
peritoneum; and beyond the right border of the smaller sac the transverse 
colon crosses the duodenum with the general peritoneum surrounding it 
more or less completely. 692 
VISCERA. 
The hepatic and splenic flexures of the colon are only partially sur- 
rounded with peritoneum, and above the hepatic flexure the peritoneum 
is in contact with the upper part of the right kidney. 
At the right and left sides of the posterior wall of the abdomen the 
ascending and descending colon are retained in position by the peritoneum 
failing, as a rule, to invest them completely; but portions of mesocolon 
may exist in connection with both one and other. The vermiform 
appendage of the caecum has always a mesenteric fold. Below the 
descending colon the sigmoid flexure is attached by an elongated mesentery 
continuoiis below with the mesorectum which intervenes between the upper 
part of the rectum and the sacrum. 
The mesentery, properly so called, is a fold of the peritoneum between 
the posterior wall of the abdomen and the whole length of the jejunum 
and ileum. At its intestinal edge it has the length of the intestines round 
which its layers are prolonged, but at the parietal edge it has a short 
straight line of attachment extending from where the transverse mesocolon 
crosses the mesial plane as far as the position of the caecum in the right 
iliac fossa, altogether a distance not more than five inches long. At its 
commencement it lies on the last part of the duodenum in such a manner 
as to leave a detectable portion to the right, clothed in front with peri- 
toneum between mesentery and transverse colon, while half the breadth 
of the last two inches can invariably be seen on the left (Fig. 551). 
Within the pelvis the peritoneum in the male presents a recto-vesical pouch 
descending between the bladder and rectum down to near the entrance of 
the ureters into the bladder. On each side a linear prominence is formed 
by the obliterated hypogastric artery passing forwards; and it is customary 
to distinguish the portions of peritoneum extending to the bladder as five 
false ligaments of the bladder, the parts below the hypogastric arteries con- 
stituting the two posterior ligaments, those above and outside them being 
the two lateral ligaments, and the mesial part above and between them 
being the anterior false ligament. 
In the female the uterus and vagina lie behind the bladder, and the 
peritoneum covers the posterior aspect of the uterus and upper part of the 
vagina, thus forming a recto vaginal pouch (pouch of Douglas). It also clothes 
the greater part of the front of the uterus, and on each side is extended 
so as to form the broad ligament of the uterus (ala vespertilionis). This 
surrounds the Fallopian tube, attaching it by a wide fold to the pelvic 
wall, and anteriorly invests partially the round ligament of the uterus, 
while posteriorly there comes off from it another fold which at its free 
edge completely surrounds the ovary, and less completely the round liga- 
ment of the ovary. The openings of the fimbriated extremities of the 
Fallopian tubes offer the only exception in mammalia to the rule that 
serous membranes become in process of development completely closed 
sacs; but it is to be remembered that in the lower vertebrates abdominal 
pores occur. THE TEETH. 
693 
THE DIGESTIVE ORGANS. 
Under this head may be conveniently included the alimentary canal 
and the glands which open into it. The divisions of the alimentary canal 
are the mouth, pharynx, oesophagus, stomach and intestine. The teeth5 
though situated within the mouth, are structures of such a special kind 
that it is better to describe their structure and development before pro- 
ceeding to the description of the soft structures. Of glands limited in 
number and so considerable in size as not to take part in the formation 
of the walls of the alimentary canal, one set, the salivary, open into the 
mouth, while the only others, the pancreas and 
the liver, open into the duodenum which is the 
uppermost part of the small intestine. 
THE TEETH. 
In the human subject the permanent teeth are 
thirty-two in number, eight on each side in each 
jaw, which it is customary to enumerate from 
before backwards, namely, first and second incisors, 
one canine or eye-tooth, first and second bicuspids 
or premolars, and first, second and third molars. 
The temporary or milk-teeth are twenty in number, 
five on each side in each jaw, namely, two incisors 
and a canine, displaced by the corresponding per- 
manent teeth, and two milk-molars displaced by 
the bicuspids. The molars of the permanent set 
are not preceded by any temporary teeth. 
Each tooth consists of a crown and a root, 
with a slight constriction where these meet, 
called the neck The crown presents in the 
different teeth differences in the number of cusps 
or prominences at the summit, while the root 
presents one or more fangs. The hard structure 
consists mainly of dentine, but on the crown 
this is covered with enamel, and on the root 
with a certain amount of crusta petrosa. In the 
interior there is left a hollow, the pulp-cavity, 
communicating, at the tip of each fang, with the 
outside, by a foramen through which pass an 
artery, a vein and a nerve; and in the adult, 
the contained pulp consists principally of branches 
of vessels and nerves, with a small amount of delicate connective tissue 
supporting them, and is surrounded by a continuous layer of corpuscles 
called odontoblasts, belonging to the dentine. 
Fig. 525.—Incisor Tooth, 
vertical section, a, Pulp cavity; 
b, dentine ; c, enamel ; d, crusta 
petrosa. The lines on the enamel 
indicate the direction of coloured 
bands ; those on the dentine are 
the concentric or contour lines of 
defective mineralization. 694 
THE DIGESTIVE ORGANS. 
Dentine is a texture slightly harder than compact hone and yielding 
about 72 per cent, mineral matter, principally phosphate of lime. It presents, in 
a mineralized gelatiniferous matrix, tubules lying side by side, and extending 
from the pulp-cavity to the circumference, bifurcating sometimes in their 
course, and dividing into branches close to the surface. They also give 
off exceedingly fine lateral branches easier seen in young teeth than in 
the adult. They present in their course a large or primary, and a finer 
or secondary set of undulations in the vertical plane. The secondary 
undulations are small and irregular, but the primary are regularly disposed 
so as to throw the tubules in most places into a letter S curve, only to 
be seen in longitudinal sections and causing a satin-like play of light. The 
walls of the tubules resist the action of solution of caustic potash or strong- 
acid longer than the matrix around, and may be more or less completely 
liberated. The lumen of the larger tubules may average about 
of an inch in diameter. In dried teeth the tubules are filled with air, 
but in the fresh state they contain a thread, 
the dentine-fibre. In sections through dentine 
and pulp, the dentine-fibres are seen to be 
continuous with processes from the layer of 
corpuscles surrounding the pulp, namely, the 
odontoblasts. The odontoblasts are elongated 
corpuscles arranged in a single continuous 
layer and sending processes, more than one 
from each, into the dentine canals. They can 
be observed from the earliest period of the 
development of the dentine; and as the dentine 
is originally formed first at the surface, and 
grows inwards at the expense of the pulp, the 
proof is complete that the odontoblasts are the dentine-corpuscles, and 
that they elongate their processes as these become embedded in dentinal 
matrix; thus differing from bone-corpuscles in being pushed in front of 
the calcifying matrix, instead of becoming completely embedded. This 
being the case, it is plain, as I have pointed out (Nature, 1890), that 
while bone corpuscles have only a limited individual existence, the same 
odontoblasts last during the whole life of the tooth. As age advances the 
pulp is more and more encroached on, to almost complete disappearance, 
and the tubules in the later dentine become irregularly disposed. Wearing 
away of the crown, such as happens in some persons and races more than 
in others, promotes growth inwards of the dentine, and in the centre of 
the worn surface the newer dentine is more deeply coloured. 
Fig. 526.—Longitudinal Section 
of Pulp and Dentine, a, Vessels, 
nerves and stroma of pulp ; 6, odonto- 
blasts ; c, dentine fibres. 
Where the dentine is covered with enamel the tuhules pass occasionally 
out to be continued a little distance into the enamel, sometimes in a 
dilated form. Where it is covered with crusta petrosa, tubules may also 
sometimes be followed out into that substance, and, very generally, there 
is a granular layer (of Furkinje) underneath the crusta petrosa, which owes THE TEETH. 
695 
its appearance to small spaces, often communicating one with another and 
with the tubules, and sometimes taking the form of interstices between 
aggregated globules of matrix, the globules varying in size but averaging 
about -joVfrth of an inch in diameter. On this account they have been 
described as inter globular spaces. But these are not to be confounded with 
much larger spaces of similar interglobular appearance arranged in conical 
sheets, so as to form concentric lines in horizontal sections, particularly 
of the crown.1 The latter are bounded by much larger lobes and neither 
communicate with the tubules nor affect their course, and though less 
densely mineralized than the rest of the matrix, are so filled up that they 
cease to exist in decalcified sections. Some of the concentric lines show 
Fig. 527.—Sections of Human Tooth. A, a, Dentine; b, cmsta petrosa; c, granular 
layer; B, a, dentine ; b, enamel; c, spaces forming a line of contour or concentric 
line ; ’c, dentine canals in transverse section. (Toldt.) 
this deficient mineralization in less definitely bounded patches, while yet 
others are caused by a finely granular disposition of mineralized particles, 
and such granular lines are the rule in some non-mammalian teeth. 
Separate small globules of mineralization occur close to the pulp, both in 
old teeth and in the first commencement of dentine in development. In 
decalcified dentine, lamination and fibrillation, similar to Avhat occurs in 
bone, has been noticed (Sharpey). 
Enamel is much the hardest texture in the body. Different analyses 
have yielded from 2 per cent, to 3| per cent, organic matter; while the 
remainder consists of mineral salts, principally phosphate of lime. It 
1 These are the contour lines of Owen, the incremental lines of Salter. The only- 
objection to the first name is that they approach the surface at their extremities. 
It is perfectly certain that they have nothing to do with increment of any sort. 696 
THE DIGESTIVE ORGANS. 
consists of hexagonal prisms about T of an inch in diameter, extending 
vertically from the dentine to the surface, and packed closely together, for 
the most part parallel, but sometimes exhibiting groups irregularly crossing 
one another as if crushed down to a slight extent by vertical pressure. 
They can be isolated to some extent by the action of hydrochloric acid, 
when they can be seen more distinctly than in continuous sections to have 
a regular transverse striation, due neither to varicosity nor pigment. 
Superficially the enamel is overlaid by a continuous structureless layer, 
separable by the action of hydrochloric acid, 
Nasmyth’s membrane, which at the base of the 
crown ends in the crusta petrosa. The 
inner ends of the enamel-prisms impress the 
surface of the dentine, and their outer ends 
can sometimes be seen forming a hexagonal 
pattern when examined with a high power. 
But with a simple lens there can always be 
detected on the surface of uninjured per- 
manent teeth another pattern, which has 
apparently escaped notice, namely, a fine 
ripple-mark of horizontal lines, interesting 
in connection with the exaggerated and 
irregular ridges which occur pathologically. 
The milk teeth have no such lines on their 
enamel, but may present minute and shallow 
pits. Coloured bands often occur in the 
enamel, crossing the prisms in such a direc- 
tion as to cause lines seen in longitudinal sections to extend upwards and 
outwards from the dentinal to the free surface. 
Pig. 528.—Section through Enamel 
of Elderly Subject, a, Enamel prisms; 
b, their free extremities in perspective ; c, 
dentine, with some of its tubes prolonged 
into spaces between the enamel prisms. 
Crusta petrosa or cement is much less regular, both in disposition and 
structure, in the human subject, than dentine and enamel. To understand 
it properly it should be looked at in teeth such as those of the horse, with 
deep recesses on the crown, when it will be seen to fill up the recesses lying 
superficial to the enamel, and to coat the fangs with regularly disposed 
laminae of osseous tissue. It is softer than dentine. In the human subject 
it occurs only on the root, and is found most abundantly at the tips of 
fangs, between the fangs of molars, and on the grooves of double fangs. 
Where thickly deposited, it has lacunae and canaliculi irregularly scattered, 
and usually ragged and irregular in form. It frequently shows lamination, 
and in portions exhibits minute spaces like the smallest of those in the 
granular layer of dentine; also lines may be seen at right angles to the 
dentine and the lamination. It is most abundant in old teeth. 
The permanent teeth. The incisors have chisel-shaped crowns and single- 
fanged roots. The summit of the crown when unworn is undulated, showing 
three slight elevations separated by depressions which are prolonged down 
on the superficial aspect; on the lingual aspect it presents a slight depres- THE TEETH. 
697 
sion where it begins to flatten out to the summit. The single-fanged root 
tapers, without constriction, at the neck, and is broader from front to 
hack than from side to side. The upper incisors are larger than the lower. 
The first upper is the largest of all and has the longest fang; the first 
lower is the smallest of all and has the shortest fang. The second upper 
incisor is always unsymmetrical, being prolonged as far as the edge of the 
first incisor on the one side, and on the other bevelled to allow the lower 
canine to fit between it and the upper canine. Normally the summits of 
the lower incisors are overlapped by the upper; and deviation from this 
is the essence of the peculiarity of jaw called “ underhung.” 
Fia. 529.—Permanent Teeth, a, First upper incisor from labial and lingual aspects ; 
b, upper canine from labial and lingual aspects ; c, upper bicuspid from dental and buccal 
aspects ; d, upper true molar showing its single inner and two outer fangs ; e, crown of 
the same ; /, left lower true molar from buccal aspect. 
The canine or eye-teeth have the middle of the three elevations seen on 
the summits of the incisors greatly exaggerated, and the depression on 
the lingual aspect less marked. The root is single-fanged 1 and both longer 
and stronger than the fangs of the adjacent teeth, causing projection of 
the walls of their sockets, so as to form the outer boundary of the incisor 
fossa in both upper and lower jaw. In the most regular dentition both 
the summits and labial surfaces of the canines are in line with the other 
teeth, but they often project both upwards and outwards. 
The bicuspids or false molars have each an outer and an inner cusp on the 
crown, the outer somewhat the larger. Their roots are deeply grooved in 
front and behind, and most frequently end in a single extremity, but are 
often somewhat bifid, and this hifidity is more frequent in the first than 
in the second or hinder of the two. 
The molars of the upper and lower jaws, though somewhat similar in the 
form of their crowns, are easily distinguishable. The upper molars have four 
cusps, two outer and two inner, and have three fangs, two of them placed 
one in front of the other on the side next the cheek, cylindrical in form; 
and a third on the lingual side, broader from before backwards at the base, 
hut rapidly becoming cylindrical, and lying side by side with the hinder 
of the two outer fangs. The lower molars have a fifth cusp behind the 
others, and have two broad fangs one in front of the other, each with two 
foramina at the extremity, and liable to a certain degree of bifidity. The 
lln one specimen in my possession an inferior canine occurs with a bifid fang. 698 
THE DIGESTIVE ORGANS. 
fangs of the lower molars may curve a little backwards; and it is im- 
portant in dentistry to note that they are directed downwards and outwards, 
and that therefore a slightly inward inclination should be given to the 
traction when the forceps is applied to them. In both jaws the third 
molars, or wisdom teeth, are smaller than the others and may have the 
fangs dwarfed, the root coming to a single point. In the upper jaw the 
third molar occasionally has a fang directed quite inwards. 
The temporary or milk teeth are smaller than those which replace 
them. The incisors differ from permanent incisors in having no grooves- 
on the labial surface, and in the fangs being generally narrower at the 
base as compared with the breadth of the crown. The milk molars have 
characters similar to the permanent molars, but their fangs diverge and 
bend round the crowns of the bicuspids, to some extent grasping them. 
Fig. 530.—Temporary and Permanent Teeth in the jaws of a child six years old. 
The temporary teeth are all still present, and the crowns of the corresponding permanent 
teeth are formed ; the first molars have appeared, and behind them are the second molars 
with the divisions between the fangs in process of formation. 
Development of the teeth. A tooth, like a hair, is developed in con- 
nection with a single papilla which appears in a previously developed 
recess filled with epithelium. The enamel is, however, the only part 
developed from epithelium, and even the enamel is derived altogether 
from the elongated or deepest stratum of corpuscles, while the other layers- 
ultimately disappear. The existence in both jaws of a furrow with ten 
recesses for the milk teeth was detected at the ninth week of foetal life 
by F. Arnold (1831), and the details connected with these and with the first 
appearance of the permanent teeth in the human subject, so far as can 
be seen with the simple lens on removal of the epithelium, was worked 
out by Goodsir (1839). His researches show that in the seventh week 
the primitive groove filled with thickened epithelium appears, and from 
the bottom of this the series of recesses or follicles of the milk teeth, each 
containing a papilla, is formed, the follicle for the first milk molar appearing 
first, then that for the second milk molar, next that for the canine, and THE TEETH. 
lastly those for the incisors, the first incisor before the second. Goodsir 
demonstrated that the sacs so formed become closed by folds or opercula 
meeting over them, the incisor sacs by two, the canines by three, and the 
molars by four; also that above these the lips of the groove adhere, the 
outer lip overlapping the inner; and that between the inner lip and the 
adjacent operculum another follicle, the cavity of reserve, dips in to form 
the sac of the permanent tooth, and rapidly descends so as to lie deeper 
than the milk sac, while it continues to be connected with the surface 
from which it sprang by a cord which passes through the foramen always 
present on the deep side of the alveolus of the temporary tooth. The 
sacs of the true molars he showed to be separated in succession backwards 
from a posterior or great cavity of reserve continued back from the primitive 
groove. Later writers, who have observed in section the epithelium filling 
the various recesses, speak of the epithelium in the groove as the common- 
enamel-germ, and of the process descending to the cavity of reserve as the 
Fig. 531. Development of a Temporary and a Permanent Tooth, a, Papilla in 
primitive groove ; b, follicle with opercula over it in the secondary groove; c, follicle 
converted into closed sac by adhesion of opercula, and permanent tooth sac left above 
inner operculum ; d, e, f, permanent tooth sac descending, and temporary tooth growing 
up ; g, permanent tooth sac connected with surface by cord passing through foramen in 
the deep wall of the temporary socket. 
secondary enamel-germ, while for the mass inclosed in each sac and for its 
deepest or columnar layer the terms enamel-organ and enamel-membrane 
(Purkinje) are retained. The enamel-membrane is the only part concerned 
in producing the enamel-prisms; the corpuscles in the middle of the enamel- 
organ become drawn asunder by fluid, while retaining connection one with 
another by long and slender branches, and ultimately disappear. Beneath 
the enamel-membrane a delicate structureless layer appears to exist, for 
which the old term preformative membrane is used. More deeply placed 
is the layer of odontoblasts, easily distinguished from the corpuscles of the 
enamel-membrane by their larger size. As the enamel-corpuscles elongate 
to form prisms, their nuclei remain at the extremity furthest from the 
dentine. 
The enamel and dentine appear simultaneously at the tips of the cusps, 
each cusp in the multicuspid teeth forming at first a distinct toothlet. The 
separate cusps unite, and the crowns are completed from above downwards. 
The roots extend by continuation of growth beyond the sac. In the molar 
teeth bridges of dentine are formed below the crown by processes growing 
in to meet one another between separate bundles of vessels and nerves, 
and the fangs increase in length by growth downwards round those bundles 700 
THE DIGESTIVE ORGANS. 
or divisions of the pulp. It is the increasing length of the root and the 
resistance offered to it by the neighbouring bone which forces the crown 
out through the gum. Increase of length of the body of the lower jaw 
being effected by absorption of the front of the ramus and addition to it 
behind, the true molars, which at first lie further back than the anterior 
border of the ramus, find room in front of it before coming to the surface; 
but the difficulty mentioned at p. 36, in the way of accounting for the 
growth of either jaw without expansion of osseous tissue already laid down, 
is illustrated by the position of the permanent canines in Fig. 530. 
The eruption of the teeth, both temporary and permanent, occurs generally 
in very regular order, though in individuals the exact periods vary. The 
teeth of the lower jaw appear usually a little later than the corresponding 
teeth of the upper. Of the milk set, the first incisors are the earliest, 
and appear from the sixth to the ninth month. They are followed by 
the second incisors, and these by the first molars; then come the canines, 
and, lastly, about two years of age, the second molars. The milk teeth are 
shed in consequence of absorption of their fangs, caused by pressure of 
the permanent teeth ; the first and second incisors and first and second 
molars being displaced respectively about the seventh, eighth, ninth and tenth 
years of age, and the canines about the eleventh. The first permanent 
molar appears before the shedding of any of the milk teeth, and the second 
soon after they have all been shed, while the third molar gets the name 
of wisdom tooth, on account of the lateness of its appearance, because 
it does not cut the gum till the seventeenth year or a much later period. 
As an abnormality, additional incisors or canines, one or more, may 
appear. They are formed on the lingual side of the permanent teeth, 
and may cut the gum and give trouble, pushing the normal teeth outside 
the range, or themselves projecting inside the arch. They may fail ever to 
come to the surface, or may appear after absorption of alveolar processes. 
They illustrate that the permanent teeth are each merely the second in a 
transverse series which may be carried further, as it normally is in many 
fishes. This circumstance has not received due attention, and was, I believe, 
noted for the first time in a communication of mine to the British Association 
in 1893 ; but both a longitudinal and a transverse series must be recognised 
in dentition, and this not only affords the true key to explain Goodsir’s 
cavities of reserve, but unifies the scheme of dentition in different animals. 
THE MOUTH. 
The cavity of the mouth extends back to the pharynx. In front of 
the ramus of the lower jaw it is divided into a part inclosing the dental 
arches and a part within them. The mucous membrane is reflected from 
the lips and cheeks on to the outer surface of both jaws, embraces the 
teeth, forming around them the gums, and thence is continued on the upper 
jaw to cover the palate, while, inside the lower jaw, it descends considerably THE MOUTH. 
701 
before being folded round on the under surface of the tongue. But, behind 
the teeth, internal to the ramus of the jaw, the floor of the mouth suddenly 
rises almost to a level with the dorsum of the tongue, and, internal to the 
hindermost tooth of the upper jaw, the hard palate is continued into the 
velum palati or soft palate. The comparatively constricted passage thus 
bounded above and below, leading into the pharynx, is termed the fauces, 
and has the pendent uvula above, and on each side two prominent folds, 
the anterior and posterior pillars, separated by the tonsil, and corresponding 
respectively with the positions of the palato-glossus and palato-pharyngeus 
muscle. At the margin of the lips a sudden change takes place in the 
integuments. Both sebaceous and sudoriparous glands suddenly disappear, 
while the papillae become longer and more closely set as far as the lips 
come in contact, and then diminish. Papillae, however, are found every- 
where on the mucous membrane of the oral cavity, and the epithelium 
remains stratified squamous. 
Inside the cheek a slight elevation opposite the second molar tooth of 
the upper jaw marks the opening of the duct of the parotid gland (Stenson’s 
duct). On the inner surface of each lip there is a slightly prominent fold 
or fraenum made by the mucous membrane in the middle line as it turns 
round on the jaw. 
The labio-buccal mucous membrane rests on loose areolar tissue, and 
shows on its deep side a number of small glands like lentils which open 
on its surface. These glands, 
termed labial, buccal and molar, 
are situated abundantly inside 
both lips, and are continued 
in a line from the angle of 
the mouth back to the neigh- 
bourhood of Stenson’s duct, 
where they may be more 
abundant. In structure they 
are acinated. Their acini are 
flask-shaped with a strong 
membrana propria, and with 
an elastic fibrous coat wrapped 
round the lobules. They are 
lined with small nucleated 
corpuscles, and are filled with 
masses of muciparous substance unstainable with carmine 
Pig. 532.—Labial Glands exhibited by removal of mucous, 
membrane from inside the lips. 1, Oral aperture; 2, 3, upper 
and lower lip ; 4, cut edge of mucous membrane ; 5, a gland; 
6, 6, facial arteries; 7, 8, superior and inferior coronary 
arteries; 9, orbicularis oris; 10, buccinator; 11, depressor 
anguli oris; 12, levator anguli oris; 13, nerve to lower lip 
from inferior dental; 14, nerve to upper lip from infraorbital. 
(Luschka.) 
The mucous membrane of the gums and palate differs from that of the 
cheeks and lips, in being immovable. It is everywhere distinct from the 
periosteum, and on the hard palate is even separated from it by a con- 
siderable thickness of tissue, but white fibrous bands keep it in position. 
The papillae in the middle of the palate are very short, but they are 
longer on the gums, especially at the dental margins. The palate presents 702 
THE DIGESTIVE ORGANS. 
■two or three transverse rugae in its fore part, representative of those so 
much more obvious in many mammals; also, it has a slight raphe in the 
middle line, and in front of the raphe, in a portion corresponding with 
the incisor foramen, there is a slight elevation, with sometimes a depression 
behind it, a vestige of the mode of development, and representing the 
orifices which in a number of animals lead up to the floor of the nose 
opposite the organ of Jacobson. The palate has a large number of acinated 
glands similar in appearance 
to those of the lips and cheeks. 
They are crowded in the soft 
palate, and are continued for- 
wards into the middle of the 
hard palate in two patches, 
one on each side. They have 
a watery secretion. In the 
floor of the mouth and on the 
under surface of the tongue 
the mucous membrane is more 
movable than on the cheeks. 
It presents in the middle line 
a prominent bridle, fraenum 
linguae, toward whose lower 
end there is a thickening in which are placed, side by side, the openings 
of the ducts of the submaxillary glands (Wharton’s ducts). On each 
side, in the hollow between jaw and tongue, there can always be re- 
cognised during life a slight elevation produced by the sublingual glands, 
sometimes presenting a fringe-like line in which lie openings of sub- 
lingual ducts (ducts of Walther). There also extends forwards under the 
tongue, on each side of the fraenum, a little out from it, a scalloped fold, 
plica fimbriata, directed outwards, which has a certain importance as con- 
stituting with its fellow the representative of the under tongue found in 
various animals, especially lemurs and marsupials (Gegenbaur). 
Fig. 533. —Acini op Labial Gland treated with sulphuric 
acid to show the elastic covering. 
Superior lingualis 
Stylo-glossus. 
Inferior lingualis 
Hyo-glossus 
Fig. 534. —Diagram of Transverse Section of Tongue. The transverse and vertical 
fibres are seen in addition to the named muscles. 
Genio-glossus 
The tongue is a muscular structure with a mesial fibrous septum 
extending forwards from the hyoid bone, and with a specialized form THE MOUTH. 
703 
of raucous membrane on its upper surface. It may be said to be based 
on the two genio-glossi muscles, already described, whose insertions extend 
from the tip to the hyoid bone and from the middle line to the lateral 
margins, so that their fibres are much spread. The other extrinsic 
muscles, namely, the hyo-glossi, the stylo glossi, and the palato-glossi take 
less part in the formation of the tongue, and their fibres do not become 
so scattered, but along with the linguales muscles and the bodies of the 
genio-glossi, make a firmer or cortical layer surrounding the main sub- 
stance of the tongue. 
Posterior pillar of fauces Uvula 
Tonsili 
Anterior pillar of fauces 
■Epiglottis 
.Posterior area of tongue 
Foramen caecum 
(Circumvallate papilla 
.Fimbria 
Fig. 535. The Fauces with the Tongue Protruded, showing the lingual aspect of 
the epiglottis and the V line behind the circumvallate papillae. 
The intrinsic muscles are sets of fibres altogether belonging to the 
tongue, and take longitudinal, transverse and vertical directions. The 
longitudinal fibres form two pairs of muscles, named superior and inferior 
linguales. The lingualis superior lies underneath the whole upper surface, 
and consists of fibres of much shorter length attached to the mucous 
membrane. The lingualis inferior lies beneath the outermost fibres of the 
genio-glossus, where they are curved outwards, and internal to the insertion 
of the hyo-glossus muscle. The transverse and vertical fibres are nowhere 
collected into distinct muscles, but are diffused throughout their extent 
between the others; the transverse fibres extending outwards from the 704 
THE DIGESTIVE ORGANS. 
mesial septum, the lowermost with a downward and the uppermost with 
an upward curve; and the vertical fibres stretching between the upper 
and under surfaces, in curves with the convexity inwards. 
The dorsum of the tongue presents a different appearance from the rest 
of the mucous membrane of the mouth. It is marked in the middle line 
by a more or less distinct furrow or raphe which terminates behind, 
between the anterior pillars of the fauces, in a blind depression, foramen 
caecum, in the centre of a V-shaped furrow separating a posterior area 
from the rest of the tongue.1 In front of this, it is covered with papillae 
much larger than those of the rest of the mouth or of the skin, and 
bearing on their surface others corresponding to those. The 'papillae are 
of three kinds—filiform, fungiform and circumvallate. The filiform papillae 
are set closely all over the surface, with a certain amount of regularity, 
giving an appearance of lines diverging with forward inclination from the 
raphe, and ending in distinct ridges at the sides of the tongue, the hinder- 
most of which are best marked, constituting what is sometimes termed 
Umbria linguae, and correspond with more differentiated structures in the 
rabbit called the foliate papillae; their secondary papillae are collected at 
their tips. The fungiform papillae, larger and rounder, are scattered 
singly at irregular intervals broadcast among the filiform; their secondary 
papillae are short and abundant, so as to combine superior vascularity and 
less abundant epithelium, which sometimes suffice to produce a distinctive 
red colour. The circumvallate papillae are larger than the fungiform, about 
eight or ten in number, ranged in single line in front of the V-shaped 
furrow. They are somewhat flattened on the summit, and covered with 
secondary papillae; but their sides, which are sunk in a circular depres- 
sion, are devoid of these, and are studded with peculiar sense-organs 
called taste-buds. Behind the V-shaped furrow there is a distance of about 
ah inch in which the convexity of the tongue is continued back towards 
the epiglottis, and a mesial fold, fraenum epiglottidis, joins it to the dorsum of 
that structure, while a shallow depression is left at each side. In this 
region the characteristic lingual papillae are absent, though irregular 
rugae extend back for some distance behind the V-shaped furrow; and 
the surface presents a number of little openings which are mouths 
of crypts with closed follicles in their walls, similar to those of the tonsils. 
The nerves of the mucous membrane of the tongue are the glosso- 
pharyngeal, distributed principally to the region of the circumvallate 
papillae, and the lingual branch of the fifth, extending to the whole 
surface. The secondary papillae contain in many instances end-bulbs and 
sometimes touch-corpuscles. 
The taste-buds are organs of sense discovered independently by Loven 
llt is to be noted that this relic of the ductus thyreoglossus (p. 99) was suspected 
by Yater to be the duct of the thyroid, and that after many dissections he succeeded, 
in a child of nine months, in injecting through it what he described and figured as 
a salivary gland extending under the tongue and round the larynx (1720). THE MOUTH. 
705 
and Schwalbe (1867), easily studied in the foliate papillae of the rabbit and 
in other mammals. They were at first supposed to be confined in the 
human subject to the sides of the circumvallate papillae, but have since 
been found not only in the opposed surfaces of the valla surrounding these, 
but also scattered on the tongue, especially in the fimbria, and on the 
Fig. 536.—Taste-Buds from foliate papillae of rabbit. A, Papillae with taste-buds on 
their sides ; B, separated structures; a, under surface of horny epithelium with three 
perforated hemispherical impressions corresponding with summits of taste-buds ; 6, 6, 
isolated taste-buds ; c, form of nucleated corpuscle found in taste-buds. 
under surface of the velum palati and on the epiglottis. They are pointed 
domes occupying the whole depth of the epidermis. They are composed 
of elongated nucleated corpuscles with their bases on the corium, and 
therefore to be considered as modifications of the deepest or perpendicular 
Fig. 537.—Section of an Injected Tonsil, a, a, Mucous membrane of fauces; b, a 
recess ; c, c, c, closed follicles. 
corpuscles of the cuticle; and their tips occupy openings left in the 
superficial scaly layers. The circumferent or cortical corpuscles are 
flattened like staves of a barrel, but pointed at the ends; the central 
corpuscles are narrow and rounded, with a swelling in the middle caused 
by the nucleus, a short wire-like extremity projecting at the tip, and with 
the deep extremity prolonged into continuity with a nerve-fibre. 
2 Y 706 
THE DIGESTIVE ORGANS. 
The glands of the tongue are small acinated glands embedded in the 
muscular substance. Two minute groups, known as glands of Nuhn or 
glands of Blandin, are placed on the inner margins of the inferior lingual 
muscles close to the tip. Others open into the circular depressions round 
the circumvallate papillae, others into the crypts at the back of the 
tongue, and others on the margins. Also a row of openings, not usually 
noticed, lies in the recess concealed by the plica fimbriata. The secreting 
cells of these glands are many of them of the serous type. 
The tonsils (amygdalae) are spongy developments of the mucous mem- 
brane, which are situated on the sides of the fauces between their anterior 
and posterior pillars. They are slightly convex on the surface and present 
a number of irregular orifices leading into crypts simple and branched, and 
are about a quarter of an inch in thickness. Their thickness and prominence 
is principally due to closed follicles (p. 68) which are ranged all round the 
crypts and are embedded in retiform tissue. They rest on fibres of the 
superior constrictors of the pharynx which lie between them and the 
internal carotid arteries. 
THE SALIVARY GLANDS. 
There are three pairs of glands distinguished as salivary which all 
secrete alkaline saliva containing ptyaline and contrasting with the acid 
mucus of the labial glands. They are all of them acinated glands, the 
secreting cells presenting in certain cases the appearance termed serous, 
and in others that which is distinguished as mucous (p. 58); and beneath 
the secreting cells so distinguished are others spread out on the basement 
membrane and pushing in between them, the lunules or crescents of Gianuzzi. 
The ducts have vertically striated columnar epithelium, excepting close to 
the acini, where there is an intercalary portion with flattened epithelium. 
The parotid gland. This is the largest of the salivary glands. It 
occupies the space below the ear between the sterno-mastoid muscle and 
the ramus of the jaw, and extends forwards over the back part of the 
masseter muscle. Superiorly, it dips deeply in, both in front and behind 
the styloid process, filling up the interval between the jaw in front and 
the mastoid process and sterno-mastoid muscle behind. Interiorly, it 
extends as low as the angle of the jaw, resting on the stylo-maxillary 
ligament or fascia, which separates it from the position of the sub- 
maxillary gland so effectually that, however much both glands may be 
swollen, they always remain quite distinct. Embedded in the parotid are 
the external carotid artery and origins of posterior auricular, superficial 
temporal and internal maxillary; also, more superficially, the junction of 
the temporal and internal maxillary veins; and piercing the gland from 
the posterior and deep part so as to emerge in front are the branches of 
the facial nerve, while others from the great auricular nerve enter from 
below and are connected with them. The duct, called usually Stenson’s 
duct (ductus Stenonis), emerges from the anterior border of the gland at THE SALIVARY GLANDS. 
707 
the level of the upper teeth, and crosses the masseter immediately below 
the transverse facial artery to pierce the buccinator muscle and open into 
the mouth opposite the second molar of the upper jaw. It is large 
enough to admit a crow-quill, but is constricted at its orifice. At the 
origin of the duct the gland is prolonged on the upper border and some- 
times presents a distinct lobe opening separately into it, the pars soda 
parotidis. The lobulation of the parotid gland is finer than that of the 
other salivary glands, and the lobules less easily dissected out from the 
tissue around. The membrana propria of the acini is delicate. The 
secreting corpuscles belong to the so-called serous group, being easily 
stained with carmine, and having spherical nuclei. The place of opening 
of the duct shows the parotid to be premandibular. the gland having been 
developed by ramification of the duct, while the submaxillary and sub- 
lingual glands are postmandibular. 
Parotid 
Pars socia 
Stenson’s duct 
■Gland of Nuhn 
-■Orifice of duct 
» Levator menti 
■ Duct of Wharton 
~Duct of Eivini 
..iiSubmaxillary gland 
Fig. 538.—Salivary Glands. A portion of the lower jaw is removed. The mylo-hyoid 
muscle is seen in section, with the submaxillary gland embracing its free border, and the 
sublingual gland with Walther’s ducts lying above it. 
The submaxillary gland is placed in the digastric space, between the 
base of the jaw and the digastric muscle. Its larger part is superficial to 
the mylo-hyoid muscle, and is of somewhat circular figure, more than an 
inch in diameter; but posteriorly it curves round the border of the mylo- 
hyoid muscle, and from this deep part, which lies beneath the mucous 
membrane of the mouth, the duct, generally known as Wharton’s dud, is 
given off and passes forwards to open near the root of the fraenum linguae 
by a constricted orifice, on a papilla common to the two ducts of opposite 
sides. The facial artery crosses the gland near the back, more or less 
deeply embedded in it and furnishing branches to it. Ihe lingual branch 708 
THE DIGESTIVE ORGANS. 
of the inferior maxillary nerve, descending on the inner side of the jaw, 
passes under Wharton’s duct before ascending to the side of the tongue; 
and descending from the nerve as it approaches the duct are its branches to 
the submaxillary ganglion which lies above the duct, near its origin. The 
Connective 
tissue 
fDuct with 
columnar 
epithelium 
Secreting cells 
I Intercalary 
duct with 
squamous 
epithelium 
Fig. 539.—Section of Parotid Gland, human. (Bohm and v. Davidoff.) 
submaxillary gland lies loose jn the surrounding textures. Its acini have 
a stronger memhrana propria than the parotid, and in connection with this 
there is a network of stellate corpuscles. The acini are some of them 
filled with corpuscles of the muciparous and unstainable kind, and some of 
them with stainable or serous corpuscles like those of the parotid. 
Intercalary 
duct 
Crescent of 
Gianuzzi 
Fig. 540.—Section of Submaxillary Gland, human. (Bohm and v. Davidoff.) 
The sublingual gland, much the smallest of the salivary glands, is 
about an inch long and is narrow, lying under the mucous membrane of 
the floor of the mouth. It rests on the mylo-hyoid muscle, at the side of 
the genio-glossus and duct of Wharton. It consists of a number of separable 
lobules, some of which may open into Wharton’s duct; but the majority 
of them, ten to twenty in number, open separately in a line (ducts of 
Walther); while a larger outermost lobule has a separate duct running 
along to open near the orifice of Wharton’s duct, and was described both THE PHARYNX. 
709 
by Eivini and Bartholin before the separate ducts were discovered. The 
acini are mostly of the muciparous kind and large; but my sections in the 
human subject show patches of the serous kind, deeply stainable and small. 
The pharynx is that part of the throat which lies behind the posterior 
nares, the fauces and the larynx. It is distinguished from the oesophagus 
by its proper muscular wall being deficient in front and consisting of 
three constrictors already described (p. 345). It is wide above, and extends 
from the base of the skull to the level of the lower border of the cricoid 
cartilage, where the lower border of the inferior constrictor grasps the 
longitudinal muscular fibres of the oesophagus. It has seven openings, 
four of them above the soft palate, namely, the posterior nares and, at 
the sides of these, the orifices of the Eustachian tubes; while, beneath the 
level of the palate, it communicates with the fauces, the larynx and the 
oesophagus. The upper border of each superior constrictor forms a curved 
line, and above this the wall of the pharynx is completed by strong fibrous 
membrane, which is attached to the prominent margin bounding the front 
of the depressed line near the back of the body of the sphenoid bone and 
to the edge of the internal pterygoid plate and the cartilaginous wall of 
the Eustachian tube. In the middle line a ligamentous band of fibres 
descends from the tubercle underneath the basilar process of the occipital 
bone to the raphe between the constrictors. 
THE PHARYNX. 
The mucous membrane of the pharynx, where it quits the fibrous 
wall to be reflected on the base of the skull, is thrown into irregular 
ridges and hollows, and on each side forms a blind pouch, the pharyngeal 
recess or fossa of Rosenmilller, above and behind the cartilaginous wall of the 
Eustachian tube, so that the cartilage lies between the recess and the tube. 
On the back and sides of the suprapalatal part of the pharynx patches of 
closed follicles are seen. The epithelium above the level of the palate is 
ciliated columnar, as in the lower part of the nasal fossae; while below the 
palate it is squamous stratified, as in the fauces and oral cavity. 
THE OESOPHAGUS. 
The oesophagus or gullet, extending from the pharynx to the stomach, 
commences opposite the lower border of the cricoid cartilage and of the 
fifth cervical vertebra, and terminates after piercing the diaphragm opposite 
the tenth dorsal vertebra. It is nine or ten inches long, and is the 
most muscular and constricted part of the alimentary tube. It is slightly 
narrower at its commencement and near its termination than elsewhere. 
Though nearly straight, it deviates slightly to the left side at its commence- 
ment, regaining the mesial position about the level of the fifth dorsal 
vertebra, and is again inclined to the left where it pierces the diaphragm. 710 
THE DIGESTIVE ORGANS. 
Resting in the neck and upper part of the thorax on the longus colli and 
bodies of vertebrae, as it descends further it is bent forwards and removed 
from contact with the vertebral column by the intervention of the aorta 
which, placed to the left at the commencement of its descent, is mesial 
in position where it passes between the crura of the diaphragm. In front 
are the trachea and commencement of the left bronchus and, below this, the 
pericardium. The left common carotid artery is more closely in contact 
with the oesophagus than the right, partly because it arises nearer the 
vertebral column and partly on account of the deviation of the oesophagus 
to the left side. The recurrent laryngeal nerves lie close in between the 
oesophagus and sides of the trachea. The vagus nerves come into close 
contact with the oesophagus below the arch of the aorta, and as they 
descend, giving branches to its walls, the right nerve turns to the posterior 
and the left to the anterior surface. The thoracic duct lies between the 
oesophagus and right vena azygos in the lower part of the thorax, and 
between oesophagus and vertebral column higher up. 
The walls of the oesophagus present three coats—muscular, submucous 
and mucous. 
The muscular coat has its fibres evenly disposed in two layers, longi- 
tudinal and circular. The longitudinal fibres are most superficial, and at the 
upper part take origin from the cricoid cartilage anteriorly, and from the 
inner surface of the inferior constrictor of the pharynx behind and at the 
sides. The circular fibres are surrounded by the longitudinal, and above 
are separated by them from the constrictors of the pharynx. 
The submucous coat consists of loose areolar tissue which allows the 
mucous coat to fall into longitudinal folds within the grasp of the muscular 
coat. 
The mucous membrane presents, besides epithelium, two layers which can 
be stripped separate one from the other. That which is next to the 
submucous areolar tissue consists of longitudinal fibres, which interiorly 
are muscular (Toldt) and continuous with the muscularis mucosae of the 
stomach. The other, the mucous membrane proper, is a firm felted tissue, 
and on the surface presents loosely scattered papillae, some isolated and some 
connected in rows, which when denuded of epithelium are filiform. The 
epithelium is stratified squamous, like the lower part of the pharynx, and 
forms tubercular elevations over the papillae. 
Small mucous glands are sparsely scattered in the upper part of the 
oesophagus, in the submucous layer. 
THE STOMACH. 
The oesophagus, after piercing the diaphragm, opens into the stomach, 
the first abdominal portion of the digestive tract, and separated from the 
intestine by a valve termed the pylorus, which consists of a ring of addi- 
tional fibres of the inner muscular coat and a circular fold of mucous THE STOMACH. 
711 
membrane constricting the diameter of the aperture of communication 
to about half an inch when at rest. The oesophageal or cardiac orifice 
is opposite the tenth thoracic vertebra, a little to the left of the mesial 
plane, while the pylorus is about two inches lower, and a little to the right of 
the mesial plane, beneath the left end of the portal fissure of the liver, with 
which it is connected by means of the gastro-hepatic omentum. 
The stomach presents an anterior and a posterior surface, which are applied 
one to the other when it is empty, and are limited by two borders. The 
upper border or smaller curvature, short and concave, descends from the right 
side of the cardiac orifice and crosses the middle line to reach the pylorus ; 
to it the gastro-hepatic omentum and gastro-phrenic ligament are attached. 
Fio. 541.—Stomach showing Superficial Muscular Fibres. 1, Oesophagus; 2, 
carotid; 3, cul-de-sac ; 4, pyloric antrum; 5, anterior pyloric ligament of Helvetius; 6, 
pylorus; 7, 8, smaller and greater curvature ; 9, duodenum. (Luschka.) 
The other border, the great curvature, is much larger and sweeps to the left 
from the cardiac orifice, then turns round below, and as it nears the jiylorus, 
gradually approaches to the upper border; to it is attached the pendulous 
gastro-colic omentum. When the stomach is empty and contracted it descends 
for about two-thirds of its extent before curving to the right. In the dis- 
tended condition the surfaces are rounded out; the greatest vertical antero- 
posterior section is opposite the cardiac orifice, the part properly termed the 
fundus ; to the left of this there is a large hemispherical recess, the great cul- 
de-sac, sometimes, but improperly, called fundus; while to the right the 
diameter gradually diminishes. Near the pylorus the curve is completed, and 
a slight bend in the opposite direction distinguishes the antrum of the pylorus. 712 
THE DIGESTIVE ORGANS. 
When distended the stomach fills the greater part of the left hypochondrium, 
the epigastrium below the liver, and part of the right hypochondrium ; and 
it may reach to as much as a foot in length, and five inches in width. In 
this state, also, it is changed in position in two respects : it is rotated so 
as to throw the inferior border forwards, in consequence of enlargement 
backwards being impossible, and it is thrown into a transverse position 
by the levels of the orifices remaining the same while the dimensions of the 
organ are increased. The nervous supply is from the pneumogastrics and 
the sympathetic. The left pneumogastric descends from the oesophagus on 
the front, and the right on the back of the stomach. The sympathetic 
branches accompany the arteries. Minute ganglia {of Bemak) are scattered 
in the walls. 
The walls of the stomach present four coats, namely, the serous, muscular, 
submucous and mucous. 
The serous or peritoneal coat is derived in front from the general peri- 
toneum, and behind from the smaller sac, and is complete except along 
the lines of the great and small curvatures. 
Fig. 542.—Stomach everted to show muscles seen on removal of mucous membrane. 1 
Oesophagus ; 2, duodenum ; 3, circular fibres ; 4, oblique fibres. (Luschka.) 
The muscular coat presents three different sets of fibres. The outermost 
are longitudinal, continuous with the longitudinal fibres of the oesophagus, 
and are most abundant along the two curvatures. The intermediate 
layer is the most complete, and consists of circular fibres, which on the 
cardiac cul-de-sac are comparatively thin, but are interesting in respect that 
they form rings altogether to the left of the oesophageal orifice, and thus 
demonstrate it to be no mere expansion, but a caecal outgrowth such as is 
found more distinctly in many other mammals. The circular fibres become 
more abundant as the pylorus is approached, and take part in the formation 
of the valve by means of a specially developed thick ring. The innermost THE STOMACH. 
713 
set of muscular fibres is the least perfect layer, and, like the circular fibres, 
it is continuous with the circular layer of the oesophagus. Its fibres are 
oblique, and form arches to the left of the oesophagus, which spread 
obliquely downwards and to the right on the front and back, the uppermost 
fibres being the strongest and running nearly parallel to the smaller curva- 
ture. They have been described as a cravate de suisse, and leave uncovered 
between the cardiac and pyloric orifices a tract which by their contraction 
might be separated by a constriction from the rest of the cavity and serve 
to conduct fluids directly to the intestine (Larger). 
The submucous coat consists of loose areolar tissue. In it the arteries 
for the mucous membrane break up into small branches, and the emerging 
veins are gathered into larger vessels, and it allows the mucous membrane 
to be thrown into folds when the muscular coat is contracted. 
Fig. 543.—Gastric Mucous Membrane, q5-, 
hardened in chromic acid, showing the mam- 
illated condition, and over the mamillae the de- 
pressions into which the follicles open. (Luschka.) 
Fig. 544.—Opaque Injection of Mucous Mem- 
brane op Stomach, -7to-, showing, besides the 
bloodvessels, the shallow depressions into which 
the gastric follicles open. (Luschka.) 
The mucous membrane is smooth, soft, lustreless, spongy and thick com- 
pared with that of the intestine, and without thread-like or villous projections 
on its surface. It differs both in thickness and in superficial appearance 
in different conditions of engorgement. The thickness may reach to as 
much as a twelfth of an inch in the fundus, but probably is never more 
than half so great near the pylorus, and it is still less in the great cul- 
de-sac. The largest inequalities of surface are the rugae, a set of irregular 
temporary elevations caused by folding of the whole thickness of the mucous 
membrane in consequence of contraction of the muscular coat; the more 
prominent rugae follow a longitudinal direction. The surface in the least 
swollen condition of the mucous membrane is uniform, but in other instances 
or other parts it is mamillated, exhibiting minute curving elevations separated 
by shallow linear depressions, which, when the swelling is still greater, are 
converted into larger dimples separated by prominent ridges. A more 
minute inequality of surface can be brought into view under low powers 
of the microscope, namely, a series of shallow depressions into which the 
gastric follicles open in groups of from four to twelve. Formerly they 714 
THE DIGESTIVE ORGANS. 
were described in an exaggerated manner, which has led to their being, 
latterly overlooked almost altogether. 
The mucous membrane is bounded on its deep side by a thin but firm 
layer of decussating muscular fibres, muscularis mucosae. In the rest of its 
depth it consists principally of secreting tubes, 
the gastric follicles. These, save in the neigh- 
bourhood of the pylorus and close to the 
oesophagus, are simple tubules embedded in 
loose retiform tissue, their somewhat dilated 
extremities reaching down to the muscularis 
mucosae, and their necks bound more firmly 
together. The whole surface of the mucous 
membrane, and also the necks of the follicles, 
are lined with columnar epithelium, which 
takes the place of the stratified squamous 
when the oesophagus has opened into the 
stomach. But, beyond their necks, the simple 
tubular gastric follicles have their secreting 
cells polyhedral and of very various size, the 
larger cells more distinctly granular and the 
smaller interspersed between them in a rather 
irregular fashion, by no means covering them 
nor arranged in very definite order. 
In the dog, the cat, and other animals, the 
two kinds of corpuscles found in the gastric 
follicles are more definitely distinguished. 
One set, the principal or, more properly, the 
central cells, is continuous with the columnar 
epithelium of the necks of the follicles, and 
consists of small, clear, nearly cubical cor- 
puscles. The other, the parietal or underlying 
cells, are large, oval and granular, much less 
liable to alteration after death, and, in some 
conditions of the tubules, bulge out hemi- 
spherically from their sides; they were at one 
time named peptic from an erroneous idea that 
they were the sole secretors of pepsin, while 
the small set secreted mucus. In the dog, 
towards the pylorus, the glands are more 
branched, and are destitute of the larger or 
marginal cells; and numerous experiments 
have been made to decide the functions of 
the two orders of cells by working with 
Pig. 545.—Section of Mucous Mem- 
brane of Human Stomach at its 
thickest part, a, Necks of follicles 
lined with columnar epithelium; b, 
dilated ends of follicles ; c, retiform 
tissue ; d, muscularis mucosae. 
portions of mucous membrane from the cardiac and pyloric regions. 
In the human subject, within the pyloric antrum, the follicles become THE STOMACH. 
715 
shorter and the larger corpuscles more scarce, and close to the valve short 
tubules are arranged in groups opening into the duct. On the valvular 
Fig. 546.—Mucous Membrane of Stomachic Side of Pyloric Valve, showing 
branched glands, a, Muscularis mucosae interrupted by large pyloric glands. 
Fig. 547.—Mucous Membrane immediately below Oesophageal opening of Stomach, 
showing branching glands, and on the surface thread-like papillae denuded of epithelium, 
human. 
fold itself the branching of tubes is carried much further, and the glands 
increase in size and burst through the muscularis mucosae which is inter- 
Lumen 
' Connective 
tissue 
Central cell 
.Parietal cell 
rupted by them; and they present the appearance in section of racemose 
Fig. 548.—From Fundus of Human Stomach, -f-. (Bohm and v. Davidoff.) 716 
THE DIGESTIVE ORGANS. 
glands lined with regular cubical epithelium surrounding a considerable 
lumen. At the summit of the valvular fold these glands suddenly cease, 
villi and simple tubules at once begin, and the intestinal muscularis mucosae 
starts close to the surface. Compound tubular glands containing large cells 
are found close to the cardiac orifice where the oesophageal epithelium 
and papillae have not yet disappeared.1 
Between the glands and towards the surface special collections of minute 
unwalled corpuscles are here and there scattered in the retiform tissue, 
sometimes uninclosed, and generally less distinctly bounded than the closed 
follicles of the intestine. These are the conglobate or lenticular glands of 
authors, though other structures may have been sometimes confused with 
them 
Fig. 549.—Section of Injected Mucous Membrane of Stomach of Cat. Arteries 
and arterial capillaries, black ; veins and venous capillaries, grey. (Toldt.) 
The bloodvessels of the mucous membrane are arranged in such a manner 
as to secure the flow of pure blood through its texture. Immediately on 
1A good, deal of work remains to be done on the differences of the mucous 
membrane of the human stomach in different parts and in different conditions. The 
operations now sometimes performed may afford means for obtaining fresh material 
for such research. Meanwhile, the account by Edinger (Archiv. Micr. Anat., 1880) 
is probably as accurate as any, and 1 quite agree with the view there suggested, 
that in the human subject the different sizes of corpuscles are probably different 
stages of one series. The glands of the pyloric valve have been confused with 
Brunner’s glands, but are quite different both in their relation to the muscularis 
mucosae and in their contents. The compound glands at the cardiac orifice were 
noted and figured by Allen Thomson in Goodsir’s Annals, 1850. THE STOMACH. 
717 
piercing the muscularis mucosae the arteries break up into a network of 
capillaries for the supply of the glands; and on the surface there is a 
closer capillary network from which the venous radicles, fewer in number 
than the arterioles, and larger, descend in straight course, taking at once 
away from the tissue the impure blood to which have been added sub- 
stances imbibed from the cavity of the viscus. The lymphatics begin near 
the surface of the mucous membrane in loops and dilated spaces which 
fall into a finer network, whence 
vessels pierce the muscularis 
mucosae to enter the valved lym- 
phatics of the submucous coat. 
THE INTESTINE. 
The intestine extends from 
the pyloric valve to the anus, 
and is divided into small and 
great intestines, separated one 
from the other by the ileo-colic 
valve. It presents a more or 
less complete peritoneal covering, 
a muscular coat arranged in two 
layers, of which the outer consists 
of longitudinal and the inner of 
circular fibres, and a mucous 
membrane separated from the 
muscular coat by a submucous 
coat of loose connective tissue 
thinner than that of the stomach. 
The small intestine is counted 
as about twenty feet in length 
and is characterized throughout 
by its regular cylindrical form 
and the even distribution of 
both the thin longitudinal and 
the thicker circular muscular 
fibres. Its diameter diminishes 
gradually from the commence- 
ment, where it reaches from an 
inch and a quarter to an inch 
and a half, as far as its termina- 
Fig. 550.—Abdominal Part of Digestive Tube, a, 
Oesophageal opening of stomach; b, pylorus; b to c, 
duodenum ; c to d, jejunum and ileum with line of 
attachment of mesentery ; d, above the caecum, below 
the ascending colon, and opposite the ileo-colic valve ; 
e, vermiform appendage; /, g, h, ascending, transverse 
and descending colon ; i, sigmoid flexure ; k, rectum. 
tion, where it is less than an inch. It is divided into duodenum, 
jejunum and ileum. 
The duodenum is that part which is fixed in position and destitute of 
mesentery. It is about nine or ten inches long, and got its name to 718 
THE DIGESTIVE ORGANS. 
indicate twelve fingerbreadths as its length. It is directed in its first 
part from the pylorus horizontally toward the right under cover of the 
liver and gall-bladder, and invested like the stomach with the general 
peritoneum in front and the smaller sac behind. It then gets beyond the 
smaller sac and descends in front of the right kidney opposite the second 
and third lumbar vertebrae, and covered with peritoneum in front only. 
The remainder or third part turns to the left as far as the middle line, 
crossing the inferior vena cava, and then proceeds almost vertically 
upwards in front of the aorta to end abruptly opposite the second lumbar 
vertebra by being suspended in a constant position from the surface of 
the left crus of the diaphragm by a long, broad and strong fibrous sheet 
Gastro-hepatic omentum 
Cut gall bladder 
Duodenum, first part 
-Stomach 
Kidney 
■Splenic flexure of colon 
Ligament of Treitz 
J Commencement of 
I jejunum denuded 
Duodenum, last part 
Commencement of 
ascending colon 
Jejunum cut 
—Aorta 
Cut edge of mesentery 
Vena cava inferior 
Fig. 551.—Relations of Duodenum. (Alexander Macphail, M.8.) 
containing muscular fibres, the ligament of Treitz. This third part, being 
crossed first by the transverse mesocolon, and afterwards by the commence- 
ment of the mesentery, is only in contact with the peritoneum between 
these two structures, and in half the breadth of its ascending portion to 
the left of the mesentery. The common bile-duct and the pancreatic duct 
or ducts open on the posterior wall of the descending part of the duo- 
denum. The concavity of its curve is occupied by the head of the 
pancreas, and the arteries which supply it are the superior and inferior 
pancreatico-duodenal, one a branch of the hepatic artery and the other of 
the superior mesenteric. 
The jejunum and the ileum include the whole of that part of the 
small intestine which is connected by mesentery with the abdominal wall, THE INTESTINE. 
719 
namely, from the duodenum to the ileo-colic valve. It is customary to give 
the name jejunum .to the upper two-fifths and to call the other three-fifths 
ileum, but the only structural differences between the upper and lower 
parts take place in quite a gradual manner. The distinction to which the 
jejunum owes its name is its usually more empty condition both as regards 
solid and gaseous matters. The arrangements for absorption are most 
developed in the upper part of the intestine, and the muscular activity 
may be habitually greater, but, whatever may be the cause, it is an easily 
observed fact that the jejunum is not so habitually distended as the ileum. 
Both jejunum and ileum receive their blood entirely from the superior 
mesenteric artery and their nerves from the plexus of the same name. 
An occasional diverticulum occurs on the ileum, perhaps as often as 
once in a hundred bodies. These diverticula are short blind protrusions 
lined with mucous membrane, and presenting regular muscular walls with 
circular and longitudinal fibres. They are confined to a limited region, 
usually from eighteen inches to four feet above the ileo-colic valve, and may 
project at right angles to the intestine or slope in a downward direction. 
There can be no doubt that their position corresponds with that of the 
extremity of the loop which projected in connection with the umbilical 
vesicle in the embryo, as was first recognized by Meckel, though the 
structure had been often observed before, and had been figured by Buysch. 
Fig. 552.—Valvulae Connivbntbs exhibited in a piece of jejunum cut open, f. 
Fig. 553—Villi, human, denuded of epithelium, lacteals and bloodvessels injected. 
Fig. 552. 
Fig. 553. 
I.acteals, white ; 'bloodvessels, black. (After Teichmann.) 
The mucous membrane presents in a great part of its extent permanent 
transverse folds of its whole thickness. These are called valmlae conniventes, 
and, where most developed, have a crescentic form, extending two-thirds 
round the intestine, projecting a quartet of an inch in the middle, and 
placed about the same distance one from another. No one fold directly 
overlies the next, but they are placed irregulaily so as to be equally dis- 
tributed round about. They begin about two inches from the pyloius, and 720 
THE DIGESTIVE ORGANS. 
are largest and most frequent in the last part of the duodenum and 
beginning of the jejunum. They become smaller, and are placed at greater 
distances apart in the lower part of the jejunum, and dwindle away 
altogether below the middle of the ileum. 
The mucous membrane of the intestine is firmer and thinner than that of 
the stomach, and has this distinctive character that it is covered with minute 
processes called villi, which begin at the margin of the pyloric valve and 
cease at the margin of the ileo-caecal valve, and stand out like velvet-pile 
when the membrane is placed in water. It consists of closely set secreting 
tubules, supported by retiform tissue and resting on a thin stratum of 
muscular fibre, the muscularis mucosae. 
Deep texture 
Nucleus of euithelial cell 
| Thickened epithelial wall 
Goblet-cell 
Fig. 554.—Section of Tip of Villus, man, —. (Bohm and v. Davidoff.) 
The epithelium of the surface, both of the villi and the intervals between, 
is columnar and characterized by a thickening on the free extremities of 
the cells. This thickening is a pulpy substance continuous over them, less 
firm than their deep walls, neither swelling nor collapsing so easily as 
they, and permeable by the oily particles of the chyme, which thus enter 
the interior of the cells and may load them to the extent of concealing the 
nucleus ; it presents in different conditions more or less distinct vertical 
striation. Scattered among the other columnar cells are some distended 
with mucus which displaces the nucleus to the deep end, and others widely 
open by escape of this mucus and called goblet-cells (p. 58). THE INTESTINE. 
721 
The villi are longest in the duodenum and upper part of the jejunum, 
where they may reach to the thirty-sixth of an inch in length, and are 
placed exceedingly closely; and they become shorter and sparser till at 
the lower part of the ileum they are no longer than broad and are scattered 
distinctly one from another. They are liable to considerable variation in 
different subjects, being, in the jejunum, sometimes filiform and sometimes 
flattened and connected. In many animals they are longer, narrower and 
covered with larger epithelial cells than in man. That the epithelial cells 
of the villi are actually prolonged into processes in continuity with branched 
corpuscles more deeply placed may be questioned, although there is high 
authority for the allegation, but there can be no doubt that the molecular 
substance which they take in from the chyme is passed on from them into 
the lymphatic radicles. One or more such radicles run down the centre of 
each villus and begin as an unwalled space, which may be clavately enlarged; 
while the bloodvessels are arranged in a single layer at the circumference. 
Fig. 555.—Tw0 Peyeb’s Patobbs 
natural size. 
Fig. 550.—Section of Duodenum. 
a, Villi; 6, Lieberktihu’s follicles ; c, 
a Brunner’s gland; d, muscular 
wall. 
The glands which take part in the structure of the mucous membrane 
are the crypts or follicles of Licbevh'dhn, simple tubes passing straight from 
the surface down to the muscularis mucosae, lined throughout with columnar 
epithelium. But in the duodenum there is a special set of glands called 
Brunner's glands not found in the rest of the intestine. These are small 
acinated glands, barely visible with the naked eye, lying in numbers in 
the submucous tissue, immediately underneath the muscularis mucosae, 
which is pierced by the single duct of each. 
Closed follicles or lymphatic nodules, distinguished as solitary glands, 
are scattered in the mucous membrane of the whole small intestine. Others 
are gathered together in groups, and are termed agminated glands or Poyer’s 
2 z 722 
THE DIGESTIVE ORGANS. 
patches. These may be said to be peculiar to the ileum, and at first are 
scattered and small, but increase in size and frequency lower down. They 
are about half an inch in breadth, and vary from the circular form to a 
length of more than two inches. The closed follicles have firm walls of 
connective tissue, and contain minute lymphoid corpuscles and fine threads 
of connective tissue, with loops of capillary bloodvessels converging to the 
centre. They slightly project on the surface in the recent state, and 
reach down into the submucous tissue. 
a, Injected lacteals of 
villi 
Summit of closed 
follicle 
Muscularis mucosae 
Chyle-paths around 
the follicle 
Base of closed follicle 
(Chyle-paths around 
[ the follicle 
Lymphatic of ) 
submucous layer j 
Fig. 557.—Closed Follicles, Villi and Lacteals, Cat, (After Frey.) 
Chyle-paths around the follicle 
The bloodvessels of the mucous membrane present the peculiarity seen 
more distinctly in the stomach that the glands are supplied by capillaries 
given off from arterioles after piercing the muscularis mucosae, 
and pour their blood into larger capillaries on the surface where the venous 
radicles take origin; but the arterioles are continued on to supply the villi, 
breaking up at the bases of these into large capillaries, which in the broader 
villi run parallel one to another, united by smaller branches. Each villus 
has its bloodvessels confined to the surface, so as to form a web in the 
form of a hollow cone. The lacteals arise, as already described, in the 
interior of the villi, and fall into a network of smaller vessels in the sub- 
stance of the mucous membrane, which discharges its contents into a network 
of wider vessels in the submucous coat, immediately beneath the muscularis 
mucosae. This network specially surrounds the base of each closed follicle, 
but does not seem to communicate with its interior, and has never been 
alleged to do so. THE INTESTINE. 
723 
The nerves of the small intestine are supplied by the superior mesenteric 
plexus of the sympathetic, and form in the walls two meshed and gangliated 
plexuses. One of these, Auerbach’s 
plexus, is situated between the longi- 
tudinal and circular layers of the 
muscular coat; the other, Meissner’s 
plexus, is in the submucous coat. 
From the latter, fine branches have 
been traced forming a netted plexus 
both in the substance of the mucous 
membrane and in the villi. 
or six feet long; it may be said in 
general terms to be about twice the 
diameter of the small intestine, and, 
like it, is largest at the commence- 
ment, and gradually narrows as far as 
The large intestine is about five 
Fig. 558.—Intermuscular Lymphatics and My- 
enteric Plexus of Guinea Pig, L, Lymphatics; 
(x, ganglia ; N, nerve-cords. (Auerbach.) 
the rectal dilatation. It begins in a short and wide blind pouch, the caecum-, 
the caecum, at the place where the ileum opens into it laterally, is con- 
tinued into the colon; the colon 
constitutes the greater part of 
the large intestine, and is 
divided into ascending, trans- 
verse and descending colon 
and the sigmoid flexure ; and 
the sigmoid flexure falls into 
the rectum. In its whole 
extent, with the exception of 
the rectum, the large intestine 
has a sacculated appearance, 
contrasting with the even 
cylindrical form of the small 
intestine. This sacculation in- 
volves the mucous, submucous, 
muscular and serous coats, but 
is maintained by the arrange- 
ment of the fibres of the 
muscular coat. The longi- 
tudinal muscular fibres are 
arranged principally in three 
strong bands or taeniae, dis- 
tinguished as mesenteric, pos- 
Fig. 559.—Section of Small Intestine of Guinea Pig. A, 
Longitudinal muscular layer; B, circular layer; C, sub- 
mucous layer ; D, Lieberkilhn’s follicles ; E, villi; a, Auer- 
bach’s plexus; b, deep myenteric plexus cut across; c, 
Meissner’s plexus ; e, periglandular plexus ; /, intravillous 
plexus. (Cajal.) 
terior and lateral, and only a 
few are scattered between the bands. The circular fibres also are more 
numerous between the saccules than over them. An additional peculiarity 724 
THE DIGESTIVE ORGANS. 
of appearance is given by little appendages and projections of peritoneum 
inclosing fat, appendices epiploicae; they may be as much as an inch or 
more in length, and are most numerous near one of the longitudinal bands 
on the concavity of the arch formed by the colon. 
The mucous membrane is destitute of villi, thinner, firmer and more 
glistening than that of the stomach. It presents, like the small intestine, 
straight secreting tubules extending down to the muscularis mucosae, and 
lined with columnar epithelium. The name of follicles of Lieberhuhn is 
sometimes extended to them. They are longer and more closety set than 
those of the small intestine. Closed follicles are scattered singly (solitary 
glands) over the surface. The bloodvessels and lymphatics are arranged 
as in the stomach. 
epithelium 
Lumen of gland 
Goblet-cell 
.Connective tissue 
Retiform connective 
tissue 
■Muscularis mucosae 
Pro. 560.—Mucous Membrane of Colon, human, (Rohm and v. I'avidofl.) 
The nerves of the great intestine come from the superior and inferior 
mesenteric plexuses, and form gangliated networks on the coats, similar 
to those in the small intestine. 
The caecum (intestinum caecum or caput caecum coli), the blind pouch 
below the ileo-colic valve, is situated in the right iliac fossa, opposite the THE INTESTINE. 
725 
outer half of Poupart’s ligament. It is about as deep as it is broad when 
distended, and similar in appearance to the colon, but represents a portion 
of the intestine which in some animals is largely developed and quite 
distinct from the colon. It has coming off from it at the inner side of 
its lower end a prolongation, the vermiform appendage, usually about three 
inches in length, and sufficiently wide to admit a crow-quill easily. This 
appendix has considerable pathological importance, being liable to inflam- 
mation, and appendicitis often requiring surgical interference; and it may 
well be doubted if this affection is always determined by mechanical causes, 
when it is considered that, like the tonsils and Peyer’s patches, its mucous 
membrane is principally devoted to closed follicles. It has also a con- 
siderable importance morphologically, for, present in the orang and 
chimpanzee, it is generally absent in monkeys and in the majority of 
mammals, yet is present among marsupials, the caecum and vermiform 
Fig. 561.—Development of Caecum and Vermiform Appendage. A, Prom embryo of 
eighth week; B, from a girl three years old ; C, caecum ; Co, colon ; Gr, boundary-fold ; 
H. habenula caeci; /, ileum ; Pr, processus yermiformis; Tp, taenia posterior. (Toldt.) 
appendage of the wombat having sometimes been compared with those of 
man; and in certain rodents, as in the rabbit, it is of large dimensions, 
while in others, as the rat, it is completely absent. The caecum is 
completely surrounded with peritoneum, and a mesocaecum extends from 
below the ileo-caecal valve along the vermiform appendage. The vermiform 
appendage is in point of fact the true starting-point of the taeniae of 
the colon. The caecum and appendix have their origin so early as in 
the embryo of six weeks, in the form of a projection taking an upward 
direction, as do the caeca of monotremata, birds, reptiles and fishes in 
which caeca occur. The three fraena of the colon together spring from the 
vermiform appendix, and persist distinct for a variable number of years. 
The fraenum mesentericum, however, early becomes short as compared with 
the others, and is concerned in a folding inwards and backwards of the 
caecum which commences in the embryo of nine weeks. The part of the 726 
THE DIGESTIVE ORGANS. 
fraenum crossing the fold is called the habenula. The importance of this 
fold in the development of the under lip of the ileo-colic valve has been 
shown by Toldt, and derives additional interest from the circumstance 
that the form of the human ileo-colic valve is peculiar, the usual form in 
mammals being circular, as it is originally in the human foetus. The 
varieties of peritoneal connection of the caecum and vermiform appendix, 
and the tendency of the latter to be coiled up and concealed behind the 
caecum, have recently received great attention at the hands of various 
anatomists, especially Treves and Huntington. 
The ileo-caecal or ileo-colic valve is an arrangement by which reflux of the 
contents of the great intestine into the ileum is prevented. It consists of an 
upper and a lower lip of mucous membrane 
projecting from the aperture of the ileum 
into the colon, while the anterior and 
posterior angles of junction of the two lips 
are prolonged as projecting folds (fraena) 
more or less round the colon. The upper 
lip projects transversely, and the lower 
obliquely upwards, and the lower is much 
the broader. Villi and closed follicles, 
agminated glands, are found on the opposed 
surfaces of the lips and cease at their edges. 
Distension of the colon puts the lips on 
the stretch, and thus keeps them in close 
apposition. 
The colon. The ascending colon extends 
upwards from the caecum, in contact with 
the posterior wall of the abdomen, being 
to a certain exent uncovered by peritoneum 
behind. It passes from the right iliac 
Fig. 562.—The Caecum and Ileo-colic 
Valve, a, Ileum ; b, ascending colon : c, 
caecum ; d, vermiform appendage. 
region, through the right lumbar, and into the right hypochondriac region, 
where it is continued into the transverse colon by making a sharp turn, 
the hepatic flexure, which rests against a slight depression on the anterior 
half of the under surface of the right lobe of the liver. 
The transverse colon at its commencement runs with a forward and 
downward inclination; it then crosses in front of the small intestines below 
the stomach, and inclines upwards and backwards below the spleen to end 
in the descending colon by taking a sudden turn, the splenic flexure, at a 
higher level and further back than the hepatic flexure. The transverse 
colon may be said to have a mesocolon in its whole length, but at its 
commencement the mesocolon is so narrow that the colon is almost in contact 
with the duodenum where it crosses it; and it is narrower again at the 
splenic flexure, where it ends in a prominent (costo-colic) fold. But in the 
intervening part, where the smaller sac of the peritoneum takes part in 
its formation, the mesocolon is broad, and sometimes it is greatly stretched THE INTESTINE.’ 
727 
and the transverse colon arched downwards so as to approach the brim of 
the pelvis. 
The descending colon extends from the splenic flexure in the left hypo- 
chondrium, through the left lumbar region, to the upper and back part of the 
left iliac, and is imperfectly covered with peritoneum, being in contact with 
the posterior abdominal wall. 
The sigmoid flexure is a loop continuous with the descending colon, 
forming in conjunction with the commencement of the rectum the double 
curve from which it takes its name. The loop hangs loose by a mesocolon, 
continuous below with the mesorectum. 
Promontory 
Summit of bladder 
Recto-vesical pouch 
( Prepubie angle of 
I urethra 
Seminal vesicle, 
Prostatic part of urethra 
Sphincter vesicae 
Membranous part of urethra 
Fig. 563.—Mesial Section of Male Pelvis. 2, Symphysis pubis; 3, rectum; 4, 
sigmoid flexure ; 5, 5, small intestine ; 7, urinary bladder ; 10, prostate ; 13, spongy part 
of urethra. (Luschka.) 
The rectum, about eight inches in length, extends from opposite the left 
sacro iliac articulation to the anus. It is attached in its upper half to the 
posterior wall of the pelvis by a mesorectum, and slopes at first inwards and 
downwards then lies in the mesial plane and follows the curve of the sacrum 
and coccyx till immediately above the sphincter and an inch or two beyond 
the coccyx, when it is directed abruptly downwards and backwards to the 
outlet. In the lower part of its curve it is considerably dilated, and being 
beyond the recto-vesical pouch, it is devoid of peritoneal covering. Here it 
has in the male the trigone of the bladder and the prostate gland resting in 
front of it, and in the female the vagina. The longitudinal fibres of the 728 
THE DIGESTIVE OEGANS. 
muscular coat are strong, and cease to be gathered into bands, and are 
disposed pretty equally, as also are the circular fibres down as far as the 
recurved outlet, where they are accumulated in large quantity to form 
the internal sphincter. The mucous membrane presents a few crescentic folds 
(valves of Houston), the most prominent of them being situated in front, 
behind the prostate, and the next above it projecting from the posterior 
wall a little higher up. The constricted part within the grasp of the internal 
sphincter is thrown into longitudinal folds; and lower down than this the 
mucous membrane, covered with columnar epithelium, comes in contact with 
a thin prolongation upwards of integument with squamous epithelium of the 
cuticle. The line of termination of the mucous membrane is distinct and 
crenated; and between the crenations there run upwards some short 
narrow prolongations of integument about eight in number (columns of 
Morgagni) separating shallow depressions of the mucous membrane, which 
when engorged may become convex. 
THE PANCREAS. 
The pancreas is an elongated gland, of soft structure and lobulated 
appearance, not unlike a salivary gland. It lies across the posterior wall 
Fig. 564.—Pancreas from behind. 1, Duodenum ;2, common bile duct; 3, 4, 5, duct 
of Wirsung dissected out; 6, 7, communicating branch and accessory pancreatic duct. 
(Beaunis.) 
of the abdomen, extending from the duodenum, whose loop it fills up, 
to the spleen, which it barely touches. The end embraced by the duo- THE PANCEEAS. 
729 
denum is broad, and is called the head; the greater part of the succeeding 
length is about an inch and a half broad, and is called the body; and 
the narrow extremity next the spleen is called the tail. With the ex- 
ception of part of the head, it is clothed in front with peritoneum by 
the posterior wall of the smaller sac. It is in contact behind, from right 
to left, with the diaphragm, the inferior vena cava, the superior mesenteric 
vein and artery, the inferior mesenteric vein, the aorta and the left crus 
of the diaphragm; and close to its upper border is the splenic vein, 
partly concealed by it, with the splenic artery above it, as also the 
coeliac axis and hepatic artery. 
Bases of 
secreting cells 
Centro-acinary 
cells 
Connective ' 
tissue 
Larger duct. 
.Commencing duct 
Inner zone of 
secreting cells 
Fig. 565.—Human Pancreas, . (Bohm and v. Davidoff.) 
The pancreas pours its secretion into the duodenum by a duct (duct 
of Wirsung) with thin non-muscular walls, which can be easily traced 
running in the middle of the gland in its whole length, receiving in its 
course numerous tributary ducts from above and below. The duct opens 
mainly or altogether into the descending part of the duodenum about four 
inches from the pylorus into a shallow depression on the posterior wall, 
common to it and the common bile-duct, having pierced the intestinal 
wall obliquely. Near its exit it receives a tributary from the lower part 
of the head, rather larger than the others, and often there is in addition 
a superior or accessory duct opening fully an inch above the main duct, to 
which it can be traced back. 
The larger lobules of the pancreas consist of smaller lobules as in the 
case of a salivary gland. The acini are small in transverse section, and 
sometimes so elongated that some observers describe the pancreas as a 730 
THE DIGESTIVE ORGANS. 
tubular or acino-tubular gland; but the same difficulty may with equal 
justice be raised with reference to other glands, as the parotid and 
Brunner’s glands. The secreting corpuscles leave little central lumen, but 
a network of intercellular passages has been displayed by injection by 
various observers, and compared with the network of canals demonstrated 
in the liver. The secreting corpuscles are loaded with granules towards 
the centre of the acinus to such an extent as to add difficulty to their 
examination, and the number of granules is alleged to varj*- according 
to the period of digestion. Amoeboid corpuscles, centro-acinary cells of 
Langerhans, are frequent within the acini. 
THE LIVER. 
The liver is much the largest gland in the body, weighing ordinarily 
between 50 and 60 ounces in the adult male, and between 40 and 50 in 
the female. It is of a deep brown colour more or less mingled with 
claret colour according to the amount of blood which it happens to con- 
tain. Symmetrical, or almost so, in its earliest development, it occupies 
in the young foetus the whole upper part of the abdomen; but in conse- 
quence of the left side growing less rapidly than the right, it comes in 
the adult to occupy principally the right hypochondrium, stretching across 
the epigastrium to the left hypochondrium, which it invades to a small 
and variable extent. When laid out on a flat surface it is somewhat 
quadrate in form, thick behind, sharp-edged in front and to the sides, 
and decreasing both in thickness and in antero-posterior diameter 
toward the left, and it presents an unbroken dorsum looking upwards. 
But in the natural position within the body the differences in thickness 
of different parts are greater; for the dorsum not only lies against the 
diaphragm both behind and above, but descends on the right side to the 
level of the eleventh rib, and in front comes in contact with the trans- 
versalis abdominis, its anterior edge lying inside the seventh, eighth and 
ninth costal cartilages before sloping upwards across the middle line, and 
backwards in a manner varying somewhat in different persons and attitudes. 
The posterior surface is also formed in great part by the dorsum, and is 
deep and convex on the right, thinning to an edge toward the left. 
As it approaches the mesial plane it is thrown into a concavity by the pro- 
jection of the vertebral column; and on the right side of this concavity, 
it presents a deep vertical groove for the inferior vena cava, which is firmly 
embedded in it, and receives the emerging veins termed hepatic, carrying 
the blood away from the liver. 
The anterior edge is interrupted by two notches, one lying above the 
fundus of the gall-bladder, while the other, placed about an inch and a 
quarter more internally, but still situated about an inch to the right of the 
middle line, receives the obliterated umbilical vein, the round ligament, as 
it passes to the under surface. On each side of this ligament the peritoneum THE LIVER. 
731 
extends upwards and backwards over the liver and the opposed surface of 
the diaphragm, thus forming a septum, the falciform or suspensory ligament, 
whose hepatic attachment corresponds with the division of the inferior sur- 
face into right and left lobes. The other peritoneal connections of the liver 
are the coronary and right and left triangular ligaments, and the attachment 
of the gastro-hepatic omentum (p. 689). 
The inferior surface presents a number of fissures and lobes. The longi- 
tudinal fissure, dividing it into a right and a left lobe, extends from front to 
back, and consists of two parts, an anterior, the fissure of the umbilical 
vein, and a posterior, distinguished as the fissure of the ductus venosus, and 
also giving attachment to part of the gastro-hepatic omentum. The portal 
Quadrate 
lobe 
Suspensory ligament 
Colic depression 
Gall bladder 
1 Obliterated 
i umbilical vein 
.Ductus venosus 
Lobule of 
Spigelius 
Renal depression 
Hepatic artery 
| Inferior vena cava 
Common bile duct 
Cystic duct 
Hepatic duct 
Portal vein 
Fig. 566.—Under Surface of Liver. 
or transverse fissure falls at its left extremity into the longitudinal, dividing 
it into its two parts, and at its right extremity meets the posterior end 
of the fissure of the gall-bladder, which extends forwards from it. Behind 
the right extremity of the portal fissure is the groove or fissure of the inferior 
vena cava, separated from it by a narrow elevation. The portal fissure is 
the site of attachment of the part of the gastro-hepatic omentum containing 
structures entering and emerging from the liver. The structures in question 
enter and emerge at its extremities and are the right and left branches of 
the hepatic artery, the right and left branches of the portal vein, the right 
and left hepatic ducts, together with nerves and lymphatics. At the left 
end of the portal fissure the obliterated umbilical vein ends in the left 
branch of the portal vein, and the obliterated ductus venosus starts from 
the same point to go backwards and upwards to join the inferior vena 
cava. 732 
THE DIGESTIVE ORGANS. 
Three portions of the right lobe are named as separate lobes; and 
two of these, namely, the quadrate and the Spigelian lobes, are definitely 
bounded. The quadrate lobe is in front of the portal fissure and is between 
the fissure of the umbilical vein and the fissure of the gall-bladder. The 
Spigelian lobe is behind the portal fissure, between the vena cava inferior and 
the fissure of the ductus venosus; it projects downwards as a three-sided 
pyramid, and is much more elongated in many animals, and is always 
distinguishable as the only lobe looking into the smaller sac of the 
peritoneum. The caudate lobe, the third portion of the right lobe dis- 
tinguished by the name of lobe, is merely a slight eminence outside the 
foramen of Winslow, and continuous with the narrow elevation separating 
the portal fissure from the vena cava inferior, but it is developed as a 
distinct lobe in many animals. The remaining part of the right lobe has 
a constant slight concavity toward the back, the renal impression, fitting over 
the right kidney, and another further forwards, the colic impression, lying 
over the hepatic flexure of the colon. The under surface of the left lobe 
exhibits a slight convexity corresponding with the smaller curvature of the 
stomach and a shallow concavity beyond over the fundus. 
Main ducts and gall-bladder. The right and left hepatic ducts, emerg- 
ing from the portal fissure, approach each other rapidly to form the hepatic 
duct, the right and left ducts joining in front of the right and left 
branches of the hepatic artery, while the portal vein bifurcates behind 
them, and lower down the hepatic duct lies to the right, the artery to 
the left, and the portal vein between and behind. The hepatic duct runs 
for about two inches and is met at an acute angle by the cystic duct. 
The duct resulting from the junction of the hepatic and cystic ducts is 
called the common bile duct (ductus communis choledochus) and continues 
in the same direction as the hepatic duct; it is about one sixth of an inch 
in diameter when distended, and is about three inches long. It passes 
down behind the descending part of the duodenum, between it and the head 
of the pancreas, pierces along with the pancreatic duct obliquely through 
the coats of the posterior wall of the duodenum, and opens by means of 
a constricted orifice into a slight depression common to it and the pan- 
creatic duct, about four inches from the pylorus. The gall-bladder is 
pyriform, three or four inches long and about an inch and a quarter in 
diameter at its broadest part when moderately distended. Its fundus or 
broad extremity projects to a certain extent free at the notch in the over- 
hanging margin of the liver, and it tapers backwards closely adherent to 
the floor of the groove in which it lies. It is continued into the cystic duct, 
which is about an inch and a half long, and turns downwards to join the 
hepatic duct. The raucous membrane of the gall-bladder has a fine reticu- 
lated pattern, throwing it into shallow honeycomb-like depressions visible 
to the naked eye and better seen with a lens. At the neck and in the 
cystic duct it is thrown into irregular folds liable to obstruct the passage 
of a probe. THE LIVER. 
733 
Hepatic structure. The liver presents in section and even through its 
investments a mottled appearance, which, when more closely examined, 
resolves itself into closely-set lobules varying in diameter from the twenty- 
fifth of an inch to twice that size, and each presenting a paler spot 
surrounded with darker colour, or a dark spot surrounded with paler 
colour, according as the blood happens to be more abundant at the cir- 
cumference or in the centre. The substance is friable, and torn surfaces 
exhibit lobules torn partially separate. 
Beneath the peritoneal covering, which is transparent, there is a certain 
amount of connective tissue not very visible when healthy, but important 
pathologically, the seat of bloodvessels and lymphatics, and easily seen in 
section with the aid of the 
microscope : this is called the 
fibrous or areolar capsule. But 
a larger amount of areolar 
tissue enters at the portal 
fissure and invests the 
branches of the portal vein, 
hepatic artery and ducts, as 
well as nerves and lymphatics, 
which may be traced back- 
wards together in branching 
hollows called portal canals; 
and this investment gets the 
name of capsule of Glisson. 
When the substance of the 
liver IS CUt across, the sections 
, 
of the portal canals, each con- 
. . . , , 
taming the loose wnite tissue 
„ , , p f. |. i 
of the capsule of txiisson and 
Fig. 567.—Hepatic Lobule Magnified, showing intra- 
lobular radicle of hepatic vein in the centre, and inter- 
lobular branches of the portal vein at its circumference. 
The grey lines are the columns of hepatic cells, the black 
spots their nuclei, the white spaces the lamina of the 
capillaries, the black lines the threads of white fibrous tissue 
hardened and stained. 
in it a more or less collapsed 
branch of portal vein, with a much smaller artery and still smaller duct, 
contrast with other gaping openings, namely, the sections of hepatic veins 
with their thin walls closely attached to the hepatic substance. 
Examined microscopically, each lobule presents in the centre a venous 
radicle called an intralobular vein, which falls into a sublobular branch of the 
hepatic vein; while, between the lobules, there are situated interlobular 
branches of the portal vein; but the texture appears principally composed of 
secreting corpuscles, the hepatic cells. These are unwalled polyhedral bodies, 
varying in size, but averaging of an inch, pressed with flattened 
sides each against others; they are of yellowish colour and granular appear- 
ance, each containing one large spherical nucleus, and some of them two. 
They may also contain oil globules and coarse granules, which are not, 
however, part of their proper substance. The hepatic cells present a dis- 
tinctly radiating arrangement in each lobule, but, when looked at more 734 
THE DIGESTIVE ORGANS. 
closely, are seen to constitute a continuous mass filling up the whole space 
left between the blood-capillaries, which form a very regular network with 
meshes elongated in a radiating direction, so that the whole lobule may he 
looked on as consisting mainly of two networks interlaced, the one vascular, 
the other cellular. Both the capillary and the cellular network are con- 
tinuous from one lobule to another, and, where the lobules meet, the radiating 
arrangement is lost. 
There are mammals, especially the pigs, camels, and giraffe, which have 
the lobules distinctly separated by connective tissue, but in most animals they 
are not so separated ; and in the human subject the connective tissue is so 
slight as to have been till recently somewhat overlooked. There is, however, 
both in the adult and the infant, a distinct set of isolated bands with netted 
branches uniting the tunica adventitia of the intralobular vein with the 
ultimate branches of Glisson’s capsule and other fibres coursing between the 
lobules. An abundance of minute leucocytes or lymphoid corpuscles may 
be found in scattered groups, and stellate corpuscles have been described. 
Within the lobules there remains to be described a network of intercellular 
ducts or canals. 
Fig. 568.—Hepatic Tissue Highly Magnified. 
A, Capillaries and bile-ducts injected; a, capillary 
bloodvessels ; b, intercellular ducts (after Hering); 
B, separate hepatic cells. 
Fig. 569.—Intralobular Ducts, silver chromate prepara- 
tion. (Bohm and v. Davidoff.) 
The ducts. Within the lobules there cease to be found any ducts lined 
with epithelium. The finest interlobular ducts have simple membranous walls 
lined with flattened cells which at the periphery of the lobules come into 
direct contact with the hepatic cells. But in the interior of the lobes there 
is a network of minute intercellular canals much finer than the capillary 
vessels, channelling the opposed surfaces of the hepatic cells, and only very THE LIYER. 
735 
imperfectly to be made out save with the aid of injection. They were first 
observed by means of coloured fluid injected backwards, but considerable 
doubt was felt by many until Chrzonszezewsky (1866) put an end to all 
question of their existence as canals during life, by his process of “natural 
injection,” which consisted of introducing solution of indigo into the veins of 
an animal, when, in consequence of this substance being eliminated from the, 
blood by the liver, injection of the intralobular canals was got by the 
action of the hepatic cells. These were found full of indigo when the animal 
was at once killed, but clear when the killing was delayed half an hour. 
Later researches, particularly by means of the Golgi method, have not only 
extended the acquaintance with the intercellular passages, but traced their 
origins from tributaries within the hepatic cells. Only the finest inter- 
lobular ducts have flattened epithelium; the rest are lined with columnar 
cells, and the larger ducts have a mucous membrane distinct from the outer 
Fio. 570.—Aberrant Ducts with Blind Glandular-looking Off-shoots, from the 
fissure of the ductus yenosus, -\0-. (Luschka.) 
wall. The outer wall of the larger ducts contains a certain amount of 
muscular fibres, especially those outside the liver, and the gall-bladder has 
a still more distinct muscular wall arranged in longitudinal and circular 
layers. The main ducts are beset with numerous branched pouches secreting 
mucus which in the ramifications within the liver become simple and 
arranged in two rows, and in the smaller ducts are absent. Remarkable 
networks of gall-ducts without hepatic substance around them, but accom- 
panied with twigs of portal and hepatic veins, vasa aberrantia, are found in 
the portal fissure, in a membrane joining the right and left hepatic ducts, and 
continued thence in the fissure of the umbilical vein, the fissure of the 
ductus venosus, round the vena cava inferior and into the left triangular 
ligament. The larger of these vasa aberrantia have mucous pouches like the 
other ducts. They are absent in the new-born child (Toldt). 
The hepatic artery after entering the liver ramifies in the portal canals, 736 
THE DIGESTIVE ORGANS. 
and its terminal branches are termed interlobular. But in its course it gives 
off vaginal branches to the other structures in the capsule of Glisson and 
capsular branches which pass to the surface and ramify in the capsule of 
the liver, often in stellate fashion. The lobules of the liver can be injected 
from the hepatic artery, but the injection always enters the lobules from 
the centre, and the probability is that it is taken up by radicles of the 
hepatic vein in Glisson’s capsule, and is sent backwards when exit by the 
inferior vena cava is blocked. 
The lymphatics of the liver are deep and superficial. The deep 
lymphatics emerge by the portal fissure; the superficial lymphatics form 
a plexus of remarkable closeness whose vessels principally join the deep 
lymphatics at the portal fissure, but also communicate with the parietal 
lymphatics in the ligaments. 
The nerves are principally sympathetic, the hepatic branches of the 
coeliac plexus; but filaments can be followed into the liver from the 
pneumogastric nerves. 
DEVELOPMENT OF STOMACH, INTESTINE AND LIVER. 
The part of the foregut within the grasp of the visceral arches forms a 
dilated pharyngeal pouch (pp. 94 and 99). The stomach makes its appearance 
immediately beyond this, as a spindle-shaped mesial structure, but descends 
as the heart descends, its descent giving rise to the oesophagus. The 
pylorus being the first part to be arrested in its downward movement, 
the stomach is bent and its dorsal surface thrown to the left, when the 
surface originally placed to the left is turned to the front. Meanwhile 
Fig. 571.—Diagrams of Stomach and 
Intestine in Third Month. A, Before 
the colon has crossed over the duodenum; 
B, after the crossing; 1, 2, 3, the coeliac, 
superior mesenteric and inferior mesen- 
teric loops; a, the caecum. 
Fig. 572.—Section from 
Liver of Foetus of Five 
Months, showing from three 
to seven corpuscles abreast 
between adjacent capillaries. 
the part of the intestine succeeding the stomach is lengthened into a loop 
projecting ventrally with the umbilical duct coming off from its turning- 
point, which during the second month reaches out beyond the abdominal 
wall. The lower end of this primary loop becomes approximated to the 
pylorus and forms the part of the transverse colon which remains per- 
manently in this connection. The caecum and vermiform appendage make 
their appearance close to this point, and push their way over the upper DEVELOPMENT OF STOMACH, INTESTINE AND LIVER. 
limb of the loop, turning it round, as they travel first to the right and 
then downwards. This twist of the loop is not, however, altogether due 
to travelling of its lower limb, for the base of its upper limb is at the 
same time elongated semicircularly to form the duodenum. The part of 
the intestine beyond the primary loop, at first straight, becomes arched and 
thrown over to the left side by elongation of its mesocolon, which in the 
third month is still mesial, the descending colon being merely in contact with 
the left side of the posterior wall of the abdomen, but not at that date 
attached to it. The smaller sac of the peritoneum is originally simply the 
right side of the mesogastrium. By the turning of the stomach on its side, 
and the descent of its oesophageal extremity, the mesogastrium becomes 
pouched, and the pouch so begun increases in size but is at first quite 
independent of the colon. Afterwards the inferior wall of the mesogastrium 
and the left wall of the mesial mesocolon become pulled away from the 
posterior wall of the abdomen near the middle line, and this brings the 
transverse colon into connection with the smaller sac of the peritoneum. 
The liver makes its first appearance close to the pylorus as a bifurcating 
protrusion or, more correctly, a pair of protrusions from the ventral aspect 
of the intestine, which elongate in close connection with the omphalo- 
mesenteric veins. In mammals it would seem that those protrusions com- 
mence after the stomach has begun to turn on its side, and the left protrusion 
appears first. Each protrusion sends out ramifying branches which go on 
dividing, and the hepatic cells are derived from the hypoblastic corpuscles 
within the ramifications, and are thus similar in origin to the secreting 
cells of other intestinal glands. Subsequently the processes anastomose, 
while they still give off side-shoots, and outgrowing branches from the 
vitelline vein form a network interlacing with them, and developing into 
a system of venae advehentes and revehentes, which result in the portal and 
hepatic veins. In later development there is still considerable difference from 
the adult arrangements. In a foetus of five months, adjacent capillaries 
have still a number of hepatic cells between them, and even at birth the 
columns of cells in the lobules are more liable to present two or three 
abreast than afterwards. 
The pancreas in the vertebrata generally is now known to take rise 
from three distinct intestinal outgrowths—a dorsal opposite the biliary pro- 
trusion, and two ventral, right and left of it. 
THE RESPIRATORY ORGANS. 
Leaving out of consideration the nasal passages and mouth, the respir- 
atory organs consist of larynx, trachea and bronchi, and the lungs, in 
which the bronchial tubes, continuous with the bronchi, pursue their course 
to the air-cells. 738 
THE RESPIRATORY ORGANS. 
THE LARYNX. 
The larynx is the upper part of the wind-pipe, modified in connection 
with the production of voice and protection from foreign bodies. It presents 
a special arrangement of cartilages, ligaments, muscles and mucous mem- 
brane, the general character of which is that a firm ring, the cricoid cartilage, 
furnishes the base on which the thyroid cartilage in front and the arytenoid 
cartilages behind are raised and depressed, so as to alter the position and 
tension of two lateral folds of mucous membrane, the true vocal cords, 
which project from the floors of two ventricles, and by their approximation 
and vibration produce the voice, while the aperture is overhung by the 
epiglottis and other structures for protection. 
Fig. 573.—Cartilages of Larynx. A, From behind: 1, thyroid cartilage; 2, de- 
pression on the cricoid cartilage for posterior crico-arytenoid muscle; 3, median crest of 
cricoid; 4, arytenoid; 5, cartilage of Santorini; 6, cartilage of Wrisberg; 7, epiglottis; 
8, posterior crico-arytenoid ligament; 9, 10, upper and lower posterior kerato-criooid 
ligament; 11, posterior wall of trachea. B, from the front: 1, thyroid cartilage ; 2, 3, its 
upper and lower cornua; 4, cricoid cartilage ; 5, crico-thyroid ligament; 6, lateral part 
of the same, continued into the orico-thyro-arytenoid membrane ; 7, epiglottis ; 8, trachea ; 
9, anterior kerato-cricoid ligament. (Beaunis.) 
Cartilages. The cricoid cartilage is a strong and complete ring. Its 
inferior border is horizontal and continuous with the trachea, while the 
upper border rises with a concavo-convex curve on each side from before 
backwards, so as to give a height behind more than three times greater 
than in front. The posterior elevated part is likewise thicker, and placed 
on it are two convex articular surfaces for the arytenoid cartilages. These THE LARYNX. 
739 
surfaces look upwards, and have an interval of about quarter of an inch 
between them. On each side, placed well back, and about the level of 
the fore part of the upper border, is a slightly elevated circular articular 
surface for the inferior cornu of the thyroid cartilage. On the posterior 
surface there is a vertical mesial ridge, and an impression on each side 
of it for the posterior crico-arytenoid muscle. 
The thyroid cartilage, the largest and most prominent cartilage of the 
larynx, is a plate consisting of two symmetrical alae, widely separate 
behind and united in the middle line in front, the line of junction of the 
two halves being the narrowest portion, and projecting 
superiorly so as to form the prominence called pomum 
Adanxi. From this point the upper border on each 
side at first curves upwards, commencing an S curve 
which -ends behind in a long process, the superior 
cornu. From the tip of this cornu the posterior 
border descends in a straight line to the tip of 
the inferior cornu. The inferior cornu is shorter 
than the superior, and at its extremity has a small 
circular surface looking inwards to articulate with 
the cricoid cartilage. On the external surface of 
o 
the thyroid cartilage an oblique line, slightly pro- 
minent, extends downwards and forwards, separating 
the insertion of the sterno-thyroid from the origin 
of the thyro-hyoid muscle, and ending inferiorly in 
an overhanging tubercle. 
The arytenoid cartilages present each three elon- 
gated sides ascending from a triangular base to a 
pointed summit which is curved backwards. Of 
the three sides, one looks backwards and is concave 
from above downwards, another looks inwards and 
is flat, while the third, looking forwards and out- 
Fig. 574.—Mesial Section 
of Larynx, a, Hyoid bone; 
b, c, d, thyroid, cricoid, and 
arytenoid cartilages ; e, true 
vocal cord; /, false vocal 
cord, and beneath it the 
ventricle of the larynx; g, 
epiglottis; k, tongue. 
wards, is convex. The base has a slightly concave surface for articulation 
with the cricoid cartilage; its outer angle (processus muscularis) is prominent, 
and its anterior angle (processus vocalis) is prolonged, giving attachment to 
the inferior thyro arytenoid ligament. 
The cornicula laryngis, or cartilages of Santorini, are two small nodules 
on the summits of the arytenoid cartilages. 
The cuneiform cartilages, or cartilages of JFrisberg, are still smaller, soft 
and yellowish, placed outside and in front of the cornicula, in the aryteno- 
epiglottidean folds. 
The epiglottis is an obcordate plate of yellow cartilage. Its narrow 
and elongated inferior extremity is connected by means of loose elastic 
tissue with the interior of the thyroid cartilage as far down as the vocal 
cords, and with the hyoid bone and the raphe of the tongue. Its upper 
part projects free, the mucous membrane being reflected upwards on it 740 
THE RESPIRATORY ORGANS. 
from the tongue, and presenting a mesial and two lateral glosso-epiglottidean- 
fraenula with shallow depressions between. The sides of this upper part 
are folded back round the front of the laryngeal opening. The laryngeal 
surface is closely invested with mucous membrane in its whole extent and 
deeply pitted with mucous glands, and presents in its lower half a distinct 
convexity, the pulvinus, which lies over the glottis when the epiglottis is 
depressed by the movement of the tongue and contraction of the thyro- 
hyoid muscles in swallowing.1 
Joints and ligaments. The thyroid cartilage is attached to the cricoid 
by a pair of synovial joints and a crico-thyroid ligament. The crico-thyroid 
articulation has, besides a synovial capsule, three ligaments spreading in 
different directions, the anterior and the upper and lower posterior kerato- 
cricoicl ligaments, and admits of only one description of movement, namely,, 
revolution round an axis passing through the joints of opposite sides. 
The crico-thyroid ligament is thick and strong, and consists of yellow-elastic 
fibres spread out at their attachment to that part of the upper border of 
the cricoid cartilage left uncovered by the thyroid cartilage, and converging 
as they ascend to be inserted into the deep surface of the mesial part of 
the thyroid cartilage. A small pit or perforation is left in the middle 
line, and the lateral border is continued into a much thinner structure,, 
the crico-thyro-arytenoid membrane, which arises from the inner lip of the 
remainder of the upper border of the cricoid cartilage as far back as the 
arytenoid cartilage, and is continued in contact with the mucous membrane 
up to the true vocal cord. 
Fig. 575.—Larynx, from above ; laryngoscopic views, a, In deep respiration, showing 
the trachea down to its bifurcation ; b, in uttering a high pitched note, a, Epiglottis ; 
6, c, swellings corresponding to cartilaginous nodules of Wrisberg and Santorini; d, true 
vocal cord ; e, false vocal cord. (After Czermak.) 
The thyroid cartilage is attached to the hyoid bone by two ligaments 
and an intervening membrane. The lateral thyro-hyoid ligaments are two- 
rounded cords, somewhat elastic, extending on each side from the tip of 
the superior cornu of the thyroid cartilage to the extremity of the great 
cornu of the hyoid bone, and sometimes containing one or more cartilaginous 
1 The epiglottis unquestionably comes like a lid over the larynx in swallowing, 
notwithstanding that Professors Anderson Stuart and M‘Cormick of Sydney record a 
case where food glided over the upper part of its laryngeal surface, after an operation, 
in which the hypoglossal nerve was admittedly destroyed, and the glosso-pharyngeal 
may have been (Journal of Anatomy and Physiology, Yol. xxv.). THE LARYNX. 
741 
nodules (cartilagines triliceae). The thyro-hyoid membrane extends from side 
to side between the ligaments, and is perforated on each side by the 
superior laryngeal artery and nerve. In front of it, in the middle line, 
there is a bursa between it and the posterior surface of the hyoid bone ; it is 
pretty constant and may be prolonged linearly to near the thyroid cartilage. 
The crico-arytenoid articulation is a synovial joint with a capsule and a 
strong triquetrous posterior ligament, whose fibres spread upwards and 
outwards. This joint permits two sets of movements, namely, angular 
movement, by which'the arytenoid cartilages are raised and depressed, and 
rotation round a vertical axis, by which the vocal cords are brought 
together and separated. 
Epiglottis^ 
/Pulvinus 
Thyroid cartilage 
Ventricle— 
_ False vocal cord 
. Vocal cord 
Thyro-arytenoid muscle 
_ Crico-thyroid muscle 
Cricoid cartilage. 
First tracheal ring. 
Fig. 576.—Anterior Half of Larynx from Behind. (Pansch.) 
The superior and inferior thyro-arytenoid ligaments consist each of a small 
number of elastic fibres, the superior lying in the fold called the false 
vocal cord, and the inferior, more distinct, placed in the margin of the 
true vocal cord, strengthening the thickened upper border of the crico- 
thyro-arytenoid membrane already described. 
Laryngeal cavity and mucous membrane. The entrance into the larynx 
is bounded on the sides by the aryteno-epiglottidean folds, which stretch from 
the epiglottis, at its broadest part, to the cornicula laryngis. The cornicula 
incline over into the pharynx, and between them the edge of the larynx 
is depressed in the spout-like fashion which has earned to the arytenoid 
cartilages their name. The sides of this depression are bounded by two 
rounded little swellings caused by the cornicula, and two others beyond 742 
THE RESPIRATORY ORGANS. 
them correspond with the cartilages of Wrisherg. In the interior of the 
larynx, in front of the bases of the arytenoid cartilages, the cavity is 
narrowed between the vocal cords, and the narrow part is called the glottis, 
rima glottidis or chink of the glottis, the passage being reduced to a mere 
chink when the vocal cords are approximated; but even then the back 
part of the glottis between the two arytenoid cartilages presents a gap. 
Below the glottis the sides of the cavity slope smoothly out to the full 
breadth of the trachea beyond; but immediately above it there is on each 
side a recess, the door of which is horizontal, forming the upper surface of 
the true vocal cord, and limited above by the arched margin of the false 
vocal cord. This recess is called the ventricle of the larynx, and toward 
the front has a prolongation upwards called the saccule, in contact with 
the thyroid cartilage. 
The mucous membrane of the larynx is thin and firm. The submucous 
tissue of the aryteno-epiglottidean folds is loose, capable of being swollen 
up by oedema. The squamous epithelium of the fauces is exchanged for 
ciliated columnar stratified epithelium a little below the margin of the 
aryteno-epiglottidean folds ; and with this the whole of the rest of the larynx, 
as well as the trachea and bronchi, is lined, save only the true vocal 
cords, which are clothed with stratified squamous epithelium. Taste-bulbs, 
similar to those of the tongue, are found on those parts of the epiglottis 
and aryteno-epiglottidean folds which have stratified epithelium, parts which 
are exceptionally sensitive. The mucous membrane is pierced by the ducts 
of mucous glands, of which one group, epiglottidean, lies in the pits of the 
epiglottis; others are in front of the arytenoid cartilages and above the 
false vocal cords, and a number open into the saccule. 
Muscles. The crico-thyroid muscles arise one on each side of the middle 
line from the fore part of the cricoid cartilage, and the fibres of each diverge 
as they pass upwards and outwards to be inserted into the inferior edge of 
the thyroid cartilage as far back as the tip of the inferior cornu, leaving 
only a space of about half an inch between the two muscles in front. By 
their contraction these muscles approximate the cricoid and thyroid cartilage 
in front, and thus make tense the vocal cords in raising the pitch of the 
voice. If the tip of the finger be placed over the space between the 
thyroid and cricoid cartilages the space will be felt to be diminished in 
singing high notes and increased in singing bass notes. 
The posterior crico-arytenoid muscles arise fieshily from the whole of the 
depressed portion of the posterior surface of the cricoid cartilage external to- 
the mesial ridges, and extend upwards and outwards, the fibres of each- 
converging to be inserted into the back of the processus muscularis of the 
arytenoid cartilage. They rotate the external angles of the arytenoid 
cartilages inwards, and thereby rotate outwards the anterior angles on the 
cessation of vocalization. Plainly also they re-elevate the arytenoid carti- 
lages when they have been depressed. 
The lateral crico-arytenoid muscles arise one on each side from the whole THE LARYNX. 
lateral part of the upper border of the cricoid cartilage, and the fibres 
converge from this origin to the front of the outer angle of the base of the 
arytenoid cartilage of the same side. They rotate the outer angles of the 
arytenoid cartilages forwards and the anterior angles inwards so as to 
approximate the vocal cords to the middle line ; and they come into action 
in every act of vocalization. 
Fig. 577.—Muscles of Larynx, a, From rig'ht side; 1, 2, 3, body, small cornu and 
great cornu of hyoid bone; 4, thyro-hyoid membrane ; 5, thyro-hyoid muscle; 6, upper 
end of the oblique line separating the thyroid attachments of the inferior pharyngeal 
constrictor and the thyro-hyoid muscle ; 7, 8, anterior and posterior fibres of crico-thyroid 
muscle* 9 trachea, b, From behind; 1, epiglottis j 2, triticeal cartilage, 3, thyio-hjoid 
membrane; 4, cartilage of Santorini; 5, arytenoid group of mucous glands; 6, arytenoideus 
muscle ; 7, aryteno-epig’lottideus muscle \ 8, posterior crico-cirytenoid muscle, 9, trachea. 
(Beaunis.) 
The thyro-urytenoid muscle of each side has its inferior and outer fibres 
in contact with the foremost and longest fibres of the lateral crico-arytenoid 
muscle, but above these it is divided into an external and an internal part, 
the external part lying against the outer wall of the ventricle and above 
it, while the internal part is in its floor, within the fold of the true vocal 
cord. The inferior fibres arise in part from the side of the crico-thyroid 
ligament immediately below the thyroid cartilage; the lest arise from the 
thyroid cartilage, close to the front of the cnco-thyro-arytenoid membrane. 
The external part is inserted behind into the outer margin of the aryte- 
noid cartilage; and the internal part into the lower portion of the anterior 
surface of that cartilage. 
Though thus divisible into parts, variously described by different authors, 744 
THE RESPIRATORY ORGANS. 
the thyro-arytenoid muscles have a very distinct action, namely, to approach 
the front of the thyroid cartilage to the arytenoids. They therefore come 
into action in the production of deep notes. The approach of the bases 
of the arytenoid cartilages to the thyroid being effected by revolution of 
the cricoid cartilage on the inferior cornua of the thyroid, the crico-thyroid 
space is enlarged, as can be felt with the finger in making a deep note. 
Thus the thyro-arytenoidei are the opponents of 
the crico-thyroidei muscles. 
The arytenoid muscle is a single muscle whose 
transverse fibres cross the middle line, being 
attached to the posterior surfaces of the ary- 
tenoid cartilages. 
The aryteno-epiglottidean muscles are two long- 
slips which, arising one behind each processus 
muscularis, decussate in the middle line, and, 
turning each round the summit of the opposite 
arytenoid cartilage, extend into the aryteno- 
epiglottidean fold beyond. .Fibres may take 
origin from the arytenoid cartilage as they turn 
round it, and sometimes the fibres on the surface 
of the arytenoid muscle are absent. 
The thyro-epiglottidean muscles consist of fibres 
of the same sheet as the external part of the 
thyro-arytenoid muscle, arising higher from the 
thyroid cartilage external to the saccule and 
passing upwards and backwards to the aryteno- 
epiglottidean fold. 
Two pairs of hyo-epiglottidean muscles have been 
described by Macintyre (British Medical Journal, 
15th September, 1888), one pair arising near the 
middle line, from the body of the hyoid, and the other arising from the 
great cornua, and both inserted into the dorsum of the epiglottis near its 
base. 
Vessels and nerves. The superior laryngeal artery enters the larynx 
by piercing the thyro-hyoid membrane along with the superior laryngeal 
nerve. It is given off by the superior thyroid, which also supplies the 
crico-thyroid muscle, its crico-thyroid branch anastomosing with its fellow, 
in front of the crico-thyroid ligament. The inferior laryngeal artery enters 
the larynx in company with the recurrent laryngeal nerve beneath the 
inferior constrictor of the pharynx. The laryngeal nerves are branches of 
the vagus; the superior laryngeal supplies the mucous membrane, and 
before entering the larynx gives off the external laryngeal to supply the 
crico-thyroid muscle, while the other muscles are supplied by the recurrent 
laryngeal. 
Fig. 578.—Larynx from the 
Left and Behind, a, Section of 
thyroid cartilage, the left side of 
which is removed with the ex- 
ception of b, the part articulating 
with the cricoid cartilage; c, 
arytenoideus muscle; d, posterior 
crico-arytenoideus ; e, crico-thy- 
roideus; /, crico-thyroid liga- 
ment ; g, crico-arytenoideus 
lateralis; h, thyro-arytenoideus, 
its upper edge corresponding 
with the edge of the vocal cord ; 
i, k, thyro- and aryteno-epi- 
glottideus,resting on the aryteno- 
epigiottidean fold of mucous 
membrane. A portion of the 
mucous membrane is removed 
between h and k to show the 
position of the glottis. THE TRACHEA. 
745 
THE TRACHEA. 
Ihe trachea is continuous with the larynx and ends by dividing into 
the two bronchi for the right and left lungs. It is about inches in 
length and f inch or more in breadth, but is capable of elongation by 
elasticity, and of diminution in diameter by muscular contraction. Its 
commencement is opposite the 
lower border of the fifth cervical 
vertebra, and its termination in 
the adult is opposite the lower 
border of the fourth dorsal 
vertebra. It lies in the middle 
line, and rests on the oesophagus. 
At its commencement it is 
covered at the sides by the 
lobes of the thyroid body; and 
it is crossed by the isthmus of 
the thyroid body, opposite the 
second and third rings. Beneath 
this is the spot usually chosen 
for tracheotomy ; and here the 
trachea has in front of it a 
layer of deep cervical fascia 
stretched between the sterno- 
hyoid and sterno-thyroid muscles, 
and separated from it the further 
it descends by a greater depth 
of loose tissue. In this tissue 
lie the inferior thyroid veins 
and the ima thyroidea artery 
when it is present; and at the 
sides, are the common carotid 
arteries, the right artery further 
forward than the left. The 
trachea terminates opposite the 
lower border of the fourth 
dorsal vertebra, with the arch 
of the aorta in contact with it 
in front and on the left side. 
The branches of the arch are in 
Hyoid 
Upper cornu 
Thyroid - 
Lower cornu 
Cricoid— 
Trachea 
Right bronchus 
Left bronchus 
Bronchia 
Bronchia 
close contact with it, the innominate to the right of the middle line, and 
the left common carotid and subclavian on the left side. The recurrent 
laryngeal nerves ascend in contact with it, in the angle between it and 
the oesophagus. 
The trachea is strengthened on its front and sides by cartilaginous bands 746 
THE RESPIRATORY ORGANS. 
or incomplete rings, from about sixteen to twenty in number, Avith rect- 
angular extremities resting on the oesophagus. These rings are not quite 
regular, some being single at one end and double at the other, and 
occasionally two being joined together in the middle. The lowest has a 
branch descending in the middle, separating the two bronchi. They are 
Hat on their superficial aspect, and more convex on the deep. 
The rings are joined together by a distinctly elastic fibrous membrane 
surrounding their perichondrium, and forming a continuous sheet behind. On 
removing the fibrous membrane at the back, a layer of unstriped muscle 
is brought into view, arranged in transverse bundles attached to the fibrous 
membrane inside the extremities of the cartilages and also betAveen them. 
Loose tissue lies between the muscular layer and the mucous membrane, but, 
except at the back part, is very limited in amount. The proper substance of 
the mucous membrane is very thin and firm, and in close contact with the 
deep surface there is a strong coat of longitudinal yelloAv-elastic fibres visible 
Avith the naked eye, forming bands internal to the cartilages, and still 
stronger behind, Avhere they give the 
interior of the trachea a character- 
istic longitudinally striated appearance. 
The epithelium is stratified columnar 
ciliated, the deepest corpuscles small 
and rounded, those of the intermediate 
stratum spindle-shaped, prolonged at 
both extremities into a thread, Avhile 
the superficial corpuscles are elongated 
and ciliated. 
The surface is studded Avith open- 
ings of ducts of small lobulated glands, the largest of which are in the 
posterior Avail and are seen in the dissection of the fibrous and muscular 
layers. Those on the front and sides open betAveen the rings, and occupy 
the depressions between successive rings, spreading on the deep side of 
their upper and lower margins. The acini are mostly, but not all, of the 
mucous character, and the secreting cells elongated columnar. 
Pig. 580.—Vertical Section of Epithelium of 
Trachea. 
THE LUNGS. 
The lungs correspond in general form with the pleural cavities, being 
convex laterally, posteriorly and superiorly, but hollowed out internally where 
in contact with the pericardium, and interiorly where they rest on the 
diaphragm. They present each a sharp edge in front intruded between 
the pericardium and the thoracic wall, and another surrounding the base 
or diaphragmatic surface, so as to separate it from the external, internal 
and posterior surfaces. The upper part or apex reaches up through the 
first costal arch so far as to have in front of it, above, the subclavian 
artery where that vessel arches outwards in the first part of its course. THE LUNGS. 
747 
The posterior surface is the longest, lying in the vertebral fossa and con- 
tinued gradually into the external and internal surfaces; and the greatest 
volume of lung is behind, immediately above the highest level of the 
diaphragm. The whole lung is invested with pleura except at the root 
and the part opposite the attachment of the broad ligament below the 
root (p. 686). 
First rib 
Apex of lung 
Clavicle 
Superior lobe 
.Aorta 
Vena cava superior 
Pulmonary'arter jr 
Right auricle 
Right ventricle 
• LefF ventricle 
Inferior lobe 
Curve of 
diaphragm 
Sulcus between; 
lobes 
Costo-phrenic ) 
space j 
’Attachments of 
diaphragm 
• Edge of pleura 
Costo-pleural 
space 
Fig. 581.—Position of Thoracic Viscera, t, Cardiac incisura of left lung; ft, where 
pericardium touches the thoracic wall. (Pansch.) 
The root of the lung is the part where it is continuous with other 
parts, and consists of bronchus, right or left pulmonary artery and pulmonary 
veins, together with bronchial vessels and lymphatics and nerves. It is 
situated on the inner surface of the lung, nearer the back than the front, 
and above the middle. The phrenic nerve descends in front of it, and 
the pneumogastric behind it. The pulmonary veins emerge in front of the 
corresjDonding arteries and at a lower level, while the bronchus and 
bronchial vessels are behind. 
The right and left lung differ one from the other in the number of lobes,. THE RESPIRATORY ORGANS. 
748 
ill shape and in weight, as well as in the arrangement of the large air-tubes. 
The right lung has three lobes and the left only two. The lobes are separated 
one from another by deep fissures into which the pleura extends. In both 
lungs a deep fissure passes inwards and somewhat upwards from a line 
which cuts the surface, beginning behind between two and three inches 
from the apex, and extending downwards and forwards to the base near 
the anterior edge; and by this means the inferior lobe is defined in both 
lungs. But on the right lung there is an additional fissure which begins 
from the first mentioned fissure more than midway back, and cuts the 
outer surface in a nearly horizontal direction so as to separate a middle 
lobe from the lower and fore part of the upper. This separation of the 
upper from the middle lobe often falls short of the anterior edge and is 
never as complete as the separation of the inferior lobe, although we shall 
find that in its bronchial arrangements the middle lobe is more closely 
connected with the inferior. The right lung has less vertical height than 
the left, for though the apex usually reaches a little higher than that of 
the left lung, the base is raised by the bulk of the liver below it. On the 
other hand, the weight of the liver offers an obstacle to pathological diminu- 
tion of height of the right lung which is not offered by the stomach to 
the diminution of the height of the left lung. The right lung is much 
less hollowed out on its inner surface by the heart than is the left, and 
its anterior edge approaches the middle line or slightly crosses it. The 
left lung is excavated by the heart, both on its inner surface and at its 
anterior edge, where the upper lobe retreats above the apex of the heart 
and turns forwards below in a tongue-like process round it. The average 
weight of the right lung, as compared with the left, has been estimated as 
being about twenty-two ounces compared with twenty. 
Internal structure. Healthy lung-substance is spongy, easily compressed 
between the fingers, but recovering its form immediately. It gives, on 
pressure, a peculiar sensation termed crepitation, due to the movement of 
air in minute spaces. When air is blown in by the wind-pipe it is seen 
to expand the substance of the lung in every part, and to be forcibly 
expelled by the elasticity of the minute texture, unless the wind-pipe be 
thoroughly closed. But even in the collapsed state the lung-substance is 
permeated with air, which cannot, without much difficulty, be perfectly 
removed; and hence it floats in water, and when cut presents a frothy 
section. 
The proper texture of the lung is white, but it is tinged to a variable 
extent according to the amount of blood which it contains, and has its 
white converted into a grey appearance by deposits of black substance. 
■Only once have I met with a pair of adult human lungs absolutely devoid 
■of such deposits; often they are in such abundance as to make the lungs 
very dark, even if we keep out of consideration colliers’ and knife-grinders’ 
lungs which have been subjected to the inhalation of solid particles of a 
•comparatively coarse description. When the deposits are moderate in THE LUNGS. 
749 
amount, they are most abundant in the planes of contact of the lobules 
of which the lung is made up; and on the surface they mark by polygonal 
lines the bases of the lobules, and extend into the deeper parts of the 
pleura. They consist of amorphous granules irregularly aggregated, unsur- 
Fig. 583.—Pulmonary Alveoli Highly 
Magnified, a, Denuded elastic par- 
titions ; b, denuded alveoli; c, simple 
squamous epithelium lining alveoli; d, 
epithelium covering the partitions. 
Fig. 582.—Lobules of Lung. Separated one from 
another after removal of the pleura. 
rounded by cell-walls, and affecting rather the tissue between the air-spaces 
than the walls of these; and that they are independent of the textural 
elements appears to be shown by their being found abundantly in the 
tymphatic glands into which the lungs pour lymph. 
Fig. 585.—Capillary Injection of 
Walls of Alveoli. 
Fig. 584.—Finest Air-Tubes with Infundi- 
bula and Alveoli, from child at birth, 
(Luschka.) 
The hum consists of a multitude of lobules, each of which receives air 
by a single bronchial tube, and has an air-system quite independent of others 750 
THE RESPIRATORY ORGANS. 
when not united adventitiously with them by the pathological breaking 
down of septa, namely, by emphysema. But the lobules are onty to a 
limited degree separable in the adult, although those which abut against 
the surface can often be isolated to a much greater extent than usually 
supposed. They are pressed together so as to have flat sides and an 
irregular polygonal form, and their diameters may vary from a quarter to 
two-thirds of an inch. The bronchial tube of each lobule divides into 
smaller tubes or bronchioles supplying smaller lobules, which are composed 
Fig. 586.—The Lungs from behind, a, Trachea ; 6, branch of right bronchus for upper 
Jobe of right lung ; c, arch of aorta united by obliterated ductus arteriosus to commence- 
ment of left pulmonary artery; d, left auricle receiving from each side the pulmonary 
veins ; e, middle lobe of right lung; f, g, anterior inferior angles of the two lungs ; h, h, 
groove where the aorta lies against the left lung ; i, groove where superior vena cava lies 
against right lung. 
of groups of ultimate lobules or infundibula. Each infundibulum consists of 
an ultimate or respiratory bronchiole, which may be as small as one-fiftieth 
of an inch, and expands into an irregular passage which dilates and is 
walled all round by hemispherical alveoli or air-cells. The alveoli have a 
framework of elastic tissue, specially strong at the edges which separate 
them one from another. Spread out in this framework is a single layer 
of large capillaries forming a close network, the capillaries being about 
one-thousandth of an inch in diameter and the meshes not much wider; 
and in the septa between the alveoli one layer of capillaries is exposed to 
the air on both sides. Lining the interior of the alveoli there is a single THE LUNGS. 
751 
layer of very thin delicate squamous epithelium, which is exchanged at 
the free margins for much smaller, thicker, but still squamous cells, which 
are also found in the ultimate bronchioles. 
The bronchi and bronchial tubes. The trachea divides into two bronchi, 
one for each lung. The right bronchus is somewhat larger than the left. 
The left bronchus slopes more downwards than the right (though an opposite 
statement has been made), the right forming an angle of 60° with the 
perpendicular, and the left an angle of 40° (Macalister). The vena azygos 
turns forwards over the right bronchus; the arch of the aorta passes back 
over the left. The bifurcation of the trachea is in the mesial plane, but 
the left lung is kept by the aorta and heart more away from the mesial 
plane than the right, and thus the exposed part of the bronchus is longer 
on the left than the right side. From the upper side of the right bronchus 
a branch, which immediately divides into three, is given off for the upper- 
lobe about three-quarters of an inch from the commencement and before 
entrance into the lung; and owing to this the right bronchus appears 
higher than the right pulmonary artery, while the left bronchus lies alto- 
gether behind the left artery. The branch for the upper lobe of the left 
lung comes off close to those for the lower lobe, the distance from the 
trachea to its origin being rather greater than to the breaking up of the 
right main bronchus into branches for the middle and lower lobes. Alone- 
o 
to the origin of branches for the inferior lobe the main tubes have the 
same arrangement of cartilaginous rings as the trachea, and these are the 
parts properly termed the bronchi. But beyond this, in each lung a con- 
tinuation may be distinguished prolonging the bronchus directly onwards, 
with the cartilages no longer in regular bars, but broken up into irregular 
pieces, as if composed of portions of successive bars partially united. This 
ends in a set of elongated bronchial tubes to the back part of the base, and 
gives off in its course others springing, some of them directly, some from 
short peduncles, and running a few of them inwards, but the greater number 
forwards and outwards. The elongated bronchial tubes have quadrate and 
angular plates of cartilage scattered irregularly in their walls. They branch 
dichotomously to a certain extent, but principally give off from their sides 
numerous small bronchioles devoid of cartilage. It is advisable to restrict 
the use of the term bronchioles to these and the still smaller tubes into 
which they divide. 
The bronchi and their ramifications, including the elongated bronchial 
tubes, have microscopic structure similar to the trachea, stratified ciliated 
columnar epithelium, racemose glands, longitudinal elastic fibres and a 
transverse muscular coat; but when the cartilages become distributed 
all round, the muscular fibres are so also. After the cartilages have 
disappeared, the muscular coat is still found on the bronchioles, as are 
also the elastic fibres; while the epithelium becomes simple, and the 
surface of the mucous membrane continues longitudinally plicated. In 
the smallest bronchioles the muscular coat has disappeared, and the 752 
THE RESPIRATORY ORGANS. 
simple ciliated columnar epithelium becomes exchanged for small non- 
ciliated squamous cells similar to those on the edges of the alveoli. 
Vessels and nerves. The pulmonary artery is distributed to the lungs, 
supplying them with the dark blood which it is their office to purify 
from carbonic acid and replenish with oxygen. The branches of the 
pulmonary artery end altogether in the capillary network already de- 
scribed as surrounding the air-cells; and the purified blood is returned to 
the heart by the pulmonary veins, an upper and a lower from each lung. 
The superior pulmonary vein comes from the upper lobe, lying in front 
of the stems of artery and bronchial tube. The inferior pulmonary vein 
ascends on the inner side of the bronchus and its continuation; while 
the corresponding branch of the pulmonary artery descends external to 
them. The nutrition of the lungs is effected by means of the bronchial 
arteries, small vessels from one to three in number for each lung, arising 
irregularly from the aorta or intercostal arteries. They receive their 
name from being distributed mainly along by the course of the bronchial 
tubes, and as they supply the bronchial mucous membrane, as well as 
the other textures, their capillaries communicate with those of the 
pulmonary artery when the smaller tubes are reached. But they also 
furnish superficial branches by which the pleura gets a vascular supply 
independent of the lungs. The bronchial veins, which have likewise 
superficial and deep branches, fall into the azygos veins. The lymphatics 
of the lung are deep and superficial, and the superficial lymphatics form a 
network with larger meshes and vessels than are found on any other viscus. 
The nerves, the anterior and posterior pulmonary plexuses, are derived from 
the pneumogastric and sympathetic. They follow the bronchial tubes and 
have minute ganglia. 
Right pulmonary artery- 
Trachea 
Left pulmonary artery 
Oesophagus 
Upper lobe 
Upper lobe 
Middle lobe- 
Lower lobe 
Lower lobe 
Blind extremity 
dividing 
Blind extremity 
dividing 
Pig. 587.-—Embryonic Human Lungs. (Hertwig, after His.) 
Development of respiratory organs. The deep groove which in early 
development is seen within the horse-shoe-elevation called the furcula 
(p. 99) deepens into an elongated tube of mesoblast with hypoblast within. 
This tube bifurcates, and already in an embryo two-thirds of an inch 
long, the lungs exist in the form of expansions outwards from the ends of THE LUNGS. 
753 
the bronchi; the left lung showing two, one for the upper and one for 
the lower lobe, while the right lung is larger and shows three, the beginnings 
of the three lobes of its adult condition. The right and left pulmonary 
arteries in the young embryo are also not symmetrically arranged; the 
right descends from its origin in a slightly more ventral position than the 
left, and passes on the ventral side of the neck of the upper lobe before 
entering the lung on the dorsal side of the others; while the left artery lies 
on the dorsal side of the necks of both lobes. Ramification rapidly proceeds; 
the extremities of the lobules always preserving a dilated appearance. It has 
been observed that in the fifth month the air-cells are only half the size 
of those found in the fourth month ; the larger cells would therefore appear 
to become divided by septa. 
Until birth the lungs, being unexpanded by entrance of air, occupy 
comparatively little space at the back part of the thorax, and have a specific 
gravity corresponding with that of similar textures in other parts ; but after 
birth the expansion takes place immediately, and the air penetrates to the 
air-cells in a uniform manner depending on the mode in which the expanding 
force is applied. 
The opening into the larynx soon exchanges its elongated slit-like form 
for a T shape, being transverse behind the epiglottis, and mesial between 
the arytenoid folds. The larynx of the male undergoes rapid enlargement 
at the time of puberty, and it is then that the pomum Adami becomes 
more prominent in the male than in the female. In connection with this 
the difference of pitch according to age and sex is to be noticed. Shortly 
it may be stated that the register of the voice in the child and adult, and 
in the male and female, depends on the length of the vocal cords, while 
the pitch of a particular note depends on the degree of tension to which 
they are subjected. 
DUCTLESS GLANDS. 
Under this old, but by no means indefensible designation, may be con- 
veniently gathered various organs connected with elaboration or purification 
of the blood, viz., the spleen, the thyroid, the thymus and the suprarenal 
capsules, also certain arterial glomerular structures. To the same heterogen- 
eous category belong the lymphatic glands, the closed follicles and the 
pituitary body; but these have been already described in the section on 
General Anatomy or with the parts to which they belong. 
The spleen is attached by two folds of peritoneum, viz., the gastro- 
splenic omentum and the splenic ligament, to the great cul-de-sac of the 
stomach and to the diaphragm. It lies in the back part of the left 
hypochondrium and rests on the diaphragm and left kidney. When not 
3 B 
THE SPLEEN. 754 
DUCTLESS GLANDS. 
unduly enlarged it measures in the adult usually from four to live inches 
in length, from three to three and a half in breadth, and from one to one 
and a half in thickness; but it is subject to continual changes of dimensions, 
increasing in size for hours after food has been taken, and in disease it 
may he enormously enlarged. 
The spleen has a convex surface or dorsum looking backwards and to 
the left, continuous behind with a rounded posterior margin, and in front 
with a thinner anterior margin interrupted 
usually with irregular notches. The re- 
maining or internal surface, flattened behind 
where in contact with the left kidney, and 
concave in front where in apposition with 
the stomach, presents in the middle a 
vertical fissure, the hilus, at which the 
branches of the splenic artery enter and 
the tributaries of the splenic vein emerge 
between the anterior layer of the gastro- 
splenic omentum and the posterior layer of 
the splenic ligament, while the smaller sac 
of the peritoneum barely comes in contact 
with the spleen. Distinct supplementary 
splenules are sometimes found near the 
hilus both in man and other mammals. 
Pro. 588.—Deep Surface of Spleen, 
showing the hilus, with the branches of 
the splenic artery entering. 
Structure. Beneath its peritoneal coat and closely adherent to it, the 
spleen is surrounded by a strong fibrous capsule (tunica propria) closely 
bound down by continuity of its deepest fibres with a network of trabeculae 
running through the whole substance. On section the substance is seen 
to be of a dark venous hue, which, being covered by the fibrous capsule, 
gives a more or less dull purple colour to the surface ; and on slight pres- 
sure there oozes from the section an abundance of dark pulp, which, when 
washed away, leaves displayed the fibrous trabeculae arranged in bars and 
imperfect septa round passages communicating one with another like those 
of a sponge. By repeated washing the whole pulp can be removed from 
the supporting framework of trabeculae, and the amount of elastic tissue 
in the trabeculae is sufficient to cause the framework to recover its original 
form when left for a short time in water or spirit. The pulp consists of 
corpuscles floating in a coloured fluid, and the corpuscles are of various 
kinds, namely, first, red blood-corpuscles; secondly, leucocytes in great 
number and variety, some of them similar to those found in the cir- 
culation, others much smaller, and some greatly larger, containing sometimes 
coloured substances, and sometimes undestroyed red blood-corpuscles (Stohr); 
thirdly, caudate or other branched corpuscles. Sections of spleen under the 
microscope exhibit also networks of branched corpuscles whose size diminishes 
while their branches elongate the farther they are from the trabeculae, and 
pervade the pulp spaces with meshes of exceedingly fine threads. The THE SPLEEN. 
755 
ramifications of the arteries and veins part company after a little, the small 
vessels quitting the trabeculae; and between the tunica media and tunica 
adventitia of the minute arteries there is a layer of retiform tissue which 
is swollen out in nodules by masses of minute nucleated corpuscles like 
the medullary substance of lymphatic glands or the contents of closed 
follicles, and contrasts with the pulp by absence of colour. These modules 
are called Malpighian bodies. They are not distinguishable in the healthy 
adult human spleen cut open, but in the spleens of children, and in patho- 
logical circumstances, and also in mammals other than man, they appear in 
M 1 M- tr Ji3 
Pig. 589.—Structure of Splebw. tr, Trabeculae ; ret, reticulum ; Ml, Malpighian cor- 
puscle with arteriole on one side; AT2, another partially surrounding arteriole; M 3, a 
third with arteriole in the centre ; M*, a fourth without visible arteriole. 
sections as semi-transparent grey spots, which have been likened to boiled 
sago grains. A Malpighian body may be pierced in the middle by the 
arteriole on which it is placed, but more frequently lies to one side. The 
branches of the splenic artery end in long and wide capillaries which do 
not form meshes as elsewhere, but open into the pulp-spaces, whence also 
the venous radicles take origin. This agrees with the fact that the serum 
of blood from the splenic vein has been found, like the splenic pulp, to 
be coloured with escaped haemoglobin. The spleen makes its appearance 
as a corpuscular mass in the second month of embryonic life. 
THE THYMUS AND THE THYROID BODY. 
These two structures have a closer connection with one another than 
with other ductless glands, being both of them originally developed like 
secreting glands from the pharynx, and losing their ducts in early em- 
bryonic life. 
The thymus is an organ of early life. It has a colour and appearance 
resembling a salivary gland. It increases in absolute and proportionate 756 
DUCTLESS GLANDS. 
size till birth, preserves its proportionate size for a year or even two 
(Meckel), then begins to dwindle, and usually ceases to exist even vestigially 
in the adult, save perhaps in the form of a deposit of deep-coloured adipose 
tissue. It lies in the upper part of the anterior mediastinum of the thorax, 
and at birth forms a mesial mass reaching higher than the sternum and 
down over the great vessels and heart so as to conceal the auricles. It 
is most voluminous inferiorly, and superiorly is produced upwards on each 
side of the trachea as far as the thyroid body. By dissection it is easy 
to show that it consists throughout of a right and a left portion quite 
distinct one from the other, but closely in contact inferiorly, and not 
symmetrical. It is embedded in a sheath of connective tissue, and each 
Fig. 590.—Windpipe and Thoracic Viscera of Foetus 
of Six Months, a, Thyroid body; b, b, thymus; c, c, 
unexpanded lungs ; d, right ventricle of heart. 
Fig. 591.—Section of Lobule of Thymus, from 
foetus of 8 months, with bloodvessels injected. 
half can be dissected out into a number of lobules attached to a central 
cord or column, and consisting of smaller lobules. The lobules, surrounded 
by a dense vascular network sending into the interior bloodvessels whose 
capillaries fall short of the centre, contain a reticulum loaded with minute 
nucleated corpuscles. In the outer or cortical part, the corpuscles principally 
abound, while in the central or medullary part the reticulum is more evident; 
and it is this part which is continued into the central cord. In the medullary 
part a certain number of large corpuscles are found, some of them inclosed 
in concentric laminae (corpuscles of Hassall). 
The thyroid body contrasts with the thymus in being firmer, of more 
definite form and less separable into lobules, in being of a dark purplish 
colour, in having very definite bloodvessels, and in continuing throughout 
life. It is larger in the female than the healthy adult male, and diminishes 
in the proportion which it bears to the whole body, from birth till adult 
age. It consists of two lateral lobes united by a narrow isthmus. The THE THYMUS AND THE THYEOID BODY. 
757 
lobes are covered by the sterno hyoid and sterno-thyroid muscles, and 
reach up on the lower part of the sides of the thyroid cartilage and as low 
as the fifth or sixth ring of the trachea. The isthmus conceals the third 
tracheal ring completely, and more or less the second and fourth; and 
from it there sometimes ascends a pyramidal process or middle lobe, which 
may have muscular fibres descending to it, constituting a levator muscle. 
The thyroid body consists of multitudes of closed vesicles varying mostly 
from the sixtieth to the thirtieth of an inch in size, filled with glairy fluid, 
lined with a single layer of cubical epithelial cells, and surrounded with 
a distinct single layer of capillary bloodvessels. These vesicles are embedded 
in firm tissue, in which the vessels ramify. The arteries are the superior 
and inferior thyroid arteries, and the occasional lowest thyroid (ima thyroidea). 
The veins are the superior, middle and inferior thyroid. Of nerves to 
the proper structure of the thyroid body and thymus nothing is known. 
Pig. 592.—Texture of Thyroid Body. A, The vesicles lined with epithelium 
B, Injection of capillaries showing a network round each vesicle. 
Development of thymus and thyroid body. It will be observed from the 
statement made at p. 99 that those structures are closely related, in respect 
that they originate as glandular pouches from the visceral clefts, the 
thymus from the third clefts, the right and left lobes of the thyroid from 
the fourth clefts, and the mesial part of the thyroid from the ductus thyreo- 
glossus in the mesial plane opposite the third cleft. The close relation 
of both thyroid body and thymus to secreting glands is thus obvious; 
and in the thyroid body it would appear that the epithelial lining survives; 
while in the thymus it has disappeared altogether, and the structure 
which becomes developed corresponds with the retiform surroundings of 
the secreting pouches of an ordinary gland. In the foetus there are con- 
stantly found prolongations of both right and left parts of the thymus high 
up on the trachea, and it is probably from these that small bodies are 
derived described as parathyroids, an outer and an inner on each side, in 
contact with the lobes of the thyroid body. 758 
DUCTLESS GLANDS. 
THE SUPRARENAL CAPSULES. 
The suprarenal bodies or capsules, or more properly the adrenals (Owen), 
are two flat bodies close above the kidneys, an inch and a half or more 
long, about an inch high, and diminishing in thickness from below upwards. 
The inferior edge of each fits over the convex upper end of the kidney, 
and an outer and an inner straight side slope upwards to a blunt apex. Its 
anterior surface is marked in the middle by a horizontal fissure, the hilus. 
It is of a dull ochreous colour, and is soft and easily torn, breaking open 
readily so as to lay bare a deeper brown and exceedingly soft texture in 
the interior, distinguished as the medullary part, while the surrounding 
substance is called the cortical. The right body is covered by the liver, 
Fig. 593.—Right Suprarenal Capsule and Solar Plexus from right side, a, 
Kidney; h, at the outer end of the hilus of the suprarenal capsule. The vein is shown 
emerging from the hilus, and the nerves and arteries entering the circumference of the 
capsule. The capsular nerves are seen, most of them coming from the semilunar ganglion, 
c, Aorta and aortic plexus ; d, renal artery and renal x'lexus; e, coeliao axis and coeliac 
plexus ; /, superior mesenteric artery and plexus ; g, inferior phrenic artery. 
the left by the spleen and pancreas, and both lie on the crura of the 
diaphragm, external to the solar plexus. At their margins they receive 
numbers of nerves from the solar and renal plexuses, and numbers of small 
arteries coming irregularly from the phrenic, the aorta and the renal. The 
arteries break up into smaller branches on the surface and supply the cortical 
part with a capillary network, whence the venous radicles gather the blood 
into the medullary part, to escape from the hilus by larger branches which 
unite into a single trunk, ending on the right side in the inferior vena cava 
and on the left in the left renal vein. The cortical part examined micro- 
scopically exhibits a fibrous stroma continuous with a sheath round the whole 
organ, and ending on the deep side in a bounding layer separating it from THE SUPRARENAL CAPSULES. 
759 
the medullary part. Within this stroma is inclosed the essential structure, 
consisting of nucleated corpuscles averaging inch in diameter. These 
are arranged in the greater part of the depth in intercommunicating 
columns T-yth inch wide {zona fasciculata), continued superficially into 
irregular masses (zona glomervlosa), and at their deep extremities into a 
close network (zona reticularis). The medullary part receives the vessels 
and nerves which penetrate from the cortical structure, and while the vessels 
are gathered within it into venous trunks the nerves form a plexus. It also 
contains numbers of granular nucleated corpuscles connected one with 
another, but further observation is required to decide the detailed connec- 
tions of the nerves and the relations of the medullary corpuscles to them. 
The development of the suprarenal capsules is but imperfectly under- 
stood, but is alleged to be partly in connection with the solar plexus and 
partly from another origin. It is noteworthy that at an early period they 
are of a deep crimson tint very different from nervous structures, and only 
acquire their lighter colour afterwards. 
ARTERIAL GLOMERULI. 
Under this name may be mentioned some unimportant structures of 
small size, consisting mainly of convoluted and ramifying arterioles in 
minute clusters and of unknown history and function. They are : (1) the 
intercarotid ganglion, about quarter of an inch long, or broken into smaller 
nodules, between the external and internal carotid artery; (2) the coccygeal 
gland (Luschka), of the size of a lentil, between the tendons attached to the 
tip of the coccyx; and (3) some similar and still smaller structures appended 
to the coccygeal part of the middle sacral artery, found better developed 
in dogs (J. Arnold). 
THE URINARY ORGANS. 
The urinary organs consist of the kidneys, ureters, bladder and urethra; 
but the male urethra, being a passage common to the urinary and repro- 
ductive systems, will fall to be considered with the organs of generation. 
THE KIDNEYS. 
The kidneys are situated one on each side of the vertebral column, 
opposite the last dorsal and two or three upper lumbar vertebrae, but the 
right a little lower than the left. They are embedded in loose adipose 
tissue, and rest on the diaphragm and fascia of the quadratus lumborum 
behind them, and the psoas muscles internally, and are surmounted by the 
suprarenal capsules. They are pretty nearly on a level with the bodies 
of the last dorsal and two first lumbar vertebrae, and thus have the twelfth 
pair of ribs obliquely crossing them in their upper half behind. The right 
kidney is in contact anteriorly with peritoneum in its upper part, where 760 
THE URINARY ORGANS. 
it impresses the under surface of the liver, and lower down is crossed by 
the duodenum and colon which are between it and the peritoneum. The 
left kidney is to a greater extent in contact with peritoneum, but is crossed 
by the descending colon. 
The kidney weighs from four to six ounces, and may be as much as 
four inches long, two and a half broad, and one and a half thick. The 
surface is dark, smooth and 
even, sometimes with two or 
three curved indentations, the 
remaining traces of former 
lobulation. On its inner side, 
however, it presents a deep 
and limited depression, the 
hilus, in which is placed pos- 
teriorly the dilated commence- 
ment of the ureter turning 
downwards, and in front of 
it the renal artery, with the 
renal vein foremost of all, 
both artery and vein being 
higher than the ureter. As 
a general rule the kidney is 
flatter behind than in front, 
and the part below the hilus 
narrower and more elongated 
than the part above. 
Varieties. A kidney may 
receive one or more additional 
renal arteries entering it 
above or below the hilus. 
A kidney may be found in 
a position much lower than 
usual, even within the pelvis, 
and also at the other side of 
the middle line from its proper 
position, and receive its arterial 
supply from the nearest part of 
the aorta or one of its divisions. A number of instances of absence of 
one kidney are on record, and several cases of absence of both kidneys 
have been recorded in infants at birth. Horseshoe kidney is the name 
given to union of the two kidneys by their lower ends : it may be 
unsymmetrical. 
Structure. The kidney is surrounded by a firm fibrous capsule, toler- 
ably adherent, but easily separated in healthy specimens, and continuous 
with the tough connective tissue surrounding the structures which enter and 
Fig. 594.—Female Urinary Apparatus. 1, Left kidney ; 
2, right kidney in section; 3, Malpighian pyramid; 4, 
cortex; 5, columnae Bertini; 6, layer calyx ; 7, pelvis; 8, 
ureter ; 9, bladder, surmounted by urachus; 10, urethra. 
(Luschka.) THE KIDNEYS. 
761 
emerge at the hilus. The proper substance of the kidney consists of an 
outer or cortical part and an inner part or medullary between the cortical 
part and the sinus or cavity continuous with the hilus. The medullary 
substance is paler than the cortical and is arranged in masses averaging 
in number about a dozen, called pyramids of Malpighi, each with a rounded 
base continuous with the cortex and ending at its deep extremity in a 
free papilla which dips into the sinus. They present a distinct striation 
Fig. 595.—Fkontal Section of Kidney, a, Ureter; b, pelvis c, c, calyces; d, d, d, d, 
Malpighian pyramids in section from base to apex, showing their papillae dipping tree 
into calyces; e, e, e, e, oblique sections of pyramids; /,/,/>/,adipose tissue with cut 
bloodvessels; g, g, g, g, g, cut bloodvessels opposite septula; h, papilla looking out at 
the constricted end of a calyx. The uniformly granular stratum at the surface of the 
cortex is distinguished from the larger portion pervaded by medullary rays. 
from papilla to base. The cortical substance is about quarter of an inch 
thick opposite the middle of each Malpighian pyramid and dips between 
the pyramids, forming septula (columns of Bertin). Along the plane of 
contact of the cortical and medullary parts a zona intermedia is distinguished 
by a slight displacement of striae due to bloodvessels coursing in this 
plane and sometimes by a tendency to venous congestion. Close to the 
surface the cortical substance is uniformly granular in its appearance to 
the naked eye, but further inwards the granular appearance is alternated with 
minute columns of striated material prolonged from the Malpighian pyramids 
and called medullary rays, while in the granular-looking part between each 762 
THE UEINAEY OEGANS. 
pair of rays there may be seen on careful inspection, especially when the 
minute vessels have been injected or if a lens be used, scattered spherules, 
the Malpighian corpuscles. 
Fig. 596.—Cortex of Kidney. Semi-diagrammatic. a, Tubules and Malpighian 
corpuscles round medullary rays (constituting with them two pyramids of Ferrein); 
d, afferent and efferent bloodvessels of Malpighian corpuscles, and the capillary networks. 
The free papillae of the Malpighian pyramids are each embraced by a 
single division of the excretory tube. Such a dilatation, called a calyx or 
Fig. 597.—Renal Structure Highly Magnified. A, Malpighian corpuscle, showing 
glomerulus, epithelium and capsule, embedded in convoluted tubules with turbid striated 
epithelium ; B, straight tubule with clear epithelium. 
infundibulum, is attached at the base of the papilla to the renal substance, 
and narrows toward the summit, which it allows to look out by a small 
opening into one or other of two or three main divisions (larger calyces) 
of a dilated cavity, the pelvis. The pelvis may be as much as three- THE KIDNEYS. 
quarters of an inch in vertical diameter, and as it escapes at the hilus turns 
downwards and narrows to the ureter. 
The renal substance is made up of closely set tubuli uriniferi, which, 
together with the vessels supplying them, are bound firmly together by 
tissue so small in amount that the tubes seem in close contact; and 
though there are copious lymphatic channels between them, it is only by 
such means as maceration in muriatic acid that they can be separated to- 
any considerable extent. To the patho- 
logist this connective substance is important 
as the seat of scirrhosis. 
The tubuli uriniferi begin in the 
cortical substance, each in a Malpighian 
corpuscle, and are in the first part of 
their course convoluted (tubuli contorti), in 
the latter part straight (tubuli recti), the 
convoluted part being confined to the cortex, 
and the straight part being principally in 
the medulla; but between the portions pro- 
perly so-called are interposed two other 
parts, the loop of Henle, plunging with 
straight limbs far into the medulla, and 
the intercalary tube in the cortex. 
The Malpighian corpuscle consists of a 
spherical wall called capsule of Bowman, 
from which on one side the convoluted 
tubule commences abruptly, while at an 
exactly opposite point two small blood- 
vessels, the afferent and the efferent artery, 
pierce it and are continuous with a bunch 
of small bloodvessels, the glomerulus, which 
fills in great measure its interior. In 
the glomerulus the afferent artery breaks 
up rapidly into convoluted branches which 
keep to the circumference of the globe and 
then turn towards the centre in loops to join 
together to form the efferent artery; and by 
this means the more the blood enters the 
glomerulus the more its circumference is ex- 
panded so as to leave room for the return 
current in the middle (Ludwig). A fine mem- 
Fig. 598.—Diagram of Tubuli Urini- 
feri. R, Cortical part; Gr, intermediate- 
zone ; M, medullary part; 1, Malpighian 
corpuscles; 2, convoluted tubules; 3, 
Henle’s loops ; a, descending limb ; b, 
reascending limb; c, intercalary tubule; 
4, straight tubules ; d, junction tubules; 
e, smaller collecting tubules ; /, larger 
collecting tubules ; g, papillary opening. 
(Schweiger-Seidel.) 
brane, continuous with the capsule of Bowman, is reflected over the 
glomerulus from the neck at which the afferent and efferent arteries enter 
and emerge, and the opposed surfaces of this membrane and the capsule 
of Bowman are lined each with a single layer of fine squamous epithelium, 
the cells of the capsular layer larger than those of the glomerular layer. THE URINARY ORGANS. 
The tubuli contorti begin by a somewhat constricted neck, one from 
each capsule of Bowman. They are so winding in their course as to give 
the granular appearance to the cortex. They are about inch or more 
in diameter and have a dense cubical epithelium, presenting a vertically 
striated or rod-like structure, with the limits of their corpuscles indistinct, 
while their nuclei are obscured by the turbidity of their protoplasm. Each 
convoluted tubule ends by turning inwards, forming what has been described 
as the spiral tube, and narrowing to the loop of Henle. 
The loop of Henle is a constricted section of the uriniferous tubule, 
extending in a straight course far into the Malpighian pyramid and then 
abruptly turning back in an equally direct manner to the cortex. Its 
entering or descending limb is narrower than its emerging limb, being 
reduced to about or YXooth inch in diameter, while the emerging 
limb is more than twice as wide. In the entering limb the epithelium is 
squamous, in the emerging limb it is more nearly cubical. 
The intercalary or second convoluted tubule is in its greater part somewhat 
similar in character to the first convoluted tubule, but its convolution is 
less and its cells less turbid. Towards its termination, however, it becomes 
narrower and its epithelium clear; and this part is what has been called 
the junctional tube, because it terminates the course of the simple tubule by 
opening into a collecting tubule. The collecting tubules in the outer part of 
the Malpighian pyramid are about lll in diameter, and each 
receives in the medullary ray junctional tubes one after another. As they 
near the papilla they join together and enlarge, until papillary tubes are 
formed as much as inch 111 diameter. They have clear cubical 
epithelium with distinct nuclei and distinct boundary lines'between the 
individual corpuscles. The papillary tubes gather into groups which open 
into from ten to twenty depressions on the papilla, which may be seen 
with a lens.1 
Each medullary ray receives the tubules which spring from the Mal- 
pighian corpuscles around and invest it superficially and on every side, 
and thus is constituted a simple lobule often spoken of as a pyramid of 
Ferrein. 
Bloodvessels. The renal artery divides as it approaches the hilus into 
several branches, which, entering in front of the pelvis and passing in 
between its divisions, continue to bifurcate in the fat between the calyces 
and in the columns of Bertin, and end in numerous arched arteries in the 
zona intermedia, without, however, completing arches by anastomosis. 
From the convexities of these the radiating or interlobular arteries arise 
which are directed toward the surface between the pyramids of Ferrein, 
1 It ought to be explained that much of the microscopic structure of the kidney is 
by no means easy to verify, and in particular the sequence of the different parts of 
the tubules, though generally assented to as determined mainly by the researches of 
Ludwig and of Schweiger-Seidel, following up those of Henle, is difficult, and requires 
the examination of the kidneys of infants and of small animals. THE KIDNEYS. 
765 
and give off from their sides the afferent arteries, which proceed each to a 
Malpighian corpuscle without branching. Also branches are given to the 
fibrous capsule, which anastomose with twigs of the lumbar arteries. The 
afferent artery on entering the Malpighian corpuscle branches several times, 
and the resulting vessels of the glomerulus resemble capillaries in having 
simple walls; but their nuclei are very abundant, their walls are thicker 
than those of capillaries, and they are easily stained with carmine. The 
efferent vessel into which the blood from the glomerulus passes is some- 
times termed a vein and sometimes an artery, but it has the structure of 
an arterjr, strong walls in which circular muscular fibres are a prominent 
feature. This efferent vessel breaks up again into capillaries, which among 
the convoluted tubules form a polygonal meshwork, and among the straight 
tubules run longitudinally with transverse communications. The vasa 
efferentia, emerging from the glomeruli nearest to the medullary part, differ 
from the others in turning towards the medullary part and dividing into 
straight vessels ending in capillaries which have been supposed to be the 
only sources of supply to that part; but though they are the principal 
they are not the only vessels, for vasa recta come also from the bases of 
the interlobular arteries and concave side of the arched arteries; and in 
contradistinction to these the branches of the efferent vessels are some- 
times called false vasa recta. The venous blood is gathered from the 
cortex by interlobular veins, and some form on the surface little stars (stars 
of Verheyen); in the medullary part straight veins take their course, and 
both sets are gathered into arched veins which anastomose freely in the 
zona intermedia. 
The lymphatics of the kidney consist of a sparse superficial set in the 
capsule and of a deep set opening into the valved vessels which emerge 
at the biins. Within the renal substance lymphatics were first described 
by Ludwig and Zawarykin, who injected the intercommunicating spaces 
(1864). Eyndowsky (1872) found that the lymphatics were walled and 
lined with endothelium. 
Development. After originating in connection with the Wolffian duct 
(p. 96), the ureter shows thickening at its extremity, the commencement of 
the kidney ; and already in a foetus one and a half inches long from crown 
to coccyx, Malpighian corpuscles may be seen to form the greater part of 
its substance. A little later, when the kidney is only a sixth of an inch 
long, the Malpighian corpuscles are nearly as large as in the adult, and, 
together with other rounded structures which are folded dilatations of 
tubules and are evidently rudimentary capsules of Bowman, may, in vertical 
sections of the kidney, be seen ranged in continuous series folded back- 
wards and forwards from surface to deep part. Convoluted tubes have 
been described as existing at this stage, but the convolutions are not 
those of the adult kidney; they present in their course the folded dilata- 
tions mentioned, placed more than one on a single tubule and filled with 
elongated columnar epithelium. The extremity of the ureter at an early 766 
THE URINARY ORGANS. 
date shows dilated divisions. The loops of Henle appear early and have 
been seen in the human subject in the fourth month. 
It has been pointed out that the kidney is derived from an elongated 
-structure running the length of the body, and thus the mesonephros or 
Wolffian body is the permanent urinary gland of the lower vertebrates. 
It may be further mentioned that the mammalian kidney is considerably 
less diffuse than even that of the bird and is the only kidney confined in 
a fibrous capsule completely surrounding it. But to understand the 
-development of the human kidney it is necessary also to know that the 
kidneys of mammals are not all alike. While some, like the rabbit and 
the kangaroo, gather their tubules to one papilla, or, like the sheep, to a 
•central ridge, in others each kidney consists of a host of renules, separate 
as in the porpoise, or coherent as in the seal; and, much more commonly, 
Fig. 600.—Male Bladder, Urethra 
and Rectum, a, Anus; 6, bladder; c, 
central point of perineum; d, d, vas 
deferens cut across; /, bulb of corpus 
spongiosum ; r, rectum ; s, sacrum ; t, 
left testis; u, ureter; v, vesicula 
seminalis. 
Fig. 599. Suprarenal 
Capsule and Lobdlated 
Kidney op Foetus of Six 
Months. 
there are lobulated kidneys like that of the ox in which a number of 
Malpighian pyramids occur, each with its portion of cortex forming a con- 
vexity on the surface. This lobulated condition is that which occurs in 
the human subject at birth, and becomes gradually concealed by the more 
abundant growth of the cortex. In some animals, as in the horse, the 
running together of lobes is still more complete than in man, the ureter 
ramifying backwards within a single mass of medullary tubules. Thus 
there are two kinds of smooth-surfaced kidneys among mammals, and the 
human kidney belongs to the compound kind and passes through an early 
smooth and a later lobulated stage. Lobules are noticed as early as in 
the tenth week of the embryo, and are most fully developed toward the 
■end of foetal life. THE URETERS. 
767 
THE URETERS. 
The ureter is the duct conveying the urine from the kidney to the 
urinary bladder. It is from about fourteen to sixteen inches in length. 
Commencing at the pelvis of the kidney, which narrows as it emerges 
from the hilus, it curves downwards and is soon reduced to about a fifth 
of an inch in diameter. It ends in the lower part of the bladder, begin- 
ning to pierce the wall of that viscus about two inches from its fellow of 
the opposite side and an inch and a half from the base of the prostate. 
It is slightly dilated before entering the vesical coats, but becomes con- 
tracted in its succeeding part which courses gradually through them for 
more than half an inch to end in an oblique slit-like orifice pouting on 
the outflow of urine, but pressed shut by the contents of a distended 
bladder, so as to prevent regurgitation. In the abdomen the ureter lies 
behind the peritoneum, resting on the psoas muscle, and is crossed by the 
spermatic vessels and nerves; also, on the right side, by the mesentery of 
the lower end of the ileum, and, on the left, by the mesentery of the 
sigmoid flexure. It dips into the pelvis over the termination of the 
common iliac artery or the commencement of the external iliac, and as it 
courses forward is crossed in the male on its inner or peritoneal side by 
the vas deferens, while in the female it is in contact with the vagina before 
reaching the bladder. 
Varieties. It may happen that the renal calyces, instead of opening into 
one pelvis, are gathered into two ureters (even three have been known to 
occur); and these may either join together or remain separate till close 
to the bladder. 
Structure. The walls of the ureter present fibrous, muscular and 
mucous coats. The fibrous or outer coat consists of felted fibrous tissue. 
The muscular coat consists of a layer of circular fibres, and of deeper 
longitudinal fibres in the whole length of the duct; while, superficial to 
the circular fibres, longitudinal fibres are found in the lower third, but 
only in isolated bundles in the upper half (Toldt). The mucous membrane 
consists of a membrana propria and subjacent loose tissue, and is clothed 
with a stratified epithelium, whose superficial cells are flattened, while the 
deepest are smaller, rounded and oval, and intermediately placed are 
others of an elongated form, rounded at their superficial ends, and sending 
down pointed processes between the deeper cells. The vessels and nerves 
are from renal, vesical and mesenteric sources. The occurrence of 
lymphatic nodules and minute recesses, sometimes described as glands, 
seems to have been made out in the pelvis of the kidney and the upper 
part of the urethra. 
THE URINARY BLADDER. 
The bladder, as seen when artificially distended after death, is of an 
ovoid form, with the long axis mesial and the broader end below, and 768 
THE UEINAEY OEGANS. 
measures from four to five and a half inches in length, and from three to four 
inches in width. During life it may be enlarged by habitually repeated 
distension, or diminished by continued irritability within the limits of 
health; while, by pathological retention of urine, it may be distended enor- 
mously. Conflicting statements, none of them sufficiently proved, have been 
made as to the comparative capacity of the male and female bladder; but, 
on an average, the female bladder is broader and more nearly spherical. 
The bladder presents a neck or outlet, a base or fundus behind the neck, 
and, at the uppermost point of contact with the abdominal wall, a summit 
with a more or less distinct fibrous cord extending up from it to the 
umbilicus, which is the remains of the portion of the allantois termed 
the urachus, and sometimes shows vestiges of its original tubular condition. 
The outlet is fixed in position; it is separated from the posterior layer of 
the triangular ligament by about an inch of urethra, surrounded in the 
male by the prostate gland, and in the female by the thick muscular 
walls. From the outlet there extends, in the empty but uncontracted 
condition of the organ, an anterior wall resting against the pubic bones 
and reaching over the brim of the pelvis, and an inferior part, the fund as, 
curving backwards and receiving the ureters, in contact with the rectum 
in the male, and with the vagina in the female. The remaining and greater 
part of the posterior wall is laid over the base and anterior wall, in 
contact with them, and continuous with the anterior wall at lateral edges 
which meet at the summit. These edges disappear as the organ becomes 
rounded out, and then the surfaces pass gradually one into another. In 
like manner the edges disappear when the organ is drawn together in full 
contraction. 
On each side of the bladder the obliterated hypogastric artery, as it 
courses upwards and inwards, runs for some distance in contact with it; 
and the reflections of peritoneum which reach the bladder at this part 
are called its lateral false ligaments, while that which descends to it between 
the arteries of opposite sides is called the superior false ligament, and 
those which in the male turn inwards to the lower part of its posterior 
surface below the contact of the arteries, are distinguished as the posterior 
false ligaments. In the female the posterior false ligaments can hardly 
be said to exist, the peritoneum being arrested, as it descends over the 
bladder, at the level of the cervix uteri; and so far as they do exist they 
are reflected from the sides of the uterus. 
When the peritoneum is separated from the pelvic walls, the recto- 
vesical fascia is brought into view passing down to the neck and to the 
sides of the fundus, there to terminate by investing the bladder and, 
in the male, the prostate. The broad bands of fascia thus grasping the 
bladder, one on each side, are called its lateral true ligaments, and end 
in front in a pair of short stout bundles of fibres, the anterior true 
ligaments, one at each side of the symphysis, and separated by a mesial 
depression (p. 393). THE URINARY BLADDER. 
The triangular portion of the bladder between the neck and the orifices 
of the meters is called the trigone, and in the male rests on the rectum, 
so that it can be felt through the rectal wall immediately beyond the 
prostate, and can be punctured from the bowel without injury to the 
peritoneum. On each side of the trigone in the male is the yesicula semi- 
nalis, and internal to it the vas deferens, which descends on the side of 
the bladder, crossing between it and the ureter. In the male the peritoneum 
reaches down much nearer to the trigone than in the female, and the fundus 
piojects further backwards, but is not, as sometimes described, lower in 
position in the erect posture than the. outlet. 
769 
Orifices of ureters 
Trigone 
Neck of bladder 
Veins cut across 
Openings of prostatic tubules. 
Prostatic sinus 
Ejaculatory duct 
Membranous part of urethra 
Bulb of urethra^ 
spongiosum 
Pig. 601.—Base of Bladder, and the Prostatio and Membranous Parts of the 
Urethra, from the front. 
The interior of the bladder has a smooth surface, which is thrown into 
folds when the muscular wall is contracted. The trigone as seen from the 
interior is an equilateral triangle with sides about an inch and a quarter 
long, the posterior angles formed by the oblique slit-like openings of the 
ureters and the anterior inferior angle by the outlet. Its floor presents 
a slight triradiate elevation caused by firm fibrous tissue subjacent to the 
mucous membrane, and connected with it so as to' make it firmer and 
prevent its falling into rugae like the other parts. At the outlet of the 
bladder the mucous membrane is longitudinally corrugated, and in the male 
there is a slight elevation of the lower edge of the orifice, called uvula 
vesicae, due to the prostate gland which grasps the outlet, and liable when 770 
THE URINARY ORGANS. 
the prostate is enlarged to be increased in size, and so offer obstruction 
to the entrance of instruments. 
Structure. The walls of the bladder present, besides the partial invest- 
ment of peritoneum and the connective tissue prolonged from the recto-vesical 
fascia, a muscular coat and a mucous membrane, separated one from the 
other by a submucous coat of loose areolar tissue, rich in elastic fibres, in 
which the arteries for the mucous membrane divide. 
The muscular coat consists of fibres somewhat complexly arranged, yet 
easily resolvable into three layers closely connected one with another— 
a superficial, a deep longitudinal and an intervening circular layer. The 
superficial longitudinal fibres are arranged in two broad and strong bands, 
one in front and the other behind the neck, which both spread out on 
all sides as they ascend; the posterior band is traced downwards at the 
neck, between the bladder and at least the lateral lobes of the prostate, 
while the anterior band extends forwards on the surface of the prostatic 
part of the urethra, and some of its fibres reach the pubic bones in the 
substance of the anterior true ligaments. The lateral fibres of both bands 
spread out the most speedily, and are continued into the circular layer, 
while others arch round the summit, and a few, mesial in position, are con- 
tinued to the urachus. The circular layer is the strongest, and at the neck 
is considerably thickened, forming a ring, the division of which by a special 
cut in lithotomy causes the outlet to expand. Higher up, its bundles cross 
in a reticulated fashion, which imparts its character to the interior in cases 
in which the muscular wall has been much exaggerated. The deep longi- 
tudinal fibres form a thin layer, regular below, scattered above. 
The mucous membrane is similar to that of the ureters in so far as it is 
covered with a stratified squamous epithelium. The deepest cells are small; 
those superficial to them oval, caudate and spindle-shaped, while the super- 
ficial cells are granular and by no means as much flattened out as those 
of the epidermis. The superficial cells are clear at the surface and granular 
in their deeper part, in which are the nuclei. The nuclei are subject to 
direct or amitotic proliferation, sometimes as many as four being present 
in one large irregular plate like corpuscle; and the granular portion of the 
corpuscle is pitted with deep depressions, into which are fitted elongated 
projections of the underlying corpuscles (Dogiel, 1890). 
Vessels and nerves. The arteries are derived from the superior, middle 
and inferior vesical branches of the internal iliac. The veins fall into a 
copious plexus at the neck partljr derived from the genitalia, and fall into 
the internal iliac veins. The nerves are derived from the inferior hypogastric 
plexuses of the sympathetic, and from the anterior divisions of the third 
and fourth sacral nerves. Small ganglia have been found on them, and 
their fibres would appear to have been traced into the epithelium. 
Development. Derived originally from the proximal part of the allantois, 
the urinary bladder first communicates with the outside by its connection 
with the gut. A cloaca is formed by the junction of the allantois and the THE URINARY BLADDER 
771 
bowel, and thereafter a septum separates a uro-genital sinus from the rectum. 
The subsequent stages by which the urinary part of -this sinus becomes 
separated from the genital part do not seem to have been as yet followed 
in sufficient detail, but manifestly the trigone is the partition between them. 
At a later period the foetal bladder has the mucous membrane thrown into 
deep longitudinal corrugations, which cease suddenly at a transverse line and 
are replaced by a smooth surface at the level of the opening of the ureters. 
THE REPRODUCTIVE ORGANS. 
The organs of reproduction consist of structures which, in the two sexes, 
are differently developed but homologous, and are divisible into essential 
and accessory. The essential organs are the testes in the male and the 
ovaries in the female, and provide the living elements which unite within 
the impregnated ovum. The accessory organs are passages, glands and 
erectile organs, which in various ways facilitate the coming together of the 
products of ovary and testis, or in the female provide protection or nourish- 
ment for the embryo. In the male the urethra is in its greater part a 
genito-urinary passage, developed in connection with genital function; and 
in the female, although the urethra is urinary and homologous with the 
purely urinary commencement of the male urethra, yet it opens into the 
vestibule, which is thus a genito-urinary orifice. 
I. The Testes, Scrotum and Seminal Ducts. 
MALE ORGANS. 
The testes or testicles, originally developed within the abdomen, where 
in non-mammalian vertebrates they remain permanently, have in man, as 
in the majority of mammals, the peculiarity that they descend before birth 
into the scrotum. They are placed at slightly different levels, the left 
usually the lower, so as to slide easily past one another when pressed on 
by the thighs. Each is hung by a spermatic cord consisting of the main 
duct termed vas deferens and the spermatic artery and spermatic vein, 
together with the spermatic plexus of sympathetic nerves and lymphatics, 
surrounded with coverings which are prolonged down over the testis itself 
and the special sac of serous membrane, tunica vaginalis, with which the 
testis is invested. 
The coverings of the spermatic cord and testis are, in series beginning 
at the surface, the skin, subcutaneous tissue, dartos, intercolumnar fascia, 
cremaster muscle and cremasteric fascia, and the fascia termed in the upper 
part infundibuliform, and in the lower part fascia propria of Astley Cooper. 
The skin of the scrotum is thin, pigmented, highly extensible, furnished 
with scattered hairs provided with prominent sebaceous glands, presents a 
mesial raphe traceable back to the central point of the perineum and for- 772 
THE REPRODUCTIVE ORGANS. 
ward to the penis, and in childhood and in the strong adult is thrown 
into transverse corrugations. The subcutaneous tissue is destitute of fat. 
The dartos, the highly muscular deep fascia, governs the corrugations of 
the skin. The scrotum is supplied with blood by the superficial perineal 
branch of the internal pudic artery 
and the superior and inferior pudic 
branches of the femoral, and with 
sensation by the ilio-inguinal nerve 
in front and the inferior pudendal 
branch of the small sciatic and two 
superficial perineal branches of the 
pudic nerve behind. Its lymphatics 
enter the oblique group of superficial 
inguinal glands. 
The testis is of oval form, ap- 
proaching in size and shape to a 
pigeon’s egg, but with the»transverse 
breadth about a third narrower than 
the breadth from before backwards. 
The elements of the spermatic cord 
are continued to the back of the testis, 
where they are supported by a 
certain amount of unstriped muscular 
tissue, the vessels entering and emerg- 
ing behind, and the vas deferens 
lying internal to them against the 
testis in its whole length. When 
the tunica vaginalis is laid open 
the form of the testis is laid bare. 
It is seen to be incased in a firm fibrous capsule, the tunica albuginea, over 
which the tunica vaginalis is firmly stretched, and to have above, below and 
to the outside of it, uninclosed by the tunica albuginea, an elongated structure 
which is called the epididymis; its swollen upper end above the testis 
proper being termed caput epididymis or globus major, the part alongside of 
the testis the body of the epididymis, and the part below the testis the globus 
minor. The globus major and minor are closely adherent to the tunica albu- 
ginea, while the intervening body of the epididymis, placed behind and to the 
outside, is separated from it by a pouch of tunica vaginalis, the digital fossa. 
Projecting from the lower and fore part of the globus major are one or more 
minute threadlike, clavate or pedunculated bodies called hydatids of Mwgagni, 
vestiges probably of the upper end of an embryonic structure, the duct of 
Muller; and further up, where the tunica vaginalis is prolonged a little 
above the globus major, there may be found some less evident nodules 
beneath the membrane, which are known as corps de Giraldes, and are un- 
doubtedly remains of the Wolffian body. 
Spermatic cord 
Spermatic artery 
- Veins 
Vas deferens- 
Organ of GiraldfeS' 
Globus major 
Hydatids of 
Morgagni 
Globus minor. 
Fig. 602.—Left Testicle. Tunica vaginalis 
thrown open. Undulating branches of the sper- 
matic artery are seen in the tunica albuginea 
covering the body of the testicle. THE TESTES, SCROTUM AND SEMINAL DUCTS. 
773 
Structure. The whole secreting substance is inclosed within the tunica 
albuginea, which is a leathery white fibrous structure, resisting all efforts to 
stretch it by manipulation, but yielding before the continued pressure 
exercised in health, and enormously in orchitis. This is the better under- 
stood when it is observed that it is pierced behind by the numerous 
branches of the spermatic artery and veins, which coarse forwards in its 
substance and form by their finest twigs and capillaries an abundant network 
on its deep surface, the tunica vasculosa of Astley Cooper. The arteries also 
exhibit a fine undulation in their course forwards, permitting stretching 
without diminution of calibre. From behind, a fibrous septum projects a 
little forwards into the interior, the corpus Highmorianum or mediastinum 
testis ; and from this mediastinum a number of slender cords and bloodvessels 
radiate forwards and to the sides to be attached all over the interior of the 
tunica albuginea. 
Fig. 603.—Ducts of Testis, a, a, Tubuli seminiferi ; 
b, b, vasa recta; c, rete; d, vasa offerentia; e, . coni 
vaseulosi; /, /, epididymis; g, vas aberrans ; h, vas 
deferens. 
Fio. 604.—Section of Longi- 
tudinal Lobes of Seminal Tubules. 
a, Tunica albuginea; b, tubuli 
seminiferi; c, tubuli recti ; d, medi- 
astinum. 
The secreting substance, protected and supported by these fibrous structures, 
is soft, loosely adherent to its surroundings, and easily seen with the naked 
eye to consist of a mass of delicate threads, long portions of which can be 
partially unravelled and detached with ease, so slight is the cohesion of their 
convolutions. When the tunica albuginea is divided in front and reflected 
backwards, the contained mass presents a lobulated appearance; and about 
three or four hundred lobes can be separated pretty completely, all converging 
to the mediastinum, and consisting of tubuli seminiferi closely coiled. The 774 
THE REPRODUCTIVE ORGANS. 
tubules, about a hundredth of an inch in diameter, can be uncoiled to lengths 
of as much as two feet. More than one enter into the formation of each 
lobule, and at the circumference the lobules are less easily separated than 
nearer to the mediastinum, because of connections between tubules of 
different lobules. Loops also occur within lobules, and it is difficult to make 
certain if blind extremities of tubules really occur, though the connective 
tissue supporting them is of the most delicate description. This connective 
tissue is remarkable in containing besides the ordinary connective-tissue- 
corpuscles, large rounded corpuscles, granular and sometimes pigmented, the 
nature of which has not been determined. The tubules exhibit throughout 
a fine uniform zig-zag which causes them when stretched to spring back, and 
are, besides this, thrown into laterally compressed folds. They are continued 
into tubuli recti. 
The tubuli seminiferi have a strong membrana propria or basement 
membrane sometimes concentrically striated (Toldt), which like other base- 
ment membranes is alleged to consist of endothelial cells (Mihalkovics). 
Their interior exhibits in the condition of rest several layers of small 
nucleated corpuscles surrounding a lumen. But portions which are in a 
state of activity show a more complicated arrangement connected with the 
production of spermatozoa. 
The spermatozoa constitute the essential product of the tubuli seminiferi, 
in the interior of which they are crowded closely together, as also in the 
epididymis and vas deferens, where they reach their 
maturity. They are firm structures, consisting of a 
head, neck and tail, and are in perpetual motion, 
moving head foremost with an eel-like movement of 
the tail as long as they retain their vitality, which in 
suitable fluids may be conserved for many hours. The 
head is about « oVoth inch long, pyriform, with the 
narrow end foremost, and is somewhat flattened, so as 
to seem broader in one position, narrower in another ; 
it is succeeded by a cylindrical neck about half as 
long again, and the neck tapers into the slender tail, 
varying from f° inch in length. A delicate membrane with 
a frilled free edge has over and over again been described as attached to 
one side of the tail of the spermatozoon of many animals and even of man, 
but there seems room to question if the appearances seen have been really 
due to a membrane. 
In tubuli seminiferi in which the formation of spermatozoa is going 
on, the corpuscles nearest to the membrana propria exhibit various stages 
of mitosis in their nuclei, and are, certain of them, at intervals round the 
tubule, greatly elongated into spermatoblasts, each presenting peripheral!}" 
a base containing one distinct nucleus, and internally a clavate expansion 
which is supported on a constricted neck, and contains a number of nuclei. 
These spermatoblasts develop further, the clavate extremity becoming 
Fig. 605.—Human 
Spermatozoa. THE TESTES, SCROTUM AND SEMINAL DUCTS. 
775 
digitate, each projection in connection with a nucleus ; the nucleus throws 
out a tail, and, with a certain amount of protoplasm adherent to it, becomes 
free as a spermatozoon. Small portions of protoplasm have been observed 
sometimes surrounding the head like a cap, or adherent in a mass to the 
neck of a spermatozoon in later stages of its existence. 
Fig. 606.—Section of Tubulds Semisifercs of Rat, showing genesis of spermatozoa, 
(Rohm and v. Davidoff after v. Ebner.) 
The tubuli recti, into which the tubuli seminiferi pour their contents, are 
only about one-tenth of an inch in length, and are reduced to about one- 
fourth the diameter of the tubuli 
seminiferi. They are lined with 
a single layer of cubical epithelium, 
and open into the rete testis. 
The rete testis, occupying the 
whole length of the mediastinum, 
is, as its name implies, a network 
of communicating passages. These 
have no membrana propria, and 
are lined with simple squamous 
epithelium ; they vary in diameter, 
but are larger than the tubuli 
recti, and convey the secretion 
to the upper and back part of 
the tunica albuginea, when it falls 
into the rasa efferentia. 
The rasa efferentia and coni 
vasculosi, from about ten to sixteen 
in number, are about a thirtieth of 
an inch in diameter. Escaping 
from the tunica albuginea, the 
msa efferentia become each one almost immediately coiled up into a 
separate cone. These coni vasculosi are each over a third of an inch in 
length with the base at the further end about a tenth of an inch in 
diameter; but, in proportion as the cone gets wider, the tubule of which 
it is composed gets narrower till it is reduced to about a sixtieth of an 
inch, where it ends in the epididymis independent of its neighbours, the 
Fia. 607.—Ducts of Testis. 1, Tubuli seminiferi; 
2, vasa recta; 3, rete; 4, vasa efferentia; 6, 7 
epididymis; 8, vas aberrans; 0, vas deferens! 
(Beaunis, after Kcker.) 776 
THE EEPEOHUCTIYE OEGANS. 
whole series lying buried beneath the globus major of that duct. Like 
both epididymis and vas deferens, the vas efferentia and coni vasculosi 
have ciliated columnar epithelium and membrana propria, with muscular 
fibres outside. 
The epididymis, when dissected out, is found to consist of one elongated 
tube about a sixtieth of an inch in diameter in the globus major, and 
diminishing to a third of that diameter as it is followed to the globus 
minor, in which it again enlarges, prior to being continued into the vas 
deferens. It is three times folded on itself, first into uniform close-set 
semicircular waves, then backwards and forwards, and lastly in larger 
backward and forward folds, so as to produce lobes separated from others 
by loose connective tissue. It begins in a blind extremity, and receives 
the coni vasculosi in series at short intervals. The whole tube is indubit- 
ably twelve feet at least in length, and has even been estimated at twenty 
feet or more. The Avail presents beneath the columnar epithelial cells 
a layer of rounded nuclei, and round the membrana propria a thin 
stratum of muscular fibres. 
The vas aberrans (Haller) is a tubule coiled on itself of about the same 
diameter as the epididymis, and opening into that duct where it is con- 
tinued into the vas deferens. It may reach to eight inches or more in 
length, but may be absent, and is said sometimes to be unconnected 
with the epididymis. It lies in the concavity between epididymis and 
vas deferens, and would appear to be a vestigial structure, resulting from 
processes in development not yet sufficiently studied. 
The vas deferens is continuous with the epididymis where that duct 
has reached the lower end of the globus minor. It turns upAvards behind 
the testicle, internal to the spermatic vessels and nerves, enlarging rapidly 
while in contact with the globus minor, and getting less tortuous till it 
reaches more than half way up the back of the testicle. It there becomes 
straight and has already acquired a uniform cylindrical shape with dense 
Avails of such thickness and firmness as to make it feel like whip cord. It 
extends upwards in the spermatic cord, behind the spermatic vessels and 
nerves, to the external abdominal ring, traverses along with them the 
inguinal canal, and, on reaching the internal inguinal ring, quits them 
and, turning down over the external iliac vessels, enters the pelvis and 
SAveeps downwards in contact with the bladder. It crosses backwards 
between the bladder and ureter to reach the posterior edge of the base 
of the prostate gland, Avhere it terminates by joining with the outlet of 
the vesicula seminalis to form the ejaculatory duct. In this course it is 
about sixteen to twenty inches long. In the last two inches, where it is 
internal to the ureter, it becomes dilated and sacculated, forming a sort 
of elongated ampulla before ultimately narroAving again at its termination. 
The vas deferens has an outer coat of loose fibrous tissue, and a strong 
muscular wall in Avhich three layers are distinguished, an outer and an 
inner of longitudinal fibres, and an intervening layer of circular fibres, THE TESTES, SCROTUM AND SEMINAL DUCTS. 
777 
which is as thick as the two other layers put together. The mucous 
membrane exhibits mostly three longitudinal rugae, apd has elongated 
non-ciliated columnar epithelium with elongated nuclei resting on a layer 
with spherical nuclei; but the sacculated terminal part has some special 
peculiarities, being thrown into shallow recesses lined with cubical 
epithelium The vas deferens is supplied by a special branch of the inferior 
vesical artery, which runs its whole length as far as the epididymis; and 
its nerves are derived from the inferior hypogastric plexus. 
•Ureter 
•Vas deferens 
Vesicula sominalis 
Third lobe of prostate 
Lateral lobe of prostate 
Prostate concealing 
ejaculatory ducts ; 
.Membranous part of urethra 
Cowper’s gland 
.Crus penis 
Bulb 
Corpus spongiosum 
.Corpus cavernosum 
Pig. 60S.—Bladder, Prostate and Bulb, from behind. 
The vesiculae seminales are sacculated pouches folded together so as to 
form structures less than two inches in length, and about two-thirds of 
an inch wide, lying on each side against the bladder, immediately external 
to the vas deferens. The pouch may be as much as four or five inches long 
when unfolded, and has saccules of unequal length, some of which may even 
be branched. It is narrow at the outlet, but in its course its mucous mem- 
brane may be about quarter of an inch broad when slit open. Like 
the vas deferens, it is lined with non-ciliated columnar epithelium, and has 
circular muscular fibres with longitudinal bundles superficial and subjacent 
to them. The surface of the mucous membrane is reticulated like that 
of the gall-bladder, but more finely. Muscular fibres have been found 778 
THE REPRODUCTIVE ORGANS. 
crossing the folds, and even joining the vesiculae seminales of opposite 
sides. 
The ejaculatory ducts, one on each side, are formed each by the union 
of the vesicula seminalis and vas deferens. They are not much more 
than half an inch in length, extending from the base of the prostate, 
between the lateral and middle lobes to open into the floor of the urethra, 
slightly in front and to one side of the sinus pocularis. Each narrows 
from its commencement to its termination, where it is only wide enough 
to admit a fine bristle. Its walls are thinner than those of the vas deferens 
and vesicula seminalis, but are supported by the prostatic structures. 
11. The Prostate, Penis and Urethra. 
Firmly united to the neck of the bladder in the male there is a firm and 
thick mass, the prostate gland; and it is in the part of its course within 
the prostate that the urethra receives the openings of the ejaculatory ducts, 
and becomes a common genito-urinary passage. Half-an inch beyond the pro- 
state, the urethra emerges outside the pelvis, having pierced the triangular 
ligament, and is surrounded by an erectile structure, the corpus spongiosum, 
which, together with the two corpora cavernosa, the glans and integuments, 
enters into the structure of the penis. 
The prostate gland is a structure aptly enough compared in shape and 
size to a chestnut. Its base surrounds the outlet of the bladder; it is 
elongated and convex behind and comparatively short in front, and owes 
its name to the erroneous conceptions formerly prevalent as to the position 
of the pelvis in the erect posture, which led it to be supposed that the 
prostate lay in front of the bladder, whereas in the erect posture it really 
lies below it. It rests behind on the rectum, and can be felt through the 
rectal wall above the internal sphincter, and below and in front of the 
trigone of the bladder. It is supported by both anterior and lateral true liga- 
ments of the bladder, formed by the recto-vesical fascia (p. 393), and in front 
of these is separated from the posterior layer of the triangular ligament 
or subpubic fascia by the anterior fibres of the levatores ani. The 
recto-vesical fascia invests it with a strong fibrous capsule, and where the 
fibres of this capsule extend to the bladder, an angular interval is left 
round the base, which lithotomists avoid, because the looseness of the tissue 
contained in it is apt to lead to urinary infiltration, and the prostatic 
plexus of veins is liable to be specially developed at the base. The prostate 
has a bilobate appearance as seen from behind, and when the ejaculatory 
ducts are followed into its substance the greater part of it is found to be in 
continuity with these lateral lobes; but between the structure through which 
the ejaculatory ducts pass and the bladder there is left a mesial third lobe. 
Structure. This structure is partly muscular and partly glandular. The 
glands open by about twenty orifices into the floor of the urethra. They are 
elongated branching tubules with sparse and small acini at their extremities. THE PROSTATE, PENIS AND URETHRA. 
779 
and both ducts and acini lined with columnar epithelium. They are absent,, 
or nearly so, from in front of the urethra. The muscular substance is 
wrapped round about at different depths; -the deepest fibres are continuous 
with the circular fibres already described at the neck of the bladder, and 
superficial to them are others decussating with different degrees of obliquity 
on the urethra and continued into the vesical wall. On section of the pro- 
state, fibres are seen embracing the urethra, others at the circumference, 
and a third set extending in the intervening depth between the glands. 
The arrangement of the glandular part of the third lobe between the urethra 
in front and muscular and white-fibrous tissue behind is of importance from 
a surgical point of view, inasmuch as the prostate is prone to enlargement 
in later life, and the enlarged glandular part of the third lobe, being 
supported behind by muscle and thickened fibrous tissue, tends to press 
forwards and make an increased convexity in the floor of the urethra, 
which offers resistance to the direct passage of instruments and has to be 
carefully humoured. 
The prostate is supplied principally by the inferior vesical arteries. The 
plexus of veins around it is not so much derived from branches bringing 
blood from its substance as from the veins of the penis; the nerves are 
derived from the inferior hypogastric plexuses, and are said to present 
nerve-cells in their course, and also Pacinian bodies. 
The penis consists fundamentally of two erectile bodies called corpora 
cavernosa, but in mammals is complicated by the prolongation of the urethra 
Superficial and deep dorsal veins- 
Dorsal artery 
Dorsal nerve 
Cavernous artery 
Fibrous wall of 
corpus cavevnosum 
I) rethra in corpus spongiosum 
Septum 
Fio. 609.—Body of Penis in Transverse Section, 
along its under surface, surrounded by a mesial erectile bod}r, the corpus 
spongiosum, in connection with the fore part of which is the glans, an 
erectile structure expanding over the extremities of the corpora cavernosa. 
The corpora cavernosa are cylindrical structures consisting of spongy 
erectile tissue surrounded by a strong fibrous sheath. They arise separately, 
attached, one on each side, to the margins of the pubic arch, and taper 
backwards as far as the front of the ischial tuberosity, with the ischio- 
cavernosi or erectores penis muscles covering them. They become united 
opposite the inferior margin of the symphysis so as to leave only a single 
fibrous septum between the two columns of erectile tissue, and constitute 
with the corpus spongiosum the body of the penis, while the separate portions 780 
THE EEPEODUCTIYE OEGANS. 
are called the crura. In front they terminate under cover of the closely 
adherent glans in two blunt extremities like the tips of two fingers held 
together. The septum is strongest towards the root, and consists of bundles 
passing directly between the dorsal and lower surfaces with narrow 
clefts alleged to afford communication between the right and left corpora 
cavernosa. The circumferent fibrous walls form a thick, white and smooth 
covering, with its bundles in large part longitudinally arranged, and con- 
taining a considerable quantity of elastic fibres. From the deep surface of 
the walls, rounded and flattened trabeculae extend into the interior of each 
corpus cavernosura, forming the supporting part of its structure, while the 
cavities between them intercommunicate freely and are blood-sinuses. The 
cavernous artery from the internal pudic trunk passes right up through the 
middle of each cavernous body, and the dorsal artery of the penis gives 
branches as well. The arterial twigs ramify in the trabeculae, and are 
continued into capillaries which open into the sinuses. Some of the small 
arteries project sinuously from the walls of the sinuses in a curling fashion, 
and constitute the helicine arteries (of J. Muller). The blood escapes by 
veins falling into the internal pudic and the dorsal vein of the penis. 
Prepuce 
Gians 
.Praenum 
.Fossa navicularis 
Corpus cavernosum/ "" 'Corpus spongiosum 
Pig. 610.—Terminal Parts of Penis. A, Corpora cavernosa dissected away from the 
glans and corpus cavernosum. B, Longitudinal section. 
The corpus spongiosum is an erectile structure surrounding the urethra 
after its escape from the pelvis. It begins between the crura penis on 
the surface of the triangular ligament, and occupies the groove on the 
under surface of the corpora cavernosa as far as the glans, with which it 
is continuous. It is dilated at its commencement, where it is covered by 
the acceleratores urinae or bulbo-cavernosi muscles, and reaches back to 
their origin from the central point of the perineum. This part is called 
the bulb, and extends nearly half an inch further back in the perineum 
than the urethra which it surrounds. The average thickness of the erec- 
tile covering given to the urethra by the corpus spongiosum is about the 
eighth of an inch. Both the erectile tissue and the sheath encircling 
it are much weaker than those of the corpora cavernosa. The corpus 
spongiosum receives its arterial supply from the artery of the bulb, given 
off by the internal pudic, and from a smaller subsequent branch of the 
same trunk. THE PEOSTATE, PENIS AND UEETHEA. 
781 
7he glans penis presents at its summit the linearly shaped urethral 
orifice, but fails to surround it at its inferior angle, from which a mere 
fibrous union, the septum, extends back half an inch, uniting the urethra 
with the fibrous sheath of the corpus spongiosum. From each side of the 
septum the margin of the glans retreats from the urethral orifice in its 
course round to the dorsum, at the same time that it becomes more over- 
hanging and constitutes the corona glandis, while the constriction beneath 
it is called the cervix. The erectile tissue of the glans is continuous with 
that of the corpus spongiosum, but has claim to be considered as a separate 
development, being fully developed in the congenital deformity termed 
epispadias, in which the urethra is an open groove placed above the 
corpora cavernosa. Moreover, its trabecular structure is stronger, and its 
lacunae have been found to have more the character of dilated and con- 
voluted veins. Its fibrous covering is the cutis vera of the delicate 
integument which constitutes its free surface. The pajDillae of the surface 
of the glans are close-set and rounded, scarcely longer than broad, except 
at the corona; and both in the papillae and more deeply there are situated 
nerve-terminations, distinguished by Krause as more complex than end- 
bulbs and called genital corpuscles, in which recently there have been 
discovered convoluted networks of nerve-fibres marvellously complex 
(Dogiel, 1893). 
The integument of the penis, with the exception of that entering into 
the structure of the glans, is loose, and has a raphe continued forwards 
from the scrotum. It is thin and free from hairs and fat. The folded 
part which covers the glans is called the prepuce or foreskin, and where it 
is attached to the septum of the glans it forms a prominent fraenwn. 
Around the corona, on the cervix and on the inner layer of the prepuce, 
there are sebaceous glands, though no hairs are present.1 
The male urethra may be counted as about nine inches long, and 
consists of three parts, prostatic, membranous and spongy. The prostatic 
part, from an inch to an inch and a half in length, is narrower at its 
commencement at the outlet of the bladder and at its termination in the 
membranous part than in the middle where it has its convex floor or 
posterior surface in contact with its anterior surface. From the uvula 
vesicae at the orifice of the bladder a prominent line runs along the floor 
to the middle of the prostatic part and is there continued into a little 
rounded eminence, the colliculus seminalis, verumontanum or caput gallinaginis, 
then resumes the linear form and ends by bifurcating in front. In the 
depression at each side of the colliculus are the openings of the prostatic 
glands, while connected with the colliculus itself are three openings. In 
its fore part in the middle line is an orifice which admits the end of a 
probe and leads into a blind pouch sometimes as much as half an inch 
long, the sinus pocularis {uterus masculinus or Weber's pouch), corresponding 
lOn the subject of the glands in this situation (commonly called Tyson’s), consult 
Henle, Anat. d. Menschen, Eingeiveidekhre, p. 418. 782 
THE REPRODUCTIVE ORGANS. 
not only with the uterus of the female but with the vagina also (Banks, 
1864); and, close to the simis pocularis but somewhat further forward, 
•one on each side, are situated the openings of the ejaculatory ducts A 
certain slight amount of erectile tissue, prolonged back in the floor of 
the urethra from the bulb, increases in amount in the colliculus, and 
must serve when gorged to obstruct for the moment the exit from the 
bladder. 
The membranous part of the urethra is half an inch long, extending from the 
apex of the prostate to the entrance into the bulb, and lies between the 
deep and superficial layers of the subpubic fascia, surrounded by the con- 
strictor urethrae muscle. It is the narrowest part of the urethra, with the 
exception of the orifice.1 
The spongy part of the urethra extends from the opening in the triangular 
ligament to the outlet. At its commencement in the bulbous portion of the 
corpus spongiosum it is slightly dilated and somewhat rugose longitudinally ; 
and when the constrictor urethrae is contracted, an instrument can be pushed 
a little further back in the perineum than the opening in the triangular 
ligament, but if held gently against the easily felt opening, it will pass in of its 
own accord when the constrictor relaxes. At its entrance into the bulb, the 
urethra changes its course from a downward to a forward direction, so that a 
curved instrument introduced so far with the handle close to the abdomen 
moves away from the abdominal wall on entering the membranous part. 
In front of the bulb, the diameter of the urethra is very slightly diminished 
and continues unchanged till about half an inch from the orifice, where there 
is a distinct dilatation, the fossa navicularis, bounded in front by the more 
constricted slitlike orifice. While surrounded by the corpus spongiosum the 
tube has the upper and lower walls in contact; but near the outlet it is 
compressed from side to side by the glans, so as to present mesial contact 
of two lateral walls. A variable number of blind depressions called lacunae, 
with their mouths directed forwards and capable of intangling the point of 
an instrument, are found principally on the floor, near the bulb ; a large one 
found very frequently on the upper surface of the fossa navicularis is known 
as the lacuna magna (also valvule of Guerin). 
The mucous membrane of the urethra presents columnar epithelium on a 
smooth surface, except within the glans, where, as on the exposed part, there 
is a papillary surface covered with stratified squamous epithelium. The 
ju’oper substance of the mucous membrane is firm, and contains a large 
amount of elastic tissue longitudinally arranged. It has a copious capillary 
network and venous plexus. The prostatic part of the urethra is in contact 
with the muscular tissue of the prostate; the membranous part has a strong 
IThis part of the urethra is well known to he specially liable to injury in con- 
sequence of falls on the pelvis, even when there is no fracture of the bones. There can 
be no doubt that the explanation once offered by Goodsir in answer to an inquiry by 
Syme, and accepted by the latter, is correct, namely, that the weight of the body pro- 
pelling downwards the base of the sacrum unduly wedges upwards the part nearer the 
coccyx, so as to force open the arch of the pnbis and tear the structures contained in it. THE PROSTATE, PENIS AND URETHRA. 
783 
covering of circularly arranged unstriped muscular fibres, in contact with the 
striped fibres of the constrictor urethra, and is said to have longitudinal fibres 
embraced by them; the circular fibres are continued in the bulb, but get 
fewer further forwards, and ultimately disappear. 
Mucous glands, lined with columnar or cubical epithelium and with ducts 
directed forwards, are found over the whole urethra, as far as the squamously 
lined part at the outlet. Some are simple, while others are racemose and 
have longer ducts, and are situated in the submucous tissue, and are known 
as glands of Littre. Lastly, Cowper's glands are a pair of firm racemose 
glands about the size of small peas, with unstriped muscular fibres around 
them, situated on the surface of the constrictor urethrae and under cover of 
the deep transversus perinaei muscle. Their ducts, an inch or more in length, 
are directed forwards beneath the mucous membrane, and terminate separately 
in the floor of the bulbous portion of the urethra. 
FEMALE ORGANS. 
I. The Ovaries, Uterus and Fallopian Tubes. 
The ovaries are a pair of firm, white fibrous bodies, which in the 
young adult measure about an inch and a quarter in length, three-quarters 
of an inch in breadth, and three-eighths in thickness, and have a smooth 
Ovary 
Ovary 
Dilated end of 
tube 
Round ligament of uterus 
Anterior lip of os 
Fimbriae 
Orifice of tube 
Fig. 611.-Uterus, Ovaries and Fallopian Tubes, from the front. 
Vaginal wall 
surface covered with peritoneum. But in consequence of the ova escaping 
at the monthly molimen, by laceration of the peritoneal surface, cicatrices 
gradually accumulate; and the ovaries in elderly subjects are not only 
shrivelled but marked with indentations and linear depressions. They are 
attached each by the anterior border to a fold of peritoneum, broad or 
suspensory ligament of the ovary, projecting slightly backwards fiom the bioad 
ligament of the uterus, below and behind the Fallopian tube; and within 
this fold a fibrous band, the round ligament of the ovary {ovarian ligament of 784 
THE REPRODUCTIVE ORGANS. 
some authors) unites each to the corresponding cornu uteri. The exact 
position of the ovary, when its ligaments remain unaltered, may be said to 
be determined by the position of the uterus and by the entrance of the 
round ligament of the uterus into the inguinal canal. When the uterus is 
neither pregnant nor displaced, the ovary rests in the depression between the 
external and internal iliac arteries, and the end furthest from the uterus is 
superior and posterior to the other. Along the attached border it presents 
a linear depression or hilus, from which the vessels and nerves can be traced 
spreading out in the interior. 
Within the ovary, tortuous vessels abound, some only for a depth of 
from a sixteenth to a twenty-fifth of an inch below the peritoneum, which is dis- 
tinguished as the cortex, while the rest is termed the medulla. The stroma of 
the ovary consists of a richly corpuscular fibrous tissue, in which the great 
majority of the corpuscles are spindle-shaped, and contains a notable number 
Intruding stream of epithelial cells Primitive ova 
Germinal \ 
epithelium / 
Bloodvessels 
f Ova and surround- 
ing cells in the 
form of chains 
I extending in 
f from the surface 
Ova becoming) 
isolated | 
Bloodvessels 
/ Mass of ova and 
\ surrounding cells 
/ Ova becoming 
\ isolated 
Fig. 612.—Section of Ovary of Child at Birth. (Hertwig, after Waldeyer.) 
of elastic fibres. The medulla abounds in winding arteries and veins, and 
contains a number of spindle-shaped corpuscles, larger than those of the 
cortex and considered by some as muscular, and it has also stellate corpuscles, 
held by many as nervous. The cortex or ovigenous stratum has its fibres 
more uniformly felted and more nearly parallel to the peritoneum, and 
is but slightly vascular; it is the part in which the ova are developed, 
and when examined with the microscope is seen from foetal life up to 
the young adult condition to abound in multitudes of minute ova in different 
stages of development. Scattered about in the cortex in active ovaries 
there are always visible a few clear cysts, the larger members of a vast 
number of follicles, each surrounding an ovum, the Graafian vesicles. The 
smaller of those visible encroach on the medulla, and the larger occupy the THE OVARIES, UTERUS AND FALLOPIAN TUBES. 
785 
whole thickness of the cortex, showing themselves at the peritoneal surface, 
and reaching to a sixth of an inch in diameter. Sometimes also there is 
seen a yellow body, corpus luteum, or a large Graafian vesicle filled with 
blood-clot, or a corpus luteum with blood-clot in the centre; the explanation 
being that one or more Graafian vesicles burst at each menstrual period, 
liberating the contained ovum and becoming filled with blood, and that, as 
the clot disappears, a yellow structure is developed in the surrounding wall, 
increasing for a number of days and afterwards disappearing, except when 
pregnancy takes place, in which case it becomes larger and persists for a 
number of months. 
The ovum is a spherical body, measuring in a full-sized Graafian vesicle in 
the human subject T-|o-th inch in diameter, and presents a clear wall, the zona 
'pellucida, surrounding the granular 
vitellus or yelk, in the interior of 
which is a clear spherical germinal 
vesicle about inch in diameter, 
inclined toward the superficial side 
and containing a granular body, 
the germinal spot. Around the 
ovum is a heap of small corpuscles, 
the discus proligerus, which adheres 
to the inside of the Graafian vesicle 
at the part nearest to the peri- 
toneum, and is continuous with 
corpuscles of the same kind lining the 
whole vesicle, the tunica gramdosa. In the wall of the Graafian vesicle 
two layers are distinguished, an outer or fibrous layer continuous with 
the stroma, and an inner or vascular layer named the ovisac. It is in the 
ovisac that the development of cells loaded with oil globules, giving character 
to the corpus luteum, takes place after bursting of the vesicle. In smaller 
Graafian vesicles than those visible to the naked eye, the ovum occupies 
the middle of the Graafian vesicle and the germinal vesicle the middle of 
the ovum, and one mass of corpuscles fills the cavity of the Graafian vesicle 
around the ovum. The Graafian vesicles get smaller toward the surface of 
the cortex by diminution of the number of lining corpuscles much more 
than by diminution of the ovum, and the smallest ova have only a few 
corpuscles round them. The peritoneum on the surface of the ovary is covered 
not with the delicate epithelium or endothelium found on the peritoneum 
elsewhere, but with minute columnar epithelium, the remaining portion of 
the germinal epithelium (p. 97) from which the ova and probably the 
cells around them are derived, most of them in foetal life. Thus it appears 
that the ova, beginning on the peritoneal surface as elements of the germinal 
epithelium, travel in through the stroma of the ovary till they reach the 
deep limit of the cortex, where the vascularity is favourable to the develop- 
ment of the ovisac, and that afterwards the expansion of the Graafian vesicle 
3 D 
Fio. 613.—Human Ovum within Graafian vesicle, 
\O-. a, Germinal vesicle and spot; b, vitellus or 
yelk ; c, zona pellucida; d, discus proligerus; e, 
membrana granulosa; /, vascular wall of ovisac; g, 
stroma of ovary; h, surface of ovary. 786 
THE REPRODUCTIVE ORGANS. 
with fluid causes it to follow the same law as governs other collections of 
fluid, and push aside the textures on the side on which there is least 
resistance.1 
The uterus, or womb, is a hollow organ reaching above to the brim 
of the pelvis, continuous above on ‘ each side with the Fallopian tubes, 
and opening below into the vagina. It is a pyriform body, with thick 
muscular walls which give it the firmness of a solid structure, and is in 
the adult and unimpregnated condition about three inches long, two inches 
broad, and one inch thick at the upper and broadest part. A slight 
concavity of the lateral outline about two-thirds down marks superfically 
the division into the body above, and the cervix or neck below; but the 
interior shows more clearly the distinction. The cavity of the body is 
triangular, with the anterior and posterior walls in contact, and with all 
Cavity of Body 
Opening of Fallopian tube 
Os internum 
Cavity of Cervix, arbor vitae 
Os externum 
Fig. 614.—Uterus, in vertical transverse section, 
three margins curving inwards, and has a perfectly smooth surface. Its 
upper angles taper to the Fallopian tubes, and represent the parts which 
are prolonged into cornua in many animals; and its lower angle is separated 
by a constriction termed os uteri internum, from the cavity of the cervix. 
The cavity of the cervix is limited below by another constriction, the 
os externum,, and has its walls circularly compressed. Its surface is marked 
by two longitudinal lines, one in front and one behind, from each of which 
JThe ovaries were recognised as homologous with testes by Galen, and continued 
to be called testes muliebres till the time of De Graaf. Fallopius mentioned in the testes 
muliebres both clear vesicles and yellow bodies, but it was left for De Graaf to give 
a description of both, and to demonstrate that mammals had ovaries like oviparous 
animals, and that the Fallopian tubes received ova from them; while it was not 
until 1827 that the true mammalian! ovum was discovered by von Baer. THE OVARIES, UTERUS AND FALLOPIAN TUBES. 
787 
a number of rugae extend upwards and outwards, giving an appearance 
known as arbor vitae or palmae plicatae. The os externum is in the 
virgin uterus a transverse orifice, about -V-th inch in extent; and the 
vaginal part of the cervix, in front and behind it, takes the form of two 
lips, of which the anterior descends further than the posterior, although 
the vagina is prolonged further behind the posterior lip than in front 
of the anterior lip; hence the os externum (called from the inequality of 
the lips os tincae) looks to the posterior wall of the vagina. 
Round ligament of ovary 
Ovary laid open 
Isthmus tubae 
Fallopian 
tube cut 
Epoophoron 
Vein 
Parovarium 
Lips 
of os 
Graafian 
vesicles 
Corpus luteum 
Pavilion of 
Fallopian tube 
Os uteri externum 
Vaginal wall 
Hydatid 
Graafian vesicles 
Fig. 615.—Uterus, Ovaries and Fallopian Tubbs from behind. 
The whole posterior surface of the uterus above the -vagina, the upper 
end or fundus, and the anterior surface of the body are covered with 
peritoneum, while the fore part of the cervix, down to the vaginal attach- 
ment, is in contact with the bladder, and, at the sides, the uterine vessels 
and nerves lie between the folds of peritoneum constituting the broad 
ligament of the uterus. In the upper edge of the broad ligament the 
Fallopian tube is placed, and in a projecting anterior fold of the broad 
ligament a strong band of fibres, the round ligament of the uterus, extends 
outwards from immediately below and in front of the origin of the Fallopian 
tube to the internal abdominal ring. Having reached that ring the round 
ligament loses its peritoneal investment, and traverses the inguinal canal, 
like the spermatic cord in the male, and emerges to be lost in the connective 
tissue of the labium rnajus. 
Structure. The muscular wall is resolvable into three layers, very 
closely connected one with another and difficult to follow. The superficial 
fibres are longitudinal in front and behind, the majority arching over the 
fundus, but those situated more to the sides curving outwards as they 
ascend, and extending into the round ligaments of the uterus and on to 
the walls of the Fallopian tubes. Much the thickest layer is the next, and 
has the fibres very intricately arranged winding among numerous vessels 
in the body, but becoming circular in the cervix. The innermost layer 788 
THE REPRODUCTIVE ORGANS. 
has its fasciculi interspersed with areolar tissue and tubular glands, and 
is arranged longitudinally in the cervix, obliquely higher up, and circularly 
toward the mouths of the Fallopian tubes. But even these distinctions 
into layers are vague, and there seems no advantage to be gained by 
calling the inner fibres muscularis mucosae, as has been proposed (Williams), 
for that could only indicate a layer belonging to the mucous membrane, 
and separated from the others by a submucous layer of loose tissue, 
whereas the most marked peculiarity of the mucous membrane of the 
uterus is that it is not separated from the subjacent textures by any such 
layer. The epithelium lining the uterus is simple columnar ciliated. The 
surface outside the os externum has stratified scaly epithelium continuous 
with that of the vagina. This is continued at first into stratified columnar 
epithelium on the prominent ridges of the cervix, while already the recesses 
between have ciliated columnar epithelium. Scattered through the mucous 
membrane of the body are elongated, straight or somewhat winding 
tubular follicles (glandulae utriculares), lined, unlike secreting glands generally, 
with ciliated columnar epithelium. And these extend also down into 
the upper part of the cervix, but in the lower part are exchanged for 
wider follicles with cubical epithelium secreting mucus. Clear vesicles 
(ovuli Nabothi) also occur, embedded in the mucous membrane of the 
cervix, probably resulting from closure of some of the mucous follicles 
(Toldt). In menstruation there is at first a general swelling and softening 
of the whole mucous membrane, increased vascularity, also enlargement 
of the epithelial cells, and afterwards extravasation, formation of oil 
globules both within and around the epithelial cells, and abundance of 
lymphoid corpuscles or leucocytes. 
Vessels and nerves. The uterus is principally supplied with blood by 
the right and left uterine arteries, given off from the anterior divisions of 
the internal iliac arteries. These reach it opposite the cervix. Each gives 
off a vaginal branch downwards, and is directed upwards on the side, giving 
off undulating branches to the anterior and posterior walls, and anastomosing 
above with the ovarian artery along by the Fallopian tube. The uterine 
and ovarian veins anastomose much more freely than the corresponding 
arteries. The lymphatics are very abundant, and are deep and superficial. 
The nerves are derived from the inferior hypogastric plexus, which are 
joined by branches from the third and fourth sacral nerves. 
Bicornute uterus is an abnormality arising from imperfect development. 
The uterus may divide into two cornua or be completely double, and the 
vagina may partake either in whole or in part in the duplicity. One-horned 
uterus results from suppression of the part connected with one Fallopian tube. 
In pregnancy the menstrual thickening of the mucous membrane, instead 
of terminating with relief of the swollen capillaries, associated with a certain 
degree of fatty degeneration of texture, goes on further to the formation of 
the decidua (p. 103). The rapid increase of the uterus is accompanied with 
ascent into the abdomen, and the cervix undergoes remarkable changes. THE OVARIES, UTERUS AND FALLOPIAN TUBES. 
789 
the lower part secreting a tenacious substance, while the upper part would 
appear to alter its relations and enter into the formation of the enlarged body. 
The Fallopian tubes are the ducts by which the ova, escaped from the 
ovaries, reach the uterus. They are between three and four inches long, 
and open by one extremity (ostium uterinum) into the uterus, and by the 
other (ostium abdominale) into the peritoneal cavity. They spring abruptly 
from the uterus, and are continuous with the superior and lateral angles 
of its cavity. For about an inch from its uterine extremity the Fallopian 
tube is so narrow as only to admit a bristle, and this part is known as the 
isthmus. Beyond it the tube dilates in the rest of its length to about an 
eighth of an inch in diameter, and is again slightly narrower close to the 
peritoneal orifice, and the dilated part is often alluded to as the ampulla. 
The peritoneal orifice is expanded like the corolla of a flower, and the free 
margin of its expansion is prolonged into fringe-like processes, the fimbriae, 
one of which is attached by peritoneum so as to approach close to the 
outer end of the while to another there is often appended a minute 
cyst, probably vestigial, like the hydatids of Morgagni in the male. 
The mucous membrane is lined with simple ciliated columnar epithelium 
up to the edge of the fimbriated extremity. It is thrown into longitudinal 
rugae, which are simple in the isthmus, but in the ampulla bear secondary 
rugae, and communicate one with another and exhibit blind recesses. 
Beneath the mucous membrane there is a submucous layer of connective 
tissue containing some longitudinal muscular fibres. The main thickness 
of the muscular coat consists of circular fibres, but there are some longi- 
tudinal fibres external to them. 
The Fallopian tubes are supplied by the ovarian vessels and nerves. 
The parovarium (epoophoron or organ of Bosenmilller) is a vestigial structure, 
the epididymis and coni vasculosi of the male. It is without apparent 
function, and is seen to advantage on holding up against the light the fold 
of peritoneum between Fallopian tube and ovary. It is always present, 
but is most distinct in young subjects. It consists of a thread-like tube 
running parallel to the outer part of the Fallopian tube, with several others 
(not, however, tubules of the Wolffian body) coming off from it and running 
towards the ovary. No opening has been found into those tubes. They 
contain ciliated columnar epithelium. Other vestigial remains placed nearer 
to the uterine end of the Fallopian tube have been named paroopho'ron. 
11. The External Organs of the Female. 
Under this head may be included the superficial sexual parts, together 
with those near the surface, or opening in its neighbourhood. 
The superficial parts, pubes or pudendum, consist of the vulva, bounding 
the genito urinary orifice, and the mons veneris. The mons veneris is the 
prominence of thickened adipose and areolar tissue on the front of the 
pubes, covered with hair, the abdominal margin of which differs from the 790 
THE EEPEODUCTIVE OEGANS. 
corresponding part in the male in forming one crescentic curve from side 
to side, instead of two which meet in the middle line. The vulva is limited 
externally by thickened margins, labia majora, continued back from the 
mons veneris; and internal to them presents two smaller folds, the 
nymphae, meeting together in front at the praeputium clitoridis. The labia 
majora are rounded and filled out with adipose tissue from infancy till 
after the prime of life, and are liable to shrivel at a later period. Into 
them may be traced from above the deep layer of the superficial fascia of 
the abdomen and the round ligament of the uterus, which both become 
lost in the web supporting the adipose tissue, which is distinct from the 
adipose tissue of the thigh and hinder part of the perineum, and still more 
firmly separated from the nymphae. The points where the inner margins 
of the labia majora meet in front and behind are called the anterior and 
posterior commissures, and the posterior commissure has in the uninjured 
condition a bridle-like margin or fraenulum often called the fourchette. 
Praeputium 
clitoridis 
Labium tnajup, 
-Gians clitoridis 
Fraenulum 
clitoridis 
iSympha 
Vestibulun 
Urethra 
Ostium 
gl. Bartholini 
Vagina 
Hymen 
Fraenulum labiorum 
Fio. 616.—Female Genitalia. (Pansch.) 
The nymphae, or labia minora, are a pair of narrow tegumental folds 
internal to the labia majora. They meet together in front in connection 
with an erectile prominence, the glans clitoridis, hid in a smooth depression 
within the anterior commissure. They bifurcate on approaching the glans, 
the upper division joining with its fellow above that structure to form the 
praeputium clitoridis, and the lower division meeting its fellow on the 
under surface of the glans to form the fraenum clitoridis. The nymphae THE EXTERNAL ORGANS OF THE FEMALE. 
791 
are of a firm fibrous texture, but contain a number of minute arteries 
which may give serious trouble when divided during life. Though hairless, 
they have numerous branched sebaceous glands opening on both their inner 
and outer surface. Occasionally the nymphae are considerably longer than 
usual; and in Hottentot women they form an “apron ” which may descend 
for several inches. 
The vestibule is the space bounded superficially by the nymphae and 
deeply by the position of the hymen. Anteriorly it presents a smooth 
depression bounded by the glans clitoridis in front and by the rough sur- 
face within the vagina behind. It is covered with stratified squamous 
epithelium. In the deepest part of this depression just in front of the 
vaginal orifice is the meatus urinarius which, from its position, can always 
be quite easily detected with the finger, without the aid of vision, as a 
pit. Acinated mucous glands open on the surface of the vestibule. 
The hymen is a membrane which, in the virgin, is stretched more or 
less completely across the entrance to the vagina. Its typical and proper- 
form is best understood by examining it in the foetal condition. It is 
developed as a funnel-like fold of mucous membrane, prolonging the vagina 
downwards behind, but absent in front so as to place the opening of the 
vagina immediately behind the meatus urinarius. As growth proceeds, the 
opening does not develop at the rate of the parts around, and the hymen 
comes thus to form a septum across the entrance into the vagina. While 
the normal position of the opening is undoubtedly in front, cases occur 
both of imperforate hymen and, more frequently, of irregular apertures, 
very probably the result of a prior imperforate condition. Little papillary 
prominences left at the line of attachment of the hymen after its destruc- 
tion are called carunculae myrtiformes. 
The female urethra, opening into the vestibule, as already described, is 
an inch and a half long, wider than in the male, and lies parallel and 
close to the vaginal wall, so that when the meatus has been found with 
the tip of the finger, an instrument slips in easily if the finger be slid 
slightly into the vagina and the instrument pointed in the same direction. 
The muscular wall is strong, its innermost fibres longitudinal, the others 
circular, the outermost layers containing striped fibres. The mucous mem- 
brane is thrown into longitudinal folds which in the lower half are 
unobliterable, and have between them little crypts looking downwards; and 
some of the lowest of these are prolonged upwards and branched (as 
figured first by De Graaf), and are lined with cylindrical epithelium. The 
urethra itself is lined in its upper part with epithelium like that of the 
bladder, and its lower half like that of the vestibule. In its upper half 
tubular mucous glands are found. 
The clitoris consists of two corpora cavernosa, like those of the male, 
but smaller, surmounted by a rudimentary glans. The corpora cavernosa 
spring each from a crus attached to the arch of the pubis and covered by 
an erector clitoridis muscle. They join to form a body an inch and a 792 
THE REPRODUCTIVE ORGANS. 
half long with a more or less complete septum between. The body is hid 
in adipose tissue and loosely attached by a suspensory ligament to the 
lower part of the symphysis pubis, but it is surmounted by a glans distinct 
from the corpora cavernosa. 
The bulbi vestibuli are two erectile masses of convoluted veins placed 
one on each side of the vestibule at the attached border of the nymphae 
and internal to the sphincter vaginae muscle. They receive blood from 
the nymphae and pass it forwards into a number of larger veins between 
Promontory _ 
Peritoneum _ 
Plica trans- i 
versa (valve of 
Houston) J 
.Vesico-uterine fossa 
.Symphysis 
Rccto-uterine 
fossa 
,Mons Veneris 
.Clitoris 
Nympha 
.Labium majus 
Fig. 617.—Mesial Section of Female Pelvis. 7, Sigmoid flexure; 8, rectum; 10, 
small intestine; 11, bladder; 12, urethra; 13, septum urethro-vaginale ; 14, septum 
reoto-vaginale ; 15, uterus ; 16, vagina. (Luschka.) 
it and the glans clitoridis, whence it is conveyed upwards into the vaginal 
plexus. The bulbi vestibuli correspond with the corpus spongiosum of the 
male, and the sphincter vaginae with the acceleratores urinae, while the 
nymphae correspond with the spongy part of the urethra and the integu- 
ment on the under surface of the penis. 
The glands of Bartholin, or of Duverney, sometimes also called Cowper’s 
glands because corresponding with Cowper’s glands in the male, are two 
small acinated glands about the size and shape of field-beans. They lie 
close to the posterior commissure, partly under cover of the deep transverse THE EXTERNAL ORGANS OF THE FEMALE. 
793 
perineal muscles, and pour their secretion each into a long duct which opens 
into the vestibule well forward. 
The vagina, the passage extending from the vestibule to the uterus, 
has in front of it the urethra, with which it is closely connected, and 
also the bladder, while the rectum is in contact with it behind, excepting 
for a little distance above, where the pouch of Douglas intervenes. At the 
sides it is supported by the recto-vesical fascia, by which and the levator 
ani it is separated from the ischio-rectal fossa. Being curved, and also pro- 
longed further up on the posterior than on the anterior lip of the uterus, 
it has a greater length of posterior than of anterior wall. 
Prepuce of clitoris - 
■ Gians and fraenum of clitoris 
Urethral orifice. 
Vestibule 
Duct of gland of Bartholin 
,Nympha 
Remains of 
hymen 
Fig. 618.—External Organs of Female, with Lower Part of Vagina, laid open 
from behind. 
The mucous membrane is continuous below with the vestibule or hymen 
as the case may be, and is reflected above on the lips of the uterus. It has 
stratified squamous epithelium, and is furnished with papillae more abundant 
in the lower part, and with mucous glands more abundant in the upper part. 
It is thrown to a variable extent upwards into rough transverse rugae, 
which are specially prominent at the lower end, and gathered together in 
anterior and posterior columns, from which they arch upwards as they become 
less prominent on the sides. Both the anterior and posterior columns have 
a tendency to duplicity, but the mesial part of the anterior column is pro- 
jected by the thick muscular wall of the urethra. The anterior and posterior 
columns lie in contact one with the other, while the lateral parts of the 
wall are pressed against them so as to give a transverse section the form 
of the letter H. The muscular wall presents longitudinal and circular fibres 
not separable into distinct layers, and the lower and anterior part is not 
distinctly separable from the fibres surrounding the urethra. In the mucous 794 
THE REPRODUCTIVE ORGANS. 
membrane there is free supply of vessels to the papillae, and in the muscular 
substance there is an abundance of winding and anastomosing veins which 
is sometimes referred to as erectile tissue, while a plexus of larger veins is 
particularly rich round the lower part of the vagina and the urethra. In 
the fibrous tissue round the muscular wall numerous small ganglia are said 
to exist. 
DEVELOPMENT OF THE REPRODUCTIVE ORGANS. 
As already stated (p. 97), a tract of germinal epithelium, different from 
the cells which bound the rest of the abdominal cavity, appears in the 
embryo on the surface of the Wolffian body, and it is from this that, 
according to the sex, the essential reproductive elements of the testicle or 
of the ovary are developed. In both sexes a white body covered with a 
thickening of this epithelium becomes apparent on the inner side of the 
crimson-coloured Wolffian body, mid-way between its extremities, before it 
has begun to dwindle or change its position, but the ovary is from the 
first of a distinctly longer shape than the testicle. Indeed, this difference 
of shape is, in man and in other mammals with short or pendulous penis, 
the earliest indication by which the sex can be determined, though in pigs 
and ruminants the production of the penis toward the umbilicus affords a 
more obvious distinction. 
Pig. 620.—Organs on 
Right Side of Embryo 
Ram. a, Kidney; b, 
suprarenal capsule ; c, 
testis; d, Wolffian body; 
/, vas deferens ; g, coni 
vasculosi; between /'and 
g, epididymis ; i, ureter. 
Fig. 619.—Ovaries and 
Wolffian Bodies of Embryo 
Pig, f. a, Kidney; h, 
Wolffian body, and on its 
surface the Mullerian duct; 
c, ovary ; d, urinary bladder 
turned down ; e, rectum. 
The ovary has been more fully worked out in its development than the 
testicle. The ova destined to be discharged periodically after sexual activity 
has been arrived at are cells of the germinal epithelium. From an early 
period of foetal life certain of these cells become round, and assume all the 
characters of minute ova; they are carried in, partly at least, by the growth 
of the deep-seated connective and vascular tissue ; other smaller epithelial 
cells follow them, and thus elongated masses are embedded in tubules of DEVELOPMENT OF THE REPRODUCTIVE ORGANS. 
795 
stroma. At intervals other cells in these masses assume the characters of 
ova, and the stroma separates each ovum with its surrounding cells from 
the others, so as to produce separate Graafian follicles arranged at first in 
chains or egg-hands (Fig. 612). 
The testicle seems on the whole to be well made out to have its seminal 
elements derived like those of the ovary by intrusion of epithelial elements, 
arranged in processes which become elongated as the connective and vascular 
tissue grows up round about them. 
Ducts. The Mullerian duct can be easily seen with the naked eye, forming 
on the outer border of the Wolffian body at the time of its maximum 
development a prominent white column • and in connection with the upper 
end of this column there is soon afterwards seen in both sexes a white 
conical mass (Cleland, 1856) containing tubules, and in greater part distinct 
from the Mullerian duct, which duct turns inwards in front of the base of 
the conical mass to terminate on the inner border (Banks, 1864). 
In the female the Miillerian duct is developed in so far as it is in contact 
with the Wolffian body into the Fallopian tube, and the lower end of the 
Wolffian body marks the point where uterus and Fallopian tube meet. To 
this point a cord descends from the lower end of the ovary, and becomes 
developed into round ligament of ovary, while continuous with it another 
fold extends to the inguinal canal, and becomes round ligament of uterus.. 
But the two ligaments are not long continuous in direction, as the Wolffian 
body and the ovary are rotated outwards, and the deep end of the inguinal 
canal also retreats from the mesial plane. In later development the peri- 
toneum descends into the inguinal canal for a short distance on the round 
ligament of the uterus as a pouch, the canal of Nuck. The Miillerian duct 
opens at first independently of its neighbour into the uro-genital sinus; but 
while in monotremata and non-mammalian vertebrates it remains distinct 
from its fellow, in all placental mammals the ducts of opposite sides become 
fused into one tube a little distance from their outlets to form the fundus 
uteri, and the fusion is afterwards extended as far as the sinus so as to 
make a single vagina. It is failure in this fusion which produces various 
anomalies met with in the human subject, such as bicornute uterus and 
duplicity of vagina.l 
In the male the Mullerian ducts are early arrested in development. 
The united part of the two ducts remains as the sinus pocularis; which 
(as first pointed out by Banks) represents both uterus and vagina, while 
the portion of the male urethra between the sinus and the bladder is- 
homologous with the female urethra. The ununited portions of the 
Mullerian ducts persist in the male in many mammals as cornua of the sinus 
pocularis and two threads extending from them. The vas deferens is- 
developed from that part of the Wolffian duct between the base of the 
1 Specimens in my museum demonstrate that, in marsupials, the ureters pass between 
the two vaginae to reach the bladder. In this respect the marsupial arrangement is not 
comparable with anomalous double vagina in the human subject. 796 
THE REPRODUCTIVE ORGANS. 
Wolffian body and the sinus uro-gemtahs. ihe epididymis is developed 
dose behind the Mullerian duct, along the outer side of the Wolffian 
Germ-gland 
Wolffian body 
Mliller’s duct 
[ Wolffian duct 
_ Ureter 
Bladder 
. .Rectum 
Pigs. 621, 022, 623.—-Diagrammatic View of the Development of the Sexual 
Organs. (Pansch.) 
Fig. 621.—Undifferentiated. 
Hydatid of Morgagni. 
Testis- 
•Epididymis 
-Miillor’s duct 
-Vas deferens 
Bladder 
Ureter 
Vas deferens 
Vesicula seminalis 
Penis 
Prostatic sinus 
Rectum 
Testis decended 
Prostate 
body, and is held to be the altered Wolffian duct. But it is beyond doubt 
Fig. 622.—Male. DEVELOPMENT OF THE REPRODUCTIVE ORGANS. 
797 
that the coni vasculosi and commencement of the epididymis are developed 
in the conical mass surmounting the Wolffian body. The canals of this 
mass remain in the female as the parovarium (or epoophoron), while the 
portion of it which forms in the female the extremity of the Fallopian 
tube persists as the hydatid of Morgagni in the male. The proper sub- 
stance of the Wolffian body leaves only small vestiges in either sex, viz., 
in the male, the organ of Giraldes, and in the female, the paroophoron. 
Ovary _ 
Ostium tubae 
Parovarium 
Fallopian tube 
Uterus 
Wolffian duct 
Ureter 
Rectum 
Clitoris 
Fig. 623.—Female. 
Descent of the testicles. Unlike the ovary, the testicle retains the 
longitudinal position, while it gradually descends and carries with it the 
epididymis on the outer side and the vas deferens on the inner. It 
reaches the internal inguinal ring about the end of the sixth month of 
foetal life, and usually completes its descent about the beginning of the 
ninth month. A band homologous with the round ligament of the ovary 
passes from the lower end of the testicle to the lower end of the Wolffian 
body. It joins the testicle to the point where the epididymis becomes vas 
deferens, and is the upper portion of the structure named by Hunter 
gubernaculum testis. Continuous with it, a larger band descends to the in- 
guinal canal, and thence afterwards to the scrotum, constituting the lower, 
larger and more generally recognised portion of the gubernaculum, 
homologous with the round ligament of the uterus. The upper portion 
very early disappears by the shrinking of the Wolffian body and 
approach of the testicle to the globus minor of the epididymis, while the 
lower portion becomes more fully developed and extends down into the 
scrotum. The peritoneal sac is prolonged downwards as processus vaginalis 
prior to the testicle leaving the abdomen, and reaches the bottom of the 798 
THE REPRODUCTIVE ORGANS. 
scrotum before the testicle has quite entered it. The gubernaculum 
presents a band extending from the fascia transversalis to the bottom 
of the scrotum, with fibres passing upwards and downwards on it from 
the different depths of the abdominal wall, and a projection into the 
pouch of the tunica vaginalis, inclosed in a fold called plica gubernatrix; 
but the contents of the plica do not extend beyond the pouch of the 
processus vaginalis, and the cremaster muscle is from the first directed 
downwards. The descent of the testicle sometimes fails to be completed 
on one or both sides, in which case the patient is called a monorchid or 
■cryptorchicl. This failure of descent may or may not be accompanied 
with arrest in size. Sometimes descent proceeds again in the young adult 
and gives trouble in the inguinal canal. 
Fig. 624.—Left Testis and Gubebnacu 
lum in Foetus of Fifth Month, a,Testis; 
b, vas deferens ; c, processus vaginalis slit 
open ; d, plica gubernatrix; e, the cavity 
described by Weber as a shut sac ; ff, 
fibres inserted interiorly in a bundle into 
the scrotum, and superiorly into the 
abdominal wall; g, fibres to the pro- 
cessus vaginalis; h, internal oblique 
muscle; i, aponeurosis of the external 
oblique muscle ; k, integument reflected 
down. 
Fig. 625.—Dissection of a Mamma in Active 
Condition. The nipple is left undissected. On it 
are seen the openings of the galactophorous ducts, and, 
beyond it, their ampullae embedded in connective 
tissue, while the lobules are round about. 
External organs. Before the fifth week there is a cloaca common to 
the rectum and genito-urinary organs. By the eighth week the anus 
is completely separated as a rounded orifice from the genito-urinary 
opening, which forms in both sexes a mesial slit, surmounted by an 
organ which may be developed either into clitoris or penis. Thereafter, 
the margins of this aperture come together in the male to form the 
raphe of the scrotum and the wall of the spongy part of the urethra, 
while in the female they remain separate as the nymphae and labia 
majora. The corpora cavernosa appear separately and afterwards unite. MAMMARY GLANDS. 
799 
THE MAMMARY GLANDS. 
The mammae, like the other organs connected with reproduction, are 
represented in both sexes. They are fully developed in the female only. 
Their representatives in the male are in no way altered or disguised, but 
simply arrested in development. Both in the virgin and in the male the 
nipples are on a level with the lower end of the body of the sternum ; 
and in the virgin they form with the depression between the clavicles an 
equilateral triangle. 
The glandular substance of the mamma is arranged in a circular disc 
around the nipple. It lies in the subcutaneous adipose tissue, which pene- 
trates more or less between its lobules. The integument on its surface is 
easily removed, as is also a firm lajmr of superficial fascia beneath the 
deep surface of the gland, while between its lobules the raeshwork of 
connective tissue is abundant and tough, forming as it were shut locules. 
Hence it happens that superficial abscesses rise up easily and give little 
Fig. 626.—Section through Centre 
of Mamma, parallel to base of nipple. 
The ducts are seen embedded in tough 
connective tissue; while lobules are 
scattered round about. Natural size. 
Fig. 627.—Sections of Human Mamma 
ready for Lactation. A, lobules in fibrous 
stroma, ; B, acini and secreting cor- 
puscles, —f-2-. 
trouble, and a single abscess may enlarge to a considerable size on the deep 
surface before being detected ; but the more frequently occurring abscesses in 
the substance of the gland are multiple and require to be separately 
opened. Both the circumference and the deep surface of the mamma are 
thrown into a number of large lobes consisting of smaller lobules or groups 
of ultimate acini, and these are lined with an epithelium of small cells 
which when active expand laterally, and subsequently in depth also, while 
both they and the interior of the acinus are filled with milk characterized 
by its butericeous globules of different sizes. 800 
THE EEPRODUCTIYE ORGANS. 
The galactopherous ducts are from twelve to twenty, and open by minute 
orifices at the extremity of the nipple. Traced backwards, each gradually 
enlarges, forming an ampulla or sinus widest towards its deep end, where 
it is capable of being swollen to quarter of an inch or more in diameter, 
and extending an inch or more from the base of the nipple. Each ampulla 
originates in the union of two ducts, themselves formed by the union of 
others in pairs. In sections of specimens prepared with acid {e.g. sulphuric) 
the closely set and larger masses of secreting lobes are seen arranged at 
the circumference, while in the deeper parts the sections of lobules are 
small and separated by copious connective tissue, and in the centre the 
connective tissue is collected in a large mass betAveen and around the 
ampullae. The walls of the ducts are highly elastic and lined with 
columnar epithelium. 
The nipple {mammilla) and the rosy ring around it {areola) have adherent 
to the integument a well-marked layer of circularly arranged unstriped 
muscle Avhich no doubt in contracting obstructs the cutaneous veins, and in 
conjunction with a considerable vascularity of these parts causes turgidity, 
approaching in the nipple to erection. The interior of the nipple is destitute 
of fat and contains the narrowing ducts emerging from the ampullae. The 
areola often presents a tuberculated appearance dependent on large sebaceous 
glands (glands of Montgomery). 
In the male the mammary gland, though rudimentary, is complete in 
its parts, its feeble deATelopment being merely the permanence of the con- 
dition in children both male and female. 
Vessels and nerves. The arteries are derived in an inconstant manner 
from the long thoracic or external mammary and some of the anterior 
intercostal branches of the internal mammary. The nerves are from anterior 
and lateral cutaneous branches of intercostal nerves. The lymphatics pass 
principally to the axillary glands, but some of them join the internal 
mammary plexus. 
Supernumerary mammae occasionally occur both on the chest and on other 
parts. They are mostly small and liable to be mistaken for moles, but one 
or more may reach a considerable size. APPENDIX. 
ON THE UTILIZATION OF EONTGEN BAYS. 
Since this book was taken in hand, and even since the completion of the 
bulk of the manuscript, there has come before the world a revelation of 
the possibility of seeing structures in the interior of the living body. The 
part to be played in this respect by the Rontgen rays is as yet only 
beginning to be seen, but sufficient progress has been already accomplished 
to make it rash for any one to limit the amount of anatomical detail which 
may ultimately be displayed by their aid. Meanwhile it is fitting in this 
place to acknowledge the existence of an agent which may be utilized not 
merely in Surgery and Pathology, but in studying with accuracy the relations 
of healthy organs. I content myself with taking the joints at the wrist for 
illustration. 
Through the kindness of Dr. Macintyre of this city, whose successful 
experiments in this new branch of inquiry have already done much and 
are full of promise for the future, I am enabled to exhibit the shadows 
cast by the bones of this region when the hand is in a straight line with 
the pronated forearm, when it is bent over to the ulnar side as far as it 
will go, and when pressure is made on it in over-extension. Every ana- 
tomical student has already had the opportunity of seeing in the views 
sold in the shops that the cuneiform is not in the relation to the ulna 
which has generally been supposed. It is to be clearly understood at the 
outset, that cartilage presents no apparent hindrance to the passage of the 
rays, and that therefore articular surfaces, even when pressed together, 
exhibit a space between them. But after making allowance for the thick- 
ness of the articular cartilages and of the radio-ulnar triangular fibroplate, 
the gap between the ulna and cuneiform bone when the hand is stretched 
out is exceedingly remarkable. Nor is this all. The semilunar is to a 
considerable extent underneath the fibroplate, and its upper surface only 
half the vertical distance below the lower surface of the ulna that the 
nearest point of the cuneiform is, while the upper articular surface of the 
cuneiform looks more to the side than upwards. One has to recall to 
mind that the triangular fibroplate is not an articular cartilage, and to 
acknowledge that we have gone too far if we have looked on its contact 
3 E 802 
APPENDIX. 
with the cuneiform bone as the play of two articular surfaces. One sees 
also that where articular surfaces are opposed, as the upper surfaces of the 
scaphoid and semilunar are to the radius, each surface presses in all positions 
Fig. 628.—Eontoen-ray-shadow of Wrist of Hand, stretched in a line with the forearm. 
only on the district specially set aside for it, and never on that set aside 
for another. When the hand is in a line with the forearm, the inner part 
of the scaphoid is indeed below the semilunar facet of the radius, but it 
Fig. 629.—The same, with the stretched hand hent over the ulna. 
is not in contact with it; and when the hand is inclined to the ulnar side, 
the semilunar bone is to a considerable extent beneath the scaphoid surface 
of the radius, but is very far from being in contact with it. In both lateral 
flexion and over-extension of the hand there is seen to be lateral movement APPENDIX. 
803 
of the lower range of carpal bones on the upper range, for in both these 
positions the unciform is approached to the semilunar, while in the straight 
position of the hand it is quite separated from it. That this lateral move- 
ment is accompanied by movement in which the scaphoid and cuneiform 
are thrown back at the extremities removed from the semilunar is shown 
by the apparent elongation of scaphoid and cuneiform. This is in keeping 
with the description of movements given at p. 161; also the gaps there 
Fio. 630.--The same, with the hand completely over-extended. 
pointed out as existing in different positions between trapezium and first 
metacarpal are to a certain extent illustrated. Another point may be noted. 
The hand employed happened to be that of a man over sixty, and the 
shadows exhibit the lines of union of the shafts and epiphyses of the 
radius and ulna, a thing which might be seen over and over again in 
macerated bones without the age of the bones being known. This reminds 
us that much accurate information can now be got on the subject of the 
condition of epiphyses at different ages. INDEX. 
Abdominal, aorta, 447 ; arteries, surgical an- 
atomy, 457 ; cavity, 687; muscles, actions of, 
381; muscles, nerve supply, 381; regions, 
688; ring, deep, 384; ring, external, 376. 
Abduction of joints, 39. 
Abductor, hallucis muscle, 321; minimi digiti 
muscle, 283, 321; pollicis muscle, 281; pollicis 
longus muscle, 279. 
Abducent ocular nerve, 549. 
Absorbent system, definition of, 64. 
Absorption spaces of bone, 27. 
Accelerator urinae muscle, 390. 
Accessory, cartilages of nose, 640; duct of 
pancreas, 729; lachrymal glands, 644; liga- 
ment, atlanto-axial, 124; ligament, knee- 
joint, 192 ; ligament, occipito-atlantal, 123 ; 
obturator nerve, 527. 
Acervulus cerebri, 611. 
Acetabulum, 162, 166. 
Achillis, tendo, 313, 314. 
Achromatin, 7. 
Acinated glands, 57. 
Acini, of glands, 57; mucous and serous, 58. 
Acino-tubular gland, 730. 
Acrocephalus, 243. 
Acromegaly, 612. 
Acromio-clavicular articulation, 151. 
Acromio-thoracic artery, 435. 
Acromion, 134. 
Actions of muscles, 41; of abdominal muscles, 
381; of muscles of arm, 267 ; of deep muscles 
of back, 364; of muscles of forearm and 
hand, 285 ; of muscles of hip and thigh, 302 ; 
of infra-hyoid muscles, 351; of intercostal 
muscles, 372 ; of muscles of leg and foot, 323 ; 
of muscles of mastication, 344 ; of muscles of 
orbit, 337 ; of muscles of palate, 349 ; of con- 
strictors of pharynx, 346; of muscles of 
perineum, 392; of muscles of shoulder, 267 ; 
of supra-hyoid muscles, 340, 341; of muscles 
of thorax, 372. 
Adam’s ajrple, 739, 753. 
Additamentum suturae squamosae, 211. 
Additional incisors of canine teeth, 700. 
Adduction of joints, 39. 
Adenoid tissue, 16. 
Adenoids, naso-pharyngeal, 612. 
Adipose, tissue, 18 ; vesicles, 19. 
Adductor, brevis muscle, 295 ; hallucis brevis 
muscle, 321; longus muscle, 295; magnus 
muscle, 295 ; obliquus muscle, 321; pollicis 
muscle, 282 ; transversus muscle, 321. 
Adrenals, 758. 
Afferent, arteries of glomeruli, 763, 765; lym- 
phatics, 67, 88; nerves, 46, 506; nerves of 
sympathetic, 562. 
Agger nasi, 640. 
Agminated glands, 721. 
Air cells of lungs, 750. 
Alae, of cerebellum, 603; cinereae, 601; orbital, 
214, 216; sphenoidal, 214; of vomer, 231; 
vespertilionis, 692. 
Alar, cartilages of nose, 639 folds of knee-joint, 
192 ; ligaments of knee-joint, 192. 
Albinus, os acetabuli, 203. 
Alisphenoids, 248. 
Allantois, 95, 102. 
Alveolar, process, 226, 234; ridge, 234. 
Alveoli, 226; of lungs, 750; of lymphatic 
glands, 68. 
American-Indian skulls, 242. 
Amnion, 102; false, 102. 
Amoebae, 6. 
Amoeboid corpuscles of connective tissue, 15. 
Amphiarthrosis, 39. 
Amphioxus, embryo of, 86; ova of, 82; polar 
body of, 85. 
Ampulla of Fallopian tube, 789. 
Ampullae, of nerve-fibres, 50; of semicircular 
canals, 676. 
Amygdala, cerebellum, 604; nucleus of, 626; 
or tonsil, 706. 
Amygdalo-glossus muscle, 348. 
Anal fascia, 393, 395. 
Anapophyses, 110. 
Anastomoses, of axillary artery, 435; round 
elbow-joint, 443; of bloodvessels, 61. 
Anastomotic artery, arm, 438. 
Anastomotica magna artery, thigh, 460. 
Anatomical neck of humerus, 137. 
Anatomy, morphological and physiological, de- 
finition of, 1; descriptive, general, human, 
regional, systematic, topographical, definition 
of, and methods, 2; terms, 3. 
Anconeus muscle, 267. 
Andaman Islanders, cranial capacity, 244. 
Angle, of mandible, 234; orbito-nasal, 241 ; of 
ribs, 118. 
Angular, artery, 417 : gyrus, 626 ; movement of 
joints, 39; vein, 470. 
Ankle-joint, 195 ; ligaments of, 195; transverse 
ligament of, 194. 
Ankle, movements of, 198. 
Annular ligament, elbow, 155; ligaments of 
ankle, 326 ; ligaments, anterior and posterior 
of wrist, 286. INDEX 
805 
Annulus ovalis, 402. 
Ansa, hypoglossi, 513, 560. 
Ansae of optic thalamus, 614. 
Anterior, use of term, 3; chamber of eye, 654 ; 
common ligament, 123; costo-vertebral 
ligament, 126; limiting sulcus, 94; perforated 
spot, 593. 
Antero-lateral, column, 584; furrow, 582. 
Antihelix, 668 ; fossa of, 668. 
Antitragus, 668. 
Antrum, maxillary of Highmore, 228; of pylorus, 
711. 
Anus, 728; origin of, 94; superficial sphincter 
of, 389. 
Aorta, 410 ; abdominal, 447 ; ascending portion 
of, 410; descending thoracic, 445 ; great sinus 
of, 410; varieties of, 412; transverse portion 
Of, 411. 
Aortae, primitive, 101, 489. 
Aortic, vestibule, 405; plexus, 567. 
Apex of lung, 746. 
Apical pole, 628. 
Aponeurosis, 14, 16 ; epicranial, 329 ; of external 
oblique muscle, 376 ; of insertion, 17; lumbar, 
365; palmar, 286 ; plantar, 327 ;of protection, 
17. 
Apparatus, lachrymal, 645; ligamentosus, 124. 
Appendages of cruciform ligament, 124. 
Appendage, vermiform, 725. 
Appendices, auricular, 401 ; epiploicae, 724. 
Appendicular skeleton, The, 105. 
“ Apron ” of Hottentot women, 791. 
Aqueduct, of cochlea, 222; of Fallopius, 222; 
of Sylvius, 602-609; of vestibule, 222, 670. 
Arachnoid, 578; space, 577. 
Arantii, nodulus or corpus, 403. 
Arbor vitae, of cerebellum, 603 ; of uterus, 787. 
Arborizations, 52. 
Arch, atlas, anterior and posterior, 112 ; crural, 
deep, 384 ; hyoid, 98 ; hyoid, development of, 
246; mandibular, 98, 246; orbital, 213; pal- 
mar, deep, 445 ; jialmar, superficial, 444; 
pubic, 167 ; zygomatic, 220. 
Arch of aorta, 411, 412 ; right, 412. 
Arched arteries and veins of kidney, 764, 765. 
Arches, arterial, 489, 490 ; branchial, 101; cos- 
tal, 107 ; neural, 105-107 ; post-stomal, 98 ; 
of vertebrae, 107 ; visceral, 98. 
Arciform fibres of Lockhart Clarke, 629; of 
Solly, 600. 
Area, opaca in bird’s egg, 87 ; pellucida, 87, 89 ; 
vasculosa, 8-13, 90. 
Areola, 800. 
Areolae, primitive, of ossification, 35. 
Areolar tissue, 16 ; subcutaneous, 70. 
Arm, bone, 137 : fascia of, 269. 
Arnold, F., auricular nerve of, 556 ; develop- 
ment of teeth, 698. 
Arnold, J., arterial glomeruli, 759 ; nerve-cor- 
puscles, 52 ; nerves of unstriped muscle, 42. 
Arterial, arches, 489, 490 ; circle of TV illis, 422 ; 
fissure of mastoid, 222; foramen of bones, 2oj 
glomeruli, 759 ; valves, 403. 
Arteries, 59; coats of, 59 ; development of, 
489; of brain, 422; branchial, 489 ; bron- 
chial 445, 752; calcaneal, 466; capsular, 451; 
capsular of liver, 736 ; cerebral, 422 ; cerebral, 
ascending frontal of, 424 ; cerebral, inferior 
frontal, 424; cerebral, internal frontal, 424; 
ciliary ’ 421; of cochlea, 682 ; coronary, 411 ; 
coronary of lips, 416; digital, 444; afferent, 
glomeruli, 763, 765; efferent, glomeruli, 763, 
765 ; ethmoidal, 422 ; of hip-joint, articular, 
453, 459; helicine, J. Muller, 780; hyoid, 415; 
iliac, common, 452 ; intercostal, 446 ; arched, 
kidney, 764 ; intercostal anterior, 432; inter- 
lobular, kidney, 764 ; interlobular, liver, 736; 
interosseous, anterior and posterior, 441 ; of 
knee-joint, articular, 461; lumbar, 447 ; mal- 
leolar, 463, 465 ; mastoid, 417 ; mediastinal, 
432 ; meningeal, 418, 429 ; nutrient, of bones, 
25; oesophageal, 430; palmar interosseous, 
445 ; palpebral, 422; pancreatic, 448, 449 ; 
perforating, thigh, 460; pericardial, 432 ; 
peroneal, superficial, 454; plantar digital, 
466; pubic, 456 ; pudic, superficial, 459; 
pterygoid, 419 ; radial carpal, 442; small in- 
testine, 450; spinal, 429; sternal, 432; supra- 
renal, 451; tibial recurrent, 463; tracheal, 
430; transverse, 430; ulnar carpal, 441; vagi- 
nal, of liver, 736; vesical, superior and inferior, 
453; vitelline, 101. 
Arterio-vertebral foramina, 111. 
Arterioles, 61. 
Artery, anastomotic, arm, 438; anastomotica 
magna, thigh, 460; angular, 417; acromio- 
thoracic, 435 ; internal auditory, 430; auri- 
cular, posterior, 417; axillary, 434; basilar, 
429, 430; brachial, 437; buccal, 419; of bulb, 
454 ; capsular, inferior, 451; common carotid, 
413; carotid, external, 414; carotid, internal, 
420 ; central of retina, 660; anterior inferior 
cerebellar, 430; cerebellar, posterior inferior, 
429; superior cerebellar, 430; cerebral, an- 
terior, 423, 424; cerebral, middle, 423, 424; 
cerebral, posterior, 423-425; ascending cer- 
vical, 431; deep cervical, 432; cervical, de- 
scending, 417; superficial cervical, 431; 
transverse cervical, 431; princeps cervicis, 
417; choroid, anterior, 423; choroid, pos- 
terior, 425; circumflex, anterior, 435; cir- 
cumflex, internal, 459; circumflex, external, 
459; circumflex, posterior, 435; circum- 
flex iliac, deep, 457 ; circumflex iliac, 
superficial, 459; coccygeal, 454; left colic, 
450; middle colic, 450; right colic, 450; 
comes nervi ischiadici, 454 ; comes nervi 
phrenici, 432; anterior communicating, 424 ; 
coronary, stomach, 449; to corpus callosum, 
424; of corpus cavernosum, 454; cremasteric, 
451, 456; 415; cystic, 449; 
dental, inferior, 419; dental, posterior 
superior, 419 ; dorsal, of foot, 463; dorsalis 
indicis, 443; dorsalis pollicis, 443; dorsal, of 
penis, 454 ; dorsal, of tongue, 415 ; epigastric, 
deep, 456; epigastric, superficial, 459; epi- 
gastric, superior, 432; facial, 416; facial, 
transverse, 418; femoral, 458; femoral, com- 
mon, 459; femoral, deep, 459; femoral, 
superficial, 459; frontal, 422; gastric, 449; 
gastro-duodenal, 448; gastro-epiploic, 448, 
449; gluteal, 455; haemorrhoidal, inferior, 
454; haemorrhoidal, middle, 453; haemor- 
rhoidal, superior, 451; hepatic, 448, 735; 
hypogastric, 453, 496; iliac, external, 456; 
iliac, internal, 452; ilio-colic, 450; ilio-lumbar, 
455 ; infracostal, 432; infraorbital, 419; 
innominate, 412; superior intercostal, 432; 
interosseous, 440; interosseous, first dorsal, 
443; interosseous, first dorsal of foot, 463; 
recurrent posterior, interosseous, 441; labial, 
416 ; lachrymal, 421; laryngeal, inferior, 430 ; 
laryngeal, superior, 415 ; lingual, 415; mam- 
mary, internal, 431; mammary, external, 435 ; 
masseteric, 419; maxillary, internal, 418; 
median, 441; meningeal, middle, 418; men- 
ingeal, small, 419; mesenteric, inferior, 
450; mesenteric, superior, 450; metatarsal, 
463 ; musculo-phrenic, 432 ; nasal, 422; nasal, 
lateral, 417; obturator, 453; obturator, 806 
INDEX 
aberrant, 457; occipital, 417; ophthalmic, 
421; ovarian, 451; palatine, 416 ; palatine, 
superior or descending, 419; pancreatico-duo- 
denal inferior, 450; 2jancreatico-duodenal 
superior, 449; peroneal, transverse, 454; 
peroneal, 465 ; peroneal, anterior, 465; pha- 
ryngeal, ascending, 415; phrenic, inferior, 
447; plantar, external, 465 ; plantar, internal, 
466 ; popliteal, 461; princeps cervicis, 417 ; 
princeps hallucis, 464 ; princeps pollicis, 443 ; 
profunda femoris, 459; profunda, inferior, 
438; profunda, superior, 437; pterygo-palatine, 
420; pudic, 454; pulmonary, 409; pyloric, 
448; radial, 441; radial recurrent, 442; 
radialis indicis, 443 ; ranine, 415 ; renal, 451; 
retina, central of, 421; sacral, lateral, 455; 
sacral, middle, 448; scapular, posterior, 431; 
sciatic, 453; sigmoid, 450; spermatic, 451; 
spheno-palatine, 419; splenic, 449; sterno- 
mastoid, 415; stylo-mastoid, 417 ; subclavian, 
427 ; sublingual, 415; submental, 416; sub- 
scapular, 431, 435 ; supraorbital, 421; supra- 
renal, superior, 447; suprascapular, 431; 
tarsal, 463; temporal, 417; temporal, an- 
terior, 418; temporal, deep, 419; temporal, 
middle, 418; temporal, posterior, 418; 
thoracic, long, 435; thyroidea ima, 413; thy- 
roid, inferior, 430, 433; thyroid, superior, 415; 
tibial, anterior, 462; tibial, posterior, 464; 
tonsillar, 416; tympanic, 418; ulnar, 440; 
ulnar, deep branch, 441 ; recurrent ulnar pos- 
terior, 440; uterine, 453; vaginal, 453 ; of 
vas deferens, 453 ; vertebral, 428, 433; Vidian, 
419; superficial volar, 442. 
Arthrodia, 40. 
Articular arteries of hip-joint, 453-459 ; of knee- 
joint, 461. 
Articular, processes superior and inferior, 108; 
cartilage, 22 ; surfaces, gliding and rolling, 
39; surfaces, movements of, 39. 
Articulation, acromio-clavicular, 151; atlanto- 
occipital, 128; ankle, 195; astragalo-calcaneal 
posterior, 195; astragalo-calcaneo-scaphoid, 
195; atlanto-axial, 127; calcaneo-cuboid, 195 ; 
crico-arytenoid, 741; crico-thyroid, 740; coraco- 
clavicular, 151; hip-joint, 186; ilio-sacral, 184; 
knee, 189 ; of pisiform, 159 ; radio-carpal, 
801; sterno-clavicular, 150. 
Articulations, 36; carpal, 158; carpo-metacarpal, 
158 ; costo-transverse, 126; costo vertebral, 
126 ; inter-metacarpal, 158 ; inter-phalangeal, 
hand, 161; inter-phalangeal, foot, 197; 
metacarpo-phalangeal, 160; metatarso-phal- 
angeal, 197 ; of the pelvis, 184 ; radio-ulnar, 
155, 156 ; tarsal, 195 ; tarso-metatarsal, 195 ; 
of thorax, 125; tibio-fibular, 194; temporo- 
maxillary, 244. 
Aryteno-epiglottidean, folds, 741; muscle, 744. 
Arytenoid, cartilages, 739; muscle, 744. 
Ascending, cerebellar tracts, 585; cervical artery, 
431; colon, 726; degeneration, 53; pharyngeal 
artery, 415 ; portion of aorta, 410; pole, 628. 
Association nerve-fibres, 630. 
Asterion, 243. 
Asternal ribs, 118. 
Astragalo-calcaneal articulation, posterior, 195; 
ligaments, 195; scaphoid articulation, 195. 
Astragalus, 177. 
Atlanto axial, ligaments or membranes, 125; 
articulation, movements, 127. 
Atlanto-occipital articulation, movements, 128. 
Atlas, 107, 112; articulations of, 124; defects 
of, 113 ; lateral masses of, 113; ossification of, 
131; tubercles, anterior and posterior of, 113. 
Attollens auriculam muscle, 330. 
Attrahens auriculam muscle, 330. 
Auditory, artery, internal, 430 ; cells of cochlea, 
681; meatus, internal, 222; meatus, external, 
219; nerve, 652, 595; nerve, nuclei of, 601; 
pit, 98; process, external, 219; vesicle, 98. 
Auerbach’s myenteric plexus, 723. 
Auricle, left, 402; right, 401. 
Auricles, walls of, 407. 
Auricular, appendages, 401; artery, posterior, 
417 ; nerve of Arnold, 556 ; nerve, great, 512 ; 
nerve of facial, 551; surface of ilium, 164 ; 
surface of sacrum, 116; veins, anterior and 
posterior, 472. 
Auricularis, anterior muscle, 330; posterior 
muscle, 330 ; superior muscle, 330. 
Auriculo-temporal nerve, 547. 
Auriculo-ventricular sulcus, 400. 
Auriculo-ventricular valve, 403. 
Auscultatory triangle, 255. 
Axial skeleton, 105 ; movements of, 127. 
Axilla, 268. 
Axillary artery, 434 ; surgical anatomy, 436. 
Axillary, border of scapula, 135; fascia, 269 ; 
glands, 503; vein, 485. 
Axis, 107, 114; articulations of, 124; cerebro- 
spinal, 576 ; coeliac, 448 ; cylinder, 48 ; 
cylinder-poles, 52 ; cylinders, ramifications 
of, 52; odontoid process, Cunningham, 132; 
of pelvis, 167 ; of vision, 646 ; ossification, 
Macalister, 132 ; thyroid, 430. 
Azygos, uvulae muscle, 348 ; vein, great or right, 
479; veins, left, 480; veins, 479. 
Bacillary layer of retina, 657. 
von Baer, ovum, 786. 
Balance of skeleton, 129. 
Balfour, F. M., polar bodies, 84. 
Ball and socket joint, 40. 
Band, of Henle, 381; moderator, 404. 
Banks, Mullerian duct, 795 ; sinus pocularis, 
782. 
Bardeleben, tunica media of arteries, 60. 
Bars, cranial, 246. 
Bartholin, glands of, 792; duct of, 709; position 
of pelvis, 163. 
Base, of bladder, 768 ; of brain, 593; of first 
metatarsal bone, 182; of scapula, 135; of 
skull, level and steep, 241. 
Bases of metacarpal bones, 149. 
Basement membrane of glands, 58. 
Basilar, artery, 429, 430; bone, 206 ; groove, 208; 
membrane of cochlea, 679 ; prrocess, 206; pro- 
cess, perforation of, 245; vein, 474. 
Basilic vein, 485. 
Basion, 243. 
Bauhin, valve of (see ileo-colic valve), 726. 
Beale, nerve-corpuscles, 52. 
Beard, rudimentary branchial sense-organs, 570. 
Bell, Sir Charles, respiratory nerves, 516, 571. 
v. Beneden, female pronucleus of, 84. 
Bertin, columns of, kidney, 761, 764; triangular 
bone of, 216. 
Biceps, brachii muscle, 263; femoris muscle, 292. 
Bicipital, groove, 137, 138; tuberosity, 141. 
Bicornute uterus, 788. 
Bicuspid, teeth, 697 ; valve, 405. 
Bigelow, ligament of, 170, 188. 
Bile duct, common, 732. 
Binding tissues, 13. 
Bird’s egg, area pellucida, 87; area opaca, 87; 
ectoderm, 87; entoderm, 87; formation of 
embryo, 87; germinal wall, 87; medullary 
folds, 87 ; primitive groove, 87 ; primitive 
streak, 87 ; shield, 88; sickle, 87. 
Birds, kidneys in, 766. INDEX 
807 
Biventer cervicis muscle, 361. 
Biventral lobe, cerebellum, 604. 
Bizzozero, blood-plate of, 12; red corpuscles in 
marrow, 12. 
Bladder, gall, 732. 
Bladder, urinary, 767 ; structure and develop- 
ment of, 770; false ligaments of, 692 ; true 
ligaments of, 393, 768 ; lymphatics of, 500 ; 
vessels and nerves of, 770. 
Blandin, glands of, 706. 
Blastoderm, 86; mammalian, 88. 
Blastopore, 87, 88, 97. 
Blood, 8; buffing of, 0; centripetal development 
of, 90 ; crystals, 10; cupped, 9 ; discs, 8, 9; 
elementary" granules of Zimmerman, 12 ; hae- 
matoblasts of Hayem, 12 ; plates of Bizzozero, 
12; plasma or liquor sanguinis, 8. 
Blood-corpuscles, 8 ; size of, in different animals, 
12 ; the invisible, of Norris, 12 ; in non-mam- 
malian vertebrates, 11; red, 9 ; white, 10. 
Bloodvessels, 58 ; in adipose tissue, 18 ; anasto- 
moses of, 61; development of, 64. 
Blumenbach, skulls, 242. 
Bodies, first and second polar, 84; geniculate, 
612 ; Malpighian of spleen, 755, and of kidney, 
763; Pacchionian, 579; Pacinian, 81, 779; 
Wolffian, 96, 766, 794. 
Body, of astragalus, 177; cavity, 87; of epi- 
didymis, 772 ; of hyoid bone, 236 ; of incus, 
671; of mandible, 234 ; olivary, 595 ; of penis, 
779; perineal, 388; pineal, 610; pituitary, 
594, 611; restiform, 595; of rib, 118; of 
scapula, 134; of sternum, 121; thyroid, 756; 
of uterus, 786 ; of vertebra, 107 ; of vomer, 231. 
8011, on tendon, 18. 
Bone, 23; at various ages, 27, 28; primitive 
areolae of, 35; arterial or nutrient foramen 
of, 25; canaliculi of, 25; cancellated, 24; 
compact, 24 ; corpuscle, 25; general charac- 
ters of, 24 ; Haversian canals, 25 ; Haversian 
systems, 26; Humphry on growth of, 35; 
lacunae of, 25; microscopic structure of, 25; 
osteoblasts, 28 ; perforating fibres, 29; perios- 
teum, vessels and nerves, 30 ; pits of Howship, 
29; synostosis of, 35; the astragalus, 177 ; 
the atlas, 112; the axis, 112; the basilar of 
Sommering, 206; the calcaneum, 179; the 
clavicle or collar-bone, 133; the coccyx, 116 ; 
the cuboid, 182; the cuneiform, 145, 146; 
the internal, middle and external cuneiform, 
181, 182 ; the ethmoid, 224 ; the femur, 168 ; 
the fibula, 176; the frontal, 212; the hip, 
162; the humerus, 137; the hyoid, 236; 
ilium, 163; the incus, 671; the innominate, 
162; the ischium, 162, 165; the lachrymal, 
233; the lunar or semilunar, 145, 146; the 
malar, 232 ; the malleus, 671; the maxillary, 
inferior, 234 ; the maxillary, superior, 226; 
the nasal, 234 ; the navicular, of foot, 180; 
the occipital, 206; the orbicular, 671; the 
os magnum, 146, 148; the palatal, 229 ; the 
parietal, 211; the patella, 172; the 
162; the pisiform, 145-147 ; the pyramidal, 
147 ; the radius, 141; the sacrum, 114; the 
sphenoid, 213; the scaphoid, of hand, 145, 
146; the scaphoid, of foot, 180; scapula, 
134; the sternum, 120 ; the stapes, 671; the 
talus, 177 ; the temporal, 218 ; the tibia, 173 ; 
the trapezium, 146, 147; the trapezoid, 146- 
148; the triangular, of Bertin, 216; the in- 
ferior turbinated, 233; the ulna, 143; the 
unciform, 146, 148. 
Bones, the carpal, 145; the metacarpal, 149; 
the metatarsus, 182 ; the phalanges, 183; the 
ribs, 117; the sesamoid of thumb, 150; the 
spongy superior and inferior ethmoidal, 225; 
the sutural or Wormian, 237 ; the tarsal, 177 ; 
the sphenoidal turbinated, 216; the vertebrae, 
107; diaphysis of, 35; enlargement of, 35; 
epiphyses of, 35; ligaments of the carpal, 
i 59, 160 ; nutrient artery of, 25. 
Hones of limbs, compared, 199 ; development of, 
200. 
Bosjes, cranial capacity, 244. 
Bottcher, sacculus endolymphaticus, 677. 
Boveri, polar bodies, 85. 
Bowman, capsule of, 763; elastic laminae of, 
649 ; glands of, 641 ; muscle of cochlea, 680; 
sarcous elements of, 43. 
Brachia, 612. 
Brachial artery, 437 ; surgical anatomy, 439, 
Brachial plexus, 514. 
Brachialis anticus muscle, 264. 
I irachio-radialis muscle, 275. 
Brachycephalic skulls, 241. 
Brain, general construction of, 590; arteries of, 
422; anterior, posterior and middle lobes of, 
593 ; base of, 593; choroid plexuses, 607, 619, 
620; corpora quadrigemina, 608; corpus 
callosum, 615; of Cuvier, 632; development 
of, 634; fornix, 618 ; hippocampi, 620; 
lateral ventricles, 620; lymphatics of, 505; 
optic thalami, 609; third ventricle, 620; 
transverse fissure, 619; veins of, 473 ; weight 
of, 632. 
Branchial, arches, 101; arteries, 489. 
Bregma, 243, 260. 
Brim of pelvis, 167. 
British skulls, 241. 
Broad ligament, of lung, 686; of ovary, 783; 
of uterus, 692. 
Broca, le cap, 625; limbic lobe of, 626. 
Bronchi, 751. 
Bronchial, arteries, 445, 752; glands, 502; 
tubes, 751; veins, 480. 
Bronchioles, 750, 751. 
Brown, Robert, the nucleus, 5. 
Biown-Sequard, sensory tracts, 589. 
Bruch, membrane of, 652. 
Brunner’s glands, 721. 
von Brunn, Jacobson’s organ, 642; olfactory 
tract, 641. 
Buccal, artery, 419; glands, 701; nerve, 546; 
pad, 345. 
Buccinator muscle, 333. 
Buffing of blood, 9. 
Bulb, artery of, 454; of hairs, 75; olfactory, 
630. 
Bulbar portion of spinal accessory nerve, 559. 
Bulbi vestibuli, 792. 
Bulbo-cavernosus muscle, 390. 
Bulbus arteriosus, 487. 
Bulbs, cylindrical, of Krause, 81 ; end-, of 
Krause, 79 ; of lymphatic glands, 68. 
Bulbus hippocampi, 626. 
Bundle, posterior-longitudinal, 600, 613; of 
Vicq-d’Azyr, 618. 
Burdach, tract of, 585. 
Bursa, of biceps, 263; of gluteus maximus, 288; 
of obturator interims, 291 ; of patella, 304 ; of 
ligamentum patellae, 191; of psoas magnus, 
302; of semi-membranosus, 294; of semi- 
tendinosus, 294; subacromial, 152, 261; of 
tendo Achillis, 313. 
Bursae mucosae, 36, 69, 253. 
Butschli, polar bodies, 85. 
Caecum, 723, 724. 
Cajal, Ramon Y., cerebellar fibres, 606 ; ending 
of rod-fibres, 659 ; fibres in corona radiata, 808 
INDEX, 
630; mossy branches, 606; on nerve corpuscles, 
52; posterior roots, centrifugal fibres, 588; 
posterior vesicular column, 587. 
Calamus scriptorius, 583, 596. 
Calcaneal arteries, 466. 
Calcaneo-cuboid, articulation, 195; ligament, 
inferior, 197. 
Calcaneo-scaphoid, ligament, external, 197; 
inferior, 196. 
Calcaneum, 179. 
Calcar, J., plates of Yesalius, 163. 
Calcarine sulcus, 626; anterior, 626. 
Calcified cartilage, 22, 34. 
Callosal gyrus, 626. 
Calloso-marginal sulcus, 626. 
Calyces of kidney, 762. 
Campbell, J. A., brains over 60 ounces, 632. 
Canal, carotid, 223 ; central of spinal cord, 582 ; 
of Cloquet, 662 ; crural, 383 ; dental, 234 ; ex- 
ternal auditory, 669 ; of Fontana, 655 ; Hun- 
ter’s, 295, 304; infraorbital, 228; inguinal, 
375, 384 ; malar, 233 ; neural, 107 ; neuren- 
teric, 87, 94; of Nuck, .795; palatine, anterior, 
227; of Petit, 664; posterior palatine, 228, 
230; pterygo-palatine, 216, 230; sacral, 115; 
of Schlemm, 655; temporal of malar, 233 ; 
Vidian, 218. 
Canals, internal orbital, 212; lachrymal, 645; 
anterior and posterior and middle dental, 228; 
Haversian, 25; intercellular, of pancreas, 730; 
intercellular, of liver, 734 ; portal, 733; semi- 
circular, 219, 676. 
Canaliculi, of bone, 25 ; lachrymal, 646. 
Canalis, cochleae, 679 ; reunions, 677. 
Cancellated bone, 24. 
Canine, fossa, 227 ; teeth, 697. 
Canines, additional, 700. 
Canthi, of eyelids, 643. 
Capacity, cranial, 243. 
Capillaries, 61. 
Capillary lymphatics, 65. 
Capitellum of humerus, 139. 
Capsular, or suprarenal arteries, 451 ; arteries, 
liver, 736; artery, inferior, 451; cartilage, 
23; ligament of hip-joint, 187 ; ligament of 
shoulder-joint, 153. 
Capsule, of Bowman, 763; external of brain, 615; 
of Glisson, 733; internal of brain, 613, 614; of 
kidney, 760; of lens, 663; of liver, 733; ex- 
ternal, of orbital fascia, 335; internal of 
orbital fascia, 336; of spleen, 754 ; of Tenon, 
336. 
Capsules, suprarenal, 758. 
Caput, caecum coli, 724; epididymis, 772; gal- 
linaginis, 781. 
Cardiac, nerves from vagus, 557 ; nerves, 
sympathetic, 563, 564; orifice of stomach, 711; 
plexus, 565 ; tube, 100. 
Cardinal vein, 491, 494. 
Carotid, arteries, common, 413 ; arteries, surgi- 
cal anatomy, 426 ; artery, external, 414; 
artery, internal, 420 ; canal, 223; foramen, 
223 ; groove, 215 ; plexus, 563. 
Carpal, arteries, radial, 442 ; arteries, ulnar, 
441; joints, 158 ; ligaments, 159, 160. 
Carpo-metacarpal joints, 158. 
Carpus, 133, 145 ; ossification, 202. 
Cartilage, 19, 22, 34 ; articular, 22; capsular, 
23; corpuscles, 32; costal, 21; embryonic, 
23; fibre, 23; hyaline, 19, 20; ossification 
from, 32 ; permament, 20 ; temporary, 20 ; 
yellow, or reticular, 23 ; the cricoid, 738; 
Meckel’s, 246 ; of pinna, 668 ; mesial, of 
nose, 639; the septal, 639; the thyroid, 
739. 
Cartilages, the arytenoid, 739 ; the costal, 117, 
120; the cuneiform, 739; of larynx, 738; 
of nose, the accessory of, 640; of nose, the 
alar, 639; of nose, the triangular, 639; the 
parachordal, 245; the prochordal, 245 ; of 
Santorini, 739; the triticeal, 741; of Wrisberg, 
739. 
Caruncula of eyelids, 643. 
Carunculae myrtiformes, 791. 
Cauda equina, 50,8, 578, 582. 
Caudate, nucleus, 610; lobe of liver, 732. 
Cavernous nerves, 567 ; plexus, 563 ; plexuses of 
penis, 567 ; sinus, 476. 
Cavities, great and small sigmoid, 143; of reserve 
of teeth, 699. 
Cavity, abdominal, 687 ; of larynx, 741; neural, 
683; visceral, 683. 
Cell, use of term, 5; mass, intermediate, 96; 
wall, the, 5, 8; auditory, of cochlea, 681; 
centro-acinary, of Langerhans, 730. 
Cells, epithelial, 54; epithelioid, 55; ethmoidal, 
225 ; germinal, of spinal cord, 633 ; goblet, 58, 
720 ; hepatic, 733; mitral, 631; nucleated, 5; 
olfactory, 641; of Claudius, 681; of Deiters, 
681; of Hensen, 681; of Langerhans, 78; of 
Eanvier, quadrate, 17; peptic, 714; prickle, 
73; touch, 79. 
Cement of tooth, 696. 
Centra], artery of retina, 660; canal of spinal 
cord, 582; sulcus, 625; lobe of cerebellum, 
603; plate of ethmoid, 224; point of perineum, 
388; tendon, 367. 
Centro-acinary cells, 730. 
Centrifugal development of form of embryo, 90. 
Centrifugal posterior nerve-roots, 588. 
Centripetal developments in embryo, 90. 
Centrum, 107. 
Cephalic, index, 242 ; vein, 485. 
Cerebellar artery, anterior inferior, 430 ; pos- 
terior inferior, 429 ; superior, 430. 
Cerebellar tracts, 585 ; veins, 474. 
Cerebellum, 602 ; peduncles of, 597, 602. 
Cerebral arteries, ascending frontal of, 424; in- 
ferior frontal, 424 ; internal frontal, 424. 
Cerebral artery, anterior, 423, 424; middle, 423, 
424 ; posterior, 423, 425. 
Cerebral, convolutions and fissures, 623; con- 
volutions, structure, 627 ; hemispheres, 621; 
vesicles, 90, 97, 634. 
Cerebro-spinal axis, 576 ; development, 633. 
Cerebro-spinal fluid, 576, 578; nerves, 506. 
Cerebrum, arteries of, 422; veins of, 473. 
Ceruminous glands, 74, 669. 
Cervical artery, ascending, 431 ; deep, 432; de- 
scending, 417 ; superficial, 431; transverse, 
431. 
Cervical, fascia, deep, 355 ; ganglia, 563; glands, 
deep, 605; glands, superficial, 504; nerve, 
superficial, 512; nerves, posterior divisions, 
509; plexus, 511 $ plexus, deep branches, 513; 
sympathetic, 562 ; vein, deep, 469, 470 ; trans- 
verse, 472; vertebrae, 107, 111. 
Cervicalis ascendens muscle, 360. 
Cervix, uteri, 786 ; of glans, 781. 
Chamber, anterior, of eye, 654; posterior, of 
eye, 654. 
Check ligaments, 124. 
Cheselden, position of pelvis, 163. 
Chiasma, 538, 613. 
Chondrification in embryo, 130. 
Chondro-glossus muscle, 340. 
Chorda, dorsalis, 91; tympani, 551. 
Chordae tendineae, 404. 
Chorion, 102 ; frondosum, 104. 
Choroid artery, anterior, 423; posterior, 425. INDEX, 
809 
Choroid, coat of eye, 650; plexus, 592; plexus of 
lateral ventricle, 619 ; plexuses, 580; plexuses 
of third ventricle, 619. 
Choroidal fissures, 638. 
Chromatin, 7. 
Chrzonszezewsky, structure of liver, 735. 
Chyle, 65. 
Cicatricula, 83. 
Cilia, 56, 643. 
Ciliary, arteries, 421; glands, 665 ; muscle, 652; 
nerves, 543; part of retina, 657; processes, 
652; veins, 475. 
Ciliated epithelium, 56. 
Cineritious nervous substance, 47. 
Circle of Willis, 422. 
Circular sinus, 477. 
Circulation, omphalo-mesenteric, 494; placental, 
495; vitelline, 494. 
Circulus, major, 654 ; minor, 654. 
Circumduction of joints, 39. 
Circumflex artery, anterior, 435 ; internal, 459 ; 
external, 459; posterior, 435. 
Circumflex-iliac artery, superficial, 459; deep, 
457. 
Circumflex-iliac vein, 482 
Circumflex nerve, 521. 
Oircumflexus palati muscle, 348. 
Circumvallate papillae of tongue, 704. 
Cisternae, 579. 
Clarke, intermedio-lateral tract of, 586; posterior 
vesicular column of, 587. 
Claudius, cells of, 681. 
Claustrum, 610. 
Clavae, 596. 
Clavicle, 133; ossification, 201. 
Cleavage of yelk, 82, 85. 
Cleido-occipitalis muscle, 351. 
Cleft, digastric, 221. 
Cleft palate, 249. 
Clefts, visceral, 98. 
Cleland, balance of head, 210; compartments of 
third cerebral vesicle, 635 ; nerve-growth, 634 ; 
conical mass, 795; ligamentum conjugale, 126; 
longevity of odontoblasts, 694 ; movements of 
toes, 199; series of teeth, 700; skulls, 242; 
four pairs of sphenoidal turbinated bones, 
216 : unbroadened pelvis, 168. 
Clinoid processes, 214, 215. 
Clitoris, 791; dorsal nerve of, 532. 
Clivus, 214. 
Cloaca, 770. 
Cloquet, canal of, 662. 
Closed follicles, 68; of small intestine, 721. 
Club-foot, 325. 
Coccygeal, artery, 454; gland, 759; ligaments, 
124; nerves, 511; plexus, 536. 
Coccygeus muscle, 389. 
Coccyx, 107, 116. 
Cochlea, 219, 678; arteries of, 682; nerves of, 
681; osseous and membranous, 678. 
Cochleariform process, 224. 
Coeliac, axis, 448; glands, 500; plexus, 566. 
Coelom, 87, 92, 683. 
Cohnheim, diapedesis, 11. 
Colic artery, left, 450 ; middle, 450; right, 450. 
Collar-bone, 133. 
Collaterals, 52 ; of posterior-spinal nerve roots, 
589. 
Collateral sulci, 626. 
Collecting tubules, kidney, 764. 
Colies’ fascia, 392. 
Colliculus seminalis, 781. 
Colon, 723, 726. 
Colour of eye, 656. 
Columella of nose, 639 ; development of, 98. 
Columnae carneae, 404. 
Columnar epithelia, 55. 
Column, of Coll, 585, 596 ; of Tiirck, 584, GOO; 
posterior vesicular, of spinal cord, 687 ; 
vertebral, 105. 
Columns, anterior and posterior of vagina, 
793; of Bertin, kidney, 761, 764 ;of Morgagni, 
728 ; of spinal cord, 584. 
Comes, nervi phrenici, arteria, 432 ; nervi 
ischiadici, arteria, 454. 
Comma, 583, 585, 586. 
Commissure, great, of brain, 615; of Gudden, 
538, 613 ; of Meynart, 538 ; optic, 593, 612. 
Commissures, 52 ; spinal cord, 582 ; third ven- 
tricle, 610 ; vulva, 790. 
Common, bile duct, 732 ; carotid arteries, 413; 
carotid artery and branches, surgical anatomy7 
of, 425, 426 ; carpal ligaments, 160; enamel- 
germ, 699 ; femoral artery, 459 ; iliac arteries, 
452 ; iliac veins, 481; ligaments of vertebral 
column, 123 ; sensation, organs of, 78. 
Compact, bone, 24; decidua, 103. 
Compartments of third primary cerebral vesicle, 
635. 
Complete joints, 36. 
Com plexus muscle, 360. 
Compressor, naris muscle, 332; urethrae muscle, 
391, 392. 
Communicans hypoglossi nerve, 560. 
Communicating artery, anterior, 424 ; posterior, 
424. 
Conarium, 610. 
Concentric lines of dentine, 695. 
Concha of ear, 667. 
Conchae, nasal, 640. 
Condylar surfaces of tibia, 173. 
Condyle of mandible, 234, 236. 
Condyles, occipital, 210. 
Condyloid foramen, anterior and posterior, 208* 
Cones of retina, 657. 
Conglobate glands, 67 ; of stomach, 716. 
Conical, mass, 795 ; process of cuboid, 182. 
Coni vasculosi, 775 ; development of, 796. 
Conjoined tendon, 379. 
Conjugal ligament, 126. 
Conjunctiva, 644. 
Conoid, ligament, 151; tubercle, 134. 
Connections of heart, pericardial, 409. 
Connective tissue, corpuscles, 15; leucocytes 
of, 15. 
Connective tissues, 13; varieties of, 16. 
Constrictor urethrae muscle, 391, 392. 
Constrictors of pharynx, 345, 346. 
Contour lines of dentine, 695. 
Contractility of protoplasm, 6. 
Conus arteriosus, 404. 
Convoluted tubules, kidney, 764. 
Convolution, marginal, 626. 
Convolutions, cerebral hemispheres, 623; struc- 
ture, 627. 
Cooper, Astley, fascia propria, 771; reflected 
tendon of, 379 ; tunica vasculosa of, 773. 
Coraco-acromial ligament, 152. 
Coraco-brachialis muscle, 263. 
Coraco-clavicular ligament or articulation, 151. 
Coraco-humeral ligament, 153. 
Coracoid process, 134, 137- 
Cord, spermatic, 771; spinal, 580; lumbo- 
sacral, 524, 531. 
Cords, of brachial plexus, 515 ; gangliated, 560; 
of lymphatic glands, 67 ; vocal, 742. 
Corium, 70, 71; the papillae of, 71; strata of, 71- 
Cornea, 647 ; epithelium of, 649; laminae and 
corpuscles of, 648. 
Cornicula laryngis, 739. 810 
INDEX, 
Cornu Ammonis, 621. 
Cornua, of cartilaginous cranium, 245 ; of coccyx, 
116 ; of hyoid bone, 236 ; of lateral ventricles, 
620 ; sacral, 116 ; of thyroid cartilage, 739. 
Corrugator supercilii muscle, 331. 
Corona, glandis, 781; radiata, 609. 
Coronal, use of term, 3 ; suture, 211. 
Coronary, arteries, 411; arteries of lips, 416 ; 
artery, stomach, 449; ligament of liver, 689, 
731; plexus, 566 ; sinus, 402, 468 ; veins, 468; 
vein of stomach, 483. 
Coronoid process, of jaw, 234 ; of ulna, 144. 
Corpora, albicantia, 594, 618 ; cavernosa, 779 ; 
dentata, 605 ; spongiosum, 780 ; raammillaria, 
618; striata, 610. 
Corpora quadrigemina, 608. 
Corps de Giraldes, 772. 
Corpus, Arantii, 403; callosum, 615 ; callosum, 
artery to, 424 ; cavernosum, artery of, 454; 
dentatum, 598 ; Highmorianum, 773 ; luteum, 
785 ; striatum, 621; striatum, vein of, 474; 
subthalamicum, 614. 
Corpuscle, the living, 5 ; bone, 25. 
Corpuscles, in adipose tissue, 19; in connective 
tissue, 15; of cartilage, 32; corneal, 648; 
genital, 81, 781; of Hassall, 756; invisible 
blood, 12; lymph, 67 ; Malpighian, of kidney, 
762; Malpighian, of spleen, 755; migratory, of 
connective tissue, 15; nerve, 46, 50; nucleated, 
of connective tissue, 15 ; nucleated varieties 
of, 8; Pacchionian, marks of, 211; Pacinian, 
70; red and wdiite blood, 8, 10; touch, 79; 
unwalled, 6 ; Yater’s, 81. 
Cortex of ovary, 784. 
Corti, membrane of, 681; organ of, 680 ; rods 
of, 680. 
Cortical, part of kidney, 761 ; part of supra- 
renals, 758; part of thymus, 756 ; substance 
of hemispheres, 623, 627 ; tract, direct of 
Gudden, 612. 
Costal, arches, 107; cartilage, 21; cartilages, 
117-120; elements, 107 ; fossae, 121. 
Costo-clavicular ligament, 151. 
Costo-colic fold, 726. 
Costo-coracoid membrane, 134. 
Costo-diaphragmatic space, 686. 
Costo-phrenic space, 686. 
Costo-transverse, articulations, 126; ligament, 
126. 
Costo-vertebral, articulations, 126 ; foramina, 
111. 
Cotunnius, nerve of, 545. 
Cotyledons of ruminant placenta, 103. 
Cotyloid, cavity, 166 ; ligament, 186. 
Coverings, of embrvo, 102 ; of spermatic cord, 
771. 
Cowper’s glands, 783, 792. 
Cranial, bars, 246 ; capacity, 243; synostosis, 
243. 
Cranial nerve, first, 537 ; second, 538 ; third, 
539 ; fourth, 539 ; fifth, 540 ; sixth, 549; 
seventh, 550 ; eighth, 552 ; ninth, 553 ; tenth, 
555; eleventh, 558; twelfth, 559. 
Cranial nerves, 537 ; development, 569; nuclei 
of, 601; superficial origins of, 595. 
Cranium, 204; primitive, 245; primitive, cornua 
of, 245 ; sinuses, venous, 475. 
Cravate de Suisse, 713. 
Cremaster muscle, 378. 
Cremasteric, artery, 451, 456 ; fascia, 378. 
Crescents or lunules of Gianuzzi, 706. 
Crest, frontal, 213; of ilium, 163; nasal or 
intermaxillary, 227 ; neural, 56S ; internal and 
external, occipital, 208 ; of pubis, 166 ; sphe- 
noidal, 216 ; supramastoid, 221. 
Cretin skull, 243. 
Cribriform fascia, 305 ; plate, 225. 
Crico-arytenoid, articulation, 741; muscles, 
lateral and posterior, 743. 
Crico-thyro-arytenoid membrane, 740. 
Crico-thyroid, articulation, 740; artery, 415 ; 
ligament, 740; membrane, 15; muscle, 742. 
Cricoid cartilage, 738. 
Cristae acusticae, 678. 
Crista, galli, 225 ; spiralis, 679 ; vestibuli, 676. 
Crowns of teeth, 693. 
Crossed pyramidal tract, 585. 
Crucial ligament of knee-joint, 191. 
Cruciform ligament, 124. 
Crura, cerebri, 593; of corpus callosum, 616; 
of diaphragm, 368 ; of fornix, 618; of optic 
thalamus, 614 ; of penis, 779 ; of pineal body, 
611. 
Crural, arch, deep, 384; canal, 383; nerve, 
anterior, 527 ; nerve of genito-crural, 526. 
Crureus muscle, 300. 
Crusta, 613; petrosa, tooth, 693, 696. 
Cryptorchid, 798. 
Crypts, of Lieberkiihn, 721, 724; urethral, 
female, 791. 
Crystals of haemoglobin, 10. 
Crystalline lens, 662. 
Cubical epithelium, 55. 
Cuboid bone, 182. 
Cul-de-sac, great, of stomach, 711. 
Culmen of cerebellum, 603. 
Cuneate lobe, cerebellum, 604. 
Cuneiform bone, 145, 147 ; articulation with 
pisiform, 159; external, 182; internal, 181; 
middle, 181. 
Cuneiform cartilages, 739. 
Cuneus, 626. 
Cunningham, D. J., opercula of insula, 624; 
ossification of axis, 132. 
Cupola of cochlea, 678, 680, 
Cupping of blood, 9. 
Curvatures, great and small, of stomach, 711. 
Curved lines, of ilium, 64; of occipital bone, 
208. 
Curves of vertebral column, 116, 117. 
Cusps, of teeth, 693 ; of valves, 403. 
Cutaneous, glands, 73; nerve, internal, arm, 
517; nerve, internal, small, 517; nerve, 
middle, 527 ; nerve, external, thigh, 526; 
nerve, internal of thigh, 527. 
Cuticle, 72. 
Cutis vera, 71. 
Cuvier, G., brain of, 632; ducts of, 468, 488, 
491. 
Cyanosis, 496. 
Cylinders of lymphatic glands, 67. 
Cylindrical bulbs of Krause, 81. 
Cystic, artery, 449; duct, 732; vein, 483. 
Dartos, 71, 172, 392. 
Darwin, tubercle on pinna, 668. 
Debierre, lingula of sphenoid, 248. 
Decidua, 103; compact, 103; reflexa, 103; 
serotina, 103; vera, 103; spongy, 103. 
Declivus, 603. 
Decussation, of pyramids, 595; of fillets or 
superior pyramidal, 597. 
Deep, cervical artery, 431, 432; fascia, 253. 
Defects of atlas, 113. 
Degeneration, ascending and descending, 53. 
Deiters, cells of, 681; nucleus of, 552; pole of, 
52. 
Deltoid, eminence, 139 ; ligament, 152 ; muscle, 
260. 
Demours, membrane of, 649. INDEX 
811 
Dental, artery, inferior, 419 ; artery, posterior, 
superior, 419; canal, 234; canal, anterior, 
posterior and middle, 228 ; foramen, inferior, 
235; margin, 226; nerve, inferior, 547; nerve, 
superior, 544. 
Dentate gyrus, 627. 
Dentine, 693, 694; fibres, 694; lines in, 695. 
Dentition, prognathous, 242. 
Depressor, alae nasi muscle, 332; anguli oris 
muscle, 333; labii inferioris muscle, 333. 
Descendens hypoglossi (noni) nerve, 560. 
Descending, cerebellar tract, 585; cervical artery, 
417; colon, 727; cornu of lateral ventricle, 
620; degeneration, 53. 
Descemet, membrane of, 649. 
Descartes, seat of soul, 611. 
Descent of the testicles, 797. 
Descending thoracic aorta, 445. 
Descriptive, anatomy, definition of, 2 ; terms, 3. 
Development, 765; of arteries, 489; of axial 
skeleton of trunk, 130; of bladder, 770; of 
blood, centripetal, 90; of bloodvessels, 64; 
cerebro-spinal axis, 633; of cranial nerves, 
569, 570; centripetal in embryo, 90; of coni 
vasculosi, 796; of columella of nose, 98; of 
ear, 682; of elbow, 100; of epididymis, 97, 
796; of Eustachian tube, 98; of external 
sexual organs, 798; of eye, 665; of form 
of embryo, centrifugal, 90; general, 82; 
of hairs, 78; of hand, 100; of head, 97; 
of heart, 97, 486; of hyoid arch, 246; of 
jaw, 246; of intestine, 736 ; of joints, 37 ; of 
lachrymal duct, 99 ; of lens, 666 ; of limbs, 99; 
of liver, 737; of muscles, 396; of neck, 97; 
of nerves, 54, 568; of oesophagus, 736; of 
olfactory lobe, 637; of olfactory organ, 642; 
of optic tract, 636 ; ossicles of ear, 246 ; of 
oviduct, 97; of ovar3% 97, 194; of palate, 99; 
of pituitary body, 98; of portal system, 491; 
of reproductive organs, 794; of respiratory 
organs, 752; of sinus pocularis, 795 ; of skull, 
245; of small sac of peritoneum, 737; of 
stomach, 736; of striped muscle, 45 ; of supra- 
renals, 759 ; of sympathetic, 569; of teeth, 
698; of testicle, 97, 795; of thalamencephalon, 
637 ; of thymus, 99, 757 ; of thyroid body, 99, 
757 ; of tongue, 99 ; vas deferens, 97, 795; 
of veins, 491. 
Diapedesis, 11, 
Diaphragm, 367 ; lymphatics of, 502. 
Diaphyses of bones, 35. 
Diarthrosis, 39; trochoides, 40. 
Digastric, cleft or fossa, 221; muscle, 338; muscle, 
nerves to, 548, 551. 
Digestive, organs, 693 ; tube, formation of, 94. 
Digital, arteries, 444 ; fossa of femur, 170 ; fossa 
of testis, 772; impressions, 211; nerves, dor- 
sal, of hand, 522; veins, superficial of foot, 
485. 
Dilatator iridis muscle, 653. 
Dilatatores naris muscles, 332. 
Dilator nerves of pupil, 562. 
Diploe, 24, 206 ; veins of, 475. 
Direct, cerebellar tracts, 585 ; inguinal hernia,, 
385 ; pyramidal tract, 584. _ 
Directions of movement of joints, 39. 
Discs, blood, 8, 9; interpubic, 185; interver- 
tebral, 38, 123; of joints, 37 ; of striped 
muscle, 43. 
Discus proligerus, 785. 
Distal ganglia, 561. 
Dissection, 1, 2. 
Distinct vertebrae, 107. 
Divarication, iliac, 168. 
Diverticulum, intestinal, 95, 719. 
Divisions of nerves, 507 ; posterior, 509. 
Dobie’s lines, 43. 
Dogiel, ending of rod-fibres, 659 ; genital cor- 
puscles, 781; nerves of larchymal gland, 645. 
Dolichocephalic skulls, 241. 
Dorsal, use of term, 3 ; mesocardium, 102 ; 
nerve, last, 524; plate, 92 ; vertebrae, 107. 
Dorsalis, indicis artery, 443 ; pollicis artery, 443. 
Dorso-ventral, use of term, 3. 
Dorsum, ilii, 164 ; scapulae, 135; sellae, 214; of 
spleen, 754 ; of tongue, 704. 
Douglas, semilunar fold of, 381; pouch of, 692, 
793. 
Duchenne, action of facial muscles, 328. 
Duct, accessory or superior of pancreas, 729 ; 
common bile, 732 ; cystic, 732 ; ejaculatory, 
776, 778; lymphatic, right, 497 ; nasal, 228 ; 
of Bartholin, 709; of Cuvier, 468, 488, 491; of 
Muller, J., 96, 795 ; of Eivini, 709 ; of Sten- 
son, 333, 701, 706 ; of Walther, 702, 708 ; of 
Wharton, 342, 702, 707; of Wirsung, 729; 
pancreatic, 729; thoracic, 497; Wolffian, 96 : 
vitelline, 94. 
Ductless glands, 753. 
Ducts of glands, 57; hepatic, 732, 734; inter- 
calary, salivary, 706; of liver and gall bladder, 
732, 734; sweat, 72. 
Ductus, arteriosus, 410, 496; communis chole- 
dochus, 732; endolymphaticus, 677; Stenonis, 
706; thyreoglossus, 99, 704, 757; venosus, 483, 
492, 495 ; venosus, obliterated, 731; venosus, 
fissure of, 731. 
Duhamel, experiments on bone, 35. 
Duodenum, 717- 
Dura mater, 576. 
Dursy, Jacobson’s organ in man, 642. 
Duverney, glands of, 792. 
Dyaster, 8. 
Ear, 667 ; development of, 682 ; external, 667 ; 
external, muscles of, 669; internal or laby- 
rinth, 675; lobule, 667; middle, 669; pinna, 
667. 
Eberstaller, anterior and posterior insula, 624. 
Ectoderm, 87, 88. 
Edinger; gastric follicles, 716; sensory tracts, 
590. 
Efferent, arteries of glomeruli, 763, 765; lym- 
phatics, 67, 68; nerves, 46, 506 ; nerves, 
gangliated and non-gangliated, 572. 
Egg, formation of embryo in bird’s, 87; bands, 
795. 
Ejaculatory duct, 776, 778. 
Ejaculator urinae muscle, 390. 
Elastic, lamina of cornea, 649 ; substance, 
yellow, 14. 
Elbow-joint, 155; anastomoses round, 443. 
Elbow, lymphatic gland, 503; movements of, 157. 
Embryo,of amphioxus, 86; chondrificationin, 130; 
coverings of, 102; formation of, 86 ; formation 
of, in vertebrates, 87 ; layers of, 89 ; ossifica- 
tion in, 130. 
Embryology, 82. 
Embryonic cartilage, 23. 
Eminentia collateralis hippocampi, 621. 
Eminence, deltoid, 139; frontal, 212; hypo- 
thenar, 283; ilio-pectineal, 164; olivary, 214 ; 
thenar, 281. 
Enamel, 693, 695. 
Enamel-germs, 699. 
Enamel-membrane, 699. 
Enamel-organ, 699. 
Bnarthrosis, 40. 
Encephalon, 590. 
End-bulbs of Krause, 79. 812 
INDEX 
End-plates, motorial, 44. 
Endocardium, 407. 
Endomysium of muscle, 41. 
Endoneurium, 48. 
Endosteum, 30. 
Endothelium, 55. 
Enlargement, of bones, 35; cervical, of spinal 
cord, 580 ; lumbar, of spinal cord, 580. 
Ensiform process, 121. 
Entoderm, 87, 88 ; of ampliioxus, 87. 
Ependyma, 47. 
Ephippium, 214. 
Epiblast, 89; of ampliioxus, 87. 
Epicardium, 407. 
Epicranial aponeurosis, 329. 
Epicondyles, 137, 139. 
Epicondylar glands, 503. 
Epidermis, 70, 72. 
Epididymis, 772, 776; development of, 97, 796. 
Epidermal, nerve-endings, 78; growths, special, 
74. 
Epigastric artery, deep, 436; superior, 432; 
superficial, 459. 
Epigastric, plexus, 566; region, 688; vein, 
482. 
Epiglottis, 739 ; fraenum of, 704. 
Epineurium, 48. 
Epiotic, 249. 
Epiploic appendages, 724. 
Epiphyses, 35; their union with shafts, 802 ; 
of vertebrae, 131. 
Epistrophei, ligamentum latum, 124. 
Episternal ossifications, 121. 
Epithelial cells, 54 ; spheroidal, 56. 
Epithelioid cells, 55. 
Epithelium, definition of, 54; ciliated, 56; 
columnar, 55; of cornea, 649 ; cubical, 55; 
functions of, 56 ; germinal, 97, 794 ; glandular, 
56; of hairs, 75; of intestine, 720; nomen- 
clature of, 55; polyhedral, 56; simple, 54; 
squamous, 54; stratified, 54; stratified 
squamous, 55; transitional, 55; of tunica 
media of eye, 655; varieties of forms of, 54 ; 
visual, 657. 
Epoophoron, 789, 797. 
Equator of eyeball, 646. 
Erector, clitoridis muscle, 391; penis muscle, 
391; spinae muscle, 358. 
Erectores pilorum muscles, 77. 
Eruption of teeth, 700. 
Erectile tissue, 780. 
Ethmoid, bone, 224; bone, ossification of, 249; 
lateral, 225 ; notch of frontal, 212. 
Ethmoidal, arteries, 422; cells, 225; incisura, 
212 ; spine of sphenoid, 216 ; turbinated pro- 
cesses, 225. 
Eustachian, tube, 674, 709 ; tube, development 
of, 98 ; orifice, 223 ; valve, 402. 
Experiment on animals, 2. 
Extension of joints, 39. 
Extensor, brevis digitorum muscle, 323 ; carpi 
radialis brevior muscle, 277 ; carpi radialis 
longior muscle, 276 ; carpi ulnaris muscle, 
278 ; digitorum communis muscle, 278; digi- 
torum pedis longus muscle, 309; hallucis 
longus muscle, 309; indicis muscle, 280 ; 
minimi digiti muscle, 278; ossis metacarpi 
pollicis muscle, 279; pollicis brevis muscle, 
280 ; pollicis longus muscle, 280 ; primi inter - 
nodii pollicis muscle, 280; secundi internodii 
pollicis muscle, 280. 
External, use of term, 3; angular process of 
frontal, 212 ; auditory meatus, 219 ; auditory 
process, 219; capsule, brain, 615; carotid 
artery, 414; ear, 667; ear, vascular and ner- 
vous supply, 669; mouth of uterus, 7861 
organs, female, 789 ; respiratory nerves, 516. 
Extra-spinal veins, 478. 
Extrinsic muscles of tongue, 340. 
Eye, 642 ; anterior and posterior chambers, 654; 
capsule of lens, 663 ; tunics or coats, 646; 
colour of, 656 ; development of, 665 ; primary 
vesicles, 90; pupil, 653; transparent structures 
within, 661. 
Eyeball, 643, 646. 
Eyebrows, 643. 
Eyelashes, 643. 
Eyelids, 643. 
Eye-teeth, 697. 
Facial, artery, 416 ; artery, surgical anatomy, 
426 ; artery, transverse, 418 ; nerve, 550, 595; 
vein, 470; vein, transverse, 472. 
Falciform, ligament of liver, 689, 731; processes, 
305. 
Fallopian tubes, 789. 
Fallopius, aqueduct of, 222, 670. 
False, amnion, 102; ligaments of bladder, 692, 
768 ; molar teeth, 697 ; pelvis, 162; ribs, 118 5 
vasa recta, kidney, 765. 
Falx, cerebelli, 578; cerebri, 578. 
Fangs of teeth, 693. 
Fascia, 16; anal, 393, 395; of arm, 269 ; axillary, 
269; deep of back, 365; deep cervical, 355; 
of Colies, 392; cremasteric, 378; cribriform, 
305; dentata, 627 ; of forearm and hand, 285; 
superficial of head and neck, 328; iliaca, 374, 
382; ilio-tibial band, 304; infundibuliform, 
384; intercolumnar, 377; interosseous of 
hand, 287; lata, 303; of leg and foot, 325; 
masseteric, 345 ; obturator, 393, 394 ; of orbit, 
335; pelvic, 392; of perineum and pelvis, 
392; plantar, 327; recto-vesical, 393; of 
Scarpa, 382; semilunar, 263; of shoulder, 
269; spermatic, 377; subpubic, 395; super- 
ficial, 70 ; temporal, 344; of thigh, 303; trans- 
versalis, 374, 383 ; triangular, 377. 
Fasciae, 252. 
Fasciculus, retroflexus of Meinert, 614. 
Fauces, 701. 
Female, organs, 783; organs, external, 789; 
pelvis, 167; pronucleus, 84 ; skull, 241; ure- 
thra, 791. 
Femoral artery, 458; common, 459; deep, 459; 
superficial, 459 ; surgical anatomy, 460. 
Femoral hernia, 375, 383; vein, 486. 
Femur, 168 ; ossification of, 203; shaft of, 170- 
Fenestra, ovalis, 670; rotunda, 670. 
Fenestrated membrane of Henle, 60. 
Ferrein, pyramids of, 764. 
Fibre, muscular, 40. 
Fibres, arched, of medulla oblongata, 599; 
arciform of Lockhart Clarke, 629; arciform ot 
Solly, 600; dentine, 694; of lens, 663; H- 
Muller’s, of retina, 657; nerve, 46, 48; 
osteogenic, 32; perforating of Sharpey, 29; 
of Remak, 50 ; zonular, 665. 
Fibrin, 8. 
Fibro-cartilage, 23, 37. 
Fibro-plates, 37 ; sterno-clavicular, 151; tarsal- 
of eyelids, 643 ; of temporo-maxillary articula- 
tion, 244; triangular, 156; semilunar, of 
knee-joint, 191. 
Fibrillae of striped muscle, 43. 
Fibrin of blood, 8 ; of muscle, 41. 
Fibrous, pericardium, 685; tissue, white, 13, 16- 
Fibula, 176 ; ossification of, 204. 
Fifth ventricle, 617. 
Filiform papillae of tongue, 704. 
Fillet, 599, 600, 614; decussation of, 597. INDEX, 
813 
Filum terminale, 580-582. 
Fimbria, 618; linguae, 704; tubae, 789. 
First, dorsal interosseous artery of foot, 463; 
intercostal vein, 470 ; polar body, 84. 
Fissiparous division, 6. 
Fissura arcuata, 638. 
Fissure, arterial of mastoid, 222 ; choroidal, 
638; of ductus venosus, 731; of gall-bladder, 
731; of Glaser, 220; great horizontal of 
cerebellum, 603; great longitudinal, 593; of 
inferior vena cava, 731; portal, 731; of 
Rolando, 625; sphenoidal, 217; spheno- 
maxillary, 218; of Sylvius, 593, 623; trans- 
verse of brain, 619 ; transverse of liver, 731; 
of umbilical vein, 731. 
Fissures, of hemispheres, 623; of liver, 731; 
of Santorini, 668; of spinal cord, 582 ; transi- 
tory of hemispheres, 638. 
Flechsig’s, cerebellar tract, 585; method of 
tracing nerve tracts, 54, 584; posterior 
vesicular column, 587. 
Flexion of joints, 39. 
Flexor, accessorius muscle, 317; brevis digitorum 
muscle, 321; brevis minimi digiti muscle, 283; 
carpi radialis muscle, 271; carpi ulnaris muscle, 
272; digitorum pedis longus muscle, 317; 
digitorum profundus muscle, 273; digitorum 
sublimis muscle, 272; hallucis brevis muscle, 
321; hallucis longus muscle, 317; minimi digiti 
brevis muscle, 321; pollicis brevis muscle, 
2§l; pollicis longus muscle, 275. 
Flexors of fingers, sheaths of, 275. 
Flexure, hepatic of colon, 726; sigmoid, 727 ; 
splenic of colon, 726. 
Floating ribs, 118. 
Flocculus, 604. 
Floor of third ventricle, 610. 
Fluid, cerebro-spinal, 576, 578. 
Fold, aryteno-epiglottidean, 741; costo-colic, 
726 ; of Douglas, 381; of Marshall, 409, 493 ; 
mesocardial, 409. 
Folds, alar of knee-joint, 192 ; medullary, 90. 
Folia of cerebellum, 603. 
Foliate papillae of tongue, 704. 
Follicle, hair, 77. 
Follicles, gastric, 714 ; closed, 68; closed of in- 
testine, 721; of Lieberkiihn, 721, 724; of 
Meibomius, 643 ; of teeth, 698. 
Fontana, canal of, 655 ; spaces of, 655. 
Fontanelle, sagittal, 247. 
Fontanelles, 250. 
Foot, bones of, 177 ; club, 325 ; dorsal artery of, 
463 ; movements of, 198. 
Footplate of rods of Corti, 680. 
Foramen, anterior and posterior condyloid, 208; 
caecum, brain, 595; caecum of skull, 213 ; 
caecum of tongue, 704; carotid, 223 ; dental, 
inferior, 235 ; incisor, 227 ; infraorbital, 227; 
jugulare, 206: lacerum medium, 218, 224; 
lacerum orbitale, 217; lacerum posticum, 206; 
of Luschka, 608 ; of Magendie, 608; magnum, 
206 ; mastoideum, 222 ; mental, 234 ; of 
Monro, 620; of Monro, primitive, 636 ; obtu- 
rator, 163; opticum, 214; ovale, 217 ; ovale, 
heart, 402, 495 ; parietal, 211; rotundum, 217; 
spheno-palatine, 216, 230 ; spinosum, 217 ; 
stylo-mastoid, 223 ; thyroid, 163; of Winslow, 
689. 
Foramina, arterio-vertebral, 111; costo-verte- 
bral, 111; intervertebral, 103; sacral, anterior 
and posterior, 115; of Scarpa, 227 ; of Sten- 
son, 227 ; of Thebesius, 402. 
Forceps, major and minor, 617. 
Forearm, arteries of, surgical anatomy, 444 ; 
movements of, 140, 157. 
Fore-gut, 94. 
Fore-kMneys, 96. 
Foreskin, 781. 
Forel, stratum dor sale, 613. 
Formation of layers, blastoderm, 86. 
Formation reticular, 597. 
Formative yelk, 82. 
Fornix, 618. 
Fossa, of antihelix, 668; basis cranii, 240; canine, 
227; digastric, 221; digital of testis, 772 ; of 
helix, 668 ; glenoid, of temporal, 220 ; incisor 
of mandible, 234; incisor, superior, 227; infra- 
spinous, 135; intercondylar, 171; ischio-rectal, 
395; jugular, 222; myrtiform, 227 ; nasal, 
238 ; navicularis, 782 ; ovalis, 402 ; patellaris, 
662; pituitary, 214, 246 ; pterygoid, 218, 237 ; 
of Rosenm filler, 675, 709; scaphoid, 218; 
spheno-maxillary, 218, 237 ; subscapular, 135 ; 
supraspinous, 135; temporal, 237 ; trochan- 
teric or digital, 170 ; zygomatic, 218, 237. 
Fossae, costal, 121; inguinal, 387 ; nasal, 640 ; 
superior and inferior occipital, 208; supra- 
pubic of peritoneum, 688 ; of skull, 237; of 
tympanum, 673. 
Fourchette, 790. 
Fourth, cranial nerve, 595; ventricle, 600, 607. 
Fovea, centralis, 660 ; of fourth ventricle, 600 ; 
hemielliptica vestibuli, 676; hemispherica 
vestibuli, 676; laohrymalis, 213 ; troclilearis, 
213. 
Fraena of lips, 701; of ileo-colic valve, 726. 
Fraenula, glosso-epiglottidean, 740. 
Fraenulum veli, 609. 
Fraenum, clitoridis, 790 ; epiglottidis, 704 ; 
glandis, 781; linguae, 702. 
Frankenhausen, nerves of unstriped muscle, 
42. 
Fraser, hyoid arch, 246. 
French skulls, 242. 
Frontal, use of term, 3; artery, 422; bone, 212 ; 
bone, ossification of, 247; crest, 213; eminence, 
212; gyri, 625; lobe of hemisphere, 625; 
nerve, 541; process of maxilla, 226 ; sinus, 
212 ; suture, 212 ; vein, 470. 
Frontalis muscle, 330. 
Fronto-nasal process, 98. 
Froriep, ganglion of hypoglossal, 571. 
Functions of epithelium, 56. 
Fundus of bladder, 768 ; of stomach, 711 ; uteri, 
787. 
Fungiform papillae of tongue, 704. 
Funiculi of nerves, 47. 
Funiculus gracilis, 596 ; solitarius, 553, 601. 
Furcula, 99. 
Furrow, antero-lateral, 582; postero-lateral, 
582 ; V-shaped of tongue, 704. 
Galactopherous ducts, 800. 
Galen, testes muliebres, 786 ; veins of, 474, 578 
619. 
Gall-bladder, 732 ; fissure of, 731. 
Ganglia, cervical, 563 ; lymphatic, 67 ; of pelvic 
plexuses, 567 ; of pneamogastric nerve, 555 ; 
primitive, 568 ; proximal, 561; stomachic of 
Remak, 712 ; secondary or distal, 561 ; spinal 
53, 582; sympathetic, 53; ventricular of heart 
409. 
Gangliated, cords, 560; nerves, afferent and 
efferent, 572. 
Ganglion, 46 ; Gasserian, 541; geniculate, 550 ; 
habenulae, 614; intercarotid, 759; jugular, 
553 ; lenticular, 543 ; Meckel’s, 545 ; mesen- 
teric, inferior, 567 ; otic, 548 ; petrous, 553 • 
semilunar, 566 ; spirale, 682; sphenopalatine, 
545 ; stellatum, 564 ; submaxillary, 548. 814 
INDEX 
Ganglionic layer of retina, 659. 
Gaskell, development of fifth nerve, 570; mor- 
phology of nerves, 571-575; posterior vesicular 
column, 587. 
Gasserian ganglion, 541; mask for, 222. 
Gastric, artery, 449 ; follicles, 714 ; glands, 714; 
lymphatic glands, 500. 
Gastro-colic omentum, 690. 
Gastro-duodenal artery, 448. 
Gastro-epiploic arteries, 448, 449. 
Gastro-hepatic omentum, 690. 
Gastro-phrenic ligament, 690; left, 691. 
Gastro-splenic omentum, 690. 
Gastrocnemius, muscle, 311; nerve, 533. 
Gastrula, 88. 
Gegeubaur, under-tongue, 702. 
Gelatiniferous substance, 13. 
Gemelli muscles, 291. 
Gemmill, J. F., Wolffian duct, 96. 
Gemmiparous division, 6. 
General anatomy, 5 ; definition of, 2. 
Geniculate, bodies, 612 ; ganglion, 550. 
Genio-glossus, muscle, 341; nerve to, 560. 
Genio-hyoid, muscle, 339 ; nerve to, 562. 
Genital corpuscles, 81, 781. 
Genito-crural nerve, 526. 
Geoffrey, St. Hilaire, 8., pineal body, 611. 
Genu, of corpus callosum, 616; of internal 
capsule, 615; upper and lower of Eolandic 
fissure, 625. 
German skulls, 242. 
Germinal, cells of spinal cord, 633; disc, 86; 
epithelium, 97, 794 ; membrane, 86 ; spot, 82, 
785 ; wall in birds, 87 ; vesicle, 82, 785. 
Germs, common enamel, 699. 
Gianuzzi, lunules or crescents of, 706. 
Gimbernat’s ligament, 376. 
Ginglymus, 40. 
Giraldes, corps de, 772 ; organ of, 797. 
Glabella, 213. 
Gland, acinotubular, 730; coccygeal, 759; lachry- 
mal, 645 ; lymphatic at elbow, 503 ; parotid, 
706 ; post-pharyngeal, 505 ; prostate, 778 ; 
submaxillary, 707. 
Glands, definition of, 57 ; ducts of, 57; accessory 
lachrymal, 644; acinated, 57; agminated, 721; 
axillary, 503; of Bartholin, 792 ; basement 
membrane of, 58; of Blandin, 706; of Bow- 
man, 641; bronchia], 502 ; of Brunner, 721; 
buccal, 701; of cardiac orifice, 716; ceruminous, 
74, 669; cervical, deep, 505; cervical, super- 
ficial, 504; ciliary, 665 ; coeliac, 500 ; con- 
globate, 67; Cowper’s, 783, 792; cutaneous* 
73; ductless, 753 ; of Duverney, 792 ; epi- 
condylar, 503; gastric, 714; gastric, lymphatic, 
500 ; Haversian, 37 ; hepatic lymphatic, 500 ; 
iliac, 499 ; ileo-colic, 500 ; inguinal, superficial 
and deep, 498 ; intercostal, 501; laryngeal, 
505; lenticular or conglobate, of stomach, 716; 
of Littre, 783; lumbar, 499; lymphatic, 67, 
498; mammary, 799 ; mastoid, 504; maxillary, 
internal, 504 ; mediastinal, 502 ; membrana 
propria of, 57 ; mesenteric, 499 ; mesocolic, 
500; molar, 701; of Montgomery, 800; mucous, 
58 ; mucous, salivary, 707, 708 ; mucous, of 
stomach, 714 ; of Nuhn, 706 ; parotid, 504 ; 
popliteal, 498; pyloric, 714-716; racemose, 57; 
rectal, 499; sacral, 499; salivary, 706; seba- 
ceous, 74; secreting, 57 ; serous, 58 ; serous 
salivary, 707, 708; of small intestine, 721 ; 
solitary, 721, 724 ; splenic, 500 ; sternal, 501; 
submaxillary lymphatic, 504 ; sudoriparous 
or sweat, 72, 74; of tongue, 706; of Tyson, 
781; of urethra, 783. 
Glandular epithelium, 56. 
Glandulae, mucilaginosae of Havers, 37; utri- 
culares, 788. 
Gians, clitoridis, 790 ; penis, 781. 
Glaser, fissure of, 220. 
Glenoid, fossa of scapula, 137; fossa of temporal, 
220; ligament, 153. 
Glia, 47. 
Gliding of articular surfaces, 39. 
Glisson, capsule of, 733. 
Globular tubercles, 98. 
Globus, major, 772 ; minor, 772; pallidus of 
nucleus lenticularis of the corpus striatum, 
615. 
Glottis, 742. 
Glomeruli, arterial, 759; arteriosi cochleae, 
682 ; kidney, 763; of olfactory lobe, 631. 
Glosso-epiglottidean fraenula, 740. 
Glosso-pharyngeal nerve, 553, 595. 
Gluteal, artery, 455; nerves, superior and in- 
ferior, 531; veins, 482. 
Gluteus, maximus muscle, 288 ; medius muscle, 
289 ; minimus muscle, 289. 
Goblet-cells, 58, 720. 
Golgi’s method of staining, 52. 
Golgi, organ of, 44. 
Goll, column and tract of, 585, 596, 600. 
Gomphosis, 40. 
Goodsir, development of teeth, 698; falls on 
pelvis, 782; locking of knee-joint in flexion, 
193 ; pineal body, 611; popliteus, 324 ; spicule 
beneath vomer, 231. 
Gowers, tract of, 585. 
de Graaf, urethral crypts, 791; vesicles of, 784. 
Gracilis muscle, 295. 
Grandry, touch-corpuscles of, 79. 
Granular layer, of cerebellum, 605; of ossifi- 
cation, 33; internal of retina, 659; external 
of retina, 658 ; of tooth, 694. 
Granular white blood corpuscles, 11. 
Granules, elementary of Zimmerman, 12. 
Gratiolet, frontal lobe, 625; orbital lobe, 627. 
Great, auricular nerve, 512; cul-de-sacof stomach, 
711; curvature of stomach, 711; deep petrosal 
nerve, 563; horizontal fissure, 603; longi- 
tudinal fissure, 593; occipital nerve, 510; 
omentum, 690; sciatic nerves, 532; sinus of 
aorta, 410; splanchnic nerve, 564; superficial 
petrosal nerve, 545. 
Grey, bands of corpus callosum, 616; nervous 
substance, 47. 
Groove, basilar, 208 ; bicipital, 137,138 ; carotid, 
215; infraorbital, 228 ; lachrymal, 239, 646; 
medullary, 90; mylo-hyoid, 235; musculo- 
spiral, 139; occipital of temporal, 221; pop- 
liteal, 172 ; subcostal, 118 ; supracostal, 118. 
Ground part, anterior of cord, 584; lateral, 585. 
Groux, M., case of, 131. 
Growth-cones of nerves, 634. 
Gruber, peroneo-tibial muscle of, 318. 
Gubernaculum testis, 797. 
Gudden, commissure of, 538, 613; direct cortical 
tract of, 612. 
Guerin, valvule of, 782. 
Gullet, 710. 
Gums, 701. 
Gustatory nerve, 548. 
Guthrie, muscle of, 391. 
Gyri, breves of insula, 624; superior, middle 
and inferior frontal, 625; of hemispheres, 623; 
occipital, 626; operti, 624; orbital, 627; tem- 
poral, 626. 
Gyrus, angular, 626; callosal, 626; cinguli, 626 ; 
dentatus, 627 ; fornicatus, 626 ; hippocampi, 
626 ; preangular, 626 ; rectus, 627 ; superior 
parietal, 626; supramarginal, 626. INDEX 
815 
Haeraatoblasts of Hayem, 12. 
Haemoglobin, 9, 10. 
Haemorrhoidal artery, inferior, 454; middle, 
453; superior, 451. 
Haemorrhoidai, nerves, inferior, 532; plexus, 483, 
567; plexus, venous, 482; veins, superior, 433. 
Hairs, 75 ; development of, 78. 
Hair-follicle, 77 ; sheath, 77. 
Haller, intercostal muscle, 372; vas aberrans of, 
776. 
Hamberger, intercostal muscles, 372. 
Hamular, process of sphenoid, 218; process of 
lachrymal, 233. 
Hamulus of cochlea, 679. 
Hand, bones of, 133 ; development of, 100; 
joints of, 158 ; movements of, 161; varieties 
of arteries, 445. 
Harmonia, 38. 
Hassall, corpuscles of, 756. 
Havers, glandulae mucilaginosae of, 37. 
Haversian, canals, 25 ; glands, 37 ; spaces, 27 ; 
systems, 26. 
Hayem, haematoblasts of, 12. 
Head, coelom in, 93 ; development of, 97 ; 
muscular segments of, 93. 
Head and neck, lymphatic vessels of, 505. 
Head-jdates of rods of Corti, 680. 
Head of, astragalus, 179; femur, 168; fibula, 
176; first metatarsal bone, 182; humerus, 
137; kidneys, 96 ; malleus, 671; metacarpal 
bones, 149; os magnum, 148; radius, 141; 
ribs, 118; scapula, 134; tibia, 173. 
Heart, 58, 400; development of, 97, 486 ; fora- 
men ovale of, 495 ; lymphatics of, 502 ; 
muscular fibres of, 44; nerve supply, 409 ; 
pericardial connections of, 409 ; relations of, 
406 ; size and weight of, 409 ; veins of, 468 ; 
ventricular ganglia, 409 ; vessels of, 409. 
Heart-wall, structure of, 407. 
Hearts, primitive, 100. 
Helicine arteries, J. Muller, 780. 
Helicotrema, 679. 
Helix, 668 ; fossa of, 668. 
Hemisphere, mantle of, 610. 
Hemisphere-vesicles, 592, 621. 
Hemispheres, cerebral, 621; transitory fissures 
of, 638. 
Henle, band of, 381; fenestrated membrane of, 
60; foramina for cochlear nerves, 680 ; 
layer of, 77; loops of 55, 763, 764; sheath of, 
47 ; transitional epithelium, 55. 
Hensen, cells of, 681. 
Hepatic artery, 448, 735; cells, 733 ; ducts, 732, 
734; fissures, 731; flexure, 726; ligaments, 
731; lobes, 731, 732 ; lobules, 733; lymphatics, 
736; lymphatic glands, 500; plexus, 566; 
structure, 733; veins, 481. 
Hernia, femoral, 375, 383; inguinal, 384 ; ingui- 
nal, direct and oblique, 385 ; lumbar, 374. 
Hertwig, polar bodies, 85. 
Hertwig’s theory of mesoblast, 89. 
Hesselbach, triangle of, 387. 
Hiatus Fallopii, 222. 
Highmore, antrum of, 228 ; mediastinum testis, 
773. 
Hilus, of ovary, 784; of spleen, 754; of supra- 
renals, 758. 
Hind-gut, 94. 
Hind-kidneys, 96. 
Hinge-joint, 40. 
Hip-bone, 162. 
Hip-joint, 186 ; articular arteries of, 453-459 ; 
movements of, 188 ; nerve to, 527. 
Hippocampus, bulb of, 626; gyrus of, 626; 
major and minor, 620, 621; sulcus of, 627. 
His, development of cord, 633; development of 
spinal nerves, 569; olfactory lobe, 637; optic 
tract, 636. 
His, W., Junr., ganglion for labyrinth, 682. 
Histology, 2. 
Holoblastic ova, 85. 
Homology, 1. 
Horizontal fissure, great, of cerebellum, 603. 
Horizontal cells of retina, 659. 
Horner, muscle of, 331. 
Horny epidermis, 73. 
Horse-shoe kidney, 760. 
Horsley, position of limbs of Sylvian fissure, 624. 
Hottentot women, “ apron ” of, 791. 
Houston, valves of, 728. 
Howship, pits of, 29. 
Hubrecht on placenta, 104. 
Human anatomy, definition of, 2. 
Humerus, 133, 137 ; ossification, 202. 
Humphry, experiments on bone, 28, 35. 
Hunter, J., canal of, 295, 304; experiments on 
bone, 35; gubernaculum testis, 797. 
Huntington, on caecum, 726. 
Huschke, development of cochlea, 682. 
Hutchinson, intercostal muscles, 372. 
Huxley, layer of, 77; ossification of temporal, 
249. 
Hyaline cartilage, 19, 20. 
Hyaline white blood corpuscles, 11. 
Hyaloid, artery, 667 ; membrane, 661. 
Hyaloido-capsular membrane, 665. 
Hyaloplasm, 6. 
Hyrtl, epithelium, 55. 
Hydatids of Morgagni, 772. 
Hymen, 791. 
Hyo-epiglottidean muscles, 744. 
Hyoid arch, 98; development of, 246. 
Hyoid, arteries, 415; bone, 236. 
Hypochondriac regions, right and left, 688. 
Hypoblast, 89 ; of amphioxus, 87. 
Hypogastric, artery, 453; arteries, 496; plexus, 
567; region, 688. 
Hypoglossal nerve, 559, 595. 
Hyoglossus muscle, 340 ; nerve to, 566. 
Hypothenar eminence, 283. 
Ileo-caecal or ileo-colic valve, 726. 
Ileo-colic, artery, 450; glands, 500. 
Ileum, 718. 
Iliac artery, external, 456; internal, 452. 
Iliac arteries, common, 452. 
Iliac, divarication, 168; fascia, 374, 382; fossa, 
164 ; glands, 499 ; vein, external, 482 ; vein, 
internal, 481; veins, common, 481. 
Iliac regions, right and left, 688. 
Iliaeus muscle, 301. 
Ilio-costalis, muscle, 360 ; cervicis muscle, 360 ; 
dorsi muscle, 360 ; lumborum muscle, 360. 
Ilio-femoral ligament, 187. 
Ilio-hypogastric nerve, 525. 
Ilio-inguinal nerve, 525. 
Ilio-lumbar, artery, 455; ligaments, 184; vein 
481. 
Ilio-pectineal, eminence, 164; line, 164. 
Ilio-psoas muscle, 301. 
Ilio-tibial band, 304. 
Ilio-trochanteric ligament, 187. 
Ilium, 162, 163; spines of, 164. 
Inca skulls, 242. 
Incisor, foramen, 227; fossa of mandible, 234; 
fossa, superior, 227; teeth, 696. 
Incisors, additional, 708. 
Incisura, ethnoidal of frontal bone, 212 ; nasalis, 
227 ; semilunar of sternum, 120. 
Incomplete joints, 38. 816 
INDEX. 
Incremental lines of dentine, 695. 
Incus, 671; development of, 246. 
Index, cephalic, 242. 
Indirect ascending cerebellar tract, 585. 
Indusium of corpus callosum, 616. 
Inferior, use of term, 3; maxillary bone, 234; 
meatus, nasal, 238 ; turbinated bone, 233. 
Infracostal artery, 432. 
Infrahyoid muscles, 350; actions of, 351; 
nerve supply of, 351; relations of, 350. 
Infrahyoid nerves, 513. 
Infraorbital, artery, 419 ; canal, 228 ; foramen, 
227 ; groove, 228 ; nerves, 544. 
Infraspinatus muscle, 261. 
Infraspinous fossa, 135. 
Infratrochlear nerve, 543. 
Infundibula, of kidney, 762 ; of lung, 750. 
Infundibuliform fascia, 384. 
Infundibulum, brain, 594; heart, 404; nose, 
226. 
Inguinal, canal, 375, 384; fossae, 387; glands, 
superficial and deep, 498; hernia, 384, 385. 
Inion, 243. 
Injection, 2. 
Immovable joints, 38. 
Imjnegnation of ovum, 85. 
Impression, colic of liver, 732; renal of liver, 
732. 
Innominate, artery, 412; bone, 162; bone, 
ossification, 203 ; bone, position of, 163 ; veins, 
469. 
Insula, 624 ; anterior and posterior, 624. 
Integuments, 70. 
Interarticular fibro-plate, sterno-clavicular, 151; 
of temporo-maxillary articulation, 244. 
Interarticular, ligament of ribs, 126; septum, 
126. 
Interauricular septum, 402. 
Intercarotid ganglion, 759. 
Intercalary, tubes, kidney, 763, 764; ducts, 
salivary, 706. 
Intercellular canals, of pancreas, 730; of liver, 
734. 
Interclavicular ligament, 750. 
Intercolumnar fascia, 377. 
Intercondylar fossa, 171. 
Intercostal arteries, 446 ; anterior, 432. 
Intercostal, artery, superior, 432; glands, 501; 
muscles, 365; muscles, actions of, 372; nerves, 
523; vein, first, 470; veins, 479. 
Intercosto-humeral nerve, 523. 
Intercristal pubic ligament, 185. 
Intercrural pubic ligament, 185. 
Interglobular spaces of tooth, 695. 
Interlobular, arteries, kidney, 764; arteries, 
liver, 736; ducts, liver, 734; veins, kidney, 
765; veins, liver, 733. 
Intermaxillaries, 249. 
Intermaxillary, crest, 227; process of vomer, 
231. 
Intermediary lamination of bone, 27. 
Intermediate cell mass, 96. 
Intermedio-lateral tract, 586. 
Intermetacarpal joints, 158. 
Intermuscular septa, primitive, 397; of arm, 
270; of sole, 327 ; of thigh, 304. 
Internal, use of term, 3; angular process of 
frontal, 213; auditory meatus, 222 ; capsule, 
brain, 613, 614 ; carotid artery, 420 ; ear, 675; 
lamination of bone, 26; malleolus, 175; mouth 
of uterus, 786 ; sphincter, 728. 
Interosseous arteries, anterior and posterior, 441; 
palmar, 445. 
Interosseous artery, common, 440; first dorsal 
of foot, 463; dorsal, 443. 
Interosseous, astragalo-calcaneal ligament, 195; 
costo-transverse ligament, 126; fascia of hand, 
287; ligament, inferior tibio-fibular, 194; 
membrane of leg, 194 ; membrane, radio-ulnar, 
156; muscles of hand, 284; muscles of foot, 
322; nerve, anterior, 520; nerve, posterior, 
522 ; tarsal ligaments, 197. 
Interphalangeal articulations, 161, 197 ; hand, 
161. 
Interpubic disc, 185. 
Interspinous ligaments, 124. 
Interstitial lamination of bone, 27. 
Intertransverse ligaments, 124. 
Intertransversales muscles, 362. 
Intertrochanteric ridges, 170. 
Interventricular, grooves, 400; septum, 403. 
Intervertebral discs, 38, 123; foramina, 108. 
Intestinal, diverticulum, 719 ; epithelium, 720. 
Intestine, 717 ; development of, 736; lymphatics 
of, 500 ; primary loop, 736 ; large, 723 ; small, 
717; small, arteries of, 450; small, closed 
follicles of, 721; small, glands of, 721; small, 
mucous membrane, bloodvessels and lacteals, 
722; small, nerves of, 723. 
Intestinum caecum, 724. 
Intralobular veins, liver, 733. 
Intrapelvic pubic ligament, 185. 
Intraspinal veins, 478. 
Intrinsic muscles of tongue, 703. 
Involuntary muscular fibre, 40. 
Iris, 653; pars retinalis, 653; pars uvealis, 653. 
Irish skulls, 242. 
Ischio-cavernosus muscle, 391. 
Ischio-rectal fossa, 395. 
Ischium, 162, 165; spine of, 165. 
Island of Reil, 593, 621. 
Isthmus, cerebri, 578, 590, 608; tubae, 789; of 
thyroid body, 756. 
Iter a tertio ad quartum ventriculum, 609. 
Jacobson’s, nerve, 554 ; organ, 99, 642, 702. 
Japanese malar, 233. 
Jaw, 226, 234; movements of, 245; underbung, 
697. 
Jejunum, 718. 
Joints, anterior thoracic, 126; complete, in- 
complete, 36, 38; development of, 37; direction 
of movements of, 39 ; elbow, 155 ; fibro-plates, 
fibro-cartilages, menisci or discs in, 37: 
of larynx, 740; movable, 38; movements 
of, 39; movements of shoulder, 154; nomen- 
clature of, 39; proper or movable, 38; radio- 
ulnar, 155; shoulder, 152; of wrist and 
hand, 158. 
Jugular, foramen, 206; fossa, 222; ganglion, 
553; lymphatic trunk, 505; notch, 208; 
process, 206 ; vein, external, 471; vein, in- 
ternal, 470; vein, primitive, 491; veins, 
anterior and posterior, 472. 
Kaffir skulls, 241. 
Karyokinesis, 6. 
Kerato-cricoid ligaments, 740. 
Kerckring, ossification of temporal, 249. 
Kernels, lymphatic, 67. 
Kidney, 759; bloodvessels in, 764; develop- 
ment of, 765; horse-shoe, 760; lymphatics, 
765 ; structure of, 760. 
Kidneys, in birds, 766; lobulated, 766; in 
mammals, 766; varieties, 760. 
Klebs, nerves of unstriped muscle, 42. 
Knee, articular nerves of, 527, 533 ; development 
of, 100. 
Knee-joint, 189; articular arteries of, 461; 
ligaments of, 189; movements of, 192. INDEX, 
Knee-pan, 172. 
Kolliker, double origin of heart, 100; cochlear 
nerves, 680; Jacobson’s organ in man, 642; 
membrana reunions inferior, 102; nerves in 
bone, 30; ossification in rachitis, 34; osteo- 
clasts of, 29, 31; placenta, 104; terminal 
baskets of, 606. 
Krause, cylindrical bulbs of, 81; end-bulbs of, 
79; genital corpuscles, 781; membranes of, 
43; ulnar collateral nerve, 522. 
Kuhne, motorial end-plates of, 44. 
Kyphosis, 243. 
ani muscle, 388 ; labii superioris muscle, 332 ; 
labii superioris alaeque nasi muscle, 332; 
menti muscle, 333; palati muscle, 348; pal- 
pebrae superioris muscle, 335 ; uvulae muscle, 
348. 
Levatores costarum muscles, 367. 
Level base of skull, 241. 
Levers, 251. 
Lieberkiihn, follicles of, 721, 724. 
Ligament, 16, 17 ; accessory, of knee-joint, 192; 
accessory, occipito-atlantal, 123; annular, of 
elbow, 155; Bigelow’s, 170; broad, of ovary, 
783; broad, of uterus, 692; calcaneo cuboid, 
inferior, 197; calcaneo-scaphoid, external, 197;: 
calcaneo-scaphoid, inferior, 196 ; capsular, of 
hip-joint, 187 ; capsular, shoulder, 153 ; com- 
mon anterior, 123; common posterior, 123 ; 
conoid, 151 ; coraco-acromial, 152; coraco- 
humeral, 153; coronary, of liver, 689, 731; 
costo-clavicular, 151; costo-vertebral, anterior, 
126; cotyloid, 186; crico-thyroid, 740; crucial, 
of knee-joint, 191; cruciform, 124; coraco- 
clavicular, 134, 151; deltoid, 152 ; falciform of 
liver, 689, 731; gastro-phrenic, 690 ; gastro- 
phrenic, left, 691; Gimbernat’s, 376; glenoid, 
153; ilio-femoral, 187; ilio-troohanteric, 187; 
interarticular, of ribs, 126; interclavicular, 
150 ; interosseous astragalo-calcaneal, 195 ; 
interosseous tibio-fibular, inferior, 194 ; meta- 
carpal, of thumb, interna], 159; mucous, of 
knee-joint, 192; oblique radio-ulnar, 156; occi- 
pito-axial, long or posterior, 124; odontoid, 
lateral, 124 ; odontoid, middle, 125; orbicular, 
elbow, 155; plantar, long, 197 ; plantar, short, 
197; Poupart’s, 375, 376; prismatic, of lens, 
664; pterygo-maxillary, 356 ; pterygo-spinous,, 
357; pubic, intercristal, intercrural, intrapelvie, 
pre-urethral, 185 ; pubo femoral, 188 ; radiate, 
126; of rectum, 394; rhomboid, 134, 151; 
round, of hip-joint, 186; round, of liver, 689; 
round, of ovary, 783; round, of uterus, 787; 
spheno-maxillary, 356; spiral, 680; spleno- 
phrenic, 690; stellate, 126 ; stylo-maxillary, 
245, 356 ; suprascapular, 152 ; supraspinous, 
123; suspensory, 125; suspensory of lens, 664; 
suspensory of liver, 689, 731; suspensory of 
ovary, 783; suspensory of penis, 382 ; terminal 
sacro-iliac. 185 ; transverse, of ankle-joint, 
194; transverse, of atlas, 124; transverse, of 
hand, superficial, 287 ; transverse, of hip- 
joint, 186 ; transverse, of knee-joint, 192 ; 
transverse, metatarsal. 197; trapezoid, 152; 
trapezio-metacarpal, of Bruce Young, 160 ; 
triangular, 395 ; of Treitz, 717 ; vaginal, 273; 
of Winslow, 190; Y-shaped, 188. 
Ligamenta, arcuata, 370, 382 ; subfiava, 15, 123. 
Ligaments, alar, 192; of ankle-joint, 195; 
annular of ankle, 326 ; annular of wrist, 286 ; 
atlanto-axial, 125; of bladder, false and true, 
768; carpal, 159, 160; check, 124; common 
carpal, 160 ; coccygeal, 124 ; conjugal, 126 ; 
costo-transverse, 126; of external ear, 669; 
elbow, 155; of false bladder, 692; hepatic, 731; 
ilio-lumbar, 184; interosseous tarsal, 197; 
interspinous, 124 ; in ter transverse, 124 ; 
kerato-cricoid, 740; of knee-joint, 189; of 
larynx, 740; lumbo-sacral, 184; lunar inter- 
osseous, 158; of malleus, 671; metacarpo- 
phalangeal, 160; occipito-atlantal, 125; of 
patella, 191; peritoneal, 688; radio-ulnar, 
155, 156; sacro-coccygeal, 124; sacro-iliac, 
184; sacro-sciatic, 185; of scapula, 152; 
shoulder, 153 ; sterno-clavicular, 150 ; tarsal, 
330; temporo-maxillary, 244; of thorax, 125; 
thyro-arytenoid, 741; thyro hyoid, 740 ; tibio- 
Labia, majora, 790; minora, 790. 
Labial, artery, 416; glands, 701; nerves, superior, 
545; veins, 471. 
Labium, tympanicum, 680; vestibulare, 679. 
Labyrinth, 219; osseous and membranous, 675, 
676. 
Lachrymal, apparatus, 645; artery, 421; bone, 
233; canaliculi, 646; canals, 645; duct, de- 
velopment of, 99; gland, 645; glands, acces- 
sory, 644; groove, 228; nerve, 542; papilla, 
643; sac, 646 ; sac, groove for, 228. 
Lacteals, 64, 500, 722. 
Lacuna magna, 782. 
Lacunae, of bone, 25 ; of urethra, 782. 
Lambda, 243. 
Lambdoidal suture, 211. 
Lamina, cribrosa of temporal, 222; cribrosa of 
sclerotic, 647; elastic, anterior, 649; elastic, 
posterior, 649; cinerea, 594; spiralis, 679. 
Laminae, of cerebellum, 603; of cornea, 648 ; of 
vertebrae, 108. 
Laminated tubercle, cerebellum, 604. 
Lamination of bone, 26; internal, 26; inter- 
mediary, 27 ; interstitial, 27 ; perimedullary, 
26 ; peripheral, 26 ; primary, 26. 
Lancisi, nerves of, 616. 
Langerhans, cells of, 78; centro-acinary cells of, 
730. 
Lantermann, notches of, 50. 
Lanugo, 78. 
Large intestine, 723. 
Larger, cravate de suisse, 713. 
Laryngeal, artery, inferior, 430; artery, superior, 
415 ; glands, 505; nerves, 556, 557. 
Larjmx, cartilages of, 738; cavity of, 741 ; joints 
and ligaments, 740; and trachea, lymphatics 
of, 506 ; muscles of, 742 ; saccule of, 742 ; ven- 
tricles of, 742 ; vessels and nerves of, 744. 
Lateral, lobes of prostate, 778 ; nasal process, 
98 ; ventricles, 620; plates, 92; recess, 600; 
sinus, 476 ; zone, 92. 
Lateral, mass of, ethmoid, 225; sacrum, 110 ; 
atlas, 113. 
Latissimus dorsi muscle, 254. 
Layer, of Malpighi, 72; Rauber’s, 88. 
Layers, of germinal membrane, 86; vertebrate 
embryo, 87, 89. 
Le cap, Broca, 625. 
Lecithin, 82. 
Leg, interosseous membrane of, 194; surgical 
anatomy of arteries of, 467. 
Lemniscus, 600. 
Lemurs, under-tongue of, 702. 
Lenhossek, centrifugal fibres of posterior roots, 
588. 
Lens, crystalline, 662; development of, 666. 
Lenticular, ganglion, 543; glands of stomach, 
716; nucleus, 610. 
Leucocytes, 10; of connective tissue, 15; of 
lymphatics, 67. 
Levator, anguli oris muscle, 333; anguli scapulae 
muscle, 256; anguli scapulae, nerve to, 513; 818 
INDEX, 
fibular, 194; triangular, of liver, 689, 731; 
true of bladder, 393. 
Ligamentum, arteriosum, 410; colli costae, 126; 
conjugate costarum, 126; denticulatum, 580; 
latum epistrophei, 124 ; latum pulmonis, 686 ; 
mucosum, 192; nuchae, 15, 123 1 patellae, 
191, 299; pectinatum iridis, 653; teres, of 
hip-joint, 186. 
Ligulae, 596, 604, 608. 
Limb, bones compared, 199; development of, 200. 
Limb, lower or pelvic, 162. 
Limbic lobe of brain, 626. 
Limbs, development of, 99; of Sjdvian fissure, 
624. 
Limbus cochlea, 679. 
Limiting membrane, external, of von Brunn, 641. 
Limiting membranes of retina, external and 
internal, 657. 
Line, ilio-pectineal, 164 ; middle, use of term, 3. 
Linea, alba, 373, 381; albuginea, 393; aspera, 
170; semilunares, 374; splendens, 580. 
Lineae transversae, 374. 
Lines, supracondylar, 170. 
Lingual artery, 415 ; surgical anatomy, 426 ; 
Lingual, vein, 470; nerve, 548. 
Lingualis, inferior muscle, 703; superior muscle, 
703. 
Lingula, of mandible, 235; of sphenoid, 215. 
Liquor, Morgagni, 663; sanguinis, 8. 
Lissauer, marginal of, 585. 
Littre, glands of, 783. 
Liver, 730 ; coronary ligament of, 689 ; develop- 
ment of, 737; falciform ligament of, 689; 
lymphatics of, 501; nerve supply of, 736; 
round ligament of, 689; suspensory ligament 
of, 689 ; triangular ligaments of, 689. 
Living corpuscle, 5. 
Locus caeruleus, 613. 
Lobe, biventral, central, cuneate, lunate, quad- 
rangular, semilunar, and slender of, cerebel- 
lum, 603, 604; frontal, 625; maxillary, 98; 
occipital, 626; olfactory, 621; olfactory, de- 
velopment of, 637 ; Spigelian, 732; sub- 
pedunculated, 604. 
Lobes, cerebellar, 603; cerebral, 593; hepatic, 
731, 732; of lung, 747 ; olfactory, 595, 630; 
of projection, 593; of prostate, 778 ; of thyroid 
body, 757. 
Lobulated kidneys, 766. 
Lobule, of ear, 667 ; quadrate of brain, 626. 
Lobules, of cerebellum, 603; of liver, 733; of 
lung, 749. 
Lobulus Spigelii, 690. 
Long, costo-transverse ligament, 126; occipito- 
axial ligament, 124; plantar ligament, 197; 
subscapular nerve, 521. 
Longissimus, capitis muscle, 360; cervicis 
muscle, 360 ; dorsi muscle, 360. 
Longitudinal, bundle, posterior, 613; cords of 
sympathetic, 561; fissure, great of brain, 603 ; 
fissure of liver, 731; sinuses, inferior and 
superior, 475. 
Longus colli muscle, 354. 
Loop, primary of intestine, 736. 
Loops of Henle, 55, 763, 764. 
Loven, taste-buds, 704; on ossification from 
cartilage, 34. 
Lowenthal, tract of, 585. 
Lucas, groove for chorda tympani, 217- 
Ludwig, kidney, 763, 764. 
Lumbar, aponeurosis, 365 ; arteries, 447 ; glands, 
499; hernia, 374; nerves, posterior divisions, 
510 ; plexus, 524 ; regions, right and left, 688; 
sympathetic, 565; veins, 480; vertebra, fifth, 
111; vertebrae, 107, 110. 
Lumbo-sacral, cord, 524, 531; ligaments, 184. 
Lumbricales, muscles, 274, 317 ; of hand, nerves 
to, 620; of foot, nerves to, 534. 
Lunar, bone, 145, 146; interosseous ligaments, 
158. 
Lunate lobes of cerebellum, 603. 
Lung, 746 ; broad ligament, 686 ; internal struc- 
ture of, 748; lymphatics of, 502; vessels and 
nerves of, 752. 
Lunulae, 403. 
Lunules or crescents of Gianuzzi, 706. 
Luschka, coccygeal gland, 759 ; foramen of, 608 ; 
intervertebral discs, 38; Pacchionian bodies, 
579. 
Luys, corpus subthalamicum, 614. 
Lymph, 65. 
Lymph-corpuscles, 67. 
Lymph-paths, 68. 
Lymph spaces, 66. 
Lymphatic, duct, right, 497 ; ganglia, 67. 
Lymphatic glands, 67, 498 ; alveoli of, 68 ; 
cylinders of, 67; cords of, 67; nodules or 
bulbs of, 68. 
’Lymphatic nodules, 58. 
Lymphatic trunk, 65. 
Lymphatic trunk, jugular, 505. 
Lvmphatic vessels, 65; of head and neck, 
505. 
Lymphatics, 64, 496; afferent, 67; capillary, 
65; efferent, 67; simple-walled tributaries, 
65; of abdomen and pelvis, 499; of bladder, 
500; of brain, 505; of diaphragm, 502 ; of 
head and neck, 505 ; of heart, 502 ; of in- 
testine, 500 ; of kidney, 765 ; of larynx and 
trachea, 506; of liver, 501, 736; of lower 
limb, 498; of lungs, 502; of mamma, 502; 
of meninges, 505 ; of oesophagus, 502 ; of 
ovary, 500 ; of pharynx, 506 ; of pancreas, 
501; of pelvis, 500 ; of pericardium, 502 ; of 
perineum, 500 ; of spinal cord, 505 ; of spleen, 
501; of stomach, 717; of testicle, 500; of 
thorax, 502 ; of thyroid body, 506 ; of tongue, 
506 ; of upper limb, deep, 503 ; of upper limb, 
superficial, 503; of uterus, 500 ; of vagina, 
500; stomata of, 66. 
Lymphoid tissue, 16. 
Lyra, 617. 
Macalister, angles of bronchi, 751; on cerebral 
lobes, 593; ossification of axis, 132. 
M'Cormick, epiglottis, 740. 
Macintyre, hyo-epiglottidean muscles, 744; Ront- 
gen rays, 801. 
Mackay, conjoined tendon, 379; popliteal groove, 
172. 
Maceration, 2. 
Macula lutea, 656, 660. 
Maculae acusticae, 678. 
Magendie, foramen of, 608. 
Malar, bone, 232; canal, 233; duplicity of, 233 ; 
ossification of, 250; process, 226, 227; tuber- 
osity, 233. 
Male, organs, 771; pronucleus, 85; skull, 241; 
urethra, 781. 
Malpighi, 635; layer of, in epidermis, 72; 
pyramids of, 761; bodies of, spleen, 755; 
corpuscles of, kidney, 762. 
Malleolar arteries, 463, 465. 
Malleoli, 173. 
Malleolus, external, 176; internal, 175. 
Malleus, 671; development of, 246. 
Mamma, 799 ; supernumerary, 800; vessels and 
nerves of, 800. 
Mammalia, blastoderm, 88; kidneys in, 766; 
primitive streak, 88. INDEX 
819 
30; mucous of bladder, 770 ; mucous of small 
intestine, 719 ; mucous of stomach, 713 ; 
mucous of urethra, 782; obturator, 186; of 
Bruch, 652; of Corti, 681; of Demours or 
of Descemet, 649; of Henle, fenestrated, 60; 
of Krause, 43; of Nasmyth, 696 ; of Eeissner, 
679 ; of Ruysch, 651 ; Schneiderian, 640 ; 
synovial, 36 ; thyro-hyoid, 741; vitelline, 82. 
Membranes, atlanto-axial, 125; occipito-atlantal, 
125; saccular, 68 ; serous, 69 ; vaginal, 69. 
Membrano-chorio-capillaris, 651. 
Membranous, part of urethra, 782; vertebral 
column, 92. 
Meningeal, artery, middle, 418; artery, small, 
419 ; arteries, 429 ; lymphatics, 505. 
Meninges, 576. 
Meniscus, 37. 
Mental, foramen, 234; nerve, 548; protuberance, 
234. 
Merkel, touch corpuscles of, 79. 
Meroblastic ova, 85. 
Mesencephalon, 591, 
Mesenchyma, 90. 
Mesenteric, artery, inferior, 450; artery, superior, 
450; ganglion, inferior, 567; glands, 499; 
plexuses, 566, 567 ; veins, superior and in- 
ferior, 483. 
Mesentery, 688, 692. 
Mesethmoid, 224. 
Mesial, cartilage of nose, 639; plane, use of term, 
3; plate of ethmoid, 224. 
Mesoblast, 89. 
Mesoblastic somites, 87, 92, 397. 
Mesocardial fold, 409. 
Mesocardium, dorsal and ventral, 102. 
Mesocephalic skulls, 242. 
Meso-colic glands, 500. 
Mesocolon, 688 ; transverse, 691. 
Mesogastrium, 737. 
Mesonephros, 96, 766. 
Mesorectum, 688. 
Mesosternum, 121. 
Metacarpal bones, 149; ossification of, 202. 
Metacarpo-phalangeal articulations, 160. 
Metacarpus, 133, 149. 
Metameres, 1. 
Metanephros, 96. 
Metapophyses, 111. 
Metasternum, 121. 
Metatarsal, artery, 463; bones, 182, 183; bones, 
ossification of, 204; ligament, transverse, 197. 
Metatarso-phalangeal articulations, 197. 
Metatarsus, 182. 
Metencephalon, 591. 
Method of Flechsig, 584; of Golgi, 52. 
Methods of anatomy, 2. 
Meynert, commissure of, 538. 
Middle, cutaneous nerve, 527; ear, 669; hae- 
morrhoidal artery, 453; line, use of term, 3; 
lobe of right lung, 748 ; lobe of thyroid body, 
757 ; meatus nasal, 238; nasal process, 98 : 
plates, 96 ; sacral vein, 481; splanchnic nerve 
564. 
Middlemass, brain weighing 654 ounces, 632. 
Midriff, 367. 
Migratory corpuscles of connective tissue, 15. 
Mihalkovics, tubuli seminiferi, 774. 
Milk teeth, 698. 
Milnes Marshall, somites of head, 93. 
Mitosis, 6. 
Mitral cells, 631; valve, 405. 
Mixed nerves, 506. 
Moderator band, 404. 
Modiolus of cochlea, 679. 
v. Mold protoplasm, 5. 
Mammary, abscesses, 799 ; artery, external, 435; 
artery, internal, 431; glands, 799; lym- 
phatics, 502; veins, internal, 479. 
Mammilla, 800. 
Mammillary processes of vertebrae, 110. 
Mammillation of gastric mucous membrane, 713. 
Mandible, 234 ; ossification of, 250. 
Mandibular arch, 98, 246. 
Mann, G., nerve corpuscles during activity, 51. 
Manubrium, of malleus, 671; of sternum, 120. 
Manouvrier, first frontal convolution, 626. 
Mantle, of hemisphere, 610, 621; in mammals, 
reptiles and birds, 622. 
Marchi, tract of, 585. 
Marginal, convolution, 626; tract of Lissauer, 
585. 
Margo acutus, margo obtusus, 401. 
Marie, Pierre, acromegaly, 612. 
Mark, polar bodies, 85. 
Marrow, 30. 
Marshall, fold of, 409, 493 ; oblique vein of, 468 ; 
weight of female brain, 632. 
Marsupials, under-tongue of, 702; ureters and 
vaginae, 795. 
Martin, prickle-cells, 73.5 
Masseter muscle, 342 ; nerve to, 546. 
Masseteric, artery, 419; fascia, 345. 
Mastication, actions of muscles of, 344; nerve 
supply of muscles of, 344 ; relations of muscles 
of, 343. 
Mastoid, antrum, 670 ; arteries, 417 ; foramen, 
222; glands, 504 ; part of temporal, 221; pro- 
cess, 221. 
Maturation of ovum, 83. 
Maxilla, 226 ; ossification of, 249. 
Maxillary, artery, internal, 418; bone, inferior, 
234; bone, superior, 226; glands, internal, 
504; lobe, 98; nerve, inferior, 546; nerve, 
superior, 543; sinus, 228; tuberosity, 228; 
vein, internal, 472. 
Meatus, auditorius externus, 219, 667, 669; 
auditorius internus, 222 ; inferior nasal, 238 ; 
middle nasal, 226, 238; superior nasal, 225, 
238; urinarius, 791. 
Meckel, diverticulum, 719; thymus, 756. 
Meckel’s cartilage, 246 ; ganglion, 545. 
Median, artery, 441; basilic vein, 484 cephalic 
vein, 484; nerve, 520; vein, superficial, 484. 
Mediastina, thoracic, 684, 686. 
Mediastinal, arteries, 432; glands, 502. 
Mediastinum testis, 773. 
Medulla, of hairs, 76 ; oblongata, 580, 595; 
of ovary, 784; spinalis, 580. 
Medullary, folds, 87, 88, 90; groove, 87, 90; 
membrane, 30; part of kidney, 761; part of 
suprarenals, 758 ; part of thymus, 756 ; sub- 
stance of nerve-fibre, 49; velum, anterior, 
602 ; velum, posterior, 604. 
Medullated nerve-fibres, 48. 
Meibomius, follicles of, 643. 
Meinert, fasciculus retroflexus of, 614. 
Meissner’s submucous plexus, 723. 
Meissner, touch corpuscles of, 79. 
Membrana, flaccida of Shrapnell, 674; fusca, 
647 ; propria of glands, 57 ; nictitans of birds, 
644; pupillaris, 667 ; reticularis cochleae, 681; 
reunions inferior, 92, 102 ; reunions superior, 
92; tectoria (occipito-axial), 124; tympani, 
673; tympani, secondary, 670. 
Membrane, basilar of cochlea, 679; bones, 31; 
costo-coracoid, 134; crico-thyro-arytenoid, 
740; germinal, 86; hyaloido-capsular, 665; 
hyaloid, 661; interosseous of leg, 194; limiting, 
external of olfactory cells, 641; limiting, ex- 
ternal and internal of retina, 657 ; medullary, 820 
INDEX 
Molar glands, 701; teeth, 697 ; teeth, false, 697. 
Molecular layer, cerebellum, 605; inner of 
retina, 659; outer of retina, 658. 
Molecular layers, cerebral gyri, 627. 
Monaster, 7. 
Monro (primus), sphenoidal turbinated bone, 216. 
Monro (secundus), foramen of, 620 ; foramen of, 
primitive, 636. 
Monorchid, 798. 
Mons veneris, 789. 
Montgomery, glands of, 800. 
Monticulus, cerebellum, 603. 
Morgagni, columns of, 728; liquor of, 663; 
hydatids of, 772. 
Morphological anatomy, definition of, 1. 
Morphology of muscles, 396. 
Morula, 86. 
Mossy branches of Cajal, 606. 
Motorial end-plates, 44. 
Mouth, 700; primitive, 97. 
Movable joints, 38 ; vertebrae, 107. 
Movements, of ankle and foot, 198 ; of articular 
surfaces, 39 ; of axial skeleton, 127 ; of elbow 
and forearm, 157 ; of eyeball, 337 ; of forearm, 
140; of hand, 161; of hip-joint, 188; of jaw, 
245; of joints, 39; of knee-joint, 192; of 
pelvis, 186; of ribs, 128; of shoulder-girdle, 
152, 154 ; of wrist, 161, 801. 
Mucous acini, 58. 
Mucous ligament of knee-joint, 192. 
Mucous membrane, 81; of bladder, 770; of 
larynx, 742 ; small intestine, 719 ; of stomach, 
713; trachea, 746 ; of urethra, 782. 
Mucous tract of embryo, 94. 
Mucus, 81. 
Mulberry mass, 86. 
Muller, H., circular muscle of, 652; fibres of, in 
retina, 657 ; orbital muscle of, 643. 
Muller, J., duct of, 96, 795; helicine arteries, 
780. 
Multifldus spinae muscle, 361. 
Multiplication of nucleated corpuscles, 6. 
Mumps, 356. 
Muscle, 40; actions of, 41; development of 
striped, 45 ; fibrillae of, 43; fibrin, 41; micro- 
scopic structure, 42 ; motorial end-plates, 44 ; 
nerves of striped, 44 ; nerves of unstriped, 42 ; 
plates, 93; striped or striated, 42; structure 
of, 41. 
Muscle, abductor hallucis, 321; abductor minimi 
digiti manus, 283 ; abductor minimi digiti 
pedis, 321; abductor pollicis, 281; ab- 
ductor pollicis longus, 279; accelerator 
urinae, 390; adductor brevis, 295; adductor 
hallucis brevis, 321; adductor longus, 295; 
adductor magnus, 295; adductor obliquus, 
321; adductor pollicis, 282; adductor trans- 
versus, 321; amygdalo-glossus, 348 ; anconeus, 
267; arytenoid, 744; aryteno-epiglottidean, 744; 
attrahens auriculam, 330; attollens auriculam, 
330; auricularis anterior, 330; auricularis pos- 
terior, 330 ; auricularis superior, 330 ; azygos, 
uvulae, 348; biceps brachialis, 263; biceps 
femoris, 292 ; biventer cervicis, 361; brachialis 
anticus, 264; brachio-radialis, 275; buccin- 
ator, 333; bulbo-cavernosus, 390 ; cervicalis 
ascendens, 360 ; chondro-glossus, 340 ; ciliary, 
652; circumflexus palati, 348 ; cleido-occipi- 
talis, 351; coccygeus, 389; complexus, 360; 
compressor naris, 332; compressor urethrae, 
391, 392; constrictor of pharynx, inferior, 345 ; 
constrictor of pharynx, middle, 346; con- 
strictor of pharynx, superior, 346; constrictor 
urethrae, 391, 392; coraco-brachialis, 263; 
corrugator supercilii, 331; cremaster, 378; 
crico-thyroid, 742; crureus, 300; deltoid, 
260; depressor alae nasi, 332; depressor 
anguli oris, 333; depressor labii inferioris, 
333; digastric, 338; dilatator naris, 332; 
ejaculator urinae, 390; erector clitoridis, 
391; erector penis, 391; erector spinae, 358; 
extensor carpi radialis brevior, 277; ex- 
tensor carpi radialis longior, 276; extensor 
carpi ulnaris, 278 ; extensor digitorum 
brevis, 323; extensor digitorum communis, 
278 ; extensor digitorum pedis longus, 309; 
extensor hallucis longus, 309; extensor in- 
dicis, 280; extensor minimi digiti, 278 ; 
extensor ossis metacarpi pollicis, 279; extensor 
pollicis brevis, 280; extensor pollicis longus, 
280 ; extensor primi internodii pollicis, 280 ; 
extensor secundi internodii pollicis, 280 ; flexor 
accessorius, 317 ; flexor carpi radialis, 271 : 
flexor carpi ulnaris, 272 ; flexor digitorum 
brevis, 321; flexor digitorum pedis longus, 
317 ; flexor digitorum profundus, 273 ; flexor 
digitorum sublimis, 272; flexor hallucis brevis, 
321; flexor hallucis longus, 317 ; flexor minimi 
digiti brevis manus, 283; flexor minimi digiti 
brevis pedis, 321; flexor pollicis brevis, 281; 
flexor pollicis longus, 275 ; frontalis, 330 ; 
gastrocnemius, 311; gemellus superior, 291; 
gemellus inferior, 291 ; genio-glossus, 341 ; 
genio-hyoid, 339 ; gluteus maximus, 288 ; 
gluteus medius, 289; gluteus minimus, 289; 
gracilis, 295; of Guthrie, 391; of Horner, 331; 
hyo-glossus, 340; iliacus, 301; ilio-costalis, 360; 
ilio-costalis cervicis, 360 ; ilio-costalis dorsi, 
360; ilio-costalis lumborum, 360 ; ilio-psoas, 
301; infraspinatus, 261; ischio-cavernous, 
391; latissimus dorsi, 254 ; levator anguli oris, 
333; levator anguli scapulae, 256; levator 
ani, 388 ; levator labii superioris alaeque nasi, 
332; levator labii superioris proprius, 332; 
levator menti, 333 ; levator palati, 348 ; 
levator palpobrae superioris, 335 ; levator 
uvulae, 348; lingualis inferior, 703; lingualis 
superior, 703; longissimus capitis, 360; longis- 
simus cervicis, 360; longissimus dorsi, 360; 
longus colli, 354; masseter, 342; multifidus 
spinae, 361; musculus accessorius ad sacro- 
lumbalem, 360 ; musculus superbus, 333; 
mylo-hyoid, 338 ; obliquus externus, 376 ; 
obliquus internus, 377 ; obliquus capitis in- 
ferior, 363 ; obliquus capitis superior, 363 ; 
obliquus oculi inferior, 335 ; obliquus oculi 
superior, 335 ; obturator externus, 291 ; ob- 
turator internus, 290 ; occipitalis, 330; occi- 
pito-frontalis, 330 ; omo-hyoid, 350 ; opponens 
minimi digiti, 283; opponens pollicis, 281; 
orbicularis oris, 33.3 ; orbicularis palpebrarum, 
330; orbital, of H. Muller, 643; palato-glossus, 
348 ; palato-pharyngeus, 348 ; palmaris brevis, 
281; palmaris longus, 272; pectineus, 295; pec- 
toralis major, 258; pectoralis minor, 259; pero- 
neo-tibial of Gruber, 318; peroneus brevis, 306; 
peroneus longus, 306; peroneus tertius, 311; 
plantaris, 314; platysma myoides, 328 ; pop- 
liteus, 314 ; pronator quadratus, 273 ; pronator 
radii teres, 270; psoas magnus, 302; psoas 
parvus, 302; pterygoideus externus, 343; ptery- 
goideus internus, 343; pyramidalis, 380; pyra- 
midalis nasi, 332 ; pyriformis, 290 ; quadratus 
femoris, 291; quadratus lumborum, 379; quad- 
ratus menti, 333 ; quadriceps extensor cruris, 
297; rectus abdominis, 380; rectus capitis 
anticus major, 354 ; rectus capitis anticus 
minor, 354; rectus capitis lateralis, 355; 
rectus capitis posticus major, 362 ; rectus 
capitis posticus minor, 362 ; rectus femoris, INDEX 
821 
299 ; rectus oculi externus, 334 ; rectus oculi 
inferior, 334 ; rectus oculi internus, 334 ; 
rectus oculi superior, 334; retrahens auricu- 
lam, 330; rhomboideus major, 255; rhom- 
boideus minor, 255 ; risorius of Santorini, 333; 
rotatores spinae, 362 ; sacro-lumbalis, 36 ; 
salpingo-pharyngeus, 348 ; sartorius, 297 ; 
scalenus anticus, 353 ; scalenus medius, 353 ; 
scalenus posticus, 354; semimembranosus, 41, 
294; semispinalis colli, 361; semispinalis 
dorsi, 361; semitendinosus, 41, 293; serratus 
anticus, 256; serratus magnus, 256; serratus 
posticus inferior, 371 ; serratus posticus 
superior, 371 ; soleus, 313 ; sphincter ani 
externus, 389 ; sphincter vaginae, 391; spinalis 
dorsi, 360 ; splenius capitis, 358 ; splenius 
colli, 358 ; stapedius, 672 ; sternalis, 259 ; 
sterno-cleido mastoid, 351; sterno-hyoid, 350; 
sterno-mastoid, 351 ; sterno-thyroid, 350 ; 
stylo-glossus, 340; stylo-hyoid, 339; stylo- 
hyoideus alter, 339; stylo-pharyngeus, 341 ; 
subanconeus, 267; subclavius, 259; subscapu- 
laris, 261; supinator brevis, 279; supinator 
longus, 275; supraspinatus, 261; temporal, 
342; tensor fasciae latae, 290 ; tensor palati, 
348 ; tensor tarsi, 331; tensor tympani, 672 ; 
tensor vaginae femoris, 290; teres major, 
262; teres minor, 262; thyro-arytenoid, 743; 
thyro-epiglottidean, 744; thyro-hyoid, 350; 
tibialis anticus, 309 ; tibialis posticus, 315; 
tracbelo-mastoid, 360; transversalis abdom- 
inis, 378; transversalis cervicis, 360; trans- 
versus pedis, 321; transversus perinaei, deep, 
391, 392 ; transversus perinaei, superficial, 
390; transversus thoracis, 370 ; trapezius, 253; 
triangularis menti, 333; triangularis sterni, 
370; triceps brachii, 265; trochlearis, 335; 
vastus externus, 300; vastus interims, 300 ; 
of Wilson, 392 ; zygomaticus major, 333 ; 
zygomaticus, minor, 332. 
Muscles, abdominal, actions of, 381; abdominal, 
nerve supply, 381; arm, actions of, 267 ; 
back, deep, actions of, 364 ; back, deep, 
nerve supply, 364 ; back, deep, relations, 
364 ; femoral anterior, inner and posterior, 
variations, 294, 297, 302; forearm and hand, 
actions, 285 ; forearm, back of, nerve supply, 
280; forearm, front of, nerve supply, 275; 
forearm, variations, 280; hand, nerve supply, 
284; hip and thigh, actions, 302; hip, 
variations, 292 ; hyo-epiglottidean, 744 ; infra- 
hyoid, 350 ; intercostal, external and internal, 
365, 366 ; intercostal, actions, 372 ; interossei, 
dorsal of hand, 284 ; interossei of foot, 322; 
interossei palmar, 284 ; intertransversales 
laterales, 362; intertransversales mediales, 362; 
intrinsic of pinna, 669; of larynx, 742; leg, 
external, variations, 306 ; leg and foot, 
actions, 323; leg, front of, variations, 311; 
leg, posterior, variations, 317; levatores 
costarum, 367; lumbricales, foot, 317; 
lumbricales, hand, 274; orbit, actions of, 337; 
palate, 347; perineum, actions of, 392 ; peri- 
neum, nerve supply of, 392; rotatores dorsi, 
362; shoulder, actions, 267; suprahyoid, 338 ; 
thigh, variations, 297; thorax, actions, 372; 
tissue of, 251; tongue, extrinsic, 340 ; tongue, 
intrinsic of, 703. 
Muscles generally, actions, 41, 252; attachments 
and forms, 251; development and morpho- 
logy, 396. 
Muscular, action of respiration, 373; coat of 
bladder, 770 ; coat of stomach, 712 ; fibre, 40 ; 
fibre, regeneration of, 46 ; fibres of heart, 44 ; 
layers of sole, 318; segments of head, 93. 
Muscularis mucosae, of intestine, 720; of 
stomach, 713; uterus, 788. 
Musculi incisivi, 333; papillares, 404; 
pectinati, 401. 
Musculo-cutaneous nerve, arm, 517; leg, 535. 
Musculo-phrenic artery, 432. 
Musculo-spiral, groove, 139; nerve, 521. 
Musculus, accessorius, 360; superbus, 333. 
Myelencephalon, 591, 595. 
Myelin, 49. 
Myeloplaxes, 29. 
Myelospongium, 633. 
Myenteric plexus, 723. 
Mylo-hyoid, groove, 235; muscle, 338; nerve, 
548; ridge, 235. 
Myolemma, 43. 
Myosin, 41. 
Myrtiform, caruncles, 791; fossa, 227. 
Naboth, ovules of, 788. 
Nails, 75. 
Nasal, artery, 422; artery, lateral, 417; bone, 
234 ; bone, ossification of, 250 ; cartilages, 
639 ; conchae, 640; crest, 227; duct, 228 ; 
fossae, 238, 640 ; fossae, nerve supply to, 641; 
fossae, vascular supply, 641; fossae, vestibule 
of, 640 ; meatuses, 238 ; nerve, 542 ; nerves, 
lateral, 545; process, 226; spine, 227 ; spine 
of frontal bone, 212. 
Nasmyth’s membrane, 696. 
Naso-palatine nerve, 545. 
Nates, brain, 609. 
Navel, 381. 
Navicular bone, 180; hand, 146. 
Neck, of astragalus, 177; of bladder, 768 ; 
development of, 97; of femur, 168; of humerus, 
137; of rib, 118; of scapula, 137; of uterus, 
786. 
Necks of teeth, 693. 
Nerve, abducent ocular, 549, 595 ; auditory, 552, 
595; auditory, nuclei of, 601; auricular of 
facial, 551; auricular of vagus, Arnold’s, 556 ; 
auriculo-temporal, 547 ; of Bell, 516 ; buccal, 
546; cervical, superficial, 512; circumflex, 521; 
communicating of hypoglossal, 560; of Co- 
tunnius, 545; crural, anterior, 527; cutaneous, 
internal small, 517; cutaneous, internal of 
thigh, 527; dental, inferior, 547; descendens 
hypoglossi (noni), 560 ; dorsal of clitoris, 532 ; 
dorsal, last, 524 ; dorsal of penis, 532 ; ex- 
ternal cutaneous thigh, 526 ; external respira- 
tory, 516; facial, 550, 595; frontal, 541 ;to 
geniohyoid, 560 ; to genio-glossus, 560; genito- 
crural, 526; glosso-pharyngeal, 553, 595; 
gluteal, superior and inferior, 531; great 
auricular, 512; to hip-joint, 527; to hyo- 
glossus, 560; hypoglossal, 559, 595; ilio- 
inguinal, 525; ilio-hypogastric, 525; infra- 
trochlear, 543; intercosto-huraeral, 523; in- 
ternal cutaneous, arm, 517; interosseous, 
posterior, 522; interosseous, anterior, fore- 
arm, 520 ; of Jacobson, 554 ; lachrymal, 542 ; 
to levator anguli scapulae, 513 ; lingual, 548 ; 
to masseter, 546; maxillary, superior, 543; 
maxillary, inferior, 546; median, 520; mental, 
548 ; middle cutaneous, 527 ; musculo- 
cutaneous, arm, 517 ; rnusculo-cutaneous, leg, 
535 ; musculo-spiral, 521; mylo-hyoid, 548 ; 
nasal, 542; naso-palatine, 545; obturator, 
526; obturator, accessory, 527 ; to obturator 
interims, 531; occipital, great, 510; occipital, 
small, 511 ; occipital, smallest, 510; oculo- 
motor, 539, 595; olfactory, 537; to omo- 
hyoid, 560; optic, 538 ; ophthalmic, 541 ; 
orbital, 544; pathetic, 539, 595 ; to pectineus, 822 
INDEX 
527 ; peroneal, 535 ; peroneal cummunicating, 
535; petrosal, external superficial, 551; 
petrosal, great deep, 545; petrosal, great 
superficial, 551; petrosal, small deep, 554; 
petrosal, small superficial, 554; pharyngeal, 
556 ; phrenic, 513 ; to plantaris, 533 ; pneumo- 
gastric, 555; popliteal, internal, 533; popli- 
teal, external, 535 ; to popliteus, 533; to 
pterygoideus externus, 547 ; to pterygoideus 
internus, 546 ; pudendal, inferior, 531 ; 
pudic, 531 ; to quadratics femoris, 531 ; 
radial, 522 ; to rectus femoris, 527; sacral, 
fourth, 536; saphenous, internal, 528; sa- 
phenous, short or external, 533 ; to sartorius, 
527 ; to scalenus medius, 513; small occipital, 
511; small sciatic, 531; spinal accessory, 558, 
595 ; spheno-palatine, 544 ; to stapedius, 551; 
to sterno-mastoid, 513 ; to stylo-hyoid, 551; 
to stylo-glossus, 560; suboccipital, 507; to sub- 
clavius, 51.6; supraorbital, 541; suprascapular, 
516; suprasternal, 512; trochlear, 539 ; supra- 
trochlear, 541; temporo-malar, 544 ; to tensor 
palati, 549 ; to tensor tympani, 549 ; thoracic 
anterior, the external and internal, 516 ; 
thoracic, posterior, 516; to thyro-hyoid, 560; 
tibial, 533; tibial-communicating, 533; tibial, 
anterior, 536; tibial, posterior, 533; to trape- 
zius, 513; trifacial or trigeminal, 540, 595; 
trochlear, 539 ; tympanic, 554 ; ulnar, 517; 
ulnar collateral of Krause, 522; ulnar, deep, 
520; vagus, 555; Vidian, 545; of Wrisberg, 
517. 
Nerve-corpuscles, 46, 50; of Purkinje, 606; 
poles or branches of, 50 ; polymorphous, 628 ; 
pyramidal, 628. 
Nerve-endings, epidermal, 78. 
Nerve-fibres, 46, 48; ampullae of, 50; associa- 
tion, 630 ; glandular, 562 ; medullated, 48 ; 
non-medullated, 50 ; pilo-motor, 562. 
Nerve-growth in hernia cerebri, 634. 
Nerve-roots, 507, 508; in spinal cord, 587, 
590. 
Nerve-supply, bladder, 770; external ear, 669; 
heart, 409 ; iris, 654 ; larynx, 744 ; liver, 736 ; 
lungs, 752; mamma, 800; mucous membrane 
of tongue, 704 ; muscles, abdominal, 381 ; 
constrictors of pharynx, 346 ; muscles of 
back, deep, 364 ; muscles of forearm, 275; 
muscles, posterior of forearm, 280; muscles 
of hand, 284; muscles of mastication, 344; 
muscles of palate, 349 ; muscles of perineum, 
392; muscles, supra-hyoid, 340, 341 ; nasal 
fossae, 641; tympanum, 673 ; uterus, 788. 
Nerves, afferent, 46, 506 ; afferent sympa- 
thetic, 562 ; articular, of knee, 527-533 ; 
cardiac, from vagus, 557; cardiac sympathetic, 
564; cavernous, 567 ; cervical, posterior 
divisions, 509; cerebro-spinal, 506; ciliary, 
543; coccygeal, 511; of cochlea, 681; of 
cornea, 649; cranial, 537; cranial, nuclei of, 
601 ; deep petrosal, 563 ; dental, superior, 
544; develojament of, 54, 568; to digastric, 
548-551; dorsal digital of hand, 522; dilator 
of pupil, 562 ; of distribution, 46; divisions 
of, 507 ; divisions, posterior, 509 ; efferent, 46, 
506; erigent, 562, 567; funiculi of, 47; gan- 
gliated afferent and efferent, 572 ; growth- 
cones of, 634 ; gustatory, 548 ; haemorrhoidal, 
inferior, 532; infraorbital, 544; infrahyoid, 
513 ; intercostal, 523 ; labial, superior, 545 ; 
of Lancisi, 616; laryngeal, 556, 557 ; lumbar, 
posterior divisions, 510; to gastrocnemius, 
533 ; to lumbricales of hand, 520 ; mixed, 506 ; 
nasal, lateral, 545; oesophageal, 558; palatine, 
546; palmar, 520,521; palpebral, 544; perineal, 
532; of periosteum, 30; peripheral, 46; 
pharyngeal, sympathetic, 564; plantar, ex- 
ternal and internal, 534 ; pulmonary of vagus, 
557 ; pulmonary, sympathetic, 564 ; to quad- 
riceps, 527 ; rami communicantes hypoglossi, 
513; regeneration of, 54; to rhomboid muscles, 
515; sacral, posterior divisions, 510; sciatic, 
great, 532 ; segmental, 573 ; of small intestine, 
723; to soleus, 533; spinal, 507 ; spinal, roots 
of, 582; splanchnic, 564; of striped muscle, 
44; to stylo-pharyngeus, 555; subscapular, 
521; supraacromial, 512; supraclavicular, 
512 ; sympathetic, 560 ; temporal, deep, 547 ; 
of tendon, 18, 44; thoracic, 523; thoracic, 
posterior divisions, 510; of unstriped muscle, 
42 ; vaso-inhibitory, 562 ; vaso-motor, 561; 
viscero-inhibitory, 562 ; viscero-motor, 562. 
Nervous, elements, 46, 511; substance, white and 
grey or cineritious, 47- 
Neumann, red corpuscles in marrow, 12. 
Neural, arches, 105, 107; canal, 107; cavity, 
683; crest, 568. 
Neurenteric canal, 87-94. 
Neurilemma, 48. 
Neuroblasts, 633. 
Neuro-fibrous layer of retina, 660. 
Neuroglia, 47- 
Nipple, 800. 
Nodes of Eanvier, 49. 
Nodule, cerebellum, 604. 
Nodules, lymphatic, 68. 
Nodulus Arantii, 403. 
Nomenclature, 3 ; of joints, 39 ; of epithelium, 
55. 
Non-medullated nerve-fibres, 50. 
Norma verticalis, 242. 
Norris, invisible corpuscles of, 12. 
Nose, 639; accessory cartilages of, 640; alar 
cartilages of, 639 ; columella of, 639; inferior 
meatus, 238 ; mesial cartilage of, 639; middle 
meatus of, 226, 238 ; respiratory tract of, 640; 
superior meatus of, 225, 238; triangular car- 
tilages of, 639. 
Notch, of acetabulum, 166 ; ethmoid, of frontal, 
212; great sciatic, 164; jugular, 206; of 
Eivini, 670, 673; popliteal, 173; posterior 
cerebellar, 603; of pterygoid process, 218; 
sigmoid, 234; spheno-palatine, 230; supra- 
scapular, 135 ; supraorbital, 213. 
Notochord, 38, 91; sheath of, 91. 
Notches, of Lantermann, 50; superior and 
inferior of vertebrae, 108. 
Nucleoli, 6. 
Nuck, canal of, 795. 
Nuclear layer, external and internal of retina, 
658, 659. 
Nuclei, 6; of auditory nerve, 601; cranial 
nerves, 601; of facial nerve, 560; of glosso- 
pharyngeal nerve, 553; of oculo-motor nerve, 
539 ; of pneumogastric nerve, 555 ; of primary 
pale band, 628 ; of spinal accessory, 558; of 
striped fibre, 43; of trifacial nerve, 540; of 
trochlear nerve, 539. 
Nucleus, 5 ; of abducent nerve, 550 ; ambiguus, 
553; amygdalae, 626; caudatus, 610, 614; 
cuneatus, 597; emboliformis, 605; of hypo- 
glossal nerve, 559; fastigii, 605; globosus, 
605; gracilis, 597 ; lenticularis, 610, 614 ; of 
ala cinerea, 553 ; olivary, 598 ; red, 614. 
Nucleated cells or corpuscles, 5; varieties of, 
8 ; of connective tissue, 15. 
Nuhn, glands of, 706. 
Nutrient, artery of bones, 25; foramen of bones, 
25; yelk, 82. 
Nymphae, 790. INDEX 
823 
Obelion, 243. 
Obex, 596. 
Oblique, inguinal hernia, 385; radio-ulnar 
ligament, 156 ; vein of Marshall, 468. 
Obliquus, capitis, superior and inferior, 363; 
externus abdominis, 376 ; internus abdominis, 
377 ; oculi, superior and inferior, 335. 
Obliterated, ductus venosus, 731; hypogastric 
artery, 453 ; umbilical vein, 731. 
Obturator artery, 453; aberrant, 457. 
Obturator, externus muscle, 291; fascia, 393, 
394; foramen, 163; internus muscle, 290; 
internus, nerve to, 531; membrane, 186; 
nerve, 526; nerve, accessory, 527; veins, 482. 
Occipital, artery, 417 ; bone, 206 ; bone, ossifica- 
tion of, 247; condyles, 210; crest, internal 
and external, 208; fossae, inferior and superior, 
208; groove of temporal, 221; gyri, 626 ; lobe, 
626 ; nerves, great and smallest, 510; nerve, 
small, 511; probole, 208; protuberance, in- 
ternal, 20S ; sinus, 476 ; sulci, 626 ; veins, 470. 
Occipitalis muscle, 330. 
Occipito-axial ligament, long or posterior, 124. 
Occipito-atlantal ligaments, 125. 
Occipito-frontalis muscle, 330. 
Occipito-temporal sulci, 626. 
Oculo-motor nerve, 539, 595. 
Odontoblasts, 693, 694. 
Odontoid ligaments, lateral, 124; ligament, 
middle, 125; process, 112, 114. 
Oesophageal, arteries, 430; nerves, 558. 
Oesophagus, 709; development of, 736; lym- 
phatics of, 502. 
Olecranon, 143. 
Olfactory, bulb, 630; cells, 641. 
Olfactory lobe, definition, 621; description, 630; 
development, 637 ; nature, 595. 
Olfactory nerve, 537. 
Olfactory organ, 639 ; development of, 642 ; in 
fishes, 639. 
Olfactory, pit, 98; sulcus, 627; tract or peduncle, 
630, 641; tract, roots of, 630. 
Olivary, body, 595; eminence, 214; nucleus, 598. 
Olive, inferior, 598 ; superior, 598. 
Omenta, 688. 
Omentum, great or gastro-colic, 690; gastro- 
splenic, 690 ; small or gastro-hepatic, 690. 
Omo-hyoid muscle, 350 ; nerve to, 560. 
Omphalo-mesenteric, circulation, 494. 
One-horned uterus, 788. 
Opening, saphenous, 304. 
Opercula, of insula, 624 ; of tooth-sacs, 699. 
Ophryon, 243. 
#Opisthion, 243. 
Opisthotic, 249. 
Opponens, minimi digit! muscle, 283; pollicis 
muscle, 281. 
Optic, chiasma or commissure, 538, 593, 612; 
foramen, 214; nerve, 538 ; papilla, 656 ; pore, 
656, 658 ; recess, 610 ; thalamus, 609, 614 ; 
tract, 593, 612, 636; vesicle, primary, 90, 634, 
635, 636 ; vesicle, secondary, 666. 
Ophthalmic, artery, 421; nerve, 541; vein, 474. 
Ora serrata, 657. 
Orbicular, bone, 671; ligament of elbow, 155. 
Orbicularis, oris muscle, 333 ; palpebrarum 
muscle, 330. 
Orbiculus ciliaris, 652. 
Orbit, 239 ; fascia of, 335. 
Orbital, alae, 214, 216 ; arch, 213; canals, in- 
ternal, 212 ; gyri, 627 ; lobe, 627 ; nerve, 544 ; 
plate of ethmoid, 225; plate of sphenoid, in- 
ternal, 217 ; process of palatal, 230 ; wings, 
214, 216. 
Orbito-nasal angle, 241. 
Orbito-sphenoids, 248. 
Organ, of Corti, 680 ; of Giraldes, 797 ; of Golgi, 
44; of Jacobson, 99, 642, 702; of Rosen - 
miiller, 789. 
Organs, of common sensation, 78 ; digestive, 693 ; 
external sexual, development of, 798 ; female, 
783; male, 771; reproductive, 771; repro- 
ductive, development of, 794 ; respiratory, 
737; respiratory, development of, 752; of 
special sense, 638; urinary, 759. 
Origins of cranial nerves, superficial, 595. 
Orlando, fissure of, 625; substantia gelatinosa 
of, 587. 
Orthognathous skulls, 242. 
Os, acetabuli, 203; centrale, 146; calcis, 179; 
magnum, 146, 148 ; orbiculare, 671; planum, 
225 ; pubis, 162, 165 ; tincae, 787 ; trigonum, 
179 ; unguis, 233; uteri, 786. 
Ossa triquetra, 237. 
Osseous tissue, 23; lamination of, 26. 
Ossicle in connection with scaphoid, 146. 
Ossification, 31; of atlas, 131; of carpus, 202; 
from cartilage, 32; of clavicle, 201; of ethmoid 
bone, 249; of femur, 203; of fibula, 204; 
of frontal bone, 247; granular layer, 33; 
humerus, 202; of innominate bone, 203; of 
inferior turbinated bone, 250 ; of malar, 250; 
of mandible, 250; of maxillary bone, 249; 
from membrane, 31; of metacarpal bones, 
202 ; of metatarsal bones, 204 ; of nasal bones, 
250 ; of occipital bone, 247; of patella, 204; 
of palatal bone, 250; of parietal bone, 247; 
of phalanges of hand, 202; of phalanges of 
foot, 204 ; primitive areolae of, 35 ; of radius, 
202 ; of ribs, 132 ; of sacrum, 131; of scapula, 
201; of skull, 247; of sphenoid bone, 247; 
of sternum, 133; of styloid process, 249; of 
tarsus, 204; of temporal bone, 248; of tibia, 
204; of ulna, 202; of tympanic plate, 249; 
of vertebrae, 131; of vomer, 250. 
Ossifications, episternal, 121. 
Osteoblasts, 28. 
Osteoclasts, 29. 
Osteogenic fibres, 32. 
Ostium abdominale and uterinum tubae, 789. 
Otic, ganglion, 548; vesicle, 682. 
Otoconia, 678. 
Ova, 82; of amphioxus, 82; development, 784, 
794; holoblastic, 85; meroblastic, 85; par theno- 
genetic, 85 ; telolecithal, 83. 
Ovarian, artery, 451; veins, 481; lymphatics, 
500. 
Ovary, 783; development of, 97, 794. 
Over-extension of joints, 39. 
Oviduct, development of, 97, 
Ovigenous stratum, 784. 
Ovisac, 785. 
Ovuli Nabothi, 788. 
Ovum, cicatricula of, 83; cleavage or segment- 
ation, 82, 85; human, 785; impregnation of, 
85 ; maturation of. 83. 
Ovum-morula or mulberry mass, 86. 
Owen, adrenals, 758; anapophyses, 110; con- 
tour lines of dentine, 695 ; metapophyses, 111; 
pineal body, 611; rhinencephalon, 622. 
Oxyhaemoglobin, 10. 
Pacchionian corpuscles, 579; marks of, 211. 
Pacinian corpuscles, 70, 81; prostate, 779. 
Palatal bone, 229 ; ossification of, 250. 
Palatal spine, 229. 
Palate, actions of muscles of, 349; cleft, 249; 
development of, .99; muscles of, 347 ; nerve 
supply of muscles, 349 ; plate, 226, 229 ; rugae 
of, 702; soft, 701. 824 
INDEX. 
Palatine, artery, 416 ; artery, superior or de- 
scending, 419 ; canal, anterior, 227 ; posterior, 
228, 230 ; nerves, 546 ; vein, inferior, 471. 
Palato-glossns muscle, 348. 
Palato-pharyngeus muscle, 348. 
Palmae plicatae, 787. 
Palmar, aponeurosis, 286 ; arch, deep, 445; arch, 
superficial, 444; interosseous arteries, 445; 
interosseous muscles, 284 ; nerves, 520, 521. 
Palmaris, brevis muscle, 281; longus muscle, 
272. 
Palpebral, arteries, 422; nerves, 544 ; vein, 471. 
Pampiniform plexus, 481. 
Pancreas, 728; lymphatics of, 501. 
Pancreatic arteries, 448, 449. 
Pancreatico-duodenal artery, superior, 449; 
inferior, 450. 
Pansch, Rolandic gyri, 625. 
Papilla, lachrymalis, 643; optica, 656; spiralis, 
680. 
Papillae, of corium, 71; of kidney, 761; of 
tongue, 704. 
Paracentral lobule, 626. 
Parachordal cartilage, 245. 
Parathyroids, 757. 
Paraxial zone, 92. 
Parietal, bone, 211; bone, ossification of, 247; 
foramen, 211; gyrus, superior, 626; pleura, 
686. 
Parietes of embryo, 94. 
Parieto-occipital sulcus, 626. 
Parker, Kitchen, cranial bars, 246. 
Parker, W. N., primordial cranium, 245. 
Paroophoron, 789, 797. 
Parotid, gland, 706 ; lymphatic glands, 504. 
Parovarium, 789, 797. 
Pars, intermedia, 550; mastoidea, 221; mem- 
branacea, 403 ; petrosa, 222 ; retinalis iridis, 
653; socia parotidis, 707; squamosa, 219; 
triangularis of third frontal convolution, 625 ; 
uvealis iridis, 653. 
Parthenogenetic ova, 85. 
Patella, 272; ligaments, 191; ossification of, 
204. 
Patellar, plexus, 529; retinacula, 191; strip of 
femur, 172; surface of femur, 171. 
Paterson, origin of limb-muscles, 100. 
Pathetic nerve, 539. 
Pectineus, muscle, 295 ; nerve to, 527. 
Pectoral limb and arch, 133. 
Pectoralis, maior muscle, 258; minor muscle, 
259. 
Pedicles of vertebrae, 108. 
Peduncle, olfactory, 630. 
Peduncles of cerebellum, 597, 602. 
Pelvic, bone, 162 ; fascia, 392 ; fasciae, surgical 
anatomy, 396; limb, 162 ; lymphatics, 500; 
plexuses, 567. 
Pelvis, 167 ; articulations of, 184; false, 162 ; 
movements of, 186 ; sexual characters, 167; 
shape at different ages, 168. 
Pericardial, arteries, 432; connections of heart, 
409. 
Pericardium, 685; lymphatics of, 502; trans- 
verse sinus of, 409. 
Penis, 779; dorsal artery of, 454; dorsal nerve 
of, 532; dorsal vein of, 482; suspensory liga- 
ment of, 382. 
Peptic cells, 714. 
Perforated spot, anterior, 593; posterior, 594. 
Perforating, arteries of thigh, 460; fibres of 
Sharjjey, 29. 
Perichondrium, 21. 
Perimedullary lamination of bone, 26. 
Perimysium, 41. 
Perineal, artery, transverse, 454 ; body, 388 ; 
lymphatics, 500 ; nerve, 532. 
Perineum, actions of muscles, 392; central 
point, 388; nerve supply of muscles of, 392. 
Perineurium, 47. 
Periosteum, 24, 30. 
Peripheral, nerves, 46; lamination of bone, 26. 
Peritoneal, fossae suprapubic, 688; ligaments, 
688. 
Peritoneum, 688 ; smaller sac of, 689, 690 ; 
development of smaller sac, 737. 
Permanent, cartilage, 20; teeth, 696. 
Peroneal arteries, superficial, 454. 
Peroneal artery, 465 ; anterior, 465. 
Peroneal bone, 176. 
Peroneal nerve, 535 ; communicating, 535. 
Peroneus, brevis muscle, 306 ; longus muscle, 
306 ; tertius muscle, 311. 
Peroneo-tibial muscle of Gruber, 318. 
Pes, accessorius, 621; anserinus, 552; hippo- 
campi, 621. 
Petit, canal of, 664. 
Petrous, ganglion, 553 ; part of temporal, 222. 
Petrosal nerve, small deep, 554, 563. 
Petrosal nerves, great, 545; superficial, 551. 
Petrosal sinuses, 477. 
Peyer’s patches, 721. 
Phalanges, 133, 150, 183; of organ of Corti, 
681. 
Pharyngeal, artery, ascending, 415 ; tubercle, 
210; nerve, 556; nerves, sympathetic, 563; 
plexus, 554 ; recess of Rosenmiiller, 709 ; 
plexus venous, 471. 
Pharynx, 345, 709; constrictors of, 345, 346; 
nerve supply of constrictors and oesophagus, 
346 ; lymphatics of, 506 ; relations of, 345. 
Pneumogastric nerve, 555, 595. 
Phrenic arteries, inferior, 447. 
Phrenic, nerve, 513; plexuses, 566; veins, in- 
ferior, 481. 
Physiological anatomy, definition of, 1. 
Pia mater, 579. 
Pigment in hair, 76. 
Pigmented layer of retina, 655. 
Pillars, of fauces, 701; of fornix, 618. 
Pilo-motor nerve-fibres, 562. 
Pinna of ear, 667. 
Pineal body, 610. 
Pisiform, articulation, 159; bone, 145, 147. 
Pit, auditory, 98; olfactory, 98. 
Pituitary, body, 98, 594, 611 ; fossa, 214, 246. 
Pivot joint, 40. 
Placenta, 95, 103, 104. 
Placental circulation, ,495. 
Plane, mesial, use of term, 3. 
Plantar, aponeurosis, 327 ; artery, internal, 466; 
artery, external, 465; digital arteries, 466 ; 
interosseous muscles, 322 ; ligaments, 197 ; 
nerves, external and internal, 534. 
Plantaris, muscle, 314 ; nerve to, 533. 
Plasma, 8. 
Plate, ascending of palatal bone, 230 ; cribriform, 
225 ; dorsal, 92 ; internal orbital of sphenoid, 
217; lateral, 92; mesial or central, of eth- 
moid, 224; orbital of ethmoid, 225; palate, 
226, 229 ; tympanic, 223. 
Plates, middle, 96 ; muscle, 93; pterygoid, 218. 
Platysma myoides, 328. 
Pleurae, 686. 
Plexiform layer, internal of retina, 659; exter- 
nal of retina, 658. 
Plexus, choroid, 580, 592. 
Plexus, nervous, aortic, 567; brachial, 514; 
cardiac, 565; carotid, 563; cavernous, 563; 
cervical, 511; coccygeal, 536; coeliac, 566; INDEX, 
825 
coronary, 566; haemorrhoidal, 567; hypo- 
gastric, 567 ; lumbar; 524; mesenteric inferior, 
567 ; mesenteric superior, 566 ; myenteric of 
Auerbach, 723; patellar, 529; pelvic, 567; 
pharyngeal, 554; phrenic, 566; prostatic, 
567 ; pterygoid, 473 ; renal, 566 ; sacral, 530 ; 
solar or epigastric, 566; spermatic, 567; 
splenic, 566; submucous of Meissner, 723; 
subsartorial, 529; suprarenal, 566; uterine, 
567; vaginal, 567; vesical, 567. 
Plexus, venous, haemorrhoidal, 482, 483 ; pam- 
piniform, 481; pharyngeal, 471; prostatic, 482; 
sacral, anterior, 481; suboccipital, 470; vaginal, 
482; vesical, 482. 
Plica, frimbiata of tongue, 702; gubernatrix, 798 ; 
semilunaris, 644. 
Polar body, first, 84 ; second, 84. 
Polar rays, 7. 
Pole, ascending or apical, 628 ; of Deiters, 52. 
Poles, or nerve-corpuscles, 50; protoplasmic, 
52. 
Polymorphous nerve-corpuscles, 628. 
Polyhedral, epithelium, 56 ; strata of epidermis, 
73. 
Pomus Adami, 739, 753. 
Pons Yarolii, 596. 
Popliteal artery, 461; surgical anatomy of, 462. 
Popliteal, glands, 498; groove, 172; nerve, ex- 
ternal, 535; nerve, internal, 533; notch, 173; 
vein, 486. 
Popliteus muscle, 314; action of, 323; nerve 
to, 533. 
Pore, optic, 656, 658. 
Portal, canals, 733; fissure, 731; system, de- 
velopment of, 491; vein, 482. 
Portio, dura, 550 ; mollis, 552. 
Post-auricular depression, 221. 
Postcentral sulcus, 625. 
Posterior, 3; chamber of eye, 634; common 
ligament, 123 ; longitudinal bundle, 600, 613 ; 
perforated spot, 594; vesicular column of 
spinal cord, 587. 
Postglenoid tubercle, 220. 
Postpharyngeal gland, 505. 
Postsphenoid, 248. 
Poststomal arches, 98. 
Pouch, of Douglas, 692, 793 ; recto-vaginal, 692 ; 
recto-vesical, 692; Weber’s, 781. 
Poupart’s ligament, 164, 375, 376. 
Praecuneus, 626. 
Praeputium clitoridis, 790. 
Preangular gyrus, 626. 
Precentral sulcus, 625. 
Preformative membrane of tooth, 699. 
Prefrontal, 225. 
Pregnant uterus, 788. 
Prepuce, 781. 
Presphenoid, 247. 
Presternum, 120. 
Preurethral ligament of symphysis pubis, 185. 
Prickle cells, 73. 
Primary, cerebral vesicles, 90, 97, 634; lamina- 
tion of bone, 26; loop, intestine, 736; optic 
vesicle, 90, 634, 635; pale band, 627. 
Primitive, aortae, 101; cranium, 245; foramen 
of Monro, 636; ganglia, 568; groove, 87, 88; 
hearts, 100 ; intermuscular septa, 397; mouth, 
97; segments, 93; sheath, 48; streak, 87, 88. 
Princeps, hallucis arteria, 464 ; pollicis artery. 
443. 
Probole, occipital, 208. 
Process, articular, superior and inferior of ver- 
tebra, 108 ; accessory, vertebra, 110 ; alveolar, 
226, 234; angular, external, 212; angular, 
internal, 213; auditory, external, 219; basilar, 
206; clinoid, anterior and middle, 215; clinoid, 
posterior, 214; cochleariform, 224 ; coracoid, 
134, 137; coronoid, ulna, 144; coronoid, jaw, 
234; ensiform or xiphoid, 121; falciform, 
305 ; frontal or nasal, 226 ; fronto-nasal, 98 ; 
hamular, 218; hamular of lachrymal, 233; 
incus, inferior or long, 671; intermaxillary of 
vomer, 231; jugular, 206; malar, 226, 227; 
mammillary of vertebra, 110; mastoid, 221; 
nasal, middle, 98; nasal, lateral, 98 ; odontoid, 
112, 114; orbital, of palatal, 230; pterygoid, 
218; pyramidal of palatal, 229; pyramidal of 
thyroid body, 757 ; short, malleus, 671; short 
or posterior of incus, 671; slender, malleus, 
671; sphenoidal of palatal, 230; spinous of 
sphenoid, 217; spinous of vertebra, 108; 
styloid of radius, 142; styloid of temporal, 
223, 249 ; styloid of ulna, 145; supracondylar, 
140; transverse, 108; uncinate, 225; vaginal 
of sphenoid, 216; vaginal of temporal, 223; 
vermiform, superior and inferior, 603; zygo- 
matic, 220. 
Processes, ciliary, 652; turbinated, ethmoidal, 
225. 
Processus, gracilis, 671; muscularis arytenoideus, 
739; vocalis arytenoideus, 739; vaginalis, 797. 
Prochordal cartilage, 245. 
Prochorion, 102. 
Profunda artery, inferior, 438 ; superior, 437. 
Profunda femoris artery, 459. 
Prognathous dentition, 242 ; skulls, 242. 
Promontory, sacral, 115. 
Pronation, 140, 157. 
Pronator, quadratus muscle, 273; radii teres 
muscle, 270. 
Pronephros, 96. 
Pronucleus, female, 84; male, 85. 
Pro-otic, 249. 
Prosencephalon, 636. 
Proserial, use of term, 3. 
Prostate gland, 778. 
Prostatic, part of urethra, 781. 
Prostatic plexus, 567 ; venous, 482. 
Protoplasm, 5, 82 ; structure in, 6. 
Protoplasmic poles, 52. 
Protovertebrae, 92. 
Protuberance, external occipital, 208; internal 
occipital, 208 ; mental, 234. 
Proximal, ganglia, 561. 
Psoas, magnus muscle, 302; parvus muscle, 302. 
Pterion, 211, 243. 
Pterygo-maxillary ligament, 356. 
Pterygopalatine, artery, 420 ; canal, 216, 230 ; 
spinous ligament, 357. 
Pterygoid, arteries, 419; fossa, 218, 237; muscle, 
external, 343 ; muscle, external, nerve to, 547 ; 
muscle, internal, 343; muscle, internal, nerve 
to, 546 ; plates, 218; plexus, 473; process, 218. 
Pubes, 789. 
Pubic, arch, 167 ; arteries, 456; ligaments, inter- 
cristal, intercrural, intrapelvic, and preure- 
tinal, 185. 
Pubis, symphysis of, 185. 
Pubo-fern oral ligament, 188. 
Pudendal nerve, inferior, 531. 
Pudendum, 789. 
Pudic, arteries, superficial, 459; artery, 454; 
nerve, 531; veins, internal, 482. 
Pulmonary, artery, 409 ; nerves, 557 ; nerves, 
sympathetic, 564; pleura, 686; texture, 748; 
veins, 410. 
Pulp, of tooth, 693 ; of spleen, 754. 
Pulvinus of epiglottis, 740. 
Punctum lachrymale, 643-645. 
Pupil, 653; dilator, nerves of, 562. 826 
INDEX 
Purkinje, corpuscles of, 606 ; enamel-membrane, 
699; granular layer of tooth, 694. 
Prismatic ligament, 664. 
Putamen of nucleus lenticularis, 615. 
Pyloric, antrum, 711; artery, 448; glands, 714- 
716; valve, 710. 
Pylorus, 710. 
Pyramid, cerebellum, 604 ; of Ferrein, 764 ; 
tympanic wall, 670. 
Pyramidal, bone, 145,146; decussation, superior, 
597 ; nerve-corpuscles, 628 ; process of palatal, 
229; process of thyroid body, 757 ; tract, 
crossed, 585. 
Pyramidalis, muscle, 380; nasi muscle, 332. 
Pyramids, anterior, 595; posterior, 596 ; of 
Malpighi, 761. 
Pyriformis muscle, 290. 
Region, epigastric, 688 ; hypogastric, 688 ; um- 
bilical, 688. 
Regional anatomy, definition of, 2. 
Regions, abdominal, 688; hypochondriac, right 
and left, 688 ; iliac, right and left, 688 ; lum- 
bar, right and left, 688. 
Reichert, hyoid arch, 246 ; mantle and stem 
part of hemisphere, 610, 622 ; section of brain, 
592. 
Reid, R. W., cerebro-spiual fluid, 608. 
Reid, T., retinal cells behind iris, 657. 
Reil, island of, 593, 621, 624. 
Reissner, membrane of, cochlea, 679. 
Relations, of deep muscles of back, 364; of 
heart, 406; of infrahyoid muscles, 351; 
muscles of mastication, 343; suprahyoid 
muscles, 341. 
Remak, fibres of, 50; ganglia of, 712; proto- 
vertebrae, 93. 
Renal, arteries, 451; lymphatics, 500 ; plexuses, 
566; structure, 760; veins, 480. 
Reproductive organs, 771 ; development of, 
794. 
Respiration, 129 ; muscular action of, 373. 
Respiratory, nerve, external, 516 ; organs, 737 ; 
organs, development of, 752; tract of nose, 
640. 
Restiform body, 595. 
Rete, mirabile, 60; mucosum, 72; testis, 775. 
Reticular, cartilage, 23; formation, 597 ; layer 
of retina, 658; membrane of cochlea, 681; 
process, spinal cord, 586. 
Reticulated, stratum of cerium, 71; white sub- 
stance, 627. 
Retiform tissue, 16. 
Retina, 656 ; of birds, etc., coloured globules in, 
657 ; central artery of, 421; pigmented layer 
of, 655. 
Retinacula of patella, 191. 
Retrahens auriculam muscle, 330. 
Retroserial, use of term, 3. 
Retzius, Anders, skulls, 241, 242. 
Rhabdia, 43. 
Rhinal fissure of Turner, 622. 
Rhinencephalon, 621; of fishes, 622. 
Rhodopsin, 656. 
Rhomboid ligament, 134, 151. 
Rhomboidei, nerves to, 515. 
Rhomboideus, major muscle, 255; minor muscle, 
255. 
Ribs, 117; development of, 130; first, second, 
tenth, eleventh and twelfth, 119; movements 
of, 128; ossification of, 132; rudimentary, 
107. 
Ridge, alveolar, 234; mylo-hyoid, 235; super- 
ciliary, 212; temporal, 211, 213; temporo- 
zygomatic, 218; trapezoid, 134. 
Ridges, intertrochanteric, 170; supracondylar, 
139. 
Rima glottidis, 742. 
Ring, abdominal, deep, 384; abdominal, ex- 
ternal, 376; vertebral, 108. 
Rings of trachea, 746. 
Risorius muscle of Santorini, 333. 
Rivini, duct of, 709; notch of, 670, 673. 
Robin, myeloplaxes,' 29. 
Rods, of retina, 657 ; of Corti, 680. 
Rods and cones of retina, action of, 658. 
Rolandic gyri, 625. 
Rolando, fissure of, 625; gelatinous substance 
of, 587; tubercle of, 597. 
Rolling of articular surfaces, 39. 
Rontgen rays, 801. 
Roof of fourth ventricle, 607. 
Root, of hair, 75; of lung, 747. 
Quadrangular lobes of cerebellum, 603. 
Quadrate, cells of Ranvier, 17; lobe of liver, 
732 ; lobule of brain, 626. 
Quadratus, femoris muscle, 291; femoris, nerve 
to, 531; lumborum muscle, 379; menti muscle, 
333. 
Quadriceps, extensor cruris muscle, 297 ; nerve 
to, 527. 
Racemose glands, 57. 
Racial, characters of pelvis, 168 ; characters of 
skull, 241. 
Radial, artery, 441; nerve, 522; vein, super- 
ficial, 484. 
Radialis indicis artery, 443. 
Radiate ligament, 126. 
Radio-carpal articulation, 158. 
Radio-ulnar articulations, 155, 156. 
Radius, 133, 140, 141; ossification, 202. 
Rami communicantes, sympathetico-spinales, 
561; hypoglossi, 513. 
Rami ossis pubis, 166. 
Ramus, cervicalis princeps artery, 417 ; of 
ischium, 165; of mandible, 234. 
Ranine, artery, 415; vein, 470. 
Ranvier, nodes of, 49 ; quadrate cells of, 17 ; 
regeneration of nerves, 54. 
Raphe, of corpus callosum, 616; of pons and 
medulla, 599; of scrotum, 771; of tongue, 
704. 
Rathke, branchial arches, 491. 
Rauber’s layer, 88. 
Receptaculum chyli, 497. 
Recess, lateral, 600; optic, 610; pineal, 611. 
Recessus, cochleae, 676 ; pharyngeus, 675. 
Rectal glands, 499. 
Recti oculi muscles, 334. 
Recto-vaginal pouch, 692. 
Recto-vesical, fascia, 393 ; pouch, 692. 
Rectum, 723, 727 ; ligament of, 394. 
Rectus, abdominis muscle, 380; capitis anticus 
minor muscle, 354; capitis lateralis muscle, 
355; capitis posticus major muscle, 362; 
capitis posticus minor muscle, 362; capitis 
anticus major muscle, 354; femoris muscle, 
299 ; femoris, nerve to, 527. 
Recurrent artery, posterior interosseous, 441; 
arteries, posterior ulnar, 440; radial artery, 
442 ; tibial arteries, 462, 463. 
Red blood-corpuscles, 9. 
Red marrow, 30. 
Red nucleus, 614. 
Reflected tendon of A. Cooper, 379. 
Reflection, in rods and cones, 658 ; by tapetum, 
651. 
Regeneration, of muscular fibre, 46; of nerves, 
54. INDEX. 
827 
Boots, of nerves, 507, 508; of olfactory tract, 
630; of spinal nerves, 582; of teeth, 693; of 
zygomatic process, 220, 221. 
Rorie, olfactory tracts, 631. 
Rosenmiiller, body of, 789; fossa of, 675, 709. 
Rosette stage of mitosis, 7. 
Rostrum of corpus callosum, 616; of sphenoid, 
216. 
Rotation of joints, 39. 
Rotatores dorsi muscles, 362. 
Rotula, 172. 
Round ligament of, hip-joint, 186; liver, 689; 
ovary, 783 ; uterus, 787. 
Rudimentary branchial sense-organs, 570 
Rudimentary ribs, 107. 
Rugae, of palate, 702; of stomach, 713; vagina, 
793. 
Ruminant placenta, 103. 
Russac’s space, 673. 
Ruysch, diverticulum, 719; epithelium, 55; 
membrane of, 651. 
Ryndowsky, lymphatics of kidney, 765. 
Schafer, Haversian canals, 30; olfactory lobe, 
621; red corpuscles in marrow, 12; transi- 
tional epithelium, 55. 
Schindylesis, 40. 
Schlemm, canal of, 655. 
Schlocker, fronto-squamous suture, 237. 
Schneider, proliferation of epidermal cells, 73. 
Schneiderian membrane, 640. 
Schultze, Max, grooves on rods and cones, 657; 
olfactory tract, 641. 
Schwalbe, canal of Cloquet, 662; glomeruli 
arteriosi, 682; olfactory lobe, 621; organ of 
Corti, 680; taste-buds, 705; tuber olfac- 
torium, 631. 
Schwann, on the cell, 5 ; primitive sheath of, 48; 
white substance of, 49. 
Schweiger-Seidel, kidney, 764. 
Sciatic, artery, 453; nerves, great, 532; nerve, 
small, 531; notch, great, 164 ; notch, small, 
165; veins, 482. 
Sclerotic, 647. 
Scotch skulls, 242. 
Scrotum, 771. 
Sebaceous glands, 74. 
Second polar body, 84. 
Secondary enamel-germ, 699 ; ganglia, 561; 
optic vesicle, 666. 
Secreting glands, 57 ; surfaces, 57. 
Sections, 2. 
Segmental, nerves, 573; tubules, 96. 
Segmentation, of ovum, 85. 
Segments, 1; of embryo, 92; primitive, 93. 
Sella turcica, 214. 
Semicircular canals, 219, 676. 
Semilunar, bone, 146 ; fascia, 263; fibro-plates 
of knee-joint, 191; ganglion, 566; lobes, 
cerebellum, 603. 
Semimembranosus muscle, 41, 294. 
Seminal tubules, 773. 
Semispinalis muscle, 361. 
Semitendinosus muscle, 41, 293. 
Sensation, organs of common, 78. 
Septa, intermuscular, of arm, 270; primitive, 
397 ; sole, 327 ; of thigh, 304. 
Septal cartilage, 639, 
Septula of kidney, 761, 764. 
Septum, corpora cavernosa, 780; crurale, 384; 
of glans, 781; interarticular, 126; inter- 
auricular, 402; interventricular, 403; lucidura, 
617 ; posticum, 580 ; sphenoidale, 216 ; spinal 
cord, posterior of, 582. 
Series of teeth, 700. 
Serous, glands, 58; membranes, 69; pericar- 
dium, 685. 
Serrated sutures, 38. 
Serrations of lens-fibres, 663. 
Serratus, anticus muscle, 256; magnus muscle, 
256; posticus inferior muscle, 371; posticus 
superior muscle, 371. 
Serum, 8. 
Sesamoid bones of thumb, 150. 
Sexual, characters of skull, 241; characters of 
pelvis, 167. 
Sexual organs, external, development of, 798. 
Shaft, of femur, 170 ; of fibula, 177; of hairs, 
75 ; of humerus, 137; of radius, 141; of tibia, 
175 ; of ulna, 144. 
Shafts, of metacarpal bones, 149; of ribs, 118. 
Sharpey, epithelium, 55; lamination and 
fibrillation of dentine, 695 ; perforating fibres 
of, 29 ; proliferation of epidermal cells, 73. 
Sheath, of hair, 77 ; of Henle, 47 ; primitive, of 
Schwann, 48 ; of rectus, 380. 
Sheaths, synovial, 36, 253; of extensor tendons 
of hand, 280 ; of flexors of fingers, 275. 
Sac of great omentum, or smaller of peritoneum, 
GB9, 690; development, 737. 
Sac, lachrymal, 646. 
Sacs, synovial, 69 ; of teeth, 699. 
Saccule, of labyrinth, 677; of larynx, 742. 
Saccular membranes, 68. 
Sacculus endolymphaticus, 677. 
Sacral, artery, lateral, 455 ; artery, middle, 448; 
glands, 499; plexus, 530; plexus venous, an- 
terior, 481; nerve, fourth, 536; nerves, pos- 
terior divisions, 510 ; sympathetic, 565; vein, 
middle, 481. 
Sacro-coccygeal ligaments, 124. 
Sacro-iliac articulation 184. 
Sacro-iliac ligaments, 184. 
Sacro-iliac ligament, terminal, 185. 
Sacro-lumbalis muscle, 360. 
Sacro-sciatic ligaments, 185. 
Sacrum, 114 ; auricular surface of, 116 ; ossifica- 
tion of, 131. 
Sagitta, 86. 
Sagittal, use of term, 3 ; fontanelle, 247 ; suture, 
211. 
Salensky, hyoid arch, 247. 
Salivary, ducts, intercalary, 706; glands, 706. 
Salpingo-pharyngeus muscle, 348. 
Salpinx, 675, 789. 
Salter, incremental lines of, 695. 
Santorini, cartilages of, 739 ; fissures of, 668; 
risorius muscle of, 333. 
Saphenous, nerve, internal, 528; nerve, short or 
external, 533; opening, 304; vein, internal, 
486; vein, external, 485. 
Sarcoglia, 43. 
Sarcolemma, 42, 43. 
Sarcomeres, 43. 
Sarcoplasma, 43. 
Sarcous elements of Bowman, 43. 
Sartorius, muscle, 297 ; nerve to, 527. 
Scala, tympani, 679; vestibuli, 679. 
Scalenus, anticus muscle, 353; medius muscle, 
353; medius, nerve to, 513; posticus muscle, 
354. 
Scaly sutures, 38. 
Scaphoid, bone, 146, 180; fossa, 218. 
Scaphocephalus, 243. 
Scapula, 134; ligaments of, 152; ossification, 
201. 
Scapular artery, posterior, 4 31. 
Scarfskin, 72. 
Scarpa, fascia of, 382; foramina of, 227; triangle 
of, 294. 828 
INDEX 
Sherrington, cerebro-spinal fluid, 608; white 
blood-corpuscles, 11. 
Shield, bird’s embryo, 88. 
Shin-bone, 173. 
Short, plantar ligament, 197; subscapular 
nerve, 521. 
Shoulder-blade, 134. 
Shoulder, fascia of, 269. 
Shoulder-girdle, 133, 150; movements of, 152. 
Shoulder-joint, 152 ; movements of, 154. 
Shrapnell, membrana flaccida of, 674. 
Sickle of bird’s embryo, 87. 
Sigmoid, artery, 450; cavities, 143; cavity, 
great of ulna, 143; cavity, small of ulna, 
143 ; flexure, 727 ; notch, 234. 
Simple epithelia, 54. 
Sinus, of aorta, great, 410; cavernous, 476; 
circular, 477; circularis iridis, 655; coronary, 
402, 468 ; frontal, 212 ;of kidney, 761; lateral, 
476; maxillary, 228; occipital, 476; of peri- 
cardium transverse, 409, 685; pocularis, 781; 
pocularis, development, 795 ; spheno-parietal, 
477 ; sphenoidal, 216 ; straight, 475 ; termin- 
alis, 101; uro-genital, 771; venosus, 487. 
Sinuses, longitudinal, inferior and superior, 475 ; 
petrosal, 477 ; of Yalsalva, 403, 406 ; venous of 
cranium, 475. 
Sixth cranial nerve, 595. 
Size of heart, 409. 
Skeleton, the, 105 ; appendicular, 105 ; articula- 
tions of, 36; axial, 105; balance of, 129; 
development of trunk, 130; articulations of 
atlas and axis, 124. 
Skin, 70. 
Skull, 204 ; development, of, 245 ; at different 
ages, 241; distinctive characters of human, 
240 ; fossae of, 237 ; ossification of, 247 ; racial 
characters, 241; sexual characters, 241; shape 
of, 240; tables of, 206; variations, 240. 
Skulls, brachycephalic, 241; dolichocephalic, 241; 
individual peculiarities, 243; mesocephalic, 
242 ; orthognathous, 242 ; prognathous, 242. 
Small, curvature of stomach, 711; cutaneous 
nerve, internal, 517 ; petrosal nerves, 551, 554, 
563; occipital nerve, 511; omentum, 690; 
sciatic nerve, 531; splanchnic nerve, 564. 
Small intestine, 717 ; closed follicles of, 721; 
glands of, 721; mucous membrane, 722; 
nerves of, 723. 
Smaller sac of peritoneum, 689, 690. 
Smallest occipital nerve, 510. 
Sobotta, polar bodies, 85. 
Soemmerring, basilar bone, 206 ; cranial nerves, 
537 ; yellow spot of, 660. 
Soft palate, 701. 
Solar plexus, 566. 
Sole, muscular layers of, 318. 
Soleus muscle, 313. 
Solitary glands, 721, 724. 
Solly, arciform fibres of, 600. 
Somatic nerve-trunks, 573. 
Somatomes, 1. 
Somatopleure, 92. 
Somites, mesoblastic, 87, 92, 397. 
Space, arachnoid or subdural, 577; costo-phre- 
nic, 686 ; Russac’s, 673 ; sub-arachnoid, 578. 
Spaces, absorption, 27 ; of Fontana, 655 ; Haver- 
sian, 27 ; interglobular of tooth, 695. 
Special sense, organs of, 638. 
Spermatic, artery, 451; cord, 771; fascia, 377 ; 
plexus, 567 ; veins, 481. 
Spermatoblasts, 774. 
Spermatozoa, 82, 774. 
Spheno-maxillary fissure, 218 ; fossa, 218, 237 ; 
ligament, 356. 
Spheno-palatine, artery, 419; foramen, 216, 230; 
ganglion, 545 ; nerve, 544; notch, 230. 
Spheno-parietal sinus, 477. 
Sphenoid bone, 213 ; ossification of, 247. 
Sphenoidal, alae or wings, 214 ; crest, 216 ; 
fissure, 217 ; process of palatal, 230; septum, 
216 ; sinus, 216 ; turbinated bones, 216. 
Spheroidal epithelial cells, 56. 
Sphincter ani muscle, external, 389 ; internal, 
728. 
Sphincter, iridis, 653 ; vaginae muscle, 391. 
Spigelius, lobe or lobule of, 690, 732. 
Spinal accessory nerve, 558, 595. 
Spinal arteries, 429. 
Spinal cord, 580 ; central canal of, 582 ; columns 
of, 584; commissures of, 582; cornua of, 583, 
586 ; development of, 633 ; enlargements of, 
580; fissures of, 582; lymphatics of, 505; 
posterior vesicular columns of, 587; nerve- 
roots in, 587-590; reticular process, 586 ; 
septum, posterior of, 582 ; tracts of, 584. 
Spinal, ganglia, 53, 582; nerves, 507 ; nerves, 
roots of, 582 ; veins, 478. 
Spinalis dorsi muscle, 360. 
Spindle, 7. 
Spine, the, 108 ; adductor of femur, 171; eth- 
moidal, of sphenoid, 216 ; of ischium, 165 ; 
nasal, 227; nasal, of frontal bone, 212; pala- 
tal, 229; of pubis, 166; of scapula, 134, 136 ; 
of tibia, 173. 
Spines of ilium, 164. 
Spinous of vertebra, process, 108; of sphenoid, 
217. 
Spiral canal of lamina spiralis, 679. 
Spiral, ganglion, 682; lamina, 679; ligament, 
680; line of femur, 170 ; papilla, 680 ; tubes, 
kidney, 764. 
Splanchnic nerves, 564 ; nerve-trunks, 573. 
Splanchnopleure, 92, 94. 
Spleen, 754 ; lymphatics of, 501. 
Splenic, artery, 449 ; flexure, 726 ; glands, 500 ; 
plexus, 566 ; veins, 483. 
Splenium, 617. 
Splenius muscle, 358. 
Spleno-phrenic ligament, 690. 
Spongioblasts, 633 ; of retina, 659. 
Spongioplasm, 6. 
Spongy, bone, inferior, 233; bones, ethmoidal, 
225 ; part of urethra, 782. 
Spot, anterior perforated, 594 ; posterior per- 
forated, 593 ; germinal, 82, 785. 
Sprains, 17. 
Squamous, epithelium, 54; epithelium, strati- 
fied, 55 ; part of temporal, 219 ; suture, 211, 
220 ; sutures, 38. 
Staining, 2. 
Stapedius, muscle, 672; nerve to, 551. 
Stapes, 671; development of, 247. 
Stars of Yerheyen, 765. 
Steep base of skull, 241. 
Stellate ligament, 126. 
Stenson’s duct, 333, 701, 706. 
Stenson, foramina of, 227. 
Stephanion, 243. 
Stem-part of hemispheres, 621. 
Sternal, arteries, 432 ; glands, 501; ribs, 118. 
Sternalis muscle, 259. 
Sterno-clavicular articulation, 150. 
Sterno-cleido-mastoid muscle, 351. 
Sterno-hyoid muscle, 350. 
Sterno-mastoid, artery, 415 ; muscle, 351; nerve 
to, 513. 
Sterno-thyroid muscle, 350. 
Sternum, 120; development of, 130; ossification 
of, 133. INDEX 
829 
Stilling, canal of Cloquet, 662; nuclei of cere- 
bellum, 605. 
Stohr, red corpuscles within leucocytes, 754; 
the tonsils, 68. 
Stomach, 710 ; development of, 736 ; veins of, 
483. 
Stomata of lymphatics, 66. 
Stomodaeum, 97. 
Straight, sinus, 475 ; veins of kidney, 765. 
Stratified, epithelia, 54 ; squamous epithelium, 
55. 
Stratum, dorsale of Forel, 613; laciniosum, 630 ; 
lucidum, 73; granulosum, 73, 630; radiatum, 
630; zonule, 614. 
Stria terminalis, 610. 
Striae, acousticae, 600; of pineal body, 611. 
Striated or striped muscle, 40, 42. 
Striped muscle, development of, 45. 
Stroma of blood discs, 9. 
Structure, of bladder, 770 ; of cerebellum, 605; of 
cerebral convolutions, 627; of root of cerebrum, 
613 ; hepatic, 733; of kidney, 760; of lung, 
748; of prostate, 778; of testis, 773; of 
ureter, 767 ; of uterus, 787. 
Stuart, Anderson, epiglottis, 740. 
Stylo-glossus, muscle, 340 ; nerve to, 560. 
Stylo-hyoid, muscle, 339; nerve to, 551. 
Stylo-hyoideus alter muscle, 339. 
Stylo-mastoid, artery, 417 ; foramen, 223. 
Stylo-maxillary ligament, 245, 356. 
Stylo-pharyngeus, muscle, 341; nerve to, 555. 
Styloid process, radius, 142 ; of fibula, 176; of 
temporal, 223; of temporal, ossification of, 249. 
Subanconeus muscle, 267. 
Subarachnoid space, 578. 
Subclavian artery, 427 ; surgical anatomy of, 
433. 
Subclavian vein, 471. 
Subclavius, muscle, 259; nerve to, 516. 
Subcostal groove, 118. 
Subcutaneous areolar tissue, 70. 
Subdural space, 577. 
Sublingual, artery, 415 ; gland, 70S. 
Sublobular veins, 733. 
Submaxillar}-, ganglion, 548 ; gland, 707 ; gland, 
arteries to, 416; lymphatic glands, 504. 
Submental, artery, 416; vein, 471. 
Subnasal depression, 242. 
Suboccipital, nerve, 507 ; plexus venous, 470. 
Subpedunculated lobe, 604. 
Subpubie, arch, 167; fascia, 395. 
Subreticular cells of retina, 659. 
Subsartorial plexus, 529. 
Subscapular, artery, 431, 435; fossa, 135; nerves, 
521. 
Subscapularis muscle, 261. 
Substance, elastic, 14; gelatiniferous, 13; ner- 
vous, white and grey, 47 ; white of Schwann, 
49. 
Substantia, gelatinosa of Orlando, 587; nigra, 
613. 
Sudoriparous glands, 74. 
Sulci, collateral, 626; of hemispheres, 623; 
occipital, 626; occipito temporal, 626; tem- 
poral, 626. 
Sulcus, anterior limiting, 94; auriculo-ventriculo, 
400; calcarine and anterior calcarine, 626; 
calloso-marginal, 626; centralis, 625 ; circu- 
laris, 624 ; frontal, superior and inferior, 625; 
hippocampi, 627; interventricular, 400; limi- 
tans, 624; olfactory, 627; parieto-occipital, 
626 ; precentral, 625; postcentral, 625; sclerae, 
652 ; terminalis, 402, 488. 
Summit of bladder, 768. 
Supination, 140, 157- 
Supinator, brevis muscle, 279; longus muscle, 
275. 
Superciliary ridge, 212. 
Superficial, cervical artery, 431; cervical nerve,. 
512 ; fascia, 70, 252 ; lymphatics, lower limb, 
498; lymphatics, upper limb, 503; veins of 
lower limb, 485 ; veins of upper limb, 484. 
Superior, use of term, 3; maxillary bone, 226; 
meatus, nasal, 238. 
Supernumerary mammae, 800. 
Supraacromial nerves, 512. 
Supraclavicular nerves, 512. 
Supracondylar, lines, 170; process, 140; ridges,. 
139. 
Supracostal groove, 118. 
Suprahyoid muscles, 338; actions, 340, 341; 
nerve supply, 340, 341; relations of, 341. 
Supramarginal gyrus, 626. 
Supramastoid crest, 221. 
Supraorbital, artery, 421; nerve, 541; notch,. 
213; vein, 470. 
Suprarenal, arteries, 451; arteries, superior,. 
447 ; capsules, 758 ; plexuses, 566 ; veins, 481. 
Suprarenals, development of, 759. 
Suprascapular, artery, 431; ligament, 152 ; 
nerve, 516 ; notch, 135 ; vein, 472. 
Supraspinatus muscle, 261. 
Supraspinous, fossa, 135; ligament, 123. 
Suprasternal nerve, 512. 
Supratrochlear nerve, 541. 
Surface-lobes of cerebrum, 593. 
Surgical anatomy, abdominal arteries, 457; 
arteries of forearm, 444 ; arteries of leg, 467 ; 
axillary artery, 436; brachial artery, 439; 
common carotid artery and branches, 425, 426 ; 
external carotid, 426; facial artery, 426; 
femoral artery, 460 ; fifth nerve, 549 ; internal 
carotid, 426; lingual artery, 426; pelvic fas- 
ciae, 396; popliteal artery, 462; subclavian 
artery, 433. 
Surgical neck of humerus, 137. 
Suspensory ligament of axis, 125; of lens, 664; 
of liver, 689, 731; of ovary, 783; of penis,. 
382. 
Sustentaculum tali, 179. 
Sutton, lingula of sphenoid, 248. 
Sutural bones, 237. 
Suture, coronal, 211; frontal, 212; lambdoidal,, 
211; sagittal, 211; squamous, 211, 220. 
Sutures, 38 ; harmonia, 38 ; scaly or squamous,, 
38 ; serrated, 38. 
Sweat, ducts, 72; glands, 72, 74. 
Sylvian veins, 473, 474. 
Sylvius, aqueduct of, 602,609; fissure of, 593,623.. 
Syme, falls on pelvis, 781. 
Sympathetic, afferent nerves of, 562; cervical, 
562 ; development of, 569 ; ganglia, 53 ; lum- 
bar, 565; nerves, 566 ; sacral, 565 ; thoracic, 
564. 
Symphysis, of lower jaw, 40, 234; pubis, 40, 
163, 185. 
Sjmarthrosis, 39. 
Synchondrosis, 40. 
Synostosis, of bones, 35 ; cranial, 243. 
Synovial, cavity, 36 ; fluid, 36 ; membrane, 36 ; 
sacs, 69 ; sheaths, 36, 253 ; sheaths of extensor- 
tendons of hand, 280; sheaths of flexors of 
fingers, 275 ; villi, 37. 
Syntonin, 42. 
Systematic anatomy, 105 ; definition of, 2. 
Tables of skull, 206. 
Taenia, hippocampi, 618 ; semicircularis, 610. 
Taeniae of colon, 723. 
Talipes, 325. INDEX 
Talus, 177. 
Tapetum, 651. 
Tarsal, artery, 463; articulations, 195; liga- 
ments, 330; plates, 643. 
Tarsi, 643. 
Tarso-metatarsal articulations, 195. 
Tarsus, 177 ; ossification of, 204. 
Tartar skulls, 241. 
Tartuferi, ending of rod-fibres, 659. 
Taste-buds, 704. 
Teeth, 693; bicuspid, 697; cavities of reserve, 
699 ; canine, 697 ; crown, 693 ; cusps, 693 ; 
development of, 698; eruption of, 700; eye, 
697; fangs, 693; false molar, 697; incisor, 
696 ; milk, 698 ; molar, 697 ; necks, 693 ; per- 
manent, 696 ; pulp cavity, 693 ; roots, 693 ; 
temporary, 698 ; transverse series of, 700. 
Tegmen tympani, 222, 670. 
Tegmentum, 613. 
Teloleoithal ova, 83. 
Temporal, artery, 417; artery, anterior, 418; 
artery, deep, 419 ; artery, middle, 418; artery, 
posterior, 418 ; bone, 218 ; bone, ossification 
of, 248 ; canal of malar, 233 ; fascia, 344 ; 
fossa, 237; gyri, 626; muscle, 342 ; nerves, 
deejj, 547 ; ridge, 211, 213 ; sulci, 626 ; vein, 
472. 
Temporary, cartilage, 20; teeth, 698. 
Temporo-malar nerve, 544. 
Temporo-maxillary, articulation, 244; ligaments, 
244; vein, 471, 472. 
Temporo-zygomatic ridge, 218. 
Tendo Achillis or calcaneus, 313, 314. 
Tendon, 16, 17; central or trefoil, 367; con- 
joined, 379; nerves of, 18, 44; reflected, of 
Cooper, 379. 
Tenon, capsule of, 336. 
Tensor, fascia latae muscle, 290; palati muscle, 
348; palati, nerve to, 549; tarsi muscle, 331; 
tympani muscle, 672; tympani, nerve to, 549 ; 
vaginae femoris muscle, 290. 
Tentorium cerebelli, 577. 
Teres, major muscle, 262 ; minor muscle, 262. 
Terminal, baskets of Kolliker, 606; sacro-iliac 
ligament, 185. 
Terms, descriptive, 3. 
Testes, brain, 609; muliebres, 786. 
Testicles, 772; descent of, 797; development 
of, 97, 795 ; lymphatics, 500; structure of, 
773. 
Testut, ossification of frontal bone, 247. 
Thalamencephalon, 592; development of, 637. 
Thalami optici, 609, 614. 
Thebesius, foramina of, 402; valve of, 402. 
Thecae, 36, 69. 
Thenar eminence, 281. 
Theories of polar bodies, 84. 
Theory of mesoblast, Hertwig’s, 89. 
Thomson, Allen, glands of oesophageal orifice 
of stomach, 716; epithelium, 55; estimation 
of cranial capacity, 243. 
Thigh, perforating arteries of, 460. 
Third, eyelid, 644; lobe of prostate, 678 ; occi- 
pital nerve, 510; primary cerebral vesicle, 
compartments of, 635 ; ventricle of brain, 620 ; 
ventricle, commissures and floor of, 610. 
Thoracic, artery, long, 435; duct, 497; joints, 
anterior, 126; lymphatics, 502 ; mediastina, 
684, 686 ; nerve, posterior, 516 ; nerves, 523 ; 
nerves, anterior, 516; nerves, posterior 
division, 510; sympathetic, 564; vertebrae, 
107, 108, 109. 
Thorax, 121; actions of muscles of, 372; 
articulations of, 125. 
Throat, 709. 
Thymus, 755; development of, 99, 757. 
Thyreo-glossal duct, 99, 704, 757. 
Thyro-arytenoid, ligaments, 741; muscle, 743. 
Thyro-epiglottidean muscle, 744. 
Thyro-hyoid, ligaments, 740; membrane, 741; 
muscle, 350; nerve to, 560. 
Thyroid artery, inferior, 430, 483; superior, 
415. 
Thyroid body, 756; development of, 99, 757; 
lymphatics of, 506. 
Thyroid, axis, 430; cartilage, 739; foramen, 
163; veins, 470. 
Thyroidea ima, 413. 
Tibia, 173; ossification of, 204. 
Tibial arteries, recurrent, 463. 
Tibial artery, anterior, 462 ; posterior, 464. 
Tibial nerve, 533; anterior, 536; communicating, 
533; posterior, 533. 
Tibialis, anticus muscle, 309; posticus muscle, 
315. 
Tibio-fibular, articulations, 194 ; ligaments, 194. 
Tiedemann, olfactory lobe, 637. 
Tissue, adenoid, 16; adipose, 18; areolar, 16 ; 
connective, 13; connective, varieties of, 16; 
erectile, 780 ; lymphoid, 16 ; of muscles, 251; 
osseous, 23; retiform, 16; subcutaneous 
areolar, 70; white fibrous, 13, 16. 
Tissues, the connective or binding, 13. 
Titian, anatomical plates, 163. 
Toldt, on caecum, 726 ; glands of Bowman, 641; 
muscularity of ureters, 767; oesophageal wall, 
710; tubuli seminiferi, 774; vasa aberrantia 
of liver, 735. 
Tongue, 702 ; development of, 99 ; dorsal artery 
of, 415; lymphatics of, 506. 
Tonsils, 701, 706. 
Tonsillar artery, 416. 
Tooth, cement, 696; crusta petrosa, 693, 696; 
dentine, 693, 694 ; enamel, 693, 695 ; follicles 
of, 698 ; granular layer of, 694; interglobular 
spaces of, 695 ; pulp, 693; sacs, 699. 
Topographical anatomy, definition of, 2. 
Torcular Herophili, 476. 
Touch-cells, 79. 
Touch-corpuscles, 79; of Grandry or Merkel, 
79 ; of Wagner or Meissner, 79. 
Trabeculae, cranii, 245; of lymphatic glands, 
67 ; of spleen, 754. 
Trachea, 745. 
Tracheal arteries, 439. 
Trachelo-mastoid muscle, 360. 
Tract, of Burdach, 585 ; cerebellar, of Flechsig, 
585; direct cortical, of Guddeu, 612; direct 
pyramidal, 584; of Goll, 600; of Gowers, 
585 ; intermedio-lateral, 586 ; of Lowenthal, 
585; of Marchi, tract of, 585 ; marginal, of 
Lissauer, 585 ; olfactory, 630, 641; optic, 593, 
612 ; pyramidal, crossed, 585. 
Tracts, cerebellar, 585 ; of spinal cord, 584. 
Tragus, 668. 
Transitory fissures of hemispheres, 638. 
Transitional epithelium, 55. 
Transparent structures within eyeball, 661. 
Transversalis, abdominis muscle, 378 ; cervicis 
or colli muscle, 360; fascia, 374, 383. 
Transverse, aorta, 411 ; arteries, 430 ; cervical 
artery, 431; cervical vein, 472; colon, 726; 
fissure of brain, 619 ; fissure of liver, 731; 
ligament of ankle-joint, 194; ligament of 
atlas, 124 ; superficial ligament of hand, 287 ; 
ligament of hip-joint, 186 ; ligament of knee- 
joint, 192 ; mesocolon, 691; metatarsal liga" 
ment, 197 ; muscles of tongue, 703 ; peroneal 
artery, 454; processes, 108; sinus of peri- 
cardium, 409, 685. INDEX 
831 
Transversus, pedis muscle, 321; perinaei muscle, 
deep, 392; perinaei muscle, superficial, 390 ; 
thoracis muscle, 370. 
Trapezium, 146, 147. 
Trapezius muscle, 253 ; action of, 268 ; nerve to, 
513. 
Trapezoid, bone, 146, 148; ligament, 152 ; ridge, 
134. 
Trefoil tendon, 367. 
Treves, on caecum, 726. 
Triangle, auscultatory, 255; of Hesselbach, 
387 ; Scarpa’s, 294. 
Triangles of neck, anterior and posterior, 352. 
Triangular, bone of Bertin, 216; cartilages of 
nose, 639; fascia, 377 ; fibro-plate, 156; liga- 
ment, 395 ; ligaments of liver, 689, 731. 
Triangularis, menti muscle, 333; sterni muscle, 
370. 
Triceps brachii muscle, 265. 
Tricuspid valve, 404. 
Treitz, ligament of, 717. 
Trifacial nerve, 540. 
Trigeminal nerve, 540, 595. 
Trigone of bladder, 769. 
Trigonocephalus, 243. 
Triquetrous bones, 237. 
Triradiate sulcus, 627. 
Triton, mesoblast in, 89. 
Trochanter, great, 168 ; small, 170. 
Trochanteric, or digital fossa, 170. 
Trochlea of humerus, 139. 
Trochlear muscle, 335; nerve, 539. 
True, ligaments of bladder, 768; pelvis, 162; 
ribs, 118. 
Truncus arteriosus, 101. 
Trunk, axial skeleton of, 105 ; development of 
skeleton of, 130. 
Tube, cardiac, 100; Eustachian, 674, 709 ; Fal- 
lopian, 789. 
Tuber, cinereum, 594; olfactorium, 631; vermis, 
603. 
Tubercle, atlas, anterior and posterior, 113 ; 
of calcaneum, outer and inner, 180 ; conoid, 
134; of head of scapula, 137 ; helix, 668 ; 
laminated, cerebellum, 604; pharyngeal, 210; 
posterior astragalus, 179; postglenoid, 220; 
of rib, 118; of Rolando, 597; of tibia, 175. 
Tubercles, globular, 98 ; of metacarpal bones, 
149 ; of optic thalami, 610. 
Tuberculum impar, 99. 
Tuberosity, bicipital, 141 ; of first metatarsal 
bone, 182; of ischium, 165 ; malar, 233 ; of 
maxilla, 228 ; of palatal, 229 ; scaphoid, foot, 
181; scaphoid, hand, 146. 
Tuberosities, of femur, 172; great and small, 
humerus, 137 ; of tibia, 173. 
Tubes, bronchial, 751; intercalary, kidney, 763, 
764. 
Tubules, collecting, kidney, 764; convoluted, 
kidney, 764; segmental, 96; spiral, kidney, 
764. 
Tubuli, contorti, 763, 764; recti, 763, 774, 775; 
seminiferi, 773 ; uriniferi, 763. 
Tunica, adventitia of arteries, 59; adventitia of 
capillaries, 62 ; adventitia of veins, 62 ; 
albuginea, 772, 773 ; granulosa, 785; intima 
of arteries, 60; intima of veins, 62; media 
of arteries, 59; media of eye, 655; propria 
of spleen, 754; vaginalis, 771; vasculosa of 
Astley Cooper, 773 ; vasculosa of eye, 646. 
Turbinated bone, inferior, 233; ossification of, 
250. 
Turbinated, processes, ethmoidal, 225; bones, 
sphenoidal, 216. 
Turck, column of, 584, 600. 
Turner, Sir W., dolichopellic pelvis, 168; frontal 
lobe, 625; olfactory lobe, 621; triradiate 
sulcus, 627 ; villi of chorion, 103. 
Tutamina oculi, 643. 
Tympanic, artery, 418; nerve, 554 ; plate, 223 ; 
plate, ossification of, 249. 
Tympanum, 98, 219, 669; secondary membrane 
of, 670. 
Tyson’s glands, 781. 
Ulna, 133, 140, 143; ossification, 202. 
Ulnar, artery, 440; artery, deep branch, 441; 
collateral nerve, 522; nerve, 517; nerve, 
deep, 520 ; vein, superficial, 484. 
Umbilical, region, 688; vein, 483; vein, fissure 
of, 731; vein obliterated, 731; veins, 491 ; 
vesicle, 94. 
Umbilicus, 373, 381. 
Umbo of membrana tympani, 674. 
Unciform bone, 146, 148. 
Uncinate process, 225. 
Underhung jaw, 697. 
Under-tongue, 702. 
Ungual phalanges, 150. 
Unstriped muscular fibre, 40. 
Urachus, 95, 768. 
Ureters, 767. 
Urethra, female, 791; male, 781. 
Urethral crypts, female, 791. 
Urinary, bladder, 767 ; organs, 759. 
Urogenital sinus, 771. 
Uterine, artery, 453; plexus, 567. 
Uterus, 786; bicornutus, 788; broad ligament 
of, 692 ; lymphatics of, 500 ; masculinus, 781; 
one-horned, 788 ; pregnant, 788 ; structure of, 
787 ; vessels and nerves of, 788. 
Utricle of labryinth, 676. 
Uvula, 791; cerebellum, 604; vesicae, 769, 781. 
V-shaped furrow of tongue, 704. 
Vagina, 793; lymphatics of, 500. 
Vaginal, arteries of liver, 736 ; artery, 453 ; 
ligament, 273; membranes, 69; plexus, venous, 
482 ; plexuses, 567 ; process of sphenoid, 216 ; 
process of temporal, 223. 
Vagus nerve, 555. 
Valsalva, sinuses of, 403, 406. 
Vallecula, of cerebellum, 603 ; of Sylvius, 623. 
Valve, auriculo-ventricular, 403; bicuspid, 405 ; 
Eustachian, 402 ; ileo-caecal or ileo-colic, 726 ; 
mitral, 405 ; pyloric, 710 ; of Thebesius, 402 ; 
tricuspid, 404; ofVieussens, 602. 
Valves, arterial, 403; of Houston, 728; of veins, 63. 
Valvulae conniventes, 719. 
Valvule of Guerin, 782. 
Variations, muscular, posterior femoral, 294; 
anterior femoral, 302; forearm, 280; hip, 
292; leg, external, 306; leg, front of, 311; 
leg, posterior, 317 ; of thigh, 297. 
Variations of ribs, 119. 
Varieties, of aorta, 412; of arteries of hand, 
445; of arteries of leg and foot, 466; of 
axillary artery, 436; of brachial artery, 438 ; 
of femoral artery, 460; of kidneys, 760; of 
popliteal artery, 462 ; of pubic artery, 455 ; of 
radial artery, 443; of ulnar artery, 441 ; of 
ureters, 767. 
Vas aberrans of Haller, 776. 
Vas deferens, 776 ; artery of, 453 ; development 
of, 97, 795. 
Vas prominens cochleae, 682. 
Vasa, aberrantia, liver, 735; brevia, splenic 
artery, 449; efferentia, 775; intestini tenuis, 
450; recta, kidney, 765; recta, false, kidney, 
765; vasorum, 61. 832 
INDEX, 
Vascular arrangement of gastric mucous mem- 
mbrane, 716. 
Vascular supply, of bladder, 770; of external 
ear, 669; of iris, 654; of larynx, 744; of lungs, 
752; of mamma, 800; of nasal fossae, 641; of 
uterus, 788. 
Vascular system, commencement.of, 100. 
Vaso-inhibitory nerves, 562. 
Vaso-motor nerves, 561. 
Vastus, externus muscle, 300; interims muscle, 
300. 
Vater’s corpuscles, 81. 
Vater, duct of thyroid, 704. 
Veddahs, cranial capacity, 244. 
Vein, angular, 470; auricular, anterior and 
posterior, 472: axillary, 485; azygos, great, 
479; basilar, 474; basilic, 485; cardinal, 491, 
494 ; cephalic, 485 ; cervical, transverse, 472 ; 
cervical, deep, 469, 470; circumflex-iliac, 482; 
coronary, great or left, 468; coronary, small 
or right, 468; coronary, of stomach, 483; of 
corpus striatum, 474; cystic, 483; epigastric, 
482; facial, 470; facial transverse, 472; 
femoral, 486; frontal, 470; great, of Galen, 
474; hepatic, 481; iliac, common, 481; ilio- 
lumbar, 481; iliac, external, 482; iliac, internal, 
481; innominate, left, 469 ; innominate, right, 
469 ; intercostal, first, 470 ; jugular, anterior, 
472 ; jugular, external, 471; jugular, internal, 
470; jugular, posterior, 472; jugular, primitive, 
491; lingual, 470; mammary, internal, 479; 
maxillary, internal, 472 ; median basilic, 484 ; 
median cephalic, 484; median, superficial, 
484; mesenteric, superior and inferior, 483; 
oblique of Marshall, 468; obturator, 482; 
occipital, 470; ophthalmic, 474; palatine, 
inferior, 471; palpebral, 471; penis, dorsal of, 
482 ; phrenic, inferior, 481; popliteal, 486; 
portal, 482; pudic, internal, 482; radial, 
superficial, 484; ranine, 470; renal, 480; 
sacral, middle, 481; saphenous, external, 485; 
saphenous, internal, 486; sciatic, 482; sper- 
matic, 481 ; splenic, 483 ; subclavian, 471; 
submental, 471 ; supraorbital, 470 ; supra- 
scapular, 472 ; temporal, 472; temporo-max- 
illary, 471, 472; thyroid, superior and inferior, 
470 ; ulnar, superficial, 484 ; umbilical, 483 ; 
umbilical, obliterated, 731; vertebral, 469; 
vertebral, anterior, 469; Vesalian, 477; vitel- 
line, 488, 491. 
Veins, 62 ; development of, 491; arched, kidney, 
765; azygos, left, 480; bronchial, 480; 
cerebellar, 474; of cerebrum, 473 ; ciliary, 
475; digital, superficial of foot, 485; of 
diploe, 475; extraspinal, 478; of Galen, 474, 
578, 619; gluteal, 482; of heart, 468; 
haemorrhoidal, superior, 483; of hand, super- 
ficial, 484; intercostal, 479; interlobular, 
liver, 733; interlobular, kidney, 765 ; intra- 
lobular, liver, 733; intraspinal, 478 ; labial, 
471; lumbar, 480 ; ovarian, 481; pulmonary, 
410; spinal, 478; straight, kidney, 765; 
sublobular, liver, 733; suprarenal, 481; 
Sylvian, 473, 474; umbilical, right and left, 
491; of upper limb, deep, 485 ; of upper limb, 
superficial, 484. 
Velum, interpositum, 619 ; medullary, anterior, 
602; medullary, posterior, 604; palati, 
701. 
Vena cava, inferior, 480 ; inferior, fissure of, 
731; superior, 468. 
Vena magna Galeni, 474. 
Vena terminalis, 101. 
Venae advehentes, 491, 737; minimae cordis, 
468; revehentes, 591, 737 ; vorticosae, 650. 
Venae comites, 62 ; lingual, 470 ; of lower limb, 
486 ; of upper limb, 485. 
Venous sinuses of cranium, 475. 
Venter scapulae, 135. 
Ventral, 3 ; mesocardium, 102. 
Ventricle, of brain, third, 620; of brain, fifth, 
617; cardiac, left, 405; caidiac, right, 404; 
floor of third, 610; fourth, 600, 607 ; of larynx, 
742. 
Ventricles, brain, lateral, 620; cardiac walls of, 
408 ; of larynx, 742. 
Ventricular ganglia of heart, 409. 
Verheyen, stars of, 765. 
Vermiform, appendage, 725; processes, 603. 
Vertebra, fifth lumbar, 111; first thoracic, 109 ; 
prominens, 112 ; seventh cervical, 112. 
Vertebrae, 105, 107; arch, 107 ; body, 105, 107; 
centrum, 107 ; cervical, 107, 111; dorsal or 
thoracic, 107, 108; distinct or movable, 107; 
laminae, 108; lumbar, 107, 110; mammillary 
processes, 110 ; notches, superior and inferior, 
108 ; ossification of, 131; pedicles of, 108; 
processes, articular, 108 ; processes, accessory, 
110; processes, transverse, 108; ring, 108; 
spinous process or spine, 108; thoracic or 
dorsal, 107, 108; tenth, eleventh, and twelfth 
thoracic, 109. 
Vertebral artery, 428, 433. 
Vertebral column, 105 ; common ligaments, 123 ; 
curves of, 116, 117; membranous, 92; move- 
ments of, 127. 
Vertebral vein, 469; anterior, 469. 
Vertical muscles of tongue, 704. 
Verumontanum, 781. 
Vesalian vein, 477. 
Vesalius, position of pelvis, 163. 
Vesical arteries, superior and inferior, 453. 
Vesical plexus, 567 ; venous, 482. 
Vesicle, auditory, 98; germinal, 82, 785; otic, 682; 
primary optic, 634, 665 ; secondary optic, 666; 
third primary cerebral compartments, 635; 
umbilical, 94. 
Vesicles, adipose, 19; primary cerebral, 90, 97, 
634; primary optic, 90; Graafian, 784. 
Vesiculae, seminales, 777. 
Vessels, of heart, 409 ; lymphatic, 65 ; of peri- 
osteum, 30. 
Vestibule, aortic, 405 ; ear, 219, 676 ; of nasal 
fossae, 640; osseous and membranous, 676; 
of vulva, 791. 
Vicq-d’Azyr, 618. 
Vidian, artery, 419; canal, 218; nerve, 545. 
Vieussens, valve of, 602. 
Villi, 720; of chorion, 103; synovial, 37. 
da Vinci, position of pelvis, 163. 
Vincula, tendinum, 273; of thecae, 70. 
Virchow, kyphosis, 243. 
Visceral, arches, 98; cavity, 683; clefts, 98. 
Viscero, inhibitory nerves, 562; motor nerves, 
562. 
Vision, axis of, 646; at fovea centralis, 661. 
Visual, epithelium, 657; purple, 656. 
Vitelline, arteries, 101; circulation, 494; duct, 
94 ; membrane, 82; veins, 488, 491. 
Vitellus, 82. 
Vitreous, body or humour, 661; table of skull, 
206. 
Vocal cords, 742. 
Volar artery, superficial, 442. 
Voluntary muscular fibre, 40. 
Vomer, 231; ossification of, 250. 
Vulva, 790. 
AVagner, touch-corpuscles of, 79. 
AAraller, diapedesis, 11. INDEX 
833 
Waller’s law, 53. 
Walls, of auricles, 407; of ventricles, 408. 
Waltlier, ducts of, 702, 70S. 
Weber’s pouch, 781. 
Weight, of brain, 632; of heart, 409. 
Weismann, polar bodies, 84. 
Welcker, forms of skull, 243. 
Wharton’s duct, 342, 702, 707. 
White, blood-corpuscles, 10 ; fibrous tissue, 13 ; 
nervous substance, 47 ; substance of Schwann, 
49. 
Wiedersheim, primordial cranium, 245. 
Williams, muscularis mucosae of uterus, 788. 
Willis, circle of, 422; cranial nerves, 537. 
Wilson, muscle of, 392. 
Windpipe, 738, 745. 
Wings, see Alae. 
Winslow, foramen of, 689 ; ligament of, 190. 
Wirsung, duct of, 729. 
Wolffian, body, 96, 766, 794; duct, 96. 
Wolters, sap canals in cartilage, 20. 
AYomb, 786. 
AVoolner, tubercle on pinna, 669. 
Wormian bones, 237. 
AYrisberg, cartilages of, 739; nerve of, 517. 
AYrist, joints of, 158; movements.of, 161, 801. 
AArry neck, 353. 
Xiphoid process of sternum, 121. 
Y-shaped ligament of Bigelow, ISB. 
Yelk, 82; cleavage or segmentation, 82, 85; 
formative and nutrient, 82. 
Yellow, cartilage, 23; elastic substance, 14; 
marrow, 30 ; spot of Soemmerring, 660. 
Young, Bruce, locking of knee-joint, 193; 
trapezio-metacarpal ligament, 160. 
Zawarykin, lymphatics of kidney, 765. 
Zenker on regeneration of nerves, 46. 
Zimmerman, elementary granules of, 12. 
Zinn, zonule of, 664. 
Zona, fasciculata, 759 ; glomerulosa, 759 ; inter- 
media, kidney, 761 ; pellucida, 82, 785 ; 
radiata, 82; reticularis, 759. 
Zone, lateral, 92; paraxial, 92. 
Zones of embryo, 92. 
Zonular fibres, 665. 
Zonule of Zinn, 664. 
Zygoma, 220. 
Zygomatic arch, 220 ; fossa, 218, 237 ; process, 
220. 
Zygomaticus, major muscle, 333 ; minor muscle, 
'332. A TEXT-BOOK OF PHYSIOLOGY. 
BY 
M. FOSTER, M.A., M.D., LL.D., F.R.S., 
Professor of Physiology in the University of Cambridge, and Fellow of Trinity College, 
Cambridge. 
Bvo. Cloth. Price $5.00, net; Sheep, $5.50. 
REVISED AND CONDENSED FROM THE AUTHOR’S TEXT-BOOK 
OF PHYSIOLOGY, IN FIVE VOLUMES. 
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which have made it a standard authority upon the subject of which it treats.” 
Professor S. W. Williston, University of Kansas, Lawrence, Kansas. —“I shall 
be very glad to recommend this edition to my students. I have regretted much that 
the only full and reliable edition in the late past has been the original English, rather 
too full in some parts and too expensive for the ordinary medical student. I regard 
Foster as the only physiology for the medical student.” 
THE MACMILLAN COMPANY, 
66 FIFTH AVENUE, NEWYORK. A TEXT-BOOK OF 
SPECIAL PATHOLOGICAL ANATOMY 
BY 
ERNST ZIEGLER, 
Professor of Pathology in the University of Freiburg, 
TRANSLATED AND EDITED FROM THE EIGHTH GERMAN EDITION BY 
DONALD MacALISTER, M.A., M.D., 
Linacre Lecturer of Physic, and Tutor of St. John’s College, Cambridge, 
AND 
HENRY W. CATTELL, M.A., M.D., 
Demonstrator of Morbid Anatomy in the University of Pennsylvania. 
VOL. I. SECTIONS 1.-VIII. 
Bvo. Cloth. Price $ net. 
FROM THE TRANSLATORS’ PREFACE. 
Since the publication, in 1884, of the first English edition of Ziegler’s Special 
Pathological Anatomy, great advances have been made in our knowledge of its 
subject-matter. These have been duly embodied in the five successive German 
editions that have appeared in the meanwhile. The work has accordingly been 
so altered and enlarged that in preparing a third English edition we have had 
entirely to rewrite the text, and to recast the bibliographical and other supple- 
mentary portions. The number of pathological papers and monographs, to 
which reference might fitly be made, is now so great that only the more recent 
and important can be dealt with. But the student of historical tastes will find 
ample references to the earlier literature in the previous English editions ; and, 
by omitting them in this, much valuable space has been gained. 
The second volume, containing the sections on the alimentary tract with the 
liver and pancreas, the respiratory and genito-urinary systems, the eye, and the 
ear, is already in the press and will shortly be published. 
THE MACMILLAN COMPANY, 
66 FIFTH AVENUE, NEWYORK. IN PREPARATION, 
A SYSTEM OF GYNECOLOGY. 
BY MANY WRITERS. 
THOMAS CLIFFORD ALLBUTT, 
EDITED BY 
M.A., M.D., LL.D., F.R.C.P., F.R.S., F.L.S., F.S.A. 
Regius Professor of Physic in the University of Cambridge, Fellow of Gonville 
and Caius College, 
AND 
WILLIAM SMOULT PLAYFAIR, 
M.D., LL.D., F.R.C.P., 
Professor of Obstetric Medicine at King's College, and Physician to Women and Children 
at King's College Hospital. 
MEDIUM OCTAVO, ABOUT 1000 PAGES, WITH MANY ILLUSTRATIONS. 
Cloth, $6.00, net; Half Leather, $7.00, net. 
OR TO SUBSCRIBERS TO "A SYSTEM OF MEDICINE,” EDITED BY THOMAS 
CLIFFORD ALLBUTT, 
Cloth, $5.00, net; Half Leather, $6.00, net. 
CONTENTS. 
Development of Modern Gynaecology, M. Handfield Jones.—Anatomy of the Female 
Genital Organs, D. Berry Plart.'—Malformations of the Genital Organs in Women, 
J. William Ballantyne. Etiology of Diseases of the Genital Organs in Women, W. 
Balls-Headley.—Diagnosis in Gynaecology, Robert Boxall. Inflammatory Diseases 
of the Uterus, A. H. Freeland Barbour. The Nervous System in Relation to Gynae- 
cology, W. S. Playfair. Sterility, Henry Gervis. Gynaecological Therapeutics, 
Amand Routh. Electricity in Gynaecology, Robert Milne Murray. Diseases of 
Halliday Groom. Diseases of the Vulva and Vagina, William J. 
Smyly. Displacements of the Uterus, Alexander Russell Simpson.— Morbid Condi- 
tions of Female Genitals, George Ernest Herman. Extra-Uterine 
Bland Sutton. Pelvic Inflammations, Charles James Cullingworth. Pelvic Haema- 
tocele, William Overend Priestley. Tumours of the Uterus, F. W. N. Haultam. 
Malignant Diseases of the Genital Organs in Women. W.J. Sinclair. Hysterectomy 
and Allied Operations,/. Knowsley Thornton. —Viatic Gynaecological Operations, 
John Phillips. Diseases of the Fallopian Tubes, Alban Doran. Diseases of the 
Ovary, W. S. A. Griffith. Ovariotomy and Allied Operations, J. Greig Smith. 
Chronic Inversion of the Uterus, Edward Malms. Diseases of the Female Bladder 
and Urethra, Henry Morris. 
THE MACMILLAN COMPANY, 
66 FIFTH AVENUE, NEWYORK. 
3 MANUAL OF MIDWIFERY. 
BY 
W. E. FOTHERGILL, 
M.A., B.Sc., M.8., C.M., Etc., Etc. 
WITH DOUBLE COLOURED PLATE AND SIXTY-NINE ILLUSTRATIONS 
IN THE TEXT. 
i2mo. Cloth. Price $2.25, net. 
CONTENTS. 
Chapters 1 and 2. STRUCTURE AND FUNCTIONS OF THE FEMALE 
REPRODUCTIVE ORGANS. 
Chapters 3 to 6. PREGNANCY, DIAGNOSIS AND DEVELOPMENT. 
Chapters 7 to 9. PATHOLOGY OF PREGNANCY. 
Chapters 10 to 14. LABOUR. 
Chapter 15. MORBID LABOUR. 
Chapter 16. PRETERNATURAL LABOUR. 
Chapters 17 to 19. COMPLEX LABOUR. 
Chapters 20 and 21. OBSTETRIC OPERATIONS. 
Chapter 22. THE PUERPERIUM. 
Chapter 23. HYGIENE OF INFANCY. 
COMMENTS. 
“An exceedingly interesting and instructive volume by one of the most 
advanced writers in the specialty treated.”—The Medical Examiner. 
“ A well prepared and very interesting work. Will prove invaluable to any 
one interested in this subject, and is well calculated to answer the purpose of the 
general practitioner who desires to brighten up on the important features. We 
commend it to the examination of all interested in the subject.”—Charlotte 
Medical Journal. 
“ Few books are so well worth the money as is this terse and well-written 
book. It is one of the few modern books that bear the stamp of individuality 
and originality. The entire field is covered. A production that will make every 
practitioner think who reads it, and will make him a better obstetrician.” The 
Medical Council. 
THE MACMILLAN COMPANY, 
66 FIFTH AVENUE, NEWYORK. 
4