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A^ I Vv/S. 
 
A
SYSTEM   OF   ANATOMY
fOR THE USE 01
STUDENTS  OF MEDICINE.
         BY CASPAR WISTAR, M. D.

LATH rROFESSOB OF ANATOMY IK TUE UNIVERSITY 01 fENVglLVANIA,
     jmm 2St»rttow.

WITH NOTES AND ADDITIONS.
     BY WILLIAM EDMONDS HORNER, M.  D.

ADJUNCT PROFESSOR OF ANATOMY IN THE TTNITEHSITY OF PENNSYLVANIA,
      MEMBER OF THE AMERICAN PHILOSOPHICAL SOCIETY, &C.
IN TWO VOLUMES.—VOL. II.
^EONGE^ERALT

CAREY & LEA—CHESHUTLSTREEJ

            1830,
 
                Q.S
               W«Hs




f;fi<G/(>,   l$H
JEastern District of Pennsylvania) to wit:

••••••••  BE IT REMEMBERED, that on the twentieth day of
* seal. *  August, in the forty-ninth year of the Independence of the
********  United States  of America, A. D. 1825, H. C. Carey & I.
Lea, of the said district, have deposited in this office the title of a book,
the right whereof they claim as Proprietors, in the words following, to
wit:

  cc A System of Anatomy for the use of Students of Medicine.  By Cas-
    "par Wistar,  M. D. Late Professor of Anatomy in the University of
    " Pennsylvania.  Third edition. With notes and additions.  By Wil-
    "liam Edmonds Horner, M.  D. Adjunct Professor of Anatomy in the
    " University of Pennsylvania, and member of the American Philosophi-
    "cal Society, &c.  In  two volumes. Volume II."

  In conformity to the Act of  the Congi-ess of the United States, en-
titled, " An Act for the Encouragement of Learning, by securing the
Copies of Maps,  Charts, and Books, to the  Authors and  Proprietors
of such Copies, during the times therein mentioned"—And also  to the
Act, entitled, "An Act supplementary to an Act, entitled,  * An Act
for the Encouragement of Learning, by securing the Copies of Maps,
Charts and Books, to the  Authors  and Proprietors of such Copies
during the times therein mentioned,' and extending the benefits there-
of to the arts of designing, engraving, and etching "Historical and other
Prints."
                                     D. CALDWELL,
                  Clerk of the Eastern District of Pennsylvania. 
CONTENTS  OF VOL. IL
                  PART VI.
    OF THE NOSE—THE MOUTH—AND THE THROAf -
                  CHAPTER I.
                   Of the Nose.
                  SECTION I,
Of the External Nose     --***«
                  SECTION II.
Of the Cavities of the Nose   -
                  CHAPTER II.
           Of the Mouth and Salivary GlandSi
Of the Mouth  --------
Of the Salivary Glands    ----*-
                  CHAPTER III-
                   Of the Throat.
                   SECTION L
Of the Isthmus of the Fauces   ---«.-*
                   SECTION II.
Of the Larynx ■    .------
Of the Thyroid Gland     --.--.
                  SECTION III.
 Of the Pharynx      -                x 
IV                     CON IK.NT-

                    PART MI.

                  OF  THE THORAX

                    CHAPTER I.

           Of the General Cavity of the Thorax.

                    SECTION I.

Of the Form of the Cavity of the Thorax                44

                    SECTION II.

Of the Arrangement of the Pleursc                      45
Preparation of the Thorax.....47

                    CHAPTER II.

 Of the Heart and the Pericardium,  and the Great Vessels con-
                  nected with the Heart.

                     SECTION L

Of the Pericardium -         -    -                  49

                    SECTION  II.

 Of the Heart.....         -     -    50

                    SECTION III.
 Of the Aorta, the Pulmonary Artery and Veins, and the Vena
  Cavae at their commencement                        59

                    CHAPTER III.

                Of the  Trachea and Lungs.

                      SECTION I.

 Of the Trachea      --...--    62
 The Black Glands on  the Bronchia;            -     •    61

                      SECTION II.
 Of the Lungs                                       65
                                                   69
Thorax of the Foetus
Physiological observations, &c.                         71 
COXTENTS.
                    PART VIII.
                  OF THE ABDOMEN.
                     CHAPTER I.
d general view of the Mdomen and Pelvis, and their Contents ;
            with an account of the Peritoneum.

                     SECTION I.
Construction of the Abdomen                          g£
Contents of the Abdomen      -----    85

                    SECTION II.
Of the Peritoneum.....,..    90

                    CHAPTER II.
     Of the Oesophagus, the Stomach, and the Intestines.

                     SECTION I.
Of the GSsophagus   -

                    SECTION II.
Of the Stomach    ....
Of the Gastric Liquor    -

                ,   SECTION III.
Of the Intestines   -
Division of the Intestines
The Small Intestines      ...
The Duodenum     ....
Jejunum and Ileon   -
The Mesentery     -
Of the Great Intestines  -
The Caecum and Colon
The Rectum.....
The Omentum      -

                   CHAPTER III.
        Of the Liver, the Pancreas, and the Spleen.

                    SECTION I.
Of the Liver  -*--..*.,    123
 96
101
104
109
110
111
113
115
117
118
122
125 
VI
CONTENTS.
                    SECTION II.
Of the Pancreas    .-..-■•-    14)

                   SECTION III.
Of the Spleen       ...    -                  145

                   CHAPTER IV.
     Of the Urinary Organs, and the Glandulx Renales.

                    SECTION I.
Of the Glandule Renales     -                      154

                    SECTION II.
Of the Kidneys and Ureters   -        -    -    -    155

                   SECTION III.
Of the Urinary Bladder  -                           162

                   CHAPTER V.
            Of the Male Organs of Generation.
                    SECTION I.
Of the Testicles and their Appendages   -    -    *    171
                    SECTION II.
Of the Vesiculse Seminales and the Prostate Gland  -    181
                   SECTION III.
Of the Penis.......         184
                   CHAPTER VI.
           Of the Female Organs of Generation.
                    SECTION I.
Of the External Parts of Generation    ~        -    200
                    SECTION II.
Of the Vagina.....        _    093
                   SECTION III.
Of the Uterus, the Ovaries, and their Appendages  -    205
                   SECTION IV.
Of the Bladder and Urethra   -        ,.             21^ 
                       CON*i tiS'i*.                     Vll

                      PART IX.
                OF THE BLOOD VESSELS-
                     CHAPTER  1.
 Of the General Structure and arrangement of the BloodVessels.
                      SECTION I.
 Of the Arteries......-    226
                     SECTION II.
 Of the Veins........233

                     CHAPTER II.
   A Particular Account of the Distribution of the Arteries.
                      SECTION I.
 Of the Aorta, or the Great Trunk of the Arterial System 236
                     SECTION II.
 Of the Branches which go off from the Arch of the Aorta  238
                     SECTION III.
Of the Branches which  go off between the Arch and the Great
  Bifurcation of the Aorta.....272
                     SECTION IV.
Of the Arteries which originate at and below the Great Bi-
  furcation of the Aorta  ......283
                    CHAPTER III.
        Of the particular Distribution of the  Veins.
                     SECTION I.
Of the Superior, or Descending Vena Cava,  and  the Veins
  which communicate with it.....300
                     SECTION II.
Of the Inferior Vena Cava,and theVeins connected with it  309 
viii
CONTENT-
                     PART X.

                   OF THE NERVES.

Nerves of the Brain     -
Of the Cervical Nerves  -
Nerves of the Diaphragm
Brachial Plexus     -
Nerves of the Arm      -
The Dorsal Nerves      -
Of the Lumbar Nerves   -
The Sacral Nerves      -
Sciatic Plexus      -
Great  Sciatic Nerve     -
Great  Sympathetic Nerve     -
Nerves of the Heart     -
Nerves of the Abdominal Viscera   -

                    PART XI.

             OF THE ABSORBENT VESSELS

                    CHAPTER I.
Of the Absorbents of the Lower Extremities—the Abdomen and
                     the  Thorax.

                    SECTION I.
The Absorbents of the Lower Extremities     -   -  - ••♦  376

                    SECTION II.
The Absorbents of the Abdomen and Thorax  -     -    381

                   CHAPTER II.
Of the Absorbents of the Head and Neck, of the Upper Extre-
   mities, and the  Upper Part of the Trunk of the Body.

                    SECTION I.
Of the Absorbents of the Head and Neck      .     .    391

                    SECTION II.
Of the Absorbents of the Arm, and Upper Part of the
  Trunk.......         «0?J
323
343
346
347
348
352
353
356
357
358
361
363
368 
SYSTEM  OF ANATOMY.

                PAUT VI.
OF THE NOSE :  THE. MOUTH!  AND THE THROAT.
CHAPTER I.
                   OF THE NOSE.

  The prominent part of the face, to which the word
nose is exclusively applied in ordinary language, is the
anterior covering of two  cavities which contain  the
organ of  smelling.
  These cavities are formed principally by the upper
maxillary and palate bones; and,  therefore, to acquire
a complete idea of  them, it is necessary to study these
bones, as well as the os etiimoides, the vomer, and the
ossa spongiosa inferiora, which are likewise concerned
in their formation.
  In addition to the description of these bones, in the
account of the bones of the head, it will be useful to
study the description of the cavities of the nose which
follows it. See vol. i. page 72.
  After thus acquiring a knowledge of the bony struc-
ture, the student will be prepared for a description of
the softer parts.
  vol. ir,                i 
The EUcrnul ..\t/.sr.
                     SKCTIOX  I.

               Of the External J\bse.

   The superior part of the nose is formed by the ossa
 nasi, and the nasal  processes of the upper maxillary
 bones, which have been already doscribed; (see vol. i.
 pages 50—54.) but  the inferior part, which  is  com-
 posed principally of cartilages, is much more complex
 in its structure.
   The  orifice,  formed by  the  upper maxillary and
 nasal bones, is  divided by a cartilaginous plate, which
 is the anterior  and  inferior part  of  the  septum, or
 partition between the two cavities of the nose.   The
 anterior edge of this plate projects  beyond the orifice
in the bones, and  continues in  the direction of the
suture between the   ossa nasi.   This  edge forms an
angle with  the lower  edge of the same  cartilage,
which continues from it in a horizontal direction, until
 it reaches the lower  part of the orifice of the nose, at
 the junction of  the  palatine processes of the upper
 maxillary  bones; where a bony prominence is formed,
to which it is firmly united.  The  upper  part of the
anterior edge of this cartilage, which is in contact
 with the ossa nasi, is flat, and is continued into  two
lateral portions that  are extended from it, one on each
side, and form a part of the nose:  these  lateral  por-
tions are sometimes  spoken of  as  distinct cartilages;
but they are .really continuations of the middle  por-
tion or septum.
   Below the lower edge of  these lateral portions are
situated the cartilages which form the  orifices of the
nose, or the nostrils.  Of  these, there is one  of con-
siderable size,  and   several  small fragments, on  each
side of the  septum.   Each of the larger cartilages
forms a portion of an oval  ring, which is  placed ob-
liquely on the side of the septum:   so that  the extre- 
Of the. Yost.                  3
mity of the oval points downward and forward, while
the middle part of the oval  is directed upwards and
backwards.  The sides of this cartilage  are flat, and
unequal in breadth.   The narrowest  side is internal,
and projects lower down than  the cartilaginous sep-
tum ;  so that it is applied to its fellow of the other nos-
tril.  The external side is broader, and continues back-
ward  and upward to a considerable distance.
  The upper and posterior  part of  this oval ring is
deficient;  but the remainder of the  nostril  consists of
several small pieces of cartilage, which are fixed in  a
ligamentous membrane that is connected by  each of its
extremities to the oval cartilage, and  thus  completes
the orifice.
  The anterior parts  of the oval cartilage  form  the
point of  the nose;  and the ligamentous portions, the
alse or lateral parts of the nostrils.
  When the external integuments and muscles are re-
moved from the lower portion of the nose, so that the
internal  membrane and these cartilages only remain,
the internal membrane will be  found attached to the
whole bony margin of each orifice, and to each side of
the whole anterior edge of the middle cartilage, which
projects  beyond the bones.  This membrane is after-
wards continued so as to line  the oval cartilages  and
the elastic membrane of the ala nasi, to the margin of
the orifice of the nostril.
  The internal  portions of the  oval  cartilages being
situated without the septum, and applied to each other,
they  form the external edge of  the  partition between
the nostrils, or the columna nasi; which is very move-
able upon the edge of the  middle cartilage.
   The orifices  of  the  nostrils, thus constructed, are
dilated by that portion of  the  muscle, called Levator
Labii Superioris Alseque Nasi, which is inserted into
the altB nasi. 
4
Of the ( av/tics of thf »\ W.
   They are drawn down by the depressor labii  supe-
rioris alaeque nasi.  They are pressed against the sep-
tum and the  nose by the  muscle called  Compressor
Naris,  which has however an opposite effect when its
upper extremity is drawn upwards by those fibres of
the occipito-frontalis, which descend upon the  nose,
and are in contact with it.
  The  end of the nose  is also  occasionally  drawn
down, by some muscular fibres which descend from it,
on the septum of the nose, to the orbicularis oris : they
are considered as a portion of  this  muscle by many
anatomists, but were described by Albinus as a  sepa-
rate muscle, and called JVasalis Labii Superioris.
  When inspiration takes place with great force, the
alaB nasi would be pressed against the septum, if they
were  not drawn out and dilated by some of the  mus-
cles above mentioned.

                   SECTION II.

            Of the Cavities of  the Nose.

   To the  description  of the osseous parts of the  nasal
cavities  in vol. i. page 72, it ought now to be added,
that the vacuity in the anterior part  of  the  osseous
septum  is filled up by a cartilaginous plate, connected
with the nasal lamella of the ethmoid bone above, and
with the vomer below.  This plate sends off those la-
teral portions already  described,  which form the  carti-
laginous part of the bridge of the nose.
  It should also be observed that at the back parts  of
these  cavities are  two orifices  called the Posterior
Nares,  which are formed by the palate bones,  the vo-
mer, and the  body of the  sphenoidal  bone, and are
somewhat  oval.
  The nasal cavaties,  thus constructed, are lined  by  a
peculiar membrane, which is called pituitary from its 
Schneider ian Membrane.
5
secretion of mucus, or Schnciderian after an anatomist
who described it with accuracy.*
  This membrane is very thick and strong, and abounds
with so many blood vessels, that in the  living subject
it is of a red colour.   It  adheres to the bones  and
septum of  the nose like the periosteum, but  separates
from them more easily.  The surface  which adheres
to  the bones has  some resemblance to periosteum;
while the other surface is soft, spongy,  and rather vil-
lous.   Bichat seems to have considered this membrane
as  formed of two lamina,  viz.  periosteum,  and the
proper mucous membrane;  but he adds, that it is al-
most impossible to separate them.
   It has been supposed that many  distinct  glandular
bodies were to be seen in the structure of this mem-
brane  by examining the surface  next to the bones ;f
but this opinion is adopted by very few of the  anato-
mists of  the present day.  The  texture of the mem-
brane  appears to be uniform ; and on its surface are  a
great number of follicles of various  sizes, from  which
flows the mucous of the nose.
   These follicles  appear  like  pits,  made by pushing
a pin obliquely into a surface which  retains  the  form
of  the impression.  They can be seen  very distinctly
 with a common magnifying glass when  the membrane
 is immersed in water,  both on  the septum and  on the
 opposite surface.   They are  scattered  over the  mem-
 brane without order  or  regularity, except  that  in  a
 few places they occur  so  as  to  form lines  of various
 lengths, from half an  inch to an inch.   The largest  of
 them  are  in the lower parts of the cavities.
    It may be presumed that  the secretion of mucous is
 effected here by vessels which are mere continuations
 of arteries spread upon a  surface analogous  to the ex-

   * Conrad Schneider, a German professor, in a  large work, " De  Catarr-
 his," published about 1660.
   t See Winslow, Section X. No. 337. 
■ 6
Olfactory Nerves.
halents, and not convoluted in circumscribed masses,
as in the case of ordinary glands.
   The arteries of this  membrane  are  derived from
various sources:  the most important of  them is the
nasal  branch of the internal  maxillary, which passes
into the nose through  the spheno-palatine  foramen,
and is  therefore called  the Spheno-palatine Artery.
It divides into several  twigs, which  are  spent upon
the different parts of the surface of the nasal cavities.
Two of them  are  generally found  on  the septum of
the nose :  one,  which  is small, passes  forwards  near
the middle; the other,  which is much larger, is  near
the lower part of it.
   Two small arteries called the anterior and posterior
ethmoidals which are branches of the ophthalmic, en-
ter the nose by foramina of the  cribriform plate of
the ethmoidal bone.   These arteries  pass  from  the
orbit to the cavity of the  cranium, and  then through
the cribriform plate to the nose.   In addition to these,
there are some small arteries derived from the infra
orbital, the  alveolar and  the  palatine,  which extend
to the  Schneiderian  membrane;  but they are not of
much importance.
   The veins of the nose correspond with the arteries.
Those  which accompany the ethmoidal  arteries open
into the ocular vein of the orbit, which terminates in
the cavernous sinuses of the  head.   The other veins
ultimately terminate in the external jugulars.
   The nerves of the nose form an important part of
the structure ; they  are derived from several sources ;
but the most important  branches  are  those of the ol-
factory.
   The olfactory nerves  form  oblong bulbs, which lie
on each side of the crista galli, on the depressed  por-
tions of  the cribriform  plate of  the  ethmoid bone,
within  the dura mater.   These  bulbs  are  of a  soft
consistence,  and  resemble  the cortical part of  the 
Olfactory Nerves.
 brain mixed with streaks of  medullary matter.  They
 send off numerous filaments, which  pass  through the
 foramina of the ethmoid bone, and receive a coat from
 the dura mater as they pass through it.
   These filaments are so arranged that they form two
 rows, one running near to the septum, and the other
 to the surface of the cellular  part of the ethmoid bone,
 and the os turbinatum : and  in  addition to these arc
 some intermediate filaments.
   When the Schneiderian membrane is  peeled  from
 the bones to which it  is attached, these nervous  fila-
 ments are seen passing from the foramina of the eth-
 moid bone to the attached surfaces:  one  row passing
 upon that which  covered the septum, and  the  other
 to that of  the  opposite side; while  the  intermediate
 filaments take an anterior direction,  but unite to the
 membrane  as soon as they come in contact with it.
   All of these  can be traced  downwards on  the afore-
 said surfaces of the membrane for a  considerable  dis-
 tance, when they gradually sink into the substance of
 the  membrane, and  most probably terminate on  the
 internal villous surface ; but they have not been traced
 to their ultimate  termination.   They ramify so  that
 the branches form very acute angles with each other.
 On the septum  the different branches are arranged  so
 as to form  brushes, which lie in contact with  each
 other.  On the opposite sides, the different ramifica-
 tions unite  so as to form a plexus.
  Dr. Soemmering published last year some very ele-
gant engravings of the  nose,  representing one of his
dissections, which appears to  have been uncommonly
 minute and successful.*  These  represent the ramifi-
 cations as becoming more expanded  and delicate  in
 the  progress towards  their  terminations, and as  ob-
* They are entitled, Icones organorum humanorum olfactus 
8  Spheno-palatine and other Nerves of the Nose.

serving a tortuous course, with very short meandering
flexures.
  It is to be  observed  that  the ramifications  of the
olfactory nerve, thus arranged, do not  extend  to the
bottom of the  cavity.   On the external  side, they are
not traced lower than the lower edge of the ethmoid,
or of the  superior spongy bone : and on the septum,
they do not extend to the bottom,  although  they are
lower than on  the opposite side.   On the parts  of the
membrane not occupied  by the branches  of the  olfac-
tory nerves, several other nerves can be traced.  The
nasal twig of the ophthalmic branch of the fifth pair,
after passing  from the  orbit into  the  cavity of the
cranium, proceeds to the nasal cavity on each side by
a foramen of the cribriform  plate;  and  after sending
off  some fibrillae, descends upon the anterior part  of
the septum to  the point  of the nose. The spheno-pa-
latine nerve, which is derived from the second branch
of the  fifth pair, and enters the  nose by the spheno-
palatine foramen, is  spread  upon  the lower  part  of
the septum and of  the opposite side of the nose  also,
and transmits  a branch  through a  canal in the fora-
men incisivum to the mouth.   Several  small  bmnches
also pass  to  the nose  from  the palatine and  other
nerves; but those already mentioned are the most im-
portant.
  A question  has been  proposed,  whether the  olfac-
tory nerve is exclusively concerned in the function
of smelling, or whether the  other nerves  above men-
tioned  are also concerned  in it.    It seems  probable
that this  function is exclusively  performed  by  the
olfactory nerve, and  that the other nerves are like
the ophthalmic branch of the fifth  pair, with respect
to the optic nerve.   In proof  of  this, it is asserted
that the sense of smelling has entirely ceased in some
cases,  where  the sensibility to  mechanical irritation
of  every kind has remained  unchanged.   If the ol- 
      Extent of the Schneiderian Membrane.     9

factory nerve alone  is concerned  in  the  function of
smelling, it follows, that this function must be confined
to the upper parts of the nasal cavities; but it ought
to be remembered, that the  structure of the Schnei-
derian membrane, in the lower parts of these cavities,
appears exactly like  that which is above.
  The surface of the nasal cavities and their septum,
when covered with the  Schneiderian membrane, cor-
responds with the osseous  surface formerly described.
The membrane covers the bones and  cartilage  of the
septum, so as to make one  uniform regular surface.
From the upper part of the septum, is  is continued
to the under side of  the cribriform plate  of the  eth-
moid, and lines  it; the filaments  of  the olfactory
nerve passing  through the  foramina of  that bone
into the fibrous surface of the membrane.   It  is con-
tinued from  the septum, and from the cribriform plate,
to the internal surface of the external nose, and lines
it.   It is also continued backwards to  the anterior
surface  of the  body of  the sphenoidal bone; and,
passing through the foramina or openings of the sphe-
noidal  cells, it lines these  cavities completely; but
in these, as well  as the  other cavities,  its structure
appears somewhat changed;  it becomes  thinner and
less vascular.
  At the above mentioned foramina, in some subjects,
it forms a plate or fold, which diminishes the aperture
considerably.
  From the  upper surface of the  nasal cavities, the
membrane is continued  downwards  over  the  surface
opposite to the septum.  On the upper  flat surfaces
of the  cellular portions of  the ethmoid,  it forms a
smooth uniform surface.   After passing over the first
turbinated bone, or that  called after Morgagni, it is
reflected into the  groove, or upper meatus, immedi-
ately  within and  under it;  the  fold formed  by the
membrane, as it is reflected into the meatus, is rather
  Vor,.  IT.               % 
10  Distribution of the Schneiderian Membrane.

larger than the bone :  and the edge of the fold there-
fore extends lower down than the  edge of the  bone,
and partly covers the  meatus  like  a  flap, consisting
only of the doubled membrane.  This fold generally
continues backwards as  far  as  the spheno-maxillary
foramen,  which it closes; the periosteum,  exterior to
the foramen, passing through  it, and blending itself
with the fibrous  surface of the  Schneiderian  mem-
brane within.   Here  the speno-palatine nerves  and
arteries join the membrane.   Below  this  meatus, it
extends over the middle,  (formerly called the upper,)
turbinated  bone, and  is reflected  or  folded  inwTards
on the under  side  of this bone, and continued into
the middle meatus below it.   In  the middle meatus,
which is partly covered by the  last mentioned  turbi-
nated  bone, there  are  two foramina: one communi-
cating with the maxillary sinus; and the  other with
the anterior cells of the ethmoid  and the frontal si-
nuses.   The  aperture into the  maxillary sinuses is
much less in the recent head, in  which the  Schnei-
derian  membrene  lines  the nose, than it is in  the
bare bones.  A portion of the aperture in  the  bones
is  closed by the Schneiderian membrane,  which is
extended over it:  the remainder of the aperture is
unclosed ; and through  this foramen, the membrane
is reflected so  as to line the whole cavity.  As a por-
tion of the foramen is covered  by  the membrane,  and
this portion, as well as the other parts of  the cavity,
is  lined by the membrane, it  is  obvious that at  the
place  where  the  membrane  is  extended over  the
foramen in the  bone,  it  must be  doubled;  or, in
other words, a part of the aperture of the maxillary
sinus is closed  by a fold  of  the  Schneiderian  mem-
brane.
  This aperture varies in size in different  subjects,
and is often equal in diameter to a common quill.   It
is situated in the middle of the meatus, and is covered 
Unstitchian Tube.
1 I
by the middle turbinated bone :  immediately above it,
is a prominence of the  cellular  structure of the eth-
moid bone, which has a curved or semicircular figure.
Near this prominence, in the same  meatus, a  groove
terminates,  which leads from the  anterior ethmoid
cells and the frontal  sinuses.
  From the  middle  meatus, the membrane proceeds
over the  inferior turbinated bone, and is reflected
round and under it into the lower meatus.   It appears '
rather larger than  the  bone  which  it covers;  and
therefore  the lower edge of the bone does not  extend
so low as  the lower edge of  the  membrane, which of
course is like  a fold or plait.   The  membrane then
continues  and lines the lower meatus:  here it appears
less full than it  is in the  turbinated  bone.   In this
meatus, near to its anterior  end, is  the lower  orifice
of the lachrymal duct: this is  simply lined  by the
Schneiderian membrane, which  is continued  into it,
and forms no plaits or folds that affect the orifice.

          Orifice of the Eustachian  Tube.

  Immediately  behind each  of the  nasal  cavities, on
the external side, is the  orifice  of  the Eustachian
Tube.  It has an oval  form, and is large  enough  to
admit a very large quill.   Its position is oblique ; the
upper extremity being anterior to the other parts  of
the aperture, and on a  line with the  middle  meatus,
while  the centre is  behind  the inferior  turbinated
bone.   The lower part of the oval is  deficient.  This
tube is formed posteriorly  by a cartilaginous plate.   It
is lined by the  membrane  continued from the nose.

      The cavities of  the  nose  answer a two-fold purpose  in
        the  animal economy: they afford  a surface for the
        expansion of  the olfactory nerves : and a passage for
        the external air to the windpipe, in respiration.
       The function of smelling  appears  to be dependent, to
        a certain degree, upon  respiration.  It  has  been as- 
     Obstr rat ions respecting the No*t.

   serted that unless the air passes  in  a  stream through
   the  nose, as in respiration, the  perception  of odour
   does not  take  place ; that in persons  who  breathe
   through wounds and apertures in the windpipe, the
   function of  smelling is not performed.   It  is rather
   in confirmation of this proposition, that most persons,
   when they wish to have an accurate perception of any
   odour, draw in air rapidly through the nose.
Although the  ultimate terminations  of the  olfactory
   nerves cannot  be demonstrated  like those of the op-
   tic and auditory nerves, it is  probable,  from the ap-
   pearance of the fibres, while they are  distinguishable,
   that they are finally arranged with  great  delicacy.
   It is certain that the impressions from whence we de-
   rive the perceptions of many odours must be  very
   slight; as some odorous bodies will  impregnate the
   air of a large  chamber for a great  length of time,
   without losing  any sensible weight.
With respect to delicacy of structure and sensibility,
   it is probable that the nose holds a middle  rank be-
   tween the eye or ear, and the tongue: and on this ac-
   count the  mucous is  necessary as a  covering and de-
   fence of its  surface.
It has been ascertained, by the investigations of che-
   mists, that this mucous contains the same ingredients
   as the tears already described, viz. animal mucous
   and  water ; and muriate of soda, and  soda uncom-
   bined; phosphate of  lime, and phosphate of soda.
The animal  mucous, which is a  most important ingre-
   dient in the  composition, resembles  the   mucilage
   formed by some of the vegetable gums in several par-
   ticulars ; and differs from them in others.
The mucous of the nose, if it  remain there long  after
  it is  secreted, becomes much more viscid in consist-
   ence, and  changes from a whitish colour to one which
   partakes more or less of the yellow.   It is  probable
   that an incipient  putrefaction  may  occasion  these
   changes in it.
The use of the  frontal, maxillary and other  sinuses
   communicating with the nose, has  been the subject
   of some inquiry.  As there can be  no stream of air
   through them, and  as the membrane  lining  them is
   neither so thick, villous  nor flexible as that linin"-
   the  nose,  it may be concluded, a  priori, that  they
   are not concerned in the function of smelling   Thi~ 
     Use of the Sinuses of the Nose.        13

  opinion is  strengthened  by the fact, that very young
  children, in whom these  sinuses scarcely exist, enjoy
  the sense of smelling in perfection.   The  following
  fact is also in support of it.  The celebrated Desault
  attended a patient, in whom one of the frontal sinuses
  was laid open by the destruction  of the bone which
  covered it anteriorly.   This  patient was able  to
  breathe a short  time through  the sinus when the
  mouth  and nose were  closed: at the  request of De-
  sault he breathed in this manner when a cup of some
  aromatic  liquor was held near the opening  of the  si-
  nus : and had  not the least perception  of  odour.
  This experiment was repeated several times.
Many physiologists believe that  these sinuses have  an
  effect in modulating the voice. 
CHAPTER II.
                  OF THE MOUTH.

  The general  cavity of the mouth is  formed ante-
riorly and laterally by the connexion of the lips  and
cheeks to the upper and lower jaws : so that the teeth
and  the  alveoli  of both  jaws may be considered as
within the cavity.  Above, it is bounded principally
by the palatine processes of the upper maxillary and
palate  bones, and the  soft palate,  which  continues
backward from them  in the same direction.
  Below, the cavity  is completed by several muscles,
which proceed from almost the whole internal circum-
ference of the  lower jaw, and, by their connexions
with each other, with the tongue and the os-hyoides,
from a floor or bottom to it.   The tongue is particu-
larly connected to this surface, and may be considered
as resting upon and supported by it.
  To acquire an idea of  the  parieties of this  cavity,
after studying the upper and  lower maxillary bones,
the orbicularis oris and the muscles connected  with it,
especially the buccinator, ought to be examined ; and
also the digastricus, the mylo-hyoideus, genio-hyoi-
deus, and genio-hyoglossus.    By this it  will  appear
that the  lips and cheeks, and the basis or floor of the
mouth, are formed  in  a great measure by muscles.
Upon the internal surface of  these  muscles, a  portion
of cellular and adipose substance is  arranged, as well
as glandular bodies of different sizes; and to  these  is
attached the membrane which lines  the  inside of the
mouth.
   This  membrane passes from  the skin  of the face
to  the lips, and the inside  of  the mouth ; and, al-
though it  is really  a continuation of the skin, there 
          Internal Surface of the Mouth.        13

is so great a change of structure, that  it ought  to be
considered as a different membrane.   At the  orifice
of the lips it is extremely thin, and so vascular, that
it produces the fine florid colour which appears  there
in health.  It is covered by a cuticle, called by some
anatomists, Epithelium,  which  has  a proportionate
degree of delicacy, and can be separated like the  cu-
ticle in other parts.   When this cuticle is separated,
the lips and the membrane of the mouth appear to be
covered  with  very fine  villi, which  are  particularly
apparent in some preparations of the  lips after  injec-
tion and maceration.*
  Under this  membrane are  many  small  glandular
bodies of a roundish  form,  called glandulae labiales,
whose excretory ducts pass  through  it to  the inner
surface of the  mouth, for the  purpose of  lubrifying
it with  their  secretion, which is mingled  with  the
saliva.
   The membrane which  lines the inside of the  lips
and cheeks,  is somewhat different from that  which
forms the surface of  the  orifice of the mouth  : it  is
not  so  florid; the blood vessels in  its texture  arc
larger, and not so numerous.  This change,  however,
takes place very gradually, in  the  progress  of  the
membrane, from  the  orifice  of  the lips to  the back
part of the  cheeks.  Glandular bodies, like those  of
the  lips, are  situated  immediately exterior to  this
membrane of the cheeks, between it and the muscles:
their ducts open on its  surface.  These  glands  are
called Buccales.
   This lining membrane is continued from  the  inter-
nal surface of the lips and cheeks to the alveolar por-
tions of  the upper and lower jaws, which  are   in  the
cavity of the mouth,  and covers them, adhering firm-
ly to the periosteum.

  * Ruyseh had a fine  preparation of this structure.  See Thesaurus VIS.
Tab. IH. Fig. 5, 
16      Gums.—Surface of the Hard Palate.

  The  teeth  appear to have  passed  through aper-
tures in this  membrane, and  are  surrounded by it
closely at their respective necks.
  The portion of membrane, which thus  invests  the
jaws, constitutes the gums ;  which have now acquired
a texture very different from that of the  membrane,
from which they  were  continued.    They  are   ex-
tremely  firm  and  dense, and  very vascular.   It is
probable that  their ultimate structure is not perfectly
understood.
  In the disease called  scurvy, they tumify and  lose
the firmness of their texture : they acquire  a  livid
colour, and are much disposed to hemorrhage*
  From  the   alveoli of  the upper jaw,  the lining
membrane is continued upon the palatine processes  of
the upper maxillary and palate  bones, or the  roof of
the mouth.
  This membrane of the plate is not quite so  firm  as
that of the gums, and is  also less  florid:  it  adheres
firmly to the periosteum, and thus is closely fixed to
the bones.  There is generally  a ridge on its  surface,
immediately under the sature between the  two upper
maxillary bones ; and some transverse ridges are  also
to be seen upon it.   On  the  internal surface  of  this
membrane are  small glandular bodies, whose ducts
open on the surface of the palate.
  It is asserted, that this membrane has a limited  de-
gree of  that sensibility which is essential to the func-
tion of tasting; and, that if  certain  sapid substances
are carefully applied to it, their respective tastes  will
be perceived,  although they  have  not been in  contact
with the tongue.
  The membrane is continued from  the bones above
mentioned to the soft palate, or velum  pendulum  pa-
lati, which is situated immediately behind them. This
soft palate may be considered as a continuation   of
the partition between the nose  and  mouth; it is  at- 
Soft Palate*—Uvula.
17
tached to the posterior edge of the palatine  processes
of the ossa palati, and to the  pterygoid  processes of
the sphenoidal bone.  Its interior structure  is muscu-
lar.  The upper surface is covered by the  membrane
of the nose, the lower surface by the  membrane which
lines the mouth.
  The muscles, which  contribute to the composition
of this  structure, are the circumflexi, and  the  leva-
tores palatine above, and the constrictors isthmi  fau-
cium and palato-pharyngei   below.   (See vol. i. page
198—199.)  Thus composed, the  soft palate consti-
tutes the back part of the partition between the  nose
and  mouth.   When viewed  from  before,  with the
mouth open, it presents towards the tongue an arched
surface, which continues downwards  on each side, un-
til it comes nearly in contact with  the edges of that
organ.  On each of the lateral parts  of this arch, are
two pillars,  or rather prominent ridges, which project
into the mouth.   These ridges are at some distance
from  each  other  below, and  approach much nearer
above, so that they include a triangular space.  They
are called  the lateral  half  arches  of the  palate.
Each  of them is formed by a plate or fold of the lining
membrane of the mouth, and contains one of the two
last mentioned muscles:  the anterior, the  constrictor
isthmi faucium ;  the posterior, the  palato-pharyngeus.
These muscles of course, draw  the  palate  down to-
ward  the tongue when they contract.
  From the centre of the arch, near  its posterior
edge, is suspended the uvula, a conical body, which
varies in length from less than half an  inch, to rather
more  than one inch.  It is  connected  by its basis to
the palate;  but  its appex is loose and pendulous.
This  body is covered by the lining membrane  of the
mouth.  It contains many small glands, and a muscle
also, the azygos uvulae, which arises from  the posterior
edge  of the ossa palati, at the suture which connects
   vol. n.                3 
i!>                 The Tongue.
 them to each other, and, passing posteriorly upon  the
 soft palate, extends from the basis to the  apex  of  the
 uvula, into which  it is inserted.   By the  action  of
 this muscle, the length of the uvula can be very much
 diminished: and  when its contraction  ceases,  that
 body is elongated.
   The pendulous part of the uvula can also be moved,
 in certain cases, to either side.
   It is commonly supposed, that the principal  use of
 this little organ is  to modulate  the voice ; but there
 are  good reasons  for believing, that  it has another
 object.  It was remarked by Fallopius, (and the ob-
 servation has been  confirmed  by many surgeons since
 his time,) that  the  uvula may be removed completely
 without  occasioning  any  alteration of  the  voice, or
 any  difficulty of deglutition, if the soft palate  be left
 entire.
  The soft  palate is so flexible,  that it yields  to the
 actions of the levatores palati, which draw  it  up so
 as to close the posterior nares  completely.
  It also yields to the circumflexi or  tensores,  which
 stretch it so as to do away its arched appearance.
  It is therefore very properly called  the  Palatum.
 Molle.   It is also frequently called the Velum Pendu-
 lum palati, from the position which it assumes.

                   The Tongue,

  Which is a very important  part  of this  structure,
 is retained  in its position and connected with the parts
 adjoining it, by the following arrangements.
  The os-hyoides, which as its name imports,  resem-
bles  the  Greek letter ".or half an  oval, is situated
rather helow the angles of the lower jaw, in the mid-
dle of the upper part of the neck.   It is retained  in
its position by the sterno-hyoidei muscles, which con-
 nect it to the upper part of  the sternum ; by the co-
 raco-hyoidei, which pass to it  obliquely from the sea 
Structure of t\\e longuc.
19
pula; by the thyro-hyoidei, which pass to  it directly
upward from the thyroid cartilage: all of which con-
nect it to parts below.   To these should be added the
stylo-hyoidei, which pass to it obliquely from behind
and rather from above ;  the mylo-hyoidei, which come
rather anteriorly from the lateral parts of the  lower
jaw ;  and the genio-hyoidei, which arise from a situ-
ation  directly anterior and superior, the chin.   When
these muscles are at rest, the situation of the  os-hyo-
ides is, as  above  described, below the  angles  of the
lower jaw :  when those, in one  particular  direction,
act while  the  others are passive, the  bone may be
moved upwards or downwards, backwards or forwards,
or to either side.   This bone  may be  considered  as
the basis of the tongue ; for the posterior  extremity
of that organ  is attached to it; and  of  course the
movements of the bone must have an immediate effect
upon those of the tongue.
   The  tongue is a flat body of an oval  figure, but
subject to considerable changes of form.
   The posterior extremity, connected  to  the os-hy-
oides, is  commonly called  its basis; the  anterior ex-
tremity,  which, when the tongue is quiescent, is  ra-
ther more  acute, is called its apex.
   The lower surface of the tongue is connected with
a number of muscles, which are continued into its sub-
stance.   This connexion is such, that the edges of the
tongue are perfectly free and unconnected ; and so is
the anterior extremity for a considerable distance from
the apex towards the base.
   The substance of the tongue consists principally of
muscular fibres intermixed with a delicate  adipose
substance.   It is connected  to the os-hyoides by the
hyoglossus muscle, and  also by some other  muscular
fibres, as well  as  by a  dense  membranous  substance,
which appears to perform  the  part of  a ligament. 
20
Structure of the  Tongue.
This connexion is also strengthened by the continuance
of the integuments from the tongue  to  the  epiglottis
cartilage, to be hereafter described ; for that cartilage
is attached  by ligaments to the os-hyoides.
  The tongue is thin at its commencement as the os-
hyoides ;  hut it soon increases  in thickness.   The
muscular fibres in its composition have been considered
as intrinsic, or belonging wholly to  its  internal struc-
ture ;  and  extrinsic, or existing in part outside of this
structure.  The linguales muscles are intrinsic : (vol.'i.
page 197,) they are  situated near the under surface of
the  tongue,  one on each  side, separated from  each
other by the genio-hyo-glossi muscles, and  extending
from the basis of the tongue to  its apex.  These  mus-
cles can be easily traced as above described ;  but there
are also many fibres in the structure  of the tongue,
which seem to pass in  every direction, and  of course
are different from those of  the lingualis muscles.   To
these two  sets of fibres are owing many of the im-
mensely varied motions of  the  different parts of the
tongue.
  In addition to these, are the extrinsic muscles, which
originate from the neighbouring parts, and are insert-
ed and continued into  the substance of  the tongue.
  Among  the  most important of  these  muscles, are
those which proceed from the chin, or the genio-hyo-
glossi.  They are in contact with  each other;  their
fibres radiate from a central point on. the inside of the
chin, and are inserted  into the middle of the lower
surface of the  tongue: the  insertion commencing  at
a short distance from its apex, and continuing to its
base.
   As the genio-hyo-glossi  muscles have a considerable
degree of  thickness, they add  much  to  the bulk  of
the tongue in the middle of the posterior parts of it.
   The hyo-glossi and  the stylo-glossi, being continued 
              Papilla of the Tongue.            i\

into the posterior and lateral parts, contribute also to
the bulk of these parts.
  The  tongue,  thus  composed  and  connected,  lies,
when at rest, on  the mylo-hyoidei muscles;  and the
space between it and these  muscles is  divided  into
two lateral parts by the above  described  genio-hyo-
glossi.  In the space above mentioned, is a small sa-
livary gland, of an irregular oval form ; the greatest
diameter  of which extends from before backwards,
and its edges present outwards and  inwards.    It has
several excretory ducts,  the orifices  of which form  a
line on each side of the  tongue.   This gland  is  very
prominent under the tongue; and when the tongue is
raised it is particularly conspicuous;  it  is called the
Sublingual.
  The lining membrane of the mouth continues  from
the inside of the alveoli  of the  lower  jaw,  which it
covers, over the  sublingual glands to the lower surface
of the tongue.   In  this situation  it is remarkably thin;
but, as it proceeds  to the upper  surface of the tongue,
its  texture changes considerably; and on this  surface
it constitutes the organ of taste.
  The  upper  surface of the tongue,  although  it  is
continued from the  thin membrane  above described,
is formed by a rough integument which consists, like
the skin,  of three lamina.  The cuticle is  very  thin;
and under it, the rete mucosum* is thicker and softer
than  in other places.
   The true skin here abounds with eminences of va-
rious sizes  and forms, all  of which are denominated
Papillse.   The largest  of these are situated  on the
posterior part  of the tongue, and are so arranged that
they  form an angle rather acute, with its point back-

  *  M. Bichat appears  to have had doubts whether the real rete mucosum
existed here.  He says that he could  only perceive a decussation of vessels
in the intervals of the papilla*, which, as he supposes, occasioned the florid
colour of the tongue. 
!,iL.l
Papillse of the  Tongue.
wards.  They  are commonly nine  in number:  they
resemble an  inverted cone; or, are larger at  their
head than their basis.   They are situated in pits or
depressions, to  the  bottoms of which they  are  con-
nected.   In many of them there are follicles, or per-
forations, which have occasioned them to be  regarded
as glands.  They are called Papillae Maximse, or Ca-
pitals.
   The papillae, next in size, are denominated fungi-
form  by some  anatomists, and  Medice, or Semilenti-
eulares  by others.   They are  nearly  cylindrical in
form, with  their upper extremities regularly rounded.
They are  scattered over  the upper  surface  of the
tongue, in almost every part of it, at irregular distances
from each other.
   The third  class are called conoidal or villous. They
are  very numerous, and occupy the greatest part  of
the  surface of the tongue.    Although they are  called
conoidal, there is a great difference in  their  form ;
many of them being irregularly angular and serrated,
as well as conical.
   Soemmering and other German anatomists consider
the  smallest papillae as a fourth class, which they call
the  filiform: these lie between  the others.
   It is probable that these papillae are essential  parts
of the organ of taste ; and their structure is of course
an interesting object of inquiry.
   The nerves of the tongue have been traced to the
papillae, and  have been compared by some anatomists
to the stalk of the apple, while the papillae resembled
the  fruit;  but their ultimate termination does not ap-
pear to  have been ascertained.*

  • In the explanation of the plates, referred to in the following sentence,
Soemmering observes, that when the fibrillse of  the lingual nerve of the
fifth pair are traced to the papilla? of the second class, they swell out into
 a conical form ; and these  nervous cones are in  such close contact with
 each other, that the point of the finest needle could not be insinuated into
 the papil';r without touching a nerve. 
Blood vessels of the  Tongue.         &J
  Soemmering has lately published some elegant en-
graved  copies of drawings of these papillse,  when
they were magnified twenty-five  times ; from which
it appears that a very large number  of vessels,  parti-
cularly of arteries, exist in them.  These vessels are
arranged in a serpentine direction, and are  prominent
on  the  surface; but  they appear doubled,  and the
most prominent part is the doubled end.—This ar-
rangement of  vessels is perceptible on the sides of the
tongue, as well as on the papillse.
  Behind the large  papillse  is a foramen, first de-
scribed  by Morgagni,  and called by him Foramen
Cateum.  It  is the  orifice of a  cavity which  is not
deep ; the excretory ducts of several  mucous  glands
open into it.
  On the upper  surface  of  the  tongue, a  groove  is
often  to be seen, which is called  the linea  rnediana,
and divides it into two equal lateral parts.   Below,
the lining membrane of the mouth, as it  is  continued
from the lower jaw to  the tongue, forms a plait, which
acts as a ligament, and is called the frainum lingux.
It is attached to  the  middle  of  the tongue, at some
distance behind the apex.
  The  tongue is  well supplied  with  blood  vessels,
which are derived from  the lingual branch  of the
external carotid on each  side.   This artery passes
from the external carotid, upwards,  inwards, and for-
wards,  to the body of the  tongue.   In  this course it
sends off several small arteries to the contiguous parts,
and one which is spent about  the epiglottis and  the
adjoining parts, called the Dorsalis  Lingua:.   About
the anterior  edge  of  the hyo-glossus  muscle, it di-
vides into two large  branches: one of  which, called
the Sublingual, passes under the  tongue between
the genio-hyo-glossus and the sublingual  gland, and
extends near to the  symphysis of  the upper jaw;
sending branches to the sublingual gland, to the  mus- 
24         Blood vessels of the Tongue.

cles under  the  tongue,  to the skin, and  the  lower
lip.   The other is in the substance of the tongue, on
the under side near  the surface, and extends to  the
apex.
   The veins of this  organ are not  so regular as  the
arteries: they communicate with the external  jugu-
lar ; and some of them are always very conspicuous
under the tongue : these are called ranular.
   It is to be observed, that the vessels on  each side
have but little connexion with each  other ; for  those
of one side may  be injected while the others continue
empty.
   The tongue is also well supplied  with nerves, and
derives them  from  three  different sources on each
side, viz. from the fifth, the eighth, and ninth pairs of
the head.
   The lingual portion of the third branch of the fifth
pair,  passing under  the  tongue, enters  its substance
about the middle, and forms many minute  branches,
which  pass  to the  papillae of the  fore  part of  the
tongue.
   The glosso- pharyngeal portion of the  eighth  pair,
sending off  several  branches in its  course, passes to
the tongue near its basis, and divides into many small
branches, which  are  spent  upon the sides  and mid-
dle of the root of the tongue, and also upon the large
papillse.
   The  ninth pair of nerves  are  principally appro-
priated to the tongue.  They pass on each side to  the
most fleshy part  of it, and  after sending one branch
to the  mylo-hyoideus, and another  to  communicate
with the lingual  branch of the fifth pair, they  are
spent principally upon the  genio-glossi, and  linguales
muscles.
   The  tongue answers  a threefold purpose.   It is
the principal organ of taste.   It is a very important
agent in the articulation  of words; and  it assists  in 
                  Salivary Glands.              25

those operations upon our food, which are performed
in the mouth.

                The Salivary Glands.

  The salivary glands have such an  intimate connex-
ion with the  mouth that they may be described with
it.*
  There are three principal glands on each side:  the
Parotid, the Submaxillary and the Sublingual.  They
are of a whitish or pale flesh-colour, and are composed
of many small united masses or lobuli, each of which
sends a  small excretory duct to join similar ducts from
the other lobuli, and thereby form the great duct of
the gland.
  The Parotid is much larger than the other  glands.
It occupies a large portion  of the  vacuity between
the mastoid  process and the posterior  parts  of  the
lower jaw.   It extends from the ear and  the  mastoid
process  over a  portion of the masseter  muscle,  and
from the zygoma to the basis of the lower jaw.   Its
name is supposed to be derived from two Greek words
which signify contiguity to the ear.   It is  of  a firm
consistence.  It receives branches  from the external
carotid  artery and from its facial branch.
   From the anterior edge  of this gland, rather  above
the middle, the great duct  proceeds  anteriorly across
the masseter muscle;  and, after it has  passed over
it, bends inward through  the adipose  matter  of  the
cheek to the  buccinator  muscle, which  it  perforates
obliquely and opens on the inside of the cheek  oppo-
site to the  interval between the second and  third  mo-
lar teeth  of the upper jaw.  The aperture  of  the
duct is  rather  less  than the  general diameter  of it,
and this  circumstance has  the  effect  of a  valve.
When   the duct leaves  the parotid,  several  small

    * For a general account of glands, see the appendix to this volume.
   VOL.  II.              4 
2b       Parotid and Submaxillary Glands,

glandular bodies called socize  parotidis, are  often  at-
tached  to  it, and  their ducts  communicate with  it.
The main duct is  sometimes called  after Steno, who
first described it.
  When  the mouth is opened wide, as  in gaping,
there is often a jet of saliva from it into the mouth.
  The parotid gland furnishes the largest proportion
of saliva.
  It covers  the nerve called Portio Dura, after it
has emerged from the foramen stylo-mastoideum.
  The second gland is  called  the Submaxillary.    It
is much smaller than the parotid, and rather round in
form.   It is situated  immediately within  the angle
of the lower jaw,  between  it, on the outside, and  the
tendon of the digastric muscle and the  ninth  pair of
nerves  internally.   Its  posterior  extremity  is con-
nected  by cellular membrane to the  parotid  gland ;
its anterior portion lies over a part of the mylo-hyoi-
deus  muscles; and from  it  proceeds  the excretory
duct, which is of  considerable length, and passes  be-
tween the mylo-hyoideus and  the genio-glossus mus-
cles along the under and inner edge of the  sublingual
gland.  In this course the duct is sometimes surround-
ed  with small glandular bodies,  which  seem to  be
appendices  to the sublingual gland.   It terminates
under the tongue, on the side of the  frsenum  linguae,
by a small orifice which sometimes forms a papilla.*
  The orifice is often smaller than the duct;  in con-
sequence of which, obstruction frequently occurs here,
and produces the  disease called ranula.
  The sublingual  gland, which has already been men-
tioned,  lies so that, when the tongue is  turned up, it

 * Lassus informs us  that Oribases, afterwards all the Arabians, and sub-
sequently  Guy  De Chauliac, Lanfranc, Achillini, Berenger De Carpi,
Charles Etienne, Casserius and  several others have given the description
of  these salivary ducts, notwithstanding which Wharton, a physician of
London, attributed to himself the discovery of them on the bullock in
1«&6— Ed 
            Sublingual Gland.—Saliva.          27

can be seen protruding into the  cavity of the mouth,
and  covered  by the lining membrane,  which seems
to keep it fixed in its place.  It lies upon the mylo-
hyoideus, by the  side  of  the genio-hyoideus;  and is
rather oval in form and flat.    Its  greatest length is
from before backwards ; its position is rather oblique,
one edge being placed obliquely inwards and upwards,
and the other outwards and downwards.   It has many
short excretory ducts, which open by orifices arranged
in a line on each side:  they are discovered with diffi-
culty on account  of  their  small size, and sometimes
amount to eighteen or  twenty in number.   In some
few instances, this gland sends off a single duct, which
communicates with the duct of the submaxillary gland.
   The  salivary fluid secreted by these  glands  is in-
odorous, insipid,  and limpid, like  water; but much
more viscid, and of greater specific gravity.    Water
constitutes at least four-fifths  of  its  bulk  ; and  animal
mucus one half of its solid contents.  It also contains
some albumen, and  several saline  substances;  as the
muriate of soda,  and the phosphates of lime, of soda,
and of ammonia.
   It  is probable  that this fluid possesses  a  solvent
power with respect to  the  articles of food.
   There are small glandular  bodies, situated between
the masseter and  buccinator  muscles, opposite to the
last molar tooth of the  upper jaw, whose nature is not
well understood :  they are called Glandulse  Molares.

      The motions of the tongue are  very intelligible  to  a
        person who has a  preparation  of the lower  jaw  be-
        fore him, with the tongue in its natural situation, and
        the  muscles which influence it, properly dissected.
        Its complicated movements will appear the necessary
        result  of the action  of  those muscles upon it, and
        the os-hyoides; and also upon the larynx, with which
        the os-hyoides is  connected.   The muscular fibres
        of the tongue  itself  are also to be taken into this
        view, a? they act a very important part. 
28           Observations on the Tongue.

       Although the  tongue appears very necessary in a  me-
         chanical point of view, to the articulation  of many
         words, yet there are cases where it has been  entirely
         deficient, in which the parties thus affected, have been
         able to speak very well in general, as well as to dis-
         tinguish different tastes.*
       The tongue  is also a very delicate organ of touch.—
         We can perceive the form of the teeth,  and the state
         of the surface of the  mouth, more accurately by the
         application  of the tongue than of  the fingers.
       On  the three nerves which go to the tongue, it  is gene-
         rally supposed that the lingual portion of the  third
         branch of the fifth pair is  most  immediately  con-
         cerned in the function of tasting,  as it passes to  the
         front part of the surface of the tongue.   The glosso-
         pharyngeal are probably concerned in the same  func-
         tion on the posterior  part, while  the  ninth  pair of
         nerves seems principally  spent upon  the  muscular
         parts of the organ.
       It is obvious that the tongue is most copiously  supplied
         with nerves.  This  probably accounts  for the  great
         facility of its motions, and  the  power  of continuing
         them.

  * There is  a very interesting paper  on this subject, in the Memoirs of the
Academy of  Sciences for the year 1718, by Jussieu; in which he describes
the case of a female, fifteen years old,  examined by himself, who was bora
without a tongue.  In this paper he refers to another case, described by Hol-
land, a surgeon of  Saumur, of a boy nine years old, whose  tongue was de-
stroyed by gangrene.  In each of these cases the subject was able to  articu-
late very well, with the exception of  a few letters; and  also enjoyed the
sense of taste. 
CHAPTER III.
                 OF THE THUOAT.

  To avoid  circumlocution, the  word throat is  used
as a general  term to comprehend the structure which
occurs behind  the  nose and  mouth, and above the
oesophagus and trachea.  This structure consists,
  1st.  Of the parts  immediately behind the mouth,
which  constitute the Isthmus of the Fauces :
  2nd.  Of the parts  which form the orifice of the
windpipe, or the Larynx ;—and
  3d.  Of the muscular hag, which forms the cavity
behind  the  nose and  mouth  that terminates in the
oesophagus,  or the Pharynx.

                    SECTION  I.

           Of the Isthmus of the Fauces.

  In the hack part of  the mouth, on each side, are to
be  seen the two  ridges  or  half arches, passing  from
the soft palate of the  root of the tongue,  mentioned
in page 25, and  said  to be  formed  by plaits of the
skin containing muscular fibres.   The anterior  plait,
which contains the muscle called Constrictor Isthmi
Faucium, passes directly from the side of the root of
the  tongue  to the  palate, and  terminates  near the
commencement  of  the uvula.   The  posterior  plait
runs from the palate obliquely downwards and  back-
wards, as it contains  the  palato-pharyngeus muscle,
which passes from the  palate to the upper and  poste-
rior part of the thyroid cartilage.
  In the triangular space between these  ridges  is si-
tuated  a  glandular  body,  called the Tonsil Jmyg- 
30             Tons iis. —Epiglottis.

dala.  This gland has an oval form, its longest dia-
meter extending from  above downwards.   Its surface
is rather convex, its natural colour is a pale red.  On
its surface are the large orifices of many cells of con-
siderable  size, which exist  throughout  the  gland.
These  cells often communicate with  each other, so
that a probe can be passed in  at  one orifice and out
at the other.
  Into these cells open  many  mucous  ducts, which
discharge the mucous of the throat, for the purpose
of lubricating the surface, and facilitating the  trans-
mission of food.
  The epiglottis, or fifth  cartilage  of the larynx, is
situated at the root of  the tongue, in the middle, be-
tween the tonsils.   The part which is in sight is part-
ly oval in form, and of a whitish colour.  Its position,
as respects the  tongue, is nearly perpendicular, and
its anterior surface rather convex.
  The membrane  continued from the tongue over the
epiglottis is so arranged that it  forms a plait, which
extends from  the  middle of the root of  the  tongue
along the middle of the  anterior surface of the epi-
glottis, from its base upwards.
  On each side of this plait,  or fraenum, at the junc-
tion of the surfaces of the tongue and of the  epiglot-
tis, there is often a depression, in which small portions
of food sometimes remain : and a small fraenum,  simi-
lar  to that above described, is sometimes seen on the
outside of each of these cavities.
  The epiglottis  is situated  immediately before the
opening  into  the  larynx.
  The above described parts can be  well  ascertained
in the living subject, by a person  who  has a general
knowledge of the structure.  Thus, looking into the
mouth, with the tongue depressed, the uvula and soft
palate are  in  full view  above, and  the epiglottis  is
very perceptible below :  while the two ridges or  la- 
Of  the Laryru:,               31
teral half arches can be  seeu on each side, with the
tonsil between  them.

                    SECTION 11.

                  Of the Larynx.

   In this structure are live cartilages, upon which its
form and  strength  depends,  viz.  the  Cricoid,  the
 Thyroid, the  two Arytenoid,  and the Epiglottis.
These cartilages are articulated  to  each  other, and
are  supplied with muscles  by which certain  limited
motions are effected.
   The basis of the structure is a cartilaginous ring,
called the cricoid cartilage, which  may be considered
as the commencement of the windpipe.
   It may be  described  as  an irregular section  of  a
 tube: its lower  edge connected  with  the  windpipe,
 being nearly horizontal when the body is  erect;  and
 the  upper  edge  very oblique, sloping from before,
 backwards  and upwards :  in  consequence of this, it
 has  but little depth before,  but is eight or nine lines
 deep behind.
   The  Thyroid cartilage is a single plate, bent in such
 manner  that it forms an acute angle  with  two similar
 broad surfaces on each side of it.   It is so applied  to
 the  cricoid  cartilage, that the lower edge of the angu-
 lar part is at a small distance above the front  part  of
 that cartilage, and  connected to it by ligamentous
 membrane : while its broad sides are applied  to it la-
 terally,  and thus partially enclose it.
   The upper  edge of the angular part of the thyroid
 cartilage forms a  notch ; and  the natural position  of
 the cartilage is such, that this part is very prominent
 in the neck;  it is called the Pomum Adami.
   Both the upper and lower edges of the thyroid car-
 tilage terminate  posteriorly in processes, which air 
32     Arytenoid Cartilages and Ligaments.

called  Cornua.   The  two  uppermost are longest :
they are joined by ligaments to the extremities of  the
os-hyoides.   The lower  and shorter  processes  are
fixed  to the cricoid cartilage.   The thyroid cartilage,
therefore, partly rests upon the cricoid cartilage  be-
low, and  is attached to the os-hyoides above.   It is in-
fluenced  by the muscles  which act upon  the os-hyoi-
des, and  also by some muscles which are inserted into
itself.   It is  moved obliquely downwards and  for-
wards, in a slight degree,  upon the  cricoid  cartilage,
by a small  muscle,  the  crico-thyoideus, vyhich arises
from that cartilage  and is inserted into it.
  The Arytenoid cartilages are  two small  bodies of
a triangular pyramidal form, but slightly curved back-
wards.  They are placed  upon the upper and poste-
rior edge of the cricoid  cartilage, near to each other;
and their upper  ends,  taken together, resemble  the
mouth  of a pitcher or  ewer ;  from  which circum-
stance their name  is derived.  Their bases are broad ;
and on  their lower  surfaces, is a cavity, which  cor-
responds with the convex edge of the cricoid cartilage,
to which they are applied.   At these places, a  regular
moveable articulation is  formed, by a capsular ligament
between each of these cartilages  and  the  cricoid, in
consequence of  which they can  be inclined  backward
or forward, inward or outward.
  From the anterior part  of each of these cartilages,
near the base, a tendinous  cord passes forward, in a di-
rection which is horizontal when the  body is erect, to
the internal surface of the angle of the thyroid.   These
ligaments are not perfectly  parallel  to  each other;
for they are nearer before than behind.  The aper-
ture between them is  from two to  five  lines wide
when the muscles are not in action ;  and this aperture
is the orifice of the  windpipe : for the  exterior space,
between these  ligaments  and the  circumference  of
the thyroid, is  closed up  by membrane  and  muscle.. 
Epiglottis.
33
At  a small  distance above these ligaments are two
others, which also pass from the arytenoid to the thy-
roid cartilages.  They are not so tendinous and dis-
tinct as the first mentioned, and cannot be  drawn  so
tense  by the  mucles  of  the  arytenoid cartilages.
They are also situated at a greater distance  from each
other, and thus form a large aperture.
  On  the  external  side  of the  upper  extremity  of
each of the arytenoid cartilages, and nearly  in contact
with it, is a small cartilaginous body, not  so large  as
a grain of wheat, and  nearly oval  in form.   These
are connected firmly to the arytenoid cartilages, and
are called their appendices.  Being in the  margin  of
the aperture of  the larynx, they  have an effect upon
its form.
  The arytenoid cartilages are the  posterior parts  of
the larynx :  the Epiglottis, which  has  already been
mentioned is  the  anterior.   When this cartilage is
divested of  its membrane, it is oval  in  its upper ex-
tremity,  and rather angular below, terminating in a
long narrow process, which is like the stalk of  a leaf.
  It is firmly attached to  the  internal surface  of the
angular part  of the thyroid  by this lower process;
and, being placed in a perpendicular position,  one  of
its broad surfaces is anterior towards the  tongue, and
the other posterior, towards the opening of the wind-
pipe.
  It is attached to the os-hyoides  by dense cellular
texture or ligament, and to the tongue by those plaits
of the membrane of the mouth, which have been  al-
ready described.
   It is elastic, but more flexible  than the other carti-
lages ; being somewhat different in its  structure.—
Its surface is perforated by the orifices  of  many mu-
cus ducts.
   There is a small space  between the  lower part of
this cartilage, and the upper part of the  thyroid and
   vol, n.                5 
34
Rima Glottidis.—Glottis.
 the ligamentous membrane passing from it  to  the  os-
 hyoides.   In this  is a  substance, which  appears  to
 consist of glandular and of adipose matter.   It is sup-
 posed that some of  the orifices on  the lower  part  of
 the epiglottis communicate with this substance.
   In the  erect position of the body, the epiglottis is
 situated  rather  higher up than the arytenoid  carti-
 lages, and at the distance of ten or twelve  lines  from
 them.
   The membrane which  covers the  epiglottis, is ex-
 tended from each side of it to the arytenoid  carti-
 lages : and being continued into  the  cavity of the la-
 rynx, as  well  as  upon  the  general  surface  of the
 throat, it is necessarily doubled :  this doubling  forms
 the lateral margins of the orifice of the cavity of the
 larynx.    In these  folds  of the  membrane are seen
 very  delicate muscular fibres, called the Aryteno-epi-
 glottidei.
   The membrane  continues  down the cavity of the
 larynx, and, covering the upper ligaments, penetrates
 into the   vacuity between  them and  the  lower  liga-
 ments, so  as to form a cavity on each  side  of  the  la-
 rynx, opening between the two  ligaments, which  is
 called the Ventricle  of Morgagni.   The shape  of
 these cavities is oblong.   Its greatest length extends
 from  behind forward, on  each side  of the  opening
 into the windpipe formed by the two lower or princi-
 pal ligaments; so that when  the larynx is removed
 frpm  the  subject, upon looking into  it from above,
 you perceive three  apertures:  one  in the middle,
formed by the two lower ligaments; and one on  each
 side of it, between  the  lower and  upper ligament,
which is the orifice of the ventricle of Morgagni.
  The aperture  between the two lower ligaments  is
called the Rima Glottidis, or Chink  of the Glottis ;
the upper aperture, formed by the fold  of  the mem- 
        Arteries and Nerves of the Larynx.      :',j

brane extending from the epiglottis  to the arytenoid
cartilages, may be  termed Glottis.
  If the windpipe is divided near the larynx, and the
larynx inverted, so that the rima glottidis may be ex-
amined from below, the structure  appears still  more
simple : it resembles a septum  fixed abruptly in the
windpipe, with an aperture in it of the figure of the
rima glottidis.
  The anterior surface of  the  two arytenoid  cartila-
ges is concave.  This concavity is occupied in each
by a glandular substance, which lies between the car-
tilage and the  lining  membrane ; and  extends itself
horizontally,  covered  by the  upper ligament  of the
glottis.   The nature of these bodies is not perfectly
understood ; but they are supposed to secrete mucus.
  The membrane, which lines the cavity of the glottis
being continued from the mouth and throat, resembles
the membranes  which invest  those parts.   In some
places, where it is in close  contact with the cartilages,
it appears united with the perichondrium, and acquires
more firmness and density.
  The general motions of  the  larynx  are very intel-
ligible to those who are acquainted  with  the  muscles
which  are connected  with  the thyroid cartilage, and
which  move the os-hyoides.  They take place  parti-
cularly in deglutition, and in some  modifications of the
voice ; and also in vomiting.
  The motions of the particular cartilages on  each
other can also be well  understood, by attending  to
the origin and insertion of  the  various  small  muscles
connected with them.   The most  important of these
muscles are the crico arytenoidei postici and laterales,
the thyreo-arytenoidei, the arytenoidei  obliqui, and
the arytenoideus  transversus.   The effects of their
actions appear to be  the dilating  or contracting the 
30       Arteries and nerves of the Larynx.
rima glottidis, and relaxing or extending the ligaments
which form it.
   The arteries of the  larynx  are derived  from  two
sources, viz. the superior thyroid, or laryngeal branch
of the external  carotid ;  and  the thyroid branch  of
the  subclavian.
   The nerves of the larynx also come  to it in  two
very different directions on  each  side.    It receives
two  branches from the  par vagum ;  one  which leaves
that nerve  high up in the neck, and is called the  Su-
perior Laryngeal  branch ; and another  which  pro-
ceeds from  it after it has passed into the cavity of the
thorax, and is called from its direction the Recurrent.
The extreme irritability of the glottis is unequivocally
  demonstrated by the cough which is excited when a
  drop of water, or any other mild liquid, or a  crumb
  of bread enters it.   Notwithstanding this, a flexible
  tube, or catheter, has several times been passed  into
  the  windpipe through the rima glottidis,  and been
  endured by the patient a considerable time.
The cough, which occurs when these parts are irritated,
  does not appear to arise exclusively from  the  irrita-
  tion of the membrane within the glottis; for,  if it
  were so,  mucilaginous substances, when  swallowed
  slowly, could not suspend it.   Their effect in  reliev-
  ing cough is universally known ; and as they are only
  applied to the surface exterior to the glottis, it is evi-
  dent that the irritation of this surface must also  pro-
  duce coughing.
Several curious experiments have been made to  deter-
  mine the effect of dividing the different nerves which
  go to the  larynx ;  by which  it appears that  the re-
  current branches supply parts  which  are  essentially
  necessary to the  formation of the  voice, whilst the
  laryngeal branches supply parts which  merely influ-
  ence its modulation, or tone.   See Mr.  Haighton's
  Essay on this subject: memoiies of the  Medical So-
  ciety of London,  vol. iii. 
         The Thyroid Gland*-The Pharjjn.r.     3,7

                 The  Thyroid Gland

  May be described here, although a part of it is si-
tuated below the larynx.
  This body consists of two lobes, which  are  united
at their  lower extremities by a portion which extends
across the anterior part of the windpipe.  Each  lobe
generally rises upwards and  backwards  from the  se-
cond cartilaginous ring of the windpipe over the cri-
coid cartilage and  a portion of the thyroid.   It lies be-
hind the sterno-hyoidei, and sterno-thyroidei muscles.
It is of a reddish-brown colour, and appears to  con-
sist of a  granulous substance;  but  its ultimate  struc-
ture  is  not  understood.   It is  plentifully supplied
with blood, and receives  two arteries  on  each  side :
one  from the laryngeal branch of  the external carotid :
and  the  other from  the thyroid  branch of the  sub-
clavian.
  Notwithstanding this  large supply of blood, there
is no  proof that  it  performs  any  secretion : for al-
though several respectable anatomists  have  supposed
that they discovered  excretory ducts  passing  to  the
windpipe,  larynx,  or  tongue, it  is  now  generally
agreed that such excretory ducts are not to be  found.
Several   instances have however  occurred,  in  which
air  has  been  forced,  by violent  straining,  from  the
windpipe into the substance of this gland.*

  * There are two membranous expansions in the neck which should be no-
ticed in its dissection.  The first called Fascia Superficialis lies immediately
beneath the skin, may be considered as a continuation of the fascia supeii-
ciales abdominis, and  is  strongly connected to the base of the lower jaw,
being also spread over the parotid gland  It is not very distinct in all sub-
jects.  The second is called the Fascia Profunda Cervicis ; it extends from
the larynx and thyroid gland to the upper part of the sternum and first ribs,
the great vessels, &c. of  the superior mediastinum are placed immediately
below it.—Er>. 
38          Structure of the Pharynx.
                    SECTION in.

                  Of the Pharynx.

   The pharynx is a large muscular  bag, which forms
 the great cavity behind the nose and mouth  that  ter-
 minates in the oesophagus.
   It has been  compared  to a funnel, of which the
 oesophagus is the pipe; but it differs from a funnel in
 this respect, that it is incomplete in  front, at the part
 occupied  by the nose and mouth and larynx.
   It is connected above, to  the cuneiform process of
 the occipital bone", to the pterygoid  processes of the
 sphenoidal, and to both  the upper and lower maxillary
 bones.  It is in contact  with  the cervical vertebrae be-
 hind ; and, opposite to  the cricoid cartilage, it termi-
 nates in the oesophagus.
   If the pharynx and oesophagus be carefully dissect-
 ed and detached from the vertebrae,  preserving the
 connexion of the pharynx with the head ; and the head
 then be separated  from the body, by dividing  the ar-
 ticulation  of the atlas and the os-occipitis, and cutting
 through the soft parts below  the larynx ; the  resem-
 blance to a funnel  will be very obvious.
   In this situation, if an incision be  made from above
 downwards through the whole extent of the posterior
 part of the pharynx, the communication of the nose,
 mouth, and windpipe, with  this cavity, will be  seen
 from behind at one view.
   The openings into the nose, or the posterior nares,
 appear uppermost.   Their figure is  irregularly oval,
 or oblong; they are separated from  each other by a
 thin partition,  the vomer.   Immediately behind, on
 the  external side of each  of  these orifices,  is  the
 Eustachian tube.
   The  soft palate will  appear extending from the
lower  boundary  of  the  posterior  nares, obliciuelv 
            Structure of the Pharynx.          3'.)

backwards and downwards, so as nearly to close the
passage into the  mouth.   The uvula hangs  from it;
and, on each side of the uvula, the edge of the palate
is regularly  concave.
  Below the palate, in the isthmus of the fauces, are
the ridges  or half arches,  and the tonsils  between
them.   The half arch  which  presents  first, in this
view, runs  obliquely  downward and backward, and
not parallel  to the other.
  Close to  the  root  of the  tongue  is  the  epiglottis
erect; and, immediately adjoining it, is an  aperture
large enough to  admit the end of a middle-sized fin-
ger.  This  aperture is widest at the extremity next
to the epiglottis, and rather narrower at the other ex-
tremity :  it  is the glottis or opening of the windpipe.
When  the larynx  is  elevated, the  epiglottis can be
readily depressed so as to cover it  completely.
  The  extremities of  the  arytenoid cartilages, and
their appendices, may be  recognised at the  posterior
edge of the glottis.   At a short distance below this
edge, the  oesophagus begins.
  The Pharynx is composed of the membrane  conti-
nued from the  nose and  mouth internally, and of a
stratum of muscular fibres externally.   The internal
membrane is very soft and flexible, and  perforated by
many muciferous ducts.   The surface which  it  forms
is rather rough,  owing to the mucous glands  which it
covers.  It  has a red  colour, but not so  deep as that
of  some other parts.  It is connected to the  muscular
stratum by a loose cellular membrane.
  The muscular coat consists of three different por-
tions, which are  considered  as  so many distinct mus-
cles.
  The  fibres of each of  these  muscles  originate  on
each side, and run in  an oblique direction to meet  in 
40          Structure of the Pharynx.
the middle, thus forming the posterior  external  sur-
face of the dissected pharynx.
  The fibres of the upper muscle originate  from the
cuneiform process of the occipital bone,  from the  pte-
rygoid processes of the os-sphenoides,  and  from the
upper and  lower jaws, near the last  dentes molares,
on each side.   They unite  in  a middle  line in the
back of the pharynx.
  The fibres of the  middle muscle originate  princi-
pally  from  the lateral  parts of the  os-hyoides,  and
from the ligaments  which connect  that bone to the
thyroid cartilage.  The superior fibres  run  obliquely
upwards, so as to cover a part of the  first mentioned
muscle, and terminate in the cuneform process of the
occipital bone ; while the other fibres unite with those
of the opposite side in the middle line.
  The fibres of the lower muscles arise  from the thy-
roid and the cricoid cartilages, and  terminate  also  in
the middle line.  Those which are  superior, running
obliquely  upwards;  the inferior, nearly  in a trans-
verse  direction.
  It is obvious, from the origin and  insertion of these
fibres, that the pharynx must have the power  of con-
tracting its dimensions in  every respect; and, parti-
cularly, that its diameter may be lessened at any place;
and that the whole may be drawn upwards. 
SYSTEM  OF ANATOMY;

               PART VII.
                 OF THE THORAX.

  Before the thorax is described, it will be in order
to consider the

                     Mammse ;

  Or those glandular bodies  situated on the anterior
part of it, which, in females, are destined  to the se-
cretion of milk.
  These glands lie between  the skin and the pectoral
muscles, and are attached to  the surfaces of those mus-
cles by cellular membrane.
  They  are  of a circular  form;  and consist  of  a
whitish  firm substance, divisible into small  masses or
lobes, which are composed of smaller  portions or lo-
buli.  Between these glandular portions, a great deal
of adipose matter is so diffused, that,  it constitutes  a
considerable part of the bulk of the mammae.
  The gland, however, varies greatly in thickness in
the same person at different periods of life.
  The mammae become much enlarged about the age
of puberty.  They are also very large during preg-
nancy and lactation;  but after the period  of child-
bearing, they diminish considerably.   They are sup-
plied with blood by the external and internal mamary
  VOL.  II.              6 
 42                    Mamniu'.

 arteries, the branches of which enter them irregularly
 in several different places.
   The veins correspond with the arteries.
   From the small glandular portions that compose the
 mamma, fine excretory tubes arise, which unite  toge-
 ther and  form  the great lactiferous ducts of  the gland.
 These ducts proceed in a radiated  manner  from  the
 circumference  to the centre, and terminate on the sur-
 face of the nipple.*
   They are commonly  about fifteen in number, and
 vary considerably in size :  the  largest of them being
 more than one sixth of an inch in diameter.
   They can be very readily injected by the  orifices
 of the  nipple, from  a pipe  filled  with murcury,  in
 subjects who have died during lactation or pregnancy;
 but they are very small in subjects of  a different de-
 scription.
   It has been asserted  by respectable anatomists,  that
 these ducts communicate freely with each other ; but
 they do not appear to do so : each  duct seems to be
 connected with its proper branches only.f
   Haller appears to have entertained the remarkable
 sentiment,  that some  of the ducts  originated in the
 adipose matter about the gland, as well as in the glan-
 dular substance,:{:
   The  papilla, or  nipple, in which these ducts  ter-
 minate, is in the  centre of the  mamma: it consists  of
 a firm elastic  substance, and is nearly cylindrical  in
 form.   It is rendered tumid by irritation, and  by cer-
 tain  emotions.
   The lactiferous ducts terminate upon its extremity.
When it is elongated they can  freely discharge their
  * Described in the 16th century, by Charles Etienne, Vesalius and Posthius
bat their uses were unknown.—Ed.
  t See Edinburg Medical Commentaries, vol. i. page 31—a paper bv Mec-
kel.—-0,d.
  $ Elementa Physiologiae, Tom. 7, Pars II, pa^e 7 
Main m&.
43
contents;  but when it contracts, this discharge is im-
peded.
  The skin immediately  around the  nipple is of a
bright red colour in virgins of mature age.  In preg-
nant women it is sometimes almost black ;  and  in wo-
men who have borne children it is often brownish.  It
abounds with sebaceus glands, which form small  emi-
nences on its surface.
  This gland exists in males, although it is very small.
In boys, soon after birth, it has often been known to
tumefy, and become  very painful, in consequence of
the  secretion  and accumulation  of a  whitish  fluid,
which can be discharged by pressure.   It also some-
times swells and is painful, in males at the age of pu-
berty.
  There have been some instances in which it has se-
creted milk in adult  males ; and a  few instances also
in which it has been affected with cancer, in the same
sex.
  The mamma is plentifully supplied  witli  absorbent
vessels, which pass from it to the lymphatic glands in
the axilla.
  Its nerves are principally derived from the  great
plexus formed by the nerves of the arm. 
CHAPTER I.
     OF THE GENERAL CAVITY OF. THE THORAX.

                    SECTION I.

     Of the form of the Cavity of the Thorax.

  The osseous structure of the thorax is described in
vol. i. page 102.   The cavity is completed by the in-
tercostal muscles, which close  the vacuities  between
the ribs ; and by the diaphragm, which fills up  the
whole space included within its lower  margin.
  If we except  the apertures of the  diaphragm,
which are completely occupied by the  aorta,  the vena
cava, and the oesophagus, &c. the  only outlet of  this
cavity is above :  it is formed by the   upper  ribs, the
first dorsal  vertebra, and  the sternum.   The figure of
this aperture  is between  that  of the  circle  and  the
oval; but it is made irregular  by the vertebras,  and
by the upper edge of the sternum.
  When the superior extremities  and  the muscles ap-
propriated  to them  are removed, the  external figure
of the thorax is conical;  but the cavity formed by it
is considerably influenced by the spine, which pro-
trudes into it; while the  ribs,  as  they proceed from
the spine, curve backwards, and thus increase its pro-
minency in the cavity.
  The diaphragm  has a great effect upon the  figure
of the cavity of the thorax.  It protrudes into it from
below, with a convexity of such form  that  it  has been
compared to an  inverted bowl; so that, although it
arises from the lower margin of the thorax,  the cen-
tral parts of it are nearly as high as the fourth rib. 
Plcurw.
■4."»
  The  position of the  diaphragm is  also  oblique.
The anterior portion  of  its margin, being connected
to the seventh and eighth ribs, is  much higher than
the posterior portion, which is attached to the eleventh
and twelfth.
  In consequence of the figure and position  of  the
diaphragm, the form  of  the  cavity of the  thorax  re-
sembles that of the hoof  of the ox when its  posterior
part is presented forwards.

                    SECTION II.

         Of the arrangement of the Pleura:.

  The  thorax  contains the  two lungs and  heart, as
well as  several very important parts of smaller size.
  The  lungs occupy the greatest part of the cavity ;
and to each of them  is appropriated a complete  sac,
called Pleura, which is so arranged  that  it covers
the  surface of the lungs, and is continued  from it to
the contiguous surface of the thorax, which it lines.
After covering the lung, it is extended from it to  the
spine posteriorly,  and the  sternum  anteriorly :  so  that
in tracing the  pleura  in a circular  direction, if  you
begin at the sternum,  it proceeds on the inside of the
ribs to  the spine ; at the spine it  leaves  the  surface
of  the thorax, and proceeds directly forwards towards
the sternum.   In  its course from the spine to the ster-
num, it soon meets with  the great branch of  the wind-
pipe and the blood vessels, which go to the lung :  it
continues on these vessels  and round the lung  until  it
arrives at the anterior  side  of  the vessels, when  it
again proceeds forwards until it arrives  at  the  ster-
num.   Each sac  being arranged  in the same  way,
there is a part of  each extended from the  spine to the
sternum.  These  two lamina, form the great  vertical
septum of the thorax,  called Mediastinum.   They
are situated at some distance  from  each  other; and 
■4ti
Mediastinum.
the heart, with  its investing  membrane or  pericar-
dium, is placed between them.
  The pericardium is also a complete sac or  bladder,
which, after covering perfectly  the surface of the
heart, is extended from it so as to form a sac, which
lies loose about it, and appears to contain it.   This
loose portion adheres to those parts of the  laminse
of the  mediastinum with  which  it  is contiguous;
and thus  three chambers are formed within the cavity
of the  thorax :  one for each  lung,  and one for the
heart.
  The two lamina of the pleura, which constitute the
mediastinum,  are  at different distances  from  each
other, in different places.   At the upper part  of the
thorax,  they  approach  each other  from  the  inter-
nal edges of the  first ribs; and, as these include  a
space which is  nearly circular, the vacuity between
these lamina is  necessarily  of that form, at  its com-
mencement above.
  Here,  therefore, is a space between them  above,
which is  occupied by the  great  transverse vein  that
carries the blood of the left subclavian and the left in-
ternal jugular to the superior cava; by the  trachea;
by the oesophagus ; and by the subclavian and carotid
arteries,  as  they  rise from the  curve of the aorta.
This space is bounded below by the above mentioned
curve of the aorta.
  The heart and pericardium are so placed that there
is a small distance between them and the sternum :  in
this space the two lamina of the mediastinum are very
near to each other ; and cellular substance  intervenes
between them.  This portion of the mediastinum  is
called the Anterior Mediastinum.
   Posteriorly, the heart and pericardium  are also  at
a small distance from the spine ;  and here  the lamina
of the mediastinum are  at a greater distance from
each other,  and form a  long narrow cavity which 
              Preparation of the Tliorax.          4 J"

 extends down the  thorax in front of the  vertebrce:
 this is  called the Posterior Mediastinum.   It con-
 tains a  considerable portion of the aorta as it descends
 from its curve,  the  oesophagus,  the thoracic duct, and
 the vena azygos.   The aorta is in contact with  the
" left lamen,  and can often be seen through it when  the
 left lung is lifted up.
    The oesophagus is in contact with the right lamen:
 in its progress downwards, it inclines to  the left side
 and is advanced before the aorta.
    The vena azygos appears posterior to  the  oesopha-
 gus ; it proceeds upwards until it is as high  as  the
 right branch of the windpipe:  here it bends  forward,
 round that branch, and opens into the superior cava,
 before  that vein opens into the right auricle.
    The thoracic duct  proceeds upwards  from  below,
 lying in the space  between  the aorta and the vena
 azygos, until the beginning of  the curve of the aorta,
 when it  inclines to the left, proceeding towards  the
 place of its termination.


       The formation  of the mediastinum, and the arrangement
          of  the pleura, as well as the connexion of these mem-
          branes with the parts contained in the thorax, may be
          studied advantageously, after the subject has been
          prepared in the manner now to be described.
       Take away, from each side, the five ribs which  are  situ-
          ated between the first and  last true ribs, by separating
          their cartilages from the sternum, and their heads from
          the spine; so that the great cavities of the thorax
          may be laid open.
       The precise course of the mediastinum is thus rendered
          obvious ; and the sternum may now be divided with a
          saw throughout its whole length in the same direction ;
          so  that the division of the bone may correspond  with
          the space between the lamina of the mediastinum.
        Separate the portion of the sternum cautiously, so as to
          avoid lacerating the lamina of mediastinum ; and keep
          them separate, while the trachea is dissected from the
          neck iuto the cavity of the thorax; the great trans- 
48
Preparation of the Thorax.
  verse vein and the descending cava are dissected  to
  the pericardium;  and the left carotid  artery, with
  the right subclavian and carotid, are dissected to the
  curve of the aorta, taking care not to destroy the  la-
  mina of the mediastinum.
After this preparation the upper space between the la-
  mina of the mediastinum can be examined; and the'
  relative situation of the trachea and the great vessels
  in it can be understood.   The anterior mediastinum
  can also be studied : the root of each lung, or its
  connexion with the mediastinum, may be seen  per-
  fectly j  and the precise  situation  of the lung, in its
  proper cavity, may be well conceived.
After this,  while the portions of the sternum are  sepa-
  rated, the pericardium may be opened, and the heart
  brought into  view :  the  attachment of the  pericar-
  dium, and to  the mediastinum, and to the diaphragm,
  may be seen  with  advantage  in this situation.  The
  portions of the  sternum may now be  detached from
  the ribs, with  which they remain connected ;  and fur-
  ther dissection may be performed to examine the pos-
  terior mediastinum ana  its contents,  and the  parts
  v hich constitute the roots of the lunjrs. 
CHAPTER II.
OF THE HEART  AND THE  PERICARDIUM, AND THE
  GREAT VESSELS CONNECTED WITH  THE  HEART.

                    SECTION I.

                Of the Pericardium.

  The heart is enclosed by a membranous sac, which,
upon  a  superficial  view,  seems only connected  with
its great vessels : but which, in fact, adheres closely
to the whole of its surface.   From this  surface it is
extended to those vessels  ; from  which  it  proceeds,
after  the  manner of the  reflected  membranes,  and
forms an enclosure that lies loosely about the  heart.
If it were dissected from the heart, without laceration
or wounding, it would  be an entire sac.
  The pericardium,  thus arranged, is placed between
the two  lamina of the mediastinum, and adheres firm-
ly to them  where they are  contiguous to it; it  also
adheres firmly to the diaphragm below, and thus pre-
serves the heart  in its proper position.
  The figure of  the  pericardium, when it is  distend-
ed, is somewhat  conical ;  the base being on  the dia-
phragm.   The cavity formed by it is larger  than  the
heart after death, but  it is probable, that the heart
nearly fills it during  life ;  for, when this organ is dis-
tended by injection,  it  often occupies the  whole cavi-
ty of the pericardium.
  The  pericardium  is  composed  of two lamina, the
internal of which covers the heart, as has been  alrea-
dy  described;   while   the  external  merely extends
over the loose portion of the other, and  blends itself
  VOL.  II.                7 
50
Of the Heart.
with the mediastinum, where that  membrane  invests
the great vessels.
   The  internal surface of  the  pericardium  is  very
smooth  and  polished; and  in  the living  subject is
constantly moistened with  a fluid, which is probably
effused  from  the exhalent vessels on its surface.
   The  quantity of this fluid does  not commonly ex-
ceed two drachms;  but in  cases of disease it some-
times amounts to many ounces.*   It is naturally trans-
parent, but slightly tinged  with red  in  children, and
yellow in old persons.  It is often slightly tinged with
red in persons who have died by violence.

                     SECTION II.

                   Of the  Heart

   The great organ of the circulation consists of mus-
cular fibres,  which are so arranged that  they give it
a  conical form, and compose  four distinct   cavities
within it.
   Two of these cavities, which are  called Auricles,
receive the contents of the  veins ;  the other two com-
municate  with  the arteries, and are called Ventricles.
   The auricles form  the basis of the  cone ;  the ven-
tricles the body and apex.
   The structure of the auricles is much  less firm than
that of  the ventricles, and  consists  of a  smaller pro-
portion  of muscular fibres.   They appear like  ap-
pendages of  the heart, while the  ventricles  compose
the body of  the viscus.
   The  ventricles are very thick, and are composed
of muscular fibres closely compacted.

  "The pericardium has been so distended, by  effusion in dropsy, that it
has formed a tumour, protruding on  the neck  from under the sternum.
This tumoar had  a  strong  pulsating  motion. It disappeared  completely
when the other hydropic symptom? were relieved. 
Connexions of the Heart           51
The figure of the heart is not regularly conical;  for
a portion of it, extending from the apex to the base,
is flattened ;  and in its natural position, this flat part
of the surface is downwards.
  It is placed obliquely in the body; so that its base
presents backward and to the right, and its apex for-
ward and  to the left.
  Notwithstanding this obliquity, the terms right and
left are applied to the different  sides  of  the  heart,
and  to the different auricles and  ventricles ;  although
they might, with equal  propriety, be called  anterior,
and  posterior.
  The  two great veins  called  Vense  Cavse,  which
bring the  blood from every part of the  body, open
into the right auricle from above and below;  the right
auricle opens  into the right ventricle;  and from  this
ventricle arises  the  artery denominated Pulmonary,
which passes to the lungs.
  The Pulmonary veins, which  bring back the blood
from the  lungs, open into the left auricle ; this auri-,
cle opens  into the left  ventricle ;  and from  this ven-
tricle proceeds the Aorta, or great artery, which  car-
ries blood to every part of the body.
  The heart is preserved in  its  position,  1st, by the
venae cavse, which are  connected to all the parts to
which they are contiguous in their course; 2d, by the
vessels which pass between  it and the lungs, which
are  retained in a particular position by the  mediasti-
num ; 3d, by the aorta, which is attached to the  me-
diastinum in its  course  downwards, after  making its
great curve ;  and 4th, by the pericardium, which is
attached to the great vessels and to the mediastinum.
By  these  different  modes the basis of the  heart is
fixed, while its body and apex are perfectly  free from
attachment, and only contiguous  to the pericardium. 
yz                Might Auricit

  The external surface of the heart, being formed by
the pericardium, is very smooth : under this  surface
a large quantity of fat is often found.
  The two auricles are contiguous to each other at the
base, and are separated by a partition which is com-
mon to both.                             .
  The Right Auricle originates from the junction of
the two venze cavse.   These veins are united at some
distance behind the  right ventricle,* and  are dilated
anteriorly into a sac or pouch, which is called the Si-
nus, and extends to the right ventricle, to which it is
united.
   The upper part of  this pouch,  or sinus, forms a
point with  indented edges, which  is detached from
the  ventricle, and lies loose on  the  right side  of the
aorta.  This point has some resemblance to the ear  of
a dog, from  which circumstance the whole  cavity has
been called auricle;  but by many persons  the cavity
is considered as consisting of two  portions : the  Au-
ricle,  strictly speaking;  and  the  Sinus  Venosus,
 above described  : they however form but  one  cavity.
   This portion of the heart, or Right Auricle, is  of
 an irregular oblong figure.  In its  posterior  surface,
 it is indented; for the direction of the  two cavae, at
 their  junction,  is not precisely the same; but  they
 form an  angle,  which causes  this  indentation.   The
 anterior portion of the auricle, or that which appears
 like a pouch between the ventricle and the  veins, is
 different in its structure from the  posterior  part,
 which is strictly a portion of  the  veins.   It  consists
 simply of muscular fibres, which are arranged in fas-
  ciculi that cover the whole  internal  surface :  this is
  also the case  with  the  point, or that part which is
  strictly called auricle.
' In this description the heart is supposed to be in its natural position: 
Right Ventricle.
53
  These fasciuli are denominated Musculi  Pectinati,
from their resemblance to the teeth of a comb.
  That part of the internal surface, which  is formed
by the septum, is smooth; and the whole is covered by
a delicate membrane.
  On the surface of the septum, below the  middle, is
an oval depression, which  has a  thick edge or mar-
gin : this is  called  the Fossa  Ovalis.  In the foetal
heart,  it  was the Foramen  Ovale, or aperture  which
forms the communication between the two auricles.
  Near this fossa is a large  semilunar plait, or valve,
with its   points and concave  edge  uppermost, and
convex  edge downwards.   It was described by Eu~
stachius, and, therefore, is  called the Valve of Eu-
stachius.
  Anterior to this valve, and near the union  of the
auricle and ventricle, is the orifice of the proper vein
of the heart,  or  the conorary vein.  This orifice is
covered by another semilunar valve, which is sometimes
reticulated.
  The aperture, wThich forms  the communication be-
tween the right auricle  and  right ventricle, is  about
an inch  in diameter, and is called  ostium  venosum.
From its whole margin arises a valvular ring,  or du-
plicature  of the  membrane  lining the surface : this
circular valve is  divided  into three angular portions,
which  are called  Valvulse Tricuspides.  From their
margins  proceed a  great number  of fine  tendinous
threads, which are connected to a  number of distinct
portions  of muscular substance, which arise from the
ventricle.
  The  Right  Ventricle,  when examined  separately
from the other parts of the  heart, is-rather  triangular
in its figure.   It  is  composed entirely of muscular
fibres closely compacted;  and  is much  thicker than
the auricle, although not so  thick  as  the other ven- 
54                 Right  Ventricle.

tricle.   Its internal surface is  composed  of bundles
or  columns of  fleshy  fibres,  which  are of various
thickness and  length.   Some of these columns  arise
from the ventricle, and  are connected with  the ten-
dinous threads, which are attached to the margin of
the tricuspid valves:  the  direction  of them is  from
the apex of the heart towards the base.   Others of the
columns arise  from one part of the  surface  of the
ventricle,   and are inserted  into another  part.  A
third species are attached to the ventricle  throughout
their whole length, forming  ridges or eminences  on
it.   The columns of the two last described species are
very numerous.  They present  an elegant reticula-
ted  surface when  the  ventricle is  laid  open,  and
appear also to occupy  a considerable  portion  of the
cavity of the heart, which  some  of them run across in
every direction near the apex.   They are all covered
by a membrane continued  from  the  auricle and the
tricuspid  valves ;  but   this membrane appears  more
delicate and transparent in the ventricle than it  is in
the auricle.
  A portion of the internal surface  of the ventricle,
which is to the left, is much smoother  and less  fasci-
culated than the rest: it leads to the orifice of the pul-
monary artery, which arises from it near the basis of
the ventricle.   This artery is very conspicuous, exter-
nally, at the basis of the heart.
  It is very evident, upon the first inspection of the
heart,  that the  valvulae tricuspides  will  permit the
blood to flow from the   auricle to the ventricle ; but
must rise   and  close the orifice, and  thereby prevent
its passage back again, when the  ventricle contracts.
  The use of the  tendinous threads, which connect
the  valves to the  fleshy  columns, is  also very evi-
dent ;  the valve  is  supported  by  this  connexion,
and  prevented from  yielding to the pressure  and
opening a passage into  the auricle.   The  blood. 
Left Auricle.
oi>
therefore,  upon  the contraction of the ventricle,  is
necessarily  forced  into the  pulmonary  artery; the
passage to  which is now perfectly free.   Into this
artery the  membrane lining the ventricle  seems con-
tinued ; but immediately  within  the  orifice of the
artery, it  is formed into three semi-circular folds,
each of which  adheres to the surface of the artery
by its circumference, while the edge constituting its
diameter is loose.  In the  middle of this loose edge,
is a small firm tubercle, called Corpusculum Arantii,*
which adds to  the  strength  of  the valve.   Each  of
these valves, by its connexion with the artery, forms a
sack  or  pocket, the orifice  of which opens forward
towards the course of the artery, and the bottom of it
presents towards the ventricle.   Blood will,  there-
fore,  pass from the  ventricle in the artery, and  along
it, without filling these sacks ; and  on  the contrary,
in this course,  will  compress them and  keep  them
empty.  If it  moves in the artery towards the heart,
it will necessarily fill these sacks, and press the  semi-
circular  portions,  from  the  sides of  the  artery,
against each other ;  by this means  a partition or sep-
tum, consisting of three portions, will be formed be-
tween the artery and  the heart,  which will always
exist when the artery compresses,  (or acts upon,)  its
contents.   It is demonstrable, by  injecting wax into
the artery, in a retrograde direction, that these valves
do not form a flat septum, but one  which is convex
towards  the heart,  and concave towards the artery;
and that this convexity is composed  of  three  distinct
parts, each of which is convex.  At the place where
these valves are fixed,  the  artery bulges out  when
distended  by  a retrograde injection.   The  enlarge-
ments thus produced are  called the  Sinuses of  Val-
salva, after the  anatomist  who first described them.
* After Arantius, a professor at Bologna, who first described it. 
56
Left Ventricle.
  The valves are called Semilunar—and, although they
  are formed by a very thin membrane, they are very
  strong.
    The Left Auricle is situated on the left side of the
  basis of the heart.  It originates from the junction  of
  the four pulmonary veins ;  two of which come from
  each side of the thorax, and appear to  form  a large
  part of it.   It is nearly of a cubic form ; but has also
  an angular portion, which constitutes the  proper auri-
  cle, that  proceeds from the upper and left part of the
 cavity, and is situated on the leftside of the pulmonary
 artery.
   This auricle is  lined  by a strong membrane, from
 which the  valves between it and  the  ventricle ori-
 ginate ; but it has  no fleshy columns or musculi pec-
 tinati, except in  the angular  process  properly  called
 auricle.
   These  valves  and the orifice communicating with
 the  ventricle, resembles  those  which  have  been al-
 ready described between  the right auricle  and  ven-
 tricle ;  but with  this difference, that the valvular ring
 is divided into  two portions only, instead  of three,
 which  are called Vulvulve Mitrales.  The  tendinous
 threads, which are connected to the muscular columns,
 are also attached  to these  valves, as in the case  of the
 right auricle.
   These valves admit the  passage of blood  from the
 auricle into the ventricle, but completely  prevent its
 return  when the ventricle contracts.   One of them is
 so situated that it covers the mouth of the aorta  while
 the blood  is flowing into the ventricle, and leaves that
 orifice open when the ventricle contracts, and the pas-
 sage to the auricle is closed.
   The Left Ventricle is situated posteriorly, and to the
left of the Right Ventricle.   Its figure is different, for
 it is rather conical,  and it is also longer.
   The  internal  surface  of this  ventricle resembles 
Muscular Fibres of the heart.
57
that of the right ventricle :  but the columns  carnesa
are stronger and larger.
  On the right side of  this ventricle is the mouth  of
the aorta.   The surface  of the ventricle near this
opening is smooth and  polished  to facilitate the  pas-
sage of the  blood.
  The mouth of the aorta is furnished with three se-
milunar valves, after the manner of the pulmonary ar-
tery, but the  former  are  stronger;   the corpuscula
arantii are better developed  in  them.   Indeed  Mr.
Hunter does not admit  of their existence in the  pul-
monary artery.    The  sinuses  of  Valsalva are  about
the same size in both arteries.
  The  cavity  of  this  ventricle  is supposed to  be
smaller than that of the right; but the amount of the
difference has not been accurately  ascertained.
  This ventricle must have much more force than the
right, as its parieties are so  much  thicker.   Their
thickness often exceeds half an inch.
  The difference in the strength of the two ventricles
probably corresponds with the difference between the
extent of the pulmonary artery and the aorta.
  The thickness of the septum between the ventricles
is thicker than the sides or parieties of the right ven-
tricle, and less  thick than those of the left.
   The muscular fibres of the heart are generally less
florid than  those of the  voluntary muscles ; they are
also more closely compacted together.   The  direction
of  many of them is oblique or spiral; but this  gene-
ral arrangement is very intricate : it is  such, howe-
ver,  that the cavities of the  heart are lessened, and
probably completely obliterated, by the contraction of
these fibres.*

  * Mr. Home has given a precise description of the muscular fibres of the
heart in his Croonian Lecture. London Philosophical Transactions for 1795,
part I. page 215.
    VOL.  IT.                8 
58              Coronary Vessels, $c.

  The  external surface  of  the heart  is  covered  by
that portion of  the pericardium which  adheres  to  it.
Adipose matter is often deposited between this  mem-
brane and the muscular surface ; being distributed  ir-
regularly in various places.
  This membrane is continued from the surface of the
ventricles over  that of the auricles.   When it is dis-
sected off from  the place of their junction, these sur-
faces appear very distinct from each other.
  The proper  blood vessels of the heart appear to be
arranged in conformity to the general laws of the cir-
culation, and  are  very  conspicuous on the  surface.
There are two  arteries which arise from the aorta im-
mediately  after it leaves the heart, so  that their ori-
fices are covered by two of the semilunar valves. One
of these* passes  from the aorta between the pulmonary
artery and the  right auricle, and continues in a  circu-
lar course in the groove between the right auricle and
the right ventricle, and sends off its principal branches
to the right side of the heart.
  The  other artery of the  heart passes between  the
pulmonary artery and the left auricle.   It divides into
two branches :   one, which is anterior,  passes to  a
groove  on  the   surface,  corresponding  to  the septum
between the two ventricles, and continues on it  to  the
apex of the heart, sending off branches in its course ;
another, which  is posterior  and circumflex, passes  be-
tween the  left auricle and ventricle.
  The  great vein of the heart opens into the  under
side of the right  auricle, as has  been already men-
tioned : the main trunk of this vein passes  for  some
distance between the left auricle and ventricle.*

  * It was asserted by Vieussens at an early period, in the last century, and
soon afterwards by Thebesius, a German Professor, that there were a number
of small orifices in the texture of the heart, which opened into the different
cavities on both sides  of it.
  This assertion of a fact so difficult to reconcile with the general  prin-
ciples of the circulation, was received with great hesitation : and aHhoup!- 
The Great Vessels.
59
   From the course of these  different vessels  round
 the basis of  the ventricles of the  heart, they are ge-
 nerally called  Coronary Vessels:  the arteries are de-
 nominated, from their position, Right and  Left  Co-
 ronary,
   The nerves  of  the  heart come from the cardiac
 plexus, which  is  composed  of threads derived  from
 the intercostal or great  sympathetic  nerves, and the
 nerves of the eighth pair.

                      SECTION III.

 Of the Aorta,  the Pulmonary Artery  and  Veins,
   and the  Vensc Cavse;  at their commencement.

   The two great arteries, which arise from  the  heart,
 commence abruptly, and appear to  be  extremely dif-
 ferent  in their composition  and  structure  from the
 heart.
   They are composed of a  substance, which  has  a
 whitish colour,  and very dense texture,  and  is  very
 elastic  as well as firm and strong.
   When the pericardium  is  removed, these  arteries
appear to proceed together from the upper part  of the
basis of the heart:  the pulmonary artery being placed

it was confirmed  by some  very respectable anatomists of the last  century,
it was denied by others.  Some of the anatomists of the  present day have
denied the existence of these orifices, and some others have neglected them
entirely.
  The subject has lately been brought forward in  the London  Philosophical
Transactions of 1798, Part I. by a very respectable anatomist, Mr.  Aberne-
thy, who states, that he has often passed a coarse waxen injection from the
proper arteries and veins of the heart into all the cavities of that organ, and
particularly into the Left Ventricle.  But it was  only in subjects with dis-
eased lungs that this  was practicable.
  The existence of this communication between the coronary vessels and
the great  cavities of the heart seems therefore to be proved.  The easy
demonstration in  such subjects is ingeniously referred by Mr. Ahernethy,
to the obstruction of the circulation in the lungs ;  and he regards the com-
munication as a provision enabling the coronary vessels to  unload them-
selves, when the coronary vein  cannot discharge freely into the right
auricle. 
60 Pulmonary Artery and  Veins and lent, i anc.

to the left of the aorta with the left auricle on the left
side of it, and the right auricle on  the  right  side  of
the  aorta.   The  pulmonary artery arises from the
most anterior,  and left part of the basis of the  right
ventricle, and  proceeds  obliquely backwards  and up-
wards ;  inclining gradually to the left side for about
eighteen or  twenty lines; when  it divides into two
branches which pass to the two lungs.
  The aorta arises from the left ventricle, under the
origin of the pulmonary artery, and immediately pro-
ceeds to the  right, covered  by that vessel, until it
mounts up between it and the  right auricle : it then
forms a great curve, or arch, which turns backward
and to the left, to a considerable distance  beyond the
pulmonary artery.  In this course, it crosses the right
branch of the  pulmonary artery; and, turning down
in the angle between it and  the left branch, takes a
position on the left side of the spine.
  The course of this artery,  from its commencement
at the ventricle, to the end of the great curve or arch,
is extremely varied.
  The uppermost part of the curve is in  the bottom
of the chamber formed  by the separation of the  la-
mina of the mediastinum when  they join the first  rib
on each side.
  From this part of the curve three large branches
go off', viz. one, which soon divides into  the carotid
and the subclavian arteries of  the  right  side ;  a  se-
cond, somewhat smaller, which is  the  left  carotid ;
and a third, which is the left  subclavian  artery.
  When the heart and  its great vessels  are  viewed
from behind, (after they have all  been filled with  in-
jection; and the pericardium, mediastinum, and wind-
pipe have been removed,) the aorta appears first, de-
scending behind the other vessels ;  the pulmonary ar-
tery then appears, dividing so  as to form an obtuse
angle with its  two great branches, each  of which  di- 
  Pulmonary Artery and Veins and Venzc Cavx.  til

vides again before it enters the  lung to which  it is
destined.
  Under the main  trunk of  the  pulmonary artery is
the left auricle:  its  posterior surface is nearly of a
square form, and each  of the  pulmonary veins pro-
ceeds from one of its angles.   These veins  ramify in
the substance of the lungs,  at a  very short distance
from the auricle: the two uppermost of  them are  si-
tuated rather anterior to the branches of the  pulmo-
nary artery.
  In  this posterior  view, the pulmonary vessels of
the right side cover a great part of  the right auricle,
as it is anterior to them.  The  lower portion of the
auricle, with the termination  of the inferior cava is to
be seen below them.  Above them the  superior cava
appears ; and in that part of it which is immediately
above  the  right  branch of the pulmonary artery, is
the orifice of the vena azygos.
  In its natural situation in  the thorax, the  superior
cava is connected by cellular  membrane  to  the  right
lamen of the mediastinum, and supported by it.   At
a small distance below the upper edge of the sternum,
it receives the trunk formed by the left subclavian and
internal  jugular  vein,  which passes obliquely across
the sternum below its inner edge,  in the upper  space
between the lamina of the mediastinum. 
CHAPTER III.
         OF THE TRACHEA AND THE LUNGS.

   Although the principal  part of the windpipe is
situated in the neck above the  cavity of the thorax,
it is so intimately connected with the lungs, that it is
necessary to describe them together.

                    section  I.

                 Of  the  Trachea.

   Trachea is the technical name for the windpipe, or
tube which passes from the larynx to the lungs.
   This tube begins at the  lower edge of the cricoid
cartilage, and passes down the neck  in front of the
cesophagus as low as the third dorsal  vertebrae,  when
it divides into two branches called Bronchia, one of
which goes to the right and the other to the  left lung
and ramifies very minutely in them.
   There is in its structure a number of flat cartilagi-
nous rings  placed at small distances from each other,
the edges of which  are connected by membrane so
that they compose a tube.
   These cartilaginous rings are not complete, for they
do not form more than three-fourths  or four-fifths of
a  circle;  but  their ends  are connected by  a  mem-
brane which forms the posterior part of the tube.
   They are not alike in their size or form ;  some of
them are rendered broader than others, by the  union
of two or three rings with each other, as  the upper-
most.   The lowermost also is broad, and  has a form
which is accommodated to  the bifurcation of the tube.
Their number varies, in different persons  from fifteen
to twentv. 
Structure of the Trachea.          63
   These rings  may be considered as forming a part
 of the first proper coat of the trachea; which is com-
 posed of them, and of an elastic membrane that occu-
 pies all the interstice between them ; so that the car-
 tilages may be regarded as fixed in this membrane.
   A similar arrangement of rings exists in the great
 branches of the bronchia ; but  after they ramify in
 the lungs, the cartilages are no longer in the  form of
 rings : they are irregular in their figures, and are so
 arranged in the membrane,  that they keep the tube
 completely open.   These portions of cartilage do not
 continue throughout the whole  extent  of the  ramifi-
 cations ; for they become smaller, and  finally disap-
 pear, while the membranous  tube continues  without
 them,  ramifying minutely, and  probably forming  the
 air cells  of the lungs.
   This membrane is very elastic : the lungs are very
 elastic also; and it is probable that their elasticity is
 derived  from this membrane.
   On the inside of this coat of the trachea is  an  ar-
 rangement  of muscular  fibres,  which may be called
 a muscular coat.  It is best seen by peeling off or re-
 moving the internal coat to be  next described.
   On the membranous part of the trachea, where  the
 cartilaginous rings are  deficient, these muscular  fibres
 run evidently  in a transverse  direction : in the spaces
 between the cartilages their direction is  longitudinal.
 There is some reason to doubt whether these longitu-
 dinal fibres are confined altogether to the  spaces be-
 tween  the cartilaginous  rings, and attached  only to
 their edges, because there is a fleshy substance on the
 internal surface  of the  rings, which appears to be
 continued from the spaces between them.
  The internal coat of the trachea is a thin and de-
licate membrane, perforated with an immense number 
64        Black Glands of the Bronchix.
 of small foramina, which are  the  orifices  of  mucous
 ducts.
   On the surface  of this membrane there  is an  ap-
 pearance of longitudinal fibres which are  not distri-
 buted uniformly over it, but  run in fasciculi  in some
 places,  and appear to be deficient in others.   These
 fasciculi are particularly conspicuous in the ramifica-
 tions of the bronchia in the lungs.
   On the  posterior membranous portion of the  tra-
 chea, where the cartilages are deficient, a considera-
 ble  number  of small  glandular bodies  are  placed,
 which are  supposed to  communicate with the  mucous
 ducts that  open on the  internal surface.   If these  bo-
 dies are removed from the external surface of this por-
 tion, and the  muscular fibres  are also removed from
 the  internal,  a very  thin  membrane only remains,
 which is very different  from that which is left between
 the rings, when the fleshy substance is  removed from
 that situation.
  The reason of the  deficiency in  the rings, at this
 posterior part, is  not  very obvious.*   It continues
 in the bronchia until the form of  their  cartilages is
 changed in the lungs:  if it  were only to  accommo-
 date  the  oesophagus,  during the  passage of  food,
 there would be no occasion for  its extension to  the
 bronchia.
  At the  bifurcation  of  the  trachea,  and  on  the
bronchia, are a  number of  black  coloured  bodies,
 which  resemble  the lymphatic  glands in  form and
 texture.  They continue on the ramifications of  the
 bronchia some distance  into  the substance  of  the
 lungs.    Their number is  often very considerable :
 and  they vary in size from three or four lines  in  dia

  * Dr. Physic has advanced the opinion that it enables a person to expel the
 mucus of the lungs by contracting the size  of the trachea, and consequent! v
 increasing the velocity or impetus of the air.—FaL 
                Root of the Langs.             65

meter to eighteen or twenty.   As lymphatic  vessels
have been traced to and from them during their course
to the thoracic duct, they are considered as lymphatic
glands.

                    SECTION II.

                   Of the  Lungs.

  There are two of these organs: each of which oc*
cupies one of the great cavities of the thorax.
  When  placed together,  in  their natural position,
they resemble the hoof of the ox, with its back part
forward ;  but they  are at such  a  distance from  each
other, and of such a figure, that they allow the medi-
astinum and heart to intervene ; and they cover every
part of the heart anteriorly, except a small portion at
the apex.
  Each lung fills completely the cavity in which it is
placed, and every  part  of its  external  surface  is in
contact with some part of the internal surface of the
cavity; but when in a natural and healthy state, it is
not connected with any part except the lamina of the
mediastinum.   One great branch  of  the  trachea and
of the pulmonary artery passes from  the  mediastinum
to each lung, and enters it at a place which is rather
nearer to the upper rib  than to  the  diaphragm, and
much nearer to the spine than  the  sternum : at this
place also the pulmonary veins return from the  lungs
to the heart.
  These vessels are enclosed  in  a membrane, which
is continued over them from the mediastinum, and ex-
tended from them  to the lung.    Thus covered, they
constitute what has been  called the Root of the Lung.
   When  their  covering, derived from  the mediasti-
num,  is removed,  the situation  of these vessels ap-
pears to be such that the bronchia are  posterior, the
   vol. it.              0 
66             Colour of the Lungs.
branches of the pulmonary artery are rather above
and before, and the veins below and before them.
  Each of these vessels ramifies before  it enters into
the substance  of  the lungs:  the bronchia and  the
branches of the pulmonary artery send each  a large
branch downward to  the inferior part of the lungs,
from which the lower pulmonary veins pass  in a di-
rection nearly horizontal.  In general,  each of the
smaller ramifications of the bronchia in the lungs is at-
tended by an artery and a vein.
  Each lung is divided, by very deep fissures,  into
portions which are called Lobes.  The right lung  is
composed of three of these lobes, and the left lung  of
two.
  The lungs are covered, as has been  already stated,
with  the  reflected portion  of the pleura continued
from the mediastinum, which  is very delicate and al-
most  transparent.    They have,  therefore, a  very
smooth surface, which is kept moist by exudation from
the arteries of the membrane.
  The Colour of the Lungs  is different in different
subjects.  In children they are of a light red colour;
in adults they are often of a light gray;  owing to the
deposition of a black pigment in the substance imme-
diately under  the membranes which form their exter-
nal surface.   Their colour is  often formed  by a  mix-
ture of red and black.   In this  case  they  are  more
loaded  with  blood,  and the  vessels  of  the internal
membranes being distended with it, the red  colour is
derived from them.
   The black  pigment  sometimes appears  in  round
spots of  three or four lines in diameter:  under the
external membrane it is often in much smaller portions,
and sometimes is arranged  in  lines in  the  interstices
of  the lobuli, to be hereafter  mentioned.   It is also
diffused in small quantities throughout the  substance
of  the lungs. 
Structure of the Lungs.
6?
  The source of this substance, and the use of it, are
unknown.
  The lungs are of a soft  spongy texture ;  and, in
animals that have breathed,  they have always a consi-
derable quantity of  air in them.
  They consist of cells, which communicate with the
branches of the trachea that ramify through them in
every part.  These cells are extremely small, and the
membranes which compose them are so thin and  deli-
cate, that if they are all filled by an injection of  wax,
thrown into the trachea, the whole  cellular part of
the lung  will appear like a  mass of wax.   If a  cor-
roded preparation be made of a lung injected  in  this
manner with force,  the wax will  appear like  a  con-
cretion.
  These effects of injections prove that the membranes
of which the cells are  formed are very thin;  and, of
course, that their volume is very small when compared
with the capacity of the cells.
  In those corroded preparations, in which the rami-
fications  of the bronchia are detached  from the  wax
of  the cells,  these ramifications  become  extremely
small indeed.
  If the lungs of the  human subjects, or  of  animals
of similar  construction, be  examined when they are
inflated, their cellular  structure  will be very obvious,
although their cells are so small that they cannot com-
monly  be distinguished by  the naked  eye.   Each of
the extreme ramifications of the bronchia appears to
be surrounded  by a portion  of this cellular substance,
which  is gradually distended when air  is blown into
the ramification.
   This cellular substance is formed into small portions
of  various  angular figures,  which are  denominated
Lobuli: these can be separated to a considerable  ex-
tent from each other.  They are covered by the pro-
per coat of the  lungs, which  is  extremely delicate. 
6S
Structure e>f the Lungs.
and closely connected to the general covering derived
from  the  pleura.   Between the  lobuli, where they
are in contact with each other, there is  a portion of
common  cellular substance,  which is  easily  distin-
guished through the  membrane covering  the  lungs.
This is very distinct from  the cellular structure which
communicates with the ramifications of the bronchia,
and contains air; for it has no communication with the
air, unless the proper coat of the lungs be  ruptured.
If a pipe  be introduced by a puncture of the  exter-
nal coat of the  lungs,  and this  interstitial cellular
membrane be inflated, it will  compress  the  lobuli.
This cellular membrane is always free from adipose
matter : it may  be easily examined in the lungs of the
bullock.
   Upon the membranes which compose the air cells,
the pulmonary artery and  vein ramify most minutely;
and it seems to have been  proved within the last thir-
ty years, by the  united labours  of  chemists  and phy-
siologists,  that the great object of  respiration is to ef-
fect a chemical process between  the atmospheric  air,
when taken into the  air  cells, and  the  blood  which
circulates  in these vessels.
   In addition to the blood vessels which thus  pass
through the substance of the lungs, there are  several
smaller arteries  denominated Bronchial, which arise
either from the  upper intercostal, or from the aorta
itself: they pass upon the bronchia, and  are distribu-
ted to the substance of the lungs.   The  veins which
correspond with these arteries terminate  ultimately in
the vena azygos.
   The nerves of the lungs are small in proportion to
the bulk of  these organs.   They  are derived  princi-
pally  from the par vagum  and the intercostal nerves.
   The elasticity of  the air cells of the lungs  and of
the ramificasions of the  bronchia which lead to them,
appears by their rapid contraction  after distension, 
The Thorax of the Foetus.          69
and by the force with which they expel the air which
is used to inflate them when taken out of the thorax.
             The Thorax of the Foetus.
  In the cavity between the lamina of the mediasti-
num, where they approach each other from  the  first
ribs, is  situated a  substance  which  is  denominated
the
                  Thymus Gland.
  This substance gradually diminishes after birth, so
that in the adult it is often not to be found :  and when
it exists it is changed in its texture, being much firmer,
as well as greatly diminished.
  In the foetus it is of a pale red colour ;  and during
infancy it has a yellowish tinge.  It generally extends
from the thyroid gland, or a little below it, to the pe-
ricardium.  From its superior portion two lateral  pro-
cesses are extended upwards:  below,  it is formed into
two lobes, which lie on  the pericardium.
  If an incision be made into its substance, a fluid can
be pressed out, which has a whitish colour, and coagu-
lates upon the addition of alcohol.
  Although it  is called a gland, no  excretory  duct
has ever been found connected  with it.
  The  blood  vessels  of this body are  derived  from
the thyroid branches of the subclavians, from  the in-
ternal mammaries, and the  vessels of the pericardium
and mediastinum.
                    The Heart,
And the great arteries  which proceed  from it, have
some very interesting peculiarities in  the fcetus.
  In the septum between the two  auricles, is a  fora-
men of sufficient size to permit the passage of a large
quill, which inclines to  the oval form, with its longest
diameter vertical when the body is  erect.   On   the
left side of  the septum, a valve, formed by the lining
membranes, is connected to this foramen ; and  allows 
70
The Thorax of the Fcetus.
 a free passage to a fluid moving from the right auricle
 to the left, but prevents the  passage  of a  fluid  from
 the left to the right.  This structure is evidently cal-
 culated  to allow some of the  blood which flows  into
 the right auricle from the two venas cavse to pass  into
 the left  auricle of the heart, instead of going into the
 right ventricle.  As the contents of the  left  auricle
 pass into the left ventricle, and from thence  into the
 aorta, it is obvious that the blood, which passes  from
 the right auricle into the left through these foramen,
 must be transmitted from the system of the vena cava
 to the system of the aorta, without going through the
 lungs, as it must necessarily do in subjects who do not
 enjoy the foetal structure.

        The Pulmonary Artery and the Aorta

 Have a  communication in  the  fcetus, which  is very
 analogous to the communication between the auricles
 of the heart.
   From  the pulmonary artery,  where it divides into
 the two  great  branches, another large  branch conti-
 nues, in  the direction of the main trunk, until  it joins
 the aorta ;  with which it communicates at a small dis-
 tance below the origin of the left  subclavian  artery.
 In the young subject that  has  never respired,  it  ap-
 pears as  if the  pulmonary  artery was continued into
 the aorta, and sent off in its course, a branch on each
 side,  much smaller than itself, to each lung.  In sub-
jects  that have lived a few days, these branches to the
 lungs are much  larger ; and then the main pulmonary
 artery appears to have  divided into three  branches:
 one to each  lung, and one to the aorta; but that which
 continues to the aorta is  larger  than either  of the
others.
  In  the course of time, however,  this branch  of the
 aorta is contracted, so that no  fluid passes through  it: 
General Observations.
71
and it has  the appearance of a  ligament, in  which
state it remains.
  The course of the blood  from the right ventricle,
through the pulmonary artery, to the aorta below its
curve, is more direct than that from the left ventricle
to the same spot, through the aorta  at  its commence-
ment.   The column of  blood in  the aorta  below its
curve is evidently propelled by the force of both ven-
tricles : and this circumstance, although  it seems to
proceed merely from the state of the  faital  lungs, is
particularly calculated for the very extensive circula-
tion which  the fcetus carries on, by means of the um-
bilical arteries and vein in the placenta.

              The Lungs of the Foetus.

Differ greatly from  those of the adult.    They  appear
solid, as if they were composed of the parenchymatous
substance which constitutes  the  matter of glands, ra-
ther than the light  spongy substance of the lungs of
adults.   They differ also in colour from  the  lungs of
older subjects, being of a dull red.
  They have greater specific  gravity  than   water;
but if air be once inspired, so much of it remains in
them that they ever afterwards float in that fluid.

       The nature of the process of respiration, and its ef-
         fects upon the animal  economy,  particularly upon
         the action of the heart, appear to be much better un-
         derstood at this time than they were before  the dis-
         covery of the composition of the atmosphere, by Dr.
         Priestly and by Mr. Scheele. The publications upon
         this subject, which have appeared  since that period,
         viz.  1774, are therefore much more interesting to
         the student of medicine than those which preceded
         them.  Two of these publications ought to be parti-
         cularly noticed by him : viz,  an  essay, by Dr. Ed-
         ward Goodwyn, entitled, " The Connexion of life 
 <"~              Cases of Malformation.

          with respiration}"—and  the  "Physiological  Re-
          searches of M.  Bichat  upon  Life and Death.   Part
          Second.*
        The general doctrines respecting  the oxygenation or
          decarbonation of the blood, and the absolute necessi-
          ty that it should take place to a certain degree in or-
          der  to preserve life, are confirmed  by a number of
          cases of malformation of the  heart or the great  ves-
          sels, in which the structure was such that a  conside-
          rable portion of venous blood passed from the right
          side of the heart to the aorta, without going through
          the lungs.   In these different cases, notwithstanding
          the  structure  was  somewhat varied, the  symptoms
          produced were very much alike ; differing in the re-
          spective patients in degree only,  and not in  kind.
             The  symptoms indicating  this structure,  are blue
          colour  of the  face, (such  as  generally accompanies
          suffocation,) extending  more  or less over the whole
          body, and particularly  apparent under the  nails of
          the fingers and  toes j  anxiety  about the region of the
          heart ;  palpitation j laborious respiration; sensations
          of great debility, &c.: all of which are greatly aggra-
          vated by muscular exertion.  These effects have ge-
          nerally appeared  to be  proportioned to the  quantity
          of venous  blood  admitted into the aortic system.t
            When these appearances take  place immediately
          after birth, it is probable that they depend  entirely
          upon malformation of the heart or great vessels ; but
          when they commence at a subsequent period,  they are


  * The student will derive much information respecting the publications on
this subject, prior to 1804, from Dr. Bostock's Essay on Respiration.—Since
the publication of that essay several interesting  papers on respiration have
appeared, viz. Two memoires by the late Abbe Spalanzani;—" An  Inquiry
into the Changes induced on Atmospheric Air by the Germination of Seeds,"
&c. by Ellis;—two  very important communications  by Messrs. Allen and
Pepys in the Transactions of the Royal Society of London  for  1808 and
1809 ;—and " Further Inquiries into the  Changes induced on Atmospheric
Air."  Also by Ellis.
  f Cases of this kind are related in several of the periodical publications on
medical subjects.  Two of them were described by the late Dr. William Hun-
ter in the sixth volume of Medical Observations  and Inquiries, by  a Society
of Physicians in London ; one,  quoted by Dr. Goodwyn,)  is in the Obser-
vationes  Anatomicae of Sandifort; and another, by Dr. J. S. Dorsey,  has
lately been  published in  the first number of the New England Journal of
Medicine and Surgery. 
Cases of Malformation.              73
      commonly the effect of a diseased alteration in the
      lungs.  They sometimes occur near the termination
      of fatal cases of pneumonia or catarrh ; but a diffe-
      rent cause, which has not latterly been suspected,
      appears to have produced them in the following case
      related by Dr. Marcet, in the  first volume of the
      Edinburgh Medical and Physical Journal.
        The blue colour occurred in a young woman, twen-
      ty-one years of age, in whom it had never been ob-
      served  before.  It came  on during an affection of
      the breast, and was attended with great prostration
      of strength and difficulty of breathing; as well as
      cough, oedema  of the  hands and  feet,  and several
      other symptoms.   About seven weeks after the com-
      mencement of these symptoms,  she died  ; when it
      was ascertained  by dissection, that there was no
      unnatural communication whatever between the ca-
      vities of  the heart, and that  its valves were all in
      a perfect  and  natural  state.  The lungs  were free
      from tubercles, or any other appearance, of disease.
      Their substance seemed  wiore  compact than usual,
      especially the left lung, although it did not sink in
      water ; but  they adhered every  where to the inner
      surface of the  thorax, to  the diaphragm, and to the
      pleura covering the pericardium.—This case is the
      more  remarkable, because   numberless   instances
      have occurred, in which very large  portions of the
      external surface of the lungs have been found, upon
      dissection, to adhere  to the internal surface of the
      thorax, without the occurrence of such  symptoms
      during life.

     It may be inferred, from  a  statement published by M.
      Dupuytren, in a late volume of the Proceedings of
      the National Institute  of France, that the oxygena-
      tion or decarbonation of the blood is much affected,
      in  respiration,  by an  influence exercised by the
      nerves which are appropriated to the lungs.  From
      his account  it appears, that although  the  complete
      division of the eighth pair of  nerves produces death
      after some time ; yet in the horse whose nerves are
      thus  divided,  life  continues, and  respiration  goes
      on, from half an hour to  ten hours ; but his arterial
      blood is in a state of great disoxygenation or carbo-
      nation during this time.   This fact is more remarka-
VOL. II.                 10 
74     Effect of Venous Blood on the Heart.

          ble, because  venous blood,  contained in a bladder
          exposed to the open air, will  become  oxygenated or
          decarbonated.                                  ,
            It is also asserted in another Memoir, read  to the
          National Institute by Dr. J.  M. Provencal; that ani-
          mals, in whom  the eighth pair of nerves  has been
          divided, do not consume so much oxygen, or produce
          so much carbonic acid, by a considerable degree, as
          they did before the division of these nerves ;  and that
          their temperature is considerably reduced.*

        The fact, that venous blood occasions death, when it is
          admitted into the left ventricle of the heart, and the
          aorta, is truly important.  Dr. Goodwin explained it
          by suggesting that this blood was not sufficiently sti-
          mulating to produce the necessary excitement of the
          heart ; but on this occasion  one of his friends propo-
          sed to him the following question : Why does venous
          blood affect the left side of the heart in  this injurious
          manner, when it appears to exert no  noxious  effects
          whatever on the right side of that organ ?   His reply
          may be seen in a note at the 82d page  of his  Essay,
          in the first  edition.   Bichat has offered a solution
          which completely resolves this difficulty, viz.  "The
          effect of venous blood upon the heart is produced by
          the presence of this blood in the proper, or coronary
          arteries of that organ,  and not in its great cavities."
          For the animation of the heart, like that of the other
          parts of the body, depends upon the state of the blood
          in the  arteries which penetrate  its texture.t  And
          while the heart acts, the blood of the coronary arte-
          ries will be the same with that of the left ventricle.—
          See Bichat's Researches, P. II. art. G. § 2.
        The French Anatomists appear to entertain some pecu-
          liar opinions respecting the course of  the  blood in
          the fcetus, which have a particular relation to the sub-
          ject last mentioned.  Winslow,  who paid great at-
          tention to the valve of Eustachius in the right  auricle
          of the heart, was of opinion, that this valve was cal-
  * These Memoirs are republished in the Eclectic Repertory of Philadelphia
for April and October, 1811.
  t It is probable that the contents of the great cavities of the heart have no
more eflfect upon its animation than the contents of the stomach and bowels
have upon the animation of those organs. 
Sentiments of Sabatier, $v.
75
   culated for some important purpose in the foetal eco-
   nomy.*  Although his hypothesis respecting its par-
   ticular use has not been retained by his countrymen,
   many of them have adopted his general sentiment;
   and among others Sabatier.   That learned anatomist
   believed that this valve, in  the  foetal  state,  serves
   to  direct the blood of the inferior cava, after  its ar-
   rival in the right auricle, through the foramen ovale
   into the left auricle ; while the blood of the upper cava
   passes directly into the right ventricle.   His opinion
   seems to be supported to a certain degree.
     1.  By the direction in which the two columns of
   blood  enter the auricle from the two vene cava?.
     2. By the position of the Eustachian valve.
     3. By the  foramen ovale, when  its valve is com-
   plete; as the passage through it from the right to the
   left, is at that time oblique, and from below upwards.
     The theory of Sabatier appears to be this:—the um-
   bilical vein brings from the placenta blood which has
   a quality essential to the animation of the fcetus.  If
   there were no particular provision to the contrary, a
   large  portion  of this  blood, after passing from the
   umbilical  vein by the inferior cava into the right
   auricle of the heart, would proceed by the right ven-
   tricle, through the pulmonary artery and arterial ca-
   nal, into the aorta, below the  origins  of the carotid
   and subclavian arteries ;  and  consequently  none of
   it would pass to  the head and upper extremities, but
   a considerable part would return again by the  umbi-
   lical  arteries  to the  placenta,  without circulating
   through the body:  while on  the other  hand, the
   blood  which passed by the carotid  and subclavian
   arteries  to  the head and  upper extremities return-
   ing from them to the heart  by the  superior  cava,
   might  pass from  the right auricle to the  left auricle
   and ventricle and the aorta,  and so to the head and
   upper extremities  again, without  passing  through
   the placenta.   But by means  of this valve, the blood
   of  the  lower cava,  and of course  of the umbilical
   vein, is  directed to the  left auricle and  ventricle
   and the  aorta, by which a considerable portion of
   it will necessarily pass  to the head and upper ex-
   tremities : while the blood which returns from  these

See Memoirs of the Academy of Sciences for 1717 and 172") 
7(r>           Sentiments  of Sabatier, <.yt

         parts by the superior cava, must consequently  pass
         from the right auricle  into the  right ventricle  and
         pulmonary artery; from whence a large portion of it
         will proceed through the arterial canal into the aorta
         beyond the carotids and subclavians, and of this por-
         tion a considerable part will go to the placenta by the
         umbilical arteries.   Sabatier compares the course of
         the blood in the foetus to the course of a fluid in a tube
         which has the form of the numeral character 8.*—If
         this doctrine be true, the progress of the blood in the
         fcetus and placenta is very analogous to  that of the
         double circulation of the  adult;  the character 8 an-
         swering equally well in the description of either sub-.
         ject.
           According to Sabatier, the  blood  of the placenta
         takes this peculiar course through the heart, in order
         that some of it may be carried to the head and upper
         extremities.  But an additional reason may  be  sug-
         gested, which appears to be  of great importance ;
         viz. the supplying of the  coronary or proper vessels
         of the  heart with some of the  same blood.
           The heart of the adult, as has been before stated,
         cannot act without its proper or coronary arteries are
         supplied  with arterial blood.   The heart of the foetus
         performs a more extensive circulation than that of the
         adult, and, therefore, is probably in greater need of
         such blood.  But unless the blood of the placenta pas-
         ses  through the foramen ovale into the left auricle and
         ventricle, and so to the aorta, it cannot enter the coro-
         nary arteries which originate  at the commencement
         of the  aorta; for  the  blood which  flows from the
         right side  of the  heart through the arterial canal,
         passes  into the aorta at so great a distance from the
         orifices of the conorary arteries, that it certainly can-
         not enter them.
           The whole of this doctrine seems to be supported by
         a fact very familiar to accoucheurs, viz. the occur-
         rence of death in the fcetus whenever the circulation
         through the umbilical cord is suspended during fifteen
         or twenty minutes ; for as the placenta imparts to the
         foetal blood a quality essential to life, some arrano-e-
         ment seems necesary to provide for the equal disfri
         bution of the blood which  comes from this organ  and
subjeet, in the Memoirs of the Academy of 
  Unusual Cases of Malformation.        r;

especially for carrying the requisite proportion of it
to the substance of the heart.
Life has existed for some time  with a structure very
  different indeed from that which is natural.   Iq  the
  series of elegant engravings relating to morbid anat-
  omy, published by Dr.  Badlie, is  the  representation
  of a heart, in which the  vene cavae opened into the
  right  auricle, and the pulmonary veins into the  left
  auricle,  in the usual manner j but the aorta arose
  entirely from the  right ventricle, and the  pulmo-
  nary artery as completely  from the  left.   The  ca-
  nalis arteriosus, however, passed from the pulmonary
  artery to  the aorta, and  the foramen ovale exis-
  ted.   In this  case, it is evident, that the pulmonary
  artery must  have  carried back to  the  lungs  the
  arterial  blood which came from them by the pulmo-
  nary veins, with a  small  quantity of venous blood
  that passed into the left auricle through the  foramen
  ovale j and that  the aorta must have returned to the
  body, the venous blood which just before had been
  brought from it by the venae cavae, with a small ad-
  dition of  arterial  blood that passed  through  the
  ductus arteriosus.  Yet with this structure the child
  lived two months after  its birth.
    A  case, which  had  a strong resemblance to the
  foregoing, occurred lately  in Philadelphia, and  was
  examined  by  the  author of  this work.   The vene
  cavaj terminated regularly in the right auricle,  and
  the pulmonary veins in the same regular manner in
  the left; but the pulmonary artery  arose  from  the
  left ventricle, and the  aorta from the right.   There
  ivas no  communication between these vessels by a ca-
  natis arteriosus ; but a large opening existed in the
  septum between the auricles.

     It  is very evident,  that, in this case also the  pul-
  monary artery must have returned to the lungs the
  arterial blood as  it came from them, and the aorta
  must have carried  back to the general  system the
  venous  blood brought to the  heart by the cavse ; ex-
  cepting only those portions of the arterial and venous
  blood which must have flowed reciprocally from one
  auricle  into the other,  and thus charged their respec*
  tive situations. 
ra
Foramen  Ovale.
  The subject was about  two years and a half old.
The heart was  nearly double  the  natural size, and
the  foramen, or opening in the septum between the
auricles, was eight or nine lines in diameter,  lhe
pulmonary artery was larger in proportion than the
aorta or the heart.
  With this organization,  the  child lived to  the age
above  specified.   His countenance  was generally
rather livid : and this colour  was  always much in-
creased by the least irregularity of respiration.  His
nails were always livid.   He sometimes  appeared
placid, but more  frequently in distress.  He never
walked, and  seldom, if  ever, stood  on his  feet.
When  sitting on the floor, he  would sometimes push
himself about  the room ;  but  this  muscular exertion
always greatly affected his respiration.  He attained
the size common to children of his age, and had gene-
rally a great appetite.  For some weeks before death
his  legs and feet were swelled.
  It is probable that the protraction of life depended
upon the mixture of the blood in the two auricles  ; and
that they really were to be considered as one cavity,
in this case.
There  seems reason to believe, that in adults of the
  common structure, there is no passage of blood from
  one  auricle to the other, when the foramen ovale
  has remained  open; because  in several persons in
  whom it was found by dissection to  have remained
  open, there were no appearances during life, that in-
  dicated the presence of disoxygeuated blood in the
  aortic system.  It is probable, that  the small size
  of the foramen ovale, the valvular structure  which
  generally  exists  there, and the complete occupation
  of the left auricle by the blood flowing from the pul-
  monary veins, prevent the passage of blood  from the
  right auricle to the left, in such persons j  whereas, in
  the case in question, the opening between the auricles
  was very  large indeed, and there  was no appearance
  of a valve about it.
  Although  it be  admitted, that in  adults with the
foramen ovale pervious, there is no transmission of 
On the Source of the motion of the Heart.    7&
blood from the right to the left auricle; there is every
reason  to  believe,  that  this  transmission  goes on
steadily in the fcetus.  To  the  arguments derived
from  the  structure  and  the nature  of the case, it
may  be added,  that the pulmonary  veins, in  the
foetal state, carry to the  left auricle a quantity of
blood, not sufficient to fill it;  while the vene  cavae
carry to the right auricle, not only  the whole blood
of the  body,  but of the  umbilical cord  and  pla-
centa:  some of  which  must flow into the unfilled
left auricle, when the right auricle becomes fully dis-
tended.
The question, how far the functions of the heart and
  lungs are dependent upon  the brain, is very impor-
  tant, and has often  been agitated  with great zeal.
  In favour of the opinion  that the motions of the
  heart are independent of the  brain, may  be stated
  the numerous cases  in which the brain has been de-
  ficient in children, who have  notwithstanding lived
  the  full  period of utero-gestation, and even a short
  time after birth, and have arrived at their  full  size,
  with every appearance of perfect  vigour and action
  in the heart.   In support  of  the  doctrine, that the
  action of the heart  is immediately dependent upon
  the brain, it may be observed,  that no  organ of the
  body appears to be  so much influenced  by passions
  and other  mental  affections  as  the heart.  These
  contradictory facts have occasioned this question to
  be considered as undecided, if not incapable of solu-
  tion; although Cruikshank  and Bichat* have stated
  circumstances very  favourable to  the  opinion that
  the  motions  of the heart  are independent  of the
  brain.
  This question seems now to be settled by the ex-
periments  of Dr. Legallois, a  physician  of  Paris,
  • See Cruikshank's Experiments on the Nerves and Spinal Marrow of living
Animals; London Philosophical Transactions for 1795.  The eighth experiment
has a  particular relation to this subject. Bichat's Researches, part 2, article 9.
  The Abbe Fontana has considered this subject in his Treatise on the Venom
of the Viper, vol. ii. page 194, English translation; and also in some of his other
works. 
80  Humboldt and others on Legallois' Paper.

         which prove, that in animals who have suffered  de-
         capitation, the action  of the heart does not cease as
         an immediate  consequence  of the  removal ot  the
         head ; but its cessation is an indirect effect, induced
         by the suspension of  respiration.  That respiration
         is immediately affected by decapitation, and depends
         upon the influence of the brain transmitted through
         the eighth pair of nerves.  That  the  action of  the
         heart will  continue  a Ion? time after decapitation,
         if inflation of the lungs, or artificial respiration, be
         performed; but,  on the contrary, if the spinal mar-
         row be destroyed, the action of the heart ceases irre-
         coverably.
           The inference from these experiments seems very
         conclusive, that  the  Spinal  Marrow, and not  the
         brain, is the source of the motions of the heart.
           It appears also by some of  the experiments, that
         the power of motion in the trunk of the body, is  de-
         rived from the spinal  marrow; and that, when this
         organ is partially destroyed, the parts which  receive
         nerves from the destroyed portion soon cease to live.
         By particular management of the spinal marrow, one
         part of the body  can be preserved alive for some time
         after the other parts are dead.
           These experiments of Dr. Legallois commenced in
         1806 or 1807, and were communicated to the Impe-
         rial Institute of France, in 1811.  The committee
         of that  body  to whom they were referred, viz.
         Messrs. Humboldt, Halle, and Percy, reported that
         the  experiments had  been repeated before them, at
         three different meetings of several hours  each; and
         that, to allow themselves sufficient time for reflec-
         tion, they suffered an interval of a week to take place
         between the meetings.  The committee believe these
         experiments to have proved,
           1st. That the principle upon which all the  move-
         ments of inspiration depend, has its seat about that
         part of the medulla oblongata from which the nerves
         of the eighth pair arise.
           2d. That the principle which animates each part of
         the trunk of the body, is seated in that portion of the
         spinal marrow from which the nerves of the part arise.
           3. That the source of the life and strength of  the
         heart is also in the spinal marrow; not in any distinct
         portion, but in the whole of it. 
Brodie on the Source of the Motion of the Heart. 81

        4th. That the great sympathetic nerve is to be consi-
      dered as originating in  the spinal marrow, and that the
      particular  character  of this nerve is  to place each of
      the parts to which it is distributed under the immedi-
      ate influence of the whole nervous power.
    The interesting memoir of Dr. Legallois is Confirmed to a
      certain degree by a communication of B. C. Brodie to
      the Royal Society of London in 1810, in which are de-
      tailed  many very  interesting  experiments  which in-
      duced the author to conclude,—
        That the influence of the brain is not directly neces-
      sary to the action of the heart; and
        That when the brain is injured or removed, the action
      of the heart ceases, only because respiration is under its
      influence; and if, under these  circumstances, respira-
      tion is  artificially  produced,  the circulation will still
      continue.
    These various experiments apply particularly to the cases
      in which the brain is deficient.   The effects  of mental
      agitations on the heart are likewise reconcilable to the
      tlieory which arises out of them.   But they throw  no
      light on the question why the motions  of the heart are
      so perfectly free from  the  influence of the  will : and
      although they seem to prove incontestibly that the mo-
      tion of the heart is independent of  the brain, it  ought
      to be remembered that in certain diseased states of the
      brain, where that organ appears to be compressed, the
      action  of the heart is often very irregular, and its con-
      tractions less frequent than usual.
VOL. II.
11 
SYSTEM  OF ANATOMY.

              PART VIII.
                OF THE ABDOMEN.

   The lowermost of the two  great cavities of the-
 trunk of the body is called Abdomen.   The pelvis
 may be considered as  a chamber of this cavity, al-
 though its structure is very different.

                  CHAPTER  I.

 A GENERAL VIEW OP THE ABDOMEN AND PELVIS AND
   THEIR CONTENTS, WITH AN ACCOUNT OF  THE  PE-
   RITONEUM.

                   SECTION I.

                Of the Abdomen.

   This great cavity occupies  more than half of the
 space enclosed by the ribs, and all the interior of the
 trunk of the body below the thorax.
   It is formed  by the  diaphragm, supported  by the
 lower ribs;  by a portion of the  spine ;  by the vari-
 ous muscles which occur between  the lower margin of
 the thorax and the upper margin of the  ossa  innomi-
 nata: and by the ossa  innominata, which contribute,
for the purpose, the costae of the  ossa ilia, as well as
the pelvis. 
             Construction of the Abdomen.        «:■;

   The general  figure  of this cavity partakes  of the
 figure of the lower part of the trunk  of the  body;
 with these exceptions, that  the diaphragm  makes  it
 arched or vaulted above, that the  spine and  psoae
 muscles,  &c. are rather  prominent on  the  posterior
 surface, and that the lower part corresponds  with the
 costae of  the ossa ilia and with the  pelvis.
   To acquire a precise idea  of this  cavity,  it is ne-
 cessary first to study the bones concerned in  its  struc-
 ture,  in their natural situation in  the  skeleton ; and
 then the  muscles, which form so large a part of it.
   The arrangement of  the tendons of  some of  these
 muscles, with a view to complete the cavity,  is  parti-
 cularly interesting; as that  of the external oblique
 where it  forms the crural arch.*   The ligaments of
 the  pelvis and the levatores ani muscles, as  they also
 contribute to the formation  of the cavity, and  have
 an influence  upon  its  figure, should likewise  be at-
 tended to.
   In the  walls of the  cavity thus  constructed, there
 are  many foramina by  which the  viscera and  other
 contained parts communicate externally; but few of
 them pass directly into the cavity ;  for  like  the tho-
 rax, there are no  vacuities in it exterior  to  the  con-
 tained organs.
   Three  of  these  foramina  are in  the diaphragm.
 One for the transmission of the aorta, another for the
 vena cava, and a third for the CBsophagus.   Below,
 there is an aperture at  each of the crural arches, for
 the transmission of  the great femoral vessels ; in each
 of the ligamentous membranes, which close the  fora-
 men thyroideum,  for the obturator vessels and nerve;
 and  at the sacro sciatic  notches, for  nerves and  blood
 vessels.
                                                  i
  * See the accouatof this tendon, vol. i. in the description of the " Obli-
quis Deeendens Rxternus.*' 
84        Construction of the Abdomen.

  There are also two apertures at the  bottom of the
pelvis, for the orifice of the  rectum  and of the ure-
thra.   In the tendons of the external oblique muscles
are two orifices, covered by the integuments, for the
spermatic cords ; and, in the foetal  state, one for the
umblical cord.
  The  apertures in the  tendons,  and  under  their
edges, for the  transmission  of the spermatic  cords,
and the blood vessels, &c. are not to be  considered  as
simple perforations made abruptly ;  but the edges  pf
these foramina  are  formed  by tendinous membranes   i
turned inwards and continued so as to compose  a cy-
lindrical tube, which becomes gradually so thin  that it
cannot be readily distinguished from the cellular mem-
brane with which it is connected.*   The blood  ves-
sels, &c. pass along this tube before  they go through   i
the apertures.
  It is evident from the  construction  of this cavity,
that it is essentially different  from the thorax.   It has
no power of spontaneous dilatation whatever: it yields
passively  to the distention  of the  stomach  and  intes-
tines, during deglutition, and when air is  extricated
from the aliment, &c; but it is particularly calculated
for compressing its contents by the contraction  of the
muscles which compose it.  The diminution of its ca-
pacity,  which is thus effected, not only takes place  to
a  great degree, but occasionally  with  great  force.
The diaphragm  and the  abdominal muscles may  be
considered in  some  measure as antagonists  of each
other.  When the diaphragm  descends, if the abdo-
minal muscles are passive, they are distended  by the
contents of the abdomen, which are  forcibly pressed
from above: but if the abdominal  muscles  act  at  the
same  time, an eifort to  diminish the  cavity in  every

  ♦ The student of anatomy, when engaged with this sqbject, will be
gratified by  the examination of Mr  Astley Cooper's plates relating o
hernie. 
Contents of the %lbdvnten
&'j
direction takes place,  and the  contained  parts are
compressed with more or less force according to the
exertion made.  This will be  very evident  upon ex-
amining the situation of the diaphragm and of the ab-
dominal muscles.   When their force is considered, it
will also be very obvious  that the various outlets  of
the cavity are constructed most advantageously; other-
wise hernia or protrusion of its  contents would  be a
daily occurrence.
   The abdomen contains, 1st.   The Stomach and the
ivhole  Intestinal Tube, consisting of the small and
the great intestines.
   2d.  The Assisting Chylopoietic Viscera,—the  Li-
ver, the Pancreas  and the Spleen.
   3d.  The Urinary Organs,—the Kidneys, the Ure-
ters, and the Bladder.   To  which should  be  added
the Glandulee Renales.
   4th.  The  Organs of Generation in part: those of
the female sex  being  almost  wholly included  in  the
pelvis; and those  of the male  being situated partly
within and partly without it.
   5th.   Tke Peritoneum and its  various  processes.
The Mesentery, Omentum, &c.              /
   6th. A portion of the Aorta, and almost the  ivhole
of the Inferior Cava, and their great ramifications:
with  sucjh  of their branches  as  are  appropriated to
the Viscera of the Abdomen and Pelvis.
   7th. Those portions of the Par Vagum and Inter-
costal Nerves which are appropriated to  the cavity ;
and portions  of some  of the  nerves destined  to the
lower extremities.
   8th. The  lower part of the Thoracic Duct, or the
Great Trunk of the Absorbent System, with the large
branches that compose  it, and  the  glands  connected
 with  them :  and  also .those  absorbent vessels  called
 Lacteals, and their glands.
   As the cavity of the abdomen has  no natural divi- 
80
Regions of the Abdomen.
sions, anatomists  have divided it by imaginary lines
into various regions, with a view to precision in their
accounts of the situation  of the  different  contained
parts.   Thus,
  They  have,  very generally, agreed  to  apply two
transverse lines to form three great divisions; viz. the
Upper, Middle and Lower: and they have also agreed
that each of these divisions shall be  subdivided into
three regions.
  The three regions of the uppermost division  are
defined  with some precision.   Those on  each side,
which are called the Right and  Left Hypochondriac
regions,  occupy  the spaces immediately within  thej|
lower ribs and their  cartilages;   while the  middle.Jg
space, included within the margins of these  cartilages,
and a line drawn  from  the  lower  edge  of the  thorax H
on one side  to that on  the  other, is denominated  the
Epigastric  region.
  Th,e boundaries of the regions  below are less  pre-
cisely defined.
  Many anatomists have fixed the two transverse lines
above mentioned  at an arbitrary distance  above and
below the umbilicus : some choosing for this  purpose
two inches, and others a hand's breadth.   As these
distances will occupy different proportions of  the  ca-
vity in persons of different stature, other anatomists,
with a view to avoid  this  inconvenience, have  pro-
posed to connect these lines with certain fixed points
of the skeleton.
  It is of  importance that the boundaries of these re-
gions should be fixed,  and  therefore  the proposition
of Sabatier may  be adopted: viz.  To draw the  up-
per transverse line from the most inferior part of the
lower margin of the thorax, on one side, to the  cor-
responding part on the opposite side ; and  the lower
transverse line from the uppermost part of  the spine 
Region's of the  Abdomen.
K7
of one ilium to the same  part  of the  other.   These
lines will mark the three great divisions.   If, then,
two parallel lines are  drawn  directly Upwards,  one
from each of the superior anterior  spinous  processes
of the ilium until it touches the lower  margin of the
thorax, they will divide each of the two lower  divi-
sions of  the abdomen into three regions.   The centre
of the middle division  is the umbilical, and  on each
side of it is the  right and left  lumbar  region.   The
middle of the lower division is the  hypogastric ;  and
on each side of it the right and left iliac region.
  It is true, that the three,  middle regions of the ab-
domen will  be made very small by the  vicinity of the
transverse lines  to each other ; but the advantages de-
rived from a principle  which  is  similar in its appli-
cation  to all subjects, fully compensates for this incon-
venience.
  There are  therefore nine of  these  regions :  viz.
The Epigastric and the two Hypochondriac :  the Um-
bilical, and  the  two Lumbar :  the Hypogastric, and
the two Iliac regions.*   And it should be added, that
the space immediately around the end of the sternum
is sometimes called the  Scrobiculus Cordis ; and the
space  immediately  within  the  os pubis, the  Regio
Pubis.
  These different  regions  are  generally occupied  in
the following manner.    The  liver fills nearly the
whole  of the right hypocondriac  region, and  extends
through the upper part of the epigastric region into
the left hypocondriac.   The stomach occupies the
principal part of the epigastric region, and a conside-
rable portion of the left hypochondriac.   The spleen
is  also  situated in  the left  hypochondriac  region.

  * It is to be observed that the lateral regions of the middle and lower <h'
visions of the abdomen *re named differently by different writers. 
 88      Situation of the Viscera, $c. in the

 That portion of the intestinal tube, which is composed
 of small  intestines, is generally found in the umbilical,
 the hypogastric, and the iliac/regions ;  and when the
 bladder is empty, in the pelvis.   But the duodenum,
 or first of the small intestines, which proceeds imme-
 diately from the stomach, is situated  in  the epigastric
 and  umbilical  regions.   The  great  intestine  com-
 mences in or near the right iliac region, and ascends
 through  the right lumbar to the right hypochondriac
 region.   It then crosses the abdomen, passing through
 the lower part of the epigastric, or upper part of the
 umbilical to the left lumbar region :  from this it  con-
 tinues into the left iliac region, and  curves in such  a
 manner that  it finally arrives at the middle of the
 upper part of the os  sacrum, when  it  descends into
 the pelvis, and, partaking of the curvature of the last
 mentioned bone, continues to the  termination of the
 os coccygis.
  In the back part of the epigastric  region, and  very
low down in it, is situated  the pancreas.  The  kid-
neys lie in the most posterior parts of the  lumbar re-
gions, and from each of  them is  continued a  tube or
duct,  called  Ureter, that passes into the pelvis to con-
vey the urine  to the bladder.   This viscus, in males,
is in contact with the last portion of the great intes-
tine called the Rectum, and with it occupies almost
all the cavity of the pelvis;  while in females, the
uterus and its  appendages  are  situated between this
intestine  and the  bladder.
  In  the posterior part of the abdomen, in contact
with the  spine is  the aorta.  This great blood vessel
passes from the thorax between the crura of  the  dia-
phragm,  and  continues  down  the spine until it  ap-
proaches towards the  pelvis,  when it  divides  into
two great branches called the  Mac  Arteries.   Each
of these  great branches divides again, on  the  side 
Cavity of the Abdomen.            89
of  the pelvis,  into  two ; viz. the  External Iliac,
which passes under the crural arch to the thigh, and
the Internal Iliac, or Hypogastric, which  descends
into the cavity of the pelvis.
  Soon after the arrival of the aorta in  the  abdomen
it gives off two large  branches.   The first,  which  is
called the Cceliac, is distributed to the liver, the sto-
mach, and the spleen : the  second,  called the  Supe-
rior Mesenteric, is spent upon the intestines.  Lower
down, in the abdomen, it also sends off a small branch
for  the intestines, called  Inferior Mesenteric.   Be-
sides  these  vessels  for the  chylopoietic viscera, the
aorta  sends  off a large branch, called  Emulgent, to
each kidney.
  The inferior or ascending  vena cava  is situated on
the right of the  aorta, in front of the  spine.   It  is
formed below by the union of the iliac  veins, and in
its progress  upwards,  it receives the  emulgent  veins,
which correspond to the arteries of the  kidneys ; but
it receives in its  course no veins which correspond di-
rectly with the ccelic  and mesenteric arteries.   The
smaller  veins, that  answer to the  branches  of these
arteries, unite and form one large vein,  which goes to
the liver, and is called (from the part of that  viscus
at which it enters,) Vena Portarum.  From the liver
three large veins pass into the vena cava, and deposit
there the blood of the vena portarum, after it has fur-
nished materials  for the secretion of bile.  The vena
cava,  in its passage upwards, is in close contact with
the posterior thick edge of the liver : it often  passes
along a deep groove in this edge, and sometimes it  is
completely surrounded  by  the liver in its course.
The veins of the liver enter the vena  cava  at this
place, and of course they are not to be   seen without
dissection.   Immediately after leaving the  liver, the
vena cava passes through an aperture  in the  tendi=
  VOL. It.               12 
90
The Peritoneum.
nous centre of the diaphragm to unite itself to the
right auricle of the heart.

                    SECTION II.

                 Of the Peritoneum.

   The abdomen, thus constructed  and occupied, is
lined by  a  thin  firm  membrane called Peritoneum,
which is extremely smooth on its internal surface, and
is immediately connected with the cellular substance
exterior to it.   This membrane adheres closely to the
anterior, lateral, and superior portions of the surface
of the abdomen ; and is extended from  the posterior
surface so as to cover, more  or less completely, the
viscera of the  cavity.   Those  viscera which are in
close contact with the posterior  surface  of the  abdo-
men, as some portions of the large  intestine,  are co-
vered only on their anterior surfaces, and are  fixed in
their precise situation by the peritoneum ;  which ex-
tends from them to the contiguous surface  of the ca-
vity, and  adheres where it is in contact, so as  to pro-
duce this effect.
   Other viscera, which are not in  close contact, but
moveable  to a distance  from  the  posterior surface of
the abdomen, are covered by this membrane, which is
extended to them from  the surface ;  and this  extend-
ed portion forms an important  part of  the  connexion
between the  viscus and the  cavity in  which it lies.
This connecting part is called Mesentery, when it thus
passes  to the  small intestines;  Mesocolon,  when it
goes to  the  colon, one  of  the  larger intestines;  and
Ligoment, when it passes  to some  of the  other  vis-
cera.
   The peritoneum is a complete but empty sac, which
is fixed in the abdomen anterior to the  viscera.   The
anterior portion of this sac forms the lining to the an-
terior and lateral parts of the surface of the abdomen: 
The Peritoneum.
91
 the  posterior portion covers the viscera, and  forms
 the  mesentery, mesocolon,  and ligaments above  de-
 scribed.
   It necessarily follows that the mesentery and  the
 other similar processes are mere plaits or  folds  of  the
 sac,  which invests the viscera;  and that they must
 consist of two lamina ; and as the blood vessels, nerves,
 and  absorbents, are all posterior  to  the  peritoneum,
 they naturally pass between these  lamina  of the me-
 sentery.
   Some  of the viscera are much  more completely in-
 vested with the peritoneum  than  others.   The sto-
 mach,  liver,  and  spleen, are almost completely sur-
 rounded  by it; and it is said to form a coat for each
 of these  viscera.   That  portion of the smaller  intes-
 tinal tube, which  is called jejunum and ileum, and
 the  transverse portion of the large intestine, called
 the arch of the colon, are invested by it in  the same
 way.  But a  considerable portion of the duodenum
 and the pancreas is behind it.   The lateral portions of
 the colon are in close  contact with the posterior sur-
 face  of the abdomen,  and the  peritoneum  only  covers
 that  portion of their  surfaces  which  looks anteriorly
 towards the cavity of  the abdomen, and is not in con-
 tact  with its posterior surface.
  The urinary organs are  not much connected with
the peritoneum.  The kidneys appear exterior to  it,
and behind it:  the bladder  of urine is below it, and
has but a partial covering from it, on its  upper por-
 tion.
  The peritoneum, which covers  the stomach,  is ex-
tended from the great  curvature of that organ  so  as
to form  a  large  membrane,  which descends like  an
apron before the intestines.   This process of perito-
 neum is composed of  two lamina,  so thin and delicate
 as to resemble  cellular  membrane,  which, after ex-
tending downwards to the lower part of the abdomen* 
92
The Peritoneum.
are turned  backwards  and upwards, and proceed  hi
that direction until they arrive at the  colon, which
they enclose,  and then continue to the back of the ab-
domen, forming the mesocolon.  The part of this pro-
cess which  is between the stomach  and  the colon, is
called Epiploon or Omentum.
   This extension of a membrane, from the surface  of
a cavity, which it  lines to the external  surface  of a
viscus in  that  cavity, is called,  by some anatomists,
"reflection;" and the technical term reflected  mem-
brane is  therefore applied to a membrane distributed
like the peritoneum.
   It must be evident that this distribution of the pe-
ritoneum is very complex, and that it is not easy to
form an accurate  conception  of it  from  description,
but it can be  readily understood by demonstration;
therefore no  further account of its arrangement will
now be attempted, but each  of its  processes  will  be
considered with the organs to  which  they are  parti-
cularly subservient.
   That portion of the peritoneum which lines the ab-
domen, and covers the  viscera, is thin and delicate,
but very firm.   It yields to detension, as in pregnan-
cy, ascites, &c. and again recovers its dimensions.  It
was formerly thought to be composed of two lamina,
but this cannot be proved.   The internal  surface of
this membrane is very smooth, and highly polished;
and from it exudes a liquor which  is well  calculated
for lubrication, and barely sufficient to keep the sur-
face moist  during health ; but sometimes  it is very
abundant, and  occasions the aforesaid  disease—ascites.
This fluid  appears to exude from  the surface  of the
peritoneum when  it is compressed in  a  living animal,
or in one recently dead.  It is probably effused from
the extremities of arteries, for an effusion takes place
when water  is  injected into these vessels.
   The  peritoneum abounds  with  absorbent vessels. 
The Peritoneum.
93
and therefore possesses the power of absorption  to  a
great degree.   This power may be inferred, not  only
from the spontaneous removal  of the  fluid of ascites,
but if milk and water be introduced into the abdomen
of a living animal, through a puncture, it will also dis-
appear.
  The blood vessels of the peritoneum are derived
from  those  which supply  the  neighbouring  parts.
Nerves have not yet been traced into  it, and it has lit-
tle or no sensibility.
   This membrane supports the viscera  of the abdo-
men in their proper situations :  and also forms a  sur-
face for them, and for the cavities which contain them,
so smooth  and  lubricated,  that no  injury can  arise
from their friction.
   The cellular substance, by which the peritoneum is
connected to the contiguous parts, is very different in
different places.  It is very short indeed between this
membrane and the  stomach and intestines, and also be-
tween  it and the tendinous centre of the diaphragm.
Between the peritoneum  and the  muscles  generally,
it is much longer.   When it covers the kidneys  and
the psoas muscles it is very lax and yielding.   About
the  kidneys a large quantity of adeps very commonly
collects in it.   On  the psoas muscle it yields with but
little resistance to the passage of pus, or any other ef-
fused fluid,  as in the case of the psoas abscess. 
CHAPTER II.
 OF  THE OESOPHAGUS, THE STOMACH,  AND THE IN-
                     TESTINES.

                     SECTION I.

                Of the  (Esophagus.

   The (Esophagus is a  muscular tube  which passes
 from the pharynx to the stomach, and is so  intimately
 connected with the stomach, that it will  be advanta-
 geous to the student to attend to  its structure immedi-
 ately  before he engages  in  the  examination of that
 important organ.
   The pharynx  has been  lately described* as com-
 posed of a varied stratum of muscular fibres, lined by
 a membrane which  is continued from the internal sur-
 face of the nose and mouth.  From the  pharynx the
 oesophagus passes downwards between the trachea and
 the vertebrae.  After the bifurcation  of the trachea,
 it proceeds in contact with the spine,  between the la-
 mina of the mediastinum, to the diaphragm, which  it
 passes  through, and  then terminates in the stomach.
   The oesophagus is a flexible tube, which,  when dis-
 tended, is nearly cylindrical.   It  consists of  a  muscu-
 lar coat externally,  and  an internal  tunic  evidently
 continued from  that of the pharynx.   These coats are
 connected by a  cellular substance  called  the Nervous
 Coat, which  is  remarkably loose,  and  allows them to
 move considerably upon each other.   The  muscular
 coat which is very distinguishable from  that of the
pharynx, consists of two  substantial strata of fibres;
"See j.o«re 37- 
The (Esophagus.
95
the exterior of which is nearly longitudinal in its  di-
rection, and the interior circular or transverse.
  The  internal coat of the  oesophagus, resembling
that of the fauces, is soft and spongy.  It is covered
with a  very delicate cuticle,  which Haller supposed
to be too  tender to confine the matter  of variolous
pustules, as he had never found these  extending into
the oesophagus.   It is very   vascular,  and abounds
with the  orifices  of mucous  follicles, from which is
constantly poured out the mucous that is'spread over
this surface.   When the oesophagus is not distended,
many longitudinal  plaits are found  in  this membrane
by  the contraction of the circular or transverse  fibres
exterior to it.   These plaits are calculated to  admit
readily  of the distension which is requisite  in  deglu-
tition.   This tunic is continued from the lining  mem-
brane of the pharynx above, and terminates  below in
the villous coat of the stomach ; from which, however,
it is very different.
   The  blood vessels of the  oesophagus come from
those which are in the vicinity.  The nerves are  de-
rived from the eighth  pair.   The lymphatic  vessels
are very abundant.
   In the neck, the oesophagus inclines rather to  the
left of  the middle  line.   As it proceeds  down  the
back between the lamina of the mediastinum, it pre-
serves the same course to the  fourth dorsal vertebrae,
when it assumes  the  middle portion and  proceeds
downwards, with the aorta to  its left, and the pericar-
dium before it.   About the ninth  dorsal  vertebrae it
inclines again rather to the left, and somewhat forward,
to arrive at the aperture  in  the  diaphragm  through
which it passes.
   Throughout this course  it is connected by cellular
membrane to the contiguous parts ; and  this investi-
ture of cellular membrane has been called its  Exter-
nal Coat. 
9t?             Form of the Stomach.
    While the oesophagus is in  the posterior mediasti-
  num, it  is  in  contact  with  several  small  absorbent
  glands, especially when it first assumes a  situation  to
  the right of the aorta.   These glands  were formerly
  believed to be  particularly connected  with this  tube,
  but they are now considered as belonging to the ab-
  sorbent  system.   They are  sometimes  greatly en-
  larged.

                      SECTION II.

                   Of the Stomach.

    This most important  organ  which occasionally ex-
 erts  a powerful influence upon  every part of the body,
 appears very simple in its structure.
    It is a large sac, which is so thin when  much in-
 flated, that at first view it seems  membranous,  but
 upon examination is found to be composed of several
 lamina or coats,  each of  a different  structure.   It is
 of considerable length, but  incurvated.   It  is much
 larger at one extremity than the  other, and changes
 so gradually in this respect, that it would  appear  co-
 nical if it were straight.   It is not, however, strictly
 conical, unless it is greatly distended ;  for when  mo-
 derately distended, a transverse section is rather oval
 than  circular.   It is therefore  considered  as having
 two broad  sides  or  surfaces, and two  edges,  which
 are the  curvatures.   It  has been compared by the
 anatomists  of different nations  to the  wind sac  of
 the musical  instrument called  the bagpipe.*   The
 orifice in which  the oesophagus  terminates  is  at a
 small   distance  from its   largest  extremity, and is
 called Cardia.    The orifice  which  communicates

  * The student ought not to attempt to acquire an idea of the form of the
stomach without demonstration, for a view of one moment will be more ser-
viceable than a long description. 
Position of the Stomach.          97
with the intestines is at the  termination of its small
incurvated extremity, and is called the Pylorus.
  The two ends of the stomach being  thus  very dif-
ferent in size, are  denominated  the great and small
extremities.  The two curved portions of the surface
are also called the great and  small curvatures.   The
two flat portions of the surface, or the  broadsides, are
called the anterior and posterior surfaces.
  The  situation of the  stomach in the abdomen  is •
nearly transverse :  it lies principally in the left hypo-
chondriac and epigastric regions, immediately below
the liver.  The great extremity of  the stomach  is in
the left hypochondriac region, and the lesser extremi-
ty in the epigastric region, under the left  lobe of the
liver.   The upper orifice, or Cardia,  is nearly oppo-
site to the body of  the last dorsal vertebra; and owing
to the curved form of the stomach,  the other  orifice,
or Pylorus, is situated at a small distance to the right
of that  bone, and rather lower and more forward than
the cardia:  both orifices being in the epigastric re-
gion.   The position of the stomach is  oblique in  two
respects; it inclines  in  a small  degree from above
downwards, from the left to the right;  and it also in-
clines downwards and forwards, from behind.   Its two
orifices  are situated obliquely with respect to  each
other;  for,  if the stomach, when placed with its small
curvature upwards, were divided into two equal parts
by a vertical  plane passing lengthways through it,
they would be found on different sides of the plane.
  As the oesophagus terminates in the  stomach imrae-
mediately after it has passed  through an aperture  of
the diaphragm, it is evident that the stomach must be
somewhat fixed at that place ; but it is more movea-
ble at its other orifice ;  for the extremity of the duo-
denum into which  it is continued is  moveable.
  The  stomach is connected to  the concave surface
   vol. n.               13 
98        External Coat of the Stomach.
of the liver  by the reflexion or continuation of^ the
peritoneum which forms the lesser omentum,   rhis
membrane, after extending over each  surface of the
stomach, continues from its great curve in the form of
the large omentum, and connects it to different  parts,
especially to the colon.  There are  likewise  folds of
the peritoneum, as it passes from the  diaphragm and
from the spleen to the stomach, which appear like li-
gaments.
  Notwithstanding these various connexions,  the sto-
mach undergoes considerable changes in its  position.
When  it  is nearly empty, and the intestines are in
the same  situation, its broad surfaces are presented
forwards and backwards; but  when  it  is distended,
these surfaces  are  presented  obliquely upwards and
downwards, and the great curvature forwards.   When
its anterior surface is presented upwards, its orifices
are considerably influenced in their direction, and the
oesophagus forms an angle with the  plane of the sto-
mach.
  The stomach is composed of four dissimilar lamina,
which  may be  demonstrated by a  simple  process of
dissection.
  There is first a coat or external covering continued
from the peritoneum : within this, and  connected to
it by delicate cellular substance, is  a coat or stratum
of muscular fibres : contiguous to these  fibres,  inter-
nally, is a layer of dense cellular  substance, called  a
nervous coat; and last is the internal  coat of the sto-
mach, called villous or fungous, from the structure of
its surface.
  The  external or first coat of the  stomach,  as has
been already stated,  is continued  from the concave
surface of the liver to the lesser curve of the stomach
in two delicate lamina, which separate when  they ap-
proach  the stomach, and pass down, one  on each side 
   Muscular and Nervous Coats of the Stomach. 99

of it, adhering firmly to it in their course : at the op-
posite curve of the stomach they again unite to form
the great omentum.   The stomach is therefore closely
invested by the peritoneum on  every part  of  its  sur-
face except two strips, one at the lesser and the other
at the greater curvature.   These strips or uncovered
places  are formed by the separation of the lamina
above  mentioned, which  includes a triangular space
bounded by the stomach  and these two lamina.  In
these triangular spaces, at each curvature of the sto-
mach, are situated the blood  vessels  which run along
the stomach in those directions, and also the glands
which belong to the absorbent vessels of  this viscus.
The peculiar arrangement of the lamina at this  place
is particularly calculated  to  permit  the dilatation  of
the stomach.   When it is dilated, the  lamina are  in
close contact  with its  surface, and  the blood vessels
being in the angle formed by the adhesion of the two
lamina to each other, are  so  likewise :  when  it  con-
tracts,  the  blood vessels appear to recede from it, and
the lamina are then applied to each other.
   Where the peritoneum  thus forms a coat to  the sto-
mach, it is stronger and  thicker than  it is between
the liver and stomach.  In a recent subject it is very
smooth  and moist,  but so thin that the muscular fibres,
blood vessels, &c.  appear  through it.  If it is  careful-
ly dissected from  the muscular coat, it appears some-
what flocculent on that surface  which adhered to the
muscular fibres.   It seems to be most abundantly fur-
nished with serous vessels; but it has  been asserted
by Mascagni and Soemmering, that a large proportion
of its texture consists of absorbent vessels.   The cel-
lular substance which connects  this to the muscular
coat appears no way different from  ordinary  cellular
membrane.
   The  Museular Coat of the stomach has  been  de- 
100
Internal Coat of the Stomach.
scribed  very differently by  respectable anatomists;
some considering it as forming three strata or fibres,
and others but two.   If the stomach and a  portion  of
the oesophagus attached to it be moderately distended
with air,  and the  external  coat carefully dissected
away, many longitudinal fibres will  appear on  every
part of it, that evidently proceed from the oesophagus:
these fibres are particularly numerous and strong on
the lesser curvature of the stomach.—Beside the lon-
gitudinal fibres there  are  many that  have  a circular
direction, and these are particularly numerous towards
the small extremity; but it has been doubted whether
there are any fibres in the muscular coat of the sto-
mach that go directly round  it.   The  whole surface
of the stomach, when the peritoneal coat is removed,
appears at first view to be uniformly covered by mus-
cular fibres; but upon close examination, there  are
interstices perceived,  which are occupied  with firm
cellular  membrane.
   In contact with the internal surface of the  muscular
coat is the cellular stratum, which has been called  the
Nervous Coat of the stomach.  It is dense and  firm,
of a whitish colour,   resembling condensed cellular
membrane.  It was considered as different  from  ordi-
nary cellular membrane; but if air be insinuated into
its texture, by blowing between the muscular and vil-
lous coats, while it connects them to each other, it  ex-
hibits the  proper  appearance  of cellular  substance.
It however  adds greatly  to  the  general strength  of
the stomach, and the  vessels  which  terminate in  the
villous coat ramify in it.
   The internal coat of the stomach in the  dead sub-
ject is commonly of a whitish colour, with  a tinge of
red.  It is  named villous, from its  supposed resem-
blance to the surface of velvet.  It has also  been called
fungous, because the processes  analogous to  the villi 
Gastric Liquor.
101
are extremely short, and its surface  has  a granulated
appearance;  differing in these respects from  the in-
ternal surface of the intestines.   It is continued  from
the lining membrane  of the oesophagus,  but  is  very
different in its structure.   Many very  small  vessels
seem to enter into its texture, which are  derived from
branches that ramify in the nervous  coat.  It  is sup-
posed by several anatomists of the highest authority,
to have a cuticle or  epithelium; and  it  is said that
such a membrane has been separated by  disease.   It
ought, however, to be remembered,  that the structure
of the villous coat of the stomach and intestines, is es-
sentially  different from the structure of  the cuticle.
  The internal coat of the stomach is generally found
covered, or spread over  with mucous, which can  be
readily scraped off.  This mucous is certainly effused
upon it by secreting organs, and it has been supposed
that there were small glandular bodies exterior  to the
villous coat, which furnished this  secretion ;  but the
existence of  such  bodies is very doubtful, as  many
skilful anatomists have not  met with any appearance
that could be taken for glands, except  in a very few-
instances, which would not  be  the case  if those ap-
pearances had been natural.   Pores, perhaps the ori-
fices of mucous follicles,  and also of exhalent  vessels,
are very numerous, but  no proper  glandular masses
are attached  to them.  Glands, as have been  already
said, are found in  the  triangular spaces  between the
lamina of the peritoneum at the great  and small cur-
vatures of  the  stomach, but these evidently belong to
the absorbent  system.   Besides the mucous  above
mentioned, a large quantity of a  different liquor, the
proper Gastric Juice, or fluid of the stomach,  is ef-
fused from its surface.   It has been supposed that this
fluid is furnished  by the small  glandular bodies be-
lieved to exist between the coats  of  this origin; but, 
102
The Pylorus.
admitting the existence of these glands,  they are  not
sufficiently numerous to produce so  much  of it as is
found, and it is therefore probable  that  this fluid is
discharged from  the orifices of exhalent  vessels in the
internal  surface.
   Much  information  respecting  the  gastric  liquor
has  been  obtained  within  a few years  past  by  the
researches of physiologists,  and  they  are  generally
agreed that it is the  principal agent in  the  effects
produced by the  stomach  upon  alimentery substan-
ces.*
   As the muscular coat of the stomach frequently va-
ries  its  dimensions, the villous  and nervous  coats,
which have no such power of contraction,  cannot  ex-
actly fit it.   They therefore generally appear larger,
and  of course are thrown into folds  or rugae.   These
folds are commonly in a longitudinal direction ;  but at
the orifices of the stomach they are arranged in a ra-
diated manner, and sometimes they are observed  in  a
transverse  direction.    They depend upon  the  con-
traction  of the muscular fibres, and disappear entirely  .
when the stomach is laid open and spread  out.
   At  the lower  orifice is  a circular fold, which is
permanent, and constitutes the valve denominated Py-


  * On this subject the student may consult with advantage.
  M. Reaumur.  In the Memoires of the Academy of Sciences for 1752.
  John Hunter.  London Philosophical Transactions for 1772 ; and also his
observations on the Animal economy, 1786.
  Dr. Edward Stephens.  Inaugural Thesis de Alimentorum Concoctione.
Edinburg,  1777.
  The Abbe Spalanzarii.  Dissertations relative  to Natural History, &c.
The first volume of the English translation contains the author's disserta-
tions on digestion, and also the first paper of  Mr. liunter, and the Thesis
of Dr. Stevens, as well as an account of the  experiments  of Mr. Gosse of
Geneva.
  In addition to these,  there are several interesting essays in the French,
German, and Italian languages, a compilation  of which  is  to be found in
Johnson's " History of  the progress and present state of Animal Chemistry."
-See Vol. I. page 188. 
      Lymphatics and Nerves of the Stomach.  103

lorous.  It appears like a circular septum with a large
foramen in its centre, or like a flat ring.   The  villous
and nervous coats of the stomach contribute to this,
merely  by forming  the circular fold  or ruga ;  and
within this fold is a ring of  muscular fibres, evidently
connected  with  the circular fibres  of the muscular
coat of the stomach, the diameter of which  at this
place is not larger than  that of an intestine: the fibres
of this ring seem a part of  the muscular coat project-
ing into the cavity of the stomach and  duodenum.   If
a portion of the lesser extremity of  the  stomach and
the adjoining part of the duodenum  be detached, and
laid open  by a longitudinal  incision, and  then  spread
out upon a board,  the internal coat can be very easily
dissected  from the  muscular, and the  pylorous will
then appear like a ridge or  narrow bundle  of  muscu-
lar fibres, which runs across the  extended muscular
membrane.   It is evident that when the parts are re-
placed so  as to form a cylinder, this narrow fasciculous
will form  a ring in  it.   Thus  arranged, the circular
fibres can readily close  the  lower orifice  of the sto-
mach.
   The Pylorus separates the stomach  from the intes-
tine duodenum ; and this separation is marked  exteri-
orly by a  small circular depression, which corresponds
exactly with the situation of the pylorous.
   The arteries of the stomach are derived from  the
Coeliac, the first branch which the aorta sends off to
the viscera of the abdomen.  This  great artery, im-
mediately after it  leaves  the aorta,  is  divided into
three branches,  which are distributed  to the stomach,
the liver, and the spleen, and are called the Superior
 Coronary or  Gastric, the Hepatic, and  the Splenic.
Beside the first mentioned branch, which is distributed
principally to the neighbourhood of the  cardia and to
the lesser curvature, the stomach receives a conside-
rable branch from the hepatic, which passes along the 
104           Tfie Intestines in general.
right portion of its great curvature, and has been
called the  right  gastroepiploic,  and another from
the spleen, which passes along the  left portion of the
great curvature, and has been called  the left  gastro-
epiploic.   In addition to these branches, the  splenic
artery, before it  enters  the spleen, sends  off several
small arteries to the great  extremity  of  the  stomach,
which are  called vasa brevia.
   These  vasa brevia generally arise from the main
trunk of  the splenic artery, but  sometimes from  its
branches.
   The veins which receive the blood from these ar-
teries have  similar names,  and pursue corresponding
courses  backwards; but they terminate  in the vena
portarum.
   The absorbent vessels of the stomach are very  nu-
merous and large :  they pass  to  the glands which
are on the  two curvatures, and  from thence to  the
thoracic  duct.   It is an important fact relative  to
the history of digestion, that there are  good reasons
for doubting whether chyle commonly passes through
them, notwithstanding their number  and  size.*
   The nerves of the stomach  are  derived principal'
ly from the  two great branches of the par vagum,
which accompany the oesophagus and  are mostly spent
upon this organ.  It also  receives branches  from se-
veral plexus, which  are  derived  from   the  splanch-
nic portions  of the  intercostal  nerves.

                    SECTION III.

                 Of the Intestines.

   The  intestines  form  a  continued  canal from  the
pylorus to the  anus,  which  is generally six  times

  * Sabatier, however, in one subject observed white lines on the stomach.
which he suspected to be  lacteals.  See hi* account of  the absorbents of
•Ire stomach 
           Villous  Coat of the Intestines.       105

the length of the subject to which they belong.  Al-
though the different parts of this tube  appear some-
what  different from each other, they agree  in their
general structure.   The coats or lamina of which they
are composed, are  much like those of the stomach,
but the peritoneum which  forms  their  external  coat
does not approach them in  the  same manner;  nor  is
it continued in the  form of omentum from  the whole
tube, there being only a certain portion of intestine,
viz. the colon, from which  such  a process of perito-
neum is continued.
  The Muscular Coat, like that of the stomach, con-
sists of two strata, the exterior of which is  composed
of longitudinal  fibres, which adhere  to the externa!
coat, and do not appear very strong.  The other stra-
tum,  consisting  of circular or transverse fibres,  is
stronger, as the  fibres are more numerous.   It is ob-
servable that they adhere to the longitudinal  fibres:
and they seldom if ever form complete circles.
  The cellular substance immediately within the mus-
cular fibres resembles the nervous coat of the stomach
in its firmness and density.   It is likewise so arranged
as to form many  circular ridges on its internal surface,
which support to a certain  degree the permanent cir-
cular plaits of the internal  coat, called valvulse  con-
niventes.
   The inner surface  of the internal coat has been
commonly compared to that of velvet, and the coat is
therefore called  villous; but there is  certainly a  con-
siderable difference between these  surfaces ;  for if a
portion of the small intestine be  inverted, and  then
suspended in perfectly transparent water, in  a clear
glass, and examined with a strong light, it will appear
like the external surface of the skin of a  peach,  on
which the down or hair-like processes are not so close
as those on velvet.   On  this surface, between  the vil-
   vol. n,               14 
106       Lieberkuhn on the  Villous Coat.
Ii, there are many orifices of mucus  follicles and of
exhaling vessels.*   Exterior to  the villous coat, many
very  small  glandular  bodies are  sometimes  found,
which are called after their describers Glandul* Brun-
neri and Peyeri.
  The internal  coat of the upper  portion  of the in-
terstitial tube is arranged so as to form  a great num-
ber  of transverse or  circular  folds or plaits, called
Valvulse Conniventes, which do not generally extend
round the intestine, but are segments of circles; they
are  so near each other, that  their  internal edges,
which are very moveable, may be laid  upon  the folds
next to them, like tiles or shingles.  It is evident that
this arrangement of the internal coat must add  great-
ly to its length.   This coat  is extremely vascular, so
that in the dead subject it can  be  uniformly coloured
by a successful injection.  The minute structure of it
has been the subject of very diligent inquiry.  There
can be no doubt but that an  immense   number of ex-
haling  and of absorbent  vessels open  upon it;  but
there are many different opinions  respecting the  ter-
mination of one set of vessels and  the  commencement
of the other,
  A very interesting account of the Villous Coat was
published  in  1744,  by Lieberkuhn,  who  was consi-
dered by his contemporaries as a most expert practical
anatomist, and was  also  very skilful  in microscopical
examinations, for which he was particularly calculated,
as his natural  powers  of  vision were uncommonly
strong.  In  his essay he refers to his preparations,
which were at Berlin, and which appear to  have ex-

  * It appears clearly, from the  account of Lieberkuhn, that the orifices
or terminations of  the  arteries on the intestines, are distinct  from the'
follicles ; for he forced injection from the  arteries into the cavity of the
intestines, and found the follicles still filled with mucous.  He then urged
the injection further, and filled the follicles, or forced the mucous out of
them- 
Hewson and others on the Villi.      107
cited great surprise in the  minds of the members of
the Academy of Sciences of Prussia, at a time  when
one of the first anatomists  of Europe, the  celebrated
Meckel, was of their number.
  According to this account, the internal  surface  of
the small intestines abounds with villi,  and with the
orifices of follicles.  These villi  are  about the fifth
part of a line in breadth.   In each of them is a  cavi-
ty filled with a soft spongy substance, which has one
or more orifices communicating with  the  intestines,
and from which  also  proceeds  a lacteal vessel.    On
the membrane which forms  this cavity, blood vessels
are most minutely  ramified.  This cavity he calls an
ampullula, and supposes it to constitute  the principal
part of the villous.  By injecting the arteries of the
intestine, he was able to pass a fluid through the am-
pullula into the cavity of the gut; he  kept a stream
of air in this way  passing through the ampullula until
it was  nearly dry and stiff, and then laid it  open with
a fine instrument.   From the appearances which then
presented, he inferred that the cavity  of the ampul-
lula was occupied with a spongy or cellular substance.
Around each villous  he  found a number  of mucous
follicles, which often were filled with a  tenacious  mu-
cous :  and distinct from  these  must  be  the  exhalent
orifices, which discharged a fluid injected by the  ar-
teries  without passing through the mucous  follicles.
  Lieberkuhu died early, and left but one essay on this
subject, which was originally published  in Holland, in
1744, but has been  republished  by the Academy of
Berlin, in their Memoirs; and also by Mr. John Shel-
don, of London.
  This account of Lieberkuhn  appears  to  have been
admitted by Haller: but it has  been  rigidly scruti-
nized by some of the anatomists of London, who were 
108        Fyfe and others on the Villi.

particulary interested with the subject; as they had
paid great attention to the absorbent system, and were
very successful in the investigation of it.
  The late Mr. Hewson, whose opinion  is entitled to
the greatest respect, rejected the  idea of  the ampul-
lula, and believed that the  villi are composed of net-
works  of lacteals, as  well  as  arteries and veins; al-
though he added that " this is the only circumstance
concerning these parts in which he should  differ from
this very acute observer."*
  Mr. Sheldon agrees.with  Lieberkuhn:  but  Mr.
Cruikshank  asserts, that, " in  some hundred  villi,  he
has seen the lacteals  originate by radiated branches,
whose orifices were distinct on the surface  of the  vil-
lus."  The villus being transparent, when the intes-
tine was immersed in water, these branches, filled with
chyle could  be seen  passing  into  the lacteal.   Mr.
Cruikshank  therefore supposes that Lieberkuhn  was
mistaken, and that  the spongy cavity, or ampullula,
was the common cellular membrane, connecting toge-
ther all the  arteries, veins, nerves, and lacteals.
  It seems  probable, from Mr.  Cruikshank's  state*
ment, that Dr. William Hunter held the same opinion
with himself.   And there is also reason to believe  that
Monro  the  second, who  studied  anatomy at Berlin,
held a different opinion from Lieberkuhn.
  Mr. Fyfe, who has been much employed in the in-
vestigation of the absorbent system, and must be per-
fectly acquainted with the preparations of Monro, as-
serts that each lacteal takes its rise upon  one of the
villi by numerous  short radiated  branches, and  each
branch is furnished with an orifice for imbibing chyle.
   Several of the late French  writers adopt the  opi-
* See Hewson's Experimental Inquiries, vol. 2, page 171. 
Division of the Intestines.          109
nion of Lieberkuhn;  but his countryman  Soemmer-
ing gives a different account of the subject.  He says,
that, besides the blood vessels,  each  villus consists  of
a fine net-work of absorbent  vessels, whose  orifices
may be  distinctly recognized ; and  that from six  to
ten of these orifices are sometimes discovered.
  Mascagni, who has published  the  most  extensive
work upon the absorbent system that has yet appear-
ed, supposes Lieberkuhn to have  been  mistaken and
confirms the description  of  Hewson :  but  he also
agrees with Hewson in his opinion of  the general  ac-
curacy of Lieberkuhn.
  Notwithstanding  their differences  respecting the
origin of the lacteals,  all these  observers have  agreed,
that the orifices which communicate with the  lacteals
are on the  villi; and  that these villi contain also very
fine ramifications of blood vessels.    They have also
agreed,  that the surface of the intestines in  the inter-
vals of  the villi seems occupied  with  the  orifices  of
ducts or of exhalent vessels.*

             Division of the Intestines.

   Although there is a considerable degree  of unifor-
mity in the structure  of  the intestinal  canal, different
parts of it  are very distinguishable from each other  by
their exterior appearance, by their  size, their invest-
ments, and their position.
   The first division is into two great  portions, which
are very different from each  other in  their diameter
and length, as well as  their situation:  the first portion
being much smaller in diameter,  and  near  four  times
the length of the other.

  ■"'On this subject the student will consult  with  advantage, Hewsoa's
Experimental Inquiries, vol. 2 ; Sheldon's  History of the Absorbent Sys-
tem, part 1st; Cruikshank on  the Anatomy of the Absorbing Vessels;  and
the Historfa Vasoram Lymphaticorum Corporis Humani, of Mascagni. 
110         Division of the Intestines.
   These portions are therefore  known by the names
 of Great and Small Intestines,  and the  line of sepa-
 ration between them is very strongly marked; for they
 do not gradually change into each other, but the  alte-
 ration in size and in exterior appearance is  very ab-
 rupt, and their communication is not  perfectly  direct.
 A considerable portion of the Great Intestine is fixed
 immoveably in the abdomen, while a large part of the
 Small Intestine is very moveable.
   Each of these great portions of the intestinal  tube
 is subdivided  into three parts.   Thus, in the  Small
 Intestine, there is a piece at the commencement called
 Duodenum, a great part of which  has no coat  from
 the peritoneum, and is immoveably fixed in one situa-
 tion ; while all the remainder  of the small intestine
 has a uniform  covering  from the peritoneum,  and is
very moveable.  This last  piece, notwithstanding its
exterior uniformity, is considered as forming two parts.
The uppermost two-fifths from  one part,  which is
called Jejunum:  and the remainder is  called  Ileum.
The Great Intestine commences in the lower part of
the right side  of  the  abdomen,  and after proceeding
up that side, crosses over to the  left,  along  which it
descends to the lower part again, when  by a  peculiar
flexure it proceeds to the centre of the posterior mar-
gin of the pelvis, from which it passes down  to  the
anus.   A  short  portion of  this intestine,  which is
above its junction with  the  ileum, is called Ccecum;
the part which proceeds from this, round the abdo-
men, is called Colon ; and the portion which is in the
pelvis is called Rectum.

              Of the Small Intestines.

  Previous to the description of the small intestines,
it is necessary to observe, that the Mesocolon, or pro-
cess of the peritoneum  connected to the transverse
portion of the colon,  forms  a kind of moveable  and 
      Commencement of the Small Intestines,  m

incomplete septum, which  divides the abdomen into
an upper and  lower apartment.   Above this  sep-
tum are the stomach, with the commencement of the
duodenum, the  liver, and the spleen; below it, that
portion of the small intestine which is called jejunum
and ileum, makes its appearance.   The portion of the
intestine which passes from the  stomach to the jeju-
num, and  is called Duodenum, is so much involved  by
the mesocolon, that the greatest  part of it  cannot  be
seen without dissecting the mesocolon from its connex-
ion with the back of the  abdomen.—For the duode-
num proceeds backwards  from the  pylorus, and pass-
ing down behind the  peritoneum, enters a  vacant
space between the  two  lamina  of the  mesocolon ; it
proceeds  for some  distance  in this  space, and  then
emerges on the  lower side  of the  mesocolon.   Here
the duodenum terminates, and the small intestine then
is invested by the peritoneum in such a manner as to
form the mesentery, which continues with it through-
out its whole course to the great intestine.   This por-
tion of the intestine, although very uniform in its ex-
terior appearance, as has been observed before, is di-
vided into Jejunum and  Ileum: the jejunum  being
the upper portion, which  begins  at the  mesocolon;
and the ileum the lower portion, which opens into the
great intestine.

                 Of the Duodenum.

   The length of this intestine is equal to the breadth
of twelve fingers, and hence its name.  It is very dif-
ferent from the rest of the small intestine, not only as
respects its position and investment by the peritoneum,
but on account  of its -connexion  with the liver  and
pancreas, by means of  their excretory ducts, which
open into it.  From this connexion with these glands,
probably, all the peculiarities of its position are to be
deduced. 
11£        Situation of the Duodenum.

  When the  stomach is  in  its natural  situation, the
pylorus is at some distance from  the  back of the ab-
domen.   The duodenum  proceeds backwards from
this point, and passes near the neck  of  the  gall-blad-
der, being here connected with  the  small omentum ;
it then curves downwards,  and  descends before the
right kidney, sometimes as low as  the lower part  of
it;  then it curves again, and passes over to  the left:
after it has arrived at the left side  of the spine, at the,
second or third lumbar vertebra, it projects forwards
and downwards to form the  jejunum.   The only por-
tion of this intestine which is moveable, is that which
is in sight as it proceeds  immediately from the  pylo-
rus, being about an  inch and a half, or two  inches  in
length.  The remainder is connected to the back  of
the abdomen, and lies,  between the two lamina of the   1
mesocolon.   In its progress it passes before the  aorta
and the vena cava,  but the  principal  branch  of the
vena portarum is before it.
  The duodenum is larger in diameter than  any other
part of the small intestines, and has a stronger muscu-
lar coat.  Its general situation admits of great dilata-
tion, and it has been called a second Stomach.  Its in-
ternal coat is strictly villous, in the anatomical sense of
the word ;  and its folds, the valvulae conniventes, be-
gin  at a small distance from the pylorus.  The orifices
of many mucous ducts  are to be seen on  its surface.
It is supposed that some of these are the terminations
of ducts from  the  glands  of Brunner, which  some-
times appear in  the  villous coat, or very close  to  it
exteriorly; being small flat  bodies, with a  depressioB
in the  centre, and a foramen in the depression.   They
are sometimes very  numerous at the upper extremity
of this intestine, and diminish  gradually towards the
other extremity.
  The. biliary and pancreatic ducts  open posteriorly 
               Jejunum and lleUtn.           113

into  the duodenum, rather  above the middle  of it.
The orifice of these ducts is generally surrounded by
a small  tubercle, which is oblong, somewhat rounded
at one extremity, and pointed at the other.   Some-
times this orifice is in a plait, like one of  the  valvulas
conniventes.   Most commonly the two  ducts  unite
before they perforate the coat, so  as to form but one
orifice; and  sometimes they open separately, but al-
ways very near to each other.
   Absorbent vessels, which  contain chyle, are  found
on the duodenum.

              The Jejunum and Ileum

Are  situated in the abdomen  very differently from
the duodenum.   When the cavity is opened, and  the
omentum  raised,  they are  in  full view ; and  every
portion  of them, except the two extremities and  the
parts near them, can  readily be moved.    This free-
dom of  motion is owing to the manner in which they
are invested by the peritoneum ;  or in the technical
language of anatomy, to the  length of their mesente-
ry.  They agree in their structure with  the  general
description of the small intestines, but their muscular
coat is rather weaker than that of the duodenum. The
valvulae conniventes are very numerous and large in
the upper part of the tube, or the jejunum; and gra-
dually diminish in number, until they finally  disap-
pear in  the  lower part of  the ileum.   The villous
coat  is in  perfection  in the jejunum, the villi  being
more conspicuous there than in any other part of  the
intestinal  tube.   There are frequently found, exterior
to this  coat,  but  intimately connected with it, many
small glandular bodies of a roundish form, which  are
often clustered together at that part of  the intestine
which corresponds with the interstice of the lamina
Of the mesentery.  They are  called Peyer's glands
   VOL. n.              15 
 114 Distinction between  Jejunum and Ileum:

 after the anatomists who first described them; and are
 supposed, like the glands of Brunner, to secrete  mu-
 cus.  If a portion of the jejunum be  inverted, and
 moderately distended with air, these bodies appear
 very distinctly in it, dispersed at small distances from
 each other.   In  the ileum they appear in small clus-
 ters, which often have the appearance of disease.
  No natural line of separation for distinguishing the
jejunum and ileum from  each  other, is to be found;
 but these names are still retained; and  therefore a
 rule laid down by Winslow is  generally adopted, viz.
 to name the first two-fifths of the  tube jejunum, and
 the remainder ileum.    There are, however, some
 important differences between these portions  of the
 intestine.
  In the jejunum, the valvulae conniventes are  so nu-
 merous, that they lie in  contact with each other, as
 shingles on the  roof of a house;  in the  ileum they
 gradually diminish in number, and finally disappear.
 In the jejunum,  the villi are much stronger than they
are  in the ileum.
  It is very difficult to acquire a precise  idea  of the
arrangement of this part of the intestinal tube, while
 it is in the abdomen, especially if it be much distend-
 ed ; but if it be separated at each  extremity from the
 intestine with which it is connected, and the mesente-
 ry  cut  off from  the back of the abdomen, and the
whole then spread out upon a  flat  surface, it will ap-
pear,  as has been already said, that the intestine is ar-
ranged so as to form a semicircle, or large curve; the
 concavity of which is opposite to the back of the ab-
 domen,  while the convexity presents forward.   It will
 also appear, when thus  placed upon a table, that the
 intestine, while connected with the mesentery,  is laid
 into many folds.   It has been supposed, that the mid-
 dle portion of the mesentery, and  the intestine  con-
 nected with it, is generally in the umbilical region; 
           Construction of the Mesentery.       115

and  the two portions on the sides  of  it are in the
iliac regions;  but their situation in the abdomen va-
ries considerably at different times.   When  the vis-
cera of the pelvis are empty, a large portion of the
small intestine is in the pelvis; but  when those vis-
cera are filled, the intestine is in the general cavity of
the abdomen.

                   The Mesentery

  Is a process of the peritoneum, which is formed  in
the manner of a plait or fold, and of course consists
of two lamina.  These lamina proceed  from the back
part of the abdomen, and are so near to  each other,
that they compose one substantial  process; having
cellular  and  adipose substance,  blood  vessels and
nerves, with absorbent or  lacteal vessels and  their
glands between them.
  The form of this process, when it is separated from
the back, and  the intestines  are  detached from  it, is
somewhat semicircular: that portion of  its margin  or
edge which corresponds to the diameter of the  semi-
circle, is connected  to the back of the  abdomen, and
called the root of the mesentery ;  the edge, which  is
the circumference of the semicircle, is connected with
the intestine.   The edge connected with the back  of
the abdomen is commonly about five  or  six  inches  in
length : the semicircular  edge, instead of extending
fifteen or eighteen inches, the ordinary  proportion, is
attached to a portion of intestine  sometimes twenty-
four feet in length.   The mesentery, on account  of
this great difference between its diameter and circum-
ference, has been compared to  the  ruffle of a  shirt
sleeve ; its roots being taken for the  plaited edge  of
the ruffle, and the circumference  for its  loose  edge.
But the comparison is not precisely accurate ; for the
mesentery  is  not plaited at  its  root,  but  perfectly 
116           Root of the Mesentery.
smooth, and free from  every kind of fold.   It begwg
to enlarge towards its circumference, and  enlarges to
that degree, that it falls into plaits or folds:  precisely
such as would exist in  a semicircular piece of mem-
brane  about  six  inches in  diameter, if a number  of
simple incisions, of about an inch and a half in length,
were made in a radiated direction from its  circumfe-
rence, and if portions like a sextant or quadrant were
taken from a circular membrane three  inches  in  dia-
meter, and united by  their edges to these  incisions,
so that their circumference  might be continuous  with
the circumference of the large semicircular piece.  In
this case,  the portions like quadrants  or sextanto
would assume a folded position like  the edge of the
mesentery, while the middle of the semicircular piece
would preserve its regular  form  without  folds;  as is
the case with the mesentery at some distance  within  «
its circumference.   By many additions of this  kind,
the circumference of a membrane, which was original-
ly a semicircle of five  or six inches, may be extended
so as to exceed  greatly that of  the mesentery.   It
seems  of course impossible to form an  accurate model
of the mesentery with a single piece of membrane or
paper; but it may be easily made  with clay, or any
ductile substance.  A model of this kind  must neces-
sarily  be folded after the manner of the  mesentery;
and its circumference, like  the mesentery, would ap-
pear as if formed of portions of  the circumference of
smaller circles united to each other.*
   The root  of  the mesentery  commences  with the
jejunum on the  lower side of the mesocolon, at the
left of the spine, and  extends  downwards near to the
right  iliac  region; crossing   the  spine  obliquely.

  * A model, upon the plan first mentioned, was invented by Dr. J. G. Ship-
pen.  It has been proposed, I believe by Mr. Gavard, to make one with
a single piece of buckskin, of a semicircular form, by stretching it *t the
circumference 
       Appearance of the Ccecum and  Colon.    117

When it is examined in its natural situation, the peri-
toneum is found continued from the back of the abdo-
men to the intestine ; it then surrounds  the intestine,
and continues  from  it to the back of  the abdomen
again.   There must  therefore be two lamina of peri-
toneum in the  mesentery, and there must be a small
portion of intestine  answering to the interstice  be-
tween these lamina, which is not covered by the pe-
ritoneum.  The blood vessels, and  absorbent  or  lac-
teals,  pass most commodiously to the intestines between
these lamina ; for they are connected with large trunks
that lie on or near the spine, and the root of the  me-
sentery commences there.
  The glands connected with the lacteals  or absorb-
ents are very conspicuous in the mesentery, and are
commonly called mesenteric glands.   They are of dif-
ferent sizes, from more than half an inch to one  or
two lines in diameter.  They are very numerous, and
scattered irregularly, but are seldom observed  very
near  to  the intestine.   They are  often enlarged  in
consequence of disease, especially in children.
  The nerves of the  small  intestines which are de-
rived principally from the superior mesenteric plexus,
are also to be  found  here.
  The adipose matter between the lamina  of the me-
sentery is very often in a large  quantity, but varies,
in proportion  to the  general  quantity of adeps in the
subject.

            OF THE  GREAT INTESTINES.

               The  Cwcum and Colon

   Are very  different from the small  intestines  in
many respects.  They are  much  larger in diameter.
Their external surface is marked by three longitudi-
nal bands of a light  colour,  which extend the greatest 
118           Position of the Csecum.
  part of their length, and are placed  nearly at equal
  distances from each other.   The spaces between these
  bands are marked  by transverse indentations, which
  pass from one hand  to the other at short  but unequal
  distances.  At these indentations the coats  of the in-
  testine are pressed  inwards, as if  a  fine thread  had
  been drawn round it externally, while the spaces  be-
  tween them are full  and  tumid, and on  this  account
  are called cells.
    The great intestine, with these appearances, be-
  gins, as has been already observed, in the  right  iliac
  region, by a  rounded end which rests on  the fossa or
  concave  surface formed by the  costa of the  ileum ;
  from this it is continued upwards in the  right  lumbar
  region, anterior to  the kidney, until  it  arrives near,
  the  liver, when it forms a  curve, and  passes directly
  across the abdomen to the left side.  In this course it
  approaches so near to the under side of the liver,  that
  it is often in contact  with it, and with the gall bladder,
  which, after death,  tinges it  with a yellow  colour.
%  On the left side  it passes down  the  lumbar region, be-
  fore  the  kidney, to  the  left  iliac region ;  here it is
  curved so as to resemble the  Roman letter S, invert-
  ed ;  this curve generally carries it to the  right side of
  the spine, and then brings it back to the centre of the
  sacrum.  Here the intestine changes  its course, and
  passing into the  pelvis, continues downward, in con-
  tact with the sacrum and coccygis, and  partaking of
  the curvature of those bones, until it terminates at
  the anus, where  it  is connected with the  sphincter
 and levator ani muscles.
   About two inches  from the  commencement of the
 great intestine, the ileum opens into it laterally ;  and
 all that portion which is between  its  commencement
 and the insertion of the  ileum  is termed Caecum, or
  the blind intestine:  that part of the great tube, which 
Structure of the Colon.
119
is included in its course from the insertion of the ileum
to the posterior part of the brim of the pelvis is called
Colon ;  and the remainder, or the part which is  con-
tained in the pelvis, is termed Rectum.
  The Caecum is nearly as wide as  it  is long ;  it is
fixed in the right iliac fossa by the peritoneum, which
invests it so that the great body of the  intestine  pro-
jects from the surface of the fossa covered by the  pe-
ritoneum ;  but a portion is in  close  contact with  the
surface, and connected to it by cellular membrane.
Its external  surface, covered  by the  peritoneum, is
marked  by two of the bands  or stripes before men-
tioned, which proceed on it lengthways.  These bands
are in full view, but  the  third band is generally on
that part of* the intestine which rests on the  iliac fossa,
and is therefore out of sight.   At the rounded extre-
mity of  the cascum, situated anteriorly and internally,
is a small process resembling  an earth-worm in form
and size:  this is therefore called  Appendicula  Ver-
miformis.   It is hollow and  communicates  with  the
cavity of the  csecum at  the  place  of junction;  and
like the caecum, has its  other  extremity closed  up.
It is composed of the same number  of  coats and  has
the same structure as the  great  intestine :  its  length
varies from two to four inches.
  The longitudinal  bands  above mentioned commence
at the junction of this appendix with the csecum, and
continue throughout the extent of the colon.   They
appear to be formed by some of the longitudinal fibres
of the muscular coat, which are arranged close to each
other.   These fibres seem to be shorter than the coats
of the intestine, and the interior coats  adhere  firmly
to them.  Thus are  produced  the indentations and
cells; for if the bands are divided  transversely, the
indentations disappear, and the  surface  of the intes- 
120             Valve of the Colon,
 tine becomes uniform.   One of these bands is covered
 by the mesocolon.
   The circular or  transverse fibres of the  muscular
 coat of the ccecum  and  colon are  very delicate, and
 not numerous.
   The internal coat differs materially from that of the
 small  intestines, although at  first view they seem to
 resemble each other; for if a  portion of the ileum and
 of the colon be inverted and  suspended  in  water, no
 villi can be seen with the naked eye on the internal
 coat of the colon, while those  of the ileum  are very
 visible.   The glands exterior  to this coat  are  larger
 than those on the small intestines.
   Instead of valvulae conniventes, are the ridges made
 by the indentations or  depressions  above  described,
 which separate the incomplete cells  from each  other.
 These ridges differ  essentially from  the  valvulae  con-
 niventes, because all the coats  of the  intestine are con-
 cerned in their formation, whereas the valvulae  conni-
 ventes are formed by the villous coat only;  they also
 project into the cavity of the intestine, while the  val-
 vulae are  laid  on  its surface.    They pass only from
 one longitudinal band to another, and, in consequence
of this, the cells are small, and  the  position of each
band is very evident when the intestine is laid open.
   The communication  of the ileum with the great
intestine  has  been  already stated to be on  the  left
side of it, about two  inches  from its commencement.
The aperture is so constructed,  that it  is considered
as a valve, and is called  the Valve  of Bauhin, or  of
Tulpius,  after  the  anatomists  who have  described
it.*   The appearance of the  aperture is  as  follows:
If the csecum, with  a small portion of the ileum  and

  * Posthiusin 1566 ; Vidus Vidius about 1569 ; Alberti in 1581: and Varo
Bus who died in 1575, each jlay claims to the discovery of it  Bauhin's
claims are in 1579—E». 
        Structure of the Valve of the Colon.    121

of the colon, be separated from  the  other intestines,
and kept in an inflated  state until it be  so  dry as to
preserve its form when opened, and  then if the cae-
cum and colon be laid open opposite to the aperture
of the ileum, a  large  transverse ridge, resembling
some of the ridges or folds just described, will be seen
projecting into the cavity of the intestine.  In the in-
ternal  edge of this fold is a long slit or opening, which
forms the communication between the two intestines.
It is obvious that the form of this fold must be that of
a crescent; and that its two surfaces with  the slit be-
tween them, must have  the appearance  of  two lips,
which  would  readily permit a fluid or  substance of
soft consistence to pass from the ileum  into.the  great
intestines,  but must  impede,  if not  prevent, its pas-
sage back ;  especially if the large intestines were dis-
tended, as  then the lips would be pressed against each
other.
   When the peritoneal  coat is dissected from each of
the intestines at their place of junction, and this struc-
ture is then examined from without, it appears as if a
transverse or half circular  indentation had been formed
by the villous coat of the  great intestine,  and that the
internal coat of the extremity of the ileum was pressed
into  this indentation, and  united  to  the internal coat
of the great intestine which formed it;  while  there
was a slit,  both in the indentation and in  the  end of
the ileum,  which formed a communication between the
cavity of the great intestine and the ileum.  The lon-
gitudinal fibres of both intestines, as  well as their ex-
ternal coats, seemed  to be united, so as  to form a com-
mon cover for them; while the  circular  fibres  were
blended in the two portions of the indentation  which
form the lips of the  orifice.
   This orifice is, of course, transverse with respect
to the intestine.   It has been  observed, that  there
was a difference in the thickness  and strength of the
   VOL. II.               16 
122           Position of the Rectum.

two  lips or valves;  that  the lower valve  was the
strongest, and appeared to have  the  largest propor-
tion of muscular fibres in its composition.  At the ex-
tremities of the orifice, and near each end of the fold
or ridge, are tendinous fibres, which give strength  to
the structure;  they are called the Retinacula of Mor-
gagni, as they were first described by that anatomist.
  There is great reason for believing that this valve
cannot prevent the retrograde motion of the contents
of the intestines in all cases; for in some instances  of
hernia and of colic, matter perfectly stercoraceous has
been vomited, and the probable inference from  such a
state  of  the ejected  matter  is, that this matter has
been in the large intestines.  It is also said, that sup-
positories and enemata have  been discharged  by vo-
miting.
  On the  right and  left sides of the  abdomen, the
colon is in close contact with  the  posterior surrace of
the cavity.  The peritoneum, which covers  this sur-
face, extends over the intestine also, and thus  retains
it in its position.   The great arch of the colon, which
is loose and moves far from the back of  the  abdomen,
is invested by the  two lamina of the omentum,  which,
after surrounding it, unite again and form the meso-
colon.   Connected with the  exterior surface   of the
colon are many processes, composed of adipose mem-
brane, varying in length from half an inch to an inch
and a half.* these appear to  be of  the  nature   of the
omentum,  and are therefore generally denominated
Appendices Epiploicae.

                   The Rectum.

  After forming the sigmoid  flexure, the colon termi-
nates ; and the rectum begins opposite to  the lower
surface of the last  lumbar vertebra, and nearly  in con-
tact with it; from this it  proceeds downwards, form- 
Structure of the Rectum.
12:.i
 ing a curve like the sacrum, until it terminates at the
 anus, where it is invested with the  muscles called the
 sphincter, and levator ani.  It  is  called  rectum, be-
 cause in this course it is supposed not to incline to ei-
 ther side; but it is often found on one  side  of the
 middle line.*
   This intestine being in contact with the posterior
 surface of the pelvis, is covered, on its anterior  sur-
 face only, by the  peritoneum which lines the poste-
 rior surface of the pelvis ; and it is fixed  in this  situ-
 ation by the peritoneum, as the colon is on  the right
 and left sides of the abdomen, but more loosely; and
 therefore the  term Mesorectum has sometimes  been
 applied to that portion of the peritoneum which is
 analogous to the mesentery and mesocolon.   The peri-
 toneum does not extend to the end of the  rectum ; for
 it is reflected at the lower part of the pelvis from the
 rectum to the  bladder, or  uterus, and does not line
 the bottom of the pelvis; so that the  lower part  of
 this intestine, as well as  of the other  viscera  of the
 pelvis,  is below the  peritoneum, and  not connected
 with it.
  The muscular coat  of the  rectum is much thicker
 and stronger than that of any other intestine.    The
 strata of longitudinal  and circular fibres  which com-
 pose it are very distinct from each other.   The longi-
 tudinal  fibres are  most  numerous,  and terminate at
 the insertion of  the fibres of the levator ani muscle.
  The lower circular  fibres  are intimately connected
 with the sphincter ani.
  The internal coat is  very vascular, but  the villous
structure is not apparent.   Mucous follicles  are  also
very numerous; and there are likewise some distinct
glandular bodies exterior  to this coat, which vary in
 size in different subjects.

  * Morgagni and Haller supposed it to be commonly on the left of the mid-
dle line : and Sabatier on the right. 
124  Absorbents and  Nerves of the Intestines.

  The quantity of  mucous discharged  from the  rec-
tum  in  certain  cases  of disease,  is  sometimes very
great.   The internal coat, in consequence of the  con-
traction of  the circular fibres  exterior  to it, some-
times forms  longitudinal folds, which have been called
its columns; these  often disappear when the intestine
is opened lengthways  and spread  out.   By the con-
traction of the longitudinal fibres,  the internal  coat is
often thrown into folds or doublings, that must  assume
a transverse or circular  direction ;  they occasionally
pass down through the sphincter, and  form the  pro-
lapsus ani.  The rectum is most  plentifully supplied
with blood vessels, to  be  described hereafter; and it
may be observed, that, on the lower part of the inter-
nal coat, the veins  are particularly numerous.
   The  internal coat of the rectum terminates abrupt-
ly just within the anus, and is united to a  production
of the  skin, which, like  the covering  of  the  lips, is
very delicate  and vascular, and has an epithelium, or
very thin cuticle, spread over  it.    The levator and
sphincter ani  muscles, with which  the termination of
the rectum  is  invested, are described in the first vo-
lume.
   The  Absorbents of the Intestines are commonly de-
nominated Lacteals.*  They originate on the internal
surfaces of these viscera, as has been already described.
After  passing through  the lymphatic glands, which
are  so  numerous on  the  mesentery,  they generally
unite and form one of the  great trunks which compose
the thoracic duct.   It  is  asserted, that  some of the
absorbent vessels of the lower  intestines unite to the
lymphatics  of the loins.
   The  Nerves  of the Intestines  are principally de-

  • The Lacteals were first observed by Erasistratus and Herophilus, of the
school of Alexandria, during the i eign of the Ptolemies ; and subsequently
by Aselli, of Pavia, in 1622. the knowledge of them having been  lost for
1900 years__Ed. 
    Origin and Arrangement of the Omentum. 125

rived from  the  intercostals, or great sympathetics.
From each of these nerves, while they are in the tho-
rax, an important branch, called the ramus splanchni-
eus, arises.   These splanchnic branches pass through
the diaphragm, and are the  chief contributers  to the
ganglions aqd plexuses formed  in the  abdomen.   A
plexus, derived from this source surrounds the  supe-
rior mesenteric artery, and another the inferior me-
senteric ; and from these proceeds  the nerves  of the
intestines.
                  The Omentum

  Requires  a separate  description, although several
circumstances connected with its structure have been
already noticed.   It often varies in its  position ; but
when it  is  rendered firm  by  a quantity of adipose
matter, it is spread over the intestines  like an  apron,
extending from the lower edge, or  great curvature of
the stomach, towards the bottom of the ahdomen.
  As has been already said, it is an extension of the
peritoneum, in two lamina, from the  concave  surface
of the liver to the lesser curvature of the stomach ;
and these lamina, after surrounding the stomach, come
in contact with  each  other  near its great curvature.
From this portion of  the stomach, from the commence-
ment of the duodenum, and also from  the spleen, the
Omentum,  composed of  two lamina,  descends over
the colon and the small  intestines more  or less low
into the  abdomen ; it is  then  folded  backwards .and
upwards, and is  continued  until it  meets the  great
arch in the colon : here the lamina again separate and
enclose that portion of the intestine, on the  posterior
side  of which they  again approach  each other, and
form a membrane like the mesentery, of two  lamina,
which passes from the concave  or posterior surface of
the colon to the  back of the abdomen, where it is con-
tinued into the  membrane which lines that surface. 
 126 Origin and Arrangement of the Omentum.

 This last portion is the Mesocolon: the portion  be-
 tween the liver and stomach is called the Omentum of
 Winslow, or the lesser omentum ; and the great por-
 tion between the stomach and colon is called the Great
 Omentum, or the omentum gastro colicum.   There is
 also a process of peritoneum continued from that por-
 tion of the colon which is on the right side of the ab-
 domen, and from the cascum, which extends  to some
 distance; it is formed of two lamina,  that compose  a
 cavity of an angular  form.   This has been called  the    !
 Omentum Colicum.
   The great and small  omentum, with a portion of
 the peritoneum on the back of the  abdomen, form  a
 sac, which encloses a distinct cavity in the  abdomen.
 The anterior part of this sac is composed of two la-,   \
 mina, and between these lamina are  the  stomach and
 the great arch of the colon.   This cavity, formed by
 the  two omenta, communicates with the general cavi-
 ty  of  the  abdomen by  a foramen  of a  semicircular
 form, called the Foramen of Winslow, which is  be-
 hind the great cord of the  vessels  that go  to the liver.
   The omentum is so delicate in structure, that  when
 free from fat, it is very liable to laceration, merely by   ]
 adhering to the fingers, if they are dry.   Winslow
 therefore advised that some unctuous substance should
 be  rubbed on the hands, before they were  applied
to it.
  The appearance of the great omentum  is  very dif-
 ferent in different persons.   In the  emaciated, it  ap-
 pears like a delicate transparent membrane: in  the
 corpulent, it is like a broad mass of adeps, which some-
 times is  very thick.   When it  is  thus  loaded witl#
 adeps, it is most commonly spread over the small in-
 testines :  when  it  is free  from fat, it is often com-
 pressed together, so as to form a small mass  near  the
 arch of the colon, on  the  left side.
   The principal blood vessels of the omentum are de- 
Varieties in the Appearance of the Omentum*    127

rived from those of the stomach, and are called gastro
epiploic arteries and veins.
  The use of this  membrane in the animal  economy
has not been ascertained with certainty.   It  seems
probable that one of its principle object is to protect
the small intestines, and lessen the friction  consequent
upon  their motion; but it has  been supposed to an-
swer  several other important purposes.*
•See Halleri Elementa Physiologiae, vol. vi. page 381.
Cavard. Traite de Splanchnologie, page 350.
Dr. James Rush's Inquiry into the use of the Omentum. 
                  CHAPTER III.

  OF THE LIVER,  THE PANCREAS, AND THE SPLEEN.

                    SECTION I.

                   Of the Liver.

   This  largest viscus of the abdomen, when in a
healthy condition, is of a reddish brown  colour.   If
it is taken out of  the subject, and laid on a  flat sur-
face, it is flat, but in the abdomen it is  convex and
concave.
   It is situated in the right hypochondriac region,
which it occupies entirely ;  and extends through the
upper portion of the epigastric into the left hypochon-
driac region.   Being  placed  immediately under, the
diaphragm, and in close contact with it, as well as with
the inner surface of the  right hypochondriac region,
it partakes  of  their form, and is  convex above and
concave below.   When thus situated, it is of an irre-
gular figure, between the circular and the oval,  but it
is broader at the right  extremity than at the  left, and
very irregular  in thickness.   The  edge or margin
which is  in contact with the posterior  part of the right
hypochondriac region, is very thick.   It gradually be-
comes thinner towards  the left, and also  towards the
front;  so that the right margin, and  a large portion
of the posterior margin, is very thick, while the left
and the anterior margin is thin.
   The upper convex surface of the liver, when in its
natural situation, is smooth :  the  lower concave sur-
face is  marked by  several grooves  or  fissures and
eminences.   One  of these, called the  Umbilical or
the great fissure,  commences at a  notch in  the  ante- 
          Lobes and Fissures of the  Liver.      129

rior edge of the liver, to the  left  of  the  middle, and
continues to the posterior edge.   At the commence-
ment  of this  fissure  the umbilical  ligament  enters;
and at the termination, or near  it, the vena  cava is
situated.  Opposite to this fissure, on  the  upper  or
convex surface, is a  ligament passing from  the dia-
phragm  to  the liver, which  is called the  falciform.
The "fissure  and the ligament divide the liver  into  its
two great lobes, the Right and Left.
   Another  great  fissure, called the  transverse  or
principal, commences in the  right lobe  and  extends
to the left, crossing the first mentioned fissure  at right
angles, and  extending a  very short  distance  beyond
it.  It is very deep, and rather nearer to the poste-
rior than the anterior edge of the liver.   In  this fis-
sure, near to its right extremity, the great vein, called
vena portarum, and the hepatic artery enter,  and the
excretory duct of the liver, commonly called  the he-
patic  duct, comes out.  About the middle of  the fis-
sure are two  prominences, one on each  side; these
were  called  the portse, or gates of the liver, and hence
the great vein was called vena portarum.   This vein
has two very large rectangular branches, which consti-
tute what is called the sinus  of  the  vena portarum,
and they occupy the principal extent  of the fissure.
   The liver is  in close contact  with the vena cava
behind ;  and there is  either a  groove in it for the pas-
sage of the vein, or this great vessel is completely en-
closed by it.   There is  also an excavation  on the
lower surface of the liver, which is occupied by a por-
tion of the gall bladder.
   Besides the great lobes above mentioned, there are
also two or three prominent parts on the concave sur-
face, which  are denominated lobes.   One  of these,
called Lobulus  Spigelii, is oblong,  with two sides,
and an angle continued along its whole length, which
extends from the transverse fissure to the posterior
   vol. n.               17 
130          Ligaments of the Liver.

margin of the liver.   It is situated between  the pos-
terior part of the transverse fissure, or  ductus veno-
sus, and the vena cava.
  The anterior  extremity of this  lobe, which forms
one of the margins of the transverse  fissure, is some-
what bifurcated, and has been called lobulus caudatus.
The largest portion of the bifurcated  end forms a pro-
cess like a papilla, and is one of the portae.
  Between the umbilical fissure and the depression
for  the gall  bladder is  a  protuberant  space, which
varies from an inch and  a  quarter to  two inches in
breadth.   This has also been called  a  lobe, Lobulus
Quartus or  Anonymous, its posterior  point opposite
the papilla of the lobulus spigelii forms the other por-
ta of the liver.
  The peritoneum  is extended from the surface of
the abdomen to the surface of  the  liver, in such man-
ner as to cover it, and to form ligaments, which have
a great effect in retaining it in its proper situation.
The whole posterior edge of the  liver  is in  contact
with the  back  of  the abdomen.   The  peritoneum
above the liver is reflected to the upper surface of it,
and the peritoneum below it to  the lower  surface; so
that two lamina of the peritoneum pass from the lower
part of the diaphragm at the back of the abdomen to
the posterior edge of  the liver.   These processes of
the peritoneum are considered  as  forming two liga-
ments, which are called the right and left lateral li-
gaments.   A portion of the posterior  surface  of the
liver, uncovered by the peritoneum,  is often   in con-
tact with a portion  of the tendon  of the  diaphragm,
also uncovered  by peritoneum : around this place of
contact, the  peritoneum is extended  from the dia-
phragm to the liver, and thus  forms what has been
called the coronary ligament of the liver.
  The peritoneum of the right side of the  diaphraem,
and of the abdominal  muscles, as far down as the urn- 
          Mode of supporting the Liver.     .   131

bilicus, is extended to the liver, and joins  it on the
convex surface immediately opposite to  the  umbilical
fissure.  The peritoneum from the  left  side of these
parts does the same; and as these reflexions of the
peritoneum are continued from so low a part as the
umbilicus, they are extended not only to the convex
surface of the liver,  but also  to the great notch, and
along the umbilical fissure.
  From the umbilicus proceeds a round cord-like li-
gament, which in the fcetal state  was a  vein,  that
passes to the great fissure of the liver,  and  along it.
The process  of the  peritoneum above  mentioned  is
so connected with this cord, that it encloses it  in its
lower edge, and the  whole is called the falciform li-
gament of the liver.  The  cord, when named sepa-
rately, is the umbilical or the round  ligament; and
the membrane or lamina of the peritoneum forms the
suspensory ligament.   Besides these, the peritoneum
on the lower side of  the  liver is so arranged, that  it
not only extends to the stomach, but to the  duodenum
and the colon.
  By these ligaments the position of the liver must
be fixed to a great degree; and there is  one additional
connexion, which must have a great effect  in retain-
ing it in its proper situation.   The vena cava receives
two or three great veins  from the liver, at  the place
where  it is in contact with the posterior edge of that
viscus: these veins of  course pass  directly from the
substance of the liver into the cava, and connect it to
that vessel.   As the cava is supported  by the  heart,
and also by the diaphragm, it must afford a considera-
ble support to the liver.
   When the stomach  and  intestines are distended,
they must also contribute in a considerable  degree to
the support of the liver.
   The liver has a strong tendency, when we are erect; 
132 Acini of the Liver.-Proper Coat of the Liver,

to change its situation ; and some considerable support
is necessary to counteract this tendency.   It would
move to the right, when we  lie  on the right  side, if
it were not in contact with the ribs;  and it inclines to
the left, for want of such support, when we he on the
left side.
  It has been computed, that the liver descends about
two inches, when the position of the subject is changed
from the horizontal to the erect.   As it  is in  contact
with the diaphragm, it is obvious that it  must  be  in-
fluenced by the motions  of  that  muscle, and  that it
must descend when  the diaphragm contracts.
  The liver is composed of  a  substance which has
some firmness of consistence, although it is  yielding;
and is also somewhat brittle  or friable.*   When cut
into, the sections of  many tubes, or vessels of different
diameters, appear on the  cut surface.   When  the tex-
ture of this substance is more closely examined, it ap-
pears somewhat granulated, or composed of very small
bodies, which were  called acini by the anatomists who
first described them.  The whole substance is enclosed
by  the peritoneum,  which is extended to  it from the
surface of the abdomen in the manner that has been
already described.   It has also a proper coat  or cap-
sule ;  and on the posterior edge,  where the lamina of
the lateral ligaments pass from the diaphragm  to the
liver, at some distance from  each  other, a portion of
the liver, covered by this coat  and by cellular sub-
stance, is in contact  with  the diaphragm.   The same
thing occurs likewise at the  coronary ligament.-}-
  The liver holds the first place  among the glands of


  * It has been fractured in the living body by external violence.
  t Many anatomists deny the existence of this coat; but if one of the la-
mina of the ligaments be carefully peeled off from the surface of a liver
which is slightiy affected by putrefaction, it will be apparent, although very
thin.  It was described by M. Laennec, in Le Journal de Medicine for 1803. 
       Vessels of the  Liver.—Hepatic Artery.   133

the body for size, but it is still  more remarkable for
some other circumstances in its economy.  In addition
to an artery,  which passes to it as arteries do to  other
glands, there is a large vein which also enters it as an
artery; and after ramifying thoughout the liver, com-
municates, as does the artery, with other veins, which
carry the blood from this gland into the vena cava and
the general circulation.    There are  therefore  three
species of blood  vessels in the liver;  and with  these
are found the vessels which carry out of the gland the
fluid secreted by it, or the bile.
  The artery of the liver is denominated the Hepatic
Artery.  The vein which goes to the  liver is  called
the Vena Portarum,  from the place at  which it en-
ters.   The veins which  carry to the vena cava the
blood brought to the liver by the  hepatic artery and
the vena  portarum, are  called  the  Hepatic  Veins;
and the duct through which the  bile flows out of the
liver, is called the Hepatic  Duct.   Three of these
vessels, the Hepatic Artery, the  Vena Portarum, and
the Hepatic Duct, enter the liver at the  great fissure,
at the spot where the prominences exist called the
portae; hence the name vena portarum was  applied
to the  vein.
  These vessels ramify in the manner presently to be
described ; and  it is ascertained  by minute anatomical
investigation, that the  liver is  entirely composed  of
the ramifications of these vessels and  of the  hepatic
veins,  with absorbent vessels  and  nerves, which are
connected together by cellular membrane.
  It has been  already observed, that the first great
branch sent off  by the aorta in the abdomen, the C02-
liac, divides into three branches, which go respective-
ly to the stomach, the liver, and the spleen.
  The Hepatic  is  generally the  largest  of  these
branches.  In its progress towards the liver it  sends 
134
Vena Portarum.
off an artery to the stomach, called the  gastrica dex-
tra.  At the great fissure it divides into two branches:
the right branch, which supplies the right lobe of the
liver, is of course the largest.  This branch sends off
one to the gall-bladder, which is called the cystic ar-
tery; and also some smaller branches: it passes under
the hepatic duct, and ramifies through the great lobe
of the liver.   The left branch is distributed through
the left lobe of the viscus.   It can be proved  by in-
jection, that the hepatic artery communicates not only
with the hepatic  veins, but with the biliary  duct, and
the vena portarum also.   It has been disputed whe-
ther the size of this artery is greater than  would be
requisite for the nourishment and animation of the
liver.
   The  Vena Portarum, the  great peculiarity  of the
liver, originates from all the  chylopoetic viscera ex-
cept the liver, and is of course formed  by the  union
of the veins which correspond to all  the branches of
the cceliac and mesenteric arteries, as  they are  distri-
buted to the stomach  and  intestines, the  spleen, the
pancreas, and the omentum.  The veins from the in-
testines generally form  two great trunks, which are
denominated the  greater and lesser mesenteric  veins.
The great  mesenteric vein is situated  to the  right,
and rather before the mesenteric artery.—After it has
approached the origin of the artery,  it separates from
it, and passes behind the pancreas: at this place, nearly
in front of the spine, it is joined by the great vein of
the spleen, which forms almost a right angle with it,
and these constitute  the great trunk of the  vena por-
tarum.  The lesser mesenteric vein, which corresponds
to  the  inferior  mesenteric artery,  and brings blood
from the pelvis and from the left part  of the  colon,
becomes finally a large vessel, and  commonly unites
with  the splenic about an  inch and a half  before its
junction with the superior mesenseric vein.   The vena 
          Vena Portarum.—Hepatic Duct.      135

portarum, thus formed, proceeds towards the liver, in-
clining to the right, and is generally about three inches
in length : in its course it sometimes receives small
veins, which in other cases pass to its splenic and me-
senteric branches.   When it has arrived at the great
transverse sinus of the liver, it divides into two large
branches,  each of which  forms nearly a right  angle
with it.   Their size is so great, that, when distended
with injection, they appear like an independent vessel,
into which the vena portarum  enters;  and on  this ac-
count they are called the  Great  Sinus of the  vena
portarum.   They do not adhere firmly to the glandu-
lar substance of the liver, but are  united to it by cel-
lular membrane.  The right branch is the widest and
shortest.   It generally divides into three branches;
an anterior, a posterior, and a lateral  branch  ; which
ramify minutely, and extend themselves  in the right
lobe.   The  left  branch  is much longer, and conti-
nues to the extent of the transverse fissure.   Near its
termination it is joined by the  umbilical ligament,
which has been already mentioned.   This branch is
generally in contact with a branch of the hepatic ar-
tery, and of the hepatic duct; and ramifies,  like the
right branch,  into the contiguous parts of the liver.
  The Hepatic or excretory duct  originates,  by  very
small vessels, from the acini or corpuscles  of which
the liver is composed, and into which the minute ra-
mifications of the vena portarum and  hepatic artery
extend.    They accompany these  vessels, increasing
as they increase, although the fluid they contain moves
in an opposite  direction;  and two large  branches
which they ultimately form are situated at the portae
of the liver, in contact with the great branches of the
vena portarum and the hepatic artery.
  These three vessels are in contact with each other 
 136    Hepatic  Veins.—Nerves of the Liver.

 before they enter the liver.   The  biliary duct is an-
 terior, the vena portarum posterior, and the artery to
 the left  of them.   They are accompanied by nerves
 and lymphatic vessels, and are surrounded by a consi-
 derable  quantity  of  cellular  substance, and  thus ar-
 ranged are partially covered with  peritoneum.  The
 cellular substance  which invests them continues  with
 them into the liver, and is more  particularly  connect-
 ed with  the  vena portarum.   It is  called Glisson's
 Capsule, and was supposed to have  some contractile
 power, which assisted the circulation of the vena por-
 tarum ;  but that idea is now altogether abandoned.
 The hepatic veins, which receive the blood of  the he-
 patic artery and the vena portarum, open into the an-
 terior part of the vena  cava, where  it is in  contact
 with the liver.   Generally there are three of these
 veins, but  sometimes there are  only two ; in which
 case one  of them is formed by two others, which unite
 immediately before they open into the vena cava.  It
 is to be observed,  that the various  brandies  of these
 veins do not  accompany those branches  of the  vena
 portarum or hepatic artery to which they correspond,
 but form very large angles with them.  This   is  pro-
 bably owing merely to their termination in  a  part so
 distant from that in  which  the  artery and the vena
 portarum originate; but it is very different from what
 occurs in other glands.
   The Nerves of  the Liver are derived from  the se-
 milunar  ganglions of the splanchnic nerves.   From
 these many nerves proceed, which form  a net-work
 denominated  the  solar  plexus.    From  this  plexus
 many threads are sent off, which form a net-work that
 is divided  into  the  right and  left hepatic  plexus.
 These plexuses surround the  hepatic artery and the
 vena portarum, and  accompany them in  their rami-
eations throughout the liver, being enclosed by Glis- 
Lymphatics.
137
 son's capsule.   They receive some threads  from the
 stomachic plexus,  formed  by the par vagum.   Al-
 though the number of nervous fibres is very conside-
 rable, their bulk, compared with that of  the liver, is
 very small.
   The Lymphatics of the Liver are extremely nu-
 merous ;  and those in that portion  of the peritoneum
 which invests the  liver may easily be rendered con-
 spicuous : for by pressure the injected  fluid can be
 forced  from  the trunks  and large branches into  the
 small ramifications, in opposition to the valves.  When
 all the surface is injected in this manner, it  has  the
 colour of  the substance  injected ; as is the case with
 parts which are very vascular, when the blood vessels
 are injected.
   The  deep-seated lymphatics are also  very nume-
 rous in  the liver, and communicate freely with the su-
 perficial.
   The superficial lymphatics which are on the upper
 surface, proceed through the diaphragm into  the tho-
 rax in their course to the thoracic duct.  Those which
 are deep-seated  emerge from the liver at  the portae,
 where the great vessels  enter, and unite with the tho-
 racic duct in the abdomen, after passing through seve-
 ral glands.    The  lymphatics of  the lower surface
 unite with the deep-seated.
   The glandular or parenchymatous substance of the
liver  is of a reddish-brown colour,  and  moderately
firm consistence.  When it is cut into, the cut surface
exhibits the sections of the branches of the  different
blood vessels above mentioned, and of the excretory
ducts.   These vessels are often distinguishable  from
each other.   The section of the biliary duct  appears
the thickest; that of  the artery next; the vena por-
tarum is next in  order ;  and, last of all, the vena he-
paticae.
  vol. ir„               18 
138     Glandular Substance of the Liver.

  The branches of the vena portarum are surrounded
by cellular substance, or Glisson's capsule ;  and there-
fore  adhere less to the substance of  the liver than the
branches of the hepatic veins.   The sections  of the
hepatic ducts have often bile in them, and are  there-
fore  termed pori biliarii.   The branches of the  arte-
ry are also very distinguishable.
  When the internal substance of the liver is brought
into  view,  and examined accurately, it appears to  be
formed of small bodies, or acini, which are distinguish-
able  from each other.   If the liver happens to be torn
or lacerated, the lacerated surfaces are rough and  ir-
regular, owing to  the separation of these acini  from
each other.
  It  is asserted by  several  microscopical observers,
that  a minute branch of each of the aforesaid  vessels
can be traced into each of the  acini.  It  is also de-
clared, that if each of these vessels  be injected  sepa-
rately with mercury, oil of  turpentine coloured, or a
saturated aqueous  solution of gutta gamba, there is no
part of the glandular mass as large as a grain of  mus-
tard  seed in which these vessels will not be found.
  Several  anatomists of the first character have  like-
wise declared, that a fluid properly injected into one
of these vessels, will occasionally pass into all of them.
Thus an injection  will not  only pass from the  vena
portarum to the biliary duct, but to the hepatic artery
and veins also.  It will likewise pass, in a retrograde
course, from the biliary ducts to the vena  portarum,
and to the  hepatic artery and  the  hepatic veins; or
from  any one of the four  orders of vessels into the
three others.*
  The great  peculiarity of the liver  is, that  venous
blood, instead of arterial, is brought to it for the pur-
pose of secretion.   Thus, the great vein  of the  chy-
• I have tried the experiment and fold the assertion to be correct.™Ec 
      Peculiarity of the Liver.—Gall Bladder.   139

lopoietic viscera,  instead of passing  to  the cava, en-
ters the liver by the transverse fissure, and  takes on
the office of an artery ; its coats, on this account, be-
ing much thicker and stronger than  those of the  he-
patic  veins.*
  The  Biliary or Hepatic  Duct is formed  of very
minute vessels, which originate in the acini above de-
scribed ;  these unite together like  veins  until  they
form  considerable branches, which finally compose the
great ramifications of the biliary duct.  This duct is
very  strong and firm, and on  its internal  surface are
the orifices  of many mucous  follicles or ducts.    It
passes from the transverse fissure of the liver, with
the hepatic  artery,  as  before described, and  at the
distance  of an inch and a half or two inches from the
fissure, it unites with a duct  from  the gall  bladder,
which is called the Cystic Duct.   This duct is nearly
equal in  length to the  hepatic, and  after  running al-
most  parallel  to it, at length unites  so as  to  form an
acute angle with it.   The cystic  duct is smaller than
the hepatic, and they unite much like  two  branches
of an artery.
  The  Gall  Bladder,  from  which the cystic  duct
arises, has the shape of a pear, with a very long neck,
curved in a  way  to be hereafter described.   It is si-
tuated in a superficial pit or cavity in the concave sur-
face of the right  lobe of the liver;  and its fundus, or
basis, often projects a small distance beyond the ante-
rior edge of the viscus.   Its position is such,  that it
extends from before  backwards, and inclines rather  to
the left; of course,  therefore, when  the subject lies
on his back, the bottom of the bladder is  the upper-

  * A  case is related by Mr. Abernethy, in the  London  Philosophical
Transactions, in which the vena portarum terminated in the  vena cava be-
low the liver, without communicating with it.  The hepatic artery was the
only vessel which carried blood to the organ, and was unusually large, the
liver being nearly of the natural size. Some bile  was in the gall bladder,
but it was less acrid than usual. 
140
Gall Bladder.
most part of it; when he  lies on the  left side, it is
also higher than the neck; and when he  lies on  the
right side it is the lowermost.
  The gall bladder consists  of an internal  coat, and
one that is cellular  or nervous, and has somewhat of a
fibrous appearance.  This coat connects the  gall blad-
der to the surface of the pit or cavity in which it lies.
The peritoneal coat of the liver is extended  from  the
surface of the viscus over that part  of  the surface of
the gall bladder which is not in contact with it.
  The internal coat has a peculiar structure, with a
faint  resemblance  to that of  the  villous  membrane.
It is  so  arranged  as to form very fine folds, which
have  various  directions :  in  some  places they make
a net-work;  in  others,  as the neck of a bladder, they
are longitudinal.  Many mucous follicles  exist on its
internal surface.
  The neck of the gall-bladder is suddenly bent down
or curved upon  itself, and  twisted, so that  it  resembles
the neck of  the  swan, when the head  of that  bird is
applied to one side of its breast.
  A branch of the hepatic artery, which leaves it be-
fore it enters  the  liver, is appropriated to  the gall-
bladder, and is therefore denominated the  cystic arte-
ry.    The veins  corresponding to this artery empty
themselves into  the vena portarum.*   The  lymphatic
vessels are united  to those which  are  found  on  the
lower surface  of the liver, and the nerves are derived
from  the hepatic plexus.
  The gall bladder appears to be merely  a  reservoir,
into which bile  passes through its duct in  a retrograde
direction.  If air  be blown through the hepatic  duct
from  the liver, it will pass to  the gall-bladder almost
as freely as it passes to the duodenum.
  * It has been justly observed by John Bell, that the veins would not ter-
minate thus, if bile were secreted by the gall-bladder. 
  Ductus  Communis  Choledochus.—The Bile.  141

  The biliary duct from the liver, after receiving the
duct from the gall  bladder, takes the name of Ductus
Communis Choledochus.  It is wider than  either of
the other ducts, and near three inches in  length.  It
passes down before the vena  portarum,  and  on the
right of  the hepatic artery, to  the  posterior surface of
the right extremity of the pancreas.   It passes through
a small portion of  that gland, and then perforates the
muscular coat of the duodenum ; after which  it pro-
ceeds from half an  inch to an inch  between  this coat
and the villous, and opens into the  cavity of the intes-
tine.   The orifice forms a tubercle  which extends
lengthwise of the intestine, and is  rounded above and
pointed below, with a slit in it.  While this duct is in
contact with the pancreas, a duct from that gland ge-
nerally opens into  it, so that the biliary and  pancrea-
tic fluids enter the duodenum by the  same orifice ; but
sometimes the pancreatic  duct  opens  into the  duode-
num, by a distinct orifice, very near  to that of the bi-
liary duct.


    The Bile, or  fluid secreted  by the liver, appears to an-
      swer a two-fold purpose in  the  animal  economy.   It
      produces a chemical eflfect  upon the alimentary mix-
      ture  which passes from the stomach through the intes-
      tines? and it  increases the  peristaltic motion of those
      important organs.
        By an inverted action of the duodenum, some of this
      fluid is frequently carried upwards  into  the  stomach :
      it then often produces only  slight derangement of the
      functions and  sensations connected with  that  viscous ;
      but sometimes violent vertigo, and even convulsions,
      seem to have  arisen merely from  the  presence of a
      large quantity of  bile in the stomach:  for they have
      gone off completely upon the discharge of bile by vo-
      miting.
        Notwithstanding  these effects of bile  in  certain
      cases, in which a great deal of  it  exists in  the sto-
      mach, it is often carried into the  mass of blood in
      large  quantities, and  appears to be mixed  with the 
142
The Pancreas.
      serum, and to circulate through the body, without pro-
      ducing any  very sensible effect:  thus  many  persons
      who are deeply tinged by bile in their blood, experience
      but few effects that can be imputed to the mixture of it
      with the circulating fluids : and neither  the brain nor
      the heart appear to be  much influenced by the  circum-
      stuncp
        Bile' is miscible with water and with alcohol, and
      also with oily substances5 and it often assumes a green
      colour, when mixed with acids.  The colour of the al-
      vine discharges is derived from the bile, and they are
      therefore sometimes very green, when the  acetous fer-
      mentation takes place in the contents of the stomach
      and bowels.                                      .
        It  is asserted bv some chemists, that ten parts  in
      eleven of the human bile consists of water; that albu-
      minous matter  composes about one forty-sixth  part  of
      it; and that there is nearly an equal quantity of resi-
      nous matter in it.   There is also a small  quantity, (one
      part in 244,) of uncombined  soda dissolved in it, and a
      smaller  quantity of neutral salts, consisting of  soda
      combined with  the  phosphoric, sulphuric and muriatic
      acids.  In addition to these is a very small quantity of
      phosphate of lime and  of oxide of iron, and some yel-
      low insoluble matter.
        The bile in the Gall Bladder is generally more viscid
      than that which is found in the Hepatic  Duct.


                     SECTION  II.

                  Of the  Pancreas.

  The  pancreas is a  glandular  body,  which  has  a
strong  resemblance  to the salivary  glands in  several
particulars.   It is seven inches in length, and is irre-
gularly oblong in its form, one extremity being  much
larger than the other.   Its large extremity is in con-
tact with the duodenum, and it extends from  this in-
testine in a transverse direction to the spleen, to which
it is connected by the omentum and by blood vessels.
It is not invested by the  peritoneum, but is situated
in the space which exists  between  the two lamina  of 
The  Pancreas.
143
the mesocolon, as they proceed from the back  of the
abdomen, before they come in contact with each other.
It is anterior to the aorta  and vena  cava, and  to  the
mesenteric vein, or main  branch of the vena  porta-
rum ; being connected to these parts by cellular mem-
brane.  At the  right  extremity, which  is connected
with the duodenum, is a process of the gland that ex-
tends downwards in close  contact with the intestine.
This is called the head of the pancreas, or the lesser
pancreas.
  The position of the pancreas is such, that one of its
surfaces looks forwards and rather  upwards, and  the
other backwards and downwards; one edge is of course
posterior and superior, and the other anterior and in-
ferior.  The posterior of  these edges is much thicker
than the other, and has a groove or excavation which
is occupied by the splenic blood vessels.
  This gland differs from  the other large glands of
the abdomen, inasmuch as it  has  not  a large  artery
particularly appropriated  to  it; but instead of  this,
it receives branches  from  the contiguous arteries.
  The arterial blood of this gland  is  partly supplied
by the splenic arter, whichy, in  its course from  the
main trunk of the cceliac to the spleen, while it is in
the groove at the edge of the pancreas, sends off into
the gland one  considerable  branch called the great
pancreatic, and a number  of small  branches, which go
off  in succession.  In addition to these, the  pancreas
receives vessels from one of the branches of the hepa-
tic artery, before it sends off its great ramifications,
as well as small twigs from several other contiguous ar-
teries.  The veins correspond with the arteries, but
ultimately are discharged into the vena  portarum.
  The pancreas resembles the salivary glands  in co- 
144              Pancreatic Duct.
lour, and also in texture; for it is of a dull white co-
lour with a tinge of red, and it appears to consist of
small bodies of a granulated form, which  are so ar-
ranged as to compose  small  masses or  lobes that are
united to each other by cellular membrane.  Each of
these granulated bodies receives one or more small ar-
terial twigs, and from it proceeds not only a  vein but
a  small  excretory duct, which, uniting with  similar
ducts from the adjoining granulated portions  or acini,
forms a larger duct in each lobe or mass; these  open
into the great duct  of the gland, which  proceeds
through  it lengthwise  from the  left   extremity,  in
which it commences, to the right.
   This duct is situated  in the  body  of  the  gland,
which must be dissected to bring  it into view.   It is
thin and transparant,  like the ducts of the salivary
glands, and is rather larger in diameter than a  crow's
quill.  In its progress towards the right extremity of
the  gland, it gradually enlarges, and  commonly re-
ceives a branch from the part called  the lesser  pan-
creas.   It most commonly unites with  the  biliary
duct before it opens  into the duodenum :  sometimes
these ducts  open separately,  but very near to  each
other.   They penetrate the coats of the intestine, ra-
ther obliquely,  and between four  and five inches  from
the pylorus.  This canal is  sometimes called  Dustus
Virsungii, after an anatomist who published a  plate
of it.
   The pancreas has an irregular surface, and no coat
which covers it uniformly.   It is  invested  by cellular
membrane, which also connects its different lobes to
each other.   Absorbent vessels and nerves are  traced
into it.
   The portion  called the lesser  pancreas  adheres to
the  duodenum? and when  it is enlarged  by disease. 
                 Size of the Spleen.             14j

the passage of aliment through that intestine  is much
impeded, and sometimes completely obstructed.*
  It is now generally believed that the fluid  secreted
by the pancreas is similar to that which  is produced
by the salivary glands.

                     section ni.

                   Of the  Spleen.

  The Spleen is a flat  body of a  bluish  colour, and
an irregular oblong form, with thick edges, which are
indented in some places.
  It is various in different subjects, both  in  size and
form.  Its most common size is between four  and  five
inches in  length, and about three  or four inches in
breadth ; but it  has  often  been found of more than
four times this size ; and  it  has also been  seen not
much longer than an  inch.   Its ordinary weight is be-
tween six and nine ounces; but it has varied  in diffe-
rent subjects from eleven pounds to one  ounce.   It is
supposed,  by many  physiologists,   that  it frequently
varies in size in the same individual.
  It is situated in  the  left hypochondriac region, in
contact  with  the diaphragm,  below  the  eighth  rib.
The position of the spleen is somewhat oblique,—one
extremity being directed downwards  and  rather  for-
wards, and the other  upwards and  backwards; but
when the stomach is  distended, the  lower end of it is
pushed forward by the great extremity of  that viscus.
  In general it is so  deeply seated  in the left hypo-

  * In several cases where examination after death evinced that the pancreas
had become enlarged and indurated, particularly at the right extremity, the
principal symptoms were jaundice ; great uneasiness after taking food;,
c(uniting some time after eating,  but not immediately; extreme acidity of
'he matter rejected,
  VOL 11,              19 
i46        Enlargement of the Spleen.
chondriac region, that it is out of view when the sub-
ject is opened in the ordinary way: but in some cases
of enlargement, after the intermitting fever, it has ex-
tended downwards, nearly as low as  the pelvis ; and
towards the right side beyond the umbilicus.
   The external  surface of the  spleen  is  convex, in
conformity to the  surface  of  the diaphragm, with
which it is in  contact.   The internal  surface  of the
spleen is irregularly  concave,  having a longitudinal
fissure which divides it into two portions.
   The spleen is invested by the peritoneum, one pro-
cess of which is often extended from the diaphragm,
above and behind it, in the  form of  ligament.   Ano-
ther process of the same membrane is extended to  it
from the great extremity of the stomach.   The peri-
toneum is also continued from the spleen in the form of
omentum.
   Within this peritoneal covering is  the proper coat
of the spleen, which is so  closely connected to it, that
many anatomists have considered them  as  one mem-
brane : they are, however, very distinct at  the great
fissure, but the external coat is extremely thin.
  The proper coat of the  spleen is not very thick ; it
is dense and firm, and somewhat elastic,  but not much
so.   It is partly transparent.
  The spleen has a large artery, which  is one  of the
three great branches of  the cceliac.   This vessel runs
in an undulating manner in a groove in the upper edge
of the pancreas,  and in this course sends off many
small branches to supply that gland.   The splenic ar-
tery, before it arrives at the spleen, divides into five
or six  branches, which  are also undulating  in their
progress, and  penetrate into the body of  the  viscus
at the above mentioned fissure.   These branches are
distributed to every part  of the viscus, and ramify
minutely. 
Vessels of the Spleen.
147
  From these branches, or from  the main trunk be-
fore it ramifies, three or four smaller branches proceed
to the left extremity of the stomach.   Tney are called
vasa brevia or arteriae breves.
  The arteries which enter the spleen  are accompa-
nied by veins that emerge from it, and unite to form
a great trunk.  This trunk observes a  course  corres-
ponding  to  that  of the  splenic artery, and  receives
veins from the stomach and  pancreas, which  corres-
pond with the arterial branches sent  to  those  organs.
The splenic vein is one  of the principal  branches  of
the vena portarum.
  The splenic  artery is  very large  in proportion  to
the viscus to which it is sent, and the vein is unusual-
ly large in proportion to  the artery.   The vein is also
very tender and delicate in its structure.
  The absorbent vessels of the spleen are very nume-
rous.   It has been asserted, that when those  of the
external coat of the spleen are injected, they  are suf-
ficient to form a fine net-work on it.   The absorbents
of the deep seated parts  unite to the superficial at the
fissure where the blood vessels enter.   They terminate
in the thoracic duct, after passing through several lym-
phatic glands.
  The nerves of the spleen are derived from the solar
plexus:  they form a plexus round the vessels and ac-
company them through the viscus.
  The spleen consists of a substance which is much
softer than that of any other  viscus  of the abdomen.
This substance  is made up either wholly  or in great
part of the ramifications of the splenic artery and vein,
which are demonstrated by injections to  be very mi-
nute and numerous in this body.   There are also many
fine white cords, like threads, which pass from the in-
ternal surface of the inner coat of the spleen  into its
soft substance, in which some of them ramify.   These
cords connect the substance of the spleen  pretty firm- 
U8  Maipighi on  the Structure of the Spleen.

ly to its coat, and they seem to have the effect of ren-
dering the exterior part of the substance  more  firm
and dense  than  the internal.  They are particularly
conspicuous if the spleen be immersed  in  water, and
the coat pulled off  while it is in that situation.
  The spleen has a strong resemblance to the glandu-
lar organs, but has  no excretory duct, and  its particu-
lar function is not very obvious : for these  reasons the
Structure of this organ is a subject of  very interesting
inquiry.
  Maipighi, who took the lead in  researches of this
nature, before injections of the blood vessels with wax
were in use, after  investigating  the structure of the
spleen by long maceration, by boiling, by inflation, by
the injection of ink or coloured fluids, and by exami-
nation  with  microscopes,  declared  that  its  structure
was cellular ; that  the cells communicated more freely
with the veins than the arteries;  and that  they might
be considered as appendices of the veins.   He also as-
serted, that a large number of white bodies or vesicles
were to be found in those cells  and throughout the
whole substance of the spleen, which were in bunches
like grapes, and preserved their whitish colour  al-
though the vessels  around them were injected with  a
coloured fluid.   This description of Maipighi appears
to have been admitted by some of the very respectable
anatomists who  were cotemporary with him ; but it
was zealously opposed by Ruysch, who exhibited the
spleen so completely injected with wax, that it appeared
to be composed entirely of vessels.*
   Ruysch appears to have paid great attention to this
subject, and to have made  many preparations of  the

  * Two plates, taken from drawings of these preparations, are published in
Buysch's works.  One is  attached to Epistola Problematica Quarta, in the
second volume ; and the other to Thesaurus Septimus, in the third volume. 
             De La Sone on the Spleen.         149

spleen.   From these he derived the opinion, that the
substance of this organ was entirely composed  of ar-
teries, veins, absorbent vessels, and nerves;  and  that
if it were properly injected before it was dissected, no
other structure would be found.  He stated, that the
minute ramifications of the blood vessels appeared  to
have acquired a peculiar quality, and  were so soft and
delicate, that their texture was destroyed by the least
friction ; and that by the slightest degree of  putrefac-
tion they appeared to be reduced to a fluid  state.  He
also denied the existence of cells, or of the whitish bo-
dies  described by Maipighi.
  The question thus at issue between these great mas-
ters of their art, was very carefully examined  by M.
De La Sone, a French physician, whose observations
are published in the Memoirs of the Academy  of Sci-
ences for 1754.   After repeating the processes of each
of these anatomists, and instituting some others in ad-
dition, he adopted the opinion that there was  in the
texture of the spleen a pulpy substance which was not
a mere coagulum, but which, however, could  not be
injected.
  He derived his opinion from this fact among others.
After macerating the spleen a considerable time, and
injecting water into the vessels until  it returned co-
lourless,  he  injected ink, and confined it some time  in
the vessels by tying them : he then allowed the ink to
flow out of  the vessels, and made various  sections  of
the spleen, but no ink appeared in the pulpy substance,
although it was visible in many small vessels which ra-
mified in that substance.   He observes that this could
not have been the case, if the pulpy substance  had
been  composed entirely of vessels, as was supposed by
Ruysch.
  He also examined the spleen after it  had  been in- 
\l50 Haller and the French Anatomists on the Spleen.

 jected with wax, according to the manner of Ruysch,
 and believed not only that the pulpy matter remained
 uninjected, but that Ruysch himself, in his own pre-
 parations, removed this substance, supposing it to ex-
 ist for the mere purpose of connecting the vessels to
 each other.
   To see the blood vessels in the same state of disten-
 tion in which they were during life, he tied the sple-
 nic vessels in a living animal, and removed the spleen
 with the ligatures on the vessels.   In this situation he
 boiled it, and then examined  the appearance of the
 vessels and the pulpy substance.—From these, as well
 as his other observations, he decided, that the  pulpy
 substance did not  consist entirely of vessels,  but was
 an  additional and different structure.
    He also suggested, that as the  brain and the muscu-
 lar fibres were so covered by blood vessels in the  in-
 jected preparations of Ruysch, that they appeared to
 be  composed entirely of vessels, when in fact they con-
 sisted of a different substance, so the pulpy substance
 of  the spleen was covered or  obscured by the  blood
 vessels which passed through  it, without constituting
 its  whole substance.
   He confirms the account of Maipighi respecting the
  Whitish Vesicles or Follicles ; and states, that in a ma-
 jority of cases they are not to  be discovered without
 a particular preparation; but that they are  generally
 made obvious by long maceration of the spleen in wa-
 ter.  In his  opinion they are the most essential part of
 the organ.
    Notwithstanding these investigations of M. De  La
 Sone, the  question  respecting  the structure of the
 spleen  remains not completely  decided even to this
 day.
    Haller, who was perfectly well acquainted  with the 
         British Anatomists on the Spleen.      151

subject, inclined to the opinion of Ruysch ; while Sa-
batier adopted completely the opinion of De La Sone.
  It appears from the statement of Gavard, that De-
sault did not admit  the  existence of the  transparent
bodies; although he believed that the pulpy substance
of the spleen, consisted of cells which resembled  those
of the cavernous bodies of the penis.
  Boyer, whose  descriptions of the animal structure
appear to have been formed with  scrupulous exacti-
tude, admits the existence of transparent bodies; some-
times so small as to be scarcely visible, and sometimes
as large as the head of a pin.  He observes, that the
best method of examining them is to place a very thin
slice of the spleen between the eye and a strong light,
when the transparency of these  bodies occasions the
slice of  the  spleen to appear as if perforated.
  As to the general structure of the pulpy substance,
he avows himself unable to decide respecting it; but
observes, that upon examining the cut surface of the
spleen, you  perceive black liquid blood flow from the
vessels;  if you then scrape this surface, you may ex-
press easily a  species of  sanies different from that
which flows from the vessels, which, after exposure,
becomes red, and resembles coagulated blood;  whe-
ther this is contained in  the capillary vessels, or in the
cavities of this organ, he acknowledges himself unable
to determine.
  Notwithstanding  the  sentiments  of these French
gentlemen, many of the  British Anatomists, who are
entitled to great attention on account of their skill in
minute injections, have adopted the ideas  of  Ruysch.
Among  these are to be mentioned the late  Dr. F. Ni-
cholls, and many of the anatomists of London, as well
as the second Professor Monro, of Edinburgh.  There
are, however, two remarkable exceptions  to this ac-
count of the British anatomists.  The late Mr. Falco- 
152      British Anatomists oil the Spleen.
 nar,  who wrote a dissertation on  the situation  and
 structure of the spleen, which contains the sentiments
 of the late truly respectable Mr.  Hewson,* after  sta-
 ting  that the organ  was extremely vascular, so that
 when injected, it  appeared  like  a  mere  congeries of
 vessels, makes this unequivocal assertion—that  there
 are innumerable cells dispersed throughout the whole
 substance of it, which are so small that they  are only
 to be discovered by  the  aid of  a  microscope;   and
 are to be seen after steeping a thin piece of spleen,
 the blood vessels of which have been minutely inject-
 ed, in clear water during   a  day,  and changing  the
 water frequently.   He  also  adds, that the ultimate
 branches of the arteries  and veins form  a  beautiful ;t.
 net-work on each cell; and  that these  cells are  suffi-
 ciently distinguished from the irregular interstices of
 the cellular substance, by their round figure and  their
 great regularity.
   Mr. Everard Home, in his papers on the structure
 and uses of the spleen, confirms the  account of the  ve-
 sicles in this organ ;  and adds  that  these vesicles  are^
 occasionally seen in a  distended and in a  contracted
 state.  That when distended they are twice  as large *
 as when contracted, and are distinguishable by the  na-
 ked eye;  whereas, when contracted, they require a
 magnifying glass to be distinctly seen.  These obser-
vations appear to have been made upon quadrupeds.-^
   Professor Soemmering appears to unite  in the ge-
 neral sentiment of the British anatomists,  that the
spleen is simply vascular.  He says, that the tuber-
 culi which  sometimes appear  in it, when examined
 with a magnifying glass appear to  be composed entire-
 ly of  vessels.
* See Experimental Inquiries, vol. iii.
T See the London Philosophical Transactions for 1808 
 Questions relating to the Structure of the Spleen. 153

   There are therefore two questions not perfectly de-
 cided respecting the spleen.
   First.  Whether its general structure is simply vas-
 cular, or whether there is  any other structure  either
 cellular or more substantial, which composes its gene-
 ral bulk.
   Second.   Whether the  small  transparent vesicles,
 originally described by Maipighi, are to be  regarded
 as essential parts of the structure of the spleen.
   With respect to the first question, the  injections of
 Ruysh, and of the British Anatomists in general, and
 even of Mr. Hewson, as well as of Haller and Soem-
 mering, seem to afford positive facts in opposition to
 those of a negative kind adduced by M. De La Sone,
 and  render it highly probable that the general struc-
 ture is simply vascular.
   But the second question stands on different grounds.
 The existence of small  transparent vesicles, although
 denied by Ruysch, and  neglected by the British Ana-
 tomists in general, was inserted as a positive fact  by
 Maipighi and De La Sone ; and their assertions  have
 been confirmed, not only by most of  the French Ana-
 tomists,  but also by Hewson and  Home among the
 British.
  The sentiments of physiologists respecting the func-
 tions of the spleen, are  more discordant than those of
 anatomists respecting its structure;  although the sub-
ject  has been considered by many authors of great in-
genuity.*

       * See M. Lieutaud. Eleraenta Physiologiae.
       Hewson's Experimental Inquiries, vol. iii.
       Dr. Bush. Medical Museum, vol. iii.
       Haller. Eleraenta Physiologia;, torn. vi. page 414.
"VOL. II.
20 
CHAPTER IV.
    OF THE URINARY ORGANS AND THE GLANDULE
                     RENALES.

   The urinary organs consist of the Kidneys, which
 are situated in the  lumbar regions; of the Bladder,*
 which is in the pelvis; of the Ureters, which are flex-
 ible tubes or canals that pass from the kidneys  to the
 bladder; and of the  Urethra,  or tube through which
 the urine is discharged from the bladder.            ^
   These organs have but little connexion with the pe4|
 ritoneum.  The kidneys are behind it; and a conside-™
 rable quantity of cellular membrane is placed between }
 them and it.   The  ureters are also behind it; and but
 a part of the bladder is invested with it.
   The Glandulx Renales are described with the uri-
 nary organs, on account of their contiguity to the kid-
 neys :  and to avoid a derangement of the  natural or-
 der of description they are considered first.
   The urethra pertains to the organs of generation as
 well as to the urinary organs, and  can  be  described 3
 most advantageously with them.                      !

                    SECTION I.

            Of the Glanduhe Renales.

   These are two small  bodies, situated on the psoas
 muscles, one on each side of  the spine, behind the pe-
ritoneum and above the kidney, being in contact with
its upp'er and anterior edge.  They have an irregular
semilunar figure with three sides, one of which b ac- 
             The Kidneys and Ureters.          155

commodated to the convexity of the kidney.   Their
colour is commonly a dull yellow.
  The appearance and  texture  of these bodies have
some resemblance to those of glands,  and hence their
name, but they have no excretory duct.
  When they are laid  open by an incision, a cavity
often appears, which is  somewhat triangular, and from
the lower part of it a small thin ridge arises.*
  A small  quantity of fluid  is generally found  in it,
which has a very dark colour in adults, is yellowish in
young subjects, and red in infants.
  These bodies  have not a single artery appropriated
to them, as the spleen has, but receive small branches
from several contiguous  sources ; viz. from the arteries
of the diaphragm, from  the cceliac artery or the aorta,
and from the arteries of the kidneys.   There  is gene-
rally one principal vein, as well as some that are small-
er,  belonging to each of these bodies : the large vein
on the right side generally opens into the  vena cava,
and on  the left into the left emulgent vein.
  These bodies were first  described by Eustachtus,
and have been regarded with attention  by many ana-
tomists since that period.  They exist in a great num-
ber of animals ;  but their nature and  functions are al-
together unknown.

                     SECTION II.

           Of the Kidneys  and Ureters.

  The kidneys are two  glandular bodies which secrete
the urine.  They are of a dull red colour, and their
form  has a strong  resemblance  to  that of the bean
which bears their name.  They have a peculiar tex-
 * The cavity in these bodies has sometimes been sought for in vain,
Haller found it in sixteen cases out of nineteen. 
15$
The Kidneys.
ture, which  is uniform, and not granulated or com-
posed of acini; and they are covered by a thin deli-
cate tunic, which has no connexion with the perito-
neum.
  They are  situated in the lumbar regions of the  ab-
domen, one on each side of  the spine.  They are  op-
posite to the two last dorsal and the two first lumbar
vertebra.   They rest principally upon the psoas  and
quadratus lumborum muscles, and their position is ob-
lique ; the concave edge presenting inwards and  for-
wards, the convex edge backwards, and the upper ex-
tremity  approaching  nearer  to the spine  than  the
lower.
  The Right Kidney is situated  rather  lower that*
the left: it  is below  the posterior  part of the right
lobe of  the liver, and behind the duodenum and  the
colon.   The Left Kidney is below the spleen, and be-
hind the descending portion of the colon.  Each of the
kidneys is below and very near to one of the glandute  1
renales.
  They are surrounded with a  large quantity  of lax
adipose  membrane, which in corpulent  persons  forms
a very large mass of adeps around them ; while in the
emaciated they are surrounded with a membrane al-
most free from fat.  Each kidney has two broad sides,
two extremities, and two edges.   The  side or surface
which is posterior, when the kidney is in its natural
situation, is  rather broader than the other.   The  up-
per extremity, or portion, is also broader and  larger
than the lower.  The edge which is posterior and ex-
ternal is regularly convex ; the anterior edge  is con-
cave ; but the concave edge or margin is not very re-
gular.  In  the middle it is largely indented ;  in  this
indentation is a deep fissure, which separates the  two
broad surfaces or sides of the gland from each  other;
and here the breadth of the posterior surface is  evi-
dently greater than the  anterior. 
The Kidneys.
137
   Each of the kidneys receives a large artery, which
 proceeds immediately from the aorta, nearly in a rec-
 tangular direction.  A vein, which opens into the vena
 cava, accompanies the artery.   It is obvious, from the
 situation of the kidneys with respect to the great ves-
 sels, that the artery on the right side must be  longer
 than that on the left, and that  the reverse of this must
 be the case with the veins; the veins are also anterior
 to the arteries.  At the great  fissure these vessels di-
 vide into several branches, which enter the  kidney at
 that place.   The branches of the vein are before and
 above;  those of the artery are below, and in the mid-
 dle.  Surrounded more or less  by the  branches of
 those vessels, is  a  membranous  sac, the breadth of
 which extends from above downwards.  This sac ter-
 minates in a tube that proceeds from the lower part of
 the  fissure down to the bladder.   The sac is denomi-
 nated the pelvis of the kidney, and the tube a ureter:
 each of these parts will  soon be more particularly de-
 scribed.
'  The substance  of the kidney,  as has been already
 said, is uniform in its texture,  and of a reddish brown
 colour.  When it is divided by  an incision made length-
 ways, and from its convex to its concave  edge, there
 appears to be a small difference in the different parts
 of it.   The exterior part, which  is called cortical, is
 rather more pale  in colour and  softer in consistence
 than the internal part.   It varies in thickness, so that
 some writers have described it as equal to two  lines,
 and others to one-third of the  kidney.  In a majority
 of subjects  it  will be found  between  the two  state-
 ments.
   The interior part is  called  medullary, or  tubular,
 and appears to be composed of very fine tubes.   These
 tubes are so arranged, that a number of papillae  or
 cones are formed  by their convergence, and project
 into the fissure of the kidney.   These papillae have 
158                The Kidneys.
been supposed to consist of a substance different from
either of the two above  mentioned, but they appear
to be  formed merely by the tubular part.
   The arteries, accompanied by corresponding veins,
and by nerves and absorbent vessels, after ramifying
in the fissure of the kidney, proceed into its substance,
and continue their aborescent ramifications until they
have arrived very  near the  exterior surface.   They
are so uniformly distributed to  the different parts  of
the organ, that when the blood  vessels are  injected
with wax, and the substance of the kidney is removed
from the injected matter, as is the case in corroded pre-
parations, the injection exhibits accurately the form of
the kidney.
   The large branches of the blood vessels occupy the
vacuities between the papilla; in the fissure of the kid-
ney.  When they penetrate the substance of the kid-
ney, they are enclosed by sheaths which are derived
from  the  coat of the gland, and  are surrounded by j
membrane, which frequently contains adeps.          1|
   There are commonly ten or twelve papillae in the
fissure of each kidney, but there are sometimes  more
and sometimes less than this number.  These  papilla i
are surrounded by a membranous sac of  a correspond-1
ing form ; the papillae being a  cone, and  the sac re-
sembling the upper part of a funnel.  The sac is there- ''"
fore called  an. infundibulum, or calyx.  Sometimes
there  are two papillae in each infundibulum, and then
the form of the sac is not so regular.  The infundibu-
lum adheres to the base of  the  papillae, but lies loose
about the other parts of it.   Each infundibulum com-
municates at its apex with the pelvis of  the kidney.
   The Pelvis, as  has been  already mentioned,  is a
membranous sac which terminates in the ureter, exte-
rior to the kidney.   This sac generally  divides itself, 
Cortical and  Tubular Portions of the Kidney.  159

in the fissure of the kidney, into three large irregular
branches, each of which very soon terminates in three
or four of the infundibula above described.   That por-
tion of the sac which terminates in the ureter is exte-
rior to the kidney.
   When the interior parts of  the kidney are exposed
to view, by the  section above mentioned, after  the ar-
teries and veins have been minutely injected, the cor-
tical part will be found to consist almost entirely of the
minute ramifications of these vessels.    Among them
are some small  bodies, which are dispersed through
the substance, like berries on a bush : these are assert-
ed also  to  be  composed of vessels.
   The tubular part certainly proceeds from this vascu-
lar cortical substance: for Ruysch, and after him seve-
ral other injectors, have filled these tubes  with injec-
tion thrown into the arteries.
   The tubuli, of which this part is composed, seem to
arise obscurely from the cortical part.   They soon as-
sume somewhat  of a radiated direction, and are finally
arranged so as to form the papillae or cones above de-
scribed.
   On these papillse or cones some of them can be traced,
uniting with each other, to form  larger tubes, which
terminate  on  the surfaces of the  papillae, in  orifices
large enough to be seen distinctly.  From  these orifi-
ces urine may be forced out by compressing the papil-
lae.  On this account the tubes have been called tubuli
uriniferi.
   In the foetal state the kidney is formed of a number
of distinct lobuli, each of which consists of a  papilla
with the cortical matter connected to its base.   Soon
after birth these lobuli coalesce  ; and in two or three
years the substance of the kidney appears  uniform, as
above described.  In some animals this lobulated struc-
ture continues during life: in  them, and also in the 
 160 Nerves and Lymphatics.—Coat of the Kidney.

 foetus, each lobe appears  like a  distinct organ.   Al-
 though in the adult kidney this  structure has disap-
 peared, the papillae and the tubular part connected
 with them are somewhat detached from each other, in
a manner corresponding to their original arrangement.
  The Nerves  of the  Kidneys originate from the se-
milunar ganglion, formerly mentioned.  They form a
plexus round the blood vessels, and go with them into
the gland.
  The kidneys have internal and external absorbent
vessels, although the external vessels are very small.
These absorbents pass  through glands in the lumbar
region to the thoracic duct.
  The proper coat of the kidney  is said, by some ana-
tomists, to consist of two lamina ; but  this cannot  be
shown in common cases.  It appears simple in its struc-
ture, and very  flexible.  It is but slightly connected^
to the glandular substance which  it encloses, and may
be easily pealed off.  It is reflected inwards at the fis-'  T
sure of the kidney, and  can be  traced  inwardly to
some distance, forming sheaths for the vessels.  In this
internal situation it is very thin.

                   The Ureters.

  The pelvis of the kidney terminates exteriorly in
the Ureter,  which is a membranous  cylindrical  tube/
rather flattened, and between three and five  lines  in
diameter, with  some variations in this respect.
  The Ureters  descend from the pelvis of the  kid-
ney so as to pass  obliquely across the psoas muscle
and the  great  iliac vessels.   They are behind the
peritoneum, but in  contact with  it.   They approach
the pelvis near  the  junction of the os ilium with the
sacrum,  and thence descend forwards  and inwards,
surrounded  with  loose cellular  membrane,  to  the 
              Structure of the  Ureters.          161

lower part of the bladder, into which they are insert-
ed at its external and posterior  part.  They first pe-
netrate  obliquely the muscular coat, and then proceed
between the muscular and internal  coats, from half an
inch to  an inch, in an oblique direction, from without
inwards and forwards, when they  terminate by small
orifices  in  the internal coat, each  of which is at an
equal distance, (rather more than an inch,) from the
orifice of the urethra,  thus forming a triangle with it.
  The ureters are said to have three coats.   The ex-
terior appear to be derived from the cellular substance:
within it is  another, which has been  regarded  very
differently by  different anatomists ,* some considering
it as merely membranous, and others as muscular.  If
the ureter be laid open and the  internal  coat  peeled
off, the  muscular structure of this  coat is often very
perceptible.
  The internal coat is called villous, or  mucous, and is
continued from the internal coat of the bladder.  Over
this coat mucous is constantly spread, which defends
it from  the acrimony of the urine.   It is'very  diffi-
cult to separate the two last  mentioned coats from each
other.
  The ureters receive blood vessels and nerves  from
those of the neighbouring parts.   Their internal coat
is very vascular, and is also very sensible of  irritation.
The passage of a small urinary calculus can  be traced
from the pelvis of the  kidney to the bladder, by the
exquisite pain and the spasmodic  affections  which it
often excites.
VOL. II.
'.IX 
162
Situation of the Bladder.
                    SECTION  III.

              Of the  Urinary Bladder.

  The urinary bladder is a large  sac, of a muscular
and membranous structure, which occupies  the  ante-
rior part of the cavity of the pelvis, immediately with-
in the ossa pubis.
  The size of the bladder is in  a  continued state of
variation, according to the quantity of urine secreted?
When moderately distended, it is of  an irregular oval
form, but rather more flat at its lower extremity than
above.   It varies in  form according to the  different
circumstances of the pelvis to which  it has been sub-
jected.
   It is fixed firmly and immoveably  to the pelvis im-
mediately within the symphysis pubis; so  that it is al-
ways  to  be found there of a larger or smaller size.
This  fixture is  produced by  the  attachment  of the
lower portion of fundus of the bladder to  the  parts
beneath it, but principally by the  anterior ligametfts
of the bladder which proceed one on each  side  from
the lateral surfaces of the prostate gland, and  are in-
serted into the pubis of  the corresponding side at the
lower  part of the symphysis.    These ligaments are
in fact the extension of a membrane, (called  by the
French  Anatomists,  the pelvic aponeurosis,)  which
proceeds from the upper part of the  pelvis to the side
of the prostate gland and bladder, and  which may
be seen by turning off the peritoneum from the  leva-
tor ani muscle.*   It is sometimes  completely empty,
and occupies no more space than the thickness  of its

  • See Thesis on Femoral  Hernia, &c. by Gilbert Breschet. Paris, April,
1819.  Colles'Surgical Anatomy, Dublin, 1811, for a more minute account
of this membrane.—Ed 
              Situation of the Bladder.          i 63

 coats requires.  When moderately distended, it occu-
 pies a considerable portion of the pelvis : when dis-
 tention increases, it presses the  parts posterior to it
 against the sacrum, and.extends itself above the brim
 of the pelvis into the  general cavity, rising  not only
 to the umbilicus, but in  some cases  to  the  epigastric
 region.
   In males the relative  situation  of the  bladder and
 rectum is such, that the upper and middle part of the
 rectum is behind the bladder; but the  lower part of
 the rectum, following the curve of the os sacrum and
 coccygis, is below the posterior part  of the bladder.
  In females the  vagina and  uterus are  situated  be-
 tween the bladder and rectum ; so that the connexion
 of these last mentioned parts is very  different  in  the
 two sexes.
  The peritoneum is reflected at the anterior part of
 the brim of the pelvis from the  abdominal  muscles,
 which it lines, to the upper part of the bladder, which
 is generally contiguous to the brim of the pelvis.   It
 continues  over to  the  posterior side of the  bladder,
and passes down upon it some distance towards  the
 lower part; but before it has arrived at the  bottom, it
 is reflected towards the sacrum.
  In males it extends from the bladder to the rectum,
and in females to the vagina and  uterus;  so that there
is a considerable portion of the lower part of the blad-
der which is not invested by the peritoneum.   It also
follows that when the bladder is extended into the ab-
domen, and  rises  above  the brim of the pelvis, that
part of it  which presents anteriorly,  and is in  contact
with the abdominal muscles, is without a  covering  of
 peritoneum, being below it.
  The bladder is composed  of a coat  consisting  of
 muscular fibres, of a stratum of cellular substance im-
 mediately within this, and of an internal lining mem- 
L64       Muscular Coat of the Bladder.

brane, which has been called villous, but, as there are
no villi perceptible on  it, may be  more  properly de-
nominated mucous.
  It  should  be observed, that, in addition  to these
coats, the bladder  has a peculiar investment of the pe-
ritoneum, as has been already described; and  also of
the common cellular membrane, which is placed be-
tween it  and every part to which it is contiguous.
  The  Muscular Coat of the Bladder consists of
fibres which are not spread over it of a uniform thick-
ness,  but are thin  in some  places, and  in others are
collected in fasciculi.   They run  in every direction:
some  appear longitudinal, others circular, and some ob-
lique  ; and  there are interstices between  them  which
are occupied by cellular membrane.   The longitudi-
nal fibres originate from the lower part of the bladder;
and as this is the  fixed part of that  viscus, it  is the
place from  which these  fibres must necessarily act.
These fibres are generally  exterior.   There is no ar-
rangement of muscular fibres to  which  the  term of
sphincter can properly be  applied;  but many anato-
mists  have thought that the fibres near the neck of
the bladder, by their separate contraction, might pre-
vent the escape of urine;  this sentiment, however, is
contrary to that of several very respectable writers.
  The  direction  of the  fibres taken collectively, is
such, that,  when  they all  contract, the cavity of the
bladder is completely obliterated.
  The cellular substance between the  muscular and
internal coats is dense.  It yields in a remarkable man-
ner to distention,  and recovers its original dimensions
very  easily.  From its analogy to a similar coat in the
intestines, it is called the Nervous Coat.
   The Internal Coat of the bladder is of a light co-
lour in the dead subject, when it  has been free from 
           Internal Coat of tlie Bladder.        165

disease.   It had  been called villous improperly; for
the villous structure is not apparent upon its  surface.
Being continued from the integuments  of the body
which are extended along the urethra, it has been in-
ferred,  that the surface of this coat was formed by the
epidermis ; and  some respectable  authors have sup-
posed that they had seen  cases in  which portions of
the epidermis of the bladder had separated and been
discharged;  but these appearances  are  very equivo-
cal, and it is by no means certain that an epidermis ex-
ists there.*
  The fasciculi of fibres of the  muscular coat occasion
this coat to appear very irregular, but these irregula-
rities  correspond exactly with the arrangement of  the
fibres of the  muscular coat.
  When the  internal  coat is separated  by dissection
from the muscular, its surface is very smooth and uni-
form.   In the recent subject, when no disease has pre-
viously  existed, it is always  spread over with mucous
of a light colour, but nearly transparent, which can be
easily scraped off.   This  mucous is spread upon  the
surface  so uniformly,  that it must  be  derived from
sources  which are situated upon every part of the sur-
face ; but these sources are not  very obvious.   On the
membrane of the nose the orifices of many mucous
ducts are very visible, but such orifices are not  to be
seen  on  this surface.—Haller  mentions that  he  has
seen mucous glands  near the neck of the bladder; and
it is stated by the  pupils of Desault, that, in one of
his courses, he pointed out a  number of these  glands,
in a subject who  had been afflicted with a catarrhal af-
fection of the bladder.
   In the fauces and the follicles of the tonsils, an effusion of coagulable
matter, in consequence of inflammation, often forms crusts, that may be mis-
taken for sloughs of the integuments, although those integuments remain 
166
Mucous of the Bladder.
   Notwithstanding that the sources of this mucous are
obscure, the quantity of it is sometimes immense.   In
some cases,  where the secretion is increased by the ir-
ritation of a calculus in the bladder, the urine is ren-
dered somewhat viscid and white coloured by the mu-
cous mixed  with it; which, after the urine has been al-
lowed to remain for some time, subsides in such quan-
tities as demonstrates that many ounces must be secre-
ted  in  the  course of  the twenty-four hours.   The
same circumstances occur without the irritation of cal-
culus, in the disease called catarrhus vesicae.*
   It is probable that,  in healthy persons,  a great deal
of it passes  off unperceived, being dissolved or diffu-
sed in the urine.  From  the quantity and the regular
diffusion of  this mucous on the surface of  the bladder,
there is the greatest reason for believing that it is  ef-
fused from every part of the surface ;  and it is a ques-
tion that has not been decided whether it is discharged
from glandular ducts too small to be perceived, or from
the exhalent extremities of the blood  vessels.   It is
probable that the use of it is  to  defend the  internal
coat of the bladder from the acrimony of the urine.
   The symptoms of a  stone in  the bladder, as  well as
of several other diseases, evinces that this coat is  en-
dued with a great degree of sensibility.
   It is evident that the essential parts in  the  general
structure of the bladder are the muscular coat and the
internal coat last described :  but in addition to the  ac-
count of them, there are some other important circum-
stances to be noted in  the description of this organ.
It has been  already stated, that the form  of the blad-
der was  an  irregular oval, although it was  somewhat
 * In some cases this mucous soon becomes putrid, and during the putrefac-
tive process deposits a substance which appears to be calcareous. 
Orifice of the  Urethra.           167
varied in  different persons.   The  oval  form  is  not
much altered at the part called the neck of the blad-
der, where the  urethra passes off from it.   The orifice
of the urethra  is situated anteriorly at the  lowermost
part of the bladder.   On the lower surface of the ure-
thra, at its commencement, and on the  bottom  of the
bladder, immediately connected with  the urethra, is
situated  the  Prostate  Gland, (to  be hereafter  de-
scribed with the organs of generation,) which  is a firm
body, that adheres strongly both  to the bladder and
urethra.    This circumstance gives particular  firmness
and solidity to that part of the bladder.  It  has also
been observed, that the bladder is attached  firmly to
the ossa  pubis, at its neck, {ibout the origin  of the
urethra.    Each of these circumstances have  an  effect
upon the orifice of the urethra; and when  the blad-
der is opened, and this orifice is examined from with-
in, it appears to be kept open  by the connexion of the
bladder  with the prostate, and has  been  very justly
compared  to the opening of the neck of a  bottle into
the great cavity of that vessel.*
   The orifices of the two ureters are at equal distances
from the orifice of the urethra, and  form with  it  the
angles of a triangle.   That part of the internal sur-
face of the  bladder which  is  within  this  triangular
space, is more smooth than the remainder of the same
surface,  probably in  consequence  of the adhesion of
the bladder to the prostate, and to other parts exte-
rior to it.
  * The late Mr. Lieutaud, and after him the French anatomists of the pre-
sent day, have described a small tubercle at the lower and posterior part of
the orifice of the urethra, which resembles the uvula in form.  It has not
been noticed here ; and M. Boyer states, that it is often scarcely perceptible.
He, however, makes a remark which is very worthy of attention, viz. that
it is very subject to enlargement in old people, forming a tumour which im-
pedes the discharge of urine.  Sabatier has also made the same  observation. 
168   Ligaments and vessels of  the  Bladder.

  That part of the bottom  of the bladder, which  is
immediately behind the triangular space, is rather
lower than this space; and but a small portion of cel-
lular membrane exists between it  and the  rectum in
males, and the vagina in females.
  The upper part of the bladder  is connected  with
the umbilicus by means of a ligament, which passes
between the peritoneum and  the  abdominal  muscles.
This ligament consists of three cords.   One of these,
which is in the middle, arises from the coats of the  blad-
der, and was, in the fcetus,  the duct called  urachus;
the other two, which are connected to the  bladder,
principally by cellular membrane, were  originally the
umbilical  arteries.*   The  middle  cord is  of a  light
colour and fibrous structure ; it is thickest at the  bladV
der, and gradually diminishes as it approaches the um-
bilicus.  In a few instances  it has been  found to be
hollow.   In its progress to  the umbilicus it  becomes
more or less blended with the linea alba or the tendons
of the abdominal muscles.   The other cords are gene-
rally solid.  After passing from the umbilicus to the
bladder, they continue on the sides of that viscus, and
finally terminate at the  hypogastric  or internal  iliac
artery.
  In the very young subject these cords are  invested
by distinct processes of the peritoneum, but their po-
sition is exterior to the peritoneum.
  As the bladder  is  situated very near most of the
large ramifications  of the  hypogastric  artery in the
pelvis, it receives branches from several of them ; viz.
from  the umbilical  arteries  before they terminate;
from  the pubic;  from  the obturators, &c.   These
branches  ramify  in the cellular  membrane  exterior
to the  muscular  coat, and also in  the cellular  sub-
stance between the  muscular and  internal  coats.  It

  * See the accounts of these parts in the description of the Abdomen of tbt
Foetus. 
General Observations.            Itiy
has been c&njeetured, that their termination in  exha-
lents on the surface of the bladder are remarkably nu-
merous.
   The veins correspond  with  the  arteries, but  they
are very numerous on the lower and lateral  parts of
the bladder, and by uniting with the veins of the rec-
tum form a remarkable plexus.
   The Lymphatic Vessels of this organ do  not appear
more numerous than those of other parts.   They pass
on each side the  bladder in  the course  of its  blood
vessels, and unite with the larger lymphatics, and  the
glands which lie upon the great blood vessels on  the
sides of the pelvis.
   The Nerves of the bladder are derived  both from
the intercostal  nerve and  from the nerves of the me-
dulla spinalis,  which  pass off through  the  sacrum ;
and therefore the bladder is  more  affected than  the
viscera of the abdomen,  by injuries  of  the  medulla
spinalis.
   The action of the muscular fibres of the bladder in  ex-
     pelling urine, and the effect of those fibres which  are
     situated near the orifice of the urethra in retaining it,
     can  be  considered  with more advantage  after  the
     structure of the urethra and the muscles  connected
     with that canal have been described.
       It has  been staled, that  the internal coat of  the
     bladder is very sensible ; but it may be added, that
     in consequence of disease about the  neck of the blad-
     der,  the natural  sensibility appears most inordinately
     increased.   When the intensity of pain  which  ac-
     companies these complaints, the frequent  recurrence
     of paroxysms, and their duration, are taken into view,
     there seems reason to  believe that none of the pain-
     ful affections of  the human race exceed those which
     arise from certain diseases of the bladder.  Happily
     these diseases are not very common.
       The functions of the kidneys  is  to  secret urine,
     and that of the bladder to retain it,  until the proper
     time for evacuation.
vol.. n.                 ^ 
170             General  Observations.

           The urine may be regarded as an excrementitioua
         fluid,  which contains  many  substances  in  solution
         that are constantly found in it, and many others that
         are occasionally in it, which are taken as aliment or
         medicine, and pass to the bladder with little, if any
         change.   The odour of the rose leaf, the colour of
         rhubarb, &c are occasionally perceived in urine.
           The substances constantly found in urine are nu-
         merous.  The chemical account of the subject  is so
         long,  that it cannot be detailed here; but the student
         ought to make himself acquainted with it, and he will
         read with great advantage  Johnson's History of Ani-
         mal Chemistry, vol. 2d, page  363 ; and also Thomp-
         son's  Elements of Chemistry, page 333. 
CHAPTER V.
       OF THE MALE ORGANS OF GENERATION.

   These organs consist, 1st, of the  Testicles,  and
 their appendages.
   2d. Of certain parts denominated the Vesiculae Se-
minales and the Prostrate Gland, which are  situated
near the commencement of the urethra, and are sub-
servient to the purposes of generation.
   3d. Of the Penis.

                    SECTION I."

      Of the Testicles and their Appendages.

   The  Testicles  are  two bodies of a flattened oval
form.  Each of them has a protuberance on its upper
and posterior part called Epididymis, and is connect-
ed to parts within  the cavity of the  abdomen by a
thick cord, which proceeds to it  through the abdomi-
nal ring.  Each testicle also  appears to be contained
in a sac, which is suspended  by this cord and  covered
by the common integuments.
  That   portion of the  common integuments which
forms the external covering of the  testicles, is deno*
minated

                   The Scrotum.

  The skin  of the scrotum, although it is  very often
in a state of corrugation, has the same  structure with
that on other parts of the body,  except that it  is r v 
172          Structure of the Scrotum.

ther thinner and more delicate.  The superior delica-
cy of this portion of the skin  is evinced by the great
irritation produced  by the application  of stimulating
substances, and the desquamation of the cuticle, which
seems to be the effect of irritation.  There are many
sebaceous  follicles in this portion  of skin ; and  after
puberty there are often a few long hairs growing out
of it, the  bulbs of which are  often very conspicuous.
There is a small raised line in the middle of this skin,
which commences at the root of the penis,  and pro-
ceeds  backwards, dividing  it into two equal parts:
this line is denominated Raphe.
   The corrugation which so often takes place in the
skin of the scrotum, appears  to be occasioned by the
contraction of certain fibres, which ire in the  cellular
substance  immediately within  it.  This cellular sub-
stance appears to be attached  in a particular  way  to
the skin ;  and it also invests  each testicle in such  a
manner, that when  they are withdrawn, a cavity is
left in it.   It has long been observed, that no  adipose
matter is found in this cellular substance : but it is
often distended with water in hydropic diseases.   As
the  contraction and  corrugation  of the scrotum  has
been imputed to this substance, it has been  examined
with particular attention by anatomists, and very dif-
ferent sentiments have been entertained respecting it.
While some  dissectors have  asserted  that muscular
fibres could be seen  in it, which they have  denomi-
nated the Dartos Muscle;  others have said that this
substance was  simply cellular, and  without any mus-
 cular  fibres.   This difference  of sentiment may pos-
sibly have arisen from the different conditions of this
part in different subjects ;  for in  some cases there are
appearances which seem to justify  the assertion that
muscular fibres exist in this structure.
   After the testicles are removed, so  as to  leave  the 
          Action of  the Dartos Muscle.        173

cellular substance connected with the skin, if the scro-
tum  be inverted, and  this substance examined in a
strong  light, many fibres will appear superadded to
the common cellular structure ;  and sometimes  their
colour can be distinguished to be red.   It  is not  as-
serted  that this will be uniformly the case ; but cer-
tainly it has often been observed in this  way.
  The existence of  an organ  which  possesses the
power of contraction, within  the skin of the scrotum
and  connected  to  it,  is evinced by  the  corrugation
which takes place when the  scrotum  is suddenly ex-
posed to cold, after having been very  warm.   This
corrugation occurs in a  very sudden and  rapid man-
ner, in some cases, in which  the wounded scrotum is
thus exposed for the purpose of dressing : for  exam-
ple, upon removing  an  emollient  poultice from this
part some days after the operation for the cure of hy-
drops testis, by incision, if the air of the chamber be
cool, a motion of the scrotum will  take place, almost
equal to the peristaltic movements of the intestines.
   The Arteries of the scrotum are derived from two
sources.   One or two small arteries,  which arise from
the  femoral artery, between Poupart's  ligament and
the origin of the profunda, are spent upon it.   These
are  called the  external pudic arteries.   It also re-
ceives some small  branches  from  the internal  pudic
artery.
   The Nerves of the scrotum are principally derived
from the  lumbar nerves.

                The Spermatic  Cord.

   The eord which proceeds  to the testicle, through
the abdominal ring, appears at first view like a bundle
of muscular fibres ;  but it consists  of  an  artery and
veins, with many lymphatic  vessels and  nerves, and
also the excretory duct  of the testicle, connected  to 
174 Cremaster Muscle.—Blooa Vessels of the Testicle.

each other by cellular substance, and covered  by an
expansion of muscular fibres which are derived from
the lower edge of the internal oblique  muscle  of the
abdomen, and continue from it  to  the upper part of
the testicle.  These fibres  constitute the Cremaster
Muscle.
  The artery above mentioned is called  the  Sperma-
tic.   It commonly arises from the front of the  aorta,
very  near  its fellow, at a  small distance below  the
emulgents; and is not much larger than a crow's quill.
It proceeds  downwards behind the  peritoneum  and
before the  psoas muscle and ureter.—While it is in
contact with  the  psoas muscle, it joins the  ramifica-
tions of the vein.  It afterwards meets the  vas  defe-
rens,  and proceeds through  the abdominal ring to  the
back part of  the  testis.  Before it arrives at the  tes-
tis, it divides into several branches, two of which  ge-
nerally go to  the epididymis, and the  others penetrate
the tunica albuginea on the  upper and back of  the
testicle, and  ramify very minutely on the fine  mem-
branous partitions which exist in that body.
  In addition to the spermatic artery, there is a small
twig from the umbilical branch of  the hypogastric,
which passes  to the spermatic cord along the vas  de-
ferens.
  The branches of the spermatic vein are much larger
than those of the artery :  several of them proceed
from the testicle so as to correspond with  the arterial
branches ;  and in addition to these  there  are  many
smaller, which also arise from the  testicle and  epidi-
dymis.   In their course up  the cord  they ramify,  and
again  unite, so as to form a considerable plexus, which
is called the  Corpus Pampiniforme, and constitutes
a considerable part of the  volume of the  spermatic
cord.
  As  they proceed upwards, they unite into  a  few 
Lymphatics and Nerves of the Spermatic Cord. 175

larger veins; and  finally, on the psoas muscle, they
generally form one trunk, which continues upwards so
as to unite with the vena cava on  the right side, and
the emulgent vein  on the left.
   Sometimes, but not often, there are several  sperma-
tic veins on each side.
   The Lymphatic Vessels of the testicle are very nu-
merous, considering the size  of the  organ.    Six  or
eight, and sometimes more, large trunks have  been in-
jected, running upon the cord,  and continuing to the
glands on the back part of the abdomen.
   The Nerves of the testicle are derived  from those
which supply the viscera of the abdomen, and are to
be found in the cord, although they can scarcely be
traced to the  testicle.  A  small plexus, called the
spermatic, is formed by fibres from the renal plexus,
and from the sympathetic nerve.  These fibres accom-
pany the spermatic vessels, and  in all probability enter
the body of the testis and the epididymis.   The sper-
matic cord and cremaster  muscle receive filaments
from the second lumbar nerve.
   In  addition  to  these  vessels,  the  Vas  Deferens,
Which is much firmer than  either  of them, is always
to be distinguished in the back part of the cord.
   They are all covered in front and on the  sides  by
the cremaster muscle,  which passes  with them from
the lower margin of the internal oblique, through the
abdominal ring, and continues  to  the upper part  of
the external coat of the testicle, which is a sac appa-
 rently containing that  organ, and upon this  sac it is
spread out and terminates.

               The Tunica Vaginalis.

   The External Coat of the testicle, which is com-
 monly  called the  Tunica Vaginalis,  is a  complete
 sac which encloses the testicle as the  pericardium  en-
 closes the heart,   It  covers  the  body of the testicle 
176
Coats of the Testicle.
 and epididymis, and adheres closely to them.   It is
 then reflected from  them so  as  to  form a  loose sac,
 which appears to  contain them.   The cavity of the
 tunica vaginalis commonly extends above the body of
 the testis up the cord, and is oval or pyriform.—This
 sac is so reflected  from the  body of the testicle that
 there is a place on the  upper and back  part  of that
 body, at which the blood vessels enters it, without pe-  ,
 netrating the sac.
   It resembles the peritoneum and other serous mem-
 branes in texture, and is therefore thin and delicate..  '
 It always contains a  quantity of moisture, sufiicient to
 lubricate the surface which  it forms.                jy
   When the tunica  vaginalis is laid open, the testicleJH
 appears as if it were contained  in  the  posterior part
 of  its cavity.
   The  testicles, as has been already stated, are of a
 flattened oval form.   Their position is somewhat ob-
 lique, so that  their  upper extremities look upwards
 and forwards, their lower extremities  downwards and
 backwards, and their edges present forwards and back-$
 wards.
  The  body  of the testicle  is very firm,  in   conse-
 quence of its enclosure in a  very firm coat called Tu-
 nica Albuginea.   Upon the upper and posterior part
 of it is the protuberant substance, called Epididymis,
 which is less firm,  being exterior to the tunica albu-
 ginea.  The blood vessels of the testicle pass  into it
 on the posterior edge, at some distance below the up-
 per end.

              The Tunica Albuginea,

  In  which the  body  of the testicle is completely
 enclosed, is firm and dense;  and upon this coat its
particular form depends.  It is  of a whitish colour,
and has a  smooth  external  surface.   It is  thick  as
well as  strong.   The  epididymis is  exterior  to it. 
    Form and Connexions of the Epididymis.  177

It is only  perforated by the blood vessels, lymphatics
and  nerves, and by the  vasa  efferentia, which  carry
out the secretion of the  testis.   One  portion  of the
tunica  vaginalis adheres  very closely  to  it, and the
other appears to contain it.   The portion which ad-
heres to it is with difficulty separated, but it is a dis-
tinct membrane.
                  The Epididymis.
   Differs in  colour from the testicle, being more or less
reddish.   It commences at the upper and anterior ex-
tremity of the testicle, and  passes down the  posterior
edge to the  lower end.
   At the commencement the epididymis is somewhat
rounded in form, and its upper part, or head, has been
called the globus major:  as  it descends it lessens, and
about the  middle of  the testicle it is  flattish.
   It is firmly attached to  the  body of the testicle, at
the upper end, where the vasa efferentia pass  to  it;
and it is also attached to it below ; but at the middle
it appears nearly detached from it.   It has therefore
been compared to an arch resting with its two  extre-
mities  on  the back  of the  testis ; it is,  however, in
contact with it at its middle ;  but about the middle it
only adheres by one of its edges to the  body of the
testis, and generally by its internal edge.   It has a coat
which is less firm than the tunica albuginea of the tes-
ticle, described on the last page.  The tunica vagina-
lis of the the testicle is so reflected as to cover a great
part of the epididymis which is  not in  contact with
the testicle,  and also those surfaces of the epididymis
and testis which are  in contact with each other and do
not adhere.
             The Body of  the Testicle.
   When the tunica albuginea  is cut through, and the
substance  of the testicle examined, it appears to con-
   vol. n                23 
 178 Tubuli, Septa and Blood Vessels of the Testicle.

 sist of a soft pulpy substance of convoluted threads, of
 a yellowish brown colour, which is divided  into sepa-
 rate portions by very delicate septa, attached to the in-
 ternal surface of the tunica albuginea at the posterior
 part of the testicle.   After maceration, by using a fine
 needle to detach them from the cellular substance, these
 threads may be drawn out to a great  length.   In some
 animals they are larger than in  the human species; in
 them, it is said, they are evidently hollow, and that
 very small blood vessels appear in their coats.   When
 mercury is injected  into the vas deferens, or excretory
 duct of the testis, in a  retrograde course, it  can be
 perceived  in these ducts in the human subject.
   These delicate septa, or partitions, are united to the
 internal surface of the tunica albuginea at  the poste-
 rior part of the testicle, at which place there is a body
 called Corpus Highmorianum, which has been re-
 garded very differently by different anatomists.   It is
 a long whitish  substance, which extends lengthwise on
 the posterior part of the testis; and  was supposed by
 Haller to resemble one of the salivary ducts.   It is
 now,  however, generally agreed  to  be of a  cellular
 structure, and to contain and support the ducts which
 pass from the substance of the  testicle to  the epidi-
dymis.
  The blood vessels pass into the body of the  testicle
 upon these septa, and are continued from them to the
 filaments or tubes of which  the body of the  testicle
 consists.  As in some animals blood vessels are distin-
 guished on these tubes, there is the greatest reason to
 believe that a direct communication  subsists between
 them, without the intervention of any other structure,
 no other structure having been discovered : but at the
 same time it ought  to be observed,  that these tubes
 have  not yet  been  injected  from  the blood  vessels.
 Some ingenious anatomists have injected the artery 
 Blood Vessels and Structure of the Testicle, fyc.  179

 going to the testicle so successfully, that the injection
 has passed from  it into the veins coming out of the tes-
 ticle ;  but it is not now said by any of them, that they
 have filled the tubes in this manner.
   Mercury will pass into these vessels from the excre-
 tory duct of the testicle; and  by means of an  injec-
 tion in that way, the structure  of the testicle  can be
 unravelled.
   This structure is as follows :  The cavity formed  by
 the tunica albuginea is divided into a  number of apart-
 ments by the very thin septa or partitions above men-
 tioned.   From the filamentary or tubular matter which
 fills  each of these  chambers, proceeds a  number of
 small tubes or vessels, which observe a straight course ;
 they are therefore  called Vasa Recta.   These vasa
 recta unite with each other and  form  a net-work  on
 the  back of the testis, within  the tunica albuginea,
 which  is called Rete  Testis.   From  this net work
 other vessels, from twelve to eighteen in number, de-
 nominated Vasa Efferentia,  proceed  through the al-
buginea to the epididymis.  These vessels  are  convo-
luted in such a manner as to form bundles of a conical
form, which are  called Coni Vasculosi.   The number
of these corresponds with the number of the vasa effe-
rentia, and they compose about one third of the epi-
didymis, viz. all the upper part of it.   The  single
 tubes which  form  each  of these cones, successively
 unite into one duct, which is convoluted so as to form
 all the  remainder of the epididymis.   The lower part
 of the epididymis  is turned upwards  on the back  of
 the testicle, the tube  gradually enlarges  and  is less
 convoluted, and finally becomes straight:  it then takes
 the name of Vas Deferens, and continues on the back 
180         Course of the  Vas  Deferens.


of tbe tcr,ticle and at the inner side of the epididymis

to the spermatic cord.*|
   A small solitary vessel or  duct, has  been observed
by Haller, Monro", and several other anatomists, to pro-

ceed from the upper part  of the epididymis:  some-

times it unites to the epididymis below, and sometimes

it proceeds upwards.  The nature of  this vessel has

not  been ascertained with certainty.


                    The Vas Deferens


   Is  a very firm tube, about one line  in  diameter,
which is  not perfectly cylindrical exteriorly, although

the  cavity formed by  it is so.   This cavity is so small

in diameter, that it will  only admit a fine bristle.  The
coats of the  duct have, of course, a considerable thick-

ness.   The internal coat forms a soft surface, analogous

to  that of the  mucous  membranes: the external 'is

firm, and  its texture resembles that of cartilage.   Ow-

ing to the small size  of the  cavity, the  internal  coat

has not been separated from the external.


  * De Graff appears to have been the first anatomist who  made much pro-
gress in the successful investigation of the structure of the testicle ; and Hal*
ler ought to be mentioned next to him, on account of the plate exhibiting this
structure, and the explanation of it, which he published in  the Philosopbkiil
transactions of London, for 1749.  This plate has been republished by Jthe
second Monro, in the Literary and Physical  Essays of Edinburgh, and alio
in his Inaugural Thesis.  Haller has likewise republished it in his Opera  Mi-
nora.  It represents not only the  vasa efferentia, and the  cones formed by
their convolutions, but also the rete tesis, and the vasa recta.   Haller could
inject no further than this ; but Monro and Hunter  soon after succeeded so
as to fill a considerable portion of the body of the testicle  with mercury, in-
jected by the vas deferens.
  t In Mr. Charles Bell's Anatomical collection in London, there is a prepa-
ration by his assistant, Mr. Shaw, in which the tubuli testis are completely
injected with quicksilver and unravelled. I saw also in  Leyden, one nearly
as successfully executed by Professor Sandifort<—Ed. 
            Course of the  Vas Deferens.        181

   It passes upwards in the posterior part of the sper-
matic cord,  and continues with it through the abdomi-
nal ring, under and exterior to the peritoneum ;  soon •
after this it leaves the cord  and  dips  down  into the
cavity of the pelvis, forming a curve on the  side  of
the bladder, and proceeding  backwards, downwards,
and inwards.   In this course it crosses the ureter, and
passes between it and the bladder.  On the lower part
of  the bladder the two vasa deferentia approach  each
other so gradually, that they appear to  be  nearly pa-
rallel.   They  proceed forward between  the  vesicular
seminales, which are two  bodies  irregularly convolu-
ted, that are placed in a converging position with re-
spect  to each other, and  communicate with the  vasa
deferentia.  The vasa deferentia  finally  terminate al-
most in  contact with each other in the posterior  part
of the prostate gland, where they perforate the  ure-
thra.   At the distance of about two inches and a half
from their termination they enlarge  in diameter, and
become  somewhat convoluted.   At the posterior mar-
gin of the prostate they come in contact  with the an-
terior extremities of the vesiculae seminales, and unite
with them.  After this  union they diminish  in size,
and become conical;  and  passing  a  short  distance
through the substance of the  prostate, during  which
they approach  each other  more  rapidly, they pene-
trate the urethra, so as to open in it on each side of a
small tubercle, called  the  Kaput  Gallinaginis,  soon
to be described.

                    SECTION II.

Of the  Vesiculae Seminalis and the Prostate Gland.

   The  Vesiculae Seminales are two bodies of a whitish
colour, and irregular form, being broad and flat at their 
 182   Structure of the  Vesiculce Seminales.

 posterior extremities, and terminating  in  a point at
 the other.  Their surfaces are so convoluted, that they
 have been compared to those of the brain.  They are
 situated between the rectum and bladder, and are con-
 nected to each by cellular membrane.
   When the  vesiculae seminales are laid open  by an
 incision, they appear to consist of cells of a considera-
 ble size, irregularly arranged ;  but when they are
 carefully examined exteriorly, and  the  cellular  mem-
 brane about them is detached and divided, they appear'
 to be formed  by a tube of rather more than two  lines  j
 diameter, and several inches  in length, which termi-  ,
 nates like the caecum, in  a  closed  extremity.   From.  J
 this tube proceed from ten to fifteen short branches,
 which are closed in the same manner.   All these tubes
 are convoluted so as  to assume the form of the visicu-
 lae seminales  above described ; and they are fixed in
 this convoluted  state  by cellular  membrane, which  |
 firmly connects their different parts to each other.  It
 is obvious,  that tubes thus convoluted,  when cut  into,
 will exhibit the appearance of cells, as in the present
 instance.
  This convoluted tube composing  the vesiculae semi-
 nales, terminates in a very short duct, which is nearly
of the same diameter with the vas  deferens, and  this
 duct joins  the vas deferens so as to form an acute
angle.
  From the union of the  vesiculae seminales with the
 vas deferens on each side, a canal, which seems  to  be ■
 the continuation of the vas deferens, proceeds through  j
 part of the prostate to the urethra, which it perforates.
 These canals  are from eight to twelve lines in length;
 they are conical in form, their largest extremity being
 equal to the vas deferens at that part.
  If air  or any other  fluid be injected  through the
 vas deferens into the urethra, it will pass at the  same 
        Function of the Vesiculae  Seminales.    183

 time into the vesiculae seminales, and distend them.   It
 has been observed, that a fluid passes  in this manner
 much  more readily from the  vasa deferentia into  the
 vesiculae seminales, than it  does from these last men-
 tioned organs into the duct.
   These organs were generally regarded as reservoirs
 of semen, and analogous to the gall bladder in their func-
 tions, until the late Mr. J. Hunter published his opinion
 that they were not intended  to contain semen, but to se-
 crete a peculiar mucous subservient to the purposes of
 generation.
   He states the  following facts in support of his opinion.
   A fluid,  very different from  semen, is found after
 death  in the vesiculae seminales.
   In persons who  have lost  one testicle, a considerable
 time before death, the vesiculse seminales on each side
 are equally distended with this peculiar fluid.   In  the
 case of a person who had a  deficiency of  the epididy-
 mis on one side, and of the vas deferens on the other,
 the vesiculae were filled with their peculiar fluid!
   The sensation arising from redundance  of the secre-
 tion of the testis,  is referred to the  testes, and  not to
 the vesiculae seminales.
   In some  animals there is no connexion between the
 vasa deferentia and the vesiculae seminales.
   See Observations on certain parts of  the Animal
 Economy, by John Hunter.

                The Prostate Gland.

   Is situated on  the under and  posterior  part of the
 neck of the bladder, so  as  to  surround the urethra.
Its form has some resemblance to that of the chesnut,
but it has a notch on the basis like that of the figure
of the  heart on  playing cards, and it is much larger
than the  chesnut of this part of America.    The basis 
184        Prostate Gland.—The Penis.
of this  body is  posterior, and  its apex anterior; its
position is oblique, between the rectum and the  sym-
phisis pubis.  Below there is in some cases a small fur-
row, which, in addition to the  notch  above,  gives to
the gland an  appearance of being  divided into two
lobes.  By  turning away the  vesiculae seminales and
vasa deferentia from the under surface of the bladder
we bring into  view a small tubercle at the upper part
of  the  base of the  prostate, called by Sir  Everard
Home the third lobe.  When diseased it projects into
the cavity of the bladder.
  It adheres to the urethra and neck of the bladder.
Its consistence is very firm and dense, resembling the
induration of scirrhus rather more than the ordinary
texture of glands.
  This gland receives small branches from the neigh-
bouring blood  vessels, and has no artery of  considera-
ble size exclusively appropriated to  it.
  As it lies  in close contact with the  urethra, the ducts
which pass between it and the urethra are not  to be
seen separate from these bodies : but ducts can be seen
in the substance of the  gland, which perforate the ure-
thra, and open on the sides of the caput gallinaginis to
the numher  of five or six on each  side.  By pressure
a small quantity of a whitish  fluid can be  forced  from
these orifices,  which is rather  viscid, and coagulablt I
in alcohol.                                           *
  The particular use of this fluid  is  not known.

                    SECTION  III.

                   Of the Penis.

  The penis,  when  detached from  the bladder, and
the bones, to which  it is  connected, and  divested of
the skin which covers it, is an oblong body, which is
rounded at one extremity and bifurcated at the other. 
Penis.
185
   It is composed of three parts, viz. two  oblong bo-
dies, called Corpora Cavernosa, which, at their com-
mencement, form  the bifurcated portions,  and then
unite to compose the body of the organ ; and a  third
part, of a spongy texture, which is connected to these
bodies where they unite to each other, on the  under
side, and continues attached to them during the whole
extent of their union, terminating in an expanded head
which covers the anterior  extremities of the corpora
cavernosa.   The urethra passes from the neck of the
bladder, on the under side of the penis, to its anterior
extremity, invested by this third body,  which is there-
fore called Corpus Spongiosum Urethras..
  The two bifurcated extremities are attached each of
them to one of the crura of the pubis and  ischium  ;
and they unite to form the body of the penis immedi-
ately anterior  to the symphisis pubis, to which the
lower part of it is also attached ; so that the penis is
firmly connected to the middle of the anterior part of
the pelvis.   The urethra proceeds from  the neck of
the bladder, between the crura of the ischium and pu-
bis and the crura of the penis, to join the body of the
penis at  its commencement,  and near this  place  its
connexion with the corpus spongiosum begins ; so that
there is a small portion  of the urethra between the
neck of the bladder  and  the commencement of the
corpus spongiosum, which is not covered by the cor-
pus spongiosum.  / This is called the membranous part
of the urethra.
  The penis, therefore, consists of two oblong bodies
of a cellular structure, which originate  separately, but
unite together to form it; and of the urethra,  which
joins these bodies immediately after their union, and is
invested by a spongy covering, which by its expansion
forms the anterior  extremity not  only of the urethra
but of the whole penis.   These three bodies, thus ar-
   VOL.  II.              '.11 
186         Corpora Cavernosa Penis.

ranged and connected, are covered  by cellular  mem-
brane and skin in a manner to be hereafter described.   j

              The Corpora Cavernosa,

  Which compose the body of the penis, are two  ir-
regular cylinders, that are formed  by a thick dense
elastic membrane, of a whitish ligamentous appearance
and great firmness.   They are filled with a substance
of a cellular structure, which is occasionally distended,  J
with  blood.  The crura of these  cylindrical  bodies,;  ]
which are attached to the  crura  of the ischium and
pubis, are small and  pointed at the commencement,
and are united to the  periosteum  of the  bones.  In
their progress upwards they enlarge, and at the sym-   ^
phisis of the pubis they unite so as to form  an  oblong
body, which retains the appearance of a union  of two
cylinders applied to each other lengthways ; for above
there is a superficial groove passing in that direction,
which is occupied by a large vein: and below there is
a much deeper groove, in which the urethra is placed.   '
Between these grooves is a septum which divides  one
side of the penis from the other.  It appears to pro-
ceed from the strong membrane  which  forms the  pe-
nis, and is composed of bundles  of fibres,  which pass
from one groove of the penis to the other, with many
intervals between them, through which blood or in-
jection passes very freely.  Sometimes these bundles  I
of fibres, with their intervals, are so regularly arran-
 ged, that they have  been compared to  the  teeth of a
 comb.  This septum extends from the union of the   ,
 two crura to their termination.
   Each of these cylinders is penetrated by the main
 branch of the pudic artery, which is  about equal in
 size to a crow's quill.   These arteries enter the corpo-
 ra cavernosa near their union, and continue through   , 
            Cells of the Corpora Cavernosa.       187

  their  whole  extent,  sending  off  branches  in their
  course ; the  turgescence and erection of the penis  is
  unquestionably  produced by the  blood which flows
  through these vessels  into the penis.
    The interior structure of the penis, when examined
  in the recent subject, is  of  a soft spongy nature, and
  seems stained with blood.    If any fluid  be injected
  through the  arteries  this substance appears cellular,
  and may be completely distended by it.   When air is
  injected, and  the structure becomes dry, the penis may
  be  laid open ; the cellular structure then appears as if
  formed by a number of lamina and  of filaments, which
  proceed from one  part of the internal  surface  of the
  penis to another, and form irregular cells.   It has been
  compared to the lattice-work in the interior of  bones ;
  and it is suggested by M.  Roux,  that  the  fibres of
  which the  structure  consists resemble  those of  the
  strong elastic coat  of  the penis.*   If these  cells are
  filled with coloured wax, injected by the  artery, and
  the animal substance is then  destroyed by placing  the
  preparation in a corroding liquor, the wax  which re-
  mains shows that the membranes forming the cells  are
  very thin.
   These cells communicate  freely  with each other;
  and therefore, if a pipe be passed through the  strong
  coat of the penis, the whole of them can  be  filled from
  it by the ordinary process of injection.

   * Mr. John Hunter says on this subject, " That the cells  of the corpora
 cavernosa are muscular, although no such appearance is to be observed in
 men: for the penis in  erection is not at all times equally distended.  The
 penis, in a cold day, is not so large in erection as in a  warm one : which
 probably arises from a kind of spasm, that could not act if it were not mus-
 cular.
   In the horse, the  parts composing the cells of the penis appear evidently
 muscular to the eye, and  in a  horse just killed, they contract upon being
' stimulated.—Ed. 
188        Corpus  Spongiosum.—Bulb.

                   The  Urethra

  Is a membranous canal  which extends from the neck
of the bladder to the orifice at  the  extremity of the
penis; and for a very great part of  its length is in-
vested by a spongy  structure,  called  the corpus spon-
giosum urethrse.  It proceeds  from  the neck of the
bladder along the upper part  of the  prostate; from
the prostate it continues  between the crura of the pe-
nis until  their junction: it then  occupies the  great  ;
groove formed by the corpora cavernosa on the lower
side of the penis, and continues to the orifice above-  \
mentioned.   At a small distance from the  prostatljjj
gland the spongy substance which invests it commences;
and continues to its termination.  After  this spongy ^
substance has arrived at  the termination of the corpora
cavernosa, it expands and forms a body of a particular
figure which covers the extremities of  the corpora ca-
vernosa, and is denominated the Glans Penis.
   The Corpus Spongiosum begins at the distance of
eight or ten  lines from the anterior part of the pro#  .
tate.  It is much larger at  its commencement than at
any other part except the glans, and  this enlarged part
is called the Bulb.   It surrounds  the whole of the,
urethra, and with the exception of  the bulb and the
glans penis,  is of a cylindrical  figure.  It  is formed by
a membrane which has some resemblance  to the coat of
 the penis, but is much thinner, and by  a peculiar spon-
 gy substance, which occupies the space  between the
 internal surface of this membrane and the  external sur-
 face of the  canal of the  urethra.  The membrane and
 the spongy substance, form a coat to the urethra, which,
 with the exception of the enlargement before mention-
 ed, is about one line thick.   After this spongy sub-
 stance has arrived  at the termination,  its  coat adheres
 firmly to the coat  of the penis. 
        Structure of the Corpus Spongiosum.    189

   The  Bulb, or first enlargement of the corpus spon-
giosum, is oblong, and rather oval in form ; it  is mark-
ed by a longitudinal depression in the middle, which
is very  superficial.  It consists entirely of the spongy
substance above mentioned.
   The  Glans Penis is also composed of the same spon-
gy substance, but the coat which covers it is more thin
and delicate  than that of the  other  parts  of the  ure-
thra.    The lower surface of the glans is fitted to  the
extremities of the corpora cavernosa, but it is  broader
than  the  corpora cavernosa,  and therefore  projects
over them on the upper and  lateral parts of the sur-
face of  the penis.   The edge of the prominent part is
regularly  rounded, and is denominated  the  Corona
Glandis.
   Several small arteries pass to this spongy structure.
The pudic artery, as it passes on each side to  the cor-
pora cavernosa, sends a branch to  the bulb of the ure-
thra.    The same vessel in the substance of the penis,
also sends branches to the urethra :  and the artery on
the back of  the  penis  terminates in small  branches,
which penetrate the substance of the glans.
   By these vessels blood is carried to the  spongy sub-
stance of the urethra, which  is occasionally distended
in the same manner that the  cavernous bodies of the
penis are distended during the erection of that organ.
But the cellular structure of this organ is not  so  une-
quivocal as that of the corpora cavernosa ; for if it be
injected with coloured wax,  and corroded in the usual
manner, the injected matter will exhibit an appearance
which has the strongest resemblance to a convoluted
vessel, like the vas deferens  in the epididymis.*
  * Mr. Hunter says, " that the corpus spongiosum urethra? and glans penis
are not spongy or cellular, but made up of a plexus of veins. This structure
is discernible in the human subject; but is much more distinctly seen in many
»nimals,as the horse," &c.—Ed. 
190       Internal Surface of the Urethra.

             The Canal of the Urethra,

   Which conveys the urine from the bladder, is a very
important part of the urinary organs.   It consists of a
vascular membrane  with a smooth surface, which is
perforated by the orifices of many mucous follicles,
some of which are of considerable size.   It is extreme-
ly sensible,  and  has so much  power  of contraction,
that some persons have supposed muscular fibres to ex-
ist in its structure.
   It is differently circumstanced in different parts of
its course.   While surrounded with the prostate it ad-
heres firmly to that body, seeming to be supported by
it; and here its diameter is larger than it is  fartherj
forward.  On the lower or posterior side of this po
tion of the urethra, is an oblong eminence,  called Ve-\
rumontanum, or Caput  Gallinaginis, which  com-
mences  at the orifice of the urethra, and  continues
throughout the whole portion  that  is  surrounded  by
the  prostate gland, terminating at the  point  of that*
body.   The posterior extremity of this tubercle begi
abruptly, and soon becomes thick and large; anterioi
ly it gradually diminishes to a line, which is sometimes
perceptible for a considerable  distance in the urethra,
in a  straight forward direction.  In  the upper  edge
or top of this body  is a groove, which is produced by
a mucous follicle ; on the  lateral  surfaces, anterior to
the middle,  are  the  orifices of the common ducts of
the vesiculae seminales, and vasa deferentia, (see  page .
182,) which are sufficiently large to receive a  thick
bristle.   Near  these, on  each  side, are five  or six
smaller orifices of the excretory ducts of the prostate
gland.  At  the distance of an inch before the extre-
mity of the  bulb of the urethra, in  the lining mem-
brane, are the openings of two  ducts,  one on  each
side, that lead to small  glandular bodies called Cow-
per's glands, which are situated on each side  of the
)y .
ati__j 
           Mucous Ducts of the Urethra.       191

 urethra below the bulb, but are covered by the acce-
 lerators urinae muscles.
   The diameter of the urethra lessens  after it leaves
 the prostate.  That portion  of the canal which is be-
 tween this gland  and the bulb, without investment,
 and therefore called the membranous part, is the small-
 est in diameter.
   After it is invested  with  the sponjry substance,  it
 has a small enlargement, and then continues  nearly  of
 one size, until it arrives near the glans  penis, when  it
 again enlarges and alters its form, being no longer cy-
 lindrical but flattened.  Its broad surfaces have now a
 lateral aspect.
   From the bulb of  the corpus spongiosum to this last
 enlargement, the appearance of the inner  surface  of
 the urethra is uniform.   The membrane  is  thin and
 delicate, and in a healthy subject, who  has  been free
 from disease of these parts, is of a whitish colour; but
 blood vessels are very perceptible in it.   When it is re-
 laxed, it appears to be thrown into longitudinal wrin-
 kles ; but it admits of considerable extension, being
 somewhat elastic :  when extended, its surface appears
 smooth, as if it  were  covered with  an epithelium.
Mr.  Shaw, of London,  has described a  set  of vessels
 immediately below the internal membrane of the  ure-
 thra,  which,  when empty, are very similar in appear-
 ance to muscular fibres.   He says  he  has  discovered
 that these vessels form an internal spongy body, which
 passes down to the membranous  part of the urethra,
and forms  even a small bulb there.   His  preparation
 with a quicksilver  injection of the part is certainly  a
very satisfactory proof of its  existence.*   Through-
out the whole extent of this part of the urethra, are
the orifices of a great many mucous ducts or  sinuses,
which pass obliquely backwards.  Many of  these are
* See Med. Chirurg—Transactions of London,—vol. 10th. 
192        Mucous Ducts of the  Urethra.
 so small that they cannot  be penetrated  by a bristle,
 or probe of that size ; but some are larger.   It has
 not been observed  that any glandular body immedi-
 ately surrounds them, although they secrete the mucous
 with which the urethra is lubricated.   On the  lower
 side  of the urethra,  near the commencement of the
 glans penis, there is one or more of them, so large that
 their  orifices  sometimes  admit the  point of a  small
 bougie.*
   These organs, when inflamed, secrete the puriform
 discharge which takes place in gonorrhoea.—In  a na-
 tural state they produce the mucous which is constant-
 ly spread over the  surface of the  urethra, to defend
 it from the acrimony  of the  urine, and  which  passes
 away with that fluid unperceived.
   The surface of the  urethra is  endued with  great
 sensibility,  and is therefore liable  to  great irritation
 from  contact with  any rough body or any acrid sub-
 stance.   Irritation, thus  excited,  induces a state of
 contraction, which  is particularly  remarkable, as  no
 muscular fibres are to  be seen in its structure.   When.
a bougie has been passed into the urethra for a  consi-
derable distance, if  it cannot proceed the whole  way,
it sometimes happens that  the instrument  will be dis-
charged by a steady uniform motion, which seems  to
proceed from a progressive contraction of the urethra,
beginning very low  down.   At particular times, after
the urethra has been much irritated, it will not receive
a bougie, although at  other times  a  bougie of equal
size may be passed to  the  bladder without opposition.
This cannot depend upon that elasticity which was no-
ticed  before, f

  * They were discovered by Plazzoni, of Padua, in 1621. Their number,
according to Loder, amounts to about 65—See his plates___Ed.
  f Sir Everard Home, whose professional opinions are  of "great weight,
has lately described  in the  Transactions of the Royal Society, the appear-
ance of the lining membrane  of the Urethra, when viewed through a 
Contractile Power of the Urethra.      193
   Upon the two crura of the penis, or the beginning
of the corpora cavernosa, are fixed the muscles called
Erectores Penis, which are described in the  first vo-
lume.*  These muscles cover the crura  of the penis
from their origin to the  junction, and not only com-
press them, but also influence the motion of the penis
when it is distended.
   The bulb of the urethra is covered by a muscular
coat, called the  Accelerator  Urinae,* which has  the
effect of driving forwards any fluid  contained  in  the
cavity of the urethra, and also of giving the same di-
rection to the blood in that part  of the  corpus spon-
giosum.   There is also the   Transversus Perinei  on
each side, that passes transversely  from  the  tubero-
sity of the ischium to  the bulb  of the urethra.__Fi-
nally the lower part of the sphincter ani musele, which
is nearly elliptical in form is inserted by its  anterior
point into the muscular covering of the bulb  of the
urethra.  Upon removing the integuments, these mus-
cles are in view;  and the course of the  urethra from
the bladder is concealed, particularly by the  anterior
point of the sphincter ani.  When the  sphincter ani
is  dissected  away from  its  anterior  connexions, and
the cellular and adipose substance, which is sometimes
very abundant, is also  removed, the  lower surface of
the membranous  part of the  urethra  may be  brought
into view,  as it  proceeds from the prostrate gland to
the bulb of the corpus spongiosum.!
microscope of great powers.  From this paper it seems that he is fully con-
vinced of its muscular structure__Ed.
*, *, See dMeription of " Muscles about the Male  Organs of Generation,"
Vol. I. Part II. Chap. II.
  t The natural situation of the membranous part of the urethra, and of the
prostrate gland, as well as their relative position with respect to the sphincter
am, rectum, &c. cen be best studied by a lateral view of the contents of th»
  VOL. II.               25 
194      Contractile Power of the Urethra.

   When the accelerator urinae is  removed from  the
bulb of the  urethra, there will appear two  bodies,
which   have  some   resemblance   to  flattened  peas.
They lie one on each side of the  urethra, in  contact
or nearly so with its bulb, and from each  gland pro-
ceeds an excretory duct of  an inch and a  quarter in
length, between the corpus spongiosum and the lining
membrane of the canal of the urethra, and opens into
the  latter.   Its orifice is found  with  some  difficulty,
but  is large enough  to  admit a  bristle.    These  are
Cowper's glands.*
   The penis is connected to  the symphisis pubis  by
a  ligamentous  substance,   which proceeds  from  the
back or upper  surface  of  the  organ  to  the  anterior
part of  the symphisis, and  connects these parts firmly
to each  other.
   Thus constructed, of the corpora cavernosa and the
urethra with  its  corpus spongiosum,  and  attached to
the  pelvis  as above  mentioned, the penis  is invested
with its integuments in  the following manner.!
pelvis ; which is to be obtained by removing carefully one of the ossa inncp
minata, and dissecting the parts which were enclosed by it.
  • These glands were discovered by Mery, in 1684, and described by Cow-
per, in 1699.  A third gland, smaller than the preceding, connected with the
curve of the urethra under the symphisis pubis, was discovered  by Cowper,
and Morgagni speaks of having observed a fourth.—Ed.
  f There are several fasciae and ligaments about the perineum which should
be connected with the account of its viscera.  Immediately beneath the skin
of the perineum is the Perineal Fascia, a thin but strong membrane, which
extends from bone to bone, occupying the space between the anus and the
posterior part of the scrotum. It is rather better seen in lean subjects than
in fat ones, for in the latter it is converted in part into adipose membrane.
When a rupture occurs in the posterior part of the urethra, this fascia pre-
vents the urine from showing itself immediately in the perineum, and drives
it into the cellular structure of the scrotum.
  Immediately beneath the perineal fascia are placed the muscles; when
they are removed, the bulb of the urethra may be seen very advantageously,
extending in the middle of the perineum almost to the anus. It  is not lease' 
integuments of the Penis.           195
                 Integuments of the Penis.

     The glans penis, the  structure  of which has  been
   already described, is covered by a continuation of the
   skin, which appears altered in its texture so as to re-
   semble in some respects  the skin of the lips, and in
   like  manner  is  covered by a delicate production of
   cuticle.
     Around the  corona  of the  glans, especially on  its
   upper part, there are whitish tubercles,  which are of
   different sizes in  different  persons, but always  very
   small.  The skin adheres firmly to  the  whole  extent
   of the corona of the glans, and  is very delicate in  its
   structure as it continues  from the glans upon the body
   of the penis; but it gradually changes so as to assume
   the appearance and structure  of a common skin, and
*   continues in this state over the penis.   The adhesion
   of the skin to the ligamentous coat of the corpora ca-
   vernosa also becomes more loose, owing to the  quanti-
   ty and  texture  of the cellular substance which  con-
   nects them.   The skin,  thus connected to   the  penis,
   has commonly more length  than  that  organ, even  in
  its extended state.    In  consequence  of this greater
  length, and of its adhering firmly around  the corona
  glandis, it necessarily forms  a circular  fold or plait,

  and pendulous, but is attached by its pelvic surface to the triangular ligament
  of the urethra.  This ligament is  a septum between the perineum and the
  pelvis, and connects itself to the pelvic or internal edges of the rami  of the
  pubis and ischi as far down as the organs of the crura penis.  It extends
  from the arch of the pubis to the line mentioned, and fills up all the  space
  between the bones of the opposite sides.  It consists of two lamina, and
  Cowper's glands are placed between them.  About an inch below the sym-
  phisis pubis a perforation is  made in this ligament for the passage of the
  membranous part of the urethra.
   Just below the symphisis pubis, between the two lamina of the  triangular
  ligament, is placed a much stronger ligament called the pubic, which is about
  half an inch broad, its lower edge is thick and rounded.   For further  detail
  on the subject of the fasciae of the pelvis, see Lessons in Practical Anato-
  m\ by the present editor.—Eb. 
196
Integuments of the Penis.
which varies in size  according  to the length  of the
skin.   This fold  is generally situated  at  the com-
mencement of the firm attachment of the skin  to the
body of the penis, or around the glands; but it may
be formed any where upon the  body of the penis by
artificial management.
  This duplicature,  or fold of the skin, when it takes
place so as to cover the glans, is called the  Prepuce ;
and  the skin  which is very tender and delicate for
some distance from the glans, form that surface of the
prepuce which is in contact  with the glans when  it
covers that body.
  There is also a small fold of the skin,  which is lon-
gitudinal in its direction, that commences at the orifice
of the urethra, and  extends  backwards on  the  lower
surface of  the penis.  Jt is unvarying in  its position,
and is called the Frenum.
  It is a general  observation, that adeps is  not found
in the cellular substance  which  connects the skin  to
the body of the penis; but this  cellular  substance  is
distended with water in some hydropic cases.
  From  the  skin immediately  below  the glans,  and
from small follicles on each side  of the frenum, is se-
creted an unctuous fluid, which, when allowed to con-
tinue, becomes inspissated, and acquires a caseous con-
sistence and colour,  as well as a peculiar  odour.    It
sometimes also acquires an acrimony which produces
inflammation on the surface with which  it  is in con-
tact, as well as the copious secretion of puriform fluid.
   The distribution of  the  pudic artery  in  the  penis,
has already been mentioned ; and a further account of
its origin and progress to its destination, will be found
in the general account of  the  arteries.    Sometimes
small branches of the  external  pudic arteries  which
originate from the femoral, are extended to the  penis:
 and it has been asserted, that branches of the middle 
    Blood Vessels and Absorbents of the Penis.  197

hemorrhoidal artery have also been found there, but
this does not often occur.
  The Veins of  the  penis  are  of  two kinds; those
which originate in the corpora cavernosa, accompany
the corresponding branches of the pudic artery, but
communicate more or less with the plexus of veins on
the lower and lateral  part of the  bladder.   There  is
also a great vein, which occupies the  groove on the
back  of  the penis,  between the  corpora cavernosa,
that appears particularly appropriated to the corpus
spongiosum  urethrae ;  for  it originates  in  the  glans
penis, and receives branches from  the urethra  as  it
proceeds backwards.   There are  often two of these
veins, one in the  groove, and the other more superfi-
cial :  they generally unite near the root of the penis.
The common trunk then  passes  between  the body of
the penis and the symphisis pubis,  and terminates  in
a plexus of veins at the neck of  the bladder, which is
connected to the plexus above mentioned on  the lower
and lateral parts of the same viscus.
  The Absorbent Vessels of the penis take two diffe-
rent directions on each side.  Those which arise from
the integuments generally, unite so as to  form  a few
trunks on the back  of the penis, which divide  near
the root of  the organ, and proceed to  the  glands  of
the groin.   Those which  originate  from the interior
parts of the  penis, accompany the  blood  vessels, and
terminate  in the plexus of lymphatics in the pelvis.
  It ought to be noted, that the superficial lymphatics
generally  enter the upper inguinal glands.
  The Nerves of the penis are principally derived
from the  lower  secral nerves,  which  unite  in  the
plexus that forms the great ischiatic.    From these
nerves a branch on each side originates, which passes
like  the pudic artery, between the  sacro-sciatic  liga-
ments.  In this course it divides into two branches, one 
198      Nerves.—General  Observations.
of which passes below to the muscles of the penis and
urethra, and to the contiguous parts ; and some of its
branches seem  finally to terminate in the  dartos : the
other branch proceeds along  the  crura of the pubis
and  ischium, and passing  between  the symphisis pu-
bis and the  body of  the  penis, arrives  at the  upper
surface or dorsum of the penis, along which it conti-
nues on the outside of the veins to the glans, in which
it  terminates.   In this   course  it  sends  off  several
branches, some of which terminate in the  integuments
of the penis.
After an examination of the relative situation of the mus-
  cles and blood vessels of the male organs of generation,
  there appears reason  to doubt, whether the erection of
  the penis can be referred to pressure  upon the veins
  which return from that organ.   Albinus has written on
  this subject.   See Academicarum  Annotationum, lib.
  ii.  caput xviii.   Haller has also  considered  it,  and
  stated the opinions of several  anatomists, in his Ele-
  menta Physiologiae, torn. vii. page 555.
The manner in which the urine is confined in the bladder
  does not appear to be clearly understood.  The con-
  nexion of the neck of the bladder with the prostate,
  and the appearance of the contiguous parts of the blad-
  der, do not render it  probable that these parts  act  like
  a sphincter.   The late J. Hunter, who paid great at-
  tention to the functions of these organs, was very de-
  cided  in his opinion that the contraction of the  urethra
  produced the effect of a sphincter of the bladder.  He
  lias published some very ingenious observations respect-
  ing the manner in which urine  is discharged from the
  bladder, in his Treatise on the Venereal Disease, part
  III. chapter IX.
y[r.  Hunter also  long  since asserted, that the vascular
  convoluted  appearance of the corpus spongiosum ure-
  thrae was more distinct in the horse than the man.   In
  the fifth volume of the Lecons  d'Anatornie Compare
  of Cuvier, the very learned  and ingenious  author con-
  firms  the declaration  of Hunter, respecting  the vascu-
  lar convolutions of the corpus spongiosum of the horse. 
General Observations.
199
  He states, that the corpora cavernosa of the penis of
  the elephant appear to be filled in a great degree with
  the ramifications of veins,  which communicate with
  each other by such large and frequent anastomoses,
  that they have a cellular  appearance.   A  similar
  structure exists in the  horse, camel,  bullock, deer,
  &c. and in them all  these  communicating branches
  can be distinguished from those  which extend  the
  whole length of the penis.
The corpus spongiosum urethras, according to  M. Cu-
  vier, is constructed  in a  similar manner.    From
  these facts he is induced to believe that this struc-
  ture pervades the whole class of mammalia. 
CHAPTER VI.
      OF THE FEMALE ORGANS OF GENERATION.

   The female organs of  generation  consist of the
 Uterus and Ovaries, with their  appendages; and of
 the Vagina, with the  structure   which surrounds its
 external orifice.  The uterus is situated in the pelvis,
 between the bladder and rectum; and the ovaries are
 on each side of it.   The vagina is a very large mem-
 branous canal,  which passes from the  uterus down-
 wards and forwards, also between the bladder and rec-
 tum,  and opens externally.
   Connected with the orifice of the vagina are  seve-
 ral bodies,  which are called the external parts of ge-
neration, in order to distinguish  them  from the  ute-
rus and ovaries, and their appendages, and also  from
the canal of the vagina ;  which are called the inter-
nal parts.
   The bladder of urine lies above and in contact with
the vagina: the urethra  is also  intimately connected
with it.  The description of the bladder and urethra
is  therefore placed at the end of this chapter.

                    SECTION I.

      Of the External Parts of Generation.

   The adipose  membrane, immediately anterior to
the symphisis pubis, and on  each  side of it, forms  a
considerable prominence in females, which, at the age
of puberty, is covered with hair,  as in males.   This
prominence is denominated the Mbns  Veneris.
   The exterior orifice commences immediately be-
low this.    On  each side of this orifice is a  promi- 
             Labia Externa—Clitoris.         201

 nence continued from the mons veneris, which is largest
 above, and gradually diminishes as it descends. These
 prominences have some hair upon  them.   They are
 called the Labia  Externa.   Their junction below is
 denominated the  Fourchette.   The space between the
 place of their junction and the anus is rather more
 than an inch in extent, and is demoninated  the Peri-
 neum.
   As the skin which forms the labia is  continued in-
 ternally, it becomes more thin and soft, and is  covered
 by a more delicate cuticle.  It is also more or less florid,
 and secretes a peculiar mucous.
   In the upper angle, formed by the labia externa, is
 the upper extremity and glans of the clitoris.
   The Clitoris is a body which has a very  strong re-
 semblance to the penis, but there is no urethra attached
 to it.   It has two crura of  considerable  length, which
 originate, like those of the  penis, from  the crura  of
 the pubis and ischium, and  unite at  the  symphisis  of
 the pubis so as to form a body, which is not much more
 than an inch in length, and  is broad in  proportion.
 The extremity of this organ, called the  Glans of the
 Clitoris,  forms a small  tubercle, which is covered
 above and on the  sides by a small  plait or fold of the
 skin,  denominated the Prepuce.  These  parts  are lu-
 bricated by a secretion similar to  that which is ob-
 served round the  glans penis.
   The crura of the clitoris have muscles similar  to
 the erectores penis.   The interior structure  of the
 Clitoris is very similar"to that of the corpora caver-
nosa of the penis, or the corpus spongiosum  of the
urethra.   It appears constructed for a similar  disten-
 tion, and is endued with the same sensibility as  the pe-
nis.   The two lateral parts  are also separated from
each other by a septum, resembling that of the penis.
 It is united to the symphisis pubis by a ligament.
   vol. ir.              <26 
202
Nymphee—Hymen.
  The Prepuce of the clitoris has a semicircular form :
below its extremities tw6  folds or  plaits  commence,
one on each side, which are situated  obliquely with
respect to each other, so as to form  an  angle.  These
folds are denominated the Nymphac.
  The Nymphce extend from the clitoris  downwards
nearly as far as the middle of the orifice of the vagina.
They are situated within the external  labia, and are
formed by the skin after it has  become more delicate
in its  texture.   Their surface however is often some-
what  corrugated.  There are many blood vessels in
their  internal  structure, and it is  supposed they are
occasionally  somewhat tumid.   They are  flat,  and
their exterior edge is convex ; so that they are narrow
at their extremities,  and broad in the middle.  Their
breadth is very variable, and in some instances is great.
In a majority of cases, it is equal to one-fourth of their
length.   Their colour in young subjects is of a bright
red;  in women advanced in years,  and who have had
many children, they  are of a brown red, and some-
times  of a dark colour.
  The use of these parts is not very evident.   The*
have been supposed to regulate the course of the  urine
as it flows froni the urethra, but their effect in this re-
spect  is not great. They  have also been supposed to
favour the necessary  enlargement of the parts in par-
turition.
  The orifice of the  urethra is situated about an inch
and one quarter further inward than the clitoris.  It
is often rather less than the  diameter of the  urethra,
and is somewhat protuberant.  The orifices of mucous
ducts  are to  be perceived around it.
  The orifice  of  the urethra is at the  commencement
of the canal  of the vagina.  Immediately  within this
orifice is situated  the membrane denominated Hymen.
  The Hymen is an incomplete septum, made by a 
The Vagina.
203
fold or duplicature of the membrane which forms  the
surface  contiguous to it.   Sometimes it  is circular,
with an aperture in the centre.   Sometimes it has a
resemblance to the crescent, the aperture being at the
upper part of it.   The hymen  has  frequently been
found without a perforation, and has therefore  pre-
vented the discharge of  the menstrual evacuation.  It
is generally ruptured in  the  first intercourse of the
sexes; and some small tubercles, which are found  on
the surface of the vagina  near the spot where it was
situated, are supposed to  be the remains of it.   These
tubercles are called Carunculce Myrtiformes.

                    SECTION II.

                  Of the Vagina.

  The canal of the vagina,  commencing at the hymen
and the orifice of the urethra, is rather more  narrow
at its begining than it is further inward.   From this
place it  extends backwards and upwards, and partakes
in a small degree of the curve of the  rectum : while
the bladder, which is above it, and  rests  upon it, in-
creases the curvature of the anterior part.   It is much
larger in women who have had children than in those
who have not.
  The membrane which lines the vagina resembles to
a certain degree, the membranes which secrete  mucous
in different parts of the body.  Its surface appears to
consist of very small papillae;  and at  the anterior ex-
tremity of the vagina it forms a great number of rugae,
which are arranged in a transverse direction,  both  on
the part of the vagina connected to the bladder, and
on that  part which is connected to the rectum, while
the lateral parts of the  vagina  are smooth.   These 
204   Corpora Cavernosa.—Sphincter Vaginae.

rugae are most  prominent in  the  middle;  so  that a
raised line appears to pass through  them at right an-
gles.   This line extends from without inwards.   The
rugae on the part next to the bladder are the strongest.
   This arrangement of  the  surface  of the vagina does
not extend beyond the external half of the  canal: on
the internal half  part, or that nearest  the uterus, the
surface  is smooth.
   The  rugae are considerably diminished  in  women
wtio have had children.
   Throughout  this surface are to be seen, in  some cases
with  the naked eye, the orifices of  mucous follicles or
ducts, which occasionally discharge considerable quan-
tities of mucous.
   Exterior to this lining membrane of the vagina is a
dense cellular structure, which has not yet  been com-
pletely investigated : it is of a lightish colour, and has
some resemblance to  the texture  of the body  of the
uterus.   It is very vascular, and appears to be of a
fibrous  structure.   It may be very much  distended,
and seems to have a contractile power.
   At the anterior  extremity of the  vagina, on each
side of it, there  is superadded  to  this, a cellular, or
vascular substance,  from  eight  lines  to an  inch in
breadth: which, when cut into, resembles the corpora
cavernosa, or  the corpus  spongiosum of  the  penis.
These bodies commence near the body of the clitoris,
and  extend  downwards on each side  of the  vagina.
They have been called  Plexus Reteformis, and Cor-
pora Cavernosa  Vaginae, and are supposed to  be oc-
casionally distended  with blood, like the clitoris and
penis.
   These corpora cavernosa are covered by muscular
fibres,  which pass over  them on  each side from the
sphincter ani to the  body of the clitoris ; to each of
which organs they are  attached.   These  fibres con- 
Unimpregnated Uterus.
205
stitute the sphincter vagina muscle, and contract the
diameter of the vagina at the place where  they are
situated.
  The transversus perinei muscles  also exist in the
female.  They pass from the tuberosities of the ischia,
and are inserted into a dense whitish substance in the
perineum,  to which the  anterior extremity of the
sphincter ani is likewise attached.
  The vagina is in contact with the rectum  behind;
the bladder lies upon it and  anterior to it.   A  small
portion of peritoneum, to  be  reflected to the rectum,
is continued from the uterus upon the posterior part of
it.  The lateral portions of it are invested with cellular
substance.   The  anterior  extremity of the uterus,
which  is called  the Os Tincae, projects into it from
above.

                   SECTION III.

Of the Uterus,  the  Ovaries  and  their Appendages.
                    The  Uterus

  Has been compared to  a pear with a long neck.—
There is of course a considerable  difference  between,
the body and neck ; the first being twice as  broad as
the last.  Each of these parts is somewhat flattened.
  In  subjects of mature  age,  who  have never  been
pregnant, the whole of the uterus is about  two inches
and a half in length, and  more than one inch and  a
half in breadth at the broadest  part of the  body: it is
also near an inch in thickness.
  It is generally larger than this in women who  have
lately had children.
  The uterus is situated in the pelvis between the
bladder and rectum, and  is enclosed in a duplicature
or fold of the peritoneum, which forms a loose septum
that extends from one side of the  pelvis to the other,
and divides it into an anterior and  posterior cham- 
206         Ligaments of the Uterus.

ber.  The posterior surface of this septum is opposed to
the rectum, and the anterior to the bladder.   The two
portions of this septum which  are between the uterus
and the lateral parts of the pelvis, are called the Broad
Ligaments.
  On the posterior surface, the Ovaries are situated on
each side of the uterus, being enclosed by a process of
the ligament or septum.   Above them, in the upper
edge of the septum, are the Fallopian Tubes, which
are ducts that commence  at  the upper  part of  the
uterus on each side, and proceed in a lateral direction
for some distance, when they form an angle and incline
downwards to the  ovaries.  These ducts are  en-
closed between  the two lamina of the septum for
the greater part of their length.
  The  peritoneum which forms the  septum, is re-
flected  from it,  posteriorly, to the rectum and  the
posterior surface of the pelvis, and anteriorly, to  the
bladder.  In its  progress in each direction, it forms
small plaits or folds; two of which extend from  the
uterus to the rectum  posteriorly, and two more to
the bladder anteriorly: these are called the AnteriM
and Posterior Ligaments of the Uterus.
  The other ligaments, which proceed more imme-
diately from the  uterus, are called the Round Liga*
ments.  These arise from each side of the uterus, at
a small  distance  before and below the origins of the
fallopian tubes, and proceed in an oblique course to
the abdominal rings.   These ligaments are also in-
vested by the peritoneum.  They  pass through  the
rings and soon terminate.
  In the body of the uterus is a cavity, which  ap-
proaches to the  triangular form ; and from which a
canal proceeds through its neck.  This cavity is so
small that its sides are almost in contact, and the ca-
nal is in proportion; so that this organ is very thick
in proportion to  its bulk 
        Structure and Cavity of the  Uterus.     207

  The substance of which  the uterus consists is very
firm and dense :  it is of a whitish colour, with a slight
tinge  of red.   There are many blood vessels, with
nerves and  absorbent vessels, in its texture.  The
nature and  structure of  this substance has  not  yet
been precisely ascertained.  It appears very different
indeed from muscle ; but  the  uterus occasionly con-
tracts, with great force, during labour.   It is not ren-
dered thin by its enlargement during pregnancy,  and
the blood vessels in its texture are generally enlarged
at that time.
  Exteriorly, the uterus is covered by the peritoneum,
as has already been mentioned.  Internally it is lined
with a delicate membrane that has some resemblance to
those  which secrete mucous, and is generally of a
whitish colour, abounding with small  orifices that  can
be seen with a magnifying glass.  This membrane  is
so intimately connected to the substance of  the uterus
that some anatomists have supposed it was merely the
internal surface of that substance, but this  opinion is
now generally abandoned.  It  is supposed that  the
colour of this membrane is more florid about the period
of menstruation.
  The cavity of the uterus, as has been observed be-
fore,  is triangular in form.  When the organ is in its
natural  position, the upper  side of this triangle  is
transverse with  respect to the body, and  the other
sides  pass downwards and inwards.   In each of the
upper angles are  the orifices or the fallopian tubes,
which are of such size as to admit a hog's bristle.
  The  two lower lines of the  triangle are slightly
curved outwards at their upper extremities;  so  that
the upper angles of the triangle project outwards and
the orifices  of the fallopian tubes are nearer to the ex-
ternal surface than they otherwise would be.
   The lower angle of the cavity of the uterus is oc- 
 208     Structure and Cavity of the Uterus.

 cupied  by the  orifice  of  the  canal,  which  passes
 through the neck of the organ ; this orifice is from
 three  to four lines in diameter.   The canal  is about
 an inch  in length, and is rather  wider in the middle
 than at either  end.   On  the anterior  and posterior
 portions of its  surface  are  many small  ridges  which
 have an arborescent  arrangement, one large ridge
 passing  internally  from  the commencement  of  the
 canal,  from which a number of other ridges go off in
 a  transverse direction.  These ridges  extend nearly
 the  whole length of the canal.   In the grooves,  be-
 tween  the  ridges,  are the  orifices of many mucous
 ducts.    There are also  on this  surface a number of
 transparent bodies of a round form, equal in bulk  to a
 middle sized grain of sand ; the nature and use of which
 is unknown.  They have been called Ovula Nabothi.
 after a  physiologist who published some speculations
 respecting their use, about the commencement of the
 last century.
   The  canal of  the neck  of the uterus is very  dif-
 ferent from other ducts, for it seems to  be  a part of
 the cavity to which it leads,  and when  the  cavity of
 the uterus  becomes enlarged  in the progress of  preg-
 nancy, this canal is  gradually converted into a part of
 that cavity.
   The lower extremity of the neck of  the uterus is
 irregularly convex  and  tumid.  The orifice of  the
 canal in it is oval, and so situated that it divides  the
 convex  surface of the neck into  two portions, which
 are called the Lips.   The anterior or upper portion
 is  thicker than the other.
   This extremity of the  uterus protrudes into the  va-
 gina, and is commonly called   Os  Tincx.  As the  an-
 terior portion or lip is  larger and more tumid than
 the posterior, the vagina extends further beyond  the
os tincse  on the posterior part than on the anterior. 
       Fallopian  Tubes.—Round Ligaments.   209


                The Fallopian Tubes
   Are two canals, from four to five inches in  length,
 which proceed between the lamina of the broad liga-
 ments, from the upper angles of the uterus, in a trans-
 verse direction, to some distance from the uterus, when
 they form an angle, and take  a direction downwards
 towards the ovaries.
   They are formed, for a considerable part of their ex-
 tent, by a substance which resembles  that  of which
 the uterus consists, and are lined by a membrane con-
 tinued from the  internal membrane of  the  uterus.
 Their extremities appear to be composed of membrane,
 which is rendered florid by the blood vessels in  its
 texture.   At the commencement, their diameters are
 extremely small; but they  enlarge in their  progress.
 This enlargement is gradual for the first half, and  af-
 terwards sudden ;  the enlarged part is more membra-
 nous than the small part, and has a bright red  colour.
 The large extremity is loose in the cavity of the pel-
 vis, and is not invested by the lamina of the  broad li-
 gaments.   Near the termination the diameter is often
 contracted ;  after which  the membrane which  forms
 the tube expands  nto an open mouth, the margin  of
 which  consists  of  fringed  processes : this margin is
 also oblique, as respects the  axis of the tube; and
 the different fringed processes  are not all of the same
length ; but the longest are in the  middle, and the
others regularly diminish on each side of them :  these
processes constitute the Fimbriae,  of the  fallopian
tubes.
  The internal  surface  of the large extremities  of
these tubes is extremely vascular; and there are some
longitudinal fibres of a red colour to be seen on it.

              The Round Ligaments,
  Which have already  been mentioned, are  cords  of
  VOL. I!.              27 
210          Structure of the Ovaries.
 a fibrous structure, with many blood vessels in them.
 They arise from the uterus below the origin of the fal-
 lopian tubes, and proceed under the anterior lamina
 of the broad ligaments to the abdominal rings,  through
 which they  pass ;  and then  the fibres and  vessels  are
 expanded upon the contiguous cellular substance.

                    The Ovaries

  Are two  bodies  of a  flattened  oval  form ; one of
 which is situated on each side of the  uterus on  the
 posterior surface of the broad ligament, and invested
 completely by a process of the posterior lamen, which
 forms a coat, and also a ligament for it.  The size of
 this organ varies in different subjects, but in a majori-
 ty of those who are about the age of maturity, it is
 between ten and twelve  lines  in  length.   It is con-
 nected to the uterus by a small ligament, or bundle of
 fibres of the same structure  with the round ligaments,
 which  is not more than two  lines in diameter, and is
 included between the lamina of the broad ligament.
  The process of the broad ligament  forms an exter-
nal  coat to the ovary; within this is  the proper coat
of the organ, which is a  firm membrane.   This mem-
brane is so firmly connected to the substance of  the
ovary which it encloses,  that it cannot be  easily sepa-
rated from it.   The ovary is of a whitish  colour and
soft texture, and has many blood vessels.   In virgins
of mature age it contains from ten  to  twenty vesicles,
formed of a delicate membrane, filled with a transpa-
rent coagulable fluid.  Some of these vesicles are  si-
tuated  so near to the surface of the  ovary, that they
are prominent on its surface; others are near the cen-
tre.   They  are very different in size; the largest  be-
ing between two and three lines in diameter, and others
not more than one-third of that size. 
              Arteries of the  Uterus.           211

  In women who have had children, or in whom con-
ception has taken place, some of these vesicles are re-
moved ; and in their place a cicatrix is found.
  It has been  ascertained, that during  the  sexual in-
tercourse with males,  one of these vesicles, which was
protuberant on the surface, is often ruptured, and a
cavity is found.  A cicatrix is soon formed, where the
membrane was ruptured; and in  the place occupied
by the vesicle  there is a yellow substance denominated
Corpus Luteum.  This corpus luteum generally con-
tinues until the middle of pregnancy: it often remains
during that state, and for  some time after delivery,
but it gradually vanishes.   The cicatrization continues
during life.
  In many cases these cicatrices correspond with the
number of conceptions which  have taken place; but
they often exceed the number of conceptions, and they
have  been found in cases  where  conception  has not
been known to have taken place.
  In  very old subjects, where conception has never
taken place, the vesicles  are either entirely removed,
or small dense tubercles only remain in their place.

                    The Arteries

  Of the uterus are derived  from two  very different
sources ;  viz.  from  the spermatic and from the hypo-
gastric arteries.
  The spermatic arteries, instead of passing directly
down to the abdominal ring, proceed between the la-
mina of the broad ligament, and send branches to the
ovaries, which may sometimes be  traced to the vesi-
cles.  They also send branches to the  fallopian tubes
and to the uterus.   Those  which are on the  opposite
sides  of the uterus anastomose with each  other, and
also with  the branches  of the hypogastric  arteries, 
212            Veins of the  Uterus.

There arc also branches of these arteries in the round
ligaments which accompany  them to their termination
outside of the abdominal ring.
  The principal arteries of  the  uterus  are those de-
rived from  the hypogastric,  which sends to each  side
of it a considerable branch, called the Uterine.  This
vessel leaves the hypogastric very near  the origin of
the internal pudic, and proceeds to the  cervix  of the
uterus: it passes between  the lamina of the broad li-
gaments, and sends branches to the edge  of  the  ute-
rus, which penetrate its texture.   The branches which
are in the texture of the uterus, are very small indeed,
in young subjects.   In women who have had children,
they are considerably larger; but during  pregnancy
they gradually enlarge with  the growth  of the uterus,
and  become  very considerable.   These arteries ob-
serve  a  serpentine and peculiarly  tortuous course.
Those on the opposite sides anastomose with each other.

                    The Veins

  Of the uterus, like the arteries, form  spermatic and
uterine trunks.   The spermatic  vein  is much  larger
than the artery.   It  ramifies as in males, and forms a
very large  plexus, which constitutes the corpus pam-
piniforme.   Many of the  veins which form this body,
originate near the ovary :  a considerable number also
come from  the fallopian tubes and the  uterus.    The
spermatic vein and its  branches  are greatly  enlarged
indeed during pregnancy : and it is said that they are
enlarged the same way during the menstrual discharge.
  The  most  important veins of  the uterus are the
branches of the  Uterine Veins.   They are  extreme-
ly numerous, and form a plexus on the side of the ute-
rus ;  from  which two or more uterine  veins proceed
in the course of  the artery,  and  join the hypogastric. 
I
        Lymphatics.—Bladder and Urethra..    213

These veins also are  greatly enlarged  during preg-
nancv.

              The Lymphatic Vessels

   Of the uterus, and its appendages, are  very nume-
rous.   In  the unimpregnated state they are  small;
but, during pregnancy, they increase greatly.  They
proceed from the uterus in  very different directions.
Some that accompany the round ligaments go  to the
lymphatic glands of the groin.    Others  which  take
the course of the uterine blood vessels pass to  glands
in the pelvis, and a third set follows the spermatic ar-
teries and veins  to the glands on the loins.

                    The Nerves

   Of the ovaries are derived from the  renal  plexus,
and those of the uterus and  vagina from the hypogas-
tric plexus,  or the lower portions of  the sympathetic,
and the third and fourth sacral nerves.

                    SECTION iv.

            Of the  Bladder and  Urethra.

   The situation of the Bladder, as respects the sym-
phisis pubis, is nearly alike in both sexes; but  that
part of  it which is  immediately behind  the insertion
of the uterus is rather lower in males than in  females.
The bottom  of the bladder rests upon the  upper part
of the vagina, a thin stratum of cellular substance only
intervening : when  that viscus is distended it forms  a
tumour, which compresses the vagina.
   The ureters are inserted,  and the urethra commen-
ces in the same part of the bladder, in both sexes.
  The  length of the  Urethra is between one  and
two inches.  When the body is in a direct position,
it is nearly horizontal ;  but it  is slightly curved, with 
214  General Change in the Gravid Uterus.

its  convexity  downwards.   It  is immediately above
the vagina, and it passes below the body of the clito-
ris.   The external orifice of is  rather  more  than an
inch within the glans or head of the  clitoris.   This
orifice is somewhat prominent in the vagina.
   In the internal or lining membrane of the urethra
there  are many  orifices of mucous follicles, and also
longitudinal wrinkles, as in the urethra of males.  The
diameter of the female urethra and its orifice in the
bladder are greater than they are  in the  male.   For
this reason it has been supposed, that women are less
liable to calculus of the bladder than men.*
   The urethra is intimately connected with the exter-
nal coat of the vagina, and between  them there  is a
spongy cellular substance which makes the rough  sur-
face of the vagina prominent; so that the urethra has
been supposed, although erroneously, to be invested
with the prostate.  It is capable of great artificial di-
latation.

Of the Changes induced in the  Uterus in the pro-
                gress  of Pregnancy.

  The alteration which takes place in the  size of the
uterus during  pregnancy is  truly great.   About the
conclusion  of that  period, instead of the small  body
above described, which is almost solid, the uterus forms
an immense sac, which extends  from the  termination
of the vagina in the pelvis, into the epigastric region;
and from one side of the abdomen to the other; pre-
serving, however, an ovoid figure.
  This change is so gradual  at  first, that the uterus
does not extend beyond the cavity of the pelvis before
the third month,  although at the  end of the seventh
month it is very near the epigastric region.

  * It has however been asserted that they are also less liable to calculi in
the kfdnevs. 
               Change in the Uterus.           215

   For the first six months the body of the uterus ap-
 pears principally concerned in the enlargement:  after
 this the cervix begins to change, and is gradually al-
 tered so  as  to compose a portion of the sac, rather
 of less thickness than  the rest of the uterus ; the mouth
 being ultimately an aperture in a part which is much
 thinner than the other portions of the organ.
   The change which takes  place  in  the texture  of
 some of the appendages of the uterus is  very impor-
 tant.                                          v
   The  Broad Ligaments, which  seem  particularly
 calculated to favour the  extension  of the  uterus, are
 necessarily altered by the change in the  size of that
 organ, but not entirely done  away.  The portion  of
 peritoneum of which  they are formed must  be  very
 much enlarged with the growth  of the uterus,  as  it
 continues  to  cover it.  The  Round Ligaments are
 much elongated; and they observe a more straight
 course to the abdominal ring.  The Fallopian  Tubes
 are enlarged; and  instead of  passing off laterally  from
 the uterus, they now  proceed  downwards  by  the  side
 of it.  The  Ovaries  appear rather larger and more
 spongy : their relative situation is necessarily lower.
   The change in the  Uterus itself is particularly in-
 teresting.   The great increase of its size is not attend-
 ed with any considerable diminution  of  thickness in
 its substance ; nor are the arteries much less convo-
 luted than before pregnancy, as might have been  ex-
 pected.   They are greatly enlarged in diameter, and
 the orifices of the exhalent vessels on the internal  sur-
face of the uterus are much more  perceptible.
  The veins are much more enlarged  than the arte-
ries,  and in  some  places appear more  than  half an
inch  in diameter.    They are  not  regularly cylindri-* 
216             General Observations.
cal, but rather flat.   They anastomose so as  to  form
an irregular net-work.
  The uterous appears much more  fibrous and  mus-
cular in the gravid than in the  unimpregnated state.
The contractile power of the gravid uterus is not only-
proved by the expulsion  of its  contents, but also by
very vigorous contractions, which are occasionally ob-
served by accoucheurs.

    Although the general effects which result from the parti-
       cular conditions of the uterus in pregnancy, menstrua-
       tion, &c, evince that the influence of this organ upon
      the whole system is  very great, yet it seems probable
       that the sexual peculiarities of females are especially
       dependent upon the ovaria.
         This sentiment is confirmed by an occount of a wo-
       man in whom the ovaria were deficient, which is pub-
       lished in  the London  Philosophical Transactions for
       1805, by Mr. C.  Pears.   The subject lived to the age
       of twenty-nine years.  She ceased to grow after the age
      of ten years, and therefore was not more than four  feet
      six inches in height:  her breadth across the hips  was
      but nine inches, although the breadth of the  shoulders
      was fourteen.  Her breast and nipples never enlarged
      more than they are in the male subject.  There was no
      hair on the pubes,nor were there any indications of pu-
      berty in mind or  body.  She never menstruated.   At
      the age of twenty-nine she died of a complaint in the
      breast, attended with convulsions.—The uterus and os
      tincae were found not increased beyond their usual size
      during infancy.   The cavity of the uterus was of the
      common shape, but its coats were  membranous.  The
      Fallopian tubes were pervious.  " The Ovaria were so
      indistinct  that they rather showed the rudiments which
      ought to have formed them,  than any part of the natu-
      ral structure.'^
    Another case, which confirms  the aforesaid  sentiment, is
      related in  one of  the  French periodical publications.
        It has been long known that a race of savages  near
      the Cape of Good  Hope  were distinguished from the
      generality of their species  by a peculiarity about the
      pudendum.   An account of this structure  has been 
     Peculiarities in the Abdomen of the Fostus. 21?

       given with some precision by Messrs. Peron  and Le-
       9ueur,in a paper which was read to the National Institute
       of France. It is a flap or apron, four inches in length,
       which is united to the external labia near their  upper
       angle, and hangs down before the clitoris and the  exter-
       nal orifice of the parts of generation.  It is divided be-
       low into two lobes, which covers the orifice.  It is form-
       ed by a soft distensible skin, free from hair, which is oc-
       casionally eorrugated like  the scrotum, and  is rather
       more florid than the ordinary cutis.*
             The Abdomen of the Fcetus.
   The difference between the fcetus and the  adult, in
 the  cavity of the abdomen,  is very conspicuous at the
 first view.
   The Liver in the foetus is so large that it occupies a
 very-considerable part of the abdomen.   Its left  lobe,
 which is larger in proportion than the  right,  extends
 far into the left hypochondriac region.
   The Bladder of urine, when  filled, extends  from
 the  cavity of  the  pelvis a  considerable  distance to-
 wards the umbilicus : so that the greatest part of it is
 in the cavity of the abdomen.   A ligament of a coni-
 cal figure extends from the centre of the upper part of
 the bladder to the umbilicus ;  with an artery on  each
 side of it, which is soon to be  described.   This  liga-
 ment,  which is  in the situation of the urachus of the
 foetus  of  quadrupeds, is  hollow, and thus frequently
 forms  a canal, which has a  very small diameter, that
 communicates  with  the  bladder  by an aperture still
 smaller, and continues  a short distance from  the blad-
 der towards the umbilicus.   In a few rare instances,
 this  canal has extended to the umbilicus, so that urine
 has been discharged  through it, but the ligament is
 commonly solid there.

 * This paper has not yet been published by the Institute, but it is referred
toby M. Cuvier in his Legons d'Anatomie Comparee, vol. v. page  124.—
Messrs. Peron and Lesueur were naturalist? who accompanied captain Bau-
din in his voyage of discovery, the latter has been for some years resident in
 Philadelphia.
   VOL. II.                9.X 
218     Descent of the  Testicle in the Fcetus.

  The Stomach appears to be more curved in the fte-
tus than in the adult.
  The Great Intestine does not extend sufficiently far,
beyond the insertion of  the ileon, to form the caecum
completely.
  The Glandulm Renales are much larger in propor-
tion in the fcetus than in the adult.  The colour of the
fluid they contain is more florid.
  The Kidneys are lobulated.
  The Testicles in the fcetus are found above the pel-
vis, in the lumbar region, behind the peritoneum, until
two months before birth.  Thus situated, their  blood
vessels and nerves proceed from sources which are near
them ; but the  vas deferens, being connected to the ve-
siculae seminales by one extremity, is necessarily in a
very different situation  from what it is in the adult: it
proceeds from the  testicle downwards to  the  neck of
the bladder.—While each testicle is in  this situation,
it is connected with a substance or ligament, called Gu-
bernaculum, of a conical or pyramidical form, attached
to its lower end, and extends from it to the abdominal
ring.  This substance is vascular, and of a fibrous tex-
ture : its large  extremity adheres  to the testicle, its
lower and small extremity passes through the abdomi-
nal ring, and appears to terminate in the cellular sub-
stance exterior to that opening, like the round ligament
in females.   The  Gubernticulum, as well as the testi-
cle, is behind the peritoneum ; and the peritoneum ad-
heres to each of them more firmly  than it does to any
of the surrounding parts.   It seems that, by the con-
traction  of the Gubernaculum, the  testicle is  moved
down from its original situation to the abdominal ring,
and through the abdominal ring into the scrotum. The
peritoneum, which adheres  firmly to the  gubernacu-
lum and testicle, and is loosely connected to the other
parts, yields to this operation ; and when the testicle 
        Descent of the Testicle in the Foetus.     219

 has arrived near the abdominal ring,  a portion of the
 peritoneum is protruded a little way before it into the
 scrotum ; forming a cavity like the finger of a glove.
 The testicle passes  down behind  this process of the
 peritoneum, and is covered by it as it was in the abdo-
 men.   Although  it appears protruded into the cavity,
 it is exterior  to it, and behind  it: and the vessels, &c.
 which belong to the testicle are also exterior to it.
   The cavity formed in the  scrotum, by this process
 of the peritoneum, necessarily communicates with the
 cavity of  the  abdomen  at its formation ; but  very soon
 after the testicle has descended into  the  scrotum, the
 upper part of this cavity is closed up, while  the lower
 part of the  process continues  unchanged, and consti-
 tutes the  Tunica Vaginalis  Testis.   In some instan-
 ces the upper part of  this process does not  close  up,
 and the communication with the cavity of the abdomen
 continues.   The descent of the intestine into, the ca-
 vity  thus circumstanced,  constitutes  that species of
 hernia which  is denominated  Congenital.*
   The most important peculiarities in the abdomen of
 the fcetus  are  those connected with the circulation  of
 the blood.
   The internal iliac  or hypogastric arteries are larger
 than the external iliacs.   Their main trunks are conti-

  * These interesting circumstances respecting the original situation of the
 testicle, and its descent into the scrotum, were discovered and elucidated by
Haller, Hunter, Pott, Camper, and several other very respectable anatomists
 and surgeons.  There is, however, a diflference of opinion, between some of
 them, as to the time when the testicle leaves the abdomen.  Haller thought
 the testicles were seldom in the scrotum at birth.  Hunter and Camper found
 them so generally.
  It has been suggested that there are some national 'peculiarities in this re-
 spect ; that amongst the Hungarians, for example, the testicles often remain
 above the abdominal ring until near the age of puberty.
  The student will find an interesting description of the situation of the testis,
and its descent in the foetus, in the " Observations on certain  parts of the
 Anirml Economy," by John Hunter.                 •» 
■i:iO
Umbilical  Vessels.
nued on-each side of the bladder to its  fundus; and
proceed from it, with the ligament, to  the  umbilicus;
when they pass out of the  abdomen to go  along  the
umbilical  cord  to the placenta.   These arteries  are
now denominated the  Umbilical, and  are  very consi-
derable in size.  After birth, as there  is no circulation
in them,  they  soon begin  to change  : the cavity of
them is gradually obliterated, and they are converted
into ligaments.   They are exterior to the peritoneum.
and contained in a duplicative of it.
  A vein also  called the  Umbilical,  which is much
larger in diameter than  both of the arteries, returns
from the placenta along the cord, and  enters the cavi-
ty of the abdomen  at the  umbilicus.  It proceeds
thence, exterior to  the peritoneum, but in  a duplica-
tive of it called the Falciform Ligament, to  the  li-
ver, and enters that viscus  at the great fissure ; along
which  it passes to the left branch of the sinus of the
vena portarum, into which  it opens and discharges the
blood which flows through Jt from the placenta.   It
opens on the anterior side of the branch of the vena
portarum, and from the posterior side  of the  branch,
opposite to this opening, proceeds a  duct or canal,
which opens into the left hepatic vein  near its junc-
tion with the vena cava.  This communicating vessel
is called the Ductus, or Canalis  Venosus ; to distin-
guish it from the duct which passes from the pulmona-
ry artery to the aorta, and  is called Ductus, or Kam-
lis Arteriosus.   This venous duct carries some of the
blood of the umbilical vein directly to  the  vena cava;
but it is much smaller than the  umbilical  vein, and of
course a  considerable quantity of the  blood which
passes through the umbilical  vein must pass through
the liver, by the vena portarum, before  it  can enter
the cava.
  In some fetal subjects, if a probe of sufficient length 
     Object of the Circulation in the Placenta.  221

be introduced within the umbilical vein and  pushed
forwards, it will pass to the heart, without much diffi-
culty or opposition, as if it proceeded along one conti-
nued tube, although it really passes from the umbilical
vein across the  branch of the vena portarum, and  then
through the ductus venosus, and through a portion of
the left hepatic vein, into the inferior vena cava.
   If the umbilical vein be injected with a composition,
which will be firm  when cool, it appears to  terminate
in a rounded end, which is situated in  the' transverse
fissure of the liver : the sinus of the vena portarum,
into which this vein enters, appears like two branches
going off,  one from each side of it, and  the ductus ve-
nosus like a branch continuing in the direction of the
main trunk of the umbilical vein.
   The umbilical vein, in its progress through the fis-
sure of the liver, before it arrives at the sinus of the
vena portarum, sends  off a considerable number of
branches to each of the lobes of  that organ,  but  more
to the left than to the right lobe.
   After birth,  when blood ceases to flow through the
umbilical  vein, it  is gradually converted into a  liga-
ment ; and the venous duct is also converted into a liga-
ment in the same manner.  The vena portarum, which
before appeared very small, when compared  with the
umbilical  vein, now brings all the blood which fills its
great sinus, and increases considerably  in size.
   It has been ascertained by anatomical investigation,
that the umbilical arteries above mentioned, after rami-
 fying minutely in the placenta, communicate with the
 minute branches of the umbilical vein ; and it is pro-
 bable that the  whole  blood carried to the placenta by
 these  arteries, returns by the umbilical vein to the
 fcetus.
   It is clearly proved by the  effects  of pressure on 
 .J22  Object of  the Circulation in the  Placenta.


 the umbilical cord, in cases of delivery by the feet, as

 well as  by other similar circumstances,  that this  circu-

 lation cannot be suspended for any length of time with-

 out destroying the life of the foetus.   From these cir-

 cumstances, and from the florid colour which the blood

 acquires by circulating in the placenta, it  seems pro-

 bable  that the object of  the  circulation through that

 organ is somewhat analogous  to the object of the pul-

 monary circulation through the lungs of adults.*


  * During the  first four months of pregnancy a very  small vesicle, whicb
 does not exceed the size of a pea,  is found between the  chorion and the am-
 nios, near the insertion of the umbilical cord into the placenta. It is connect-
 ed to the foetus by an artery and a vein, which pass from the abdomen through
 the umbilicus, and proceeding along the cord to the placenta, continue from
 it to the vesicle.  The artery arises from  the mesenteric, and the vein is uni-
 ted to the mesenteric branch of the vena portarum.  It is probabl  that these
 vessels commonly exist no longer than the vesicle, viz.  about four mouths ;
 but they have been seen by Haller and Chaussier at the termination of preg-
 nancy.  They are called Omphalo Mesenteric vessels.   The vesicle is deno-
 minated the Umbilical Vesicle.
  This inexplicable structure is delineated in Hunter's Anatomy of the Gra-
 vid Uterus, plate xxxiii. figures v. and vi ; in the Academical Annotations of
Albinus, first book, plate i. figure xii.; and also in, the  Icones Embryonum
Humanorum of Soemmering, figure ii. 
SYSTEM  OF  ANATOMY.

                PART IX.
              OF THE BLOOD VESSELS.

  The blood vessels are flexible tubes, of a peculiar
texture, through which blood passes from the heart to
the different  parts  of  the  body, and returns  again
from these parts to the heart.   They are to be found,
in varying proportions, in  almost every part  of the
body, and seem  to enter into its texture.
  The tubes  which  carry blood from the heart, are
more substantial and more elastic than those through
which it  returns to  the heart.   They are generally
found empty after death; and,  therefore, were called
Arteries by the  ancient anatomists, who supposed that
they carried air, and not blood.
  The tubes which return the blood to the heart  are
denominated  Veins.   They are less substantial and
less elastic than arteries, and are generally full of blood
in the dead subject.
  There are two  great arteries, from which all  the
other arterial vessels of the body are derived.  They
are  very justly compared to the trunks of trees, and
the smaller vessels to their  branches.   One  of these
great arteries, called the Aorta, carries blood to every
part of the body.   The other great  vessel, called  the
Pulmonary Artery, carries blood exclusively to  the
lungs. 
224       The Blood  Vessels in general.

   The veins which correspond to the branches of the
Aorta, unite to each  other, so as to form  two great
trunks that proceed to the heart.   One of these trunks,
coming from  the superior parts of the body, is called
the Superior, or Descending Vena Cava.  The other,
which comes  from the lower parts of the body, is called
the Inferior, or Ascending Vena Cava.
   The veins which correspond with the branches of
the Pulmonary Artery, and  return  to  the  heart the
blood of  the  lungs, are four in number : two of them
proceeding from each lung.  They are called Pulmo-
nary  Veins.
   In  many of the veins there are valves which prevent
the blood they contain from moving towards the surface
and extremities of the body, but allow it to pass towards
the heart without impediment.
   From the construction of the cavities  of the heart,
and the position of  the valves which are in  them ; as
well as the situation of the valves at the commencement
of the great arteries, and the above  mentioned valves
of the veins, it is evident, that when the blood circu-
lates,  it must move  from the heart, through  the aorta
and its branchs, to the different parts of  the body, and
return from these parts through the vense cavse, to the
heart; that, when deposited in the heart by the vense
cav», it must proceed through the  pulmonary artery
to the lungs,  and return from  the  lungs through the
pulmonary veins to  the heart, in order  to pass  again
from that organ into the aorta.
   It is also certain, that the blood is forced  from the
heart  into the arteries, by the contraction of the mus-
cular  fibres of which the heart is composed ; and that
the blood vessels likewise perform a part in the circu-
lation, they propelling the blood  which is thus  thrown
into them : but their action appears  to  depend  upon
causes of a complex nature. 
CHAPTER  I.
OF THE GENERAL STRUCTURE AND  AKRANGEMEMT  OF
                THE BLOOD VESSELS.

                    SECTION I.

                  Of the Arteries.

  The arteries are so much concerned in the  import-
ant function of the circulation of the blood, that every
circumstance connected  with them is  very interesting
  They are  composed  of coats or tunics, which  are
very elastic and  strong,  and which are also very thick.
In consequence of the firmness of their coats, they con-
tinue open, after their  contents are  discharged, like
hard tubes.   They submit to great dilatation, and elon-
gation, when fluids are forced into them, and return to
their former dimensions when  the distending cause is
withdrawn.  This elasticity is particularly subservient
to the circulation of the  blood.  It admits the artery to
distend readily, and receive the blood which is thrown
into it by the contraction of the heart.   It also  pro-
duces the contraction of the artery ; which takes place
as soon as the action of the heart ceases; and this con-
traction of the heart necessarily forces the blood for-
ward, as the valves at its  orifice  prevent it from  re-
turning to the heart.
  The motion of the artery, which  is so easily per-
ceived by the touch, and in many instances also by the
eye, is completely explained by the discharge of blood
into the artery from the heart,  and by the elasticity of
  vol. n.             29 
226
Structure of the Arteries.
the vessel, by which it re-acts upon the blood.   In
some cases it is not simply the diameter of the artery
which is enlarged, but a portion of the vessel is elon-
gated ;  and  this elongation, by producing a curvature
of it, renders its motion more visible.
   In the aorta,and probably in its large branches, Elas-
ticity seems to be the principal cause of the  continu-
ance of  the  motion which  is originally given to  the
blood by the heart.  But there are many circumstances
connected with the smaller vessels, which  evince that
thev exert a power which is very different indeed from
elasticity.   Thus the application  of local stimulants or
rubefacients, and of heat, is followed by an increase of
motion in the arteries of the parts  to which they are
applied.  Neither of these causes could produce their
effect by the influence of elasticity: but the effect of
these and other similar causes is uniformly produced :
and a power of independent motion, or  Irritability, is
thus proved to exist in  these vessels, and seems essen-
tially necessary to the circulation  of the blood.

           The Structure of the Arteries

   Is, therefore, a subject of importance, and has  re-
ceived a considerable degree of attention from  anato-
mists.
   They are composed of a dense elastic substance, of a
whitish  colour.  Their external surface is rough, and
intimately connected with the cellular membrane, which
every where surrounds  it in varying quantities.    In-
ternally, they are  lined with a thin membrane, which
is very  smooth and flexible, and  is also  very elastic.
The substance which  composes the artery, and is situ-
ated between  the cellular investment and the internal
membrane, consists of fibres, which are nearly, though
not completely circular, but  so arranged as to consti- 
              Structure of the Arteries.         227

 tute a cylinder.  These fibres may be separated from
 each  other so as to form lamina, which have been con-
 sidered as different coats of the arteries ;  but there is
 no arrangement of them  which composes regular dis-
 tinct  strata.   The  coats of arteries may, therefore, be
 separated into a greater or smaller number of  lamina,
 according to the thickness of  these lamina.
   The fibres which compose these  lamina appear to be
 united to each other in a way which readily allows of
 their separation, at the  same  time that they form a
 firm texture.  Although arteries thus appear essential-
 ly different  from muscles in their hardness and  their
 elasticity, as well as in their general texture, they are
 considered,  by a great majority of anatomists,  as par-
 taking more or less of a muscular structure.
   In  the human subject  their  structure is very diffi-
 cult of demonstration, and great  differences exist in
 the accounts which are given of it, even by anatomists
 who agree in  the general sentiment that the arteries
 are muscular.
   Thus Haller believed that muscular fibres were most
 abundant in  the large arteries, while J. Hunter thought
 the reverse.
   Hunter appears  to have investigated this  subject
 with great attention, and  supposed the  muscular sub-
stance, in the composition of  arteries, to be interior,
 and the elastic matter exterior ; that in  large arteries
 this muscular substance is very small in  quantity, and
gradually increases  in proportion as the artery dimi-
nishes in size.  He however  observes,  that  he never
could discover the direction of the muscular fibres *
   When the great talents of Mr. Hunter as an anato-
' Treatise on the Blood, &c. vol. i. p. 113. Bradford's edition. 
228  Question respecting the muscularity of Arteries.

mist, are considered, this circumstance  cannot fail to
excite  a belief that the existence of these fibres is not
certain :  and if to this be  added the  fact, that  even
the red coloured substance  of the  arteries  is  elastic,
and  in that respect different from muscular substance,
the reasons for doubting must be increased.
   Bichat appears  to  have  entertained  very strong
doubts on the subject; but he stands almost alone; for
a large number both of  the preceding and cotempora-
ry anatomists, seem  to have adopted the  sentiment,
that the arteries have a muscular structure.
   The student of anatomy can very easily examine
this subject himself, by separating the coats of arteries
into different lamina ; and by viewing the edges of the
transverse and  longitudinal sections of those  vessels.
While thus engaged with this  question, he will read
with great advantage what has been  written upon  it
by Mr. Hunter, in  his treatise  on the Blood, &c. See
chapter second, section  3.   Bichat ought  also  to be
read upon this subject, which he has  discussed  in  his
Anatomic  Generate—Systeme  Vasculaire a  Sang
Rouge, article Troisieme &c. and also in his Traite
des  Membranes, article Sixicme.
   The belief of the irritability of arteries does not,
however, rest upon the appearance of their fibres.
   1.  It  is asserted by very respectable authors,* that
they have been made to contract by the application of
mechanical and of chemical irritation, and also of the
electric and galvanic  power.
   2.  A partial or local  action of  arteries is often pro-
 duced by the local application of heat  and rubefacients,
 as has been  already observed.
  * See Soemmering on the structure of the Human Body, vol. iv. German
edition.  Dr. Jones on the Process employed by nature for suppressing Hae-
morrhage, &c. 
      Proofs of the Irritability of the Arteries.  229

  3.  Arterial action is often suspended in a particular
part by the application of cold.   It has also been ob-
served that the arteries have for a short  time ceased
to pulsate in cases of extreme contusion and laceration
of the limbs.*
  4. When arteries are divided transversely in living
animals, they often contract so as  to close completely
the orifice made  by the division.
  5.  In a horse, bled to  death,  it was ascertained by
Mr. Hunter, that the  transverse diameter  of the ar-
teries was diminished  to  a degree that could not be
explained by their elasticity.  He also found that, af-
ter  death, the arteries, especially those of the smaller
size, are generally in  a state  of contraction, which is
greater than can be explained by their elasticity: for if
they are distended mechanically, they do not contract
again to their former size, but continue of a larger dia-
meter than  they  were before  the distention ; although
their elasticity may act so as to restore a very conside-
rable degree of  the contraction  observed at death.
  The contraction, which is  thus done away by dis-
tention, Mr. Hunter supposed to have been produced
by  Muscular fibres : for,  if it had been dependent on
elasticity, it must have re-appeared when the distend-
ing power was withdrawn.
  It therefore seems certain, that the  arteries have  a
power of contraction different from that which depends
upon elasticity;  but whether this depends upon mus-
cular fibres superadded to them, or upon an irritable
quality in the ordinary elastic fibres of blood  vessels,
is a question wThich is not perhaps completely decided.
  The motion of the blood in the arteries appears  to
depend,

  *  This local suspension of arterial motion by cold, &c. applied locally, is
very difficult to explain; as the action of the heart and the elasticity of the
arteries appear sufficient to account for the pulsation of <he large arteries. 
230    General Observations on the Arteries.

   1st, Upon the impulse given to it by the action of
the heart.
   2dly,  Upon the  elasticity of the  arteries, in conse-
quence of which they first give way to the blood  im-
pelled into them, and then re-act upon it; and
   3dly,  Upon the  power of contraction in  the arte-
ries, or their irritability.
   In the larger arteries the  blood seems to move as it
would through an  inanimate elastic tube, in conse-
quence of the impulse given by the  heart, and kept
up by the arteries  themselves.   In  the smaller vessels
it seems probable that the motion of the blood depend^
in a considerable degree  upon the  contraction which
arises from  their irritability.
   The obvious effect of the elasticity of  the  arteries
is to resist  distention and elongation, and  to  contract
the artery to its natural state, when the distending or
elongating cause ceases to act.  But it must also resist
the contraction induced by the muscular fibres, and re-
store the artery to  its natural size when the muscular
fibres cease to act after contracting  it, as has been ob-
served by Mr. Hunter.
   It seems  probable that all  the fibres of which the
artery consists are  nearly but not completely circular,
for it  is not certain  that there are any longitudinal
fibres in the structure of an artery.
   The internal coat of these vessels is very smooth,
but extremely dense and firm; and seems  to  be ren-
 dered moist and flexible by an  exudation on its  sur-
 face.  It adheres very closely to the contiguous fibres
 of the coat exterior to it,  but may be  very readily
 peeled  off  from  them.   It is of  a  whitish colour,
 and, like the fibrous structure of the artery, is very
 elastic.   Like that substance also it  is easily torn or
 broken,  and when  ligatures have been  applied to 
       General Observatidns on the Arteries.    231

arteries, it has often been  observed that the fibrous
structure, and  the internal  coat have been separated
while  this  external  cellular* coat has  remained en-
tire.
  The arteries are supplied with their  proper blood
vessels and lymphatics.  It  is to be observed,  that
the blood vessels are not derived from  the artery on
which they run, but from the contiguous vessels.
  These vessels have nerves also,  which are  rather
small in size, when compared with those which go to
other parts.
  Arteries appear to have  a cylindrical form, for no
diminution of diameter is observable in those  portions
of them which  send off no ramifications.
  When an artery ramifies  the  area  of the  differ-
ent branches exceeds  considerably that of the main
trunk.  Upon this principle the aorta and its  branches
have  been  compared to a  cone, the basis of which
is formed  by  the  branches, and  the  apex by the
trunk.*
  The transverse  section of an artery is circular.
  There are no valves in  the  arteries,  except those
of the orifices of the aorta and the pulmonary artery,
at the heart.  The valves  of the  pulmonary  artery
have  been described  in  the 51st page of this volume,
and those of the aorta have an  exact resemblance  to
them, but are rather larger.
  The course of the arteries throughout  the body is
obviously calculated  to prevent their  exposure  to
pressure, or to  great extension from the flexure of the
articulations by which  they pass.  With this view
they  sometimes proceed in  a winding direction ;  and
when they  pass over parts  which are subject to great
distension or enlargement,  as the  cheeks, they often

  * According to Brussiere the relation of the branches of the aorta to its
trunk is as 25 to 16; Helvetius reckons the orifice of the aorta in comparison
with its branchs as 64 to  71  Lasjsus—Ed. 
 232    General Observations on the Arteries.

 meander;  and,  therefore,  their  length  may be  in-
 creased by straightening,  without stretching them.
   Their course  appears sometimes  to  have been cal-
 culated to  lessen  the force  of the  blood, as  is  the
 case  with the Internal Carotid and the Vertebral  ar-
 teries.
   In the trunk of the  body the branches of arteries
 generally form obtuse  angles  with the trunks from
 which they proceed.   In  the limbs these angles are
 acute.
   The communication of arteries with  each  other is
 termed Anastomoses.  In some instances, two branches
 which proceed  in  a course  nearly  similar,  unite
 with  an acute angle, and form one  common trunk.—
 Sometimes a transverse  branch  runs from  one to  the
 other so  as  to  form  a right  angle with each.   In
 other cases,  the  two  anastomosing branches  form  an
 arch, or portion of a circle, from which  many branches
 go off.
   By successive  ramifications,  arteries gradually di-
 minish in size, until they are finally extremely small.
   The small  arteries do not carry red blood,  their
 diameters being smaller than those of the red particles
of that fluid,  the  serous or  aqueous part of the blood
 can, therefore, only pass through them.
   Many of the arteries which carry red blood, and of
 the last mentioned  serous arteries terminate in veins,
which are in  some respects, a continuation  of the tube
reflected backwards.*
  * Maipighi and Leeuwenboek declare, that by the aid of a microscope
they have seen arteries terminating in the veins. Haller advances formally
his own experience in support of his assertion.  Other anatomists have seen,
that in blowing into an artery, the  air passed into the corresponding veins.
Nevertheless, Duverney and some others say, that a particular substance is
interposed between the extremities  of these  vessels.   Ruysch in his The-
sauras Anatomicus, VI, No. 73, says, in repletione arteriarum, replentur et
plurimum quosque vena;, et vice versa, ita ut impossible videatur prsecisedi-
fere quomodo res se habeat,  Discours sur l'Anat__Ed. 
         General Observations on the Veins.     233

  They likewise terminate in exhalent vessels, which
open upon the external surface, and upon the various
internal surfaces of the body.  The secretory vessels
of glands  are likewise the termination of many arte-
ries.

                    section n.

                   Of the Veins

  These tubes, which return to the heart  the blood
carried from it by the arteries, are more numerous than
the arteries, and often are larger in diameter.
  They  generally accompany the arteries,  and very
often two veins are found with one artery.
  In addition to these last mentioned veins, which may
be  called deep-seated,  there are many subcutaneous
veins which appear on almost every part of the surface
of  the body.
  The capacity of all the  veins  is therefore much
greater than that of all the arteries.
  Those subcutaneous veins,  which are of considerable
size, communicate  very freely with each  other,  and
also with the deep-seated veins.
  The trunks of the veins, in those places  where  no
branches go off, are generally cylindrical.  There are,
however, some exceptions, in which these vessels are
irregularly dilated, as sometimes happens in the case
of the internal jugular  vein.   It is however, not easy
to determine from  the appearance of veins  injected
after death, respecting their situation during life, as
their coats arc  very yielding ;  and it is very probable
that they are, therefore, preternaturally dilated by the
injection.
   Veins, directly or indirectly, originate from the ter-
mination of arteries: but they do  not pulsate as the
arteries do,  because the impulse given to the blood by
  vol. n.               30 
234
Coats  of Veins.
 the heart is very much diminished  in  consequence of
 the great diminution of the size of the vessels through
 which the blood has passed.
   In some  cases, however,  when  blood flows from an
 opened vein ;  the extent of its projection is alternate-
 ly increased and diminished, in quick  succession, as if
 it were influenced by the pulsation of the heart.
   The Coats of  Veins differ  considerably from those
 of Arteries,—for they are  thinner, and so much  less
firm, that veins,  unlike  arteries, collapse  when  they
are empty.
   They consist of a dense  elastic substance, the fibres
 of which are much less distinct than those of arteries,
 but some of them are to be seen  in a  longitudinal  di-
 rection.   These fibres can  be made to contract by lo-
 cal irritation ; for if a vein be laid bare  in a living
 animal, and then  punctured, it will often contract so as
 to diminish its diameter very considerably, although
 no blood shall  have escaped from  the punctures.       ,
   Next  to  the elastic substance is  the internal coat,
 which is smooth and polished.  It  is  separated  from
 the substance exterior to it with difficulty, although j
 it may be taken from it very easily in the  vena cava.
   This internal coat is more ostensible than the inter-
 nal coat  of  arteries, and is not, like the latter, disposed
 to ossification.   It is frequently so arranged as to form M
 valves, which  are plaits or  folds,  of a  semilunar form,
 that project from the surfaces  into the cavities of these
vessels.*
   Two of these valves  are generally  placed opposite

  * The valves  of the veins were first described by Charles  Etienne of Pa-
 ris, in 1546.  In 1547, Amatus, a  Portuguese, saw at Ferrara, those at the
 mouth of the vena azygos. Sylvius, of Paris, announced them  about the
 same time in the jugular, brachial and crural veins.  Fabricus ab  Aquapen-
 dente claims the discovery for himself  in 1574.  Lassus—Ed. 
         Colour of the Blood in the Veins.      :l&>

to each other; and, when raised up, they form a sep-
tum in the cylindrical cavity of the vessel.   The sep-
tum, thus composed, is concave towards the heart.
   The valves have  a great effect in preventing the
contents  of the  veins  from moving in a  retrograde
course: they therefore necessarily modify the  effects
of lateral pressure,  in such a manner, that it propels
the blood forward, or to the heart.
   These valves are  generally found in the veins of the
muscular parts of the body, especially in those  of the
extremities.   They are not found in those veins which
are in the cavities of the body, nor in the internal ju-
gulars.   They are placed  at unequal  distances from
each other.
   The coats of the  veins are  somewhat transparent;
and therefore those  veins which are subcutaneous have
a bluish aspect, which  is derived from  the colour  of
the blood they contain.
   The colour of the blood in  the veins is  different
from that in the arteries, being of a darker red.
   The situation  and arrangement of the large  trunks
of veins is much alike  in different  subjects; but the
branches, especially those which are subcutaneous, are
very variable in their situations. 
CHAPTER  II.
 A PARTICULAR ACCOUNT OF THE DISTRIBUTION OF
                   THE ARTERIES.

                      SECTION I.

                 Of the AORTA,*

     Or the Great  Trunk of the Arterial System.

   When the heart is in its natural position j the right
 ventricle is nearly anterior to the left, and, therefore,
 the aouta, where it originates from the left ventricle,
 is behind the pulmonary artery, and covered by it.  Its
 first direction is so oblique towards the right side of
 the body, that it crosses the pulmonary artery behind,
 and appears on the right side of it.   It  has scarcely
 assumed this position before its course  alters, for it then
 proceeds obliquely backwards, and to the left;  so as
 to form a large curve or  arch, which extends to the
 left of the spine.
   The position of this  curve or  arch  is so oblique,
 with respect to the body, that the cord or diameter of
 it,  if  it were  extended anteriorly  and  posteriorly,
 would strike  the cartilage of the second or third right
 rib about the middle of  its length, and the left rib near
*the  head.   In  consequence  of  this position of the
 curve, the aorta  crosses over the right branch of the
^pulmonary artery, and the left branch of the windpipe:
 and  jssumes a situation, in front, and  to the left of the
 third dorsal vertebra:  from this situation  it  proceeds
• This name was given by Aristotle.—Ep. 
A     TABLE
f To free page 297.]
EXHIBITING TBE  DISTRIBUTION OF  THE  BRANCHES OF  THE AORTA.
At the Curvature,
  The COMMON  TRUNK
Of the Right Subclavian am
   Right Common Carotid.
the side of the trachea, and <
divide at  the  upper edge of
the thyroid cartilage, into
■ted to  the exterior  of  the
head, and  the upper parts of
the neck.  It gives off
which are spent upon the substance of the Heart.
[The Tongue.  Sublingual Gland.  The Pirn
The inferior PhW, $£ SSPtf SSST ""^

The Occipital      -      The posterior part of the Cranium externally.
_.  _  .  .   ,  •  ,   K The cavity of the Tvmpanum.
The Posterior Auricular J part8 c0nfol0W to \Ul! externaI ^

                      ("The Superior and Inferior Maxillary bones.
„  ,      ...  -ii      ]  The Fauces.  The  Pterygoid muscles.  The
The Internal Maxillary   <  PliIale.   The Dura Malcr.  The Interior of the


                      c The anterior and lateral parts of the Cranium,
                      £  externally.
The Temporal
                            r  The Ophthalmic Arterj-, to the Eye and its appendages
The ISTERXII. CAROTID, \  The Anterior Artery ofCT,w
which is appropriated to the  ,
interior of t"
sends off
                             ..w..-r portion of the Cerebrum.
      the Brain        I            l
The  Middle  Artery  of I The middle, and part of the posterior portion
      the Brain        c   of the Cerebrum.
           f,  ..   f" Anterior portion of the
The  Internal  Mam-)  pwietca of the Tho-
aS   =
Between the  cui
  ture and the great <
  Bifurcation,
The LEFT SCJBCL.iiy.LX.
The I5FKH10
The Phrenic Jirterit*  •
C(ELlJiC ARTERY
SUPERIOR MESESTER1C
Capsular Arteries  -
EMULGENTS
Each of the Subchmans i
  Upper Extremity of its
It gives or!"
i the first portion of the great o
respective tide.
Spermaties
     rcerel
to the <  ter
;bellum.  The pos-
    portion of the
The Vertebral

The Inferior Thyroid $ Thvroid Gland.  Tra-
      to the         I   chea.   Oesophagus.
The  Superior Inter-5 Some of the Intercostal
      costal, to      ?       Spaces.
                   (Muscles, Glands, and
The Cervical,  to thc<   Nerves, &c.  on the
                   C   Neck.
The Scapular)', to the
    .  „.. the dorsum of
(_  the Scapula
 The AXILLARY
s the next portion of
 the artery  of  the
 upper extremity. It
 gives oft"
The Thoracic  and the External
  Mammary arteries,
To the Pectoral and other mus-
  cles on the anterior part of the
  thorax and shoulders.

    The Scapulary Arter>'i
To the muscles about the sca-
  pula and the posterior part of
of the Os Humeri.
The Profunda Humeri
At the Elbow it gives off
Branches to the muscles i
          t branch.
A branch to the thumb.
To the rulial side of the index.
To the arcus profundus.
 The cLiraa


which send off
To the Trachea and substance of the Lungs.
To the Oesophagus.
To nine or ten of the lower intercostal spaces.
To the diaphragm.
To the stomach, liver, and spleen.
Almost all the small intestines, and part of the great.
Glandule Renales.
The Kidneys.
The Testicles.  The Ovaries.
The left portion of the Colon, and the Rectum.            ,
Muscles on the loins and the abdomen.  The spine and the spinal canty.
Which is spent upon the Sacrum, Coccyx, and Rectum.
The arcus sublimit in the palm of
  the hand, which sends tyF the
  digital arteries to the aide* of
  the fingers,
H. B.  The Interoweftl mnd tbe Ulnar
  come off from the Humeral, by a com-
  mon trunk.
At the great Bifurca* «
  The PRIMITIVE  ILIACS.
One of which is divided on each
  side of the Pelvis into
The R*e Lumbar artery t
  The  EXTERNAL ILIAC,
The first portion of the great
  artery of the lower extremity,  j
  which passes under Poupart's
  ligameat to the thigh, but pre-
  viously sends off
("The Sacrum, internally  and ex
c  ternally.
(The Cauda Equina.

r The Bladder.
I The Uterus.
(.The Rectum.

fTlif Muscles on the upper and
<  interior part of the thigh.
(The Hip joint, &c.

f The Muscles on the lateral and
<  posterior parts of the Ossa In-
'  nominata.

rThe Muscles, be. on the upper
<  and the posterior part of the
L  thigh.
(Which is often given offCThc Organs of Generation.
    by thclschiatic.)    j
  The CireumJUxa Ilii,
A small artery,  which  is
  spent upon the iliacus
  interims,  and the con-
  tiguous portions of the
  abdominal muscles and
  the psoas.

     The Epigastric,
Which is spent upon the
  muscles,  and  integu-
  ments of tbe anterior
  part of the abdomen.
  The FEMORAL
      Artery.
The  second portio..
  of the great artery y
 The External Pudic
To the exterior parts of
  the Organs of Gene-
of the lower extre-
mity begins at Pou-
part's ligament. It
sends off
   The Profunda,
And  its branches, the
  two circumflex*, to
  the muscles on the
  thigh.
  Tlit POPLITEAL,
The  third portion of the
  great artery, lies on the
  back of the thigh.
It sends off the  articular

  mose  with each other,
  and supply the contigu-

It divides into
   The
Which proceeds down the an-
  terior part of the leg to the '
  top of the foot, from which
  it descends to the sole.  It
  lends off
      Thei
Which is near the fibula on the
  posterior side of the intcros-
  sca) ligament.  It  is spent
tibia and the internal ankle
U/the sole of the foot, where
it divides.  It sends off
A  recurrent branch to anasto-
  mose  with  branches  from
  above.
Branches to the anterior muscles
  of the leg.
Tarsal and  metatarsal branches
  to the upper part of the foot.
The  muscles on the outside of
  the leg.
The ankle and the outside of the
Branches to the muscles.
The  medullary  artery  of the
  tibia.
The internal and the  external
  plantar arteries, to the parts
c off frwn the PapUual by 

ff
Forms a curve immediately after leaving the Heart«
o" to


    H
is a «


o 219
^r
Sii"
p*
'4
H 
Sitmtion of the Aorta in the Thorax $• Abdomen. 237

downwards: in front, but rather on the left side of th**
spine, and in contact with that column.
  Ilie aorta, as well as the  Pulmonary Artery, for
a'small distance from the heart, is invested by the pe-
ricardium ;  and, when that sac is opened, appears  to
be contained in it.
  After crossing the right branch of the Pulmonary
Artery, a ligament  is inserted into it, which  proceeds
from the main trunk of the pulmonary artery at its di-
vision :  this ligament was the  Canalis Arteriosus  in
the fcetus.
  As the aorta proceeds down the spine, it is  situa-
ted between the two lamina of the  mediastinum, and
in contact with the left lamen, through which it may
be seen.  It descends between the  crura of the dia-
phragm, in  a vacuity which is sufficiently large  to ad-
mit of its passage without pressure from the surround-
ing parts, and is still in contact with the anterior sur-
face of  the  spine, but rather to the left of the middle
of it.   It continues this  course along the spine until it
arrives at the cartilaginous substance between the fourth
and f ffh lumbar vertebrae, when it divides  into two
great branches of equal size, which form an  acute an-
gle  with each other.   These are denominated the
comk xn, or primitive iliac Arteries.
   From the aorta in this  course are sent off the  ar-
teries which are  distributed  to  all the  parts  of the  /
body for their nourishment and animation.
   From the curve proceed  the great  branches  which
 supply the  heart, the head, the upper  extremities,
and part of the thorax.   Between the curve and the
 great primitive iliac  arteries,  the  Aorta  sends  off
 those branches which  supply the  viscera  contained
 in the cavities of  the thorax and abdomen,* and part


   * It ought to be observed here, that the viscera, in the lower part of tbe
 pelvis, receive  some branches from the internal iliac arteries. 
 238 Origin of the Subclavian and Carotid Arteries.

 of the trunk of the body.   The great ILIAC branches
 of  the AORTA are divided into smaller arteries,
 which supply the whole of the lower extremities and *
 some of the viscera of  the pelvis.

                    SECTION II.

 Of the Branches which go off from the arch  of the
                    AORTA.

  The proper arteries of the heart, denominated Co-
 ronary Arteries, proceed from  the  Aorta so  near
 to the heart that their orifices are  covered  by the
 semilunar  valves, when  those  valves  are  pressed
 against the sides of the artery.   These arteries  have
 been  described  in the account  of the  heart.—See
p. 50.
  The arteries of the head and of the upper extremi-
ties proceed from the upper part of the curve  in the  ^
following  manner.
  A  large trunk, called Arteria  Innominata,  goes
off first.   This is more than sixteen  lines in length,
when it divides into two branches: one of which sup-
plies the right side of the  head, and  is denominated
the Right Carotid:  the other proceeds to  the right
arm, and from its course under the clavicle, is called,
at first, the Right  Subclavian.    Almost in contact
with  the  first trunk, another artery goes  off, which
proceeds to the left side of the head, and  is called the
Left Carotid.  Very near to  this, arises the third ar-
tery,  which proceeds to the left arm, and is denomi-
nated the Left Subclavian. From these great branches
originate the  blood vessels, which are spent upon the
Head and neck and the  upper extremities.
  As these  arteries  arise from the  curve  of the
Aorta, they  are  situated obliquely with  respect  to
each other.   The Arteria Innominata is not only 
    Situation of the Common  Carotid  Arteries. 239

 to the right, but it is also anterior to the two others:
 and the left subclavian is posterior, as well as to
" the left of the left carotid  and the arteria rn-
 NOMINATA.

           THE CAROTID ARTERIES.

    The two carotid arteries above mentioned have
 been denominated commor carotids, to distinguish
 them from their first ramifications which are called
 internal and external carotids.

           THE COMMON CAROTIDS

    Proceed towards the head on each side of the tra-
 chea at first they diverge, but they soon become near-
 ly parallel to each other, and continue  so until they
 have ascended as high as the upper edge of the thyroid
 cartilage, when they  divide  into the  Internal and
 External Carotids.
    These  arteries are at first very  near each  other,
  and rather in front of  the trachea; they gradually di-
  verge and pass backwards and  outwards on the sides
  of it, and of the oesophagus, until they have arrived at
  the larynx.  In the lower part of the neck they, are co-
  vered by the sterno mastoidei, the sterno hyoidei, and
  thyroidei, as well as by the platysma myoidei muscles.
  Above, their situation is more superficial; and they are
  immediately under the platysma myoides.
    On the inside, they are very near the trachea and la-
  rynx, and the oesophagus ; on the outside, and ratheran-
  teriortothem, are the internal  jugular veins;  and be-
  hind, on each side, are two important nerves called the
  intercostal and the par vagum. These blood  vessels
  and nerves are surrounded by absorbent vessels. 
240
External Carotid Artery.
    The Common Carotid Arteries send off no branches
 from their  origin to their  bifurcation;  and they ap-
 pear to preserve the same diameter throughout their
 whole extent.   In some few instances the right carotid
 has been found larger  than the  left.    The  external
 and  internal  branches into which  they divide,  are
 nearly equal in the adult; but it is supposed that the in-
 ternal is the largest during infancy.   The relative posi-
 tion of these branches is also different at the commence-
 ment from what it is afterwards.  The  Internal  Ca-
 rotid forms a curve  which projects outwardly, so as to
 be exterior to the External Carotid, while  this  last
 proceeds upwards, and rather backwards.

    THE  EXTERNAL  CAROTID  ARTERY

   May be considered as extending from its commence-
 ment, which is on a  line with the superior margin of
 the thyroid cartilage, to the neck of the  condyle of
 the lower jaw, or near it.
   At first it is superficial; but as it proceeds upwards
 it becomes deep-seated ; and passing under the digas-
 tric and stylo-hyoidei muscles, and the  ninth  pair of
 nerves, is covered by the Parotid Gland.  After this,
 it again becomes superficial; for the temporal artery,
 which may be regarded as the continuation of the  ex-
 ternal  carotid, passes over  the zygomatic process of
 the temporal bone.
   As the external carotid  supplies with blood  the
 upper part of the neck  and  throat, the exterior of  the
 head and face, and the inside of the mouth and nose;
 its branches must  necessarily be  numerous,  and must
 pass in very various  directions.
   Thus, soon after its commencement, it  sends off, in
 an anterior direction, three large branches; viz. to  the
 upper part of the neck, to the parts  within the lower
jaw, and to the cheeks and  lips.   These are deno- 
        External Carotid and its Branches.     241

minated, the Superior Thyroid, the  Sublingual, and
the Facial.  It then sends off to the back of the head
one which is called the Occipital; and, as it proceeds
upwards near the condyle of the lower jaw, another
which passes internally, behind the jaw, to the  deep-
seated parts in that direction.  After this,  it forms the
temporal artery,  which  supplies  the forehead  and
central  parts of the cranium.   Besides  these  larger
branches, the external carotid sends off two which are
smaller; one from near the origin of the sublingual
artery, which is spent principally upon the pharynx
and fauces, and  is called  the Inferior Pharyngeal :
and another, while  it is  involved  with  the parotid
gland, which goes to the ear; and is therefore  called
Posterior Auris.
  These arteries are distributed in the following man-
ner:

         1 The superior thyroid branch

  Comes off very near the root of the external carotid,
and sometimes from the common trunk;  it runs ob-
liquely  downwards and  forwards,  in  a  meandering
course, to the thyroid gland, where it is spent.   Du-
ring this course it sends off one branch to the  parts
contiguous to the os hyoides; another to the neighbour-
hood of the larynx:  and a third branch,  which may
be termed laryngeal, that passes with a small  nerve
derived from the laryngeal branch of the par vagum,
either between the os hyoides and thyroid cartilage?
or the thyroid and cricoid cartilages, to the interior
muscles of the larynx; and finally returns again to
terminate externally.
  While in the thyroid gland this artery  anastomoses
with the inferior thyroid, and also with its fellow on
the opposite side.
  vol.  ii.             31 
242      Branches of the External Carotid.

     2. The lingual, or sublingual branch,
  Goes off above the last mentioned artery, and  very
near it;  but in a very different direction, for it runs
upwards and forwards, to the tongue.  In this course
it crosses obliquely the  6s hyoides, and is commonly
within the hyoglossus muscle.   It gives  off branches
to the middle constrictors of the pharynx, and to the
muscles contiguous to the tongue.  It also sends off a
branch which penetrates to  the  back  of the tongue,
which is called, from its situation, Dorsalis Linguae.
At tbe anterior margin  of the hyoglossus muscle it di-
vides into two branches, one of which passes to  the
sublingual gland and the adjacent parts, and is thence
called  Sublingual; while the other  branch, the  Ra-
nina, passes by the side of the genio glossos muscle to
the apex of the tongue.

     3. The facial or external maxillary?

  Runs obliquely upwards  and  forwards  under  the
ninth pair of nerves,  the stylo hyoideus  muscle and
the tendon of the digastric, across the lower jaw and
cheek, towards the inner corner of the eye, in  a ser-
pentine course.   Before it crosses the jaw it sends off   <
several branches-, viz.  to the pharynx,  the tonsils,  the
inferior maxillary gland and  the parts contiguous to it.   t
It also sends a branch towards the  chin, which  passes
between the mylo-hyoideus, the anterior  belly of the $4
digastric,  and the margin of the lower jaw :  and some
of its branches  continue to the  muscles of the  under
lip.  This branch is called the Submental.
  This artery then passes round the basis or inferior
edge of the lower jaw,  very near the anterior margin   \
of the masseter muscle, and  is so superficial that its   j
pulsations can be readily perceived.   After this turn,
its course is obliquely upwards and forwards.    Near
the basis of the jaw it sends off a branch to the mas-   i 
         Branches of the External Carotid.     243

seter, which anastamoses with small branches from the
temporal ;  and another which passes superficially  to
the under lip and contiguous parts of the cheeks.  This
last is called the Inferior Labial.
  After the artery has passed as high as  the teeth  in
the lower jaw, it divides into two branches;  which
go, one to the under, and the other to the upper lip;
that to the upper lip is largest.  These branches are
called  Coronary.
  The Coronary Artery of the lower lip passes under
the muscles called Depressor  Anguli Oris, and Orbi-
cularis Oris, into the substance of the lip, and  anas-
tomoses with its fellow of  the opposite side.
  The Coronary Artery of the upper lip passes under
the zygomaticus major and the orbicularis, and  very
near the margin of the upper lip  internally.   It also
anastomoses freely with its fellow on the opposite side.
These anastomoses are frequently so considerable that
the arteries on one side  can be well filled by injecting
those of the other.  The coronary branches, as well  as
the main trunk of the facial artery* observe a serpen-
tine or tortuous course; in consequence of which they
admit of the motions  of the  cheeks and  lips,  which
they would greatly impede if they were straight.
  From the upper coronary artery a branch continues
in the direction of the m-iin trunk of the facial artery,
by the side of the nose, which extends  upwards, send-
ing off small branches in its course, and finally termi-
nates about the internal angle of the eye and the fore-
head.

           4. The inferior pharyngeal

  Is a very small artery;  it rises  posteriorly from the
external carotid,  opposite to the origin of the sublin-
gual, and passes upwards to the basis of the cranium. 
244      Branches of the External Carotid.

In this course it sends several branches to the pharynx,
and to the deep-seated parts immediately contiguous.
   It also sends branches  to  the  first  ganglion of the
intercostal nerve, to the  par vagum, and  to the  lym-
phatic glands of the neck ;  and finally it  enters the
cavity of the  cranium by the  posterior foramen  lace-
rum.
   In some cases it also sends a small  branch through   I
the anterior foramen lacerum.

            5. The occipital artery

   Arises from  the posterior side of the  external ca-
rotid, nearly opposite to the facial, but sometimes high-
er up ; it ascends obliquely, and passes  to the  back
part of the cranium, between the transverse  process
of the  atlas and the mastoid  process of the temporal
bone.
   In  this course it passes over the internal  jugular
vein and the eighth pair of nerves, and under the pos-   !
terior part of the digastric muscle; it lies very near
to the  base of the  mastoid process, and under the   J
muscles which are inserted into it.  After emerging   1
from these muscles, it runs superficially upon  the oc-   1
ciput, dividing into branches which extend to those of  jfl
the temporal artery.                                 m
  The occipital artery sends off branches to the  1
muscles which are contiguous to it, and to  the glands    .
of the neck.
  It also gives off  the following branches : one called
the Meningeal, which  passes through  the posterior  -  j
foramen lacerum to the  under and back part of the   ><
dura mater : one to the  exterior  parts  of the  ear:    1
another which passes downwards,  and is spent  upon
the complexus, trachelo mastoideus, and other muscles
of the neck : and several smaller arteries. 
Branches of the External Carotid.     245
  The artery next to be described, is sometimes sent
off by the occipital artery.

0. The posterior auricular, or stylo mastoid
                      artery.

   When it arises from  the external carotid, comes off
posteriorly from the artery, where it is involved with
the parotid gland, and  passes backwards between the
meatus auditorious externus and the mastoid  process.
It then ascends, in a curved direction, and  terminates
behind the ear.
   In this course it sends off small branches to the parotid
gland, and to the digastric and sterno mastoid  muscles.
Sometimes a distinct  branch,  which is particularly
visible in children,  passes through an aperture in the
meatus auditorius externus, and is spent on its internal
surface.
   It also sends  off  a  branch  which  enters  into the
Stylo  Mastoid Foramen, and supplies small vessels to
the membrana tympani and  the  lining  membrane  of
the cavity of the  tympanum ;  to the mastoid cells;  to
the muscle of the stapes, and to the external  semicir-
cular canal.  One of these vessels anastomoses, in the
upper and posterior part of  the cavity of the tympa*
num, with a small twig derived from the artery of the
dura mater.   When it  has arrived behind the ear, the
Posterior Auricular Artery terminates  upon the ex-
ternal ear and the parts contiguous to it.

      7. The INTERNAL MAXILLARY ARTERY.*

   Arises from the external carotid under the parotid
gland, at a little distance below the neck of  the  con-

  * The general situation of this artery, and the distribution of several of its
most important branches, cannot be understood without a knowledge ot the
bones through which they pass.  The student of surgery will therefore derive
benefit from a reexamination of these bones, and of the zygomatic lossa, &c. 
246       The Internal Maxillary Artery,
 dyloid process of the lower jaw,  and  extends to  the
 bottom of the zygomatic fossa ;  varying its direction
 in its course.  It is  rather larger than the temporal.
   a.  It first sends  off one or two  small  branches to
 the ear, and a twig  which penetrates into the cavity
 of the tympanum by the glenoid fissure.
   b. It also sends off a small artery called the Lesser
 Meningeal, which passes upwards,  and  after giving
 branches to the external pterygoid and the muscles of
 the palate, passes through  the foramen  ovale and is
 spent upon the dura mater about the sella turcica.
   c. It then sends off one of its largest branches, the
 Great  or middle  Artery of the Dura Mater, which
 passes in a straight direction  to  the foramen  spinale,
 by which  it enters into the cavity of the cranium.
   This  artery  ramifies largely on  the dura  mater,
 and makes those aborescent impressions which are so
 visible in the parietal bone.   It generally divides into
 two great  branches:  the anterior  of 'which  is  the
 largest, passes over the  anterior and inferior  angle of
 the parietal bone :  the  posterior branch soon  divides
 into many ramifications, which are extended laterally
 and posteriorly..
   It  furnishes the twig which  passes  to  the ear by
 the hyatus of Fallopius, and  anastomoses with  the
 small branches of the stylo mastoid artery.
   It also supplies some  other small vessels which pass
 to the cavity of the tympanum by small foramina near
 the junction of the squamous and petrous portions of
the temporal bone.
   d. The next branch  sent  off by the  internal  max-
illary leaves it about an  inch  from its origin, and is
when he studies this artery  (See Vol. I. page 73.)—He ought to be well ac-
quainted with this subject, if he should undertake the management of necro-
sis of the jaw bones; or of those fungous tumours, which sometimes originate
m the antrum maxillare; as well as of several other complaints. 
          The Internal Maxillary Artery.       247

called the Inferior Maxillary.   It passes between the
internal  pterygoid  muscle and the bone, and after
giving small branches to the contiguous muscles, en-
ters the canal in the lower jaw, in company  with the
nerve.  This canal  has  a very free  communication
with the cellular structure of the  jaw  and  the artery
in its progress along it sends branches to the respective
teeth and the bone.   At  the anterior  maxillary fora-
men this artery sends off a considerable branch which
passes out and anastomoses with the  vessels on the
chin, while another branch passes forward and  sup-
plies the canine and incisor teeth and the bone  con-
tiguous to them.
   Sometimes  the  inferior maxillary  artery divides
into two branches before  it has arrived at this fora-
men.   In this case, one  of the arteries passes out  of
the foramen,  while  the  other continues to the sym-
phisis.
   e.   Two branches pass off to the temporal muscle,
which originate at a small distance from each other;
one of them  passes  upwards  on the  tendon  of the
temporal muscle;  the other arises near the tuberosity
of the upper maxillary bone :  they are called the ex*
terior deep, and the interior  deep temporal artery*
They are both spent upon the temporal muscle ; but
the interior branch sends  a small twig into  the orbit
of the eye.
   f.  There are some small  branches which pass  to
the Pterygoid Muscles and to the Masseter, which
arise either from the internal maxillary artery, or from
the interior deep temporal. They are  generally small,
and often irregular.
   g.  An  artery,  particularly appropriated  to the
cheek, perforates the buccinator  muscle from within
outwards, and generally terminates on the buccinator,
the zygomaticus major and the muscles of  the  lips.
This Artery of the Cheeh  is very irregular in  its 
 248        The Internal Maxillary Artery.

 origin, sometimes arising from the internal  maxillary,
 sometimes  from the deep temporal, and  sometimes
 from the suborbitary, or from the alveolar artery, to
 be immediately described.
   h. The Alveolar Artery, or the Artery of the Up-
 per Jaw, arises generally from the internal  maxillary,
 but sometimes  from one of its branches.   It  winds
 round  the  tuberosity of  the upper jaw, and  sends
 branches to the buccinator muscle, to the bone and the
 gums, to the antrum highmorianum, and some  of the
 molar teeth :  and also to the teeth generally, by means
 of a canal which is analogous  to that of the lower jaw.
   i.  The Infra orbitar Artery, arises from the inter-
 nal maxillary in the zygomatic fossa, and soon enters
 the infra orbitary canal, through which it  passes to
 the face, and emerges  below the  orbit of the eye,
 supplying the muscles  in  the vincinity, and anasto-
 mosing  with  the  small  ramifications of the  two last
 described arteries, and  also of the  facial  artery and
 the ophthalmic.
   This artery in its course sends off small twigs to the
 periosteum,  the adipose membrane, and the muscles
 in the inferior part of the orbit, and also to the great
 maxillary sinus  or antrum highmorianum, and to the
 canine and incisor teeth.
   j.  The Palato  Maxillary or  Superior Palatine
 Artery, arises also  in the  zygomatic fossa,  and, de-
 scending behind the upper maxillary bone, enters the
 posterior palatine  canal.   It generally forms  two
 branches, the largest of which advances forward, sup-
 plying the palate and gums, and finally sends  a  twig
 through the foramen incisivum to the  nose, while the
 posterior branch, which is much smaller, supplies the
 velum pendulum palati.
  k. The Peterygo Palatine, or Superior Pharyngeal,....
is  a small vessel;  which sometimes arises  from the 
Temporal Artery.              24 U
artery next to be mentioned.   It is spent upon the up-
per part of the pharynx, and a branch passes through
the pterygo  palatine foramen, which is spent upon
the arch of the palate and the contiguous parts.
  L.  The internal maxillary at length terminates
in the  Spheno-Palatine,  or Large  Nasal Artery,
which passes through the spheno-palatine  foramen to
the back part of the nose.  This artery sometimes se-
parates  into two branches before it enters the foramen ;
sometimes it enters singly, and divides into two branch-
es soon after; one  of them is spread upon the septum,
and the other upon the external side of the nose; each
of these branches ramifies very minutely  upon  the
Schneiderian membrane and its processes in  the diffe-
rent sinuses,  and also in the ethmoidal cells.

            8. The temporal artery

  Is considered as  the continuation of the external ca-
rotid, because it preserves the direction of  the main
trunk, although the internal maxillary is larger.
  After parting with  the internal maxillary it  pro-
jects outwards ; and  passing between the Meatus Au-
ditorius Externus and the condyle  of the lower jaw,
continues upwards, behind the root of the  zygomatic
process  of the  temporal  bone, to  the aponeurosis of
the temporal muscle  : on the outside of which, imme-
diately under the integuments, it divides into two large
branches denominated anterior and posterior.
  Before this division  the temporal artery  sends off
several  branches of very different sizes.
  One,  which is considerable  in size, and called  the
Transverse Facial Branch, advances  forwards across
the neck of the condyle of the lower jaw, and giving
small  branches to the masseter, runs parallel to the pa-
rotid duct, and below it.  This branch is spent upon
  vol.  ii.               32 
250     Temporal Artery.—Internal Carotid.

the muscles of the face, and anastomoses with the other
vessels of that part.
  The temporal gives off small branches to the parotid
gland and to the articulation of the jaw.  From  the
last mentioned branch small twigs pass to the ear,  one
of which enters the cavity of the tympanum  by the
glenoid fissure.
  While this artery is on a line with the zygoma, it
sends off a  branch called the middle temporal  artery,
which penetrates the aponeurosis of the temporal mus-
cle, and ramifies under it upon the muscle in an ante-
rior  direction.
  The two great branches of the temporal artery are
distributed in  the following manner.   The  Anterior
passes up in a serpentine direction on the anterior part
of the temple, and supplies the front side of the head,
and  the upper part of the forehead.
   The Posterior  extends  upwards  and  backwards,
and  supplies the scalp on the lateral  and middle part
of the cranium, and also the bone.
   Ramifications from  each  of these  branches  anasto-
mose on the upper part of the cranium with those of
its fellow of the opposite side.  The  anterior  branch
also  anastomoses on the forehead with  the  facial  and
ophthalmic artery; and the posterior branch with the
occipital artery on the back part of the head.

     THE  INTERNAL CAROTID ARTERY

   Is sometimes called the Artery of the Brain, as it is
almost entirely appropriated to that viscus.
   From its origin to the commencement of its  ramifi-
cations, the course of this  blood  vessel is peculiarly
tortuous.   In consequence of  which  the force of the
blood in it is greatly diminished before it arrives at the
brain.
   An instance of  this curvature  occurs immediately 
         Curvatures of the Internal Carotid.     251

after its separation from the external carotid, when it
protrudes outwards so much as to be exterior to that
vessel; after this it ascends to the  carotid  canal, and
in its course is in contact, or very near the par vagum
and intercostal nerves.
   The carotid canal in the os  petrosum is by no means
straight;  it form a semicircular curve, forwards  and
inwards; and its upper portion, which  is nearly hori-
zontal, opens obliquely against the  body of  the  sphe-
noidal bone, at a small distance  from  it.   Therefore,
after the artery  has passed through the canal, it must
turn upwards to get fairly into the cavity of the cra-
nium ; and of course, its direction while  in the canal,
forms almost a right angle with its  direction before it
enters, and after it emerges from it.
   In consequence of  this curvature, much of the mo-
mentum of the blood must be  impressed upon the cra-
nium.
   After the artery has arrived at the end of the caro-
tid canal, and has turned  upwards to get within the
cavity of the cranium, it  bends forwards, and  passes
nearly in a horizontal direction, through the cavernous
sinus on the side of  the  sella turcica, to the anterior
clinoid process;  here it again forms  a considerable
curve, which is directly upwards, and  then it  perfo-
 rates the dura mater.
   These curvatures must also deprive the blood of the
carotid of a  portion  of the momentum which  it has
retained after leaving the bone.
   The object of these various flexures of the internal
 carotid appears to be analogous to that of the Rete
 Mirabile  in certain quadrupeds, which is  formed by
 the division of  this  artery into many small  branches,
 that reunite again,   without  producing any other ef-
 fect than the  diminution of the momentum  of  the
 blood. 
252             Ophthalmic Artery.
   During its course from the  place  of bifurcation  to
its entrance into the carotid canal, the internal carotid ar-
tery very rarely sends ofi'any branches.  In the canal it
gives off a small twig which enters the cavity of the
tympanum;  and sometimes  a second which unites
with the Pterygoid branch of the internal maxillary.
   As it goes by the sella turcica, it passes through the
cavernous sinuses, and gives off two branches which
are called the Posterior and Anterior Arteries of the
Cavernous Sinus or Receptacle.
   The posterior branch goes to that  part  of  the  dura
mater which is connected with  the  posterior  clinoid
process, and the cuneiform process of the  occipital
bone.   It  likewise gives branches  to  several of the
nerves which are contiguous, and  to the  pituitary
gland.
   The anterior artery also gives branches to  the  con-
tiguous nerves, to the dura  mater, and the  pituitary
gland.
   When the internal  carotid turns upwards at the an-
terior clinoid process, it sends off  the

               ophthalmic artery

   Which passes under the  optic  nerve through the
foramen opticum into the orbit of the eye, and is about
a line and a half in diameter.
   Although this artery enters the  orbit under the op-
tic nerve, it soon takes a position on  the outside of it,
but afterwards gradually proceeds  to" the inner side of
the orbit, crossing over  this nerve in an oblique .di-
rection, and finally passes out of the  orbit near the in-
ternal angle.  In this spiral course it sends off nume-
rous branches, viz.
   a.  To those parts which are auxiliary to the eye.
   b. To the ball of the eve. 
Branches of the Ophthalmic Artery.    253
  c. To the  cavity of the nose, through small fora-
mina in the ethmoid bone, and
  d. To the forehead and  external side  of the nose.
  These branches  generally go off in the following
order.
  1. The Lachrymal Artery  arises soon after  the
ophthalmic arrives within the orbit, and  passes above
the  abductor muscle  to  the lachrymal gland, where
it  terminates, sending  off many small branches in its
course.
  2.  The  Central artery of the retina  also  leaves
the ophthalmic soon after its arrival in  the orbit: it
is a small vessel which penetrates into  the  centre of
the optic nerve, and passing with  it into the eye  is
spread upon  the internal  surface of the retina.  Here
it appears to terminate in the adult; but in the foetus
it is continued through the vitreous humour to the cap-
sule of the crystaline  lens.
   3.  while  the ophthalmic  is  passing over the optic
nerve  the branches which enter  the ball of the eye
leave it.  Their  number varies, but they form three
classes, viz.  The Long  Ciliary,  the  Short Ciliary.
and the Anterior Ciliary arteries.  (See description
of  the  eye,  vol. i. p. 360,) the  supra orbitary and
muscular branches leave  it also near the same places.
   4. The  Supra  Orbitary Branch  often gives  off
several muscular twigs :  but it passes out of the  orbit
through the supra  orbitar foramen, and  generally di-
vides  into two branches, one  of  which is spent  upon
the periosteum, and the  other upon the skin and  mus-
cles of the forehead.
   5. There  are sometimes  two muscular branches, a
 Superior and an Inferior.  The superior  branch is
 often  deficient: when it exists it supplies the  levator
 palpebrae, the levator oculi, obliquus superior,  &c.;
 but these  parts are  often supplied by  the branches 
254    Branches of the Ophthalmic Artery.

above  mentioned.  The supra orbitar so frequently
gives off branches to the muscles that it has been call-
ed  the Superior  Muscular Branch.   The inferior
muscular branch  is more constant.   It commonly sup-
plies the rectus inferior, the adductor, and the inferior
oblique muscles, and also the lachrymal  sac, and the
lower eyelid, &c.
  When the artery is on  the inside.of  the nerve  it
sends off the two branches to the  cavity  of  the  nose,
viz. The Ethmoidal Arteries ; and also, branches  to
the eyelids.
  6. The Posterior Ethmoidal branch is  first.   It
passes  between the levator and  abductor muscles,
and above the obliquus  superior; and  penetrates the
cavity  of the cranium by the posterior orbitary fora-
men :  after giving some twigs to the dura mater,  it
passes  to  the  posterior cells of the ethmoid  by the
foramina of the cribriform plate of that bone,  and sends
a small branch  to the Schneiderian membrane on the
back part of the septum of the nose.
  7. The Anterior Ethmoidal artery arises from the
ophthalmic  nearly opposite  to the anterior orbitary
foramen, through which it passes:  and after entering
the cranium is distributed like the other through some
of a foramina of the cribriform plate to  the anterior
cells of the  ethmoid  bone, and to the anterior part
of the  Schneiderian membrane on the septum of the
nose, to which it sends a considerable branch.
  In its course it  sends  twigs to the  frontal sinuses,
and to  the dura mater and its falciform process.
  8. The arteries of the Palpebrae are called  Supe-
rior and Inferior;  they leave the ophthalmic near
the loop  or pully of  the  superior oblique muscle.
The inferior comes off first; it sends branches to the
ligaments  of the tarsus, the caruncula  lachrymalis,
and the parts connected  with the cartilage of the un- 
 Branches of the Ophthalmic Artery.—Carotid. 255

der eyelid, and unites with  the lachrymal artery near
the external canthus, forming an arch called the Infe-
rior Tarsal Arch.
  9. The Superior Artery supplies the superior part
of the orbicularis muscles, the ligament and caruncula
also : and it likewise unites  with a twig of the lachry-
mal, and forms the superior tarsal arch.
  Soon after sending off the palpebral branches,  the
Ophthalmic  Artery arrives at the internal canthus,
and then  finally divides into two branches, the nasal
and the frontal.
  10.  The Nasdil Branch  passes above the superior
part of the lachrymal sac, and the ligament of the eye-
lid  to the nose;  after sending a twig to  the  frontal
muscle and  the lachrymal sac, it passes down the side
of the nose and anastomoses with the facial artery.
   11. The Frontal Artery is not so large as the na-
 sal ; it generally divides into three parts.   A super-
 ciliary branch, which  is principally spent upon the
 eye-brows;  a superficial branch which is  spent upon
 the forehead;  and a branch which is distributed to the
 pericranium.
   The internal carotid, soon after parting with the
 ophthalmic, sends off, in a posterior direction, a branch
 to join one from the vertebral artery. From its destina-
 tion this vessel is called the arteria communicans.
    After this it sends off another branch which is so large
 that it may be considered as a continuation of the main
 trunk : this is called the middle artery of the brain, or
 the Arteria Sylviana.   It runs outwards nearly in the
 direction of the fossa Sylvii, which separates the ante-
 rior from the middle lobes of the  cerebrum.   In its
 course it divides and subdivides into  numerous branches
 which are spread upon the Pia Mater, and finally en-
 ter the surface of the brain in a very minute state.
    The internal carotid then terminates in a  branch 
256     Right and Left Subclavian Arteries.

which is smaller than the last mentioned, and from its
situation is called the  Anterior Artery of the Brain,
or Arteria Callosa.  This vessel first inclines towards
its fellow on the opposite side, and after approaching
within half an  inch  of it, forms  another curve, and
runs forward to the anterior part of the brain, dividing
itself gradually into two branches which pass in sever-
al directions.
  When these anterior arteries are  nearest to each
other, a small transverse branch, which passes at right
angles  connects them  together.   This  branch com-
pletes the anterior part of the Circle of  Willes.
  It crosses immediately before the  sella turcica and
pituitary gland, and sends off branches which pass to the
third ventricle, to the fornix and septum  lucidum, and
also to the pia mater.
  The  Anterior Arteries of  the brain  also send off
branches to the optic and olfactory nerves; to the oppo-
site surfaces of the two hemispheres on each side of the
falx; to their inferior  surfaces, and to the  corpus cal-
Josum.
  They have likewise some branches which anasto-
mose with those of the middle artery of the brain, and
of the vertebral artery.

           The SUBCLAVIAN  Arteries.
  The  right  subclavian  may be  considered as the
continuation  of  the  arteria  innominata.   This  last
mentioned artery after  leaving  the aorta, forms  a
curve  or arch, which extends  obliquely backwards
and  outwards, over the first rib to the axilla, crossing
the trachea in its course.  At the distance of an inch
and  a quarter,  or an inch and  a half from   its  origin,
it sends off the right carotid,  and then,  assuming  the
name of Right Subclavian, continues  in  the above
stated direction. 
The Left Subclavian Artery.
257
  The chord of the  curve of this  artery, and  the
chord of the curve of the aorta, are not in the same
direction, but form an angle with each other.
  The position of the left subclavian is somewhat
different from that of the right.  Its origin is pos-
terior, and, therefore, the direction  of the chord of
its curve is more immediately lateral.  The  curve
or arch is also smaller.  The situation of the two
subclavians  as relative to the contiguous parts, is,
therefore,  somewhat different;  but  each  of them
proceeds between the anterior and  the middle sca-
leni muscles, and when they  have arrived at these
muscles, their respective positions are very similar.
  The anterior and  middle  scaleni muscles arise
from the transverse processes of several of the cer-
vical vertebras, and are inserted into the first rib, one
before the other, so as to leave a considerable space
between them.  The subclavian arteries pass through
this  space, and before they  arrive  at it, but when
they are very near the above mentioned muscles,
they send off several very important branches in va-
rious directions,  viz. to  the  cavity  of the cranium,
to the parietes of the thorax, to the thyroid gland,
and to the lower part of the  neck.
  They proceed near to the  scaleni muscles before
they send off any branches; and  it is to be observed,
that the subclavian veins  which correspond with
these arteries, are  anterior  to them, for they pass
before the scaleni muscles, and not between them.
          The internal mammary Artery
  Goes downwards, from the lower and anterior part
of the subclavian, along the  inner side of the ante-
rior  scalenus  muscle.  It proceeds, exterior  to the
pleura, across the  cartilages of the true ribs,  and
near their middle; and, continuing between the car-
tilages and  the diaphragm, exterior to the perito-
   vol. ii.                33 
258    Course and Distribution of the Inferior

neum, terminates on the rectus  abdominis muscle,
in branches which  anastomose with those of the
epigastric artery.  In this course it gives  branches
to almost all the parts to which it is contiguous, viz.
to the muscles and glands at the lower part of the
neck; to the thymus gland;  to the parts  in the in-
tercostal spaces;  to the sternum;  to the  mediasti-
num and pericardium; to the diaphragm and to the
muscles of the abdomen.
  From some of its ramifications upon the parts be-
tween the ribs, small branches go off to the mamma,
and thereby give a name to the artery.  There is
also a  small vessel which is sent off by the mam-
mary artery, or by one of its upper branches, which
accompanies the phrenic nerve to the diaphragm.

           The inferior thyroid Artery
  Arises from the  upper side of the subclavian near-
ly opposite to the  origin of the internal mammary.
It passes upwards and inwards, between the carotid
artery and the spine, to the thyroid gland: then it
anastomoses with  the branches of the superior thy-
roid  on the same side, and with those of  its fellow
on the opposite side.
  This vessel sometimes  sends off large  branches
to the muscles at the lower part of the neck.

              The vertebral Artery
  Arises from the upper and posterior part of the sub-
clavian.  It goes upwards and backwards between
the muscles which lie on the front of the spine, and
passing under the transverse process of the sixth or
seventh cervical vertebra, enters into the canal form-
ed in the transverse processes of the vertebrae.  In
this course, as it proceeds from the third  to the se-
cond cervical vertebra, it inclines outwards laterally,
and, in its  passage  from the  transverse process of 
         Thyroid and the Vertebral Arteries.     259

the second to that of the first vertebra, it forms a
considerable curve, the convexity of which has a la-
teral and external aspect.  After passing the trans-
verse process of the Atlas, it is turned suddenly back-
wards, in a  groove, and finally passes through the
great occipital foramen into the cavity of the  cra-
nium.  It then proceeds upon the cuneiform process
of the occipital bone, under the Medulla Oblongata,
and joins its fellow  so as to form an acute angle with
it near the  union of the medulla oblongata with the
pons Varolii.   From each of the vertebral arteries
before their union, there generally goes off a small
branch called the Posterior Meningeal, which is spent
upon the posterior part of the dura mater.
  The trunk formed by the union of  the vertebral
arteries is  called

             The BASILAR Artery.
  It extends forward near to the anterior part of the
pons Varolii,  where it bifurcates;  but previously
sends off several branches on each side.  The first
pair go off in a lateral direction, soon  after its com-
mencement, near the back part of the pons Varolii,
and are spent upon the medulla oblongata, the pons
Varolii,  and the other contiguous parts,  and also
upon the fourth ventricle and the Plexus Croroides
of that cavity.   They are called the Posterior or In-
ferior Arteries of the Cerebellum.
  Two other lateral branches, which are called the
Superior Arteries of the Cerebellum, go off from the
Basilar artery,  near its  anterior extremity.   These
are principally spent upon the crura of the cerebel-
lum and cerebrum: upon the cerebellum itself, and
the contiguous parts.
  Soon after sending off the last mentioned arteries,
the Basilar artery divides into two branches, which
also takes  a lateral direction, and are of considerable 
260    Arteries of the lower part of the Neck.

size.   In their course outward, these  branches are
curved with their convexity forward.  About ten or
twelve lines from its commencement, each of them
sends off a branch called the  Arteria Communicans,
which passes directly  forward, and communicates
with the internal carotid, thus forming the arrange-
ment which is called  the Circle of Willis.*  After
sending off these arteries, they continue their  late-
ral direction, and are distributed principally to the
posterior parts of the cerebrum.  These terminating
branches of the Basilar Artery,  are called the Pos-
terior Arteries of the Cerebrum.

         The superior  intercostal Artery
   Arises from the upper part of the Subclavian, after
the  Vertebral and Thyroid arteries, and  very  near
them.  It  descends  by the side  of the spine across
the first and second ribs, near their heads,  and ex-
terior to the great intercostal nerve.  It generally forms
two branches, which are appropriated to the  mus-
cles, &c. in the first and second  intercostal spaces,
and sometimes a small  branch is continued to the
third intercostal space.  From each of these branch-
es a small vessel proceeds backwards, and  is spent
upon the contiguous muscles, &c. on the back of the
thorax.  The Intercostal Artery also sends a branch
upwards to the deep-seated parts of the neck.
   In addition to the arteries above  mentioned, there
are several others of considerable size  which origi-
nate either directly or  indirectly from the subcla-


  • The arteria communicans is also considered as a branch of the Internal
Carotid. The arrangement here alluded to is very remarkable.  As the
branches which pass offlaterally from the single trunk of the Basilar Arte-
ry unite to the Internal Carotids, and the Internal Carotids are united to
each other, there is an uninterrupted continuation of artery, which en-
closes a portion of space of a determined form; but this form resembles an
oblong square more than a circle.  By this connexion blood will pass from
any one of the four arteries of the brain to all the oUiers. 
          Branches that go off in the Axilla.      261

man, and are spent  upon the lower portion of the
neck and the contiguous parts.  These arteries are
very  different in different subjects, especially as to
their origin.  Two of them, which have been called
the Anterior and Posterior  Cervicals, are  generally
distributed to the muscles and other parts which lie
on the lower portion of the neck anteriorly and pos-
teriorly.
  A third, which passes transversely on the lower
part of the neck, is called the Superior Scapular.
  In some cases the two Cervical Arteries arise from
the subclavian, after  the mammary and the thyroid,
in a common trunk, which soon divides.   Very fre-
quently they go off from the Inferior Thyroid.—Some-
times one of them goes off from the Inferior Thyroid
and  the other from one of the branches  of the Sub-
clavian*
   The Superior Scapular most commonly arises with
some other artery,  and very often  from  the  Inferior
Thyroid.  It runs transversely outwards  within and
above the clavicle, and passing through the notch
in the upper costa of the scapula, divides into branch-
es which are distributed to the parts on the dorsum
of that bone.
   The subclavian  artery,  in its  progress from the
aorta to  the axilla, forms an arch  or curve, over the
first rib, as has been already observed.  The  ante-
rior scalenus muscle is before it, and the great nerves
of the upper extremity are above it.  After passing
  * Haller paid great attention to the arterial system, and made many dis-
sections, with a view to engravings of it, which he published with descrip-
tions, in folio fasciculi.
  These fasciculi have been collected, and with some other engravings,
form a large volume, entitled icoxes anatomise, which is truly valuable.
  There are some very interesting  observations on this work of nailer's,
and also on these arteries, in a description of the arteries, by Dr. Bar-
clay of Edinburgh, which I have read with advantage, as well as a work
on the muscles by the same author. 
262
Branches that go off in the Axilla.
between the scaleni, it descends upon the first and
second rib into the  axilla.  The nerves which were
above descend with  it: at first they are necessa-
rily exterior to it, but they form  a plexus which the
artery enters into, so  as to be partly surrounded by
them.  This course of the artery is obliquely under
the clavicle, and behind the pectoral muscle.   In the
axilla, the vessel  and nerves which surround it are
placed between the tendons  of the  pectoralis and
the latissimus dorsi muscles.   Here the artery takes
the name of axillary, and sends off several impor-
tant branches.
  The principal branches that go off from the axil-
lary artery are  distributed,
  1st. Anteriorly, to the pectoral muscle, and the
parts on the anterior surface  of the thorax.
  2d.  Posteriorly, to the muscles which are on the
scapula and contiguous to it; and,
  3d.  To the  parts which are  near the  upper ex-
tremity of the os  humeri.

               Anterior Branches.

  The arteries which go to the pectoral muscle, &c.
are very  various in different subjects, both as to
their number, origin, and size.
  They have also been called by different  names,
as Thoracicae, Mammarix Externa,  &fc.
  There are almost always three of them, and very
often more; one of them, which is called by  several
authors the Acromialis, proceeds towards the end of
the clavicle, and generally passes out at the interval
between the deltoid and the pectoral muscle, sending
various branches to the contiguous  parts;  the lar-
gest of its branches often passing in the direction of
the interstice between those muscles.
  Another of these arteries, which is called Superior 
         Branches that go off in the Axilla.      263

Thoracic, is generally very small: it often is a branch
of the above mentioned Acromialis.
  There is very often to be found here  an  artery
called the Inferior Thoracic, or the External Mamma-
ry, which is of  considerable length, although its di-
ameter  is  not  very great.  This artery  originates
near the two last mentioned, and sometimes from
the Acromialis.   It often extends downwards as low
as the  sixth  rib, and send branches to the anterior
part of the thorax, to the mamma, and the other
contiguous parts.   Many of the  small branches of
this artery anastomose very freely with those of the
internal mammary.
  There are  always small arterial branches in the ax-
illa, which ramify upon the glands and adipose mat-
ter always existing there.  They often arise by one
common trunk, which is called the Axillary  Thora-
cic.

                Posterior Branch.
   One large  artery is commonly sent to the muscles
on the scapula, which is called the Scapular,  the
 Common Scapular, or the Internal Scapular.  It com-
monly passes off from  the axillary after the thoracic
arteries, and supplies the muscles on both surfaces
of the scapula.   This large vessel passes downwards
a short distance in the direction of the inferior cos-
ta of the scapula, and soon sends off a branch that
 winds round to the dorsum of the bone, to  be  dis-
 tributed to the infra spinatus  and the  contiguous
 muscles, which is called -the Dorsalis Scapulas.  The
 main trunk then inclines to the subscapularis mus-
 cle, and generally divides into two branches, which
 are distributed to  the subscapularis, teres major,
 latissimus dorsi, &c.
   Sometimes  the  Scapular artery divides into  two
 branches before it sends off the dorsal.   In this case 
264             Humeral Artery.
the last mentioned artery goes off from one of those
branches.

          Branches near the Os Humeri.
  The arteries which are near the body of the  os
humeri at its upper end, are generally two in num-
ber, and denominated the Anterior and Posterior Cir-
cumflex. Sometimes they arise separately, and some-
times in a common trunk from the axillary artery.
Frequently one of them arises from the scapular.
  The Anterior Circumflex passes between the united
heads of the biceps and  coraco-brachialis muscles
and the body of the os humeri, at a small distance
below its head.   It sends branches to the capsular
ligament, the periosteum of the os humeri, the mem-
branes of the groove for the long head of the biceps,
the upper portions of the biceps and coraco-brachia-
lis,  and some contiguous  muscles.
  The Posterior  Circumflex  proceeds between  the
subscapularis and teres  major  muscles, and conti-
nues between the os humeri and the head of the tri-
ceps and the deltoides.  It is distributed to the mus-
cles and parts about the joint, especially the deltoides.
  These arteries surround the os humeri, and  the
small branches anastomose with each other.  The
Posterior Circumflex is much larger than the Anterior.
  The great artery of the arm proceeds from  the
axilla to the elbow; and, during  this course, is gene-
rally denominated

            The HUMERAL Artery*

  Its direction is influenced by the position of the os
humeri.  When the arm hangs  down, with the palm
of  the hand  presenting  forward, this direction is
* It is called Brachial Artery by several writers. 
Branches of the Humeral Artery.       269
somewhat spiral.  The situation of the artery is on
the inside of the biceps muscles, and between that
muscle, and the triceps extensor.  It  also continues
very near and on the inside of the tendon of the bi-
ceps, and  under the Aponeurosis which proceeds
from that tendon.   In consequence of the spiral or
oblique course of the artery, its direction would be
from the inside of the tendon of the biceps to the raj
dial side of the fore-arm; but soon after it passes
across the joint of the  elbow, it divides into two
branches: one which preserves* for some distance*
the direction of the  Main Trunk, is called the Ra-
dial artery: the other, which inclines obliquely down-
wards  and towards the ulna, is  the Common Trunk
of the Ulnar and Interosseal Arteries.
  During this course, the humeral artery sends oft?
several branches to the muscles and  other parts on
the os humeri.  The largest of them is denominated
the Profunda Humeri or Spiralisi  This  artery very
often arises as high as the insertion of the latissimus
dorsi, and passing between the heads of the triceps
extensor muscle, proceeds downwards  under  that
muscle, in a spiral direction, towards the external
or radial condyle.  It sends several branches to the
triceps and the contiguous  muscles, and one consij
derable  branch, which is generally called the Pro-
funda Minor, to the parts contiguous  to tbe internal
condyle.  The  ramification of these  branches near
the  condyle  frequently  anastomose  with small
branches of the radial and ulnar arteries.*
  A small branch frequently arises from the Hume-
ral artery, at  a short distance  from  the Profunda
Humeri, which sends a ramification to the medullary

  • The Profunda sometimes originates from the scapular, or one of the cir-«
cumnex.  The profunda minor sometimes has a distinct and separate ori-
gin,  lower down than the other.
VOL.  If.
34 
266
Radial Artery.
foramen of the os humeri. This vessel is, therefore,
denominated Arteria Nutritia.
  There are very often several anastomoses between
the branches of the humeral artery which originate
above the elbow, and certain branches of the Radi-
al and Ulnar arteries, which are called from their di-
rection recurrents.   Among these arteries there is
generally one of considerable size, which  proceeds
across the elbow joint near the internal condyle.—
Sometimes this is  the ulnar recurrent, which goes
up to anastomose with the branches of the profun-
da ; but more frequently it is  a separate branch of
the Humeral artery which goes off a little above the
elbow, and passes across the articulation, near the
internal condyle, to anastomose with the  branches
of the ulnar artery.  This artery is denominated the
Anastomotica.
  There are often  other branches  sent off by the
humeral artery; but they are commonly small, and
very irregular.
   The two  great ramifications of the humeral ar-
tery on the fore-arm have very different directions.
The Radial artery preserving the course of the main
trunk, while the Common  Trunk of the Ulnar and In-
terosseal projects from it in a direction downwards
and towards the ulna, passing  under the  pronator
teres, &c.

                The radial Artery

   Passing over the pronator teres muscle, proceeds
between the supinator radii  longus  and the  flexor
carpi radialis, very near to the lower end  of the ra-
dius, without changing its direction materially, being
deep-seated above  and superficial below;  it then al-
ters its course, and, passing under the tendons of the
extensors of the thumb, to the back part  of the ra- 
  Course and Ramifications of the Radial Artery.  267

dius, it continues between the  metacarpal bones of
the thumb, and of the index finger, when it divides
into three branches.
  In this course it gives off but few branches. The
first is the Radial Recurrent, which  passes upwards
and  towards the external condyle, and frequently
anastomoses with the ramifications of the profunda
hunieri.
  The branches which it sends off between  the ori-
gin of the recurrent and the lower end of the radius
are generally very small, and distributed to the parts
immediately contiguous  to  the  artery.—Before it
turns under the tendons of the extensors of the
thumb, it sends a branch over the wrist towards the
root of the  thumb, from which proceeds a branch
to anastomose with the volar  branch of the ulnar;
and another, not so large, which is frequently conti-
nued on  the radial or external side of the thumb,
very near to its extremity.  While  the radial artery
is under the aforesaid  tendons,  it sends of small
branches to the back of the wrist and back of the
hand, and often to the  back of the thumb.   Those
which are distributed  to the wrist  and back of the
hand, generally anastomose with the small branches
of the ulnar and interosseal arteries.
   The three branches  into which the radial artery
divides between the metacarpal bones of the thumb
and index are, 1st, a branch to the external side of the
index; 2dly, a branch to the thumb, that sometimes di-
vides into two which pass up on the anterior or vo-
lar surface,  and sometimes continues, without much
diminution,  on the internal  side of the thumb, near
to the end of the last phalanx; and, 3dly, a branch,
called Palmaris Profunda, which dips down into the
palm of the hand, and  proceeding in contact with
the metacarpal bones, under the flexor tendons, &c.
forms an arch which extends across the hand, and 
268  Origin of the Ulnar and Interosseal Arteries.

often terminates by anastomoses with another arch,
soon to be described, which is formed by the ulnar
artery.
   This flexure, which is  denominated Arcus Pro-
fundus, sends off branches of a very small size, which
are distributed to the bones, ligaments, muscles, &c.
contiguous to it.

   The common  trunk of the ulnar  and interos-
                  seal Arteries
   Passes under several of the muscles which origi-
nate from the internal condyle, and between the flexor
sublimis and  the flexor profundus. Before the Ulnar
Recurrent goes off from this  vessel, the interosseal
artery often leaves it.  This recurrent artery passes
upwards between the muscles of the internal condyle,
and distributes branches among them. It then passes
up in the groove  behind the  internal condyle, and
anastomoses  with the branches of the Anastomotica
or Profunda Humeri.
   The ulnar and interosseal arteries separate from
each other at the distance of fifteen or twenty lines
from the origin of the radial artery, very near the
commencement of the interosseanigament.

             The interosseal Artery
   In a majority of cases, arises in a single branch from
the common trunk of the ulnar and interosseal. When
it does so, the single branch soon sends off the Pos-
terior Interosseal artery,  which perforates the inte-
rosseous ligament, and passes down on its posterior
surface, while the main branch continues on the an^
terior surface of the ligament, and  is denominated
the  Anterior  Interosseal Artery.  In  some cases the
main branch proceeds on the anterior surface as low
as the upper edge of the pronator quadratus muscle,
before it sends off the posterior branch.  Sometimes 
Course of the Ulnar Artery.        269
the anterior and posterior interosseals arise separate-
ly. In this case the posterior soon perforates the li-
gament.
  The Anterior  Interosseal passes down almost in
contact with the ligament, and gives branches to the
contiguous parts in its course. It generally perforates
the interosseous ligament near the wrist, and sends
off many small branches to the back of the wrist and
hand, which anastomose with the small branches of
the radial and the posterior interosseal arteries.
  The Posterior Interosseal soon gives off a recur-
rent or anastomosing  branch, and then proceeds
downwards towards  the wrist, sending branches in
its course to the extensor muscles and tendons.
  This vessel sometimes divides into two branches.

                The ulnar Artery.

   The Ulnar artery proceeds among the muscles ob-
liquely downwards, and is not superficial until it has
arrived within three  or four inches of the carpus: it
then continues towards the hand, sending off very
small branches  in its  progress.  It passes over the
annular ligament at  the wrist, and winds round the
pisiform bone: here it is supported by a delicate liga-
ment, which seems to lie upon it: from this it passes
upon the  palm of the hand,  under the aponeurosis
palmaris, and over the tendons of the flexors of the
fingers.   When thus situated, it forms, in perhaps a
majority of subjects, an arch or bow, called Arcus
Sublimis, which  extends across the palm of the hand,
from the  ulnar towards the radial edge, and, after
sending branches to the fingers, &c. from its convex
side, terminates near the root of the thumb, by anas-
 tomoses with that important branch of the radial ar-
tery, which passes up  on the inside of the thumb. 
270             Digital Arteries.

The Arcus Sublimis almost always sends off small
branches to the integuments, &c. on the palm of the
hand.  It often sends off, near the  root of the meta-
carpal bone of the little finger, a branch which passes
between the flexor tendons and the metacarpal bones,
and anastomoses with the Arcus Profundus.  It then
generally sends off a branch  to the inner or ulnar
side of the  little  finger;  and  afterwards three
branches in succession, which pass from its convex
side towards the angles formed by the fingers. These
are called
               The Digital Arteries.
  When they have arrived near to the heads of the
first phalanges of the fingers,  each of these arteries
divides into two branches, one of which passes along
the side of one of the fingers to its extremity, and the
other on the opposite side of the next finger: and in
this way they pass on the sides of all the fingers, ex-
cept the inside of the little finger and the outside of
the index.
  These branches  of the digital arteries are called
Digito Radial  and Digito Ulnar arteries, according
to the sides of the fingers on which they are placed.
They are situated on the angle, if it may be so term-
ed, which is formed by the anterior and lateral sur-
faces of each finger. In their course from the basis
to the extremity of the  finger, they send off  very
small transverse branches, which anastomose  with
each other, especially near the other.  Some trans-
verse branches are observable on the posterior  as
well as the anterior surfaces.  Near the extremity
of each finger, beyond the insertion of the flexor
tendon, the extremities of these arteries ramify mi-
nutely.  Some of these  small branches go to the
skin,  and others anastomose  with their fellows of 
Bronchial Artery.
271
the opposite side.  Some also go to the back of the
fingers.*


                      section III.


Of the Branches  which go off between the arch and the

          great bifurcation of the AORTA.


                       PART 1.


              In the Cavity of the Thorax.


   The  aorta  sends  branches to the Lungs, to the

oesophagus,  and to the parietes  of the thorax.


                The bronchial Arteries


   Are the vessels which go from the aorta to the

ramifications of the  trachea,  and the substance of

the lungs.   They are not  large, and  are  very irre-
gular as to number and origin.

   In a majority of cases the right lung is supplied, in

part, by a  branch from  the first  aortic intercostal of

that  side;  while the  left lung receives two or three
branches from the aorta directly.   In  some cases a

large vessel arises from the aorta, which divides into

two branches, one of which goes to each lung.


  • The distribution of the radial and ulnar  arteries in the hand, is very
different in different subjects.
  Upon examining a large number of injected preparations in Philadelphia,
it was found that, in a very small majority of them, the ulnar artery form-
ed an arcus sublimis, whose branches extended as far as the ulnar side of
the index, and sometimes beyond it.
  That, in near a third of the preparations, the ulnar artery ramified with-
out forming an arcus, and supplied only two of the digital branches, viz.
the first two on the ulnar side.  In such cases the radial artery generally
made up the deficiency of the ulnar, but in a few instances the interosseal
was extended on the palm of the hand, and supplied the radial side of the
middle finger and the corresponding side of the index.
  In a few instances also the ulnar artery was still more deficient, and the  .
radial was proportionally extended. 
272     (Esophageal and Intercostal Arteries.

   The  Bronchial  arteries frequently  send  small
branches to the posterior mediastinum, the pericar-
dium, &c.
   Injections have shown, that there is a direct com-
munication between these vessels and the branches
of the pulmonary artery.

            The (Esophageal Arteries

   Are very small vessels, which generally arise from
the aorta, but sometimes are branches of the bron-
chials or intercostals that are spent upon the oesopha-
gus.  They occur  in succession, and sometimes are
five or six in number.  They also send twigs to the
contiguous parts, and the lowermost often descend to
the stomach.

             The Inferior Intercostals

   Are the arteries which proceed directly from the
aorta to the parietes  of the thorax.   Their name is
derived from their  position between the ribs.  They
are ramified on the intercostal muscles and ribs, and
on the pleura and some of the contiguous parts. They
are called  Inferior or Aorta Intercostals, to distin-
guish them from the superior intercostals, which are
derived from the subclavian  artery.   Their number
varies from ten to  eight,  according as the superior
intercostals are more  or less numerous.
  They originate in pairs on the posterior surface of
the aorta.   The  uppermost of them  pass obliquely
upwards, and the  lowermost nearly in a horizontal
direction, to the, lower edges of those ribs to which
they are appropriated.  They meet the rib near its
tubercle, or place of junction  with the transverse
process of the vertebra, and then proceed forward,
between the internal and external  intercostal mus-
cles, in a superficial but  large groove, which is ge- 
Intercostal Arteries.
273
nearly to be found on  the  interior  margin of the
lower surface of the  rib.*  There is necessarily a
difference in the length of the right and left intercos-
tals, owing to the position of the aorta,  which is
rather on the left of the spine.   In consequence of
this circumstance, the oesophagus is anterior to, and
also in contact with those of the right side.
  They generally send offan important branch, call-
ed the Dorsal, which  arises near their origin, and,
passing backwards, sends ramifications to the mus-
cles of the back.  From this dorsal branch also pro-
ceeds a ramification, which enters the spinal cavity,
and  is spent upon its membrane and upon the me-
dulla spinalis.
  After the Intercostals, in  their progress forward,
have passed beyond the middle of the ribs, they send
off a branch, which generally proceeds very near to
the upper side of the lower rib.  The main trunk
generally leaves the lower edge of the rib when it
has arrived within one-third of the length of the bone
from its anterior extremity.  It then generally divides
into several branches, some of which  are spent upon
the pleura, and others on the intercostal and  the
contiguous muscles.
  According to the situation of the different intercos-
tals, some of their ramifications communicate with
those of the internal and external mammaries, of the
phrenic, the lumbar, or the epigastric arteries.
• See Vol. I. page 103i
VOL. It.
35 
274
Cavity of the Abdomen.
                   PART II.

           In the Cavity of the Abdomen.

  The aorta passes into the  cavity of the abdomen
between the crura of the diaphragm, as has been al-
ready mentioned.  In its course from the crura to
its great bifurcation, it sends off one  pair of small
arteries, called Phrenic,  to the diaphragm.   Three
single arteries, the cceliac, the superior, and the in-
ferior mesenteric, to the viscera  of the abdomen.
A pair of large arteries, the emulgents, to the kid-
neys, with several that are  very small to their ap-   ^
pendages; as the Spermatices, Capsular, the Ureteric,   »
and the Adipose.  In addition to these, there is one    '
pair of small arteries that go to the testicles, or to    j
the ovaria and the uterus, and four or five pair, cal-
led Lumbar Arteries, that go off laterally, like the    3
intercostals, to the parietes of the abdomen, and to
the muscles, &c. on the  back, which are contiguous    j
to them.

               The phrenic Arteries

  Are  ramified on the concave surface of the dia-
phragm, and are almost always two in  number; they    i
are denominated right  and left from their position.
They commonly originate separately from the aorta,
but sometimes they arise in a common trunk  which
soon divides.  In some  instances they are derived
from the coeliac. In a few cases, the aorta furnishes
one, and the cceliac the  other.  Each of the phre-
nic arteries commonly crosses the  crus of the dia-
phragm  on  its respective side, and proceeding late-
rally, in a circular direction,  often ramifies so as to 
         Distribution of the Coeliac Artery.       275

form an internal and external branch.   Each of them
generally sends branches to the cardia or oesophagus,
to the glandulae renales, and other contiguous parts.

              The CCELIAC  Artery,
   Is the  first great branch given off by the aorta in
the abdomen, and  is distributed almost entirely to
the stomach, the liver and the spleen.  It projects
from the anterior part of the aorta so as to form a
right angle with it, and is of course nearly horizon-
tal, when the body is erect.
   The main trunk of this great artery is so remark-
ably short, that it has been  compared to the stump
of a tree;  for at the distance of half an inch from
its origin,  it generally divides into three  branches,
which  pass to the stomach, the liver, and the spleen,
and are therefore, denominated the Gastric or Coro-
nary, the hepatic and the splenic arteries.
   The first mentioned branch may be called

   the superior coronary  or gastric artery,
   To  distinguish it from other branches, soon to be
described.  It is commonly in the centre of the three
great  ramifications of the coeliac,  and is also the
smallest of them.   It proceeds from its origin to the
upper  orifice of the stomach or cardia, and conti-
nues thence along the lesser curvature of that viscus
until it  approaches near to the pylorus.   In  this
 course it sends  branches to the oesophagus, which
frequently  inosculate with the oesophageal arteries.
 It also furnishes branches to the cardia, which par-
 tially surround it;  and on this account, the artery
 has been called Coronary.   Some of these last men-
 tioned branches are often continued on the great ex-
 tremity  of the stomach, and anastomose with those
 ramifications of the splenic artery,called Vasa Brevia.
   It continues on the lesser curvature between the 
276
Distribution of
     •
lamina of the small omentum, and sends off succes-
sively branches which pass between  the peritoneal
and muscular coats, and are distributed to the ante-
rior and posterior surfaces of the stomach, commu-
nicating with the branches of the inferior gastric ar-
teries, soon to be described.*

              THE  HEPATIC ARTERY

  Proceeds from the great ramification of the cceliac
to the transverse fissure of the liver called the Portse,
in which it generally divides into two branches.  In
this course it very frequently sends off an artery to
the pylorus, which ramifies about the small extremi-
ty of the stomach, and often inosculates with some of   I
the branches of the superior coronary.  This branch
is called the Pylorica, and  sometimes it arises from
the  artery next to be mentioned.

         The gastrica  inferior dextra,

  Which also  generally originates from the main
trunk of the hepatic, but sometimes from one of its
branches.   It is an artery of considerable size,  which   j
proceeds along the great curvature of the stomach,   *
from the pylorus towards the great extremity between
the  lamina of the anterior  portion of the omentum,
and distributes its ramifications to both sides  of the   j
stomach, and also to the Omentum.   In its progress
from the hepatic artery to the stomach, it sends off
branches to the Duodenum  and to the right end of the
Pancreas.
  The two great branches into  which  the hepatic
artery divides, are denominated right and  left, from
the lobes of the viscus, to which they  are respective-
ly appropriated.  The right branch is the largest.—   *

  * This artery sometimes sends a branch to the liver.  When this is the   <
case, it is always very large. 
The Splenic Artery.          277
Before it penetrates the substance of the liver, itsends
off a  branch to the gall bladder, called the Cystic
Artery.
  The branches  of the hepatic artery ramify very
minutely in  the liver,  as has been stated in the ac-
count of that organ.
   The last great  branch of the coeliac is

              The SPLENIC Artery,

   Which is  generally supposed to be larger than the
hepatic in adults, although it is less in children.   It
proceeds in  a transverse direction from its origin to
the spleen: its course is not straight, but meandering
or serpentine.  It is situated behind and above the
pancreas, and passes along the groove in the  upper
edge  of that viscus.  In  its progress, it sends off
many small  branches, and one that is of considera-
ble size, to the Pancreas.   It also sends one branch
to the left  extremity  of the stomach, which  arises
commonly from the main trunk, but sometimes from
the ramifications, which are soon to be  mentioned.
This  branch, which is called

          The gastrica inferior sinistra,

   Is sometimes, but not often  very large: its course
is from left  to right.  It is situated between the lami-
na of the anterior portion of the omentum.   It sends
some small  branches  to the omentum, and others
which are larger and more numerous, to both sides
of the stomach.   Some of these last mentioned anas-
tomose with the ramifications of the gastrica dextra
 which come from the hepatic.
   When the splenic artery approaches near  to the
 spleen, it divides  into  four, five, or six branches,
 each of which penetrates into that viscus by  a dis 
278    Distribution of the Superior Mesenteric.

tinct foramen, and then ramifies in the manner de-
scribed in the account ofthe structure ofthe splcei *
  Either from the splenic artery, or from these ra>
fixations, four or five branches pass to the large.
tremity ofthe stomach, and  ramify there, communi-
cating with the vessels already  described.  These
arteries have received  great attention from physio-
logists, and are denominated Vasa Brevia.

        The  SUPERIOR MESENTERIC,
  Which is the second great branch given off in the
abdomen by  the aorta, is not very different in size,
from the coeliac, and originates  about half an inch
below  it.  It  is distributed  to the small intestines;
to that portion ofthe great intestine, which is situa-
ted on the right side of the abdomen ; and to the arch
ofthe colon.  From its origin it proceeds downwards,
under the pancreas, and over the lower portion ofthe
duodenum, to the commencement of the mesentery.
When it has arrived between the lamina of that mem-
brane, it descends in a  direction which corresponds
with that ofthe root ofthe mesentery ,t and forms a
gentle  curve, with its convexity directed towards the
intestines.  It necessarily diminishes as  it descends,
and generally terminates by anastomosing with one
of its  own branches.—This  great artery sends off
some  very small ramifications to  the pancreas and
the duodenum, while it is in their vicinity.  It also
sends two or three branches to the transverse part of
the colon, to the right portion of the colon, to the be-
ginning of the great  intestine,  and the contiguous
portion ofthe ileon.  These branches are commonly
termed the  Colica Media, Colica Dextra, and Ileo

  * It frequently happens that the splenic artery divides only into two or
three branches, and they subdivide so as to form five or six, which pene-
trate the spleen.
  tVol. II. p. 115. 
        and the Inferior Mesenteric Arteries.     279

Colica.  From  the  convex side of the curve, the
superior  mesenteric  sends  off  the  important
b -inches which pass between the lamina of the me-
  "tery,  and supply the  Small Intestines.   These
0: [nches are numerous, and many of their ramjfica-
ticns  anastomose with  each other so as to form
arches.   From these arches go off other branches,
which anastomose again with some of similar origin;
and this process  is repeated  successively  several
times, so that a net-work of blood vessels seems to
be formed on the mesentery.  From the mesentery
the small ramifications are continued in great num-
bers to the intestines.   Some of them  anastomose
with each other on the coats of the intestine; but an
immense number of minute arteries are continued to
the villous coat, so that, when they are successfully
injected, the surface of that coat appears uniformly
coloured by the injection.*

   The INFERIOR MESENTERIC Artery

  Does not go off from the aorta next, in order after the
superior mesenteric, but succeeds it immediately  on
the intestines, and continues the arterial ramifications
to the left portion of the colon, to which the branches
ofthe superior mesenteric do not extend.
  This  artery arises between the origin of the emul-
gents and the great bifurcation of the aorta, and pro-
ceeds downwards, inclining to  the left, but keeping
near to the aorta. There are generally three branches
distributed to the left portion ofthe colon, which arise
from  this artery, either separately, or by a common
trunk which soon divides.  It  frequently happens,
that one of these arteries  arises separately, and two
by a  common trunk.   These  are  called the Left

  • See the account of the termination of these arteries, at page 110 of
tliis volume. 
 280       Emulgent and Capsular Arteries.

 Colic arteries; and are also sometimes denominated,
 from their position, Superior, Middle,  and Inferior.
 The  Superior  generally  anastomoses  with that
 branch of the  superior mesenteric, which is called
 Colica Media, and forms a remarkable arch, called
 the Great Mesocolic Arch.   The ramifications ofthe
 other  branches frequently anastomose with  each
 other, and are finally  spent upon the left portion of
 the colon.
   The main trunk, diminished by sending off these
 branches, but still of  considerable size, runs down-
 wards on the posterior part ofthe intestine rectum,
 between that intestine and the sacrum, where it often
 divides into two  branches, which continue near to
 the termination of the rectum. From them proceed
 many ramifications that are spent upon the rectum.
 Some of these ramifications anastomose  with each
 other, and others with the ramifications of the hae-
 morrhoidal artery, soon to be mentioned.

      The EMULGENT or RENAL Arteries
  Are the large vessels which pass from  the aorta to
 the kidneys.  They arise between the superior and
 inferior mesenteries, one on each side; and proceed
 in a direction which  is nearly rectangular  to the
 aorta.   The  right emulgent artery is necessarily
 longer than the left, and it generally passes behind
 the vena cava.  When they approach near the con-
 cave edges of the kidneys, each emulgent commonly
 divides into three or four branches, which pass into
 the fissure of that organ, and ramify in the manner
described in the account of it. Sometimes two arte-
ries proceed from the  aorta to the kidney: but this
is not a frequent occurrence.

              The Capsular Arteries
  Are the small vessels which pass to the glandulse 
           Adipose and Spermatic Arteries.      281

 renales.  There are almost always several of them
 appropriated to each gland.   They often arise on
 each side from the coeliac artery, the aorta, and the
 emulgent.

               The Adipose Arteries

   Supply the adipose substance surrounding the kid-
 neys.—There are several of them on each side, and,
 like the last mentioned arteries, they are very small,
 and arise from several sources as well as the aorta.
   The testicles and ovaria are supplied by the

                Spermatic Arteries,

   Which are very remarkable for their great length
 and small diameter. In a majority of cases these ves-
 sels arise from the anterior surface of the aorta, a
 little below the emulgents: but it often happens that
 the left spermatic arises from  the emulgent on that
 side.  They also sometimes arise from other neigh-
 bouring arteries.   It has been observed  when they
 arise from the aorta, that the origin of one of them
 is generally higher than that of the other.
   They pass downwards, so as to form an acute an-
gle with the aorta, and proceed behind the perito-
neum, and before the psoas muscle and ureter. While
this artery is  in  contact  with  the psoas muscle, it
meets with the  ramifications  of the spermatic vein,
and, in its progress to the abdominal ring, also joins
the spermatic cord.  In this course it sends off some
very small twigs to the contiguous parts, and others
that anastomose with similar ramifications from the
mesenteric, epigastric, &c.  Before it arrives at the
testicle, it divides into several branches, two of which
generally go to the epididymis, and the others pene-
trate the upper and back part ofthe tunica albuginea.
  vol. n.               36 
282            Spermatic Arteries.
       The Spermatic Arteries in the Female,

  Instead of passing to the abdominal ring, proceed
between  the  lamina  of the  broad ligaments,  and
send branches to the ovaria, which in some cases,
may be traced to the  vesicles.   They also  send
branches to the Fallopian tubes and uterus, and to
the round ligaments.   Those which are on the op-
posite sides of the uterus, anastomose with  each
other, and with the branches of the hypogastric ar-
teries.
  The lumbar regions  are  supplied with arteries
which originate, like the intercostals, from the  pos-
terior part of the aorta between the thorax and pel-
vis.  There are four or five of these vessels on each
side, and they are denominated

              The Lumbar Arteries.
  They pass between the spine and the psoas mus-
cles, and send branches to the spinal cavity, to the
muscles of the lumbar regions, and the abdominal
muscles.   They anastomose with the internal mam-
mary, the epigastric, the circumflex of the ilium, &c.
  A small artery passes off singly from the posterior
part of the aorta at its bifurcation, which is called

            The Middle Sacral Artery.
  It proceeds down the middle ofthe sacrum to the
os coccygis, and sends off lateral branches, which
are spent upon the contiguous parts, and inosculate
with the  arteria? sacra laterales.
..; 
General Account of the Internal Iliac.    283
                   section IV.

Of the Arteries which originate at and below the Great
             Bifurcation of the Aorta.

           The PRIMITIVE ILIACS.

  Form an acute angle with each other. They pro-
ceed downwards behind the peritoneum, very near
the margin of the pelvis,  without seuding off any
branch of importance.  At the junction of the sa-
crum  with the ossa ilea, they divide into two great
branches: the internal iliac, or hypogastric, which
descends into the  pelvis;  and the external iliac,
which passes under the crural arch to the lower ex-
tremity.

 The  INTERNAL ILIAC, or HYPOGASTRIC,

  Is distributed, in part, to the viscera of the pelvis
and the organs of generation, and also  to the  large
muscles exterior to the pelvis: it is therefore, very
large, though not quite equal to the external  iliac
  It has already been mentioned, that  in the  foetal
state, this vessel  appeared to continue  in a curved
direction from its origin to  the lower part of the side
of the bladder, and from thence to  the Umbilicus,
under the  denomination  of  the Umbilical Artery.
From the convex side  of this  curve the  different
branches of the  internal iliac go off.   In the  foetal
state  they are very small, in proportion to the umbi-
lical artery; but as the artery becomes ligamentous,
these branches increase in size.
  In the adult, the arrangements of these vessels is
very different.   The internal iliac generally di-
vides  into two great branches:  the  Gluteal, which
passes through the sacro sciatic notch, and ramifies 
284     Smaller Branches of the Internal Iliac.

on the exterior and upper part of the os ilium:  and
the Ischiatic, which passes downwards on the  out-
side of the tuberosity of the ischium.
  The first of these large ramifications passes out
of the pelvis  above  the pyriform muscle, and the
last of them  below  it.  Several smaller arteries
arise from these branches near their origin, or from
the main trunk of the internal iliac, which are dis-
tributed to the different parts of the pelvis; and one
important branch of  the ischiatic, called the Pudic,
proceeds downwards on the inside of the tuberosi-
ty of the ischium.
  The first of the smaller branches which the ex-
ternal iliac commonly sends off, is called  the

                  Ileo Lumbalis:
  It sometimes arises from the gluteal artery, and
sometimes from the main trunk of the internal iliac.
It passes outwards under the psoas muscle, and sud-
denly divides into two branches.   One of them pro-
ceeds upwards, and is distributed in the lumbar re-
gion, while the other ramifies on the iliacus internus
muscle, and is spent  on the contiguous parts.
  There are also two or three small arteries called

              Arteria Sacrx Laterales,
  Which sometimes  arise singly, and sometimes in
common, from the great trunk. They also "occasion-
ally originate from the gluteal artery.  These ves-
sels enter the anterior foramina  of  the os sacrum,
to be distributed on the cauda equina and the mem-
branes which invest it. Some of their ramifications
anastomose with branches of the sacra media and
other contiguous arteries.
  On the anterior side of the internal iliac, near the
origin of the  above  mentioned vessels, a ligament
which was  originally the umbilical artery, goes off 
Smaller Branches of the Internal Iliac.     283
to the side of the bladder, and continues from thence
to the umbilicus.  Sometimes it continues pervious
for a short distance, and then small branches pass
from it to the bladder.
   In the female it also sends small branches to the
uterus and vagina.
   In addition to these Vesical Arteries  derived from
the umbilicals, there are other branches distributed
to the bladder, which arise very differently, in dif-
ferent subjects, from branches which are soon to be
described, as the hemorrhoidal, pudic, &c
   From the anterior side ofthe internal iliac, or from
one of its great branches, an artery often arises which
passes out of the pelvis  through the aperture in the
margin of the ligamentous membrane which closes
the foramen thyroideum ofthe os innominatum; this
is called the
                 Obturator Artery.
   This vessel, while it  is in the pelvis, often sends
small branches to  the bladder and its appendages,
and to the obturator internus muscle. After it passes
out ofthe pelvis, it frequently divides into branches;
some of which  are spent on the obturator externus,
and the contiguous muscles, and others go to the hip
joint.  The origin of this artery is variable.   Most
 commonly it arises from the internal iliac, but often
 from the ischiatic, and  sometimes from the gluteal,
 In some instances it originates in a way that is par-
 ticularly interesting when the operation for crural
 hernia is to be performed, viz. from the  epigastric
 artery, soon to be described: for in  this case the ob-
 turator artery sometimes  nearly surrounds the neck
 of the hernial sac*

   • See Astley Cooper's great work on Hernia, Vol. I.
   There is reason to believe that this position of the artery occurs more
 frequently than has been supposed. 
 286    Larger Branches of the Internal Iliac.

   A small artery passes from the internal iliac or
 one of its branches, to  the rectum, which is called
 the
              Middle Hcemorrhoidal,
  From its situation between the branches which are
 sent to that intestine from the inferior mesenteric,
 and those which go to it from the pudic. This  arte-
 ry is spent upon that part of the rectum, which is
 above and in contact with  the sphincter.  It sends
 branches to the prostate and vesiculae seminales in
 males, and the vagina and bladder in  females.
  In females there is a peculiar artery,
                   The Uterine,
  Which originates either from the internal iliac, near
 the origin ofthe ischiatic, or from one of its branches.
 It passes between the lamina of the broad ligaments
 to the cervix uteri, and penetrates the texture of that
 organ. The size of this  vessel varies with the  vary-
 ing size of the uterus.
      The gluteal or posterior iliac Artery,
  One of the two great branches of the internal  iliac,
 proceeds exteriorly through the sciatic notch above
the pyriform muscle, very near the edge of the bone.
On the outside of the ilium it generally divides into
two branches, one of which ramifies between the
gluteus medius and minimus, and the other between
the medius  and maximus.   It is principally spent
upon these muscles, and sends branches to the con-
tiguous parts.
              The  ischiatic Artery,
  The other great branch ofthe internal iliac, passes
through the sciatic notch below the pyriform muscle,
 and proceeds downwards,  between the great tro-
 chanter of the os femoris and the tuberosity of the
ischium, under the gluteus maximus muscle.  Soon 
Pudic Artery.
287
after its origin, it commonly sends off a considerable
branch, the Arteria Pudica, which also passes down-
wards: it  then continues its course as above men-
tioned, and its principal branches are distributed to
the gluteus maximus and the muscles of the upper
and back part ofthe thigh, while its smaller branches
go to the os sacrum and coccyx, and the contiguous
small muscles.

               The pudica  interna,
  As has been just mentioned, is often a branch of
the ischiatic artery, but sometimes originates imme-
diately from the internal iliac.  It proceeds down-
wards and inwards, diverging from the ischiatic, and
passing between the two sacro-sciatic ligaments to
the interior  side of the tuberosity of the ischium,
whence it continues on the inside of the crus of the
os ischium and pubis  until  it  approaches the sym-
phisis, when it generally divides into three branches,
which are spent upon the organs of generation, from
which circumstance the name of this artery is derived.
   One or more branches from it also pass to the
lower part of the rectum and sphincter ani, and are
called the Lower Haemorrhoidal Arteries.
   In its course it sends off many  small branches to
the contiguous parts; one of which, called the Peri-
neal, leaves it near the transversus perinei, and passes
between that  muscle and the skin, and between the
bulb ofthe urethra and the crus ofthe penis, to the
scrotum.
   When the Pudic has arrived near the bulb of the
urethra it sends a branch into it, which is continued
into  the  corpus spongiosum urethrae, and ramifies
 there minutely.
   At the symphisis of the pubis, it sends off a second
 branch, which passes to the back of each crus, and,
 proceeding along it, parallel to its fellow, terminates 
288  External Iliac-
Rranches of the External Iliac.
in the glans penis: in this course it sends branches
to' the elastic coat, to the integuments, and to the
prepuce.  This vessel is called the Arteria Dorsalis.
   The main trunk ofthe pudic artery then penetrates
the corpus cavernosum, and proceeds through it in
a straight direction.   Its ramifications appear tobe
distributed through the internal structure of the cor-
pus cavernosum, and some of them extend through
the septum to the other side, while  others pass to
the corpus spongiosum urethra.

            The EXTERNAL ILIAC,

   The great artery of the lower extremity, appears
soon after birth, like a continuation of the primitive
iliac, and proceeds along the brim of  the pelvis be-
hind the peritoneum, to  Poupart's ligament or the
crural arch, under which it passes.
  The psoas muscle is at first in contact with it on
the outside, and the internal iliac vein on the inside.
As it passes  under Poupart's ligament, it is immedi-
ately anterior to the psoas and iliacus  internus mus-
cles where they are united, and the crural nerve is
exterior to it.  Before it arrives  at the lower  edge
of Poupart's ligament, it sends off

              The Epigastric Artery,

  Which arises  on its internal side,  and proceeds
downwards and inwards about half an inch, then it
turns upwards and inwards, and continues in that
direction for a small distance, after which its course
is less oblique.  It passes between the peritoneum
and the abdominal muscles, behind the spermatic
cord, and the round ligaments in females.
  It  generally changes its  oblique  direction   after
passing about two inches, and then proceeds in con- 
        General Account of the Femoral Artery.   289

tact with the rectus, and very near its external edge.
its ramifications are expended upon the anterior pa-
rietes of the abdomen; and, after it has arrived as
high as the umbilicus, it commonly divides into
branches, which often inosculate with the ramifica-
tions of the internal mammary.*
   An artery, which is rather smaller than the epi-
gastric, arises nearly opposite to it, but rather lower,
from the external side of the external  iliac.  It is
called

       The Circumflex Artery of the Os Ilium,

   And proceeds upwards and outwards to the upper
margin of the os ilium,  along which it continues
very near to the spine.  It is distributed principally
to the abdominal muscles, to the iliacus internus and
the psoas, and the parts contiguous.
   The artery of the lower extremity, after passing
under Poupart's ligament, takes the name of

                FEMORAL Artery,

   And proceeds downwards in a direction so spiral,
that although it is in front at the upper part of the
thigh, it is completely  behind at the lower part.  It
sends branches to the muscles of the thigh, as the
aorta does to the viscera of the abdomen, viz. by a
few large vessels which extend and ramify to a great
distance among them.
   The situation of the abductor muscles, and their
attachment to the os femoris, is such, that the artery
in this course must necessarily perforate their com-

  * Several respectable surgeons have been taught by experience, that
when the abdomen is distended by ascites, the position of the epigastric
artery is so much altered, that it will sometimes be found in the middle^ of
the oblique line, which extends from the umbilicus to the superior anterior
spine of the ilium.
  vol. ii.               37 
290  Branches of the Profunda and the Femoj-al.

mon tendon, which it docs at the distance of one-
third of the length of the bone from its lower end.
The aperture in this tendon corresponds  precisely
with the general course of the artery; and before
the artery enters this perforation, it is  on the inter-
nal side of the bone; after it has passed the perfo-
ration, it is on the posterior side of  it.  After pass-
ing through the tendon of the abductors, it is deno-
minated The Popliteal Artery, and it retains this name
until it divides.
   It then proceeds downwards, being very near the
bone, and between the tendons ofthe  flexors ofthe
leg, covered  by the great nerve of the lower extre-
mity, and very often also by the vein.  After cross-
ing the articulation of the knee, when it is between
the  heads of  the gastrocnemii muscles, at the
lower edge  of  the  popliteus  muscle,  it  divides
into the anterior tibial and the common trunk of the
peroneal and posterior tibial arteries.
   The  femoral artery, soon after  emerging from
Poupart's ligament, sends off very small branches to
the inguinal glands, and other contiguous parts.  It
also sends off the

                 External Pudics,
   Which are two or three small arteries that are
 generally spent upon the Scrotum in males, and the
 Labia Pudendi in females.
   About two inches below Poupart's ligament, the
 great branch which has been called  the  muscular
 artery of the thigh, leaves it.   This vessel is com-
 monly denominated
                arteria profunda.
   It arises from the back part of the trunk of the
 femoral, and passes downwards and  backwards, in
 a way that has been compared to the separation of 
     Branches of the Profunda and the Femoral.  291

the internal iliac and the external.   Very soon after
its origin, it sends off two branches, which proceed,
one on the internal, and the other on  the  external
side ofthe thigh, and are called the circumflexa in-
terna and externa.  It  then  passes downwards be-
hind the  trunk of the  femoral, and sometimes very
near it, on the adductor muscles, and finally divides
into branches, which are called the Perforating.

             The External Circumflex
  Sometimes arises from the femoral, but most com-
monly is  a branch ofthe profunda, as above stated.
It passes under the rectus and tensor vaginae femoris
towards the great trochanter, and generally divides
into two branches, one of which continues in the
transverse direction, and sends  branches to the up-
per and back part ofthe thigh, and the parts conti-
guous to the joint; while the other descends in the
course of the rectus femoris muscle, and some of its
ramifications extend near to the outside of the knee.

              The Internal Circumflex
   Is often smaller than the other. It generally passes
between the psoas, and the pectineus muscles, and
continues round the thigh  towards the lesser  tro-
chanter.  Its ramifications are expended on the up-
per portions of the adductor muscles and the mus-
cular parts contiguous to the lesser trochanter.  It
also sends branches to the articulation.

             The Perforating Arteries
   Are two or three ramifications of the profunda,
which pass through the adductor muscles, and are
 expended upon the flexor muscles on the back of
 the thigh. Some ofthe terminating branches ofthe
 profunda itself are also called perforating  arteries.
   The next branch of importance which is sent off 
292
Branches about the Ham.
by the femoral artery, leaves it before it enters the
aperture in the tendon ofthe adductors, and is called
             The Anastomotic Artery.
  This vessel soon inclines downwards.  Its ramifi-
cations  extend into the vastus internus  muscle;
some of them follow the tendon of the adductors,
and ramify about the internal condyle.
  Several small branches go off from the great ar-
tery soon after it passes through the tendon of the
adductors, which are distributed to the contiguous
muscles.  Some of them are also called
               Perforating Arteries.
  Among them is  the  principal Medullary artery of
the os femoris.
  In the ham, the great vessels there called

                POPLITEAL,
generally send off several small branches.  Two of
them  go off on the inside, one  above and the other
below the knee; and two on the outside in the same
manner. They are  named, from their situation, The
Superior and  Inferior Internal, and The Superior and
Inferior  External Articulary Arteries.
  The Superior Internal artery perforates the tendon
ofthe adductors above the internal condyle, and ra-
mifies minutely on  the inner side of the joint.
  The Superior External artery passes through the
lower portion of the biceps above the external con-
dyle, and ramifies minutely on the outer side of the
joint.  Its superior ramifications anastomose with
those of the descending branch of  the external cir-
cumflex, while its  inferior ramifications communi-
cate with those of the corresponding artery below.
  The two inferior arteries originate nearly opposite
to the middle ofthe joint, and  pass downwards.
  The  Inferior Internal  artery passes  under the 
Artery of the Leg.
293
internal head of the gastrocnemius muscle, on the
posterior and internal side of the head of the tibia.
Its ramifications communicate with those of the cor-
responding artery above and of the tibialis antica.—
Below they also extend to the interior of the joint.
  The Inferior External artery passes under the ex-
ternal head of the gastrocnemius and the plantaris
muscle, and continues under the external lateral  and
the capsular ligament.  It is distributed on the ex-
ternal and inferior part of the articulation, and sends
also some branches to the interior ofthe joint.
  There is frequently an azygous  vessel, called the
Middle Articular artery, which arises from the back
of the popliteal, and  is distributed to the posterior
part of the articulation.
  The popliteal artery, after this, sends off a few
small branches to the heads of the muscles of the
leg, and among them one of considerable length, to
each ofthe heads ofthe gastrocnemii.  At the under
edge of the popliteus muscle, it sends off horizon-
tally a large branch which passes  directly forward
between the tibia and fibula, above the commence-
ment of the interosseous ligament.  After this it con-
tinues to descend, nearly in the  same direction, un-
der the soleus muscle, behind the  tibia; but before
it has proceeded further than twelve or fifteen lines,
it sends off a branch which forms an acute angle with
it, and  approaches near the fibula, along which it
descends.
   The branch sent off anteriorly, is called the An-
terior Tibial artery.
   The main trunk, which continues downwards, is
called the Posterior Tibial artery ;
   And the branch which descends near the fibula is
called the Peroneal  or Fibular artery. 
 294       Anterior Artery of the Leg.


            The anterior tibial Artery,

   After its arrival on the anterior part of the leg,
 passes down close to the interosseous ligament, with
 the tibialis anticus muscle on the inside, and the ex-
 tensor communis on the  outside, in the first part of
 its course; and afterwards, with the extensor pollicis
 pedis on the outside of it.  It gradually inclines in-
 ternally as it descends, so that a little above the an-
 kle it is upon the front part of the tibia. It proceeds
 thence with the  tendons  of the extensor digitorum
 pedis, under the annular  ligament, to the upper sur-
 face of the foot, on which it continues to the inter-
 Btice ofthe first and second metatarsal bones, where
 it  descends to anastomose in the way presently to
 be mentioned.
   In this course it sends off, soon after it has arrived
 at its anterior  situation, a recurrent branch, which is
 distributed to the heads of the muscles and the liga-
ments of the articulation, and which anastomoses
with the branches of the inferior articular arteries.
It  also sends off, on each side, many arterial twigs
to the contiguous muscles, and very frequently one
branch of considerable size, which passes down near
 the fibula.
   When it has arrived near the end of the  tibia, it
sends a branch on each side, called the Internal and
External Malleolar.  On the top of the  foot, among
 several smaller arteries, it sends off a branch under
the extensor brevis  digitorum pedis, which passes
 outwards  and forwards,  and  supplies  the muscles,
 &c on the upper part of the foot.  This vessel  is
 called Arteria Tar sea. There is also another  branch,
 called Metatarsea, which  generally arises  about the
 middle of the foot, and passes obliquely outward and
 forward, supplying the contiguous parts. 
      Posterior Tibial and Peroneal Arteries.   295

  The Anterior Tibial artery, having arrived at the
space between the metatarsal bones of the first and
second toes, bends down to the sole of the foot, but
previously sends off a branch which passes near the
external edge of the  metatarsal bone of the great
toe,  and divides into two  branches,  one  of which
goes to the outside of the  great toe, and the other
to the opposite side of the toe next to it.

           The posterior tibial Artery,
  After sending off the anterior tibial, parts with the
Peroneal or Fibular, as has been already stated, and
then continues on the back of the tibia, behind the
internal ankle, to the sole of the foot.

           The Peroneal or  Fibular Artery,
   Is  not  commonly so large as  either of the two
other arteries of the  leg, nor is it  so constant.  It
passes down very near the internal edge of the fibu-
la.  It is in contact, for some distance, with the ti-
bialis posticus muscle, and is anterior to the soleus
and the flexor pollicis longus; it sends branches to
the contiguous muscles.   After it has passed along
two-thirds of the  length of the fibula, it frequently,
but not always, divides into  an anterior and a pos-
terior branch.
   The  anterior peroneal soon perforates the interos-
seous ligament, and passing down some distance on
 its anterior surface,  continues to the ankle and up-
 per surface ofthe foot.  It gives ramifications to all
 the contiguous parts in its  progress, and  anasto-
 moses with some of the small ramifications of the
 tibialis antica.
   The posterior peroneal branch is the continuation
 of the  main trunk.  It  passes behind the external
 malleolus, and ramifies upon the  external side of the
 foot. 
296
Arteries ofthe Foot.
   The posterior tibial artery passes down, inclining
 rather obliquely inwards, between the gastrocnemius
 internus, which is posterior to it, and the tibialis
 posticus and flexor digitorum, which are anterior to
 it.   Upon the leg it gives off many small  branches,
 one of which, termed  the Arteria Nulritia Tibiae,
 comes off high up,* and, after ramifying as it de-
 scends, sends a branch  to the medullary foramen of
 the tibia.
   At the lower part of the leg the Posterior  Tibial,
 is situated rather superficially between the tendo
 Achillis  and the tibia.  It  proceeds thence behind
 the internal ankle in a  deep situation, covered by
 an annular ligament, and passes between the abduc-
 tor muscle of the great  toe and the bones of the tar-
 sus.   It then divides into two branches—the internal
 and  the external plantar arteries.

            The Internal Plantar Artery

  Is commonly much smaller than the other ramifi-
 cation.   It passes in the direction of the internal
 edge of the foot, but at  some distance from it, and
 often lies between the aponeurosis plantaris and the
 abductor pollicis.  It frequently terminates by anas-
 tomosing with one of the arteries of the great toe,
 and in its course sends off several branches to  the
contiguous parts on each side of it.

          The External Plantar Arteries

  Is the continuation of the main trunk.  It proceeds
outwards and forwards between the short flexor of
the toes  and the flexor accessorius;  and continues
afterwards between the first of these muscles and the
abductor of the little toe. At the metatarsal bone of

      • This artery sometimes comes off from the popliteal. 
Arteries of the Foot.
297
the little toe it begins to curve, and continues its cur-
vature across the other metatarsal bones to the in-
terstice between the great toe and the one next to
it, passing between the tendons of the long extensor and
the metatarsal bones.  At the interstice  above  men-
tioned, it anastomoses with the tibialis antica. The
curvature, thus formed, is called the Arcus Plantaris.
  In this course, the External Plantar sends off se-
veral branches, to the heel and the parts of the foot,
especially on the external side;  the  deep-seated
parts of the foot being supplied from the curve.
  Digital branches go off  from  the  curve, as they
do in the hand, from the curve ofthe ulnar, fhere
is first a small branch  to  the  outside of the little
toe; and then three regular branches, which pass to
the junction of the roots of the four small toes, and
divide, like the digital arteries ofthe hand, so as to
send a branch to the side of each toe.  These di-
gital arteries pass between the muscle called Trans-
versalis Pedis and the metatarsal bones.   Near  the
heads of these bones, each of them generally sends
off two arteries that pass upwards between the in-
terossei muscles and the bones, and anastomose with
the ramifications from the  top of the foot.
   The External Plantar, soon after sending off  the
third digital  artery, anastomoses with  the  anterior
tibial,  and then  continues to  the junction of  the
root of the great toe with  the one next to it,  when
it divides into two branches, which go to  the  op-
posite  sides  of those toes.  In its course it also
sends a branch to the internal side ofthe great toe.
vol. n.
38 
CHAPTER III.
   of the particular distribution of the veins.

  Anatomists of great respectability have very diC
ferent sentiments respecting the best method of de^
scribing the veins.  Some of them, in order  to fol-
low  the course of the circulation, commence with
(he small veins, and  proceed  to the large trunks
which are formed by their union. Others begin with
the great veins that empty into  the heart, and pro-
ceed from them to the small  ramifications of the
venous system, in a direction the reverse of the cir-
culation.
  As the last method is the easiest for the student of
anatomy, it will be adopted here;  but it must al-
ways be kept in mind, that the blood flows from the
small veins into the larger, and  not from the latter
into the former, as the mode of description  seems
to imply.
  The great trunk of the venous system differs con«-
siderably from that of the arterial with  respect to
its connexion with the heart; for it communicates
With that organ in such a manner that, when viewed
from before, it appears like two vessels; one open-
ing into the upper, and the other into the lower part
of the right auricle.   When viewed  from behind, it
appears like a continued tube, three-fourths of which
are deficient anteriorly; and to the  margin of this
deficiency the right sinus or pouch of the heart is
connected.
  In some preparations of the  heart, where all the
great vessels connected with it are much distended
by the injection,  and the  pulmonary vessels are m- 
The Veins ofthe Heart.
299
jected first, the right auricle is so much pressed
upon from behind, by the vessels which go  to the
right lung, that the direction ofthe superior and in-
ferior portions ofthe vena cava, which thus commu-
nicate with it,  is altered.  Each of them is turned
obliquely forwards, so that it forms an angle with
the other.  This occasions them to appear more like
distinct vessels than they otherwise would do.
   The above mentioned portions of the great veins
are denominated the Superior or Descending, and the
Inferior or  Ascending Vena Cava; as if they were per-
fectly distinct and unconnected with each other.

               The Coronary Veins,

   Which are exclusively appropriated to the heart,
may be considered here, as they are  not included
in the general arrangement of the veins.
   The great vein of  the heart begins at the lower
part of the right  auricle, very near to the septum,
which divides the two auricles.  It soon proceeds to
the left in  a circular direction, surrounded with adi-
pose matter, in the deep groove which exists between
the left auricle and the  left ventricle.   It continues
between the auricle and ventricle, until it is imme-
diately over  the septum, which divides the two ven-
tricles. Here its direction changes, and it proceeds
to the apex of the heart, where its small ramifications
anastomose with others soon to be described. In its
course round the basis of the left ventricle, it sends
off several branches, one of which is  considerable,
that proceed from the basis towards the apex of the
heart, ramifying on the surface of the left ventricle.
   A second vein, much less than the first, appears
to proceed from the  great vessel  at its commence-
ment,* and  continues  on the lower flat surface of

        • It often opens into the auricle by a separate orifice. 
300   Superior Vena Cava and its Great Branches.

tbe heart, between the two ventricles, to  the  apex,
accompanied by a branch ofthe right coronary ar-
tery.  This has been called  the Middle Vein of the
heart.
  In addition to these there are several veins which
begin at the right auricle, and extend on the surface
of the right ventricle towards the apex of the heart.
These have been called the Anterior Veins.

                   section i.

Of the  SUPERIOR  or  DESCENDING VENA
   CAVA, and the Veins ivhich communicate with it.
  This  great vessel proceeds upwards from the su-
perior and posterior part ofthe right sinus or pouch
ofthe heart;* and a portion of it is so involved by
the pericardium, that it seems to be included in that
sac, as the heart is in  this situation. It is somewhat
anterior as well as to  the right of the aorta.  It con-
tinues above the pericardium, adhering to the right
lamen of the mediastinum, and  rather inclining for-
ward.  When it is as high as the  lower margin of
the upper rib, it sends off a very large branch, which
conveys the venous blood of the left arm and the left
side ofthe head and neck.  This large vein, which
is very important, both on account of its size and
its situation, proceeds in a transverse direction with-
in the sternum, almost in contact with and but little
below the upper and  internal margin of that  bone.
Immediately behind or within the  origin of the left
sterno-mastoid muscle, it divides into the left sub-
clavian,  which preserves a transverse course, and
the left internal  jugular, which  proceeds to the ca-
vity ofthe cranium by the foramen lacerum.
   After  sending off this transverse branch  to the
    * See the description ofthe heart, in page 51, of this volume. 
Vena Azygos.
301
left, the great vein continues npwards and behind the
right  sterno-mastoid  muscle, and there  sends off,
nearly at right angles, the right subclavian vein. After
it has parted with this vein, it takes the name of In-
ternal Jugular, and continues to the right foramen
lacerum, in the basis ofthe cranium. The superior
vena  cava is, therefore, principally formed by the
union of the subclavians and internal jugulars from
each side ofthe body.
  Immediately after the superior cava rises above
the pericardium, before it divides as above stated, it
sends off, from its posterior part, a large vein which
is single, and therefore called

                  vena azygos.
  This vessel  projects  backward above the  right
pulmonary artery and right branch of  the trachea,
and then curves downwards behind them.  It pro-
ceeds down the spine  to the right ofthe aorta and at
a small distance from it, into the abdomen, between
the crura ofthe diaphragm, and sometimes between
some of the portions  of that muscle, which are  at-
tached to the dorsal vertebrae.   In  the abdomen it
often anastomoses either with the lumbar veins or
the vena cava.
  The azygos frequently  sends off several  small
veins from its curvature to the contiguous parts, and
also the right Bronchial Vein,  which passes  along
the ramifications of the trachea into the  substance
ofthe lungs.*  In its  course downwards it gives off
branches to the oesophagus, some of which are con-
siderable.
   The Inferior Intercostal Veins originate directly or
indirectly from the azygos.  In some cases there is
no Superior Intercostal on the right side; and then
* This bronchial vein sometimes arises from the superior cava. 
 302         Inferior Intercostal Veins.

 the two or three uppermost of the right intercostals
 are also derived from the azygos;  and often origi-
 nate from it by a common trunk, which soon divides.
 Most commonly the ten inferior  intercostals on the
 right side proceed directly from the azygos, and ac-
 company the intercostal  arteries.  Their  posterior
 branches pass into the vertebral cavity, and com-
 municate with the veins which are there.
  About the sixth or seventh rib, the vena  azygos
 frequently sends off a branch to the  left which de-
 scends on the left side of the vertebrae, and sends off
 those left intercostal veins which are below its  ori-
 gin. It passes through the diaphragm with the aorta,
 or to  the left of it, and anastomoses either with the
 azygos itself, or in a way which is analagous to the
 anastomosis of that vessel.
  The Vena Azygos may be regarded as the great
 trunk of the veins of the parietes  of  the thorax,
 which are thus collected, because  they could not
 with convenience pass singly to  the  vena cava, as
 the arteries do to the aorta.
  Soon after sending off the vena azygos, the Su-
perior Cava sends off the great transverse  branch
 above mentioned.  From this it  continues upwards
 but a short distance,  when it divides, behind the
 right sterno-mastoid muscle, into the right  subcla-
 vian and right internal jugular.
  The branches of the superior cava,  which thus
 intervene between the great trunk and the subdi-
 visions behind the sterno-mastoid muscles, are often
 called the Subclavian Veins; but they do not appear
 to be accurately named.  For, 1st, they are not situ-
 ated under the clavicle, and, 2dly, they are the com-
 mon trunks ofthe subclavians and internal jugulars
 united.
   There is a difference in the places where some of
 the smaller veins originate on each side. The inter- 
Superior Intercostal Veins.
308
nal mammary and the  inferior thyroid, on the right
side, arise from the superior cava, or from the sub-
clavian at its origin. On the left side they arise from
the subclavian.
         The superior intercostal Veins
  Are somewhat different on the two sides. That on
the  right is  often the smallest  and the least exten-
sive.  It commonly originates from the posterior and
inferior  part ofthe subclavian opposite to the origin
of the vertebral,  and is generally distributed to the
first and second intercostal spaces, but rarely to the
third.
   The Left  Intercostal frequently originates near the
left internal mammary, and sometimes in common
with it.   It descends behind the aorta, on the left of
the spine, and commonly sends off the six upper in-
tercostal veins, of which* the two or three superior
pass  upwards from a part of the vein which is oppo-
site to the third dorsal vertebra.   Its extent is very
different in  different subjects.   In some instances it
passes so low as  to supply the seventh or eighth in-
tercostal space.  This vein also gives off the Left
Bronchial Vein, which  sends branches to the oeso-
phagus and bronchial  glands.
               The vertebral Veins
   Arise from the subclavians, but sometimes they
proceed differently in  different subjects: the right
passing behind, and the left before, the subclavian
artery of its respective side. Each of them, however,
becomes contiguous to  its corresponding artery.
When it has arrived at  the place in the transverse
processes, where the artery enters the vertebral ca-
nal, it sends off an external branch, which passes up,
before and  nearly in contact with, those processes,
and gives ramifications  to the contiguous muscles, 
304              Vertebral Veins.
and also to the cavity of the spine. These last men-
tioned ramifications enter by the lateral apertures
between the  transverse processes, and anastomose
with the veins and sinuses of the cavity. The branch
often  finally terminates in the lateral sinus  of the
dura mater, bypassing through the foramen near the
mastoid process  of the temporal bone.  Tbe Main
Trunk ofthe vertebral vein generally sends off another
external branch to the muscles near the basis ofthe
neck, and afterwards enters the canal with the ver-
tebral artery.  While in this canal, it generally sends
off two branches through each of the lateral aper-
tures between the vertebrae.  One of these branches
passes backwards to  the muscles of the neck, and
the other proceeds into the great spinal cavity, and
communicates with  the venous  sinuses.
   When it has  arrived at the  atlas, the Vertebral
vein sends branches to the contiguous  muscles of the
neck.  It also frequently sends a branch through the
posterior condyloid foramen of the  occipital bone
to the lateral  sinus.
   It is evident, from these circumstances that the
vertebral vein carries a portion of blood  from the
sinuses  of the brain and of the spinal  marrow  as
well as from the  muscles of the  neck, into the sub-
clavian veins.
   The veins of the  head are frequently very diffe-
rent in different subjects.

         The INTERNAL JUGULAR,
   Already mentioned, is often almost exclusively ap-
propriated to the cavity ofthe cranium; and all the
exterior veins of the head are ramifications of one or
more smaller vessels, which pass up superficially  on
the neck, and are  denominated External Jugulars.
In some instances almost all the exterior veins ofthe
head are united  to the internal jugular at the upper 
               The Internal Jugular.            305

part ofthe neck,  and it of course conveys the blood
of the exterior as well as of the  interior parts of
the head.  Frequently these veins are divided be-
tween the  internal and  external jugulars, but they
are divided very differently in different subjects.
  The  Internal Jugular, however,  almost  always
passes in the same direction from the inside of the
origin of the sterno-mastoid muscle to the posterior
foramen lacerum of the cranium.  It is deeply seat-
ed on the external side of the common carotid ar-
tery, and under the sterno-mastoid muscle. Between
the upper margin of the thyroid cartilage and the
angle of the lower jaw, it often sends off branches
which are very different in different subjects, but
commonly pass  to the  anterior parts of the neck
and face: above  these it generally sends another to
communicate  with  the external jugular.   One of
the branches  which often go off from the internal
jugular is that which corresponds with the superior
thyroid or laryngeal artery.   This vein, which has
sometimes been  called the Guttural,  sends many
ramifications  to  the thyroid gland.   The Ranular
veins, which are so conspicuous under the  tongue,
are  also derived from it;  and it likewise sends
branches to the larynx and pharynx.
  Before the internal jugular enters the foramen la-
cerum,  it suffers  a partial dilatation,  which is gene-
rally larger on one side than the other.*  This dila-
tation occupies  the fossa at the foramen lacerum.
After passing  through the aforesaid foramen, the in-
ternal jugular terminates in the  lateral sinuses of


  • When the veins of the neck are injected, it very often appears tha
a considerable portion of the internal jugular is much larger on one side
than the other, as if it were affected with varicose distention.
  It also often appears that the general arrangement ofthe exterior vein is.
different on the two sides of the head and neck.
VOL. II.
39 
306
The External Jugular.
the dura mater.* These and the other sinuses with-
in the cavity of the cranium are important portions
ofthe venous system, which are interposed between
the smaller branches spread upon the pia mater and
the great trunks of the neck.  They are described
in the account of the brain, Vol. I. page 324.)  Into
these sinuses  the very numerous  veins of the  pia
mater open, proceeding to the sinuses in a direction
the reverse of that in which the blood flows in those
channels.
   These veins are divided very minutely on the pia
mater before they enter the substance ofthe  brain.
   Into one of these  sinuses, denominated the Ca-
vernous, the ophthalmic vein discharges its contents.
This vein proceeds from  the anterior part of the   ]
sinus into the orbit ofthe eye through the sphenoid
fissure.t    Its  ramifications  correspond generally
with those of the ophthalmic artery,^ and some of
them pass out of the orbit to  anastomose with the   '
branches of  the facial vein.                          '
   The superficial veins of the  neck  are variously
arranged in different persons.   There is often one
considerable vein.

         The EXTERNAL JUGULAR,

   Which  is sent off by the subclavian, very near its
union with the internal jugular; but sometimes it
goes off from that vein much  nearer the shoulder.
There are sometimes two external jugulars, an ante-

  * It is asserted that the internal coat, or lining membrane of the internal   f
jugulars, is continued into the lateral sinuses, and extends throughout all
the sinuses of the dura mater; so that the blood, during its passage through
the sinuses, does  not come in contact with any membrane different from
that of the veins.
  -{-Sec the account of this fissure in vol. i. p. 71.
  i The Vasa Yorticosa of the choroides are one ofthe exceptions to this.
Sec vol. i. p. 364. 
  General Account of the Great Vein of the Arm. 307

rior and a posterior, nearly of equal size.  More fre-
quently one of them is much smaller than the other.
In a majority of cases, the principal external jugular
goes off near the junction of the internal jugular and
subclavian, as  above stated, and proceeds upwards
towards the angle ofthe lower jaw, passing between
the platysma myoides and the sterno-mastoid mus-
cle.  It  often  sends off, at the basis of the  neck,
one or more branches to the contiguous muscles, and
then proceeds upwards. Near the angle of the jaw, it
often communicates with the internal jugular: it then
continues upwards, covered with the parotid gland,
near  the temporal  artery,  and  finally divides into
superficial and deep-seated temporal branches.
  The External Jugular, near the angle  of the jaw,
often sends offthe facial vein, which crosses the basis
of the lower jaw, near the facial artery, and distri-
butes branches to the side of the  face and to the fore-
head.   It also  very often sends off, near this place,
the internal maxillary vein, which generally ramifies
in such a manner that its branches correspond with
those ofthe internal maxillary artery.  Veins which
correspond to some of the other branches of the
external  carotid  artery, the lingual, occipital, &c
are often sent off near this  place by the external ju-
gular. They take the names ofthe arteries to which
they correspond, and commonly accompany them.
           The  SUBCLAVIAN Vein,
  Although it originates differently on the two sides
of the neck, is  situated alike  on each of them.
After parting with the internal jugular, it proceeds
over the first rib, under the clavicle, and does not pass
between  the scaleni muscles, as  is the case with the
arteries,  but before the anterior  muscle.  It soon
joins the great artery of the arm, and proceeds be-
fore or below it to the axilla. In this situation it gives 
308  General Account of the Great  Vein of the Arm.

off branches to the contiguous parts, which corre-
spond with those given off by the  artery.  In  this
course it also often gives off a large branch, called
the
                    cephalic,
  Which soon becomes superficial,  and proceeds
downwards between the margins  of the deltoid and
pectoral muscles: it continues  superficial on the
external side ofthe biceps muscle, sending off many
subcutaneous branches. Near the external condyle
ofthe os humeri, it generally sends off a branch to-
wards the middle of the anterior part of the fore-arm,
which is called  the Median Cephalic, and also some
other superficial branches.  It then continues over   j
the radius, and inclining to the back ofthe fore-arm,
until it arrives at the back ofthe hand, where  it di-  W
vides into branches, some of which go to the thumb.   {
  In the axilla, the great vein, there called

            The AXILLARY Vein,
  Generally divides into two or three branches.  One,  "\
which is commonly the largest, and appears like the
continuation ofthe main trunk, is called

                The basilic Vein.
  This vessel passes down, deeply seated, to the bend
ofthe elbow. It becomes superficial near the inter-
nal condyle, and divides into several branches.—One
of these generally  proceeds to join the median
branch of the  cephalic, and from the union of the
two branches  is  formed the  median vein, which
passes down near the middle of the anterior part of
the fore-arm. This vein generally sends off a branch
which proceeds internally, and anastomoses with the
deep-seated veins ofthe fore-arm.
   There are frequently two other branches of the
basilic vein.  One, which is small, passes  down on 
        Situation of the Inferior Vena Cava.       309

the ulnar side of the anterior part of the fore-arm,
but does not extend to the wrist. The other passes
down on  the ulna, and  gradually proceeds to the
back of  the hand,  when  it divides into several
branches, one of which is generally appropriated to
the little finger.
   The  axillary  vein, after the Basilic leaves it,
sometimes divides into two branches, and sometimes
continues undivided. In either case it accompanies
the humeral artery, and takes the name  of humeral
Vein or Feins.   It sends off  branches which corres-
pond to those  of the artery, and continues to the
bend of the elbow; here it is so divided, that two
of its ramifications accompany each ofthe three ar-
teries of the fore-arm.  These ramifications some-
times communicate with  each other  by anastomo-
sing branches near the elbow,  and they communi-
cate also with the superficial veins.

    The superficial veins of the arm are so different in differ-
      ent  subjects, that a general description will rarely ap-
      ply accurately to an individual case.  It may, however,
      be observed, that a Cephalic vein will generally be found,
      which very frequently arises from the subclavian instead
      of the axillary, and commonly continues to the hand on
      the  radial side of the arm.  The superficial veins, on
      the  ulnar side of the fore-arm, very frequently are
      branches of a large vein which accompanies the humeral
      artery  to the elbow, viz. the  basilic; but the median
      vein,  formed by branches of the cephalic and  basilic
      veins, is very often not to be found.
                    SECTION II.

 Of tlie INFERIOR VENA CAVA and the  Veins
             which are connected with it.

  This great vessel exceeds the Superior Cava in
diameter.  It proceeds from the lower part of the 
 310     ' Situation ofthe Inferior  Vena Cava.

 right auricle, and very soon perforates the diaphragm,
 at a small distance in  front ofthe spine, and rather
 to the right ofthe centre.   As the  pericardium ad-
 heres to the diaphragm at this place, the vessel ap-
 pears to leave it abruptly.  Immediately after leaving
 the diaphragm, it proceeds along a groove in the
 posterior edge of the liver, formed by the great lobe
 and the lobulus Spigelii.*   After leaving the liver,
 it continues downwards, inclining backward and to
 the left, and is soon in  contact with the aorta, which
 is on the left of it.  It  accompanies the aorta to its
 great bifurcation, and divides in the same manner.
 It sends off, during this course, branches to the Dia-
 phragm, Liver, Right  Renal Glands, the Kidneys,
 and the Testicles; and also the Lumbar and Middle
 Sacral veins.

            The Inferior Phrenic  Veins
   Are thus denominated to  distinguish  them  from
 other veins, which are derived from  the  internal
 mammary, &c  They generally accompany the phre-
 nic arteries, and are distributed in the same manner.

                The  hepatic Veins

   Pass off from the vena cava, nearly at right angles
 into the substance of  the liver, while it is in the
 groove of that viscus,  and before it has proceeded
 more than  eight or ten lines from the heart.
   They arise  from the anterior  part of the vena
cava,  and are  generally three  in number.   Some-
times there are two only, but then one of them di-
vides immediately after it  enters  the  substance  of
the gland.
  The distribution of these vessels in the liver has
* Sometimes it is completely surrounded by the liver. 
        The Vena Portarum.—Splenic Vein.     311

been detailed in the account of that organ, and there-
fore need not be  stated here; but the veins which
unite to form  the  vena  portarum, and  the trunk of
that great vein also, before it is connected with the
liver, may be regarded  as  a  portion of the regular
venous system, and ought now to be considered.

           The VENA PORTARUM

  Passes downwards from the great sinus ofthe liver
behind the pancreas, and inclining to the left. In this
course it sends branches  to  the gall  bladder, the
stomach and pylorus, and the duodenum. At the up-
per and posterior  edge  of the pancreas, it sends off
a very large branch to the spleen, which often passes,
with slight meanders,  along  a groove in the pan-
creas.
              The SPLENIC Vein

  Often sends off the  inferior mesenteric  vein,
which proceeds downwards between the aorta and
the left portion ofthe colon.   It also sends off some
of the coronary veins  and the left gastro  epiploic
vein to the stomach; many small branches  to the
pancreas; and, finally, either  from the main trunk
or its branches before they enter the spleen, the venas
breves, which pass to the great extremity ofthe sto-
mach.  Before it  enters the spleen, it forms several
ramifications, which accompany the branches of the
splenic artery.
   After sending off the splenic, the Vena Portarum
takes the name of

     The SUPERIOR  MESENTERIC Vein;

   Which is larger than the splenic, and passes/rom
behind the pancreas, before the transverse portion ofthe 
 312  Superior Mesenteric Vein,  tfypq^mt. Veins.

 duodenum, into the mesentery; where it accompanies
 the superior mesenteric artery.
   It is evident that the above described portion of
 the vena portarum simply performs the functions of
 a great vein; but when it takes on the arrangements
 for entering the liver, it no  longer acts like a vein,
 but an artery.
   The lower portion ofthe trunk of this vein and its
 ramifications is  denominated  Vena Portac  Ventralis.
 The part which  ramifies  in the liver, Vena Portae
 Hepatica.
                The Capsular Veins

  Are small vessels, one on each side.  That on the
 right passes from the vena cava to the right glan-
 dula renalis.  That  on the left arises from  the  left
 emulgent vein.

      The EMULGENT, or RENAL  Veins,

  Are very large vessels; and, like the arteries, go
 off nearly at right angles, one to each  kidney.
  The right emulgent vein is not so long as the left,
 and it is rather anterior to its corresponding artery.
 The left emulgent, in its course to the kidney, crosses
 the aorta, and is anterior to it.
  These veins pass  to the sinus of each kidney, and
 ramify before they enter it.  The ramifications fol-
 low those of the  arteries.

               The Spermatic Veins

  Arise one on each side; the right from the vena ca-
 va and the left from the emulgent vein. They proceed
 downwards behind the peritoneum, and on the psoas
 muscle generally divide into many branches which
 communicate with each other as they progress down-
 wards, and form a plexus denominated Corpus
Pampiniforme.  These branches  proceed in  the 
         internal Iliac and its Ramifications.      313

spermatic cord to the back of the testis.  The prin-
cipal part enters the body of that gland; but some of
the branches go to the  epididymis.   In  females the
spermatic vein, like the artery, passes to the ovary,
the uterus and its appendages, &c

               The Lumbar Veins
  Correspond to the arteries of the  same name.
They arise from the  posterior and  lateral  parts of
the inferior cava, and those on the left side  pass un-
der the aorta.
             The Middle Sacral Vein
  Resembles the artery of the same name in its ori-
gin and distribution.
  The INFERIOR VENA CAVA accompanies
the aorta to the space between  the fourth  and fifth
lumbar vertebrae, and there it  also divides into the
two
          PRIMITIVE ILIAC VEINS.
  The left vein crosses behind the artery of the right
side, and rather behind the left primitive iliac artery,
which it  accompanies until they are opposite to the
junction  of the sacrum and ilium, when it divides
again, like  the artery, into the internal and external
iliac veins.

The INTERNAL ILIAC, or HYPOGASTRIC
                      Vein
  Descends into the  pelvis behind the artery, which
it accompanies.  Its ramifications correspond in ge-
neral with those of the artery, and, therefore,  need
not be particularly described.
               The VENjE  VESICALES
  Have  such  peculiarities that their ramifications
require particular attention. They arise from the hy-
  vol. n.              40 
314      Ramifications ofthe External Iliac.

pogastric, very near the origin of the obturator, and
are large as well as numerous.
  They are somewhat different in the two sexes. In
men they form a remarkable plexus on the lateral
and inferior portions of the bladder, and on the ve-
siculae seminales.   This plexus extends more or less
to the prostate: from it a number of veins proceed
to the symphisis ©f the os pubis, which communicate
in their course with the pudic vein.  From thence
arises the great vein  ofthe penis, which proceeds in
the groove between the corpora cavernosa, and ter-
minates in the glans  penis.  This vein often divides,
near the root ofthe penis, into two: one of which is
in the groove, and the other more superficial.*
  In females, the venae vesicales form  a considera-
ble plexus on each side of the bladder and vagina.
Many veins pass  from these to the upper portions
of the bladder and the contiguous  parts, and form
plexuses.   The clitoris has a dorsal vein like the
penis, and it originates in  a manner analogous to
the dorsal vein of the male.

         The EXTERNAL ILIAC Vein.

  The great trunk of the veins  of  the lower extre-
mity proceeds on the inside ofthe artery, under the
crural arch or Poupart's ligament.   Before it passes
from under the arch, it sends off two branches which
answer to the circumflex artery of the  ilium and to
the epigastric  artery.

               The  Circumflex Vein

   Arises from the external side of the iliac vein, and
passes towards the anterior end of the spine of the

  * The pudic veins accompany the arteries  of that name. They com-
municate with the plexus, as above mentioned,  and continue into the
penis. 
Veins of the Leg.             315
ilium.  It  divides into branches which accompany
those ofthe artery of the same name.

               The Epigastric Vein
  Arises from the external iliac, and accompanies
the epigastric artery. After passing a small distance
inward and downward, it turns up on the inside of
the abdominal muscles. In the first part of its course
it sends off some  small branches to the spermatic
cord.
  After passing beyond Poupart's  ligament,  the
name of the great vessel is changed from external
iliac  to

              FEMORAL  VEIN.
  It proceeds downwards at first on the inside ofthe
femoral artery,  but gradually changes  its relative
situation, so that in the thigh and in the ham  it is
behind or on the outside of that vessel.
  At a short distance below Poupart's ligament, af-
ter giving off some small branches to the external
organs of generation, and to the glands of the groin,
it sends off on the internal side of the thigh a very
large vein which is called the
                saphena major.
  This vein immediately becomes superficial,  and
passes down on  the internal side ofthe thigh, some-
what anteriorly; giving off some small branches to
the contiguous  parts soon after it originates;  and
many superficial veins afterwards.  It continues along
the inside ofthe knee and leg to the  internal ankle,
the anterior part of which it passes  over.   It  then
proceeds along the internal part of the upper surface
of the foot to  the middle, when it curves towards the
external edge, and joins the lesser saphena.  On the 
316  Instances of peculiar Arrangement ofthe Veins.

leg and foot it also sends off many branches, which
anastomose with each other, and with those of the
aforesaid vein.
  The femoral vein, after parting with the saphena,
soon sends off the vena profunda, and the circum-
flexa also, when they do not arise from the  profun-
da.  These veins are generally larger than the arte-
ries to which they correspond, and their branches
are more  numerous;  but they observe  the  same
course.
  The great vein accompanies the artery down the
thigh and  through  the  perforation in the  biceps;
but it  changes its relative position, so  that it  is
placed behind or on the exterior side of the artery
at the lower part of the thigh.   It is very often be-
hind it in the ham, where, like the  artery,  it takes
the name of popliteal.  In the ham it sends off an-
other superficial vein, which seems very analogous
to the basilar vein of the arm.   This is called
          The Lesser or External Saphena.
  It proceeds  from the ham over the external head
of the  gastrocnemius, and down the outside of the
leg, sending off many branches in its course. It passes
behind the external ankle and near the exterior edge
ofthe upper surface ofthe foot, about the middle of
which  it inclines  towards the great saphena, and
forms with it the anastomosis already mentioned.
  The popliteal vein, after passing across  the arti-
culation, ramifies like  the artery, but sends two
veins, which accompany each of the three  arteries
of the  leg.

  In a few instances some of the larger veins have
been found to be arranged in a manner very differ-
ent from that which is commonly observed. 
Pulmonary Vessels.               317
  One case of this kind has already been mentioned
in the account of the liver,* where the Vena Porta-
rum terminated in the  Vena Cava, below the liver,
without entering into it.
  Another very remarkable instance of peculiar ar-
rangement is to be seen in a preparation now in the
University of  Pennsylvania, in which  the  Inferior
Cava, instead of opening into the lower part of the
right auricle, passes behind  it, in the tract of the
Vena Azygos, and opens  into the Superior Cava, in
the place  where the  Vena Azygos  usually communi-
cates with that vessel, receiving the Intercostal Veins
in its course.
  In this preparation, the Hepatic Veins communicate
directly with the right auricle, at its lower part; the
middle and left hepatic veins forming one trunk before
they enter, and the right vein passing in singly.t

     Ofthe PULMONARY Arteries and Veins.
   Those portions of the Pulmonary artery and veins
which are distinct from the lungs  may be described
very briefly.
   It has been already observed,! that the pulmonary
artery arises from the left and most anterior part of
the basis of the right ventricle, and proceeds thence

  * See note to p. 132, of this volume.
  f The foregoing preparation was made by the present editor in 1814,
since which two other anomalous cases have occurred to him.
  1819. Case 1st. The ascending cava passed into the thorax on the left
side of the spine, and getting as far as its upper part, was joined there by
the trunk ofthe internal jugular and subclavian of the left side.  It there
passed across the vessels of the arch of the aorta and joined with the de-
scending cava.  The vessels of the liver entered the heart at the usual
place, in the lower part of the right auricle.
  1820.  Case 2d.  The trunk formed by the junction ofthe internal jugu-
lar and subclavian ofthe left  side, instead of taking its usual course, passed
down vertically, before the left branch ofthe pulmonary artery and before
the left auricle, then making a slight curve between this auricle and the
diaphragm joined with the ascending cava.—Ed.
  i See page  59 of this volume. 
 318            Pulmonary Vessels.  ,

 obliquely backwards, inclining gradually to the left
 side for about eighteen or twenty lines when it divides
 into two branches, which pass to the two lungs. This
 course places it under the curve ofthe aorta: for that
 great vessel passes over the right branch ofthe pul-
 monary: artery, and the right side ofthe main trunk
 of it, in such a manner that it proceeds downwards
 between the two branches,  and behind the angle
 formed  by their bifurcation.   From this place of bi-
 furcation a short ligament proceeds to the lower
 part of  the curve of the aorta, which is almost in
 contact with it.  This  ligament was originally the
 canal that formed the communication between the
 pulmonary artery and the aorta of the fcetus.  Each
 of the great branches of the pulmonary artery takes
 a direction backwards, and to its respective side. It
 soon joins the corresponding branch of the trachea
 and the  two pulmonary veins, being anterior to the
 branch  of  the trachea, and  above  the pulmonary
 veins. It is also invested, in common with them, by
 that portion of the pleura which forms the medias-
tinum, and thus enters into the composition of the
root of the lungs.
   The Pulmonary Veins are  four  in  number—two
on each  side. In  conformity to the mode of descrip-
tion which we have adopted, it may be said that they
arise from the sides of the Left Auricle, and proceed
nearly in a transverse direction, two of them to each
lung;  where they accompany the  branches of the
artery and  of  the  trachea, being invested  by the
mediastinum in common with these  branches.  It
has been observed that they differ from veins in
general, by preserving a diameter nearly similar to
that of the arteries which they accompany. 
SYSTEM  OP  AXATOMY.

              PART X.
                OF THE NERVES.

  The nerves are  those whitish cords which pass
from the brain and spinal marrow to the various parts
ofthe body.
  A general account of their origin is contained in
the description of the basis of the brain and of the
spinal marrow,* which may be considered as intro-
ductory to the present subject.
  The nerves, in general, appear to be bundles or
fasciculi of small cords, each of which is composed
of a series  of fibres that are still smaller.  These
fibres consist of medullary matter, which is derived
from the brain and spinal marrow, and  is enclosed
in a membranous sheath that  appears to arise from
the pia mater.  The smaller the fibre the more de-
licate is the  membrane which invests it.
  As the nerves proceed  from the brain and spinal
marrow, through the foramina of the cranium and
the spine, they are enclosed in a sheath formed by
the dura mater; but when they arrive at the exterior
extremities ofthe foramina in those bones, this coat,
derived from  the dura mater, appears to separate
into two  lamina.  The  exterior  lamen combines
with the periosteum, and the  interior continues to
■ See volume I. page 349. 
 320        General Structure of the Nerve.

 invest the nerve, but seems to change immediately
 into cellular substance; so that the exterior coat of
 the nerves may be regarded as composed of cellular
 membrane, which is continued from the sheath de-
 rived from the dura mater.
   It has  been supposed that the membrane which
 forms the sheaths for the medullary fibrils, of which
 the nerves are composed, is of a peculiar nature;
 but it appears to be derived from the pia mater, in-
 vesting the brain and the spinal marrow.   It is very
 vascular.*
   The ramification of a nerve is simply the separa-
 tion of some fibres from the general fasciculus.  The
 branch commonly forms an acute angle with the main
 trunk.
   The course of these branches from their origin to
 their termination, is generally as straight as possible.
   When the nervous cords are examined in an ani-
 mal recently dead, there is an appearance  of white
 lines arranged  in  a transverse or spiral  direction.
 The cause of this appearance is not well understood.
   In various parts ofthe body net works are formed
 by the combination of different nerves, or the branches
 of nerves.  In those instances the  branches of one
 nerve, unite with those of  another,  and form new
 branches.   These new branches again divide, and
 their ramifications unite with other new ramifications
 to form other new trunks.  These new trunks divide
 again, and form new combinations  in the same way.
   The trunks last formed proceed to the  different

  ~* Several authors have written professedly on the structure of the
 nerves, viz. Monro, in his " Observations on the Structure and Functions
 of the  Nervous System." —Bichat, " Anatomie Generale. "—Fontana,
 " Treatise on the Poison of the Viper."—Reil, " Exercitationes Anatomi-
es."—Scarpa, " Annotationes Academics."—Prochaska, " De Structure
Nervorum."
  I regret, that it has not been in my power to procure Reil, Prochaska,
or Scarpa. 
              Plexuses.—Ganglions.           321

parts  of the body, as other nerves do which arise
immediatelyvfrom the brain.
  These combinations are  denominated Plexuses.
There are several of them in the cavities ofthe ab-
domen and thorax, formed by the  ramifications of
the par vagum and the sympathetic nerves. The four
lower cervical and the first dorsal nerve form a very
remarkable plexus of this kind, which extends from
the side of the  neck to the axilla, and forms the
nerves of the arm. The lumbar nerves form a similar
plexus, although not so complex, from which the cru-
ral nerve arises.  The anterior nerves ofthe sacrum
also unite for the formation of the great sciatic nerve.
  It appears to be clearly ascertained, that the great
object of this peculiar arrangement is the combina-
tion of nervous fibres from many different sources,
in each ofthe nerves, which are distributed to any
organ.  Thus, the smaller nerves of the arm that
are distributed to the different parts, are not to be
regarded simply as branches of any one of the five
nerves which are appropriated to  the  upper extre-
mity, but as composed of fibres which are derived
from each of them.
  Many of the nerves are enlarged  in particular
places so as to form small circumscribed tumours,
which are denominated Ganglions.
  These Ganglions are generally of a reddish colour.
By very dexterous management, they can be shown
to consist of a texture of fibres. The larger cords,
which compose  the nerve, seem suddenly to be re-
solved into the small fibres, of which they consist.
These small fibres, after proceeding separately a
greater or lesser  distance, according to the  size of
the  ganglion, and changing their relative situation,
are again combined in cords which recompose  the
nerve.
  These fibres appear to be  surrounded by a fine
  vol. n.              41 
322           Structure of Ganglions.

cellular substance, which is vascular, moist and soft.
It is asserted that, in fat subjects, an oiiy substance,
resembling fat; and in hydropic subjects, a serous
fluid has been  found in this texture.
  Ganglions are often connected with but one nerve*
which  seems to enter at one extremity and go out
at the other.   But they frequently receive additional
branches from other nerves, and send off additional
branches to parts different from those to which their
principal nerves are directed.  When connected with
but one nerve, they have been called simple  gang-
lions: when they receive and  give  off additional
branches, they are denominated compound ganglions.
It  does not appear that there is any important dif-
ference in their structure in these cases.
  The simple  ganglions occur in the nerves  of the
spinal marrow—the posterior fasciculus ofthe nerves
having always  formed a ganglion before  it is joined
by the anterior fasciculus.   The sympathetic nerve,
throughout its  whole extent, forms compound gang-
lions.
  The use of this particular structure does not ap-
pear to  be perfectly known.   It seems, however,
certain, that  the different fibres—(of  which the
nerves forming ganglions are composed)—are blend-
ed together and arranged in a manner different from
that in which they were arranged before  the nerve
entered the ganglion.
  It ought to be observed, that the  combination  of    <
nervous fibrillae, so as to bring together those fibrils
which  originally belonged to different cords, seems
to have been kept in view throughout the whole ar-
rangement of the nervous system.   It is not only in
the plexus and the ganglion that this appears, but
also in some of the larger  nerves;  for in them, the    I
fibres which form the cords that compose the  nerve,
instead of running parallel to each other, along the 
              Reproduction of Nerves.          323

whole extent of the nerve, form a species of plexus
in their course; separating from the fibres with which
they were originally combined, and uniting with the
fibres of other cords;  as  in other cases  of plexus.*
   There have been doubts respecting the possibility
of a reproduction ofthe substance ofthe nerves when
it  has  been destroyed; but it appears to have been
clearly proved by the experiments of Mr. Haighton,
that a reproduction does really take placet
   Nine pair of nerves proceed from the brain through
the foramina of the cranium.  They are called Nerves
ofthe Brain, or Cerebral Nerves.  One pair passes
off between the cranium and the spine, which  is
called Sub-Occipital.  Twenty-nine or thirty pair pass
through the foramina  of  the spine: they are deno-
minated  Cervical, Dorsal,  Lumbar, and Sacral, from
the bones with which they are respectively connect-
ed.  There are seven pair of Cervical nerves, twelve
Dorsal, five Lumbar, and five or six Sacral—amount-
ing, with the nerves of the brain,  to thirty-nine or
forty pair.
          NERVES OF  THE BRAIN.
   The nerves which go off from the brain and me-
dulla oblongata are named numerically, according
to the order in which they occur;  beginning with
the anterior.   They also  have other names, which
generally are expressive of the functions of the dif-
ferent parts to which they are distributed.
   Those which go to the nose are anterior to all
the others, and are therefore denominated
     THE FIRST  PAIR, OR THE OLFACTORY NERVES.
   They arise by three  delicate white fibres from the

 * See Monro's Observations on the Structure and Functions of the Ner-
vous System.  Plate xviii.
 f See London Philosophical Transactions, fqr 1795, Part I. 
324             Olfactory Nerves.

Under and posterior part ofthe anterior lobes ofthe
brain, being derived from the Corpora Striata. They
proceed forward to the depression on the cribriform
plate of the ethmoid bone, on each side of the crista
galli.  The upper surface occupies  a  small  sulcus
formed by the convolutions of the lower surface of
the brain, and, therefore, has a longitudinal ridge on
it.  The lower surface is flat.   Their texture is like
that ofthe medullary part ofthe brain.
  On each side of the crista galli each  of them
forms  a  pulpy enlargement of  a  brownish colour,
which is called the bulb, and has been considered as
a ganglion.
  From  this bulb many fine and  delicate  cords go
off, which  proceed through the dura mater and the
foramina ofthe cribriform plate to the Schneiderian
membrane.—These ramifications of the  olfactory
nerve seem to receive  a coat from the dura mater,
as they are much more firm after they have passed
through it. They appear to  be arranged in two rows
as they proceed from the ethmoid bone—one running
near  to the septum, and the other to  the  opposite
surface ofthe ethmoid bone.*

       THE SECOND PAIR, OR THE  OPTIC NERVES,

  Originate from the Thalami Nervorum Oplicorum,
and appear on the external and  lower surface of the
brain, on each side ofthe sella  turcica.
  Each of them seems like a cord of medullary mat-
ter enclosed in a coat derived  from the pia mater,
and has not the fasciculated appearance ofthe other
nerves.  The medullary matter however, appears to
be divided by processes that pass through it, which
are derived from the coat of the nerve.
* See Vol. II. p. 6. 
         Second and Third Pair of Nerves.     325

*They proceed  obliquely forward, and  inward  on
each side of the cella  turcica, in contact with the
brownish cineritious substance, in which the infundi-
bulum and the corpora albicantia of Willis are situa-
ted.*  Anterior to this substance they come in con-
tact with each  other,  and again  separate, in such a
v/ay, that it is an undecided question whether they
decussate each other, or whether each forms an an-
gle, and is in contact  with the other at the angle.
  From this place of contact, each nerve proceeds
to its respective foramen opticum, where it receives
a coat from the dura  mater, which extends with it to
the eye, as has been described inthe account of that
organ.

           THE THIRD  PAIR  OF  NERVES
  Are sometimes called Motores Oculorum, in conse-
quence of their distribution to several muscles ofthe
eye.  They arise at the inside of the crura cerebri,
and make their appearance on the basis ofthe brain,
at the interior part ofthe pons Varolii.
  They originate by numerous threads, which soon
unite so as to form  a cord, which passes through the
dura mater, on  each side of the posterior clinoid pro-
cess, and continues through the cavernous sinus, and
the foramen lacerum, to the orbit ofthe eye.
   Before this nerve enters the orbit it generally di-
vides into two branches which are situated one above
the other.  The Uppermost  Branch is spent princi-
pally upon the  rectus superior muscle ofthe eye, but
sends a twig to the levator palpebrae.  The Inferior
Branch is distributed to two of the  recti muscles,
viz. the  internus and the inferior, and also to  the
inferior oblique.  It likewise sends a twig to a small
ganglion in the orbit, called  the Lenticular or Oph-
* See Vol. I. page 331. 
 326      Fourth and Fifth  Pair of Nerves.

 thalmic Ganglion,* from which proceed the fine ner-
 vous fibres that perforate the sclerotic coat.f

            THE FOURTH PAIR  OF NERVES
   Are called the Pathetic, in consequence of the ex-
 pression of the countenance produced by the action
 ofthe muscle on which they are spent.  They arise
 from the side of the valve of the brain, below and be-
 hind the TuberculaQuadrigemina,! and are so small
 that they appear like sewing thread.   They proceed
 round the  crura ofthe cerebrum, and appear on the
 surface between the  pons  Varolii  and the middle
 lobes  of the  brain.   They proceed along the edge
 of the tentorium which they perforate, and passing,
 through the upper part of  the cavernous  sinus, en-
 ter the orbit by the  foramina lacera.  They are ex-
 clusively  appropriated to  the Superior Oblique  or
 Trochlearis muscle.

            THE FIFTH PAIR OF NERVES
   Are called Trigemina, because each nerve divides
 into three great branches.
   These nerves arise  from  the crura ofthe cerebel-
 lum where they unite to the pons Varolii, by distinct
 fibres, which are connected so as to form  a cord or
 nerve, that is  larger  than  any other nerve  of the
 brain.   In  many subjects this  cord  seems partially
 divided into two portions, the  anterior of which is
much smaller than the posterior, and appears softer
 at its origin.
   It passes into a short canal formed by  the dura
mater, near the anterior extremity ofthe petrous por-

  * This ganglion, which is considered as the smallest in the  body lies on
the outside of the optic neve, near its entrance into the orbit, and is gene-
rally surrounded by soft adipose matter.
  f See Vol. I. page 364.
  * See Vol. I. page 343. 
          First Branch of the Fifth Pair.       327

tion of the temporal bone, at a small distance below
the edge of the tentorium.  It is perfectly loose and
free from adhesion to the surface of this canal; but
it soon passes out of it under the dura mater, and then
adheres to that membrane.   After leaving the canal
it expands like a fan, but still consists of fine fibres
which have some firmness.   It is said that there are
seventy or eighty of these fibres in the expansion, but
they appear to be more numerous.  Round the cir-
cumference of  the expansion  is  a substance of a
brownish colour, into which the fibres enter.  This
is the Semilunar Ganglion, or the Ganglion of Gasser,
and from it the three nerves go off.
  These nerves pass  off from the convex side ofthe
Ganglion, and are denominated the Ophthalmic, the
Superior Maxillary, and the Inferior Maxillary.

              T%e Ophthalmic Nerve

  Passes into the orbit ofthe eye through the foramen
lacerum: it there divides into several branches, which
are called, from their distribution, the Frontal or Su-
pra Orbitar, the  Nasal and the Lachrymal.
   The  Frontal or Supra Orbitar branch proceeds
forward in the  upper part of the  orbit, exterior to
the membrane which lines  it, and  divides  into two
ramifications.  One of these is small, and passes out
of the orbit near the pulley of the superior oblique,.
to be spent upon the orbicularis muscle and the con-
tiguous parts.
   The  other ramification passes through the Supra
Orbitary Foramen, or through the notch, which is in
the place  of that foramen, and divides into a number
of twigs, some  of which pass  transversely towards
the side ofthe  head, and communicate with twigs
from the portio dura.   Most of the others extend up-
wards on  the head.   Some are distributed to the an- 
328       Second Branch of the Fifth Pair.

terior part ofthe occipito-frontalis muscle, and the
integuments ofthe forehead; others are spent upon
the upper portion of the scalp.  Some of the extreme
parts of these ramifications also communicate with
the portio dura.
   The  Nasal Branch  proceeds  obliquely forward
towards the inner side of the orbit, and sends a twig
in its course to the lenticular ganglion.  It also sends
off some small twigs, to join the ciliary nerves which
go from the ganglion.   On the inside of the orbit a
branch leaves it  which proceeds through  the Fora-
men  Orbitare  Internum Anterius  to  the  cavity of
the cranium, and passes a small distance upon the
cribriform plate of the ethmoid bone, under the dura
mater, to a fissure in the said plate near  the crista
galli, through which it proceeds into the cavity of
the nose.  Here it divides into twigs, some of which
pass on the septum near its anterior edge, and ter-
minate on the integuments at the end of the nose,
while others pass down on the inferior turbinated
bone.
  After parting with the ramifications to the nose, the
remainder ofthe nasal branch continues  to the in-
ternal canthus of the  eye, and sends twigs to the
lachrymal sac, the caruncula lachrymalis, the eye-
lids, and the exterior surface of the upper part of the
nose.
   The Lachrymal Branch  proceeds obliquely for-
ward and outwards, towards the  lachrymal gland.
In its course it sends off a twig which passes through
the spheno maxillary fissure, and communicates with
a  twig of the upper  maxillary nerve, and  one or
more twigs that pass to foramina in the malar bone.
The main branch passes to the lachrymal gland, and
some twigs  continue  beyond it to the contiguous
parts. 
          Second Branch ofthe Fifth Pair.       329

           The Superior Maxillary Nerve.

  The second branch of the fifth pair is examined
with great difficulty on account of its peculiar situa-
tion.  It proceeds from the semilunar ganglion, and
passes through the foramen rotundum of the sphe-
noid bone into the upper part of the zygomatic fossa.
In this  situation it sends a twig to the orbit by the
spheno  maxillary fissure, and a branch, called the
Infra Orbitar, which appears like  the main nerve, as
it preserves a similar direction, to the infra orbitar
canal.   At the same place it sends downwards two
branches which  unite together almost immediately
after their origin, and, as soon as they have united,
enlarge into a ganglion.*  This ganglion is called the
Spheno Palatine.   It is rather of a triangular figure,
and lies very near the spheno-palatine foramen.  It
gives off a posterior branch, which passes through
the pterygoid foramen to the cavity of the cranium:
some branches which proceed through the spheno-
palatine foramen to the nose, and  are called the Sphe-
nopalatine or Lateral Nasal Nerves: and an  inferior
branch that proceeds through the posterior palatine
canal, and is called the Palatine Nerve.
  The small branch, which was first mentioned, as
going to the orbit by the spheno maxillary fissure, di-
vides into two ramificaions. One of them unites with
a twig of the lachrymal branch  above mentioned,
and passes out of the orbit, through  a foramen in
the malar bone,  to the face; where it  is distributed.
The other passes also through a foramen of the  ma-
lar bone, into the temporal fossa, and, after uniting
with twigs from  the Inferior Maxillary Nerve, pro-
ceeds backwards and perforates the aponeurosis of

 * Sometimes a single  branch passes downwards instead of two; but it
forms a ganglion in the same place.
  VOL. II.               12 
330         Superior Maxillary Nerve.

the temporal muscle,  to  terminate on the integu-
ments ofthe temporal region.
  Before the Infra Orbitar branch  enters the  canal
of that name, it sends  off two twigs, called Posterior
Dental  Nerves, which pass downwards  on the tube-
rosity of the upper maxillary bone, and enter into
small canals in that bone, that  are situated behind
the Antrum Maxillare.   They subdivide into fine
twigs that proceed forward to the alveoli of three or
four ofthe last molar teeth; and penetrate  each of
the roots by a cavity at its extremity.  Twigs also
proceed from these  nerves to the  posterior part of
the gums and buccinator muscle.
  After the posterior  dental nerves have left it, the
Infra Orbitar nerve proceeds forwards in the canal of
that name; and near the extremity of it, gives off the
anterior dental nerve, which  accompanies it for some
distance, and then proceeds downwards in a canal in
the bone  anterior to  the antrum maxillare.  In its
course this nerve divides into many fibres, which pass
to the roots of the incisor, canine, and small molar
teeth, each in its proper canal. These dental branch-
es sometimes pass in the  antrum maxillare between
the lining membrane  and the bones.   The  Infra
Orbitar nerve passes  out of the foramen upon  the
cheek,  and divides into several branches of consi-
derable size, which  are distributed on the face from
the side of the nose  to the back of the cheek, and
also upon the under eye-lid  and the  upper lip.
  The Pterygoid Nerve, or posterior branch, passes
backwards, from the ganglion to a canal in the base
ofthe pterygoid process ofthe Os Sphenoides, and
proceeds  through it.  After leaving this canal, it
passes through a substance almost as firm as carti-
lage, which closes the anterior foramen lacerum, at
the basis  of the  cranium; and  divides into two
branches.  The smallest of them, called the  Vidian 
             Superior Maxillary Nerve.          331

Nerve, proceeds with a small artery to the small fo-
ramen, or Hiatus Fallopii, on the anterior side ofthe
petrous portion ofthe temporal bone, and continues,
through a small canal, to join the Portio Dura of the
seventh pair in the larger canal, called the Aqueduct
of Fallopius, at the first turn in that canal.*  The
other branch of the pterygoid nerve proceeds to the
Foramen Caroticum, and passes through it, with a
twig of the sixth pair, to join the first cervical gan-
glion of the Intercostal Nerve.
   The Spheno-Palatine, or Lateral Nasal Nerves, con-
sist of several branches which pass from the sphe-
no-palatine ganglion through the Spheno-palatine
foramen into the nose.   Some of them are distri-
buted to that part of the pituitary membrane, which
is above  the upper  meatus, and others to the part
which is immediately below it.  Some ofthe branches
which thus enter the nose are spread upon the sep-
tum; one  among them extends upon it, downwards
and forwards to the anterior part of the palatine pro-
cess ofthe upper maxillary bone, where it enters into
the foramen  incisivum, and terminates in a papilla
in the roof of the mouth.t
   The Palatine Branch proceeds through the canal
formed by the upper maxillary and palate bones, to
the roof of the mouth and the soft palate.   Soon af-
ter its origin, it sends  off a twig which proceeds
down a small canal that is behind it.  It also sends
off, as  it proceeds downwards, several twigs  to that
part ofthe membrane ofthe nose which covers the

  * The late Mr. John Hunter believed that this nerve parts from the
portio dura at the lower end of the aqueduct, and is the chorda tym-
  + The curious distribution of this nerve appears to have been known to
the late John Hunter, and also to Cotunnius; but it is minutely described by
Scarpa, and is delineated by Soemmering in his plate of the nose—See
" Observations on certain parts of the Animal Economy, by J. Hunter,
page 219, and also Scarpa " De Organo Olfactus."  In this last are some
interesting observations relative to the ducts of Steno. 
332       Third Branch of the Fifth Pair.

inferior  turbinated bone.   When it  arrives at the
roof of the mouth, it divides into several branches
which run forwards, and are distributed to the mem-
brane which lines the roof of the mouth.  Some of
its branches pass to the soft palate, the uvula,  and
the tonsils; small filaments pass  into the back part
ofthe upper jaw.

The inferior Maxillary Nerve, or the Third Branch of
                 the Fifth Pair.

  Passes through the foramen ovale into the zygoma-
tic fossa, and divides into two branches, one of which
sends ramifications to many of the contiguous mus-
cles, as  the Temporal, the Masseter, the  Buccina-
tor the Pterygoid;  and also to the anterior part of
the ear  and the side of the head.  The other branch
passes between the pterygoid  muscles, and divides
into two ramifications, one of which  proceeds to the
tongue,  and  is  called  the Lingual or Gustatory,
while the other passes  into the  canal of the lower
jaw.
  The Lingual Nerve  proceeds between the ptery-
goid muscles, and in its course is joined by the chor-
da  tympani.   It continues forward between the
maxillary  gland and the lining membrane  of the
mouth;  and passes near the excretory duct of that
gland, above the mylo-hyoideus and  the sublingual
gland to the under side of the tongue, near the
point: it then divides  into  a  number of branches
which enter into that body between  the genio-hyoi-
deus  and lingualis muscles.  This nerve has been
supposed to be particularly concerned in the func-
tion of taste, because many of its branches continue
to the upper surface ofthe tongue, especially near the
point.  In its course it has a  communication with
the ninth pair of nerves, and it sends twigs to the 
            The Sixth Pair of Nerves.         333

membrane  of the mouth and gums, and the con-
tiguous parts.
  After parting with the lingual nerve, the inferior
maxillary continues to the upper and posterior orifice
ofthe canal in the lower jaw.  Before it enters this
canal it sends a branch  to the sub-maxillary gland,
and to the muscles under the jaw.  It then enters the
canal, attended by blood vessels, and proceeds along
ittothe anterior maxillary foramen, on the side ofthe
chin, through which it  passes out.   In this course
it sends twigs to the sockets of the teeth, and gen-
erally supplies all the large  and one  of the small
grinders.  Before it leaves the jaw it sends a branch
forwards, which supplies the remaining teeth on the
side to which it belongs.   After passing out, through
the anterior foramen, it is spent upon the muscles
and integuments of the  front of the cheek, the  chin
and the under lip.

            THE SIXTH PAIR OF NERVES

  Are called Motores Externi.  They arise from the
commencement of the medulla oblongata, and pro-
ceed forward under the pons Varolii.   They proceed
through the dura mater on the inside of the fifth pair,
and appear to pass through the cavernous sinuses,
but are enclosed in sheaths of cellular membrane
while they are in those sinuses.  When in this situa-
tion they are near the carotid arteries, and each nerve
sends off one or more very fine  twigs, which being
joined by a twig from the pterygoid branch  of the
fifth pair, accompany the carotid artery through the
carotid canal, and then unite themselves to the upper
extremity of the upper  cervical ganglion of the in-
tercostal nerve.
  The sixth pair afterwards pass into the orbit of the
eye, each through the foramen lacerum of its respec- 
 334      Composition of the Seventh Pair.

 tive side, and is spent upon the Rectus Externus or
 Abductor muscle of the eye.

            THE SEVENTH PAIR OF NERVES
   Comprises two distinct cords which have very dif-
 ferent destinations; and have, therefore been consid-
 ered as different nerves, by several anatomists.   One
 of these cords is appropriated to the interior of the
 ear, and is the  proper Auditory Nerve.   The other
 is principally spent upon the face, and therefore, has
 been called the Facial.   They  have however more
 frequently been denominated the Seventh Pair, and
 distinguished from each other, in consequence  of a
 great difference in their texture, by the appellations
 of Portio Dura and Portio Mollis.
   These two cords pass off nearly in contact with
 each other, from the  side of the upper  part of the
Medulla  Oblongata, where it is in contact with the
pons Varolii; but the Portio Mollis can be traced to
the fourth ventricle, while the Portio Dura is seen to
rise from the union ofthe pons Varolii with the me-
dulla oblongata and the crura Cerebelli.  The Porio
Dura, at its origin, is on the inside of the Portio
Mollis.   Between these cords are one or more small
fibres, called Portio Media, which seem to originate
very near them, and finally unite with the Portio
Dura.
  Each ofthe seventh pair of nerves, thus compo-
sed, proceeds from its origin to the Meatus Audito-
rius Internus of the temporal bone; and the Portio
Mollis divides into fasciculi,  which proceed to the
different parts of the organ of hearing in  the man-
ner described in the  account ofthe ear.*
  The Portio Dura enters  an orifice at  the upper
and anterior part of the end or bottom ofthe Meatus
* See Vol. I. p. 344. 
         Chorda Tympani.—Pes Anserinus.      335

Auditorius Internus.   This orifice is the commence-
ment of a canal, which has been called the Aqueduct
of Fallopius, and proceeds from the Meatus Audito-
rius  Internus to  the  external foramen, between the
mastoid and styloid processes at the basis ofthe cra-
nium.   This canal first curves backwards and out-
wards, near to the upper surface of the petrous bone,
then forms an acute angle, and proceeds, (back-
wards and downwards,) to the stylo-mastoid foramen,
passing very near the cavity of the tympanum in its
course.
  The Portio Dura, as it passes into the canal from
the meatus internus, seems to receive an investment
from the dura mater.  It fills up the canal, but does
not appear to  be compressed.   Near the angle it is
joined by the  twig of the vidian nerve, which pro-
ceeds from the pterygoid branch of the fifth pair, and
enters the petrous bone by the small foramen innomi-
natum on its anterior surface.  In its  course through
the canal it sends off some very small tvyigs to the
muscles and appurtenances of the small bones ofthe
ear, and to the mastoid cells; and, when  it has  ar-
rived almost at the end of the canal, it sends off, in a
retrograde direction, a small branch which proceeds
into the cavity of the tympanum, (entering  it by a
foramen near  the base ofthe pyramid,) and crosess
the  upper part  of it, near the membrana  tympani,
between the long processes of the Malleus and Incus.
This twig is  the Corda Tympani; it proceeds from
the cavity, by a fissure on the outside ofthe Eusta-
chian tube, to join the lingual branch of the fifth
pair, as has been already mentioned.*
   The Portio Dura, after passing out of the  Fora-

  * The late John Hunter believed that the chorda tympani is merely a
continuation of the twig ofthe pterygoid branch which joins the portio du-
ra above.—See Observations on certain parts of the Animal Economy,
page 220. 
 336   Composition of the Eighth Pair of Nerves.

 men Stylo-Mastoideum, is situated behind and  within
 the parotid gland.  Here it gives small twigs to the
 back of the ear and head, and to the digastric and
 stylo-hyoideus muscles.   It perforates the gland af-
 ter  sending filaments to it, and  then divides  into
 branches which are arranged in such a manner that
 they constitute what has been called the  Pes Ansc-
 rinus.
   To  describe the various branches in this expan-
 sion would be more laborious than useful.   Some of
 them are spread upon the temple and the upper part
 ofthe side of the head, and unite with the supra-or-
 bitar branches of the ophthalmic nerve. Some pass
 above and below  the eye, and are distributed to the
 orbicularis muscle, and communicate with nervous
 twigs that pass through foramina in the malar bone,
 &c   Some large branches pass transversely.  They
 cross the masseter muscle, and  divide into ramifica-
 tions which are spent upon the cheek and the side of
 the nose and lips, and communicate with the small
 branches of the superior maxillary nerve.
   A large  number of branches  pass downwards.
 Many  of them incline forwards,  and  are spent on
 the soft parts about the under jaw; while others pro-
 ceed below the jaw to the superficial muscles and
 integuments ofthe upper part ofthe neck, commu-
 nicating with the branches ofthe contiguous nerves.*

            THE EIGHTH PAIR OF NERVES

   Are  very frequently denominated the Par Vagum,
 on account of their very extensive distribution.

  *A most minute and laboured description ofthe nerves ofthe face was
published by the celebrated Meckel, in the seventh volume of Memoirs of
the Royal Academy of Sciences of Uerlin, for the year 1751,  accompanied
with a plate, exhibiting the side of the head, of three times the natural
size.  This is republished in the Collection Acadcmique: Partie Etrangere.
—Tom. viii. 
      Composition ofthe Eighth Pair of Nerves.  337

   They arise from those portions ofthe medulla ob-
longata which are denominated the Corpora Olivaria.
Each nerve consists of a cord, which is anterior, and
called the Glosso-Pharyngeal; and of a considerable
number of small filaments, which  arise separately,
but unite and form another cord, the proper Par Va-
gum.   Associated with these is a third cord, called
the Spinal, or Accessory Nerve of Willis, which origi-
nates in the great canal of the spine, and, passing
up into the cavity of the cranium, goes out of it with
these nerves through the foramen lacerum.
   The two first mentioned nerves proceed from their
origin to the  posterior foramen lacerum, and  pass
through it with the Internal Jugular vein,—being se-
parated from  the vein by  a  small process  of bone.
They are also separated from each other by a small
process of the dura mater.   In the  foramen they are
very close to each other;  but  soon after they have
passed through it/they separate and proceed towards
their different destinations.
   The  Glosso-Pharyngeal proceeds  towards  the
tongue, between the stylo-pharyngeus and the stylo-
glossus muscles, following the course ofthe last men-
tioned muscle to the posterior part of the tongue.
At the commencement of its course it receives a  twig
from the Portio Dura, and one also  from the Par Va-
gum.  It soon gives off a branch which passes down
on the inside of the common carotid to the lower part
ofthe neck, where it joins some twigs ofthe intercos-
tal to form the cardiac nerves. Afterwards it sends off
several twigs to the muscles of the pharynx and its
internal membrane, and also some twigs which unite
with others from the upper cervical ganglion ofthe
Sympathetic, and form a network that lies over the
anterior branches ofthe external carotid. The Glosso-
pharyngeal finally enters the  tongue, at the termina-
   vol. n.              43 
338    Gbsso-Pharyngeal Nerve.—Par Vagum.

tion of the hyo-glossus  muscle; and after sending
branches  to the lingualis, and the various muscles
inserted into the tongue, terminates in small ramifi-
cations that are spent upon the sides and middle of
the root of the tongue, and upon the large papillae.

                 THE PAR VAGUM
   Are slightly enlarged after passing through the fo-
ramen lacerum.  As  they descend they adhere to
the superior ganglion  of the intercostal, and also to
the ninth pair.  They proceed behind and on the out-
side ofthe carotid, and are contained in the  same
sheath of cellular membrane which encloses that ar-
tery and the internal  jugular vein.   Each  of  these
nerves, soon after it leaves the cranium, gives a twig
to theglosso-pharyngeal; that soon after it sends off
a branch called the Pharyngeal, which unites to one
from the accessory nerve, and to one or more from
the glossopharyngeal, and  proceeds to the middle
constrictor of the pharynx, when it expands into ra-
mifications that form  a  plexus from which proceed
a number of small twigs that go to the larynx, and
some that pass down on the common carotid artery.
   It then sends off,  downward and forward, the Su-
perior Laryngeal nerve, which continues in  that di-
rection behind the  carotid artery, and divides into
an external and internal branch.
   The Internal Branch,  which  is  the largest, pro-
ceeds between the os  hyoides and the thyroid carti-
lage;  and divides into  numerous ramifications which
are distributed to the  arytenoid muscles and to the
membrane which lines the larynx and covers the epi-
glottis. It is said, that fine twigs can be traced into
the foramina, which are to be seen in the cartilage
ofthe epiglottis;—some ramifications can be traced
to the pharynx;—others communicate with  the
branches of the recurrent nerve. 
  Superior Laryngeal Branch ofthe Par Vagum. 339

  The External Branch sends twigs to the pharynx,
to the lower and inner part ofthe larynx, and to the
thyroid gland.
  In its course downwards, the great nerve some-
times sends  off a twig, which unites with one from
the ninth pair that passes to the sterno-hyoidei and
sterno-thyroidei muscles.
  It uniformly sends off one or more twigs, which
pass into the thorax and combine with small branches
from the sympathetic or  intercostal  nerve, to form
the Cardiac plexus, which sends nerves to the heart.
  After entering the thorax, the right trunk of the
Par Vagum passes before the subclavian  artery; and
the left trunk before the arch of the aorta; and im-
mediately after passing these arteries, each of the
nerves divides into an anterior and posterior branch.
The anterior is the continuation of the Par Vagum;
the  posterior is  a  nerve  of the Larynx; which,
from its retrograde course, is called the Recurrent
Nerve.
  On the left side  the Recurrent Nerve winds back-
wards round the aorta, and on the right  side round
the subclavian artery, and proceeds upwards, deeply
seated, on the side of the trachea,  to the Larynx.
Soon after its origin it sends filaments to a ganglion
of the sympathetic, to the cardiac plexus, and to a
pulmonary plexus  soon to be mentioned.  In its
course upwards it sends twigs to the trachea and the
oesophagus.   It proceeds behind the thyroid gland,
and sends twigs to that organ.  At  the lower part
ofthe larynx it sends off a branch which communi-
cates with branches of the superior laryngeal nerve.
It also divides into branches which are spread upon
the posterior crico-arytenoid, and the arytenoid mus-
cles; and also upon the lateral crico-arytenoid and the
thyro-arytenoid muscles, as well as upon the mem- 
340     Recurrent Branch of the Par Vagum.

brane which lines the back part of the larynx and
the contiguous surface ofthe pharynx.
  There is a difference in the arrangement of the
recurrents on the different sides, in consequence of
one winding round the aorta, while the other winds
round the subclavian artery.
  After sending off the recurrents, each trunk ofthe
par Vagum proceeds behind the ramifications of the
trachea; but previously detaches some small branches,
which are joined by twigs from the intercostal and
from the recurrent, and form a plexus upon the an-
terior part  of the vessels going to the lungs.   This
Anterior plexus, after sending off some minute branch-
es to the cardiac nerves and the pericardium, trans-
mits its branches with the bronchia  and the blood
vessels, into the substance ofthe lungs.
  Some of the branches which proceed from the par
vagum, pass down on the posterior part of the tra-
chea, and enter into the membrane which forms it,
and the mucous glands which are upon it; and some
pass to the oesophagus.
  When the par vagum is behind the great  vessels
of the lungs, a  number of branches go off transverse-
ly, and are also joined by some fibres from the sym-
pathetic.   These form the Posterior pulmonary plex-
us; the  ramifications from which proceed into the
substance  of  the  lungs,  and are principally spent
upon the ramifications of the bronchia.  It has been
said,* that the small twigs into which they divide,
very generally penetrate into the small ramifications
of the bronchia, and are spent upon their internal
membrane.
   Soon after sending off the nerves of the  pulmo-
nary  plexus, the Par  Vagum proceed downwards


  * See Buisson, in the continuation of the Descriptive Anatomy of
Bichat.                                        ' 
      Different Functions of the Laryngeal, fyc.   341

upon the oesophagus;  the left nerve being situated
anteriorly, and the right posteriorly.  Each of these
nerves forms a plexus  so as nearly to surround the
oesophagus, as they descend on it; but the net-work
is thickest on the posterior side.  They pass through
the diaphragm with the oesophagus, and unite again
so as to form considerable trunks.
  The Anterior, which is the smallest, proceeds along
the lesser curvature of the stomach to the pylorus.
Some of its fibres are  spread upon  the anterior side
ofthe stomach and the lesser omentum.  Others of
them extend to the left hepatic, and also to the so-
lar plexus.
  The Posterior trunk sends branches to  surround
the cardiac orifice of the stomach.   Many branches
are spread upon the under side of the great curva-
ture of the stomach.   Some of them pass  in  the
course of the coronary artery to  the  cceliac, and
unite to  the hepatic and splenic plexuses; and one
trunk, which is thick,  although short, proceeds to
the solar plexus.

           The Accessory Nerve of Willis,

  Which has been mentioned as associated with the
eighth pair of nerves, within the cranium, has a very
peculiar origin.
  It arises by small filaments, which come off from
the spinal marrow, between the anterior and posteri-
or fasciculi of the cervical nerves, and proceeds up-
wards to the great occipital  foramen, between these
fasciculi.  It commences sometimes at the sixth or
seventh cervical vertebra, and sometimes  about the
fourth.   It enters the cavity ofthe cranium through
the foramen magnum, and  proceeds upwards and
outwards, so as to join the  eighth pair of nerves at
some distance from its origin, and in this course  it
receives filaments from the  medulla oblongata. 
342           Ninth Pair of Nerves.
   After approaching very near to the eighth pair of
 nerves, it accompanies it to the foramen lacerum, and
 passes out in its own separate sheath.  It then leaves
 the eighth pair and descends towards the  shoulder,
 proceeding through the sterno-mastoid muscle. Soon
 after it emerges from the cranium, it sends a ramifi-
 cation to the pharyngeal branch of the  Par Vagum
 and another to the par vagum itself.  After passing
 through the upper and back part ofthe sterno-mastoid
 muscle it terminates in the  trapezius.   It adheres
 to  the  ninth  pair of nerves  as it passes by it, and
 sends a twig to the sub-occipital and some ofthe
 cervical nerves.  It also gives  ramifications to the
 sterno-mastoid  muscle as it passes through  it.
    It has already been stated that the Laryngeal and Recur-
      rent Nerves appear to answer different purposes in their
      distribution to the Larynx.—When both  of the recur-
      rent nerves are divided in a living animal, the voice
      seems to be lost.  When the laryngeal nerves only are
      divided, the strength of the voice remains, but it is flat-
      ter. The recurrent nerves, therefore, seem essential to
      the formation of the voice.  The laryngeal nerves  are
      necessary to its modulation.
       The history of the investigation of this subject is con-
         tained in Mr. Haighton's paper in the third volume
         of Memoirs of the Medical Society of London.
           THE NINTH  PAIR  OF NERVES.
  Each of these nerves arises from the groove in the
medulla oblongata, between the corpora pyramidalia
and the corpora olivaria.   Three or four fasciculi, of
distinct filaments, unite to form it.  Thus composed,
it proceeds to the anterior condyloid foramen ofthe
occipital bone, and passes through the dura mater.
It seems firmly united, by the cellular membrane, to
the eighth pair, and to the first ganglion of the sym-
pathetic, soon after it passes from the occipital bone.
It is either connected to the sub-occipital nerve by a
small ramification, or it joins a branch  which  pro- 
         Ninth and Tenth Pair of Nerves.      343

ceeds from  the sub-occipital to  the  cervical, and
bends round the transverse process of the atlas.  It
passes between the internal carotid artery and the
internal jugular vein, and crosses the external caro-
tid  at the origin of the occipital artery.  At this
place it generally sends downwards a large branch
which is called the Descendens Noni.  Passing for-
wards, it  is on the outside ofthe posterior portion
ofthe digastric muscle, and inclines downwards; but
near the tendon of the  muscle it turns upwards, and
proceeds on the inside  of the mylo-hyoideus, where
it divides into ramifications, which,  at the anterior
edge of the  hyo-glossus muscle, begin to enter into
the substance ofthe tongue, between the genio-glos-
sus and  the lingualis muscles.
  Some  of  the  branches  of this nerve unite with
those ofthe lingual branch  ofthe fifth pair.  Others
are distributed to almost all the muscles connected
with the tongue.
  The branch  called descendens noni passes  down
in the course of the common carotid artery, and
sends branches in its progress to the upper portions
ofthe coraco-hyoidei and sterno-thyroidei muscles;
it unites with ramifications  of various sizes from the
first, second and third cervical nerves, which form a
bow under the  sterno-mastoid  muscle,  from which'
ramifications go to the lower portions of the sterno-
hyoidei  and  thyroidei  muscles and of the  coraco-
hyoidei.

      OF THE CERVICAL NERVES.

  The tenth or last pair of the head, commonly call-
ed  the Sub-occipital, may be arranged  with  these
nerves, because they arise, like them, from the me-
dulla spinalis, and are distributed to the muscles on
the neck. 
 344    Sub-Occipital or, Tenth pair of Nerves.

            The sub-occipital Nerves

   Arise on each side of the spinal  marrow, nearly
 opposite to the interval between the great foramen
 of the os occipitis and the atlas.
   Each of these nerves consists of an anterior and
 posterior fasciculus, or bundle of fibres, which pass
 outwards immediately under the  vertebral arteries,
 and form a ganglion, from which proceeds an an-
 terior  and  a posterior branch.
   The anterior branch is united to the second  cer-
 vical nerve below, and to the ninth nerve, or the hyo-
 glossal, above.   It also sends filaments to the upper
 ganglion of the great sympathetic nerve.
   The posterior branch is spent upon the Recti, the
 Obliqui, and some other muscles ofthe head.
   The proper Cervical Nerves consist of seven pair;
 of which the first six go off between  the vertebrae of
 the neck, and  the  seventh between the last of the
 neck and the first ofthe back.

            The first cervical Nerve

   Passes out between the atlas and the VertebraDen-
tata.  It  originates  from two fasciculi,  which  are
 connected to each other  at a ganglion, and then se-
 parate into an anterior and  a posterior branch.*
   The anterior  branch is  connected  by filaments
with the accessory nerve, with the ninth  pair ofthe
head, and with the upper ganglion of the sympathe-
 tic.  It is also connected with the second cervical
nerve, and sends some branches to the muscles on
the anterior part of the spine.
   The posterior branch, after communicating with
the posterior branches ofthe sub-occipital and  the
  * This arrangement is common to the nerves of the spine.
glion is formed by the posterior fasciculus..
The gan- 
             Cervical and Phrenic Nerves.         345

 second nerves ofthe neck, perforates the complexus
 muscle, and ascending upon the back ofthe head, is
 distributed with the occipital artery.
             THE SECOND CERVICAL NERVE
   Sends off, from its Anterior Branch, a  twig which
 descends to the lower cervical ganglion  ofthe sym-
 pathetic, and a considerable ramification  to the third
 cervical nerve.  It also sends off some twigs to the
 sterno-mastoid muscle, and others to join the acces-
 sory nerve.  Some of its small  ramifications pass
 down upon the external jugular vein, and others unite
 with the descending branch of the ninth pair ofthe
 head.   A small  branch is also concerned in the  for-
 mation ofthe phrenic nerve.  Two  larger branches
 of this nerve wind round the posterior edge of  the
 sterno-mastoid,  and are spread  under the integu-
 ments ofthe anterior, lateral and posterior parts of
 the neck and lower parts of the head; they have a
 communication  with the portio dura of the seventh
 pair.*—The posterior branch of  this nerve is spent
 upon the extensor muscles ofthe head and neck.
             THE THIRD CERVICAL NERVE
  Sends down, from its Anterior Branch,  the princi-
pal trunk ofthe phrenic nerve.  It also sends twigs
to the  fourth cervical, to the lower cervical ganglion
of the intercostal, and to the descending branch of
the ninth of the head.   Some of its  branches, unite
with twigs of the  accessory nerve, and  others  are
spent upon the muscles and integuments ofthe shoul-
der and lower part of the neck.   A small Posterior
Branch is spent upon the muscles ofthe back ofthe
neck.
 * These superficial branches have sometimes been described as coming
from a plexus ; but they  often arise directly from the Second Cervical
nerve.
  vol. 11.               44 
346
Cervical Nerves.
          THE NERVES OF THE DIAPHRAGM
  Are generally denominated the Phrenic. The prin-
cipal root of each of them is commonly derived from
the third cervical nerve, but frequently the second
and the fourth cervical nerves contribute to the for-
mation; and they are sometimes joined by a twig
which is derived from the ninth pair.
  Each nerve proceeds down the neck, between the
rectus capitis major  and the scalenus anticus, and
continues along the fore part of the  scalenus anti-
cus; it descends into the thorax within the anterior
end of the first rib, between the subclavian vein and
the artery.   It sometimes  receives a twig from the
fifth cervical nerve, and a twig passes between it
and the great sympathetic  After entering the thorax,
they descend,  attached  to the mediastinum, before
the root of the lungs.  In consequence of the projec-
tion of the  point of the heart to the left, the course
of the left is a little different from that ofthe right;
that of the right proceeding in a more perpendicular
direction.   W hen they arrive at the diaphragm, they
divide into many ramifications, which have a radiated
arrangement, and terminate on the fibres of that mus-
cle,both on the upper and lower surface. Some fibres
from each nerve are continued downward, and com-
municate in the  abdomen with fibres from the inter-
costal.
  THE FOURTH, FIFTH, SIXTH, AND SEVENTH CERVICAL
                     NERVES,
   May be comprised in one description. They pass
off successively from the Medulla Spinalis, between
the vertebrae, like the other nerves.  Their Posterior
Branches are generally distributed to the back ofthe
neck, and  are very small.   Their Anterior  Branches
are principally appropriated to the upper  extremi-
ties, and  are  large.  They generally send each a 
   Remaining Cervical Nerves.—Brachial Plexus.  347

small twig to the lower cervical ganglion ofthe inter-
costal  nerve, and a few small branches  to some of
the contiguous muscles.  They are arranged and
combined so as to form the net-work, now to be de-
scribed, which is  called the  Brachial or Axillary
plexus; and, in the formation of this plexus, they are
joined by the first dorsal nerve.

           The BRACHIAL PLEXUS

   Extends from the lower part ofthe side ofthe neck,
into the  arm-pit.  It  commences in the following
manner.   The fourth  and  fifth cervical nerves  pro-
ceed downwards, and after uniting to each other
about an inch and a half below their egress from the
spine, they separate again, almost immediately, into
two branches.
   The sixth cervical nerve, after passing downwards,
divides also into two branches, one of which unites
with the uppermost branch that proceeds from the
union of the fourth and fifth, and the other with the
lowermost, and they all proceed downwards.
   The seventh cervical is joined by the first dorsal,
which  proceeds upwards, and unites with it  at a
short distance from the spine.   The cord produced
by their junction soon unites with one of the cords
above  described.   As these different cords proceed
downwards, they divide, and their  branches again
unite.  The axillary artery, which passes in the same
direction,  is surrounded by them.   In this manner
the axillary plexus  is often formed.
   The muscles about the shoulder, both before and
behind, are supplied by the axillary plexus.   Thus,
it sends branches to the Subscapularis, Teres Major,
and Latissimus Dorsi, behind; and to the Pectoralis
Major  and Minor, and the Mamma, before. It also
sends off a branch  called the Scapularis, which com- 
348            Nerves of the Arm.

monly arises from the upper part of the plexus, and
proceeds through the notch in  the  upper costa of
the scapula, to the  supra and infra spihatus, teres,
minor, &c

               Nerves ofthe Arm.  ,

   All the  great nerves of the arm are derived from
the axillary plexus.   There  are six  of them, which
are denominated  The Musculo Cutaneous;  The Medi-
an;*  The  Cubital, or Ulnar; The Internal  Cutaneous;
The Radial or Muscular Spiral; and the Circumflex or
Articular.
   The Musculo Cutaneous, or Perforating Nerve, passes
obliquely through the upper part ofthe coraco bra-
chialis muscle.  Before it enters the muscle, it sends
a branch  to it.  After leaving the muscle, it passes
down the  arm between the biceps and the  brachia-
lis internus, to which it  also  gives branches.   It
proceeds  to the outside  ofthe biceps, and continues
under the median cephalic vein to the anterior and
external part ofthe fore-arm; along which it passes
under the integuments.   On the lower part of the
fore-arm  it divides  into  many branches, which ex-
tend to the root of the  thumb and the back of the
hand, and terminate in the integuments.
   The Median Nerve, which is one ofthe largest of
the arm, often proceeds  from the axillary plexus next
to the musculo cutaneous; it passes down the arm,
verj near  the humeral artery, within the edge ofthe
biceps flexor muscle, and, during this course, gives
 off no branches of any importance.  After passing
the bend  of the  elbow, it proceeds, under the apo-
neurosis ofthe biceps, between the brachialis inter-
nus and the pronator teres, and continues down near
* Sometimes called Radial. 
       Median and Cubital or Ulnar Nerves.     349

the middle.of the fore-arm, between the flexor subli-
mis and the flexor profundus.  At the elbow it sends
branches to several muscles  on the anterior side of
the fore-arm, and to the integuments.  Among these
branches is one, called the Interosseal Nerve, which
passes down on the anterior surface of the interos-
seal ligament,  with the artery of that name.   This
nerve sends branches, in its course, to the long flexor
of the thumb  and the  deep flexor of the fingers.
When it arrives at the pronator quadratus, it sends
branches to that muscle, and passing between it and
the interosseous ligament, perforates the ligament,
and soon  terminates  on the posterior side  of the
wrist and  hand.
  As the Median Nerve proceeds downwards, it be-
comes more superficial; and continuing among the
tendons of the flexors of the fingers, it gives off a
branch which is principally spent upon the integu-
ments of the palm of the hand.   This  great nerve
passes with the tendons under the annular ligament;
and immediately after, while it is covered by the Apo-
neurosis Palmaris, and by that portion of the artery
which is called Arcus Sublimits, it divides into branch-
es, which separate from each other at acute angles,
and subdivide  so as to send  a ramification to each
side of the thumb, of the index, and of the  middle
finger; and to  the radial side ofthe ring finger.
  The Cubital or Ulnar Nerve is  also of considerable
size.  It passes down on the inside  of the  triceps
extensor muscle, to the great groove formed by the
olecranon process  and the internal condyle ofthe os
humeri; and in this course if often sends a branch to
the triceps, and some smaller twigs to the upper part
ofthe fore-arm.  From the groove it proceeds on the
anterior part ofthe fore-arm, between the flexor carpi
ulnaris and  the flexor sublimis, to  the wrist.  At a
small distance above the wrist it sends oft* a branch, 
 350      Radial, or Muscular Spiral Nerve.

 called the Dorsalis, which passes between the flexor
 ulnaris and the ulna, to the back ofthe fore-arm and
 wrist, where, after sending ramifications to the inte-
 guments and contiguous parts, it divides into branch-
 es which pass to the little finger and the  finger next    !
 to it.  Those branches  send off,  in their course,
 many twigs which pass to the skin  and cellular sub-
 stance.
   The ulnar nerve then proceeds  with the  artery,
 over the annular ligament, on the radial side of the   ]
 os pisiforme, and divides into two  branches; one of
 which is superficial, and the other  deep-seated.
   The Superficial divides into two principal branch-
 es, an external and an internal.  The external passes
 under the aponeurosis palmaris;  and, after  send-   .
 ing a branch to combine with one  from the median
 and  some twigs to the contiguous muscles, it sub-
 divides into two branches, one of which goes to the   \
 ulnar side ofthe ring finger and the opposite side ofthe
 little finger.  The other branch sends offsome twigs
 to the muscles, and proceeds along the ulnar side
 ofthe little finger.
   The Deep-seated palmer branch of the ulnar nerve
 passes between the muscles of the little finger, under
 the tendons  of the  flexors, and accompanies  the
 deep-seated arterial arch in the palm of  the  hand,
 giving branches to  the  interossei, and other conti-
guous muscles.
  The Radial or Muscular Spiral  nerve  is one of
the largest nerves of the arm.  It  passes from the
 axillary plexus downward, backward, and outward,
under the triceps muscle, to the external side ofthe
 os humeri.  In this course it gives off several branch-    |
 es to the different portions of the triceps.  It  also
frequently gives off  a large branch,  which passes
downwards on the  outside of the olecranon, to the
back of the fore-arm, and continues to the back of 
         Radial, or Muscular Spiral Nerve.     351

the hand furnishing many branches which terminate
in the integuments.  It then proceeds downwards be-
tween the supinator radii  longus and the brachialis
internus.  Immediately after passing the articulation
ofthe elbow, it divides into two branches, denomi-
nated the Superficial and the Profound.  The Super-
ficial sopn joins the radial artery, and proceeds down-
wards,  sending  branches  to  the contiguous mus-
cles.   In its course about  the  middle of the arm
it crosses the tendon  of the supinator longus, and
proceeds between it and the tendon of the extensor
carpi radialis longior; it soon after divides the two
branches, which are  principally distributed to the
thumb and fore  finger, and also to the integuments.
   The Profound branch proceeds to the back of the
fore-arm under the radial extensor, and continues to
the back of the wrist and hand.  Into this course it
divides into two branches, which are distributed to
the contiguous muscles and tendons, and the integu-
ments.
   The Internal Cutaneous nerve is the smallest ofthe
nerves which proceed from the axillary  plexus.   It
descends in the course of the basilic  vein, and very
near it. Above the elbow it divides into an Internal
branch, which  proceeds over the Basilic Vein,  and
separates into branches that pass down on the side
ofthe fore-arm; and an External Branch that passes
under  the Median Basilic Vein, and continues down
on the anterior part ofthe fore-arm.
   The Articular or Circumflex nerve proceeds back-
wards  from the plexus,  between the teres major
and minor, and  passes nearly around the  body of the
os humeri, at a small distance below its head.  It is
 distributed to the contiguous muscles and to the ar-
 ticulation ; but  its principal branches terminate in
 the deltoid muscle. 
352
The Dorsal Nerves.
           THE DORSAL NERVES

   Proceed from the cavity of the spine between the
 dorsal vertebras.  They are sometimes called Inter-
 costals, because they pass  between the ribs, like the
 blood vessels of that name.   There are twelve pair
 of them, and they are named numerically, beginning
 from above.
   These nerves proceed from the medulla spinalis
 by two fasciculi of fibres—one from each of its late-
 ral portions—the posterior fasciculus is the largest.
 After passing through the lateral  foramen and the
 dura mater,  a ganglion is formed by the posterior
 fasciculus: the anterior fasciculus unites to this gang-
 lion at its external extremity: and one nerve is form-
 ed,  which almost immediately divides into  an ante-
 rior and a posterior branch, of which the anterior is
 the largest.
   The posterior branch proceeds backwards, and is
 distributed to the muscles of the back.   The ante-
 rior branch passes towards the angle of the rib, in
 contact with  the pleura.   Soon after its origin, this
 anterior branch sends off two ramifications which
 unite to the intercostal nerve, at the ganglion; it
 then proceeds forwards with the blood  vessels, be-
 tween the internal and external intercostal muscles,
 in the groove near the lower margin of the ribs; and
terminates  on the anterior part of the  thorax.  In
 its  course it  sends branches, not only to the inter-
 costal muscles and pleura, but to the other  muscles
 and the integuments of the thorax.
   Some of the dorsal nerves differ from the others,
 as to the ramifications which they send off.
   The first nerve, of this order, joins  the lower cer-
 vical nerves in the axillary plexus;  but it sends off
the ramifications  to the sympathetic;  and also a 
       General Account of the Lumbar Nerves.   353

branch, which passes under the first rib, like the
other dorsal nerves.
   The second nerve, send off a branch, which passes
through the external intercostal muscle into  the ax-
illa, and combines there with a branch of the cuta-
neous nerve, being distributed to the internal and
posterior part ofthe arm.
   The third dorsal nerve also  sends off a branch,
which is distributed to the axilla and the back part
ofthe arm.
   These branches of the second and third dorsal
nerves, are called intercosto-humeral nerves.
   The lower dorsal nerves  supply the muscles and
integuments ofthe abdomen.
            Of the LUMBAR Nerves.
   There are five  pair of these nerves.   The first
of them passes off between the first and second  of
the lumbar vertebrae, and the others  succeed regu-
larly; so that the last pair  is situated between the
last lumbar vertebra  and the sacrum.
   The first lumbar nerves  arise from the medulla
spinalis, before it forms the cauda equina; the other
four pair are formed  by the cauda equina.
   They commence by anterior and posterior fasci-
culi, which are united at a  ganglion.  From  these
ganglion, anterior and posterior branches  go off,
which are very different  in size, the anterior being
the largest.
  The posterior branches are distributed to the mus-
cles of the back.   The anterior sends branches to
the ganglions  of the sympathetic nerve, and also
communicate with each other to form the Lumbar
Plexus, which is situated on the lateral parts  of the
bodies ofthe Lumbar Vertebrae,  before their trans-
verse processes, and  supplies nerves to the muscles
of the thigh.
  vol. ii.              45 
354      Lumbar Nerves.—Lumbar Plexus.

            THE FIRST LUMBAR NERVE

  Is connected, by its anterior branch, to  the  last
dorsal and the second lumbar. From the same branch
ramifications go off to the QuadratusLumborum, and
obliquely across that muscle, to the lower part of
the abdominal  muscles near the spine ofthe ilium.

            THE SECOND LUMBAR  NERVE
  Sends off a muscular branch downwards  and  out-
wards: it also sends off the small  branch, called the
External Spermatic, which passes  down in such a di-
rection, that it perforates the transversalis  and the
obliquus  internus muscles, near their lower margin,
at a small distance from the superior anterior spine
ofthe ilium, and then proceeds within the lower edge
ofthe tendon ofthe external oblique to the abdomi-
nal ring, through which it passes.  In the male it is
distributed  to the spermatic cord and scrotum, and
in the female, to the labia  pudendi.  In the female
it also sends a branch to the uterus.*  The  Second
Lumbar,  after sending off these branches, passes
downwards, and joins the Third lumbar nerve.  From
this union ofthe second and third nerves, a branch
called  the  Cutaneus Medius, which will be  soon de-
scribed, proceeds downwards.
   After sending off this branch, the united trunk of
the second and third joins the Fourth; and  from this
union is sent off the Obturator Nerve, which  passes
through the aperture in the membrane that  closes
the foramen thyroideum; the  Crural Nerve, which
passes under Poupart's ligament; and a third branch
that proceeds  downwards, and joins the Fifth  lum-
bar nerve.   The Fifth lumbar nerve, with this acces-
sion from above descends into the pelvis, and unites
with the sacral nerves.

  • The external spermatic often comes off from the first lumbar nerve. 
          Obturator Nerve.—Crural Nerve.      355

  This arrangement ofthe lumbar nerves constitutes
the Lumbar Plexus, which, as has been already sta-
ted, furnishes three nerves to the lower extremity,
viz. the Cutaneus Medius, the Obturator, and the Cru-
ral Nerve.
  The Cutaneus Medius, which arises from the union
ofthe second and third nerves, as has been already
observed, proceeds downwards, and  frequently ad-
heres to the crural nerve, for a short distance, near
Poupart's ligament, but soon leaves it, and descends
on the inside of the thigh, supplying the integuments
as low as the knee.

              THE OBTURATOR NERVE
  Descends into the pelvis, and passes out of it at
the upper part of the foramen thyroideum ; proceed-
ing downwards in an internal direction, to be  dis-
tributed on the inside ofthe thigh.
  This nerve is generally accompanied by the obtu-
rator artery and vein; the artery being above,  and
the vein below it.  When it has arrived at the fora-
men ovale or thyroideum, it sends  off a branch to
the internal and external obturator muscles, and,
after passing these muscles, divides into two branches
which are distributed to the muscles on the  inside
of the thighs, the adductors, the pectineus, the gra-
cilis, &c

               THE  CRURAL  NERVE
  Is situated at first behind, and then on the out-
side of the psoas muscle. It passes under Poupart's
ligament  with the great femoral vessels, being on
the outside ofthe  artery.
  It is distributed to the integuments, and also to
the muscles, which are situated on the anterior  and
internal parts of the thigh.   Some of its ramifications
go  off before  it passes under Poupart's ligament. 
 356       Crural Nerve.—Sacral Nerves.

 Several of them are spent upon the integuments, and
 are  therefore   denominated  Cutaneus.—They  are
 distinguished by the terms Cutaneus Anterior, Cuta-
 neus Internus, &c according to their situations.
   The deep-seated branches are the largest.   They
 are principally spent upon the muscles on the ante-
 rior and the internal side of the thigh, viz. the four
 extensors, the adductors, the pectineus, the sartorius
 and the gracilis.  Among these nerves there is one,
 called the Saphenus, which has a different destina-
 tion. It accompanies the  great artery of the thigh
 to the place where it perforates the  Adductors;  it
 there separates  from the artery,  and passes over
 the tendon of the Adductors, under the sartorius mus-
 cle ; thence it continues, with the great saphena vein
 on the inside ofthe leg, to the internal ankle; send-
 ing  branches  to the integument, in its course.   It
 terminates in skin and cellular substance on the up-
 per and internal surface of the foot.

              The SACRAL Nerves
   Are composed of those cords of the cauda equina,
 which remain  after  the formation of the lumbar
 nerves.   They  are frequently stated  to consist of
 five or six pair, four of which pass through the fora-
mina ofthe sacrum, and the  fifth  between  the sa-
 crum and the os coccygis.*  The  cords of which   I
they are respectively composed arise by anterior   I
and  posterior  fasciculi.  When they  have arrived
opposite to the foramina ofthe sacrum, through which   j
they are to pass, a ganglion is formed,  at which they
 unite, and then divide into anterior  and posterior
branches/!"  The uppermost ofthe anterior branches

  • The sixth pair, when they exist, proceed in a groove in the os coc-
 cygis.
  \ The ganglions of the fourth and fifth nerves are extremely small and
not so near the foramina as those ofthe others. 
           Sciatic Plexus.—Pudic Nerve.        357

are large, and pass through the anterior foramina of
the sacrum.  The posterior are small, and go through
the posterior foramina.
  The Posterior branches are generally spent upon
the muscles which lie on the sacrum, and posterior
parts ofthe pelvis, externally.
  The anterior branches of the  three first nerves
send ramifications to the sympathetic.  They unite
to each  other,  and are joined by the  last lumbar
nerve, and  by a branch of the fourth sacral, in the
formation of the great sciatic nerve.  This union
constitutes the  Sciatic plexus.          *
  The anterior branch of the fourth nerve transmits
branches to the sympathetic: it also sometimes sends
a branch to the united nerves above, or the sciatic
plexus. It sends branches to the hypogastric plexus,
and to the  contiguous muscles.
  The fifth and sixth  pairs, which are very small,
terminate also  in  the contiguous muscles and in the
integuments.
  From the Sciatic plexus, or the nerves which com-
pose it, several smaller branches go off.  There are
generally two which pass off backwards through the
ischiatic notch, and are denominated Gluteal, as they
are distributed  to the glutei muscles. From the low-
ermost of these a branch  descends on the thigh.
  The Pudic nerve, which is appropriated to the or-
gans of generation, also passes off from this plexus,
and appears to consist of fibres which are derived
from each ofthe nerves that compose it.  It proceeds
between  the sacrosciatic ligaments, and divides into
two branches—an inferior and a superior.   The in-
ferior passes between the erector penis and the ac-
celerator urinse muscles, and is distributed to those
muscles, to the bulb of the urethra and the interior
of that canal, to the scrotum and dartos.
  The superior proceeds  along the os pubis to the 
 358     Course of the Great Sciatic Nerve.

 symphisis, and passes between the bone and the body
 ofthe penis to the dorsum.  A considerable branch
 accompanies the artery on the  dorsum, and termi-
 nates, by many ramifications, on the glans penis;
 after sending  branches in its course to the integu-   ,
 ments generally, and to the prepuce.
   In females, the Inferior pudic nerve proceeds along
 the external labia pudendi to the mons veneris, send-   |
 ing off many ramifications in its course.
   The Superior pudic nerve proceeds as in males,
 along the branch of the pubis to  the  superior sur-
 face ofthe ohtoris, and terminates principally upon
 the extremity of that organ.
   The sacral nerves unite in the sciatic plexus  to
 form the great nerve of the lower extremity, which   !
 is next to be described.                             3

          The GREAT SCIATIC Nerve.

   Proceeds from the pelvis through  the ischiatic
 notch, between the pyramidalis and the superior ge-
 mellus muscle; it then passes down to the back part
 ofthe thigh, between the tuberosity  of the ischium
 and the great trochanter ofthe os femoris; and con-
 tinues downwards inclining from  within  outwards,   1
 to the ham, where it is situated between the tendons   j
 of the semi-tendinosus and semi-membranosus on
 the internal side, and the tendon of the biceps on the   j
 external.  In this course it sends off branches to
 the muscles on the posterior part of the thigh.
  As the great nerve passes down the thigh,  it sends
 off obliquely downwards and  outwards, a  large
 branch which  is  called the Fibular, that  passes    j
across the head of the fibula to the  external  and
 anterior part of the leg.  The place where  this
branch separates from the main nerve  is different in
different subjects.  It continues in contact  with  it    i 
         Distribution of the Fibular Nerve.      359

for some distance, connected only by cellular mem-
brane.

         THE FIBULAR OR PERONEAL NERVE

  Proceeds downwards on the inside of the tendon
ofthe biceps, and crosses obliquely to the outside
ofthe external  head of the  gastrocnemius: it then
passes inwards between the long peroneus muscle
and the fibula: and descending between the muscles
on the front of the leg, divides  into  two branches,
one of which inclines to the exterior side ofthe leg,
and the other preserves an internal situation.  In its
course from the great sciatic nerve to the fibula, it
sends off some superficial ramifications.   The two
branches into which it divides, after passing over the
fibula, continue downwards.   The Internal, after sup-
plying the muscles on the anterior part ofthe leg,
passes under the annular ligament like the anterior
tibial artery; and on the upper part  of the foot, di-
vides into two ramifications, one of which proceeds
forwards near the internal edge of the foot and the
other near the  external; they divide again, and are
distributed to the parts on the  upper surface ofthe
foot, one of their ramula descending with the conti-
nuation of the anterior tibial artery to the sole of the
foot.
   The External Branch of the fibular nerve, as  it
 proceeds downwards, supplies  ramifications to the
 contiguous muscles, and passing through the fascia
 on the outside of the leg, continues  between it and
 the skin towards the foot.   In this course it  gener-
 ally divides into  two branches which are spent upon
 the upper surface ofthe foot.
   The GREAT SCIATIC Nerve, after the  fibular
 nerve leaves it, continues down the thigh, between
 the tendons of the  flexors,  behind the great blood
 vessels, and of course exterior to them. 
 360      Distribution of the Tibial Nerve.

   In the ham, this  great  nerve takes the name of
 POPLITEAL, and proceeds across the articulation
 ofthe knee, between the heads of the gastrocnemii,
 to the posterior side of the tibia: here  it passes
 through the upper portion of the  soleus or gastroc-
 nemius internus, and  continues between it and the
 long flexor of the toes, near the Posterior Tibial Ar-
 tery; descending with that artery to the hollow of the
 os calcis.   In this situation it has the name of
             POSTERIOR TIBIAL NERVE.

   At the commencement of this course, a  small dis-
 tance below the internal condyle  of the os femoris
 it sends off a branch of considerable size called the
 Communicans Tibia, or  Saphena Externa,  which
 passes down behind the gastrocnemii, and  gradually
 inclines externally, so that it is situated on the ex-
 ternal edge ofthe tendo Achillis, soon after the com-
 mencement of that tendon, and proceeds behind the
 external ankle, near the outer side ofthe foot, to the
 smaller toes: distributing branches to the contiguous
 parts.   In its course on the back ofthe leg, it sends
 off a branch which unites with one ofthe superficial
 ramifications  of  the fibular nerve, and descends to
 the outer part ofthe foot.
   The Tibial Nerve, in its course downwards, sends
 branches to the contiguous muscles; and a few twigs
 which form a species of net-work on  the  artery.
 In the hollow of  the os calcis it sends off a superfi-
 cial branch to the integuments of the sole  of the
 foot which proceeds on  the outside of the aponeu-
 rosis  plantaris:  it there also divides into branches,
 which are denominated  the Internal  and External
 Plantar Nerves.
   The  Internal  Plantar  Nerve  proceeds forwards,
along side of the tendon of the long flexor muscle of
the great toe, giving off small branches in its course, 
      Commencement of the Sympathetic Nerve.  361

About the middle  of  the foot it divides into four
branches, one of which proceeds to the inside ofthe
great toe; and a second to the angle formed by the
great toe and the toe next to it, where it divides and
sends a branch to the opposite sides of those toes:
the other two branches are  distributed in  a similar
manner, to the succeeding toes. These digital branch-
es are connected with each other by small ramifica-
tions.
   The External Plantar Nerve proceeds with the ex-
ternaljplantar artery towards  the external side  of
the foot, between the short flexor of the toes and the
flexor accessories.  Near the external edge of the
foot, about the posterior end ofthe metacarpal bones,
it divides into three branches.  One proceeds to the
outside ofthe little toe; another passes to the angle
between the fourth toe and the little toe, and divides
into branches which  are  distributed to the corres-
ponding sides of these toes.   The third branch pro-
ceeds more deeply in  the foot, from the external to-
wards the internal edge of it, and is spent upon the
deep seated contiguous muscles.
  THE GREAT SYMPATHETIC OR INTERCOSTAL NERVE
  Commences in the cranium with thqse small ram-
ifications ofthe pterygoid branch of the upper max-
illary nerve, and  ofthe sixth  pair, which accompany
the carotid artery through the canal in the petrous
portion ofthe temporal bone.  These small nerves
form a net-work which surrounds the artery in the ca-
nal and gives rise to the incipient sympathetic, a small
cord which passes down close to the nerves of the
eighth and ninth pair ofthe neck.  Opposite to the
second  cervical  vertebra, this nerve is swelled or
dilated, so as to  form  a body of a light red  colour,
which is more than an inch in length, and has the
form of  two  cones united  to  each  other at their
  vol. n.              46 
362      First Ganglion, and other Cervical

bases.   This is the Superior  Cervical Ganglion of
the Sympathetic  Nerve, and from  it the nerve de-
scends, behind the Par Vagum, on  the front part of
the neck.
  This ganglion receives twigs from  the  first,  se-
cond, third and fourth pairs of cervical nerves, and
also from the eighth and ninth nerves of the head.
It sends off several twigs, which pass behind the ca-
rotid artery, at its bifurcation, and are joined by twigs
ofthe Portio Dura and the Glasso- Pharyngeal nerves.
From these united twigs proceed very small rami-
fications, Which accompany several branches of the
external carotid artery, and some of them pass down
with the  Common Carotid.
  This superior ganglion also  furnishes small twigs
which accompany the Glosso-Pharnygealto the tongue
and pharynx.  Sometimes a twig from it passes on
the back part of the thyroid gland  to communicate
with the recurrent nerve.  From this ganglion go
off some small branches, which, uniting with others
from the superior laryngeal nerves, form the superior
or superficial cardiac nerve, which will be  soon de-
scribed.
  The trunk of the Sympathetic Nerve descends, on
the front of the neck, from this  ganglion, as has been
already stated.   In its course it receives very small
twigs from the fourth and fifth  cervical nerves, and
sends some very small twigs which appear to goto
the oesophagus, and some which unite to the laryn-
geal nerve and go to the thyroid gland.  Some twigs
which  are larger proceed from it into the thorax, and
go to the cardiac plexus hereafter to be described.
  Opposite to the interval between the fifth  and sixth
cervical  vertebrae it forms another ganglion, of an ir-
regular shape, much  smaller that  the first.  This
ganglion, in different subjects,  differs in size as well
as in several other respects.   Sometimes it is en-
J 
     Ganglions and Branches of the Sympathetic.   363

tirely wanting, and sometimes it is doubled.  It is
denominated the Middle Cervical,  or Thyroid Gan-
glion.  When the fourth, fifth, and sixth  cervical
nerves do not send ramifications to the sympathetic
nerve, this ganglion receives twigs from them.
   The Middle Cervical, or  Thyroid Ganglion sends
many ramifications downwards.  Some of them en-
ter the thorax and contribute to the formation of the
Cardiac Plexus; others accompany the inferior thy-
roid artery, and, with twigs from the recurrent nerve,
form a plexus which  extends  towards the thyroid
gland.   Some  proceed downwards  before, and
others behind, the subclavian  artery, to the next
ganglion; and among them  is generally one which
may be regarded as the trunk of the Sympathetic.
   This third Ganglion is denominated the  Inferior
Cervical, or the First Thoracic.  It is almost constant-
ly found in the same situation, viz. between the trans-
verse process of the  last cervical vertebra and the
head of the  first rib, and is partly covered by the
origin  of the vertebral artery.  It is  generally larger
than the middle ganglion.  It receives branches from
the sixth and seventh  cervical, and the two first dor-
sal nerves.   Ramifications pass from it to the par
vagum and recurrent nerve, and also to the cardiac
and pulmonary plexus.
   From  this  ganglion the  Sympathetic Nerve pro-
ceeds downwards on the side of the spine, as will be
described hereafter.
              The Nerves of the Heart,
   Being derived from branches which have already
been mentioned, are now to be described.
   They arise principally from  an arrangement of
nerves denominated the Cardiac Plexus, or Plexuses,
which  is situated above the curve of the aorta, and
extends, on the posterior side of it, from the root of
the arteria innominata to the bifurcation of the pul- 
364
Branches of the Sympathetic.
monary artery.  This plexus is composed of nerves
which are principally formed by the union of small
ramifications that are derived  from the three above
. mentioned ganglions of the Sympathetic Nerve, and
the nerve itself; and also from the Par Vagum and
some of its branches.
   These nerves are denominated the Cardiac. They
descend on their respective sides  of the  neck, but
are somewhat different on the different sides.  On
the right side three nerves have been described as
particularly entitled to this name, and on  the left
side but two.
   The first on the right side is denominated Supe-
rior, or Superficial Cardiac Nerve.  It generally arises
by several fine threads, which unite into one delicate
cord that passes down by the  side  of the common
carotid.   When  it  has arrived on a line with the
middle ganglion, it sends a twig to the thyroid plex-
us, and another that communicates with a twig from
the par vagum, which  continues downwards on the
carotid artery.  After passing beyond the ganglion,
it divides into several branches, which unite them-
selves to branches of  the recurrent nerve that are
going to the  middle  ganglion.
   The second, which  is  denominated the Middle
Cardiac, the Great Cardiac, or  the  Deep  Cardiac, is
the largest of the three.  It arises from the Middle
Cervical, or Thyroid Ganglion,hy five or six fine fibrils,
which finally form one, that passes before and across
the subclavian; and at that place as well as lower
down, it receives twigs from the par vagum: below
this, it is joined by a considerable twig from the re-
current,  and terminates in the Cardiac Plexus, to
which it contributes largely.
   The third  cardiac nerve ofthe right side is called
the Inferior, or the  Small Cardiac  Nerve.   It origi-
nates from the third, or lower cervical ganglion, by 
           Branches of the Sympathetic.        365

many fibrils which unite into a smaller number that
form  a  plexus.  It crosses behind  the subclavian,
and proceeds on the outside of the Arteria Innomi-
nata to the curve of the aorta; continuing between
it and the pulmonary artery, to the anterior corona-
ry plexus.  In this course it receives several fibres
from the recurrent and the  par vagum.
  On the left side the first cardiac nerve arises from
the upper ganglion.  The second derives its origin
from the two lower ganglions.
  The left superior or superficial cardiac nerve arises
like the  right, by many distinct fibres, and proceeds
downwards in the same way.   It descends between
the carotid and the subclavian, and  when it has ar-
rived  at  the  place  where they originate from  the
aorta, it divides into a great number of small rami-
fications.   Some pass before the aorta, either to join
the branches of the inferior cardiac, or to unite with
the cardiac branches ofthe left nerve  ofthe par va-
gum.  The others proceed behind the aorta, and
enter into the common cardiac plexus.
  The second cardiac nerve of the left side may be
called the Great Left Cardiac, and has  a double ori-
gin as above mentioned.  The principal branch in
its composition arises from the lowest cervical gan-
glion, and  passes behind the transverse portion of
the  subclavian artery.  Where the  inferior thyroid
arises from the  subclavian, this  branch receives a
considerable  number  of ramifications, which arise
from the upper ganglion, and  are interwoven with
each other before they unite to it.  It passes behind
the curve of the aorta, and terminates in the great
cardiac  plexus, which it particularly contributes to
form.  Here it is joined by many fibres from the par
vagum. 
 366   Plexus formed by the Nerves ofthe Heart.

                The Cardiac Plexus

   Is  situated  principally behind the curve of the
 aorta, at a small distance above the heart.   It com-
 mences as high as the origin of the Arteria Innomi-
 nata, and extends downwards to the bifurcation  of
 the pulmonary artery.
   As has been already mentioned, it  is principally
 composed of branches from the middle cardiac nerve
 of the right side, and the inferior cardiac  nerve  of
 the left;  but it receives branches from the superior
 cardiac ofthe left, and sometimes ofthe right side.
 Some fibres of the inferior cardiac of  the right are
 also united to it.
  Many branches proceed from this plexus.
  A small number  pass  upon the aorta, and seem
 to enter into its texture.*
  Some of them also combine with the ramifications
 ofthe Par Vagum in the anterior pulmonary plexus.
  The majority proceed to the basis  of the heart,
 near the origin ofthe pulmonary artery and the aorta,
 and constitute the proper nerves of that organ.  They
 accompany  the coronary arteries, and are so ar-
ranged around them that, by some anatomists, they
have been said to form plexuses, which have been
 denominated Coronary.
  The Sympathetic Nerve, as has been stated above,
proceeds from the ganglion, called the Lower Cervi-
cal, or the First Thoracic, before the neck of the first
rib.  It continues to descend, in the same direction,
along the spine, exterior to the  pleura, to  the infe-
rior part of the thorax.  Near the head of each rib
it forms a ganglion, which unites with the intercos-
tal nerve behind it, by two branches, and thus forms
an indirect communication with the medulla spinalis.
 * It has been asserted, that some of the anatomists of Paris have traced
these nerves on the aorta, to a great distance from the heart. 
   Sympathetic Nerve, & its Splanchnic Branches. 367

  From several of the uppermost of these ganglions
small twigs proceed to the pulmonary plexus, and
also to the great trunk of the aorta, below the curve
forming a species of net work, or plexus upon it.
  From the ganglions near the heads of the fifth
and sixth ribs, and from four or five ofthe ganglions
which succeed them, small nerves arise, which pro-
ceed downwards on the sides of the bodies of the
vertebrae, and unite  into one trunk that is  denomi-
nated the Splanchnic Nerve, because it is distributed
to the viscera ofthe abdomen.—This nerve proceeds
behind the crus ofthe diaphragm, on its respective
side, into the abdomen.   A second  and  smaller
nerve, of the same  destination, called the Lesser
Splanchnic Nerve, arises lower  down, from two or
three ofthe lowermost dorsal ganglions, and pene-
trates separately into the cavity ofthe abdomen: it
then generally divides into  two branches, one of
which unites to the  great splanchnic nerve, and the
other proceeds to the renalplexus soon to be described.
  As soon as the great splanchnic nerve has entered
the abdomen, it divides into many branches, which
commonly form small ganglions on each side ofthe
cceliac artery, but above it.  These ganglions are
generally contiguous; but  sometimes they are at a
small distance from each other, and united by nerves.
They are however commonly spoken of as one, and
called the Semilunar Ganglion.   They are of irregu-
lar forms, and very different from each other in size,
as well as form.   Those formed by the splanchnic
nerve on one  side are sometimes different  from
those on the other.
  From this assemblage of ganglions proceed many
small nerves, which are woven together so  as to
form a net-work denominated the Solar Plexus.
  This  plexus is situated anterior to the  spine and
the crura of the diaphragm; behind the stomach and 
 368      Arrangement of the Nerves of the

 above the pancreas; and is extended upon the cceliac
 and superior mesenteric arteries. Some ramifications
 from the par vagum and the phrenic also join it.
   The lower  part  of the solar plexus, which  sur-
 rounds more immediately the cceliac artery, is term-
 ed the  Cceliac  Plexus.   From it net-works of nerves
 extends upon the great branches of the artery to
 the  organs which they go to.
   They extend to the stomach, (although it is sup-
 plied by the par vagum,) along the superior corona-
 ry or gastric branch of the  cceliac; and the fibres
 in their composition being spread upon the coats of
 the  stomach, unite with the  branches ofthe par va-
 gum, which are also spread upon them.
   A similar  net-work, denominated  the Hepatic
 Plexus,  extends upon  the Hepatic Artery, and from
 it to the Vena Portarum; and accompanies those
 vessels  into the substance of the liver.   It also sends
 branches to the biliary duct and gall bladder; to the
 stomach by the arteria gastrica dextra;  and to the
 omentum.
   The  Splenic Artery is  invested by a similar but
 smaller  arrangement of  nerves,  denominated the
 Splenic  Plexus.  In its course  to the spleen,  this
 plexus sends some nerves to  the pancreas; and also
 to the stomach and omentum, with the left gastric
 artery.
   The superior mesenteric artery is surrounded by a
 net-work, which extends to it directly from the solar
 plexus, and is the largest of all which proceed from
 that  plexus.  The Mesenteric Plexus at first  nearly
 surrounds the artery, and proceeds with it between
the lamina of the mesentery.  In this course it sends
 branches, with the arteria colica dextra, to the trans-
 verse portion ofthe colon.  Between the lamina  of
the mesentery, it sends ramifications  with all the
branches ofthe artery, to the small intestines gene- 
Abdominal Viscera.
369
 rally; to the ccecum, and the right portion of the co-
 lon; as well as to the mesenteric glands.
   From the lower part ofthe solar plexus a net-work
 proceeds, on  the front  of the aorta, to the  inferior
 mesenteric  artery, and surrounds  it.  Nerves from
 this plexus  accompany the artery to the left portion
 ofthe colon and the rectum.  Some of their ramifi-
 cations combine with those of the hypogastric plexus.
   The Emulgent Artery is attended by nerves, which
 are arranged like a net-work on its anterior and pos-
 terior surfaces, and are denominated the Renal Plex-
 us.  They are  derived from the  solar plexus, and
 frequently contain small  ganglions.  They proceed
 with the artery to the fissure of the kidney, and are
 distributed  with its different ramifications, in the
 substance of the organ.
   Some branches pass from them to the renal gland
 with the capsular artery.
   Before the renal plexus arrives at the  kidney, it
 sends off, from its  inferior part, some new fibres,
 which, after joining some others from one of the lum-
 bar nerves,  accompany the spermatic arteries, and
 are, therefore, called the Spermatic Plexus.  In the
 male  these  fibres proceed through the abdominal
 ring, and many of them  go to the testis, but they
 are followed with great difficulty, on account of their
 small size.
  In the female, they go to the ovary and the  Fallo-
 pian tube.
  From the great plexuses above, a small net-work
 continues downwards on the aorta, receiving fibres
 from the intercostals on each side; at the great bifur-
 cation of the aorta it divides, and is joined on each
side by many ramifications from the third lumbar
nerves, which thus form  a plexus  of  considerable
extent, that sends nerves to the bladder, rectum, and
  vol. ii.              47 
370     Termination of the Sympathetic Nerve.

vesiculae seminales in males; and to the uterus and
vagina, as well as the  bladder and rectum, in fe-
males.*  This is called the Hypogastric Plexus.
  The plexuses above mentioned are derived from
the splanchnic nerve, which come off from the Sym-
pathetic in the thorax.
  The Sympathetic Nerve, after giving  off the lesser
splanchnic, is diminished  in  size, and approaches
nearer  to the  bodies  of the vertebrae.  It  passes
through the crura of the diaphragm, and then pro-
ceeds forwards and downwards upon the spine, be-
tween the tendinous crura of the diaphragm and
psoas muscle; near the vena cava on the right side,
and the aorta on the left.  In this  course, it gene-
rally receives one or two small cords from the ante-
rior branch of each ofthe lumbar nerves; these cords
proceed downwards and forwards, between the bo-
dies of the vertebrae and  the psoas muscle, and  a
ganglion is generally formed at the place where they
join the nerve.
  In its descent on the lumbar vertebrae, the Sym-
pathetic sends  off several nerves  that unite to the
net-work which descends on the aorta from the plex-
us above.  After passing over the lumbar vertebrae,
it descends into the pelvis, close to  the sacrum, on
the inner side of the great foramina :  here  it also
forms ganglions, and commmunicates with the sa-
cral nerves, and likewise with the hypogastric plexus.
It terminates on the os coccygis, where its  minute
fibres join those of the opposite side.

  * Although the testicle receives nerves which are derived from the Sym-
pathetic, the penis and other external parts ofthe organs of generation do
not: the  nerves which accompany the pudic artery being derived from
those which unite to form the great Sciatic 
SYSTEM  OF  ANATOMY.

              PART XL
            OF THE ABSORBENT VESSELS.*

   The absorbent vessels are small transparent tubes,
•of a delicate structure, which exist in considerable
numbers in almost every part of the body.
   These tubes originate upon the surfaces of all the
cavities ofthe body; and of the cellular membrane,
in all the various parts into which it penetrates; upon
the internal surface of the stomach and the intes*-
tines; and  probably upon the skin.
   Those which originate in the Lower  Extremities
and  the Cavity of the Abdomen, unite and form a large
trunk  called  the Thoracic Duct,  which proceeds
through the thorax, and terminates in the left Sub-
clavian Vein, at its junction with the Internal Jugular.
Those of the  Left Upper Extremity, the Left &ide of
the Head, and the contiguous parts, form  a trunk
which terminates in the same place.  While the re-
maining absorbents, or those of the Right Upper Ex-
tremity, and the Right side of the Head, §-c. also form
a trunk, which terminates in the corresponding part
ofthe Right Subclavian Vein.
   The absorbent vessels of the middle size, which

  * Discovered at Leyden in 1650, by Olaus Rudbcck, «nd at Copenhagen
in 1651, by Bartholine.—Ed. 
372      Structure of the Absorbent Vessels.

arise from the union of the small vessels, and unite
to form the larger,  in their progress to these large
vessels, pass through certain bodies which have been
denominated  Conglobate Glands,  and may be consi-
dered  as appendages of the absorbent system.
   The absorbent vessels are composed of two coats,
which  are thin, but dense and firm, and also elastic.
The coats of the thoracic  duct may be separated
from each other.  The internal surface ofthe exte-
rior coat is fibrous.  The internal coat is a delicate
but strong membrane.—There is great reason to be-
lieve that the above mentioned fibres are muscular,
or at least irritable; for the absorbent vessels have
been observed, by Haller, to contract upon the  ap-
plication of strong sulphuric acid.  They have also
been observed to propel their contents  with consi-
derable rapidity, by their own contraction, indepen-
dent of pressure, or of motion communicated by any
other body.
   Blood vessels  are sometimes observable in  the
coats ofthe larger absorbents, in injected  subjects.
The vascularity of these tubes may also be inferred
from the inflammation  which frequently  takes place
in them.
  Nerves have not been traced into their texture;
but the absorbents  seem to be painful when they are
inflamed, and, therefore, it is probable that they are
supplied with nerves.
  The  absorbent vessels, are very generally supplied
with valves, which are much more numerous in some
of them than  in  others; and are different in their
number, in the same vessels, in different subjects.
   Very frequently  there  are  several valves in  the
course of an inch: sometimes a valve will not appear
in the course of several inches.  Inthe Thoracic Duct
the number of valves  is very different  in different
subjects.  These valves are folds or plaits of the in- 
          Commencement of the Absorbents.      373

ternal membrane, and are of a  semi-circular form.
There are commonly two of them together origina-
ting from opposite sides of the vessel.
  The absorbents  are  generally somewhat dilated
on the side ofthe valve which is next to their termi-
nation, and this occasions their knotted appearance
when they are injected.   The object of this valvu-
lar  structure seems to be the prevention of retro-
grade motion of the contained fluid, in consequence
of lateral pressure.
  Where the different trunks ofthe absorbents open
into the veins, there are one or two valves to prevent
the  regurgitation of the blood into them.
  The valves of course  prevent the injection ofthe
branches  of these vessels  from their trunks.—In
some animals the valves have sometimes been rup-
tured, or forced back; and the absorbents have been
injected in a retrograde direction.   There are but
two or three instances upon  record where this has
been practicable in the Human Subject.
  In consequence of the impracticability of inject-
ing the  small branches from  the larger, the absor-
bent vessels cannot, generally, be demonstrated at
their commencement, or origin.   It is, however, to
be  observed, that  the Lacteals, or Absorbents of the
Intestines, appear no way different from other absor-
bents; and they have been seen distended with chyle,
from their commencement, in certain subjects who
had died  suddenly.   Their origins have  been de-
scribed very differently by different observers.
  Mr. Cruikshank describes them as originating on
the surfaces of the villi, by a number of very small
radiated branches with  open orifices;  which  bran-
ches soon unite to form a trunk.
  Lieberkuhn  believed them to commence in the
form of an ampullula.—Seepage 105 of this volume.
  The second Monro also believes that the absorb- 
 374             Conglobate Glands.

 ents begin by very small tubes, with open orifices, in
 several species of fish.*
   It is stated  by Dr. Soemmering upon the autho-
 rity of Haase, a German anatomist, that when mer-
 cury is forced backwards in the absorbent vessels of
 the foot and the  heart, it has sometimes escaped on
 the surfaces of those parts. The probable inference
 from these  facts is, that those vessels originate by
 open orifices on  the surfaces of the heart and foot.
   The bodies connected with the absorbent vessels,
 which are called Conglobate Glands, are generally of
 a roundish, or irregular oval form, and somewhat
 flattened.  They are of various sizes, from two lines
 in diameter to more than  twelve.  Their  colour is
 frequently whitish,  but sometimes it is slightly in-
 clined to red.  They are  invested with a covering
 of cellular membrane, which appears like  a mem-
 branous coat;  and they are connected to the conti-
 guous parts  by a loose cellular substance.  When
 the  absorbent  vessels connected  with these bodies
 approach near to them, they divide  into a number
 of ramifications,  most of which enter into the sub-
stance ofthe gland, while some of them run over it.
 On the opposite side ofthe gland a number of bran-
 ches go out, which unite and form trunks similar to
those which entered the gland.   The vessels which
enter the gland are called  Vasa inferentia, and those
which go out of it Vasa efferentia.
  These vessels  are generally much convoluted in
the substance of the glands, so  that those  bodies
sometimes appear like a mere convolution of absorb-
ent vessels.   There has been much diversity of sen-
timent respecting the structure of these organs/]"

  * See his work on the  Structure and Physiology of Fishes, p. 34.
  f Mr- Ahernethy states, that the mesenteric gland of the  Whale con-
sists of large spherical bags into which a number of the lacteals open.—
Numerous blood vessels are ramified on the surfaces of these cysts? 
Fluid contained in the Absorbents.
375
  The  absorbent  vessels, in the different parts  of
the body, generally contain fluids resembling those
which are found in those parts.   Mr. Hewson open-
ed the large absorbents in many living animals of dif-
ferent kinds, and found that they contained a trans-
parent fluid, which coagulated when exposed to the
open air.
  The  arrangement of these vessels resembles that
of the veins in several respects.   Many of them are
superficial; but there are also deep-seated absorbents
which accompany the blood vessels.

and injection passes from them into the cyst.  He also found cells in the
glands ofthe absorbent vessels, in the groin and the axilla of the horse.—
See Philosophical Transactions, for 1796, Part I. 
CHAPTER I.
 OF THE ABSORBENTS OF THE LOWER EXTREMITIES, THE
            ABDOMEN, AND THE THORAX.

   Under this head are arranged the ramifications of
 all the vessels which unite to form the Thoracic Duct.

                    SECTION I.

      Of the Absorbents of the Lower Extremities.
   These absorbents, like the  veins, are superficial
 and deep-seated.  The Superficial lie in the cellular
 membrane, very near the skin; and form an irregu-
 lar net-work  which extends over the whole  limb.
 They are, however, most numerous on the internal
 side.
   The deep-seated accompany the arteries  like the
 veins, and there are two at least  to each artery.

            The Superficial Absorbents,
   Have been injected from the toes so as toform a net-
 work, which occupies the upper surface ofthe foot.
 They have also been injected  in a similar manner
 on the sole.   Those on the upper surface of the
 foot generally proceed upward on the anterior  and
 inner side ofthe leg; but some of them pass on the
 external side of it.  Those on  the  sole  are conti-
 nued on the back of the leg, but communicate very
 frequently with  the anterior vessels.  Some of the
 absorbents from the outside of the foot and leg en-
 ter into some of the popliteal glands, soon to4be de-
 scribed; but they are not numerous; and the princi-
pal number continues up to the glands  ofthe groin. 
        Absorbents of the Lower Extremity.       377

 The absorbents which  originate  on the surface of
 the thigh, as well as those which pass over it from
 below, incline gradually along the anterior and pos-
 terior surface, to the internal side of it; on which
 they proceed in great numbers, and very near to each
 other to the inguinal glands.  Superficial absorbents
 proceed also from the buttock and lower part of the
 back, from the lower part of the abdomen, the peri-
 neum and the exterior of the genital organs, to these
 glands.
             The Deep-seated Absorbents,
   Are named from the arteries they accompany.

          The Anterior Tibial Absorbents.
   The anterior tibial artery is generally attended  by
 one which comes with it from the sole, and by another
 which commences on the upper surface ofthe foot.
 The first mentioned absorbent continues with the ar-
 tery.   The last often passes through an aperture in
 the interosseal ligament, about one-third of the dis-
 tance from the ankle to the knee, and accompanies
 the fibular artery, while the anterior tibial artery  is
joined by other absorbents about the same place.
 In some instances a small  absorbent gland occurs
 in this course, at a short distance  below the knee.

          The Posterior Tibial Absorbents
   Have been injected from the under side ofthe toes.
 They accompany the ramifications on the sole of the
 foot; and after uniting, continue with the main trunk
 up the leg, where they enter the popliteal glands.
  The Peroneal Absorbents arise also  from the sole
of the foot, and its external side.  They accompany
the peroneal artery, and terminate in the popliteal
glands, which receive also the absorbents from the
knee and ham.
  vol. ii.              48 
378     Absorbents of the Lower Extremity.

  From these glands four or five absorbent vessels
proceed which accompany the great blood vessels
ofthe lower extremity; and, proceeding with them
through the aperture in the tendon ofthe adductors,
continue upwards until they enter some of the glands
ofthe groin.
  The glands of the ham and groin, which are  so
intimately connected with  the absorbents  of the
lower extremity, are very different from  each other.
  The Popliteal Glands, or those of the Ham, are
but three or four in number, and very small in  size.
They are  generally deep seated, and very near the
artery.
  The Inguinal glands vary in  number,  from eight
to twelve or more.  They are superficial and deep-
seated.   The  Superficial  communicate principally
with the superficial absorbents.   The lowermost of
them are at some distance below Poupart's  liga-
ment, and the uppermost are rather above it.  They
are exterior to the fascia ofthe thigh.   Their num-
ber is generally six or eight, while that of the deep-
seated is but three or four.
  The superficial absorbents from below, approach
very near to each other, and enter these glands.—
They are commonly distributed among three or four
ofthe lowermost;  but some of them pass by these,
and  proceed to one that is higher up; and some-
times there are absorbent vessels which pass to the
abdomen without entering into any of the glands of
the groin.
   The  deep-seated absorbents  pass  into the deep-
seated glands, which, as has been already observed,
 are  but few, and lie very near the artery under the
fascia of the thigh.  The  two sets of glands are
connected to each other by many absorbent vessels
 that pass between them.   The vessels which  final-
ly go out of these glands are considerably less in num- 
         Inguinal and External Iliac Glands.      379

 ber than those which enter into them.   They pro-
 ceed under  Poupart's ligament, and, in  some  in-
 stances, a large proportion of them passes through
 three glands which lie below this ligament, and are
 often so arranged, that they lie on each side of the
 great femoral vessels, and above them.   One very
 frequently is found on the inside of the femoral vein,
 in the vacuity between it  and the internal part of the
 ligament.  All the  absorbents of the lower extre-
 mity, however, do  not enter these  glands.  Some
 pass along the great vessels and enter other glands
 near the margin of the pelvis.  Some also descend a
 short distance into the pelvis, and unite with vessels
 that are passing from the pelvis to  the  plexus and
 the glands that surround the external iliac
   The absorbents which proceed from  the glands
 last mentioned, joined to those  which  pass under
 Poupart's ligament, without entering these glands,
 and some which come from the pelvis, form a large
 plexus, which almost surrounds the external iliac
 vessels, and contains many glands.
   These External Iliac Glands vary in their number
 from six to ten or twelve. They lie on the side of
 the pelvis, in the course ofthe external iliac vessels,
 and some of them are of considerable size.  These
 glands and the plexus of absorbents, extend in  the
 track of the iliac vessels, to the first lumbar vertebra.
 In this course they  are joined by the plexus which
 comes from the pelvis; and soon after they arrive at
 the Lumbar Glands, which form a very large assem-
 blage, that extends from the bifurcation ofthe aorta
 to the crura ofthe diaphragm.
  These glands lie irregularly, on the aorta, the
vena cava, and the lumbar vertebrae.  Most if not all
the absorbents above mentioned pass through some of
them; and from the union of these absorbents, some 
380       Absorbents ofthe  Testicles, be.

of the great branches, which unite to form the tho-
racic duct, are derived.
   In this course from the thigh to the lumbar glands,
these absorbent vessels are joined by several others.
The Superficial Absorbents of the scrotum commonly
enter into the upper inguinal glands, and thus unite
to the great body of absorbents.
   The Absorbents of the Testicles, originate  in  tbe
body, and the coats of the  testicle, and in the epi-
didymis, and are remarkably large and numerous.—
They proceed along the spermatic cord, through the
abdominal ring, to the lumbar glands.   These ves-
sels are remarkable for the little communication they
have  with each other.
   The Deep-seated Absorbents of the Scrotum accom-
pany  the absorbents of the testicle to the lumbar
glands; but those which are superficial enter the up-
per inguinal glands.
   The Absorbents of the Penis are also deep-seated
and  superficial.   The deep-seated  arise  from the
body  ofthe penis, and accompany the internal pudic
artery into the pelvis.  The superficial absorbents
arise  from the prepuce, and pass along the dorsum
ofthe penis.  There are frequently several  trunks
which receive branches from the  lower surface of
the penis in their course.  At the root ofthe penis
they generally separate to the right and left, and pass
to the glands on the respective sides.
  In females, the absorbents of the  interior  of the
clitoris accompany the internal pudic artery.  Some,
which arise about the vagina, pass through the ab-
dominal ring with the round ligament; and  others
proceed to the inguinal glands. 
Absorbents of the Pelvis and the Kidneys.   381
                    SECTION II.

   Of the Absoi*bents of the Abdomen and Thorax.

  The Absorbents of the lower portions of the parietes of
the Abdomen and the Pelvis unite into trunks that fol-
low the epigastric, the circumflex and  the  iliac, as
well as the lumbar and sacral arteries, &c  They
proceed  to  some of the glands which are in the
groin: or in the external iliac, the hypogastric, or
some of the contiguous plexuses.
  The Absorbents of the Womb are extremely numer-
ous ; and, in the gravid state, are very large.  Those
which are on the neck and anterior part of the body
accompany the spermatic vessels.
  The Absorbents ofthe Bladder pass to small glands
on its lateral and inferior parts, and finally join the
hypogastric plexus.
  The Absorbents of the Rectum are of considerable
size.  They pass through glands that lie upon  that
intestine, and unite with the lumbar plexus.
  The Absorbents of the Kidney are superficial and
deep-seated.  They are very  numerous but, in a
healthy state of the parts, are discovered  with dif-
ficulty.   Cruikshank describes them as they appear-
ed, filled with blood, in consequence of pressing
upon the kidney when its veins were full of blood.
Mascagni did not inject  the superficial vessels  with
mercury; but describes them as they appeared when
filled with colourless size, after he  had injected  the
blood vessels of the organ with the coloured fluid.—
The deep-seated absorbents pass out of the fissure
ofthe kidney with  the blood vessels, and unite with
the superficial; they proceed to the lumbar plexus,
and pass into different glands. 
  382    Lacteals, or Absorbents of the Intestines.

    Absorbent vessels can be proved to proceed from
  the pelvis ofthe kidney, and the ureters, by artifices
  analogous to those above mentioned.
    The Glandulae Renales are also supplied with ab-
  sorbents, which are numerous in proportion to the
  size of the  organs.   They commonly join those of
  the kidney.

           The Absorbents of the Intestines
    Have  generally been called LACTEALS,  from
  the white colour  of the chyle which they contain:
  but there seems no reason for believing that they are
  different in their structure and nature from the ab-
 sorbents in other parts of the body.  A small num-
 ber of them appear as if they formed a part  of the
 structure ofthe intestines, and originated from their
 external surface, as they do in other parts of the ab-
 domen; while the principal part of them are  appro-
 priated to the absorption ofthe contents of the ca-
 vity of the intestines.
   The first mentioned absorbents run between the
 muscular and peritoneal coats, and proceed for some
 distance lengthways on the intestine, while the  others
 proceed for some distance within the muscular coat,
 with the arteries; and  after passing through it, con-
 tinue between the lamina ofthe mesentery.
   Branches of these different  absorbents are  fre-
 quently united in one trunk so as to prove that there
 is no essential difference between them.
  The absorbents which come from the internal sur-
 face of the intestines commence in the  villi.   The
 manner in which they originate has been the sub-
ject of considerable inquiry, as  has  been stated in
the account ofthe intestines.*
  The lacteals or absorbents of the intestines  are
• See page 105. 
       Lacteals, or Absorbents of the Intestines.   383

very numerous.  They pass between the lamina  of
the mesentery to glands which are also seated be-
tween those lamina.   The number of these glands
is very considerable,* and they are various in size—
some being very minute, and others eight or ten lines
in  diameter.  They are generally placed at a small
distance from each other, and  are most numerous
in  that part ofthe mesentery which is nearest to the
spine. They are almost always at some distance from
the intestines. They appear to be precisely like the
absorbent glands in other places.
   These absorbent vessels, in their course frequently
divide into branches; which sometimes go to the
same gland, sometimes to different glands, and some-
times unite with other absorbent vessels.  As they
proceed, they frequently enlarge in size. When they
have arrived near the spine,  they frequently form
three or four trunks, and sometimes one  or two;
which proceed in the course ofthe superior mesen-
teric artery, until they have arrived near to the aorta.
Here they either pass into the thoracic duct, or de-
scend and join the trunks  from the inferior extremi-
ties, to form the thoracic  duct.   The absorbents of
the great intestines  are not equal in size to those of
the small; but they  are numerous.  They enter into
glands, which are very near, and in some places, in
contact with the intestine; and are commonly very
small in size.   The vessels which arise from the cae-
cum, and the right  portion, as well  as the arch of
the  colon, unite with those of the small intestines;
while the vessels from the left side ofthe colon, and
the rectum, proceed to the lumbar glands.
   The  absorbents  of the intestines  are frequently
injected with mercury; but the injection does not
proceed to their termination with so much facility as
• They have been estimated between 130 and 150. 
384
Absorbents ofthe Stomach.
 it does in  other vessels of the same kind.  They
 have, however, very often been seen in animals, who
 were killed for the purpose after eating milk; and in
 several human  subjects who  died suddenly during
 digestion.—The description ofthe origin ofthe lac-
 teals, quoted in  page 108, from Mr. Cruikshank, was
 taken from  a subject of this kind, of which an ac-
 count is given in his work on the absorbing vessels,
 p. 59.
   It is worthy of note, that in several  instances, in
 which the lacteals were thus found distended with
 chyle, the glands in the mesentery were also uniform-
 ly white.
            The Absorbents of the Stomach

   Are of considerable  size, and form three divisions.
 The vessels of the first set appear upon both sides
 of the stomach, and pass through a few glands on
 the small curvature near the  omentum minus.—From
 these glands they  proceed to others, which are
 larger, and which also receive some of the  deep-
 seated absorbents  of the liver.  The vessels from
 these glands pass to the thoracic duct, near the ori-
 gin of the cceliac artery.  The second arise also on
 both sides of the stomach, and pass to the left ex-
 tremity of the great curvature  to unite with the ab-
 sorbents of that side of the  great omentum.   They
 then proceed with the lymphatics of the spleen and
pancreas, to the thoracic duct.  The last set, pass
off from the right extremity of the great curvature,
and unite  also with absorbents from the right por-
tion ofthe omentum.   They proceed near the pylo-
rus, and go to the thoracic duct, with some of the
deep-seated  absorbents of the Hver.
  Although the absorbents of the stomach are deep-
seated, as well as superficial, it is a general senti-
ment, that they do not contain chyle in the human 
             Absorbents of the Liver.          385

subject; notwithstanding chyle has been found in the
absorbents on the stomach of dogs, and some other
animals.   It ought, however to be remembered, that
Sabatier has, in some instances, seen white lines on
the stomach, which he supposed to be lacteals.

             The Absorbents of the Liver

   Are especially interesting, because they have been
more completely injected than those of any other
viscus.  They are  deep-seated and superficial.   The
superficial it  has been already observed admit of in-
jection in a retrograde direction, and, therefore, can
be exhibited  most minutely ramified.  They commu-
nicate freely with each other, and also with the deep-
seated vessels, by their small ramifications; so that the
whole gland  has been injected from one  large  ves-
sel.
   The gland is so large,  that the absorbents of the
superior and inferior surfaces proceed from it in dif-
ferent directions.
   A large absorbent is generally found on the sus-
pensory ligament.   This  is formed by the union of
a  great many branches that arise both on the right
and left lobes, but principally on the right.  It often
passes through the diaphragm at an interstice which
is anterior to the xiphoid cartilage, and then proceeds
through glands on the  anterior part of the pericar-
dium.
   Several  absorbents  proceed to the  lateral  liga-
ments on each side, and  then pass through the dia-
phragm.   Some of these  branches return  again into
the abdomen, and the others generally run forwards
in the course of the ribs, and join those which passed
up from the  suspensory  ligament.  The trunk,  or
trunks, formed by these vessels, either pass  up be-
tween the lamina ofthe mediastinum, and terminate
   vol. ii.               49 
 386     Absorbents of the Liver and Spleen.

 in the upper part of the thoracic duct; or they ac^
 company the internal mammary arteries, and termi-
 nate on the left side in the thoracic duct, and on the
 right in the trunk ofthe absorbents of that side.
   The Absorbents on the concave side of the Liver are
 as numerous as those on the convex side; they are
 also very abundant  on the surface of the gall blad-
 der.  The greatest part of them join the deep-seated
 vessels.
  The Deep-seated Absorbents proceed  in considera-
 ble numbers from the interior of the  liver through
 the porta?.   They accompany the biliary ducts and
 the great blood vessels  of the  organ;  and, after
 passing through several glands, near the vena porta-
 rum, terminate in the thoracic duct, near the com-
 mencement ofthe superior mesenteric artery.
  Mascagni states,  that the absorbents  of the liver
 will be distended, by injecting warm water into  the
biliary ducts, or the vena portarum.
  He also  observes, that  in  those  preparations in
which the superficial vessels are completely injected,
in the retrograde direction, the peritoneal coat of the
liver appears to be composed entirely of absorbent
vessels; and to be connected to the membrane within,
by many filaments which are also absorbent vessels.

            The Absorbents of the Spleen

  Are composed of superficial and deep-seated ves-
sels; but they differ greatly from those of the liver,
in this respect, that the superficial vessels are remark-
ably small in the human subject.
  Mascagni  however asserts, that when the  blood
vessels ofthe spleen are injected with size, coloured
with vermilion, these absorbents will  be filled with
colourless size.
  In the  spleen ofthe calf the superficial absorbents
are remarkably large. 
              Absorbents of the Pancreas.         387

   In the human subject the superficial absorbents of
 the spleen proceed from the convex to the concave
 surface, and there communicate with the deep-seat-
 ed absorbents, which  proceed from the interior of
 the organ with the blood vessels.
   These Deep-seated Absorbents are very numerous,
 and also large.  They accompany the splenic arte-
 ry; and in their course pass  through  many glands,
 some of which are said to be of a dark colour.  The
 glands  lie on the splenic artery, at a short distance
 from each other.  The absorbents of the spleen re-
 ceive the absorbents ofthe pancreas in their course;
 they  unite with the absorbents of the  stomach and
 the lower surface  of the liver, and  pass  with  them
 to the thoracic duct.
   Little has been latterly said by practical, anato-
 mists respecting

           The Absorbents of the Pancreas.
   Mr. Cruikshank once  injected them in the retro-
 grade direction; he found that they came out of the
 lobes of the pancreas in short branches  like the
 blood vessels, and passed at right angles into the ab-
 sorbents ofthe spleen, as they accompanied the ar-
 tery in the groove of the pancreas.

           THE  THORACIC DUCT*

  Or common trunk of the absorbent  system, is
formed by the union of those absorbent vessels which
 are collected on the lumbar vertebrae.
  These vessels, as it has been already observed, are
derived  from various sources, viz.
  The Lower Extremities; the lower  part  of the
Trunk ofthe Body; the Organs of Generation; the
 * First discovered by Eustachius in the horse, 1564; but he considers it a
vein for the nourishment of the thoracic viscera—Ed. 
388    Commencement of the Thoracic Duct.

Intestines, with the  other Viscera of the abdomen
and Pelvis, except a part of the liver.   Their num-
ber is proportioned  to the extent of their origin: for,
with the numerous glands appropriated to them, they
form the largest absorbent plexus in the body, and
are spread over a considerable portion of the aorta
and the vena cava.
  The manner in which these vessels unite to form
the thoracic  duct, is very different in different sub-
jects; but in a majority of cases it originates imme-
diately from three vessels, two of which are the trunks
of the absorbents of the lower extremities, and the
other is the common trunk of the lacteals and the
other absorbents of the intestines.
  These vessels generally unite on the second  or
third lumbar vertebrae; and, in some instances, the
trunk which they form  dilates considerably,  soon
after its commencement; in consequence of which
it was formerly called the RECEPTACLE  of the
CHYLE.  At first  it lies behind the  aorta, but it
soon inclines to the right of it, so as to be behind
the right crus of the diaphragm.  In the thorax, it
appears on the front of the spine, between the aorta
and  the  vena azygos, and continues between these
vessels until it has arrived at the fourth or third dor-
sal vertebra.  It then inclines to the left,  and pro-
ceeds  in  that  direction  until it  emerges from the
thorax, and has arisen above the left pleura, when it
continues  to ascend behind  the internal  jugular,
nearly as high as the sixth cervical vertebrae : it then
turns downward and forward, and after descending
from six to ten lines, terminates in the back part of
the angle formed by the  union of the left internal
jugular with the left subclavian vein.  Sometimes,
after rising out of  the thorax, it divides into two
branches, which unite before they terminate.  Some-
times it divides, and one of the branches terminates 
             Absorbents of the Lungs.          389

at the above mentioned angle, and the other in the
subclavian vein, to the left of it.
  The orifice ofthe thoracic duct has two  valves,
which effectually prevent the passage of blood into
it from the vena cava.
  There are sometimes slight flexures in the course
of the duct;  but it generally inclines to the left, in
the upper part of the thorax, as above mentioned;
and is then so near the left lamen of the mediastinum
that if it be filled with coloured injection,  it can be
seen through that membrane, when the left lung is
raised up and pressed to the right.
  The duct sometimes varies considerably in its di-
ameter in different parts of its course.  About the
middle of the thorax it has often been found very small.
In these cases it generally enlarges in its progress
upwards, and is often three  lines in diameter, in  its
upper part.   Many anatomists have observed it to
divide and to unite again, about the middle of the
thorax.
              Absorbents of the Lungs.
   The absorbents of the  lungs are very numerous,
and like those of other viscera, are superficial and
deep-seated.
   The large superficial vessels run in the interstices
between the lobuli, and therefore form angular figures
of considerable size.  In successful injections, the va-
cancies within these figures are filled up with small
vessels, and the whole surface appears minutely in-
jected.
   Mascagni observes, that the superficial vessels  are
 very  visible when any fluid has  been effused  into
 the cavity ofthe thorax; or when warm water is in-
jected, either into the blood vessels  of the lungs, or
 the ramifications of the  trachea.   Cruikshank  de-
 monstrated them by  inflating the lungs  of a still 
390
Absorbents of the Lungs.
born child; in which case the air passes rapidly into
them.
   The deep-seated absorbents accompany the blood
vessels and the ramifications ofthe bronchiae.  They
pass to the dark coloured glands, which are  situa-
ted on the trachea at  its bifurcation;  and on those
portions  of the bronchiae which are exterior to the
lungs.  The injection  of the absorbents, which pass
to and from these glands, seems to prove that they
are ofthe same nature with the absorbent glands in
general, notwithstanding their colour.  They are nu-
merous, and they vary in size; from a diameter of
two lines, to that of eight or ten.
   From these glands, some of the absorbents of the left
lung pass into the thoracic  duct, while it is in the
thorax, behind the bifurcation of the trachea ; others
proceed upwards and enter into it near its termina-
tion; while those ofthe right lung terminate in the
common trunk of the absorbents ofthe right side. 
CHAPTER II.
OF THE ABSORBENTS OF THE HEAD AND NECK ; OF. THE
  UPPER EXTREMITIES, AND THE UPPER PART OF THE
  TRUNK OF THE BODY.

  The absorbents from the various parts of the head
pass through glands, which are situated on the neck
or the lower part of the head.  Those on the head
are the least numerous, and also the least in size.—
Some of them, which are generally small, lie  about
the parotid gland.  Several of them, which are also
small, are on the occiput, below and  behind  the
mastoid process.  Sometimes there are two or three
on the cheek, near the basis of the lower jaw, about
the anterior  edge  of the  masseter muscle.  Below
the lower jaw, in contact with the sub-maxillary gland
and anterior to it, there are always a number of these
glands, which are generally small, but often swelled
during infancy.
  The Glands on the  Neck are the most numerous.
Many of them are within the sterno-mastoid muscle,
and accompany the internal jugular vein and  the
carotid artery down to the first rib.  Many also lie
in the triangular space between the sterno-mastoid
muscle, the trapezius, and the clavicle;  therefore it
has been truly said that the glands ofthe neck  are
more numerous than those of any other part except
the mesentery.  They are frequently called Glandu-
les Concatenate.  It has already been mentioned that
the various  absorbents, which are connected with
these glands, unite on each side into a trunk, which
on the left passes into the thoracic duct, and on  the
right into the common trunk  of the absorbents of
that side. 
392     Absorbents of the Head and Neck.

                   SECTION I.

      Ofthe Absorbents ofthe Head and Neck.

  There is the greatest reason to believe that the
brain and its appendages are supplied with absorb-
ents like the other parts.  Some of these vessels
have been discovered in the cavity of the cranium;
but very little precise information has as yet been
obtained, respecting the extent, or arrangement  of
the absorbent system, in this part of  the body.
  The absorbents on  the exterior ofthe head are as
numerous as in other  parts of the body.   On  the oc-
ciput they pass down, inclining towards the ear, and
continue behind it to  the side of the  neck;  behind
the ear they pass through several glands.—From the
middle  or temporal region ofthe cranium, they pass
with the carotid artery before the ear, and enter some
small glands that lie on the parotid; from which they
continue to the neck.
  They are on every part of the face, and unite,  so
that their principal trunks, which are very numerous,
pass over the basis ofthe lower jaw,  near the facial
artery.  They enter into glands, which are also very
numerous, immediately under the jaw, or  which
are sometimes to be found  on the cheek, at the an-
terior edge of the masseter  muscle.  All the absorb-
ents ofthe exterior part of the head pass to the glands
on the side of the neck, already described.
   Those from the interior of the nose accompany
the ramifications of the internal maxillary  artery,
and proceed to glands behind the angle ofthe lower
jaw; into which glands also enter the absorbents of
the tongue and inner  parts of the mouth.
   The absorbents of the thyroid gland, on the  left
side, pass down to the thoracic duct; those on the
right, unite to the trunk of the absorbents on that 
         Absorbents of the Hand and Arm.      393

side, near its  termination.   It has been remarked
that they can  be readily injected, by thrusting the
pipe into the substance of the gland.

                   SECTION II.
Of the Absorbents of the Arm and Upper Part of the
                     Trunk.
   The absorbents of the arm  are  superficial and
deep-seated, like those ofthe lower  extremity.
   The superficial absorbents  have been injected on
the anterior and posterior surfaces of the fingers and
the thumb, near their sides.  On the back of the
hand  they are very numerous, and  increase consi-
derably in their progress up the fore-arm.  As they
proceed upwards, they incline towards the anterior
surface of the fore-arm; so that by the time they have
arrived at the  elbow, almost all  of them are on the
anterior surface.  The absorbents  on the anterior
part of the hand are not so numerous as those on the
back.  Sometimes there  are  digital branches from
the fingers, and an arcus in the palm; but this bow
is not formed by one large absorbent, analogous to
the ulnar artery.   On the contrary, its two  extremi-
ties are continued over the wrist, and pass on the
fore-arm like the absorbents.
  At the elbow some of them often pass into one or
two small glands,  which are very superficial; but
the whole ofthe absorbents, somewhat reduced in
number, as some of them unite together, pass along
with the blood  vessels into the hollow ofthe arm-pit;
where  they enter the axillary glands.  There are
generally one  or more vessels  which pass in the
course ofthe cephalic vein, between the pectoral and
the deltoid muscle, and enter into some of the glands
under the clavicle.
  vol. n.              50 
394  Absorbents ofthe Upper part ofthe Trunk.

  There are almost always  several glands in and
near the axilla.  Some of them  are very near the
great blood vessels; sometimes one or more of them
are much lower; sometimes they are to be found
under the pectoral  muscle.  They are commonly
not so large as those of the groin, and are surround-
ed with fat.
  The deep-seated absorbents originate also at the
fingers, and soon accompany the branches of the
arteries.  Those which attend the radial  artery,
originate on the back  of the hand, and also in the
palm, where they are associated with the arcus pro-
fundus.   They go up with the radial artery to the
elbow, and  sometimes pass through a small gland
about the middle ofthe fore-arm.
  Those which attend the  ulnar artery, commence
under the aponeurosis  palmaris, and go with the ar-
tery to the elbow; at the bend ofthe elbow they are
generally joined by one or more, which accompany
the interosseal artery;  there they unite, so as to
form several trunks  which pass  up to the axillary
with the humeral artery.  They sometimes pass
through one or two glands, which are  near the el-
bow; and they receive in their course, deep-seated
branches from the muscles on the humerus.
  The  absorbents from the  anterior and  external
part ofthe thorax, and the upper part of the abdo-
men, also proceed to the axilla, and enter  into the
glands  there; those which  are deep-seated, joining
the  deep-seated vessels.   The  absorbents ofthe
mammae pass to the same glands;  and when they
are affected with the virus of cancer, can  often be
perceived, in their course, in the living subject.
  The absorbents  of the  uppermost  half of the
back, and those of  the back of the neck, go like-
wise to the axilla.
  The absorbent vessels, collected  from these vari- 
         Facts relating to Cutaneous Absorption.    395

 ous sources, proceed from the exterior to the inner^
 most glands, but with a  considerable diminution of
 their number; they accompany the subclavian vein,
 and are reduced to one or  two  trunks, that gene-
 rally  unite  before  their termination.  On the  left
 side,  the absorbents ofthe  head and neck  generally
 open into the thoracic duct, as  has been already
 observed; and those of the left arm also open into
 the thoracic duct, or into  the subclavian  vein very
 near it.   On the right side the absorbents from each
 of these parts empty into the common trunk;  which
 often  is formed by  the union of large  vessels, from
 four sources ; viz. the  Head, the Thyroid gland, the
 right  arm, and the  right  cavity of the Thorax, &c
 The  diameter of  the  trunk is very considerable;
 but it is often not more than half an inch in length.
 It generally opens into the right subclavian vein, at
 the place where it  unites  to the  right internal ju-
 gular.

    Two respectable physiologists of Europe, (M. Seguin, of
       Paris, and  the  late Dr.  Currie,  of Liverpool,)  have
       doubted whether absorption takes place on the exter-
       nal surface of the skit).*  This  question has been ex-
       amined  in a very interesting manner by several gra-
       duates of the University of Pennsylvania,  who chose
       it for the subject of their inaugural theses; viz. Drs.
       Rousseau, Klapp, Daingerfield, Mussey, and J. Brad-
       ner Stewart.
    The three  first  of  these gentlemen state that when spirit
      of turpentine, and several other- substances which are
      commonly supposed  to be absorbed by the skin, were
      applied  to it in  a way which prevented their volatile

  * I believe that M. Seguin's  Memoir on this subject was read to the
Academy of Sciences a short time before the meetings of that body were
suspended.  It was published by M. Fourcroy,  in La Medicine Eclau-e'e
par les Sciences Physiques,  vol. iii.  An extract from M. Fourcroy's pub-
lication may be seen in the 19th chapter ofthe first volume of Dr. Curne's
" Medical Reports on the Efi'eots of Water," &c. in which is also con-
tained a statement ofthe Doctor's own experiments and reflections. 
396  Experiments of K. Boerhaave and J. Hunter.

      parts from entering the lungs  by respiration,  no ab-
      sorption took place.  But  when  the inspired  air im-
      pregnated with exhalations  from these substances, they
      perceived satisfactory proofs  that  the exhalations en-
      tered the system.   From these  facts they inferred that
      when those  articles entered the body  by absorption,
      they were taken in by the lungs, and not by the exter-
      nal surface.
    On  the other  hand, the two  gentlemen last mentioned,
      state  that after immersing  themselves  in a bath  con-
      sisting of a decoction of rhubarb,  of madder, or of tur-
      meric,  their  urine  became  tinged  with these  sub-
      stances. They  also  assert that the  colouring matter
      of these different articles is  not  volatile;  and, there-
      fore, could not have entered  the  lungs  during  the  ex-
      periments.*
    The statement in page  374, from Dr.  Soemmering, that
      when mercury is  injected backwards in the absorbent
      vessels  which originate on the  foot,  it will sometimes
      appear  in small globules on the skin of the foot, has
      an important connexion with this subject.!
     About the middle of the  last century, it was  generally
       believed by anatomists,  that absorption was  performed
       by the veins.  This doctrine seemed to be established
       by the experiments of Kaaw Boerhaave, which are re-
       lated,  with many  other  interesting statements, in his
       work,  entitled  " Perspiratio  Dicta  Hippocrati,"  &c.
       published at Leyden, in  1738.   In these experiments
       it appeared  to  the  author, that  when the  stomach of a
       dog was emptied of its  contents, and filled with warm
       water, immediately after death, the water passed  into
       the minute  ramifications of the veins of the stomach,


  » The Thesis of Dr. Rousseau was published in 1800.  Those of Drs.
Klapp and Daingerfield in 1805.   Dr. Mussey published in the Third
Supplement to the Medical and Physical Journal of Dr. Barton, in 1809.
Dr. Stewart published in 1810.  Additional observations  by Drs. Klapp,
Rousseau and Smith, are published in the Philadelphia Medical Museum,
vol. i. new series.
  f Since the publication of the first volume, the author has enjoyed the
advantage of consulting a translation, in manuscript, of some parts of the
German edition of Dr. Soemmering's valuable work on the Structure of
the Human Body. 
Experiments of Magendie and Delile.      397
  and from  them to the  vena portarum, and ultimately
  to the heart, in large quantities.
This  account appears to be  disproved  by some experi-
  ments of the late John  Hunter, made about twenty
  years after, and  published in  the Medical Commenta-
  ries of Dr. William Hunter,  Part I.-----Mr.  Hunter's
  experiments  have been considered as establishing the
  fact, that absorption, (in the intestines at least,) is per-
  formed exclusively by the lacteals, or proper absorbent
  vessels, and not at all by the  veins.  Kaaw Boerhaave
  is of course supposed to have been mistaken; and  Mas-
  cagni, who has repeated  his experiment, refers the ap-
  pearance of water in the  veins to transudations through
  the coats of  the intestines; which he has observed to
  take place to a great degree.
In the year 1809, a memoir  was presented to the national
  institute of France by Messrs.  Magendie and Delile,
  which contains  an account of some  experiments that
  have an important relation to  the above mentioned sub-
  ject.*—The authors being greatly surprised at the ra-
  pidity with which the poison of Java,  &c.  appeared to
  enter  the sanguiferous system, instituted a  series of
  experiments to determine whether these substances pro-
  ceeded to that system by the circuitous route of the ab-
  sorbent vessels, or by  the shorter course of the veins.
  Two  of their experiments are especially interesting.
  They made an incision  through the parietes of the abdo-
  men of a living dog, who  had  eaten a large quantity of
  meat some hours before,  (that his lacteals might be vi-
  sible  from  their distention  with chyle,)  and  drawing
  out a portion of the small intestine, they applied two
  ligatures to it, at the distance of five inches from  each
  other.  The portion of intestine between these liga-
  tures was then separated  by incision  from the  rest of
  the intestinal tube, and all the lacteals, blood vessels,
  &c. which passed to and  from it, were divided, except
  one  artery  and  a vein.   A considerable  length  of
  this  artery  and vein were  detached from all the sur-
  rounding  parts,  so that the authors  supposed  these
  •  The title of the paper is a "Memoir on the Organs  of Absorption
in Mammiferous Animals."  A translation of it was published in the Me-
dical and Philosophical Register of New York, and in several other perio-
dical works. 
398     Experiments of Magendie and Delile.

      vessels  to form the only  connexion between the por-
      tion  of the intestine and  the rest of the body.   Into
      the  cavity of the intestine,  which was  thus circum-
      stanced, they introduced a small quantity of the prison,
      anil, to  their astonishment, it produced its fatal  effects
      in the same  manner it would have done if it had been
      introduced into the intestine while all  its connexions
      with the body were entire.  This experiment,, they as-
      sert, was repeated several times, without any  difference
      in the result.
    After several  other experiments, they  finally  separated
      the thigh from the body of a living dog in such a man-
      ner that the crural artery and vein were left undivided.
      A quill  was then introduced into the artery, and  two li-
      gatures  were applied  to  fix it round the quill.   The
      artery  was  then  divided between the two  ligatures.
      The vein was  managed in  the same manner.  T!r.:re
      was, therefore, no communication between the  limb
      and the  body, except by the blood which passed through
      the  divided vessels and the quills.  The poison was
      then introduced under the  skin of the foot, and soon
      occasioned the  death  of  the animal; its deleterious
      effects  commencing about four minutes after its appli-
      cation to the foot.   This experiment appears  to  prove
      decidedly that the blood is the vehicle by which poison,
      when applied to the extremities, is carried to the body;
      although it  may  not  determine the question whether
      this  poison  was  taken up by the absorbents or by the
      veins.*
    Some other experiments made by the authors gave re-
      sults, which are very difficult indeed to explain.   They
      wished  to know  if the blood of  an  animal  thus con-
      taminated,  would produce similar effects upon another
      animal ;  and, with a view to ascertain this point, they
      insinuated a small piece of wood, covered with the poi-
      son,  into the thick part of the left side of the nose of a
      dog.   Three minutes  after the introduction  of the poi-
      son,  they transfused  blood from  the jugular vein  of
      the same side, into one of  the veins of another  dog.
      About  one  minute after the  commencement  of the
  * This experiment has been repeated in Philadelphia.  See Professor
Chapman's Medical and Physical Journal for February, 1823, No. 10.—
En. 
Report of the Committee of the Institutes.    399
  transfusion, the effects of the poison began in  the dog
  to which it  was applied, and continued  until his death.
  Transfusion into the veins of the other dog  went on
  during the  whole time, and he  received a large quan-
  tity of blood  from  the dying dog, without producing
  any effect.  They varied this experiment in the follow-
  ing manner.  The thigh  of a dog  was  separated from
  the body: the artery and the vein were arranged as in the
  former experiment;  and poison was introduced  into the
  foot.  Three minutes after the introduction of the poison
  the blood of the crural vein was passed into the jugu-
  lar vein of another animal, and  transfusion was  con-
  tinued five  minutes  without producing any effect upon
  the animal receiving the blood; it was then  stopped,
  and  the  crural  vein was  so  arranged that the blood
  flowed from it into the animal  to which it belonged.
  This animal very soon exhibited symptoms of  the ope-
  ration of the poison.*
From these very interesting experiments the authors in-
  fer that "foreign matters do not always proceed through
  the Lymphatic or Absorbent  Vessels,  when they enter
  into the Sanguiferous system."
This memoir  was  referred by the  Institute to four of its
  members,  who are  particularly distinguished  by  then-
  profound   knowledge   of  anatomy  and   physiology.
  These gentlemen,  after  stating their belief  that the
  functions of  the lymphatic or absorbent system  have
  been  completely ascertained by the  experiments  and
  observations of  Hunter, Cruikshank,  Mascagni,  &c.
  say further, that in  their opinion, the above mention-
  ed  inference  ought to be a  little modified,  and  that
  facts  are  not sufficiently  numerous,  or  applicable to
  the  point  in  question, to justify  the inference  that
  foreign matters  do  not always  proceed  through the
  Lymphatic or Absorbent Vessels, when they  enter the
  Sanguiferous system.  But they also add, that, as the
  author is still  engaged in a series of experiments on the
  subject,  they will  suspend  their  judgment  respect-
  ing the  inferences to be deduced from  the  present
  statement.
  • An account of these experiments was published by M. Magendie in a
pamphlet.  A statement of them is also contained in the report made to
the Institute by the committee to whom the memoir was referred, which i»
published in the Journal de Physique, for March 1813.  In that statement
this last mentioned experiment is omitted, 
400            Of the Absorbent System.


     The  most  extensive account of the absorbent system is
       contained in  the  " Historia et Ichnographia Vasorum
       Lymphaticorum Corporis  Humani"  of  Mascagni.—
       *' The Anatomy ofthe Absorbing Vessels of the Human
       Body,  by W.  Cruikshankj"—and  " The Description
       of  the Lymphatic  System, by  Win.  Hewson," (the
       second  volume of his  Experimental Inquiries,)—are
       also very interesting publications.


  A most interesting series of inquiries and experiments in regard to the
laws of absorption will  be found in Professor Chapman's  Journal of  the
Medical and Physical Sciences, No. 6, in a report of a Committee of the
Academy of Medicine, signed by Doctors Lawrance and Coates, of this
city.—And a continuation  ofthe same will be found in No. 10, ofthe same
Journal, signed by Doctors Lawrance and Coates.  Since the publication
ofthe latter, to the regret of all who knew him, and to the great loss of
Anatomy and  of Physiology, the indefatigable and excellent Lawbahcb
is no more.—Ed. 
APPENDIX.
                  OF THE BLOOD.

   The blood of a healthy person indicates a tenden-
 cy to coagulate very soon after it is discharged from
 the vessels which naturally contain it, although it is
 perfectly fluid in those vessels.
   If it remain at  rest,  after it is drawn from the
 vessels, it soon coagulates into a solid mass, of a soft
 texture.   From this solid mass a fluid is soon ob-
 served to issue, which first appears in very small
 drops on almost every part of the surface.  These
 drops quickly increase and run together, and in a
 short time the fluid surrounds the solid mass, and ex-
 ceeds it in quantity.
   The solid part which thus appears upon the spon-
 taneous  separation  of the  blood, is denominated
 Crassamentum  or Cruror; the fluid part is called Se-
 rum.
   The substance which contains the red colour of
 the blood, remains  with the  Crassamentum.   The
 Serum, when it separates without agitation, is free
 from the red colour.
   The colouring matter may be separated complete-
ly  from the Crassamentum by washing it with water.
   The blood, therefore, consists of three parts, viz.
the Serum; the Substance which coagulates spontaneous-
ly ; and the Colouring Matter.
  VOL. II.               51 
402         Appendix.—of the Blood.


                    THE SERUM

   Has a considerable degree of consistence, although
it is much thinner than blood.   In its perfectly natu-
ral state, it is almost transparent, and appears to be
very lightly tinged with  a greenish  yellow colour;
but it is very often impregnated  with a portion of
bile, which is probably carried to the blood vessels
by the absorbents.   It contains a large quantity of
albumen,  or matter like the  white of an egg.  If
heated  to 140? of Fahrenheit, it becomes  opaque;
and when the heat is increased to 156 or 160,  it  is
firmly coagulated.   It is also coagulated by alcohol,
by mineral acids, and  by rennet.*  It is proved by
chemists, that it  contains a small quantity of pure
soda.   It therefore changes several  of the blue co-
lours of vegetables green.   It is  also found to  con-
tain a similar quantity of the muriate and the phos-
phate of soda,  and the phosphate of lime.  These
saline substances were  discovered  by diluting se-
rum with water, and exposing the mixture to  heat,
by which the albumen was coagulated into flocculi ;
these flocculi were  separated  by filtration: the li-
quor was then diminished by evaporation,  and the
salts obtained from it by crystallization.
   Serum likewise contains a portion of sulphur com-
bined with ammonia.
   When it is exposed to a coagulating heat, a small
portion of it remains fluid.
   This fluid portion has been  supposed to contain
a considerable quantity of gelatine; but it is contend-
ed by Mr. Brande,t that Gelatine does  not exist in

  * See Hewson,  Vol. I. p. 139.—I suspect that some  particular mange-
ment is necessary in the  use of rennet.
  f In his Researches on the Blood communicated to the Royal Society of
London, in 1812, and republished in the Eclectic Repertory, for April, 
              Appendix.—of the Blood.          403

the serum of the blood, and that this portion consists
of albumen combined with a proportion of alkali.
  It is also  asserted  by Dr. Bostock,*  one of the
latest writers on the subject, that the  serosity of the
blood, (the term applied to the last mentioned fluid,)
contains no gelatine; but that, with a minute quan-
tity of albumen, it consists of a large portion of an
animal matter,  which is different  either from gela-
tine or albumen, being unlike either of them in its
chemical qualities.

                THE CRASSAMENTUM
  Is rendered very different in its appearance, by the
different circumstances in which it may coagulate.
  When the blood remains at rest immediately after
it is drawn,  the  crassamentum which forms in it is a
concrete substance, without the smallest appearance
of fibre in its composition.  If the blood  is stirred
with a rough stick, while it is flowing from an ani-
mal, a large portion of it  will concrete  upon the
stick in a fibrous form, so as to resemble a mass  of
entangled thread, some of the red colouring matter
still adhering to it.
  The crassamentum, in either of these forms, may
be washed perfectly white; the red colouring matter
passing completely  away with the water.  In this
state it appearst to have all the chemical properties
of the fibrous matter of muscular flesh.  It also re-
sembles the  gluten of vegetables, being soft and elas-
tic.  The  name fibrine is now  generally applied
to it.
  If fibrine is washed and dried, its weight is very
small indeed when compared  with that ofthe blood

  * See his Observations on the Serum ofthe Blood, in the Medico-Chirur-
gical Transactions, Vol.  II. republished in the Eclectic Repertory,  for
October, 1812.
 f By the experiments of Mr. Charles Hatchctt, published in the London
Pliilosophical Transactions for 1800. 
404          Appendix.—of the Blood.

from which it has been  obtained.   It is,  therefore,
probable that a considerable  proportion of the bulk
of the crassamentum, as it forms spontaneously, de-
pends upon the serum which  exists in it, and can be
washed away.
   The spontaneous coagulation of the blood, which
appears to depend principally upon the Fibrine, may
be prevented by the addition of several foreign sub-
stances to the blood, when it  is drawn.  It is subject
to great variations that  depend upon the state ofthe
body at  the time of bleeding;  and in some condi-
tions, it does not take place at all.*
   In a majority of dead subjects the blood is found
more or less coagulated in the veins; but in some
subjects it is found  without coagulation.   It is  as-
serted that it does  not  coagulate  in subjects who
have died suddenly, in consequence of anger, light-
ning, or a blow on the stomach.

             THE COLOURING  MATTER.

   When the blood vessels in  the transparent parts
of certain living animals are  examined with  magni-
fying glasses, it appears that  the red colour of  the
blood is owing to bodies of a globular form, which
are diffused through a transparent fluid.   The  ap-
pearance of these bodies has been examined, with
great  attention, by  many physiologists,  since  the
publication of Leuwenhoeck, in the London Philo-
sophical Transactions.!

  * See an Inquiry into the Properties of the Blood, by  the late Wm.
Hewson: and Experiments by his son, T.  T. Hewson, in the Eclectric Re-
pertory,  Jan. 1811.—See also a  Treatise on the Blood, &c. by the late
J. Hunter.
  ■\ Among the most distinguished of these observers were Father de la
Torre, Haller, Hewson, Fontana,  Spalanzani, J. Hunter, Cavallo.
  Some short accounts of Leuwenhoeck's original observations on the
Blood arc to be found in the Philosophical Transactions  of London, for 
Appendix.—of the Blood.           405
  Several of these gentlemen have described the ap-
pearance  of the blood very differently;  but Haller,
Spalanzani  and J. Hunter  agree  that the figure of
the  red  particles is  globular.*   Hunter observes
further, that the red globules do not run into each
other as two globules of oil would do when  divided
by water; and he believes that they cannot unite.—
At the same time they seem not to have the proper-
ties  of  a solid: for when  circulating in  the  vessels,
they assume elliptical forms, adapting themselves to
the  size ofthe vessels.  They also excite no sensa-
tion of solidity when touched.
  They appear  to be  more heavy than the other
parts ofthe crassamentum: for in healthy blood the
lower part of the mass contains more of the colour-
ing  matter than the upper part; and in the blood of
persons who labour under acute local inflammation,
they often subside completely  from the  upper part;
and thus  occasion what  is called by Mr. Hewson,
the inflammatory crust, or size.
   It has  been observed  by Mr. Hewson, and also
by Mr. Hunter, that the globules do not retain their
form in every fluid.   They are said to be dissolved


1664, in the fasciculi which are numbered 102 and 106.  A more full de-
scription is contained in Boerhaave's Academical Lectures on the Theory
of Physic.  See the section on the nature ofthe blood.
  The glasses of Father de la Torre were transmitted from Naples to the
Royal Society of London in 1765. They were accompanied by a letter from
Sir F. H. E. Stiles, to which are subjoined some observations by the Rev.
Father himself. The letter and the observations are published in the 55th
volume of the Transactions of that society.
  In the year 1798, Tiberius Cavallo published an Essay on the Medicinal
Properties of Factitious Air, with an Appendix on the Nature of the
Blood, in which is contained a further account of the glasses of de  la
Torre.
  * I believe that this is also the  opinion of Fontana.—In J. Hunter's
work on the Blood there are some interesting observations on micro-
scopical deceptions. See the note commencing in page 39, Bradford's
edition. 
406         Appendix.—ofthe Blood.

very quickly in water, and then they form a fine clear
red.  Several'of the neutral salts, when dissolved in
water, prevent the solution of the globules.  Mr.
Hunter informs us, that the vitriolic acid, when great-
ly diluted, does not dissolve them, &c.   The muria-
tic acid, when three times as strong as vinegar, de-
stroys their colour without dissolving them, although
when more diluted, it dissolves them.
   The colour ofthe blood has, for a long time been
supposed  to depend upon iron.   About the middle
of the last century, Vicentius Menghini published in
the Transactions of the Academy of Sciences of Bo-
logna, an account of experiments which contributed
to establish this sentiment.   In this account he stated
that, after washing the colouring matter  from the
crassamentum, he had separated it from the water
by boiling; in which case it either rose to the sur-
face of the water, or subsided,  and left the water
clear.  After drying, with a gentle heat, some of the
colouring  matter thus  separated, and  then  repeat-
edly washing it, he found that it contained a consi-
derable quantity of iron, which was attracted by the
magnet.
  After exposing a large quantity of the colouring
matter to an  intense heat,  he found in it a  small
piece of iron, of  a spherical form, but  hollow; and
a powder which was  attracted by the  magnet, but
appeared more like rust  of iron than iron filings.
  He believes the seat of this iron to  be in the co-
louring matter of the blood, as neither the serum nor
fibrine appeared  to contain it.   According to his
calculation, the blood of a healthy man contains
more than two ounces of iron.
  This doctrine of Menghini  has been very gene-
rally admitted: and several chemists  of the first
character, viz. Bucquet, Fourcroy, Vauquelin, &c. 
            Appendix.—Of the Blood.          407

have made experiments to ascertain the substances
with which the iron in the blood is combined.
  But within a few years, doubts have been express-
ed on this subject by several physiologists, and espe-
cially by Dr. Wells, and Mr. Brande.
  The first of these gentlemen, in his " Observations
and Experiments on the Colour of the Blood" published
in the London Philosophical Transactions for 1797,
states three reasons for rejecting the opinion that
the colour of the blood is derived from iron.
  1. The colour of blood  is destroyed by a heat less
than that of boiling water; whereas no colour arising
from a metal is destroyed by exposing it, subject, in
a close vessel, to such a heat.
  2. If the colour from a metal, in any substance, be
destroyed by any alkali, it may be restored by the
immediate addition  of an acid; and  the like  will
happen by the addition of a proper quantity of an al-
kali, if the colour has been destroyed by an  acid.—
The colour of blood, on the contrary, when once de-
stroyed,  can never be  brought back, either by an
acid or an alkali.
  3. If iron be the cause of the red  colour of blood,
it must exist there in a saline state; since the red
matter is soluble in water.  The substances, there-
fore, which detect the smallest quantity ot  iron in
such a state, ought likewise to demonstrate its pre-
sence in blood; but upon adding  Prussian alkali,
and an infusion of galls, to a very saturated solution
ofthe red matter, he could not observe "in the for-
mer case the slightest blue precipitate; or in the lat-
ter  that the mixture  had acquired the least blue or
purple tint."
  Mr.  Brande, in a  paper entitled " Chemical Re-
searches on the Blood," &c. communicated to the Royal
Society  of  London  in 1812, relates many experi-
ments which were made on the colouring matter of 
408     Appendix.—Structure of the Glands.

that  fluid, with acids, alkalies, astringents, &c. &c.
From these experiments, he also infers, that the co~
louring matter of the blood is perfectly independent of
iron.
  In support of this inference, he adds, that the Ar-
menian dyers,  in the preparation of their finest and
most durable red colours, use blood in addition to
madder, in  order to ensure the permanency of these
colours.  As the compounds of iron convert the co-
lour  of madder to gray and black, the production of
a bright colour by the addition of blood to madder,
he regards as  a proof, that iron is not the colouring
matter of blood.
  Many estimates have been made of the quantity
of blood in the  human body; but some ofthe best
informed physiologists have regarded them as falla-
cious.
              STRUCTURE OF GLANDS.
  Any original structure that discharges from the
blood vessels a fluid different from those which they
naturally contain, may be  considered  as glandular.
The function or process by which such fluids are de-
rived freiii the blood vessels is called secretion.
  A structure of this kind seems to exist in very dif-
ferent situations: for it is distinctly circumscribed in
many of those bodies commonly denominated glands,
which are of a very precise form; and it is also dif-
fused on some very extensive surfaces.   The gastric
liquor, a most important secretion, is  probably dis-
charged  from vessels which open, like exhalents, on
the internal surface  of the stomach;  and not from
any circumscribed bodies, which  are  generally de-
nominated glands.
  The name  of gland  is  theoretically applied to 
         Appendix.—Structure of Glands.      409

several bodies which cannot be proved  to  secrete
any fluid whatever;  and also  to those bodies con-
nected with the absorbent vessels, which  are called
the Lymphatic Glands ; but it is most commonly ap-
propriated to those organs  which discharge a fluid
different from the blood.
  The structure by which mucus is secreted in some
places, appears  to  be  very simple.  Thus  in the
Schneiderian membrane and the urethra, there are
small  ducts from four to six lines in length,  and
equal  in  diameter to a bristle,  which appear to be
formed ofthe membrane on which they open. From
these  ducts mucus issues to cover the surfaces of
these  membranes.  In many instances  there is  no
substance resembling that of the circumscribed glan-
dular bodies, connected with  these  ducts; but the
secreted fluid seems to be discharged into the ducts
from the small vessels on their surfaces.   The ducts
of this nature in the urethra are denominated Lacunae.
  In some other parts of the body, the  cavities  into
which mucus is discharged  are somewhat different,
both in form and size, from  those above mentioned,
and are  called Follicles.  These cavities are  sur-
rounded  with more or less of a pulpy vascular sub-
stance, which has been considered as glandular,  and
essential to the mucous secretion.
  The circumscribed bodies, which  are  commonly
called  glands, differ in their internal appearance and
texture, from the other  parts of animals.   The sub-
stance of which they consist differs very much in the
different  glands;  and  thus renders the  liver, kid-
neys, salivary glands, mammsB, &c.  very different
from each other.   Some glands, as  the salivary,  &c.
are composed of several series of lobuli  that succes-
sively diminish.   The smallest of these are denomi-
nated Acini.  " Each   of  them  is  connected by a
  vol. ii.               52 
410     Appendix.—Structure of Glands.

small artery and vein, to the large blood vessels of
the glands;  and also sends a branch to join the ex-
cretory duct.  These Acini are therefore connected
to each other, by  the  blood vessels and excretory
duct of the gland, and also by the cellular membrane
which covers them  externally, and occasions them to
adhere to each other where they are in contact.  In
consequence of  this structure,  these glands have a
granulated appearance.
  The liver, when  incised with a sharp instrument,
appears differently; but when broken  into pieces, it
seems to consist of  small acini.   Some other glands,
as the Prostate,  appear to be uniform in their tex-
ture,' and  have none of this granulated appearance.
  The structure of glands has long been an interesting
object of  anatomical inquiry, and was investigated
with  great  assiduity by those  eminent  anatomists,
Maipighi  and Ruysch.
  Maipighi, as was formerly observed, used ink and
other coloured fluids in  his injections.  He was also
very skilful in the use of microscopes, and took great
pains in mascerating and preparing the subjects of his
inquiries.   Ruysch, on  the  other hand, used a  ce-
raceous injection, and  was  most eminently success-
ful in filling very small vessels with it.  Maipighi be-
lieved that there were follicles or cavities in glandu-
lar bodies, which existed between the extremities of
the arteries and the commencement  of the excretory
ducts of those bodies, and that in these cavities the
secreted fluids underwent a change.—Ruysch con-
 tended,- that the arteries of glands  were continued
into  excretory ducts, without  the  intervention  of
 any cavity or follicle; that the small bodies, which
 had been supposed to contain follicles or cripse, were
 formed by convulsions of vessels, and that the change
 of  the fluid, or the process  of secretion, is produced
 by the minute ramifications of the artery. 
         Appendix*—Structure of  Glands.     411

   A very interesting account  of this subject is con-
tained in two celebrated letters, which passed between
Boerhaave and Ruysch  in the year 1721, and are pub-
lished at the end of the fourth volume of  the  works
of Ruysch.
   The opinion  of Ruysch  has been  most generally
adopted by  anatomists, and  has derived support and
confirmation from  several anatomists since his time.
The late Mr. Hewson  declared his  conviction that
the small globular bodies which are scattered through
the kidneys,  and  were supposed to be  follicles  or
criptsB, are  merely convoluted  arteries.   He  also as-
serted, that the acini which appeared  in the mammae
as large as the  heads  of pins, when the  excretory
ducts of that gland were injected  with vermilion and
painters' size, proved to be  the  minute  ramifications
of the excretory duct,  which  divided very suddenly
into branches so small, that they could not readily  be
seen by the naked eye.*
   Notwithstanding these reasons  for supposing that
the excretory ducts of glands were derived simply from
the arteries of those bodies,it is said that the late Dr. W.
Hunter used to declare his belief, that there  was a part
in glands which was not injected in  his preparations;
and to say further, that he believed  his preparations
were injected as minutely as  those of Ruysch.
   All of these opinions have  been  strenuously  con-
troverted  by  the Italian anatomist,  Mascagni,  who
believes that  the  arteries  terminate  only  in  veins;
and of course that they neither form exhalent vessels,
nor communicate with the excretory  ducts  of glands.
His idea of  the structure of  glands  is different  from
those  either of Maipighi or of  Ruysch.
• gee Experiment*! Inquiries vol. ii.- E> 17g 
412      Appendix.—Structure of Glands.

He supposes that glands contain a great  number of
minute cells;  that  the  arteries, veins, and absorbent
vessels are spread upon  the surfaces  of these cells,
in great  numbers, and very irregularly.  From these
cells very small  canals originate, which unite  to form
the small branches of the excretory ducts.   According
to his idea, the secreted fluid is discharged  through
pores or orifices of the blood  vessels, into the cells,
and proceeds from  them through  the  canals, into the
branches of the  excretory  ducts.  Absorbent  vessels,
in great numbers, originate from these cells.
   In  his great work on the  absorbent system, when
treating on the termination of arteries and the com-
mencement of veins, (Part I. Section 2.) he asserts,
that if the kidneys are successfully injected with size,
coloured with vermilion, and  then laid open by a sec-
tion of a razor, it will be  found that  the size  without
the colour has passed into  cells which  are  very nume-
rous ; that the arteries and veins are ramified most mi-
nutely on the  surfaces of these cells, and that the tubuli
uriniferi, as well as  the absorbent vessels, originate from
them.
   He supposes that a considerable portion of the fluid
thus passing off from the blood vessels, is commonly ta-
ken up by the absorbent vessels of the kidneys: for in
two cases in which he found the absorbent vessels ob-
structed, a diabetis existed, which  he considered  as
the  effect of  the  inactivity of  the  absorbents.  He
asserts, that in the liver, pancreas, mammae,  and also
in the salivary and lachrymal glands,  the minute arte-
ries  and veins  are also distributed upon the surfaces
of cells; and that very small  canals arise from these
cells, and unite  to  form the small branches of  the ex-
cretory  ducts.
   This great anatomist  appears to have  been  much 
App endix.—Structure of Glands.       413
occupied with microscopial observations, and has gone
largely into the  discussion of this subject.*

        It must, however, be acknowledged, that no information
          which has as yet been obtained respecting the struc-
          ture of glands, enables us to explain their wonder-
          ful effect upon the fluids  which pass through them.
          It remains  yet  to be ascertained why one structure
          forms saliva and another bile; or  why  so much ap-
          paratus should be necessary for the secretion of milk
          when adiopose matter appears to be produced by the
          mere membrane in which it is contained.
        Dr. Berzelius, professor  of  Chemistry  at  Stockholm,
          in a late work  on animal chemistry, asserts, that
          if all the nerves  going to a secretory organ are di-
          vided,  secretion  will  cease,  notwithstanding  the
          continued  circulation of the blood.   From this,  he
          thinks, that secretions depend upon the  influence of
          nerves, although he cannot explain their effects.
        Mr. Home, after relating some experiments upon blood
          and serum,  made with the Voltaic  Battery, proposes
          the following questions, among others:—Whether a
          weaker power of electricity than any which  can be
          kept up by art, may be capable of separating from the
          blood the different parts of which it is composed; and
          forming  new combinations of the parts so separated ?
           Whether the structure of the nerves may enable them
          to possess a low electrical power, which can  be em-
          ployed for that purpose ? &c.
               See the  London Philosophical Transactions, for
                 1809,  Part Il.t

   * The late Dr. W. Hunter, in his Medical Commentaries, (p. 40,) avowed
 his belief, that the fluids, which appear occasionally in the various cavities of
 the body, transude through the coats of the  blood vessels.  Mr. Hewson,
 (Experimental Inquiries, Vol. II. Chap. 7.) suggested several reasons for dis-
 senting  from this opinion; but Mascagni has endeavoured to support it.—See
 a long note to the above-mentioned section of his work, page 74.
   t Mr. Wollaston has also published a small paper on this subject,  in the
 Philosophical Magazine, Vol. 33. 
 
                GLOSSARY,*

EXHIBITING THE DERIVATION OF CERTAIN ANATOMICAL
                        TERMS.
                           A.

ACETABULUM. The cavity which receives the head of the
  thigh-bone; from acetum vinegar ; so called, because it repre-
  sents the acetabulum or saucer of the ancients,  in which
  vinegar was held for the use of the table.
Acini. From acinus a grape.
Acromion.  A process of the scapula;  from tcy.p^ extremity, and
  ufMi the shoulder.
Anastomosis. The communication of vessels with one another;
  from ttvx through, and ro^x mouth.
Anatomy. The dissection of the human body;  from um and
  Tc/ive to dissect.
Anconeus. A muscle; so called from «yx»v the elbow.
Aorta.  Aopri) from, ««§ air, and -ragea  to keep.
Aponeurosis. A tendinous expansion j from «wro, and  nvpov a
  nerve; from an erroneous supposition of the ancients, that it
  was formed by an expansion of nerve.
Apophysis. A process of a bone; from ««re^f» to proceed  from.
  A synonyme of process.
Arachnoides. A net-like membrane ;  from etpcc^n a spider, and
  e«Jos likeness.
Artery.  From «»f air,  and r^eu to keep; because the ancients
  supposed that air only was contained in them.
Arthrodia. A species  of connexion  of bones;  from a.p$p«o to
  articulate.
Arytoenoides. The name of two cartilages of the larynx ; also
  applied to some muscles of the larynx; from apvrxivxa, funnel,
  and tifos a. shape.
* By Dr. Hooper. 
416
Glossary.
Astragalus. A bone of the tarsus ; so called  from  its resem-
  blance to a die used in ancient games, from xtpxyxXes  a cockal
  or die.
Atlas. The first vertebra of the neck ; so called, because it
  sustains the head ; from the fable of Atlas being supposed to
  have supported the world ; or from xtXxu to sustain, because
  it sustains the head.
Azygos. A term applied to parts without a fellow, from x priv.
  and £»y<>s a yoke, because it has no fellow.

                             B.

Bursa. A bag; from fivpo-x:  generally applied to the bursas mu-
  cosas.
                            C.
Cancelli. Lattice work; generally applied to the reticular  sub-
  stance in bones.
Cardia. The  superior opening of the stomach;  from xxphx the
  heart.
Carotid.  The name of some arteries of the neck and head, from
  Kxpaa to cause to sleep; for, if tied with a ligature, the animal
  was said to be affected  with coma.
Carpus. Kxpires; the wrist.
Clavicula.  The clavicle or collar-bone, a diminutive of clavis a
  key; so  called from its resemblance to an ancient key.
Clinoid. Four processes of the sella turcica of the ethmoid bone
  are so called, from x.xm a bed, and etdo$ likeness;  from their
  supposed resemblance to a couch.          4
Clitoris. A part of the female pudenda ; enclosed by the labia
  majora ;  from x.Xa*> to enclose or hide.
Colon. The first of the large intestines; from xuXn, quasi uottei,
  from x»ix«i hollow.
Coracoid. From *«f«f a  crow,  and e«J«s resemblance; shaped
  like the beak of a crow.
Coronary.  From  corona  a crown.   The vessels of the  heart,
  stomach, &c. are so called because they surround the parts
  in the manner of a crown.
Cotyloid. From xotuAjj the name  of an old measure, and eiSt* re-
  semblance : resembling the kotule.
Cranium.  The skull; x.pxrn>v, quasi, xxpxnov, from **p* the head.
Cremaster. A muscle so  called  ; from xqepxa to suspend, be-
  cause it suspends the testicle.
Cribriform. From cribrum a sieve, it being perforated like a
  sieve. 
?'
                         Glossary.                    U7

 Cricoid. Annular, round like a ring; from k^*; a ring and
   *<&?  likeness.
 Cuboides. A bone of the foot;  from «t£«$ a  cube,  and  uh%
   likeness; bceause it resembles a cube.
 Cuneiform. Some bones  are so called ; from cuneus a wedge*
   and forma likeness, being shaped like a wedge.

                            D.
 Deltoid. A muscle resembling the Greek letter A: from A, and
   tt&s  resemblance.
 Diaphragm.  The muscle which separates the thorax from the
   abdomen ; from ^<^«r?w to divide.
 Diarthrosis.  A moveable connexion of bones;  from  Six^tu to
   articulate.
 Digastric.  From  S~n  twice, and yx%^ a belly;  having two bel-
   lies.
 Diploe.  The spongy substance between the two  tables of the
   skull; from 2~rsr\oa to double.
 Duodenum. The  first portion ofthe small intestines; So called
   because  the  ancients  supposed that it  did not exceed thft
   breadth  of  twelve fingers ;  from  duodenus,  consisting of
   twelve.
 Dura Mater. The outermost membrane of the  brain ; called
   dura, because it is much harder than the other membranes,
   and mater, from the idea of the ancients that it was the source
   of all the other membranes.

                            E.
 Embryo. The child in the womb is so called before the fifth
   month, after which, it  is termed foetus ; from tftfyva to bud
   forth.
Enarthrosis.  An  articulation of bones; from ev in, and xgigot a
  joint or articulation.
Enteric. Belonging to the intestines; from tvreeov an entrail or
   intestine.
Epidermis. The scarf or outermost skin ;  from mi  upon, and
   <$Vfj*<s  the skin.
Epididymis. The small oblong body  which lies above the testi-
  cles;  from ctti upon, and hovf*o$  a  testicle.
Epigastric. The superior part ofthe  abdomen; from «*•< upon*
  and yxsvg the stomach.
Epiglottis.  A cartilage ofthe larynx so called; from ew< upon,
  and yxurln the aperture  of the  larynx, being situated upon
   the glottis.
   VOL. II.                   53 
- •
 US                    Glossary.

 Epiphysis. A portion of bone growing upon another bone, but
   separated from it by a cartilage; from  crt upon, and Qva to
   grow.
 Epiploon. The membranous viscus of the abdomen, which covers
   the intestines, and hangs to the bottom  of the stomach: from
   tTTiirXea to swim upon.
 Ethmoid. From e8(u>s a sieve, and uhs resemblance; being per-
   forated like a sieve.
                            F.
 Fascia. An expansion, enclosing other parts, like a band; from
  fascis  a bundle.
 Falciform. Shaped like a scythe ; from falx, a scythe.
 Fasciculus. A little bundle, dim.  of fascis a bundle.
 Fauces. The  plural of faux, the top of the throat.

                            G.
 Ganglion. TxfyXtov, a knot in the course of  a nerve.
 Gastrocnemius.  The muscle which forms the thick of the leg;
   from yxtve a belly, and xvvw the leg.
 Genio. Names compounded with  this word belong to  muscles
   which are attached to the chin,as geno-glossus,geno-hyoideuSj
   * c.; from  yevew the chin.
 Ginglymus.  An articulation; from yifyxv^oi a hinge.
 Glenoid cavity. From yXuvn a cavity, and eib>s resemblance.
 Glosso. Names compounded with this word belong to muscles
   which are attached  to the tongue;  as  glosso-pharyngeus—
  glosso-staphilinus, &c; from yXae-c-x the tongue.
 Glottis The superior opening of the larynx at the bottom of the
  tongue ; from yXurjx the tongue.
 Glulxus.  The name of a muscle; from yxzros the buttocks.
 Gomphosis. Toia.^ut^, a species of immoveable connexion of
   bones; from yopQos a nail, because one  bone is fixed in an-
  other bone  like a  nail in a board.
                            H.
Helix.  The outward circle of the ear; from etXe*> to turn about.
Hepar. The liver.   'Ht^ an abdominal viscus.
Hyaloid.  From i>xx*c, glass,  and s<&5 likeness ; the capsule of
  the vitreous humour of the  eye is so called,  from its trans-
  parent and  glassy appearance.
Hymen. The  membrane  situated at the entrance of the virgin
  vagina ; from r^v Hymen, the god of  marriage.
Hyoides.  A bone ofthe tongue, so called  from its resemblance
  to the Greek v; from v, and uhi resemblance. 
Glossary.
ilii
Jlypochondruirii. That part of the body which lies under the
   cartilages of the spurious ribs; from 6x0 under, and yjwfyw a
   cartilage.
Hypogastric. The lower region of the fore part of the abdomenj
   from utto under, and yxine the  stomach.

                             I.
Ileon.  A portion of the small intestines;  from  uXtu to  turn,
   being always convoluted.
Ischium. The part of the os innominatum upon which  we sit;
   from t<r%va> to  sustain.
                            L.
Lacuna.  The excretory duct of  the glands of the urethra and
   vagina; from lacus a channel.
Lambdoidal suture.  So called because  it is shaped like the
   letter A ; from A, and eifos  resemblance.
Larynx.  The superior part of the windpipe; xx*vy%t\\e.  larynx.

                            M.
Masseter. A muscle of the  face,  which  assists in the action of
  chewing ; t*.xrFxop.xt to chew.
Mastoid.  From  /t**s<>s a teat, and eioeg likeness ;  shaped like a
  nipple  or teat.
Mediastinum. The production of the pleura, which divides the
  thorax  into two cavities ; from medium the middle, quasi in
   medio stare.
Mesentery. The  membranes to which the intestines  are attach-
  ed :  from  /ttso-a? the middle,  and evr^eov an intestine, because
  it is in the middle of the intestines.
Mesocolon. That part of  the mesentery in the middle  of the
  colon;  from pecros the middle,  and xsXov the colon.
Metacarpus.  That part of the hand  between the carpus and
  fingers; from  f**tx after,  and kx^ttos the wrist.
Metatarsus. That part of the foot between the tarsus and toes  ;
  from [mtx after, and t#»s-os the tarsus.
Mylo.  Names compounded with this word belong to  muscles
  which are attached near the grinders, as mylo-hyoideus, &c.;
  from pt.vhn a grinder tooth.
                             O.
Odontoid. Tooth-like; from o^« a tooth, and c<&$ resemblance.
(Esophagus. The canal leading  from the pharynx  to the sto-
   mach ; from oiw to carry, and §xy» to eat: because it carries
   the food into the stomach] 
J*20
Glossary.
 Olecranon. The elbow, or head of the ulna; from uXew the cu-
   bit, xf*v«v and the head.
 Omentum. An abdominal viscus; so called from omen a guess,
   because the soothsayers prophesied from the inspection of
   the  part.
 Omo.  Names compounded with this word, belong to muscles
   which are attached to the scapula, as  omo-hyoideus, &c. from
   Ayta? the shoulder.
 Omoplata. The scapula or shoulder blade; from e^tes the shoul-
   der, and ttXxtvs broad.
 Osteology. The  doctrine of the bones; from «se«v a bone,  and
   >.ayo<; a discourse.

                             P.

Pancreas.  A viscus of the abdomen ; so called from its fleshy
   consistence ; from ttxv all, and xgext flesh.
Parenchyma.  The substance  of some  of the  viscera was so
   called,  from 7rx»tyx.'ju to pour through.
Parotid Gland. From nxgx near,  and **s the ear; because it is
   situated near the ear.
Pelvis. A bony cavity shaped like a basin; from ttcXvs a basin.
Pericardium.  The membrane which surrounds the heart ;  from
   iregt around, and %xehx the heart.
Pericranium. The membrane  which  covers the bones of the
   skull; from met around,  and xexviav the cranium or head.
Periosteum.  The membrane which surrounds the bones ;  from
   Viet around, and o««ov a bone.
Peristaltic motion of the intestines ;  from ?nemxxv to contract.
Peritoneum.  The membrane lining the abdomen, and  covering
   its viscera;  from weirum to extend around.
Phalanx. The bones of the fingers and toes are called phalanxes,
   from their regular situation, like a <$xx*y%, or arrangement of
   soldiers.
Pharynx.  A membranous bag at the end of the mouth; x™ m
   <ptenv because it conveys the food into the stomach.
Phrenic or diaphragmatic nerve,  peens the  diaphragm;  from
   pew the  mind; because the ancients supposed it to be the seat
   of the mind.
Pia Mater.  The innermost membrane of the brain,  so called
   because it embraces the brain as a careful mother folds her
   child.
Pleura. The  membrane lining the thorax;  vXevex the side.
Plexus. A kind of net-work of vessels or nerves : from plccto
  to weave together.                                 r 
Glossary.
421
Psoas. A muscle so called; from 4'oec the loin, being situated
  in the  loins.
Pterygoid process. From ir\i^v\ a pen or wing, and  eifoi like-
  ness, so called from its likeness to a pen or wing.
Pylorus.   The lower orifice of  the stomach, which opens into
  the intestines;  from tvXoco  to  guard an entrance, because it
  guards as it were the entrance of the bowels.
                             R.
Raphe. A suture ; from pxtfu to sew.
Renes. The kidneys, xir» m pu*} because through them the urine
  flows.
Retina. The net-like expansion of the optic nerve, on the inner
  surface of the eye; from rete a net.
Rhomboides. A muscle so called from its shape; from pop£ott a
  geometrical figure,  whose sides are equal, but not  right-
  angled, and uSoi a likeness.
Rotula. The knee-pan; a dim. of rota a wheel, from its shape.
                             S.
Sacrum.  A bone so  called ; from sacer  sacred, because it was
  once offered in sacrifices.
Salvatella.  A vein of the foot, so called because it was thought
  that opening it preserved health,  and cured melancholy;
  from salvo to preserve.
Sanguis. The blood ; xko m a-xnv  yvix, because it preserves
  the  body.
Sartorius. A muscle so  called, because tailors cross their legs
  with it; from  sartor a tailor.
Scapha.  The depression of the outer ear, before the anti-helix;
  from c-kx(P» a little boat or skiff*.
Scaphoides. A bone of the carpus,so called from its resemblance
  to a skiff'; from c-Kxtpqa. skiff, and ekJoj likeness.
Sclerotic. A term applied  to the outermost  or  hardest  mem-
  brane of the eye;  from <na>»f«« to make hard.
Sesamoid bones. From a-nrxftT} a grain, and eis^s likeness; from
  their resemblance to the semen sesami.
Sigmoid. Parts are  so  called  from their resemblance to  the
  letter S;  from 2, the letter Sigma, and etS'og likeness.
Sphenoid. From <r$w a wedge, and tifos likeness ; shaped like
  a wedge.
Sphincter.  The  name of several muscles, whose office it is to
  shut up the aperture around which they are  placed ; from
  a-Qiyyu tO shut Up.
Splanchnic.  From rnXxyxm  an entraiK 
422
Glossary.
Symphysis  A connexion  of bones;  from a-v^vu to grow to-
  gether.
Synarthrosis. A connexion of bones; from <rw with, and xp6p»i
  a joint.
Synchondrosis.  A species of union of bones by means of carti-
  lage; from c-w with, and ^av<J>o« a cartilage.
Synneurosis. A species  of connexion of bones by  means  of
  membrane; from cw with, and nvpos a nerve; because mem-
  branes, ligaments, and tendons, were by the ancients consid-
  ered as nerves.
Syssarcosis. A species of connexion of bones by means of mus-
  cle; from o-tiv with, and  <rxe% flesh.
Systole. The contractile motion of the heart and arteries; from
  c-ve-reXXx to contract.
                            T.
Tendon. From raw to extend.
Thorax.  ©»£<*£.   The breast or chest.
Thyroid.  From 0t>£f««, a shield, and f/&s likeness ; shaped like
  a shield.
Trachea. The wind-pipe;  so  called from its  roughness; from
  re*xt>s rough.
Trochanter. A process of the thigh-bone, so  called from t%o%*<,
  a wheel.
                            U.
Ulna. A  name for the cubit;  from uXan the cubit.
Ureter.  The canal which conveys the urine  from  the kidney
  to the bladder; from neov the urine.
Urethra.  The passage through which the urine passes from the
  bladder; from »fav the urine.
Uvea. The posterior lamen of the iris,  so called because in many
  animals it is of the colour  of  unripe  grapes;  from  uva an
  unripe grape.
Uvula. The conical substance which hangs down from the mid-
  dle of the soft palate ;  so called from its  resemblance  to a
  grape.   A dim. of uva a grape.
                            V.
Valves. From valvse, folding doors.
Vertebrse.  The bones of the spine are so called ;  from verto  to
  turn.
                            X.
Xiphoid.  So called  from  the resemblance to a sword; from
  |<4>as a  sword, and  f««5o? likeness.
                            Z.
Zygoma.  The cavity under the zygomatic process of the tem-
  poral bones:  from t,vy»s a voke\ 
ALPHABETICAL  INDEX TO VOLUME  II.
—.>.>♦« Q9«..—
                        Page.
Aorta             50 and 236
Adhesion of lungs         73
Abdomen                  82
        regions of        86
        contents of        85
        situation  of  vis-
           cera            87
Acini of liver             132
Arteries, structure of     226
Artery, axillary           262
           aorta thoracic  270
               abdominal 274
           adipose       281
           anastomotic    292
           anterior tibial  294
           basilic        259
           bronchial      270
           carotid       239
                  external 240
                  internal 250
of
callous
cervical
circumflex
coeliac
capsular
circumflex
  ilium
    of thigh
emulgent
epigastric
facial
fe mo rial
gastric
    right
    left
gluteal
humeral
hepatic
hemorrhoidal
innominata
256
261
564
275
280

289
291
280
288
242
289
275
276
277
286
264
276
285
238
                        Page.
Artery, internal maxillary 245
              mammary 257
        intercostals supe-
          rior           260
        interrosseal      267
        intercostals infe-
          rior           272
        illiac primitive   282
            internal     283
        ilio lumbar      284
        illiac external    288
        internal plantar 296
        ischiatic         286
        lingual          242
        lumbar         282
        middle of brain 255
        mammary exter-
          nal           262
        mesenteric supe-
          rior          278
                    infe-
          rior          279
                    occi-
          pital         244
        ophthalmic      252
        oesophageal      271
        obturator       285
        pharyngeal infe-
          rior           243
        phrenic         274
        pudic internal    287
              external   290
        profunda femoris  290
        perforating      291
        popliteal        292
        posterior tibial  295
        peroneal        295
        plantar external 296
        radial          266
        stylo-mastoid     245 
424
INDEX.
Artery, subclavian	256	j Chorda tympani	<■> **.".
scapular superior 260		Crassamentum	403
internal	263		
spiral	265	Duodenum	111
splenic	277	Ductus communis	141
spermatic	281	Dartos	173
sacral middle	282	Ductus venosus	220
lateral	284	Descending cava	300
thyroid superior	241	External nose	o
inferior	258	Eustachion tube	11
temporal	249	Epididymis	177
ulnar	268		
uterine	286	Fauces	28
vertebral	258	Fcetus, thorax of	69
Arterial system, plan of	297	heart of	69
Abdominal viscera, nerves		lungs of	69
of	368	abdomen of	217
Absorbents, structure of	371	Female organs of genera-	
of lower extre	-	tion	200
mity of abdomen	376 381	Fallopian tubes	209
of thorax	389	Gums	16
of head and		Glandulae molares	26
neck	391	Glottis	34
of upper ex-		Gastric liquor	101
tremity	393	Great intestines	117
Absorption, cutaneous	395	Gall bladder and. duct	139
		Glandulae renales	154
Black glands	64	Ganglions	321
Bile	141	of Gasser	327
Bladder of female	213	sphino palatine	329
Blood vessels in general	223	cervical	361
Blood	401	semilunar	367
colouring matter of	404	Glands, structure of	408
		Glossary	415
Cavities of nose	4		
Caecum	118	Heart	50
Colon	119	malformations of	71
Corpus pampiniforme	174	nerves of	363
Corpora cavernosa	186	Hepatic duct	139
Corpus spongiosum	188	Hymen	202
Canal of urethra Clitoris	190 201	Hottentots, peculiarity of	216
Canalis arteriosus	220	Intestines	104
Cavse	299	villous coat of	105
Coronary veins	299	division of	109
 
INDEX.
425
Intestines, small	110
Integuments of penis	195
Ilium	113
Jejunum	113
Kidneys	155
Larynx	31
arteries and nerves	.
of	35
Left auricle	55
ventricle	56
Lungs	65
Legallois on the heart	79
Liver	128
ligaments of	130
Labia externa	201
Lacteals	389
Mouth	14
Mammae	41
Mediastinum	46
Muscular fibres of heart	57
Mesentery	115
Male organs of generation	171
Nose                       1
     nerves of             8
Nerves of liver           136
Neck of the bladder       167
Nerves, structure of       319
        accessory         347
       of arm  *          348
        of brain          323
       cervical          343
        circumflex        351
       crural            355
       cardiac           363
       of diaphragm      246
       dorsal            352
       eighth pair        330
        fourth pair        325
        fifth pair          326
        fibular           359
        glosso-pharyngeal 337
        internal cutaneous 351
   VOL,  II.
Nerves, lumbar           353
       laryngeal superior 339
       maxillary inferior 332
                superior 329
       musculo   cutanc-
ous	348
median	348
ninth pair	342
olfactory 6.	323
optic	324
ophthalmic	327
opturator	355
parvagum	338
recurrent	339
radial	350
sixth paii-	333
seventh pair	334
sacral	356
sciatic	358
sympathetic	361
splanchnic	367
third pair	325
tibial posterior	360
ulnar	349
Oesophagus	94
Omentum	125
Orifice of urethra.	167
Ovaries	210
Parotid gland	25
Pharynx	37
Pleurae	45
Pericardium	49
Pulmonary arteries and	
veins	61
Peritoneum	90
Pylorus	102
Pancreas	141
Prostate gland	113
Penis	184
Prepuse	196
Placenta	221
Plexuses	321
pulmonary	340
brachial	347
 
426
INDEX.
Plexuses lumbar	354
cardiac	366
solar	367
Rima glottidis	34
Right auricle	52
ventricle	53
Rectum	122
Round ligaments	209
Schneiderian membrane	5
Sinuses of nose	12
Soft palate	17
Salivary elands Submaxillary gland	25
	26
Sublingual gland	26
Saliva	26
Sabatier on foetal circula	
tion	75
Stomach	96
lymphatics and	
nerves of	103
Spleen	145
Scrotum	171
Serum	402
Spermatic cord	173
Tongue	18
papillse of	2Q
blood vessels of	23
nerves of	24
Throat	28
Tonsils	29
Thyroid gland	37
Thorax	41
Trachea	62
Thymus gland	69
Tunica vaginalis	175
albuginea	176
Testicle	177
descent of	218
Thoracic duct	287
Uvula	17
Urinary organs	154
Ureters	160
Urinary bladder	162
Urethra of male	188
Urethra of female
Uterus
        changes   of,
          pregnancy
Umbilical arteries
in
202
205

214
219
Venae cavae                61
Valve of colon            120
Vena Portarum           134
Vessels of liver           133
Vas deferens             180
Vesiculae seminales       181
Vagina                   203
Veins, structure of       233
       distribution of     298
Vena azygos             301
Veins, axillary           308
       anomalies of       317
       basilic             308
       cephalic           308
       Cava inferior      309
       capsular           312
       circumflex         314
       external jugular    306
       emulgent          312
       external iliac      314
      epigastric         315
      external saphena    316
      femoral            315
      hepatic            311
      hypogastric        313
      intercostal superior 303
      primitive iliac      313
      jugular internal    304
      lumbar            313
       middle sacral      313
       mesenteric superior 311
      phrenic inferior    310
Vena portarum           311
Veins, pulmonary         317
       subclavian         307
       splenic            311
      spermatic          312
      saphena major      315
      vertebral          304
      vesical             313 
ANATOMICAL,  PLATES.
—«»«@e*<"~-
EXPLANATION OF THE PLATES OF OSTEOLOGY
Plate II.
       Fig. 1. A Front View of the Male Skeleton.
  A,  The  os  frontis.  B,  The  os parietale.   C, The coronal
suture.  D, The squamous part of the temporal bones. E, The
squamous suture.  F, The  xygoma.  G,  The mastoid process.
H, The temporal process of the  sphenoid bone.  I, The orbit.
K, The os malae.   L, The os maxillare superius.  M,  Its nasal
process.  N, The ossa nasi. O, The os unguis.  P, The maxilla
inferior.   Q,  The teeth, which  are sixteen in number in each
jaw.   R, The seven  cervical vertebrae, with their intermediate
cartilages.   S, Their  transverse processes.   T, The twelve
dorsal vertebrae, with their  intermediate cartilages.   U, The
five lumbar vertebrae.  V, Their transverse process.   W, The
upper part of the os  sacrum.   X, Its lateral parts.  The holes
seen on its fore part are the passages of the undermost spinal
nerves and small vessels.   Opposite to the holes, the marks of
the original divisions of the bones are seen.  Y, The os ilium.
Z, Its crest or spine, a, The anterior spinous processes, b, The
brim of the pelvis,  c, The ischiatic notch,  d,  The os ischium.
e, Its tuberosity,  f, Its spinous process,  g, Its crus.  h, The
foramen thyroideum. i, The os pubis, k, The symphysis pubis.
1, The crus pubis,   m, The acetabulum,  n, The seventh or last
true rib.   o, The twelfth or last  false rib.  p, The upper end of
the sternum,   q, The middle piece,  r, The under end, or car-
tila»o ensiformis.  s, The clavicle,  t, The internal surface ot
the scapula,   u, Its acromion,  v, Its  coracoid  process, w. Its
cervix,   x, The glenoid cavity,  y, The os humeri. %, Its head
which is connected to the glenoid cavity.   1, Its internal tu-
bercle.   2, Its internal tubercle.  3, The groove for lodging the
long head  of the biceps  muscle of the arm.  4, The internal 
428  Explanation of the Plates of  Osteology.

condyle.  Between 4 and 5, the trochlea.   6, The radius.  7,
Its head.  8, Its  tubercle.   9,  The ulna.  10,  Its coronoid
process.   11, 12,  13, 14, 15, 16, 17, 18, The carpus ; compo-
sed of 09  naviculare, os lunare,  os cuneiform, os pisiforme,
os trapezium, os trapezoides, os magnum, os unciforme.  19,
The five bones of  the metacarpus.  20, The two bones  of the
thumb.  21, The  three bones of each of the fingers.  22, The
os femoris.  23, Its head.  24,  Its cervix.   25, The trochan-
ter major.  26, Trochanter minor.   27, The internal condyle.
28, The external  condyle.   29, The rotula.   30,  The tibia.
31, Its head.  32, Its tubercle.   33, Its spine.   34, The mal-
leolus internus.  35,  The fibula.  36, Its head.  37, The mal-
leolus externus.  The tarsus is composed  of.  38, The astra-
galus; 39, The os calcis ; 40,  The os naviculare ; 41,  Three
ossa, cuneiformia, and the os  cuboides, which  is not seen  in
this figure.  42, The five bones of the metatarsus.   43, The
two bones of the great toe.  44, The three bones  of each  of
the snail toes.
            Fig. 2.  A Front view of the Skull.
  A, The os  frontis.   B,  The lateral part of the os frontis,
which gives origin to part of the temporal muscle.  C, The su-
perciliary  ridge.  D, The superciliary hole through which the
frontal vessels and nerves pass.   EE, The orbitar processes,
F, The middle of the transverse suture.   G, The upper part
of the orbit.  H,  The foramen  opticum.   I, The  foramen la-
cerum.  K, The  inferior orbitar fissure.   L,  The  os  unguis.
M, The ossa nasi. N, The os maxillare superius.  O, Its na-
sal process.  P, The external orbitar hole  through which the
superior maxillary vessels and nerves pass.  Q, The os malae.
R,  A passage for  small vessels  into or out of, the  orbit.   S,
The under part of the  left nostril.  T, The septum narium.
U, The os spongiosum superius.  V,  The os  spongiosum  in-
ferius.  W, The edge of the alveoli, or spongy sockets  for the
teeth.   X, The maxilla inferior.   Y, The passage for the infe-
rior maxillary vessels and nerves.
            Fig. 3.  A Side-view of the Skull.
   A, The os frontis.   B, The  coronal suture.   C, The os pa-
rietale.  I), An arched ridge, which gives origin  to the temporal
muscle.  E, The  squamous suture.   F, The squamous  part of
the temporal bone; and further  forwards, the temporal process
of the sphenoid bone. G, The zygomatic process of the  tempo-
ral bone.  H, The zygomatic suture. I, The mastoid process of
the temporal bone.  K, The meatus auditorius externus. L, The
orbitar plate of the frontal bone, under wh'rch is seen the trans- 
      Explanation of the Plates of Osteology.   429

Verse suture. M, The pars plana of the ethmoid bone. N, The
os unguis.   O, The right os nasi.  P, The superior maxillary
bone. Q, Its nasal process.   R, The two dentes incisores.  S,
The dens caninus.  T, The two small molares.  U, The three
large molares.   V, The os malae.   VV, The lower jaw.  X, Its
angle.  Y, The coronoid process.  Z, The condyloid process by
which the jaw is articulated with the temporal bone.
     Fig. 4. The posterior and Right  Side of the Skull.
  A, The os frontis.  BB, The ossa pamtalia.   C, The sagit-
tal suture. D,  The parietal  hole, through which a small vein
runs to the superior longitudinal sinus.   E, 1 he lambdoid su-
ture.  FF, Ossa triquetra.  G, The os occipitis.  II, The squa-
mous part of the temporal bone.   I, The mastoid process.  K,
The zygoma.  L, The os malae.  M, The temporal part  of  the
sphenoid bone. N, The superior maxillary bone and teeth.
      Fig. 5.  The External Surface of  the Os Frontis.
  A, The convex part.   B, Part of the temporal fossa.  C,
The external  angular process.  D, The internal angular pro-
cess.  E, The nasal process. F, The superciliary arch.  G, The
superciliary hole. 11, The orbitar plate.

      Fig.  6.  The internal surface of the Os Frontis.
  AA, The serrated  edge  which assists to form  the  coronal
suture.  B,  The  external angular process. C,  The internal
angular  process.  D,  The  nasal process.  E, The  orbitar
plate.  F, The cells which correspond with those of the eth-
moid bone.  G, The passage from the frontal sinus.  H, The
opening which receives  the  cribriform  plate of the ethmoid
bone. I,  The cavity which lodges the fore-part  of the brain.
K, The spine to which the falx is fixed.   L, The groove which
lodges the superior longitudinal sinus.
                        Plate  III.
           Fig. 1. A Back view of the  Skeleton.
  A A, The ossa parietalia.   B, The sagittal suture.  C, The
lambdoid  suture.  D, The occipital bone.   E, The squamous
suture. F, The mastoid process of the temporal bone.  G, The
os malae.  H, The palate  plates of the superior maxillary bones.
I, The maxilla inferior.   K, The teeth of both jaws.  L, The
seven cervical vertebras.  M, Their spinous processes.  N,
Their transverse and  oblique processes.  0,  The last  of  the
twelve dorsal vertebrae.   P, The fifth  or last lumbar vertebra.
Q, The tranverse processes.  R, The oblique processes. S, The
spinous process. T, The upper part of the os sacrum.  U, The
posterior holes which transmit small blood vessels and nerves. 
 430   Explanation of the Plates of Osteology.

V, The under part of the os sacrum  which is  covered by a
membrane.   W, The os coccygis.   X, The os ilium.   Y,  Its
spine or crest. Z, The ischiatic notch,  a, The os ischium,   b,
Its tuberosity, c, Its spine, d, The os pubis,  e, The foramen
thyroideum. f, The seventh or last true rib.  g, The twelfth or
last false rib. h, The clavicle, i, The scapula, k, Its spine.  1,
its acromion, in, Its oervix.   n, Its superior costa.  o, Its pos-
terior costa.  p, Its inferior costa.  q,  The os humeri,  r,  The
radius, s, The ulna,  t, Its olecranon,   u, All the bones of  the
carpus, excepting the os pisiforme, which is  seen in plate  II.
fig. 1.  v, The five bones of the metacarpus,  w, The two bones
of the  thumb,  x, The three bones of  each of the fingers,   y,
The two sesamoid bones of the root of  the left thumb,   z, The
os femoris.  1, The trochanter major.  2, The trochanter minor.
3, The linea aspera.  4, The  internal  condyle.  5,  The exter-
nal condyle. 6 6, The semilunar cartilages.   7, The tibia.   8,
The malleolus internus.  9, The fibul.  10,  The malleolus  ex-
ternus.  11,  The tarsus.  12, The metatarsus. 13, The toes.
   Fig. 2. The external Surface of the Left Os Parietale.
  A, The convex smooth surface.  B,  The parietal hole.  C,
An arch made by the beginning of the  temporal muscle.
       Fig. 3. The Internal Surface of the same bone.
  A,  Its superior edge, which, joined with the other, forms
the sagittal suture.  B, The anterior edge which assists in the
formation of the  coronal  suture.   C, The inferior edge  for
the squamous suture.  D, The posterior edge for the lambdoid
suture.   E, A depression made by the  lateral sinus.   F, The
prints of  the arteries  of the dura mater.
  Fig. 4.  The external  Surface of the Left Os Temporis.
  A, The squamous part.  B, The  mastoid process.   C, The
zygomatic process.  D,  The  styloid process.  E,  The petro-
sal  process.  F, The meatus auditorius externus.  G, The
glenoid cavity for the articulation of the lower jaw.  H, The
foramen stylo-mastoideum for the portio dura of the seventh
pair of nerves.  I, Passages  for  blood vessels  into the bone.
K, The foramen mastoideum, through which a vein goes to the
lateral sinus.
   Fig. 5.  The  Internal Surface of the Left Os Temporis.
  A, The squamous part; the upper edge of which assists in
forming the squamous suture.  B, The mastoid process.   C,
The styloid process.   D, The pars petrosa.   E,  The entry  of
the seventh pair,  or auditory nerve. F,  The fossa, which lodges
a part of the lateral sinus.  G, The foramen mastoideum. 
Explanation of the Plates of Osteology.   431
Fig. 6. The External Surface of the Osseous Circle, which
        terminates the meatus auditorious externus.
  A, The anterior part.  B,  A small part  of the  groove  in
which the membrana tympani is fixed.
  N. B. This, with the subsequent bones of the ear, are  here
delineated as large as the life.
    Fig. 7. The Internal Surface of the Osseous Circle.
  A, The anterior part.  B, The groove in which the membrana
tympani is fixed.
Fig. 8.  The Situation and Connexion of the  Small Bones of
                        the Ear.
  A, The malleus. B, The incus.   C, The  os orbiculare.  D,
The stapes.
Fig. 9.  The  Malleus,  with its  Head,  Handle, and Small
                       Processes.
  Fig. 10.  The Incus, with its Body, Superior and Inferior
                        Branches.
               Fig. 11. The Os Orbiculare.
 Fig. 12.  The  Stapes, with  its Head, Base, and two Crura.
  Fig. 13.  An Internal View of the Labyrinth of  the Ear.
  A, The hollow part of the  cochlea, which forms  a share of
the meatus auditorious internus.  B, The vestibulum.  CCC,
The semicircular canals.
       Fig. 14. An External View of the Labyrinth.
  A, The semicircular canals.  B, The fenestra ovalis, which
leads into the vestibulum.   C, The fenestra rotunda  which
opens into the cochlea.   D, The different turns of the cochlea.
    Fig. 15.  The Internal Surface of the Os Sphenoides.
  AA, The temporal processes.   BB,  The pterygoid  proces-
ses. CC, The  spinous processes.   DD,  The anterior clinoid
processes.  E,  The posterior clinoid process.  F, The anterior
process which  joins the ethmoid bone.   G, The sella turcica
for lodging the glandula pituitaria.  H, The foramen opticum.
K,  The foramen lacerum.   L, The foramen  rotundum.  M,
The foramen  ovale.  N, The foramen spinale.
    Fig. 16. The External Surface of the Os Sphenoides.
  AA, The temporal processes.  BB,  The pterygoid  proces-
ses. CC, The  spinous processes.   D, The processus azygos.
E, The small triangular processes which grow from the  body
of the bone.  FF, The orifices of the sphenoid  sinuses.   G,
The foramen lacerum.  H,  The foramen rotundum.   I, The
foramen ovale.  K, The foramen pterygoideum. 
432   Explanation of the Plates of Osteology.

     Fig. 17.  The External View of the Os Ethmoides.
   A, The nasal lamella.   BB, The grooves between the nasal
 lamella and ossa spongiosa superiora.  CC, The ossa spongiosa
 superiora.  DD, The sphenoidal cornua.   See Fig.  16. E.
       Fig. 18. The Internal View ofthe Os Ethmoides.
   A, The crista galli.   B, The cribriform plate, with the dif-
 ferent passages of  the  olfactory  nerves.  CC. Some of the
 ethmoidal cells. D, The right os planum.  EE, The Sphenoidal
cornua.
          Fig. 19.  The right Sphenoidal Cornu.
           Fig. 20.  The left Sphenoidal Cornu.
     Fig. 21.  The External Surface of the Os Occipitis.
   A, The upper part of the bone.  B,  The superior arched
ridge.  C, The inferior arched ridge.  Under the arches are
prints  made by the muscles of the neck.  DD, The  two con-
dyloid processes which articulate the head with the spine.   E,
The cuneiform  process.  F, The  foramen magnum through
which  the spinal marrow passes.  GG, The posterior condyloid
foramina which transmit veins into the  lateral sinuses. HH,
The foramina  lingualia for  the passage of the ninth  pair of
nerves.
     Fig. 22. The Internal Surface of the Os Occipitis.
   AA,t The two sides which assist to form the lambdoid suture.
B, The point  of the cuneiform process,  where  it joins  the
sphenoid bone. CC, The prints made by the posterior lobes of
the brain.   DD, Prints made by the lobes  of the cerebellum.
E, The cruciform ridge for the attachment of the process of the
dura mater.  F, The course  of the  superior  longitudinal si-
nuses.  GG, The course of the two lateral sinuses.   H, The
foramen magnum.  II, The posterior condyloid foramina.
                       Plate IV.
          Fig. 1.  A Side-view of  the Skeleton.
   AA, The ossa parietalia.   B, The  sagittal suture.  C, The
os occipitis. DD, The lambdoid suture. E, The squamous part
of the temporal bone. F, The mastoid process. G, The meatus
auditorius externus.   H, The os frontis.  I, The os malae.  K,
The os maxillare superius.  L, The maxilla inferior.   M, The
teeth of both jaws.  N, The seventh, or last cervical vertebra.
0, The spinous processes.   P, Their transverse and oblique
processes.  Q, The twelfth or last dorsal  vertebra.  R, The
fifth, or last lumbar vertebra.   S, The spinous processes.  T,
Openings between the vertebrae for the passage of the spinal
nerves. U, The under end of the os sacrum.  V, The os coc- 
       Explanation of  the Plates of  Osteology.   433

cygis.   W, The os ilium.  X, The anterior spinous processes
Y, The posterior spinous processes.  Z, Ischiatic notch, a, The
right os ilium,  b, The ossa pubis,   c, The tuberosity of the
left os  ischium,  d, The Scapula,   e, Its spine,  f, The os hu-
meri,   g, The radius,  h, The ulna,  i, The carpus,  k, The me-
tacarpal bone of the thumb.  1, The  metacarpal bones of the
fingers, m, The two bones  of  the thumb, n, The three bones
of each of the fingers,  o, The os femoris.  p, Its head,  q, The
trochanter major,   r, The external condyle.   s,Therotula.  t,
The tibia.  u,T he fibula,  v, The malleolus externus.   w, The
astragalus,   x, The os calcis.   y, The os naviculare.  z, The
three ossa cuneiforma.  1,  The os  cuboides.  2, The five me-
tatarsal bones.   3,  The two bones of the great toe.  4, The
three bones of each  of the small toes
Fig. 2. A view of  the Internal Surface of the Base of the
                          Skull.
  AAA, The two  tables of the skull  with the diploe.   BB,
The orbitar plates  of  the frontal bone.  C. The crista  galli,
with cribriform plate of the ethmoidal bones on each side  of
it, through  which the first pair of nerves pass.  D, The cunei-
form process of the occipital bone.   E, The cruciform ridge.
F, The foramen magnum for  the passage of the spinal  mar-
row.   G,  The zygoma, made  by the joining of the zygomatic
processes of the os temporum and os malas.  H, The pars squa-
mosa of the os temporis.  I, The pars inammillaris.   K, The
pars petrosa.  L, The temporal process of the  sphenoid  bone.
MM, The anterior clinoid  processes.   N, The posterior cli-
noid process.  O, The sella turcica.   P, The foramen opticum
for  the passage of  the optic nerve and ocular artery of the
left side.   Q,  the  foramen lacerum, for  the  third, fourth
sixth, and first of the fifth pair of nerves and ocular vein.  R,
The foramen rotundum,  for the second of the fifth pair.   S,
The foramen ovale,  for the third of  the fifth pair.   T, The
foramen spinale, for the principal artery of the dura mater.
U, The entry of the auditory  nerve.   V, The passage for the
lateral  sinus.  W,  The passage of the eighth pair of nerves.
X, The passage of the ninth pair.
Fig. 3. A View of  the External Surface of the Base of the
                          Skull.
  A, The two dentes incisores of the right side.   B,  The dens
caninus.  C, The two  small molares.  D, The three large mo-
lares.   E, The foramen incisivum, which gives passage to small
blood vessels and nerves.  F, The palate  plates  of the  ossa
maxillaria and  palati,  joined  by the longitudinal and trans-
verse palate sutures.   G, The foramen palatinum posterius, for
   XWh. ii.                   55 
434   Explanation of the Plates of Osteology.

the palatine vessels and nerves,  H, The os maxillare superius
of the right side.   I, The os malae.   K, The zygomatic process
of the temporal bone.  L, The posterior extremity of the ossa
spongiosa.   M, The posterior extremity of the  vomer which
forms the back part of the septum nasi.   N, The pterygoid pro-
cess of the right side of the sphenoid bone.   00, The foramina
ovalia.   PP, The foramina spinalia.  QQ,  The passages of the
internal carotid arteries.  R, A hole between the point of each
pars petrosa and cuneiform process, of the occipital bone, which
is filled up with a ligamentous substance in the recent subject.
S, The passage of the left lateral sinus.   T, The posterior con-
dyloid foramen ofthe left side.  U, The foramen mastoideum,
V, The foramen magnum.   W, The inferior orbitar fissure. X,
The glenoid cavity, for the  articulation of the lower jaw.  Y,
The squamous part of  the temporal bone.   Z,  The mastoid
 rocess, at the inner side of  which is a  fossa for the posterior
 elly ofthe digastric muscle,   a, The styloid process,  b. The
meatus auditorius  externus.  c. The left condyle of the occi-
pital bone.  Hi, The perpendicular occipital  spine,   ee.  The
inferior horizontal  ridge of the occipital bone,   ff, The supe-
rior  horizontal ridge which is opposite to the crucial  ridge
where the longitudinal  sinus divides to form the lateral sinu-
ses,  ggg,  The lambdoid suture,  h,  The left squamous su-
ture,  i, The parietal bone.
       Fig. 4, The anterior surface of the Ossa Nasi.
  A, The upper part which joins the os frontis.  B, The under
end, which joins  the cartilage of the nose.  C, The  inner
edge, where they join each other.
      Fig. 5. The posterior surface of the Ossa Nasi.
  AA, Their cavity, which  forms part of the arch of the nose.
BB, Their ridge or spine,  which projects a little to be fixed
to the fore part of the septum narium.
Fig. 6. The external surface of the Os Maxillare  Superius
                      ofthe left side.
  A, The nasal process.   B, The orbitar  plate.  C, The un-
equal surface which joins the os malae.  D, The external orbitar
hole.  E, The opening into the nostril.   F, The palate-plate.
G,  The  maxillary tuberosity.  H, Part of the os palati.   I,
The two dentes incisores.   K, The dens caninus.  L, The two
small dentes molares.   M, The three large dentes molares.
Fig. 7. The internal surface of the Os  Maxillare  Superius
                     and  Os Palati.
  A, The nasal process.  BB, Eminences for the connexion
of the os spongiosum interius.  D, The under end  of the la-
chrymal groove. E, The antrum maxillare.  F, The na«al spine
 
       Explanation of the Plates of Osteology.   435

between  which and B is  the cavity of the  nostril.  G, The
palate-plate.   H, The orbitar  part of the os palati.  I, The
nasal plate.  K, The suture which unites the maxillary and
palate bones.  The pterygoid process of the palate bone.
     Fig. 8. The external surface ofthe right Os Unguis.
  A, The  orbitar part.   B, The lachrymal part.  C, The
ridge between them.
     Fig. 9. The internal, surface of the right Os Unguis.
  This side of the bone" has a  furrow opposite to  the external
ridge; all behind this  is irregular, where it covers part of  the
ethmoidal cells
     Fig. 10, The external surface ofthe  left Os  Malx.
  A, The  superior orbitar process.   B The inferior orbitar
process.  C, The malar process.  D, The zygomatic process.
E,   The orbitar plate. F, A passage for small vessels into or
out of the orbit,
     Fig. 11.  The internal surface ofthe left Os MaljE.
  A, The  superior orbitar process.  B. The  inferior orbitar
process.   C, The malar process.  D, The zygomatic process.
E, The internal orbitar plate or  process.
  Fig. 12. The external surface ofthe right Os Spongiosum;
                        Inferius.
  A, The anterior part.   B, The hook-like process for cover-
ing part of the antrum maxillare.  C, A  small process which
covers part of the under end of the lachrymal groove.  D, The
inferior edge turned a little outwards.
Fig. 13. The internal surface of the Os Spongiosum Inferius.
  A, The anterior extremity.   B, The upper edge which joins
the superior maxillary and palate bones.
Fig. 14. The posterior and external surface of the right  Os
                          Palati.
  A, the orbiter  proces.   B, The  nasal  lamella.  C. The
pterygoid process.  D, The palate process.
  Fig 15.  The  interior and external surface of the right  Os
                          Palati.
  A, The  orbitar process.  B, An opening through which the
lateral nasal vessels and  nerves pass.  C, The nasal lamella.
D,  The pterygoid process.  E,  The posterior, edge of the pa-
late process for the connexion  of the velum palati.  F,  Ihe
inner edge by which  the two ossa palati are connected.
            Fig. 16.  The right side of the Vomer.
   A. The upper  edge which join* the nasal  lamella of  the 
436  Explanation of the Plates of  Osteology.

ethmoid bone and the middle cartilage of the nose.  B, The
inferior edge, which is connected to the superior maxillary and
palate bones. C,The superior and posterior part which receives
the processes azygos of the sphenoid bone.
             Fig. 17. The Maxilla Inferior.
  A, The chin.  B, The base and left side.  C,  The  angle.
D, The coronoid process.  E, The condyloid process.  F, The
beginning of the inferior maxillary canal of the right  side,  for
the entry of the nerves and blood vessels.   G, The termination
of the left canal.   H, The two dentes incisores.  I, The dens
caninus.  K, The two  small molares.  L, The  three large
molares.
        Fig.  18.  The different classes of the Teeth.
   1, 2, A fore and back view of the two anterior  dentes inci-
sores of the lower jaw.  3, 4, Similar teeth of the upper jaw.
5, 6, A fore and back view of the dentes canini.  7,  8, The
anterior dentes morales.  9, 10,  11, The posterior dentes mo-
lares.   12, 13,  14, 15, 16, Unusual appearances in  the shape
and size of the teeth.
      Fig.  19.  The external surface of the Os Hyoides.
    A, The body.   BB, The  cornua.  CC, The appendices.
                        Plate V.
Fig. 1. A Posterior  View  of the  Sternum and  Clavicles,
   with the ligament  connecting the clavicles to each other.
   a, The posterior surface  of the sternum,  bb,  The  broken
end of the clavicle,  cccc, The  tubercles  near the extremity
of each clavicle,   d, The ligament connecting the clavicles.
Fig. 2. A Fore-view of the Left Scapula, and a half of the
               Clavicle, with their Ligaments.
   a, The spine of the scapula,  b, The acromion,  c, The infe-
rior angle,  d, Inferior costa.   e, Cervix,   f, Glenoid  cavity,
covered with cartilage for the arm-bone, gg, The capsular liga-
ment of the joint, h, Coracoid process,  i, The broken end of
the clavicle,   k,  Its extremity joined to the acrimon.  1, A
ligament coming out single from the acromion to the coracoid
process,  m, A ligament coming out single from the acromion,
and dividing into two, which are  fixed to the coracoid process!
 Fig. 3. The Joint of the elbow of the Left Arm, with the Li-
                         gaments.
   a, The os humeri,   b, Its internal condyle,  cc, The  two
 prominent parts of its trochlea appearing through the capsular
 ligament,  d, The ulna,  e, The radius,  f, The part of the
 ligament including the head of the radius. 
      Explanation of the Plates of Osteology.   43'

Fie. 4.  The Bones of the Right Hand, with the Palm in view.
  a, The radius,   b, The ulna,  c, The scaphoid bone of the
carpus,   d, The os lunare.   e. The os cuneiforme.   f, The os
pisiforme.  g, Trapezium,   h, Trapezioides.   i, Magnum, k,
Unciforme.   1, The four metacarpal bones of the fingers,  m,
The first phalanx,   n, The second phalanx,   o, The third pha-
lanx,  p, The metacarpal bone  of  the thumb,   q, The first
joint,  r, The second joint.
  Fig. 5. The posterior View ofthe bones ofthe Left Hand.
  The explication of Fig. 4. serves for this figure ; the same
letters pointing out the same bones, though in a different view.
Fig. 6.  The  Upper Extremity of the Tibia, with the Semilunar
  Cartilages  of the Joint of the Knee, and some Ligaments.
  a, The strong ligament which connects the rotula to the tu-
bercle of the tibia,  bb, The parts of the extremity of the ti-
bia, covered  with  cartilage, which appear within the semilunar
cartilages,   cc, The semilunar cartilages,   d, The two parts of
what is called the  cross ligament.
  Fig. 7. The Posterior view of the Joint of the Right Knee.
  a, The os  femoris cut.  b,  Its internal condyle,  c, Its ex-
ternal condyle, d, The back part of the tibia, e, The superior
extremity of the fibula,   f, The edge of the internal semilunar
cartilage,  g, An  oblique ligament,  h, A large perpendicular
ligament,  i, A ligament connecting the femur and fibula.
  Fig. 8. The anterior view of the Joint of the Right Knee.
   b, The internal condyle,  c,  Its external condyle,   d, The
 part of the  os femoris,  which the patella moves,  e, A per-
 pendicular ligament,  ft', The two  parts  of the crucial  liga-
 ments,  gg,  The edges of the two moveable semilunar carti-
 lages,  h,  The tibia,  i, The strong ligament  of  the patella.
 k,  The back part  of it where the fat has been dissected away.
 1, The external depression,  m, The internal one.  n, The cut
 tibia.
  F. 9. A View of the inferior part of the Bones of the Right
                            Foot.
    a, The great knob of the os calcis.  b,  A prominence on its
 outside,   c, The  hollow for the tendons, nerves and blood ves-
 sels, d, The anterior extremity of the os calcis.  e, Part of the
 astragalus, f, Its  head covered with cartilage,  g, The internal
 prominence  of the os naviculare.  h, The os cuboides.   i, The
 os  cuneiform internum ;  k,—Medium ;  1,—Externum,   m,
 The metatarsal bones of the four lesser toes,  n, The first—*,
 The second—p. The third phalanx of the four le««or toes;  q. 
 438   Explanation of the Plates of Osteology.

 The metatarsal bones of the great toe.  r, Its first—s, Its se-
 cond  joint.
   Fig. 10.  The Inferior Surface of the  two large  Sesamoid
          Bones, at the first Joint of the  Great  Toe.
 Fig.  11.  The Superior View of the Bones of the Right  Foot.
   a, b, as in Fig. 9.  c, The superior head of the astragalus.
 d, &c. as in Fig. 9.
 Fig. 12. The view ofthe Sole ofthe Foot, with its ligaments.
   a, The great knob of the os calcis.   b, The hollow for the
 tendons, nerves, and blood vessels,  c, The sheaths of the flex-
 ores pollicis and digitorum longi opened,   d, The strong carti-
 laginous ligament supporting the head of the astragalus,   e, h,
 Two ligaments which unite into  one, and are fixed to  the  me-
 tatarsal bone of the great toe.   f, A ligament from the knob of
 the os calcis to  the  metatarsal  bone  of  the  little toe.   g, A
 strong triangular ligament, "which  supports  the bones of the
 tarsus,  i, The ligaments of the joints of the five metatarsal
 bones.
  Fig. 13. a, The head of the thigh bone of a child,  b, The
 ligamentum rotundum connecting it  to  the acetabulum,   c,
 The capsular ligament of the joint with its  arteries injected.
 d, The numerous vessels of the mucilaginous gland injected.
 Fig. 14. The Back-view of the Cartilages of the Larynx, with
                     the Os Hyoides.
  a, The posterior part of the base of the os hyoides.  bb, Its
 cornua. c, The appendix of the right side,  d, A ligament
 sent out from the appendix of the left side, to the styloid pro-
 cess of the temporal bone,  e, The union  of  the base with the
left cornu.   ft", The  posterior sides of (g) the thyroid cartilage*
hh, Its superior cornua.   ii, Its  inferior cornua.  k, the cricoid
cartilage. 11, The arytenoid cartilages, m, The  entry into the
lungs, named glottis,  n, The epiglottis,  oo,  The superior car-
tilages of the trachea,  p, Its ligamentous back  part.
Fig. 15. The superior Concave surface of the Sesamoid Bones
  at he first joint of the Great  Toe, with their Ligaments.
  a, Three sesamoid bones, b,  The ligamentous substance in
which thev are formed. 
Explanation of the Plates of the Muscles.  4M*
           EXPLANATION OF PLATES VI. and VII.

                        Plate VI.

  Fig. 1. The Muscles immediately under the common tegu-
ments on the anterior part of the body are  represented on the
right side ; and on the left side the Muscles  are  seen  which
come in view when the exterior ones are taken away.
  A, The frontal muscle. B, The  tendinous aponeurosis which
joins it to  the occipital ; hence both  named occipitofrontalis.
C, Attollens aurem. D, The ear. E, Anterior auris. FF, Orbicu-
laris  palpebrarum.  G, Levator labii superioris alaeque nasi.
II, Levator anguli oris.  I, Zygomaticus minor.  K, Zygomati-
cs major.  L, Masseter.  M, Orbicularis oris.  N, Depressor
labii inferioris.  O, Depressor anguli oris. P, Buccinator.  QQ
Platysma myoides.   RR, Sterno-cleido-mastoideus.  , S. Part
of the trapezius. T, Part of the scaleni.
  Superior extremity.—U. Deltoides.  V, Pectoralis major.
W,  Part of the latissimus dorsi.   XX, Biceps flexor  cubiti.
YY, Part of the triceps  extensor.   ZZ, The  beginning of the
tendinous aponeurosis, (from the biceps,)  which is spread over
the muscles of  the fore-arm.   aa, Its strong  tendon inserted
into the tubercle of the radius, bb, Part of the brachialis inter-
nus.  c,  Pronator radii teres,  d, Flexor carpi  radialis.  e, Part
of the flexor carpi  ulnaris.  f, Palmaris longus. g,  Aponeurosis
palmaris. 3,  Palmaris brevis. 1, Ligamentuin carpi annulare.
22,  Abductor minimi digiti. h, Supinator radii longus.  i, The
tendons of the thumb,   k, Abductor pollicis.   1, Flexor pollicis
longus.   mm, The tendons of the flexor sublimis perforatus,
profundus perforans, and lumbricales.  The sheaths are  entire
in the right hand,—in the left cut  open  to show the tendons of
the flexor profundus perforating the sublimis.
  Muscles.—not referred to—in  the left  superior extremity.
n, Pectoralis minor, seu serratus  anticus  minor,   o, The two
heads of (xx)  the biceps,  p, Coraco-brachialis. qq, The long
head of the triceps extensor cubiti. rr, Teres major, ss, Sub-
scapularis. tt, Extensores radialis. u, Supinator brevis.  v, The
cut extremity of the pronator teres,  w, Flexor sublimis per-
foratus.   x, Part ofthe flexor  profundus, y, Flexor pollicis
longus. z, Part of the flexor pollicis brevis. 4, Abductor mini-
mi digiti. 5, The four lumbricales.
   Trunk.—S, Serrated extremities of the serratus anticu^ in'u 
440  Explanation of the Plates of the Muscles.

jor.   7 1, Obliquus externus abdominis.  8 8, The linea alba.
9, The  umbilicus.   10, Pyramidalis.  11 11, The spermatic
cord.  On the left side it is covered by the cremaster.   12 12,
Rectus  abdominis.   13, Obliquus internus.  14  14, &c.  In-
tercostal muscles.
   Inferior Extremities.—a a, The gracilis.  6 b, Parts of
the triceps, c c, Pectinalis. d d, Psoas magnus.  e e, Iliacus in-
ternus.   /, Part of the glutaeus medius. g, Part of the glutaeus
minimus,  h, Cut extremity of the rectus femoris.  ii,Vastus
externus.  k, Tendon of the rectus femoris.   II, Vastus inter-
ims.  *Sartorius muscle.  **Fleshy origin of the tensor vaginze
femoris or membranosus.  Its tendinous  aponeurosis  covers
(i) the vastus externus on the right side,   m in,  Patella,  nn,
Ligament  or tendon from it to the tibia,  o, Rectus femoris.
p, Cruraeus.  q q,  The tibia,  r r, Part of the  Gemellus, or gas-
trocnemius externus. s s s, Part of the soleus or gastrocnemius
internus*   t, Tibialis amicus,   u,  Tibialis posticus, v v, Pero-
naei muscles,  ww, Extensor longus digitorum pedis, jx x, Ex-
tensor longus pollicis pedis,  y, Abductor pollicis pedis.

Fig. 2.  The Muscles, Glands, &c. of the Left Side  of the
  face and neck, after the common Teguments and  Platysma
  myoides have been taken off".
  a, The frontal muscle,   b,  Temporalis and temporal arte-
ry,  c, Orbicularis palpebrarum,   d,  Levator labii superioris
alaeque  nasi,  e,  Lavator  anguli  oris,  f,  Zygomaticus.  g,
Depressor labii inferioris.   h, Depressor anguli oris,  i, Buc-
cinator,   k, Masseter.  11, Parotid gland,   m,  Its duct,   n,
Sterno-cleido-mastoideus.   o, Part of the trapezius,  p, Ster-
no-hyoideus.  q, Sterno-thyroideus.  r, Omo-hyoideus.  f, Le-
vator  scapulae,  tt, Scaleni.   u, Part  of the splenius.
Fig. 3. The Muscles of the Face and Neck in view after the
               exterior ones are taken away.
  aa,  Corrugator  supercilii.  b,  Temporalis,  c, Tendon of
the lavator palpebrae superioris.   d, Tendon of the  orbicula-
ris palpebrarum,  e, Masseter.  f,  Buccinator,  g,  Levator
anguli oris,  h, Depressor labii superioris alaeque nasi,   i, Or-
bicularis oris,  k, Depressor anguli oris.  1, Muscles of the os
hyoides.   m, Sterno-cleido-mastoideus.
Fig. 4.  Some of the Muscles of the Os Hyoides and Submax-
                      illary Gland.
  a,  Part of the masseter muscle,   b, Posterior head  of the
digastric, c, Its anterior head,  d d, Sterno-hyoideus.  e, Omo-
hyoideus.   f, Stylo-hyoide'us.   g-, Submaxillary gland in sftm 
      Explanation of the Plates of the Muscles.  441

       Fig. 5,  The Submaxillary Gland and Duct.
   a, Musculus mylo-hyoideus. b, Hyo-glossus. c, Submaxillary
gland removed from its place,   d, Its duct.
                       Plate VII.
   Fig. 1. The Muscles immediately under the  common tegu-
ments on the posterior part of the body, are represented on the
right side; and on the left  side the Muscles are seen which
come in view when the exterior ones are taken away.
   Head.—A A,  Occipito-frontalis.  B,  Attollens aurem.  C,
Part of the orbicularis palpebrarum.  D, Masseter.  E, Ptery-
goideus internus.
   TRUNK.—Right side.    FFF,  Trapezius seu  cucullaris.
GGGG,  Latissimus dorsi.  II, Part of the  obliquus externus
abdominis.
   Trunk.—Left side. I, Splenius.  K, Part of the complexus.
L, Levator scapulae.  M, Rhomboides.  NN, Serratus posticus
inferior.   O, Part of the  longissimus dorsi.  P, Part of the
sacro-lumbalis.   Q, Part of the semi-spinalis dorsi.   R, Part of
the serratus anticus major.  S, Part of the obliquus internus
abdominis.
   Superior Extremity.—Right side.  T, Deltoides. U, Tri-
ceps extensor cubiti.  V, Supinator longus.  WW, Extensores
carpi radialis longior and brevior.  XX, Extensor carpi ulnaris.
YY, Extensor digitorum communis.   Z, Abductor indicis.  1,
2, 3, Extensores pollicis.
   Superior Extremity.—Left side,   a, Supra Spinatus.  b,
Infraspinatus, c, Teres minor. Teres major, e, Triceps exten-
sor cubiti.  ff, Extensores carpi radialis. g, Supinator brevis. h,
Indicater.   12  3, Extensores pollicis. i, Abductor minimi
digiti.  k, Interossei.
   Inferior Extremity.—Right  side,  1,  Glutaeus  maximus.
m, Part of  the Glutaeus medius.  n, Tensor  vaginae femoris.  o,
Gracilis, pp, Adductor femoris magnus.  q, Part of  the vastus
internus.  r, Semimembranosus,  s, Semitendinosus.  t, Long
head of the biceps flexor cruris,  uu, Gastrocnemius externus
seu gemellus, v, Tendo Achillis.  w, Soleus seu gastrocnemius
internus. xx, Peronaeus longus and brevis.  y, Tendons of the
flexor longus digitorum pedis ; and  under them *flexor brevis
digitorum pedis, z, Abductor minimi digiti pedis.
   Inferior Extremity.—Left side,  m, n, o, pp, q, r, s, t, v,
ww, xx, y, z, Point the same parts as in the right side,  a, Py-
riformus.   bb, Gemini,  cc, Obturator internus.  d, Quadratus
femoris. e, Coccygaeus. f, The short head of the biceps flexor cru-
ris, gg, Plantaris.  h,Popliteus.  i, Flexor longus pollicis pedis.
   VOL.  IL                   56 
442  Explanation of the Plates of the Muscles.

Fig. 2. The  Palm of the Left Hand after the common Tegu-
   ments are removed, to show the Muscles of the Fingers.
  a, Tendon of the flexor carpi radialis. b, Tendon of the flex-
or carpi ulnaris.   c, Tendons of the flexor sublimis perforatus,
profundus perforans  and lumbricales.  d, Abductor  pollicis.
ee, Flexor pollicis longus.  f, Flexor pollicis brevis. g, Palma-
ris brevis.  h, Abductor minimi digiti.  i, Ligamentum carpi-
annulare. k,  A probe put under the tendons of  the flexor di-
gitorum sublimis ; which are performed by 1, the flexor digito-
rum profundus, mmmm, Lumbricales. n, Abductor pollicis.
Fig. 3. A fore-view of the  foot and tendons of the flexores
                        Digitorum.
  a, Cut extremity of the tendo Achillis.  b, Upper part of the
astragalus,  c, Os calcis.  d, Tendon of the tibialis anticus. e,
Tendon  of the  extensor pollicis longus.  f, Tendon  of the
peroneus brevis.  g, Tendons of the flexor digitorum longus,
with the nonus Vesalii.  hh, The whole of the flexor digitorum
brevis.
               Fig. 4.  Muscles of the Anus.
  aa, An outline of the buttocks, and upper  part of the thighs.
b, The testes  contained in  the scrotum,   cc,  Sphincter ani.
d, Anus,  e, Levator ani.   ff, Erector penis,  gg, Accelerator
urinae.   h, Corpus cavernosum urethrae.
               Fig. 3.  Muscles of the Penis.
  aa, b, d, ee, ff, h, point the same as in fig. 4. c, Sphincter ani.
gg, Transversalis penis.

         EXPLANATION of PLATES VIII. IX. and X

                       Plate VIII.

Fig. 1. Shows the Contents of the Thorax and  Abdomen  In
                           situ.

  1, Top of the trachea, or windpipe. 2 2, The internal jugu-
lar veins. 3 3, The subclavian veins. 4, The vena cava descen-
dens. 5, The right auricle of the heart. 6, The right ventricle.
7, Part of the left ventricle. 8, The aorta descendens. 9, The
pulmonary artery.  10, The right lung, part of which is cut off
to show  the great blood vessels.   11, The left lung entire.
12  12, The anterior edge of the diaphragm.  13 13, The two
great lobes of the liver.   14,  The ligamentum rotundum.   15,
The gall bladder.  16, The stomach.  17 17,   The jejunum
and ilium.  18, The spleen. 
Explanation of the Plates of the Muscles. 443
Fig. 2. Shows the organs subservient to the Chylopoietic Vis-
         cera,—with those of Urine and Generation.
   11,  The under side of the two great lobes of the liver,   a,
Lobulus spigelii.   2, The ligamentum rotundum.  3, The gall-
bladder.  4, The pancreas.  5, The spleen.  6 6, The kidneys.
7, The aorta descendens.  8, Vena cava ascendens.   9 9, The
renal veins covering the arteries.   10. A probe under the sper-
matic vessels and a bit of the inferior mesentric artery, and
over the ureters.  11 11, The ureters.  12  12, The iliac arteries
and veins.   13, The intestinum rectum.   14, The bladder of
urine.
Fig. 3.  Shows the Chylopoietic Viscera, and Organs subservient
            to them, taken out of the body entire.
  AA, The under side of the two great lobes of the liver.  B,
Ligamentum rotundum.   C, The  gall-bladder.  D, Ductus
cysticus.  E, Ductus hepaticus.   F, Ductus communis chole-
dochus.  G, Vena portarum.  H, Arteria hepatica.   I, The
stomach.  KK, Venae and arteriae gastro-epiploicae, dextrae and
sinistrae.  LL, Venae and arteriae  coronariae ventriculi.  M,
The spleen.   NN, Mesocolon, with its vessels.  000, Intesti-
num colon.  P, One  of the ligaments of the colon, which is a
bundle of longitudinal muscular fibres.  QQQQ, Jejunum and
ilium.   RR, Sigmoid flexure of the colon  with  the  ligament
continued, and over.  S,  The intestinum rectum.  TT,  Leva-
tores ani.   U, Sphincter ani.  V, The  place to which the pros-
tate gland is connected.   W, The anus.
Fig. 4. Shows the Heart of  a Foetus at the full time with the
  Right Auricle cut open to show the Foramen Ovale, or passage
  between both Auricles.
  a, The right ventricle,   b, The left ventricle,  cc, The out-
er side  of the right auricle stretched out.   dd, The  posterior
side, which forms the anterior side of the septum,   e, The fora-
men ovale, with the membrane or  valve which covers the left
side,  f, Vena cava inferior  passing through,  g, A portion  of
the diaphragm.
Fig. 5. Shows the Heart and Large Vessels of a Foetus at the
                         full time.
  a The left ventricle,   b,  The right ventricle,   c, A part of
the 'right auricle,  d, Left auricle,  ee, The right branch of the
pulmonary artery,   f, Arteria pulmonalis.  gg, The left branch
ofthe pulmonary artery, with a number of its largest branches
dissected from the lungs,   h, The canalis arteriosus,   i, The
arrh of the aorta,  kk. The aorta desrendens. J.;  The left suD: 
U4  Explanation of ttic Plates of the Musette

clavian artery,  m, The left carotid artery,  n. The right caro-
tid artery, o, The right subclavian artery, p, The origin of tbe
right carotid and right subclavian arteries in one common trunk.
q, The vena cava superior or descendens. r, The right common
subclavian vein,   s, The left common subclavian vein.
  N.  B. All the parts described in this figure are to be found
in the adult, except the canalis arteriosus.
                        Plate IX.
Fig. 1.  Fxhibits the more superficial Lymphatic Vessels of the
                    Lower Extremity.
  A,  The spine of the  os  ilium.  B. The  os pubis,  c,  The
iliac artery.  D, The knee.   E, E,  F, Branches of the crural
artery.  G, The musculus gastrocnemius.  H, The  tibia. I, The
tendon of the musculus tibialis anticus.  On  the outlines, a,
A lymphatic vessel belonging to the top of the foot,   b, Its first
division into branches,  c, c, c, Other divisions  of  the  same
lymphatic vessel,  d, A small lymphatic gland,   e, The lym-
phatic vessels which lie  between the skin and the muscles of
the thigh,  ff, Two lymphatic glands at the upper part of the
thigh below the groin,  gg, Other glands,  h, A lymphatic ves-
sel which passes by the side  of those glands without communi-
cating with  them, and bending towards the inside of the  groin
at (i,) opens into  the  lymphatic gland  (k.)  11, Lymphatic-
glands m the groin, which are common to the lymphatic vessels
of the genitals and  those of  the lower extremity,   m, n, A
plexus of lymphatic vessels  passing on the inside of the iliac
artery.
Fig. 2.  Exhibits a Back-view of the Lower Extremity dissected
   so as to show the deeper-seated Lymphatic Vessels which ac-
   company the Arteries.
   A, The os pubis.  B, The tuberosity of the ischium.  C,  That
part ofthe os ilium which was articulated with the os sacrum.
I), The extremity of the iliac artery appearing above the groin.
E, The knee.  FF, The two cut surfaces of the triceps muscle,
which was  divided to show the  lymphatic vessels  that pass
through its perforation along with the  crural artery.   G, The
edge of the musculus gracilis.  II, The  gastrocnemius and so-
leus much shrunk by being dried, and by the soleus being se-
parated from the tibia to expose the vessels.   I, The  heel.  K,
 The  sole of the foot.   L, The superficial lymphatic vessels
passing over  the knee, to get to the thigh.  On  the outlines;
M, The posterior tibial artery,  a, A lymphatic vessel accom-
 panying the posterior tibial artery,  b, The same  vessel cross-
ing the artery,  c, A small lymphatic gland, through which this 
     Explanation of the Plates of the Muscles.  445

deep-seated lymphatic vessel passes, d, The lymphatic vessel
passing under a small part of the soleus, which"is left attached
to the bone, the rest being removed,  e, The lymphatic vessel
crossing the popliteal artery,   f, g, h, Lymphatic glands in the
ham, through which the  lymphatic vessel  passes,  i, The  lym-
phatic vessel  passing with the crural artery, through the perfo-
ration of the triceps muscle,   k, The lymphatic vessel, after it
has passed the perforation of the triceps, dividing into branches
which embrace the artery (1.)  m, A lymphatic gland belonging
to the deep-seated lymphatic vessel. At this place those vessels
pass to the  fore part of the groin where they  communicate with
the superficial lymphatic vessel,   n, A part  of the  superficial
lymphatic vessel appearing on the brim ofthe pelvis.
Fig. 3. Exhibits the Trunk of the  Human Subject prepared to
   show the Lymphatic Vessels and the Ductus Thoracicus.
  A, The neck.  BB, The  two jugular veins.  C, The  vena
cava superior.  DDDD, The subclavian veins.  E, The begin-
ning of the aorta, pulled to  the left side by means of a ligature,
in order to show the thoracic duct behind it.   F, The branches
arising from the curvature ofthe aorta.  GG,  The two carotid
arteries.  HH, The first  ribs.  II, The trachea.  KK, The spine.
LL, The vena azygos.   MM, The descending aorta.  N, The
cceliac artery, dividing  into three branches.   0, The  superior
mesenteric artery.  P, The right crus diaphragmatis.  QQ, The
two kidneys.  R, The right emulgent artery.   SS, The  external
iliac arteries,  g, d, The psoas muscles.  T, The internal iliac
artery.   U, The cavity  ofthe pelvis.  XX, The spine of the os
ilium.   YY, The groins,  a, A lymphatic gland in  the groin,
into which  lymphatic vessels from the lower extremity are seen
to enter,  bb, The lymphatic  vessels of the  lower  extremities
passing under Poupart's ligament,  cc, A plexus of the lympha-
tic vessels lying on each side ofthe pelvis,  d, The psoas muscle
with lymphatic vessels  lying upon  its inside,  e, A plexus of
lymphatics, which having passed over the brim of the pelvis at
(c,) having entered the  cavity of the pelvis, and received the
lymphatic vessels belonging to the viscera contained in that ca-
vity, next ascends and passes behind the illiac artery to (g.)  f,
Some lymphatic vessels of  the left side passing over the upper
part of the os sacrum, to meet those of the right side,  g, The
right psoas, with a large plexus of lymphatics lying on its inside.
hh, The plexus lying on each  side of the spine,  iii, Spaces
occupied by the lymphatic glands,  k, The trunk of the lacteals
lyin"- on the under side of the superior mesenteric artery. I, The
same dividing into two  branches, one of which passes  on  each 
 *46  Explanation of the Plates of  (he Muscles.

 side ofthe aorta: that of the right side being seen to enter the
 thoracic duct at (m.)  m, The  thoracic duct beginning  from
 the large lymphatics,  n, The duct passing  under the lower part
 of the crus diaphragmatis, and under the right emulgent artery.
 o, The  thoracic duct penetrating the thorax, p, Some lympha-
 tic vessels joining that duct in the thorax,  q, The thoracic duct
 passing under the curvature  of the aorta to get to  the left sub-
 clavian vein—the aorta being drawn aside  to show the duct. /,
 A plexus of lymphatic vessels passing upon the trachea from the
 thyroid gland to the thoracic duct.

                         Plate X.

 Fig.  1. Represents the under and posterior side of the Bladder
                      of Urine, &c.
  a, The bladder,   bb, The insertion of the ureters.'  cc, The
 vasa  deferentia, which convey the semen  from the testicles to
 dd, the vesciculse seminales,—and  pass through e, the prostate
 gland, to  discharge themselves  into f, the beginning of the
 urethra.
         Fig. 2. A transverse Section of  the Penis.
  gg, Corpora cavernosa penis, h, Corpus cavernosum urethrae.
 i, Urethra,   k,  Septum  penis.  11,  The septum  between the
 corpus cavernosum urethrae and that of the penis.
        Fig. 3.  A Longitudinal Section of the Penis.
  mm, The corpora cavernosa penis, divided by o, the septum
penis,   n, The corpus cavernosum glandis, which is the contin-
uation of that of the urethra.
    Fig. 4.  Represents the Female Organs of Generation.
  a,  That side of the uterus, which is next to the os sacrum.
 1, Its fundus,   2, Its cervix,  bb, The fallopian or uterine
tubes, which open into the cavity of the uterus;—but the other
fend is open within  the pelvis, and surrounded by  cc, the fim-
briae,   dd, The ovaria.  e, The  os internum uteri, or mouth
of the womb,   f f,  The  ligamentum rotundum,  which passes
without the belly, and is fixed to the labia  pudendi.   gg, The
 cut edges of the ligamenta lata, which  connect the uterus to
the pelvis,  h, The inside of the vagina,   i, The orifice of the
urethra. k,The  klitoris surrounded  by (!,) The praeptium.  mm,
The labia pudendi.  nn, The nymphae.
Fig.  5.  Shows the  Spermatic Ducts of the Testicle filled with
                        Mercury.
  A,  The vas deferens.  B. Iff? beginning, which  fornrs tire 
Explanation of  the Plates of the Muscles.  44?
posterior part of the epididymis.  C,  The  middle of the epi-
didymis, composed of serpentine ducts.  D, The  head  or an-
terior part of the epididymis unravelled,  e e e e, The  whole
i?!Jc£.whlch comPose the head  of the  epididymis unravelled
11, rhe vasa deferentia.  g g, Rete testis, h h, Some rectilinear
ducts which send off the vasa deferentia. i i, The substance of
the testicle.
Fig. 6. The Right Testicle  entire,  and the Epididymis  filled
                       with Mercury.
   A, The beginning of the vas  deferens.  B, The vas deferens
aseendmg towards the  abdomen.  C, The posterior part of the
epididymis,  named globus  minor.  D, The spermatic vessels
enclosed in cellular substance.  E, The body of the epididymis.
F, Its head, named globus major.   G,  Its beginning from the
testicle.   H, The body of  the testicle, enclosed  in the tunica
albuginea.

               EXPLANATION of  PLATE XI.
   This plate represents the Heart in situ, all the large Arteries
and Veins, with some of the Muscles, &c.
   Muscles,  &c.—Superior  Extremity__a, Masseter.  b,
Complexus.  c, Digastricus.  d, Os hyoides.  e,  Thyroid gland.
f, Levator scapulae,  g, Cucullaris.  h h, The clavicles, cut.  i,
The deltoid muscle, k,  Biceps flexor  cubiti, cut.  1, Coraco-
brachialis.  m, Triceps extensor cubiti.  n, The heads  of the
pronator teres,  flexor carpi radiales, and flexor digitorum sub-
limis, cut.  o, The flexor carpi-ulnaris, cut at its extremity.
p, Flexor digitorum profundus,  q, Supinator radii longus,
cut at  its extremity,  r,  Ligamentum  carpi transversale.   s.
Extensores carpi radiales.  t,  Latissimus dorsi.   u, Anterior
edge  of  the serratus anticus major, vv, The inferior  part of
the diaphragm,   ww, Its anterior edge cut.  xx, The kidneys.
y, Transversus  abdominus.  z,  Os ilium.
  Inferior Extremity.—a, Psoas magnus.  b,  Iliacus inter-
nus.  c,  The fleshy origin of the tensor vagina femoris.  dd,
The ossa pubis cut  from each  other,   e, Musculus pectineus
cut from its origin.  /,  Short head of the triceps  abductor  fe-
moris cut. g, The great head of the triceps.  /*, The long head
cut.   i,  Vastus internus.   k, Vastus  externus.   /, Crureus.
m, Gemellus,   n, Soleus.  0, Tibia, p, Peroneus longus.  q,
Peroneus brevis.   r, Fibala.
   Heart and  Blood-vessels.—A, The heart, with the coro-
nary artery and veins.  B, The right auricle of the heart.   C,
The aorta ascendensL  D, The  left subclavian artery.  E, The 
448 Explanation of the Plates of the Muscles.

left carotid artery.  F, The common trunk which sends oft' the
right subclavian and right carotid arteries.  G, The carotis ex-
terna.   H, Arteria facialis,  which sends off the coronary arte-
ries ofthe lips.  I, Arteria temporalis profunda.  K, Aorta de-
scendens.  LL, The illiac arteries, which  sends off MM, The
femoral or crural arteries.    N. B.  The other arteries in this
figure  have  the same  distribution  as the veins of the same
name :—And generally, in  the anatomical plates, the descrip-
tion to be found on the one  side, points  out the  same parts in
the other.  1, The frontal vein.  2, The facial vein.  3, Vena
temporalis profunda.  4, Vena occipitalis.  5, Vena  jugularis
externa.   6, Vena jugularis interna, covering  the arteria caro-
tis communis.   7,  The vascular arch on the palm of the hand,
which is formed by,  8, The radial artery and vein, and  9,
The ulnar artery and vein.  10 10, Cephalic, vein.  11, Basilic
vein, that on the right  side  cut.  12, Median vein.  13, The
humeral  vein, which, with  the median,  covers the humeral
artery.   14 14, The external thoracic or mammary arteries and
veins.   15, The axillary vein, covering the artery.  1616, The
subclavian veins, which with (6 6) the jugulars, form, 17, The
vena cava superior.  18, The cutaneous arch of  veins on the
fore part ofthe foot. 19, The vena tibialis  antica, covering the
artery.  20, The vena  profunda femoris, covering the artery.
21, The upper part of the vena saphena major.  22, The femo-
ral vein. 23 23, The illiac veins.   24 24,  Vena  cava inferior.
25 25, The renal veins covering the  arteries.   26 26, The dia-
phragmatic veins.
              EXPLANATION of PLATE XII.

Fig. 1. Represents the Inferior part of the Brain;—the Anterior
  part of the whole Spine, including the Medulla Spinalis;—
  with the origin and large portions of all the Nerves.
  AA, The anterior lobes  of  the  cerebrum.   BB, The lateral
lobes of the cerebrum.  CC,  The two lobes of the cerebellum.
D, Tuber annulare.   E, The passage from the third ventricle
to the infundibulum.   F, The medulla oblongata, which  sends
off the medulla spinalis through the spine.   GG, That part of
the os occipitis which is placed above (HH) the transverse pro-
cesses of the first cervical  vertebra.  II, &c.  The seven cervi-
cal  vertebrae,  with their  intermediate cartilages.   KK, &c.
The twelve dorsal vertebrae, with their intermediate cartila-
ges.   LL, &c. The five lumbar vertebrae,  with their interme-
diate cartilages.   M, The os sacrum.  N, The os coccygis. 
     Explanation of the Plates of the Muscles.  449

  Nerves.—1 1, The  first pair of nerves, named olfactory,
which go to the nose.  2 2, The second pair named optic,which
goes to form the tunica retina of the eye.  3 3,  The third pair,
named motor  oculi;  it supplies most  of the  muscles  ot the
eye-ball.   4 4,  The fourth pair,  named pathetic,—which  is
wholly spent upon the musculus trochlearis  of  the eye.   5  5,
The fifth pair divides into three branches.   The first, named
ophthalmic, goes to the orbit, supplies the lachrymal gland, and
sends branches out to the forehead and nose.  The  second,
named superior maxillary,  supplies the teeth of the upper
jaw, and some of the muscles  of the lips.  The third, named
inferior maxillary, is spent upon the muscles and teeth of the
lower jaw, tongue, and  muscles of the lips.   6 6,  The sixth
pair, which after sending off the beginning  of  the intercostal
or great sympathetic, is spent upon the abductor oculi.   7 7,
The seventh pair, named auditory, divides into two branches.
The largest, named portio mollis, is spent upon the internal
ear.  The smallest, portio dura, joins to the fifth pair within
the internal ear by a reflected branch from the second  of the
fifth, and within  the  tympanum,  by a branch from the third
of the fifth, named chorda tympani.  Vid.  fig. 3. near B 8 8,
&c.  The eighth pair, named par vagum,—which accompanies
the intercostal, and is spent upon the tongue, larynx, pharynx,
lungs, and abdominal viscera.  9 9, The ninth  pair, which are
spent upon the tongue.   10  10, &c. The intercostal, or great
sympathetic, which is seen from the sixth pair to the bottom
of the pelvis on each side  of the spine, and joining with  all
the nerves of the spine;—In its progress supplying the heart,
and, with the  par vagum, the contents of the abdomen and
pelvis. 11  11, The accessorius, which is spent  upon the sterno-
cleido-mastoideus and trapezius muscles.   12  12, The first
cervical nerves ;—13 13,  The second  cervical nerves j—both
spent upon the  muscles  that  lie  on the neck, and teguments
of the neck and head.   14 14, The third cervical nerves, which
after sending off, (15 15, &c.)  the  phrenic nerves to the dia-
phragm,  supply the  muscles and  teguments  that lie on  the
side of the neck and top of the shoulder.  16 16, The brachial
plexus, formed  by the fourth, fifth, sixth,  seventh cervicals,
and first dorsal nerves; which supply  the muscles and tegu-
ments of the superior extremity.  17 17, The twelve dorsal,
or proper intercostal nerves, which are  spent  upon the  inter-
costal muscles and some of the large muscles  which lie upon
the thorax.  18 18,  The five  lumbar pairs of nerves, which
supply the lumbar and abdominal  muscles, and some  of tlje
teguments and muscles of the inferior extremity.  19 1.9, The
    VOL. it.                   57 
450 Explanation of the Plates of the Muscles.

sacro-sciatic or posterior crural  nerve, formed by the two in-
ferior lumbar, and three superior of the os sacrum.  This large
nerve supplies the greatest part of the muscles and teguments
of the inferior extremity.   20, The  stomachic plexus, formed
by the eighth pair.  21* 21. Branches  of the  solar or cceliac
plexus, formed by the  eighth pair and intercostals, which sup-
ply the stomach and chylopoietic viscera.  22 22, Branches of
the superior and  inferior mesenteric plexuses, formed by the
eighth pair and intercostals, which supply the chylopoietic vis-
cera, with part of the organs of urine and generation.  23 23,
Nerves which accompany the spermatic cord.  24 24, The hy-
pogastric plexus, which supplies the organs of urine and gene-
ration within the pelvis.
Fig. 2, 3, 4, 5, Show different Views of the Inferior part of the
  Brain, cut perpendicularly through the Middle,—with the
  Origin and large Portions of all the Nerves which pass out
  through the Bones  of the  Cranium,—and the  three  first
  Cervicals.
  A, The anterior lobe. B, The lateral lobe of the cerebrum.
C, One of the  lobes of the cerebellum.   D, Tuber  annulare.
E, Corpus pyramidale, in the middle of the medulla oblongata.
F, The corpus olivare, in the  side of the medulla oblongata.
G, The medulla oblongata.  H, The medulla spinalis.
  Nerves.—1 2 3 4 5 6 7 8 and 9, Pairs of Nerves.  10 10,
Nerves accessorius, which comes from—11, 12, and 13, The
three first cervical nerves.
             EXPLANATION of PLATE XIII.
Fig. 1.  Shows the Lachrymal Canals, after the Common Te-
          guments and Bones have been cutaway.
  a, The lachmyral  gland,  b, The  two puncta lachrymalia,
from which the two  lachrymal canals proceed to c, The lach-
rymal sac.  d, The large lachmyral duct.   e. Its opening into
the nose,  f, The carunca lachrymalis.   g, The eye-ball.
Fig. 2.  An interior View of the Coats  and Humours of the
                          Eye.
  a a a  a, The tunica sclerotica cut in four angles, and turned
back,  b b b b, The tunica choroides adhering to the inside of
the sclerotica and the ciliary vessels are seen passing over—
c c, The retina which covers the vitreous humour,   d d, The
ciliary processes, which were continued from the choroid coat.
e e, The iris,   f, The pupil. 
       Explanation of the Plates of the Muscles.  451

    Fig. 3. Shows the Optic Nerves, and Muscles of the Eye.
    a a, The two optic nerves before  they meet,  b,  The two
  optic nerves conjoined,   c, The right optic nerve, d, Muscu-
  lus attollens palpebrae superioris.  e, Attollens oculi.  f, Ab-
  ductor,   gjr,  Obliquus superior, or trochlearis.   h, Abductor.
  i, The eye-ball.
          Fig. 4. Shows  the Eye-ball  with its Muscles.
    a, The optic nerve,  b, Musculus trochlearis.  c. Part of
  the os frontis, to which the trochlea  or pulley is fixed through
  which,—d, The tendons of the trochlearis  pass,  e,  Attollens
  oculi.  f, Adductor oculi.   g, Abductor oculi.   h, Obliquus in-
  ferior,   i, Part of the superior  maxillary bone to which it is
  fixed,  k, The eye-ball.
  Fig. 5. Represents  the Nerves and Muscles of the  Right
    Eye, after part of the Bones of the orbit have  been cut
    away.
    A, The eye-ball.   B, The lachrymal gland.   C, Musculus
  abductor occuli.  D, Attollens.   E,  Levator nalpebrae superi-
  oris.  F, Deprpisor oculi.  G, Abductor.  H, Obliquus superior,
  with its pulley.  I, Its insertion into the sclerotic coat.  K,
  Part of the obliquus inferior.  L, The anterior part  of the os
  frontis, cut.  M, The crista galli of the ethmoid bone.   N, The
- posterior part of the sphenoid bone.  O, Transverse spinous
  process of the sphenoid bone.  P, The carotid artery, denuded
  where  it passes through  the bones.  Q,  The carotid  artery
  within the cranium.   R, The ocular  artery.
    Nerves.—a a, The optic nerve,—b, The third pair,  c,  Its
  joining with a branch  of the first branch of the fifth pair, to
  form 1,—The lenticular ganglion, which  sends off the ciliary
  nerves, d.  e e, The fourth pain  f, The  trunk of the  fifth pair.
  g, The first branch of the fifth pair, named ophthalmic,  h, The
  frontal branch of it.  i, Its ciliary branches, along with which
  the nasal twig is sent to the nose, k, Its branch to the lachrymal
  gland.   1, The lenticular ganglion,   m, The second  branch of
  the fifth pair, named superior maxillary,  n, The third branch
  of the  fifth pair, named inferior maxillary,  o, The  sixth pair
  of nerves—which sends  off p, The beginning of the great sym-
  pathetic,  q, The remainder of  the sixth pair, spent  on c, The
  abductor oculi.
  Fig. 6. Represents the head of  a youth, where the upper part
    of the cranium is sawed off,—to show the upper part of the
    brain, covered by the pia mater, the vessels of which are mi-
    nutely filled with wax.
     \A, The cut edges of the upper. rart ot the cranium.  B, 
452  Explanation of  the Plates of the Muscles.

The two tables and intermediate diploe.   BB,  The two hemi-
spheres ofthe cerebrum.  CC, The incisure made by the falx.
V, Part of the tentorium cerebello super expansum.   E, Part of
the falx, which is fixed to  the crista galli.
  Fig. 7. Represents the parts of the External Ear, with the
                Parotid Gland  and its Duct.
  aa,  The helix,  b, The antihelix.  c, The antitragus.  d, The
tragus,   e, The lobe of the ear.   f, The cavitas innominata. g,
The scapha.  h,  The concha,   ii, The  parotid gland,  k, A
lymphatic gland, which is often  found  before the tragus.  1,
The duct ofthe parotid gland,   m, Its opening into the mouth.
Fig. 8.  A view of the  posterior part of the external ear, mea-
  tus auditorius,  tympanum with its small bones and Eustachian
  tube, of the right side.
  a, The back  part of the meatus, with the small  ceruminous
glands,  b, The incus, c, Malleus,   d, The chorda tympani. e,
Membrana tympani.  f, The Eustachian tube,  g, Its  mouth
from the fauces.
Fig. 9.  Represents the anterior part of the right external ear,
  the cavity of  the tympanum—its small  bones, cochlea, and
  semicircular canals.
  a, The malleus,  b, Incus, with  its long leg, resting upon the
stapes,  c,  Membrana tympani.  d,  e> The Eustachian tube
covered by part of—f f, The Musculus circumflexus palati. 1,
2, 3, The three semicircular canals. 4, The vestibule.  5, The
cochlea.  6, The portio mollis of the seventh pair of nerves.
Fig. 10. Shows the Muscles which compose the fleshy substance
                      of the Tongue.
  a a, The tip of the tongue, with some of the papillae minimae.
h, The root of the tongue,  c, Part of the membrane of the
tongue, which covered the epiglottis,  dd, Part of the,musculus
hyo-glossus.  e,  The lingualis.  f, Genio-glossus.  gg,Part of
the stylo-glossus. 
 
 
 
 
 
 
 
 
 
 
 
 
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