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SURGEON GENERAL'S OFFICE
    LIBRARY.

Section,________________________
      Mo. 112(110 
 
Vf"*' 
ELEMENTARY
ANATOMY AND PHYSIOLOGY,
FOR COLLEGES,  ACADEMIES,
AND OTHER  SCHOOL
BY
EDWARD HITCHCOCK,  D.D.,LL.D.,
          01 A MHERBT COLLEGE.
EDWARD HITCHCOCK, JR., M.D.
TEACHEK IN WILLISTOp SEMINARY.
             i
REVISED EDITION.
            P1B i o
NEW  YORK:
IVISON, PHINNEY & CO, 48 & 50 WALKER STREET.
   CHICAGO: S. C. GRIGGS & CO., 39 & 41 LAKE ST.
BOSTON: BROWN, TAGGARD <S> CHASE.  PHILADELPHIA: SOWER, BAr.NES & CO.,
 AND .1. B. LIPPINCOTT Sc CO. CINCINNATI; MOORE, WILSTACH, KEYS * CO.
   SAVANNAH : J. M. COOPER & CO. ST. LOITIS : KEITn .V WOODS. NEW
    ORLEANS: BLOOMFIELD, STEEL & CO. DETROIT : F. RAYMOND & CO.
1861. 
         Entered, according to Act of Congress, in the year ISSO, by
                    IVISON & PHINNEY,
In the Clerk's Office of the District Court for the Southern District of New York.
pULfry^
rio.  SZt-C,    *°'5
    ELECTROTYPED BT                                   PRINTED BY
Smith  &  MoDouoAi,                        J. D. Bedford & Co.,
    82 <fc 84 Beekinan-6t                                115 Franklin  St. 
PREFACE,
  THIS work is offered to the public in the hope that it has
some desirable features as a text-book, not found in any of the
able elementary works on Anatomy and  Physiology now ex-
tant.   One  is,  the introduction of more of microscopic anat-
omy than is usual.   Another is, a large addition on  Com-
parative  Anatomy, which  is  now become a science of great
importance.   A third is, the  Religious Applications of these
sciences ; which,  although  all will acknowledge to be  emi-
nently appropriate, we have found in no elementary treatise.
  We  make no pretensions to distinguished  attainments or
reputation in these sciences, as a reason for writing this book.
But both of us have  for a great number of years been in the
habit of hearing recitations and giving lectures upon them in
the College and  the Academy, and we ought to know what
sort of a text-book is needed.   But we dare not boast that we
have come up to our  ideal.  We have tried to give a condensed
yet clear exhibition of the leading principles and facts, which
are detailed  in such works as  Carpenter's Human Physiology.
his  Comparative Physiology, Hassall's Microscopic Anatomy,
Griffith,  and Henfrey's Micrographic Dictionary, Peaslee's
Histology, Todd and  Bowman's Physiological  Anatomy,  Wil-
son's Anatomy, Draper's, Dunglinson's, and Dalton's Phys-
iologies, "Van Der Hoeven's Zoology, and the works of Cuvier,
Owen, Agassiz, Wyman, Leidy, and Wagner  on Comparative
Anatomy. 
iv
PEEFACE.
   Through the liberality of the publishers we are able to pre-
sent unusually full illustrations of subjects, which could other-
wise be only imperfectly comprehended by the learner.
   Many of  the  drawings  contain  more  minute details of
the parts represented than are described in the text.   The in-
structor can require these to be recited or not, as he  pleases,
according to the  age and  ability of the pupil.   So as to the
parts on Comparative Anatomy,  as they are distinctly sepa-
rated from the rest, they can, if desired, be passed over in re-
citation.
   At the earnest solicitation of my son, my  name stands first
on the title-page.   But justice requires me to  state that most
of the body of the work  has been prepared by him.   I have
supposed it most appropriate that it should be so, since he has,
and I have not, passed regularly through the medical school.
Yet perhaps the public may have some confidence in my judg-
ment as a teacher for more  than forty years, in shaping  the
materials so as to be best adapted for  purposes of instruction.
But aware, in some measure, of our deficiencies and imperfec-
tions, neither  of us, in sending forth the work,  feels  it to be
beyond criticism and improvement.  In a field so wide, where
so many are pushing their investigations,  and  the  highest
authorities  so frequently  change their views, we do not  ex-
pect  to avoid all  mistakes; but in  our  successive editions,
we shall correct all errors which we find, and try to incorpor-
ate the new discoveries.
                                  Edward Hitchcock.
  Amherst College July, 1860. 
CONTENTS.
                                                          PAGE
Preliminary Definitions and Principles.......................   5

                     CHAPTER   I.
Osteology  and Syndesmology — Description  op the Bones and
      Ligaments.............................................>  31

                     CHAPTER  II.
Myology—Description op  the Muscles.........................  107

                   CHAPTER  III.
Splanchnology—Description op the Digestive Organs...........155

                    CHAPTER   IV.
Angiology—Description op the Heart, Blood, and Blood-Vessels.  201

                     CHAPTER  V.
Pneumonology—Description op  the Organs of Breathing........  244

                     CHAPTER   VL
Ichorology—Description  op the Organs of Secretion.....  .....282 
VI                     CONTENTS.
                  CHAPTER  VII.
                                                         PAGE
Neurology—Description op the Brain and Nerves..............316



                 CHAPTER  VIII.

The Inlets to the Sour.—The  Senses..........................361



                   CHAPTER  IX.

Religious Inferences from Anatomy and Physiology............ 420 
PRELIMINARY
DEFINITIONS  AND  PRINCIPLES.
   1.  All the objects  in  the material world are divided into
 Organic and Inorganic.
   2.  Cells, Membranes, and Fibers.—In organic bodies, the
 matter composing them is arranged in the form of cells, mem-
 branes,  and fibers, variously combined.   In inorganic bodies,
 though  the particles  are often  arranged with  mathematical
 precision  in particular modes, cells, membranes,  and fibers
 are not  formed.
   3.  Life.—The principle of life is always associated with or-
 ganic, but never with inorganic bodies.
   4.  Examples  of Organic  and  Inorganic Objects.—Or-
 ganic bodies embrace Animals and Plants ; every thing else in
 the material world is inorganic, as, air, water, minerals, rocks,
 and soils.
   5.  Man  the  Head of the Animal Kingdom.—"Man is
 the end toward which all the animal kingdom has tended
 from the first appearance of the Palaeozoic fishes."—Agassiz
 and Gould.
   6. Anatomy and Physiology.—Anatomy is the science that
 Questions.  1. Give the two kingdoms of the material world. 2. What is the arrange-
ment of matter in organic and  inorganic bodies? 3. With which is life associated?
4. State some examples of organic and inorganic bodies. 5. Why is man placed at the
bead of the animal kingdom ? 6. Define Anatomy. 
6
HITCHCOCK'S  ANATOMY
describes the different organs of animals. Physiology describes
their functions, or uses.  If  the organs of man  alone be de-
scribed, the science is called Human Anatomy and Physiology.
If the description embrace the lower animals, it is called Com-
parative Anatomy and Physiology.
   7.  Another definition of Anatomy, is the science of Organ-
ization ;  and of Physiology, the science of Life.
   8.  Animal  and  Vegetable Anatomy and  Physiology.—
There are  also  such  sciences  as  Vegetable Anatomy  and
Physiology.   Indeed,  there is a strong  analogy  between the
organs of plants  and animals, and their uses.   Nor is it easy
always  to draw the  line  between plants and animals, where
they approach the nearest to each other.
   9.  Intimate Connection of  Anatomy and  Physiology.—
Few writers confine themselves  to  the structure of animals,
when treating of their anatomy, but treat also of the function
of their organs;  and  the same thing is still more generally
true  of writers on physiology.  We do  not  separate  these
sciences in this treatise.
   10. Fifteen Chemical  Elements in the  IlumanBody.—Of
the sixty-five chemical elements or simple  bodies known to
exist, only fifteen have been found  as  normal constituents of
the human body.   The following is the list:—

    1. Oxygen,           G. Phosphorus,         11. Chlorine,
    2. Hydrogen,         7. Calcium,            12. Fluorine,
    3. Carbon,           8. Magnesium,         13. Silicon,
    4. Nitrogen,          9. Sodium,            14. Iron,
    6. Sulphur,           10. Potassium,          15. Manganese.

   11. Carbon, Ilydrogen,  Oxygen,  and Nitrogen.—The first
three of the above elements are found in all  the solids and fluids
of the body, without exception.  The first four occur in all the
  What is Physiology ?  When is the  term comparative applied? 7.  Give a more con-
cise definition of Anatomy and Physiology. 8. Describe animal and vegetable Phy-
siology. 9  Speak of the close relationship between Anatomy and Physiology.  State
the whole number of chemical Elements. 10. State those which are found in the human
body.  11. Where are the first three found? Nitrogen also ? 
AND  PHYSIOLOGY.
7
solid parts, and in all the fluids except fat.   They form the
chief and most important ingredients in animals and plants.
   12.  Sulphur and Phosphorus, Magnesium, Sodium,  Pot-
assium, Chlorine, Fluorine,  Calcium,  Silicon,  Iron,  Man-
ganese.—With scarcely an exception, these elements exist in
the body as compounds;  that  is,  two  or  more of them  are
combined,  as  in water,  in oxyds, and in various salts.    Sul-
phur and phosphorus exist in albumen and fibrine, as well as
in the brain,  about  -i^th  of its  weight being phosphorus.
Bones  are  more than half made up of Phosphate of Lime, and
they contain a small per cent,  of Phosphate of Magnesia.
Sodium, in the form of a chlorid (common salt), is found in
every  solid and fluid of the body.   Potassium occurs as  a
chlorid in  the muscles, and as an  oxycl  in salts.  Chlorine
forms  chlorohydric acid  by combining with hydrogen  in the
gastric juice.   Fluorine exists in the bones in a minute quan-
tity, combined wTith calcium.   Silicon is found in small quan-
tities in hair, wrool, and feathers, as silica.   Iron forms about
the 2000th part of the blood, and it exists also in the muscles,
hair, and  milk.  Manganese,  in  small quantities, has  been
detected in bone, and perhaps in the hair.
   13.  Copper,  Lead,  and Arsenic.—Copper, lead, and arsenic
have been  detected in  minute quantity in  human flesh.   But
it is not probable  that they are normal constituents.
   1-4.  Inferences.—From these facts we learn that our food
and drink should contain the fifteen ingredients above described.
Milk and e^gs are the only articles  that do contain them all;
and hence, the importance of  variety in diet.   And the  fact
that we  are obliged to use ten mineral ingredients in our food,
shows  the  absurdity  of a  prevalent  prejudice that no mineral
should ever be taken as a medicine.
   15.  Immediate Principles.—As they exist in the body, the
  12. State in what organs Sulphur and Phosphorus are found.  What is one of the prin-
cipal ingredients of bones ?  Where is Chlorine found? Fluorine? Silicon?  In what
paits of  the body is Iron found? 13. What is to be said of Copper, Lead and Arsenic?
1 i What should our food contain? Are mineral ingredients always poisonous? 15. De-
fine Immediate Principles. 
8             HITCHCOCK'S  A XAT O M Y

fifteen elements above described form a large number of com-
poui.ds, called Immediate Principles, or Organic  Radicals.
They exist naturally, and can be separated anatomically, that
is, mechanically, from one another; but the divisions can be
carried  no further without  chemical decomposition.   A few
elementary substances found in the system, as, oxygen, hydro-
gen, and nitrogen,  are sometimes called Immediate Principles.

  16. Immediate  Principles  Chemically Grouped—Yvre are
certain that eighty-four of these principles have been found in
the human system. If Ave group them according to their chem-
ical  characters,  they will fall into the following  divisions.
Half of them are the result of the waste or metamorphosis of
the substance of the body ; the other half exist independently
of any such change.
  1.  Gaseous, and not  saline : Oxygen, Hydrogen, Nitro-
gen, Carbonic Acid,  and Water.
  2.  Salts :  Chlorids (2), Fluoride  of Calcium, Ilydrochlo-
rate of Ammonia, Carbonates (4), Bicarbonate of Soda, Sul-
phates (3), Phosphates  (7), Lactates  (3), Oxalate of Lime,
Urates  (5),  Hippurates (3),  Inosate of Potassa,  Pneumate
of Soda, Taurochlorate of Soda, Hyocholinate of Soda, Gly-
cocholate of Soda,  Oleate of Soda, Margarate of  Soda,  Stear-
ate of Soda,  Caproate of  Potassa, Soda,  &c.
  3.  Acids: Lactic, Uric,  Hippuric, Pneumic, Lithofallic,
Margaric, and Stearic.
  4.  Neutral Nitrogenous  Compounds:  Creatine,  Urea,
Cystine, and Creatinine.
  5.  Neutral Non-Nifrogcnous Compounds:  Sugar from
the Liver,  and Sugar of Milk.
  6.  Fatty  and  Saponaceous  Compounds:   Cholesterine,
Oleic Acid,  Stearic Acid, Oleine, Stearine, &c.  (13.)
   7.  Coagidablc  Principles: Fibrine, Albumen, Caseine,
Globuline, Musculine, Osteine, Keratine, Hematine, &c. (18.)
  16. State the number of these  principles that have been already found. What are
one half of them derived from? Give the first group, or the gaseous ones.  State the
Salts. The Acids. The 4th, 5th, Cth and 7th classes. 
AND PHYSIOLOGY.
0
  17.'  Immediate  Principles  Physiologically Grouped.—
If we group the preceding substances according to their phy-
siological relations, we might, with Dr. Carpenter, bring them
all into  four divisions.
  1. Histogenetic Substances, or such as are converted into
animal substances, and are nitrogenous.
  2. Calorific Substances, mainly intended  to produce heat,
and are non-nitrogenous, as, sugar and oils.
  3.  The components of the living animal substa?ice.
  4. Excrementitions Substances, formed  Avithin  the body,
and thrown out of it.
  18.  Other Probable Principles.—Quite a number of other
substances have been  detected in the  human system, which
some regard as immediate principles.   But it is safer to Avait
till further examination has removed doubt.
  19.  Several of the above principles are capable of crystal-
lization, and are some-
times found in that state                 Fig.  1.
in the  body.   Figs. 1
and 2 shoAV two exam-
ples of these  crystals,
the  first  of  Hippuric
acid, and  the  other of
Creatine.
  20. To go into minute
details respecting the im-
mediate principles above
described,  Avould occupy
too much space in a work
like the present.   But a
few statements  respect-
ing  the  most   import-
  17. What are the Croups of these substances when physiologically grouped 1 Who la
the authority for this ?  Define the Histogenetic and the Calorific group.  What are ex-
erementitious substances ? Are there any other principles in the body ?
                             1*
 
10             HITCHCOCK'S  AXATOMY
Fig. 2.
                                     ant of them seem desir-
                                     able.
                                        21.  Oxygen.—Oxy-
                                     gen  is  regarded  as an
                                     immediate principle only
                                     when it exists in  a free
                                     state, as it  does in  the
                                     blood,   which,   in  an
                                     adult,   contains   sixty-
                                     one  grains:  nine  and
                                     a half cubic inches  be-
                                     inor found in the arte-
                                     rial,  and fourteen and a
                                     half in the venous blood.
An adult consumes in a year about eight  hundred  pounds of
oxygen.  An inhabitant of a mountainous region 18,000 feet
above the sea (in Potosi) consumes, howeArer, only two thirds
as much as one upon the sea-shore.
   22. Hydrogen  and Nitrogen.—Hydrogen is found in a free
state  in the stomach and some parts of the  intestines, and
nitrogen in the lungs, blood, and intestines.
   23.  Carbonic Acid.—Carbonic acid is found in the  lungs,
the alimentary canal, the blood, and urine.
   24.  Water; Cubical Size of the Body.—Water enters into
the composition of every  fluid, and every solid in  the body.
The bulk of the body, upon an average, is equal to a cube of a
little  more than  sixteen inches on a side ; and  the amount of
water equals a cube a little more than fourteen inches on a
side, or nearly three fourths of the  body.   Every part, ex-
cept bone, enamel, teeth, tendon, dry cuticle, and elastic tis-
sue, is more than half Avater.
 21. How much Oxygen by weight is found in the body ? What bulk of oxygen is found
in the venous and what in the arterial blood ?  How much does an adult consume by re
 pirat.on and otherw.se ,n a year?  What effect does elevation above the sea have upon
the amount consumed ? 22. State how Hydrogen and Nitrogen are found  M^rE
aeid also.  24 How important a constituent is water?  GW  the s£e othbodySr »
duced to a cube. If this cube were water, how large would it be ?           7 
AND  PHYSIOLOGY,
11
   25. Amount of  Water  Consumed  Yearly by an Adult.—-
 An adult drinks about fifteen hundred pounds of water yearly;
 and throws off through  the various waste-gates nineteen hun-
 dred pounds.   The difficulty of accounting for the four hun-
 dred pounds  has led some to suppose that water is formed in
 the  system by the union of oxygen and hydrogen.
   26. Common Salt in  the Body.—The salts that have been
 enumerated, are found in almost every part of the body.  Com-
 mon salt (Chlorid of Sodium) is found in every fluid and solid,
 except enamel.  The whole amount in man is 277 grains.  It
 subserves many important uses.
   27.  Carbonate  and  Phosphate of lime, &c—Carbonate
 of  lime  exists in  considerable quantity in the bones,  along
 with a much larger quantity of the phosphate of lime, and a
 small amount of phosphate of magnesia, and of fluoride of
 calcium.   These salts, except  the fluoride, are  found  in  most
 other parts of the body.
   28. A c i d s,  S a 11S, & c .—Most of the  acids and salts, the neu-
 tral nitrogenous compounds, the sugars,  the fatty and sapona-
 ceous compounds, exist,  or are formed  in the  fluids of the
 body, and though numerous (forty-two in all),  their quantity
 is comparatively small.  They are mostly formed by disassimi-
 lation in the  body, and  hence only  their elements  need to
 exist in our food.
   29.  Sugar  in the Body.—Only two kinds of sugar  exist, or
 are formed in  animals.   Grape sugar  is found in the liver, in
 some of  the veins,  and other organs.   In the  disease called
 Diabetes, its quantity is  very much increased, and,  in fact, an
 excess of sugar in the system is a sign of serious derangement.
  30.  Fats in the Body.—The fatty  principles, cholesterinc,
oleine, etc., exist in the body in cells, in chemical combina-
  25. How much water does a man consume in a year? How much is thrown off during
the same time?  Explain the reason. 20. Where does common salt occur in the body?
How many grains exist in the body ?  27. In what parts of the body do Carbonate and
Phosphate of Lime occnr?  2S. How many acids and salts are found ?  State how they
are formed.  29. How many kinds of sugar are found in animals? AVhat does an excess
of sugar indicate ? 80. How do the fats occur in the body ? 
j o            HITCHCOCK'S   A X A T O M Y

tion with other substances, and  as oil drops  or fat globules
not inclosed.  These principles are mostly taken as food into
the system, but  they are  most probably  also  formed there
from  elements;  certainly, the  liver has  this  power. ^  One
tenth of the brain is composed of fat;  and it  is only in the
last stages of emaciation, that this supply is exhausted.
   31.  Assimilation  Necessary.—The principles  thus far de-
scribed, constitute but a small proportion, of the animal frame.
Bat the organic, or  coagulable  principles, enter  largely into
its composition.  Indeed, they  form the principal source of
nourishment.   The most important of these principles (albu-
men, fibrine, and caseine) are in  a  fluid state  in  the body;
tti3 others are solid,  or demisolid.   Though  the materials  for
their formation must exist  in  the food,  yet there is reason to
suppose that the process of assimilation is necessary, to trans-
 form them into these principles.
   32.  Albumen,  Albuminosc,  Caseine.—Coagulation  takes
 place  when a liquid, or semi-liquid, passes into a solid state.
 The white of an egg gives a good idea of one kind of albumen
 (ovalbumen).  Seralbumen exists in the  blood,  and in other
 liquids of the body.   Albuminose is found in the same fluids,
 and  has  been, till of late, confounded Avith  albumen.  It is
 formed in the  upper intestines, but  Avhen it passes  into  the
 blood,  it becomes  mostly albumen,  sometimes  musculine,
 fibrine,  etc.  Animal caseine  is found only in milk,  being
 most abundant Avhen an animal  diet is used.   It contains from
 four to six per cent, of phosphate of lime, and hence the im-
 portance of milk for young animals, that their bones may be
 developed.
    33. Fibrine, Masculine, Globuline, Osteine, and Gluten.—
 Fibrine is found in  the blood, and when it coagulates, the mass
 i i fibrous,  the process being called fibrillation.  It is  this prin-
 ciple chiefly that causes blood  to coagulate, the great importance
   Is fat formed in the body, or taken in from the food ? 81. State the three most im-
 portant organic principles. 32. Define coagulation.  What is ovalbumen, seralbumen and
 albuminose?  In what is caseine found?  What important ingredient does it contain?
 S3. Where is fibrine found ? What causes coagulation of the blood ? What practical beno.
 fit is derived from coagulation ? 
AND  PHYSIOLOGY,
13
of which in arresting dangerous hemorrhages  is well  known.
Coagulation appears to be a vital process, that is, dependent on
life for its development, and not on chemical laws only.  It can
be prevented by any thing that destroys life, such  as poisons,
or a temperature too high, or too low.   Fibrine does not exist
in the muscles.  That which  has been called such  is  muscu-
line, which is endowed Avith  the vital property called contractil-
ity.   Globuline occurs only in the red corpuscles of the blood.
Osteine  is the substance from Avhich  gluten is  made, by  the
action of boiling water, for gluten does not naturally exist  in
the body.   Osteine is  the essential organic element in  bone.
   35. Protcine Compounds.—All the organic  or coa<nilable
principles contain  nitrogen,  or  rather, are composed  essen-
tially of oxygen, hydrogen, carbon and nitrogen.  Hence, their
value as food,  since a greater part of the body is composed of
these elements.  Albumen, fibrine,  and  caseine have been
termed Proteinc  Compounds, for  they can easily be changed

  Is fibrine found in muscular tissue i  AVhat is the proximate principle of muscular tis-
sue?  Where does globuline and osteine occur?  34. What is the coloring matter of the
blood ? Has iron any tliintr to do with its color?  AVhat is the Hematine produced from ?
85. What four simple elements make up all the organic principles?  Why are albumen,
etc., termed Proteine compounds ? 
14            HITCHCOCK'S  ANATOMY

into Proteine, a substance, however, which does  not exist m
nature,  but results from the decomposition of the  principles
above named.


                    HISTOLOGY.

   36.   Organic  and  Inorganic  Structure.—Animals  and
plants have a structure  different from that of minerals when
we examine them with the microscope.   The former is  called
Organic, and the latter Inorganic Structure.
   37.  Vitality the Cause of Organization.—Vitality, or the
principle of life,  or  the  Vital  Force, is  the  cause of organi-
zation.  The nature of life is indeed  involved in obscurity; but
its effects are manifest, and among  them is organization :  al-
though some have maintained, but  Avithout good  reason, that
the vital force is nothing but a peculiar manifestation of heat,
mechanical force, chemical action, galvanism, etc.
   38. Elementary and  Primary Tissue.—The simplest forms
of organized structure are three.
   1.  Simple Membrane.
   2.  Simple Fiber.
   3.  Cells.
   These  organic forms physiologists denominate  Elementary
 Tissue.   When united,  they form Primary Tissue.
   39.  Histology;  Proportion  of  Tissues  in  the Body.—
 Histology is the science of Tissues.  Tissue forms  nearly the
 Avhole of the solid portions of the body.   By means of the mi-
 croscope, they have been examined  Avith great care, and de-
 scribed.
   40.  Fluids of the System;  Ilygrology.—Before entering
 upon a description of the  tissues,  it seems desirable, at least,
 to enumerate the different fluids found in the system, though a
   30. Define organic and inorganic structure.  3T. Give the cause of organization.
 3S. State the three simple forms of organized structure.  AVhat is Klementary Tissue?
 What is Primary Tissue?  39. Define Histology. AVhat forms the solid parts  of the
 body ? 40. What is Ilygrology ? 
AND  PHYSIOLOGY.
15
 fuller description of them Avill  be given further on.   These
 fluids contain  the elements  of  the  tissues.  That part  of
 anatomy which treats of them is called Hygrology.
   41. Lymph.—Lymph,  a transparent,  coagulable fluid, in
 the lymphatics, emptying  into the blood.
   42. Chyle.—Chyle, a Avhite, coagulable fluid, derived from
 the food in the intestines,  and conveyed to the blood.
   43. Blood.—Blood, in the veins and  arteries,  from wliich
 nearly all the parts of the  system are sustained, a coagulable
 fluid, with an alkaline reaction.
   44.   Serum.—Serous secretions,  fluids  found on A'arious
 serous membranes, as the pleura, peritonaeum,  pericardium,
 and membranes of the brain and ear.
   45. Transudations.—Transudations, vapor from the lungs,
 and sometimes from  the skin; also, fluids in some of the  tis-
 sues, more  especially in certain diseases,  as  dropsy in  the
 head, chest, and  abdomen, certain sweats and discharges in
 cholera,  etc.
   46.   Exudations.—Exudations,  "any  organizablo  fluid
 spontaneously separated  from  the blood vessels, Avithout rupt-
 ure of their walls," chiefly occurring in inflammations, and
 wherever  new  material is  required for repair  of the system.
 The pus of wounds and sores is an example of exudation.
   47. Mucus.—Mucus, a viscid mass capable of being drawn
 into threads, secreted from the mucous membrane, but differ-
 ing in different parts.
   48.  Gastric  Juice and   Pepsin.—Gastric fluid,  a  fluid
 Gecreted  by the stomach, containing a substance called Pepsin,
 which aids in digestion.  It contains a little free chlorohydric
and lactic acids.
  41. AVhat  is Lymph and what becomes of it? 42. Define Chyle and state what be-
comes of it.  43. Deflne the blood. 44. AVhat membranes secrete the serum V 4'). Define
transudations.  In what diseases do they occur? 40. What are exudations?  AVhen are
they serviceable?  47. What does the mucous membrane secrete? 43. Define and de-
scribe the secretions of the stomach. 
10
HITCHCOCK'S   A X A T O M Y
Fig. 4.
   49.  Intestinal  Fluid.—The  intestinal fluid, a colorless,
tenacious fluid, with strong alkaline  reaction, Avhose function
is  to assist  in digestion.  . Secreted  by the epithelial  cells of
the intestinal follicles.
                                       50.  Milk.—Milk,  a
                                     glandular secretion,
                                     shoAving  under the  mi-
                                     croscope  an  immense
                                     number of fat globules,
                                     suspended  in a  clear
                                     fluid, as in fig. 4.
                                       51.  Saliva.—Saliva,
                                     a secretion chiefly from
                                     the parotid and submax-
                                     illary  gland   into  the
                                     mouth, to assist in diges-
                                     tion.
              o£b«
           ofoC^o^             5±    Bile._Bilej   a
                                     greenish   or   brownish
bitter fluid, secreted by the liver to assist*n digestion.

   53.  Pancreatic  Juice.—Pancreatic fluid, a colorless, taste-
less, but somewhat alkaline fluid, secreted by  the pancreas to
aid in digestion.

   54.  Urine.—Urine, secreted by the kidneys.

   55.  Tears.—Lachrymal fluid for lubricating  the eyeballs,
secreted by the lachrymal gland.

   56.  Oil and Wax.—Sebaceous secretions, fatty fluids thrown
out by what are  called the sebaceous follicles of the skin, to
keep it  moist.

   57.  Sweat—Perspiration,  or  sweat,  a  colorless, watery

 4D. What is the Intestinal fluid? 5X How does milk appear under the microscope ?
51.  AVhat is the origin and use of saliva?  52. State the secretion of the liver  53  &c
Describe Pancreatic Juice, Urine.  Tears.  Oil and Wax.   57. From what glands ia
sweat produced ?
 
A X D  T II Y S I 0 L O G Y.
n
 fluid, with a saltish taste, and having odor,  secreted from the
 perspiratory glands.

                    Elementary Tissues.
   58.  Simple, or  Basement Membrane__1.  Simple  Mem-
 brane.  This is usually  a structureless  layer of coagulated
 albumen, often not more  than 20booth of an inch thick.   It
 forms the walls of  all cells, and is also spread out, as  an in-
 ferior layer of the skin and mucous membrane,  and is then
 called basement  membrane.   It is the most  simple of all  the
 tissues, yet it is  the agent of secretion, and  sometimes  of ab-
 sorption,  and these  Professor Peaslee considers  as its vital
 properties, though of a Ioav grade.
   59.  Imbibition.—Simple membrane also  possesses the  re-
 markable property of allowing fluids to pass through it when
 it is placed between two fluids ; the effect depending in part
 upon the electro-chemical relations of the substances, but not,
 as  generally supposed, on the difference of specific gravity
 of  the liquids.   This  is  called endosmose  and exosmose, or
 Imbibition, and  is  the principal means by  which fluids are
 made  to pass from  one part of the  system to  another,  Avhere
 no distinct vessels are provided for that purpose.
   60. Simple Fiber.—2.  Simple Fiber.  This consists es-
 sentially of threads  of coagulated
 fibrine, Avhose average diameter is
 about g-'ooth of an inch thick.  It
 does not appear to be  a permanent
 constituent of the body, but only
 a basis  for the development of the
 more complicated tissues.  A good
 example of the simple fiber may
 be seen in the  membrane lining
 the inside of  an  egg  shell,  as in
Fie:. 5.
Fig. 5.
 58. What is simple membrane ?  How thick? AA'herc Is it found? What other name
Is given to it?  59. Describe Imbibition. What purpose does it effect?  60. Desoribe
simple fiber.  Its size. Where beat seen 1 
  62.  Contents of  Cells;  Granules;  Nucleus and Nucleo-
lus ,_T he fluid of cells is transparent, except  in  the case of
blood.   In it there generally float an immense number of gra-
nules,  having no investing membrane, but sometimes they are
thus invested.  Each cell has also a nucleus and a nucleolus ;
the first being a globular, or  lenticular  body, from ¥ o'o oth to
To'00th of an inch in diameter, attached to, or imbedded  in the
wall of the cell, though some are free.   The nucleolus is  a
granule  within the  nucleus.   Both are shoAvn, as Avell  as the
common granules, in Fig. 6.

   63. Appendages  of  Cells.—Sometimes cells have a sort of
tail attached to them, and  are hence  called caudate, as  in
Fig. 8.  Sometimes, too, they are stellate, as in Fig. 9, shoAV-
ing the pigment cells of a frog's foot.
  61. Define cells. What is the original form of them ? How do they acquire the poly-
 hedral form? 62. Explain nucleus, nucleolus and cell wall. 63. What are the appendages
 of cells? 
AND   PHYSIOLOGY.
19
Fig. 8.
Fio. 9.
   64. Cytogenesis — The cell is the most important of the ele-
mentary tissues,  for, by its multiplication, most of the  other
C4. Give the process by which cells increase and form tissues. 
Fig. 10.
20            HITCHCOCK'S  ANATOMY

tissues in animals and vegetables are made up.   This is called
cytoo-enesis.   The increase usually takes place by duplicative
subdivision, which  is shown  on Fig. 10.   The cell a a first
becomes elongated, as  at b, and  then it  divides at c c.   The
subdivision going on will give an increase  in rapid ratio—-,
4  8 16  32, etc.   Fig. 11 shows an example of this division,
                               A,  B,  C,  D,  in  its earlier
                               stages, and E,  F, G,  II,  in
                               its  more advanced condition.
                                Sometimes cells multiply by
                               the deArelopment of new cells
                                in the interior.   In  this case
                                the  nucleus  subdivides into
                                tAVO or more portions,  which
                                at length fill the original cell,
                                as is shown in Fig. 12.  Some-
                                times cells are formed  by the
                                expansion  of  homogeneous
Fig. 11.
granules into cells; or they are even produced in the midst of
a formative fluid (called a blastema), poured out from the blood.
 Describe the mode of formation as illustrated in Figures 11 and 12.  AVhat is the n
Blastema ? 
 Cells;  Chemical Trans-
 formations; Vitalization  of  the  Cells;  Chance  of  Form-
 Development  of ."Verve  Force—The multiplication of cells
 is one of the manifestations of the vital force inherent in them.
 Another is the chemical transformations exerted upon the con-
 tents of the cell in some  instances, whereby new  products
 are  generated.   Another is the vitalization of a portion of
 the  cell  contents, whereby they are  able to produce new
 cells.   Another  is permanent changes of  form in connection
 with growth.   Another  is  temporary changes of form,  ac-
 companied with  sensible  motion, as  in the oscillatory move-
 ments of  the  leaves  of Hedysarum gyrans,  and  the fold-
 ing of the leaves of the Mimosas upon touch.  Finally,  the
 development of nerve force from cells, by Avhicb all the bodily
 operations may be modified, and which is intimately connected
 Ayith mental agency.

  67. Periods in the Life of the Cells.—In cell life there is a
 65. Show how the tissues of the body are made up. G6. Mention the different chants
which cell* undergo. 
oo            HITCHCOCK'S   ANATOMY

period of augmentation, another of perfection, another of de-
cline, and, finally, one of cessation.  So long as vitality can use
chemical and  physical agencies for building  up the  system,
they tend to its preservation, but, when life ceases, they tend
to its  destruction, not,  as is generally  thought, because the
vital principle has not the power of resisting these agencies,
but because it can no longer turn them into the channel for pre-
serA'ing the system.
                 PRIMARY TISSUES.
   The chief mass of the animal system is made  up of the ele-
mentary forms that have been described,  variously combined
so as to form plexuses and webs,  which are called primary
tissues by some, and compound tissues by others.   They are
differently  classified by different  writers.   The arrangement
which follows  is that of Professor \V. B. Carpenter:
               1.  Simple Fibrous Tissues,
   68. White  and  Yellow Fibrous Tissues.—This embraces
the Avhite and  yellow fibrous tissues, as well as the areolar or
connective tissue of other Avriters.  The white fibers  are from
isVoTith to the 2000-dth of an inch in  diameter, and form the
tendons, ligaments, and fibrous membranes.  (Fig.  13.)  The
Fig 13                        Fig. 14
 67. Give the four different periods in the life of cells. 6S. Give the size of the fibers
of white and yellow fibrous tissues. 
                  AND  PHYSIOLOGY.               23

yellow fibers are about  75'66thof an inch in diameter and form
a part of the larynx, and the middle coat of the arteries.

   69. Areolar Tissue.—The areolar  tissue consists of fibers
of white and yellow tissue intenvoven, so as to leave irregular
spaces, or areolae, between them.   This tissue originates from
cells, as is shown in Fig. 16.  The areolar tissue is more widely
diffused than any other in the  body, so that  if it were  possi-
ble to remove all but this one,  the form of the part Avould be
preserved.   It surrounds all the arteries and veins, the nerves,
muscles and internal organs; and it forms one of the layers of
the skin and mucous membrane
Fig 15.
          2.  The Fibro-Cellular  Membranes.

   70.  One of the layers of the skin, of the mucous membrane,
and the serous and synovial coat that lines the shut cavities of
the body, is composed of interwoven fibers of simple basement
membrane , and of one or more layers  of cells upon the free

 69. What is the composition of areolar tissue?  What of its abundance in the body?
Where is it principally found?  70. Describe the fibro-cellular membrane.
                            2
@   §   §
 
2-1
II J T C H C O 0 K ' S  .IN -V X O M Y
surface.   This is  the fibro-ccllular membrane or tissue.   Its
position and character will be better understood when the parts
above referred to have been described in. subsequent sections.
Fiu. V
■■-mm
Fig. 18.

                   3.  Cellular Tissues
  71.  Fat and  Cartilage. —These embrace  the adipose tis-
sues, Fig. 17, and the cartilaginous, Fig. 18.  The first is the
usual form of fat, Avherever it occurs in the system.  It retains
the pure form of the primitive cells.   In cartilage, also, these
cells sometimes exist alone, but more frequently they are inter-
woven with fibers, as seen by the figures.

                   4.  Sclerous Tissues.
  72.  Bones  and  Teeth.—These constitute the bones  and
teeth, and arc composed of an animal basis of fibers and cells ce-
mented together by phosphate and carbonate of lime.  Fi<r. 19
Avhich  is a transA'erse section of one of the  bones of the arm
will give  an  idea of the  arrangement of the animal matter
the earthy part having been dissolved  by acid.   Fig. 20 sIioavs
a transverse section of the shoulder blade, exhibiting the dark
spaces called lacuna;.
 71. Describe fat and cartilage.  72. AVhat is the composition of the bones and the
tseth ?  78. AVhat are the capillaries and absorbents ? Qivo the size of the capillaihs. 
AND  PHYSIOLOGY

         Fig.  19
25
Tubular Tissues.
  73.  Capillaries  and
Absorbents.  —  These
form those minute blood
vessels called capillaries.
and others called lym-
phatics or absorbent ves-
sels, which exist in every
part of the  body,  and
are distinct  from,   al-
though connected with,
the arteries  and veins.
The  capillaries  con-
necting these are from
 2,'ooth tO   aT'outh Of
Fig  20
 
26
Fig. 21.
   HITCHCOCK'S  ANATOMY

an inch in diameter, less  often than the blood cor-
puscles.   In some other  animals they are  larger,
as may be seen  in the capillary  plexus  of a frog's
foot, shown  in  Fig.  9.   The lymphatics  abound
with valves, as may be seen in Fig. 21.
          6.  Muscular  Tissue.
   74.  Striped and  Smooth  Muscle.—This tissue
is made up of two  forms of fiber,  the striped and
unstriped.  The stripes in the first form  run both
transversely  and longitudinally, as may be seen
                    Fig.  22.
Fig. 23.
m
in Fi<T. 22.   "When separated longitudinally, the
fibrillsc have  a  beaded appearance,  each  bead
beino-  in  fact  a  cell, as is here  represented in
Fi»  23,  which  shews  the cells  a when  most
relaxed, and 6 when most contracted.   Muscular
fiber  is capable  also of being divided crosswise
in the  direction of the transverse strife into discs,
as seen in Fig. 24.   Both the striated (striped)
and  non-striated  muscles  originate  in   cells.
Figs. 25 and 26 show their development.
   75.   Myotility.—The  grand  peculiarity  of
muscular tissue  is  its  power  of contraction—a
phenomenon  as   mysterious  and  wonderful   as
any thing  in  nature.   This is called myotility
or contractility.
 What do the lymphatics abound in? 74. Distinguish between the striped and the
unstiipcd muscular fiber. Give the reason of the difference between a and b in Fig. 23,
75.  Define myotility. 
AND  PHYSIOLOGY.

          TIG 21.
27
Fig. 25.
Fig. 2C.
1
   76.   The Chemical  Composition of  Muscle.—The chem-
ical  composition of the muscular tissue  is almost exactly the
same as that of blood, as the following analysis Avill show  :
                                 Blood.          Mu tele.
            Carbon................ 51.83          51.95
            Hydrogen.............  7.G7           7.17
            Nitrogen.............. 15.01          15.07
            Oxygen............... 21.36          21.39
            Ashes................  4.23           4.52

                                100.00         100.00
76. State the chemical composition of muscle. 
23
HITCHCOCK'S  ANATOMY
                   7.  Nervous  Tissue.
   77.  Nervous  Tissue;  Tubular Cells.—This, like some of
the other tissues, is composed of cells, fibers and tubes, but it is
distinguished from all others by its vital endowments   In the
ordinary nerve trunks the tissue is the fibrous or tubular, as is
shown  in fig. 27, A, B, and C. In C some of the original eel Is
are shown.
                          FrG. 27.
   78.  Vesi-
cular  Cells;
Granular
Cells.—In
those nervous
masses called
ganglia,  Ave
find, in addi-
tion  to  the
fibers,  a sub-
stance  made
up of vesicles
or cells, as  is
Fig. 28.
shown in the ganglion of a  mouse on fig. 28.
thI7ve";nli;XUStiSSU° t0 b° a*"**^ from airothcT^^T^:
Describe 
AND  PHYSIOLOGY.
29
   Another primary element of the nervous  system is  com-
posed of nucleated  cells, containing a finely granulated sub-
stance.   These sometimes have  processes which give them a
caudate or stellate form, as in Fi"\ 29.

                           Fig. 2D.
   79.  An  Organ. The System.—Such are the tissues which,
combined in various proportions, make up the organs of the
human body.  And by the term organ wre mean a part usually
composed of several  tissues adapted to certain functions.  And
though harmoniously united  into a single system, that is, the
body, the anatomist can dissect and describe  them separately.
In this work the following order Avill be adopted:
   1.  Osteology, or an account of the Bones or framework of
the system.
   2. Myology, an account of the  Muscles or  the moving pow-
ers of the system.
   3. Splanchnology, or the  Nutritive Organs.
   4. Angiology, an account  of the  Circulating System of the
arteries and veins.

  7?. Define an organ.  What is the system ?  What is Osteology ?  Myology ?  etc 
30           HITCHCOCK'S  AKATOMY
  5. Pneumonology, or an account of the Respiratory, Yocal,
and Calorific Organs.
  6. Ichorology, or the Lymphatic and Secreting System.
  7. Neurology, or the history of the Nervous  System, the
vivifying poAver.
  8. The Inlets of the soul, or the Senses.
  9. Religious teachings of the subject. 
             CHAPTER   FIRST.

THE FRAMEWORK OF  THE SYSTEM.—OSTEOLOGY, OR
          A DESCRIPTION OF  THE BONES.
          DEFINITIONS  AND  DESCRIPTIONS.

   80.  Chemical Composition of Bone.—The Bones  of all
 vertebrate animals are principally composed of the Phosphate
 and Carbonate of  Lime, and, Avith the exception of the Teeth
 and articular extremities, are closely covered  by a firm mem-
 brane called the Periosteum.   By chemical analysis the com-
 position is as follows :                 /

            Organic substance (Osteine or Cartilage)   33.00
            Phosphate of Lime...................   57.00
            Carbonate  of Liine....,...............   8.00
            Fluorid of  Calcium...................   1.00
            Phosphate of Magnesia...............   1.00
                                            100.00

;■'  81.  Cartilage and  Salts of Lime shown.—Hence  we  see
 that the principal  constituents of bone are the salts of Lime
 and Cartilage.  The former can be easily obtained by burning
 the bone a while  in a  hot fire, Avhich appears like  a Avhite
 powder Avhen crushed.   The Cartilage is obtained  by im-
 mersing it for a considerable time in a dilute acid, when we
 have  the form of the bone  perfectly retained, although nothing
 is left  but cartilage.  Its elastic character may  be  inferred
  80. AVhat are the principal ingredients of bones?  Where  is the Periosteum found?
 Give the  chemical analysis.  81. How can the earthy ingredients be shown? The car« 
32            HITCHCOCK'S  ANATOMY

           Fig. so.            from Fig. 80, which is a human
                             Fibula tied in a knot after hav-
                             ing  been  immersed  for  some
              f»lk.        time in muriatic acid.
                   M   3   32.   mechanical   Construc-
                             tion of  Bones.—As a  general
                             law  the  extremities   arc  the
                             largest, and the bodies or  shafts
    HPJlHtStk       are smooth  and of  a uniform
              ^  -- m      surface.    They arc   in   most
            '«illHHB^i    cases so constructe(^ as  to £*vc
                       M    the greatest strength  and sup-
                             port, and at the same time fur-
                             nish as little weight a3 possible.
             IftWIii         Hence the long bones arc most-
                             ly IioIIoav,  or have  an arched
                             form,  while the flat bones are
 portions of a circle or sphere.  In the face also the bones are
 not all solid, but some of  them contain large cavities, so that
 firm attachment may be given  to the muscles, and protection
 to the more delicate parts.
    83.  Average  Weight of adult Skeleton.—The weight of
 the skeleton  is as  10.5 : 100, or about one tenth the  weight
 of the Avhole body.  And since the average weight of an adult
 man is 136  pounds, the weight of an adult skeleton  is about
 13.5 pounds.
    84.  Strength of  Bones.—The power  of the human bones
 as levers Avhen compared with different substances is remark-
 able, as is seen  by the folloAving table.
            Freestone (sandstone)..................  1.
            Lead................................   Co
            Elm and Ash (wood)...................   8.5
            Box, Yew, and Oak....................  11.
             Human Bone.........................  22.
   S2. Which part of the bones is generally the largest?  Why are many  of the bones
  hollow or partially so?  83. Give the weight of the human skeleton.  AVhat  is its pro-
  portion to that of the whole body ? 81. Give the comparative strength of the bones. 
A >' D  r II Y S I 0 L O G Y .
33
That is, bone Avhen used as a lever is  22 times  as  strong as
Sandstone,  3} times as strong  as Lead,  nearly 2;  times as
strong as Elm and Ash, and 2 times as strong as Box, Yew,
and  Oak timber.
   85. Microscopic Structure of Bone.         Fig. 31.
Haversian  Canals. — Examined  by
the microscope the bones arc found to
be  made  up  of plates or layers for
the most part, arranged concentrically
in  the  long  bones,  and  in parallel
layers in  the flat ones.   These are
traversed in all directions, and espe-
cially  in  their  long   diameters,  by
minute  tubes  or  vessels called Ha-
versian canals,  which  are   also  en-
circled  by seA'eral laminae  or  plates
besides  those  following the general
outline of  the bone.  Fig. 31.   These
canals have a diameter varying  from
TaVo  to  oioth  of  an inch, while the
accompanying lamellae show a thick-
ness of eoVoth  of an inch.   They
sometimes contain a capillary  vessel,
but more  usually carry only  the nutritive and watery portion
of the blood.

   86.  Lacuna;,  Canaliculi.—Besides these canals we  find  a
smaller set of vessels or cells located  directly in  the substance
of the concentric lamellae, called Lacunae or Bone Corpuscles,
which average ToVoth of an inch in length, and carry the fluid
which nourishes the bone.  These are of a black appearance,"
of an oval form, and with rays divergent in  all directions, as
 Transverse  section of  bone
magnified 15 diameters. 1, Outer
layer. 2 and 3, inner layers.
  S5. How are the particles of matter arranged in  the long bones ?  How in the flat
ones? Describe the Haversian canals.  Their diameter.  What vessel does  each ona
contain and what is the purpose of that vessel?  86. AVhat aro the  Lacuna) or Bon*
Corpuscles ? 
34             HITCHCOCK'S  ANATOMY
Lacunae of Bone,  a, central portion.
    b, eanaliculi or Bone Pores.
              Fig. 32.              seen  in Fig.  32.   These
                                  rays  are  minute  canals,
                                  and nearly  all of  them
                                  anastomose, or  have com-
                                  munication Avith each other.
                                  They are called Canaliculi,
                                  or  Bone Pores, and mea-
                                  sure  jolooth  of an  inch
                                  in diameter.
  87.   Ultimate  Granules.—The  ultimate histological ele-
  Fig. 33.    ment,  or  the smallest element  of bones as yet
             discovered, is made up of pale  OATal granules,
             about  e-oVoth. of an inch  in diameter.   These
             granules constitute all the substance of the bone
             except the minute vessels already mentioned.
  88. Hence the microscopic elements of bone are four :
  1. Haversian Canals.
  2. Lacunae or Bone  Corpuscles.
  3. Canaliculi or Bone Pores.
  4. Ultimate Granules.
  89. Periosteum.—In all parts of the  body, both solid and
fluid, we find that nature has made ample protection  by
providing for nearly every organ a  firm membranous sheath.
This not only serves as  a  protection and support,  but  in
many cases  a means  of nutriment.   Upon  the  bones ac-
cordingly  we  find  a  very firm Avhitish yellow  membrane
closely  attached to them  in  most  places, and  very  smooth
called the Periosteum.  This occurs on  every part of every
bone, except at the  articulations, and upon the croAvns of the
teeth.   It is, when  healthy, perfectly  insensible, and  contains
the vessels which  ramify into  the  bones, being in  fact the

  What are the Bone Pores or Canaliculi?  87. What is the smallest or ultimate element
of bones 1  88. Give the four microscopic elements of bone. 89. What is  the color of
the Periosteum ?  On what part of the bones is it wanting?  What two important
purposes does it subserve ? 
AND PHYSIOLOGY.
35
Fig. 34
nutrient membrane of  the bones.   Besides
this  function,  the periosteum  serves  as  a
point of  attachment  for  the ligaments  and
tendons, in as much  as they could not find
firm attachments  on the bone itself.
   Remark.—Diseases  of  Periosteum.—In
the diseases known as Felon  and Fever  Sore,
the Periosteum is the seat of the inflamma-
tion, although, if  it be  not soon checked, the
bone itself becomes implicated.
   90./Processes  of Bones.—The  bones  of
animals are not constructed after any regu-
lar geometrical form or curve, but are mod-
eled  upon  the  plan  Avhich  may  secure the
          P           i   r  •!•     e      •    Periosteum of a humc-
greatest nrmness  and  iacility  ot  motion. rus partlv taken off<
Accordingly  Ave   find  their  surfaces   quite
uneven, presenting in  many places prominent  projections,
which serve as  a  firm  point  of attachment for muscles and
ligaments.  These are  called  Processes, and  are  generally
found  near the extremities of bones, and are  largest Avhere
the greatest strength of muscle  and ligament is required, as
shown in the bones of the lower extremities.

   91. Nutritious Foramina.—Upon nearly all the bones of
the body may be found  small tubular  openings Avhich, after
extending  for a short distance into the bone, ramify and  give
off the minute capillary vessels which circulate through  the
larger Haversian  canals.   They arc called nutritious fora-
mina, or openings, since they convey  nutriment  to a  large
portion of the bone.

   92.  Four Classes of  Bones.—Bones are divided  according
to their shape into four  classes: long, flat, short,  and irregu-

  What is the seat of Felon and Fever Sore? 90. What is the general outline of bones?
What are Processes?  91. AVhat are the nutritious foramina, and with what vessels do
they communicate? Their use?  92. Give the four classes of bones, and give examples
of the long ones. 
OG            HITCHCOCK'S  ANATOMY

lar.   The long ones are mostly found in the extremities, and
consist of a hollow shaft with enlarged and partially smoothed
extremities,  and sometimes a rough or elevated  portion along
their  central portions.  Those which belong  to this class, are
the Clavicle, Humerus, Radius, Ulna,  Femur,  Tibia,  Meta-
tarsus, and Metacarpus, Phalanges and Ribs.
   93. Short Bones.—The Short bones are irregularly cuboid
ia form, and  arc found in  those  places  where there  is but
little  motion  cf the part.   They  arc the Vertebrae,  Coccyx,
Oirpus and  Tarsus,  Patella,  and Sesamoid bones.
   94. Flat  Bones.—The Flat bones are  arranged  to  enclose
and protect  cavities.   Those  of  the head  are  made of two
layers of bony matter,  with  an intervening  porous substance
called the DiplJl  These arc the  Occipital,  Parietal, Frontal,
ITasal,  Lachrymal,  Vomer, Sternum, Scapula, and the  Os
Innominatum.
   95j  Irregular Bones,—The Irregular  bones  are  those
which belong to neither of  the preceding  classes, and have
no typical form.   They arc the Temporal. Sphenoid, Eth-
moid, Superior  and  Inferior Maxillary,  Palate, Turbinated,
Ilyoid, and  Sacrum.
   9G. Development  of Bone   from  Cartilage.—The  early
condition of  bone is that of cartilage, Avhich has the  general
outline of the bone, and from the  subsequent  process may
be called the mould of the bone.   Very early in  life, and
even  before  birth, bony matter begins to  be deposited  in  the
cells  of the  matrix  (cartilage) until  at length,  the whole
becomes solid, as it 13  found in adults.   At birth the only
bono Avhich is completely ossified is that  portion of the tem-
poral called  the petrous, which contains the organ  of hear-
ing,  Avhib all  the  bones  arc not  completely ossified  be-
fore the 12th year  of life.   This  process  of  hardening, or os-
  C3. AVhat is the general outline of short bones and where arc they found?  Give ex-
amples. 9-1. Give the use of the flat  bones.  Examples also. 95. AVhat are some of
the irregular bones ? 95. AVhat is the first stago of bone ?   AVh.cn is the process of ossifi-
cation complete ?  AVhat bones aro the first that become ossified ? 
AND  PHYSIOLOGY.
37
^&> ^0 <*>«,»
[«i^>	•' SS^ ■	
so ,'		
ciS.	«SS*>	>a;i3
|SiA	■1£k	oii-''
 sification, begins  at                   Fig. 35.
 certain  points,  and
 continues until the
 AA'holc  is completed
 as   is  seen  in the
 Fig. 86. In some of
 these bones there is
 but  one of   these
 centers,  or  points,
 av here   ossification
 commences, while in
 the  Sphenoid  there
 arc 12.
.-   97./N limber  of
 Bones.—The  num-
 ber of bones in  the
 human   system  is
 reckoned differently
 by different anatom-
 ists  since many  of
 the  bones arc  Avell
 exhibited only  in
 hard   Avorking   or
 Aveil developed mus-
 cular subjects.   The
 number 216 will  be
 given in this  book
 as  taken from Eras-
 mus Wilson, Avhose
 work on Anatomy is
 adopted  as the text
 book in  nearly all the medical schools of this country.  This in-
 cludes the teeth, and sesamoid bones, of Avhich the latter are not
 constant in every individual.  They are summed up as folloAVs:
   Section of cartilage near the point of ossification.
1, ordinary appearance of cartilage.  2 and 3,  more ad-
vanced stages of ossification.  V,  2' and '6' portions
1, 2 and 3 more highly magnified.
97. What is tho number of bones in the human body ?  Givo tho different groups. 
38
HITCHCOCK'S   ANATOMY
Fig. 36.
Fig. 37.
  A knee joint showing points of ossification,
               1, 2 and 3.

   Head..........................    g
   Ear............................    6
   Face..........................   14.
   Teeth.........................   32
   Vertebrce, Sacrum and Coccyx....   26
   Os Hyoidcs, Sternum and Ribs___   2G
  Upper Extremities...............   6i
  Lower Extremities..............   62
  Sesamoid Bones.................    8

                                    24G.

   98.  Vertebrre,  Groups  of Verte-
bra?,  Cervical  Vertebra.—The Ver-
tebrae or Spinal  Column  claim the
first attention,  since they are the
  Description of Fig. 37.  Lateral view of tho Spinal
Column.  1, Atlas. 2, Axis (second Vertebra.) 3, Last
Cervical Vertebra.  4, Last Dorsal A'ertebra.  5, Last
Lumbar.  G and 7. Sacrum. S, Coccyx. 9, a Spinous
Process.  10, Intervertebral Foramina. 
AND  PHYSIOLOGY.                      30
Frontal Bone.   FlG. 38.   Parietal Bone.
                         /
Crbit.
Lower Jaw.
Cervical Vertebrae,
   Shoulder Blade,
Temporal Bone.
Clavicle.
Ilium.
 Tibia. -
Fibula. „
- Patella.
     . Tarsus.
 ,.--'' .. Metatarsus.
/''  ., Phalanges. 
 40            HITCHCOCK'S   ANATOMY

 first developed bones,  and the center around which the others
 are formed.   They may bo separated  into  the true and false:
 or those Avhich are  separable from,  and movable  upon each
 other, and those  which are  firmly joined  together.   Of  the
 true vertebras there arc three  sections, named  in  accordance
 Avith their location on the  body : Cervical, Dorsal,  and Lum-
 bar. The Cervical,  or  those  of the neck, are seven  in number,
 the first and second of Avhich are the  most remarkable.  The
 first is named Atlas, from the mythological story that  a giant
of this name supported the earth on  his shoulders, and it is

             Fig. 30.                            Fig. 40.
                                        The Axis. 1, Body. 2, Proces-
                                      sus dentatns.  3, Articulating sur-
                                      face.  4,  Foramen for vertebral
                                      Artery. 5, Spinous process.  6 and
                                      7, Oblique processes.

upon this one that the head is moved in a direction backwards
and forwards.   The second, called Axis,  is  characterized by
a projection or  pivot,  Avhich  admits  motion of the  head in
a horizontal direction, but  in  no other.   It  is the dislocation
of this process, and the consequent pressure  upon the  spinal
cord that causes death in criminals executed bv han^in"-
   99. Dorsal  Vertebra.—The Dorsal Vertebrae, or those of
the back, are twelve in number, and give attachments  to all
the ribs.'  The central portion or body of  each increases from
above downAvards,  that they  may more  firmly support  the
superincumbent  weight of the body.

  95. AA'hy are the A'ertebra; first described?  AVhat two groups may they be divided
into?  AVhat other  three sections  of A'ertebra!?  AVhat is the name of the first and
second Vertebra? 'Jt. How many Dorsal vertebra;, and what bones are attached to
them ?
 The Atlas.  1, Anterior Tubercle.  2, Articular
Face. 3, Posterior surface of Spinal Canal. 4, In-
tervertebral Notch.  5, Transverse process. 6, Fo-
ramen for Artery.  7, Superior oblique process.
8, Tubercle for transverse Ligament. 
AND   PHYSIOLOGY.
41
Fig. 41.
FiG. 42.
  A Dorsal Vertebra. 1, The Cody. 2 and
7, Faces for head and tubercle of Eib.  3,
Upper face of the body. 4 and 5, Interver-
tebral Notch.  6, Spinous process.  S and
9, Oblique processes.
 The Sacrum. 1 and 2, Articular sur-
faces. 3, Promontory of the Sacrum. 4
and 10, Lines of former division of Sa-
crum. 5 and 6, Foramina. 7, Sacro Ischia-
tic Notch. 8, Ahe of tho Sacrum.  9, Ob-
lique processes.
   100. Lumbar  Ycrtebrs.—The vertebrae  of the Loins,  or
the Lumbar, are  five in number, and are the  largest members
of the spinal column, since they are  the only bones  in this
part of the  body.   They are more massive and solid in all
their parts than  the rest of this column, that  they may  be
equal to the strength required of them.
   101.  Sacrum___The  Sacrum is a  single  bone,  although
its typical form is  that of five  vertebrae, Avhich are actually
found in some animals.   Its appearance is that of five verte-
brae,  which are partially anchylosed or grown  together.   The
form of the bone  is someAvhat  like a  Avedge, with  the  base
directed upwards,  and the point curving inwards  and  for-
wards.
   102.  Coccyx.—The  Coccyx is the lower
extremity of  the Spinal Column, formed
of  four anchylosed  and imperfect  verte-
bra ; and it is an extension of these bones
in the monkey which makes the tail.       **> coccyx,  i, First bone.
                      Sacrum. 4 and 5, Notches to form Foramen.  6, Last bone.
FIG. 43.
 100 How many Lumbar Vertebra;? AVhy are they the largest in size ? 101. Describe tho
Sacrum. How many rudimentary vertebras does it consist of? 102. Describe the Coccyx. 
42
HITCHCOCK'S  A NATO 31 Y
   103.   General  Remarks  on  the  Spinal  Column.— The
 Spinal Column  viewed  as a  whole  may be  considered  as
 made up of four cones, OAving to the different sizes of the ver-
 tebrae.  The apex of the upper one commences Avith the Atlas
 and extends  as  far as the first  dorsal vertebra.  Here  the
 second one commences in an inverted position, extending over
 the upper three dorsal vertebrae.   The third reaches Avith its
 base  as  far  as the  top of the Sacrum,  Avhere  the inverted
 fourth one terminates  Avith the Coccyx.   Viewed from  the
 front the spinal column should be in a straight line Avhen in a
 healthy condition; but a lateral vieAV shows two curves, one
 at the lower part of the neck, and the other at the  lumbar
 vertebrae,  the design  of this  curvature being  to  place  the
 head  and  its delicate  contents upon an elastic  and  flexible
 support,  and the design of  the straight position  in the other
 direction, being to give equal tension to the muscles on both
 sides.

   104. Intervertebral Cartilage.—Between all  the vertebrae
 is placed a thick cushion of cartilage.   This by yielding not
 only alloAVS a free and  ready motion to the column as a Avhole
 but is an additional protection to  the  brain, by diminishing
 the severity of any vibration communicated from below.

   105. Bones of the Head—The Skull  may  be considered
 as the superior expansion of the spinal column, Avhen  it__the
 spinal column—is taken as the center  of development  of the
 whole body, Avhich contains in the cranium the brain,  and in
 the face most of the organs of sense.

   106.  In the Cranium or true skull are eight bones:
          1 Frontal,        2  Temporal,      2 Parietal,
          1 Occipital,       1  Sphenoid,      1 Ethmoid.

  103. Of how many cones may the Spinal Column be considered as composed?  From
what direction docs the Spinal Column appear in a straight line? AVhat curvatures does
a lateral view show? 104. AVhat substance do we find between the vertebras?  Give
its use.  105. What may the Skull be considered as?  AVhat organs does it contain?
106. Give the bones of the Skull.                                     ' 
AND  FHYSIOLOGY.                43
   107.  Frontal,
Temporal,   Parie-
tal,   Occipital,
Sphenoid, and Eth-
moid  Bones.—The
Frontal Bone is sit-
uated  in the upper
and front part  of
the  head, occupy-
ing that portion  of
the skull called the
forehead.\   It  is
mainly a  flat bone,
but  the  portion
lying above the eye
is hollow, in order
that protection may
be afforded  to this
delicate organ,  as
 Avell as to give sufficient
 prominence  to  the  up-
 per  part of  the  face.
/Che two Temporal Bones
 cover  the front  part of
 each  side of the skull
 in  that  position  com-
 monly  known  as  the
 temples,  and each bone
 is a  little  larger than
 the space Avhich  is pro-
 tected  by  tho  external
 ear.)  In the inner por-
 tions, called the petrous,
 are  located the  organs
Fig. 44.
 1, Frontal. 2, Parietal.  S, Occipital.
5, Nasal.  G, Malar.  7, Upper Jaw.
9, Mandible.

                    Fig. 45.
 4, Temporal.
8, Lachrymal.
 Frontal Bone. 1, Frontal Protuberance of right
side.  2, Supcrciliiiry  ridu'c.  3, Superorbitaiy
ridge. 4 and 5, Angular processes.
 107. What kind of a bono is the Frontal ? Why is a portion of it hollow ?  AVhere are
the Temporal Bones located 1
55 
44
IIITCHCOCIC'S  AX ATOMY
7/'   W'"'°
  Left Temporal Bone.  1, Squamous portion.
2, Mastoid portion. 3, Petrous portion.  4, Zygo-
matic portion.  5, Articulating surface for lower
jaw.  0, Temporal ridge. 7, Glenoid fissure. S,
Mastoid foramen. 9, Canal for ear. 10, Groove
for digastric muscle. 11, Styloid process.  12, A*a-
ginal process.  13, Glenoid Foramen. 14, Groove
for Eustachian tube.
Fig. 47.
                FlG-40-                 of  hearing.    Directly
                                       behind the external ear
                                       is felt a hard projection
                                       which  is   the  mastoid
                                       process  of  this   bone,
                                       and   serves  for the
                                       attachment  of  many
                                       muscles,   which   move
                                       the head.  And directly
                                       in front of the  ear is
                                       another prominent  pro-
                                       cess,  called the  zygo-
                                       matic, Avhich articulates
                                       Avith  the  malar  bone,
                                       and  to  Avhich  is  at-
                                       tached one of  the ele-
                                       vator  muscles  of the
                                       jaAv.   The two  Parie-
                                       tal Bones are eminently
                                       flat  bones  of a  square
                                       shape, forming  the  es-
                                       sential parts of the pro-
                                       jections  on the  back
                                       sides  of  the head, and
                                       uniting Avith each other
                                       on the median line, up-
                                       on the top  of the skull.
                                       They  join  with   the
                                       frontal bone in front, the
                                       temporal  bones below,
                                       and  the occipital bone
                                       behind.  The  Occipital
Bone  has an  imperfectly circular outline, and  at its  loAver
  Wh-it i> the mastoid process?   AA'here is the zys >matic process?   Give the form of
the Parietal*. AVhat is t! e outline of the Occipital Bone ?  AVhat is the large orifice in
its lower part for?  Give tho position and general outline of the Sphenoid Bone.  With
what bones does this articulate ?
t
X"
6

'■*,.„'.■„
^M  til
w
t.....* '"  . ..4&
%#PV
,mis
■--"■*£
^^i<
 Left Parietal Bone. 1, 2. 3, 4. Superior, Infe-
rior, Anterior, and Posterior surfaces. 5, Ridge
for Temporal Fascia. G, Parietal Foramen. 7 and
8. Inferior angles. 
AND   PHYSIOLOGY.
45
edge a large  orifice for the
passage of tho spinal mar-
row,  just as it  enters  the
vertebrae.   It  is  in  the
most  posterior part of  the
skull,   joining   Avith  the
sphenoid in front,  and rest-  *i'|L
ing upon the Atlas  A'erte-
bra.    The  Sphenoid  Bone
is  directly  underneath  the
skull,  extending from side
to  side,   forming   a  very
small  portion  of  the  out-
side  of  the  skull at  the
point   where   the  frontal
and temporal bones   come
the nearest to  each other.
From  its  name  Ave   learn
that it i3 somewhat Avedge-
FiG.  48.
  External surface of Occipital Bone.  1 and 4,
Semicircular liidges.  2, Occipital Protube-
rance.  3, Attachment of ligamentum nucla;.
5, Foramen for Medulla oblongata.  6, Condylo
of right side.  7 and S,  Condyloid Foramina.
9, Jusular Eminence.  10, Jugular Foramen.
11, Basilar process.  12, Points of attachment
for odontoid ligaments.  13, Edge for attach-
ment with Parietal bone.  14, Point of attach-
ment for Temporal bone.
Fig. 49.
  The Anterior and Inferior Surface of the Sphenoid Bone.  1,1, Apophj-scs of Ingras-
sias.  2, 2, The great Winss.  3, Ethmoidal Spine.  4, Azygos Process.   5, Sphenoidal
Cells, after the removal of the Pyramids of Wistar.  6, Posterior Clinoid Processes.
7, Sphenoidal Fissure.  8, Foramen Rotundnm.  9, Depression for the Middle Lobes of
the Cerebrum.  10, Surface for the Temporal Muscle.  11, Styloid Process. 12, Exter-
nal Pterygoid Process. 13, Internal Pterygoid Process.  14, Pterygoid Foramen.  13, Ar-
ticular Face for the Os Frontis. 16, Points to the Sella Turcica. 
46
HITCHCOCK'S  ANATOMY
shaped  in its  general  outline,  although  it  is  covered  and
filled Avith  cavities and processes  for  the   protection  and
proper direction of  many of the delicate organs which  pass
through it to their destination.   This  bone  articulates  with
all those  in the cranium, and  five of those in  the face, and
serves as a point of attachment  for  twelve pairs of muscles,
and  is one of  the most complicated bones belonging to the
human  skeleton.
  The  last  bone of  the cranium  is  situated  at the   base
Cribriform Plate.  5, Superior Meatus.     A View of the Outside of the Vault of
C, Superior Turbinated Bone.  7, Middle    the Cranium, showing the Sutures. 1, The
Turbinated Bone. 8, Os Ph.num. 9, Sur-    Coronal Suture.  2, The Sagittal Suture.
face for tho Olfactory Nerve.             3, The Lambdoidal Suture.
of the  front  portion of the  brain,  between the sockets  of
the eyes,  and behind the root of the nose.   It is  called  the
Ethmoid  Bone.   Its outline is that of a cube, consisting of a
perpendicular plate,  and  two  lateral  portions.    From  the
fact that  it is extremely fragile, OAving  to the  great number
of perforations Avhich it contains, it derives its  name from the
Greek Avord signifying a sieve.  It is so deeply seated that it
receives the attachments of no muscles.
   103rSutures— Tho  bones  of the  skull  are  united  by
Give the shape and position of the Ethmoid bone. AAThy called Ethmoid? 
AND  PHYSIOLOGY.
47
ragged edges called Sutures.   These  are  small  and  rough
projections of bone  which are  largest at  their  extremities.
They are made to fit into the edge3  of  the opposite bone with
great firmness, thus joining the bones together,  by essentially
the same process Avhich in cabinet work is knoAvn as dovetail-
ing.   The  name  Suture is  applied, since Avhen  these edges
are  perfectly joined  by  this  articulation, they resemble  the
seam made  by sewing together  tAvo pieces of cloth  by  the
"over and over"  stitch.   Situated  directly Avithin these sut-
ures   are  frequently   found             FlG, ^
small  bones, uncertain as to
number, sometimes tAvo inches
in diameter,  called  Ossa  Tri-
quetra.   No  special use for
them  has been discovered as
yet.
   109.   The  Lower  Surface
of the Skull.—The whole of
the lower surface of the skull
is extremely uneven  for the
attachment of a great number
of muscles, and the  protection
of delicate nerves and  blood-
vessels  Avhich pass  to  and
from the brain and face.

/   110. Bones in  the Face.—
The  Face is that portion of
the head situated below a line
drawn from  the  orbit  of the
eye to the passage of the in-
ternal ear.  Its framework con-
tains fourteen bones. 2 Nasal;
  A Front A'iew of che Sknll, showing tho
Bones composing the Face.  1, Os Frontis.
2, Nasal Tuberosity. 3, Supra-Orbital Ridge.
4, Optic Foramen. 5, Sphenoidal Fissure.
6, Spheno-Maxillary Fissure.   7, Lachrymal
Fossa, and commencement of the Nasal Duct.
8, Opening of the Anterior Nares, and the
A'omer.  9, Infra-Orbital Foramen.  10, Ma-
lar Bone.  11, Symphysis of the Lower Jaw.
12, Anterior Mental Foramen.  13, Ramus of
the lower Jawbone.  14, Parietal Bone. 15,
Coronal Suture.  16, Temporal Bone. 17,
Squamous Suture.  18, Great AVing of the
Sphenoid.  19, Commencement of the  Tem-
poral Ridge.  20, Zygomatic Process. 21, Mas-
toid Process.
  How do the bones of the skull join with each other? What process m cabinet tnak.ng
does it correspond to ?  What are often found  in these sutures? 109. A\ hat is the sur-
face of the lower part of the skull ? 110. Give the boundaries of the face.
                              3 
48
HITCHCOCK'S  ANATOMY
2.  Malar;  2  Lachrymal;  2  Superior Maxillary;   2 Palate;
2 Turbinated;  1 Inferior Maxillary;  1 Vomer.

   111. Nasal Bones.—The Nasal Bones are oblong, foursided
bones,  about an inch  in  length,  which  together  form the
bridge  or base of the nose.

               Fig. 53,
 An Anterior and Posterior View of the
Nasal Bones. Pdght Hand Figure. 1, An-
terior Inferior Extremity. 2, Articulating
Surface for its Fellow.  3, Surface for the
Nasal Process of the Superior Maxillary
Bone.  4, Points to the Groove on the In-
ner Side, for the Nasal Nerve.  5, Articu-
lar Face for the Os Frontis. 6, Foramen
for the  Nutritious Artery.—Left Band
Figure.  1, Posterior Inferior Extremity.
2, Surface for its Fellow. 3, Surface for
the Superior  Maxilla.  4, Groove for the
Internal Nasal Nerve.  5, Surface for the
Os Frontis.  6,  Lower  portion of the
Groove for the Nasal Nerve.
  An Anterior View of the Malar Bona
of the Eight Side.  1, Anterior Oroital
Angle. 2, Orbital Face.  3, Superior An-
gle for articulating with the Os Frontis.
4, External Angle for the Zygoma of the
Temporal Bone. 5 and  6, Inferior An-
gle and Surface for the Superior Maxilla.
7, Nutritious  Foramen.
   112.  Malar  Bones.—The  Malar  Bones  give  the  promi-
nence and form to the cheek.   They are  partially hollow, of
an irregularly quadrangular outline, and  articulate Avith  the
frontal above, the zygomatic process of  the temporal  behind,
and the  superior  maxillary beloAV.   The name  is from  the
Latin Mala,  a " cheek," hence cheek bones.
   113.  Lachrymal Bones.—The  Lachrymal  Bones  are  the
  How many bones in the Face, and what are their names ?  111. Describe the Nasal
Boneg. 112. What bones are found in the cheeks ? 
AND  PHYSIOLOGY.
49
smallest bones in  the  Face,  being  about £th of  an  inch  in
diameter.   They are situated  at the  inner angle  of the  eye,
and are named from the Latin  Lachryma, a "tear." since
the  tears  pass  into  the  nostrils through a  canal  in  these
bones.    This bone is also called  Os Unguis.
Fig. 5G.
Fig. 55.
  An Anterior View of the Os Un-
guis of the Left Side.  1, Its An-
terior Inferior Angle.  2,  Orbitar
Plate and Side  for the Os  Pla-
num.  3,  Fossa for the Lachry-
mal Sac.  4, Superior Extremity.
                                A Posterior and Half Lateral View of the Pal-
                              ate Bone.  1, Palate Pla'e on its Nasal Surface.
                              2, Nasal Plate.  3, Pterygoid Process.   4, Sur-
                              face for  Articulating with its fellow.   5, Half
                              of the Crescentic Edge and Spine for the Azygos
                              Uvula; Muscle.   6, Ridge for the Inferior Spongy
                              Bone.   7, Sphcno-Palatine Foramen.   8, Orbital
           Plate. 9, Pterygoid Apophysis. 10, Depression for the External Pterygoid
           Process of the Sphenoid Bone. 11, Same for the Internal Pterygoid Process.

   114.  Palate  Bones.—The  Palate Bones are the most ir-

regular bones of the  face, and Avhen viewed  in one direction

resemble the capital letter L.   They form a part of the orbit
of the eye, the outside of the
nose, and  a large part of the
roof  of  the  mouth Avhich  is
known as  the hard palate.

   115.   Turbinal  Bones.—
The  Turbinal Bones  (really
the   Inferior  Turbinated
Bones,   since  corresponding
plates upon the ethmoid  bone
are called Superior Turbinated
Fig. 57.
  An External A'iew  of the Inferior
Spongy Bone of the Eight Side.  1, An-
terior  Extremity,  for  resting on  the
Eidge of the Upper Maxilla.  2, Posterior
for resting on  the Ridge of the  Palate
Bone.  3, Hooked portion, for resting  on
the Lower Margin of the Antrum High-
morianum.  4,  Its Inferior Border.
  113. AVhat are the smallest bones of the face, and why called Lachrymal ? 114. AA'hat
are the most irregularly-shaped bones in the face, and what portion of tho mouth is
made up by tho Palate Bones?  115. Give the description of tho Turbinal Bones. 
50
HITCHCOCK'S   ANATOMY
Bones) are curved laminae or thin plates  of bone,  resembling
a loose scroll, and are  found in each nostril,  for the purpose
of affording as large  a surface  as possible  for the expansion
of the mucous  membrane  of the  nose,  which  contains  the
nerves of  smell.   The name Turbinal  or  Turbinated  is  ap-
plied because of their scroll-like appearance.
   116.  Superior  Maxillary  Bone.—The Superior  Maxilla-
ries  are the largest bones of the face, joining Avith each other
Fig. 58.
Fig. 59.
  An External ATiew of the Superior Max-
illa of the Left Side.   1, Orbitar Process.
2, Infra-Orbitar Canal.  3, Space  for the
Os Unguis.  4, Upper part of the Lachry-
mal Canal.   5, Nasal Process, and Sur-
face for Articulating with the  Os Frontis.
G, Surface for the Nasal Bone.  7, Anterior
portion of the Floor of the Nostril.  8, Sur-
face for Articulating with its Fellow. 9, Al-
veolar Process. 10, Points to the Depression
j ist below the Infra-Orbitar Foramen. 11,
Surface for the Malar Bone.
                                      The Inferior Maxillary Bone.  1, The
                                    Body. 2, The Ramus.  3, The Symphy-
                                    sis.  4, Alveolar Process.  5, Anterior
                                    Mental Foramen.  6,  The Base.  7,
                                    Groove for the Facial Artery.   S, Tho
                                    Angle.  9, Extremity of the Ridge for
                                    the Mylo-IIyoid Muscle.  10, Coronoid
                                    Process.  11, Condyle.  12, Neck of tho
                                    Condyloid Process.  13, Posterior Men-
                                    tal Foramen.  14, Groove for the Infe-
                                    rior Maxillary Nerve. 15, Molar Teeth.
                                    1C, Bicuspidate Teeth.   IT, IS, Middle
                                    and Lateral Incisors.
on the median  line, and thus form a portion  of the  roof of
the mouth.    Each one of them articulates with ei'dit teeth
with all the bones of  the face but  the  loAver jaAV,  and tAvo of
the  cranium.   Their  name  is  from  the  Litin, Maxilla  a
"jaAV," and both of them constitute the upper  jaw.

   117.  'IaiuliMc.—The  Inferior  Maxillary, or  lower jaw is

  113. How are the Superior Maxlllaries situated? How many teeth are found in each
of them ? 117. Describe the Mandible. 
AND  PHYSIOLOGY.
51
the only movable bone of the head or face.   It contains the
sixteen  loAver teeth, is of an arched  form,  and  at  each ex-
tremity has a square-shaped process  for articulation with the
temporal bones, and the  attachment of muscles.
  118.  Vomer.—The
name of the Vomer is
derived from the  Latin
meaning  a  ''plow-
share/' on account of
its  approximate resem-
blance  to that object.
It completely separates
the  nostrils  from each
other, and like the tur-
binated bones gives at-
tachment  to no  mus-
cles.
Fig. GO.
 The ATomer. 1, 2, Posterior and Superior Surface
hollowed to receive the  Azygos Process of tho
Sphenoid Bone. 3, Anterior Surface for the Car.
tilaginous Septum of the Nose.
->   119. Number  of Teeth.—The Teeth of the Human Adult
 when all present  in the jaA\-s, number thirty-two.   And al-
 though properly bones, still they differ in three respects:
    1st, Organic Composition.
    2nd, Time of  Development and Replacement.
    3d,  Decay Avhen fractured.
    120. Organic  Composition, Cementum, Dentine, Enamel,
 Microscopic  Structure  of Enamel, Development  of Teeth,
 Nasinyth's  Membrane.—The  Teeth are  composed  of three
 substances: a Cementum  which forms a thin coating on the
 fangs of the teeth, and Avhich thickens in advanced  life ; tho
 Dentine Avhich resembles bone in  its external characteristics
 and makes the largest part of the teeth, containing the prin-
 cipal vessels  and nerves of the  teeth;  and the  Enamel, the
 hardest substance in the human  body, which is.a covering to
 113  From what does the Vomer derive its name?  AVhat two cavities docs it sep-
arate ? 113. How many teeth in an adult? In what respects do they differ from tho other
bones of the body ?  120. Of what substances are tho teeth composed ? 
52
HITCHCOCK'S  ANATOMY
Fig. 61.
Fig. 62.
  Vertical Section of Human Incisor,  a,
the point where  the Gum is attached to
the Tooth.
Fig. 63.
Fig. 64.
  A View of an Incisor and of a Molar
Tooth, given by a Longitudinal Section,
and showing that the Enamel is striated
and that the Striic are all  turned to tho
center.   The  Internal Structure is also
seen. 1, The Enamel. 2, Tho Ivory. 8,
The Cavitas Pulpi.
      A Vertical Section of an Adult Bicuspid,
    cut from without inwards; magnified four
    times.  1, 1, The Cementum which sur-
    rounds the Root up to the commencement
    of the  Enamel.   2, 2, The Dentine of
    the Tooth, in which are seen the greater
    Parallel Curvatures, as well as the position
    of the Main Tubes.  3, Apex of the Tooth,
    where the Tubes are almost perpendicular.
    4, 4. The Enamel.  5, The Cavity of the
Pulp, in which are seen, by means of the Glass,
the Openings of the Tubes of the Dental Bone.


    all  the tooth above  the gums.

    This  is a pure  white  sub-

    stance,  thickest upon  the  top

    of the   crown,  and  gradually

    growing thinner  toAvards  the

    gum, where  it  disappears al-

    together.   Under  the  micro-

    scope it is  seen  to be made

    up of minute hexagonal fibers,

    one end of Avhich rests  upon

    the  Dentine,  and  the  other

    forms the  free surface  of  the

    tooth.   These tubes or fibres

    are  slightly undulating  and 
AND  PHYSIOLOGY
53
from  g-oV oth to ^\^d  of an              Fig. 65.
inch  in  diameter.   The en-
amel is also covered by a very
thin membrane, rrhist of an
inch in diameter,  called  Nas-
myth's membrane.    This  is
a " calcified" membrane and
can be seen only with great
care, since it is not acted up-
on by the Strongest acids Or    A portion of the Surface of the Enamel
  ■ii  i-                           on which the Hexagonal Terminations of
ailiaiies.                         tjie j^res are shown ; highly magnified.
                                 1 2, 3, Are more strongly marked dark,
   121. Development Of Teeth.   crooked Crevices,  running between the
-.           „  .   _,             rows of the Hexagonal Fibres.
Temporary Set.  Permanent
Set.—The teeth in the human subject are not perfectly formed
at birth,  but exist in the form  of follicles or shut sacs, which
at the seventh or  eighth month of infantile life,  are developed
into teeth.  The process of dentition generally occupies  from
one to three  years,  during which time the temporary set, as
it is termed, make their appearance.   These  number tAventy,
ten in each jaw, and between the age  of seven and fourteen
become loose, and are easily removed to give place to the per-
manent set which numbers thirty-two.  Generally, however,
the last tooth in each jaw does not make its appearance until
the twentieth year of life.

   122. A more accurate statement of dentition  of the tempo-
rary teeth shows that they appear at the following ages:

            The Incisors, from the  7th to the 10th month.
            The Anterior Molars,   12th    ':   13th   "
»            The Canine Teeth,     14th    "   20th   "
            Posterior Molars,      18th   "   36th

   123. The- permanent  teeth appear as follows:

  Describe each of the teeth. What membrane completely covers the outside of the
tooth?  121. Illustrate the development of the teeth.  122. Give the time of appearance
of tho temporary teeth.  123.  WTien do the permanent teeth appear ? 
54             HITCHCOCK'S  ANATOMY
             Incisors, from the 8th to the 9th year.
             Bicuspids,       3 0th  "   11th  ':
             Canines,        12th  "   12£th "
             Second  Molars,   121th "   11th  "
             Third .Molar.-:,     lTth  "   19th  "

   124. Names  of Teeth.—A  third  set  of teeth  has  been
knoAvn  to  make its appearance; also a tooth extracted and
at once replaced  may become firm again at the  end of  some
months.
   The  names  and  number of the  permanent teeth  in  each
jaAV, beginning at the posterior part of the mouth, are :
   2 Wisdom, 4 Molars, 4 Bicuspids,  2 Canine, 4 Incisors.

                            Fig. 66.
a      b       c     d     «      /        a
 a     b     c     d     e       f          g         h
a, b, Incisors,  c, Canine,  d, e, Bicuspids, f, g, Molars, h, Wisdom teeth.
1%  125.  Fracture of Teeth.—All the bones of the  body, ex-
  cept the teeth, when broken will become united again ;  but if
  the teeth  lose  a portion  of their  enamel, or even if it be
  cracked, the tooth  so  injured  at once  begins to decay, and
  will be entirely consumed, unless the disease be  checked by
  artificial means.

   124. What  is said about a third set?   Give  the names of the permanent  teeth.
  125.  What it the teeth are broken or cracked ? 
AND   PHYSIOLOGY.
55
  An Anterior View of the Os Hyoides,
1, The Anterior Convex Side 01 the Body.
2, The Cornu Majus of the Left Side.  3,
The Cornu Minus of the same Side. Tho
Cornua were ossified to the Body of tho
Bone, in this specimen.
   126.   Hy.oid  Bone. —The               Fig. 67.
 Hyoid Bone is the bone Avhich
 forms the base of the tongue,
 and  the  upper  extremity of
 the  trachea.      It  has  the
 shape of the  Greek  letter  U
 (or  Upsilon)   and  articulates
 with  no  other bones,  but is
 completely  enveloped  by  the
 soft  parts.   It  has  a  consi-
 derable range of motion  in  a
 vertical  direction,  and hence gives  attachment  to  no less
 than eleven pairs of muscles.
    127.  Sternum.—The  Breast  Bone  is  flat,  about  eight
 inches in length, one and a half in  Avidth, and  is  located  on
 the median line of the body upon the front portion of the tho-
 rax  or chest,  articulating with the seven upper ribs  on  both
 sides, and also Avith the clavicle.
//"  128.;  Ribs.—There are twenty-four ribs  in  the human
  Fig. 68.  4j4&mm*±+                          Fig. 69.
                                     A View of the Upper Side of tho First
                                   Bib of the Right Side, half the size of na-
                                   ture.  1, The Head.  2. The Tubercle.  3,
                                   Anterior Surface.  4, Groove for tlie Sub-
                                   clavian Artery. 5, Groove for  the Sub-
                                   clavian A'ein.  6, Anterior Extremity for
  A Front View of the Sternum.  1, First   the Cartilage. 7, Tubercle for tho Scalenus
Piece.  2, Second Piece.  3, Ensiform Car-   Anticus Muscle.
tilagc, or Third Piece, 4, Articular Face
for tho Clavicle.  5, Articular Face for the First P.ib. 6, Articular Face for the Second
Bib.  7, S, 9, 10, Articular Faces for the Last Five True Bibs.

  120. AA'here is the Hyoid Bone ?  What Greek letter docs it resemble?  127. Describe
the Sternum.  AVith what bones does it articulate ?  12S. Number of Bibs in man?
                                3* 
56              hitchcock's   anatomy

                              Fig. 70.
  General Character of the other Ribs, seen on their Upper and Under Surface.  The
left hand figure is the Upper Face of the Rib.  1, Head of the Bib.  2, Its Tubercle.
3, Anterior Extremity for the attachment of the Costal Cartilage. 4, Groove for the Ar-
tery and Nerve.  5, Angle of the Elb.  The right hand figure is the Under Surface of
the Rib.  1, The Head.  2, Its Tubercle.  3, Anterior Extremity.  4, Groove for Inter-
costal Artery and Nerve.  5, Angle of the Bib.


body, which are  divided into  two  classes, the  true  and  the

false, or those which  are  closely united  Avith   the  sternum,

and those which are remotely attached to it by long cartilages.

They are attached at their posterior extremities  to the  verte-

brae, and run  downwards and forwards, so  that when elevated,

                              Fig. 71.
                            A'ertebral Column.     Bibs,
^Clavicle. 
AND   PHYSIOLOGY,
  An Anterior  View  of the Clavicle of the  Bight
Side.  1, The Anterior Face of the Body of the  Bone.
2, Origin of the Clavicular portion  of the Sterno-
Cleido-Mastoid Muscle.  3, The Sternal Extremity of
the Bone.  4, Tho Acromial Extremity of the  Bone.
5, Articular Face  for the Acromion Process of the Scapu-
la. 6, Point of Attachment of the Conoid Ligament
7, Point of Attachment of the Ehomboid Ligament.
 they enlarge the cavity  of the chest.   The true ribs are  the
 seven uppermost ones, and the false the five  lower ones, and
 are so arranged that they form a cone with the apex at  the
 neck.   The two lowest ribs are sometimes called  "floating,"
 because they are only attached to the  vertebrae.

    129.  Clavicle,—
 The Collar Bone is the                  Fig. 7 2.
 commencement  o f
 the upper extremity.
 It is one of the class
 of  long  bones  ex-
 tending   from  the
 highest point  of the
 scapula to the  upper
 part of the sternum,
 and  bears a partial
 resemblance to  the
 Italic  letter F.   The name  is from  the Latin  Clavis,  -'a
 key," since it  remotely resembles an antique key.

/^130.  Stapula.—A  large, flat, and  triangular bone upon
 the upper part of  the  back,  and  forming the shoulder,  is
 called  the  Scapula, or Shoulder Blade.  It has a high  and
 narroAV ridge running through  its longest  diameter, which  is
 the bone so distinctly felt  upon the shoulder and  upper  part
 of the back.   Its only articulations are with the clavicle and
 humerus,  the  posterior part being  kept in its place  by mus-
 cles and ligaments.  (Fig. 73, p. 58).

   131.  Humerus.-(-The Humerus is  the bone of the upper
 arm or shoulder.  (Fig.  74, p.#-58.)   It is a long  bone with
 a cylindrical shaft, and has a rounded  head for its upper  ex-
 tremity.   The  lower extremity is flattened from before back-

  WTiat two'classes  are they divided into? What do they all unite with behind?
 12fl. What two bones does the Clavicle unite with ? 130. What is the general outline of
 the Scapula?  Where is it located? What are its only articulations ? 181. What is tha
 bone of the upper arm ? 
58
HITCHCOCK'S  ANATOMY
Fig. 73.
Fig. 74.
  A Posterior View ot the Scapula of the
Left Side. 1, Fossa Supra-Spinata. 2, Fos-
sa Infra-Spinata.  8, Superior Margin.  4,
Coracoid Notch.  5, Inferior Margin.  6,
Glenoid Cavity. 7, Inferior Angle. 8, The
Neck and Point of Origin of the Long nead
of the Triceps Muscle.  9,  Posterior,  or
Vertebral Margin.  10,  The Spine.  11,
Smooth Facet for the Trapezius Muscle.
12, Acromion Process. 13, Nutritious Fo-
ramen.  14, Coracoid Process.  15, Part of
the Origin of tho Deltoid Muscle.
                                       An Anterior View of the Humerus of the
                                     Eight Side.  1, The Shaft, or Diaphysis of
                                     the Bone.  2, The Head.  3, Anatomical
                                     Neck.  4, Greater Tuberosity.  5,  Lesser
                                     Tuberosity.  6, The  Bicipital Groove. 7,
                                     External Bicipital Eidge  for the insertion
                                     of the Pectoralis Major.  8, Internal Bici-
   pital Eidge. 9, Point of insertion of the Deltoid Muscle.   10,  Nutritious Foramen.
   11, Articular Face for the Head of the Badius.  12, Articular Face  for  the Ulna.
   13, External Condyle.  14, Internal  Condyle.  15, 16, The Condyloid Eidges.  17,
   Lesser Sigmoid Cavity.

wards, and so formed into grooves and  elevations  that  it ar-
ticulates with the ulna in essentially the same  manner  as the
two portions of a door hinge.

   132. Fore-arm.  The  Ulna.—There  are two bones  in the
forearm, one  of which  only is articulated  with  the  humerus
and the other to the bones of the wrist alone,  in order  to  al-
low the rotation  of the hand upon the  bones of the forearm
  What is the shape of the lower, or ulnar articulation ?  132. How many bones in the
forearm ?  Why are there two instead of one ? 
AND   PHYSIOLOGY.
59
 as if they constituted a pivot;                Fig. 7:
 an instance of which is seen in
 the turning of a scjeAV,  or in
 the unlocking of  a door.   Of
 these two bones the Ulna arti-
 culates with the humerus, form-
 ing only a ligamentous union
 with the bones of the wrist.
 It is prismoid in form, and is
 of a hooked  shape  at  its up-
 per extremity,  so  that   it
 makes the union  betAveen  it-
 self and  the humerus  a very
 secure one.   The  word  ulna
 is a Latin term signifying  an
 ell,  because  the  forearm  in
 early times was used for that
 measure.
   133.   The  Radius.—The
 Radius  is  the  mate  of  the
 ulna.  Its  upper extremity is
 the  smallest,  and  the loAver
 the largest, since its only true
 articulation is at  the Avrist.
 A firm  membrane, however,
 unites this  bone to its fellow nearly its Avhole length. It prob-
 ably derives its name from the fact  that it measures the ra-
 dius of a circle  which  may  be described  by the hand  about
 the elboAV as a center.
   134. The Carpus.—The bones of  the Carpus  or Wrist are
eight in  number,  are small and irregular, and  have  the gen-
eral disposition of two rows.  The first row, commencing with
the one nearest the thumb,  contains the Scaphoid, Semilunar,
,!&*■>
  Bones of the Forearm.  1, The Ulna.
2 and  3, The Sigmoid Notches.  4, The
Olecranon Process.  5, Goronoid Process.
6, Nutritious Foramen. 7. Eidge for at-
tachment of Interosseous Membrane. 8,
Capitulum Ulnre. 9, Styloid Process.  10,
Shaft of the Eadius.  11, 12 and 13, Head,
Neck, and Tuberosity of Eadius.   14, Ob-
lique Line for muscular attachments.  15,
Styloid Process.
 In what operations do we need the two bones of the forearm?  Give the derivation of
nlna.  133. What is the mate of the ulna? Where does this articulate?  AVhat is the
derivation of its name ?  134. How many bones in the wrist? Give their names. 
60              II ITC H CO CIC'S   ANATOMY
Fig. 76.
Fig. 77.
  A Posterior A'iew of the Articulations
of the Bones of the Carpus in  the Eight
Hand.  1, The Ulna.  2, The Eadius.  3,
Inter-Articular Fibro-Cartilage.  4, Meta-
carpal Bone of the Thumb.  5, Metacarpal
Bone of the First Finger.  6, Metacarpal
Bono of the Second Finger. 7, Metacar-
pal Bone of the  Third Finger.  8, Meta-
carpal Bone of the Fourth Finger. S, The
Scaphoidcs. L. The Lunare. C, Tho Cu-
neiforme.  P, The Pisiforme. T, T, Tra-
pezium and TrapeEoides.  M, The  Mag-
num. U, The Unciforme.
  An Anterior A'iew of the Left Hand.
1, The Scaphoides.  2, THe Lunare.  3,
The Cuneiforme.  4, The.- Pisiforme. 5,
The Trapezium.  C, Groove for the Flexor
Carpi Badialis Tendon.  7, The  Trapc-
zoides.  8, The Magnum.  9,  The Unci-
forme.  10, 10,  The Five Meta-Carpal
Bones.  11, 11, First Bow of  Phalanges.
12, 12, Second  Bow of Phalanges.  13, 13,
Third Bow of Phalanges. 14.  First Pha-
lanx of the Thumb.  15, Last Phalanx of
the Thumb.
Cuneiform, and Pisiform.    The second in the same order, the
Trapezium, Trapezoid, Magnum, and Unciform.

   135.  The   Metacarpus. — The  Metacarpus  contains  five
bones.   Each of these articulate  with  the carpus above, and
the phalanges below, being found in the  space  knoAvn as the
palm or body of the hand.

   136.   The Phalanges,—The Phalanges are the bones  of
the thumb and  fingers,  two in  the former, and three in the
latter, making fourteen in each hand.
  135. Describe the Metacarpal Bones.  WThat part of the hand do  they occupy?
i36. How many Phalanges in the thumb, and how many in  each finger ?  What is the
whole number of them? 
AND PHYSIOLOGY.
61
2--   137.  Bones of the Pelvis.—The bones  of the  Pelvis are
   the two Innominata or  nameless  bones,  and the Sacrum and
   Coccyx, which have already been described. (Fig. 78.)

                              Fig. 78.
  138.  The lnnominatnm,  Ilium, Ischium, Pubes.—Each
Innominatum presents the largest surface of any bone  in the
body.  They  are  irregularly  flat bones  and  situated  just
beneath the abdomen,  to the organs of which they  give  firm
support by their broadly-expanded surface.   In young skele-
tons they are  divided into three portions, and hence they are
described in the adult  as made up of three parts, although no
line of division can actually be seen.   The Ilium constitutes
the broadly-expanded  portion  usually known as the hip or
haunch.   The Ischium, from the Greek signifying to " hold"
or " retain," is the heavy  portion projecting  downwards, and
that point on  which the body rests, when in a sitting posture.
 137  How many bones in the Pelvis, and what are their  names? 13s. Describe the
Innominatum. Into how many parts are  they divided in young animals?  Describe
the Ilium and the Ischium. 
62              HITCHCOCK'S   ANATOMY
Fig. 79.
  Outside of the Innominatum of the Bight Side.
1, Dorsum of the Ilium.  2, Ischium. 3,  Pubis.
4, Crest of the Ilium.  5, Surface of the Gluteus
Medius.  6, Surface for the Gluteus Minimus.
7, Surface for the Gluteus Maximus. 8, Anterior
Superior Spinous Process. 9, Anterior Inferior
Spinous Process.  10, Posterior Superior Spin-
ous  Process.   11,  Posterior  Inferior Spinous
Process.  12, S[iine of the Ischium.  13, Greater
Sacro-Sciatic Notch.   14, Lesser Sacro-Sciatic
No ch.  15, Tuber Ischii. 16, Ascending Ramus
of the Ischium.  17, Body of the Pubis.  IS, Ra-
mus of the Pubis.  19, Acetabulum.  20, Thyroid
Foramen.
                 An An'erior A'iew of the Femur of
               the  Eight Side.  1, Depression for
               the Round Ligament.  2, The Head.
               ", The Neck.  4,  Trochanter Major.
               5, Trochanter Minor. 6, Surface for
               the Capsular Ligament.  7, Shaft of
the Bone. 8, The External Condyle.  9, The Internal
Condyle.  10, Surfaco for tho Patella.
The Pubis is the most  central and  anterior portion.   These
three  divisions unite at the point knoAvn as the  acetabulum or
receptacle for the head  of the  femur, Avhich is a  perfect hemi-
spherical cup  lined Avith cartilage.
   130. The Femur.—The Femur is nearly two feet in length,
and consequently the  longest  bone in the body,  commonly
known as  the  Thigh Bone.   At  its  upper portion  it makes a
  139. What is the average length of the Femur?  Give its general features.  What is
the longest bone in the body ? 
AND  PHYSIOLOGY.
G3
sudden bend inwards, forming the neck of tho bone, the ter-
mination of Avhich is hemispherical, in order to articulate Avith
the innominatum,  forming  the ball  and  socket joint.   Its
lower extremity has two large condyles or  processes, for the
purpose of giving  attachments to the ligaments  of the knee,
and articulating Avith the tibia.
   110.  The Patella —Or Knee Pan is the     Fig. si.
largest sesamoid bone in the body.  It arti-
culates Avith no bones, but lies  imbedded  in
the extensor tendon of the thigh.   The chief
value  of  this bone is  to giAre  a  change  of
direction  to the force of the muscles  which
move the lower bones of this extremity we
are noAV describing.  Patella  in Latin signi-  An Anteri0r view of
fies a "plate,"  and hence the  name of this thePateiia.  i,2,sur-
       1         .        n  .    ,.            face for the Quadriceps
bone, because of its rounded outline.         Femoris Tendon.  3,
                                             Lower Extremity and
   141. The Tibia.—That portion of the  Point of origin of the
              .    ,  ,     ,   .       . . ,  .   Ligamentum Patella;.
lower  extremity  below the knee, which  is
properly the leg, has two  bones  called cruralfor its  frame-
work.  The largest of these is the Tibia (Fig. 82, p.  64.)   It
is somewhat triangular in its  general outline, having  its
upper  extremity depressed in  tAvo places  for  the reception
of the condyles of  the femur.  Besides  the  femur  above,
it articulates with the  fibula  and astragalus  beloAV.   The
name  tibia is  given to the bone, since it resembles, though
remotely,  the ancient Phrygian flute.
   142.  The Fibula.—The Fibula is the other bono  of the
lea1, lon^  and  slender.   It  articulates at  each  end with  the
tibia.   The meaning of the  Latin fibula, is a "pin,"  or
fastening  of a  clasp, owing to  its  slender form.   The lower
extremity  of this bone,  and also that  of the tibia, forms what

  140. Describe tho Patella or Knee Pan.  In what is it imbedded ?  141. What is  tho
Leg?  What are the two bones of it? Which is the largest and consequently most im-
portant one ?   142. Give the general description of the Fibula.  What compose the ex-
ternal and internal Malleoli ?
 
64
II I T C II C O C 1C > S   A N A T O M Y
Fig. 82.
;:m
Fig. 83.
fell,
                            A View of the Upper Surface of the Left
                          Foot.  1, The  Astragalus on its Epper
                          Face.  2, Its Anterior Face, Articulating
                          with the Naviculare. 3, The  Os Calcis.
                          4, Naviculare, or Scaphoides.  5, The In-
                          ternal Cuneiform.  0, The Middle Cunei-
                          form.  7,  The  External Cuneiform.   8,
                          The Cuboid Bone.  9, 9,  Metatarsal Bones.
                          10, First Phalanx of the  Big Toe. 11, Sec-
                          ond Phalanx of the Big Toe.  12, 12, 13,
13, 14, 14, The First, Second and Third Phalanges of the other Toes.
  Eight Tibia and Fibula.  1, Tibia. 2
and 3, Inner and Outer Tuberosity.  4,
Spinous Process.  5, Tubercle for attach-
ment of Muscles of the Thigh. 6, Edge of
Tibia. 8, Internal Ancle. 9, The Fibula.
10 and 11, Extremities of Fibula.
are knoAvn as the external and  internal  malleolus,  or the two
long projections on each side of the ancle.
   143. The Tarsus.—The Tarsus is  made  up of  scAren ir-
regular bones, forming  the  instep of the  foot.   The  Astra-
galus  is  of a  cubical form  (so named from  its  resemblance
to the die, used in games  of chance) and  supports the tibia
alone.  The Os  Calcis,  meaning  the  bone  of the  heel, is the
largest of the bones of the tarsus, and  is irregularly cubical
  143. How many bones make up the Tarsus? Why is the uppermost called the Astra-
galus ?  AVhich is the largest of these bones ? 
AND  PHYSIOLOGY.
65
in form, making, by a decided  projection, the heel.   Directly
beneath and  anterior to the  last two, are found the  Cuboid
(cube-shaped) and  the Scaphoid (boat-shaped),  and anterior
to these the  three Cuneiform (wedge-shaped), articulating
with the metatarsal bones in front.
  144.  Metatarsal Bones.—These are five  in  number, and
correspond with those in the metacarpus, except  that the one
in the first toe is of equal length with the others, and does not
admit of so free motion as that of the thumb.
   145. The  Phalanges.—The Phalanges of  the foot are also
like those of the hand, except that in the foot the first toav is
the longest,  while  in the hand it is in the third toav or second
finger.
   146. Sesamoid  Bones.—Besides the  bones already men-
tioned,  there are frequently  found  in stout adult  men small
bones, or portions of bony matter  called Sesamoid  Bones,
from their  resemblance  to  the  Sesamum, a kind  of bean.
And although they are not  constant either in individuals, or
in  the  same places  in  the individual, yet  anatomists are
accustomed to reckon eight,  or  four pairs   as the normal
number.  They are all found  enclosed in  tendons, and serve
like the patella  to change   the direction of  motion.   They
are  found  at  the  point Avhere  the tendon  glides  over the
joint made  by the phalanges and metatarsus  of the  foot,
and the metacarpus of the hand, in  the  tendon  which  plays
over  the under surface of the cuboid  bone in the foot; and
also in the  tendons that glide over  the lower  condyles  of
the femur.
  147.   Bones  of  the Ear.—In  the Ear are  three  bones
which will be more  appropriately described  Avith the  organ
itself.
  148.   Number  of  Bones.  Single  Bones.—Of the  246

  144. How many Metatarsal Bones ? 145.  How many Phalanges of the Foot ? How
do they differ from those of the hand?  146. Describe Sesamoid Bones.  How many are
there, and where  are they generally found ? 147. How many bones of  the Ear ? 
66
HITCHCOCK'S  ANATOMY
bones found in the human body, all but thirty-four are found
in pairs,  or  one upon each side of the  body.   The  single
bones are the  frontal,  occipital,  ethmoid,  sphenoid,  vomer,
mandible,  hyoid, sternum,  twenty-four vertebrse,  the  sa-
crum and the coccyx,
                 SYNDESMOLOGY.

         DESCRIPTION  OF  THE  LIGAMENTS.

  149.  Kinds  of Articulation.—The  modes or  manner of
connection between the different bones of the body are three :
Synarthrosis, Amphiarthrosis, and Diarthrosis.   The first of
these modes, means  the joining  of such  bones as have no
motion between them ;  the second, a joint Avith the aptitude
for movement between the immovable synarthrosis on the one
hand, and the moArable diarthrosis on the  other; the third, a
movable  articulation, which  constitutes by  far  the greater
part of the joints of the body.
  150.   Sutura, Harmonia,  Schindylesis,  Gomphosis.—Of
Synarthrosis there  are four varieties :  first, Sutura, the  ar-
ticulation between  the bones  of  the skull by  ragged inter-
locking edges ;  second, Harmonia, that between the tAvo upper
maxillaries,  where   the  bones with  comparatively  straight
edges are simply placed edge to edge;  third, Schindylesis, or
the  joint  between the  vomer and  sphenoid, Avhere tho  ex-
panded edge of one bone is fitted into a corresponding groove
in the other;  fourth, Gomphosis,  the articulation of the teeth
Avith the jaAvs, and so named  since  it  resembles  the manner
in Avhich a common nail is driven into a plank.
  148. How many bones in the human body are found in pairs? Give tho names of tho
unmated bones. 149. How many modes of connecting  the bones together?  Describe
each.  150. Give the  peculiarities of Sutura, of Harmonia, of Schindylesis, and of Gom-
phosis. Give an example of the latter. 
AND  PHYSIOLOGY.
67
   151.  Symphyses.—Of Amphiarthrosis  there  is  but one
kind, the Symphyses, or  the apposition of two  bones with
simply cartilage betAveen.    Examples  of  this are the arti-
culations of the vertebra}, and the 033a pubis.

   152.  Arthrodia, Giulymus,  Enarthrosis.—Of Diarthro-
sis there are three  v ri.'ties:  Arthrodia, Ginglymus,  and En-
arthrosis.   Arthrodia is a slightly movable  joint, as of the
Avrist and  ancle bones,  or  the radius and ulna.  Ginglymus
is the common hinge joint,  where the degree of movement
is very considerable, but only in  two  directions.  The best
example of this is in the knee.   Enarthrosis is the ball  and
socket joint, that admits of movement in all directions.  Tho
only cases  of this articulation are  in  the  shoulder, hip, and
thumb.

   153.  Anatomy   of  the  Articulations.—In  synarthrosis
there is simply a membrane interposed betAveen the tAvo bones
which keeps  them  in  their  places.   In amphiarthrosis the
 two  extremities are partly  covered with  cartilage, lined by
 synovial membrane, and partly connected by the interosseous
 ligaments, or by an elastic  fibro-cartilage Avhich adheres to
 both edges of the bones.   In  diarthrosis especially, as it is
 exhibited  in ginglymus,  the general outline of the bone is
 quadrilateral, upon each edge of Avhich is  found a ligament.
 The lateral ones, however, are the main supports of  the joint,
 Avhile tho anterior and  posterior ones are thin and a  part of
 the time  loose, Avhich  are only of service to determine  the
 amount of movement in the joint.  An  example of this i3
 seen  in the  fingers, since they can only  be  extended so as
 to lie in  tho  axis  of  the'  metacarpal bones.  The reason
 why they can  not be bent  back  upon the  dorsal surface of
 the hand is that the anterior ligament  doe3 not admit  of suffi-
 151. Describe the Symphyses. Give an example. 152. Give the three varieties of Diar-
throsis. Give an example of Arthrodia, Giiiglymus, and Enarthrosis.  153. What are
the component parts of the different articulations? Give the mode of articulation of
the fingers.  Why ean not the finger be bent upon the back of the hand? 
68            HITCHCOCK'S  ANATOMY

cient  movement in  that  direction.   In  the knee, however,
there  are thirteen ligaments.
  154.  Motions  of  the Joints.—The motions of the joints
may be comprised  under  four  principal divisions :  Gliding,
Angular movement,  Circumduction, and  Rotation.
  155.  Gliding.—Gliding  movement  is where  the bones
simply slip  over  one another in the movement of the joint,
and exists to a greater or less extent in all the joints.

  156.   Angular.—Angular movement  may be  performed
in four  directions :  forwards and  backwards,  called flexion
and  extension, and  inwards and outwards, called adduction
and abduction.  A joint, as the finger,  is said to be flexed
Avhen it is  bent  upon  itself, that  is  upon  the palm of the
hand, and  extended when it is stretched to its fullest extent,
or as  in the finger, when it is made straight with the bones of
the fore-arm.   Adduction means the bringing of one of the
extremities towards  the body, or its  fellow, while abduction
has the reverse signification.
   157.  Circumduction.'—Circumduction can be performed
only by the ball and socket joints.  It  consists in carrying
the  limb about  the joint  in a circular plane, or  in other
words, describing a  circle about the joint as a center.
   158. Rotation.—Rotation is the movement of a bone upon
its own axis.   A slight rotatory movement  can be effected in
the joints  of the shoulder  and hip, but the best instance  is
that  of the radius rotating against  the articular head of the
humerus, producing the  subdivisions  pronation and supina-
tion.   Pronation consists in rotating the fore-arm so that the
palm  of the  hand  shall be downwards, and Supination the
 reverse.  Rotation  is  also  observed in  the movement of the
 atlas upon  the pivot of the axis.

  154. What are the four motions of the joints ?  155. Describe the Gliding movement.
 156. In what four directions can Angular movements be ? 157. AVhat is Circumduction?
 153. Describe Eotation.  What is Pronation and Supination? 
AND  PHYSIOLOGY.
69
   159. Structure of
Ligaments.   Ar-
rangement of Liga-
ments.  Capsular
Ligament.   Round
Ligam ent.—The
bones  are  firmly
bound  together  by
ligaments.    These
are   for  the  most
part bands of white
glistening fibres, as
firm as steel,  Avhich
are   composed   of
Avhite  fibrous   tis-
sue.   They are gen-
erally  very  short,
and  attached  only
to the enlarged ex-
tremities   of   the
bone.   In  most  of
the  joints,  and  es-
pecially the gingly-
mus,  the ligaments
are   arranged  in  a
cross shape upon the
sides  of the bones,
so that one bone may
glide freely over the
extremity   of   an-
other,  as  one  half
of  a   door  hinge
moves upon its other
half.   In  other  in-
stances the  ligament
Burrounds the whole
Fig. 84.
 A magnified A'iew of a Vertical section of Cartilage
from a new-born Eabbit, showing the progress towards
ossification.  1, The Ordinary appearance of Tempo-
rary Cartilage. V, The same, more highly magnified.
2, The Primary Cells beginning to  assume the linear
direction.  2', Tho same, more highly magnified.  3i
The Ossification  is extending in  the intercellular
spaces, and the rows of cells are seen resting in the
cavities so formed, the  Nuclei being more  separ-
ated than above.  8', The same, magnified more
highly. 
70
HITCHCOCK'S  ANATOMY
FlG. 85.
Fig. 86.
  An Anterior ATicw of the Ligaments of
the Pelvis.  1, The Lower part of the An-
terior A'ertebral Ligament.  2, The Sacro-
ATertcbral Ligament.  3, The Ilio-Luinbar
Ligament. 4, Tho Anterior portion of tho
Sacro-Iliac Ligament,  5, The Obturator
Ligament. 0, Poupart's Ligament. 7, That
portion of the same which is known as
Gimbernat's Ligament. 8, The Capsular
Ligament of the  Hip-Joint.  9, The Ac-
cessory Ligament of the Hip-Joint.
  Ligaments from Shoulder-Joint. 1, The
Superior Acromio-Clavicular Ligament.
2,  The  Coraco-Clavicular Ligament.  3,
The Coraco-Acromial Ligament.  4, Tho
Coracoid Ligament. 5, The Capsular Liga-
ment of the Shoulder-Joint.  6, The Liga-
mentum Adscititium, or Coraco-Humcral
Ligament.  7, Tho Tendon of the Long
Head of the Biceps Muscle, issuing  from
the Capsular Ligament.
joint, making it a shut sac, thus performing the double  office
of keeping the tAvo ends in contact, and of holding the lubri-
cating fluid  in the joint.   In  addition  to these, there  is  in
the ball and socket joint another kind of  ligamentous attach-
ment between the two  bones, called  the  round ligament,  or
Ligamentum Teres.    This is a bundle of ligamentous  fibres
in the form  of a cord, Avhich is inserted into  the summit  of
the rounded head of  the bone, and also in the bottom  of the
cup-shaped  cavity that receiA'es the head.   This is somewhat
lax ordinarily, but not so much so  but that it keeps  the  head
from slipping  out  of  its socket, and  at the same time allows
the most perfect freedom of motion.
 159. AVhat arc  the. Ligaments ? To what part of tho bones are they generally at-
tached? How are they arranged in Ginglymus joints?  AVhy ore they sometimes found"
in the form of a shut sac ? Describe the round ligament. 
AND   PHYSIOLOGY.
11
Fig. 81.
Fig. 88.
'Brffi^'/'"  /
\0i
 1 ?r?i
  The Bight Knee-Joint laid open.
1, The Lower End of the Femur cov-
ered by its Articular Cartilage, 2, The
Anterior Crucial Ligament.  3, The
Posterior Crucial Ligament.  4, The
Transverse Fasciculus  adhering to
the  Semilunar  Cartilages.  5, The
Point of Attachment of the Ligamen-
tutn Mucosum.the rest of it has been
removed. 6, The Internal Semilunar
Cartilage. 7, The External Semilunar
Cartilage.  8, A part of the Ligamen-
tum Patella; turned downwards.  9,
Its Bursa laid open.  10, The Supe-
rior Peroneo-Tibial Articulation. 11,
The Interosseous Ligament.
  A Lateral View of the Ligaments of the Hip-
Joint and Pelvis.  1, The Posterior Sacro-Iliac
Ligament of the Pelvis. 2, The greater Sacro-
Sciatic Ligament 3, The Lesser Sacro-Sciatic
Ligament. 4, The Greater Sacro-Sciatic Notch.
f>, The Lesser Sacro-Sciatic Notch. G, The Co-
tyloid Ligament around the  Acetabulum.  7,
The Ligamentum Teres.  8, The Line  of At-
tachment of the Capsular Ligament of the Hip-
Joint, posteriorly.   The Ligament has been
removed, in order to show the Joint   9, Tho
Obturator Ligament.
   160.   Aid of Atmospheric Pressure.—Atmospheric  pres-
sure also helps  to  keep the bones  together.   For since the
projection of  one member  so accurately fits the depression in
the other, and as  the  lubricating  fluid makes the  coupling
most  perfect,  the  pressure   of  the  atmosphere assists  not a
little to keep the parts together.

   161.  Inter-articular Cartilage.—Another arrangement in
the joints 13 not a little  singular, and well adapted to its pur-
pose.   This is an interarticular cartilage  in the  knee called
semilunar, or  a small  disc of cartilage Avhich  lies  loosely be-

  160. AVhat besides the ligaments helps to keep the.bones.together? .161. Describe the
interarticular cartilage and its use.                                     ■ .. - 
    HITCHCOCK'S  A >" A T O M Y


Fig. 80.                          Fig. 90.
  An Anterior View of tlvc Ligaments of
the A'ertebroe and Itibs.  I, The Anterior
A'ertebra! Ligament. 2, The Anterior Costo-
A'ertebral Ligament   3, The  Internal
Transverse Ligament.  4, The Inter-Ar-
ticular Ligament, connecting the Head
of the ltib  to  tho  Intervertebral  Sub-
stance.
Fig. 91.
  A View of the Articulation of the Lower
Jaw, given by sawing through the Joint.
1, The Glenoid Fossa.  2, The Tubercle
for the Condyle  in its Forward move-
ments.  3, The Inter-Articular Cartilage.
4, The Superior Synovial Cavity.  5, Tho
Inferior Synovial Cavity.  6,  The Inter-
Articular Cartilage  removed from  tho
Joint and seen from below.

tween the bones.   The design of it is to distribute  the  fric-

tion over a larger surface, as  Avell as to diminish it.


                                        162.    In  Fig. 90  we see

                                     the  mode  of  attachment  be-

                                     tAveen the vertebrae  and ribs

                                     which  is that  of  three dis-

                                     tinct  ligaments, to  each rib,

                                     besides  one common to  each

                                     pair  of ribs.   Fig.  91 shows

                                     the  anatomy  of  the  elboAv-

                                     joint.    Here  are  no  less

                                     than four  distinct  ligaments.

                                     We see in  Fig. 92  the liga-


                                      An Internal View of  the Elbow-Joint.
                                     1, The Capsular Ligament.  2, 2, The In-
                                     ternal Lateral Ligament.  3, The Coro-
                                     nary Ligament.  4, The Ligamentum Te-
                                     res.  5,  The Interosseous Ligament.  6,
                                     The Internal Condyle, which conceals tho
                                     Capsular Ligament behind.
 162. Describe tho ligaments in Figs. 90, 91, 92 and 93.  163. How are the joints lubri
tated?                                                        J 
AND  PHYSIOLOGY.
U
ments which unite  the  loAver
end of the  fibula to the tibia
and the tarsal  bones,  and  in
Fig. 93 the ligaments  of the
foot.
   163.  Synovial  Membrane
and   its  Secretion. — The
lubrication  of  the  joints  is
effected by means  of  a thin
membrane lining  their cavi-
ties  Avhich  secretes  an oily
substance called the Synovia,
(Fig. 94,  p.  74),  that is con-
stantly applied to the  oppos-
ing surfaces.    In health the
action of  the joint stimulates
this membrane to the  secre-
tion of a proper   amount  of
                                Fig
Fig. 92.
  A Posterior ATicw of the Ankle-Joint of
the Left Side.  1, The Interosseous Liga-
ment of the Bones of the Leg.  2, The
Posterior  Inferior Ligament  connecting
the Tibia and Fibula.  3, The Transverse,
or Long Fibres of the  same Ligament
4,The Internal Lateral Ligament. 5, Tho
Posterior Fasciculus of the External Lat-
eral Ligament.   6, The  Middle Fascicu-
lus of the same.  7, The Synovial Capsule
8, The OsCalcis.
   A Vertical Section of the Ankle-Joint and Foot of the Eight Side.  1, The Tibia.
2, The Astragalus.  3, Os  Calcis. 4, The Scaphoides.  5, The Cuneifonne Internum.
G, The Metatarsal Bone of the Great  Too.  7, The  First Phalanx of the Great Toe.
8, The Second Phalanx of the Great Toe.  9, The Articular Cavity between the Tibia
and Astragalus, with its Articular Adipose Matter.  10, The Synovial Capsule between
the Astragalus  and Calcis.   11, The  Calcaneo-Astragalian  Interosseous  Ligament
12, The Synovial Capsule between the Astragalus ami Scaphoides.  13, The Caleanco-
Scaphoid Ligament. 14, The  Calcaneo-Cuboid  Ligament. 15, The Synovial  Capsule
between the Scaphoides and Cuneifonne Internum.  10, The Synovial Capsule- between
the Cuneifonne Internum and tho First Metatarsal Bone.  17, The  Metatarso-Pha-
langial Articulation of the Great Toe, with the Sesamoid Bones below.  18, The Pha-
langial Articulation of the Great Toe. 
V4              HITCHCOCK'S   ANATOMY
Fig. 94.
  An Internal View of the Ankle-Joint of
the  Eight Side.  1, Internal Malleolus.
2, 2, Part of the Astragalus, the rest being
concealed by Ligaments.  3, Os Calcis.  4,
Scaphoides.  5,  Internal Cuneiform Bone.
G, Internal Lateral, or Deltoid Ligament.
7. The Synovial  Capsule, covered by a few
Fibres of a Capsular Ligament. 8, Tendo Achillis. A small Bursa is seen
between this Tendon and the Tuberosity of the Os Calcis.
 synovia,  the superabundance
 of Avhich (when it is present)
 is  removed  by  the  absorb-
 ent vessels.   This lubricating
 fluid, liOAvever, is not poured
 out  directly upon  the  ends
 of the bones, but upon smooth
 and elastic   cartilage,  Avhich
 is found  in  every joint,  not
 only for furnishing a smooth
articular surface,  but also to
diminish the force of jars by
its clastic character.
       FUNCTIONS  OR USES  OF  THE  BON Eg.

   164.   The uses of the bones may be classed  under three
diA'isions :
   First,  for a frameAVork to the Avhole system.
   Second,  to furnish  points  of attachment to  muscles and
ligaments.
   Third, to protect the softer parts.
   165. A Framework. Ligaments used  as Braces and Pins,
—Exactly as a human architect plans and constructs a frame
to the house, so the  Great Architect has formed  the bones.
Each bone is fitted  exactly to  the position,  size, and use  of
the part where it is  placed, and noAvhere can a supernumerary
bone bo found.   In the house to be built, braces  and joining
pins  must  be  employed,  and  those  generally of a touo-her
material than  the  frame itself.    So in the human body, l1o-a-
  Whyli cartilage useful in tho lubrication  of joints?  10^0^0^,,^^^^
as classed above.  16a. Compara tho bones and ligaments with  tho timbers braco«    1
pins of a house,                                            '     s ana 
AND  PHYSIOLOGY.
T5
ments and  cartilage exist wherever two opposite extremities
need strength and support to keep them in their places.  In
the railway locomotive immense strength is required, and at
the same time perfect freedom of motion in certain positions,
all  of  Avhich is effected by  the  ponderous bars, levers  and
Avhcels, perfectly secured by bolts, keys and screws.   But in
the human frame by Iioav much more simple  means is the
same  end  secured.   No angular or  cylindrical  couplings
secure the  human joints, though beautifully adapted to pro-
duce movement in every direction, and  no attention or care is
necessary  to lubricate  and  preserve  in  good  condition the
Avorking parts of this machine, but  a feAV tough fibers and
membranes, secure at once  in a most  perfect manner every
portion of  the  frame, and provide  at the same time means for
its  lubrication.
   166. Use of the Anomalous Forms of Bones.—The  bones
are  fitted  for the  attachment of muscles  and ligaments.
Hence  it  is  that  they are  of  such  anomalous and   curi-
ous forms, apparently  constructed Avithout design or  pur-
pose.   But as Ave study them, and understand the various
motions which they must  perform, as Avell  as the  organs
Avhich many of them must protect, or provide space for, we
find that it is impossible to improve in the slightest degree on
the  construction of  the skeleton.   The size,  the form, the
quality of material, the exact position of every process, curve
and foramen of the bones, and tho manner  in which  all are
arranged,  are most wisely adapted to their  functions and to
the happiness of the vertebrated race.
   16T.  Renson  why the Long  Bones  arc  Tubes.—In this
connection should be mentioned  the reason  why  the long
bones are hollow.   It is for the same cause that the stems of
grasses, grains, and many other vegetables are  hollow  cylin-
ders, instead of solid rods : to secure great strength with as

~^Wh7^e~the bones of such peculiar shapes ?  107. Give the reason why many of
the bones are hollow. 
 76            HITCHCOCK'S   ANATOMY

 little  material  as  possible.   For example, were the  human
 femur a solid rod, instead of a hollow cylinder, as it  noAV is,
 it would require a bone twice the diameter of the present one
 to be sufficiently  strong for the  purposes  required of it.
 Hence were the Avhole skeleton constructed on this principle,
 it Avould be so cumbersome and heavy that it Avould require a
 larger amount of muscle,  making the body  unwieldy, and
 thus deprive it  of its rapid and easy motion.
   168.  Protection given to the  Brain.  Use  of the Diploe.
 Reason  for several  Bones in  the  Skull.—The bones af-
 ford much protection  to all the  enclosed  and adjacent or-
 gans.   In the  bones  of the head, for example, Iioav  perfect
 the guard over  the nenrous center.   Here are three means
 for protection,  tAvo plates of bone,  and an intervening  cel-
 lular  space.  The  outer table  being very  tough  presents
 a  substance  someAvhat yielding to bloAvs inflicted  by pointed
 substances, and eA^en  if the bloAV be so severe as  to cause
 fracture,  this   can not  extend so  far  as  in  a  hard  and
 brittle material.   And the intervening space  or dipljj very
 materially deadens the  force  of any shock   given  to  the
 outside of the head, precisely  as the springs of  a carriage
 prevent the  uncvenness  of  the  road  from  giving the same
 sudden jolt to the body that is communicated to the wheels.
 The inner table  is necessarily brittle,  since  the  brain  de-
 mands the firmest possible  support.  But  why is the skull
 made up of several bones instead of one ?  In the first place a
 more symmetrical groAvth can be effected, provided  the  points
 of increase are numerous, and especially so since in early life,
while tho growth is going on, there is a thin Liyer of cartilage
betAveen the edges of each bone, thus alloAving  all necessary
motion; secondly, because a  fracture can not extend furthei
than a suture, as all the vibrations are  overcome by the inter-
position of any soft substance like cartilage.   And  for this

 1G9. How do the bones afford a protection to tho softer parts?  What is tho
use of the diploii in tho bones of the skull?  State the reason of several bones in
tho skull.                                                   lq 
AND  PHYSIOLOGY.
11
reason the jar  of any blow  is greatly lessened  by the same
cause.
   169. Use  of  the  Ribs.—Again we see the bones  of  the
thorax arranged  for  the protection of the  enclosed  organs.
Within this  cavity are  organs delicate and  easily destroyed,
but which require elastic and  movable walls.   The elasticity
is easily  gained by the cartilaginous portion of the ribs at-
tached to the sternum, which yields considerably upon pres-
sure ;  and the motion and consequent enlargement is effected
by the oblique  position  of the ribs, as they run downwards
and  forwards from their articulation Avith the vertebrae.  As
the vertebral extremity  is the fixed point, of course the eleva-
tion of the sternal end  will enlarge the cavity of the thorax
antero-posteriorly.  Another use of the cartilaginous extrem-
ity of the ribs  is to lessen the chance of  fracture.  The tho-
rax is exposed  to bloAVS  and  falls more than many other por-
tions of  the body, and  therefore more  exposed  to fracture.
For instance, if a person suddenly falls  to  the  ground, the
head by an instinctive movement is raised, Avhile the trunk or
extremities receive the force  of the shock.   Also the  head or
extremities  can by rapid movements  be suddenly removed
from the contact with missiles, Avhile the  body, comparatively
unAvieldy, must meet  the blow.
   170.  Use  of the Innominata.—The  expanded condition
of the Innominatum affords service and protection in different
ways.   A depression, or cup-shaped cavity is  thus made  for
'giving a firm support to the organs contained in the abdomen,
as Avell as a  solid foundation to the spinal column.   It Iioav-
ever renders especial  service  by furnishing  a powerful point
of attachment for many of the muscles both above and below :
thoso  which form  the  walls  of  the abdomen, and many of
those  Avhich move the extremities.
   171.   Why   there  are  so  many  Bones  in  the   Spinal
 ""lGlTDescribe tho uses of the ribs, and  the reason why they are partly made up of car-
 tilage.  AVhy do they run obliquely from the points of attachment?  170. Explain why
 the Innominata aro so broadly expanded. 
18
HITCHCOCK'S  ANATOMY
Column.—A large number of bones in  the  spinal column is
necessary in order to give flexibility to the body.   Were the
number considerably less, the movements of  the  trunk would
be attended Avith much more difficulty than at present, and be
devoid of  grace.   And  were  the separated vertebrae long
bones, they would  be much more easily broken, thereby  en-
dangering the spinal marrow.   Another  reason for the  great
number of these bones, is the necessity of the elastic cartilage
between them, to protect  the brain.  Were  the joints  fewer,
in order to give equal protection to the brain from  jars, this
cartilage  must  of necessity have been greatly thickened,
thereby Aveakening the joint, and  injuring it as a central axis
of support to the whole body, and also increasing the  liabil-
ity to dislocations,  as Avell as greatly endangering life,  by
pressure upon the spinal cord.
   172. Use of the Clavicle.—The value of  the  clavicle lies
in keeping the upper extremity in its proper position,  so as
to prevent  the  humerus from  coming fonvard  towards  the
middle portion of the body.   By its direct resistance it also
assists in some muscular actions, such as  lifting heavy weights
with the hands.
   173. Need of  two  Bones in the Fore-Arm.—The use of
two bones in the fore-arm, as  already mentioned, is to pro-
duce the movements of supination and pronation.   And since
these movements are  of primary importance, and  one  bone
can not answer this end, two are provided.   A^ain,  if one be
fractured, the other will act as a splint  for keeping the broken
one in place, greatly superior to the artificial splint, because the
natural splint needs no compression.
   174. Why  several Bones in the Carpus.—In the carpus
are found eight bones, and yet Ave knoAV there  is  but little
motion between them.  The reason Avhy  exactly  this number

  171. AVhat is the reason why so many bones are placed  in the spinal column ?  AVhat
is the use of the intervertebral substance?  172. What service does the clavicle render
to the upper extremities?  173. AVhy are there two bones in the fore-arm? 174. AVhat
can be said of the many bones of the carpus ? 
                  AND  PHYSIOLOGY.               fg

is required, is not so easily explained,  but it is evident that
one bone could not perform their  function, nor  the  prolonga-
tion of the radius and ulna to the metacarpus.   Several bones
are required in order to give easy and graceful  motion to the
wrist, as well as strength.   One  bone  could not answer the
purpose, since the very many offices, which  the hand  has to
perform, could not be  effected, unless  the Avrist bones were
very strongly bound together, and flexible to a certain extent.
The arrangement of the  bones  in  two  rows alloAvs a little
movement  of the hand upon the wrist.
  175.  Function of Metacarpus.—The metacarpus of  five
long bones gives support to the fingers.  They are long rather
than short bones,  in order to give slenderness  to the hand,
and also to afford  a solid  surface for the fingers to meet in
tiie act of  prehension.
  176.  Need of  three  Phalanges to Hie Fingers,  and two
Phalanges  to the Thumb.—The phalanges of each  finger are
three in number, whilst  those  of the  thumb  are   but  two.
The obvious reason of this is to  give greater firmness to the
thumb,  and flexibility to  the fingers.   The hand  in man  dif-
fers from the anterior extremity of all other animals  in  the
poAver of perfectly opposing the thumb  to each of the fingers,
which of course give3 him a great superiority  in all delicate
manipulations, and especially  in grasping  minute objects.
And it is easy to see that a third phalanx in the thumb Avould
not only diminish the  firmness of this  member, but  Avould
render tho hand an aAvkward and clumsy organ, instead of an
instrument beautifully  and  perfectly adapted  to the  multi-
farious offices Avhich it has to perform.
  177.  The great Length of the lower  Extremities.   Pe-
culiarities of the Femur.— The value of the great length in
the loAver extremities, is manifest as a means  of rapid pro-

 AA'hy would not one bone bo sufficient?  17."). The use of the metacarpus. 176. AVhy
ore there but two phalanges in the thumb and three in each finger? AVhat would be
the effect <if a third phalanx in the thumb? 177. AVhy are the lower extremities pro-
portionally longer than tho upper ?
                            1* 
80            HITCHCOCK'S  ANATOMY
gression, and also  for  affording a  firm  support to the trunk
Avhen engaged in the various kinds of labor.  Were these ex-
tremities much shorter than they now are, walking Avould not
only be a tediously slow process, but a  laborious  one.   The
femur has some remarkable  peculiarities.   In the  first place
it presents in its articulation with the innominatum the most
perfect  specimen  of a ball  and  socket joint in the  system.
Besides this  it bends at nearly a right angle at its  upper end,
making Avhat is  called  the neck, and here it is that the frac-
ture of the  thigh-bone generally  occurs.   The  use of this
curvature is  to place the points  of support for  the trunk as
far  as possible from the center of graA'ity of the  body,  thereby
giving the body tho most  secure position  on the  loAATer  ex-
tremities,  and  especially  for  the  attachment  of powerful
muscles to move the thigh  and leg,  as  Avell as to maintain
securely the  trunk Avhen the legs are the fixed  points.  This
projection is  called the  Trochanter process, and is spongy or
cellular in its structure.  And it is not a little  interesting to
notice, Avhen this process is  sawn through in a  perpendicular
direction,  that tho cells are arranged  in an arched  form from
below  upAvards,  thereby greatly aiding  the  strength of the
bone.  The same arrangement is seen in some other bones of
the body,  when  they are in  an exposed position.   The  loAver
extremity  of this  bone, as  has  already  been  mentioned, is
greatly expanded, in the shape of two condyles for tho firm
articulation Avith the tibia.   The necessity for this lies in tho
fact that the  knee-joint is one of the most  exposed joints in
the whole body, and the one  which receives the hardest strain.
The protection of the nenTes and blood Aressels, Avhich arc sent
to the leg, is also worthy of a notice.   It is  effected by a
deep  groove  between the condyles  on the backside  of  tho
leg, which guards  these vessels from bloAvs  in every direc-
tion except behind, from Avhence they are the least apt to come.

 What remarkable joint between the, femur and the innominata? AVhat is the
rangement of the  cellular structure in the upper part of the femur? AVhy has the le-
mur so large processes on its lower extremity ? 
                   AND   PHYSIOLOGY.               81

    178. F sc  of the  Tarsus .—In the Tarsus we see the value
 of several bones instead  of one.  It is  the movement  of these
 upon one another that imparts .elasticity to the step and firm-
 ness of support to the whole body;  and hence  it is  that all
 artificial legs produce a limping motion in the body.   By no
 mechanical contrivance can the suppleness  of the tarsus and
 of the  muscular actions be supplied.
    179. Two Bones  in  the  Great  Toe,  and  three  Bones
 in all  the Others .—The great toe of the foot, like the thumb
 of the  hand,  has only tAvo phalanges.  This is mainly for the
 purpose of securing  greater strength to the foot in  walking
 and standing.  It is also of service for opposition to the other
 toes, as is seen in those rare cases of persons deprived of their
 upper  extremities, who can readily make use  of the  foot for
 many of the delicate  purposes to which the hand is  adapted,
 such as writing, using scissors, and  placing the crystal in a
 watch.  The remaining toes, like four  of the  fingers, receive
 a tendon only at the base of the  second and third phalanx,
 the first one  being interposed merely to give  strength and
 slenderness  to  the extremities, as well as the power  of sur-
 rounding objects in  the  act  of prehension.  The slenderness
 of the  fingers aboA'e the  toes is a distinguishing  characteristic
 of man, showing that the office  of the  foot is  merely to sup-
 port the body on the ground, and of the hand to perform  the
 business of every-day life in its ten thousand forms.


             II l&IEXIC  I N r E It ENCES,

   180.—1. Reason  of Distorted  Bones.—In the early life
 of man and other vertebrate animals,  the animal portion of
 bones greatly predominates over the earthy constituents, and
 hence  they yield more readily to  pressure, but are  not so

  17S. How do the bones of tho Tarsus give elasticity to the step?  179. How do the
 phalanges of tho foot compare with those of tho hand in number? Wrhy are the bones of
 the hand longer than thoso of the foot'' ISO What kind of matter predominates in the
«arly life of bones * 
82
HITCHCOCK'S
A N A T O M Y
 liable to break  as  in older persons.   This is tho reason why
 falls and blows so seldom  do much injury to children.  It  is
 also the reason why distortions and curvatures of some of the
 bones are so common, since too often children are either urged
 or permitted to use their limbs excessively before their bones
 are  made  solid by the deposition of  earthy matter.   These
 distortions are  most common in children Avho  are weak and
 sickly,  because in them the recuperative poAvers are small.
   181.—2. Danger  of Constrained  and Unnatural  Posi-
 tions in Children.—Hence we infer that children  should
 not be confined in any unnatural or constrained position, but
 allowed to move freely in  whatever direction nature may de-
 mand.   And all punishments of this sort, inflicted by parents,
 guardians, and  school teachers upon young  persons, such  as
 standing on one leg, or holding a book Avith an extended arm
 for a long time, are  dangerous and ought  to be proscribed,
 since they are too often the cause of boAV legs and curvature
 of the spinal column.
  182.—3. Cause of the Rickets.—The disease knoAvn  as
Rickets is produced by imperfect nutrition of the bones.  This
is generally, though not always, the result of poverty or vice,
or both  combined.  The  direct  cause of the disease is a de-
ficiency of earthy matter  in the bones.  This  is either ab-
sorbed or never produced, and as a result the bone is softened,
and by the tonicity of the  muscles the body is drawn into un-
sightly  deformity.   An observance of the laws of health  is
the best medicine for  this disease.
 *183.—4.  Need of Cleanliness of the Teeth—Tooth Pow-
ders— Tooth   Picks—Decayed   Teeth — Worthless   Teeth
shou 1 d  he Extracted.—From the almost inevitable exposure
of the teeth to mechanical  and chemical agents, we  see that
they need considerable care and attention.   They need to be
  Why do falls and blows seldom injure children as they do adults ? In what children
are distortions the most common ? 181. Why should children be unconstrained in their
bodily exercise? What is said about punishments that distort the bones of children?
182. What is the usual cause of Rickets?  What is the best medicine for it?  1S3. Give
the most important hygienic rule for the preservation of the teeth. 
AND  PHYSIOLOGY.
83
kept clean.  This can ordinarily be accomplished by the use
of a soft tooth brush and  pure water thoroughly applied at
least once in the  twenty-four hours.  A tooth-powder of an
alkaline character, or, what is the same thing, clean toilet
soap,  can  be occasionally used Avith benefit.   A tooth picK
should be possessed and  used  by every gentleman  and lady
too, though  it should be made of Avood, ivory, tortoise-shell,
bone, quill, or some substance  softer than the tooth itself.   If
the teeth  are very closely set  together, frequently drawing a
thread betAveen them will aid in preventing decay.   If any of
them have begun to decay,  a good dentist should be consulted
as soon as possible, and the cavities filled with gold, since ar-
tificial  teeth can never  be so valuable as natural ones, even
though partly filled with gold.  When teeth  are past filling
they should be removed, as they are the means of producing
decay in others, as well  as many  pains called neuralgia.
   184.—5.  The Teeth  not to be Used on very Hard Sub-
stances.—The teeth  should be used only for the purposes for
which they  were designed.   The  teeth  of squirrels, rats,  and
beavers were  made  expressly for cutting Avood and gnawing
open nuts, but not so with the human  teeth.   Even the con-
stant biting of thread, the holding of a pencil or tobacco-pipe
between the teeth, and  especially  the  cracking of nuts, are
 practices very injurious, and  often cause the decay of these
 organs.
   185.—6. Teeth Generally Decay  Early  in Life.—Ex-
 perience shows that teeth decay the most rapidly in the early
 part  of life,  generally between the   ages  of  fifteen  and
 thirty.   Hence youth need to take especial care to  preserve
 them,  not only on account of the pain and  deformity which
 their'loss occasions,  but because of their remote  effects upon
 the voice and especially upon the digestive organs. +  '  v

   What kind of tooth powder is the best ? Who should use  tooth picks ?  What treat-
 ment should be given to decaying and decayed teeth? AVhat substance alone shotdd
 Teeth be filled with ?  184. For what purposes should human teeth never be used ? 18a.
 In what period of life do teeth decay the fastest? What are important reasons for au
 especial care of the teeth J 
S4
H I T C II C 0 C IC> S  ANATOMY
   186. Classification of  Animals.—The highest and most
competent authorities differ widely in their attempts to classify
the  Animal Kingdom ; that is, to divide it into smaller groups,
which  are Sub-Kingdoms or Provinces,  Classes, Orders, Fa-
milies, Genera,  and Species.   We have no  room, had Ave the
ability, to decide  these difficult  questions.   There  is,  Iioav-
ever, a general  acquiescence in the  principle first introduced
by Cuvier, that animals were created  on  four great types or
plans,  which  he calls Vertebrata, Articulata, Mollusca,  and
Radiata.   The discrepancy lies chiefly in  tho subdivisions of
these  leading  groups.   We shall merely present the classifi-
cations of two of the most eminent living anatomists and zoolo-
gists—Professor Louis Agassiz of Cambridge, and Sir Kichard
Owen of London—not attempting to decide betAveen  them.

  187.  Agassiz divides the whole animal  kingdom into four great branches,
the same as those named  above.  The  Vertebrata he divides into eight
classes:  1. The Myzontes, subdivided into two orders;  2, Pishes proper,
into two orders; 3, Ganoids, into three orders; 4, Selachians, into three or-
ders; 5, Amphibians, into  three orders; 6, Reptiles, into four orders;  7,
Birds, into four orders;  8, Mammalia, into three orders.
  The Branch Articulata he divides into three classes:  1, Worm?, with three
orders; 2, Crustacea, with four orders; 3, Insects, with three orders.
  The Branch  Mollusca he divides into three  classes:  1,  Acephala, with
four orders; 2,  Gasteropoda, with three  orders; 3,  Cephalopoda, with two
orders.
  The Branch Radiata he divides  into  three classes: 1, Polypi, with two
orders; 2, Acalephae, with three orders;  3 Echinoderms, with lour orders.
  188.  Owen calls the above-named four divisions of the Animal Kingdom,
Provinces. The Province Vertebrata he subdivides into four classes:  1, Mam-
malia, with fifteen orders;  2, Aves,  or Birds; 3,  Keptilia, with fifteen orders;
4, Fishes, with eleven orders.  His fifteen orders of Mammalia are: 1,  Mono-
tremata;  2, Marsupialia;  3, Rodentia;  4, Jnsectivora; 5,  Cheiroptera;  6,
Bruta;  7, Cetacea;  8, Sirenia; 9, Toxodontia;  10,  Proboscidea; 11,  Peris-
soiactyla;  12, Artiodactyla; 13, Carnivora; 14, Quadrumana; 15, Bimana.
  The Province Articulata he divides into six classes:  1, Arachnid;), with
four orders; 2, Insects, with eleven orders; 3, Crustacea, with eleven orders;
4,  Epizoa, with three  orders;   5, Anellata, with four orders;  6 Cirripedia,
with three orders.
  The Mollusca he divides into six classes: 1, Cephalopoda, with two orders;
2, Gasteropoda, with ten orders; 3,  Pteropoda, with two orders; 4, Lamelli-
branchiata, with two orders; 5,  Brachiopoda; 6. Tunicata, with two orders. 
AXD  PHYSIOLOGY.
85
  Tho Radiata he divides into nine classes:  1, Echinodenmta; 2, Lryozoa;
3, Anthozoa;  4, Acalepluo;  5, Hydrczoa ; G, Coslclmintha; 7, Sterclmintha;
8, Rotifera; 9, Polygastrh.
  189. To the above Animal Kingdom Prof. Owen has added another kingdom oi
organisms, " mostly cf minute size, and retaining the form of nucleated cells,
which manifest tho common organic characters, but without the distinctive
superadditions of true plants or animals."  Theso he calls Protozoa, and ar-
ranges in three classes: 1, Tho Amorphozoa, or Sponges; 2, the  Rhizopoda,
which are the Polythalamia, or Foraminifera; 3, tho Infusoria, or  Ammalcu.a
—the last two classes being mostly microscopic.
            COMPARATIVE  OSTEOLOGY.

   191. Microscopic Structure.—In microscopic structure and
chemical composition the bones of  mammals, including man,
and of all vertebrates  are essentially the same, and in their
general outline a considerable degree of correspondence can
be traced betAA'een many of  the bones of tho human  system,
and those performing similar functions in the  loAver animals.
Thus we  almost  ahvays  find the  femur to have  a globular
head  on its upper extremity supported by a neck which makes
a considerable angle with the shaft,  and the  two  large con-
dyles  on the lower  extremity.
   192. Spinal  Column  of Mammals.  Cervical.  Dorsal,
Lumbar, Sacral, Caudal Vertebra;.—In Mammals the Spinal
Column is made  up of five classes  of vertebrae : the cervical,
of the neck ; the  dorsal, of the back; the lumbar, of the loins;
the sacral, of the hip ;  and the caudal, of the tail.   The Cervi-
cal vertebrae, with but two or three exceptions in all mammals,
consists of seven in number.  The average number of the Dor-
sal is thirteen, the Bats having eleven, and one of  the  Sloths

  191  What is tlic microscopic structure of tho  bones of Mammals?  AVhat about tho
cneral correspondence in outline, etc. ? Instance  the femur.  192. What are the five
classes of ATertebi-!C? IIow constant is the typical number seven for the Cervical ver-
tebra; 1  Give the average number of the Dorsal. 
86
HITCHCOCK'S   ANATOMY
vq
ta
  Skeleton of the Camel.  v. c. Cervical A'ertebra?.  v. d. T>orsal Vertebra;,  r. I. Lum-
bar Vertebra1,  v. 8.  Sacral Vertebra;.  1). q.  Caudal Arertebroe.  o.  Scapula,  h. Hume-
rus,  c. liibs.  cu. Ulna.  ca. Carpus,  m. c. Metacarpus,  ph. Phalanges, fe. Femur,
ro. Patella, ti. Tibia,  ta. Tarsus,  in, t. Metatarsus,  cl. Clavicle.
FlG. 96.
         Skeleton of Bat.  The descriptive letters are tho same as in FX 93,

twenty-three.    The  Lumbar are  usually the  largest  in  size
and  their  range  is from  two  to nine.    The  Sacral  consist 
AND   PHYSIOLOGY.
87
usually of four, but vary from one to nine, and as in man,
are almost  ahvays consolidated.   The  Caudal vary exceed-
ingly in number,  sometimes amounting to forty-six.   When
of this number, they gradually dwindle aAvay towards the ex-
tremity of the tail, and lose the characteristics  of vertebrae,
and become mere ossicles or bits of bone.
   193. On what  Length of Neck depends.—Hence we  see
that the length of the neck in quadrupeds does not depend
on the number, but on the length of vertebrae, since the Cam-
eleopard (Fig.  9T),
 Skeleton of Cameleopard. C. Cervical Vertebra;.  D. Dorsal A'ertebra;. L. Lumbar
A'ertebra;.  S. Sacral A'ertebra;.  cd. Caudal Vertebra;. 51. Scapula.  53. Humerus.
54. Ulna. 55. Radius. 56. Carpal Bones. 57. Metacarpus. Hi. and iv. Phalanges. 62. Inno-
minatum. 64 and 65. Femur.  66'. Patella. 66. Tibia. 6T and 68. Tarsus. 69. Metatarsus. 
88
HITCHCOCK'S  AX ATOMY
which has the longest neck, has only seven cervical vertebrae,
tho same number with the Mole (Fig. 98), an animal with

                          Fig. 98.
Skeleton of the Mole.  The illustrative Figures represent the same as in Fig. 97.
one of the shortest necks among quadrupeds.   Cuvier  states
that in general the length of the neck is such, that,  added to
the head, the length of both is equal to the height of the ani-
mal's shoulders above the ground.   If this were not the case,
grazing animals could not  reach their  food, nor any quadru-
peds their drink Avithout bending the legs.

   194.  Shape of Body.—The shape of the body of quadru-
peds, whether slender, or  short and thick, depends on the
number and size of the Lumbar  and Dorsal \-ertebrae.
   195.  Bones of  Skull.  Elephant's  Head.   Styloid, and
Tympanic  Bones.—The general arrangement  of the bones
of the skull, as well as their number, corresponds very nearly
with  those  of man.   The  two Parietals  are  usually small
bones, and  sometimes united  into one.  This is true of the
Horse and  the Bats.   In the  Hog  and Rhinoceros the tAvo
parietal bones are united in one,  while  their frontal bone  is

  What peculiarity about Lumbar?  What of the Sacral?  How large a number of Sa-
cral are sometimes found? 193. Upon what does the length of neck in quadrupeds de-
pend on ?  Instance the Giraffe and Mole. AA'hat is the general rule about the length of
the neck? 194. AVhat docs the shape of the body mainly depend on?  195. How do
the Parietals sometimes differ from man ? 
AND  PHYSIOLOGY.
89
Fig. 99.
t       f  o    n     m
                    mi            mo      c
   Skull of Horse,  oc, t., f. Occipital, Temporal, and Frontal Bones,  n., m., int.
 and mi., Nasal, Superior Maxillary, Intermaxillary, and Mandibular Bones, o. Orbit.
 i. Incisive Teeth,  mo. Molar Teeth.

in two  pieces.   In  nearly all  the orders of mammalia this
bone  (the  frontal)  is  ahvays  found  in tAvo  pieces.   In the
Elephant the bones of the  cranium are all  united into one
at an  early period in life, forming but  one piece, in  order
probably to make it  sufficiently strong  to support the  great
Aveight  which  is  brought  upon  these  bones  by  the  tusks
and  proboscis.    The Styloid  process of the temporal bone
is  usually in  mammals a separate ossicle.  The bone which
contains  the  organ  of  hearing  in all mammals,  except
man and the Apes, is a  separate bone called the Tympanic,
and  is  not simply the petrous portion of the temporal as  in
man.

   196.  Bones  of Face, Intermaxillaries, Loavci- JaAV.—
In the Face too  the bones correspond very nearly Avith  those
in man.   The essential difference is found in the upper jaw.
Instead of the tAvo superior maxillaries meeting each other  on
the median line of the body in front, there are two other bones
betAveen them called  the  Intermaxillaries.   These are very
conspicuous in animals provided with large canine teeth,  or
tusks, as the  Elephant  and Squirrel.   Tho LoAver  JaAv  in

  What peculiarity about the bones of the Klepbant's skull ?  What bono is wanting in
the Whale ?  Describe the Tympanic Bone. 196. In what respect do the bones of tho
face in Mammals differ from those in man 1  Where arc the Intermaxillaries ? 
90
HITCHCOCK'S  ANATOMY
 quadrupeds generally consists of tAvo pieces, the division being
 made on  the median line of the body.   In the  Hog, Horse
 and Cow it consists of a single bone.   In  the Greenland
 Whale it is in  its simplest form, AYhich  is that of tAvo arched
 ribs.

   197.  Form  of Skull, of  Orang  Outangs.—Viewed  as  a
 Avhole the form of the skull departs most from  that of man in
 the lowest orders.   In the Ornithorynchus  the face i3  pro-
 longed  into a beak or bill, and in the Horse the facial  por-
 tion of the head  is four times larger than the cranial, exactly
 the reverse of the case in man.  In the young Orang Outangs
 the form  of the skull very closely resembles that of man, and
 in the adult the  size of  the  exterior of the cranium nearly
 equals that of man,  though its capacity is considerably less.

   198.  Teeth  of  Quadrupeds, Carnivorous,  Herbivorous,
 Insectivorous  and  Barbed Teeth.—The Teeth  of Mammals
 vary exceedingly. They may, however, be classed under the tAvo
 divisions  of flesh and vegetable eating,  according to the food
 of the animal.   Those made  to  live on  meat  are sharp and
                           pointed, for simply tearing the flesh
                           into  such  small  portions that  it
                          can be  SAvalloAved, Avhile those eat-
                          ing herbs and grass, have the front
                          teeth with sharp edges  like  that
                           of a  knife for cropping the food,
                          and back teeth with flat surfaces,
                          or vertical ridges of  enamel  in-
                          terspersed between  the   ivory or
                          cementum, .Avhich act  the  same
                          part Avhen brought  together Avith
Teeth of a Lion (Carnivorous Animal.) a  kteral  motionj  as do the ^^

 What of the Lower Jaw ?  197. In what orders does the head differ most from that of
man?  How does the skull of the Orang Outang differ from that of man ? 19S  AVhat
are the two kinds of teeth among mammals ?  Describe each. Give tho reason why the
teeth are furnished as they are.
Flff. 100.
 
AND  PHYSIOLOGY.
91
Fig. 101.                    Fig. 102.
Teeth of an Herbivorous Animal.        Teeth of an Insectivorous Animal.
and nether millstone  for  grinding grain.   Those  which  live
upon small insects have conical teeth Avith corresponding de-
pressions in the opposite jaAV in order to crush the  skeletons
and envelops of their prey.   The Seals, which  live on Fish,
are provided with barblike appendages similar to those on fish-
hooks, in order that they may hold their slippery prey.

   199. Humerus, in Burrowing  Animals.—The  Humerus
is  generally a long cylindrical  tube, Avith  a large rounded
head at its upper extremity.  But in swimming and burrow-
ing animals it  is a short and curved bone, Avith each extrem-
ity very much modified for the attachment of muscles,  since
the fore-legs  of such animals need to be used with great fre-
quency and force.

   200.  Bones of Fore-Arm.  Carpus, Metacarpus,  Pha-
langes.—The element in Avhich mammals live, greatly modi-
fies the bones of the fore-arm and hand.   (Fig. 103, p. 92.)
In general there are tAvo bones  in the fore-arm, and but few
animals have the power to move these one upon another like
man.   The Carpus is constantly made up of two rows, though
not of the same number.  They vary from five to eleven.   The
Metacarpus consists of five elongated bones for the most part.
But  these are three  in  the Rhinoceros, and  one  Avith  two

 What \i remarkable about the teeth of the Seal ?  199. What is the general  outline of
the Humerus? In what animals ii it modified ? 200. What effect lias the element, in
which animals live, upon the anterior extremities?  How do the Carpal Bones range in
Cumber ?  What are tho exceptions to the typical number five of the Metacarpus 1 
92
HITCHCOCK'S   AXAIO M Y
FAZtH°FMu"nCrl> °f diffCI'Cnt AnImalS"  A' FiSh-  R B1,'d'  C- D°lphin- *>■ Deer-
rudimentary bones  in  the Horse.    From one to five fingers
usually found, of which the thumb is  generally  rudimentary^
             Fig. 104                        PlQ# 10-
are
___i
P*
  Hind Foot of Horse,  t. Tibia,  ta. and      r„„, „< c. „  /r>

«. rudimentary Bone.  />., 75;:.,  and pt.,                           "."ft.;
first, second and third Phalanges, 
AND  PH YSI0L0GY.
03
consisting only of a single bone.   The Elephant has five toes,
the Hog four, the Rhinoceros three, the  Coav two, and  the
Horse one.   Sometimes the  longest finger  (paddle)  of  the
Whale contains eleven bones.  In  burrowing  and SAvimmincr
animals the fore-feet are generally the largest, and among some
quadrupeds the reverse is the  case.  The posterior extremities
of quadrupeds are usually less modified than the anterior ones,
as they are used mainly for support and progression.
                OSTEOLOGY  OF  BIRDS.

   201. Vertebra;,  Cervical, Dorsal,  Caudal.—Birds exhibit
several peculiarities  in  their Spinal  Column.  The  number
of  Cervical  Vertebrae  is much  greater  than  in mammals,
giving them  long  and  flexible  necks.  (Fig.  106,  p.  94.)
The number is between ten and fifteen, but the Avhite Swan
has  tAventy-three.   The Dorsal  Vertebrae vary in  number
from seven to nine,  and admit  of but  little  motion upon
each  other, many of  them  being frequently  anchylosed to-
gether, as  in  the human  sacrum.  (Fig. 107,  p. 95.)  The
design of this is to give  the firmest point of attachment to
wings that can  be secured.   The Caudal Vertebrae are hol-
low and  form a complete canal for the spinal marrow.  The
last one  has a large disc-shaped  process upon it for the sup-
port of the long feathers of the  tail.

  202.  Bones  of  Head,  Os  Quadratum, Jugal  Bone.—
The bones of the  head correspond in number and position
for  the most part with  those of  the mammalia.   (Fig. 108,
p. 95.)  They are, however, united together  at a very early
period, and the  sutures  can  not be recognized except in very
young subjects.   One point  of difference between these skulls

 AVhat are some modification's of  Phalanges? 201. Compare the Cervical A'ertebra of
Mammals with those of Birds. AVhat number of Cervical ATertebrro lias tho Swan? Why
are the Dorsal Vertebras usually firmly fixed together ? What peculiarity of the Caudal
ATortebr» ?  202. What can be said of tho Sutures in the bead of birds ? 
94
HITCHCOCK'S   ANATOMY
                Fig. 106.
  Skeleton of Swan.   <?. C. Cervical A'ertebne.  1). D.  Dorsal Tertebrse.  g. & Sacral
Vertebnc.  cd. Caudal A'ertebra?.  51.  Scapula.  52. Coracoid Bone.  53. Humerus.  54
and 55. Radius and Ulna.  56. Carpus.  57. Metacarpus.  5S.  Furcula.  62. Innominata.
63. Sacrum.  64 Pubis.   65. Femur.  CO. Tibia.  CG'.  Patella.  67. Fibula.  C9. Tarso
Metatarsus,  i.,  ii., Hi., is. Phalanges. 
AND  PHYSIO BOGY.
95
Fig. 107.
Cervical Vertebrae.
Coccyx. _
Tibia.
Tarsus.
     ..._.....Clavicle or Furcula.

_____..........Sternum.
Phalange.
Skeleton of tho Goeland.
and those  of the mammals  is  that  the  occipital  bone con-
sists of four  parts instead of one.   A small bone, too, is  al-
ways  present called  the  Os  Quadratum, in  close proximity
with the occipital, temporal,  and  maxillary bones.   A Jugal
        Lachrymal Bone
         Nostril.
Sup. Maxil. »     \
Fig.  108.
  Orbit.  Inter-Orbitar Septum.
Cranium.
Tympanum.
Os Quadratum.
Nasal Fossa?.. Jugal Bone. Infer. Maxil.
        Head of the Eagle.
What bone in the skull of birds that demands attention?
                    5 
90             HITCHCOCK'S   A X A TO MY
Bone is also found Avhich is similar in position to the zygo-
matic process of the temporal bone in man.

   203.  Bill.—Teeth  are  entirely wanting in  Birds,  their
place being supplied by a single horny projection on each jaAV
known as the Bill.  Teeth are not needed by these animals,
since mastication,  where it is necessary that it should  be per-
formed, is done by the gizzard.

   204. Bibs.—The Ribs are very firmly articulated with the
sternum by bone  and not cartilage, so that they have a ten-
dency to keep  the thorax as  fully distended  as possible all
the time, which is its natural position.
Fig, 109.
                                   205.  Sternum,  in  what
                                 Birds  largest.—The  Ster-
                                 num is the  most  striking of
                                 all the bones  in a bird.   It
                                 is the  largest bone in their
                                 bodies, a flattened  and  some-
                                 times quadrangular bone, hav-
                                 ing  upon its  anterior surface
                                 a prominent  ridge  like  the
                                 keel of a ship, for  the attach-
                                 ment of the pectoral muscles
                                 used  in  flight.   The size of
                                 this ridge generally stands in
                                 direct relation  to the poAvers
                                 of rapid  flight, and hence in
the Humming  Bird, one  of  the SAviftest  on  the wing, it is
proportionally the largest.
   206. Clavicles,  Coracoid  Bone.—The  Clavicles of  birds
present a marked peculiarity.   They both unite  at their  an-
terior extremity, forming a forked bone  known  as the  Fur-

 203. What serves the purpose of teeth for Birds? 204. How does tho articulation of
the ribs affect the condition of the chest?  205. Which is tho  largest bone in birds?
How may we know the powers of flight in a bird by the  keel of tho Sternum. ? 206. What
dp the elavicles of bird* form aa they axe united togcthur?
I -
  Bones of Sternum and  Shoulder of
Birds.  «. The Sternum,  e. Notch of tho
Sternum,  co. Origin of the Sternal liibs.
b. Crest. /. Fourchette. c. Coracoid Cla-
vicle, o. Scapula. 
AXD  PHYSIOLOGY.
97
cula, merry thought, or wish bone.  They also possess  another
bone Avhich acts  the part of a clavicle, called  the  Coracoid.
It reaches  from  the scapula to the sternum, side by. side Avith
the Furcula,  and  is  a  principal source  of support  to the
Avings  in flight.   There  is a  bone analogous to  this among
some reptiles.
   207. Humerus.—The  Humerus is generally a larger and
stouter bone than the  femur, contrary to the relative propor-
tion in man.  This is because the anterior extremities of birds
are of much more  importance in their habits than  the poste-
rior ones, since the  hind  legs in most of the flying birds act
merely as  a support for the body Avhen at rest, and  are not of
special service for running or scratching.
   208.  Bones  of  AYings, Fingers.—The  two  bones of the
fore-arm are proportionally longer than the  same bones in
mammals, and are longest in birds of flight.   The carpus is
represented by two  short bones, and the metacarpus is of the
same number.   In  some birds the thumb is entirely wanting,
but when  present it is  made  up of  two  bones.   The  little
finger has only one bone.   The middle finger is the longest,
consisting of tAvo and even three bones.
   209.  Femur,  Tarso-Metatarsus.—The Femur  is  both
thicker and shorter than the bones beloAV it, which constitute
the leg.  The Fibula is always, partially at least, united with
the tibia at its lower extremity.   The Tarsal and Metatarsal
Bones are found as one,  called the Tarso-Metatarsus,  Avhich
has at  its  lower extremity three  pully-shaped heads for the
attachment of the toes.

   210.  Sesamoid Bones.—Sesamoid Bones are abundant in
birds,  and in many cases  even the tendons themselves become

  Is this peculiar to birds alone ? 207. AVhat is the comparative length and size of tho
Humerus nnd lYmur in birds?  AVhy arc  the anterior extremities in  most cases the
lm"est?  203. AVhat is said of the two bones of the fore-arm?  l'mv many bones aro
there in the Carpus?  Describe the fingers of birds.  209.  AVhat peculiarities in tho
lower extremities of birds? Describe the Tarso Metatarsal Bone. 210. AVhat ia eaid
about Sesamoid Bones in birds ? 
98
HITCHCOCK'S  ANATOMY
considerably ossified.    This is especially  true of  those in
the leg.
   211.   Birds Bones arc hollow.—The bones  of birds  are
more or  less hollow internally, devoid of marrow, and  per-
meated by air.   Hence they are provided Avith openings con-
nected with the respiratory apparatus through Avhich the air is
brought into them. As a general rule the capacity and extent
of these openings throughout the skeleton depends on the size
of the bird, and its powers of flight, since  small though rap-
idly flying birds have few hollow bones;  in larger  and higher
flying species, however, they are numerous.   In the  Apteryx
of New Zealand there is the greatest Avant of these cells. This
bird has no Avings, but can run and even burrow in the earth
very rapidly.  Those  bones which convey the air,  differ from
all others in appearance by their whiteness  and more com-
pactly cancellated or cellular structure.
              OSTEOLOGY  OF  REPTILES.

  212. Number  of  Vertebra; in Reptiles.—The Vertebrae
of Reptiles  vary exceedingly in  number.   "For whilst  in
the tailless Batrachia only nine or eight cervical vertebrae are
counted,  some  serpents have full 300."   Those of Batrach-
ians have long transverse processes.

   213.  Ribs;  Use  of Ribs to Serpents.—" In the serpents
the ribs  are  both very numerous and very  movable;  where
they cease the tail begins;  here the Caudal  vertebra? may be
distinguished from the other vertebrae of the  trunk, whilst all
distinction of dorsal  and lumbar vertebras fails."   They are
 211. AVhy are birds' bones usually hollow and more or less occupied by cavities?
212. AVhat is the number of vertebrae in Keptiles?  213. Give the number of ribs in
Reptiles.  How do they differ from those of quadrupeds?  Of what service are they to
the animal? 
AND PHYSIOLOGY
99
valuable instruments of progression, since  in many they can
be placed upon the ground and used as feet.
   214.  Shell of Tortoise.—In  the Tortoise that portion
which is commonly called  the shell, is made up of the Cara-
Fig. 110.
^. Tibia,  p. Fibula.

pace or upper portion,  and the Plastron, or lower one.   The
Carapace seems to be a mere expansion  of the vertebra, and
the Plastron an expanded sternum.   Hence, as the annexed

"o^Wl-t'is tbe Carapace and what is the Plastron in the Turtle family? From what
bones are they developed ? 
100
HITCHCOCK'S  ANATOMY
cut shows, the skeleton of the Tortoise is  a very simple one,
and  the skeleton  of  the  Frog, as  shoAvn  in  Fig.  Ill, is
equally simple.
   215.  Humerus.—The  Humerus  of the Tortoise is  short
and very much curved.  This  is made so in order that the
animal may thrust its  extremities out of the shell and  reach
the ground, Avhich  could  not be done if  the  humerus  were
straight as it is in most of the  other  vertebrate animals.
   216.  Femur.—The Femur is curved in  the same animals
for the same reason.

   217.  Phalanges.—Frogs generally have four  fingers, with
from  two to four phalanges in each finger.  Tortoises and
Lizards generally  have five fingers, and  from  two to five
phalanges in each finger.

                          Fig. 111.
Skeleton of the Frog.
              OSTEOLOGY  OF   FISHES.


  218.  Bony  and  Cartilaginous Fishes.—The skeletons of
Fishes are of  two kinds, those made up of bony,  and those of
cartilaginous matter.  (Fig. 112.)  The microscopic structure
of the scale of  a Pike is seen in Fig.  113.  Of the former kind

  215. AVhy is the  Humerus of the Tortoise curved?  217. How many finders  hare
Frogs, Lizards, and Tortoises? 21S. What are the two kinds of skeletons in Fishes J
Give examples of each. 
AND  PHYSIOLOGY.               101
as  representatives  are   the
Shad  and Flounder,  and  of
the  latter,  the  Shark  and
Sturgeon.
   219.  Two  Kinds  of  Ver-
tebra;.—The  only  kinds  of
Vertebrae in  Fishes  are the
Dorsal and Caudal.   These
vary  in number from seven-
teen to more than a hundred.
Their bodies (vertebrae) pre-
sent on both articulating sur-
faces a conical depression which
is filled  with  a  soft  matter
having the  same use  as the
elastic   intervertebral   sub-
stance in the human vertebral
column.
   220. Xo Sternum  or  Pel-
vis.—The Sternum and Pel-
vis are both Avanting in fishes,
and the anterior and posterior
extremities are  rudimentary,
being represented by fins.
                           Fig.  113,
Fig. 112.
Skeleton of the Perch.
 Section of the bony scale of Lepidontevs.  a. Showing llio regular distribution of tho
Lacuna; and of the connecting Canaliculi.  b. Small portion more highly magnified.

 219. What are the only A'ertebra; of Fishes?  AA'hat is peculiar about their articula-
ting surfaces ?  220. AVhy have Fishes no Sternum or Pelvis ? 
102
Hitchcock's  anatomy
   221. Bead.—The bones of the Head  in this  class  of ani-
mals  are numerous and exceedingly complicated, being in
fact a difficult portion  of study in comparative osteology.   It
is, hoAvever, a subject  of great interest  to a thorough scholar
of this branch of anatomy;  but as so little of it can be gen-
eralized, it  must be omitted here altogether.
   222.  Great Variety of Teeth.—The Teeth present every
possible  variety in position and size, and, as  Sir  Richard
Owen  says, "they average in number  from  zero to  count-

                           Fig. 114
                         TV    or
    Head of tho Pike.  c. Cranium,  n. Nasal  Fossa?,  im. Intermaxillary Bone.
  m. Upper Jaw. p., op., io. Bones peculiar to the head of fishes.

less quantities."    Some teeth,  in  shape and  location  re-
semble the pavement of the  street, others are  of a delicate
hook-shape,  and others still are fine as hairs,  and are located

                           Fig. 115.
Head of a Shark.
 221. What is remarkable with respect to the bones of the Head in this class ? 222. What
is said about the variety of Fishes' Teeth ?  How numerous are they found at times? 
AND  PHYSIOLOGY.
103
on  the jaws, tongue,  and palate.   They are repeatedly re-
newed during the  life of the animal.   Fig. 116 represents
the microscopic structure of the tooth of an Eagle Ray.
Fig. 116.
Microscopic structure of Tooth of Eagle Bay.
  223.  Skeleton,  or Ilarder  Parts of Invertebrata— The
harder parts of invertebrate animals generally differ so much
from bones in composition and structure  that the term Osteo-
logy may perhaps  be less  proper  than  that  of Skeleton  in
describing them.

  224.  Skeletons  of  Crustaceans.—Among the Articu-
lata the Crustaceans have a more or less solid external crust
of carbonate of lime in a  base of peculiar azotic matter, in-
soluble in caustic potash, called  Chitine.

  225.  Skeletons of  Insects.—Insects, the most numerous
class of articulated animals, have a  chitinous covering, gener-
ally leathery, but sometimes solid.   The Arachnoidea have a
similar skin, soft or coriaceous, rarely horny; and the Anne-
lida a very thin epidermis.   The Helminthes, Rotatoria, and
Turbellaria, reckoned in this  branch of the animal kingdom
 What is curious about their renewal? 224. Describe the skeleton of Crustaceans?
225. What is the skeleton of Insects ?
                              5* 
104           HITCHCOCK'S  AX ATOMY.
by some eminent writers, have a skin more or less hard, and
sometimes spinous.
                           Fig. 117.
            Microscopic structure of tho Spine of Sea Hedge-Hog.
  22G.  Skeleton   of   the  Mollusca. — In  all the  three
great classes  of Molluscs, the  Acephala,  the  Cephalophora,
and the Cephalopoda, the animal possesses a mantle by Avhich
it is  able  to secrete a solid  deposit, mainly composed of car-
bonate of lime, which it spreads over nearly all the body, and
is  fastened  to it by muscles.  In the Acephala  this skele-
ton is in two pieces, called valves;  in the Cephalophora, it is
in one piece, except that a calcareous plate is attached to the
foot  to  close  the orifice.   The organic base of  these  shells
sometimes, but rarely, predominates over the calcareous part.
In the Cephalopoda there are cartilages for the attachment of
muscles similar to  the  same substance in vertebrate animals.
In the  Argonauta  and Nautilina  of this class,  the mantle
secretes an external shell; but  in the Loligina, or Cuttle Fish
family,  it is internal.
  The structure of the shells of Molluscs is often  complicated
and beautiful.

  227.  Skeletons  of  the  Radiata.—Among   the  Polypi
some  are entirely soft;  others  have  a  solid skeleton, which

  22G. Describe the skeleton of Molluscs,  227.  AVhat are tho skeletons of Radiates?
What is their chemical composition ? 
AND  PHYSIOLOGY,
Microscopic view of Shell of Pinna.
38 calcareous,  horny, or  leathery.   This  skeleton,  called  a
polypary, or in popular language coral, is secreted by  the
skin of the animal, and  seems to be truly an internal skele-
ton.  It  contains,  say ninety-five  per cent, of carbonate of
lime, some two or three  per cent, of fluorides and  phosphates,
and from four to eight per cent, of organic matter.
   The Acalephae, another class of Radiates,  are mostly gela-
tinous ; but a few are cartilaginous, and  some have a nuclear
skeleton.   The  Echinodermata, with few exceptions, have an
                           Fig. 119,
Microscopic section of hinge of Mya showing a crystalline structure.
«'h*t is coral ? AVhat is the skeleton of other Radiates f 
 106           HITCHCOCK'S ANATOMY.

 external skeleton highly calcareous.   In the Asteroidea there
 is also an  internal articulated skeleton.  The  structure of
 these skeletons is too complicated for description here.  The
 Echinidse are remarkable for calcareous knobs and  rays, both
 sharp and  blunt, sometimes several inches long; hence this
 common name, Sea Hedge-Hog, or Porcupine.

   Skeletons  of  the  Protozoa.—The  organisms  brought
 together by Prof. Owen under Protozoa,  are the Amorphozoa
 or Sponges,  the  Foraminifera, and Infusoria, "which,"  he
 says,  " manifest the common organic characters, but without
 the distinctive super-additions of true plants or animals."  Of
 the skeletons of the  Infusoria we  know little, save that they
occur fossil, and are composed of silica and iron ore.
  The Foraminifera  are small, gelatinous  animals, protected
by a calcareous shell.   The  Sponges are  said to  be ceratose
or horny, siliceous or flinty, and calcareous or limy, accord-
ing as their frame-work partakes of these several characters.
AYhat is said of the skeletons of the Protozoa?  What of the Forminifera? 
CHAPTER   SECOND.
THE MOVING POWERS  OF THE  SYSTEM.—MYOLOGY,  OR THE
                 HISTORY  OF THE MUSCLES.
        DEFINITIONS  AND  DESCRIPTIONS.


   228. Microscopic  Structure  of  Mnscle.-4-The  Muscles,

known as  flesh  or lean meat,) compose  a large  part of  the

extremities,  and  the covering of  the trunk.  To the naked

eye they appear  to be fibrous, and,  with the  assistance of  the

microscope, these fibers  are found to be bundles—called Fasci-

culi—of  stiH smaller fibers,  called Ultimate Fibers.   These

seem  to  be  polygonal  in form, and with an average diameter

0f _i_th  of-an inch in man,  though in some  of the loAver ani-

mals their  size is much less.

  View of the stages  of development of               FlG. 120.  4        g
Muscular Fiber.  1, A Muscular Fiber of
Animal life enclosed  in its Sheath or
Myolemma.  2, An Ultimate Fibril of the
same.  3, A more highly magnified View
of Vis. 1, showing the trne nature of the
Longitudinal Strise, as well as the mode of
formation of the Transverse Strisc.  Tho
Myolemma is here so thin as to permit the
Ultimate Fibrils to be seen through it.  4i
A Muscular Fibre of Organic life with two
of its Nuclei; taken from the Urinary Blad-
der, and magnified 600 Diameters.  5,  A
Muscular Fibre of  Organic life from the
Stomach, magnified the same.
   229/Fibrils. — The  ulti-
mate  fibers  are still further  divisible  into  what  are termed

Fibrils.   These  have an  average  diameter  of about -rirlooth
• 228 What is lean meat?  How does muscle appear to tho naked eye?  What arc tho
three'microscopic elements?  Describe each.  229. AVhat is the diameter of the Fibrils? 
108
HITCHCOCK'S   ANATOMY
Fig. 121.
  A View of the Fragments of Striped elementary Fibers, showing a cleavage in opposite
directions—magnified 300 Diameters. 1, The Longitudinal Cleavage.  2, The Transversa
Cleavage, the Longitudinal Lines being scarcely visible.  3, Incomplete Fracture, follow-
ing the. opposite surfaces of a Disc which stretches across the Interval and retains the two
Fragments in connexi >n. The Edge and Surface of this Disc are seen to be minutely
granular, the Granules, corresponding in size to the thickness of the Disc and to the dis-
tance between the faint Longitudinal Lines.  4, Another Disc nearly detached. 5, A de-
tached Disc mono highly magnified, showing the Sarcous Elements. G, Fibrillse separated
by violence from each other at the broken end of the Fiber.  7, S. The two appearances
commonly presented by the separated single Fibrillse; more highly magnified, at 7 the
spaces are rectangular, at 8 the borders are scalloped and the spaces bead-like,

of  an  inch, and  number about  G50 in each ultimate fiber.

They are unprotected by any covering,  Avhile both the  fasicu-
FlG. 122,
                                             lus and ultimate fiber
                                             are  everywhere  pro-
                                             tected  by a delicate
                                             sheath   called   the
                                             Sarcolemma. ^
                                                230. Organic,   or
                                             lTnstripcd,  and  Ani-
                                             mal,  or  Striped Fi-
           Tlbrils of Human Muscle,              beTS.__kAH  the  mus-
cles of  the  body are divided into  tAvo classes, according  to
their  function.   Those  necessary  for  carrying  on  the  vital
functions, such  as  breathing  and digestion,  are  called Or-
ganic, and those  under  the  control  of the  will Animal Fi-
bers. >  In addition  to  their  use  as  a  means  of  distinction,
they may be known  by  their appearance under  the  micro-
  What is the Sarcolemma? On what element of muscle is  this wantinj
the two functional classes of the muscles.
230, Give 
A X D   P II Y
Fig. 123.
  Transverse Section of Human Fibrillar
showing a Polygonal form.
scope, the Animal Fiber being
marked by transverse  striae,
or stripes resembling a beaded
filament, called  Striped  Fi-
ber ;  and  the  Organic being
made up merely  of flattened
bands destitute of these cross
marks,  and hence called Un-
striped, or  smooth fiber.  The
unstriped fibrils are developed
from cylindrical  or  spindle-
shaped  nucleated cells,  and
are surrounded by a peculiar
fluid known  as muscle juice,
Avhich is unlike the plasma of
the  blood, since  it  contains
casein.
   231.  Tendons,  Aponeuro-
ses, Belly or Swcl loft lie 31 us-
cle.—The  extremities of the
muscles are composed of dense
areolar tissue in  tho form cf
tendons  or cords,  and that
extremity  Avhich is nearest  to
the  center  of motion  is called
IOLOGY.               109

           FlG. 124.
  A broken Muscular Fiber showing tho
sheath or myolemma untorn.

           FlG. 125.
   Fusiform Cells of Smooth Muscular Fi-
 ber, a, Two cells in their natural state.
 b, A cell treated to acetioacid, showing the
 nucleus c.
the Origin, while tho one most
  What is the appearance of the Animal Fibre under the microscope? Also that of tho
Organic?  231. State the composition of tho Tendons, 
110           HITCHCOCK'S   ANATOMY

remote from it is called its Insertion.  These are exceedingly
firm and  strong, perfectly inelastic, and can not be torn from
the bones without  unnatural violence.   If the  extremity of
the muscle has  a large surface for attachment, its tendon  is
expanded  into a broad  membranous portion  termed an Apo-
neurosis,  as may be seen  in the  muscles inclosing the abdo-
men ;  Avhile the greater portion of the muscles have a fleshy
portion called the SAvell or Belly) and the  tendinous portion
contracted into  the  shape of a cord,  or eAren of a thread.   In
general this belly  of the  muscle  is in a place  which is the
most firmly fixed, and distant from the point to be  moved, in
order to effect grace of motion, and beauty of form.
                           Fig. 126.
A Ladiate Muscle.
   232.f Forms  of  Muscles.—In form the muscles present a
great diArersity.  A  Radiate Muscle (Fig. 126) is one Avhere
the fibres radiate from a central portion  to  distribute them-
selves  upon a large surface.  In the Fusiform (Fig. 127) the
                           Fig. 127.
A Fusiform Muscle.
fibres diminish in size from a center to  each extremity.   In

  What is the fleshy portion of the muscle called ?  What is an Aponeurosis ?  Define tho
Origin and Insertion of a muscle.  Where is  tho  Belly of the muscle generally located?
232. Describe the Eadiato and Fusiform Muscles. 
A X D  PHYSIOLOGY.
Ill
Fig. 128.
                    A Doubly Penniform Muscle.
the Penniform the  fibres are short and arranged upon a long
tendinous line, like the plumes upon the quill of a  feather.
The circular form, called Sphincter, is found in parts of the
b)dy where the  fibres are circular, surrounding some orifice
which they partially or entirely close up by their contraction.
An example of this is seen  around  the  eye  and mouth.  A
feAV muscles resemble in structure a ribbon.  Others a cord,
and others are very thin and expanded,  so that they resemble
a membrane./ All these forms  are thus arranged  to secure
the greatest amount of power with dispatch, and also the most
perfect freedom of motion, as well as  to adapt themselves to
the amount of space furnished  them on the skeleton.
    233.  Number  of Muscles,  Single Muscles.—The number
 of muscles in man is 540,)being more than twice the number
 of the bones.  /They are nearly all arranged in pairs • that is,
 both sides of the body have similar  muscles, while the single
 or(unmated muscles are  only  thirteen.) ■ Each muscle is pro-
 vided with one  or more antagonist muscles,) or  those which
 produce motion  in  an  opposite direction, save a very few sur-
 face muscles about the head and  neck,  where the elasticity of
 the integuments produces the  antagonistic motion.
    234.  Fascia.-[Every muscle is  covered by  a  firm and
 slightly  elastic   membrane called  Fascia,  which serves the
 double purpose of keeping the fibres firmly in their place^) and
 also of  producing a  tonic  pressure, (which gives  increased
 strength to the muscle. ) An illustration of the utility of this
 pressure is seen  in the fact, that  the school-boy, when engaged
 in running as rapidly as possible in his sports, ties a handker-
   Describe tho Penniform and Circular Muscles. Are there any other forms of muscles?
  Why are muscles of these different shapes ? 233. AVhat is the number of human muscles?
  How docs this compare with the number of the bones? How many unmated muscles
  are there?  What is meant by antagonist muscles?  23L AVhat is the Fascia, and what
  purpose does it serve ? What illustration  of its use ? 
112
nrrciicocK's   anatomy
Fig. 129.
   Anterior View of the Muscles of the Body.
1, Frontal Bellies of the  Occipito-Frontalis.
2, Orbicularis Palpebrarum.  3, Levator Lubii
Superioris  Ala?que Nasi.  4, Zygomatieus  Mi-
nor.  5, Zygomatieus  Major.  6, Masseter.  7,
Orbicularis Oris.  8, Depressor Labii Inferioris.
9, PkUysma-Myoides.  10,  Deltoid.  11, Pecto-
ralis Major.   12, Axillary portion of tho Latis-
simus  Dorsi.   13,  Sciratus
Major  Anticus.   14, Biceps
Flexor Cubiti.  15, Anterior
Portion of the Triceps  Ex-
tensor Cubiti.  10, Supinator
Radii Longus.  17, Pronator
liadii  Torus.   IS, Extensor    14
Carpi Eadialis Longior.  19,
Extensor  Ossis  Metacarpi
Pollicis.  20, Annular Liga-
ment.   21,  Palmar Fascia.
22, Obliquus Kxternus Ab-
dominis. 23, Linea Alba. 24,
Tensor Vaginae Femoris. 25,
Section  of  the  Spermatic
Cord.   26,  Psoas  Magnus-
27, Adductor Longue.   28,
Sartorius.   29, Luctus Fe-
moris.    30,  A'astus Kxter-
nus.  31, Vastus  Internus.
32, Tendon Patella;. 33, Gas-
trocnemius.  34, Tibialis An-
ticus.  35, Tibia.   3G,  Ten-
dons of the Extensor Com-
munis. 
AND   PHYSIOLOGY
113
Fig.  130.
  Posterior View  of the Muscles of tho
Body.  1, Temporalis.   2,  Occipital por-
tion  of the  Occipito-Frontalis.  3,  Com-
plexus.  4,  Splenitis.   5,  Masseter.  G,
Sterno-Cleido Mastoideus.   T, Trapezius.
8, Deltoid.   9, Infra-Spinatus.   10, Tri-
ceps Extensor.  11, Teres Minor.  12, Te-
res Major.  13, Tendinous portion of the
           Triceps.   14,  Anterior Kdgo
           of the Triceps.   15, Supinator
           P.adii  Longus.   16, Pronator
           liadii   Teres.   17,  Extensor
           Communis Digitorum. 18, Kx-
           tcnsor  Ossis Metacarpi  Polli-
cis.  19, Extensor Communis Di-
gitorum Tendons.   20, Olecranon
and In.-ertion of the Triceps.  21,
Extensor Carpi Ulnaris.  22, Au-
ricularis.  23, Extensor Commu-
nis. 24, Latissimus Dorsi.  25, Its
Tendinous Origin.  26, Posterior
Part of the  Obliquus Externus.
27, Gluteus Medius. 28, Gluteus
Magnus.  29, Biceps Flexor Cru-
ris.  30,  SemiTendinosus.   31,
82,  Gastrocnemius.   33, Tendo-
Achilles. 
114            HITCHCOCK'S   ANATOMY
           Fig. 131.               chief about his waist in order
                                  to  give strength to  his mus-
                                  cles.   And  so  important is
                                  this membrane to the  muscu-
                                  lar  system,  that,  upon  the
                                  thigh,   where   very   great
                                  strength   and  rapidity  of
                                  movement  is  required,   this
                                  membrane is thicker than in
                                  most of the other  parts of the
                                  body ;  and not  only so, but a
                                  muscle is also provided for the
                                  especial purpose of rendering
                                  this  membrane  very tense,
                                  Avhen  any  violent  action  is
                                  required, or its  own elasticity
                                  is insufficient.
                                      235. Descriptions  of par-
                                  ticular  3Iusclcs.—In such a
                                  treatise as the present one,  it
                                  will of  course  be  impossible
                                  to describe all the  muscles as
                                  minutely as the  bones  have
                                  been, nor wiil it be  necessary;
                                  but only those which  are the
                                  most interesting and  instruc-
                                  tive.
   236.  Orbicularis Palpebral.—The muscle which surrounds
the eye is a sphincter  which  is  made of circular  fibres, and
when contracted closes the eye, as it is  termed.   Consequently
this action requires  the movement of no bones, and no  attach-
ment to any thing but  the soft parts of the face.   It is called
the Orbicularis Palpebrae.  Its antagonist is the Levator  Pal-
  AVhat is said about the importance of this fascia upon the thigh ? 2"G. What is the mus-
cle that opens and  closes tho eye, as it is termed ?  AVhat kind of a muscle is this ?
What is the antagonist of the Orbicularis Palpebr.-e ?
  A Transverse Section of the Neck, show-
ing the Fascia Profunda, and its  Pro-
longations  as Sheaths for the Muscles.
1,  Platysma Myoides.  2, Trapezius.  3,
Ligamcntum Nucha?. 4, Sheath of Sterno-
Cleido-Mastoid.  5, Muscle itself.  6, Point
of Union of its Fascia. 7, Point of Union
of the Fascia Profunda Colli of each side
of the Neck. 8, Section  of the Sterno-
Ilyoid Muscle.  9, Section of the Omo-
Ilyoid Muscle.  10, Section of the Sterno-
Thyroid Muscle.  11, Lateral Lobe of the
Thyroid Gland.  12. Trachea. 13, CEsoph-
agus.  14, Blood-vessels and Pneumogas-
tric Nerve  in their  Sheath. 15, Longus
Colli.  16,  Rectus  Anticus Major.   17,
Scalenus  Anticus.  IS,  Scalenus Medius
and Posticus. 19, Splenitis Capitis.  20,
Splenitis Colli.  21,  Levator Scapula.  22,
Complexus.  23, Trachelo - Mastoid.  24,
Transversalis Cervieis. 25, Cervicalis De-
scendens.  26, Semi-spinalis Cervieis.  27,
Multifidus Spina?. 2S, A Cervical A'ertebra. 
AND   PHYSIOLOGY.
115
Fig. 132.
  A Front View of tho Superficial Layer of Muscles on the Face and Neck.  1, 1, Ante-
rior Bellies of the Occipito-Frontalis.  2, Orbicularis or Sphincter Palpebrarum. 3, Na-
sal Slip of Occipito-Frontalis.  4 Anterior Auricula;.  5, Compressor Naris.  6, Levator
Labii  Superioris Alit-que Nasi.  7, Levator Anguli Oris.  8, Zygomatieus Minor.  9,
Zygomatieus Major.  10, Masseter.  11, Depressor Labii Superioris Alaeque Nasi.  12,
Buccinator.   13, Orbicularis Oris.  14,  The denuded  Surface of the Inferior Maxillary
Bone.  15, Depressor Anguli Oris.   16, Depressor Labii Inferioris.  17, The portion of
the Platysma Myoides that passes on to the Mouth, or the Musculus Risorius.  18, Sterno-
Ilyoideus.  19, Platysma-Myoides.  It is wanting on tho  other side of the Figure.  20,
Superior Belly of the Omo-Hyoideus near its insertion.  21, Sterno-Cleido-Mastoideus.
22, Scalenus Medius.  23, Inferior Belly of Omo-IIyoid.  24, Cervical Edge of the Tra-
pezius.

pebrse, Avhich  takes its  origin  far  back  on  the  sides of the _

cavity of the orbit,  and is attached to  the  upper  lid.-   When

contracted it opens the  eye.

   237.  Orbicularis  Oris.—The  Orbicularis  Oris  (circular

muscle of the face)  by  its contraction closes the mouth.   Like

the  corresponding muscle of the eye, it has its  origin  and in-

sertion in the soft parts of the face,  and is made up of concen-

              237. Where is the  Orbicularis Oris, and what is its use? 
116
II I T C II C O C EL' S  ANATOMY
trie fibres.  And the antagonists are those muscles which are
inserted into it, coming  from  the different bones of the face
moving the lips and nostrils, and giving much of the expres-
sion of emotion in the countenance.

   238. 31assetcr and  Temporal Muscles,—The elevators of
the lower jaAV are  tAvo:  the Masscter  (cheAving)  and  the
Temporal (from the bone on which it lies).  They are at-
tached to the posterior portion of the bone near the joint, since
if their position Avas nearer to the front part of the  bone they
Avould not contract sufficiently to bring the jaAvs together.

   239. Digastric  Muscle.—The loAver jaw is carried down-
wards by the Digastricus (two bellies) muscle.   This is a long
round muscle  like  a cord, which  commences just below  the
loAver front  teeth, and from thence runs downwards and back-
wards to  the  os hyoides,  Avhere it runs  through a tendinous
loop ;  after this it passes upAvards  and  backAvards to the mas-
toid  process upon the  temporal bone, just  behind the ear.
The contraction of this muscle then Avill open tho mouth, Avhen
the os hyoides is  made  fast;  but if the  jaAV bo confined  by
its elevator  muscles, the os hyoides will be the moA'able por-
tion, and will be elevated.   The necessity of such an arrange-
ment  is evident from the fact,  that no muscle  from the jaAV to
the hyoides would be of sufficient length to  open  the lower
jaAV by its contraction;  and if it  were to run backwards to
the spinal  column, the  violence Avith Avhich it must contract
to accomplish its object, AATould produce such pressure upon the
A'esscls and  nerves of the neck as to injure them.

   240. Stcrno-Clcido-  r.Iastoidcus.—A  bow, or bending  of
the bead upon the spinal column,  is effected  by  the action of
the Stemo-Cleido-Mastoideus muscle (named from  its attach-
 V.'hat are its antagonists? What muscles ai.l very much in giving expression to tho
countenance ? £03. AVhat are the two pairs of muscles that bring the jiws together in
the act ( f chev.-in ;?  230. State the muscle that opens the mouth.  AA'hat mechanical
peculiarities in its structure and operation? AVhy tl'.o necessity of such a complicated
arrangement ? 240. What i* tho muscle by whose action wo bow tho head 1 
AND   PHYSIOLOGY.                 117


           Fig. 133.
  A Lateral Yiew of the Deep-seated Layer of Muscles on the Face and Neck.  1, Tem-
poral Muscle deprived of its Fascia. 2. Corrugator Supercilii.  3, Nasal Slip of the 0c-
cipito Frontalis.  4, Superior or Nasal Extremity of the Levator Labii Superioris Altequo
Nasi.  5, Compressor Naris.  G, Levator Anguli  Oris.  7, Depressor  Labii Superioris
Alaequc Nasi.  S, Buccinator.  9, Orbicularis  Oris.  10, Depressor Labii Inferiors.  11,
Levator Labii Infcrioris.  12, Anterior Belly of the Digastricus.  13, Mylo-llyoid.  14,
Stylo-Hyoid.  13, Thyro-IIyoid.  16, Upper Belly of the Omo-IIyoid.  17, Sterno-Cleido-
Masloid.  13, Stcrno-IIyoid.  19. Scalenus Anticus.  20, Pectoralis Major.   21, Deltoid.
22, Trapezius.  23, Scalenus Medius. 24, Levator Scapulu; and Scalenus Posticus.  25,
Splenius.  23, Complexus.

ment to the  Sternum, Clavicle, the Greek for Avhich is kleis,

and the mastoid process).    The form  of this muscle is essen-

tially  that of a thick  ribbon.

    2-41.  Muscles  of  the  Scapula—The  Scapula  is  covered

Avith muscles on  both sides,  most  of Avhich arc inserted  into

the head  of  the  humerus.    Their  use is  to  rotate  the  hu-
  AVhat is tho shape of this musclo ?  211. What actions do tho muscles of th« scapula
effoct ? 
118              HITCHCOCK'S   ANATOMY

                                  Fig. 134.
  A View of the Muscles of the Back as shown after the removal of the Integuments.  1
Occipital Origin of the Trapezius.  2, Sterno-Cleiilo-Mastoideus.  8, Middle of the  Tra.
pczius.  4, Insertion of the Trapezius into the Spine of the Scapula.  5, Deltoid.  6, Sec-
ond Head of the Triceps Extensor Cubiti. 7, Its Superior Portion.  8, Scapular portion
of tho Latissimus Dorsi.   9, Axillary Border of the Pectoralis Major.  10, Axillary Bor-
der of the Pectoralis Minor.  11, Serratus Major Anticus.  12, Infra-Spinatus.  13, Teres
Minor.  14, Teres Major. 15, Middle of the Latissimus Dorsi.  16, External Oblique of
tho Abdomen.   17,  Gluteus Medius,  18, Gluteus Minimus.  19,  Gluteus Magnus. 20,
Fascia Lumborum.


merus,  as  Avell  as to  give it protection  Avhere  it articulates

Avith the scapula, and to keep it in  its  place. 
AND   PHYSIOLOGY.                119
Fig. 135.
   242.  Biceps.—The  Biceps
(tAvo  heads, or points  of at-
tachment) is the muscle Avhich
flexes or  bends  the arm to-
Avards  the   body.   It  arises
from the head of the humerus
and scapula,  and  is inserted
into  the  upper  end of  the
radius.   It is  a very fine  ex-
ample  of a  fusiform  muscle,
and though acting at a great
mechanical disadvantage as to
power, it effects a rapid move-
ment.
   243.   Triceps.—The   Tri-
ceps  (three heads), its antag-
onist, is similar in its general
form, and is attached to the
ulna  instead  of  the  radius.
It is situated upon the  poste-
rior side of the humerus,  and
the force with Avhich it  may
be  made  to contract, is  seen
in  the  powerful blow  given
by the boxer, or  the weights
raised by extending the arms
upon  the instrument made for
the purpose in a gymnasium.y
   244.  Muscles of the  Fore-
Arm.—The Fore-Arm is abun-
dinous Insertion of the Pectoralis Minor.
the Biceps.  13, Latissimus Dorsi.  14, Inner portion of the Triceps. 15, Body of the
Biceps.  16, Outer portion of the Triceps.  17, Brachialis Internus.  IS, Origin of tho
Flexor Muscles.  19, Brachialis Internus near its Insertion.  20, Tendon of the Biceps.
21, Fasciculus from the Biceps Tendon to the Fascia Brachialis. 22, Flexor Carpi Ea-
dialis.  23, Palmaris Longus. 24, Supinator Radii Longus.
  A Yiew of the Muscles on tho Front oj
 the Arm. 1, Clavicle. 2, Coracoid Pro
 cess and Origin of tho Short Head of tho
 Biceps.  S, Acromion Scapulae.  4, Head
 of the Os Humeri.  5, Tendon of the Bi-
 ceps  Muscle  in  the Bicipital Groove.  6,
 Ligamentum Adscititium dissected off.  '!,
 Cut portion  of the  Pectoralis Major.  Si
 Long Head of the Biceps.  9, Insertion of
 the Deltoid.   10, Cut portion of tho Ten-
11, Coraco-Brachialis. 12,  Short Head of
  242. AVhy is the name Biceps given to the muscle that flexes the fore-arm ?  AVhat
mechanical disadvantage in its structure ?  AVhat gain from it? 243. AVhat is the antag-
onist of the Biceps?  What actions show its modo of action ?
                               6 
120             ii itch co

           Fig. 136.
 A View of the Outer Layer of the Mus-
cles on tho Front of tho Fore-Arm (Flex-
ors).  1, Lower portion of tho  Biceps
Flexor Cubiti.  2, Brachialis Internus.  3,
Lower Internal portion of the Triceps.  4,
Pronator Radii Teres.  5, Flexor  Carpi
Eadialis. G, Palmaris Longus. 7, Part of
the Flexor Sublimis Digitorum. 8, Flexor
Carpi Ulnaris. 9, Palmar  Fascia. 10,
Palmaris Brevis Muscle. 11, Abductor
Pollicis Manus. 12, Portion of the Flexor
Brevis Pollicis Manus.  The  Line crosses
the  Adductor Pollicis.  13, Supinator
Longus.  14,  Extensor  Ossis Mctacarpi
Pollicis.

order that the fingers may be
desirable that there should be a
JK-'S  ANATOMY

     dantly supplied with muscles,
     many  of Avhich  are fusiform
     in their appearance,  and  all
     of Avhich are  for the purpose
     of moving  the  hand and fin-
     gers.   Most of  the  fibres run
     in a direction  parallel to the
     bones  of the  fore-arm,  but
     those Avhich perform the ac-
     tions of pronation and supina-
     tion lie  obliquely,  and some
     nearly at right angles to the
     long muscles.   In  this part
     of the body the muscles are
     distinguished  by  slenderness
     of form and consequent  deli-
     cateness  of  tendon, the  latter
     in many cases being equal in
     length to the muscular fibre,
     since there  are very few mus-
     cles below the wrist, and those
     only  Avhich  are  short  and
     thick, for the purpose of mov-
     ing  the  thumb  and  little
     finger.
        245. Tendons of the  Fin-
     gers.—The  arrangement  of
     the  tendons  which  are at-
     tached to the  phalanges, for
     the  motion  of  the  fingers,
     shows  the  contrivance  and
     skill of an  Infinite Being.  In
    slender and  easily moved, it is
    s small a  quantity of matter in
 244. Give the general arrangemelit of muscles in the foro-arm.  How do the Pronators
and Supinators lie ? 
AND   PHYSIOLOGY.
121
Fig. 131.                          Fig. 138.
                               1, Internal  Lateral Ligament of the El-
bow-Joint.  2, Capsular Ligament of the Elbow-Joint.  3, Coronary Ligament of the
Head of the Radius. 4, Flexor Profundus Digitorum  Perforans. 5, Flexor Longus
Pollicis.  G, Pronator Quadratus.  7, Adductor Pollicis Manus. 8, Lumbricales. 9,
Interossei.
them  as possible.   Ilence,  as  above stated, the muscle  that
moves  them  is  situated in  the fore-arm, and the  tendon  is
made as slender as possible.   But here another arrangement
claims our attention.  A set of four tendons from a common
muscle is attached to the base of  the second phalanx of each
finger,  and  a second set to the  third toav of  phalanges.   The
question  then arises,  Iioav can  these  tAvo  tendons pass upon
245. Describe the arrangement of tho tendons of the fingers. 
122
HITCHCOCK'S
A N A T O M Y
both sides (upper and  lower) of the  finger and be  firmly
enough secured to the finger to keep them in place, Avithout
making the finger of an unwieldy bulk, and at the same  time
alloAV the force  to be applied upon the  center of the finger
rather than upon one side ?   The ansAver is this :  the muscle
Avhich  sends its tendons to the second phalanx lies above the
other set of tendons,  and Avhere the superior tendons join the
second  phalanx, they are  each split into  tAvo parts, through
which  the tendons of the loAver muscle pass to the last  pha-
lanx, and move freely Avithout interruption from the  superior
muscle or tendons.  The same arrangement  is  found upon
both surfaces of the  hand and foot, for furnishing the same
movement to the toes, resembling very closely the movement
of a cord through a loop.
   246. Muscles  of  the  Thumb  and  Little Finger.—The
thumb  and little  finger, as already mentioned, are  supplied
Avith separate muscles in the body of the hand, mainly for the
purpose of giA'ing motion from side to side, as well as a partial
rotation.   In addition to this,  there are several muscles upon
the fore-arm which give their  tendons only to these  two ex-
tremities.  The obvious  use of this arrangement is  to  give
strength  and great  variety  of motion  so necessary in the
thumb and little finger.
   247.  Muscles  of  the  Back, Dorsal  Muscle.—Upon the
back are found at least thirty pairs of muscles, Avhich  are ar-
ranged in six  layers.  These are of various forms and sizes,
Avith complicated and obscure attachments.  The main use of
these muscles, taken as a  group, is  to keep the trunk in an
upright position, and give a firm attachment for  muscles to
move  the  extremities.   Tho outermost  layer  is  very super-
ficial,  lying directly  under the skin, Avhile the  deepest layer
i3 deeply imbedded betAveen different processes of the vertebrae.
  Why must one tendon pass through  another  rather than pass along by its side ?
Do wo find this arrangement upon both hands and feet? 246. AVhich two extremities
of the hand have the mot muscles given to them? 247. How many pairs of muscles
upon the back of the body?  Give the number of layers into which  they may bo dis-
sected. State tho essential purpose of them. 
AND   PHYSIOLOGY.
123
Fig. 139.
  A View of the Second Layer of Muscles of the Back.  1, Trapezius.  2, A portion of
the Tendonous ellipse formed by the Trapezius on both sides. 3, Spine of the Scapula.
4, Latissimus Dorsi. 5, Deltoid.  6, Infra-Spinatus and Teres Minor.  7, External Ob-
lique of the Abdomen.  8, Gluteus Medius.  9, Gluteus Magnus of each side.  10, Leva-
tor Scapula).  11, Rhomboideus Minor.  12, Ehomboideus Major.  13, Splerflus Capitis.
14 Splenitis Colli.  15, A portion of the Origin of the Latissimus Dorsi.  16, Serratus In-
ferior Posticus.  17, Supra-Spinatus.  IS,  Infra-Spinatus.  19, Teres Minor.  20, Teres
Major.  21, Long Head of the Triceps Extensor Cubiti. 22, Serratus Major Anticus.  23,
Internal Oblique of the Abdomen.

The largest muscle of  the back (hence the  name  Dorsal) is

of value to move the arm3.   It has  its  origin from  the lum-

bar and  sacral  vertebra, and the posterior third  of  the crest

of the  ilium, and is inserted by a short tendon into the upper

extremity of the humerus.   The action of this  muscle  brings

         Give the origin and insertion of the Dorsal muscle. State its action. 
124           HITCHCOCK'S  ANATOMY
the arm downwards and backwards, as  in  the movements  of
chopping Avood or striking with the blacksmith's sledge.   But
when the hands arc made the  fixed points, the body is raised
upwards.

   248.  Superior  and  Inferior  Serrati.—Tavo muscles of the
back arc used in forced or violent respiration.  These arc tho
Superior and  Inferior  Serrati Muscles.  The Superior  Ser-
ratus arises from the three loAver cervical and tAvo upper dorsal
vertebrae, and runs dowmvards  and fonvards to be inserted
into the border of the second,  third,  and fourth ribs.   The
Inferior Serratus arises from  the  last  two  dorsal and  three
upper lumbar vertebrae, and, running  upAvards and fonvards,
is  inserted  upon the four loAver ribs.   The name of these mus-
cles means in Latin " saAV-like," since the portions Avhich join
upon the ribs resemble the teeth  of a saAV.   The former  of
these elevates the ribs, thereby enlarging the cavity of the
chest, Avhile the latter  assists in its compression by depressing
the ribs, and consequently the diaphragm, doA\rnwards.

   249.  The Diaphragm^But the essential  muscle of respi-
ration is the Diaphragm.   This, as its name implies, is a par-
tition across the body just  beloAV the  lungs, Avith an  opening
near the center Avhich  separates the  thorax  from the  abdo-
men.   Its  attachments in general terms may be said  to be
upon an oblique  line  drawn  about  the body just  beloAV the
ribs, Avhich line  intersects the  first lumbar  vertebra, Avhere
the central tendon of the Diaphragm, as it is termed, is at-
tached.   When relaxed, it presents the appearance  of an in-
verted and irregularly shaped  cup or basin, but Avhen in a
state  of contraction it becomes nearly a plane surface.  Hence
this muscle enlarges the chest by depressing its lower surface,
thereby forming a partial vacuum.
 21S. Which muscles of the back arc used in forced rcspiratfon ? Gjvetho origin and
insertion of the two Serrate Muscles. AVhy called"" Serrate?M 249. Givo tho form of
the Diaphragm.  AA'hat  two cavities of the body does it separate? AVhat is it an essen-
tial agent in effecting ? 
AND   PHYSIOLOGY.
125
Fig. 140.
  A View of the Under Side of tho Diaphragm.  1, 2, 3, The Greater Muscle of the Dia-
phragm inserted into the Cordiform Tendon.  4, The small triangular space behind thov
Sternum, covered only by Serous Membrane, and through which Hernia sometimes
pass.  5, Ligamentum Arcuatum of the Left Side.  6, Point of Origin of the Psoas Mag-
nus.  7, A small Opening for the Lesser Splanchnic Nerve. 8, One of  the Crura of the
Diaphragm.  9, Fourth Lumbar Vertebra.  10, Another Cms or portion of the Lesser
Muscle of the Diaphragm.  11, Hiatus Aorticus.  12, Foramen CEsophageum.  13, Fora-
men Quadratum.  14, Psoas Magnus Muscle.  15, Quadratus Lumborum.
   250. (Intercostal  Muscles.—feetween the  ribs are placed
two  sets of muscular fibresj an external and an internal, called
the Intercostal Muscles, which by their  action draAV the  ribs
upwards.   The fibres run in a diagonal direction from one rib *
to another, <so that the greatest length may be given  for  their
contraction Avithout compromising too much of their  poAver.
And hence avc can see that Avhile the first rib  is firm and im-
movable, by contraction of these fibres the ribs must be raised,
and  by their relaxation they  must  be depressed.   The exter-
nal fibres run doAvnwards and toAvards the middle  line of the
abdomen, AYhile the internal run doAvnwards and backAvards.
   251. Abdominal Muscles.—The  principal  muscles of the
abdomen are  large and  thin expansions of muscular fibres,
  250. Give the arrangement of fibres in tho Intercostal Muscles.  251.  AVhat forms tho
principal part of the walls of tho abdomen ? 
126
HITCHCOCK'S  ANATOMY
Fig. 141.
                                 which  completely cover tho
                                 space beloAV the border of the
                                 ribs, and above the innomina-
                                 tum.    They are arranged un-
                                 der four different names, since
                                 they  run  in  different  direc-
                                 tions  as they encircle the ab-
                                 domen.   By their contraction
                                 they press upon the  digestive
                                 organs,  and thus diminish the
                                 cavity  of  the abdomen, and,
                                 in proportion to the  elasticity
                                 of the diaphragm, the thorax
                                 also.    Hence  these  are the
                                 essential instruments in cough-
                                 ing,  laughing,   crying,  and
                                 sneezing, as Avell  as  in  sing-
                                 ing, shouting, or any  action
                                 requiring expulsive effort. By
                                 their elasticity they  also per-
                                 form  the function of expira-
                                 tion in natural breathing,  as
                                 well as keep up a tonic  pres-
                                 sure  upon  the stomach and
                                 alimentary canal.
                                    252.  Great Psoas Muscle.
                                 —The  Great  Psoas Muscle,
                                 knoAvn in animals as the ten-
                                 der   loin   (from  the  Greek
                                 signifying   a  loin),  is   the
                               upon,   or toAvards  the trunk.
It has its origin  from  the last dorsal  and  four  upper lum-
bar  Arertebrce,  and  passes from  thence downwards ^ and for-
Avards, gliding  over the edge of the innominatum, and attaches
 A Lateral View of the Muscles of the
Trunk, especially on  the Abdomen. 1,
Latissimus Dorsi. 2, Serratus Major An-
ticus. 3,  Upper portion of the External
Oblique.  4, Two of the. External Inter-
costal Muscles.  5, Two of the  Internal
Intercostal Muscles.  6, Transversalis Ab-
dominis.  7, Fascia Lumborum. 8, Poste-
rior part of the Sheath of the Rectus, or
Anterior Aponeurosis of the Transversalis
Muscle.  9, The Rectus Abdominis cut off
and in its Sheath. 10, Rectus Abdominis
of the Risrht Side.  11, Crural Arch. 12,
Gluteus Magnus—Medius and Tensor A'a-
gina; Femoris covered by the Fascia Lata.

one which  bends  the  thigh
 Under how many heads are they arranged ?  AVhat actions do thoy accomplish when
contracted?  252. AVhat is the scientific name of the "tender loin?''  Give its attach-
ments. 
and   physiology.                  127

           Fig. 142.
  A View of the Superficial Muscles of the Left Side, and  of the Deep Muscles of the
Eight Side, on the Front of the Trunk.  1, Pectoralis Major.  2, Deltoid. 3, Anterior
Edge of Latissimus-Dorsi.  4, Serrated Edge of Serratus Major Anticus.  5, Subclavius
Muscle.  6, Pectoralis Minor.  7, Coraco-Brachialis.  8, Biceps Flexor Cubiti.  9, Cora-
coid Process of the Scapula.  10, Serratus Major Anticus after the removal of the Ob-
liquus Externus Abdominis.  11, External Intercostal Muscle of the Fifth Intercostal
Space.  12, External Oblique of the Abdomen.  13, Its Tendon.'  The Median Line is tho
Linea Alba.—The Line to the Right of the Number is tho  Linea Semilunaris. 14,  Tho
portion of the Tendon of the External Oblique, known as Poupart's Ligament.  15, Ex-
ternal Abdominal Ring.   1G, Rectus Abdominis. The AVhito Spaces arc the Linea Trans-
versa;.  17, Pyramidalis.  IS, Internal Oblique of the  Abdomen.   19, Common Tendon
of the Internal Oblique and Transversalis.  20, Crural Arch.  21, Fascia Lata Fcmoris.
22, Saphenous Opening.   The Crescentic Edge of the Sartorial Fascia is seen just abovo
fig. 22, and the Interior or Pubic Point of the Crescent is known as Iley's Ligament.


itself to the front  part of the great trochanter  process  of  the

femur.    It is made  up of a very  compact   band  of  fibers, and,

though  acting at a  great mechanical  disadvantage, it is ca-

pable of moving the loAver extremity  Avith  great power.   Bv

                                    C>* 
128
HITCHCOCK'S  ANATOMY
this muscle it is that the body
is fixed, and also by its means
in a sitting posture.
  253. Gluteus  Muscle.—A
Fig. 143.
 A View of the Muscles on the Front of
the Thigh.  1, Crest of the Ilium. 2, Its
Anterior Superior Spinous Process.  3,
Gluteus Medius. 4, Tensor A'aginse Fe-
moris.  5, Sartorlus.  6, Rectus Femoris.
7, A'astus Externus. 8, A'astus Internus.
9, Patella. 10, Iliacus Internus.  11, Psoas
Magnus.  12, Pectineus.  13, Adductor
Longus. 14, Adductor Magnus. 15, Gra-
cilis.
is bent forward when the thigh
 Ave  keep the  body erect when

movement in a direction oppo-
 site to the last muscle, is ef-
 fected by the  contraction of
 the Gluteus  muscle.   This
 has its origin and insertion at
 points  directly   opposite   to
 those  of  the psoas muscle—
 and forms  the nates  or but-
 tock.  The fibers  of this mus-
 cle are the coarsest of any in
 the Avhole body, shoAving that
 they are designed  for strength
 and not  celerity of  motion.
 Besides the moArement already
 mentioned, this muscle is  of >
 great  value when the leg  is
 made  firm  by  keeping  the
 body in  an  upright  position,
 or raising the body upon  the
 thighs Avhen it is bent forward.
    254.   Muscles   of    the
 Thigh.—The  leg (Tibia)  is
 moA'ed  upon  the  thigh (Fe-
 mur)  by the  conjoint action
 of four muscles.   These have
 their origin about  the  head of
 the femur, and the loAver por-
 tion of the innominatum, ancb
 all   unite   into   one  tendon
 which is  inserted upon  the
 tubercle,  or  process  of the
  What movements are effectod by it ?  25-3. AA'hat muscle produces motion in a con-
trary direction to the psoas muscle ? AA'hat is said of the size of the fibers of tho Gluteus ?
254. How many muscles act to extend the tibia or the femur? 
AND  PHYSIOLOGY.              129
tibia near to its upper extremity.   Spoken of together, these
muscles are called the Quadriceps Extensor Femoris.   The
tendon is one of  the  strongest  in  the body, and has inclosed
within it the patella, Avhich bears  the same relation to the
tendon as the pulley does to the cord Avhich passes over it.
The action of these muscles extends the  leg, as in walking,
running, or lifting the foot, and also places the femur in a line
above the tibia, when the latter is made the fixed point.

   255.  Sartorius Muscle.—The Sartorius  or Tailor's mus-
cle is a very long and slender muscle commencing at the an-
terior portion of the innominatum, and, descending downwards
and imvards., is inserted into the upper part  of the inside of
the tibia.  The obvious action of this muscle will be to bend
the leg somewhat backAvards, and then  to  carry it across its
fellow, as is done by the tailor when seating  himself for work
on his bench.

   256.  Tensor Vagina;  Femoris.—A muscle already alluded
to—the Tensor Vaginae Femoris, or stretcher of the sheath of
the thigh—arises at the upper and  front portion of the inno-
minatum, and  is  inserted into the very strong fasciae of the
thigh, its use being to assist the muscles in their  action, by
increasing the tonic pressure upon them.

   257.  Muscles  of the  Posterior Part  of  the Thigh.—
The muscles  found  upon  the posterior part of  the femur
and antagonizing  the compound muscle  in front, are four in
number, taking their origin  from the ischium and pubes, and
beino- inserted  into the broad head of the  tibia.   Their ten-
dons make  those portions of the thigh which  are  familiarly
known as  the  ham-strings.  Their names  are  the  Biceps,
Gracilis, Semi-tendinosus and Semi-membranosus.
  When taken together, what is the musclo called ?  What bono is imbedded in tho ten-
don of tho Quadriceps Extensor Femoris ?  255. Describe the Sartorius or Tailor's mus-
clc.  256. What is tho Tensor Vagin.-e Femoris of service for?  257. How many musclea
net as antagonists to tho Quadriceps, etc. ? Give their names.           t 
130
-n ITCH COCK'S  ANATOMY
Fig. 144.
Fig. 145.
  A View of the Muscles on the Back of
the  Thigh.  1, Gluteus Medins.  2, Glu-
teus Magnus.  8, Fascia Lata covering the
Yastus  Externus.  4, Long Head  of the
Biceps.  5, Short Head of the Biceps. 6,
Bemi-Tendinosus. 7,7, Semi-Membranosus.
8, Gracilis.  9, Edge of the Adductor Mag-
nus.  10, Edge of the Sartorius.  11, Pop-
liteal Space.  12, Gastrocnemius.
  A Yiew of the Muscles on the Front of
tho  Leg.  1,  Tendon  of the Quadriceps
Femoris. 2, Spine of the Tibia.  3, Tibi-
alis Anticus. 4, Extensor Communis Digi-
torum.  5, Extensor Proprius Pollicis. 6,
Peroneus Tertius.  7,  Peroneus  Longus.
8, Peroneus Brevis. 9, 9, Borders of the
Soleus.  10, Portion of the Gastrocnemius^
11, Extensor Brevis Digitorum.
   258. Muscles  of the  Anterior  Part  of  the  Leg.—Upon
the anterior portion of the Tibia, or leg proper, are found four
muscles with slender tendons, which are for the upward move-
ment or flexion of the foot.   They have their origin  near  the
head of the tibia, and are inserted into the bones of the meta-
  258. AVhere are the four muscles located that bend the foot upward ? Give their origin
and insertion. 
AND   PHYSIOLOGY.               131
tarsus and  phalanges.   Their
names are  the  Tibialis  Anti-
cus, Extensor  Longus  Digi-
torum,  Peroneus Tertius, and
Extensor Proprius Pollicis.
   259. Muscles of  the Pos-
terior Part of  the Leg.—The
muscles on the reverse por-
tion of the  leg are three, con-
stituting what is knoAvn as the
calf of the leg.   They are the
Gastrocnemius, Plantaris, and
Soleus.   These also, like the
last mentioned muscles, are
attached near to the top  of the
tibia on its posterior side, and
all form a conjoint tendon, the
largest in the body, and  Avhich
is  attached to the bone of the
heel.  It is called the tendon
of Achilles, because the great
Grecian Avarrior is said to have
been killed by the wound of
an arrow at this point.* The
use  of these muscles is to raise
the  body  upon tho  toes, and
are  the muscles Avhich are of
the  greatest value to us  in the
act of walking.   Immediately
beneath these muscles are six
an opposite direction to those
leg.  They are attached near
fibula,  and  inserted  into the
Fig. 146.
U
m
v.
    A View of the Muscles on the Back of tha
  Leg.  1, Tendon of the Biceps. 2, Inner
  Hamstring Tendons.  3, Popliteal Space.
  4, Gastrocnemius.  5, Soleus. G, Tendo-
  Achillcs.  7, Its Insertion on the Os Calcis.
  8, Tendons of the Peroneus Longus and
  Brevis.  9, Tendons of the Tibialis Posti-
  cus and Flexor Longus Digitorum  behind
  the Internal Malleolus.
others which produce motion in
upon the anterior  portion of the
the upper part of the tibia and
metatarsal bone3  and the  pha-
 259. State the muscles which constitute tho calf of the leg. What is Tendon of Achil-
les, and why is it so called ?  How many muscles lie deeply covered in the calf of tha
leg? 
132
HITCHCOCK'S  ANATOMY
Fig. 147.
langes.   In the tendon of one of them (Peroneus Longus) is
found a sesamoid bone, at the point AYhere it glides over the
cuboid bone.

   260.  Muscles of  the  Foot.—A  few  muscles  are  found
upon the upper and under surface of the  foot, most of  Avhich
                                arise near the tarsus, and are
                                inserted  at  the base  of the
                                phalanges.   In their  action
                                the toes  are either bent  or
                                extended.
                                  261. Annular Ligaments.
                                —An interesting contrivance
                                for preserving the slenderness
                                of the  hand and foot is found
                                in the Annular Ligaments.
                                These  are  large bundles  of
                                ligamentous tissue which pass
                                around the  wrist and  ankle,
                                very much resembling a brace-
                                let.   (Figs. 148, and 149, p.
                                133.)  They  are very firm and
                                stout,  and their design  is  to
                                keep  ^in   place  the  tendons
                                Avhich  moA'e tho extremities.
                                When, for example, Ave  move
                                the toes upwards, the muscles
                                which effect this motion Avith
their tendons AA-ould extend in a straight line from  the  upper
part of the  tibia to the last phalanx, thus making  the  leg
and foot  very cumbersome and unwieldy organs, and poorly
adapted to their present use.

  201. What is the use of tho Annular Lisamcnts ? What ornaments do they very closely
resemble? Suppose these or their equivalent was wanting ?
 A View of the Muscles on the Sole of the
Foot immediately under the Plantar Fas-
cia.  1, Os Calcis. 2, Section of the Fascia
Plantaris. 3, Abductor Pollicis. 4,  Ab-
ductor Minimi Didti.  5, Flexor Brevis
Digitorum.   6, Tendon  of tho Flexor
Longus Pollicis.  7, 7, Lumbricales. 
AND   PHYSIOLOGY.
133
Fig. 148.
Fig. 149.
  A Yiew of the  Outer Layer of Muscles
on the Back of the Fore-Arm (Extensors).
1, Lower portion of the Biceps Flexor.  2,
Part of the Brachialis Internus.  3, Lower
part of the Triceps Extensor.   4, Supinator
Radii Longus.  5, Extensor Carpi Eadialis
Longior.   6, Extensor Carpi Radialis Bre-
vier.  7, Tendinous Insertions of these two
Muscles.   S,  Extensor  Communis  Digito-
rum.   9,  Portion of the Extensor  Communis  Digitorum called Auricularis.  10,
Extensor Carpi I'lnaris.  11, Anconeus.  12, Portion of the Flexor Carpi I'lnaris.
13, Extensor Minor Pollicis.  The Muscle nearest the Figure is the Extensor Ossis
Metacarpi Pollicis.   14, Extensor Major Pollicis.   17, Posterior Annular Ligament.
The distribution of the Tendons of tho Extensor Communis is seen on the backs of
the Fingers.
  A View of the Muscles on the Front of
the Leg.   1, Tendon  of the  Quadriceps
Femoris.  2, Spine of the Tibia.  3, Tibi-
alis Anticus. 4, Extensor Communis Digi-
torum.  5, Extensor Proprius Pollicis.  6,
Peroneus  Tertius.  7,  Peroneus  Longus.
8,  Peroneus Brevis   9, 9, Borders of tho
Soleus.  10, Portion of the Gastrocnemius.
11, Extensor Brevis Digitorum. 
134
HITCHCOCK'S  ANATOMY.
FUNCTIONS  OF  THE  MUSCLES.
Fig. 150.
a
I
   262. Irritability of Muscular Fiber.—Muscular fiber has
one characteristic peculiar to this  tissue.   This is  known as
Irritability or  Myotility,  the shortening of the fiber when a
stimulus  is  applied.   The  stimulus  may  be mechanical, as
when the legs  of a grasshopper are irritated with a probe or
some pointed instrument, it produces contractions.  Electric
and  galvanic  currents, also, when  made to pass  interrupt-
edly through any muscular portions of the body produce con-
tractions ;  as when a person grasps the handles of an electro-
tome or seizes  the ball of a Leyden jar.   And  lastly, vitality
is a muscular stimulus.
                     263.  Condition  of the Fibrils in a State
                   of Contraction.—Formerly it was supposed
                   that muscular contractions were due to a
                   zig-zag position Avhich was assumed by the
                   fibrils ;  but microscopical  examination has
                   proved that the shortening of the fiber  is
                   owing to a change in  the  diameter of the
                   ultimate fibrils ;  the  cell in the fibril  at
                   rest having its longest diameter  parallel to
                   the  fiber, Avhile in  a state of contraction the
                   longest diameter is at right angles to this.
                     264.  Tonicity.—Another   characteristic
                   of muscular fiber is Tonicity.   This  is a
                   constant strain  or  stretch of the muscular
                   fiber, while irritability or contractility only
                   manifests itself when a stimulus is applied.
                   This is a property which is exhibited when
                   a bone is broken or some muscular fibers
                   are  separated.  Thus, Avhen a cut is made
Q
 Structure of the Fi-
brilla?.  a, A fibril in
the state of ordinary re-
laxation,  b, A  fibril
partially contracted.
 262. What is the prominent characteristic of muscular tissue?  Illustrate the mechan-
ical, electric, and vital stimuli. 263. How do the cells of the fibrils arransro themselves
during a contracted state?  264. What is understood by Muscular Tonicity?  When is
this only manifest ? 
AND  PHYSIOLOGY.              135
directly across the fibers the gash at once opens very widely ;
or if a bone  is broken and the ends allowed to'slide by each
other,  it is only by great force that they can be brought back
to their proper places.   The value of this property is seen in
keeping  the muscles in a state ready for action, as well as in
assisting the ligaments to keep the joints firmly together.

   265. Dependent  on  Vital  Energy—Both of these charac-
teristics  are dependent upon nervous or vital energy.   For if
life be extinct, or the nerve proceeding to any muscle be  cut
off, tonicity and irritability soon cease ; although they remain
for a longer time in the  involuntary than the voluntary mus-
cles.  As, for example, the heart of a sturgeon, after its re-
moval from the body, has been known not only to  pulsate for
a short time,  but even  to keep up its  action  until its folds
fairly rustled from inherent dryness.

   266.  Muscular Waste the Cause of Muscular Contrac-
 tion.—But here the question meets us, What is this power that
 passes through the nerves to each fibril, and how does it energize
 the muscle ?  Is it a fluid acting on the fibers in the same manner
 that water acts upon tMfe strands of a rope, or is it an  impon-
 derable agency, like electricity or  heat, passing  through the
 nerve by polar attraction or conduction from  particle to par-
 ticle ?  At present we must rest with the facts of muscular
 movement, and perhaps we can never  solve  the mystery in
 this  world.   The nature of what we vaguely denominate
 nervous or vital force has never been  determined.  No mys-
 tery  in religion exceeds that of muscular movement.   It how-
 ever  seems to be the case that muscular contraction is in a good
 decree dependent on a due  degree of arterialization  of the
 blood ;  for if a muscle bo placed in carbonic acid its irritability
  soon ceases, while in oxygen it remains a long time after  it is
  removed from the body.  A want of the proper amount of oxy-
 Of what use is this property ? 265. Upon what do both myotility and tonicity depend ?
In which muscles do they remain the longest after death ? Instance the heart of the stur-
geoT 2GG What is all we know of the power that produces this contraction I 
136
HITCHCOCK'S   ANATOMY
gen is the cause of the inability to exertion experienced in the
thin air of mountain tops and the relaxation of the muscles in
fainting from exposure to carbonic acid,  ether, or chloroform.
On the other hand, the more full the respiration, the more ener-
getic the muscular power.   The effect of oxygen upon the tis-
sues is that of Avaste, or a consumer ; that is; it produces a more
rapid  circulation of matter  by removing  the carbonic acid,
and substituting itself in its  place;  and  the deeper the respi-
ration, the more energetically Avill all  the  functions of the
body be carried on.   Ilence a plausible theory offers itself
to explain the cause of muscular contraction, which  is, that
" muscular contraction is the necessary physical result of mus-
cular disintegration."

   267.  The  Mechanical  Disadvantage  at  which many
Muscles  Act—The  Reason  of  it.—The force of muscular
contractions is almost always very great, sometimes  so pow-
erful that some of the fibers  are ruptured.   But the main
evidence of this great force is exhibited in the mechanical dis-
advantage at  Avhich most of  the muscles act.  For instance,
               Fig. 151.                   if the muscles were
                                         attached at c, a much
                                         greater Aveight could
                                         be lifted by  the  ex-
                                         penditure of the same
                                         poAver than if it Avere
attached at b ; but  a much  longer  portion of time would  be
necessary to produce  contraction  in such a length of  fiber, a
c,  than  in  a  shorter portion, a b.  Besides, in most  cases it
would  be quite impossible for the muscles  to  contract suffi-
ciently to  effect Avhat  they now do, since muscular fiber can
not shorten itself more than  one third of its Avhole length, as
measured ay hen uncontracted, or in a state of rest.
  What, however, do we know about deficiency of oxygen as affecting these properties?
Instance ether and chloroform also. AAliat hypothesis has been suggested owing to the
waste produced by oxygen?  2G7. How is muscular power well illustrated?  AVhat loss
and what gain are both experienced by this construction ?
 
AND  PHYSIOLOGY.
137
   268. Contraction  commences at one  End—Only a Part
of the  Fibrils  in  a State  of  Contraction at  Once.—The
contraction of a muscle does not take place in all parts of the
fibers at the same time, but commences at one  end, and con-
tinues through in regular               FlG  152.
strong, since the AYhole of the  muscle is made to act at once.
It also shoAvs us why Ave can keep a muscle  contracted for a
long  time, as  in  carrying a Aveight  for  a long distance, and
also why a short and violent  muscular action weakens and
tires  us more than a protracted and more moderate one.   The
simple explanation is, that but a part  of the fibrils arc  con-
tracted at once, and Avhen the nervous  force is exhausted from
one set of fibrils, a  new set  are  called into  action to supply
their poAver.

   269. Examples of Muscular Strength.—As examples of
great muscular strength, Ave have giAren to us the history of a
Samson and Goliath.  And  in more modern  times we read of
Milo  of Crete Avho killed an ox Avith his fist,  and then carried
it more than 600 feet.   He also saved the life of his felloAV-
scholars and  teacher, Pythagoras, by  supporting  the falling
roof until  they had time  to escape.   Another man  is men-
tioned Avho could raise 300 pounds by the muscles of his Ioavct
jaAV.   This  strength, hoAvever,  is exhibited  much  more  strik-
ingly in another part of this chapter under the head of Com-
parative Myology.
 2G8. Do all the fibers, or even all portions of each fiber act at once in ordinary cases?
Instance insane people.  2G9. Give examples of great muscular strengh as illustrated by
Goliah and Milo. 
138
HITCHCOCK'S  ANATOMY
   270. Rapidity of Muscular Contraction.—The  rapidity
of muscular movement is equally wonderful.  The pulsations
of the heart in children can often be counted as high as  200
per minute.   Some persons  can pronounce 1500 letters in a
minute (of course combined in words), each one requiring the
contraction  and relaxation of  one  or more  muscles, and both
occupying ^Voth of a minute, or   sVth of a second.   The
muscles,  too, which move the wings of some insects  must
contract many thousands  of  times  every second in order to
produce the musical tone  or humming that is frequently heard *
when their Avings are in motion.
   271. Duration of Muscular Contraction—Intrinsic and
Available Force—Shortening of  Muscular  Fiber—Muscu-
lar Sense—Sound  and  Heat.—The  length  of time  which
muscles may be on the stretch is astonishing, but especially
so among  the lower orders of animals soon to be mentioned.
   The intrinsic force of a muscle is no measure of its  aA^ail-
able power.   Thus the  deltoid, if able to  act in a perpendicu-
lar direction, would raise  1000 pounds;  while, acting at the
great  mechanical disadvantage (that it does) of passing over the
head of the humerus, it can not lift 50  pounds held in the
hand.
   The amount of shortening of the fiber in muscular contrac-
tion  is  differently stated  by  physiologists.   The  statements
are from  one third to one  sixth the  length  of the muscle.
That  is, a muscle three  inches long can by contraction be-
come  only tAvo inches, or one six   inches  long  become five
inches.   It  is probable, however, that the former statement is
the nearest to the truth, and  that a muscle is shortened from
one half to one third its original length.
   The muscles give but little evidence  of sensibility ; that is,
perception of objects by pressure or touch;  but when rationed or
overAvorked, they give a painful sensation,  and also give to their
 270. State instances of great rapidity  of muscular  movement, as In pulsations of
children's hearts and the power  of articulating words. 271. State the distinction be-
tween the intrinsic and available force of muscles. How much does muscular fiber
shorten during its contraction ? AA'hat is muscular sense ? 
AND  PHYSIOLOGY.
139
possessor a very delicate sense of the amount of their contrac-
tions.
  - It is also an established fact that a peculiar rumbling sound
is given off and  heat evolved during muscular contraction,
the latter of Avhich is easily  explained by the increased mus-
cular Avaste,  or  the absorption of oxygen and evolution of car-
bonic acid.

   272. Precision of Muscular  Contraction.—An astonish-
ing precision in contraction of muscles is seen in those  of the
human  larynx.   The largest of these muscles is  less than
three fourths of an inch, and the total amount of contraction
one  fifth.    And  since  the  ordinary compass  of the  human
voice is tAA*o  octaves, or twenty-four semi-tones, and ten inter-
vals between each of the contiguous semi-tones  can  be  easily
detected  by a person with a  cultiA'ated ear, there must be a
shortening of only T^Voth of an inch.   And more Avonderful
than all is the precision and readiness Avith Avhich an ordinary
singer can accurately strike one note after another Avith inter-
vals of from tAvo to twenty-four semi-tones.
                  HYGIENIC  INFERENCES.

   273.—1. Muscles need Use .—The muscles should be used.
This is necessary to stimulate the blood-vessels and lymphatics
to a healthy action, so that  the  nutritious  particles may be
deposited in proper proportion, and the Avaste particles be re-
moved •  in other  words,  to promote that constant change
which  in all the  organs of the body is so necessary for health.
Their moderate use also promotes  their groAVth and  strength,
Avhile inaction causes them to diminish both in  strength  and
size.

  Speak of sound and heat attendant upon muscular contraction. 272. What remarkahle
precision is there  in many muscular movements?  273. AVhy is it necessary that the
muscles be used to a moderate extent ? 
140
II I T C II C O C IC ; S   ANATOMY
   274.—2. Muscles need  Rest.—The muscles also need rest.
That is, after work they need repose to  restore the energies
which  they have expended, and if the amount of rest Avhich
they receiA^e is not sufficient to recruit  the strength, they Avill
soon become small and weak ; for the lymphatics are so stimu-
lated that the amount of matter removed exceeds what is de-
posited.   But sleep is the grand restoratiATe after severe mus-
cular exertion; this alone  gives back  to the  muscle its  life
and strength.
   275.—3. Muscles should  Rest gradually after  Violent
Exercise.—Experience, however, shows  that when  the  mus-
cular system has been exercised vigorously it  should not be
allowed perfect rest at once, but by degrees.   Such a course
Avould save many an ache  and stiff joint to the hard-working
farmer and mechanic, and  especially  to the  one Avho labors
till the body is in a state of perspiration.
   276.—4.  Muscles require Regular  Exercise.—Labor or
exercise that is regular and uniform is much the most conducive
to health. - The muscles will endure a much greater  amount
of effort if made steadily, rather  than  spasmodically.  Regu-
larity of action is  important in every function, but in none
more evidently so than the muscles.
   277.—5. Especial want of  Exercise  by  Students  and
Sedentary  People,—AYe see that  students and other seden-
tary persons  arc  in special need of  physical  exercise,  and
should consider it a moral duty to  secure it, for it stimulates
every  organ  to  a  healthy  action.   The  blood  flows  more
readily, and more completely fills all the minute A-esseb;  the
glands of the  skin act more vigorously ; the lymphatics and
nutritiA^e vessels perform their part more perfectly; and even
the nervous system is kept in a healthy state by exercise.   It
u best, hoAvever, to get exercise if possible Avith  some  other

  274. For what do tho muscles of hard-working men  need  rest, and especially sleep ?
275. Is it always best to gain rest at once, or gradually ?  276. What kind of labor or ex-
ercise is most conducive to health?  277. AArhy do students and sedentary peoplo stand
greatly in need of muscular exertion ?  Is mere drudge  work the best exercise? 
AND  PHYSIOLOGY.
141
motiAre than a mere conviction of its necessity and importance.
For if we are interested in pursuing  an object, the mind ac-
quires a healthy action, and by its reaction brings on a state
of perspiration in the body.  In this case we have obtained
two ends, the muscular system  has been  exercised, and the
mind has gained full recreation from study.   Hence the study
of natural history, and especially those branches of  it which
require  field  exercise in   collecting  specimens, not  only
strengthens the mind  and furnishes new objects of thought,
but is an  admirable method of gaining bodily strength.
   278.-6. Value of Gymnasia, etc., to  Colleges  and Acad-
emies.—We see hoAV injurious  to  health  is the  stimulating
plan adopted  in too many of our higher seminaries of learn-
ing.   The mind  is  crowded to its utmost Avith labor; too
much time is taken up Avith cultivating  the intellect, while
the body is  left  to  take care  of itself.   A gymnasium or
some equiA^alent  means of taking  exercise is  as important
a  thins  to  our  colleges  and academies  as  are  the  build-
ings,  libraries  and cabinets themselves.   And  may  it not
be the  reason AYhy  literary men are generally so great suf-
ferers from ill health, that so little attention is paid to  physi-
cal  exercise during the preparatory and collegiate course?
I3 it not  poor economy to  take so much pains to  cultivate the
inhabitant, Avhen  the house that it  is to live in is such a mis-
erable tenement, and receives so little care and improvement ?
 REMARKS  UPON MUSCULAR DEVELOPMENT.

  With the  existing customs  of  the  wealthier  classes  of
society, and our higher seminaries of learning especially, it is
hardly possible to say too much upon the necessity of physical
education : not that it is best to  loAver the standard of intel-
 Why docs the study of some branch of natural history secure tho best exercise? 278.
What is said of the effect of a negleet of muscular exercise in schools and upoa many
educated men of our country? 
142
HITCHCOCK'S  ANATOMY
lectual culture in the least, or  to dictate  Iioav those who  are
possessed of an abundance of Avealth  shall dispose of it,  but
simply to say that a thorough physical education is  essential
for a proper enjoyment and improvement of our Avhole nature,
body, mind, and soul.   The evils of a. neglect of this branch
of education exhibit themselves, not  only in puny clergymen
and laAvyers, but in the meager and attenuated  physiques of
our mothers and sisters.
   Boys,  especially when boys, will run, jump, shout, and
be  in  the open  air  in  spite  of any thing  but the closest
watch ;  in fact it is thought proper that boys should be ruddy
in  countenance and  healthy,  but  with  girls it is not  so.
By grossly perverted usages of society, it is considered im-
proper for girls to run and jump and shout, and especially so
out of doors;  but while mere children eA7en, they must act as
young ladies, and  never move except in a precise and meas-
ured manner,  often as unnatural as it is  injurious;  and any
thing that requires muscular  effort, is  regarded  as vulgar,
and  of course  not  to be undertaken.  Noav, physiology tells
us  that  just  the  thing  which  our  girls  and  ladies  stand
in need  of at  the  present day is active,  vigorous muscular
effort,  such as walking,  roAving,  riding  on horse-back, and
calisthenic and gymnastic exercises.   And  let  the question
be  suggested  to  parents, guardians,  and in  fact  all inter-
ested in  the prosperity or even the existence  of the Anglo-
Saxon race on this continent, whether the physical  develop-
ment of  ladies shall be  neglected through the idle  whim of
its  impropriety (Avhich  often  only  generates a false  mod-
esty or  prudishness),  and thus tend to  a deterioration of
the race  Avhich is  noAv  in fearful  progress in  the United
States.
  Without a  proper  exercise  of  the muscles  in  man  or
woman, all the other portions  of the body  must suffer, and
if so, Avhy, through an over  sensitive, prudish  caution, must
AYoman  be the unfortunate   victim?   The old Greeks__
heathen though they Avere—did not  neglect  the development 
AND  PHYSIOLOGY.
143
of the body in either men or women.   And while they most
thoroughly disciplined  the intellectual powers, their  "semi-
nary of  learning" was the gymnasium, Avhere. as prominent
characteristics, were the running, wrestling, and boxing exer-
cises, and  by them regarded as equally important Avith intel-
lectual effort.
 .  But though the neglect of muscular exercise  is the moat
sadly evident  in the  female portion  of society, yet it is  not
confined here.  For many of our educated men are of feeble
physical culture, mainly because of the cultivation of the in-
tellect at the expense of the body.  Most men in the academ-
ical  and professional schools are apt to regard study as first
and  foremost,  and a care of the body aftenvards—if there be
any time for it f  Hoav many  make it a duty—and a relig-
ious one too—to take  all the time that can  possibly be se-
cured  for  study, and  leave the exercise as a thing desirable
but not essential!  But Ave maintain that a system of educa-
tion Avhich simply croAvds the  mirid with  discipline,  to  the
neglect of  physical culture, is not  only a defectiAre, but a
monstrously pernicious system.   Students  may  bear  the
cramming  process  through the academical,  collegiate,  and
even professional course, but sooner or  later the body will  be
overpowered.   Nature's laws cannot be violated Avithout  suf-
fering the  penalty at some time; and of what service can the
most cultivated minds become, if the body is too feeble to  use
their learning?  Of  what beauty  is the most brilliant gem
without  tho art of the lapidary to  develop and  exhibit its
splendor ?
   In hoAV few educational  institutions in our country is there
any  thing like a system of exercise suggested, or  much  more
required ?   In hoAV feAV of them does  muscular development
meet with any thing but discouragement ?
  It is true that muscular development has for too long a time
among us been associated with  the loAver  class of people, as
prize-fighters,  shoulder-hitters,  bruisers and horse-racers,  in
all Avhich cases it should meet a  decided disapproval.   But is
                            7 
144
n I T C II C O C E ' S  ANATOMY
this  a natural tendency  of physical  development ?   Is  it
necessary that a  Avell-developed man must of necessity be a
brutal fighter ? or that a beautiful horse must necessarily lead
his master to expose him to  cruel excesses to test his speed ?
If we do adopt the principle  that physical development has
such  an  immoral tendency, is there any culture of body or
mind that we  shall not be  compelled to resign to  the great
tempter,  since he can so sadly pervert every thing ?
   Ought not then a gymnasium or some equivalent means  of
physical  culture, to be attached to all our educational institu-
tions (female  as well as male), as well  as models, libraries,
cabinets, and apparatus ?  And if so, why should  there not
be regular trainings of the body required by instructors as well
as mental exercises ?   And  since but a small portion of time
is required for physical exercise if it be vigorous, as it will of
necessity be in a gymnasium, Avhy may not a portion of school
duties each day be a half hour or an hour  of exercise in the
gymnasium morning and evening ?  Does not every practical
teacher see that at least this would relieve the necessity of a
great many excuses, such as for  " head-ache," " feel sick,"
" unable to study to-day," etc.
  Fig. 153.    There are, however, many simple gymnastic ex-
          ercises Avhich may be indulged  in by everybody,
          boys and girls, men and women, Avithout an outlay
          of any thing except a few dimes, and the use of a
          few yards of space anywhere on terra firma.
             From a piece of inch pine board  from  two to four
           feet long (depending on the size of the  person to
          use it), and three to  six inches Avide, let an instru-
           ment  be made called the back board, as is shown
           in  Fig. 153.   With this simple piece of apparatus
           grasped at each end, as  in Fig. 154, a great  va-
riety of exercises can be invented by any one, which will soon
set  the  whole surface in perspiration,  and if persevered in
will, in the course of several days, impart pliancy and strength
to the muscles.
/ 
AND  PHYSIOLOGY.
145
      FlG- 154,           A more vigorous exercise can Fig. 155.
                     be  obtained  by using  Avhat is
                     termed the " Indian club," or
                     " scepter,"  one in each  hand.
                     (See Fig. 155.)  These maybe
                     made by the commonest turner
                     from any sort of Avood, and it
                     is  well that there be  several
                     pairs of them, differing in weight
                     and length,  and  loaded  Avith
                     lead if necessary,  adapted  to
                     the age and  muscular  deA'elopment of
                     those using them.  And it is astonish-
                     ing Avhat great strength of muscle can
                     be acquired by this means of exercise
                     continued through a few weeks.  Some
of the different exercises Avhich may be performed with  this
club may be seen in Fig. 156, p. 146.
  Another simple mechanism  for gaining  physical  exercise,
called the " triangle," is  seen in  Figs. 157 and 158.   It  is
Fig. 158.
Fig. 157. 
146
HITCHCOCK'S  ANATOMY
Fig. 156.
bti>yu*rt^r)
 
AND  PHYSIOLOGY,              117
Fig. 159.
made by hanging a bar
betAveen the ends of two
ropes 4Avisted  together,
as in Fig. 157, or from
two ropes hanging per-
pendicularly  from  the
ceiling.    This triangle
may be  suspended from
the ceiling of any room,
or the branch  of a tree,
and is of great service
for  exercise,   since  it
calls into use  not only
the upper, but also the lower extremities.
   But much more complete exercise,  and that which tends to
give symmetry of form  to either sex, may be obtained from 
148
HITCHCOCK'S   ANATOMY
Fig. 160.
 
AND   PHYSIOLOGY.
Fig. 161.
149
 
150
HITCHCOCK'S  ANATOMY
the various  appurtenances  of the gymnasium.   Here,  by
means  of bars, ladders, ropes  and similar pieces of appara-
tus are the best arranged contrivances, not only for  a gen-
eral exercise of the Avhole body, but for developing  the most
important muscles.   A few  pieces of this kind  of furni-
ture  may be  seen in  Figures 159, 160, and 161.   These
may  be  fitted up in any large  and  unfurnished  building,
since  the essential requisites are  a   few solid  timbers  to
give firm support to the bars and ladders, and walls  mainly
to protect from exposure to severity of weather.
   The exercise of rowing is one which probably can  not be
surpassed as a means of exercise,  since it not only requires a
use of the muscles, but is exhilarating  and recreating  to the
spirits; and Avhere circumstances admit, whether as  supple-
mentary  to or in place of a gymnasium, we would say by all
means let both boys and men,  and ladies  too,  indulge  in the
invigorating and healthful exercise of boat roAving.
             COMPARATIVE  MYOLOGY.

  279.  In microscopic  structure the  muscles of the lower
orders of animals very closely resemble those of man, as may
be seen in the fibrils of the pig, Fig. 162.

  280.  Tegumentary  Muscle—Abdominal  Muscles—mus-
cles  of  Lower  Jaw—Diaphragm.—The general structure
and relations of the  muscles in  quadrupeds  differ very little
from those of man save in the extremities.   Nearly all quad-
rupeds have  a set of fibers  called the  Tegumentary Mus-
cle, which is a thin  layer of muscle lying just beneath  the
skin,  and Avhich is  only rudimentary in man.   Its func-
tion is to contract and corrugate the skin in order to remove
dust,  insects, or any offending matter, as can be seen in a
  279. AVhat is said of the structure of muscles in all mammals?  £S0. Describe the
Tegumentary Muscle. 
AND  PHYSIOLOGY.
151
Fig. 162.
                     b  a>
 Muscular Fibrils of the Pig. a, An ap-
parently single fibril, b c. Collections of
fibrils.
horse or cow during the time
when  flies  irritate by biting.
The same muscle  in  the por-
cupine and armadillo is made
use of to  roll themselves up in
a ball.   In apes the foot and
hand are similar both in mus-
cular development and  func-
tion,  but are  by no  means
equal  to the  hand of man.
The abdominal muscles of all
quadrupeds are stronger than
man's, since from  their posi-
tion the weight of the viscera
is thrown upon the muscular
Avails  of the  abdomen,  and
not upon the  bones  of the pelvis, as in  him.  In beasts of
prey the  masseter and  temporal muscles  are more strongly
developed than  in man, because  great  strength is required
in the jaw to secure the food and fit it  for digestion.  In all
mammals a more or less complete diaphragm is found, though
it is absent in  nearly all the remaining vertebrata.

   281. Muscles  of Birds—Ossification  of  Tendons.—The
muscles of most birds are remarkable  for their deep red color
and the density of their structure.   In herbivorous ones, Iioav-
ever, they are of a paler color and softer in texture, and hence
more palatable as  articles of food.   The  bellies of the muscles
are for the most part situated on the body, so that they may
not encumber  the  limbs ; and  those designed to  move the ex-
tremities  are  extended  into long  tendons, which, as already
mentioned,  become ossified  to a considerable extent.
  Of what use is this muscle in the porcupine and armadillo?  Why are the abdominal
muscles of quadrupeds proportionally stronger than in man? What is said of thestrenith
of tlie masseter and temporal muscles of beasts of prey?  What of a diaphragm? 2S1.
What are the muscles of birds remarkable for ? AVhat is said of the tendons and bellies
of muscles in birds?
                            7* 
152
HITCHCOCK'S  ANATOMY
   282. Suspensory  Muscle.—In the turkey and birds of like
character an especial muscle  is  provided for the support of
the crop,  which, so often becomes heavily loaded with food.
   283. Muscles  of  Birds'  Feathers —Their  Use—Their
Number—31 uscles of the  Breast.—Birds  are supplied with
tegumentary muscles somewhat after the manner of quadru-
peds.   The main  difference  is,  that in birds a few muscular
fibers are sent to each quill feather of the body, by Avhich the
feathers can be  violently shaken to dislodge dirt, or they may
be merely raised on end by the same muscles.   This property
is Avell  seen  in  common barn foAvls, when they shake them-
selves after having lain  in dry dirt.   A hen with a brood of
chickens,  too, Avhen disturbed shows her wish to protect her
young by ruffling up her feathers and attacking whoever may
annoy  her.   In some birds, Avhere there are 3,000 quill feath-
ers, the number of muscles  must  be  at least 12,000.   No
muscles are found upon the  face of birds, but  to secure  the
degree of motion to which the head is subject, and  the flexi-
bility of the neck,  the muscles of this portion of the body are
very strongly developed.   The  most  poAYerful muscles  of
birds are the pectoral, or those  on the  breast;  one end of
which is attached  to the keel of  the sternum and the other to
the humerus.   These muscles are  three  in  number on  each
side, and the largest one exceeds in weight all the other mus-
cles of  the body.
   284. Muscles of Fishes.—The muscles of fishes are char-
acterized  by their  slight degree of separation  from one an-
other, by the absence of long tendons, and the softness of their
fibers.   Their color  is  generally Avhite,  or  yelloAvish white,
but in microscopic  structure they do not differ  from  those of
the other  vertebrata.   By far the  largest part  of the fleshy
  282. What peculiar muscle is found in birds like the turkey ? 2S3. What is worthy of
note in the tegumentary muscle of birds?  In what condition does a hen show the ac-
tion of the tegumentary muscles?  What number are there in some birds? AVhy is
there need of so few muscles on the head of birds? Upon what portion of tho body are
there the most muscles?  Give the actual amount by weight.  284. What is tho peculiar
feature of tho muscle of fishes ? Give their color. 
AND  PHYSIOLOGY.
153
mass  of these  animals is made up  of the  lateral muscles of
the body which extend from the head to  the  caudal fin ;  and
as each lateral muscle by its contraction bends the body to its
own side, the motion of the fish through  the water  is effected
in the same manner as the oarsman sculls his boat.
                          Fig. 163.
Muscular Fiber from Leg of Meat Fly. a, Termination of Muscular Fiber,  t, Tendon.
   285.  Muscles and  Locomotive  Organs  of the  Inverte-
brates.—Muscles,  both striated  and smooth, voluntary  and
organic,  abound in all the invertebrates.   They are modified
in form and position to meet the wants of the animal as wisely
as in the higher tribes.
In some of the Polypi
movements are made by
the contraction of their
sides, in which no mus-
cular fibres have been
discovered, though ex-
existing in other parts
of the  animal.   The     Insect Fasciculi Magnified Fifty Diameters.
muscles of insects are either  colorless or of a dirty yellow.
   286.  A great variety of locomotive organs are found in the
Invertebrates.  The Echinoderms have tentacles, called Am-
bulacra, on  some of which  there are  suckers, which enable
them to hold  on to substances.   They have also forcep-like
organs of  locomotion.  Most of the acephalous molluscs move
by a highly developed foot, which, in the Cephalopoda, is used
as a sucker.   The  Cephalopoda  have arms with suckers at-
  What portion of the body is made up of them? 286.  AYhat are the locomotive organs
of Invertebrates?
 
154
HITCHCOCK'S  ANATOMY.
tached to  the  cephalic cartilage.   Annelids move  by sub-
cutaneous muscles, stings, and bristles.   The Rotatoria re-
volve by a retractile vibratile  apparatus.   Crustaceans have
usually two legs to each segment, and the Myriapods some-
times four.   Some of these appendages  are tactile, some for
oars, and some  ambulatory.  Spiders have four pairs of legs,
and insects three.
  287. Examples of Muscular Strength.—There are some
remarkable examples of muscular strength among the lower
animals.   A flea harnessed will draw from  seventy to eighty
times its own weight, while a horse can not draw more than
six times his weight.  The flea weighs less  than  a grain, and
will  clear  several  feet  at a  leap.   The common dorr bettle,
weighing but fifteen grains, has been known to heave a weight
placed upon him amounting to 4.769 grains, equal to nearly
320 times his own weight.
  288. length of Time  the   Muscles can be  Employed.
—The length of time during Avhich  some muscles can be em-
ployed without rest is also very remarkable.  Many birds will
fly uninterruptedly for hundreds of  miles,  and it is  also said
that insects will remain suspended  in the  air a whole  sum-
mer's day  without alighting.
  289. Rate  of Flight of   Birds.—Some birds  fly  sixty
feet in a second; but a race-horse scarcely ever exceeds forty
feet in the  same time.   A falcon of King Henry II. fleAV on
one day from  Fontainbleau to  Malta,  a  distance of about
1,000 miles.   The rice-bird,  which afterwards  becomes the
reed-bird of Delaware Bay and the bobolink of New  York, is
often found below Philadelphia Avith green rice  in its  crop.
The  same  thing is true of pigeons during  the  rice-growing
season.
  287. State the power of a flea compared with a horse. 283. What is wonderful about
the length of time that some insects can use their muscles without weariness ? 289. With
what speed can some birds fly? Give the iustance of King Henry's falcon. 
             CHAPTER   THIRD.

THE NUTRITIVE  SYSTEM.—SPLANCHNOLOGY,  OR HISTORY
             OF  THE  DIGESTIVE  ORGANS.
         DEFINITIONS  AND  DESCRIPTIONS.

   290. Definition of Digestive Organs.—The Digestive Or-
gans are those Avhich receive the food into the body  and effect
such  changes  in  it  that the  various tissues can be formed
from it by means  of  the  glands.  Of these organs the princi-
pal one is  the  Alimentary Canal.   This commences with the
mouth, and includes the stomach, with the whole  length of
tube  knoAvn as the  intestines.   This canal, in a full-grown
man is about thirty  feet in length, being as a general rule
five times the  height of the individual, and is  lined through-
out its entire length by mucous membrane.

   291. The Mouth;  Salivary Glands;  the  Tonsils.—The
Mouth contains the organs of  mastication including the teeth
and tongue, and receives  the saliva, which is secreted by three
pairs of glands named Parotid, Submaxillary, and Sublingual,
situated just beneath  and behind  the loAver jaw.   Besides
these three glands there  are many other  minute glands and
follicles situated upon the floor and  backsides  of the mouth,
Avhich  secrete  fluids that aid  in mastication  and  digestion.
The Tonsils are simply an aggregation of follicles situated in

 290. AVhat are Digestive Organs? Give the greneral description of the Alimentary
Canal.  291. What does the mouth contain ? Name the three principal pairs of glands
and give their location. 
156
HITCHCOCK'S  A N A T O MY

            Fig. 165.
  A View of the Salivary Glands in situ. 1, The Parotid Gland in situ and extend-
ing from the Zygoma above to the Angle of the Jaw below.  2, The Duct of Steno.
3, Tho Sub-Maxillary Gland.  4, Its Duct.  5, Sub-Lingual Gland.
Fig. 166.
                                       the upper  part of  the
                                       fauces or throat, a  few
                                       of Avhich are represent-
                                       ed in Fig.  166.   The
                                       mouth is a variable cav-
                                       ity having  no  empty
                                       space  within  it  Avhen
                                       closed,  and  Avhen fully
                                       open, containing nearly
                                       half a pint.
                                          292. The Pharynx.—
                                       The Pharynx (the Greek
                                       name for this portion of
the body) is the next division of the  alimentary canal.   It is
a  short and someAvhat irregular tubular  cavity, into  which
the mouth  opens  behind, serving as  a  portion of the canal
A few Follicles from numan Tonsil.
 What are the Tonsils?  Aro there any other glands in the mouth ? 292, Describe tha
Pharynx. 
AND  PHYSIOLOGY.
157
         Fig. 167.
Pendulous Palate.
Base of the Cranium.
Pharynx.
Esophagus
Nose.
 Torgue.

. Salivary Glands

 Lingual Bone.

 Larynx.


 Thyroid Gland.
Trachea or AVindpipc.
                Vertical Section of the Mouth and Throat.

from the mouth to the stomach, its  lower limit  being nearly
opposite to the Pomum Adami (Adam's apple) in front, and
the fifth cervical vertebra behind.  It  also communicates with
both ears,  with the nostrils and lungs,  by passages which open
directly into it.   The communication  between this cavity and
the mouth may be  entirely cut off by means  of a  movable
muscular curtain called the soft or pendulous palate,  which is
of great service in the act of swallowing.   This  portion of the
alimentary canal is made up of  muscular fibers which run in
two directions,  so  as  to cross each  other  at a large angle, in
order to give the most perfect compression upon the food as
it passes through it.    And  in its lining  (mucous) membrane
are found a great number  of follicles or  sac-like bodies of
microscopic size called Pharyngeal  Glands.
   293.  Esophagus.—The  Pharynx  terminates in the Eso-
phagus  (meaning the passage for conveying the food).  This

  AVhat cavities does it communicate with? What is said of its, muscular coat? 203.
What is the Esophagus? 
153
HITCHCOCK'S   ANATOMY
Fig. 168.
               Glands of Esophagus Magnified fifteen Times.
is a long and narroAV tube, made  up  of two  muscular  coats,
which terminates in the stomach by the cardiac orifice.   It is
smaller in size than the Pharynx, and contains a grea/t num-
ber of minute glands, (see Fig.  168),  which secrete  an oily
fluid Avhen the food is passing through it.
  294. Stomach, its  Coats,  its  Size,  its  muscular  Coat,
                            Fig. 169.
  Section of Human Stomach.  1, Esnphasus.  2, Cardiac Orifice.  3, 4, 5 6  Greater
and Lesser Curves of the Stomach.  7, Dilatation, or rudiment of a Second Stomach.
6, Folds of the Mucous Membrane.  9, Pyloric Orifice.  10, 11, and 14, Duodenum.
12, Duct of Pancreas and Liver.  15, Jejunum. 
                    AND  PHYSIOLOGY.               159

Gastric Follicles,—The Stomach is the largest expansion  of
the  alimentary canal, situated  in the upper portion  of the
left  side of the abdomen, immediately beneath the diaphragm,
inclining obliquely doAvmvards from the left to the right.  Its
walls are made up of three coats: an  outer or serous, a middle
or muscular, and an inner or mucous.   Its normal  or average
size Avill alloAv it to contain  about  a solid quart, but in gor-
mandizers, and wine and beer drinkers,  it is dilated  to three
or four times that size.   In  the  middle or muscular coat (Fig.
170) the fibers run at right  angles to each other, in order that
                            Fig. 170.
  A Front View of the Stomach, distended by flatus, with tho Peritoneal Coat turned
off.  1, Anterior Face of tho Esophagus.  2, The Cul-de-Sac, or greater Extremity.
3, The lesser or Pyloric Extremity. 4, The Duodenum.  5, 5, A portion of tho Peri-
toneal Coat turned back. 6, A portion of the Longitudinal Fibers of the Muscular Coat.
T, The Circular Fibers of the Muscujar Coat.  8, The Oblique Muscular Fibers, or
Muscle of Gavard. 9, A portion of tho Muscular Coat of the Duodenum, where its Pe-
ritoneal Coat has been removed.

they may contract in the most efficient manner upon the  con-
tents of the stomach for tho purpose of digestion,  and forcing
the contents  onwards  into  the Duodenum.  They also assist
in forcing the  contents of the stomach backward in vomiting.
In the  inner or mucous lining are situated an  immense num-

  2!M. Where is tho Stomach situated?  What is its normal size ?  now many coats has
it and what are they?  Of what service is the muscular coat? ' AVhat glands are con-
tained in tho mucous membrane of the stomach ? 
100            HITCHCOCK'S  ANATOMY
ber of tubular glands which open directly into the  stomach.
They are cup-shaped cavities about the 3-3V uth  of an inch in
diameter, and TVth  in length,  from  the bottom  of which pro-
ject two or more parallel tubes, ending in a  closed termina-
tion in the tissue beneath.  These  compose the greater por-
Fig. 111.                        Fig. 172.
 Diagram of tho Stomach and Intestines. 1, Stomach.      29o.  D U 0(1 C11U m.---
2, Esophagus.  3 and 4, Stomach.  5 and G, Duode-  The first division of the
num. 7, Jejunum.  8, Tleum. 9,C;ecum. 10, ATer-  t  ,   ,•         ,   -^
miforrn Appendix. 11, 12, 13,14, Colon. 15, Ecctum.  Intestines  IS  the DUO- 
AND  PHYSIOLOGY.
161
denum, because  in length it is equal  to the breadth of twelve
fingers.   It commences  with the pyloric  orifice on the right
extremity of the stomach,  and  runs slightly. backwards  and
upwards  until  it terminates  in the Jejunum.   It is often
called the second stomach,  because a certain part of digestion
takes  place  here, and the  food passes slowly and receives no
less than three different secretions :  one from the  Liver,  an-
other  from  the Pancreas,  and the  third from  the  Mucous
membrane of the intestine itself.
Fig. 173.
   296.  Jejunum.'—Next  below the  Duodenum  is the Jeju-
num, meaning "empty," since it is always found  in this con-
dition after death.  This, like the other divisions of the intes-
tine, has three coats,  and  is of a  slightly  pinkish color, be-
cause here the mucous membrane is thicker than in any other
of the intestines.

   297.  Ileum—The  Ileum
(from the Greek  signifying
to twist) is the third division
of the Intestines, and is about
fifteen feet in length.   It is
the smallest Intestine, and has
a darker color than either of
those already mentioned, and
is exceedingly tortuous in  its
course.
   298.  Ca;cum.—The  fourth
division  of  the  Intestine  is
the Caecum.   This is  a shut
    v--«^-~                          Tho Caecum and its Appendix. 1, Cn>
SaC  much  larger  than  the   cum. 2, Colon.  3, Ileum.  4, Entrance
    ■n  T     •       j    n       from Ileum to Colon. 5, llio-Ctecal Valve.
Small  Intestine,   and  Ot  a   C,7, 9, Parts of the Appendix Cieci.
  What do they secrete? What vessels open into the stomach, and of what service are
they? 295. What is the Duodenum? Give its general course.  Why is it sometimes
called the second stomach?  What fluids are poured into it? 296. What is the name
Jejunum derived from? What is its color?  297. How long is the Ileum? What is
said of its shape ? 293. Name the fourth divison of the intestines.  Describe it. 
162           HITCHCOCK'S  ANATOMY
grayish blue  color, and not exceeding three inches in length.
The entrance of the Ilium  into the Caecum is effected by a
valvular arrangement Avhich alloAVS the food to  pass into the
Caecum, but never in the opposite direction.   It is situated at
the right Innominatum in the lower part of the abdomen, and
its lowest portion has a worm-shaped  process  attached  to it,
which is  only  rudimentary,  and  consequently of no  great
service to man,  but largely developed and  of great service in
some of the lower animals, and especially in the herbivorous
ones.
   299. Colon.—The Colon  (from  the Greek  signifying  "to
prohibit," since the food  passes very slowly through this part
of the canal), commences at the  Caecum on the right side of
the abdomen, and in the first  part  of its course passes  in an
upward direction, and is called the ascending  Colon.   When
it reaches the loAver edge of the  liver, it crosses horizontally
to the extreme left  edge of the body, constituting the trans-
verse Colon.  After this it descends, and  joins  the Rectum,
forming  the  descending  Colon.   Its length is  from five to
eight feet.
   300. Rectum.—The Rectum completes the divisions of the
Intestines.  It is  nearly  straight in its  course, of a  larger
size than any other  division of the canal, except  the stomach,
and  from six to eight inches in length.   Its  name is  derived
from the straight direction Avhich it assumes.
   301. Division of the Intestines  into small and large.—
The last three divisions  have  a  much  larger  diameter than
the first three, and are called on that account the large Intes-
tine, and  the  Duodenum, Jejunum and  Ilium, the small In-
testine.  The latter seems  to be the portion necessary  for
preparing the food  to enter the Lacteals, while the large In-
testines act  mainly as a receptacle for the Avaste portion.
 Where is its location in the body? What curious appendage is attached to it' 299
What are the three divisions of the Colon?  How Ion- is it?  3D0. What does the'colon
terminate in?  How long is tho Lectum? 301. Define the large and the small Intestine
and give their probable uses.                                  intestine, 
A N D  PHYSIOLOGY.
163
Gall-Bladder.
Large Intestine
Appendix of the
      Cil'CUDl,
Stomach.
Spleen.
Colon.
Small Intestine.
Colon.
             Small Intestine.         Ileetum.
                   Digestive Apparatus in Man.
   302. Structure  of Intestines, Intestinal Glands.—Like
the Stomach, the Intestines are  formed by three membranes.
Also  in the inner or mucous membrane are situated an im-
mense number of microscopic glands, so that a French teacher
speaks  of  them existing  ''as  numerous as the  stars  in the
starry heavens." They are distinguished as Duodenal Glands,
Brunner's Glands,  Solitary  Glands,  Peyer's  Patches, and
Follicles  of Lieberkuhn.   (Fig. 175,  p.  164.)   They are
most  abundant along  the course of the Ilium and they seem
to be  especially affected in  Typhoid Fever, although no cer-
tain use for them in  health has as yet  been discovered.   The
  302. What is the structure  of the Alimentary Tube ?  What is said of the Glands found
in its mucous lining? State  their names. 
164
HITCHCOCK'S  ANATOMY
               Fls- n5-                   Follicles of Lieberkuhn
                                         are  found only in  the
                                         large  intestine.   T h e
                                         Mucous  membrane  of
                                         this part  of the canal,
                                         is  not smooth  and con-
                                         tinuous Avith the serous
                                         or outer  layer,  but is
                                         doubled upon itself in a
                                         great number  of folds,
                                         in order that the surface
                                   M    containing these glands
                                         may be the largest that
                                         is possible, so  that the
  A Portion of the Ilium highly magnified, show-               ' .
ing Peyer's Patches and the Villi.                Contents of the Intestine
                                         may  receive  a  large
supply from these secretions.   Minute Villi or hair-like  pro-
jections are also  found in  great  abundance upon  this mem-
Fig. 176.
Fig. 177.
A Portion of one of Brunner's Glands,
                     A ATiewof a Longitudinal Section of the
                   Jejunum, showing the Villi as seen under
the Microscope.  1,1, The Terminal Orifices of the Villi.  2, 2, The
Internal Coats of the Intestine.  3, The Peritoneal Coat.
  How is the Mucous membrane arranged through the canal, and what is the design of
Bueh an arrangement ? 
                  AND   PHYSIOLOGY.              165

brane, in order to  increase  the amount of its secretions.   It
is the presence of  villi  that gives to some parts of the mu-
cous membrane a  velvet-like appearance,  and in these villi
are  found  the commencement  of the  lacteals,  one  lacteal
usually being found in each villus.
   303.  Glands  attached  to   the  Intestines___Connected
Avith the Alimentary Canal are several large glands, a feAV of
which have already been described.   They are soft  solids, of
Ararious forms and sizes,  and are composed of lobules or small
divisions, each one  of Avhich is  supplied with an artery,  vein,
and duct.  Each of  these ducts communicates with  the prin-
cipal duct or outlet,  Avhich conveys aAvay the  product sepa-
rated from the blood by the Avhole gland.   In microscopic
structure, a  gland  is made  up of very minute  cells, which
seem to have the poAver  of secreting or  separating  from the
blood the particular  substance Avhich it is the function of the
gland to eliminate.
   304. The  Liver,  Gail-Bladder—First in  importance  of
this  class is   the Liver.  (Fig. 178, p. 166.)  This, except-
ing  the brain, is the largest organ in the body, and is situated
on the right side of the  abdomen,  corresponding to  the stom-
ach  on the left, and is of a reddish yellow color.  The average
weight of it  is  four pounds, measuring twelve inches in its
longest diameter, and it is divided into five lobes or great divis-
ions, and these  are entirely composed  of minute bodies or
lobules,  (Fig. 179,  p. 166),  which are about the size of millet
seeds, each one containing an artery,  a vein, and a plexus, or
net-work of ducts for conveying away the bile.  These differ-
ent plexuses unite with  each other and  form  the biliary duct
which discharges  the  bile into the Gall Cyst or bladder.  (Fig.
180, p. 167.)  This is   a  pear-shaped  sac, containing  from
one  to two ounces,  of a  greenish yellow color, situated under
  Describe the Villi. 303. What is said of the large glands connected with the organs of
digestion? State the structure of a gland. 304. What is the relative size of the Liver?
Where is it located? State its color and weight. Give its minute structure. What is
the Gall Cyst or Bladder ?  What is the duct that carries the Bile to the Gall Cyst, and
the one that empties the Gall  Cyst into the Duodenum 1 
HITCHCOCK'S   ANATOMY
Fig. 178.
  The Inferior or Concave Surface of the  Liver, showing its  Subdivisions into Lobes.
1, Center of the Eight Lobe.  2, Center of tho Left Lobe.  3, Its Anterior, Inferior, or
Thin Margin.  4, Its Posterior, Thick or Diaphragmatic Portion.  5, The Eight Extrem-
ity.  6, Tho Left Extremity.  7, The Notch on the Anterior Margin.  8, The Umbilical
or Longitudinal Fissure.  9, The Bound Ligament or remains  of the Umbilical Vein.
10, The Portion of the Suspensory Ligament in connection with the Bound Ligament.
11, Pons Ilepatis, or Band of Liver across  tho Umbilical  Fissure.  12, Posterior End of
Longitudinal Fissure.  13, 14, Attachment  of the Obliterated Ductus  A'enosus to the
Ascending Vena Cava.  15,  Transverse  Fissure.   16, Section  of the Hepatic Duct. 17,
Hepatic Artery.  IS,  Its Branches.  19, Vena Portarum.  20,  Its Sinus, or Division into
Itight and Left Branches. 21, Fibrous remains of tho Ductus Venosus.  22, Gall-Blad-
der.  23, Its Neck.  24, Lobulus Quartus.   25, Lobulus Spigelii.  26, Lobulus Caudatus.
27 Inferior Arena Cava.  2S, Curvature  of Liver to fit the Ascending  Colon.   29, De-
pression to fit the Eight Kidney.   30, Upper portion of its Bight Concave Surface over
the Benal Capsule.  31, Portion of Liver  uncovered by  the  Peritoneum.  32,  Inferior
Edge of the  Coronary Ligament  in  the Liver.  33, Depression made by the Vertebral
Column.
Transverse Section of a Lobule of the Human Liver.    ID   it)   IS   another 
AND   PHYSIOLOGY.

          FlG.  180.
167
   A View of the Gall-Bladder distended with Air, and witb. its Vessels  Injected.
 1, Cystic Artery.  2, The Branches of it which supply the Peritoneal Coat of tho
 Liver.  3, The Branch of the Hepatic Artery which goes to the Gall-Bladder.  4,
 The Lymphatics of the Gall-Bladdcr.
gland,  lying directly behind  the stomach.   It  is  about  six
inches  in  length,  the right end  of it  being somewhat  larger
than the left extremity, and  hence called  the head.   To the
naked eye the lobular structure is apparent:  but each lobule
is  itself made up  of much smaller lobules.   The duct of the
Pancreas   conveys the milk-like secretion of this  gland,  to
nearly the same point on the Duodenum as the Hepatic Duct,
where  they both enter that tube in a slanting manner, so that
by the valvular arrangement the contents of the intestine can
not be forced backwards into the Biliary or Pancreatic duct.
                              Fig, 181,
  An Anterior View of the Pancreas, Spleen and Duodenum, with their Blood-Ves-
sels Injected.  1, The Spleen. 2, Its Diaphragmatic Extremity.  3, Its Inferior
Portion  4, The Fissure for its Vessels.  5, The Pancreas.  6, Its Head, or the
Eesser Pancreas. 7,  Duodenum.  8, Coronary Arteries of the Stomach.   9, The
Hepatic Artery.  10,  The Splenic Artery. 11, The Splenic Vein.
  305. Describe the Pancreas.  What is its structure? Where does its duct empty, and
what mechanical structure in it makes it remarkable ?
                              8 
168
HITCHCOCK'S  ANATOMY
              fig. 182.                    306. Peri ton EEiim.—
                                      The Peritonaeum, " cov-
                                      ering about," or  exter-
                                      nal coat  of the  intes-
                                      tines is not a  little pe-
                                      culiar in  its conforma-
                                      tion.    This,   like  all
                                      serous membranes, first
                                      completely invests the
                                      organs and then  is  re-
                                      fleeted from them so as
                                      to make a lining for the
                                      AYhole cavity.     Hence
                                      the cavity of  the ab-
                                      domen, although a per-
                                      fectly shut  sac,  is  of
                                      very  irregular outline.
                                      That  it is a  shut  sac
                                      may  be seen  from the
                                      fact that in dropsy  of
                                      the abdomen—the fluid
                                      has no means  of  escape
                                      except by absorption, or
                                      puncture  from the out-
                                      side.    In  the  disease
                                      commonly known as in-
                                      flammation of the bow-
els, this membrane i3 the principal  seat  of the difficulty, and
the inflammation  of this  as well as of all other serous mem-
branes, is attended Avith  acute pain, and the progress of  the
disease, for better or Avorse, very rapid.
   307. Mesentery.—The Mesentery, meaning the " middle of
the abdomen," i3 a fold of serous membrane, Avhich hangs over
 Reflexions of tho Peritonaeum. D. Diaphragm.
S. Stomach.  C. Colon.  D. Duodenum, P. Pan-
creas. I. Small Intestine. R. llectum.  B. Blad-
der.   The numbers indicate the courso of tho
Peritoneum.
 806. What is tho Peritona?um?  Is the cavity of the abdomen of a regular outline?
What is the principal seat of disease in inflammation of the bowels ?  307. AVhat is the
Mesentery ?  What is it thickly packed with ? 
AND  PHYSIOLOGY.               169
the greater  portion of the  Intestines, and  is thickly  inlaid
with  fat, even  in persons of moderate size.   The point of
attachment on the front side of  the body is along the course
of the transverse Colon, hanging like a short apron from the
loAvest  portion  of the AATaist.  After being  reflected upon it-
self, it is attached to the posterior Avails of the abdomen near
the Spinal Column.   Small bodies called  Mesenteric Glands
are also found in this fold, Avhich has an important connection
Avith the Lacteals, which  belong to the class  of Lymphatics.
The main use of the Mesentery  is to form a cushion of fat, in
 order to protect the included organs from cold  and  violence,
 as Avell as to give them  a yielding surface to glide upon dur-
 ing their tortuous movements.   A very fat man has just died
 (1859) in NeAV  York, in Ayhom the depth of fat in the me-
 sentery was sixteen inches!
    308.  Lacteals.—The  Lacteals  are minute  vessels, which
 commence with  the inner  or mucous coat of the  intestines,
                 Fig. 183.
Aorta. Thoracic Canal. Lymphatic Glands.
  ( Radicles of the
,..•-<  Chyliferous
  |  Vessels.
-—Intestine.
Lacteals.  Mesentery.
       Chyliferous A'essels.
AVhat small bodies are found in it, and what is the use of the Mesentery? 
170
HITCHCOCK'S   ANATOMY
Fig. 184.
and terminate in the Thoracic
Duct. !  These  at their  com-
mencement  are  about   the
same  in  anatomy  with   the
radicles  or small veins,  and
at this point  act  the part of
absorbents.   Soon after they
have left the  Intestines,  sev-
eral of them  unite  into one
and pass through small bodies
of  about  the  size   of peas,
called the Mesenteric Glands.
As  they  emerge  from these
glands,  they   are  fewer  in
number  but  larger  in  size,
until they all  unite into one
tube called the Thoracic Duct,
a  little  larger  than  a goose
quill,  at about the  point of
the  last  Dorsal  Vertebra.
This vessel  passes  immedi-
ately upwards,  lying closely
upon   the  Spinal   Column,
sometimes separating into two
smaller tubes for a feAV inches,
  A View of the Course and Termination of the Thoracic Duct.  1, Arch of the Aorta.
2, Thoracic Aorta.  3, Abdominal Aorta.  4, Arteria Innominata.  5, Left  Carotid. 6,
Left Sub-Clavian.  7, Superior Cava.  8, The two Vena? Innominata;.  9, The Internal
Jugular and Sub-Clavian Vein at each side.  10, The A'ena Azygos.  11, The Termina-
tion of the Vena Hemi-Azygos in the Vena Azygos.  12, The Receptaculum Chyli: sev-
eral Lymphatic Trunks are seen opening into it.  13, The Thoracic Duct dividing, op-
posite the Middle Dorsal ATertebra, into two branches, which soon re-unite ; the course
of the Duct behind the Arch of the Aorta and Left Sub-Clavian Aorta is  shown by a
Dotted Line. 14, The Duct making its turn at the Root of the Neck and receiving sev-
eral Lymphatic Trunks previous to terminating in the Posterior Angle of the Junction
of the Internal  Jugular and Sub-Clavian Veins.  15, The Termination of the Trunk of
the Lymphatics of the Upper Extremity.
  308. Where do the Lacteals begin, and where do they terminate?  What do they re-
semble, and what do they pass through ? State the size of the Thoracic Duct, its course
and termination. 
AND  PHYSIOLOGY.
Ill
 until  it  reaches  a  point as high as  the clavicle,  where it
 gradually  curves  forward, and joins itself  to the  left  sub-
 clavian vein.   The Lacteals and Thoracic Duct are all made
 up  of three  coats and present  a silvery  Avhite  appearance
 from the color of  the fluid they contain.   Their  function is
 to convey the Chyle or nutrient  portion of the food into the
 blood.

   309. Kidneys.—The Kidneys  are two in number, situated
 upon the side of the lumbar vertebrae,  and are generally en-
 closed in a large amount of fit.   Their average size is be-
 tAveen  four  and five  inches  in length, two and a half inches in
 breadth,  and  one  in thickness.   Their color is  of a  reddish
 yellow, and form  decidedly oA'al, with a depression in one of
 the  sides.   Upon its upper extremity 13  a small body, called
 the  Renal  Capsule, and  the whole organ is abundantly  sup-
plied with blood.   The design  of it seems to be the removal

             Fig. 185.                        Fig. 18G.
                                   Diagram of the Urinary Apparatus,  rti
                                  The Kidneys,  b, The  Ureter,  c, Tho
                                  Bladder,  d, Canal of the Urethra.


  A Section of tho Right Kidney surmounted by the Bcnal Capsule. 1, Supra-Renal
Capsule.  2, Cortical Portion.  3, Medullary or  Tubular.  4, Two of the Calices
receiving tho Apex of their corresponding Cones.   5,  The Infundibula.  6, The
Pelvis.   7, The Ureter.
  What vein does it empty Into?  What fluid does it carry?  309. State the leading
features of the Kidneys.  AVhat is found upon its upper edge ?
 
1V2           HITCHCOCK'S   ANATOMY

of the waste Nitrogen of the system, and  many salts,  espe-
cially the Phosphates, Avhich can be eliminated by no  other
organ.   The secretion  of  the  kidneys is the  urine,  upon
the regular secretion of which the health of the system greatly
depends.


     FUNCTIONS   OF  THE  DIGESTIVE  ORGANS.

   310. Mastication;  Use of the Tongue;  Use of the Saliva.
Amount of Saliva.—The first process through which the food
must pass is Mastication, or reducing it to a pulp by means of
the teeth and admixture of the saliva.  The service of the tongue
is to keep the food between the teeth and to place it in such a
position that it will readily receive the saliva.   The  saliva  is
of use  to moisten  the food,  since  the gastric  fluid will much
more readily dissolve it than  if dry or solid.   It aids articu-'
lation and  the  sense  of taste by keeping the  lining  of the
mouth in a moist and  pliant state.  It also is of use to cleanse
the mucous membrane, and by its moisture to quench or pre-
vent thirst.  Air is also carried by it into the stomach  to aid
the process of digestion.  But the most important use of this
fluid is the conversion of starch  into  sugar.   This  property
depends mainly upon  a peculiar  organic active substance con-
tained in it called  Ptyalin, and  is most active Avhen in a state
of incipient decomposition.  The sabva secreted daily varies,
according to different authorities,  from  about three pounds  to
six pounds and a half, and  is alkaline in its character.   Acid,
aromatic, and  pungent  substances increase the amount of the
secretion very much.

   311. Deglutition.  A part  of the  Process  involuntary,
■—After mastication,  the  next process is that of  SAvalloAV-
ing, or deglutition.   The  first  step  is to place the  bolus,
or mouthful, upon the  back  part of  the tongue,  Avhen by

   Of what great use are the Kidneys ? 310. Describe the process of Mastication.  Of
what use is the Saliva? How much is secreted every day ?  What increases its amount?
311. Describe the process of swallowing. 
AND  PHYSIOLOGY.
173
the muscles of the tongue  and fauces it is forced into  the
Pharynx.   As soon as it  fairly enters  this passage, the mus-
cles by an iiwoluntary movement  seize it, and  force it  rap-
idly past  the opening into  the  lungs,  and  at  the  same
moment  the  epiglottis  is forced  doAvn upon  the larynx, to
prevent its entrance into the trachea.   This  part of *he  pro-
cess is involuntary, from the necessity of keeping the passage
to the lungs open  as  much  as possible, in order to  admit air,
and also from the great danger of introducing any other sub-
stance.  And so perfectly carried on is this function that it is
seldom—compared  with the frequency of  deglutition—that
even a fluid  escapes the vigilance of this sentinel.
   312. Passage of the Food  through  the Esophagus.—The
food  passes slowly through the Esophagus into  the stomach,
it being  forced along  by  the contraction  of the  muscular
fibers, aided by the oily secretion of the Esophageal glands.
   313. Gastric Digestion.—As soon as the food reaches the
stomach, the  most  important part  of the  process of digestion
commences, all the previous step3 being preliminary.  When-
ever any solid substance comes in contact Avith the inner or
mucous membrane of the stomach, it excites  the gastric glands
to pour out in abundant quantity the Gastric fluid.
   314. Gastric Fluid—its Amount—Pepsin.—This fluid is
a transparent liquid of a little greater consistency than water,
and of a perceptibly acid  taste.  It possesses the property of
coagulating albumen, and of separating the whey or serum
from the milk in a very short time, and is secreted at the  rate
of seventy ounces per day.  This property, hoAvever, is owing
to a peculiar  organic compound called Pepsin, which acts after
the manner of a  ferment at  the normal  temperature of  the
human body.   The  Gastric  fluid  also possesses  antiseptic
 AVhat part of the process is under, and what part is not under the control of the will?
81o Howis the food carried through the Esophagus? 313  AVbere does the most im-
nortant part of digestion take place ? What effect has any solid substance npon tho Gas-
Tc Glands of the Stomach ?  314. AVhat are the properties of the Gastric Fluid? How
much is secreted daily ?  What effect has it on the decay of substances ? 
174           niTC it cock's  anatomy
properties, or the  power  of preventing decay or putrefaction
for a long time.   These three  properties, the acid, fermenta-
tive, and antiseptic,  are of service in the folloAving  manner.
The acid assists in the solution of the different materials in
the stomach.   The Pepsin, Avhich  constitutes  two thirds of
the solio* materials of the gastric  juice, does its office by es-
tablishing the lactic  fermentation, such as is seen in  the
changes  through Avhich milk  passes  in hot weather.   The
antiseptic properties are important  in order to preArent  putre-
faction, Avhich Avould  be so liable to be set up among organic
substances in such a condition, and at such an elevated tem-
perature as the  stomach usually possesses.

   315. Digestion  partly dependent on Chemical Action.—
Thus we see that this part of  digestion  is mainly a chemical
affair, although  not  entirely so: since  by  experiments care-
fully conducted in a vial outside of the body, maintaining the
same temperature and all the essential conditions of digestion,
the process goes on  very slowly and quite  imperfectly.   It
was found, hoAvever,  that a piece of meat did digest  in a vial
in nine hours and a half, while that  in the stomach under
precisely similar circumstances, was digested in one hour and
a half.

   316. Digestion  partly a vital Process.—Consequently to
say exactly what stomach digestion is, must at present be  im-
possible.   We can only say that it is  a  chemico-vital process,
essentially a chemical action depending upon vital power.

   317. Movements of the Stomach in  Digestion. —In order
to bring the food in contact Avith the largest amount of Gastric
Fluid, the stomach,  by an  instinctive movement,  carries its
contents  over the  greater curve  in it, from the right  to  the
left, and  returns it in  a reverse direction, occupying about

  AVhat constituent is it that is primarily essential in this process ? 315. How much of
the process thus far described is mainly a chemical one?  AVhat experiment proves it?
310. AVhat definition can be given of Digestion ? 317. AVhat instinctive movements does
the stomach seem to possess? 
AND  PHYSIOLOGY.
175
three minutes  for each revolution.   And in order that  all of
it may be  permeated by this  fluid,  contractions frequently
take place in the muscular coat of the stomach, resembling a
churning process.
   318.   Intestinal  Digestion, Chyme.—The  process thus
far is Gastric  Digestion, or that which takes  place in the
stomach,  and the object  accomplished seems  to  be the con-
version of the  nitrogenous constituents of the food into albu-
minose called histogenetic digestion, or the preparation of the
food to be made into the tissues of the body.   But when  all
the food  is thoroughly dissolved, or made into a  liquid condi-
tion called Chyme,  the Pyloric orifice is opened,  and the food
passes into the  Duodenum.  When it arrives here—and never
sooner, in a  healthy state—the  secretions of the Liver, Pan-
creas, and mucus of the Intestine mix Avith it, performing the
second or Intestinal digestion, which is called calorifacient  or
heat making, since it prepares the food Avhich supports the heat
of the body.   The  process, hoAvever, is somewhat obscure, aU
though it is  certain that food is  not perfectly fitted for absorp-
tion until it  has Avell completed  this process.
   319. Use  of the  Pancreatic Fluid.—The Pancreatic Fluid
secreted at the rate of from five to seven ounces per day, re-
sembles quite closely the  SaliA'a, converting starch into sugar,
and aiding in  the absorption  cf fatty matters, by forming an
emulsion, Avhich, hoAvever, is  much more readily formed  by
the presence of bile.
   320.   Action  of the  Bile,  an   Antacid  and   Excre-
tory Agent.—The  Bile,  throAvn out at the rate  of fifty-four
ounces  a day,  seems  from its large  quantity  to  be of no
little  importance.   And  since the juices of the stomach are
mostly acid  in  their  character, it  seems desirable that there
should be some  counteracting agent, which is furnished in the

  SIS. What is the principal thing accomplished by stomach digestion? AA'hat is food
called after it Las passed through this process? Describe Intestinal  digestion and  its
use.  319. What amount of Pancreatic fluid is secreted daily ? AVhat is its principal use ?
320. How much Bile is secreted daily?
                            8* 
  176           HITCHCOCK'S   ANATOMY

  highly  alkaline character of the  biliary secretion.   Another
  use of the bile  is to remove certain materials from the blood
  (the carbonaceous), by allowing  them  to  pass off Avith the
  Avaste portions of the food, the liver thus performing the office
  of an excretory organ.  The liver also  seems to possess tho
  power of forming  sugar and even fat, when it i3 not contained
  in the food, thus seeming to act the part of an equilibrator in
  the process of blood  making.  And since all  the  blood re-
  turning  from the  small intestines passes  through the  liver
  before going to the heart, Avithout doubt an important change
  is accomplished in it by the liver, although the  change i3 as
  yet by no means fully understood.
/-   321.  Purposes  for Avhich Food  is required.  Two kinds
  of Materials  in  the  Food,   azotised  and  non-azotised.
  Azotiscd Constituents. Albumen, Fibrine,  Casein,  Gela-
  tin.—In the animal body Ave find that food  is required for at
  least three purposes :  First, to build  up the organism  at the
  outset, or,  in  other words, to secure its first growth.  Second,
  to maintain the organism  at  its normal standard after  its
  growth  is complete, or to furnish  material to supply the waste
  Avhich is perpetually  going  on while  life lasts.  Third, to
  maintain the proper temperature of the system.  Ilence there
  must  be at least tAvo kinds of material contained in the food:
  one that will  sustain and promote the growth  of the  tissues
  called histogenetic,  and another that Avill keep up tho heat of
  thj body to a  proper standard, called  calorifacient.   The first
  of these requisites is found in food containing Nitrogen, called
  azotised, and  the other in that Avith no Nitrogen, called non-
  azotised. Of the azotised food the most important constituents
  are Albumen, Fibrine, Casein, and Gelatin.  Albumen is fami-
  liarly knoAvn  as the transparent portion of an egg before it is
  cooked,  or the Avhite of the egg after a cooking process.   It ex-
  ists also in the blood, muscles, and bones of all anim;ils,  and is

    How is its alkaline character serviceable ?  AVhat other processes does it accomplish ?
  321. AVhat three purposes is food required for ?  Hence what two kinds of food must be
  brought into the system?  Give examples of azotised food. 
AND  PHYSIOLOGY.
177
coagulated or made hard and Avhite by heat or mixture with
Nitric Acid.   In some parts of vegetables also, especially in
the seeds and fruit, is found a  substanoe which, from its re-
semblance  to animal  albumen, is called  vegetable albumen.
Eibrine exists in the blood and muscles of animals,  forming
the coagulum or clot of blood, and the proper muscular sub-
stance.   There  is  also a corresponding substance in plants
known as vegetable Fibrine.  Casein closely resembles Albu-
men in  its constitution, but  differs in many of its physical
properties.  For  Avhile Albumen is coagulated by heat, Casein
is only coagulated  by lactic and acetic acids.   Casein is best
seen in cheese.   These three substances are the essential ele-
ments of nutrition in mammals,  and though every other prin-
ciple may be supplied  in the food, yet the body is insufficiently
nourished  without  Albumen and  Fibrine.   Gelatin, Avhich
exists abundantly in  the  cartilage  of  animals,  is  another
azotised principle  of food.    This, hoAveA'er, of itself can not
support  life, although it can be  changed into albumen,  or
some of its  compounds by  the  action of the fluids of the
stomach.
   322.  Non-azotised Constituents.—Of  the  non-azotised
constituents  of  food,  the  Saccharine and Farinaceous  and
Oily, are the principal ones, although there are many others
of less importance.   Of the  former, the principal element  is
starch, while the sugar is secondary or subsidiary to it, and
in the latter  we find an abundance of a  Hydro-Carbon, or a
compound  of Hydrogen, Carbon,  and Oxygen,  and all are
essential elements in combustion.
   323. Is  an exclusively Animal or Vegetable Diet  the
best  adapted  to   Man?   Testimony of  Experience.   Ex-
perience of  Dr.  Kane.—The question then  which naturally
suggests itself here i3, Avhether  man is adapted  to  live ex-

  What effect has heat and Nitric Acid upon Albumen ?  Where is Fibrine found ? How
does Casein differ from Albumen? Will Gelatin (or Jelly) of itself support life ?  322.
What are examples of non-azotised kinds  of food? 323. Is ma made to live on oa ex-
clusively vegetable or animal diet J 
178
HITCHCOCK'S   ANATOMY
clusively upon vegetable  or animal diet.   An answer comes
to us from both experience and chemistry.   For Avhile on  the
one hand hundreds of examples  are adduced, as showing that
some men have lived to a green  old age in solid health, Avho
have  entirely refrained from  animal  diet, and many others
who  probably  Avould  have shortened  their  lives a  score of
years by the use of animal food, have  prolonged it by adopt-
ing a vegetable regimen, an equal number of cases can be
mentioned to show that  a mixed  diet has promoted equally
long and healthy lives. The geographical distribution of man,
as well as the manner of  life, also furnishes valuable evidence
in this case.  Travelers who have  visited the polar regions, and
pre-eminently Dr.  Kane,  give us undoubted testimony of the
necessity of  eating meat and  animal  fat to keep the body in
health: since the low temperature  not  only requires a greater
amount  of combustive material; but this  greater energy of
respiration produces a  more rapid waste of all the tissues of
the body, requiring a more abundant  supply of azotised and
non-azotised  material to supply the deficiency.  And on the
other hand experience shows that in tropical climates stimu-
lating food and  drink should be  avoided, because the high
temperature  of the atmosphere  depresses vital energy, and
consequently less material for  supporting animal heat is  re-
quired  with  a  corresponding  decrease in  the waste of  the
body.
   324.  Example of the  Esquimaux.—As examples of these
principles one traveler among the  Esquimaux relates that these
people relish  very heartily tallow candles as a dessert for din-
ner.   Another states that he  has  seen the Greenlanders eat
from  twenty  to thirty pounds of  blubber, or whale-fat, at one
meal.   This, however, was a sufficiency of food to  them  for
two or three  days.

  Give  the testimony of experience.  Give the argument derived from difference, in
climate. What kind of food is necessary to support life in polar, and what in tropical
countries ?  324. State luxurious articles of diet  among Esquimaux and Greenlanders.
How much will a Grcenlander sometimes eat 1 
AND  PHYSIOLOGY.
179
     325. Voice  of  Chemistry.—Chemistry,  however,  teaches
  us that Ave can find  in  the vegetable world  all the principles
  necessary to  support the  body Avithout using animal food.
  And although  the vegetable kingdom contains those elements
  which will  support  life in  many instances,  yet  we knoAV,
  as a  general ride, that we find man  in  the highest degree
  of bodily  and  mental  vigor, only  when  he  makes use of
  a mixed diet.   And  Ave also find that all animals which are
  the most active in their  habits, and rapid in their motions, are
  feeders upon animal  flesh.   There is also a race of half civil-
  ized  savages, the Guanchos, Avho spend the greater part of
  their  lives  in  the saddle and constantly in a state of great
  activity, Avho  live almost  exclusively upon  animal diet, and
  yet are unequaled in their poAvers of physical endurance, and
  live Hats fully equal to the average in duration.
X   326.  Argument from the Teeth.—The  strongest  physio-
  logical argument in fivvor  of a mixed  diet,  is found in the
  conformation  of the  teeth and alimentary canal of man.  In
  those  animals  which live  exclusively  upon animal diet, the
  teeth  are sharp  and pointed, Avith  a very  short  alimentary
  tube, since the nutrient portion of the food is readily absorbed
  by the lacteals.   On the other  hand, the  teeth of vegetable
  feeding animals are smoothed upon their upper surfaces, being
  adapted to crush vegetable substances, and the  alimentary
  tube very long, since the nutrient portion of vegetable food is
  not so readily  parted Avith.   Now in man Ave find  neither of
  these  apparatuses perfectly complete,  but  an admixture of
  both.   Part of the  human teeth are  of the  carnivorous or
  flesh  eating kind, and  another  part  of the  herbivorous or
  vegetable eating  kind : but each of them so modified, that
  either kind of food can be readily prepared for digestion.
  The alimentary canal too is intermediate between that of the
  carnivorous and herbivorous type, being equally well adapted

    325. AVhat does chemistry teach on this subject?  How does great bodily activity
  affect the diet as illustrated by the Guanchos ?  326. State the argument derived from
  the teeth.  What two kinds of teeth arc found in man ? 
  ISO           HITCHCOCK'S  ANATOMY

  to the digestion of animal or vegetable food, or an  admixture
  of both.
>'  327. Conclusions.—The kind of  food  which is the most
  perfectly adapted to the constitution  of man, seems to be de-
  termined by the folkwing rules, based upon the temperature
  of the climate, the  habits or  employments of life, and the
  health of the individual.
    First.  The lower the temperature the greater the  amount
  of animal heat necessary for the support of  life, Avhich re-
  quires the fattest portions of the meat.
    Second.  The more active the habits of  the individual, and
  the greater the amount of exposure in the open air, the greater
  the demand for animal food.
    Third.  If the system be suffering under inflammation of
  any sort, or if there be any tendency to inflammation, animal
  food  should be  used very  sparingly, or  entirely  dispensed
  Avith.
    Fourth.  That diet seems to be the most perfectly adapted
  to the human constitution in all climates  and  seasons, Avhich
  is composed of animal and vegetable food in the proportion of
  one  to two,  or one third by Avcight of animal  food to tAvo
  thirds of vegetable food.   This proportion  is the basis  of the
  diet scales of the United  States and British Navies.
    328. Use of the  Lacteals.—The use of the Lacteals is  to
  absorb the Chyle  or nutrient material from the contents of the
  intestines, and .carry it  into the  general circulation.   The
  force by Avhich this fluid is taken from the alimentary canal,
  is by no means understood at present, unless it  be capillary
  attraction.
    329. The Chyle.—The Chyle is  a white  liquid somewhat
  thicker than milk, and is  made up  of a solution of albumen
  containing minute globules, or cells, which are mostly spher-

   327. What four conclusions aro drawn from this whole subject of diet?  328. What is
  the function of tho Lacteals? What is the force that circulates the Chyle?  S29. De-
  scribe the Chyle, 
AND  PHYSIOLOGY.
181
ical  and  about  3 ^^th of an  inch thick, and  Chyle  Cor-
puscles, which are  simple cells  about „ Jff7th of an  inch in
diameter.

   330.  The  Place where the  Chyle  enters  the  Blood.—
Principle  of  Yen tori.—As already mentioned the Chyle en-
ters  the blood through the  left Subclavian vein  of the neck.
It is not,  however,  simply by the opening of one vessel  into
another that  this is accomplished, but advantage is taken of
the  union of two currents, so  that  by  their combined  force
tho chyle is drawn  in towards the heart.   The mouth of the
    Position of the Thoracic Duct and the A'eins of the Neck where it empties.
   S. V. Subclavian A'ein. J. Jugular A'ein.  1). Thoracic Duct.

Thoracic  Duct, however, is  provided with  valves to prevent
the blood  from  entering it, in  case obstruction  in  the veins
should occur.   And " it is a physical fact that, when a small
tube is inserted perpendicularly  into the loAver side of a hori-
zontal conical pipe, in Avhich AVater is flowing from the nar-

  Give the size of the Chyle Corpuscles.  330. Give the description of the hydraulic
principle by which the chyle U drawn towards the heart. 
182
HITCHCOCK'S  ANATOMY
Fig. 188.
 Illustration of the Principle of A'en-
turi. AVhen a current passes through a
large tube, if another smaller tube open
into its side, the current in this tube
will be drawn into the large tube, even
against the force of gravity.
rower  to the  wider  portion,
if the vertical tube  be made
to dip into a vessel of Avater,
not only will the water of the
larger pipe  not descend  into
the  vessel,  but  it will draw
up  the  water  through  the
small  tube  so  as  to empty
the  vessel."   This  is called
"the principle of Venturi,"
and is Avell illustrated by the
entrance of the Thoracic Duct
into the  Subclavian  vein, as
seen in the cut No. 187.   A
diagram illustrating the same
principle is seen in Fig.  188,
the  arroAVS  representing the
direction of the currents,  and
the   smaller,   perpendicular
tube illustrating the Thoracic
duct at  its entrance  betAveen
the veins of the neck.
   331.  The  lymphatics.—The  Lymphatics   in   general
structure and function resemble the lacteals.   The  lacteals,
hoAvever, are designed exclusively  for  promoting the growth
of the lody by adding nutrient materials, Avhile  the  lympha-
tics give  up to  the general circulation not only useful  pro-
ducts, but all  those Avhich are absorbed.   Hence Avhatever is
presented to the mouths of the lymphatics, is  carried into the
general system, Avhile injurious products are not usually taken
up by the lacteals.   (See  also page 284.)
   332.  The  Action  effected  by  the  Lymphatics.—Since
the Lymphatics,  as  already described,  are  found  in every
 Illustrate the principle of A'enturi. 331. Give the general structure of the Lympha-
tics. State the probable differences in function between these and the Lacteals. 
AND  PHYSIOLOGY.
183
part of the body in great numbers, and are almost constantly
at work in removing  the  Avaste  particles, it  folloAvs that in
process of time a large part,  or even  the Avhole of the body.
will be removed.   And.it  is generally  admitted that the
whole body is actually reneAved every  feAV years, although
the precise number can not be stated, since so many circum-
stances modify the  change, such as exercise,'the amount of
food taken, and climate, as Avell as other causes not so easily
ut.derstood.   It  is, however, quite probable  that the period
of ten  years is sufficient to complete the change in most in-
dividuals,  and the number is stated by some as low as seven.


                HYGIENIC   INFERENCES.

   333.  1.  From  the structure and functions of the Digestive
Organs we can derive  some hints as to the manner  of pre-
venting acute and chronic diseases in them.
   334.  Danger of Eating too much.—2. "We see that there
is a great  danger of eating  too much.   Large quantities of
food distend the coats of the stomach, and give too much labor
for them to perform.  As a  natural consequence the  gastric
glands are Aveakened from excessive action,  and then indiges-
tion or  some other diseased action is sure to follow.  And in
how much better health would multitudes in the higher classes
of society be kept, if some of the numerous dishes they use
were  omitted!  And  in this  country  the remark applies to
nearly all classes.
  33.").  We  are  apt to  eat too many  Kinds of Food.—3. We
also see that our meals arc generally made up of too many
kinds of food.  In the habits of the loAver animals we dis-
cover a great simplicity of diet.   EAren in those whose  ana-
tomical structure closely resembles that of man, the appetites
 332. How great changes are effected in the body by the Lymphatics? In what length
of time is the body probably entirely  renewed?  334. What is the injury from eating
too much ? 335. AVhat is said about eating too many kinds of food? 
184
HITCHCOCK'S  ANATOMY
 are  easily satisfied by the simplest food.   Nor does  man's
 intellectual superiority demand a  greater variety in diet, all
 that is requisite being  the materials necessary to support the
 growth of the different tissues.
   335a.  4. It is evident that condiments and spices should
 be always used very sparingly,  and generally spices not at
 all.   To be sure nature seems to indicate the want of a mode-
 rate supply of salt (perhaps  for  the juices  of the  stomach),
 but  pepper, mustard,  and ketchup excite  the  coats of the
 stomach to an action that  is unnatural.   And  it seems  to be
 a laAV of the  system  that stimulants  and opiates,  if  used
 regularly, must  be constantly increased in quantity, other-
 wise they will  lose their  effect, and disorder will follow.   In
 fine, all experience seems  to prove that the demands of nature
 for food are very simple and easily gratified; but  the appetite
 may be so trained as to  loathe eArery thing of a simple and
 natural kind, and be satisfied only  Avith the stimulating com-
 pounds of modern cookery.   The law of nature,   hoAvever,
 cannot be reversed, that he Avho lives in the simplest manner
 lives the longest, and suffers the least from pain or disease.
  336. We  must  not  eat too fast.—5. Most  persons eat too
 fast.   No time is gained on the sum total of life,  by taking
any from that demanded by nature for eating and digesting
food.   A fortune or great reputation, it is true, may some-
 times be gained a little quicker  by using the time  Avhich the
stomach rightfully claims, yet the penalty for such robbery is
a shorter life, or a disease Avhich makes life miserable.
  337. The Time of Eating.—6.  We see that  the  time of
 eating should not encroach upon the hours devoted to sleep,
or those of hard labor.    During sleep the brain needs quiet;
but  if there be  any function  going on such  as that in the
earlier stages of digestion, the brain, as a matter of necessity,

 Does intellectual superiority require so great a variety as is often introduced? 335.
Why are condiments and spices to be used very sparingly?  AVhat are the demands of
nature upon the appetite?  IIow much  may the appetite be perverted?  836. AVhat
danger in eating too fast? 337. What time during the day should we eat? 
AND  PHYSIOLOGY.
185
must labor till the process is  accomplished, and as a result,
dreams or  imperfect trains of thought will produce that kind
of sleep which  cannot refresh  the body.  If again  the time
for meals precede  or  folloAV very closely upon hard labor, a
laAv  of nature is broken, and  the penalty is sure  to folloAV.
The  nervous  energy  cannot be  immediately called off from
the part to Avhich it has for  some time been directed  (Avhether
to the brain  or the muscles), and consequently the  stomach
for a Avhile must lie nearly inactive.  Hence a short season
of relaxation  from all active  exercise,  Avhether  mental  or
physical, just before  and  after  meals, is very conducive to
health, since in the former  case  the circulation is equalized,
and  the brain can prepare its energies to expend them on the
stomach, while after meals the  Avhole force of the nervous in-
fluence is needed for a time by the digestive function before it
can  be directed to the muscles  for exercise.  Even a short
time after  dinner devoted to a nap promotes digestion quite
rapidly, although  the habit often is an inconvenient one, to
say  the least, since if by unavoidable circumstances it is omit-
ted  for once, the person feels  uncomfortable the rest of the
day.

   338. Danger  of employing Stimulants  for weak  Stom-
achs.—7.  We sec  the error and  danger of a Arery common
practice : that when the digestive organs become weak, and
the appetite is poor, stimulants are employed to  waken the
stomach to crave more food than it can digest.  This only
aggravates the  difficulty and  makes a demand for stronger
stimulants, and  thus  often  is  the system prematurely ayoiti
out.   Whereas, Avould men  folloAV nature and  Avhen a dimin-
ished appetite teaches  them  to eat less and give the organs an
opportunity to rest, they Avould ere long rally and  digest all
that  is necessary to giAro tone and energy to the system.   To

  Why should  not hard labor and a full meal come closely together ? How does a short
nap after dinner affect digestion ? What is a serious objection to the habit? 33S. AVhat
danger results from nsinii stimulants to help weak stomachs?  Should wo eat more than
the natural appetite craves? 
186
HITCHCOCK'S  ANATOMY
eat more than the  stomach craves, is  not  the  way  to  gain
strength, but to increase Aveakness and shorten life.
        COMPARATIVE SPLANCHNOLOGY.

   339.  Digestive  Organs  of  Mammals.—In many mam-
mals  the  digestive organs in their general  arrangement and
construction resemble those of man.
Fig. 189.
Maxillary Gland.

     Trachea.
Parotid Gland.
  Gall Bladder.

      Colon.
     Csecntn.
Bmall Intestine.
Stomach.
Pancreas.
  eon.
Kidneys.
C'jlon.
Abdomen.
Rectum.

Bladder.
Digestive Apparatus of an Ape.
   340.  Esophagus  of the Horse.—In  the  Horse, however,
at the lower end of the Esophagus, there is a sickle-shaped
340. IIow does tho Esophagus of the Horse differ from that of a man? 
AND  PHYSIOLOGY.
187
fold of lining membrane, which makes it impossible for this
animal to vomit.
   341. Stomach  of  Ruminants.—Mammals,  as  a general
rule, have  very  simple  stomachs, and  particularly  those
which live  upon  animal  food.    But  in those  herbivorous
ones which chew the cud,  this organ consists of four cavities,

                           FlQ. 190.
          Gullet.

Esophagean Groove.

       Maniplies.



      Duodenum.
                  Pylorus. The Rennet. 2d Stomach. Paunch.
                       Stomach of the Sheep.

the  Ingluvies or  "Paunch,"  the   Reticulum  or  "Honey
Comb," the  Omasum  or  "Many Plies,"  and the Abomasum

                           Fig. 191.
Duodenum. -
Pylorus.
Second Stomach.
Paunch.
Interior of Stomach of the Sheep.
 341. What Is tho number of stomachs in herbivorous animals?  Give the names of
each. 
188
HITCHCOCK'S  ANATOMY
or   "Red."   As  the
food enters the  Inglu-
                                     mouth  for  the purpose
    Stomach of the Ox. A. Paunch.  B. Re-    0f re-chewing and mix-
    ticulum.  C.  Omasum.   I). Abomasum.    .      .     *r
    E. Pylorus.  F. Duodenum.  G. Esophn-    mg  With  the  Saliva.
    sus'                               After   this  process  i3
completed, they are  sent into the  Omasum, which  cavity
seems designed  to prepare  the food to enter the fourth stom-
ach where the  true  process of digestion  takes place.   And
it is from this fourth stomach or Abomasum,  that  the Rennet
is taken from  young calves, and used by cheesemakers for the
purpose of coagulating the milk.

  342.   Reason of this  Complex Stomach.—The probable
reason of such a complicated stomach in these animals is  that
since they have such poor means of self-defense, they need to
crop their food as quickly as  possible, and then  retire  to a
safe place to masticate it.   And it is also partly OAving to the
fact that vegetable substances require a longer process for di-
gestion  than does animal food.

  343.  Length of Intestine.—The length  of the Intestine
depends as a general rule  upon the food  used  by the animal,

 Give the process  of chewing the cud in these animals. 342. What is one important
reason for this complicated arrangement?  343. Upon what does the length of Intestine
depend? 
AND  PHYSIOLOGY.
180
the vegetable feeders having a long tube, and the flesh feeders
a short one,  since animal food is so easy of stomach digestion.,
and the  nutrient  portion of it so readily taken  up by the
lacteals.   Thus the  ox  has an alimentary  tube  fifteen or
twenty times  the  length of the  body,  amounting in a full
grown animal to 150 feet, the sheep one tAventy-eight times its
length, while  many of the carnivora exhibit  one  only  about
three times the length of the body.  The true Cetacea or Whale
tribe are the only  ones Avhich do  not  have a  marked distinc-
tion between the large and small intestine.
   344.  The Liver.—The  Liver  as  in  man is one  of the
largest organs in  the body, and  is much more divided into
lobes in carnivorous than herbivorous animals.   It is smallest
and least divided  in those animals Avith compound  or  rumi-
nating stomachs.
   345.  Bill of Birds.—Birds  are destitute  of teeth,  since
the process  of mastication is carried  on in  a certain portion
of the alimentary canal.  But the horny investment of the
 jaws known as the bill, is harder in birds of prey, and  those

                            Fig. 193.
Tongue...
Os Hyoides.
                     Head of the Woodpecker.

that feed on fruit and nuts, as Parrots, and in Woodpeckers.
The bill, or rather  mouth, of  Ducks and  Geese is lined by
a tender membrane,  in order that they  may be partially
 Whit is the length of the Intestine of the Ox?  Of the Sheep?  Give the proper-
tional' length of Intestine  in Carnivorous Animals.  344. What difference in the Livet
between nesh and herbivorous animals?  345.  Why are Birds destit,, e of teeth?
What Birds have the hardest bills? What peculiarity in tho hung membrane of the
mouth of Ducks, etc. ? 
190             HITCHCOCK'S   ANATOMY


                              Fig. 191.
   Digestive Apparatus of Fowl.  a. Esophagus.  6. Crop or  Ingluvies.  c. Pro-
 ventriculus.  d. Gizzard,  e. Liver.  /. Gall-Bladder.  g. Pancreas,  h. Duodenum.
 i.  Small Intestine.   k.  Cieca.  I.  Large Intestine,  m.  Ureter,  n. Oviduct.
 v.  Cloaca.


guided in the selection of their  food from the soft mud by the

sense  of touch.


   346.   Stomach   of  Birds. —The   Gizzard. —The  true

stomach of birds  consists of two divisions.   There  are, how-
346, State the usual number of stomachs in Birds, 
AND PHYSIOLOGY.               191
ever, three enlargements of the alimentary canal, all of which
prepare  the food for assimilation.  The first of these is the
"Ingluvies" or  "Crop," Avhere the food  is softened by the
mucous secretion of the lining membrane.  Then  as it passes
along into the " Proventriculus," it receives the gastric juice
from the gastric glands wThich  line it.   The second stomach,
the  "Gizzard,"  is  round  and  flat and made up of powerful
muscular fibres,  except  in birds of prey, where it  is  thinner
in texture.  In  gallinaceous birds its lining membrane  is of
a horny consistency, Avhich, with the powerful muscular fibres,
render it an organ of mastication to granivorous birds.  Gravel
and. angular stones are purposely SAvallowed by these  birds
to aid in the digestive or grinding process.

   347.  Teeth  and  Jaws  of Reptiles.—Reptiles  need teeth
only to seize and retain their prey,  since  Avhatever food  is
taken by them, is swallowed  without mastication, Avhich  is
one reason Avhy the jaws and
throats  of  serpents  are so
very  capacious.   A  peculi-
arity  in their bony construc-
 tion  renders  this  possible,
 for  the  jaw  is  not  made
 up  of  one or  at  most two
 pieces as  in mammals, but of
 several segments, which rea-
 dily move one upon another,
 as if  with different articula-
 tions.
    348. The  Tongue.—The Tongue is used as an  instrument
 for the capture of prey by many reptiles.  Frogs  and  Sala-
 manders  are able to  thrust it out with  great rapidity and
 Head of the Rattlesnake,  mi. Lower
Jaw.  t. .Tympanic Bone.  ma. Mastoid
Bone. m. Upper Jaw.
 Give the names of each. Describe the Gizzard. Why are gravel and stones swallow d
bv sratii vorous birds ?  Which is the true, stomach ? 347. \A hat is he only use of teeth
L reut lcs'  State the reason why the .jaws are so capacious.  Of how many bones are
Hey frequently made up ? 31S. Of.what use is the tongue to some reptiles? 
102           HITCH C O C K ' S  A N A T O M Y

coil  it upon insects or  any other object.  This property, to-
gether Avith  the  adhesive mucus found upon  it, makes  it for
these  animals  a  very  serviceable  apparatus   in  obtaining
food.
   349. Esophageal Teeth.—In many  animals  of this de-
scription the Esophagus is lined with  bony processes pointing
downwards,  called  Esophageal teeth, Avhich greatly  aid in
SAvallowing  the  large masses Avhich they are accustomed to
force into their stomachs.

   350.  Stomach.—Length of  Intestine.—The  Stomach
seems to be only a  dilatation of the  Intestine.  In  many
species it is divided  into two cavities resembling those of a
bird, (Fig. 196) : the first a  Gizzard, or an organ made  up
of stout muscular fibers, and  the  second a  thin walled and
secreting cavity.   In Crocodiles it is round, and the muscular
coat  is very thick,  in  order  to reduce to a  digestible size
the  coarse  food  which  it  so  greedily devours.  The length
of the intestine  in most reptiles is  about twice the length
of the body ;   in  Lizards,  however, it  is  only  about the
same  length as  the body.   A  cloaca  or additional rectum
is sometimes found  in  these animals, as is  the case among
birds.

   351. Stomach and Intestine of Fishes—In many Fishes
the intestinal tube extends from the  mouth  directly through
the  animal Avithout any enlargement  for the stomach, or any
convolutions, as  is the case Avith all the  animals thus far con-
sidered on this subject,  and Avith which no organ of secretion
is connected, except the liver.  The intestinal canal, however,
is generally more or less convoluted, and ordinarily it is  short.
In the Shark the stomach  is parceled out by  constrictions and
 With what is it covered, that renders it more serviceable as an instrument of capture?
849. What is said of Esophageal teeth?  350. Is the stomach a simple or complex cav-
ity ?  AArhat is the average length of intestine among reptiles ? AA'hat is said of a cloaca?
851. In what condition is the stomach found in most fishes ?  What peculiarity is met
withiu tha Shark ? 
AND   PHYSIOLOGY.


        Fia. 196.
193
  Anatomy of the Common Snake.  1. Tongue,  m. Esophagus, i. Stomach,  i'. Small
Intestine, cl. Cloaca, f. Liver,  o. Ovary,  o'. Eire's,  t.  Trachea,  p. p'. Lungs,  rt.
Arent.ricle.  e.e'.  Auricles,  a. ad. a'. Aorta,  ac. Carotid Arteries,  v. vc. Vena; Cavae.
vp. Pulmonary A'ein.

inversions into several  divisions  with  valve-like appendages

between them.

   352. Liver.—Fishes  have usually a large soft Liver  com-

pletely saturated  Avith  an  oil.   Its  form  is various,  but  is
3"i2. Speak of tho Liver of fishes. 
194
HITCHCOCK'S  ANATOMY
Fig. 197.
often imperfectly divided into two lobes.   The oil that is ex-
pressed from  the liver of the Cod Fish, is  often  used  with
great efficacy in the early stages or symptoms  of consumption.
                                 353. Pyloric Appendages.
                               —In many fishes with bony
                               skeletons there is found a cu-
                               rious set of gland-like organs
                               called  Pyloric  appendages.
                               They vary  in number from
                               tAATo  in   the  Plaice,  to  two
                               hundred  in the Mackerel, and
                               always   either encircle   the
                               pylorus,   or  are found near
                               the upper end of the intestine.
                               These appendages  are inva-
                               riably absent in those fishes
                               which  have  an  imperfectly
                               formed stomach, and by some
                               are considered as  analogous
                               to a Pancreas in function.
                                 354.  Salivary Glands.—
                               Salivary Glands are wanting
                               in  fishes, but their place is
                               supplied  by an increased  de-
                               velopment of the  mucous
                               glands of the mouth.
                                 355. Digestive Organs in
                               the Invertebrates.—In-the
                               Polyps of the Radiate  ani-
                               mals, Ave  have the   simplest
                               form of digestive apparatus,
                               viz.,  a simple sack, with a
                               mouth  to receive  the  food
and to disgorge the refuse,  as is seen in Fig.  198, A.   Other
Polyps, however, have two openings in their stomach or sack,
as shown in Fig. 198, B.
 Digestive Apparatus of a Beetle,  a.
Head. b. Crop and Gizzard,  c. Biliary
A'essels. d. Intestine, e. Secreting Or-
gans. 
AND  PHYSIOLOGY,

       Fig.  198.
195
Fig. 199.
               Digestive Apparatus of Unicellular Animals.
   35G. The  Hydra.—Fig. 199, an  unicellular animal, is an
example where the simplest sort of digestive  organs is  ex-
hibited.   The animal is little
else than a  gelatinous  sac,
and if it be turned inside out
digestion  will  still  go  on.
Thus,  "notwithstanding  the
simplicity  of  its structure,
this creature feeds not merely
upon algse, but upon young
active  animalcules, the young of
crustaceans, etc. ; any one of
these,  when  they happen to
came in  contact with one of
the tentacular filaments, be-
ing usually   retained    by
adhesion  to  it.    As   this
filament  shortens  itself,  all
the surviving  filaments  ap-
ply themselves to this captive
particle,  so that  it becomes  gradually inclosed,  andjrad-
             356. AVhat is the process of digestion in the hydra ?
 nydra or Fresh Water Polyp.
trance and Exit to Stomach.
a. En- 
196           HITCHCOCK'S  ANATOMY
ually shortening, so as at last to  bring the prey close to the
surface of the body.   The spot with which it is  brought  in
contact, then slowly retracts, and  forms at first a shalloAV de-
pression, gradually becoming deeper and deeper, into which
the prey sinks  little by little, for some time, however,  con-
tinuing to project from the surface.   The  depression at last
assumes a flask-like form, by the  drawing  in of  its margin,
and finally its edges close  together, and its prey is entirely
shut in.   This gradually passes  to  the center of the body,
where its soluble parts  are dissolved, whilst in the mean  time
its external portion recovers its pristine condition."
   357. Other Radiates have an alimentary canal more com-
plicated,  having a stomach and csecal appendages that appear
to perform the  office of a  liver.  Some of the Echinoderms
have teeth;  in the  Echinidre is  a  curious apparatus  in the
mouth called Aristotle's lantern.
   358.  Another form of the digestive apparatus  consists of a
central  cavity, with branches extending through every part
of the body.  Fig. 200 shoAvs this in  one of the Articulated
animals, an  Arachnoid Crustacean,  the Ammothea pycnog-
onoides.  This arrangement is found in several other  classes
of the Invertebrates.
   359.  The Crustaceans are  generally furnished with two
upper jaws, called Mandibles, which move  laterally ;  and be-
hind these, tAA'o pairs  of weaker and softer lower jaAvs, which
are  sometimes  changed into  suckers and  legs.   The  higher
branches are ahvays provided Avith prehensile organs for  seiz-
ing  the food, which are arranged in pairs.
   360.  These  are best seen in the  Lobster, where they are
enormously developed,  projecting in front  of the eyes a dis-
tance nearly equal to  that of the length of  the whole body,
and each extremity is furnished with a poAverful pair of pincers.
Some of the higher Crustaceans have a sort of horny  teeth
implanted in the coats of the stomach Avhich are Avorked by a
359. AA'hat are the jaws of crustaceans ? 
AND  PHYSIOLOGY.
197
Fig. 200.
  Digestive Organs of Ammothea pycnogonoides (Crustacean), a. Esophagur  b. Stom-
 ach,  c Intestine, d. Digestive Cavity of the Jaws. 6. Digestive Cavity of the Legs.

 powerful set of muscles, which help in the  reduction  of the
 food.  These teeth are found in the  Lobster's stomach.   The
 stomach of the  Leech is very capacious, being nearly the size
 of the whole body.   The same is essentially true of the com-
 mon  Earthworm,  which  is an  Annelid.   In many insects
 salivary glands are present, and in such cases they are placed
 at the commencement of the alimentary canal.   The different
 parts of the  alimentary canal in insects " may  be  properly
 distinguished in the folloAving manner.  The first portion is
 the Esophagus, muscular, occupying  the three thoracic seg-
ments and often dilated at its  posterior  part into a  crop
 (Ingluvies) and muscular gizzard (Proventriculus).  Some-
times there is appended to the Esophagus a sucking stomach, 
198
HITCHCOCK'S   A X A T O M Y
Fi:J. 201.
 ' Aplysia (AIollusc) laid open  to show tho viscera,  a. Esophagus,  c. Salivary Glands.
(I. Cephalic Ganglion,  e. Esophageal Ganglion. f,g  First Stomach or Crop.  A. Third
or True Stomach, i. Gizzard,  k.  Intestine.  I. Liver,  m. Posterior Gun<;lion. «. Aorta.
6.  Hepatic Artery.  p>. A^entricle  of  Heart,  q. Auricle,  r.  s. Branchiae or Gills.  i«.
Lower Intestines,   v. Ovary. 
AND PHYSIOLOGY.               199
consisting of a more or less pedunculated thin walled vesicle,
which  is multiplicated on  itself  Avhen empty.   The second
portion consists of a stomach (ventriculus) in which the chyle
is formed, and which  is continuous at the point of insertion
of the malpighian vessels Avith the third portion of the digest-
ive  canal.  This  third portion commences by a small and usu-
ally short  ileum, Avhich is followed by a  colon  larger and of
variable length.  This last  often  has a caecum at its anterior
extremity, and terminates  posteriorly in a  short,  muscular
Rectum."
   "A considerable number of insects take  no food during
their perfect state,  the object of their existence  being only to
accomplish the  act of reproduction.   Their jaws  are  often
very rudimentary, and are fit neither for  sucking  nor  for
masticating."
   361. The  Annelida  have sometimes quite  complicated
jaws, even as many as eight or nine, moving  laterally.  They
have also  salivary and hepatic glands, as have many  other
invertebrates.  These  are shown on Fig. 197, which repre-
sents the Avhole alimentary canal  of an insect.
   362. The Cephalopod Molluscs haA^c a mouth, two horny
 jaws moving  vertically  in  the pharynx, a  tongue, an oeso-
phagus, a stomach, a  pylorus, and an intestinal canal.
   363. In the Cephalophora the jaws move laterally for the
most part.  In  the whole  class  we find  a biliary  apparatus
and generally salivary glands.  Fig. 201 shows the  digestive
organs of  a Gasteropod,  the Aplysia.   Nearly all the Ceph-
alophora  have a  longer or shorter fleshy  mass attached to
the base of the  pharynx that is  comparable  to a tongue.   It
has a  longitudinal grove in it, and is sometimes included in a
sheath   It is always covered with horny denticulated plates
and spines, which are very delicate, and arranged in quite
elegant longitudinal and transverse  rows.  The points of these
 spines turn backward, which aids greatly  in swallowing. 
200           HITCHCOCK'S  ANATOMY

  •364. In  some families of the Entozoa—the  Cystici, the
Cestocles and Acanthocephali—there is no mouth nor proper
intestinal canal, but there  are vessels  for the circulation of
nourishment  Avhich is received directly through the sides of
the body, on  the principle of endosmosis. 
CHAPTER    FOURTH.
THE  CIRCULATING SYSTEM.-ANGIOLOGY,  OR  HISTORY  OF
          THE  ORGANS OF BLOOD CIRCULATION,
DEFINITIONS   AND  DESCRIPTIO
   365.  The  Circulatory   Or
 this  system  are  the  Heart,
 Arteries,  Veins,  and Capil-
 laries, and are  mainly tubes
 of various diameters  and  a
 hollow organ,  with the double
 office of receiving and propel-
 ling  the blood.
   366.  The    Heart. —The
 Heart,  or central engine  of
 circulation, is  located  in the
 thorax or chest, resting by its
 lower  surface  on  the  dia-
 phragm, and somewhat to the
 left of the middle line of the
 body.   It is of a conical form,
 made of animal muscular fiber,
 the fibers crossing themselves
in at least three  directions;
and  it is a singular  fact  that
gans.—The organs  composing
              Fig. 202.
                     £ io
  An Anterior view of the Heart in a Ver-
tical Position, with its Vessels injected. 1,
Eight Auricle. 2, Left Auricle.  3, Eight
Ventricle.  4, Left A'entricle. 5, Descend-
ing Vena Cava.  6, Aorta. 7, Left Pulmo-
nary Artery.  8, The Arteria Innominata.
9, Left Primitive Carotid.  10,  Left Sub-
Clavian Artery.  11, Anterior Cardiac Ves-
sels in the A^ertical Fissure. 12, Posterior
A'essels from the Transverse Fissure.  13,
Main Trunk of the Pulmonary Artery.
 365. What are the organs used for the circulation of the blood?  366. Give the location
of the Heart 
202
HITCHCOCK'S  AX ATOMY
                                 many of the fibers of the heart
                                 anastomose, or join with each
                                 other  in many  places, as  is
                                 seen in Fig. 203.   The heart
                                 is  a double organ,  one side
                                 being called the  arterial and
                                 the other the venous, or right
                                 and left hearts, since the for-
                                 mer receives and propels the
                                 pure  or arterial  blood, while
Anastomosing Fibers of the Human Heart.   the  latter  circulates   VenOUS
blood.  Again, each of the two sides or  hearts are divided
into an auricle and a ventricle.   Each  of these  four cavities
will ordinarily contain about three  fluid ounces, making the
whole heart to contain nearly a pint.
   36T. The Auricles and  Ventricles.—The  Auricles  are
the uppermost cavities of the heart, and are  somewhat smaller
                            Fig. 201.
                       vj ae  t  ac vj
Eight Lung,
Left Lung.
                       od    lie vd a     rcg
 Lungs, neart, and Principal Vessels in Man.  od, Eight Auricle, vd, Right Vcwtrisfc.
vg, Left Ventricle,  a, Aorta, ac, Carotid Arteries.  vcr Vena Cava. *, Trachea,  rj,
Jugular Veins.
 What are its shape,, size, and four cavities called?  What is the capacity of an, adult
heart? 
A X D   P II Y S I O L O G Y .
203
than the Ventricles, or loAver ones.   The auricles also have
the thinnest walls, and are capable of considerable dilatation,
since by a sudden effort of  the body the blood is liable to be
sent in great quantities to the  heart, and the veins would be
in danger of rupture Avere there no elasticity in the receptacle.
The thickened walls of the ventricles give increased poAver of
                             Fig. 205.
            Vena Cava Sup. Art. Pulm. Aorta. Art. Pulrn.
 Pulmonary Veins.
    Eight Auricle.
  Tricuspid Valve.
Vena Cava Inferior.
Eight Ventricle.
., Pulmonary A'eins.
 - Left Auricle.
.....' Mitral Valve.
Left Ventricle.
                        Septum.  Aorta.
                  Theoretical Section of the Heart in Man.
contraction.   This is needed because the  ventricles  drive  the
blood from the heart, and the auricles receive it on its return.
The right ATentricle, however, propels  the blood  only to the
lungs. Avhile the left ventricle sends it to all parts  of the body
except the lungs.   The  left auricle receives  only  the  blood
from the lungs, while the right auricle receives it from all the
other parts of the body.
   368.  Valves  of the Heart.—Between the auricles and ven-
tricles are peculiar forms of muscular  and tendinous  fibers,
resembling cords and pillars, that are  termed valves, making
a sort of curtain to allow the flow of blood from  the auricles
to the ventricles, but not  in the opposite  direction.   At  the

  367. Give the essential differences between the auricles and ventricles. AA'hy does the
left ventricle need the thickest walls?  36S. Describe the valves which  lie between the
auricles and ventricles. 
204
UITCIICOCK'S  ANATOMY
FlG. 206.
                       point where the arteries are given  off
                       from each ventricle are found (in each)
                       three crescent-shaped  folds of semi-
                       cartilaginous  tissue called  Semi-lunar
                       Valves, to allow the motion of blood m
                       an  outAvard direction,  but to preArent
                       the return,  which  is  called regurgita-
                       tion.
                          369. Pericardium.—In addition to
                       the fasciae and fatty matter Avhich  im-
mediately invest the heart, this organ is inclosed by another
membrane in the form of a shut sac, a serous membrane called
                            Fig. 207.
 Semi-lunar Valves  of the
Heart closed.
 Semi-lunar Aralves of the Aorta laid open,  a. Corpus Arantii on the Free Border,  b.
Attached Border,  c, Orifices of Coronary Arteries.
the Pericardium (meaning about the heart).   This contains a
small quantity of a fluid like water, so that the heart actually
floats in a liquid, and does not rest firmly upon any hard sur-
face.   The pericardium not only exists as a loose  sac about
the heart,  but it  is reflected upon it where  the vessels are
given off; covering it in the same manner as the fasciae cover
and protect the muscles.
   370.  Arteries—Their Coats.—The Arteries are tough and
cylindrical tubes Avhich convey the blood from the heart to the
different parts of the body.   They are made up of three mem-
  Describe the Semi-lunar A'alves and their location.  369. What is the sac called thnt
surrounds the heart? What fluid does it contain? How much of it is there?  Is tho
pericardium attached tit all to the heart?  870. Of how many coats are the arteries com-
posed ? 
and   physiology,

          Fig. 208.
205
Anterior
  Tibial
 Artery.
   Art.
Pediosa.
Posterior
Tibial
Artery.


Peroneal
Artery.
                        Arterial System in Man.

branes,  of which the  middle one deserves especial attention.
This is  an clastic coat composed of  yellow fibrous tissue (Fig.
209), in order, as we shall  presently see, to aid m the circu-
eh one and their peculiar value. 
206           HITCHCOCK'S   ANATOMY
 Highly Magnified Portion of the Middle Coat of   by a Capillary net-WOrk
the Arteries.                             which ig ma(Je from a(1_

joining blood-vessels.   Nerves are distributed to some arteries,
but ordinarily they only accompany them.
   371.fTlie  Aorta.—The arteries  sent to every portion of
the body from the  left ventricle  proceed from one  trunk,
called the Aorta, meaning a  starting-point.   It  is nearly an
inch in  diameter,  and  ascends  in  a perpendicular direction
for about two inches, Avhen it makes a curve upon itself,  and
descends through the  thorax and  abdomen until it  reaches
the fourth lumbar vertebra,  when, as  is the case with most
of the large  arteries,  it divides into  two branches of equal
size.  BetAveen the curve or arch of the  aorta and the heart
no branches are given off, but from the summit  of this arch
to the subdivision in the abdomen a great number of branches
are distributed to the different portions of the chest and  ab-
domen.

   372.  Description  of Particular  Arteries—Innominata
—Carotid—Subclavian—Axillary—Brachial—Ulnar  Ra-
dial— Palmar Arch.—The first  branch arising from the sum-
mit of the  aortic  arch is  the large  one called  the Innomi-
nata, or nameless  artery.   Next comes the Carotid, and both
distribute themselves   to the head and upper   extremities.
 371. What is the Aorta? AA'hat docs the word aorta mean?  Give its course till it
subdivides.  AVhei'e does it divide into tho common iliacs?  872. AVhere are the In-
nominata Arteries? The Carotid? 
AND   PHYSIOLOGY.                 20Y
Fig. 210.
  A Yiew of the Heart, with the Great Vessels of the Neck in Situ.  1, Eight Ventricle
of the Heart.  2,  Pvight Auricle.  3, Left Ventricle.   4, Left Auricle.  5, Pulmonary
Artery.  6, Arch of the Aorta.  7, Descending Vena Cava at its entrance into the Eight
Auricle.  8, Ascending ATena Cava.   9, Thoracic Aorta. 10, Arteria Innominata. 11,
Eight Brachio-Cephalic Vein.  12,  Left Brachio-Cephalic ATein.  13.  Section of the Sub-
clavian Artery.   14,  Section of the Sub-Clavian Vein. 15,  15.  Primitive Carotid Ar-
teries.  16,  16,  Internal Jugular Veins.  17, 17, External  Jugular Veins.  Between
these A'eins is seen the Section of the Sterno-Cleido-Mastoid Muscle.  IS, The Trunk
formed by the Superficial Cervical Veins, known sometimes as the Anterior  Jugular
Vein. 19, A Branch from it to the Facial. 20, Main Trunk from the Interior  Thy-
roid Veins.  21,  Superior Thyroid Vein.   22, Transverse  Cervical Artery and A ein.
23, Lingual  Artery and Arcin.  24, Facial Artery and Vein.

The Innominata on  the  right  very  soon   becomes the  Sub-

clavian,  after which the  corresponding arteries of  both  arms

receive the same name.   The Sub-clavian   Artery,  as its ety-

mology  implies,  lies  directly  beneath the  clavicle  until  it

reaches the axilla,  or arm-pit,  where it receives  the  name of
The Sub-clavian ?  The Axillary ? 
208
HITCHCOCK'S   ANATOMY
Fig. 211.
  A Alow of the Arteries of the Neck and Shoulder.  1, Primitive Carotid Artery. 2,
Internal Carotid Artery.  3, External Carotid Artery. 4, The Superior Thyroid Artery.
5, Branches to the Muscles.  6, Main Branch to the Gland.  7, Inferior Pharyngeal Ar-
tery.  S, Lingual Artery. 9, Facial Artery. 10, Its Branches to the Sub-Maxillary Gland.
11, Sub-Mental Branch.  12, Principal Branch of the Facial as it goes over the Jaw.
13, Occipital Artery.  14, Branches to the Muscles  on the Back of the Neck.  15, Main
Trunk to the  Occiput. 10, Posterior Auricular Artery.  17, A Branch cut off, which
goes to the Parotid Gland. IS, Origin of the Internal Maxillary Artery.  19, Origin of
the Temporal Artery.  20, Origin of the Anterior Auricular.  21, The Sub-Clavian.  22,
Origin of the Internal Mammary.  23, Trunk of the Inferior Thyroid, from which arise
in this subject the Anterior and Posterior Cervical Arteries.  24, Branch of tho Inferior
Thyroid going to the Thyroid  Gland.  25, Anterior  Cervical going up the Neck.  26,
Posterior or Transverse Cervical.  27, Branches to the Scaleni and Levator  Scapula;
Muscles.  2S, The Superior Scapular Artery.  29, The Thoraeica Superior of the Axil-
lary Artery.  30, A Branch to the Deltoid. 31, Eecurrent Branches  of the Intercostals.

Axillary Artery.    Then as it passes  along the  inner  side of

the humerus it is called the Brachial, until it  has passed  be-

yond the inner side of  the elbow, Avhere  it is divided into  the

Ulnar and Radial, corresponding in position  and direction to

               AVhere arc the Brachial, Ulnar, and Eadial Arteries ?
02 
AND  P II Y S I* O L O G Y .
209
the ulna and radius.  Some-
times, however, the branch-
ing takes place higher up,  as
is  seen in  cut 212.  When
these have fairly passed the
wrist, they both join again in
an artery Avhich  describes  a
curve at the base of the meta-
carpus crossing  the  palm  of
the hand,  and called the Pal-
mar  Arch.   Small  branches
are given off from this which
supply the different  parts  of
the  hand,  including the fin-
gers  and thumb.
   373. Distribution of  the
Carotids—Vertebral—Circle
of Willis.—The  common Ca-
rotid  Arteries,  one on each
side of the neck, pass upwards
from the innominata and sub-
clavian nearly as far as  the
angle of the jaw, when they
divide  into the  internal and
external  carotids, the former
furnishing blood  to the face,
and the latter to the brain and
back part of the  head.   The
 Vertebral Artery is also giv-
 en off from the  sub-clavian,
 which, passing backward, en-
 ters the  spinal column at  the
 sixth cervical  vertebra,  and
b\r
H)
■'/'-
;i*r
                               Arteries of the Arm.  1, Termination of
                              the Axillary Artery. 2, The Brachial Ar-
                              tery.  3, 3, Eadial Artery. 4, 4, Ulnar Ar-
                              tery. 5, A Recurrent Branch.  6, Anterior
                              Interosseous Artery.  7, Superficial Pal-
                              mar Arch formed by the Ulnar Artery.  S,
Deep-Seated Palmar Arch.  9, The Anastomosis of the two Arteries, much enlarged.
 What is the Palmar Arch ?
ward to the head.
Givo tho branches of the Carotid as it passes up- 
210            HITCHCOCK'S   ANATOMY

passing through a foramen or opening in the transverse process
of each  of these vertebrae, at last reaches  the posterior portion
of the brain.   This artery in the brain meets with the termi-
nal  branches of  the  internal carotid,  so that the blood can
easily  reach  the brain from  either  direction.   By  this ar-
rangement,  if,  from  pressure or accident, the flow  of blood
to the brain in either of these channels should be  obstructed,
the  other would  supply it;  for  sensation  and  consciousness
                             Fig. 213.
  Circle of Willis.  1, Vertebral Arteries.  2, 3, Anterior and Posterior Spinal Arteries.
4, Posterior Meningeal Artery. 5, Inferior Cerebellar. 6, Basilar. 7, Superior Cerebel-
lar.  S, Posterior Cerebral.  9, Branch of Carotid. 10, Internal Carotid.  11, Ophthalmio
Artery. 12,13, Cerebral Arteries.  14, Anterior Communicating Artery.

entirely cease if  the  brain be deprived of its arterial  blood.
This arrangement is called  the  " Circle  of Willis"  from  its
discoverer.
  What arteries does the ATertebral communicate with in tho brain ?
vice of this arrangement?
AVhat is the ser- 
AND  PHYSIOLOGY.
211
   874.  Thoracic  Aorta — Abdominal  Aorta—Ceeliac Axis—
Gastric,  Hepatic,  Splenic,  Renal,  Mesenteric,  and  Lum-
bar  Arteries.—After the aorta fairly commences  its  descent
—called the Thoracic Aorta—several small branches are given
off from it Avhich send nourishment to the heart and lungs, and
next a pair  Avhich are distributed  to the  diaphragm.   Then
                               Fig. 214.
  A View of the Abdominal Aorta and its Branches.  1,1, The Diaphragm.  2,foramen
QutdTatl and Section of the  Ascending Vena Cava  3 Foramen Eso hageum and
Section of the Esophagus. 4. Foram-n Aort.cum in th» Urna         l
Phrenic arteries are seen going  to the Diaphragm.  5 C psuh* ™% '      k..
nevs   7, Abdominal Aorta.  S,  Phrenic Arteries.  », [f"-?"1""" J.™' 14 Elllll.
S2"- H The Gastric.  12, The Hepatic  13, ^^^ ^JlS
gent Arteries. 15. Spermatic Arteries 10, Infe »M«^_be Middle S a,-ral. ^
IS, Division of the Ab.lom.nal Aorta.  19  Its last■*>>™          ,    al Ili!lcs<
Primitive lilacs.  21, Uretors-in their Posit.,n.to-to"^-^^  o,, Ela(1.
23 Internal lilacs.  21, Clrc.iiinflexa I.n.  2... D.stnbut.on i»    1 =
der di,t,n«le,l with Urine.  The Vesical Arteries are seen m,u it.
374. AVhat arc the first branches of Oe Thoracic Aorta? 
212
II 1 T C II 0 O C K ' S   ANA T O M Y
Fig. 215.
                                    we  meet Avith a large  trunk
                                    given off just below the  dia-
                                    phragm, about  half an  inch
                                    in length,   called the Cceliac
                                    Axis, Avhich  gives origin to
                                    the  Gastric  artery supplying
                                    the   stomach,  the  Hepatic,
                                    running to  the liArer, and  the
                                    Splenic furnishing blood for
                                    the  spleen.    BeloAV  this Ave
                                    find the Renal  arteries, sup-
                                    plying the  kidneys, and  the
                                    Superior and Inferior Mesen-
                                    teric  Arteries,   Avhich   giAre
                                    blood to the intest'nes, and the
                                    Lumbar Arteries, terminating
                                    in the external muscles of the
                                    abdomen.
                                       375.  Iliac  Arteries—Fe-
                                    moral,  Popliteal,  and Tib-
                                    ial   Arteries—Dorsalis   Pe-
                                    dis.—As already mentioned,
                                    the  aorta   divides  into  tAvo
                                    branches opposite  the  fourth
                                    lumbar   vertebra,   for   the
                                    supply of  the lower extrem-
  A Front Yiew of the Femoral Artery, as
■well as of the External  and  Primitive
Iliacsof the Eight Side. 1, Primitive Iliac Artery.  2, Internal Iliac  Artery.  8, Exter-
nal Iliac Artery.  4, Epigastric Artery.  5, Circumflexa Uii Artery.  6, Arteria Ad Cu-
tem Abdominis.  7, Commencement of the Femoral just under the Crural Arch.  8,
Point where it passes the A'astus Internus Muscle.  9, Point wlilero it leaves the Front
of the Thigh to become Popliteal.  10, Muscular Branch to the Psoas and  Iliacus.  11,
External Pudie Artery cut off.  12, Origin of the Internal Circumtlex.  13, Profunda Fe-
moris. 11, Muscular Branch.  15, 16, Artery to tho A'astus Externus Muscle.  17, Artery
to the Pectineus and Adductors.  18,  First Perforating Artery.  19, 19, Muscular Ar-
teries.  20, 21, Anastomotica.  22, Superior External Articular.  28, Middle Articular.
24, Inferior External Articular. 25, Inferior Iutemal Articular.
 Describe the Oeliac Axis.  AVhero aro the Gastric, Hepatic, Splenic, Eenal  and Lum-
bar Ar.cries ? 
AND   PHYSIOLOGY,
Fig. 2IS.
ities.   These  are  the  com-
mon iliacs, from  being near
the  ilium, and each  of them
soon subdivides into  the Ex-
ternal and Internal Iliac, the
latter of which  supplies the
greater  portion  of  the  leg
Avith  blood.    As  soon as  it
passes over the  pubis it be-
comes the Femoral  Artery,
Avhich at first  is quite exter-
nal, lying just  beneath  the
skin and upon the pubis ; but
as it passes down the femur it
plunges deeper and deeper into
the soft  parts until it appears
behind the knee, where it re-
 ceives the name  of  the  Pop-
 liteal Artery.   This is only a
 few inches in length, and  at
 the  upper extremity  of  the
 tibia divides  into the Anterior
 and Posterior Tibial Arteries.
 The  former  runs  along  the
 inner side of the tibia  and
 over  the tarsal bones,  until it
 reaches  the metatarsus, Avhen
 it becomes the Dorsalis Pedis,
 Avhich  gives  off branches  to
 Lower End of the same Artery on the Popliteus Muscle.  3, Point of Bifurcation into the
 Posterior Tibial and Peroneal.  4, Superior Internal Articular Artery.  5 Superior In-
 ternal Articular Artery.  6, Middle Articular Artery-  J>™°™ 'f 7tt So e   Mu -
 tery  S, Inferior External Articular Artery. 9, Branch to the Head of th» S^ns Mus
  1^ 10 Origin of the Anterior Tibial Artery  U, Orldn of the P«^,^»l A-t.^.
 12, Point where it passes behind th. Annular U*™*£» ^» " lsIu ar Br,„  Les.'
 15, Muscular Branches.  16, Origin of the Peroneal Arteiy. 1., 1<,  ^scula
 is! 13, Anastomosis of the Posterior Tibial and Peroneal Arteries  near the Heel. 19,
 Muscular Branch  from the Anterior Tibial._______^_________________.---------
 -^TAVh^dothe commonllhTc-ATIeVies become  as soon  as they cross th.  pubis?
 Givo tho loeation of the Femoral, Popliteal, Tibial, r.nd Dorsali* P,du Aitery.
  A A'iew of the Arteries on tho Back of
the Le^  The Muscles have been removed
so as to display the A'essels in their whola
length.  1, The Popliteal Artery, cut off
so as to show the Articular Arteries. 2i 
214
HITCHCOCK'S  ANATOMY
each of the toes, and supplies the upper part of the foot with
blood.   The Posterior Tibial Artery follows  upon the  back
side of the leg a corresponding course to the anterior tibial,
and supplies the sole of the foot and toes Avith blood.
   376.  Capillaries.—The arteries just described area few
only of the principal ones, since at nearly every inch of  their
course larger or smaller vessels are given off according to the
                          Fig. 217.
nature of the part to be supplied with blood, and, with a few
exceptions, such  as the one in the  head .(circle of Willis),
they all terminate in minute vessels called Capillaries.
   377.  Diameter  of Capillaries—Functions  Performed
in  them.—These are minute tubes sioth to  ooVoth  of an
inch in diameter, and are always the terminations of arteries.
They are of a uniform size, and very regular  in the distribu-
  te. IIow do nearly all the arteries terminate? Where is the only exception? 377.
State the diameter of the Capillaries.  AVhat of their uniformity ? 
AND   PflYSiOLOG?


            Fig. 218.
215
  A Front View of the relative Positions of the Veins and Arteries of the Face and Neck.
On the Eight side the Superficial Ve>sels are seen, and the Deep-seated ones on the Lett.
1, Primitive Carotid Arteries.  2, Superior Thyroid Arteries.  3, Internal Jugular A ems.
4, External Jugular Veins.   5, A Branch known ns the Anterior Jugular A ein.  6, Nipe-
perior Thyroid Veins.  7, Facial Arteries.  8, Facial Veins. 9, Zygomatic Branch of the
Facial  Artery.   10,  Nasal  Branch of the Facial Vein.   11, Anastomosis ot the Facial
Artery and Vein with the Ophthalmic Artery.  12,  Venmrs Arch above the Kose.  L,
Frontal Vein.   14, Temporal Vein.  15, Temporal  Artery.   16, 1 rental Branches ,,i
fhe Temporal Artery and Vein.  17, Infra-OrWtar Vessel,  1J *f*™nn£°*™*
Of the Temporal Vein. 19,  20, Venous Anastomosis around the L) e-Lids.  Zl,  1 rental
Branches of tho Ophthalmic Vessels of Willis.
                                     10 
216
HITCHCOCK'S   A N A TOMY
tion of  their branches,  Avithout any increase  in their diam-
eter.   The only exception to this is where red blood is not re-
            Fig. 219.               quired for the nourishment of
                                  the  parts ; as in the Avhite of
                                  the  eye,  the finger  nails, the
                                  tendons,  etc.,  where  the ca-
                                  pillaries  are too small to alloAV
                                  the corpuscles of blood to pass
                                  through  them.    And  yet in
                                  many of the capillaries we find
                                  their  size  to be so small that
                                  the corpuscles  could  not,  if
                                  unyielding,   pass   through.
                                  But  this  is  readily  accom-
                                  plished in  most cases  by the
                                  flexibility  of  the  corpuscle,
                                  which permits  itself  to  be
                                  doubled up to such an extent
                                  that it will easily pass through
                                  a tube much smaller than its
                                  normal diameter.   In the ca-
                                  pillaries  the  important  pro-
                                  cesses of secretion, nutrition,
                                  and the  production of a por-
                                  tion of animal heat take place ;
                                  so  that  there is no place in
                                  the  Avhole  body  except  the
                                  outer coat of the eye, the ten-
                                  dons, the  nails,   and  white
                                  portions  of the body  gener-
                                  ally Avhere true capillaries are
                                  not found.
  A View of the ATeins of the Trunk and
Neck.  1, The Descending Vena Cava. 2,
The Left Vena Innominata.  3, The Eight
Arena Innominata.  4, The Eight Sub-Cla-
vian Arein.  5, The Internal Jugular Vein.
6, The External Jugular.  7, The Anterior
Jugular. 8, The  Inferior Arena Cava. 9,
The External Iliac Vein.  10, The Internal
Iliac Arein.  11, The Primitive Iliac Veins.
12, 12, Lumbar Areins.  13, The Eight Spermatic Vein. 14, The Left Spermatic Vein.
15, The Eight Emuljrent Arein.  16, The Trunk of the Hepatic A'eins.  17, The A'ena Azy-
gos. 18, The Hemi-Azygos.  19, A Branch communicating with the Left Eenal Vein.
20, The Termination of the Hemi-Azygos in the Vena Azygos.   21, The Superior Inter-
Costal Vein.
Where are true capillaries not found? What takes place in them? 
AND   PHYSIOLOGY.               211
Fig. 220.
   378.; The Veins—Their Coats—Their Volume.—The Veins
carry the blood from all parts of the body to the heart.  Like
the arteries, they have three coats, and the larger veins follow
the same general course as the  large  arteries.  The  smaller
veins, hoAvever, are much more numerous than the smaller ar-
teries, and  are  most  abundant just beneath the  skin.   The
whole ATolume of the Areins may be regarded  as a  large  cone,
with the base at the surface of the body and the  apex at the
heart, so that in these vessels  the blood is continually fioAving
faster and faster, in consequence  of the  fluid  coming into  a
larger channel from small extremities, Avhile the reverse  hap-
pens in the arteries.   The veins are much  thinner  in struc-
ture than the arteries, so that after death  they most usually
collapse.    (See Fig. 218, p. 215.)
   379.  Location of the larg-
er Veins—Sinuses.—As al-
ready  mentioned,  the larger
ATeins  usually  lie   near  the
larger   arteries.    Both   also
frequently   have   the   same
names.   But there  are  sev-
eral remarkable exceptions to
this, as in the vessels of the
brain.   Here  are  but   feAV
veins, but  several sinuses or
channels.   These  are canals
excavated  in the  dura mater
of the brain Avith  this  mem-
brane for  an outer  coat, and
the serous  layer  of the true
 veins for an inner coat.  These
run in different directions on
the inside  of the  skull, and
                                  Pinnses of the Base of the  Skull.  1,
                                Ophthalmic Areins.  2, Cavernous Sinus.
                                3, Circular. 4, 6, Inferior Petrosal. 5, 9,
                                Occipital  Sinuses.  7, Internal Jugular
                                Vein.  ^_________
IriTTVhat course does the blood take in the" veins ? Give the eoa.s of the veins.
What is the relative proportion of small Veins and small arteries?  AVhat is sai.l of their
aggregate volume ? 379 Where are the larger veins usually found ? What are Sinuses,
and where are they found ? 
218           HITCHCOCK'S   ANATOMY
most of them empty into  the great veins of the neck.   Their
probable service is to afford a free passage of blood  from the
brain, even if by excess of arterial action this organ  should be
overcharged with blood.
   380.  Portal  System—Use of the  Portal  System.—An-
other apparent exception  to  the ordinary system of veins  is
seen in  what  is  called  the  Portal System.  This comprises
those vessels  which receive their  blood from  the  intestinal
canal, the  stomach, and the spleen.   As these small vessels
unite into  a larger trunk, instead of passing directly to the
heart, they form what is called the Portal Vein, which  emp-
ties itself into the  liArer.   This vein ramifies into every part
of the liver, where the blood is again collected  by a series of
vessels Avhich   unite into  several  trunks, called  the  Hepatic
Veins, and Avhich convey the blood to the heart.   The design
of this arrangement is not certainly known as  yet, although
it is probable  that the blood which returns from  the alimentary
canal is not fitted to enter the general circulation until it has
gone through  some change in the liver.
           fig. 221.                381.  Origin  of the Veins
             (*                  —Valves—Their Discoverer.
                                —The Veins all take their ori-
                                gin in the capillary vessels in
                                every part of the body except
                                those of  the  stomach, and in
                                number  and length of tube
                                greatly exceed   the vessels of
                                the  arterial system.  In the
                                lining membrane of  the veins,
                                also, we  find   a peculiarity
                                not presented in the arteries.
                                This is the presence of  folds,
                                so  that pouches or  bags are
formed, which readily  suffer the Aoav of blood toAA^ards the
  Of what especial service are they? 3S0. Describe the Portal Sy.stem.  AVhat is the
probable use of so marked an exception to the general circulating System ? 3S1. Where
do the Veins take their origin ?  AVhat is said of tho Valves of the Veins ?
 Vein laid open to show the Valves
Vein,  b, A'alves. 
AND   PHYSIOLOGY.
219
heart, but almost entirely pre-               Fig. 22-2.
vent its passage in  an  oppo-
site  direction.   They  act in
the same manner as valves in
machinery,  although with no
loss from friction, and conse-
quently no necessity of a lu-
bricating  fluid.    It was the
discovery  of  these  valves in
the veins  Avhich  led Harvey,
an English physician, to the
greater discovery of the cir-
culation of the blood.   He in-
ferred  that  the  blood  could
pass   in  but  one   direction
through the veins, and conse-
 quently in the opposite direc-
 tion through  the arteries.
    382. Inosculation — Use
 of Anastomosis.—The  arter-
 ies and veins open  into each
 other (i. e., their OAvn vessels)
 very  frequently,  allowing  a
 ready  flow  of blood from one
 vessel to the other, even if the
 flow does not b appen to be in the
 most favorable direction from
 the center of  circulation to the
                                      The Superficial  A'eins on the Front of
 Hie Upper Extremity.  1, Axillary Artery. 2, Axillary Vein.  3, Basilic A'ein where
 it enters the Axillary.  4, 4, Portion of the Basilic Vein which passes under the Brachial
 Fascia-a portion of tho A^ein is freed from the Fascia.  5, Point wl.ere the Median Ba-
 silic joins the Basilic Arein.   6, Points to the Posterior Basilic Vein.  8, Anterior Basilic
 Vein. 9, Point where the  Cephalic enters the  Axillary Vein.  10, A portion of the same
 Vein as seen under the Fascia; the rest is freed from it. 11, Point where the Median
 Cephalic enters the Cephalic Vein.  12, Lower portion of the Cephalic Vein.  13, Median
 Cephalic Vein.  14, Median Vein.  15,  Anastomosing Branch of the Deep and Superficial
 Veins of tho Arm.  16, Cephaliea-Pollicis Vein.  17, Sub-Cutaneous A ems of the Fin-
 gers.  1^. Sub-Cutaneous Palmar A'eins._________________________________________.
                  Who  discovered the circulation of the blood?
 
220
HITCHCOCK'S   ANATOMY
            Fig. 223.               extremities.   This relation of
                                   parts  is called Inosculation or
                                   Anastomosis.   This arrange-
                                   ment  gives a plentiful supply
                                   of blood to every part  of the
                                   body,  if, by AA'Ound or pressure,
                                   the ordinary channel of blood
                                   to  any  part  should  be  ob-
                                   structed or  completely closed
                                   up.     Inosculation   is  most
                                   abundant in the veins and su-
                                   perficial arteries, since  these
                                   are most liable to be thus  im-
                                   peded.
                                      383. The  Blood — Micro-
                                   scopic  Structure — Plasma
                                   or Serum—Red Corpuscles—
                                   White  Corpuscles—Propor-
                                   tion of one  to  the  other.—
                                   The blood of the  human sys-
                                   tem amounts to about eighteen
                                   pounds, or nearly ten  quarts.
                                   Is has a specific gravity a  lit-
                                   tle greater than that of water,
                                   is of a bright scarlet color if
  The Arteries and Deep-seated Veins on
the Back of the Leg. i, Popliteal Vein,   drawn from  an artery, or dark
2, Popliteal Artery   3,4, Vein and Artery        j  if taken f          •
in their relative Position on  the Back of   Jr   I                            J
the Knee-Joint.  5, Popliteal A'ein on the   Avith a taste  slightly alkaline,
inner Side of the  Joint.  6, Popliteal Ar-      -,       -,          , ,.     .   '
tery without and beneath it.  7, Extremity   and an odor resembling that
of Saphena Minor A'ein. S, 9, Internal Ar-
ticular A'essels, both Arteries and  A'eins.  10,11, External  Articular Vessels, both Ar-
teries and Veins.  12, Junction of the Peroneal and Posterior Tibial A'eins.  13, A Ven-
ous Branch from the Anterior Tibial  A7ein.  14, A A'ein from  the  Gastrocnemius.  15,
Anterior Tibial Artery coming through the Interosseous Ligament.  16, Posterior Tibial
Artery.  17, Its two \rena3 Comites.  18,  Peroneal Artery.  19, Its two Vena3 Comites.
20, A'essels on the Heel.
  382. What is meant by Inosculation or Anastomosis?  AVhat is the service of anasto-
mosis?  In what vessels is it most abundant?  3S3. IIow much blood is there in a hu-
man adult?  State its color and odor. 
AND  PHYSIOLOGY.
221
Crystals from Human Blood.
of the breath of the ani-                Fig. 224.
mal  from which  it  i3
taken.    It   penetrates
every solid tissue of the
system, as may be knoAvn
by puncturing any part
of the body with  even a
pin, Avhen blood is sure
to follow.   If it  be ex-
amined  with  a  micro-
scope   when    freshly
drawn, it appears to be
made up of a transparent
liquid called the  Serum
or Plasma, and  a num-
ber of  minute circular bodies, mostly of a  red color, called
corpuscles, or minute bodies.   This fluid is found, on analy-
sis, to be. made up of albumen, fibrin, and several salts, some
of Avhich are found in distinct  crystals, as is  seen in  the cur.
 After it  has been drawn from  the body a considerable time, it
 separates into a thickened mass called Coagulum, made up of
                        fibrin  and  the corpuscles, while  the
                        serum with the albumen still  remains
                        as  a  transparent  liquid.  The Red
                        Corpuscles  prove to be flattened discs
                        with both  surfaces slightly  concave,
                        and measuring  about  Wooth of an
                        inch in  diameter,  and  are in reality
                        nothing but a cell, that is  a  bag or
                         sac containing a fluid composed of the
                         two proximate principles globuline and
 hematine.   Besides  the  red corpuscles, there  exists another
 kind in the blood known  as the White  or Colorless Corpus-
 cles.  They are by no means so abundant, Avhen the body  is

 ing a while in an open vessel i Describe the Bed Corpuscles.  Describe the White Coi-
 puscles.
  Eed Corpuscles of Human
Blood,  a, Seen on the Surface.
c, Seen in Profile,  b, Seen in
aEoll Magnified 400 Diameters. 
222
HITCH COCK:'S  ANATOMY
in health, as the red corpuscles.  But in certain diseases, and
especially if there be a Avound in any part of the  body to be
healed,  the white corpuscles  are developed  at  a great rate,
although their abundance ceases when the  system is restored
to a sound  state again.   Their  average diameter  is  nearly
goVoth  of an inch, and they appear to be nucleated cells.  The
proportion of the white to the red corpuscles in health is nearly
as 1 to  346.   The Avhole amount of blood corpuscles has been
estimated as  high as 65,570,000,000,000.
   384.  Effect  of an Alternate Exposure  to  Oxygen and
Carbonic Acid.—If the  red corpuscles are alternately exposed
to oxygen and  carbonic acid they lose their circular form,
and become corrugated or star-shaped, and finally are destroyed;
and it is calculated that  millions of these corpuscles are  de-
stroyed at each pulsation of the heart.
        FUNCTIONS  OF  THE  CIRCULATORY  SYSTEM.

   385.  The  Main Use  of the Blood-Vessels—The large
Angle  made by the  Arterial  Branches near the  Heart.—
The first and most obvious use of the blood-vessels is to allow
a free and rapid  passage  of  this  fluid to every part of the
body.   This is evident from the smooth  lining of all the ar-
teries and veins, and from the fact that, Avith the exception of
the large arteries near the heart, the vessels  branch  off  at  a
small angle  from each  other,  which  arrangement  offers the
least possible obstruction to the passage of the blood.   In the
organs near the heart, as the  head and lungs,  the  blood Avould
readily  pass by smaller vessels and by less force  of the heart
in sufficient quantity.  But in that case  the parts of the body
quite distant from the center  of circulation of the  blood Avould

  When are the white ones the most abundant?  State the approximate number of blood
corpuscles in one Individual.  .^4. AA'hat effect has an alternate exposure of oxysen and
carbonic acid upon these. ? IIow many are possibly destroyed at each pulsation of tho
heart 1 3S5. Give the use of the arteries and veins. 
AND  PHYSIOLOGY.             223
be  imperfectly supplied.   And  apoplexies  and  congestions
would be much more frequent than they now are in the vital
organs,  if the arteries did not  branch off at nearly a right
angle.
   386. AVhy  a  large  Amount  of  Arteries and Veins.—
The necessity for such a large amount of arteries and veins,
and their numerous connections Avith each  other, is  evident
from the  great  variety  and  extent  of the  tissues, and also
from the great liability to obstruction from inflammations, ac-
cidents, or even the ordinary compression of clothing.   But
arranged as these vessels are in the body,  it is a very difficult
thing by any mechanical means entirely to check the Aoav of
blood to any part.   But were it not for this  system of ample
inosculation the amputation of a  portion of the body Avould
 generally produce  fatal results.
   387. Comparative  Capacity of the Arteries  and Veins.
 —If all the arteries in the body were to be made into a single
 vessel, the capacity of it Avould  be much  less than that of a
 similar vessel made by the union of  all the  veins.  This  dif-
 ference in capacity will in part result from  the feebler char-
 acter of the forces  which propel  the  blood through the veins
 than through the  arteries, and  consequently venous  obstruc-
 tion could not  be  so  easily overcome as if  it Avere in the ar-
 teries ; and in order to compensate for deficiency in power, an
 increased amount of tubing is provided.
    388. Forces  of the  Arterial  Circulation.—The inquiry
 naturally arises,  What are  the forces that send the blood
 through the circulatory channels ?
    389.  Contraction  of the  Heart—Elasticity of the Mid-
 dle  Coat.—In the first place the  contraction of the  heart  is
 the most essential  force in driving the blood outwards.  This
 force has been  estimated at  thirteen pounds, though the re-
 Why do the arteries near the heart branch off at a la-go ande ?  3 6^ Why is there .,
ta£-an amount of arteries and veins ?  8s7 What is the "'"^^^ £ ^
veins and the arteries ?  3S8. AVhat are the forces of the c.rcilation ? 389 What
If the contraction of the heart?  What is the estimate ot the lorce that xtexuU!
                            10* 
224
HITCHCOCK'S  ANATOMY
suit can not be relied on for perfect accuracy; and that this is
no inconsiderable force may be inferred from the great amount
of resistance that is offered to this current from  the ramifica-
tions of the smaller arteries, Avhereby the velocity is increased
as Avell as the surface of resistance.  It may also be seen by
Avounding an  artery of  medium  size, when the blood is sent
out  in jets, and sometimes  to  the  distance of several  feet.
This, however, is  not  the whole  amount of the  propulsive
force in the arterial system, for the middle or elastic coat as-
sists by a secondary action.  When the ventricle contracts or
the  heart  beats, the blood is driven into the  aorta and its
larger branches with so much force, that the middle coat yields
considerably, and the artery is distended beyond its ordinary
size.   As soon as the contraction of the ventricle  ceases, of
course the blood is forced back towards the heart by the elas-
ticity of the artery.   But as soon as  it commences to Aoav to-
wards the heart the semi-lunar valves close at once, prevent-
ing the floAV in that direction,  so  that the whole force of the
artery is expended in driving the blood towards the extremities.
  390.  Pressure  of  the  Muscles.—Another   power Avhich
aids in the propulsion of the arterial blood is the pressure of
the muscles upon the arteries.   This  is  effected by the en-
largement Avhich always takes place in the belly of the  mus-
cle  Avhenever it is used.   This is not a constant power, acting
only during exercise of the muscles.
  391.  Forces  of   the  Venous  Circulation.—The agencies
by Avhich the blood is returned to  the heart are not  so avcII
known as  those just considered.  The valves  in  the lining
membrane of the veins seem to be a contrivance to supply the
deficiency of poAver to drive the blood back.
   392.  Pressure   of  the Muscles. — The pressure  of  the
muscles, without  doubt,  is  another important impulse in

  When can the forces of tho circulation in arteries be well seen ?  How does the mid-
dle coat assist in this work? Of what use are the  semi-lunar valves?  390.  IIow does
the pressure of the muscles aid in the circulation?  391. IIow do the valves aid in the
venous circulation ?  392. Does muscular pressure aid in this? 
                   AND  PHYSIOLOGY.              225

aiding the return  of blood towards the heart.   For, as in the
aorta, its  elasticity forces the  blood, first against the semi-
lunar valves and  then omvards through  the  arteries, so the
muscles,  pressing  upon  the veins,  urge  the blood  into the
pouches or vah'es on their  inner coat,Avhich, preventing re-
gurgitation, assist  in returning it toAvards the heart.
   393. Respiration.—Respiration  is  another  cause  that
greatly aids in emptying the veins.   In some persons  a dis-
tinct fullness  or pulsation of one of  the veins of the neck  is
noticed during each inspiration.   This  is produced by the
partial vacuum made by  the act of inhaling air ; that is, as a
pressure is produced on  all parts of the  body by the atmos-
phere,  not only a rush of air is made into  the mouth, but the
blood is forced into the heart by the same cause.   And could
we examine all the large veins of the body during inspiration,
without doubt we should see the blood returning rapidly  in
them at each inhalation of air.
   394. Affinity  of Venous  Blood for  Oxygen—The affinity
or desire  of venous blood for the oxygen, and the arterial for
the tissues, are important causes in the  circulation, and es-
pecially in the capillaries.   It  is a principle Avell  knoAvn  in
physics, that if tAvo fluids of different degrees of affinity for a
third fluid meet each other in a capillary  tube, the fluid hav-
ing the strongest  affinity for  the third substance will  either
partially  or wholly force out the other fluid.   This takes place
equally well through porous substances, membranes, or capil-
lary tubes.
   395. So that when pure air is present  upon one side of the
membrane of  the  lungs  and A-enous blood on  the  other, the
latter u-ges itself onward to meet the oxygen, and thus force?
that Avhich is already purified into the pulmonary vessels, and
thence into the heart.
   396. The  same  thing is seen in  the capillaries of tho ex-
  393. How does the respiratory act aid the circulation of the blood? 894. !"...■.. dooi
chemical affinity aid in the circulation ? 
226            HITCHCOCK'S  ANATOMY

tremities, where  the  arterial blood, by its  affinity for the
healthy tissues, forces along that which is already surcharged
with carbonic acid into the systemic veins.
   397.  Forces  of the  whole  Circulation.—The forces, then,
which propel the blood through the whole system may be thus
briefly summed up :
               1. Contraction of the heart.
               2. Elasticity of the  arteries.
               3. Capillary force.
               4. Muscular pressure.
               5. Act of inspiration.
               6. Arterialization of the blood.
   398.  Course of the Blood  through  the  Body.—As  al-
ready mentioned, the ventricles  are the propelling and the
auricles the receiving  cavities.   Hence, in tracing the course
of the blood through the body,  beginning with the left ven-
tricle, we find the current passing through  the  aorta and  ar-
teries to all parts of the body except the lungs.  As  soon as
it has gone  through the capillaries it returns  to the  right au-
ricle by  the different veins, from which cavity it passes to the
right ventricle, and thence to the lungs.    After it has received
its due  supply of oxygen, it is  received by the left auricle,
from which it passes again to the whole  system.  The  parts
of this circle and their order  are as follows  : left ventricle, ar-
teries, capillaries, veins, right auricle, right  ventricle, lungs,
and  left auricle.  Thus we see  that the  Avhole circulation in
man and all  mammalia follows through the body a course
represented by the figure  8.
   399.  Relative  Time Occupied  by  Contraction  of Au-
ricles and  Ventricles.—The diastole or dilatation of auricles
and ventricles occupies a longer period of time than the cor-
responding  systole, or contraction.  If  we divide the whole
 397. Givo a synopsis of the circulatory forces. SOS. Give the course taken by the
blood as it circulates through the body.  By what figure may it be represented? 399.
What is the systole and diastole of the heart ? 
AND   PHYSIOLOGY.             227
Auricles.
Ventricles.
 Diagram showing the relative Time occu-
pied by the Contraction of the Auricles and
Ventricles, the converging lines from left to
right indicating the contraction, and tho di-
verging ones the dilatation.
portion of time occupied by one pulsation into eight intervals,
we shall find that the  auricles employ only one of these  in-
tervals in contraction, and the remaining seven by dilatation;
while the time occupied by the
contration of the ventricles is
the same as their dilatation, as
may be seen in the diagram.
   400. The Sounds  of the
Heart— lause  of the  First
and  Second  Sound.—If the
ear be applied over the heart
of  a  healthy  person, two
sounds  will  be  heard, one
of which corresponds in time
with  the  pulsation   noticed
 at the wrist,  or any other
 large  artery  of the   body.
 These sounds  do not  corre-
 spond to  each other  in intensity or duration,  but are some
 what indefinitely represented by the sounds given to the mono-
 syllables  "lub"  and  "dup;"  the first a  long  and heavy
 sound, and the second a short and light one.   The first sound
 is undoubtedly caused by  the  contraction  of  the heart, the
 rush of blood,"and the impulse of  the  organ against the  side
 of the chest;  while the second is  the clicking of the semi-
 lunar valves as they close at the commencement of  the aorta
 after the ventricular contraction.  That the last sound is due
 to this cause is proved by an experiment performed on a dog,
 of introducing a hook through the aorta, and holding back one
 of these valves, when the second sound entirely failed.
    401 Number  of  Pulsations per  Minutc.-The  number
  of pulsations of the heart varies considerably at different pe-
  riods of  life.   Thus the following table shows  the average
  number of pulsations each minute at different  ages^_________



  it? 
22S           II I T C II C o CK'S  ANATOMY

          New-born infant....................1110   to  140
          During the 1st yuar..................115   "   130
           "    "  2d  " .................100   "   115
          From the 7th to the 11th year........  80   "   90
             "   14th  "  21st  "  ........  75   "   85
             "   21st  "  GOth  <;  ........70   "   75
          Oldage...........................  75   "   80
   402.  Causes affecting  the  Pulsations.—Muscular exer-
tion  has a considerable influence upon the rapidity of the con-
traction of the heart.  So  also  has the position  of the  body,
Avhether sitting, lying, or standing.   The  time of  day  or
night likeAvise has an important influence, the highest number
of pulsations  being found  at noon,  and the feAvest  at mid-
night.
   403.  Use of the  Corpuscles.—The function  of the Red
Corpuscles seems to be to convey oxygen to the tissues, and
as this is the agent Avhich is continually promoting the change
or waste of the system, these corpuscles seem to be the great
agents for disassimilating the tissues and the blood itself. The
colorless or white corpuscles seem to  be  the agents by Avhich
the repair of the body is effected, since they  are  greatly aug-
mented in number Avhen there is a large Avound  to  be  healed,
or Avhen there is a great amount of internal  or  external  in-
flammation.
   403a.  Statistics.—In an ordinary life of a man the  heart
beats at least 3,000,000,000  times, and  propels  through the
aorta one half a million tons  of blood.
               HYGIENIC   INFEP„ENCE;3.

  404.   But  few  Diseases  of the  Circulatory Organs.—
1. Though the blood-vessels  are so constantly in use,  and  so
easily excited by every muscular movement and mental emo-
tion, yet they are affected  by only a few diseases, and many
  101. State the number of pulsations of the heart at different periods of life.  402. AVlmt
causes modify the number of the pulsations? 403. AA'hat is the probable business of tho
P.ed Corpuscles?  AVhat of the White? 404. Are there many -diseases of the Circulatory
organs? 
AND  PHYSIOLOGY.
229
of these affections, which seem to be diseases of the heart, are
merely  sympathetic, and the difficulty lies in other organs.
   405.  Avoidance  of  sudden Efforts.—2. But  those per-
sons Avho have  a tendency to diseases  of the heart, sympa-
thetic or  organic, should be  on  their  guard against  sudden
exertions, and, to as great  an extent as possible, avoid mental
anxiety and alarms.  Heart diseases  are most common late in
life, at  or about sixty years of age.
   406. Principal  Danger  from  Wounds.—Treatment  of
Wounds of Arteries.—3.  The principal  danger to be feared
from these organs results from Avounds.  If these are  in  the
arteries, they require prompt attention, but if in the veins,
they need scarcely ever excite fear.   If an artery be wounded
__avhich can always be knoAvn by the escape of blood in jet3, ^
and not a steady stream—the wound should be either closed,
or the  artery pressed upon between the wound  and the  heart
 with so much force as to  stop the  flow  of  blood  through it.
 In case of any such arterial wound it will  always be well to
 tie a bandage as tight as possible immediately over the wound,
 and then compress the artery as already mentioned.   If the
 wound be on the band or  forearm, the brachial artery may bo
 found  and compressed  just above the inner angle of the elbow.
 Or if it is desirable to compress the artery still higher up, the
 axillary artery may be found in the  armpit,  where by pressing
 outwards, nearly  all  the  blood flowing to  the arm  may be

  "  407 Method of  Checking  the  Blood to the Lower Ex-
  tremities .-4 If it is desired to check the flow  of blood to the
  lower  extremity, the popliteal artery lies directly against the
femur upon the backside of the knee-joint, where a compres
sion of it may be effected with great advantage.   Nearer the
heart (in the groin) the femoral  artery  is found, where  it
 405. ^natshouldthosepersons ^pos^ to these ^^f™ ^
guard against?  At what time of life are Ilea disc***            ^    ^


be cheeked in the lower extremities? 
230
HITCHCOCK'S  AX ATOMY
crosses the os innominatum lying just beneath the skin. Here
an  efficient compression  may be made,  since  all  the anterior
part of the thigh and the whole of the leg proper, is supplied
with blood from  this artery.
  408. 5. Except bad wounds, however,  a tightly draAvn band-
age, directly over the wound, thoroughly Avet Avith cold water,
will check  hemorrhage  sufficiently, until a  surgeon  can be
called.
            COMPARATIVE  ANGIOLOGY.

   409.  Heart of Mammals.—In all mammals  the heart  is
                                 divided  into  four  cavities,  as
            Fig. 227.              in man.  Its form, howeA'er, is
                                 more rounded and less elon-
                                 gated.   In one species of the
                                 Avhale this organ is cleft  in a
                                 peculiar manner, the division
                                 between  the  two   ventricles
                                 being indicated externally by
                                 a deep fissure in its apex. In
                                 the  Ox, Hog,  Sheep,  and
                                 Goat there are  always found
                                one or two bones  in  the di-
                                visions  betAveen  the  ventri-
                                cles.    In  most  mammals  it
                                is placed more in a right line
 Circulation in Man.  a. Right Auricle.    with  the  middle  of the body,
I. Eight Ventricle   ,, Left^ Auricle^ d.    an(]  n()(.      ob]iquely  a8  m
Lelt V entiicle.  e. Aorta, f. A ena Cava.                     1    J
(/.  Pulmonary Artery.  h.  Pulmonary    man.
A'eins.
 4:13. AVhat treatment will check all ordinary hemorrhages? 40'\ What is peculiar in
the heart of the AVhale, tho Ox, the Sheep, and Uoa.t,J  AS'hero is tho heart located it
quadrupeds 1 
AND  PHYSIOLOGY.
231
   410. Aorta and Pulmonary  Veins.—The manner in which
the Aorta and its branches are given off varies greatly in these
animals, as may be seen by the cut.   The number of Pulmo-
                           FlG. 228.
 A        BCDE       FGH
 Din-ram of tho Principal Varieties of the Aorta in its Principal Branches in a, Man ;
b, Elephant  c, Cetacea; d, Bat; k, Carnivora; r. Seal; o. Ruminants; n, Bcptiles.
1, Right Subclavian.  2, Right Carotid. 3, Left Carotid. 4, Left Subclavian. 5, Verte-
bral,  a, Ascending and b Descending Aorta.

nary Veins varies upon  the different sides of the body, and
is generally according  to  the  number of lobes  in the lungs,
the relations  of the sides being represented by the formula
3 + 2.
   411  Economy  of Diving  Animals.—In diving animals the
vena cava is capable of great dilatation, in order to contain an
unusual quantity of blood which accumulates there when the
animal suspends respiration under water,  since  it can not be
purified except in the lungs.   Still further protection to the
heart in divine  animals is seen  in the vena cava ascendens,
where a circular muscle, by its contraction, can completely cut
off the flow of blood to the heart
from the loAver extremities.
   412.  Blood  Corpuscles of
Mammals—Wonder Nets.—
   The blood of mammals, for
the  most part,  presents  small
round, disc-shaped corpuscles,
similar to, but smaller than those in man.
s$*.
           Fig. 229.




    B                A
 Red Corpuscles of the  Ox. A, In their
Natural State,  a, Seen in Profile,  b, Seen
on the Surface.  B, Altered Corpuscles.
            This is especially
 «7^w^■"•«*«»• «•** -1 i"iimonaTrins in ™uy mammals?  4U'
AVhat is the arrangement of the vena in diving animals? 
232
HITCHCOCK'S  ANATOMY
Fig. 230.
I V-r>V ,'ri:i2fc"'-./"I"-"' .   \/ t--^
true of ruminants.  The largest animals, such as the elephant,
have very small corpuscles.  In some of the camels and llamas
the corpuscles are  large and somewhat elongated.   The same
                                     is true of the dromedary.
                                     Crystalline  substances
                                     are found in the blood
                                     of  other   mammals as
                                     well as man.   The an-
                                     nexed cut shows crystals
                                     from  the  blood  of the
                                     Guinea pig.
                                       The  distribution  ot
                                     the arteries of  quadru-
                                     peds is a subject of con-
                                     siderable  interest.    In
                                     grazing animals, which
     Blood Crystals of the Guinea Pig.         hold their heads low, in
addition to large arterial trunks, we find a great number of
very small ones, Avhich are exceedingly tortuous in their course,
called  " Wonder Nets."   This arrangement is to prevent a too
rapid flow of blood to the  head by the force of gravity, which
would  of necessity  take place Avhen the bead is  so constantly
in a dependent position.   A similar disposition is seen in the
limbs of the sloth and other animals which are  like  them in
tardiness of movement.   In  the fore-leg of the lion, ay here
great muscular  force is exerted, the main artery passes through
a perforation in the bone,  so as to secure it from obstruction
to the  floAV of blood by pressure of the rigid muscles.
   413. Heart of Birds.—The heart of birds is highly mus-
cular and of very largo size  in proportion to  the bulk of tho
body, and in general structure resembles the same  organ in
mammals.   The valves of the right ventricles, hoAvever, arc
supplied with a strong  band of muscular  fibers, which gives
  412. What is peculiar about the blood  discs or corpuscles of tho larger animals?
AA'hat is the form of nearly all of tbcin ?  In what animals ar c they oval ? AVhat aro
AA'onder  Nets, and why are they introduced?  413. AVhat is worthy of note with refer-
ence to the heart of birds ? 
AND   PHYSIOLOGY.
233
additional impulse to the blood as it is forced  into the  pulmo-
nary  arteries    The need of this arrangement is to give a full
supply of  blood to the  lungs, which  the ordinary poAYers of
the heart could not effect.
Fu. 231.
                          Arterial System of a Bird.
  A-teries of the Grebe,  a, Aorta,  am, One of its large Branches.  It gives off tl.o
Cattid («c) and Subclavian, is ultimately distributed ^^^^^^t
corresponds to  the mammary arteries ot mammals   av. One o "Yom" formed ,
Vertebral Artery supplying the Muscles of the Shoulder. ^ At^^^Zy^.
the Branches.., the External Carotid,  al.  Lingua 1 A e.    , T..,cIn.  «      M^
ar, Renal Arteries,  ai, Isel.iatic Artery proceeding to the 1»«m  cxtem ti      ,
ral Artery, forming a continuation of the Aorta, and giving origin to the lnfei.or M-
teric Art.-ry, etc.  cf, The Cloaca._________________________------------------
 '         "        Why uo the valves have au especial muscle ? 
234
HITCHCOCK'S  ANATOMY
Fig. 232.
   414. Arteries—Wonder Sets.—The trunk of the aorta is
very short, and after giving arteries to supply the heart it di-
vides at once into  two  large branches, quite unlike the  con-
formation in  mammalia.    Wonder  nets, too,  are often found
in birds,  and especially in those arteries supplying the  brain,
eyes and  legs.
                                    415. Blood.—The blood of
                                  birds  has  the highest  tem-
                                  perature  of   the vertebrate
                                  animals—110° F.  The blood
                                  cells,  or  corpuscles, are al-
                                  ways of an elliptical form and
                                  of a very uniform diameter.
                                    416. Heart of Reptiles.—
The heart of reptiles ordinarily consists of a single  ventricle,
            Fig. 233.                         Fig. 234.
®
©
  Pigeon's Blood (red) Corpuscles Magni
fled 400 Diameters. A, In Natural State
B, Altered by Acetic Acid
                              Blood Corpuscles of the  Frog, 4Ui> Diameters.
                            A, In Serum,  a, Fully Developed, b, Nucleus
                            with clear contents.
                            or propelling cavity, and two auri-
                            cles, or receiving cavities, so  that
  circulation in Reptiles, a, Heart, the pure  blood  is mixed with  the
b, ventricle,  c, c, Auricles.       impure (or a portion of it) as  it
comes from the lnngs,  which accounts in part for the general
sluggishness of these animals.   The  blood corpuscles of rep-
tiles are large and oval, as may  be seen in Fig.  234.

  414. Into how many branches  does the aorta at once divido ?  Where are wonder nets
found in birds?  415. What is said of the temperature of birds? AVhat of blood.-cells ?
416. Describe the heart of reptiles. What is the effect upon the blood?  AVhat is the
size of their blood-vessels ? 
AND  PHYSIOL OGY.
235
   417. Blood-Vcsscls.-The  arrangement of Blood-Vessels
is very diverse, since one portion of them breathe by gills and
another by lungs,  while frogs in their early condition are fur-

                              FlG. 235.
Arches of
the Aorta. \
 Right
Auricle. ~*v
Superior
 Vena  -
 Cava.
A'entral
Aorta.
Pulmonary ^
  Arterv.  ~i—^
   Inferior <-
    Vena  r—■
    Cava.
Liver and
  Vena
 Portaj.
 Carotid
''Artery.
Kidneys.


 Ventral
 Aorta.
Circulatory Apparatus in the Lizard.
417. Why are blood-vessels arranged differently in many of the reptiles ? 
23G
HITCHCOCK'S  ANATOMY
up

vd
rp
nished with the former, but in adult age, after passing through
a metamorphosis, have the latter system of respiratory vessels.
           Fig. 236.                 418. Heart  of  Crocodile.
                                 —Crocodiles and turtles ex-
                                 hibit the most perfect form of
                                 heart,  for it agrees essentially
                                 with that of mammals, as may
                                 be seen in Figs  236 and 237.
                                 But there is a small  opening
                                 just at the  outlet of the  two
                                 ventricles,  so that  the  pure
                                 and impure blood is mixed.
                                   419.  Portal   System. -
                                 Reptiles have  a double Portal
                                 System,  one  set  of vessels
supplying the kidneys and another  the liver.
   420.  Lymphatic Hearts.—Many reptiles have small sac-
like organs lying just beneath the skin in certain  portions of
the  body, which, from their containing lymph and  showing
                            Fig. 237.
                             t
 Heart of Crocodile. ■»;, A'eins. ao, Right
Auricle,  vt. A'entricles.  ap, Pulmonary
Arteries, a, A Vessel proceeding from the
Arentricle to the Aorta.  017, Left Auricle.
Pulmonary Artery.^

  Pulmonary A'ein.-
    Right Auricle.
        Vena Cava.
Left Arch of the Aorta.
Right Aorta.
Pulmonary Artery.

Pulmonary Vein.

Left Auricle.
Single Arentricle.
Ventral Aorta.
Heart of the Turtle.
pulsations,  are called Lymphatic Hearts.   In the  Frog, two
such hearts are  situated on the back of the animal, betAveen
the joints of the thigh bones.
 418. AVhat animals of this class have the most perfect form of a heart ?  419. AA'hat kind
of a portal system do we find among reptiles ? 420. Describe lymphatic hearts. 
AND  PHYSIOLOGY.                237
Fig. 238.
   421. Heart  of Fishes.—The heart consists of one auricle
and  one ventricle, which  are  covered  by a pericardium, and
the Avhole organ is very small in proportion to the size of the
whole body, being from ^l^th.
to T¥'0- oth its weight.   In the
osseous  fishes the  heart  is        /
elongated and conical, Avhile        \
in the Sharks and Rays it is         \
broader.   The ventricle dis-      „
charges its blood through the
aortic trunk upon the  gills.
This trunk  divides  up into
a large  number of  minute        /"
branches which  ramify upon
the gills, and after the  blood
has received its  oxygen from
the  water, it  is  collected by
a corresponding  set of ves-
sels,  and emptied into another
trunk Avhich supplies all the
rest of the body—which trunk
corresponds  to  the  aorta—
though  it has no  muscular
power to propel  the  blood along.   After it has performed its
office it  is collected by a system of  vessels  similar to veins,
and  returned to  the auricle.

   422.  Pulsations  in  a  Minute.—Commonly not more than
 twenty or  thirty beats in a minute  may be counted in fishes,
 while in birds  one  hundred  may be counted  in  the same
 time.
   423.  Portal Circulation—In fishes, as in  reptiles, there
 seems to be a  double portal circulation.
 Circulation in  Fishes,  a, Heart,  b,
Auricle,  c,  Ventricle.   </, Circulation
through the Gills, or Lesser Circulation.
g.  Circulation  through  the Body,  or
Greater Circulation,  e, Arteries, f, A'eins.
 421  Why is the heart of the osseous fishes called a branchial heart ?  W hat proportion
of the body does it constitute ?  Give the course of circulation.  422  W hat number of
pulsations can be counted in the heart of fishes, and what number in birds ? 
238
       HITCHCOCK'S   ANATOMY

                    FlG. 239.

Branchial Artery. ^
 Arterial Bulb.
Ventricle of the
    Heart.
 Auricle of the
    Heart.
 Venous Sinus.
Vena Porta?,
 Liver, &c.
Intestine.
Vena Cava.
Dorsal Artery.
Kidneys.
Dorsal Artery, or
    Aorta.
                   Circulating Apparatus of the Fish.
   424.  Accessory  Hearts — Caudal  Heart.—Among many
fishes are found what are termed  Accessory Hearts, or small
muscular organs which seem to aid in the propulsion of blood
through the different parts of the body.  Thus, in the myxine,
the portal vein is distended  into a large  sac, which expands
and  contracts alternately;  and  in eels there is found upon
424. What are the accessory hearts of fishes ? 
AM)  PHYSIOLOGY.
239
both sides of the last caudal vertebra a pulsating organ which
receives the blood from the  delicate veins of the caudal fin,
and propels it into the  caudal vein, this  constituting a true
caudal heart.
   425.  Fishes'  Blood.—The blood of
fishes, almost without exception, is of a
red color, and contains oval and slightly
bi-convex  corpuscles.   In  one  family
they  are distinguished  by  their great
size, and thus resemble those of frogs;
but other families have  smaller ones.
                      Fig. 2-11.
                  Smaller  Circulation.
FlG. 210.
  Blood Corpuscles  of a,
Lamprey Eel; b, Skate.
   Branchio-Cardiae
^\  Canals.
Heart.
Arteries.
      Greater Circulation.
Diagram of the Circulation in Fishes.
   426.  Dorsal  Vessel,  or Heart  of Articulates.—In ar-
ticulata, a vessel or tube passes along the back of the body—
behind the intestines and in front of the chain of ganglia—
called the Dorsal Vessel, which is divided into as  many por-
tions as there are segments of the body.   This  is really the
  AA'hat peculiarify in the tail of the eel ?  4.5. AA'hat is the color of fishes' blood, and
what are its corpsucles?  426. AVhat is the Dorsal Vessel of articulates?
                             11 
240            HITCHCOCK'S   ANATOMY

                             Fig. 242.
  Circulatory Apparatus in the Lobster,  a, The Heart,  b, Ophthalmic Artery, c, An-
tennar Artery, d, Hepatic Artery,  e, Abdominal Artery.  /, Sternal Artery,  g, Venous
Sinuses,  h, Branchim.
heart of the animal, since by the  contraction  of its coats the
blood  or contained  fluid is forced along.   Small  arteries are
given oflf from this  dorsal vessel  all  along its course.   This

                              Fig. 243.
  Circulation In Insects,  a, Dorsal Vessel,  b, Principal Lateral Currents.  The Arrows
show the direction of the Fluid.
plan, however, is seldom completely carried  out,  but  is most
fully exemplified  in the class  of insects which is partly ex-
hibited in Fig. 243. 
AND  PHYSIOLOGY.              241
    427.  Ventral  Trunk .—The blood which is driven forwards
 ;by this dorsal A^essel is collected by a set of vessels which unite
 into a large tube called the  Ventral vessel, or trunk, which
 returns it to the posterior part of the body.

    428.  Blood  of Articulates.—This fluid called  blood is  a
 thin  liquid, yellowish brown, red,  green,  or  even colorless,
 and never containing corpuscles ;  and the  only reason Avhy it
 is called  blood is,  that it  circulates  like the blood of the
 higher animals.

    429. Chylaqueous Fluid.—But  besides this fluid there  is
 another found in tho general or abdominal  cavity of the body,
 which, though not contained in organs  expressly designed for
 its  circulation,  yet  is rapidly  carried thiough the  body by
 means of the motion of  the  different segments of the animal,
 Avhich in  many  of this order is incessant.   This fluid, unlike
 the true  blood, is rich  in  corpuscles and  easily coagulated,
 Avhich gives it one of the essential characteristics of true blood
 in the higher animals.   It, however,  must probably be re-
 garded as the cylaqueous fluid of many of the lower verte-
 brata.   Scorpions have arteries and veins.
   430. neart   and   Blood              Fig. 244.
 of  Crustacea.—Amongthe          A
 crustaceans, such as the crab   4&     w^
 and lobster, Ave find  a vessel   <|p
 much shorter than the dorsal          /gig*
 vessel  of  most  articulata,    &•     ^^
 Which resembles a heart from    Blood Corpuscles of the Crab. A, Granule
 the fact that it is a  propel-   Cells-  B' Nucleate'1 CelK
 ling organ and has muscular fibers in its coats.   The blood in
 these animals is of a Avhitish or purple color, and the pulsa-
 tions of the heart vary in number from fifty-one to two  hun-
 dred per minute.

 427. How is the blood returned that is circulated by the dorsal heart ? 42S. Describe
the blood of articulates. 429. AVhat other fluid is found in these animals ?  430. AVhat is
said of the heart and blood of the crab and lobstor ?
 
242
HITCHCOCK'S  ANATOMY
   431.  Circulation  in  Molluscs.—The  higher orders of
molluscs show a system of circulating vessels  which  seem to
be  arteries and veins, with a central  vessel  ansAvering to a
heart.   There  is  usually  a ventricle  corresponding  to  the
right ventricle in man, to send  the blood  to the  respiratory
organ.   There  is also another cavity which corresponds some-

                           FiG. 245.
 Anatomy of the Snail, a, Mouth,  b, Foot,  d, Lung, e, Stomach. /.Intestine, g,
Liver.  7f, Heart,  i, Aorta, j, Gastric Artery.  I, Hepatic Artery, k, Artery of the
Foot, m. Abdominal Cavity,  n, Canal conveying the Blood  to the Lungs, o, Vessel
carrying Blood from Lung to Heart.
what to  an auricle, which  receives  the blood as it enters the
heart.   But with the  exception of the vessels carrying blood
to the gills, there are  few separate tubes  for  carrying  this
fluid  through  the body, it being  left to circulate  by imbi-
bition, or it is  effected by means of the lacunar spaces, Fig.
245.
   432.  Blood  of  Molluscs.—The  blood of these animals is
generally destitute of corpuscles, and  is sometimes  colorless,
though often white, Ijrown, red, or green.
   433.  Contractions  of  the  Heart.—The heart  does not
 431. AVhat are the circulatory vessels In molluscs?  How is most of the fluid circu-
lated ?  432. What of the blood of molluscs ? 
AND PHYSIOLOGY.
243
expand and  contract  regularly,  but in a  spiral,  screw-like
manner, like the peristaltic motion of the intestines.
  434. Circulation in  the  Radiata  and  Protozoa.—In a
few polyps a vascular  system is quite obvious,  and  may  be
inferred in them all.   The blood is  colorless, and  has Avhite
corpuscles.   In the Acalephse there exists a circulating fluid,
which is thought by Agassiz and Dana to be merely water,
intended to subserve the purposes of respiration rather than
nutrition.  The Echinoderms have one heart, and sometimes
more.  The  Infusoria  have pulsatory cavities, but no  system
of circulation.
  433. IIow does  the heart pulsate? 434. AVhat is the plan of circulation among the
radiate animals ? 
CHAPTER   FIFTH.
PNEUMONOLOGY, OR HISTORY OF THE ORGANS OF BREATHING.
    —THE RESPIRATORY, VOCAL, AND CALORIFIC ORGANS.
         DEFINITIONS  AND   DESCRIPTIONS.

   435.  Location  of Respiratory  Organs—Sympathy  be-
tween the  Heart  and Lungs.—Within  the  thorax  are  con-
tained  not only the central organs of  circulation, but  other
organs closely related, and connected Avith them, the Respira-
Vein of the Arm. ^
Ei<rht Luns
Artery of the Arm.

A'ein of the Arm.
Left Lun<r.
  Lungs, neart, and Principal A'essels  in Man. oil. Ilight Auricle,  vd.  Eight
 Ventricle, vg. Left Ventricle,  a. Aorta, ac. Carotid Arteries, re. A'ena Cava.
 t. Trachea,  vj, Jugular A'eins.

 435. What organs are contained in the thorax?  What is  said of the sympathy be-
tween the respiratory and circulatory organs? 
ANATOMY  AND   PHYSIOLOGY.         245
tory.   These are not only related  by position, but are mutu-
ally dependent on each other for their action.  Thus,  if severe
disease affect the heart, the  lungs are very apt by imperfectly
or  irregularly performing  their  offices, to  show their sym-
pathy.   In  like  manner,   if  the  lungs  exhibit   disease,
sooner or later the heart  is sure  to  manifest its sympathy
with its  suffering neighbors.
   436.  The  Lungs,  their Shape,  their  Color,  Lobes  of
the Right  Lung, Capacity of the Right Lung, Amount of
                            Fig. 247.
  A View of tho Bronchia and Blood-Vessels of the Lungs as shown by T>is>.section
as well as the relative Position of the Lungs to tho Heart 1, End of the Left A
               -__  ~. . ^  ..■_,_ o ti.„ T./»r> Wnt.rielo With Its  \ cssus.
as well as the relative Position ot tne wings to u.o »™"- -. r,  "   ,t. Vessels
ricle of the Heart. 2, The Eight Auricle. 3, The Left Yentnc ewith  ts U« £
4, The Eight Ventricle with its Vessels.  5, The Pulmonary Art ,j  <,Arch oH«
Aorta. 7, Superior Vena Cava.  8, Arteria Innominata. 9 Left Pnmvhve Caiotid
Artery, io, Left Sub-Clavian Artery.  ^™°J™beT\^™°}?^J%£e
per Lobe of the Ei.ht Lung.  14, Upper Lobe of the Left Lung.  oT^nk of ho
Eight Pulmonary Artery.  10, Lower Lobes of the Lungs  Ihe Dis tibut^on of the
Bronchia and of the Arteries and A'eins, as well as some of tho Air-Cells ot tho mn0 .,
are also shown in this dissection. 
246             HITCHCOCK'S   ANATOMY

Blood  ill  each  Lung___The  essential  organs  of respiration
are the  Lungs.    These  are  light  solids, two in number, and
occupy nearly four fifths  of the  cavity  of the  chest.    They

                                 Fig. 248.
  An Anterior View of the Thoracic Viscera in Situ, as shown by the Eemoval of their
Anterior Parietes.  1, Superior Lobe of the Eight Lung.  2, Its Middle Lobe.  3, Its
Inferior Lobe. 4, 4, Lobular Fissures.  5, 5, Internal Layer of the Costal Pleura form-
ing the Eight Side of tho  Anterior Mediastinum.  G, 6, Tho  Eight Diaphragmatic Por-
tion of the Pleura Costalis.  7, 7, The Eight Pleura Costalis on the  Eibs.  8, Superior
Lobe on the Left Lung.  9,  Its  Inferior Lobe.  10, 10, Interlobular  Fissures.  11, The
Portion of the Pleura Costalis which forms the Left Side of  the Anterior Mediastinum.
12, The Left Diaphragmatic  Portion of tho Pleura Costalis.  13, Left Pleura  Costalis.
14,14, The Middle Space  between tho  Pleura), known  as tho Anterior Mediastinum.
15, The Pericardium.  16, Fibrous Partition  over which tho Plcuraj are reflected.  17
The Trachea.  18, Thyroid Gland.  19, Anterior Portion of  the Thyroid Cartilage.  20
Primitive Carotid  Artery.  21,  Subclavian A'ein.  22, Internal Jugular A'ein.  23, TSra-
chio-Cephalic A'ein. 24, Abdominal Aorta. 25, Xiphoid Cartilage.
436. AVhat are the Lungs? 
AND   PHYSIOLOGY.               247
are of a conical shape, the apex  pointing upwards, the base
resting on the Diaphragm, of a pinkish gray color, frequently
dotted  with black  spots,  and divided by  a deep  fissure into
two lobes.   The right lung is  shorter  in its long diameter
than the left, on account  of the  liver which raises the right
side of the diaphragm higher than the left.   The right lung
is subdivided again, so that it is  really made  up of three lobes
instead  of tAvo.  It  has  also a  larger capacity than the left,
since the  position  of the heart,  considerably upon the  left
side of the median line of the body, occupies a portion of the
left thorax.   Each of the lungs  ordinarily contains a pint of
blood.
   437.  Lobules of the Lungs.—A closer  examination  of the
lungs  shoAVS them to be made up of small  bodies called Lung-
lets. These are from T\th to y'^th of an inch in diameter,  and
of a conical or pyramidal shape.  They are much more clearly
defined in small children than  in adults.   Fig.  249,  by the
  A Lunglet with a Section of a Bronchial Tube,  of, Bronchus, b and c, Vessels of
Bronchial Lining Membrane,  d, d, e, e, Spaces between contiguous Lobules, contain-
ing Ihe Terminal Pulmonary Arteries and Afeins supplying the Capillary Plexus (//,)
to the Meshes of which tho air gains access by the Lobular Passages.

  Give their shape, color and division. AVhat aro the lobes of the lungs? AVhich is the
largest lung, and why the difference ?  437. How are the lungs made up? At what pe-
riod of life can the lunglets be best seen ?
                             11* 
248
HITCHCOCK'S  ANATOMY
hexagonal figure  surrounding the  bronchial  tube,  shows a
section of a lunglet, or lobule of the lung.
   438.  The Pleura.—Pleurisy.—Root  of  the Lungs.—The
lungs aro immediately invested with a serous membrane called
the  Pleura, Avhich is also the inner  lining  membrane of the
Avails of the chest:  so  that Avhen the lungs are fully inflated,
these tAA'O surfaces are brought in contact, and  in the act of
respiration move slightly upon each other.   And if any  por-
tion of these membranes becomes inflamed, the disease results
Avhich is known as Pleurisy.  In the acute or early stage of
this disease, if a long breath be  draAvn, intense pain is felt at
the loAver portion of the lung.   This is owing  to the  friction
of these  inflamed membranes  one  upon  the  other,  and  the
reason Avhy the pain is  severest in the loAver part  of the lung,
is that this part of the  lung moves over the largest space in
breathing.   Tho  vessels for supplying blood,  emptying it
and  nourishing the lungs, as Avell  as  the air-Yessels. nerves
and  lymphatics, are all  collected together  in  one bundle at
the inner side of these organs,  and are collectively called the
Root of the Lungs.
  439.  The Air Passages.—The A-essels Avhich are especially
designed for the purpose of conveying air into the lungs aro
the Larynx, from the Greek meaning a whistle,  since sound
is made in it—the Trachea, meaning rough, as  is its struc-
ture—the  Bronchia,  meaning the  Avindpipe,  (Fig. 250, p.
249), and  the  intercellular passages which  terminate in the
air-cells.    (Fig. 252, p. 250.)
  440.  The Larynx.—The Larynx  is a conical cartilaginous
tube from one to tAvo inches in diameter, opening upwards into
the Pharynx,  and terminating below in the Trachea.   (See
Organs of Aroice.)
  441.  The Trachea,—The Trachea is a cartilaginous tube

 438. AA'hat are tho lungs covered with, and what is the chest lined with?  ft'liat is
Pleurisy?  AA'hat is meant by the root of the lung? 439. Give the names of tho dif-
ferent parts of the air-passages.  440. Describe tho Larynx. 
AND  PHYSIOLOGY.                 249

          Fig.  230.
  The Larynx, Trachea, and Bronchia, deprived of their Fibrous Covering, and with tha
outline of the Lungs.  1, 1, Outline of the Upper Lobes of the Lungs.  2,  Outline of the
the Middle Lobe of the Eight Lung. 3,  3, Outline of the Inferior Lobes of both Lungs.
4, Outline of the Ninth Dorsal A'ertebra, showing its relation to the Lungs and the A'er-
tebral Column.  5, Thyroid  Cartilage.   C, Cricoid Cartilage.  7,  Trachea.   8, Eight
Bronchus.  9, Left Bronchus.  10, Crico-Thyroid Ligament.  11, 12, Eings of the Tra-
chea.  13, First Eing of the Trachea.  14, Last  Eing  of the Trachea, which is Corset-
shaped.  15,16, A complete Bronchial Cartilaginous Eing. 17, One which  is Bifurcated.
IS, Double Bifurcated Bronchial Eings.  19, 19,  Smaller Bronchial Eings.  20, Depres-
sions for tho Course of the large Blood-Yessels.


about  one inch in diameter, made  up of from fifteen  to twenty

cartilaginous  rings, commencing  at  a point  nearly opposite

the fifth cervical vertebra, and extending as low a3 the second

dorsal, or top of the sternum, Avhere  it divides into  tAvo bron-

chi  extending to each lung.    These  segments of the  trachea

are not perfect rings,  since they complete only about five sixths

  441. IIow is the trachea made up? Where does it divido into the two bronchi?  Are
tha segments of tho trachea perfect rings? 
250
HITCHCOCK'S   ANATOMY
Fig. 251.
                     Capillaries of the Human Lung.
of a circle,  the remaining sixth consisting of smooth or invol-
untary muscular fiber.
   442.   The  Bronchi.—Intercellular   Passages.—Caeca!
Air-Cells.   Their Number.—As  soon  as the Bronchi fairly
                              Fig. 252.
  A Magnified Yiew of a Section of the Lung, showing the Arrangement of some of
the Lobules, the Communication of the Air-Ceils in one Lobule and their Separation!
from those of the adjoining Lobule. The Eamiflcations of the Blood-Vessels in the
Texture of the Lung  and their Course through  the Air-Cells are also seen,  1, I,
Branches of the Pulmonary Veins.  2r 2. Branches of the Pulmonary Artery. 
AND  PHYSIOLOGY.              251
enter the lungs, they immediately divide and subdivide, until
they  have diminished to  a diameter about  one fiftieth of an
inch,  and some of them are Avitliin one eighth of an  inch of
the outside of the lung.    After this they are changed in their
structure, and become  channels holloAved  out in the cellular
tissue of the  lung, and  are called Intercellular  Passages.
These terminate in minute
cells,  called  Caecal Air-Ceils.
These cells haA'e an average
diameter of T^ „th of an inch,
and accumulate around each
terminal bronchus to the num-
ber of 17,790, making a total
in the lungs of 600,000,000,
which, if spread out,   would
make an area of  cell surface
of  132  square feet; Dalton
says  1,400 square feet.

   443.  Composition  of the
Air-Tubes.    Their  Mucous
and  Pleural  Surfaces.—
These air-tubes just described
are essentially composed  of
cartilage and  fibro-cartilage,
and  lined  throughout  Avith
mucous  membrane.    Ilence
we see  that this membrane,
though  situated  nearest  the
center of the body, lines the
oxdside  of the  lungs,  while
the Pleura,  although  nearer
the surface of the body, lines
 Longitudinal Section of the Termina-
tion of a Bronchus. 1, Bronchus. 2, C'a;-
cal Air-Cell.  2, Orifice of the same.

           FlG. 254.
Small Bronchial Tube laid open.
 442. What are the bronchial tubes subdivided into? IIow large are the ca?cal air-cells';
How many around each terminal bronchus? AVhat is their aggregate  number? What
Is the area of cell surface in the lungs? 443. What is tho composition  of the air-tubes.'
Which is really the inside and which the outside of the lungs?
really ■ 
252           HITCHCOCK'S  ANATOMY

the  interior of the lungs.  This apparent contradiction of
terms arises from considering that portion of the body as ex-
ternal Avhich is in contact with the air, in the same manner as
the intestines ; the anatomically external surface being phys-
iologically the internal surface.
   444.  The Substance  of the Lungs.—The substance of the
lungs is entirely made up of arteries, Areins, lymphatics, and
bronchial tubes, connected by areolar tissue.  And when in-
flammation takes place in this substance,  the disease is known
as pneumonia, or lung fever.
   445.  The  Essential Muscle  of Respiration—Process of
Breathing—The Rest Gained by the  Respiratory  Muscles-
—The  muscle Avhich performs  the most essential  part of
breathing is the diaphragm.  This by its  contraction produces
inspiration, but does not ditectly produce expiration.   Breath-
ing is performed as  folloAVs.  The cavity of the chest is Ara-
riable in  size; made  so by the movement of  the diaphragm
upwards and dowmvards.   For as the sides and upper portion
of the chest are unyielding walls,  if the  diaphragm be de-
pressed the cavity of the chest is enlarged, a  partial  A'acuum
is produced, and  the  air  rushes in to  supply the vacancy.
This is  inspiration, and is purely nn actiA'e muscular  effort.
Expiration, hoAvever, is quite the  reverse, being Avholly a pas-
sive exercise.   For Avhen the lungs are filled, the contents of
the abdomen are depressed by the descending diaphragm and
the ribs are eleA7ated, both of  Avhich parts offer resistance to
the inhaling force.   Consequently, Avhen  the diaphragm  and
the other respiratory muscles are  relaxed, several  muscles of
the back, abdomen, and  chest,  by their elastic  tonicity, force
air again out of the mouth, Avhich completes  the process of
expiration Avithout expending any nervous  energy, and  at the
same time gives rest to the  muscles employed  in breathing.
Ilence the muscles of respiration are not  all the time  in ac-

  444. What is the substance of the lung composed of ? Define pneumonia.  445. What
is the principal muscle of respiration? Describe the mechanism of breathing.  Which
act is active and which is passive ? When do the respiratory muscles re*i ? 
•
                 AND  PHYSIOLOGY.              253

tion, but as the period occupied by expiration is longer than
that of  inspiration, consequently  they rest  during a longer
time than they are in action.
           FUNCTIONS  OF  THE   LUNGS.

   446.  The  First  Object  of Breathing.—The  immediate
 object of breathing is  to  bring air into the lungs and carry
 it out again after it has performed its office; and the function
 of the lungs is to expose as large  a surface of blood as possible
 to the air inhaled.  The ultimate objects of this arrangement
 are to remove waste products from the  body, Avhich exist in
 the form of carbonic acid  and water, and also to generate the
 animal heat necessary.   A third,  big by no means an incon-
 siderable value of this function, is to convert the gluten of
 vegetable food into fibrin.
   447.  Another  Use  of  Breathing, Purifying  the  Blood
 — End osmose and Exosmose.—The impurities of the blood
 —carbonic acid and Avater—are exchanged for the oxygen of
 the atmosphere.   This  is not  effected  by actual  contact of
 blood  and air,  but through an  inter Awning membrane,  the
 wall of the  air-cells.   It  is a  remarkable property of mem-
 branes, both animal and vegetable,  called  Imbibition,  or En-
 dosmose  and  Exosmose, that alloAvs fluids and  gases to pass
 through  them  in  opposite  directions  at the same  time.
 Through the membrane of the lungs, the carbonic acid, Avhicb
 has more affinity Avith pure air than for the blood, passes out-
 Avards, while the pure air,  containing oxygen, has  an  affinity
for the blood, and passes inwards.
   448. Amount  of  Air Used in  Breathing—Causes of its
Variation—Capacity of  the Chest.—The  average   amount
of air which pisses in and  out of the lungs at each  inspiration

 446. What is the object of breathing, and what is the function of the lungs?  AVhat
three processes are accomplished by this process? 447. IIow does breathing  purify tho
blood?  Describe the process of imbibition. 
254           HITCHCOCK'S  ANATOMY
and expiration is about twenty cubic  inches, and  the  amount
passed through them in  twenty-four hours  about 360 cubic
feet, or, as  others  estimate it, from 3,000 to 5,000  gallons
every day.  This varies greatly.   In the first place, the loAver
the temperature the greater the  amount of animal heat to be
generated, and consequently the  greater the quantity of air
to be  consumed.   Also  a person laboring in the open air
breathes more deeply than one confined to the house.   Again,
the capacity of the lungs modifies the quantity of air inhaled.
And-this capacity depends more  upon the height of the indi-
vidual than any other physical  feature.  From  a series  of
5,000  observations made by Dr. Hutchinson,  the following
principle  is deduced.    " For every  inch  of  stature from
five to six feet, eight additional cubic inches of air are given
out at a forced expiration after a full inspiration."  That  is,
if a person  five feet  and six inches in height can expire 422
cubic inches, a person  five feet  and  seven inches can expire
430 cubic inches.
   449.  Effect  of Corpulence   on  Capacity  of Lungs.—
Another fact of importance  is deduced  by the  same  experi-
menter—that  if a  person exceed  the  average Aveight  on ac-
count of corpulence, the capacity of the lungs decreases in a
marked ratio,  as is stated in  these words :  '' When the man
exceeds the  average Aveight (at each height) by 7 per cent, the
vital capacity decreases one cubic inch per pound  for the next
thirty-five pounds above that Aveight."
   450.  Function  of the Red  Corpuscles.—The  red  cor-
puscles of the  blood seem to be the carriers of oxygen  from
the lungs to the various  parts of  the body.   The prominent
reason for this belief is that the serum and salts of the blood
have but a very slight  poAver of absorbing oxygen. Avhile the
discs condense this gas at once.
  44S. How much air is used in each net of inspiration, and how much each day ?  How
does temperature and exposure to the open air affect the amount respired ?  Upon what
does the capacity of the lungs depend ?  Give the law and its example. 449. IIow does
corpulence affect the capacity of the chest?  Give the formula. 450. AA'hat is the prob-
able function of the red corpuscles of tho blood ? 
AND  PHYSIOLOGY.
255
  451.  Inspirations compared  with  Pulsations—Quan-
tity of  Watery Vapor Given off  in Twenty-four Hours-
Amount of Carbonie  Acid Exhaled—The Amount of Solid
Carbon given  off.—If Ave compare  the  number of inspira-
tions in a minute Avith the pulsations of  the  heart, we  shall
find the proportion of the former  to  the  latter is as one to
four or  five in the human adult.   Every fifth breath is usually
deeper  than the preceding four,  and the time  occupied by
each respiratory act is about three  and a half seconds;  and
all  the blood in the body (Avhen in vigorous exercise) probably
is exposed to the air in the lungs every  tAvo minutes.
  The quantity of watery vapor Avhich is ordinarily exhaled
from the lungs in twenty-four hours  ranges from  sixteen to
twenty  ounces.   The amount of carbonic acid, however, varies
much more, being from one to three pounds in  tAventy-four
hours, and the causes of variation are temperature, age,  sex,
state of health  or disease, development of  the  body, muscular
exertion or repose,  sleep  or  Avatchfulness, and period of the
day.   " This gas (carbonic acid) contains in every 100 pounds
28  pounds of  carbon (charcoal)  and 72  pounds  of  oxygen
(gas).   Ilence the  weight of carbon Avhich  escapes  in  this
form from the  lungs of a full-groAvn  man varies from  five to
fifteen ounces in tAventy-four hours."
  452. Respiration  as  a Source  of  Animal  Heat.—The
value of the function of breathing as a means of producing
animal  heat, will  be considered under the organs for produc-
ing heat.
  453. Changes in  the  Food  effected  by  Respiration.—
A third object of breathing is to effect such  changes in the
food that it can be directly converted into the different tissues
of  the body.   Ilence the oxygen of the air  is a  part  of the
food that Ave live upon.   For although the gluten Avhich  is so
  451. What is the relative number of inspirations and pulsations of the heart?  AVhat
length of time is occupied in breathing?  AVhat quantity of vapor of water is exhaled in
twenty-four hours, and what amount of carbonic acid?  IIow is this amount modified ?
AVhat wei-ht of carbon or charcoal is given out of the body by the lungs everyday?
453. AVhat effect has the oxygen of the air upon the glutinous portion of our food ? 
256            HITCHCOCK'S  ANATOMY

largely contained in vegetable  food  very  closely resembles
fibrin (which is the form that the nutrient portion of the food
must be in before it can nourish  the greater part of the  body,
and especially the muscles), still chemical analysis shows that
the gluten must receive another equivalent of oxygen before
it is fitted to reproduce the different tissues of the body.   And
the only Avay in Avhich  this oxygen can be given to  the body
is either through the lungs or skin.
  454. Amount  of  Air  which the  Lungs can Contain —
The amount of air which the lungs  actually do  contain is by
no means the amount that should be actually supplied to them.
For the air Avhich surrounds  the body is very rarely indeed
perfectly pure, but is  contaminated with the  previously ex-
haled  breath,  on account of the law of diffusion of gases,
which  is, that Avhen two gases  are brought  into contact they
immediately commingle Avith each other.   Experiment  shows
that between 350 and 400 cubic feet of air are actually ex-
haled  during  the tAventy-four hours ; but  experience  shows
that the least quantity  Avhich should be allowed for  dAvelling-
houses, shops, and school-houses, should be  800  feet in order
to furnish  a sufficient supply of oxygen.
               CALORIFIC  ORGANS.

  455.  Heat-producing  Organs—Theory of  Animal neat.
—The organs which produce animal heat are essentially those
employed in the act of breathing and  the circulation of tho
blood,  and  consequently already  explained,  but  the actual
method by Avhich it is produced has for a long time perplexed
physiologists.   The theory Avhich noAV  is most readily accepted
makes the  function to be a  chemico-vital one, or a chemical

  What is that element which principally nourishes tho muscles?  451. What is the law
of diffusion of gases, and what modifying influence does this have on the hygiene of res-
piration ?  How many oubic feet of air should bo allowed to every in-door laborer or
student? 455. What are  the heat-producing organs?  AVhat is at present tho most
readily accepted theory of animal heat ? 
                 AND  PHYSIOLOGY.              257

change  (oxydization)  dependent  upon  vital  energy, being
nearly analogous to the burning of a  candle or the combus-
tion of Avood and coal in the stove.
  456.  Process of Producing  Animal  Heat.—As the oxy-
gen in the inspired air enters the  lungs  and is brought  into
contact  with the blood  through the Avail of the air-cells, the
carbon of the  venous  blood unites with it, forming carbonic
acid, and heat is generated.   This is precisely the  same thing
that takes place in the  furnace, Avhere  the air enters through
the draft supplying the  oxygen, and  the  coal furnishes the
carbon,  the result of the union being heat.   But it is  not  in
the lungs alone that this heat  is  generated : for Ave  have al-
ready seen that the blood is highly charged Avith oxygen as it
passes through the arteries to the various organs of the body.
And as it passes through the capillaries in every part  of the
system,  it there receiAres an equivalent of carbon, the Avaste
of  the  system  producing carbonic  acid, in  ayIucIi operation
heat is given off.   Hence Ave see  that  heat is generated not
only in the lungs but in every part of the body, and that it
i3 incessantly being produced, Avhich is a reason Avhy the ex-
tremities of  the body are constantly kept at their proper tem-
perature ; for if all the beat Avere to be generated in the lungs,
A'cry frequently the blood Avould become chilled in  its passage
to the extreme capillaries.  We also see that  forced respira-
tion has the same  effect as increasing the draft of air  into
the furnace, and that the fuel  of the  human system is sup-
plied by means of the food placed in the  stomach.
  457.  Temperature  of Human Body.—The temperature of
the human system is 98° F., and this it is invariably found to
be in all climates and seasons Avhen the individual  is in  pos-
session  of perfect health.   So that in most climates  the tem-
perature of the body is above that of the surrounding  atmos-

  456 Describe the process.  Is all the heat of the body generated in the lungs ? Where
in the body is \tvot generated ? AVhat is the fuel of the body? AVliere is the draft?
457.  What is the temperature of the human body? IIow is the heat of the body com-
pared with that of nearly all climates? 
258           HITCHCOCK'S  ANATOMY

phere, and we are constantly giving off heat to the air which
envelops us.
  458.  Manner  in  which  the Body is maintained at its
uniform Temperature.—The  manner in which the body is
kept at the uniform temperature of 98°,  is a subject of deep
interest.  It is  partly accomplished  by radiation,  since  the
body  is  ordinarily warmer than the air about it, and  also
partly by inhaling the cool air into the air passages.   It is a
well-known principle  in chemistry, that, when any substance
passes from a more solid to  a  less solid condition, as from
solid to liquid, or liquid to a gas, heat is absorbed, or, in more
common language, cold is made sensible.  This is seen in the
application of Avater,  alcohol,  or ether, to the  skin, Avhen a
sensation of cold is felt,  Avhich  is OAving to the  fact that  the
substance applied is  passing  from  the  form of a  liquid to
that of a vapor.   Noav the same thing takes place  Avhen the
perspiration is alloAved to evaporate from the  surface  of the
body.   The increased flow of  blood, as brought about  by the
exercise,  or the  high temperature of  the  surrounding at-
mosphere, stimulates the vessels of the skin to  more energetic
action, and sensible perspiration is poured  out upon the sur-
face of the body.  This, hoAvever, is noAV in contact Avith the
currents of air ahvays present about the body, and it is readily
throAvn out into a state of vapor, and in accordance with the
chemical principle just stated, heat is absorbed from the body
producing its uniform temperature.

   458a.   It should  be  mentioned here,  that of late many
experiments have been  carried on Avhich  seem to sIioav us
that  the above-mentioned theory of animal  heat can  not be
fully  adopted.   For  it  is well knoAvn  that many chemical
combinations  besides  those of mere oxydation or  "burning"
produce  heat;  and many of  these  processes  aro  constantly
 taking place  in the  body.   But  all the facts hitherto ad-
 459. IIow is the body kept at its uniform temperature? AVhat chemical principle
illustrates this view ? 45Sa. Give the result of recent experiments. 
                  AND  PHYSIOLOGY.               2 J 9

vanced do not  by any means entirely overthroAV the old theo-
ry.  They  sIioav us  that  the  theory of combustion does not
coA'er the  Avhole ground,  but that other causes, as Avell as
oxydation  produce  animal  heat.   And Ave  propose the  idea
that animal heat, like  digestion, is a  chemico-vital  process,
that is, a process under the immediate influence of chemical
changes, but entirely under the control of the vital principle,
since animal heat can not be maintained after death.
   ORGANS  OF  THE  VOICE.

DEFINITIONS  AND  DESCRIPTIONS.
  459.   The  Larynx;   its
Cartilages.—The Larynx in
all animals is the essential or-
gan  for the production of the
voice.  It has also  very much
the same structure in every
animal which has the poAver of
expressing its feelings by the
Aroice.   A cartilaginous tube,
imperfectly  conical, the  base
directed  upAvards,  made up
of distinct   portions  or  seg-
ments slightly movable upon
one another, and  with a cer-
tain portion of  the  channel
lengthened into a narroAV and
elongated opening, constitutes
a larynx.  In man this organ
is made  up  of seven distinct
portions  or  cartilages,  two
Arytenoid   (pitcher-shaped),
Fig. 255.
  A Lateral View of the Larynx.  1, Os
Hyoides.  2, Thyreo-Ilyoid  Ligaments.
3, Cornu Majusof the Thyroid Cartilage.
4, Its Angle and Side. 5, Cornu Minus.
C, Lateral Portion of the Cricoid Carti-
lage. 7, Lings of the Trachea. 
260
HITCHCOCK'S  ANATOMY
two Cuneiform  (Avedge-shaped), one  Cricoid (ring-like),  one
Thyroid (shield-like,) and one Epiglottis (cover to the Glottis).
These together form the small prominent portion of the neck
known as Adam's apple.
   460.  Thyroid Cartilage.—Arytenoid  Cartilages.—Cu-
neiform  Cartilages.—Cricoid Cartilage.—Vocal  Cords-
Ventricle of the Larynx.—lluscles of  the  Larynx.—The
Thyroid Cartilage is so arranged as to form  a framework  for
the movable portions  of the organs of  the voice, and  this is
the principal  cartilage  that forms  the  Adam's apple.  The
Arytenoid Cartilages can be moved by  the small muscles of
Fig. 256.
Fig. 25 T.
  A Posterior A'iew of the Left Arytenoid
Cartilage. 1, Its Posterior Face.  2, The
Summit.  3, The Base and Cavity for
Articulating with tho Cricoid Cartilage.
4, Its External Angle.  5, Its Internal
An<:le.
  A Front A'iew of the Thyroid Carti-
lage  1, Left Half of the Cartilage. 2,
Anterior projecting Angle.  3, Superior
Margin. 4, Its Notch. 5, Inferior Margin.
6, G, Cornua Majora. 7, 7, Cornua Minora.
the  larynx.   The  object of this movement is  to  relax  c
tighten the vocal cords, so that the different pitch and quality
of voice may be perfected.  The  Cuneiform  Cartilages  are
about half an inch in length, and enlarged at each extremity.
These are  sometimes Avanting.  The Cricoid Cartilage is of a
ring-like appearance, and resting directly upon  the°rin<rS  of
or
 413. AVhat is the essential organ of voice in all animals? Give the anatomy of tha
barynx Name the seven cartilages.  460. Describe the thyroid and a ytenoid cartilages
Describe tho cuneiform and cricoid cartilages.                      "unmakes. 
AND  PHYSIOLOGY.
261
the trachea, being of a little longer diameter than the trachea.
The Epiglottis is  the most movable of all the vocal cartilages.-
Fig. 253.
Fig.  253.
  A Lateral A'iew of the Epiglottis Carti-
lage. 1, Anterior or Convex Surface.  2,
Posterior or Concave Surface. 3, Superior
Margin.  4,  Inferior Margin or Pedicle.
5, Its Sides.  The Openings of  the Muci-
parous Ducts are also shown.

           Fig. 2GO.
  A Front View of the Cricoid Cartilage.
1, Its  Internal Face.   2, The Cavity of
the  Larynx as formed  by this Cartilage.
3, Its Inferior Surface. 4, The little Head
or Convexity for  Articulating with tho
Arytenoids.   5, The Surface  of the Su-
perior Edge for the Attachment  of tho
Lateral Crico-Arytenoid Muscles.

It  in shape resembles a cord-
ate or  heart-shaped  leaf, at-
tached by its apex to the up-
per edge  of  the  glottis,  and
has  a  wide range  of motion,
in  order to   completely  close
up the passage into tho lungs,
or  leave  a free communica-
tion between them  and' the
air.   It  also aids in deaden-
ing sounds, as  it is suddenly
brought doAvn upon the  glot-
tis.  All these cartilages very
  A Posterior A'iew of the Articulations of the Cartilages of the Larynx. 1, Po.tenor
Face, of the Epiglottis.  2, Appendices of the  Os Hyoides.  3, Its Cornua  4, Latera
Thyreo-Ilyoid laments. 5  Posterior Face  of the Thyroid Cartilage.  6, Arytenoid
Cartilages  7 Cricoid Cartilage.  8, Cricoarytenoid Articulation.  9, Poster or Cr co-
Thy"^ Ligament. 10, Cornu Minus  of the  Thyroid Cart "^  «.*£™' C™"
Thyroid Ligament,  12, Ligamentous Portion of the first  Uiug of the Trachea.
 
262
HITCHCOCK'S   A X A T O M Y
frequently  become  considerably  ossified  in  males  in  ad-
vanced age.
   The Vocal Cords or ligaments are folds of Avhite fibrous tis-
sue, covered by mucous membrane, and are made to vibrate
when the air is forced over them.   Hence ulceration, or any
FlG. 262.
  A View of the Larynx from above,
showing the Thyreo-Arytenoid or Vocal
Ligaments.  1, Superior Edge of the La-
rynx.  2, Its Anterior Face.  3, Cornua
Majores of the Thyroid Cartilage. 4, Pos-
terior Face of the Cricoid Cartilage.  5, 5,
Arytenoid Cartilages. 6, 6, Thyreo-Ary-
tenoid Ligaments. 7, Their Origin within
the Angle ot the Thyroid Cartilage. 8,
Their Terminations at the Base of the
Arytenoid Cartilages. 9, The Glottis. 10,
Anterior  Part of the Inferior Surface of
the Cricoid Cartilage.
  Muscles of Human Larynx.  G. F. BT.
Thyroid Cartilage,  r. w. X. w. Cricoid.
2T. F. Arytenoid.  T. V. Vocal Ligaments.
AT, X.  V. K. f. and N. I. Muscles of La-
rynx.
alteration in tffe* structure of these cords, will produce hoarse-
ness, a loss  of intonation—a whispering—or some change  in
the quality of the voice.   The cords just mentioned are not,
however, the only ones that exist in the larynx,  for  these- are
the upper ones, while another pair called  the inferior cords,
exist beloAV the others, leaving a cavity known as the ventricle
of the larynx, (Fig. 263,  p.  263),  which seems  essential  to
the  proper production of  sound: although  there is nothing
analogous  to it  in  the ordinary  musical instruments.  The
muscles  connected Avith  the larynx  are eight:  five of  them
  AA'hat is the epiglottis?  Of what are the vocal cords composed?  What is the ven-
tricle of the larynx ? How many muscles belong to the larynx ? 
AND  PHYSIOLOGY.                263

         Fig. 263.
   Cartilages of Larynx and Epiglottis, a. Arytenoid, b. Its Superior Cornu.  c. in-
  ferior Cornu.  d. Cricoid. /. Perforation of Epiglottis,  i. Upper Part of Thyroid.
  t. Trachea, h. Tubercle.
pass  between the different cartilages, and are of use  in  regu-
lating the size of the  glottis and the tension of the vocal cords,
while the three remaining  go  from  the epiglottis to the dif-
ferent parts  of the  larynx, solely for  the purpose of moving
this valve to aid in articulation and closure of this passage  to
the lungs.______________
   Which move the cartilages, and which are distributed mainly t» the epiglottis?
                                 12 
264           HITCHCOCK'S  ANATOMY
         FUNCTIONS  OF  T HE  LARYNX.

   461. Similarity of the Larynx to a Reed Instrument.—
The larynx, as  an organ  of sound, very much  resembles  a
reed  instrument,  or  the reed  pipes  in an organ.   For we
have the reed, or  rather the reeds, in the vocal cords,  and the
column of  air in  the pharynx and  mouth.  This, hoAvever,
differs from the proper reed instrument by the vibration of
free edges of the reed, and also by the power of tightening or
relaxing the cords to  produce different pitches of tone ; for in
the hautboy,  bassoon, and similar  instruments,  the  tone is
regulate'd by the length of the vibrating column of air, which
is controlled by  the keys and finger-holes.
   462. Use of  the  Cartilages.—The  arrangement  of  the
cartilages of the larynx is such as to give form  and  stability
to the organ, and  at the  same time a firm attachment to  the
vocal cords, muscles, and  ligaments.   In male adults  these
are much larger than in  females, since the voice of the former
is heavier and of a much lower tone than that  of the latter,
requiring greater length of  vocal  cord, and  consequently
firmer points of attachment.
   463. Organs  Essential  for  tnc  Production of  mere
Sound.—The vocal cords,  together  with the diaphragm,  ab-
dominal muscles,  and lungs, are all the organs which  are
necessary for  the  production of sound.   But the quality of
sound and articulation are produced  and modified very essen-
tially by other parts of the body.
   464. Use of the Cavity in the  Frontal  Bone.—The si-
nus, or cavity in the frontal  bone which communicates with
the pharynx, is a very important member of the vocal organs,
as it imparts resonance to the voice in the same manner as  the

  4G1. What kind of instrument does the larynx resemble ? AA'hat correspond to the
reeds?  462. Of what use are  the cartilages?  Are the vocal cords longest  in man*or
woman? What is the result of it?  463. AA'hat organs of  the body are necessary for the
production o f sound ?  464. Of what use is the cavity in the frontal bone ? 
AND  PHYSIOLOGY.
265
hollow portion of the violin and violincello, or the long tube of
brass instruments, gives the proper tone  to these instruments.
The Avant of such a  cavity for the perfection of the human
voice is Avell appreciated, Avhen  a person is  suffering with a
severe  cold  in the  head, as it  is  termed.   In this case the
voice is of an extremely nasal character, beoause the passage
to the frontal sinus is closed  up by a thickening of the lining
membrane, Avhich prevents a resonance of the tones  made in
the larynx.
   465. Function of  the Nostrils  in the  Voice.—An open
passage through the  nostrils is  also very important for the
production of perfect tones of the  voice.  For Avhen this is ob-
structed in any Avay, the head or nasal tone is invariably pro-
duced.
   466. Function  of the  Tongue  in the  Making of Ar-
ticulate  Sound—Not Absolutely  Essential.—The tongue
is  the chief  organ  of  articulation, and in  connection Avith
the  lips and  teeth, the tones made in the glottis are  either
lengthened or  shortened, and otherwise modified  to form the
different letters.   If  either of these organs is deficient in sub-
stance or function, the  articulate sounds are imperfect; as,
for instance, the letters T, D, L, F, and  S,  which  require a
full development of all the parts for their perfect enunciation.
It  is,  however, stated as a fact, that some people  have been
known to articulate Avords Avith distinctness after the tongue
was removed by a gun-shot wound.

             HYGIENIC   INFERENCES.

   467.__1. From the size of the lungs we see that they are
organs of great importance in the system.
   468.-2.  Liability of  the Lungs to Disease—On ac-
count of their  delicate  structure and constant use, they are
  What p^n7c~e7the talking thrown" the nose, as it is termed?  4fiT..  IIow do the nos-
trils affect the voice? 466. What use has the  tongue in speech ? Also the teeth and
Ss ? Is the tongue always absolutely essential ?  4G7. AVhat does the great size of the
lungs show us ? 
266
HITCHCOCK'S   ANATOMY
liable to disease,  and  consequently need especial  care to keep
them in health.
   469.—3.  Action   of   the   Lnngs  Essential  for   their
Health.—One important item  to  secure  the  health of these
organs,  is to keep every part of them in action.   Ilence pres-
sure of clothing,  or any thing else that prevents  the complete
filling of the lungs by breathing,  is quite sure to induce dis-
ease.   For  if but a very few of the millions of air-cells con-
tained in the lungs are allowed to  lie  inactive or useless, na-
ture Avill attempt their remoAral by means of the  lymphatics,
and this removal  is often the commencement of fatal  disease.
Therefore it is a  good  practice for  every one, and especially
sedentary persons,  several times each day to throAV back and
dowmvards  the shoulders,  and  slowly fill the lungs to  their
utmost capacity, and then permit the air to  escape slowly, be-
cause in this Avay every cell in the lungs will be  used. *
   470.—4.  Pure  Air  is  Essential  to  Healthy  Lungs-
Life  Depends  on  Breathing   Pure A ir."^—All mechanical
and chemical impurities of the air inhaled induce  and ag-
gravate disease.    Indeed, the  most important hygienic rule
for the lungs is to breathe pure air.   Mechanical impurities,
such as dust and  vapors, are eminently injurious, but not so
much so as  the chemical impurity, carbonic  acid,  which comes
from the exhalations of men and animals,  and  the burning of
  * Black Hoi.*, of Calcutta.—One of the most awful instances of suffocation on rec-
ord, is connected with what is  known as the Black Hole of Calcutta. AA'hen Calcutta
was taken by the Indian  forces, the British  garrison, numbering 146 men, were confined
as prisoners of war in the dungeon of the fortress, a room only eighteen feet square, and
intended only for confinement of two or three men. This dungeon had only two small
windows, both upon one  side of the building, in front of which  was a verandah that aided
greatly in impeding whatever slight circulation of air there might be.  Besides the great
heat of a.Tuly night, on which  this occurred, conflagrations were raging near  the fort
which greatly increased the heat. A'ery soon after tho men were confined, the suffering
became intolerable, and tho dungeon was a scene not only of the intensest anguish, but
of frightful delirium of most of the inmates. By eleven o'clock the men began to die
very rapidly, and owing to the intense heat and  overpowering stench caused by these
exertions of the frantic soldiers, in the morning at six o'clock, when tho doors were
opened, but twenty-three were alive, who were either stupefied or ravins,
  48S. What does their delicate structure show us?  469. What is said of tho necessity
of action for the lungs ?  What habit is of great service, and why is it ?  4T0. How do im-
purities of the air affect the lungs? What kind  of impurities are the most injurious 1
AVhat is one of the principal sources of disease in civilized society ? 
                 AND  PHYSIOLOGY.              267

all combustible substances.  And  it is safe  to  say, that the
greater the care we take to ventilate our rooms,  and in every
Avay to breathe pure  air,  the  longer shall we live and  with
the least amount of pain and disease.  Breathing  impure air
is one of the greatest natural evils to Avhich  civilized society
is subject, and destroys more lives than almost any other.
  471.—5. We need Pure Air  by Night  as  well  as by
Day.—Hence Ave see that the lungs need pure air all the time,
by night as well as by day—in the sitting-room, the eating-
room, and  the bed-chamber, the school-house,  the meeting-
house, rail-car, and steamboat, if Ave AA'ould do our  utmost to
ward off disease and death.
  472.-6. Capacity  of the Lungs Affected by  Posture.—
The capacity of the chest  is greatly influenced  by our posi-
tion in sitting  or  standing, and  the amount of  use to Avhich  .
it  is  subject.  If  the shoulders  are thrown forward  or the
body is  bent in the same Avay, the lungs are  compressed, and
can not be filled to their full capacity.  Hence  special pains
should be taken to maintain the body in an erect posture, and
to keep the chest throAvn forward.
  473.—7. Pure  Air  is often a Medicine.—In  most diseases
the breathing of pure air is important  for restoration to per-
fect health,  since there are often some impurities in the blood
or system which  are removed  mainly by pure air.   So that
the rule of supplying pure and Avarm air to the  sick room
should be rigidly observed.
  474.—8. Warm  and  Moist  Air  the Best for  a Healthy  j
Person.—The air best adapted  for  breathing should  contain
but a small amount of moisture,  nor should it  be perfectly
dry, especially that which comes  from intensely heated iron
surfaces.   Cold and damp air is apt to bring on irritation of
the mucous membrane, producing coughs and colds.
  475.-9.  Capacity of  the  Lungs  may  be   Increased —
~ 471 When and where do we need pure air?  472. IIow is the capacity of  the lungs
modified ? What of the necessity of an erect posture in sitting or standing? 473. AVhy is
nure air so important in sickness?  474. What is the best quality of  air for bieathing! 
268           HITCHCOCK'S  ANATOMY
The lungs, if compressed by disease or improper clothing, and
even in many cases of so-called perfect health and  soundness,
can be very much enlarged in their capacity.   This can  be
done by loud reading, or by the simple act of filling the lungs
Avith air to their utmost capacity several times each day, after
the manner mentioned under  inference  3d.   If this healthy
habit be kept up for a few years even  by some considerable
effort, nature will at  length take up the habit, and Ave shall
ultimately be found involuntarily filling  the  lungs with pure
air, and thus fix upon ourselves a hygienic habit of great im-
portance in preserving health, and of great value in repelling
disease.
   476.—10. Colds  and   Coughs—Treatment—Sympathy
between the Different  Parts of the Mncous  Membrane-
Colds and ordinary coughs are affections of the  mucous mem-
brane,  and generally only of the lungs, pharynx, and nostrils
and air  passages leading  to the  lungs.   They are  often pro-
duced by obstructions in the vessels of the skin, and hence a
great relief in  many instances for a cold, and often a cure,  is
to remove this obstruction by  stimulating  these  vessels to
powerful action, as in SAveating. This effect is produced by the
sympathy which exists between  the skin and  mucous  mem-
brane,  one often performing the  function of the other for  a
short time.   The mucous  membrane also  has  a remarkable
sympathy between its different  parts;  and hence even  the
portions which are unaffected  by the cold should be kept as
quiet as possible, by taking, for  instance, but little food  into
the alimentary canal, and that of a liquid character, so that  it
may be readily taken up by the absorbents of the stomach.
  477.—11. Injurious  Effects of Wearing  Shawls  by
Gentlemen.—From  the fact  that whatever  compresses  the
chest greatly tends to bring on diseases  of the  lungs, we in-
 475. IIow can the size of the lungs be perceptibly increased ? 476. What are colds and
common coughs ?  How are they often induced?  What is their best treatment? What
is remarkable about the sympathy between the skin and the mucous membrane? 477.
How are shawls often inj urious to the lungs ? 
AND  PHYSIOLOGY.
269
 fer that the wearing of shawls by gentlemen, inasmuch  as  it
 requires a drawing forward of the  shoulders  to make  them
 thoroughly cover the body, compresses the  lungs, and there-
 fore is highly injurious.  Moreover, it makes a person round-
 shouldered, and  thus gives the appearance of premature old
 age.

   478.—12.  The Neck  to  be  Dressed  Lightly.—From
 the many movements which are made by the larynx in speak-
 ing, we infer that it is a matter of great importance that the
 neck in health should be always loosely dressed.   For  tight
 craArats and neckcloths are sure to obstruct the proper func-
 tion of this organ, and bring on  irritation, Avhich may end in
 bronchitis or consumption.

   479.—13.  A Strong Voice  Demands Vigorous  Exer-
 cise  of  all the  Body.—We learn also that they who would
 have the strongest and best developed voices for speaking and
 singing should pay special attention  to the general health, and
 particularly to muscular exercise in  the open air, because the
 voice depends so much more  upon  the healthy condition of
 the whole body than it does upon the healthy or  unhealthy
 condition of the larynx.

   480.—14. Great Aid in Speaking can   be   Acquired
 by Enunciating  the  Simple  Vowel  Sounds.—Experience
 shows that great aid can be given to those Avho would  secure
 pure and correct tones in speaking by slowly but  distinctly
 enunciating the simple vowel sounds of the English  language.
 This not only strengthens the organs,  but  it gives  a proper
 training  to the laryngeal muscles, so that in the composi-
 tion  of  vowels and  consonants  the  muscles will contract to
their proper amount, and only to that.
      ________________________^____--------------------.
 473.  What clothing should be given to tho neck ?  What is one source of bronchitis?
479. How is the voice made and kept clear and strong ? 480. How can  poor speakers
and readers make themselves superior ones ? 
270           niTcncocK's  anatomy
        COMPARATIVE  PNEUMONOLOGY.

               respiratory  organs.

  481.  Trachea.—The Trachea in some animals, such as the
horse and cow, consists of complete rings, while in  many ani-
mals they are only portions  of rings, whose free extremities
are united  by membrane.   In man these rings number from
seventeen to tAventy, in the  whale  from seven to  twelve, in
the carnivora  from thirty to forty, and in some camels one
hundred and ten.
  482.  Bronchi.—The Bronchial  Tubes  are  usually two in
number, but in the  ruminants, the dolphins, and some  other
mammals there are three.   This  third tube  is always the
smallest, and passes to the right lung.
  483.  Lungs.—In the horse  the lungs are undivided, but
in most quadrupeds the number of lobes  is greater than in
man.  In the marmot and hamster there are five in the right,
and  three  or four in the left lung.   In the  musk deer the
right lung is nearly tAvice the size of the left.   The terminal
air-cells of all these animals correspond in size very nearly
with those of man.  The lungs are proportionally the largest
in the  more powerful  carnivora, and smallest  in  the  Aveak
herbivora, and the red blood corpuscles are much more abund-
ant in the blood of the former than of  the latter.
  484.   Respiration of Birds.  Lunglets.—In   Birds the
respiratory apparatus, like that of Insects, extends through a
large part  of the body,  (Fig. 264, p.  271), not only in the
lungs proper, but through the channeled bones  which are lined
Avith a membrane for purifying the blood. (Fig. 265, p.  271.)
  4S1. IIow does the trachea in many of tho lower animals differ from that of man?
What is the relative number of rings in each ? 4S2. AA'hat is said of the number of tho
principal bronchial tubes ? 4S3. AVhat of the number of lobes in many quadrupeds? In
what animals are tho lungs largest and in what ones weakest? 4S4. How is the respir-
atory apparatus of birds and insects alike? 
AND   PHYSIOLOGY.

            Fig. 264.
211
          Trachea.




Pulmonary Vessels.


            Lung.

 Bronchic Orifices. -I
Pl— Bronchus laid open.
> Bronchus laid open.
Lungs of a Bird.


  FlG.  265.
  Pulmonary Apparatus of a Pisenn, as seen on removing the Anterior Wall of the
Thorax,  a. Trachea,   b.  Bronchi,  c. Lungs,  d. Apertures  of Communication
with Air-Ceils.
                                  12* 
272            HITCHCOCK'S  ANATOMY
Large air-sacs are also contained  in the abdomen, freely com-
municating with the lungs,  and acting as reservoirs for them.
A minute examination of the structure of these organs shows
Fig. 266.
 Lunglet of a Fowl.  A. Section passing in the direction of the Bronchus. B. Sec-
tion cutting it across.
Fig. 267.
 Lungs of Frog.  a. Hyoid Apparatus.
b. Cartilaginous Eing.  c. Lungs Proper.
that they are made up of lo-
bules  or  lunglets,  each of
Avhich has its own system of
vessels,  and  but little com-
munication  with  the  other
lunglets.
   485.  Lungs of Reptiles.
-The Hiss of  Serpents-
Mechanism   of   Respira-
tion.— The  Lungs of  the
seA'eral orders of Reptiles are
for the  most part  capacious
sacs,  the extent of surface in
which is but little increased
by smaller  sacs  or vessels
within  them.   In the  Fro°\
 What appendages do they have which do not exist in quadrupeds ?  4S5. What are tho
lungs of reptiles ? 
AND  PHYSIOLOGY.              273

         Fig. 268.
   Lungs of Serpents,  a. Trachea,  b. Bronchi,  c. Eight Lung,  c'. Left Lung.
 d. Pulmonary Artery.

for example, the bronchi terminate in capacious cavities, upon
the sides of which are the pulmonary blood-vessels.  In many
serpents the pulmonary apparatus consists of a long cylindrical
sac or luno- upon  the right side of the body, the corresponding
one on the left side being merely rudimentary, as  seen in Fig.
268.   Serpents are capable  of  expiring and inhaling large
quantities of air,  which compensates for the want of  a great
internal  surface of lungs.   And the peculiar  hiss made by
them is simply a  prolonged expiration of air  from the lungs.
       How is it in frogs and serpents?  What makes the hiss of serpents ? 
274           HITCHCOCK'S  ANATOMY
     Lung of Turtle laid open.          Gills of Eel.  A. Enlarged Portion.

In aquatic serpents the amount  of  air contained in the body
tends to make it buoyant, and  at  the same time supplies the
wants of the animal during a long immersion.  In frogs and
many of the class  reptilia the  air  is forced into the lungs by
a process similar to  that  of swallowing.   Taken as a  whole,
this order  is remarkable  for the feebleness of its  respiratory
actions, and the length of time which the function can -be sus-
pended without injury.    The  temperature in which the ani-
mal lives, however, greatly modifies the amount of air exhaled
and inhaled.
   486. Gills  of  Fishes.—The  Respiratory  apparatus  of
Fishes  consists of Gills  for procuring the  air contained in
water.   The Gills are fringes of minute bronchial tubes sus-
pended from  cartilaginous and bony arches,  that are situated

 How do frogs inspire ?  What efiect has the temperature upon the respiration in this
class of animals ?  436. \Yhat are the organs of respiration in fishes? Describe the gills.
FlG. 269.
 
AND  PHYSIOLOGY.               275
just behind the lower jaw.   " These are disposed,  in  most
fishes, in fringed laminae, which  are  set  close together like
the barbs of  a feather,  and are attached  on each  side  of
the throat in double  rows, to the convex margins of four or
five long, bony, or cartilaginous arches, which  are suspended
from the  hyoidean arch."

  487. Air-Bladder.—Another organ which perhaps claims
attention  here, is the Air-Bladder.  This  is  a small shut sac
—sometimes nearly subdivided into two or more sections by

                           Fig. 271.
  Air-Sac of Fish (Carp),  a. b. A Divided Form.  c. d. A Tube connecting it with the
Esophagus o.

a  membranous division—which  lies near the  middle of the
back.   In most cases it has no connection with any other or-
gan,  but sometimes has an  opening into the esophagus or
stomach.  The uses for which it has been supposed to exist,
are to enable the  fish to alter its specific gravity,  and also to
aid in respiration in some manner.   It  has also been conjec-
tured that it aids  the sense of hearing, since  it  is in direct
connection Avith the  auditory apparatus.   It  is  filled  with
atmospheric air, with greatly varying proportions of oxygen
and nitrogen.   Some fishes that leave the Avater occasionally
and craAvl OArer the land, have a cavity in the side  of the  head
for water, which is in contact with  a respiratory apparatus,
and thus the  fish can live for some time out of its native ele-
ment.—Wyman.
 48T. Describe the air-bladder. AVhat docs it sometimes communicate with ? Give its
probable uses.  AVhat is it filled with 1 
276             HITCHCOCK'S   ANATOM

  488.   Trachea  of  Insects.—Spira«les —Mechanism  of
Respiration.—Wisdom  of  this  Arrangement.—The  res-
piratory vessels of  Insects are  analogous  to those  of birds
in  that they  extend  through  a large  part  of  the body.

                           Fig. 272.
  Trachea of Water-Scorpion, a. Head. b. First Pair of Legs.  c. First Segment, of
Thorax, d. Second Pair of wings.  «. Second Pair of Legs. /. Tracheal Trunk, g. One
of tho Stlgmatae. h. Air-Sac.

The essential  organs are Tracheae  or air-vessels, which open

upon the sides of the body,  and freely communicate with  one

another.   Air sacs are found in the  front parts  of the body

  483. What are the essential organs of respiration in insects ?  Whereabouts in the ani-
mal are the tracheae found ? 
AND TIIYSIOLOGY.
277
of some insects, and  the tracheae  are very minute,  ramifying
through  the most delicate  organs of  the  body, which  plan
allows a rapid aeration of the  blood,  and greatly assists in
diminishing the specific gravity of the animal.   The openings
upon the surface of the body are called  Spiracles or Stigmata,
and  are either oval or  made in  the  shape of a  slit, as is
seen in the adjoining eut.   In  the  soft-skinned insects they

                           Fig. 273.
Spiracle of Common Fly.
are surrounded by a ring of cartilage, to prevent their closing
by ordinary accidents or pressure, and all spiracles  are pro-
tected by  a kind  of sieve or grating, made  up of hairs ex-
tending  from  either side of the aperture, Avhich keeps out
dust, that  would otherAvise enter Avith the  air and  stop the
passage.   The interchange of air is effected  by the  enlarge-
ment and contraction of the abdomen.   The  rings, (or skele-
ton), which surround the abdomen,  are seldom inflexible, but
are made up in one part of membrane, and the horn-like ends
are  brought  together by  muscular  contraction,  by  Avhich
means expiration is effected.    The  enlargement  or inspira-
tion  is accomplished by the simple  elasticity of the encasing
rings of the body,  as well as of the  trachea.  Hence, full-
ness  is the  natural or  passive  state  of  the respiratory or-

  AA'hat are the spiracles?  How ore they sometimes  protected ? Give tho mechanism
of respiration. 
278
HITCHCOCK'S   ANATOMY
gans, as was seen to be  the case with birds.   Still  another
way in  Avhich respiration  is  effected, is by the sliding of one
ring inside the next one,  like the  joints of a hand telescope,
and  their return by the  elasticity of the tissues of the  body.
And Ave can not fail  to  observe the  beautiful design of the
Creator, when, though  he furnished but a limited circulation
of fluid, yet fully compensated for it by introducing the  air in
minute  tubes to the very  center of every tissue.

  489.  Crustaceans.■—These animals breathe mostly by gills.
The Myriapods have proper tracheae, though with some respi-
ration is chiefly cutaneous, that is, directly through the skin.
The Arachnoid  or  Spider tribe sometimes have  tracheae and
sometimes even lungs.   The gills of the Crustaceans are situ-
ated in different parts of the body, more  especially on the
feet.

  490.  Molluscs.—In  the Acephala the blood before  return-
ing to  the  heart  passes  through  a  bronchial  organ or gill,
which  opens and  closes  for the  ingress and egress of water.
Some of the Cephalophora have gills;  others lungs, and others
a system for the circulation  of Avater containing  air, through
different parts of the body.   The  Cephalopoda all respire by
gills; but they have also an aquiferous system.

  491.  Radiates.—"The simple exposure of  the surface of
a jelly-fish  or polyp to  the action of the fluid  around it is
sufficient to  carry on all  the changes  which take place  in its
simple kind of respiration."—Prof.  J. Wyman.   Nearly all
the Radiates  have  such an  aquiferous  system.   But many
of them have other organs for breathing.  The Echinoderms
have gills;  also sometimes  their  organs of prehension and
locomotion form a respiratory apparatus.
 What instance of compensation is shown here ? 4S">. Do any crustaceans breathe by
gills?  4^0. AVhat is the breathing apparatus of molluscs ?  431. AA'hat is tho respiratory
apparatus of radiates ? 
AND  PHYSIOLOGY.              279
            THE  SOUNDS PRODUCED  BY  ANIMALS.

   492. Among A-ertebrates the  production of vocal sounds is
confined  to  the  air-breathing classes, since  no fish or gilled
animal is able to make any sound by  means of the special
organs which are provided  for that purpose in other animals.
   493. Laryngeal  Pouches, or  Sacs.—Nearly every mam-
mal can  make some  vocal sound, and  the  structure of the
larynx in all very closely resembles that of man.  The howl-
ing apes present the most  striking difference in these organs.
They  haA'e  pouches,  or laryngeal sacs  as  they  are called,
jonnected with the larynx,  which increase  the loudness of
the voice  simply by  the resonance of the voice in these cavities.
   494. The  Two Larynges  of  Birds—The  Trill  of Birds.
—In birds the vocal organs are somewhat different from those
of man.   There  is in  them  a larynx,  called the  superior
larynx, at the summit of the trachea, which seems designed
mainly for  the  ingress  and egress  of  air.   But the vocal
sounds for which  birds  are so remarkable are  made by Avhat
is called   the  inferior larynx, which  is situated at the lower
extremity of  the  trachea.  This  is most complex  in birds
which have  the  greatest poAvevs of  song.  The two or three
loAver rings of the trachea  are  usually consolidated into one,
and in the interior a cross bone runs from front to back which
has upon its upper edge a' small membrane of a crescentic-
shape, Avhich is so lax that  it can freely vibrate when the air
is made to pass  rapidly OA'er it.   This in its action, is anal-
ogous to  the reed of the  clarionet or melodeon.   It is by the
vibration  of this  membrane  that  the  peculiar trill  of many
singing-birds is so beautifully executed.   The intensity of the
 402. AVhat vertebrates alone can make vocal sounds ?  40.1. AVhat is said of the struc-
ture of the larynx in all mammals ? AVhat is the peculiarity among the howling apes?
404. How many larynges have birds?  Give the function of each.  What peculiarity in
the lower part of the trachea 2 
280
HITCHCOCK'S ANATOMY
tune is greatly increased by the  construction of the trachea
and  bronchi.   "Birds  whose  voices  have a  very extensive
musical scale are able  to shorten and  lengthen their Avind-
pipe considerably, and to that end have very thin Avings and
large membranous interspaces."
   495. Larynx of  Reptiles.—Reptiles have an  imperfect
kind of larnyx, which is located at  the point Avhere the trachea
opens  into  the pharynx.   The only  sounds Avhich  they can
make is the croak of the frog and hiss of the serpent, turtle,
or lizard.   The common Frog  has two vesicles or little bags
behind the angle of the mouth, Avhich arc much distended at
the beginning of summer and at pairing time, which accounts
for their loud croaking at these seasons.
   496. Sounds  Made by Insects.—As we  descend the scale
of animals, we  find  in  no other a larynx or organ of voice,
and  hence all  the sounds made by them are  not  the sounds
of the voice, but simply noises which are for the  most part
made by their extremities.   The sounds made  by insects such
as approach  most nearly to those of  A'ertebrate animals,  are
produced  by vibrations of a membranous  plate  situated just
over the spiracles.   And  in general those  insects that fly the
most rapidly, and whose Avings move the fastest,  make  the
most noise, Avhile those  which move more sloAvly seem only to
fan the air Avith their wings.   Other sounds are produced by
mastication.  Thus,  an army of locusts, Avhen eating, makes a
sound Avhich Arery much resembles  the noise of a crackling fire.
A genus of ants make a sound by striking  some  hard sub-
stance with  their mandibles,  or  arm-like  appendages.   A
species of beetle that bores in old timber (called the  death
watch) makes a sound in a similar Avay, and if it be answered
by its  mate the signal will be  repeated: but if  no answer be
given,  the animal changes its  position before  it produces its
"tick"' again.   The shrill sound of the grasshopper and the
  AVhat ase is it? AVhat construction increases the intensity of their tones? 495. What
is the larynx of reptiles ? AVhat is their voice ?  49C. Do insects have a larynx ?  In
what different ways are sounds made by insects ? 
AND  PHYSIOLOGY.
281
so-called locust is made by rubbing together the anterior pair
of wings, upon the  nervures or framework of the wings, on
which are  found file-like  edges.   In a large species of this
kind living  in  Brazil, which has a drum-like  appendage un-
der the wings, the sound can be heard a mile; and if a man
of ordinary stature  possessed a proportionably loud voice, he
could be heard all over the world.
   497. Sounds  of Mollusca .—Among the  Cephalopods there
are a few individuals which are able to make a clear,  bell-like
sound, but the origin of it  is unknown.
437. What is said of sounds made by molluscs ? 
CHAPTER   SIXTH.
ICHOROLOGY,  OR HISTORY OF THE ORGANS OF SECRETION.
         THE  LYMPHATIC AND SECRETORY SYSTEM.
DEFINITIONS AND DESCRIPTIONS.
Fig. 274.
  498.  The  Body  is Constantly Undergoing a  Change.—
We have seen that the human body is constantly undergoing
                                   changes in its  constituent
                                   parts.   The nutrient por-
                                   tion of the food designed
                                   for the support and growth
                                   of the different  tissues is
                                   conveyed by the lacteals to
                                   the left  sub-clavian vein,
                                   Avhere it enters the general
                                   circulation; while the par-
                                   ticles which are constantly
                                   set free in all  parts of the
                                   body are, by vessels of the
                                   same  general   character,
                                   called  lymphatics,  con-
                                   veyed to  the blood  and
                                   thence to the  lungs.
                                      499. The  Lacteals  a
                                   Variety  of the Lymphat-
                                   ics.— A  more   correct
 A, rt, Deep-seated Lymphatic Gland, a, b. Lym-
phatics which supply and Empty the Gland,  b arrangement,     however,
a, Superficial Lymphatic, less complex in struc- Lrinos LotL spt(, nf .,V,oOVU
ture.  c, a, Lymphatic laid open  to show the urlng» DOm SetS 0I 'IDSOIO-
Vaives, c, d, e.                          ent vessels under the class
of lymphatics,  making the lacteals  only a variety, since their
 49S. How is it that the  body is constantly undergoing change?  499. What may^the'
lacteals be properly called ?
 
AND  PHYSIOLOGY
283
Fig. 275.
The Lymphatics of the Pody, 
284             HITCHCOCK'S   A.N ATOMY

chief  difference consists in the  kind of  material they convey,
and not in structure or  function.
   500.  The   Lymphatics—Their  Similarity  to  Veins  and
Arteries—Their Appearance when  Injected with  Mercury.
__The lymphatics are very delicate,  minute  and  transparent
vessels like the capillaries, remarkable for their uniformity of
                              Fig. 276.
  A View of the Vessels and Lymphatic Glands of the Axilla.  1, The Axillary Artery.
2, The Axillary Vein. 3, The Brachial Artery. 4, The Brachial Vein. 5, The Primi-
tive Carotid Artery.  6, The Internal Jugular A'ein.  7, The Sub-Cutaneous Lymphat-
ics of the Arm at its Upper Part.  8, Two or three of the  most Inferior and  Superficial
Glands into which the Superficial Lymphatics emnty. 9,  The Deep-seated Lymphatics
which accompany the Brachial Artery.  Id, The Lymphatics and Glands which accom-
pany  the Infra-Scapular Blood-A'esscls.  11, The Glands and Lymphatics accompanying
the Thoracica Longa Artery.  12, Deeper-seated  Lymphatics.  13, The Axillary Chain
of Glands.   14, The Acromial Branches of the Lymphatics.  15, The Jugular Lymphatics
and Glands  16. 17, The Lymphatics which empty into tho Sub-Clavian Vein near its
junction with tho Right Internal Jugular Vein. 
AND   PIIVSIOLOGY.
285
Fig.
 size, of a knotted appearance, and very frequently dividing into
 two nearly equal branches.   Like veins and arteries, they have
 three  coats, Avith folds of  the
 inner  coat for the  formation
 of valves, giving them a knot-
 ted  appearance.   They  com-
 mence in a  minute net-AA'ork
 in nearly  every organ of  the
 body,  and  soon unite into a
 feAV  large  trunks which take
 a direction towards the veins
 in the lower part of the neck.
 This net-work is so  exceed-
 ingly delicate,  that when filled
 with  mercury it presents the
 appearance of a sheet of silver.
 The necessity  of such an im-
 mense number of these A^essels
 arises  from the  constant  lib-
 eration of the  waste particles
 of matter  which need to  be
 removed  as  soon as possible,
 that  the  deposition   of  .neAV
 particles may not be prevented.
   501. Lymphatic  Glands.—
 As  the  minute  lymphatics
 unite into larger trunks, they     A ^
                                   racic Duct. 1, Arch  of the  Aorta.  2,
 Thoracic  Aorta. 3,  Abdominal Aorta. 4, Arteria Innominata.  5, Left Carotid.  6,
 Left Sub-Clavian.  7, Superior Cava.  8, The two A'eme  Innominatoe. 9, The Internal
 Jugular and Sub-Clavian Vein at each side.  10, The Vena Azygos.  11, The Termination
 of the Vena Hemi-Azygos in the Vena Azygos.  12, The lteceptaculum Chyli : several
 Lymphatic Trunks are seen opening into it.  13, The Thoracic Duct dividing, opposite
 the Middle Dorsal Vertebra, into two branches, which soon re-unite ; the course of tho
 Duct behind the Arch of the Aorta and Left Sub-Clavian Artery is shown by a dotted
 Line.  14, The Duct making its turn at the Boot of the Neck and receiving several Lym-
 phatic Trunks previous to terminating in the Posterior Angle of the Junction of the In-
 ternal Jusnlar and Sub-Clavian Areius. 15, The Termination of the Trunk of the Lym-
phatics of the Upper Extremity.
 500. Describe the lymphatics. How many coats have they ? AVhat is said of tho net-
work which they make ?  Why the necessity of such a multitude ?
 
286            HITCHCOCK'S  ANATOMY

pass through small bodies, varying in size from a mustard-seed
to a pea,  which are  called lymphatic  glands,  whose design is
not yet clearly understood.   They then pass upwards towards
the heart as already mentioned, those of the left side of the body
emptying themselves through the thoracic duct, Avhile those of
the right side enter  a  tube running parallel to this, called the
Ri0ht Lymphatic  Duct,  is, Fig. 277.

                              Fig. 278.
  A Pront Yiew of the Femoral, Iliac, and Aortic Lymphatic Vessels and Glands. 1, Sa-
phena Magna A'ein. 2, External Iliac Artery and Arein. 8, Primitive Iliac Artery and
A'ein.  4, The Aorta. 5, Ascending Arena Cava.  6, 7, Lymphatics which are alongside
of the Saphena A'ein on the Thigh.  8, Lower Set of Inguinal  Lymphatic Glands which
receive these A'essels.  9, Superior Set of Inguinal Lymphatic Glands which receive these
A'essels.  10, The Chain of Lymphatics in Front of the External Iliac A'essels.  11, Lym-
phatics which accompany the Circumflex Iliac Vessels.  12, Lumbar and Aortic Lym-
phatics.  1:1, Afferent Trunks of the Lumbar Glands, forming the Origin of the Thoracic
Duct.  14, Thoracic Duct at its commencement.
501. Describe the lymphatic glands.  What is the right lymphatic duct? 
AND  PHYSIOLOGY.
287
502.  Material Absorbed   by  Lymphatics —Effect  of
Fig. 279.
 Various   Substances  Ap-
 plied  to the Skin —Nutri-
 ment   Sometimes   Intro-
 duced through  the Skin-
 Thirst  Quenched   by  Wet
 Clot lies.—These A'essels not
 only remove useless particles,
 but absorb substances applied
 to the  skin, although  some
 maintain that this is done by
 the veins alone.   And this is
 sometimes an effective method
 of  administering  medicines
 which  it  is  not expedient  to
 introduce through the mouth
 and nostrils, thus  producing
 a  desired effect  upon  the cir-
 culatory and venous  systems
 without offending, or  in any
 manner affecting the senses or
 feelings of the person taking
 the  medicine.   For  instance,
 spirits  of  turpentine  rubbed
 upon the hands of many per-
 sons, and green  leaves  of to-
 bacco   placed upon  the ab-
 domen,   Avill often   produce
                                   A Front A'iew of the Deep-seated Lym-
phatics of the Thigh.  1, Lower End of the Aorta. 2, Primitive Iliac Vein. 3, 4, Ex-
ternal Iliac Artery and A'ein. 5, Femoral Artery. 6, Section of the Femoral A'ein.  7,
A'ena Saphena on the Leg. 8, Lymphatics near the Knee. 9, Lymphatics accompany-
ing the Femoral Vessels. 10, Deep Lymphatics going from the inside of the Thigh  to
the Glands in the Groin.  11, Lymphatics of the External Circumflex A'essels.  12, Lym-
phatics on the outer side of the Femoral Vessels.  13, A Lymphatic Gland always found
outside of the Vessels.  14, A collection of Vessels and Glands from the Internal Iliac
A'essels.  15, The Lymphatics of the Primitive Iliac A'essels.
 502. What do the lymphatics absorb ?  What value of this fact at times? Give a com-
mon effect of tobacco and turpentine rubbed upon the skin.
                            13 
288           HITCHCOCK'S  ANATOMY
 distressing  sickness.  Mercury, too, rubbed vigorously upon
 almost any part of the skin, will in a short time produce sali-
 vation, because the minute globules of this  metal are forced
 through the pores of the skin, and are  absorbed by the lym-
 phatics.   In  some  cases Avhere disease  has so  affected  the
 mouth  or passage  to the stomach  as to prevent the intro-
 duction  of food, life  has been maintained for a considerable
 time by nutriment introduced through the skin, by means of
 a bath of Avarm milk.   Shipwrecked  sailors  in  an open  boat
 and depriA-ed of fresh  water, can for some time partly assuage
 their thirst by wetting their clothes  with  salt water, or better
 still, by a thorough Avetting during a rain storm.
    503.  Poisons  Introduced  through  the Skin  by the Lym-
 phatics.—The poisoning which frequently occurs from  the
* contact of the skin Avith sumach or ivy, is  OAving  to  the  ab-
 sorption of poisonous influence by these vessels.   Animal poi-
 sons, too, such as the Arenom of mad  dogs,  serpents,  and in-
 sects, are introduced to the general system by the lymphatics.
    504.  Pressure  Increases their Action.—Pressure greatly
 increases the action of  the lymphatic A'essels.   This is  seen
 in a broken limb which has been tightly  bandaged, when  the
 muscles become very small from  the removal  of  the tissue  by
 the excessive action  of the lymphatics.
    505.  Venous Absorption—Radicles.—Besides  lymphat-
 ics, the  small veins  perform the  function  of absorption.  It is
 easily  seen that these  can perform the same office as the lym-
 phatics,  since both of them carry their fluids to  the heart for
 purification, and no other use is made of them  on their way
 thither.   These radicles, or small veins,  perform a Arery  im-
 portant function in the stomach  by the rapid absorption of the
 watery portion of all  liquids,  and its  conveyance to the gen-

   Is nutriment ever conveyed into tho system in this way ? Can thirst be quenched in
 this way ?  503. Do the lymphatics ever introduce poison  into the system? 504.  How
 does pressure affect the action of lymphatics?  What example of it?  505. What is said
 of absorption by the veins?  AA'hat important service do the radicles perform in the
 stomach ? 
AND  PHYSIOLOGY.
289
 eral circulation without passing through the circuitous course
 taken by the food.
   500.  Effect of Moistnrc upon the Lymphatics.—Moist-
 ure stimulates these absorbent vessels  to  a morbidly vigorous
 action.   Hence a person surrounded  by a moist atmosphere
 or immersed in  water itself, will acquire additional weight.
 And as an excessive use of  the eliminating organs of the sys-
 tem is injurious,  locations for houses should be selected as far
 as possible on dry places, and not on Avet  or low land where
 heavy fresh water fogs prevail.   For  the same  reason damp
 clothing injures  the body,  because it  unduly stimulates  the
 lymphatics.
   507.  Amount  of  Matter  taken up by  the Absorbents —
 The amount of Chyle and Lymph poured into  the blood by
 the lymphatics and  radicles  is about one  third of the Avhole
 amount in the body.


              OT. GANS  OF  SECRETION.

   508.  Follicles and Glands.—Character of Secretions —
 Size of  Follicles.—The organs  which perform  the office of
 secretion in the body are Follicles and Glands.  . The former
 of these are small bodies in  the  form of sacs or  tubes, exist-
 ing  for the most part in the skin and mucous membrane, one
 end of Avhich opens upon the surface of the membrane, for  the
 discharge of its secretion.   The secretion poured from these
 varies  in consistency from the thick Avax of the ear, to  the
 limpid juice of the  stomach.   The follicles vary also in  size
 from tubes perceptible to the naked eye doAvn to those ^\th of
 an inch in diameter.
   509. Glands.—The Glands are soft solids of various sizes
 (the liver the largest) made  up of lobules  or small bodies of
 506. How does moisture affect the lymphatic action ? How do damp clothes injure the
wearer?  507. What is the amount of matter taken up by the absorbents? 508. What
is the anatomy of the follicles ? Of what character id their  secrotion ? What Is their
Bize? 509. AVhat is a gland? 
290
HITCHCOCK'S  ANATOMY

            Fig. 280.
Intimate Structure of a Gland (the Parotid).
minute proportions, each of Avhich has an  artery, a vein, and
a duct to carry aAvay the secretion.   These  ducts  unite Avith
one  another,  until  they  form  one tube called  the principal
outlet of the organ.   In some glands these  lobules are quite

                             Fig. 281.
        Aorta. Thoracic Canal.  Lymphatic Ganglions.
,     ( Radicles of the Chyliferous
).--•'' 1  Vessels.
-Intestine.
Lymphatic Vessels. Mesentery.
                       Chyliferous Vessels. 
ANATOMY  AND  PHYSIOLOGY.
291
 large—one fourth of an inch in diameter—while  frequently
 they are nearly the size of a mustard seed.   The color is also
 various.   That of  the liver  is a dark red,  the pancreas of a
 pale white or gray,  the little gland in the. inner angle  of the
 eye pink, and the kidneys a  reddish yelloAV.

   510.  Function of  Secretion.—The function performed by
 these vessels is an exceedingly curious,  and not  easily  ex-
 plained phenomenon.   For from the  blood  are eliminated by
 the various  secretory  organs, bile, saliva, perspiration,  tears,
 etc., none of which exist there  as such, but they seem to be
 formed from the chemical elements in the blood by the glands
 themselves.

   511.  Effect  of  the  Emotions upon  the Secretions.—
 The mental emotions greatly affect the secretions.   A person
 in fear is often covered Avith  a cold perspiration, and  in  some
 persons in  the same situation the salivary glands cease to act.
 On the other hand the thought of savory food has been knoAvn
 to cause the saliva  to issue  in  a  jet  from the sides of the
 mouth.

   512.  Reserve  Glands.—Some glands also act only on parti-
 cular occasions,  as in the case of a broken bone,  or cut in the
 flesh, Avhen the appropriate vessels  set themselves at Avork to
 repair the injury.

   513.  Secretion after Death.—Certain  secretions are con-
 tinued for a time after the death of the individual.   Thus it
 has  been observed that  the hair and  nails groAV considerably
 after death, provided the disease Avas a rapid one, so that tho
 system Avas not  reduced by  loss or degeneracy  of  the  blood
 and nerArous system.   It is also related that  in dissecting the
 poison apparatus  of  a  rattle-snake,  the poison Avas secreted so

  Give the minute anatomy of the glands.  Describe their ducts. Mention their various
 colors. 510. What is the use of the glands ? Do the secretions exist ready formed in the
 blood? 511.  What is the effect of the feelings upon secretion?  Give an example. 512.
What is said of reserve glands?   513. AVhat is said of secretions continuing some time
after death ?  Give an example. 
292           HITCHCOCK'S  ANATOMY

fast that it was necessary to dry it( off occasionally during the
dissection.
   514.  Vicarious  Secretion.—Another curious  phenomenon
connected with this subject is  vicarious secretion,  where one
organ performs the whole or  part  of the office of another.
This is often seen in the function of the lungs and liver, Avhere
one imperfectly performing its office, is  aided by  the  other.
This vicarious secretion is still more apparent  betAveen the
liver and skin.  For in the disease known as Jaundice,  where
some obstruction is offered to the passage  or secretion  of the
bile, it is poured out  by the skin, coloring it deeply yelloAV,
and in some instances it has been knoAvn to stain  the linen,
Avhich is Avorn next the skin, perceptibly yelloAV.
   515.  Ductless Glands.—In  connection Avith  this subject
it is proper to mention  a class  of organs  knoAvn as Ductless
Glands, or bodies which have the form and  general structure
of glands,  but no duct or outlet, and  form no secretion, as do
the true glands.   These  are the  Spleen, the  Thymus and
Thyroid Glands, and the Supra Eenal Bodies.   Of these only
the former will be described  here,  since  the  latter are most
perfectly developed during the  earliest, or fetal stage of exist-
ence.
   51G. The Spleen.—The Spleen measures in different indi-
viduals from four to six inches  in its longest diameter,  and is
situated under the left extremity of the stomach.   (Fig. 282,
p. 293.)   It is of a reddish blue color, convex on its external,
and concave  on its internal surface.   It is  very abundantly
supplied Avith  blood-A-essels,  and  consequently vascular  or
spongy in its structure.   (Fig. 283, p. 293.)   Upon a  close
inspection it  is found to  be made up of corpuscles from one
third to one sixth of a line in diameter, each of Avhich is com-
posed  of nucleated cells about  soVoth. of an  inch in  diam-
eter.   (Fig.  284,  p. 203.)
   514. State the principle of vicarious secretion.  AA'hat remarkable facts in this connec-
 tion about jaundice? 515. Describe the ductless glands.   What are their names ? At
 what period of life are they the most fully developed ? 516. Describe the spleen. 
AND   PHYSIOLOGY.
293
Fig.  282.
Fig. 283.
  Shows the Internal Face of the Spleen              Section of the Spleen.
where it touches the Stomach.   1, Supe-
rior Extremity.  2, Inferior Extremity.  3, Posterior Part of the Concave Face.  4, An-
terior Part of the same.  5, Fissure of the Spleen.  C, Splenic Artery.  7, Splenic A'ein.
8, S, Anterior Edge of the Spleen.  y, 9, Its Posterior Edge.

                                   FlG. 284.
Section of the Spleen magnified. 
291           HITCHCOCK'S  ANATOMY
  517.  Function of  this Organ.—Produces  and  Destroys
the Red Blood  Corpuscles—As already stated there is no
duct or outlet to this organ, or evidence of any secretion out-

                           FiG. 285.
 Small Portion of the Spleen very highly magnified, showing two corpuscles and the
minute Blood-A'essels.

ward.   But  the idea has  occurred  to physiologists, though
with no positive proof as yet, that a kind of secretion is pro-
duced by the spleen which is poured  directly into the  blood,
and consequently there  is  no necessity for any outlet.   And
again experiments have been carried so far as to give plausi-
bility  to  the  idea,  that  this  organ  is designed to produce
blood corjnisc7es, and at the same time use up those  that aro

 51". Of what use is tho spleen? AArhat is said of it as an organ for producing blood
corpuscles ? 
                  AND  PHYSIOLOGY.              295

 no longer of service  to the body.   Certain it is that no other
 organ in the body has as  yet been discovered which  subserves
 this purpose,  and equally certain  that  in  cases, where large
 wounds are to be  healed, and in  certain  other conditions of
 the body, the  white corpuscles are greatly  increased in num-
 ber.

   518.  The  Skin—Among  those organs whose offices  are
 those of absorption and secretion, the Skin finds a prominent
 place.

   519. Made  up  of Three Membranes.—This is a membrane
 simple in its  general aspect, but under the  microscope it is
 found to  be composed of no less  than three distinct layers:
 the Epidermis, Basement Membrane, and Corium.   It coA-ers
 every part of the body, except the  portion immediately sur-
 rounding  the  various orifices, and  those portions of the ex-
 tremities covered by  the  nails.   It is  highly elastic, as may
 be seen by the gaping of  a long gash, and  possesses  a certain
 amount of contractility, OAving to some muscular  fibers con-
 tained in it,

   520. Papilla;; their Size.—Upon several portions  of  the
 body the  skin is roughened by  small protuberances, either
 arranged in a circular  form, or in toavs, Avhich are supplied
 Avith one  or more  loops  of
 nerA'es.   These  are  termed              Fig. 286.
 Papillae, and are  found most
 abundantly  in  the extremi-
 ties, and  especially upon  the
 palms of  the hand and soles
 of  the  foot.   They vary in        ^^^.fMS?^£
 height from ^Vrd to ^;d of a
   o         J "      •*  -           Papilla? from  Palm of the Hand, magni-
 line, being of different  lengths    fied thhty-nvc times.
in different parts of the body.
 519. Of what three membranes is tho skin made up?  State their general proper-
ties. 520. AVhat are the papilliB?   Where are they found in the greatest numbers?
State their size.
                           13* 
296           HITCHCOCK'S   ANATOMY
   521. Epidermis or Cuticle;  Has  no Vitality.—Pigment
Cells.—Composition  of  Pigment-Cells*—The  outer layer of
the skin  is  called  the Cuticle  or Epidermis,  and  bears the
same  relation to the true skin, that the outer bark of the tree
does to the inner.   In thickness it varies  considerably in the
different parts of the body.   It is ro „-th  of an inch thick on
the chin,  cheeks and brows,  and ^th  to J th of an inch thick
on the soles of the foot.   It is merely a layer  of albumen—
FiG. 287.
Fig. 2SS.
o;.^J
 Vertical Section of Epidermis from a
Negro,  rt, Deep Cells loaded with Pig-
ment, b, Cells more elevated and some-
what flattened,  c, Scaly Cells at the Sur-
face.
 Highly magnified Pigment-Cells.  A.
Scales of the Epidermis filled with Pig-
ment Cells which are seen separate at b.
B. Pigment Cells from the Choroid Coat
of the Eye.
the same substance as the white of  an egg—and is  secreted
by  the true  skin,  in the form of  scales,  Avhich are closely
compacted together, and it is in this form that they are de-
tached  from  the  body by Avashing and friction.   In some
cases, however, it  is detached in large patches, so that after
certain skin diseases haA'e  run  their career, the whole epider-
mis  of the hand with the nails  adherent may be remoA'ed in
the manner of a  glove.   The  epidermis contains no blood-
vessels or nerves, and consequently no vitality, it being merely
a secretion  Avhich hardens  into a semi-transparent membrane.
A part of  the cells of the true skin, hoAvever, instead of se-
creting the epidermis, produce what are  termed the Pigment
  521. Describe the epidermis.  To what does it correspond in the tree? State its thick-
ness and chemical composition. AVhat vessels and what cells does it contain? AYhere
are the pigment cells shown ? 
AND  PHYSIOLOGY.
297
Cells, which give color to the skin.   These cells are best ex-
hibited in the eye where the pigmentum nigrum (black paint)
is secreted,  and are of the same kind Avith those  in the epi-
dermis.   They  are oval  or rounded  granules,  measuring
2oo-ooth of  an inch in diameter,  and one quarter of this in
thickness, sometimes presenting  a polygonal or stellate form.
They have nearly the same composition as the  coloring matter
of the cuttle-fish, Avhich contains a much larger proportion of
carbon than is contained in most  organic substances, namely
58 £ parts in hundred.   The development of  these cells de-
pends mainly upon  exposure to the  sun's  light.   Ilence  we
see  that  persons Avith a fair skin become of a  darker hue, if
exposed to the strong and direct light of the sun.

  522.  The Nails;  Mode of Growth;   Rate  of Growth.—
The Nails are  composed of the same material as the epidermis,
being merely an altered  form of it.   When their newest por-
tions are examined  with the microscope, they are found to be
nucleated  cells  closely resembling  those of  the epidermis,
Epithelium cells.  The
nail increases in length
by  successiA'e additions
to its root,  Avhich push
it forward over the  end
of the finger,  Avhile at
same time  it  receives
additional  layers from
the  skin beneath.  The
nails of the  hands groAV
about  two  fifths of a
line per  week, while
those of  the  foot  re-
quire four times that period for the same amount  of growth.
The blood-vessels  of  the nails  are very abundant, and are
Fig. 280.
 Section of the Thumb, a. Last Bone of the
Thumb,  b. Epidermis reflected on the Nail.  c.
Xail.  d. Epidermis at the Point of the Tumb.
 What is very remarkable about the chemical composition of this pigment? AVhat
does the development of these cells depend on? 522. Of what composition are the nails?
Of what kind of cells are they ?  How fast do the nails of the hand grow ? 
298          HITCHCOCK'S  ANATOMY

situated just within the  corium,  into which the  nail barely
dips.   And so numerous are these, and of so low a degree of
vitality,  that frequently the nails grow  for a  short  distance
after death.  "When the nails are badly injured, they are sel-
dom perfectly regenerated, because of the injury done to  the
vessels and laminse.   A rudimentary nail sometimes is found
on the second joint, when the first is  destroyed.   Cases  are
also on record, where the nails haAre  been shed and  renewed
periodically.   The nails  are thickest  at their most  convex
portion, instead of their edges, and increase in thickness from
the base to their free edge.   They groAV  only so long as they
are cut,  and among the literary class  of the Chinese, who
never cut their nails, they are said to attain only a length  of
two inches.   The  time necessary for a nail to grow its whole
length, varies from tAvelve to twenty weeks.
   522 a.  Basement  Membrane  of  the  Skin.—The middle
layer of the skin  is simply a basement membrane, and  is  in
fact the  mucous  layer  of the epidermis.  It is, however, of
little importance  in  the functions of the skin, and is believed
to be a separate layer merely because, when it is immersed in
a  solution of potash in  connection with the  epidermis,  the
latter is dissolved, while the former is unchanged.
   523.  The  Corium;   its  Composition; Nerves  of  the
Corium.—The  Corium  or  internal layer  is the  true  skin,
since it possesses the vitality and sensibility of this membrane,
and contains all its vessels.   It is made up of Avhite and yel-
low fibrous tissue, the white predominating, except  in  those
parts where occasional extension is required, where the yellow
exists  in larger proportion.  The blood-vessels of  the corium
are very abundant, terminating  in  the  minute  tubes which
supply the sudoriparous and sebaceous glands : the proof of
the abundance of which  we have in puncturing any part of

  Why do the nails sometimes grow after death? Why do the nails seldom grow nat-
urally after an injury?  At what portion are the nails the thickest ?  522 a. What  is tho
middle layer of the skin ? 523. Of what is the corium composed?  AVhat is said of the
abundance of blood-yessels in the corium ? 
AND  PHYSIOLOGY.
299
the skin with the finest needle, when a drop of blood  is sure
to follow.  The nerves of sensation too are very abundant, as
we know by  the insertion of a pin into any part of the body,
which invariably pains us, because we have Avounded a nerve,
and not an expanded surface, like a membrane.

   524. Sebaceous  or  Oil   Glands___The  Sebaceous  Glands
are small  elongated sacs which are  generally  gathered in
clusters  about  each  of  the
hairs  of the body,  varying            Fig. 2ao.
in number from four to twen-
ty.   They pour their  secre-
tion into the hair-canals near
their  orifices,  and are most
abundant in the parts of the
body  most exposed, as in the
skin  of the  nose.  Their se-
cretion in most places resem-
bles fat,  although in the pas-
sage  of  the  external  ear a
substance   resembling   Avax
(cerumen) is poured out.
   524a.   Parasite  in  the
Sebaceous Glands.—It  is a
fact  curious, if not at  first
sight  revolting,  that there is
very  constantly found  in the
outlets to many of the sebaceous glands a parasitic animal, as
represented by the cut.   (Fig. 291, p.  300.)   The occurrence
of this animal in almost every  individual has led one anat-
omist to call  it a "denizen"  of the human body.

   525.  Sweat  Glands.—Length  of  Sweat  Tube  in  the
Human1  Body.—The  Sudoriparous  or Sweat  Glands  essen-

  What of the nerves In the corium ? 524. What are the sebaceous glands?  Where are
they the most abundant ? What is  their secretion; ? 521 a. What is said of the parasite
in the skin?
 A A'iew of the Cerumen Gland
formed by the Contorted Tubes. 1, 1,
The Tubes.  2,  The Excretory Duct.
3, The A'essels supplying it. 
300
II I T C II C O 0 K. ' S  ANATOMY
Fig. 291.
    Parasites of the Sebaceous Glands,  a. Two seen in their ordinary position at the
 Orifice of the Gland,  b. Short Variety, c. Long Variety.

 tially consist of long tubes convoluted and tAvisted upon them-
 selves, (Fig.  293,  p. 301), located just  beneath the corium,
 several of which join to form an outlet, which passes through
 the epidermis in a spiral manner, so  that  as it opens  exter-
 nally, a valve is made preventing the entrance of substances
 from without, but allowing a ready exit to all substances to be
 discharged externally.   The size of the gland proper is about
 7Vth of an inch  in diameter, and that of the  tube is about -i-th
 inch.  The outlets of these  tubes (Fig. 292,  p. 301,) are called
 the pores of the skin, and are somewhat larger than the diam-
 eter of the tubes.   The most remarkable fact,  however, con-
 nected with these glands, is their immense number in the sys-
 tem.  Each tube when straightened measures on an average one
 fourth of an inch in length, and by actual  count there  are at
 least 2,800 in  every  square inch of the body.  (Fi*r. 293
 p. 301.)  Now the number of square inches in a man of or-
dinary  height is  2,500, which  would make the number  of
pores or openings about 7,000,000, or the whole  length  of

 525. What is the general outline of the sweat glands? What is their sIzp ?  ti„„„
on every square inch of the body ?  What is their aggregate length ?             y 
         AND  PHYSIOLOGY.   .-           301

Fig. 292.                           FlG. 293.
  Skin of the Palm showing Ridges, Fur-
rows, Cross Groves, and Pores, or Orifices
of Sweat Ducts.
tube 145,853 feet, or 48,611
yards,  or  nearly  28  miles.
Dalton says, 153,000 inches
or two and a half miles.
   526.  The Perspiration.
—Sensible  and Insensible
Perspiration.—The  secre-
tion  poured  out  by  these
glands, is a transparent liquid
of an acid reaction, and of a
saltish taste, commonly knoAvn
as SAveat or perspiration. This
is produced in  two forms,
known as sensible and insen-
sible perspiration,  Avhich  is
escaping  from  the  body in
one  of these forms constantly during health, the sensible being
given off Avhenever excretion is so great  as to  leave  moisture
upon the skin.                                               _
            520. Describe the perspiration. What two forms of it?
 Vertical Section of the Sole of the Foot,
a. Epidermis,  b. Papillary Structure.
c. Cutis,  d. Sweat Gland magnified forty
diameters. 
302           HITCHCOCK'S  ANATOMY
   527. Amount  of  Watery  Vapor  Discharged  from  the
Body—The amount  of fluid which is lost from  the body both
by the skin and lungs, is about eighteen  grains per  minute,
eleven by the  skin and seven  by the lungs.   This amount,
however,  varies exceedingly with the state of the  health  and
the dryness or moisture of the air, Avhich, as  already men-
tioned, regulates the temperature of the system.
   528. The Hair.—The hair is distributed over nearly every
portion of the human frame, and presents differences according
                                to age, sex, race,  or  individ-
           FlG 294
                                ual peculiarities.   In length,
                                the hair  is  most  fully devel-
                                oped on the heads  of females,
                                sometimes equaling the length
                                of the body, while in male
                                beards it seldom  reaches to
                                the Avaist.   The coarsest hair
                                is also found on women.
                                  529. Size of  the  llair—
                                Oil Glands.—In diameter the
                                hair varies  from  TTo^h  to
                                20'outh of  an inch,  and  its
                                section is  always  of an oval
                                outline,  but  never  circular.
                                Nor is the hair of a uniform
                                diameter,  but  it  is  spindle-
                                shaped  almost  ahvays,  and
                                terminates  in a point.  At its
                                base  it  expands  into a bulb
                                Avhich is lodged  in a sac in
the true  skin, as  is seen in Fig. 295, p. 303. Just  beneath  the
epidermis one or  more glands  are  situated  Avhich  empty their
  Sections of Human Hair,  a, b, Trans-
verse  Sections showing the Cortical (or
external) and Medullary (or internal) Sur-
face,  e, d. Longitudinal Sections of Hair.
d, Shows the overlapping of the Epidermic
Scales of which hair is composed.
 527. What is the amount of watery fluid discharged from the body? 52S. What is said
of the distribution of the hair? How lone; has tho hair been known  to grow? 529.
What is the diameter of the hair?  AA'hat is the shape of it?  AVhat glands empty their
contents upon the base of each hair ? 
AND  PHYSIOLOGY.
303
contents into the same pore in
which the hair itself is  lo-
cated. This secretion is an oil
which keeps the  hair  in a
smooth and moist state.
   530. Their Number.—The
number of the hairs varies
with the color and portion of
the body.   In one  case  there
were  found on  the  same sur-
face  147   black hairs, 162
brown, and 182 blonde.   On
a  surface  one  fourth of an
inch square the same author
found on the scalp  293  hairs
and on the chin 39.
 Layer from Scalp, a, Oil Glands,  b,
Hair  e, Follicle.
   531. Their  Distribution
and   Direction.—They  are
implanted either  singly or in twos or threes,  or even four
or  five together, and  their direction is  rarely perpendicular
to the skin, being, in a natural state, downwards.  . They may,
hoAvever,  be changed in their direction by persevering efforts,
as is sometimes seen by the brushing of the hair away from
the forehead.
   532. Chemical  Composition—Durability.—They  differ
from most tissues of the body by containing ten per  cent, of
sulphur.   This, together with the fact  that  they contain a
large per cent,  of nitrogen, accounts for the unpleasant odor
giA-en  off Avhile burning.  They resist  decomposition better
than most of the  tissues.  Those  of Egyptian mummies re-
main quite unchanged.    And it is owing to their durability
that they are used as relics of departed friends.
 5.31. What is said of the number of hairs on the body? 531. IIow are they distributed,
and what direction do they take ?  532. How do they differ from most other tissues in
chemical composition?  How durable is hair? 
304
HITCHCOCK'S  ANATOMY
            Fig. 296.                 533.  Constitution. — In
                                  constitution  the  hair  con-
                                  sists of  three  distinct  por-
                                  tions, an epidermis or outer
                                  portion, a fibrous, and a med-
                                  ullary portion.   The epider-
                                  mis is arranged in the form
                                  of ring-like  scales,  Avhich
                                  overlap each other like the
                                  shingles  of a house, and is
                                  about  soVoth  of  an  inch
                                 thick (Fig. 294, d).   Hence
                                 we see  the reason  why we
                                 can  brush  the  hair in  only
                                 one  direction.   The fibrous
                                 portion  makes up the  prin-
                                 cipal bulk of the  hair, and
                                 is  composed of  longitudinal
                                 cells,  which contain  paint
granules and air  cavities which give  the color  to the  hair.
The medullary portion constitutes the central part of the hair
(usually from one third to one fifth  its diameter),  and is made
up of cells varying in diameter from e oVotn  to e o o o otn °f an
inch in diameter.
   533 a. Color.—The color of tho hair  is  thought  by some
to be owin<? to the iron contained in  it, since it  is said  that
there is the most of this metal in the darkest hair.
   533 b.   Physical   Properties.—Hair  is so elastic that it
will stretch Avithout breaking to nearly one third more than
its original  length.   A single  hair of the head will  support
six ounces  Avithout breaking.   It  readily absorbs moisture,
and is dry and brittle or moist  and  soft, according as  the skin
or atmosphere is dry or  moist.    The  beard is abundantly
< Highly Magnified Root of Hair, a, Shaft
of Hair,  b, c, Epidermic Sheath of Hair,  d,
Dermic, or External Sheath of Hair,  e, Epi-
dermic Scales.
 53-3. AVhat three portions is each hair constituted of? What makes the principal part
of each hair?  533 a. What is it possible that the color of the hair is owing to? 533 6
What is the strength of the hair ? 
AND   PHYSIOLOGY.
30*
supplied Avith blood-vessels, as              Fig. 297.
is seen by the cut.

   533 c. Rate of  Growth.—
In one  set  of  experiments
the  hair has  been found to
grow seven lines per  month.
Frequent   shaving   greatly
increases its growth.   It also
grows  faster   by  day than
by night,  and  in  summer
than in Avinter.
                                          A
                                  A small portion of the Follicle of a Hair
of the Beard, with the Arteries supplying it—very hiirhly Magnified.  1, Its Follicle.  2,
Its Pulp. 3, The Trunk of the Hair without the Follicle. 4, 4, Two Arteries going
to the  Base of the  Follicle. 5, 5, Their Distribution. 6, 6, The Reticulated Tissue of
the Follicle.


            FUNCTIONS  OF  THE  SKIN.

   534. The  Skin  a Covering.—The skin is the natural cov-
ering of the  body of  man,  and he is  not furnished Avith any
further and more complete covering, as is  the case with many
of the loAver animals,  since  he is endoAved with an ability to
devise means of covering  better suited to  his condition  than
one of hair,  avooI, or feathers.

   535. Use  of the Epidermis—To  Protect  the  Nerves —
The epidermis is of use to protect the corium and  its vessels.
Without this covering many of our sensations acquired through
the skin Avould be very painful.   The  contact of  the  softest
Eider down  Avith the exposed nervous filaments Avould impart
the acutest pain, and the rays of the  noonday sun Avould in-
flict the  keenest torture.   The body  could  not endure the
lightest clothing, and even our motion  through the air Avould

  533 c.  What is said of the rate of growth of the hair?  534.  What is said of the skin as
a covering ?  535. What is said of tho epidermis as a source of protection to the delicate
nerves of touch ?
 
306           HITCHCOCK'S  ANATOMY

be a source of misery.   But these delicate  nerves are pro-
tected by an insensible  membrane, which, though  hard, elas-
tic, and a very perfect guard of these faithful  sentinels, per-
mits all the necessary impressions to pass through them.  The
epidermis also guards the most delicate parts in a careful man-
ner,  by thickening its substance over the ends of the fingers,
and in all places where sensation  is most acute.   It  is also
speedily renewed where friction or accident removes it, as  on
the palms of the hands  and soles of the  feet.
   536.  To  prevent  Absorption.—Another important use of
the epidermis is to prevent undue absorption.   For the lym-
phatics only penetrate the corium, and cease at the under sur-
face  of the epidermis.   Consequently but very  little fluid can
enter these vessels unless the epidermis  is  removed or satu-
rated Avith fluid.   "Were it not for this protection, almost every
liquid substance brought in contact with  the surface  of the
body Avould at once be introduced into the general circulation,
thus exposing the system to serious danger by  absorbing poi-
sonous matter.
   537.  To  Prevent  Excessive Perspiration.—Danger from
an opposite direction  is  also Avarded off by the impenetrability
of the epidermis.  Were it not for the tortuous direction which
the outlets of the sweat glands take  as they empty themseh-es
upon the  surface of the body, an excessive amount of Avater
Avould be set free, and thus greatly reduce the  system.  But
owing to this arrangement of sweat ducts, it is only Avhen the
system is very much  stimulated that any considerable amount
of Avater can be  discharged by  sweating.  Were not this  the
case,  the body would  often be reduced to a Ioav  state from the
loss of the watery portion of the blood, as is  sometimes seen
in excessive SAveating.
   538.  1'sc of  the   Corium —Contains the   Blood-Vessels
 53G. AVhat is the use of the epidermis to prevent undue absorption ?  537. flow docs
the epidermis prevent undue perspiration?  AVhat harm would result from excessive
sweating ? 
                 AND   PHYSIOLOGY.              307*

and  Nerves—Amount of Waste Escaping  from  the Skin.
■—In the corium, or internal layer of the skin, resides the vi-
tality.   Here the arteries terminate in the capillaries and the
nerves double upon themselves, producing  the highest sensi-
bility to external impressions.  So that when any function of
the skin is spoken of, reference is usually made to this inner
layer.   And Ave see that the skin is not  only useful as a  pro-
tection and C0Arering  to the body, but is of great value as an
excretory  apparatus.   And  in  this  office the  skin  is pecu-
liarly valuable, since it removes  a  great amount of matter
from the system that the lungs  cannot  remove.   The actual
amount  of Avaste matter escaping daily from tho skin is given
variously  by different  writers.   All, hoAvever, make out an
average of from  thirty to  forty ounces,  or if condensed to
Avater, about two pints.   A proof that the vapor of Avater es-
capes in the form  of insensible perspiration is bad  by placing
the  dry hand upon a cold glass or polished metallic substance,
Avhen moisture in  a few seconds condenses on the surface.
   539.  Uses of   the Oil  Glands—Renders  the  Hair  Soft
— Softens  the   Skin  — Protects   the  Eye —Guards  the
Mem bra na  Tyinpani.—The function of the sebaceous, or oil
glands of the skin seems to be the secretion of substances pro-
tective to the skin.  These are  mainly oily  products, and are
 given off at the roots of the  hair,  so as to give it flexibility,
 that by its stiffness it may not irritate the skin.   The oil tubes
 are most abundant on those parts of the body which are most
 exposed, and especially the face and neck.   The design of the
 secretion seems to be to give flexibility to the skin, to prevent
 the heat and air from drying it  so that it would crack in many
 places, and also to lubricate it when brought into contact with
 foreign  substances, as is the case so frequently with the bands.
 The oil of the skin also prevents moisture from adhering  to it,
 and thus its functions can  be more perfectly carried on, and
 ~W "where lies the vitality of the skin?  What other use than a protection Is the
 Bkin ?' How much waste matter  escapes daily from the skin ?  "ow many pints ? 5.9
 What is the use of the oil glands?  How does it affect tho hair?  What value  does it
 impart to the skin ? 
^08           HITCHCOCK'S  ANATOMY

it will not retain all dust which chances to fall upon it.   At
the flexions of the joints, and all those  places where two sur-
faces of the skin are frequently brought in contact, this oily
secretion is abundantly poured out, in order that there  may
be as little friction as possible between the opposing  surfaces.
Upon the edges of the eyelids is situated a row of glands which
pour out their secretion in such a manner as to retain the tears
—the lubricating fluid of  the  eye—when  produced in their
ordinary quantity;  but when in excess, as in Aveeping,  they
run over their boundaries, and Aoav doAvn the cheek.  The use
of these glands may be well appreciated in some diseases  of
the eye, where the tears constantly run down upon the cheek,
producing irritating sores.
   In the  passages of the ears we  find  the same glands, al-
though their secretion is of a  someAvbat different  character.
Here it is a clammy, viscid substance, of a yelloAvish color,
and from its appearance  it is called  the wax of the ear.   Its
service is  to  prevent  dust and foreign substances  generally
from gaining  access  to  the  internal  ear, Avhere they would
injure the sense of hearing.
               HYGIENIC   INFERENCES.

  540.—1.  Great  Value  of  this  Membrane  in  the  Ani-
mal Economy.—From the complicated structure of the  skin,
we see that this  membrane is  of  great  service in the  animal
economy.  It stands next  in  importance  to the lungs as an
excretory organ, and if its functions are interrupted the Avhole
system very soon feels the disturbance.
  541.—2.  Its Health Requires  Cleanliness.—The  skin
must be  kept clean to secure the proper functions of the  per-
spiratory glands.   This  not only implies the necessity of fre-

  IIow does it affect the skin at thejoints ? Of what service is it to the eye ? Of what
to the ear ?  540. State the relative value of the skin in the animal economy.  541. Why
is cleanliness essential for the health of the skin? 
AND PHYSIOLOGY.
309
quently washing the whole surface of the skin, but also the
frequent change of the bed-clothes, under-clothes, etc.  And
it should be a  fixed rule with every one to change the linen
and  under-garments  both night  and morning ;  that is, the
under-garment worn  during  the  day should not be Avorn  at
night, and the  reverse.

  542.-3. Must be Kept at  a  Uniform Temperature.—
We also learn that the skin should be kept at a uniform tem-
perature, and up to its normal standard.  It therefore needs
proper clothing, not so much  in the coldest Aveather—for then
our feelings Avill impel us to do it—but  at the changes of tem-
perature so common and so great  in our climate in spring and
autumn, for then we are too  apt to neglect it because we feel
no especial inconvenience, and  yet at  these times there is
more danger of disease from  a Avant of  proper clothing than
at any other season of the year.   We seldom injure ourselves
by too much clothing, because we can easily throw of superflu-
ous garments, but often  do it  by too small an amount of pro-
tection.  An important  rule for  every one is,  Avhen  going
abroad even a short distance  from home, to carry  with  him
an over garment when exposed to evening air.
  543._4. )iust  Come  in  Contact  with  the  Air.—The
skin imbibes  oxygen from the air, and hence it  is important
that air be brought in  contact with this membrane.   The
clothing should be  worn so loosely that a thin layer of air will
be in contact Avith nearly every part of the skin.
  544.—5. Needs Friction.—Frequent and thorough dry
friction applied to every part of the skin greatly promotes the
health,  not only of this membrane, but of the whole body.  So
smooth are the clothes we generally Avear next the skin, that
but little stimulus is  received by  them,  and  hence a thorough
 542. What is necessary for the temperature of the skin, especially for changes in
weather'  AVhat is said of an over-coat as a constant traveling companion?  543. AVhy
shonldthe skin have air in contact with it?  541. AVhat is the use of friction to the
skin? 
310          HITCHCOCK'S   ANATOMY

rubbing of the  whole body every night and morning  will aid
greatly in this matter.
  545.-6. Injurious Effects of Moisture  upon  the  Skin.
__Moisture if applied to the skin for a considerable length  of
time  interrupts its  functions, and accordingly we  infer that
Avet or damp  clothing should not be allowed  to remain on the
body  any longer  than is  absolutely necessary.   If, hoAvever,
dry clothing  cannot be procured immediately, the body should
be kept in vigorous action of some kind until the clothes can
be changed.  This inference is of equal  application,  whether
the whole of the body be wet, or only a portion  of it,  as the
feet.
   546.__7.  Service  of a Daily Cold  Water Bath.—We in-
fer again that a daily cold water bath  is  of great service for
all students  and sedentary persons  who are  in health.   Not
only is it desirable on account of cleanliness,  but a serviceable
shock is thus imparted to the nervous system.   It, however,
should be  taken as  speedily as possible, the essential  thing
desired  being,  that  pure Avater should  be  spread over the
Avhole surface of the body,  and after  it  that the skin  should
be speedily and vigorously wiped dry.   The  secondary effect,
hoAvever, the stimulus imparted  to the nervous system  by the
shock, is by  no means an unimportant issue to be gained.
          COMPARATIVE   DERMATOLOGY.

   547. Covering of Mammals.—The skin of mammals very
closely resembles that of man,  Avith the exception of the epi-
dermis and its horny appendages, Avhich are usually covered by
hair.  The fat tissue, too, just beneath the skin, is often develop-
ed in a surprising degree, and the corium in many instances is
very thick.   Some  haATe horny scales, and others  long plates.

 545. What are the injurious effects of too much moisture applied to the skin?  54G.
AVhat is said of a daily bath, and what regulations concerning it?  547. AVhat is said ol
the covering of mammals? 
                  AND  PHYSIOLOGY.              311
   548. Callosities.—In many of the rodent or gnawing  ani-
mals, the carnivora and camels,  the  epidermis about the joints
becomes very thick,  making callosities or  pads for  the sup-
port and protection of the parts exposed.
   549. Epidermic Scales .—True Epidermic Scales are found
on the tails of many animals, such as the Beaver.
   550.  Horn  of Rhinoceros.—The so-called  horn  of  the
Rhinoceros is nothing but a thickening of the epidermis until
is assumes the form of a hollow cone.
   551. Varieties  of  Hair.-The  hairs upon  the  external
surface of mammals either present no greater  irregularities
            Fig. 298.                      Fig. 290.
          Hair of Sable.                    Hair of Musk Deer.

 than do those of man, or they are slightly rough, like those
 of the Squirrel, or knotty,  as in the Bear, or furnished Avith
 pointed processes, like the teeth of a  saAV, in other animals.
 Some of  these  peculiarities  are exhibited in  the  adjoining
 cuts.   The spines of the Porcupine and Hedgehog differ from
 hairs only that they contain the same materials in a more con-
 densed form.
   552.  Glands of  the  Skin. — Cutaneous and  sebaceous
glands are present in most  mammals very  abundantly.  The
 548. To which membrane of the skin do the callosities of camels, etc., belong?  519.
Where are epidermic scales found? 550. What is the horn of the rhinoceros?  551. What
are the varieties of hair in different animals ? 552. What is said of glands of the skin
 
312
HITCHCOCK'S   ANATOMY
Fig. 300.
FlG. 301.
Transverse Section of Hair of Pecari.
A. B. Hairs of Squirrel.  C. Hair of Indian Bat.

latter secrete an unctious fluid, which is usually of a strong
smell.
   553.  Skin of Birds.—The Skin of Birds is thin and desti-
tute of cutaneous glands, except one at the tail, which is gen-
erally present.  The whole body is covered by feathers, except
certain parts of the head, legs, and feet.  There it becomes very
much  thickened,  forming callosities, Avattles and  combs,  in
which, beside the cellular tissue, are found the elastic and erec-
tile tissues, as well as red and blue  cells of coloring  matter.
Upon the toes and feet are found plates and scales of horny tissue.
   554.  Feathers  of   Birds.—The  Feathers  of  Birds  are
made up of the Quill and Vane:  the former  giving it attach-
ment to the body, and  the latter forming its expanded  surface.
The Vane is made up of a small number of laminae or plates,
which both form a light  and firmly  resisting medium to the
air, and serve to retain the heat Avithin the body.   When per-
fectly formed the laminae are furnished with a booklet  at their
free extremities, by which they are  attached to each other,

  553. AVhat is the thickness of the skin of birds compared with that of mammals?
AVhat are the wattles and combs?  554. AVhat two parts are feathers made up of?  AA'hy
are the lamina; furnished with a barb at each extremity? AArhat is the design of their
overlapping each other ? 
AND  PHYSIOLOGY.
313
thus  making each  feather  an impenetrable plane  surface.
The feathers  also overlap one  another  to  a considerable de-
gree, and as they thus contain air, and are themselves non-
conductors,  they afford the most perfect  protection to the body
against the  cold.
 o
   555. Skin  of  Amphibia .—The naked  Amphibia, such  as
the Frogs, have a smooth slippery skin, which is continually
being cast off in patches  or shreds.  This  skin surrounds the
solid parts of the body \Tery  loosely, and spaces for lymphatic
A'essels are  found  beneath.    It is always composed of several
layers of fibres which lie at right angles with each other.
   556. Scales  of  Serpents .—"Upon some serpents, scales are
found which overlap one  another, like the shingles of a house,
as is also the case Avith fishes'.   Scales  Avith tubercular spines
are met with on some reptiles, and in some instances, as those
of  Crocodiles  and  Tortoises, they contain bony matter, and
coalesce with the bones of  the skeleton.
   557. Exuviation of  Serpents.—Many Serpents cast their
skin several times during the year, either by piecemeal, or by
draAving off the Avhole at once.    One species of Tortoise  d^es
the same thing, as Avell as  several Lizards.  This is an anal-
ogous function to the moulting of birds, and shedding of the
coat  in mammals.   This  generally  takes place in  Spring,
but frequently upon a change of Aveather several times in the
year.   At  each period,  when  this is effected by the Rattle-
Snake, a new segment is said  to be added to  the tail, which
seem3 quite probable,  since the rattle is merely a condensed
portion of the epidermis.
   558.  Scales  of Fishes. —Classification  of Fishes   by
their  Scales.—Fishes have an Epidermis  which is sometimes
covered Avith scales, and  sometimes not, though always lubri-
cated most  thoroughly by  a copious mucous secretion.   The
  5*5 What is said of the skin  of frogs ?  55G. Do serpents ever have scales ? 557. AVhat
is the exuviation of serpents?  AVhen does this take place? AVhat peculiarity in  the
rattle-snake ? 55S. How are tho scales of fishes arranged ? 
314
HITCHCOCK'S  ANATOMY
scales are sometimes disposed in an imbricated manner upon
the body, and are not situated in the epidermis, "but really
in the akin,  and included  by it."   The scales contain both
phosphate and carbonate of lime as a rule.   Their shapes are
various, though Professor Agassiz, the  best living authority
on fishes,  has grouped all  bony fishes under four orders, de-
pendent mainly upon the form of the scale.   First, the Pla-
coidians, including such fishes as the Sharks and Rays, where
the scales are either large  and covered with  bony tubercles,
or simply Avith small enameled  scales.   Second, the Ganoi-
dians,  including  the Sturgeon and bony  Pike, which have
angular  bony plates coated  Avith a thick  layer  of enamel.
Third, the Ctenoidians, such as the Perch,  which have hard
scales jagged on the  outer edges, like  the teeth of a comb.
Fourth, Cycloidians. These have soft and circular scales with
simple margins. In this order are found the Herring and Sal-
mon.   Sometimes the scales are provided  with a hook-like
process, which  overlaps and fastens itself into a depression in
the scale beneath.
   559.   Tegument  of Articulata.—Horny  Case  of  In-
sects.—The  Tegumentary envelop of the sub-kingdom Arti-
culata  has already been described  under Comparative Oste-
ology, since the skin of many of this sub-kingdom, especially
the Crustacea and insects, is in reality the only skeleton these
animals have.  Insects have a covering sometimes  leathery
and  soft, and sometimes  horny and solid,  which contains a
peculiar proximate (chemical) principle known as Chitine.
   560.  Mantle  of   Molluscs.—In  Molluscous  animals,  a
dermis, which  is a  muscular  skin, envelops all the viscera,
and hence is called  the cloak  or mantle, Avhich secretes the
hard calcareous covering knoAvn as  the  shell.   Generally the
shell is external  to  the mantle,  as  in the  Clam and Oyster,

 AVhat are the four orders dependent upon the form of the  scale ? Who is the author
of this arrangement? Give examples of each. 559. AVhat is the covering of the articu-
lata'. AVhat is peculiar about its chemical composition ?  5G0. Describe the outside cov-
ering of molluscs. 
AND  PHYSIOLOGY.
315
but  often,  as in the Cypraea  or Cowry,  the mantle extends
over the shell.

   561.  Radiates.—With the  exception of the hard external
skeleton of these animals already described, their proper  skin
is mostly thin and soft, allowing of great flexibility and some-
times of great expansion and contraction.
   The Protozoa have  a very  delicate,  cutaneous  envelope,
sometimes  smooth  and sometimes covered with cilia.

  Effect of Fright on Hair.—A Sepoy of the  Bengal  Army, brought as a
prisoner for examination before the British officers, Was terribly affrighted,
trembled like a leaf, and was almost stupified with fear.  Such was the  shock
upon his brain that his hair,  from a glossy jet black, became gray within the
space of an hour, the subject being only twenty-four years of age.
  Also a boy, let down from a high cliff on the  coast of Scotland to get eggs
of sea-birds.  He, in defending himself from the birds with the sword, struck
the rope by which he  was suspended, and cut off every strand but one.
When drawn up his hair was white.
  Maria Antoinette experienced a change in tho color of her hair during one
night'a excessive fear. 
         CHAPTER   SEVENTH.

THE INSTRUMENTS  OF  ANIMATION.—NEUROLOGY, OR
             THE BRAIN AND NERVES.
        DEFINITIONS  AND  DESCRIPTIONS.

  562.  Main  Features  of  the   Nervous  System.—We
now come to an  organization Avhich is very  complicated  in
structure, some of Avhose functions  are the most  obscure  of
any in the body.   It is called the Nervous System : and the
different  grades in the animal kingdom  are established  by
placing those having the most complicated nervous system
highest on the scale.  Man  having the largest brain in pro-
portion to the rest of his  body, and  possessed of the greatest
relative amount of nerves, is therefore  placed  at the head of
the animal kingdom.
  563. Microscopic Structure.—Tubular Portion.—Diam-
eter  of  the Tubes.—In  microscopic  structure the nerA'ous
tissue presents tAvo essential elements:  the fibrous or tubular,
which is mainly found in the nerve trunks, and the cellular or
vesioular, existing  more abundantly in the ganglia or nerve
centers.  In the former the tubes are the largest in the trunks
of the nerves, and  gradually diminish as  they approach  the
brain, varying in size from  the 2oVoth to the  sTo-ooth  of an
inch, and sometimes existing  even as large as the 5loth of an
inch.  They are sometimes  conical also, measuring at one end
from Woo-th of  an inch to siioTfth :  the smallest end being
found near the nerve trunks, and  are  sometimes called coarse
  5C2. Give the leading features of the nervous system. 503. AVhat are the two micro-
 scopic elements of nervous tissue ?  Give the size of the tubular portion. 
AND  PHYSIOLOGY.
517
Fig. 302.
Tubular >."erve Fibers.
nerve fibers. These fibers have the appearance of a double tube,
or a small tube within a larger one, and sometimes exhibit small
nucleated cells Avithin the tAvo.
  564.  A closer examination shows an inner or grayish por-
tion which is called the axis cylinder, and a white substance
around  this  called the  medullary  matter, or  substance of
Schwan, and outside of the whole a membranous  tube.  (Fig.
302.)   They are often called Fine Nerve Fibers.   The sym-
pathetic system, on the other hand, seems to be  made up of
tubes without  this  double structure,  and  when  several  of
them are joined in a  bundle,  tbey present  a grayish appear-
ance.   They are also of a much smaller  size, varying mostly
from  T5iooth to jAo.tn  of an  inch.
  565.   Vesicular  Structure.—The vesicular substance  is
composed of  cells or  vesicles, which  present  very  curious
forms, being someAvhat stellate or caudate.  The central  por-
tion  is  globular, consisting of a  nucleated cell, which sends
off processes  in different  directions, as  seen in the annexed
Fio-ure  303.   Their diameter  is exceedingly variable, meas-
 AA'iiat is the structure of the sympathetic system ? 564. What still more minute struc-
ture tube ttt"! by the microscope ? 505. Describe the vesicular structure. Give
the diameter of tho cells. 
SI 8            HITCHCOCK'S   ANATOMY

                           Fig. 303.
  Vesicular Nerve Corpuscles,  a. Cell AVall. b. Cell Contents,  c. Pigment, d. Nu-
cleus, e. Prolongation forming Sheath of the fiber, f. Nerve Fiber, magnified 350 diam-
eter.

uring from T-J-7th to eVooth of an inch.  These are found in
the ganglia and the substance of the brain.
   566.   Divisions  of  the  Nervous  System.—The  nervous
system  consists of a central portion contained within the cav-
ity of the skull and  the spinal column, and  a great  number
of white threads  ramifying through every part of the body.
The physical condition upon which  the  activity of the  ner-
vous system depends, is the supply of arterial blood.
   567.  Cerebrum.—If we examine the parts within the skull,
(Fig. 304, p. 319,)  we shall find the  greater mass  of it to be
of a spheroidal form, divided nearly into two  halves by a deep
fissure  or  cleft, and its surface  is singularly roughened  by
elevations and depressions called anfractuosities.
   568.  This  mass is the Cerebrum or Great Brain,  and the
two divisions are called its hemispheres. (Fig. 307, p. 321.)
   569.  In man the average Aveight of the brain is  fifty-four
ounees, in females forty-five;  the maximum being sixty-four,
  50(5. What principal divisions does the nervous  system consist of ? 507. Describe the
cerebrum.  569. What is the average weight of the brain? 
AND   PHYSIOLOGY.
319
9 10 11 6
  Vertical Section of the Brain,  Cerebellum, Pons Varolii, and  Medulla Oblongata.
a Anterior Lobe of the Brain, b, Middle Lobe, c, Posterior Lobe, d. Cerebellum, e, Me-
dulla Spinalis.  /, Section of the Corpus Callosum. The Lateral Ventricles of the Brain
are situated on either side of the Corpus Callosum, which assists In forming their Upper
Wall  g, Optic Lobes :  1, Olfactorv Nerves.  2, The Eyeball, from which may be
traced the Optic Nerve as far as the Optic Thalami or Lobes.  Close to this is the Nerve
of the Third Pair.  4, The Fourth Pair, distributed, like the Third, to the Muscles of tho
Eyes.  5, Superior Maxillary  Branch of the Fifth Pair.  5', Ophthalmic Branch of tlio
same Pair of Nerves. 5", Inferior Maxillary Branch of the same Pair of Nerves. 6, Sixth
Pair, proceeds to the Abducentes Muscle.  T, Facial Nerve r-tinder the origin of this
nerve may be seen a portion of the Acoustic   9, Nerve  called G osso-Pharyngeal. 10
Pneumogastric Nerve ;  close to it is 12, the Spinal Accessory.  These three Nerves, the
Glosso-Pharyngeal, Pneumogastrie, and Spinal Accessory, are by some reckoned as one
pair11,The Ninth Pair of some, and the Eleventh of others, called  also Hypoglossal.
14 and 15, Cervical Nerves.

and the  minimum  twenty;  the  average capacity of the  cra-

nia of  Germans  and  Anglo-Saxons   is  ninety  cubic  inches.

Daniel Webster's cranium contained 122 cubic inches.

   570   Cerebellum.—The  Cerebrum, by  a  band of thick

fibers,  is  connected  with  another  body, of a pear  shape at-

tached  to it by its base, called  the Lesser Brain or Cerebel-

lum.    (Fig. 306, p.  320.)   This has about^onejighth ot the

  ----------           TT^f~W^sTxon crania, and also that of Daniel AVebster.
  State the average capacity ot Anglo s.i.\on \,    .
5T0. Describe the cerebellum.
                                1 i* 
320
niTC II COCK'S   ANATOMY
weight  of the Cerebrum,  and  lies  directly behind  and  be-
neath  it.
                  FlG. 305.                     Tlle Lateral Ventricles of the
                                              Cerebrum.  1, 1, The two Hemi-
                                              spheres cut down to a level with
                                              the  Corpus  Callosum, so as to
                                              show the  Centrum Ovale Mnjus.
                                              The Surface is studded with the
                                              small Puncta A'asculosa.  2, A
                                              small portion of the Anterior Fx"
                                              trcmity of the Corpus Callosum.
                                              3, Its Posterior Boundary; the in-
                                              termediate portion, forming the
  (CT       I'lIIw/,  I bSI  '>'  <f i (^\    Eoof of the Lateral Ventricles, has
  v"*5i *'■"';,  &&-is IVk «M '   \'  -v  ~*"Sl    been removed so as to completely
                                              expose these Cavities. 4, A part
 ((   -i .  > i ' J/^^JW^S.'   ''^   ~^1    of the Septum Lueidum, showing
 [\  „'    '  j^Wpr^4"isx  ''i^  '* \'   Gi-7    a space between its Layers which
                                              is the Fifth A'entricle. 5, The An-
                                              terior Cornu of one Side.  6, The
                                              commencement  of the  Mi 'die
                                              Cornu.  7, The Posterior Cornu.
                                              P, The Corpus Striatum  of  one
                                              A'entricle.  9, The Taenia Striata.
                                              10,  A small part of the Thalamus
                                              Opticus.   11,  The Plexus  Cho-
                                              roides. 12, The Fornix.  10, The
                                              commencement of the Hippocam-
pus Major in  the Middle Cornu.  The Pounded  Oblong Body in the Posterior Cornu
of the Lateral  Arentriele, directly behind the Figure 13, is the Hippocampus Minor. A
Bristle is seen in the Foramen of Munro.
Fig. 306.
  A View of the Interior Surface of the Cerebellum and n Portion of the Medulla Ob-
longata. 1, 1, Thw Circumference of the Cerebellum.  2, 2, The two Hemispheres of the
Cerebellum.  3, Lobulus  Amygdaloldes.  4, The Vermis Inferior.  5, Lobulus Nervl
Pneumogastrici.  6, The Calamus Scriptorius.  7, Its Point.  8, Section of the Medulla
Oblongata.  9, Points to the Origin of the Pneumogastric Nerve. 
AND   PHYSIOLOGY
321
   571.   Cerebral  Ganglia—Also  lying  directly  upon  the
base of the brain, are  found  several  distinct  enlargements  or

                                  Fig. 307.
  A A'iew of the Base of the Cerebrum and Cerebellum, together with their Nerves.
1, Anterior Extremity of the Fissure of the Hemispheres of the Brain.  2, Posterior Ex-
tremity of the same Fissure.  3, The Anterior  Lobes of the  Cerebrum.  4, Its Middle
Lobe.  5, The Fissure of Sylvius.  6, The  Posterior Lobe of the  Cerebrum.  7, Tho
Point of  the Infundibulum.  8, Its  Body.  9, The  Corpora Albicantia.  10, Cineritius
Matter. 11, The Crura Cerebri.  12, The Pons Varolii. 13, The Top of  the Medulla
Oblongata.  14, Posterior Prolongation of the Pons A'arolii.  15, Middle of  the Cerebel-
lum.  10, Anterior Part of the Cerebellum.  17, Its Posterior Part and the Fissure of its
Hemispheres.  18, Superior Part of the  Medulla Spinalis.  19, Middle  Fissure of the
Medulla Oblongata.  20, The Corpus Pyramidale.  21, The Corpus Eestiforme. 22, Tj.j
Corpus Olivare.  23, The Olfactory Nerve.  24, Its  Bulb.  25, Its External Boot. 26,
Its  Middle  Boot.  27,  Its  Internal  Boot.  28,  The Optic Nerve  beyond the Chiasm.
29, The Optic Nerve before the Chiasm.  30, The Motor Oculi, or Third Pair of Nerves.
31, The Fourth Pair, or Pathetic Nerves.  32, The  Fifth Pair, or Trigeminus Nerves.
33, The Sixth Pair, or Motor Externus.  34. The Facial Nerve.  35, Tbe  Aud.tory_the
two making the Seventh Pair.  30, 37,  3S, The Eighth Pair of Nerves. (The Ninth Pair
are not here seen.)
571. AVhat are the cerebral c:.r<?lia« 
322
HITCHCOCK'S  ANATOMY
Fig. 308.
1 0 ..;:

ganglia,  the most important of which are the Thalami  Optici,

Corpora Striata,  Olfactive Ganglia,  and Tubercula Quadrige-

mina.

                               .572. Spinal Cord.—Upon the an-

                             terior   portion  of   the  Cerebellum,

                             commences the Spinal  Cord,  the up-

                             per  portion of which, situated within

                             the  skull,  is  about  three inches  in

                             length  and one  in  breadth,  and  is

                             called  the Medulla Oblongata.

                                573.  Cerebro-Spinal Center.—

                             These  portions of the  nervous sys-

                             tem constitute what  is  known  as the

                             Cerebro-Spinal Axis or  Center, and

                             are  all made up of two  kinds of mat-


                               The Cerebro-Spinal Axis seen Anteriorly. The
                             Nerves have been  cut through  at a short distance
                             from  their Origin or central termination,  a, The
                             Cerebrum, b, Anterior Lobe  of the Left Hemisphere
                             of the Brain, c, Middle Lobe, d, Posterior Lobe, al-
                             most  concealed by the Cerebellum, e, The Cerebel-
                             lum.  / The Medulla Oblongata or Bulb.  1, First, or
                             Olfactory Pair of Nerves.  2,  Second Pair, or Optic.
                             3, Third Pair, or Motores Oculorum. 4, Fourth Pair,
                             or Pathetic.  5, The Facial, or Fifth Pair.  6, Sixth
                             Pair,  or Abducentes. 7, Nerves of the Seventh Pair,
                             or Facial; also the Acoustic, or Portio  Mollis,  by
                             some called the Auditory, and viewed as a division
                             of the Seventh ; others call  them  the Eighth Pair.
                             9, The Glosso-Pharyngeal Nerves,  called the Ninth
                             Pair by some, by others the Anterior Division of the
                             Eighth Pair.  10,  The Pneumogastric, by some in-
                             cluded in the Eighth Pair, by others called tho Tenth
                             Pair.  11, Nerves of the Eleventh and Twelfth Pairs,
                             the first being viewed by some as a Division of the
                             Eighth Pair, and called Spinal Accessory; the latter,
                             called by some  the Ninth, by others the Twelfth, is
tho Motor Nerve of the Tongue. 13, Nerves of the Thirteenth Pair, or Sub-Occipital. 14,
15,16, The First, Second, and Third Pairs of  Cervical Nerves, g, Cervical Nerves form-
ing the Brachial Plexus.  25, One of the Pairs of  Nerves of the Dorsal Portion of tho
Spinal Marrow.  33, One of the Pairs of Lumbar Nerves, h. Lumbar and Sacral Nerves
forming the Plexus whence come the Nerves of the Lower Extremities,  i  and j, Ter-
mination of the Spinal Marrow, called Cauda Equina, k, Great Sciatic Nerve proceed-
ing to the Lower Extremities.
  572. What is the medulla oblongata?  573. What two kinds of matter does a slicing
the brain show, and how is the gray and white matter disposed ?
of 
AND  PHYSIOLOGY.
323
Fi-i. 309.
ter;  the gray or external, and the white  or  internal.   This
structure is best seen when the brain is cut through in a hori-
zontal direction; the gray shoAving itself  as  an outside layer
with an irregularly scolloped edge, while the white is internal,
and constitutes the greater portion of the Avhole brain.
   574.  Blood-Vessels  of  the  Brain—Venous  Sinuses,
—The blood-A'essels of the brain are very numerous, since one
sixth of all the blood is sent to this organ, although its weight
is about  one fortieth of the body.  The arteries are the most
numerous, and as already mentioned, those entering the bead
from the front side of the neck, communicate  very freely Avith
those coming in at the back side of the head, (see Fig. 213),
making a perfect circle of communication, so that there may
be no impediment  to the cir-
culation of the blood through
the nervous center. The veins
are not numerous.  Some are
found on  the surface of the
brain, but  only a few pene-
trate into its substance.  But
large channels are  found be-
tween the  membranes called
Sinuses,  Avhich  do not  pre-
sent the ordinary characteris-
tics  of veins, except that they
conA'ey the blood to the heart.
The tAvo sinuses Avhich are of
the   largest size,  discharge
their contents into the jugu-
lar veins.    (Fig. 309.)
   575.  Membranes   of the
Cerebro-Spinal    Center.—
Dura  Mater.—Three mem-
  Sinuses of the Base of the Skull. 1, Oph-
thalmic A'eins.  2, Cavernous Sinus.  3,
Circular. 4, 6, Inferior Petrosal. 5, 9, Oc-
cipital Sinuses. 7, Internal Jugular A'ein.
 574  What proportion of the blood goes to the brain ?  Which are the most numerous,
the arteries or the veins ? AVhat are the sinuses found there 1 
324
HITCHCOCK'S  ANATOMY
branes em'elop the brain, although to the unassisted  eye they
appear as one.   They are of great importance in the economy
of the brain, and are often the seat of severe disease.  The
outer one is called  the  Dura  Mater, that covers  both the
brain and spinal  cord,  and is  attached  firmly  to the bones
Avhich it covers.   It  has the  same  composition  as the  liga-
ments of the body—AA'hite fibrous tissue—and consequently is
Arery tough, being the firmest of the three  membranes.
   576.   Arachnoid Membrane,—The Arachnoid  Membrane
lies directly beneath  the dura mater, and  receives its name
from the Greek word signifying spider's  Aveb.
   577.  Pia  Mater.—Closely  beneath it is the Pia  Mater,
which lies directly upon  the surface of the brain, and dips
into all  the  cavities or  convolutions  on  its surface.   This
membrane is especially serviceable in the nourishment of the
brain, and receives the  arteries which enter at  the  anterior
and posterior part of the skull.   Its nerves  are  branches  of
the sympathetic system.
   578.  Surfaec of the  Brain.—The surface of the brain i3
very  uneven, being  covered  Avith  convolutions  or  tortuous
ridges and corresponding depressions, the design of Avhich  is
not as yet Avell known, though probably merely  to procure a
greater  amount of  surface, and they do not correspond to the
irregularities on the surface of the skull  from  Avhich phre-
nologists profess to judge of character.
   579.  Ventricles of  the Brain.—Within the brain are sev-
eral caA'ities called ventricles, of Avhich the special use has not
been determined.   (Fig. 305,  p. 320.)  It  is a  curious fact,
however, that a post mortem examination of the brain of  in-
ebriates frequently discovers these cavities to be partially filled
Avith alcohol.
   580.  Division  of  the  Nerves.—All the  nerves that pro-

  575. How many membranes enveloping the brain?  Describe the dura mater.  576.
Describe the arachnoid membrane. 577. Describe the pia mater.  AVhat are its nerves?
578. AA'hat is the o.onnition of the surface of the brain ? 579. What are the cavities in the
brain called ? 580. How are all the nerves given off from tho brain and spinal cord ? 
AND   PHYSIOLOGY
325
ceed from  the  cerebrospinal  axis are  given  off in  pairs on
opposite  sides of the  median line of the  body.   They are di
Tided into two sets ;  those which are given off from the great
brain, little brain, and medulla  oblongata, being called cranial
nerves, and those from the spinal cord, spinal nerves.
   581   Cranial  Nervcs.-Many  of the  cranial nerves,  and
all of the spinal nerves, arise  by two roots, and soon form a
small protuberance, which  is  called  a Ganglion or  knot in
which the  fibers  are  confusedly mixed  together, after which
they proceed in  the same sheath  to their  destination.
   582.  Of the cranial  nerves  there are  tAvelve  pairs, named
as follows
First pair
Second "
Third  "
Fourth "
Fifth   "
Sixth
.. Olfactory.
. .Optic.
. .Motores Oculorum.
. .Troclileares.
..Trifacial.
.. Abducentes.
Seventh pair. .Facial.
Eighth   "  ..Auditory.
Ninth    "  ..Glosso-Pharyngeal.
Tenth    "  .. Par Vagi.
Eleventh  "  . .Spinal Accessory.
Twelfth   "  ..Lingual.
583.  Olfactory.—The ofactory nerves arise from the an-
                           Fig. 310.
  A. View of the First Pair, or Olfactory, with the Nasal Branches of the Fifth. 1, Fron-
tal Sinus.  2, Sphenoidal Sinus. 3, Hard Palate.  4, Bulb of the Olfactory Nerve.  5,
Branches of the Olfactory on the Superior and  Middle Turbinated Bones. 6,'Spheno-
palatine Nerves from the Second of the Fifth.  7, Internal Nasal Nerve from the First
of the Fifth. S, Branches of Seven, to Schneiderian Membrane.  9, Ganglion of Cloquet
in the foramen incinivium. 10, Anastomosis on  the Inferior Turbinated Bone of the
Branches of the Fifth Pair.
  What are the two principal groups of nerves? 531. IIow many roots do most of the
nerves have ? 6S2. IIow many pairs of cranial nerves, and what are their names ? 
326
HITCHCOCK'S   ANATOMY
Fig. 311.
terior portion  of the  base  of the  brain, and are distributed
upon the  mucous  membrane of  the nostrils;  especially that
part of it which is spread out upon the turbinated bones.
                                      584. Optic—The  optic
                                   nerves arise at a point be-
                                   hind  that where  the olfac-
                                   tories  are   given  off,  and
                                   about  one  inch  from  this
                                   point  come  together  and
                                   form a ganglion ;  after this
                                   they are again separated and
                                   proceed   to  the   posterior
                                   portion  of each  eye-ball5
                                   where they  are  expanded
                                   into  a membrane, called the
                                   Retina.   (Fig. 311.)
                                      585. Motores  Oculorum.
                                   —The third pair are  also
                                   given off from the  base of
                                   the brain near to  the pons
                                   varolii, and are sent to the
                                   four   straight  muscles of
                                   the eye.   (Fig.  312.)
                                       586. Troclileares.—The
                                    trochleares have nearly the
                                    same origin as the last-men-
                                    tioned pair, and  are distrib-
                                    uted to the superior oblique
                                    muscles of each eye.   (Fig.
                                    312.)
   587.  Trifacial.—The fifth pair, or trifacial, is the largest
 of the cranial nerves.    It is analogous to the spinal nerves in
  A View of the Second Pair or Optic, and
the Origin of Seven other Pairs.  1,1, Globe
of the Eye.  The one on the left hand is per-
fect, but that on the right has the  Sclerotic
and Choroid removed to show the Retina.  2,
The Chiasm of the Optic Nerves.  3, The
Corpora Albicantia.  4, The Infundibulum.
5, The Pons A'arolii.   6, The Medulla Ob-
longata. The figure is on the Eight Corpus
Pyramidale.  7, The  Third Pair, Motores
Oeuli.  8, Fourth Pair, Pathetici.   9, Fifth
Pair,Trigemini. 10, Sixth Pair, Abduecntes.
11, Seventh Pair, Auditory and  Facial.  12,
Eighth Pair,  Pneumogastric, Spinal Acces-
sory, and Glosso-Pharyngeal. 13, Ninth Pair,
Hypoglossal.
 583. Give the anatomy of the olfactory nerves.  fWl. Describe the optic nerves.  5>5.
Describe the motores oculorum,  5S6.  Give the anatomy of the  fourth pair.  587. De-
scribe the trifacial. 
AND   PHYSIOLOGY.
Fig. 312.
  A View of the Third, Fourth, and Sixth Pairs of Nerves.  1, Ball of the Eve  tho Eec-

 11a  3 Th "Th Tp hemSTr n'anging d°W" fr°m ltB ^  2> Th. SuperoMax-
 11a  3, The Third Pair or Motor Oeuli, distributed to all the Muscles of the Eye except
 he Superior Oblique and External Pectus.  4, The Fourth Pair, or Patheticus goin^ to
the Superior Oblique Muscle.  5, Ono of the Branches of the Fifth.  C, The SWh PriV
or Motor Externus  distributed  to  the  External Rectus Muscle.  7,  Sphenopalatine
Ganglion and Branches.  S, Ciliary Nerves from the Lenticular Ganglion, the short Foot
of which is seen to  connect it with the Third Pair
FlG.
   A View of the Distribution of the Tri-
 facial, or Fifth Pair. 1, Orbit.  2, Antrum
 of Highmore.  3, Tongue. 4, Lower Max-
 illa.  5, Root of Fifth Pair, forming tha
 Ganglion of Casser. 6,  First Branch, Oph-
 thalmic.  7,  Second  Branch,  Superior
 Maxillary.  8,  Third Branch, Inferior
 Maxillary.  9, Frontal Branch, dividing
 into External and Internal  Frontal at 14.
 10, Lachrymal branch,  dividing before en-
 tering the Lachrymal  Gland.  11, Nasal
 Branch. Just under the  figure is tho long
 Root of the Lenticular or Ciliary Ganglion,
 and a few of the Ciliary  Nerves.  12, In-
 ternal  Nasal,  disappearing  through the
 Anterior Ethmoidal Foramen.  13, Exter-
 nal  Nasal.  14,  External  and  Internal
 Frontal. 15, Infra-Orbitary Nerve.  16,
 Posterior  Dental Branches.  17, Middle
 Dental  Branch.   IS,  Anterior  Dental
 Nerve.  19, Terminating  Branches of In-
 fra-Orbital, called  Labial and  Palpebral.
 20, Subcutaneous Maine,or Orbitar Branch.
 21, Pterygoid or Recurrent, from Meckel's
 Ganglion.  22, Five Anterior Branches of
 Third of Fifth, being Nerves of Motion,
and called Masseter, Temporal, Ptergoid,
and Buccal,  23,  Lingual  Branch joined at an acute angle by the Chorda Tympani.  24,
Inferior Dental Nerve  terminating in 25, Mental Branches.  26, Superficial Temporal
Nerve.  27, Auricular Branches. 28, Mylo-hyoid Branch.
 
328            HITCH COCK'S  ANATOMY
Fig. ?.U.
  Distribution of the Fifth Pair of Nerves, a, Submaxillary Gland.  1, Small  Root of
the Fifth Nerve.  2, Casserian Ganglion.  3, Ophthalmic Nerve.  4,  Upper Maxillary
Nerve.  5, Lower Maxillary Nerve.  6, Chorda Tympani.  7, Facial Nerve.
that  each nerve  arises by two  roots, and  afterwards, before

distribution, forms the  Casserian ganglion.   This  ganglion is

separated into three branches : the ophthalmic, which supplies

               Fig. 315.                 the region of the eye and

                                        nose ;  the superior maxil-

                                        lary,  supplying  different

                                        parts of the face from the
                                        temporal  muscle  to  the
                                          A A'iew of the Origin and  Disiribu-
                                        tion of the  Portio Mollis of the Sev-
                                        enth Pair, or Auditory Nerve.  1, The
                                        Medulla Oblongata.  2,  The Pons A'ar-
                                        olii. 3, 4, The Crura Cerebelli of the
                                        Right Side. 5. Eighth  Pair.  C, Ninth
                                        Pair.  7, The Auditory Nerve distrib-
                                        uted to the Cochlea and Labyrinth.
                                        8, The Sixth Pair.  9, The Portio Dura
 of the Seventh Pair.  10, The Fourth Pair.  11, Tho Third Pair.
 
AND  PHYSIOLOGY.
329
Fig. 316.
lips,  including the upper teeth

and  the  inferior  maxillary,

sending  its   branches  to the

tongue, cheeks,  and anterior

portion of the face.

   588.  Abduccntes. —The

sixth pair, abduccntes, are sent

from the  medulla oblongata to

the external muscle of the eye.

   589. Facial.—The facial

nerves have  their  origin  in

common  with  the   last  pair.

They join with  some  of the

branches  of the fifth pair, and

distribute their filaments  to

some of the muscles of the face.

   590. Auditory.—The au-

ditory nerves, as their names

imply,  are  sent to  the  ear.

They  enter  the  internal ear

  Origin and Distribution of  the  Tenth
Pair of Nerves.  1, 3, 4. The Medulla Ob-
longata.  1 Is the Corpus  Pyramidale of
one side. 3,  The Corpus Oblivare.  4, The
Corpus Eestiformc.  2, The Pons Varolii.
5, The Facial Nerve.  6, The Origin of the
Glossopharyngeal Nerve.  7. The Gang-
lion of Andersch. 8,  The  Trunk of  the
Nerve.  9, The  Spinal Accessory Nerve.
10, The Ganglion of the  Pneumogastric
Nerve.  11,  Its  Plexiform Ganglion.  12,
Its Trunk.  13,  Its  Pharyngeal  Branch
forming the  Pharyngeal Plexus (14), as-
sisted  by a Branch  from  the  Glosso-
pharyngeal (S), and one from the Superior
Laryngeal Nerve (15).  10, Cardiac Branch-
es.  17, Recurrent Laryngeal Branch.  IS,
Anterior Pulmonary Branches.  19, Posterior Pulmonary Branches.  20, Esophageal
Plexus  21  Gastric Branches.  22.  Oricin of the Spinal Accessory Nerve.  23,  Its
Branches distributed to the Sterno-Mastoid Muscle.  24, Its Branches to the Trapezius
Muscle.
 589. Describe the abduccntes. 5S9. Describe the facial nerves.  590. Describe the au-
ditory nerves. 
330
niTCH COCK'S   ANATOMY
after  receiving fibers  from  the  facial, and  there divide into

tAvo branches, which are distributed in the irregular labyrinth

of the ear.

   591.  Glossopharyngeal.—The glosso-phary?ijeal makes

the ninth pair, and is sent to the mucous surface of the fauces,

tongue, tonsils,  and mucous glands of the mouth.

   592.  Par Vazi,  or  Pneumogastric—The tenth pair,par

vagum,  spring from the medulla oblongata, and  after  giv-

               Fig. 317.                 ing branches to several of

                                       the cranial nerves,  are dis-

                                       tributed  upon  the heart,

                                       lungs,  stomach, and nearly

                                       all the organs  of the  tho-

                                       rax and abdomen.

                                          593. Spinal Accessory.

                                       —The  spinal  accessory

                                       takes   its  origin  from the

                                        The Anatomy of the side of the Neck,
                                       showing the Nerves of the Tongue.  1,
                                       A  Fragment of the Temporal Bone
                                       containing the Meatus Auditorius Ex-
                                       ternus, Mastoid, and Styloid Process.
                                       2, The Stylo-Hyoid  Muscle.   3, The
                                       Stylo-Glossus.   4, The Stylo-Pharyn-
                                       geus. 5,  The  Tongue.  6, The Hyo-
                                       Glossus Muscle; its  two portions.  7,
                                       The Genio-Hyo-Glossus  Muscle.   8,
                                       The Genio-Hyoideus: they both arise
                                       from the inner surface of the Symphy-
                                       sis of the Lower Jaw. 9, The Sterno-
Hyoid Muscle.  10, The Sterno-Thyroid. 11, The Thyro-Hyoid, upon  which the Thyro-
Hyoidean Branch of the Hypoglossal Nerve is seen ramifying.  12, The Omo-Hyoid
crossing the Common Carotid Artery (13), and Internal Jugular Arein (14). 15, The Ex-   >
ternal Carotid giving off its Branches.  16, The Internal Carotid.  17, The Gustatory
Nerve giving off a Branch to the  Submaxillary Ganglion (18), and communicating a littlo
further  on with tne Hypoglossal Nerve.  19, The  Submaxillary, or Wharton's Duct,
passing forwards to the Sublingual Gland.  20, The Glosso-Pharyngeal Nerve, passing in
behind the Ilyo-Glossus Muscle.  21. The Hypoglossal Nerve curving around the Oc-
cipital Artery.  22, The Descendens Noni Nerve, forming a Loop with (23) the Commu-
nicans Noni, which is seen to be  arising by filaments from  the Upper Cervical Nerves.
24, The Pneumogastric Nerve, emerging from between tho Internal  Jugular Arein and
Common Carotid Artery, and entering the Chest.  25, The Facial Nerve, emerging from
the Stylo-Mastoid Foramen, and crossing the External Carotid Artery.


         Describe the glosso-pharyngeal, par vagum. and spinal accessory.
 
AND  PHYSIOLOGY
331
e
 upper part of the spinal  column, and  afterwards enters the
 cranium.   After keeping  company with the par  vagum for a
 part of its course, it is distributed to some of the muscles upon
 the head and face.
    594.  Lingual.—The  lingual  nerve plunges  its  branches
 deeply into the fibers of the tongue, and communicates with a
 branch of the trifacial.
    595.  Spinal  Cord.—The spinal cord
 is  that portion of the cerebro-spinal  axis
 contained Avithin the channel  made by
 the foramina, or openings of the  verte-
 bra.   It extends from   the  medulla ob-
 longata just at the base  of the  skull, to
 the second lumbar A'ertebra, and has an          d  f
 average diameter  of half an inch.   It  r°rtion of the Spinal Cord,
 li         ,              „           'an(l Origin of one  Pair of
 has the general appearance of a flattened Nerves,  a, spinal Cord,  b,
 cord, but  on a closer inspection  it ap- ^tllf Sot!' T&
 pears to be made up of tAvo  smaller cords, foririe(i by both. /, Branch.
 called the lateral cords,  nearly separated by two clefts,  called
 the anterior and posterior median fissures.  This  cord is not
 perfectly uniform in its size, but  presents two enlargements,
 one at the point where the nerves are given off to the upper
 extremities, and  the  other  near  the lower  end of the cord.
   596. Microscopic Structure  of  the Spinal  Cord.—In
 anatomical structure we  find the spinal cord and spinal nerves
 are made up of two  kinds of nervous matter, the  Avhite and
 the gray, and also that  each pair of these  nerves arises by
 an  anterior and a posterior root.   The  posterior root is  made
 up  of gray nervous  tissue, and is called  the sensitive  root,
 since it gives the sense of feeling to the parts Avhere it is dis-
 tributed ;  the anterior root of Avhite fibers  is called the mo-
tor  root, because  it imparts motion to the different  muscles of
 594. Describe the linsual. 595. AVhat is the spinal cord ?  How many fissures has the
spinal cord?  How many enlargements?  596. AVhat is the microscopic structure of the
spinal cord?  AVhich is the sensitive and which the motor root ? 
332
HITCHCOCK'S   ANATOMY
the body.  A ganglion is found upon the posterior root, just
before it unites Avith the anterior.
   597. Origin of  the  Spinal Nerves—Between  each  of
the A-ertebrae the spinal nenTes  are givenoff.   These are made
up of fasciculi,  and  each fasciculus of  distinct fibers Avhich
somewhat resemble muscular fiber.   They arise on each side
of the cord by two roots, one given off from the anterior and
the other  from  the posterior  part of the lateral cords ;  the
anterior root being the one that is designed to produce mo-
tion, and the posterior giving sensation to the parts on which
it  is distributed.   These two roots  unite  as soon as they have
fairly left the spinal cord, after which they proceed a3 a single
nerve.  (See Fig. 318.)
                      598.  Groups of Spinal Nerves.—These
                     nerves are grouped together, and have
                     the same  name as  the  groups of verte-
                     brae in Avhich they  are located.
Fig. 319.
 8 Cervical.
12 Dorsal.
5 Lumbar.
6 Sacral.
                     The last nine are additional, or supple-
                     mentary to the spinal cord, and not prop-
                     erly a  portion  of it.   They  are  called
                     the cauda equina.
                       599. Plexuses.—Most of these nerves
                     are grouped together soon after leaving
                     the spinal column, each group  being
                     called a  plexus  (from the Greek  " to
                     weave"), Avhich is simply a net-work of
                Although there is to the naked eye a com-
plete interlacement and an apparent loss of fiber,  yet by the
microscope these fibers  can  be distinctly traced through the
whole  mass, with  the exception of  a few Avhich  are inter-
changed for purposes to be described hereafter.   After emerg-
 Diagram to show the De-
cussation  (crossing  from
side to side) of Nerve Fi-
bers in a Nerve.
nervous fibers.
 5; 7. Give the orisrin of the spinal nerves. 598. State the groups of the spinal nerves.
599. Describe the nature of the plexuses. 
AND   PHYSIOLOGY.                   333
Fig. 320.
                                Nervous System.
  a, Brain,  b, Little Brain,  c, Spinal  Marrow,  d, Facial Nerve,  e, Brachial  Plexus,
caued by the union of several Nerves coining from the Spinal Marrow,  f Med.an Nerve.
a Cubital Nerve.   A, Internal Cutaneous Nerve of the Arm.  ^, Radial  and Musculo-
Oitaneous Nerve of the Arm.  j, Intercostal  Nerves.  *, Femoral  Plexus.  I, Sciatic
pSu'^  Tibial N..rvo.  n, External Poroneal Nerve ;  o. External Saphenous Nerve. 
334            HITCHCOCK'S  ANATOMY

ing from the plexuses,  the nerves  proceed to their destination
and receive names,  many of Avhich are the same as the arteries
which they accompany.
   600.  Cervical  Plexus — Brachial  Plexus— Lumbar
Plexus—Sacral  Plexus.—The cervical plexus is made up of
the four upper cervical nerves, and the brachial plexus of  the
               Fig. 321.                           Fig. 322.
2, 2, The Median Nerve.  3, The Ulnar Nerve. 4,    Nerves of Front of Fore-Arm.  1,
The Branch to the Biceps Muscle. 5, The Nerves  Median Nerve.  2, Anterior Branch
of Wrisberg.  6,  The Phrenic Nerve from the  of Musculo-Spiral or Radial Nerve.
Third and Fourth Cervical.                   3, Ulnar Nerve. 4, Division of Me-
                                       dian  Nerve in the  Palm  to the
     Thumb, First, Second, and Radial Side, of Third  Finger.  5, Division of Ulnar
     Nerve to Ulnar Side of Third and both Sides of Fourth  Finger.
6u0. AVhat nerves go to make up the cervical and brachial plexus ? 
                   AND  PHYSIOLOGY.              335

four lower cervical and upper dorsal nerves, and they give off
their branches to  the  upper part of the  body.   The  lumbar
plexus is made up of the last dorsal nerve and the five lumbar
nerves ; and the sacral plexus of a branch of the last lumbar
and the upper sacral  nerves.  These supply the portions  of
the body below the loins, and the superficial parts of the body
between the loins  and upper part of the chest.
                              A View of the Anterior Crural Nerve
and Branches.  1, Place of emergence of the Nerve under Pouparl's Ligament.  2,
Division of the Nerve into Branches. 3, Femoral Artery. 4, Femoral A'ein.  5,
Branches of Obturator Nerve.  6, Nervus Saphenus.  ___________^_______^
             Describe the lumbar and sacral plexus.
15 
336            HITCHCOCK'S   ANATOMY
   601.  Direction  of the Nerves.—The largest and most im-
portant  nerves follow the same general direction as the larger
blood-vessels, and generally are in close proximity to them.

   602.  Motor  Nerves—Mode   of   Termination—Pacinian
Corpuscle^.—The nerve  fibers  which go from  the  anterior
columns of the spinal cord terminate in the fleshy portions of
the muscles, because they are  the motor nerves, or those ex-
FiG. 325.
Fig. 326
  A View of the Termination of
the Posterior Tibial Nerve in the
Sole of the Foot. 1, Inside of the
Foot. 2, Outer Side.  3, Heel.  4,
Internal Plantar Nerve. 5, Exter-
nal Plantar Nerve.  6, Branch  to
Flexor Brevis.  7, Branch to Out-
side of Little Toe.  8, Branch  to
Space between Fourth and Fifth Toes.  9, 9,  9, Digital Branches to remaining
Spaces.  10, Branch to Internal Side of Great Toe.
  Pacinian  Corpuscles.   A,  Single Corpuscle
highly Magnified,  a, Its Peduncle,  b, Its Nerve
Fiber, c, Outer Layers, and d, Inner Layers of
the Capsule,  e, Nerve Fibers, and /, Its Subdi-
vision and Termination.  B, Portion of Digital
Nerves, with Pacinian Corpuscles attached.
  601. Give the general direction of the nerves through the body.  602. Where do the
motor serves terminate ? 
AND  PHYSIOLOGY.
3::1
citing  motion.    Those from the posterior  columns  spread
through the surface of the body, giving sensation to the  skin.
The mode, hoAvever, in Avhich they terminate is not ahvays the
same.  As far as at present is known, they seldom terminate
in a free or single extremity,  but in loops,  returning into
themselves, or joining Avith other fibers.   And  it is  an an-
atomical fact that the nerve tube5  do not  anastomose one
Avith the other, as is the case among the  blood-vessels; but
each tube discharges its OAvn duty, and not  that  of another
under  any  circumstances.   In  the skin of the hand and
foot they terminate in minute OATal bodies  from the tis^h  to
the Tfoth of an  inch in length, and  from one twenty-sixth to
one  twentieth of an inch in breadth, called Pacinian  Cor-
puscles (from Pacini, their  discoverer), and are attached  to
the branches and extremities of the  nerves very much in the
same manner as  some kinds of  fruit are attached to  their
boughs.   (Fig-  326.)  Of these, there are about six hundred
in the hand and a somewhat smaller number in the foot.   They
are composed of connectiAre or areolar tissue in from tAventy
to sixty bands, with interspaces containing a serous fluid, and
are  attached to  their nervous  tAvig by a rounded peduncle.
The function of these bodies  is entirely unknown.

   603. Sympathetic System —  Its  Size — Connection
with  Spinal Nerves—Destination of  its Branches.—
Besides  the cerebro-spinal  center,  there  is  another  organi-
zation of  nervous tissue  which  is called the  Sympathetic
Nerve or Ganglionic System, and  is to  be  regarded  as an
appendage of the spinal nerves.   It is of very limited size,
consisting of mere reddish threads of nervous matter and oval
bodies called ganglia, never so large as peas.   These  ganglia
and nerves extend along each side of the spinal column from
 State the manner in which they terminate. Give a description of the Pacinian cor-
puscles. 603. What is said of the structure of the sympathetic system 2 
338             HITCHCOCK'S  ANATOMY
Fig. 327.

turn. 34,  Globe of the Eye.  35, 36,
             the  atlas  to  the  coccyx,

             communicating  Avith  all

             the spinal nerves  by two

             small  fibers   (see  Fig.

             328), and giving branches

             to all the internal organs

             and   viscera.    Branches

             and    ganglia   are    also

             found between the  bones

             of the  cranium and the

             face.      The    branches

             which are given off to the

             internal  organs   accom-

             pany the arteries  to the

             same, forming a net-AVork

              Great Sympathetic  Nerve.   1,
             Plexus  on the Carotid Artery in the
             Carotid Foramen.  2, Sixth  Nerve
             (Motor  Externus).  3, First Branch
             of the Fifth, or Ophthalmic Nerve.
             4, A Branch on the Septum Narium
             going to the Incisive Foramen.  5,
             Recurrent Branch, or A'idian  Nerve
             dividing into the Carotid and Petro-
             sal Branches. 6, Posterior Palatine
             Branches.  7, Lingual Nerve  joined
             by the Chorda Tympani.  8,  Portio
             Dura of the Seventh Pair.  9, Supe-
             rior Cervical Ganglion.  10, Middle
             Cervical Ganglion.  11, Inferior Cer-
             vical Ganglion.   12, Roots of tho
             Great Splanchnic Nerve arising from
             the Dorsal Ganglia.  13,  Lesser
             Splanchnic Nerve. 14, Renal Plexus.
             15, Solar  Plexus.  16, Mesenteric
             Plexus.  17, Lumbar Ganglia.  IS.
            Sacral Ganglia.  19,  Vesical  Plexus.
            20,  Rectal  Plexus.  21,  Lumbar
            Plexus  (Cerebro-Spinal).   22, Rec-
             tum. 23,  Bladder.  24, Pubis.  25,
             Crest of the Ilium.  26, Kidney. 27,
            Aorta.  28, Diaphragm.  29,  Heart.
            SO, Larynx. 31, Submaxillary Gland.
            32. Incisor Teeth.  33, Nasal Sep-
Cavity of the Cranium.
Where does it give its branches? 
AND   PHYSIOLOGY.               339

          Fig. 32S.
        Roots of a Dorsal Spinal Nerve, and its union with the Sympathetic.
  c,c, Anterior Fissure of the Spinal Cord,  a,  Anterior Root.  ^>, Posterior Root, with
its Ganglion,  a', Anterior Branch,  p', Posterior Branch.  *, Sympathetic,  e, Its
Double Junction with the Anterior Branch of the Spinal Nerve by a AArhite and Gray
Filament.
of communication around the vessels.   And  as  all  the inter-
nal  organs, especially those called vital, are supplied with this
nerve,  and  not  directly from  the cerebro-spinal  center, it is
hence called a nerve of organic life.
   604.  Sympathetic Ganglia.—Each  of these ganglia may
bo considered as a nervous center  sending  forth  strands  in
three directions; 1st, to join  the spinal  nerves in  their dis-
tribution ;  2d, to the spinal cord itself;  3d, to the next sym-
pathetic ganglion above.
604. What may each of these glands bo considered as ? 
340           HITCHCOCK'S  ANATOMY

  605.  Groups of Sympathetic  G a n g 1 i a .—These ganglia
are grouped together according to the locality, to Avhich their
branches are distributed.  Thus we have the Cranial ganglia,
Cervical ganglia,  Thoracic  ganglia, Lumbar  ganglia,  and
Sacral ganglia.  Besides these there are several large  plex-
uses Avhich  have received  distinct  names,  although a  great
number of small ones haA'e not received  any names.   Of the
most important ones Ave may name the  Pharyngeal, in the
immediate vicinity  of the Pharynx, the  Cardiac lying upon
the heart, and  the  Solar, betAveen the liver and  stomach, or,
as is more commonly known,  the pit of the stomach.
  606.  The Solar  Plexus.—The Solar Plexus seems  to be,
as its name  implies, a sun or center  for nervous power  to the
intestines, since branches from this plexus accompany  the ar-
teries to  the  vital  organs, where they  subdivide  again and
again, and enter their coats and substance.


     FUNCTIONS   OF THE  NERVOUS  SYSTEM

   607.  The functions of the Nervous System  are the most
important and delicate  of any in the body.   1. The  Brain
affords a seat and center for life and intellect.   2. The nerves
are inlets for all the senses to the sensorium or seat of sensa-
tion.  3.  They are the medium of  all the  movements of the
body, voluntary and involuntary.    4. They  establish and
maintain a sympathy between all the parts of the body, and
equalize all the vital forces.   5.  They  preside  over  the in-
Aroluntary functions, such  as the  circulation of the blood, di-
gestion, respiration, and reflex actions.
   608.   Intellect   and  Will   located  in  the  Brain.—
Voluntary   Movements   dependent   on   the  Brain.—
The  whole  Brain  not   essential. —The  Intellect and
 615. IIow are the sympathetic ganglia grouped together?  What is said of the sym-
pathetic plexuses ? 606. Describe the solar plexus. 607. What are the five principal func-
tions of the nervous system ? 
AND  PHYSIOLOGY.              341
Will  evidently reside  in the  brain (cerebrum),  and re-
quire that this organ should  be in  a healthy  state,  since,
if any  disease affects its  Avhole  substance,  their  power  is
destroyed.   Voluntary muscular movements depend  on  a
sound and healthy brain, although reflex movements, and the
motion  necessary  to  sustain  animal life, are  often  carried
on  in some  animals for a considerable  time, when they are
born  without a brain.   But the whole brain does not seem  to
be absolutely essential to life and mental operations, for  many
instances are mentioned, where a considerable portion of the
brain has been removed by accident, such as  a bullet  or iron
bar being shot through  the   head followed  by  a  discharge
of  nervous  matter:  and  yet the  persons  have  lived  for
years subsequent to the accident in as sound a condition  as
ever.

   608a. Necessity  of  two  Cerebral  Hemispheres.—One
may  be injured, and  not the other.—The  reason  of the
division of the brain into  lobes or hemispheres is not so  easily
understood.   Perhaps it may be that so large an organ of so
 soft  a  substance could not easily sustain its own weight, es-
pecially  when reclined on one side, and at the same time
properly perform its functions.   A more  probable reason,
hoAvever, is  this.  It is a well-known  fact,  that one of the
hemispheres may be diseased  or injured, so as to perform  its
functions imperfectly, and  yet the other hemisphere be in  its
ordinary healthy state.    Also one  hemisphere may  be so
much  affected, that  the  opposite side of the  whole body  is
paralyzed in  motion or  sensation, or both.   It then  seems
 reasonable to  suppose, that, since the brain would be  so liable
 to injuries,  it Avas made in two portions, so as to prevent the
 entire  destruction  of life by an injury to  one of the hemi-
 spheres.

   60S  Where are the intellect and the will located? What movements depend on the
 brain ? Is the whole brain absolutely essential for intellection ?  608 a. Why are there
 probably two hemispheres to tho brain? 
342           HITCHCOCK'S  ANATOMY

   609.  To  secure Precision in  all  Voluntary  Actions.
—In Draper's Physiology is found another hypothesis for the
division of the brain into two parts: this is to secure precision
in the efforts of the  intellect  and will.   " For there is  no
doubt," he  says, "that the hemispheres have not only the
power of acting separately,  but also conjointly; thus there is
no student but must  have observed, when busily engaged  in
reading, that his mind will wander off to other things,  though
be may  mechanically  cast his eye  over page after page; and
the same may occur in listening to a lecture or sermon.  But
though the insane man may indulge in two synchronous trains
of thought,  he never  indulges in three, for the simple reason
that  he has not three  hemispheres  to do it with, the same re-
mark applying  to the sane man in the accidental wandering
of his thoughts."
   610.  Thought,  Memory,  and  the  Reasoning  Powers
require a  Sound Brain.—As already mentioned, the brain
is not the seat of motive power : this  does not originate here,
although voluntary movements  are controlled by it.   But
automatic or reflex  movements,  such  as  the twitching of the
muscles of  the  leg and foot, when the sole of the  foot  is
tickled  with some  slightly  irritating substance,  are  entirely
beyond  the  control  of the cerebrum  or will,  since they take
place nearly as well in a person who is asleep or stunned  by
a blow, or even when  the nerves of sensation and motion are
paralyzed.   Thought,  memory,  reasoning, and all the intel-
lectual states demand a healthy and  a sound brain for their
perfect  action,  while  the ordinary muscular movements and
the  functions of respiration, circulation, and  digestion,  are
dependent upon the  Spinal  Cord, Sympathetic Nerve, and
Cerebellum.
   611.   Definition  of  Sleep.—Need  of Sleep. —Sleep,
"tired nature's sweet restorer,"  is a state  of the  body,  in

 609.  How can two hemispheres secure a precision in  voluntary actions? 610. Are
reflex  movements under tho control of tho brain ? What powers of mind are dependent
on the cerebrum ? 
AND  PHYSIOLOGY.
343
which there is a more or less perfect suspension of the activ-
ity of the  brain.   The  functions  of digestion, secretion, and
respiration,  proceed during  the soundest sleep, though with
less activity than during the wakeful state.   In many cases,
however,.the functions  of the  brain do not entirely cease, as
is seen in the phenomena of dreaming, Avhere the brain seems
to  be actively  at Avork,  but  the senses and animal functions
are quiescent.  Sleep is demanded by all animals to procure
rest to the different organs of the body, and in health it comes
to  all, though in different degrees  of soundness, but generally
the greater the exhaustion, the more complete the sleep.
   612.   Periodical  Tendency of Sleep.—The  Will  can
for  some  Time  overcome   Sleep.—The  tendency  to  sleep
is periodical.   All persons feel an inclination to sleep during
 some portion of the twenty-four hours, and during the night,
 if  health be good and  nature  not perverted.   Some strong
 intellectual effort,  however,  or some  poAverful emotion, will
 overcome drowsiness  for a  long time, as  in  the case of the
 student working  out a difficult problem, or a mother watching
 her sick child.   But when the problem  is  mastered, and the
 child has safely passed the crisis, sleep comes on Avith irresist-
 ible  force.   Cases  occur constantly  to  show that  the  brain
• must have its repose in spite  of intellectual  effort or danger.
 It is related that boys Avearied out with continued labor in the
 battle  of the Nile,  slept during a part  of the action, and in
 another naval engagement, a captain slept tAvo hours Avithin a
 yard of his largest  gun, which was kept in action during the
 whole time.   Indians at the stake of torture  will sleep on the
 least remission of agony, but awake as soon  as it is reneAved
 acniin.    And we  learn  that a most barbarous punishment is
 still practiced  in China, that of keeping a victim awake until
 he dies of sheer  exhaustion.  The distress  of it is said to be
 terrible.____________
  611. What is sleep ?  What pou-Jrs are inactive during sleep,  and what processes are
 carried on during it?  AVhat is sleep necessary  for?  6.2. State the fact of a periodica
 tendency  to sleep.  Can the will overcome sleep?  For bow long a time can it do it 1
 Relate the facts mentioned.            # 
344
HITCHCOCK'S   ANATOMY
   613. Inducements  to  Sleep—Sleep  sometimes  under
the  Control  of  the  Will.—Ordinarily  darkness and  si-
lence promote sleep; but if a person once becomes habituated
to noise during slumber—if it  be a continuous  one—he  can
not sleep Avell without it.  Thus persons living in the vicinity
of forges and noisy mills can not readily sleep elseAvhere. And
a monotonous repetition of sounds is a  most favorable provo-
cative to sleep, the cause of Avhich  is that other impressions
can not so  readily be made on the mind, and thus the sleeper
is less easily roused.  A dull reader  on a dull subject  has a
most ready effect in producing sleep, as well as the sound of
a distant Avaterfall, or the rustlinsr of leaves in a forest.  Bub-
bing many parts of the skin, or combing the hair by another
person,  will often  cause  droAvsiness,  and sometimes  sleep.
Again a person can sometimes put himself to sleep, if restless,
by a monotonous intellectual effort,  such as the rehearsal of a
Latin paradigm, or counting the rain-drops, as they fall from
the eave trough into the spout.

   614.  Effect  of  Habit   on  Sleep.—The effect of habit is
powerful in producing sleep. Let one be  accustomed to retire
early—in  accordance with  nature—and  sleepiness comes at
the usual hour  for retiring; but if a person for a series of
years is in the habit of sleeping  the latter part  of the night
and early in the  morning, it is almost  impossible  for him to
sleep  early in  the  night.   Those  persons Avho, like sailors,
soldiers, and Avatchers, are obliged  to catch sleep Avhen they
can get it,  and then only in small  amounts at a  time, sleep
with but little difficulty when the opportunity presents itself.
Captain Barclay,  Avho Avalked one thousand miles in as many
consecutive hours, had such a power over himself, that be  Avas
asleep the  moment he  lay doAvn.    Some physicians have  the
same power.
  613. AA'hat are the common inducements to sleep? Do any persons ever require  a
noise, in order to sleep soundly ? AVhat effect does rubbing or chafing certain parts of
the body have upon sleep?  Can sleep ever be brought about by an action of the  will?
How ? 614. AVhat effect has habit upon producing sleep  ?  Mention the case of Captain
Barclay. 
AND  PHYSIOLOGY.
345
  015.  Preventives  of  Sleep.—Any unusual noise or place
of sleeping will prevent or disturb the sleep of many persons.
Thus the singing  of  a mosquito keeps many a man awake a
long time.  But if a noise  be repeated often,  it will have
no effect of this kind.  The college Freshman for the few first
mornings is readily awaked  by the first stroke of the early
prayer-bell, but in a short time it has no effect whatever.
" A gentleman who had taken his passage on board a man of
war, was aroused on the first morning by the report of the
morning gun, which  chanced to be fired just above his head;
the shock was so violent as to cause him to jump out of bed.
On the second  morning he was again awakened, but this time
he merely started and sat up in bed; on the  third morning
the report had simply the effect of causing him to open his
eyes for a moment and turn in his bed ; on the fourth morn-
ing  it ceased  to affect him at all, and  his slumbers continued
to be undisturbed so  long as he remained on board."
   616.  An  Absence  of   Accustomed  Sounds  prevents
Sleep.—The reverse of this sometimes happens, if there be a
cessation of monotonous and unaccustomed sound, by which
sleep  Avas induced.  Thus  a person Avho has been  read or
preached to sleep, will awake if the reader or preacher pause
or stop, before any disturbance is  made, and a person asleep
 in a railway train, will  often awake on the stopping, or even
on the slackening  of the train.
   617.  Amount  of  Sleep.—The amount of  sleep necessary
for man, varies exceedingly, being affected by the  conditions
of a^e, temperament, habit,  and exhaustion.   Infants and
 very°old people  sleep the most.   The former require it that
the constructive  process may go on  as  uninterruptedly  as
 possible, and they generally sleep three fourths of the time
 The  latter  need  a large amount  of sleep,  because the vital
 energies arc so feeble.
  ~615  Wbat^vni^re^sn7prevent sleep? Instance the college Freshman and the
   ,i'  „ rVleman of war. 616. How does an absence of accustomed sounds affect
 Kp?  617%:>™Ltlof sleep is necessary ?  What ages sleep the most ? 
346          HITCHCOCK'S   ANATOMY
   618. A lymphatic  Temperament a Sleepy one.—Persons
 of  a lymphatic  temperament, those who are seldom excited,
 sleep more than those of a  nervous temperament, who are
 always rapid and quick in their movements.   The former live
 slowly, and but comparatively little waste is going on, and
 consequently the brain is all the time nearer to sleep than in
 the latter class,  whose brain, when awake, is very active, and
 when asleep, is asleep  very soundly.
   619. Effect  of  Habit  on  the  Amount  of  Sleep—Re-
 markable Cases.—The amount of sleep  is  greatly modified
 by habit,  and often the briefest sleepers have  been men of the
 greatest activity.   If  a person acquire the habit of sleeping
 but little, he must sleep very profoundly, so that what  is lost
 in quantity,  is made up in intensity.   The  habit  of  taking
 but little sleep, however, is not a sure indication that a  proper
 amount of it has been secured.   Frederic  the Great, and
 John Hunter slept but five hours out of the twenty-four ; and
 General Elliot, engaged in the defense of Gibraltar, and Na-
 poleon, often slept but four  hours out of the  twenty-four.
 The general rule,  however,  seems  to  be that  man  should
 take from six to eight hours of the twenty-four, for uninter-
 rupted slumber.  "Women  in  general seem  to require  rather
 more.

  620. Mode  of Access of  Sleep.—To some sleep comes on
instantly when the will determines upon  it, but to others it is
a gradual and tedious  process, especially in ill  health, or an
excited mental state.  Many physicians drop asleep as soon as
the head touches the pillow, and are aroused by no ordinary
sound,  such as the tread of another person  in the room or
the shutting of a door, but wake as soon as the night-bell  is
rung.  Sir E. Codrington, when a young man  in  the naval
service, was very active at one time in looking out for signals

 618. What are the sleepy temperaments? What the wide-awake ones?  619. How
does habit affect the amount of sleep ? State some remarkable cases. AVhat is an average
amount of sleep for men? How much for women?  620. How does sleep come on?
Give examples. 
AND  PHYSIOLOGY.              347
and was employed during his waking hours  in  this business.
Hence his sleep Avas very solid, and  he was roused by no or-
dinary sound, but his  comrades amused themselves  by whis-
pering the word  "signal" in his ear,  Avhen he was at once
aroused and fit for duty.

  621. Functions of  the  Cerebellum__The  Cerebellum
does not seem to be in any manner directly connected with
the phenomena of mind.   But it seems designed simply for
the purpose of combining the actions of different  muscles, or
presides over the coordination  of voluntary muscular  move-
ments, as  in  walking, speaking, and similar actions  requiring
several sets of muscles to be used at the same instant.  Ac-
cordingly  in animals,  Avhich possess the greatest variety of
moArements, we find the largest cerebellum.
  622. Effects  when  Removed  from  Animals.—The Con-
trolling  Power  of  Muscular  Motions—When this organ
has been removed from some of the lower animals,  it was found
that they  could  not control their movements.  When  laid
down they could not  recover their erect posture, and Avhen
threatened with a blow, they in vain endeavored  to avoid it.
Another phenomenon  attending  a wound,  or removal of both
sides  of the  cerebellum,  was the motion of the animal in a
backAvard direction,  and  the rolling from  side to side on the
longitudinal  axis of the  body,  and keeping up  this motion
uninterruptedly,  for several hours, at the rate of sixty revolu-
tions per minute.  In some men Avho have been afflicted with
a disease  of  this  organ, an  unsteadiness of gait has been ob-
served, Avhich gives additional strength to the belief that the
Cerebellum is the regulator of muscular movements.

   623. Functions  of the  Medulla   Oblongata,—The Me-
dulla Oblongata  seems to have for its function the sending of
nervous power to the muscles  of respiration and  swallowing,

  621 Docs the cerebellum control the phenomena of mind? What are its Junctions'
6"2  'What effects does  its removal  cause in animals ?   How does a disease of it affect
men ? 623. What operations are controlled by the medulla oblongata ? 
348
niTCHCOCK'S  ANATOMY
or, in other words, respiration and  deglutition are controlled
and performed by the medulla oblongata.
   624. Function of the  Cerebral Ganglia.—The series of
Ganglia, Corpora striata, Thalami optici, etc.,  are regarded by
Dr. Carpenter as the true sensorium in man,  and this  is one
of  the  most important facts established  with regard  to  the
nervous system.   A  prominent reason for the belief, that  the
brain is simply superadded to them, is seen in many instances
of children born Avithout a brain, but with the  sensory ganglia
present, Avhere the functions of animal  life have been carried
on for a considerable  length of time.
   625. Functions of the Spinal  Cord.—The functions  of
the Spinal Cord are considered in a double aspect:  First, as
the means  of communication between the  roots of the spinal
nerves, and those parts of  the nervous  system  Avithin  the
cranium, and  second, as a center of nervous  power to pro-
duce  reflex movements Avhen an impression is  made upon this
cord.
   626.  Function  of  Sympathetic   Nerve.—The   Sym-
pathetic Nerve "in its offices is a motor  nerve  to many of the
internal viscera of the body, the heart and the  intestinal canal
especially; it  is also  a sensitive nerve to  these parts,  and it
presides over the action of the blood-vessels of these as well
as of  the other parts, where  it is distributed,  as  of  the head
and neck,  and  likeAvise of all the  principal  glands  of the
body."
   627. Organic Functions depend on the  Spinal Cord.—
Effect  of  Pressure on  this Cord .—Almost all the func-
tions of organic life, such  as breathing, digestion, and circu-
lation, are greatly influenced by the condition of the  spinal
cord,  and  especially  in  its connection Avith the  sympathetic
nerve, although the  brain  has some controlling power.  Yet

  624. By what set of bodies are the principal functions of animal life carried on?  625
What are the functions of the spinal cord ?  626. Give the use of the sympathetic nerve.
627. Upon what portions of the nervous system do organic functions depend? 
AND  PHYSIOLOGY.
349
when we are asleep, or the brain  is stunned by a blow, the
organic functions are carried on as in the state of the activity
of the brain, though Avith far  less energy.   And in the case
already mentioned of animals born Avithout  a brain, life (or-
ganic) may be sustained for a considerable time merely by the
functions of the spinal cord.  If this cord be severed near the
head, or even if it  be compressed, life soon  ceases.   This is
the manner in Avhich death ensues by hanging, or breaking the
neck as it is termed; Avhere one vertebra is  slipped from  its
place (put out of joint), so that by the unequal  contraction
of the muscles such a pressure is made on the cord that life
speedily becomes extinct.   And if this cord is compressed in
any portion, sensibility and the power of motion  in muscles
supplied by the part below the point of compression are de-
stroyed ; and if the pressure be long continued, or the cord
divided,  its vitality is for ever destroyed, although the parts
above it are only indirectly affected.
   628. Sensation  Exists Previously  to   Motion—Centri-
petal and  Centrifugal Fibers —Rate of Movement through
the  Nerves.—From the fact  that one portion of each nerve is
designed for sensation, and the other for motion, it is probable
tbat°sensation  must exist previous to the motion of the part.
Thus, for example,  if the hand be brought  in contact with any
substance without any previous knowledge of its presence, no
matter bow soon the hand may seem to grasp it, yet the  in-
terval must have been long enough  for  the  sensation contact
 to have passed from the hand to the brain,  and the will to de-
 termine upon the condition of  the muscles, and the order to
 pass down  through the white fibers to  the  hand again before
 the grasping can take  place.   Or  the  same thing  may take
 place on receiving a  shock, or  series of shocks, from a gal-
 vanic battery, the  contractions in this  case  being  an instance
 of involuntary or  reflex movement.   And  although this fact
 What is the effect of pressure upon or division of the spinal cord?  628. What tvo
JoSoni exist in eachnerve?  Which exists first, motion or sedation? 
350
HITCHCOCK'S  ANATOMY
seems clearly established, that one portion of each nerve trans-
mits the sensation to the brain, called the centripetal or sen-
sory, and the other conveys the order to the muscle, called the
centrifugal or motor, yet no anatomical difference can be de-
tected between  the different fibers of the nerve.   From this
fact a  German physiologist has made  a series of curious cal-
culations, as a result of Avhich he concludes  that nervous in-
fluence, such as the will to  move a certain muscle, travels at
the rate of 195 feet per second.
   629. Ganglia Reservoirs  of  Power.—It  has  been  sug-
gested, and with reason, that the ganglia,  abundant as they are
in the body, act as reservoirs  of nerve force,  and the frequent
commissures, or union  and subsequent  divergence  of nerve
fibers, is to draw off a part of the influence Avhich is coming
along  the centripetal fiber, and directing it into a new chan-
nel.
   630.  Divisions  of  the  Cranial  Nerves.—The  cranial
nerves may be divided, according to their function, into three
groups :
                                  !  Olfactory.
                                     Optic.
                                     Auditory.
                                     Motores Oculorum.
                                     Patheticus.
        Motion.....................■{  Abducentes.
                                  j  Facial.
                                  I  Lingual.
                                     (Trifacial.
                                     Glossopharyngeal.
                                     Par Vagum.
                                      Spinal Accessory.
  . 631. The olfactory nerve is the one by which Ave  gain the
smell of odoriferous  substances, as they are  brought in  con-
tact with this nerve in the lining membrane of the nose.
 AVhat are the centripetal and what the centrifugal fibers of the nerves?  What is i
probable rate at which the influence is transmitted through the nerves to and from the
brain?  629. AVhat theory has been offered for the use of the ganglia?  630. AVhat thre
groups of the cervical nerves are here given ?  031-G10. State the function of each pair
of the cranial nerves. 
AND   PHYSIOLOGY.             351
  632.  The  optic  nerve,  as expanded in the retina, is the
nerve of sight.
  633.  The auditory nerve receives the vibrations of  the air.
Avhich produce  sound.
  634.  The motores oculorum, pathetici,  and abducentes are
the nerves which furnish motive power to  the eye-ball.
  635.  The facial nerve is distributed to  the muscles of the
face, and  is the one that aids in the expressions of the emo-
tions and  will,  as exhibited in the countenance.  It is  also the
channel of the reflex actions in respiration, as when a person
involuntarily gasps if cold water be dashed in the face.
   636.  The  lingual (hypoglossal) nerve is necessary  for the
production of articulate speech, regulating and controlling as
it does the muscles of the larynx.
   637.  The trifacial nerve administers the sense  of touch  to
the surface of the tongue,  and aids somewhat in the sense  of
taste.   One  branch of it is  a muscular branch.    Another is
sent to  the mucous surface of the eye, and if it be cut off the
eye is destroyed by suppuration.
   638. The glosso-pharyngeal is the essential nerve of taste,
and is  closely connected  in function with the  trifacial.  It
seems also to be the nerve  through which unpleasant sensa-
tions excited in the mouth are conveyed  to the  medulla ob-
lono-ata so as to excite nausea and vomiting.
   639. The par vagum sends nervous power to the heart,
stomach,  lungs, and larynx, as well  as conveys  to the brain
any disagreeable sensations  excited in these organs.   Conse-
quently  this is the essential nerve  of digestion, respiration,
circulation, and opening or  closure of the glottis under ordi-
nary circumstances.
   640   The spinal accessory seems to be  the  nerve by which
 the regulation  of  the  muscles essential to the production  of
 voice is effected. 
352          HITCHCOCK'S  ANATOMY

   641. Use  of  Spinal  Nerves. — The  use of the  Spinal
Nerves is to convey impressions made at  the  surface of the
body—including the extremities—to the brain,  and to trans-
mit impulses to the muscles from the brain.   Both of these
influences  are  transmitted by the  same  nerve or filament,
though in opposite directions.   From carefully  conducted ex-
periments  it seems quite probable  that the "coarse fibers"
transmit the impulses to the muscles,  and are called afferent,
while the fine fibers conduct the impressions to the brain, and
are called efferent.  And in the muscular nerves  the coarse
fiber  is  proportioned  to  the fine as  10 :  3.3,  Avhile  in the
trunk, as it issues  from the spinal cord, it is  in the ratio of
10 : 11.


             HYGIENIC   INFERENCES.

   642. The  Nervous   System not  easily Diseased.—1. It
is  a singular fact that  the nervous  system, so delicate in its
organization  and mysterious in many of its functions, is to
so small an  extent dependent upon any particular rules  for
the maintenance of its health, the  main thing  necessary for
its Avelfare being an attendance to  the  general  health of  the
body.

   643. It  needs Action.—2.  The  nen^ous system,  like  all
other parts  of the body,  requires  action for its  health.   If  a
person  has nothing upon Avhich  he  can  exert bis  nervous
energy, he is liable to  disease ; and no class  of people are so
subject to nervous diseases as the  wealthy, Avho  are obliged to
make little exertion to  procure the necessaries and  luxuries of
life.  Hence we infer that employment of some  kind  is indis-
pensable to the  health of the nervous system.
   644. Sleep indispensable  to its Ileal th.—3. This system

  C41. What is the use of the spinal nerves? What is the difference in function between
the coarse and the fine fibers?  612. Is the nervous system easily affected by serious dis-
ease ? 643. What is the necessity of action to the nervous system ? 
AND  PHYSIOLOGY.
353
  requires sound sleep   For this alone can return to the brain
    s  expended energies.   It is as necessary  to  the brain as
   team to the ]             ^  ^        ^
   ee ion of  ,8ukh    Qld age;  whQ ^^ ^      ^   P

  of sleep.  Hence the very ambitious student, or the man eacrer
  to make money,  whose  time, energies and  thoughts arc°so
  engrossed that he can not,  or  will not, find time  to sleep, vio-
  lates one of  nature's principal laws,  and sooner or later wilt
  receive the penalty.   And, according to insane hospital  re-
  ports, one of the principal causes of insanity is put  down to a
  want of sleep.

    645. Needs Rest and  Recreation.-4. The mind not only
  needs sleep, but also recreation or an  occasional change of its
  objects of thought.  Long-continued  trains of thought are to
  the brain what Avorking one set of muscles incessantly all day
  is to them—complete exhaustion.  He then that would  last
  the longest, must occasionally  turn his thoughts  from  his or-
 dinary avocation completely, and so give the brain rest.  This
 applies to every one, whether he is the business man, student,
 or the hard-Avorking farmer or  mechanic.   And every  one
 also needs a vacation, or at least some change of employment,
 once or twice  during the year, when, for a few weeks or days,
 he may break up the ordinary routine of life.
   646. Necessity  of various Objects for the Mind  to  di-
 vert  itself with.—5. If change or recreation be so  impor-
 tant for the  health, hoAV necessary that the mind should have
 various objects on Avhich to employ itself Avhen free from daily
 duties.  How pleasantly,  and  profitably,  for  instance, can
 one pass  his leisure  hours, if he will  but cultiA'ate a taste
 for music,  reading,  or some  branch of natural history, as  for
 example zoology,  botany, mineralogy, or  geology!   These
 pursuits not only give  healthful  physical  recreation, but  by

  644. What is the effect of a want or scarcity of sleep? AA'hat is often a prominent
cause of insanity ?  643. What kind of rest  does the mind need besides sleep? Do all
employments need a vacation ?  646. Is exercise, that is taken simply for exercise, ever
the best ?  What studies combine profit as well as recreation and exercise ? 
354           niTCHCOCK'S  ANATOMY
the attractive and  fascinating objects of  study which they
offer,  they divert the mind from the ordinary cares and trou-
bles of life, and also exert a  healthful moral  influence.   To
literary and  professional  men, as well as many  of business
engagements, such a source of recreation and improvement is
of very great importance, since often they are not interested
in many of the recreations and  pleasures which divert the
great mass of society,  and also  because  new  thoughts  and
means of illustration may be gained from them.

   647.  The Brain  must he  worked  Philosophically,  not
Spasmodically.—6. The brain and  nervous system will per-
form  more labor, if worked  philosophically, than if worked
spasmodically.  That is, mental and corporeal labor performed
regularly and steadily, and only up to the ordinary power of
the brain and nerves to sustain, will not  wear away the ner-
vous system to such an extent as if it be performed by over-
working for a few days and then lying idle.

   648.  Value of Mental  Abstraction.—7. As  a general fact
the mind acting through the brain can not successfully work in
the midst of noise and external attractions.  But  by practice
many can engage in deep study and intense thought, even in
the company of  those who are talking, laughing, singing, or
in the midst of any noise.   This is a valuable acquisition and
one that should  be sought after by every one, since all of us
are liable  to be thrown into such circumstances,  that  Ave
must  work, think, and transact business in  noise and confu-
sion.

   649.  The best Time  for Study.—8. We see from this sub-
ject that the best time for study is in the morning, for then the
brain is rested,  and can with  the greatest vigor and alacrity
engage in its efforts.  But here the fact  presents itself, that
the morning is  the best time for  physical exercise, and to

  647. How should the brain and nervous system be worked ? 64S.  What is said of the
value of mental abstraction ? 649. What is the best time for study ? 
                  AND  PHYSIOLOGY.              35g

 Which shall we give the preference ?   Shall we deprive  our

 CZ   e^re; 7slla11 we give up the best ^ « ^
 LT a tend t^t   TltanT  "* * ^^  ^ We sWd
  ay attend to  the  physical  exercise first, for if the general
 health be broken down, the brain will  sympathize  and then
 close mental effort will be at an end.  Hence, *2^JZ
 mg is the best time for study, yet we must not take the whole
 of it for that purpose, but must share it with exercise.  To a
 student who is passing through a long course  of study, early
 rising and  retiring,  and generally exercise  in the mornino-
 before commencing study, will tend to preserve and invigorate
 health.   Studying  late at night and  sleeping  Ion*  in  the
 morning  are injurious to no class of people more than to the
 hard student.

   650. Pernicious  Effect  of Tobacco  on  the Brain.-9.
 The effect of tobacco on  the brain is  thus described, in  his
 medical  lectures, by Dr. Solly, an eminent physiologist and
 practical  physician:  "I Avould  caution you,  as  students,
 from excesses in the  use of tobacco and smoking, and I would
 advise you to disabuse your patients' minds  ofthe  idea that
 it is harmless.   I have had a large experience of brain dis-
 ease, and am satisfied now that  smoking is  a most noxious
 habit.   I know of no cause or agent  that tends so  much to
 bring on functional  disease, and  through  this in the end to
 lead to organic diseases of the brain, as excessive use of to-
 bacco."
   651.  Power of the feelings over the Nervous System —
 10. It is Avonderful  and interesting to  see what is the poAver
 exerted by the  feelings and emotions upon the  nervous sys-
 tem, and through that upon the Avhole body.   Let the farmer
 feel that his severe labor is sure to bring him in  good crops,
 and hoAV happily does he  persevere  in his severe toil month
after month.  And  if the merchant can only knoAV that  his
 But how shall exercise and study both be properly attended to ?  What is said of early
rising ?  650. How does tobacco affect the brain ? 651. AVhat effect have the emotions
upon the physical system ? 
356
HITCHCOCK'S  ANATOMY
gains are great, boAV incessantly will he work  day and  night,
and yet consider his no hard life.  But if there be no encour-
agement,  no prospect of reAvard  to  the working-man  in  his
employment, Avhat drudgery does it become !   Nay, how posi-
tively injurious to health and vigor of body and mind.
   652. To the scholar, hoAveA'er, this principle is much more
important than to him Avho labors only Avith the muscles, since
these organs  can be worked to a considerable extent with an
unAvilling mind; but to work a brain already depressed and
discouraged is much more difficult, and sure to bring on grave
disease.   When the spirits are  light  and the mind free, the
memory can be more readily stored Avith facts and principles,
and the reasoning powers more easily developed.   It is hence
the duty of teachers to make study as pleasant and attractive
as possible ; it becomes those who select the location and con-
struct the buildings of colleges, academies, and school-houses,
to have a reference to taste and comfort in their plans, so that
physical  inconvenience may  not render  study irksome, and
that the taste  of the student may be improA'ed as much as pos-
sible by the construction and arrangements of these buildings.
   653.  Control of  the  Nervous  System  by  Moral  and
Religious Feelings.—11.  Finally,  of all  the sources  and
promoters of health, correct moral and religious feelings and
principles are  among the  most powerful.   The  reaction of a
guilty conscience upon the  body, in  obstructing the functions
and in bringing on Aveakness and  premature  decay, is Avell
known.   Equally powerful in promoting health and longevity
is an approving conscience.   A cheerful acquiescence  in  the
divine  will  has often done more to restore  the invalid and
maintain  good health against disease, than all medical reme-
dies ; Avhile pure and ennobling sentiments and religious hopes
have sometimes  been more efficacious to prolong life on earth
t'lan all other hygienic prescriptions.
  652. What effect  has pleasurable  feelings on the progress of the scholar?  658. State
the value of an approving conscience upon all classes of society, as it simply respects
physical health. 
        AND PHYSIOLOGY.


COMPARATIVE  NEUROLOGY.
357
   654. Among all the higher
mammals Ave are able to trace
nearly all the  different  parts
of the nervous system as they
are exhibited and arranged in
man,  though  many of  them
are considerably modified.
   655.  Weight of Brains.—
The  relative  weight of  the
brain is greater in the smaller
animals.   Thus, in the mouse
it  is said to be ^d the weight
of the body.   In the elephant
Fig. 329.
the  weight of the  brain  is
  Brain of Squirrel laid open.  B,  Cere*
brum.  D, Cerebellum.  C, Optic Lobes.
thai, Thalamus Opticus,  c, s, Corpus
Striatum.
Fig. 330.
  Upper and Under Surface of Brain ot Rabbit.  A, B, D, as before, ol, Olfactive Lobes.
op, Optic Nerve,  mo. Motor Oeuli. cm, Corpora Mamillaria.  c, c, Crus Cerebri, pv,
Pons Varolii,  pa, Patheticus.  tri, Trifacial,  ab, Abducens.  fac, Facial,  aw, Audi-
tory,  vug., Vagus, s, Spinal Accessory,  hyp., Hypoglossal.
C55. AVhat is said of the size of brains ? 
358
HITCHCOCK'S  ANATOMY
?i„th the weight of the body;  in  the ox, Tioth;  *n tne f°xj
^i^th; Avhile in man it is ^th the weight of the body.
   656. Proportion  of  the  Width  of  Brain  and  Spinal
Cord  in  Man and other  Mammalia.—This, as well as  the
comparison of cerebral mass and cerebral nerves, between man
and other animals, is interesting.   The breadth of the spinal
marrow is, to  that of the  breadth of the  brain, in man, as
1: 7;  in the  dog, as 1: 2.
   657. Cerebral Nerves.—"The cerebral  nerves correspond
to those of man.  The first pair, however, forms in some de-
gree  an  exception, for though  not absent in all  the whale
family, it is wanting in the dolphins.  In most mammals the
olfactory nerves are thick and  have a cavity in them.   The
fifth pair of nerves is, in many mammals,  of peculiar strength
and thickness when compared with  that pair in man."
   658. Sympathetic  System. — "The   nervous system of
organic life—the great sympathetic—is formed, as far as in-
vestigations  indicate, essentially as in man."   It is situated
mostly in the cavities of the thorax and abdomen, and follows
the course of the blood vessels.
   659. Tentorium.—The tentorium  cerebelli, which  in man
is a simple tough membrane that separates the cerebrum from
the cerebellum, is very delicate  in some animals, as the horse
and dolphin;  Avhile in the cat it is  supported by  a bony  plate
springing from the skull,  and is a very firm membrane.   Its
use to protect the brain in those  animals whose movements
are at times violent and sudden,  and especially those that leap
great  distances.
  660. Spinal Nerves.—The Spinal nerves also, in general
appearance, are like  those in man.   The  number of  pairs
varies in different species, as might be inferred from the dif-
fering number of their vertebrEe.
 656. State the proportion of the width of the brain and spinal cord.  657. AVhat is said
of the cerebral nerves of animals ? 658. What is said of the sympathetic system ? 669.
What is said of the tentorium ?  660. AVhat of the spinal nerves of animals ? 
AND  PHYSIOLOGY.
359
  661. Actual Proportion  between  Cerebrum  and  Cere-
bellum.—According to  Cuvier,  the  proportion of the cere-
bellum to the  cerebrum, by weight,  in  the  baboon, is  as
1:7;  in the dog, 1:8;  in the sheep, 1:5; and in the horse,
1:7.

  662. Spinal Cord.—The  essential difference between  the
spinal cord in  man  and the lower mammalia,  is  its greater
length, and a narrow canal which runs longitudinally through
the middle of it.
   663. Nervous System of  Birds.—The brain of birds is
characterized by the smallness of the  hemispheres, though
more fully developed than  in
reptiles  and  fishes.   In the
sparrow  the  weight  of the
brain to  the whole  body is  as
1: 25 ;  in  the goose, 1: 300 ;
and in the cassowary, 1:1000.
It is destitute of convolutions,
or in other words is perfectly
smooth on  its surface, and has
large cavities or ventricles con-
tained in it:  and, as in mam-
mals,  the   mass of the brain
is  greater   than  that  of the
spinal cord.  The pairs of  the cerebral  nerves are the same
as in mammals; also the  principal diA'isions  are  the  same.
The cerebellum,  as  in  man, exhibits the  arbor vitse Avhen cut
through vertically.
   664. Nervous System  of  Reptiles.—The  brain of rep-
 Brain of Buzzard.  B, Cerebrum.  C,
Optic Ganglia.  D, Cerebellum, g, Tineal
Gland.
 fifit  What is the proportion between the weight of the cerebrum and cerebellum m
c^np'of the lower animals?  602. What is the essential difference between the spinal cord
 Til and that of most quadrupeds? 663. How is the brain of birds characterized?
Gi'some of the Proportional weights of it compared with that of the whole body f   ;
                             16 
360           HITCHCOCK'S  ANATOMY
          Fig. 332.              tiles constitutes but  a very
                               small part of the  body.   In
                               the frog the proportion to the
                               whole  weight of the body is
                               as  1:  172 ;  in the  Coluber
                               matrix  (snake), 1 : 792 ; in a
                               turtle, 1 : 5688.   The hemi-
                               spheres are smooth and hollow
                               internally.   The optic lobes
                               are large in proportion to the
                               size of  the eyes, and are hoi-.
                               Ioav internally.   The  cerebel-
                               lum of frogs is  merely a thin
                               plate of nervous matter.
                                  665. Nervous  System of
                               Fishes.—We find the lowest
                               development  of the  nervous
                               system among  vertebrates in
the fishes.   The  brain here does  not fill the whole cranial
cavity, so  that between  the brain  and dura mater  there is
found a quantity of loose cellular tissue, with which  is inter-
spersed a fluid oil.   The brain in weight does not  equal that
of the spinal cord, nor is it but a little broader than the cord.
Its weight in proportion  to that of the body is about T1\ oth
part.   It  is  composed of eight lobes, partly in pairs,  and
partly unpaired behind one another, which seem to correspond
to  the  cerebellum (divided), corpora  quadrigemina,  thalami
optici, and medulla oblongata.
   666.  Electrical  Organs  in  Fishes.—There are at least
seven species of fish  that possess the  power of giving electric
discharges.   The  organs which accomplish this in the Torpedo
are two large crescent-like  bodies (see Fig. 334), which are
 Brain of Turtle.  A, Olfactive Ganglia.
B, Cerebrum. C, Optic Ganglia. D, Cere-
bellum.
 664. What is said of the brain of reptiles?  State its comparative size with that of the
whole body.  665. State some of the peculiarities of the brain in fishes.  What is its
relative weight?  666. What is said of the electrical organs of some fishes ?  Give the
anatomy of these organs. 
AND   PHYSIOLOGY.               361


          Fig. 333.
  Brains of Pishes.  A, Olfactive Lobes or Ganglia. B, Cerebral Hemispheres.  C, Op-
tic Lobes. D, Cerebellum,  ol, Olfactory Nerve, op, Optic Nerve, pa, Patheticus.
»io, Motor Oeuli. ab, Abducens.  tri, Trifacial, fa, Facial,  au, Auditory, vag, Va-
gus,  tt, Tubercles or Ganglia of the Trifacial, tv, Tubercles of the Vagus.

made up  of a  large  number of short, six-sided prisms, and

are  abundantly supplied with nerves.   And as  these organs

are made up of prisms, which  stand  end upon  end, and  not

side by side only,  as they appear in the  cut, the idea seems 
362,          HITCHCOCK'S   ANATOMY

            Fig. 334.                         Fig.  335.
  Electrical Apparatus of Torpedo,   b,      Nervous System of an Articulate.
Branchiae,  c, Brain,  e, Electric Organ.
p, Cartilage of Cranium, one, Spinal Cord,  n, Nerves to the Pectoral Fins, nl, Lat-
eral Nerves to the Body, np, Large Nerves (Pneumogastric) to the Electric Organ.
o, Eye.

plausible that  they may be regarded  as Voltaic piles, or a
reservoir of  electric  power which  the fish  can  discharge at
will.   And it is necessary  for the generation of this electrical
discharge that  the integrity of the  nervous system be  main-
tained.

   667. Nervous System  in  Articulata.—In the Crusta-
ceans the nervous system consists of ganglia and cords.   The
Central ganglion may be regarded as a brain, Avhich sends off
nerves of vision, audition, feeling, and  smelling.   A splanch-
nic or sympathetic nerve is also found, as in the Arachnoidea
and Annelida.   The  two latter classes have  ganglia,  which
C67. Slate tho general plan of tho nervous system in articulates.
 
AND  PHYSIOLOGY.
363
Fig. 336.
Nervous System of a Beetle.
may be  called  a brain.  In
Insects  " the  central  parts
of the nervDus  system  con-
sist  of a  brain  and a ven-
tral  cord,"  as  is shown  on
Fig. 336.    In  some of the
lower  tribes  of  Articulates,
as the  Ilelminthes and Rota-
toria,  the   nervous  system
is feebly and indistinctly de-
veloped.
   668. Reflex Actions  in Ar-
 ticulates.— This  sub-king-
 dom is remarkable for its reflex actions.   Thus if the head of a
 centipede be cut off  while  it  is in motion, the body will con-
 tinue  to  move  by the  action of its legs; and the same will
 take place, if the body  is divided into several segments.   The
 explanation is as  folloAVs.  "The body  is moved  fonvard by
 the regular and successive action of its legs, as in the natural
 state :  but  its  movements are  ahvays fonvards, never  back-
 wards, and are only directed  to one  side, Avhen the fonvard
 movement is checked by an  interposed  obstacle.  Ilence,  al-
 though they might seem to indicate consciousness and a  guid-
 ing will, they do  not so in  reality: for they are carried  on as
 it Avere mechanically, and  shoAV no  direction or  object,  no
 avoidance of danger.   If the body be opposed in  its  progress
 by an  object of not more than half its height, it mounts over
 it, and moves directly onwards, as in its natural state : but if
 the obstacle be equal to its  OAvn  height, its  progress is  ar-
 rested, and the  cut  extremity of the body remains forced up
 against the opposing substance, the  legs still  continuing to
move."   X
 What is the name of the principal ganglia? 66S. AVhat is sail of the reflex actions
of articulate animals ?  AVhat are these reflex actions sometimes mistaken for ?  Givo
the example. 
364            HITCHCOCK'S  ANATOMY

   669.  Nervous  System  of  Molluscs.—Cephalic  Gang-
Ha.—Pedal    Ganglia.—Parieto - Splanchnic   Ganglia.
—In  most  of the  Molluscs the  nervous system is well  de-
                             FiG. 337.
 Nervous System of Argonauta Argo.  A, As seen in front.  B, As viewed in profile,
showing the relations of the Nervous Centers to the Buccal Ma>s.  a, The Esophagus b,
and the Eye c. a,  Cephalic Ganglion,  b, Buccal Ganglion,  c, Sub-Esophageal Gang-
lion,  d, d, Stellate Ganglia of the Mantle,   e, Visceral Ganglion. /, Nerves of tho
Arms, with Ganglionic Enlargements,  g, Optic Nerves. 74, h, Eyes,  i, i, Branchial
Nerves with their Ganglia. 
AND PHYSIOLOGY.
365
veloped;  the most  so  in the  Cephalopods, which are the
highest m  organization.  In  these  we  find a  central organ
quite like  a  brain,  enveloped by a membrane analogous  to
the Dura Mater.   This system is  shown on Fig. 337.   The
general arrangement is that of three principal pairs of ganglia
with  nerves proceeding from them.   The  first pair is called
the Cephalic  ganglia, which  is  the largest, and is located
above or on the sides of the  esophagus, with a collar of nerves
surrounding that tube.  This gives off nerves  to the organs
of vision and taste, and to the muscular apparatus of the mouth.
The second pair, called the  Pedal ganglia,  is located beneath
the esophagus, giving off nerves to  the foot and the organs of
hearing, when this sense  is not  actually located  in the foot.
The third  pair, the Parieto-Splanchnic  ganglia,  are  usually
found in the  posterior part  of the  body giving nerves to the
muscular and sensitive walls of the body, the respiratory ap-
paratus, the heart and large blood vessels.
   670. Nervous  System of Radiates.—Need  of  a  Nerv-
ous  System.—Among the higher Radiates a nervous system
of inferior organization  can  be found.   For the most part it
consists of  a ring of nervous             Fig 338-
matter  about  the   mouth,
which sends off branches in
different   directions.    " In
Medusae the nenrous system
consists of  a simple cord, of
a string of  ovate cells, form-
ing a ring aroung the lower
margin  of  the  animal."—   Nervous System of star.Fish. ,,„tLlTO
Agassiz. (Fig. 338.) Gang-  Ganglia.
lia, or reservoirs of force can but seldom be found.
   671. Among the  Infusoria no nervous  system can be de-
tected, and if any exist, its participation  in the general course
 GG3  What is the principal arrangement of the nervous system among molluscs? 670.
AVhat is the nervous system of the radiates? 6TI. How is the nervous system among
Eadiates?
 
366            HITCHCOCK'S ANATOMY

of vital action must  be very trifling.  For the  simplest office
of a nervous system is to establish a communication  between
the different parts of the body;  but if every part of the body
has similar endoAvments, there  can be no object in  such com-
munication.  For instance, Avhere every part  of the surface—
as is the  case in those animals—is equally susceptible of ab-
sorption, there can be no need of a circulating  system,  and
where contractility  seems to be diffused through the body
alike, a nervous system would be superfluous.
6T1. What of the nervous system of Infusoria. 
    CHAPTER    EIGHTH.

THE INLETS  TO THE SOUL.—THE SENSES.
                GENERAL   REMARKS.

   672.  The  Senses.—Dependent on  the Mind.—These are
 commonly known under the name of senses.  Five are usually
 reckoned, Seeing, Hearing, Tasting, Feeling, and Smelling;
 and it is by these alone that we are made acquainted with ex-
 ternal objects.   In other words, sensation may be defined  as
 the  consciousness of  impressions.  The mind, for  aught we
 knoAV, might be  able to carry  on  its  functions  of thinking,
 reasoning, and memory, and also be conscious of its own ex-
 istence, if it  were deprived of  the senses:  but  it  could not
 make itself felt on other minds, nor increase in knowledge and
 discipline without their aid.  And although  the  primary ob-
 ject of the senses is to promote physical enjoyment, yet their
 highest and noblest use is to subserve the purposes of the
 mind.
   673. Senses  best   Developed in  Lowe?  Animals.—In
 man the senses are not so  fully developed as in  most  of the
 lower  animals.   But  this deficiency is much more than com-
 pensated by the superiority of his intellect.
   674. Effect of excessive Use of the Senses.—Excessive
 indulgence of any of  the senses is apt  to produce painful in-
 stead of pleasurable  sensations.   Thus heat of a  moderate
 672. What are the inlets of the soul ? Is mind necessary for the existence of sense ?
 What is the primary use of tbe senses? What should  be their hishest use? 673. In
what animals are the senses  the most  perfectly developed? 674. How does excessive
indulgence affect the senses ? 
363
HITCHCOCK'S  ANATOMY
temperature is always agreeable,  but  painful if much in-
creased.   Many odors snuffed in small quantity are pleasant,
but when given to satiety, become disgusting.   The  probable
design of this provision seems to be to prevent injury by an
inordinate stimulation of any of the nerves.  For instances are
on record,  where the mucous membrane of the  nostrils has
been  severely affected  by the  fumes of  ammonia given in
fainting.
  675. Habit makes painful  Sensations  pleasant—It
is a curious but interesting fact that the pain excited by un-
accustomed sensations  may sometimes be  exchanged  for its
opposite, after the system  has become habituated to them.
Thus tobacco and alcoholic liquors are  at first disagreeable to
most persons; but when  the disgust  has been overcome by
any  means a love  for them succeeds, and generally a strong
craving for excessive  indulgence also.
  676. Nerves  of Special  Sense  can  perform  but  one
Function.—The nerves of special sense are incapable of per-
forming any function except  that for which  they were  orig-
inally designed.   Thus the optic nerve can perform the func-
tion of vision only, the olfactory only that of smelling, and
the auditory only that of hearing.
   677. Effect  of Belief on our  Sensations.—The effect
of previous belief in  modifying  our sensations, is shown in
the  tAvo cases copied  from  Carpenter's  Physiology.    "A
clergyman told me that some  time ago  suspicions  Avere enter-
tained  in  his parish, of  a Avoman who Avas supposed to have
poisoned her  newly  born infant.   The coffin Avas exhumed,
and the procurator fiscal, Avho attended  with the medical men
to examine the body, declared that he  already perceived the
odor of decomposition, Avhich  made him feel faint, and  in con-
sequence   he  Avithdrew.  But on opening the coffin, it was

  What instance of this from  odors? 675. now does habit sometimes affect painful sen-
sations?  What examples? 676. What is said of the function of the nerves of special
sense ?  677.  How does our belie/ affect our sensations ?  Give the instance of the infant. 
                  AND   PHYSIOLOGY.             369

found to be empty;  and it was afterwards ascertained  that no
child had  been born, and consequently no murder committed
The second case  is yet  more  remarkable.   A  butcher was
brought  mto the  shop of Mr.  McFarlan, the druggist, from
the market place opposite, laboring under a  terrible accident
The man on trying to hook up a  heavy piece of meat above
his head, slipped,  and  the sharp hook penetrated his arm, so
that he himself was suspended.   On being  examined, he was
pale, almost pulseless,  and expressed himself as suffering the
acutest agony.   The arm could not be moved without causing
excessive  pain; and in cutting off the sleeve, he frequently
cried out:  yet  when the arm was exposed, it was found to be
quite uninjured, the hook having only traversed the sleeve of
his coat!I"
               THE SENSE  OF VISION.

         DEFINITIONS  AND  DESCRIPTIONS.

   678. The chief organ of this sense is the eye, although its
 appendages perform very important secondary functions.
   679. Anatomy of the Eye.—The human  eye is nearly
 globular in form, with a diameter a little less than one  inch,
 the lateral diameter  being one twentieth of an inch less than
 the antero-posterior.   (Fig. 339, p. 370.)  In general struc-
 ture it is  made up  of  three  membranes, and  three  humors,
 or transparent media, and is  covered on the surface  exposed
 to the air  by mucous membrane,  which also lines  the  inside
 of the lid, so that the two surfaces at some points are always
 in contact.                                                *"
   680. Sclerotica.—The membrane which covers  the larger
portion of the  eye  is called  the Sclerotica, from the Greek

 Give the instance of the butcher.  67S. What is the chief organ of sight?  679. What
is the shape of the eye ? Its diameter ? Of how many media and membranes is it
made up ? 
370           HITCHCOCK'S   ANATOMY
Fig. 339.
  Longitudinal Section of the Globe of the Eye. 1, Sclerotic, thicker behind than iij
'front.  2, Cornea, received within Anterior Margin of Sclerotic, and connected with it by
means of a beveled edge.  3, Choroid, connected anteriorly with (4,) Ciliary ligament,
and (5,) Ciliary Processes.  6, Iris.  7, Pupil.  8, Third Layer of Eye, Retina terminating
anteriorly by abrupt border at commencement of Ciliary Processes.  9, Canal of Petit,
encircles the Lens (12); the thin layer in front of this canal is the Zonula Ciliaris, a pro-
longation of Vascular Layer of Retina to the Lens.  10, Anterior Chamber of Eye con-
taining Aqueous Humor; the lining membrane, by which  the humor is  secreted, is
represented in diagram. 11, Posterior Chamber.  12, Lens, more convex behind than
before, enclosed in its proper Capsule. 13, Vitreous Humor enclosed in Hyaloid Mem-
brane, and in cells formed in its interior by that membrane.  14, Tubular Sheath of
Hyaloid Menlbrane, which serves for the passage of the Artery of Capsule of the Lens.
15, Neurilemma of Optic Nerve. 16, Arteria Centralis Retime, embedded in the center.


signifying hard,  because it is a firm and stout membrane.   Its

color  is nearly white, covering the posterior four fifths of the

eye, it is commonly called the white of the eye, and is  thickest

in its posterior parts.

   681.  Cornea.—The  external covering of  the  front  fifth

part  of  the  eye is called the  Cornea,  from the Latin word

meaning horn-like, and in two respects it  bears the same  rela-

tion to the ball  of  the  eye, as the crystal does to the watch,

since  it is fitted  into the sclerotic  by a beveled edge, as  is a

watch-glass,  and also because it is perfectly transparent.   The

blood-vessels of  this membrane are among the smallest in the

body, being  too  small  to  allow the  passage of the blood-cor-

puscles,  and only convey the plasma or serum.
.  680. Describe, the sclerotic coat.  68L AVhat is the cornea?  To what may it be
pared in the watch ? 
AND  PHYSIOLOGY.
371
Fig. 34.0.
   682. Choroid  Coat.—Iris.
— Ciliary  Processes.—The
middle  coat  of  the  eye  is
made  up  of three  portions,
the  Choroid  membrane, the
Iris,  and  the   Ciliary pro-
cesses.    The first, Choroid, is
named from the fact that it is
entirely  made up  of  blood-
vessels, of a  chocolate-brown
color on  the outside,  and a
deep black on the inside.   It
covers the posterior four fifths
of the eye,  and  corresponds
to the sclerotic  coat outside
of it.  The Iris, so called from
the diversity of  color  which
  Plan of the Structures in the Fore Part of the Eye, seen in Section. 1, Conjunctiva.
2  Sclerotica  3, Cornea. 4, Choroid.  5, Annulus Albidus; before this is is seen the
Canal of Fontana. 6, Ciliary Processes.  7, Iris.  8, Retina. 9, Hyaloid Membrane. 10,
Canal of Petit (made too large). 11, Membrane of  the Aqueous Humor (too thick.)  af
Aqueous Humor; Anterior Chamber, and (a,) Posterior Chamber, b, Crystalline Lens.
c, Vitreous Humor.
                             Fig. 341.
m^Mmx

PWoid Coat of the Eye.  1, Curved lines marking the arrangement of Vena. Vortl-
^^^mr/es.  3,' A long Ciliary Artery and Nerve.  4, Ciliary Ligament.
cosse.
5, Iris.  6, Pupil.
 ' 632. Of what three portions is the choroid coat composed?  Give their names.
scribe the Iris.
Do- 
372
HITCHCOCK'S   ANATOMY
it presents in different persons—and  it  is the color of this
which Ave mean Avhen we speak of the color  of the eye—cor-
responds in position to  the cornea lying immediately under it.
FiG. 342.                          Fig. 343,
External View of the Iris.           Anterior'Segment of a Transverse Section
          .<•.*                of the Globe of the Eye seen from within.
   1, Divided edge of the three Tunics ; Sclerotic, Choroid (the dark layer), and
   Retina. 2, Pupil. 3, Iris, tho surface presented to view in this section being
   the Uvea.  4, Ciliary Processes.  5, Scalloped Anterior Border of  the Retina.
It is circular in form, containing a  few muscular fibers, with
a circular opening through its center, from one third to one
twentieth of an inch in diameter, which is knoAvn as the pupil.
The Ciliary processes are minute triangular folds of the Cho-
roid coat, Avhich lie upon the interior surface of the iris, with '
their bases  directed  toward  the pupil.   They are about sixty
in number, and are divided into large  and  small, the latter
being placed between the former.   The Pigmentum Nigrum,
or  black paint,  is an extremely  tenuous membrane,  AA'hich
lines the inside of the choroid coat.   It is of a jet black color,
and is easily destroyed merely by allowing a stream of water
to fall upon it.
   683.  Retina.—The inner membrane of the eye is the Re-
tina, A\hich is merely an expansion of the optic  nerve, upon

  What is the diameter of the iris ? What are the ciliary processes ?  How many are
there? AVhat is the pigmentum nigrum ?  683. Describe the retina. 
AND   PHYSIOLOGY.
373
the inner side of a hollow sphere, formed  by the membranes
already mentioned.
   684.  Microscopic  Structure  of  these  Membranes.—
The structure of these membranes, as  revealed  by the micro-
scope, is very complex.   The Cornea is made up of four sim-
ple membranes,  the Choroid of three, and the Retina of four.

                            Fig. 344.
HP.....«PpWf«:''';;
 ink
                                             h           'It
 Vertical Section of the Human Retina and Hyaloid Membrane  h. Hyaloid Membrane
A', Nuclei on its inner surface,  c, Layer of Transparent Cells, connecting the Hyaloid
and Retina,  C, Separate Cell enlarged by imbibition of water «, Gray Nervous Lye ,
Shits Capillaries  1, Its Fibrous Lamina. 2, Its Vesicular Lamina. V Shreot FV
brous lamina detached.  2', Vesicle and Nucleus detached,  g, Granular Layer. 3, Light
Lamn^
cob's Membrane. m>, Appearance of its Particles, when detached,  m",  Its Outer
face.—Magnified 320 diameters.

The Sclerotic is  for the most part made  up of white  fibrous
tissue, and a large portion of the Choroid coat is  composed ot
blood-vessels,  although the inner membrane-tbe Pigmentum
Nigrum or black paint-consists of minute six-sided cells re-
sembling  a tesselated  pavement.   The Retina is for the most
part made up of the different forms of nervous tissue and its
membranes.
                   '.  \   ,- ..„ „f thn cornea. Of the choroid, the pigment, and
  684. Give the microscopic structuro of the cornea.
 the retina. 
374            HITCHCOCK'S  ANATOMY
   685. Humors  of  the  Eye;  Aqueous—Of the three Hu-
mors or liquid substances composing the eye, the Aqueous or
watery is situated in the anterior portion of this organ behind
the cornea, and in front  of the crystalline  humor soon to be
described.   It is  a liquid like water, with an alkaline  taste,
and only a few drops in quantity.   The Iris is placed directly
in the middle of this fluid.
   686.  The  Lens.—The  Crystalline Lens  or  Humor  (so
called because it refracts light and is transparent like a crys-
tal)  is a double  convex  lens, the posterior convexity  being

          FlG. 345.                          FlG. 346.

  Front View of tho Crystalline Lens.      Side View of the Lens.  1, Anterior Face.
                              2, Posterior Face. 3, Circumference.

greater than  the anterior, and is located directly behind the
pupil, so that all the light Avhich  enters the  eye, must pass
through this and be refracted.   This lens is made up of con-
centric layers like an onion, and also of three triangular seg-
ments,  with  their sharp edges  directed towards the center,
both of which structures, by  boiling  the lens in Avater for a
short time, can be  readily seen.   Fig.  317  represents  the
                                      difference  in  diameters
               Fig. 347.                of the lens  at different
                                      periods of life,  a, rep-
                                      resents it at birth, b, at
                                      six years of age, c, its
                                      appearance in an adult,
  Crystalline Lens,  a, At birth.  6, At six years     J J   a.   -j. i    i
old.  c, Adult,  d, Altered by alcohol.           and «j alter it lias been
 685. How many humors are there in the eye? Describe the aqueous.  686. What is
the crystalline humor? What kind of a lens is it? Of how many segments is it made up? 
AND  PHYSIOLOGY.              375
hardened and partially divided into segments by an immersion
in alcohol.
   687.  Vitreous.—The  Vitreous  Humor (from its resem-
blance to glass) is  of the form of a sphere, Avith the anterior
portion removed, and constitutes seven eighths of the globe of
the eye.   It is a transparent fluid enclosed in a transparent
membrane, and through its central portion from the entrance
of the  optic  nerve, there passes a  small artery  to  the lens,
which supplies it Avith blood.
   688.  Lachrymal Gland.—Nasal  Duct.—At the outer angle
of each eye is found a gland called the Lachrymal gland, nearly
three  fourths of an  inch in length, and of  a flattened oval

                           Fig. 348.
  Posterior View of the Eyelids and Lachrymal Gland.  1, I, Orbicularis Palbebrarum
Muscle.  2, Borders of the Lids. 3, Lachrymal Gland.  4, Its Ducts opening In the Up-
per Lid.  5, Conjunctiva covering the Lids. 6, Puncta Lachrymal.a.  7, Lachrymal Ca-
runcle as seen from behind.

shape.  (Fig. 348.)  Passing from this gland to the eye, are from
eio-ht to tw°elve small ducts, which open upon the under side
of°the  lid near its  edge,  about one twentieth of an inch apart,
which  carry the tears to the eye.   By continual winking this

  687 From what does the vitreous humor get its name? Describe it   CSS. W^rearo
the lachrymal glands situated? What is their size? How many ducts have they ? What
do they secrete ? Of what use is winking ? 
376
II itch cock's  anatomy
Fig. 349.
                                 fluid is uniformly distributed
                                 over the  Avhole ball of  the
                                 eye, and the excess is carried
                                 aAvay  from the eye  by  the
                                 two lachrymal canals, which
                                 commence  at the  two  little
                                 projections  near  the  inner
                                 angle of each lid of the eye,
                                 appearing like minute  black
                                 specks. Both of these very soon
                                 unite into a larger tube called
                                 the  nasal  duct,  (Fig. 349,)
                                 which descends  inwardly and
                                 empties itself upon the nostrils.
                                    689.  Eyebrows___The
                                 Eyebrows   arc    projecting
                                 arches  of fat and  skin, cov-
                                 ered with  short and  thick
                                       hairs Avhich encircle the
                                       upper portion  of  the
                                       eye.  They are provided
                                       with  muscles,  so  that
                                       they  can   be made  to
                                       shade the  eye  more  or
                                       less   perfectly,  as  ne-
                                       cessity may require.
                                         690.  Eyelids.—The
                                       Eyelids   are  movable
                                       membranous  and mus-
                                       cular  coverings  Avhich
                                       are placed directly  up-
                                       on the eyeball, and are
designed for protective organs against mechanical violence and
too powerful light.  Their free  edges are called  Tarsal Carti-
  Where are the lachrymal canals and what do they carry?  AVhat is the nasal duet?
<5S9. Describe the eyebrows. 690. What are the eyelids ?  What are their edges made up
of?  What glands directly in them ?
  Lachrymal Canals. 1, Puncta Lachry-
tnalia.  2, Cul-de-Sac at the Orbital End
of the Canal. 3,  Course of each Canal to
the Saccus Lacrymalis.  4, 5, Saccus La-
crymalis.  6, Lower Part of the  Ductus
ad Nasum.
FlG- 350.
  Front View of the Left Eye—moderately opened.
1, Supercilia.  2, Cilia of each Eyelid. 3, Inferior
Palpebra. 4, Internal Canthus.  5, External Can-
thus.  6, Caruncula lacrymalis.  7, Plica Semilu-
naris.  8, Eyeball.  9, PupiL 
AND  PHYSIOLOGY.
377
lages,  directly  in  the  substance  of which is placed  a large
quantity of minute glands, called Meibomian Glands.
Fig. 351.
Fig. 352.
  Meibomian Gland highly
magnified.
   Meibomian Glands seen  from the Inner or Ocu-
  lar Surface of the Eyelids, with the  Lachrymal
  Gland—of the Risht Side,  a, Palpebral Conjunc-
  tiva. 1, Lachrymal Gland. 2, Openings of Lachry-
  mal Ducts.  3, Lachrymal Puncta. 6, Meibomian
  Glands.


   691.  Muscles  of  the Eye.—The

Ball of the eye is moved by six distinct

muscles,  four straight and two oblique

muscles,  as is  shown in  the cut.  Their

names are  Rectus  Superior and Inferior, External and Inter

nal, and  Superior  and Inferior Oblique.

  Muscles of the Eyeball. 1, A small                  FlG. 353.
Fragment of the Sphenoid Bone
around entrance of Optic Nerve into
Orbit. 2, Optic Nerve.  3, Globe of
Eye. 4,  Levator Palpebrie Muscle.
5, Superior Oblique Muscle.  6, Its
Cartilaginous Pulley. 7, Its reflected
Tendon.  8, Inferior Oblique Muscle;
the small square knob at its com-
mencement  is a piece  of its bony
origin broken off.  9, Superior Rec-
tus. 10, Internal Rectus almost con-
cealed by Optic Nerve.   11, Part of External Rectus, showing its two heads of origin.
12, Extremity of External Rectus, at its Insertion; the intermediate portion of muscle
having been removed.  13, Inferior Rectus. 14, Tunica Albuginea formed by expansion
of tendons of four recti.
691. How many muscles for moving the eyeball ?  Give their names. 
378
HITCHCOCK'S  ANATOMY
            FUNCTIONS  OF  THE  EYE.

   692.  The primary and obvious use of the eye is to receive
the form and color of different objects, and  to  transmit them
to the brain.
   693.  Use of the  Coats—Sclerotica—Cornea—Choroid—
Black  Paint—Iris—Ciliary Processes—The  Retina.—The
use of the firm and hard sclerotic coat is to give a firm attach-
ment to the muscles which move the  eye, and also secure pro-
tection to the delicate parts Avithin.   The cornea is tough but
transparent, so that the anterior portion of the eye  may be
firm and at the same time admit the rays of light.   The cho-
roid coat furnishes the blood to the eye, it being  for the most
part entirely made up of blood-vessels.   It also  secretes the
black paint (Fig. 288), which  is of  great service  in  absorb-
ing the  superfluous or wandering rays of light Avhich otherwise
would obscure the image on the retina.   A similar provision
is made by painting black  the  tube  of  the  telescope and mi-
croscope.   The iris  regulates the amount of light entering the
ball, by its contraction and expansion.   This function is per-
formed by the ciliary processes and  circular muscular fibers,
which latter contract by the stimulus of strong light;  but if
the light be feeble,  the  processes contract, and thus  enlarge
the diameter of the  pupil.   The retina, with the vitreous hu-
mor in front and  the  black paint directly  behind it, receives
the image  of the object before the eye.   It bears the  same
relation to the other parts  of the eye as the silvered or glass
plate does in the camera of the photographist.   This  impres-
sion is carried to the brain by means of the optic nerve.
   694. Use of the Humors—Aqueous—The Lens—Vitreous,
—Of the three humors or media of the eye,  the aqueous is
the least important, since  if by accident or operation it is re-
  692. State the use of the eye. 693. Give the use of the sclerotic coat. Of the cornea.
What does the choroid furnish to the eye ?  Of what service is the black paint ? AVhat
does the iris do?  What is the function of the ciliary processes? AVhat is the use of the
retina ? 694. Which is the least important of the humors ? 
AND  PHYSIOLOGY.              379
moved,  nature will  soon replace it;  but this is true of no
other medium.  The aqueous humor,  however, is of great use
to keep the front parts of the  eye in  a soft and elastic condi-
tion,  and also to furnish a medium in which the iris may
readily  be contracted and relaxed.  It also aids in properly
refracting the rays of light, so that the most perfect image
may be formed on the retina.   The use of the crystalline lens
is also to refract the rays of light, so that an image of suffi-
ciently  small size  may be formed on the retina.   Otherwise,
when we look at any object larger  than  the diameter of  the
pupil, we should  be unable  to see  it,  only by successively
looking at minute portions of it.   The A'itreous humor assists
in the same refraction of the rays,  and incidentally subserves
the purpose of fixing at a proper  distance the lens, so that the
image may be formed exactly at that point on the retina called
the focus, where it will be the most distinct.
   695.  Need of Three Media.—But what is the necessity for
three media of refraction, and why will not the crystalline lens
answer the whole purpose ?   This is owing to  some of the
properties of light.   Light is composed of seven rays or colors,
some of Avhich are more easily refracted  than others ; that is,
some rays are bent  farther  from a perpendicular to  the sur-
face than others.   Hence, upon the edges of an image formed
by a single lens, every part of Avhich is of the same  density,
we should see several of the prismatic colors, which would give
an indistinct image.   In the telescope  and microscope  this
difficulty is  remedied  by forming a lens of crown and flint
glass  one  of which  has a stronger dispersive  or refractive
power than the other.   In the eye the same error  is  obviated
by means of the crystalline lens, which has a greater refrac-
tive power than the vitreous  humor, and consequently, when
the ray is too much refracted by the crystalline lens, a ccm-

                     „  ti,» n«eof the lens.  AVhat does the vitreous humor aid
   State the me of the aqueou  Tleuse o ft  en*             ^ ^    ^
 in,  695. AVhat is the need of th ee humo,., .   L>«    7           ^ ^     ?
 ei*t of? What similar purppse do lenses oi  mue.c
 Wnich of the three humors has the greatest refractive power ? 
380
HITCHCOCK'S  ANATOMY
pensation is effected by the vitreous humor, which refracts less
than the lens.
  696.  The  Secretion of the Lachrymal Glands.—The lach-
rymal gland  is designed to secrete a saltish fluid knoAvn as the
Tears.   This is of great service in  lubricating and  keeping
moist the surface of the eyeball, so that it may move readily
in its socket, and also to keep the cornea from becoming hard
and dim.   The tears also moisten the back part of the nostrils,
and are ultimately poured into the  pharynx.   The amount of
tears  which  is  daily secreted  is  estimated at four  ounces,
and it is greatly increased by strong emotions, whether pleas-
ant or sorrowful, as  it is well known that  a person is apt to
cry when very sad or very happy.
  697.  Service of  the  Eyelids—Necessity  of Constantly
Winking—Eyelashes.—The eyelids are of service  to keep
the light from the eyes when it is  too intense, or when it is
necessary to  exclude it  entirely, as  during sleep.    Another
valuable service Avhich  they perform is  to spread the  tears
constantly and uniformly over  the  eyeball.  This is the rea-
son why we are constantly but unconsciously Avinking during
every few seconds of our Avaking hours.   The eyelashes which
line the  edges of  the lids, prevent the perspiration which is
secreted on the lids from entering the eye, and thus irritating
it, since by the law  of capillary attraction  the  tears will run
towards the free extremity of the hair, where they will  accu-
mulate to such a size that they drop off.   The eyelashes also
prevent, in some degree, dust from entering the eye.
  698.  Use  of  the  Eyebrows.—The  eyebrows  perform a
similar office as  the  eyelids, though not so important.   The
hairs which cover them, like the lashes, convey away the per-
spiration from the forehead, and alloAV it  to fall in front of the
eye, and not directly upon  the ball; while, by means of the

  696. What is the secretion of the lachrymal gland? What is the use of the tears?
What quantity of tears are secreted daily? 697. Of what service are the eyelids? AVhy
do we constantly wink? Of what service are the eyelashes? 69S. What service do the
eyebrows perform ? 
AND  PHYSIOLOGY.
381
muscles  attached  to the integuments, whenever it is  desired
they bring the brows in front of and above the eye in such a
manner as to afford it a very considerable protection from ex-
cessive light.
   699.  Short  and  Long-Sightedncss—The phenomena  of
short and long-sightedness are worthy of a passing notice.
Short-sightedness results where the  lens of the  eye has too
much convexity, which causes the image to be formed in front
of the retina.   In such persons the eye generally has greater
prominence than  in others.   But  persons thus affected will
probably  in later  years have  better  eye-sight than if short-
sightedness had not existed.  A too  much  flattened  state of
the lens occurs in those who are long-sighted.  This is gener-
ally the case with those somewhat advanced  in life.   In this
case the distinct image will be formed  behind the retina, and
it requires a convex lens, in the form of spectacles, to correct
the error.
   700.  Other   Interesting Phenomena  of Vision.—A few
other phenomena connected with  the function of vision de-
serve attention.   One  is the fact, that although we have two
eyes  and two  distinct  images are transmitted to the brain,
yet but one object is seen.   And if we  look at an object with
only one eye, we see the image nearly as distinct as with both
eyes.   Another is,  that although the image on  the retina  is
inverted,  yet to the mind it appears  in its true position.  For,
since the rays  of light pass through the lens in nearly straight
lines, the ray coming, for instance, from the top of a tree, will
fall upon the lowest part of the retina,  while the  ray coming
from the bottom  will  strike the upper part,  and hence the
image will be inverted, although to the " mind's eye" it will
be erect.   Another fact is equally wonderful.   We are able
to see with distinctness an object only a few inches  from our
 699 What is the cause of short-sightedness ?  What is the reason of long-sightedness ?
What kind of a lens is required for long-sighted people, and why?  700. What curious
facts connected with the physiology of vision ? 
382          HITCHCOCK'S  ANATOMY
 eyes, and  almost instantly, by turning them to a mountain
 top several miles distant, we can see an object there with per-
 fect cleaarness.  No optical instrument  can be made which
 will so quickly do this, for it is necessary to make a new ad-
 justment of the  lenses to adapt it to different distances,  but
 the eye is at once ready.   It is supposed that this adjustment
 is effected by a shortening or lengthening of the diameter of
 the crystalline lens, or by  drawing the  lens  towards the pos-
 terior part of the  eye,  by means of a few muscular fibers
 called the ciliary muscle, running from the bones of the nose
 to the cornea, Avhich by  their  contraction -would  force  the
 aqueous humor upon the crystalline lens in such a manner as
 to flatten it, and by a relaxation of the same fibers a dilata-
 tion in an antero-posterior direction is  effected, and that  in-
 stantly.

   701.  Experiment for  Seeing the Arteries of  one's own
 Eye.—The image of the  arteries of one's own eye  can be
 readily seen in the following manner.   In a dark room place
 the left hand over the left  eye, and in the right hand hold a
 lighted  candle by the right side of the head, and  very near
 to it.   Then with  the right  eye open, looking towards  the
 darkened Avail, move the candle up and down rather quickly,
 and in a few seconds dark branches will appear at a short dis-
 tance from the eye, looking like the  limbs of a tree, which are
 images of the  arteries distributed on the retina.

   702.  Limits of  Vision.—What is the  size of minute  ob-
jects that can be seen by the naked eye ?  Ehrenberg, an
 eminent  microscopist,  says that  nearly all  eyes have equal
 power to discern minute objects, whether long or short-sighted.
 The smallest  square magnitudes visible to  the  naked eye,
 either of white particles on a dark  ground or the reverse, is
 about the T^th of an inch.   Brilliant particles which  pow-
How is tho telescopic and the. microscopic power of the eye explained ?  701 H 
AND  PHYSIOLOGY.
383
erfully reflect light may be distinctly seen when not half the
size of the foregoing.   Thus gold dust the ttVith part  of an
inch in diameter is visible in common daylight.  Lines may
be more readily seen than points.   Opaque threads  t»Vo*h of
an inch in diameter can be seen Avhen held  toAvards  the light.
Attention also  greatly helps to discern  minute objects, or at
least to retain them in sight when  once pointed out.   Thus
we are  often able to see a faint star in the sky or a ship in the
horizon after they have been pointed out to us,  although they
were not  seen  before.  "I myself," says Ehrenberg, "can
not  see aVo oth of an inch, black or white, at tAvelve  inches
distance ;  but  having found it at from four  to five  inches
distance, I can remove it to twelve  inches and still see the
object plainly."
   703.  Color Blindness.—Many people are afflicted Avith an
inability to  distinguish certain colors of the solar  spectrum.
This is called Color Blindness, or Daltonism.
   704. Formerly it was supposed that  this affection was very
rare, but  later researches show it to be quite  common.   Ac-
 cording to experiments made by Dr. Wilson  upon  1154 per-
 sons in Edinburgh in  1852 and 1853, it was found that—
                  1 in 55 confound red with brown.
                  1 in 60 confound brown with green.
                  1 in 4G confound blue with  green.
   Hence one in every 17.9 persons  is color blind.


     THE  SENSE   OF  VISION IN ANIMALS.

    705. Tapetum—Pupil—Nictitating Membrane—narde-
 rian  Gland—The general anatomy of the eye of mammals
 differs but slightly from that of man.   Between the sclerotic
 and choroid in some animals is found another  membrane of a
 _Ho^s it with brilliant particles?  How is the ready vision  of lines  compared with
 noints?  How small a thread can be seen by the naked eye? What effect has the fa-
 Eiity with an object? 703. AVhat is color blindness ? How often is  this peculiarity
 found' What colors aro most commonly confounded?
                            17 
384
HITCHCOCK'S  ANATOMY
metallic  brilliancy,  with different  shade of color, known as
the Tapetum.   In horses and cows it has a variegated luster
of green  and blue, Avhile in the tiger,  cat, and Avhale it  is  of
a  silvery brightness.   The shape  of the  pupil in the Avolf
and dog,  Avhich need vision  in all directions, is circular ;  while
the fox and cat,  Avhich need a vertical range  more than any
other,  have a perpendicular slit only.   In cattle and the more
timid grazing animals which obtain their food from the ground,
and need to look  behind with ease Avhen  pursued,  the  pupil is
a  horizontal ellipse.   Nearly all mammals except man and
the apes, have  a  third lid, Avhich is a transparent membrane
that is frequently slid over the  ball  by a peculiar muscular
apparatus.  This is called  the " haw" or Nictitating Mem-
brane, and, especially in birds, serves the purpose of remov-
ing impurities from the eye, and also of spreading the secre-
tions over it, in  order to keep it moist and transparent.   In
addition  to the  lachrymal gland, in all  animals which have
the third lid there is another gland called the Harderian Gland,'
which prepares another secretion similar to and for nearly the
same purpose as  the lachrymal.
   706.  Eyes  of  Birds —Pecten  Marsupium.—All  birds,
without  exception, are provided Avith perfect  and Avell devel-
oped eyes.  They are always large,  and  largest in birds of
prey.  They are but slightly movable  themselves,  but  this
Avant of  motion  is  compensated by the  great mobility of the
head.  The sclerotic coat is strengthened  in front by a series
of bony plates, fourteen or fifteen in  number, interposed be-
tween its  fibrous layers, a great use of Avhich is to  wive at-
tachment to the  special muscular apparatus for adapting the
eye to see objects at different distances.  The anterior chamber
is proportionally  larger than in any other animals, so  that the
iris is far back from the cornea.   The iris has different shades
of color, commonly yellow  or brownish.   The yelloAV  color of

  705. What is the tapetum ? What is its color?  What is the shape of the pupil in the
wolf, dog, and in cattle? What is tho Nictitating membrane?  Of what service is the
"haw?" For what purpose is the Harderian gland ?  706. AVhat is said of the perfection
«f oyeg in birds? How  is tha sclerotio «oat strengthened in them ? 
AND  PHYSIOLOGY.              385
this part in the oavI is owing to the presence of cells contain-
ing fat.   A curious structure is found in the eye of birds that
is found in no other animal.   It is called the " Pecten Mar-
supium," and consists of a  layer of blood-vessels arranged in
      IT"        •                                °
several plications varying greatly in size.  It extends  some-
times as far fonvards as the lens, and is covered by black pig-
ment.   Its probable use is that of absorbing rays that enter
the  eye obliquely, and  thus  rendering sight  from a forward
direction more definite and  sharp.  The membrana nictitans
and the Harderian glands are present in these animals in their
fullest perfection.

   707. Eyes of  Reptiles—All reptiles have two  eyes.   In
most,  especially  in  serpents, they  are small in comparison
with the size of the body ; in the  frog, howeA'er, in the gechos
and chameleons they are large.  In some they are covered by
the skin.    In the serpents  there  are no eyelids, but the skin
which covers  them  is kept  moist by a lachrymal gland,  and
thus performs the service of a lid.   In other reptiles there
are three lids, the middle one of Avhich moves at right angles
to the other tAvo.   Ttie  lachrymal gland often i3 very large.
In some  turtles  and lizards there is  a ring of bony plates
which supports the  eyeball.  The lens has different degrees
of sphericity in different animals.

   708. Eye of Fishes—Pigmentary  Spots.—The eyes  of
fishes are remarkable for the great size and spherical form of
the lens, which is necessary in order to give sufficient refrac-
tion to the rays of light that come from the dense medium in
which  they live.  The size  of the lens varies  greatly, being
largest in the  bony fishes  and  smallest in those  Avhich  lie
buried in  the  mud like  the  eel.   The lowest stage, however,
is seen in the amphioxus, a  condition Avhich greatly  resembles
  What makes the yellow color of the iris in birds?  AVhat is the pecten marsupium?
What is its use? 707. What is said of the eyes of reptiles? AVhat of the bony plates
in the eyeball?  708. AVhat characterizes the eyes of fishes?  AVhat ones have the
largest? 
386
niTCHCOCK'S  ANATOMY
that of the lowest  invertebrata, being nothing but two pig-
mentary spots.   The eye  is  but slightly movable  in  fishes,
since the body,  and consequently the head, can be  so readily
moved in any direction through the water.
             Fig. 354.                  709. Compound  Eyes
                                    — Numher of  F acets.—
                                    The  eyes  of many  of the
                                    articulate animals are con-
                                    structed  upon  the  com-
                                    pound type,  that is,  the
                                    visual organs are made up
                                    of an aggregation of single
                                    eyes placed upon each side
                                    of the head, each one  of
                                    which is a complete visual
                                    instrument,  but  can  re-
                                    ceive and  bring to a focus
                                    only  those rays  of light
which come to  it from a  particular  direction.  In many  in-
sects each  composite  eye  forms  a  hemispherical  protuber-
ance upon the side  of the head, which, when  examined by the
                            Fig. 355.
                      A
  nead and Compound Eyes of the Bee, show-
ing the Ocelli in situ on one side (A), and dis-
placed on the other (B).  a, a, a, Stemmata. b,
b, Antennae.
 A, Section of the Eye of Melolontha Vulgaris (Cockchaffer). B, A portion more highly
Magnified, a, Facets of the Cornea, b, Transparent Pyramids surrounded with Pi".
ment. c, Fibers of the Optic Nerve,  d, Trunk of the Optic Nerve.
 What are the pigmentary spots ? 709. What are compound eyes ?  What sub-kingdom
do they characterize ?  How does the eye appear on many insects ? 
AND  PHYSIOLOGY.
387
 magnifying glass, is found to be made up of a vast number
 of facets,  which are  generally hexagonal.   In the common
 house  fly  there  are 4,000  in  each eye, in the  dragon fly
 21,000, and in one species of the beetle  25,000.   Each  one
 of these facets  is found to be the end of a little  eye, the frus-
 trum of a slender pyramid standing by its apex on a bulbous
 expansion of the optic nerve.   The  interior of this pyramid
 is  filled Avith  a trans-
 parent substance which
 represents the vitreous
 humor, Avhile  between
 the frustra is found the
 black  pigment.    Both
 surfaces of these facets   Eye of Fossil Tribolite constructcd on tho same
 are found to be convex, Plan-
 and it  has  been calculated that the focus of these lenses Avould
 be at a point just  at  the extremity of the pyramid Avhere it
 joins the optic  nerve.   And  since the rays of light entering
 one of these facets can not enter the other on account of  the
 black pigment  intervening betAveen  them, the range of vision
 to the insect would necessarily be very limited were it not for
 their enormous multiplication, by Avhich in reality a separate
 eye is provided for  every point  to be vieAved, thus  giving to
 the insect as perfect an  apparatus of vision  as we have,  al-
 though immovably  fixed on the body.
   710. Stemmata.—Besides the composite eyes, insects usu-
 ally have a small number of simple eyes situated upon the top
 of the head, called Stemmata.  If they are covered with paint,
 the movements  of the insect are constantly upward.
   711. Other  Articulates.—A few insects that live in  dark
 places have no eyes.  Some  Crustaceans have compound eyes
 without facets,  and others Avith  them.  Some Annelids  have
eyes,  others none.   The Rotatoria have vision,  but the  Hel-
 AVhat number of facets are there in the house fly and in the dragon fly?  Give the an-
atomy of each facet or pyramid. 710. What other organs of vision besides compound
eyes do insects have?  If the stemmata are removed what is the result? 711. AVhat
of the eyes of articulates ?
 
388
HITCHCOCK'S  ANATOMY
minths  are  without  eyes.   Among Arachnida  (spiders) the
eyes bear a near relation to the vertebrate type of eyes.  Their
number is much less than among the  other articulata, seldom
more than eight, and are to be compared more Avith stemmata
than with  compound eyes.   Sometimes these  are collected
into one mass upon the second segment of the body, and some-
times they are arranged symmetrically upon the  median line.
   712.  Eyes of  Molluscs.—The organs  of vision in the
Acephala are numerous,  rising as high as  forty in the genus
Pinna, Avhere they are placed in the mantle.  The Cephalo-
phora have generally two eyes.   In the Cephalopoda the eyes
are disproportionately large, and possess nearly all the parts
found in the eyes of vertebrates.
   713.  Eyes of  Radiates.—The Polypi show a  sensibility
to light, but no  eyes  have been discovered  in  them.  The
Acalephae seem to have the sense of vision, and Agassiz seems
to have  ascertained the presence of an organ for this  purpose
in some of them.   It is more doubtful in respect to the Echi-
noderms.
  AVhat eyes have spiders? 712. What are the eyes of molluscs? 713. AVhat is said of
the organs of vision among radiates ? 
AND  PHYSIOLOGY.            38&
            THE  SENSE  OF  HEARING.

        DEFINITIONS AND  DESCRIPTIONS.

  714. Parts  of the Ear.—The organ of hearing is made
up of three distinct portions: the  Pinna or external ear, the
Tympanum or middle ear, and  the Labyrinth or internal ear.
  715.  The  Pinna.—The Pinna, commonly known  as  the
Ear, is a cartilaginous plate with numerous irregularities upon
its surface, and having  upon it a few muscular fibers, which
Fig. 357.                      Fig. 358.
 
390
HITCHCOCK'S  ANATOMY
are in fact rudimentary muscles, 5 in number.   In some men
they  have been so fully  developed that  the  ears could  be
moved by their action, Avhile among quadrupeds there are but
few  that do not possess  this power.  The Pinna somewhat
resembles a funnel, forming at its base an irregular tube called
the Auditory Canal, about ban* an inch in diameter and  an
inch  in  length, which terminates  with the Tympanum.   A
feAV stiff hairs are found upon the sides of this  canal, and in
the lining membrane some glands, which secrete the wax  of
the ear.

   716.  The  Tympanum.—Membrana  Tympani.—Little
Bones  of  the Ear.—The Tympanum  is  an irregular cav-
ity located in the  petrous  portion  of the Temporal bone,
measuring rather  more than   one half inch  in its  longest
diameter.  At  the  point  Avhere the Auditory  Canal  joins
                                     the   Tympanum,   the
             FlG- 359-                 Membrana Tympani is
              ff            d         found, which is simply
                                     an  impervious  mem-
                                     brane stretched between
                                     the  two  cavities,  dip-
                                     ping inwards at an an-
                                     gle of forty-five degrees.
                                     To this  membrane  are
                                     attached  three muscles
                                     for the purpose  of ren-
                                     dering this  membrane
                                     lax or tense, as may be
  A'iew of the Cavity of the Tympanum, the Ossicula Auditus, and their Muscles, magni-
fied, a, a, Cavity of the Tympanum, b, Membrana Tympani, or rather tho osseous
circle to which it is attached,  c, Handle of the Malleus, resting on the middlo of the
Membrana Tympani.. d, Head of the Malleus articulating with the Incus, e,  Long
Handle of the Malleus, passing into the Glenoidal Fissure ; the Anterior Muscle of the
Malleus is attached to it. f. Internal Muscle of the Malleus, g, Anvil,  h, Lenticular
Bone,  i, Stapes, k, Muscular Stapedius.
 Can the ear ever be moved?  IIow many rudimentary muscles aro placed on it?"  71G.
AVhat is the tympanum ?  Describe the membrana tympani. 
                  AND  PHYSIOLOGY.             39J
           Fig. 3G0.                           FlG. 36L
                                                a   b
                       B





                                                   d
                                       Small Bones of the Ear. a, The
                                      Malleus.  6, The Incus, c, The
                                      Lenticular Bone, d, The Stapes.

required.  This cavity contains the " little bones of hearing,"
as they are sometimes called.   These are the Malleus, a ham-
mer,—the Incus,  an  anvil,—and the Stapes, a stirrup, be-
cause they somewhat resemble these instruments.  The Mal-
leus lies  directly against  the drum  of the ear (Membrana
Tympani), its opposite side connecting Avith the Incus, which
is in connection Avith the end of  the  Stapes,  thus  forming a
continuous chain of bones through the Tympanic Cavity.  In
the walls of the Tympanum are no  less than  ten  openings,
the most important of Avhich are, one  downwards  into  the
Pharynx  knoAvn as  the  Eustachian Tube, another  into  the
Labyrinth, which is closed by the foot of the Stapes, and an-
other outAvards to the External Ear.
   717.   Labyrinth.—Cochlea.—Semicircular  Canals —
Perilymph.—V e s t i b u 1 e.—The Internal Ear is called a Laby-
rinth because of  its  very complicated structure  and  func*
tions.   (Fig. 362, p. 392.)  It mainly consists of  a series of
semicircular  canals and cavities, of Avhich  some are  made up
of cartilage,  and others of bone.   The canals are composed of
bone, three in number, and their respective planes arranged at
rio-ht angles  to each other.  They contain  the nerves of hear-
in^ and other substances, Avhich facilitate the transmission of
sound.   One of these portions is named the Cochlea,  because
  AVhat are the names of the bones of the ear?  How many openings are there In the in-
ternal car ?  717. AVhat is the labyrinth ?  Of what is it mainly ra!Uio up ?
                           17*
 Membrana Tympani from the Outer (A), and from
the Inner (B) Sides. 1, Membrana Tympani. 2, Mal-
leus. 3, Stapes. 4, Incus. 
392              HITCHCOCK'S   ANATOMY

                                  Fig. 3G2.
  A View of the Labyrinth and  Tympan'ini of the Ear, with the Bones in Situ, highly
magnified.  1, Processus Longus of the Malleus.  2, Its Processus Brevis.  3, Its Manu-
brium.  4, lis Neck.  5, Its Head.  6,  Body of the Incus.  7, Its Processus Brevis.  8, H,
Its Processus Longus, with tho little head for articulating with the Stapes.  9, Tho Ilend
of the Stapes.  10, Its Anterior Cms.  11, Its Posterior Crus.  12, Its Base.  1", 14, 15,
The first turn of the Cochlea.  IG, 17, IS, Its second turn.  19, Its  half turn.  20,  The
Cupola.  21, The Fenestra Rotunda.   22, 23, The A'estibule.  24, 25, 26, Anterior Semi-
circular  Canal.  27, Its junction  with tho Posterior Canal.  2S, 29. 30, 31, The Posterior
Semicircular Canal.  32, 33, 34, 35, The External Semicircular Canal. Tho Enlargements
en these Canals are called Ampulla;.

it resembles  a snail  shell, and some of  the others semicircular

canals, because  they  are  tubes  containing  fluid called  Peri-

                                  FlG. 3G3.
Cochlea without the Nerve. 
AND  PHYSIOLOGY
593
lymph and nerve fiber,  Avhich take  the general direction of a
semicircle   Of  these  cavities, however, the  cochlea is not
failed with the perilymph, but contains the finest subdivisions
ot  the auditory nerve.   Besides the cochlea  and semicircular
canals there is a small three-cornered cavity  called the Vesti-
bule, into which the five openings of the semicircular canals
enter.

   718. Auditory  Nerve.-The nerve of hearing belong to
the  eighth  pair  of  Cranial  nerves.    It  divides  into  two
branches  just  before it enters the ear, one of which  is called
the cochlear branch, because it is sent to the cochlea, and an-

                          Fig,  36L
  Auditory Nerve taken out of the Cochlea.  1, 1, 1, Trunk of tho Nerve.  2, 2, Its fila-
ments in the Zona Ossea of the Lamina Spiralis. 3, 3, Its Anastomoses in the Zona A'esi-
cularis.

other the vestibular,  since it  enters the A'estibule, a portion of
the labyrinth.   Besides this  a branch of the facial nerve  en-
ters the ear in company Avith the auditory.

   719. Location of the  Internal Ear.—In man  and all
the higher animals there are  two separate organs of  hearing,
 Describe the cochlea.  What are the semicircular canals ?  What are they filled with ?
718. What is the norve of hearing?  719. In what bone is the ear located ? 
394           HIT CH COCK'S  ANATOMY

or an ear upon each side of the body, and no internal connec-
tion exists between them, so that  one may be injured or  de-
stroyed while the other performs its office.   In fact, the inter-
nal ear is protected by the hardest bone (the temporal) in the
body, and is inclosed in a bony sac to which the only opening
of any considerable size is that of the auditory canal.


            FUNCTIONS  OF  THE   EAR.

   720. Functions of the Pinna.—The object of the pinna is
to convey sound to the auditory canal.  This it  does by con-
duction and convection ; that is, it acts as a funnel  to collect
the vibrations of air  and transmit them to the auditory canal,
and  also conducts  sounds by means of its OAvn  substance in
the same manner as a stick of timber conveys the sound  made
by the scratching of  a pin to its opposite extremity with great
distinctness.   Hence the use of the external  ear is to collect
sounds from as large a surface  as possible, and concentrate
them at the small end of a funnel, so as to increase somewhat
their  intensity.  The probable design of the ridges and fur-
rows upon the pinna is to give a greater exposed surface to it
as well as to receive vibrations more  accurately Avhich come
in various directions.
   721. Use  of  the  Auditory  Canal.—The use of the audi-
tory canal is to give  greater intensity to the  sounds collected
by the external ear.  This can be  illustrated by placing  a
long tube close to the ear, Avhile another person speaks at the
other extremity.   The voice will  be  greatly increased  in in-
tensity, because every vibration is transmitted  to the ear, and
none  are dissipated upon the air  or  surrounding substances.
The auditory canal performs the same office, although in a less
degree than in the above experiment.   This canal  also exists

  Is there any communication between the two ears? 720. What is the object of the
pinna?  IIow does it convey sound to the internal ear?  Why is the pinna of such an
uneven surface ?  721. Of what service is the auditory canal ? How may its use be illus-
trated ? 
AND   PHYSIOLOGY.
395
for protection to the membrana tympani and the delicate or-
gans  of  the  ear, which must  be placed within  the  head to
such a distance that no harm could come to them from exter-
nal violence.

  722.  Function of Membrana Tympani—Use of the  "Lit-
tle  Bones."—The membrana tympani is a very thin and elas-
tic membrane, not half an inch in diameter, which is designed
to receive all  the  vibrations of the air falling upon  it.   On
this account  it  is stretched directly across the auditory canal,
and is so arranged  that by means of muscles  it  may be ren-
dered more  or less tense, so that if it is desired  to catch a
very faint sound, the  drum may be made so sensitive as to
catch the  slightest vibration.  The sound received by the
drum of the ear is transmitted to the auditory nerve by means
of the chain  of bones already mentioned, the broad side of the
malleus resting directly against the drum, and the  broad  end
of the stapes closing the opening  in  the semicircular canals
which contain the nerve of hearing.  The use of this arrange-
ment seems to be to catch all the vibrations of the  drum, and
instead of. allowing them to expend themselves  upon the air
in the tympanum, to transmit them directly to  the auditory
nerve.   The use of the cavity of the  tympanum seems to be
to allow a free vibration of  the membrane of the  drum.  An-
other reason for the large size of the tympanum  is to prevent
the conveyance of sound to any other part of the ear but the
semicircular  canals, and that  by means of the chain  of little
bones.   And in order to convey the sound  only to the nerve
of hearing the  stapes joins on to  the canal, not by a solid ar-
ticulation, but  simply by cartilage, so that none of the vibra-
tions can be  conveyed to  the walls of the  canals, but all to
the nerve.
   723.  Function  of   Eustachian  Tube.-The design of the

  Whit does this canal protect? 722. What is the function of the membrana tympani 1
OfThat use are th"- little bones ?" What service is rendered by the tympanum ? How
does the stapes unite with  the canal? 
396
HITCHCOCK'S  ANATOMY
Eustachian  tube is  evidently to allow of equal atmospheric
pressure upon both sides of the membrana  tympani.   For
were the air in the tympanum closely confined, the atmosphere,
varying as it does in density, Avould sometimes create such a
pressure on  the drum that all vibrations would be indistinctly
conveyed to the  brain.  This is the same arrangement that is
found in bass and tenor drums used for musical  instruments,
a small orifice always being necessary to giAre free access  to
the air.   Hence, Avhen  we. have a cold, or especially a sore
throat, where the mucous  membrane is inflamed, we often find
hearing difficult, because  the  lining membrane of the Eus-
tachian tube is so much SAVollen that air can not pass through.
Also when the same condition prevails we can, by swallowing
the small  amount of saliva in  the mouth  with  considerable
force, drive  so much air into  the tympanum that a sense of
fullness occurs in the ear, which continues  until the  air has
found some  means of escape.

   724. Functions of the  Internal Ear.—The uses of all the
parts belonging  to the internal  ear are not perfectly under-
stood.   Probably, however, the labyrinth and cochlea serve
to give as great expansion as possible  to  the nerve  in the
small space  provided for it.  And the use of the fluid filling
the labyrinth is  to secure  all the vibrations coming in through
the bones of hearing, and  give them greater intensity.   Some
experiments worked out  by Muller, a German  physiologist,
throw  considerable  light   on  the  subject.    He  found that
sounds passing directly into water  from the air lose consider-
able of their intensity ;  but if a tense membrane is placed be-
tween  the two, greater  intensity is produced.  The intensity
is also greatly increased Avhen to this membrane is attached
a small solid body which communicates with the water  alone.
This seems to shoAV Avhy the drum receiA'es all  the  sound
 723. What is the use of the Eustachian tube ?  In what instruments of music is there
ft similar arrangement?  Why does partial deafness sometimes accompany a cold ? 724.
AVhat is said of the functions of the iuternal ear?  Relate the experiments made by
Muller, 
                 AND  PHYSIOLOGY.             397

rattier than some other part of the ear, and also the value of
the three small bones of the ear, at one extremity  fastened to
the drum and at the other  by cartilages to the semicircular
canals.   Other experiments  also  shoAved that a solid body of
the form of the stapes alone was the best to communicate with
the auditory nerve.
   725. Function of the Cochlea and Semicircular Canals.
—It has been thought by some that  the  cochlea enables one
to determine the pitch of sound, since animals Avhich possess
the fullest deArelopment  of this  organ  have the largest range
of voice.  Another speculation is, that the semicircular canals
aid in the determination of the  direction from Avhich  sounds
come,  since in  animals where  they  exist, they  are  always
placed at right angles to each other.
   725 a. Three Physical Properties of Sound.—The three
physical peculiarities of sound are intensity or loudness, pitch
or length of the waves,  and quality, or the difference between
the same note on a flute and violin, although equal  in intensity
and pitch.   And a theory has been proposed, substantiated by
many facts, that the membrana  tympani  enables us to deter-
mine the intensity,  the cochlea the pitch, and the semicircular
canals the quality of sound.
           THE  SENSE OF HEARING  IN ANIMALS.

  726.  External Ears—Semicircular  Canals—Coehlea—
Os  Quadratum.—All mammals, as  a general rule, have ex-
ternal ears.  These, in some  animals, like the  bat, are enor-
mously developed in proportion to the dimensions of the body.
Besides,  in several genera they can be turned in any direction
the animal may choose.   In man the ear consists of but one

^T^tsuggesUoThas been mado of the use of the cochlea and semicircular canals?
705I What arc the three physical peculiarities of sound ? 726. What mammals have
exteTnaT ears? What is said of them in the bat?  How many pieces has the pinna in
most animals? 
398
HITCHCOCK'S  ANATOMY
piece, while in the other mammalia it consists of three.   But
the most important part of this  organ,  the  labyrinth, agrees
in its  structure  throughout the whole  class.   The  greatest
variation that exists is in the semicircular canals and cochlea.
In the cat the canals form the  segment of a  circle, while in
the goat they furnish a portion of an  ellipse, and in the horse
a parabolic  curve.   The  cochlea varies in the number of its
coils.   In the whale and dolphin it makes but one and a half
turns ; in man two and a half;  in the ornithorynchus half a
coil much resembling that of a bird ;  while  in the squirrel it
makes nearly four  turns.   No physiological effect  of these
variations has as yet been given.   In man and the apes  the
whole  cavity of the tympanum  is concealed in a portion of
the temporal bone, but in all other mammals we find a pecu-
liar tympanic bone which varies exceedingly in the  different
classes.
   727. Ear of  Birds.—There  are but few birds which have
any thing like an external ear.   One species of owl, however,
has a  membranous  concentric fold Avhich can  be  used as a
valve.   The cochlea has the form of an obtuse cone,  which at
its  extremity swells  into  an oval tubercle.   The tympanic
cavity communicates with cavities  in  the cranial bones, which
greatly increases the resonance  of  sound,  in the same manner
as the  sounding-board in the  piano, or the  main  body of a
violin or violincello.
   728. Hearing  in  Reptiles.—Although  reptiles present a
more imperfect  form of the organ of hearing than mammals
or birds yet they possess the  tympanum, a membrana tym-
pani, and a chain of ossicles or little bones.   Also a cochlea
is found, which is most fully developed in crocodiles and formed
almost as in birds.
 How do the canals differ in different animals? What variation in the cochlea?  What
is the os quadratum ? 727.  AVhat bird has external ears?  AVhat is said of the cochlea
in birds? AA'hat does the tympanum communicate with?  AVhat is the use of this ar-
rangement ?  728. What is said of the organs'of hearing in reptiles ? 
AND PHYSIOLOGY.
399
  729.  Ilearing  of Fishes.—Among the lowest  order  of
fishes the organ of hearing is simply a sac, which is full of a
fluid that contains small bones or bits of bones called otoliths,
and  the auditory nerve is  distributed upon its walls.   In
almost all fishes there is a more or less perfect form of the
semi-circular canals.  In  some  fishes the  SAvimming bladder
extends to membranous spaces  in the  cranium which are in
connection with an auditory  apparatus.
  730.  Articulates.—Among  the Crustaceans hearing has
been  observed  only among the Decapods.   The sense  exists
in the Arachnoids, but no organ has been found.  The  same
is true of Insects, Annelids,  and Helminths.
  731.  31 o 11U s C S.—Hearing has been ascertained in Lamelli-
branchiata.   In Cephalophora  it is of a low grade: but an
auditory nerve and organs exist in the Cephalopoda.
  732.  Radiates.—The organ of hearing exists in the Polypi
and  perhaps the  Acalephs,  but  has not been  discovered in
the other Radiates.
                  SENSE  OF TOUCH.

        DEFINITIONS   AND   DESCRIPTIONS.

   733. Location of the Sense of Touch—The organ of touch,
with the exception of the upper surface of the tongue, is the
skin.   This  in  some parts is  much  more  sensitive  than in

 729. Do fishes have the regular organs of hearing? AVhat organs do they have in a
rudimentary state ? 730. What apparatus of hearing do articulates possess? Do they
seem to hear sounds?  731-732. AVhat  is said of the sense of sound in molluscs and rad-
ates?  733. AVhere are the organs of touch located? 
400            HITCHCOCK'S  ANATOMY
others, since some portions of the skin are more fully crowded
with nerve fibers than others.   We are conscious of resistance
if ayc place a substance in contact Avith any part of the body;
and  although we are able with  the tips of the fingers  to tell,
whether a body, which is pressed on them, is circular or rect-
angular,  yet we can not with certainty decide the same thing,
if the substance be pressed upon any other part of the body.
   734.  The Direct Instruments of Touch.—The direct  in-
struments of sensation are minute loops of nerve fibers from
the posterior roots of the Spinal  Column,  lying  in the true
Fig. 3G5.
Fig. 366.
         Nerves of Sensation at the Extremity of the numan Thumb.

skin, Avhich are covered only by the Epidermis,  as is seen in
Eio\ S65.  These nerves of sensation are never knoAvn to ter-
minate in a free extremity, but always  in loops;  and in  the
hand and foot are associated with the  Pacinian  Corpuscles,
described under the nervous system.
                                  735.   Papilla;.—Those
                                parts of the  skin which  are
                                the most sensitive, are  cov-
                                ered with minute projections
                                called  Papillae,  which  seem
                                to be mere elevations beyond
   Papillae of the Palm of the Hand.     the  general  surface  of  the
  What is said of the whole cutaneous surface ?  734. AA'hat are the  immediate instru-
ments of touch?  How do the sensitive nerves always terminate?  735. Describe the
papillie.
 
AND  PHYSIOLOGY.
401
skin, in which are  found the loop of  a nerve, and a  blood-
A^essel with some cellular tissue.  The main use of them seems
to be to place the nerve in such a position, that it will be most
easily impressed with whatever  external substances it may be
brought into contact.
                       FUNCTIONS.

   736.   The  Superficial   Parts   of   the   Body   most
abundantly  Supplied  with  Nerves.—The  parts  of the
body lying deep beneath the skin, are but sparingly supplied
with nerves of sensation, Avhich is a great comfort to those un-
fortunate  persons- who are subjected  to  surgical  operations,
since the most painful part is in cutting through the skin,
which is the quickest  part  of  the operation.   This, hoAvever,
is the case only Avhen the deep parts are in health  (including
the bones) ; for if any of these parts, and especially the bones
and  ligaments, are diseased, they constitute a source  of the
greatest pain.   The necessity of this arrangement  is obvious
4rom the protection Avhich  the surface of the body requires
from violence and  heat.   Were it not  for these body-guards,
we by our other senses should  seldom  know Avhen  friction or
heat  Avas consuming the skin,  nor when cold  was  destroying
its vitality.
   737. Value of this Sense to  the Blind.—To those de-
prived of the sense of vision, this sense is of great value, since
it is by this only that  they are enabled to pursue  any labor,
or  instruct  and  please themsehres by raised alphabets, or
play upon musical instruments.  And  it is interesting,  not to
say wonderful, to see Avhat  accuracy is  acquired by the blind
in detecting true from  spurious coins, or in distinguishing the
quality of cloth by feeling  alone.   It is said on good author-

  What is the function of the papilla?? 735. Why are the superficial parts of the body
the most abundantly supplied with sensitive nerves ?  AVhy does the skin ne«l sensibil-
ity ? 737. AVhat is said of the  value of this sense to the  blind ? What examples are
mentioned as illustrating its extreme acutencss in the blind? 
402           niTcncocK's  anatomy
 ity,  that  one blind man became a botanist,  another a con-
 chologist, and another a land surveyor,  simply by the aid of
 touch.

    738.  Effect  of  Habit  on  Location  of  Sensation.—
 Habit has a wonderful power in the location  of sensations on
 the skin.  Thus it is frequently the case, after an amputation of
 a limb,  that the patient declares that he feels  pain in the  re-
 moved portion.  This is OAving to some irritation in a fiber or
 fibers of the remaining nerve trunk, Avhich  were originally
 sent to the supposed  seat of the  pain, and from habit the suf-
 ferer locates it in  the removed  part.  Also after  the Talia-
 cotian operation—which consists in making a ne\v nose from
 the skin of the forehead,—if  the  nose itches,  the patient
 scratches the forehead as the seat of the irritation.

   739.  Insensibility  produced  by  a  long  continued
 Action  of some  painful Stimulus.—It is  sometimes the
 case that the nerves  are rendered insensible by the moderate
 but long continued action of some painful stimulus.   A com-
 plete insensibility of the  skin may be produced,  so  that the
 severest  surgical operations  may be performed without pain,*
 by the application of snow and salt mixed in  equal portions.
 Heat will also do the same thing, as  shown  by the folloAvino'
 example.  "A traveling man one winter's evening laid him-
 self down upon the platform of a lime kiln, placing his feet,
 probably benumbed  by the  cold,  upon  the heap of stones
 newly put on to burn through  the  night.   Sleep overcame
 him in this situation :  the fire gradually rising and increasing,
 until it ignited the stones upon  Avhich his feet were placed.
 Lulled by the warmth the man  slept on; the  fire increased
 until it burned one foot and  part of  the  leg above the ancle
entirely off, consuming that  part so effectually that a cinder-
like fragment was alone remaining, and still the wretch slept
on, and in this state was found by the kiln man in the morn-
 '      5         ~--------------------------------------_---.
 733. What effect has habit upon localizing our sensations? 739. How may insensibility
be sometimes brought about ?  What wonderful example ? 
AND  PHYSIOLOGY.
403
ing.   Insensible to any pain, and ignorant of his misfortune,
he attempted to rise and resume bis journey, but missing his
shoe,  requested to have it found :  and when he Avas raised,
putting his burnt limb to the ground to support his body, the
extremity  of his  leg bone—the tibia—crumbled into  frag-
ments, haA'ing been calcined into lime.   Still he expressed no
sense of pain,  and probably experienced  none, from the  grad-
ual operation of  the  fire, and  his  own  torpidity during  the
hours his foot was consuming."
       THE  SENSE  OF  TOUCH  IN  ANIMALS.

   740. "It is probable that among  the  loAver animals the
proportion of intuitive perceptions is  much greater than in
man;  whilst on the other hand  his power of acquiring per-
ceptions is much greater than theirs."

   741.  Touch  in  Mammals.—Cat,  Rabbit,  Elephant,
Bat.—Among  Mammals touch ordinarily depends on little
projections knoAvn as papilla?, which contain a loop of a sensi-
tive nerve.   In man this structure is principally found in the
tips of the fingers,  but in the Monkey it is found in both the
hands and  feet.   In a majority of mammals the  surface of
the  nose, upper lip, and the vibrissa? or  Avhiskers, as seen
on the face of the  cat,  are  organs  adapted to  the sense of
touch.  Cats are unable to  catch mice when  these whiskers
are removed, and Rabbits without the  assistance of their eyes
can by means  of these  hairs find an outlet in a very narrow
passage.   In the Elephant this  sense has  its  seat at the ex-
tremity of the proboscis.  The wing of the Bat possesses an
extraordinary sensitive power.   It is  said  that this animal is
 740  AVhat is said of the intuitive perceptions of the lower animals?  741 Where is
the sense of touch most perfectly developed in animals ?  Of what use are the whiskers
of the cat and rabbit? Where is tho sense of touch in the tlephan.? 
404
HITCHCOCK'S  ANATOMY
able to fly through perfectly dark and irregular narrow pas-
sages, and avoid all obstructions simply by the delicate sensi-
bility of its  membranous Avings.

   742.  Touch  in Birds.—The only portions of the skin in
Birds, on Avhich tactile papillae  exist,  are found on  the  under
surface  of the foot, and the web of the Aveb-footed birds.   The
bill of the Duck  seems also  to  subserve  the  sense of touch,
upon the inside  of  Avhich the  skin is  soft,  and  has  many
branches of the fifth  pair of nerves distributed to it.

   743.  Touch  of Reptiles.—The sense of touch seems to
exist in Reptiles,  though the  prominent use of the skin is to
afford a protection to the body.   It is  quite probable that the
acuteness of this  sense in these  animals is  no greater than
Avhat is derived to the Horse through the hoof, or to a man
through a stick or rod in the hand.

   744.   Touch of Fishes.—Fishes  probably have  a still
more imperfect sense of  toucli  than Reptiles.   It is pos-
sible that the lip3 may give  an imperfect idea of the form
of external objects;   but the  surface of the  body,  covered
as it is with  scales  and a  thick mucous secretion,  can be
of no service in  this sense.   A feAV  fishes  have hair-like
appendages about the head, which put them  in a condition
to be acquainted Avith the presence of external objects, though
they are not by any  means organs of active touch.

   745.  Touch of Articulates.—This sense is well  devel-
oped in all  the Articulates, and shoAvs itself  especially in the
antennae, the palpi,  and  feet;  and  though these  organs have
a tough,  hair-like consistence,  yet they are  efficient instru-
 Where in the bat ? 742. Where are papillae found in birds ? AYhat answers the pur-
pose of papillae in the duck ? 743. AVhat is said of the sense of touch in reptiles ? 744.
Where is the sense of touch located in fishes ? 745. Describe the Bense of touch in articu-
lates. 
AND PHYSIOLOGY.
405
ments of  sensation.                 Fig.  367.
" For just as a blind
man  judges  of the
proximity  and char-
acter of  objects by
the impressions  com-
municated to his hand
by the contact of his
cane, Avith which he
examines  them,  so
may  an   insect  or
crustacean   receive
sensory  impressions
from the nerA'es dis-                 A Foot of a re-
tributed to the  basal joints of their long antennae, although
the organs themselves may be as insensible (or rather as un-
impressible) as the stick."

   746. Touch  of  Molluscs.—The  sense  of touch in  this
group is well developed.   In some of the orders the organs
are  from two to four contractile tentacles situated upon the
head, or the anterior part of the back."   "With some Gas-
teropods these  tentacles are  hollow  and  button-like at their
extremity, and can be inArerted like the finger of a glove."
   747. Touch  of  Radiates.—"The  sense of touch is well
developed  among  the  Echinoderms."    It  exists  here  and
amono- other  Radiates  in tentacles or feelers.   Besides this,
other individual Radiates seem to possess a sensitiveness of
the Avhole  surface of the body, though nerves can not be the
agents which secure this sense to them.
 Is it by an active touch that this sensation is gained by articulates? 746. Describe
touch in molluscs. 747. What ia the touch of radiates ? 
•
406
HITCHCOCK'S  ANATOMY
                   SENSE  OF  TASTE.

      DEFINITIONS   AND  DESCRIPTIONS.

   748. Anatomy of  the  Tongue.—The  tongue is  preemi-
nently the organ of taste.   Its principal part  is  made up of
           pIG< 3GS,              muscular fibers which run  in
                                 various  directions,   although
                                 they run in similar directions
                                 upon  the  opposite  halves of
                                 this organ.   The tongue  is
                                 covered with a thick mucous
                                 membrane,  Avhich contains  a
                                 large  number of papilla? simi-
                                 lar to those of the skin, which
                                 are of three kinds, the Filiform,
                                 Fungiform, and Circum vallate.
                                 The   filiform  are from one
                                 thirty-sixth to one  eighth  of
                                 an  inch  long,  of a conical
                                 shape, and are most  abundant
                                  on the middle portion of the
                                  tongue.   The fungiform  are
                                  situated upon the tip and sides
                                  of the tongue, and are  some-
                                  what smaller than the filiform.
                                  The  circumvallate  are from
                                  six to tAvelve  in  number, and
                                  are arranged  upon   the base
                                  of the  tongue in the form of
                                  the letter V, the apex pointing
                                  doAvnwards.   They  consist of
                                  a central  round papilla flat-
 Front View of the Upper Surface of the
Tongue, as well as the Palatine Arch. 1,
1, Posterior Lateral Half Arches, with the
Palato-Pharyngeal Muscles and Tonsils. 2,
Epiglottic Cartilage, seen from before. 3,
3, Ligament and Mucous Membrane, ex-
tending from the root of the tongue to the
base of the Epiglottic  Cartilage.  4, One
of the Pouches on the Side of the Posterior
Fraenum, in which food sometimes lodges.
5, Foramen Caecum. 6, Papillae- Capitata?
sen Maxima?.  7, The white point at tho
end of the line, and all like it, are the Pa-
pilla? Fungiformes.  8, Side of the Tongue
and Iiugae Transversa of Albinus.  9, Pa-
pilla? Filiformes. 10, Point of the Tongue.
 748. What is the organ of taste ?  Of what is it made up, and with what is it covered ?
Name the three kinds of papilla?.  Describe the filiform, fungiform, and circumvallate. 
AND  PHYSIOLOGY.
407
Fig. 3G9.
tened at the end, one twenty-fourth to one twelfth of an  inch
in diameter,  Avith a lower uniform  wall closely surrounding
the papilla.  More nerves are distributed to the circumvallate
than to either of the other forms of papilla?.   At its lower cr
posterior  extremity the
tongue is attached to
the os hyoides, and at
its lower  front  portion
to the lower jaAV by the
fra?num  or  bridle of
the tongue ;  so that it
is left free to move ei-
ther backwards or for-
wards by the  contrac-
tion of the appropriate
muscles.
   749. Blood-Vessels of this Organ.—A  great quantity of
blood-vessels are distributed to this organ, as can be seen by
looking at the under side of it, as avcII as  by the free flow of
blood when it is Avounded.
   750. Nerves  of Taste.—Of nerves there are no less than
three large branches supplied  to the tongue from the cranial
group : the gustatory or  proper nerve of taste, a branch of
the fifth pair Avhich is  distributed to the papillae ; the glosso-
pharyngeal distributed to the  mucous  membrane, being both
a nerve of motion and  sensation ; and the hypoglossal distrib-
uted to the muscles, being preeminently a nerve of motion.
 One of the smallest Papilla? of the Tongue highly
Magnified.
FUNCTIONS.
   751. fse  of  the  Numerous  Muscular  Fibers  in  ihc
rrono-ue.—To effect the numerous movements of the tongue in
 Which kind receive the most nerves?  To what is the tongue attached by its lower
extremity ? 749. AVhat proportion of blood is sent to this organ ? 750. How many nerves
are sent to the tongue, and what are they ?
                           18 
408
HITCHCOCK'S   ANATOMY
 mastication, swallowing, tasting, articulation, etc., it is neces-
 sary that the  muscular fibers should run in various directions.
 That, however,  Avhich is commonly known  as  the tongue is
 only the tip of  it, Avhile  the largest  portion lies in the front
 and lower portion of the pharynx,  Avhere most of the muscu-
 lar actions are performed.

    752.  Use of the Papilla;.—The papilla? of the tongue, as
 those of the skin, are constructed  for the  purpose of giving
 as much surface of nerve to be exposed as possible, leaving it
 mostly in the  form of a loop.   The filiform papilla? are not
 the seat of the  sense of taste or  touch, but are analogous to
 the lingual spines of loAver animals  (Avhich gives  such rough-
 ness to their tongues), Avhich aid  in mastication and protec-
 tion of the tongue.  As the sense  of touch is most  acute at
 the tip of the  tongue,  it is supposed that the fungiform papillae
 are the instruments of touch to the  tongue ;  and as Ave acquire
 the sense of* taste  more  at the base  than  at the tip  of the
 tongue, and as the nerves are more abundant and finest  at the
 circumvallate papilla?, these probably administer mainly to the
 sense of taste.
   753. Object of this Sense.—The main use of this sense is
 to direct  us in  the  choice of proper articles of food, and by
 this means to  excite the Aoav of saliva and mucus, to  aid in
 digesting food.    In man, however,  this sense would be an un-
 safe guide, since  this alone can not  aid us to distinguish whole-
 some  from poisonous food, although many of the loAver animals
 seem  able to make such a distinction by this sense alone.
   754. Effect of Education on Taste.—Taste is made won-
 derfully acute  by education.  Epicures are able  to  tell  the
manner in which game was killed, the spices used in cooking
it, and the length of time since it Avas killed, Avhen eatin^ it.
  _______^^^                                '             ©
 751. Why are there so many muscular fibers in  the tonguo ? Where does the larger
frl  ' °rgan  He ? T52' 0f what use are tlle P«P"1*»  ^«at sensation is gained
by the filiform papilla? J In what  papillae does the sense of taste mainly exist? 753.
 What is the use of this sense ?  Is it alone a safe guide for  man?  754. AVhat effect has
education upon taste ?  dive instances. 
AND  PHYSIOLOGY.
400
Wine tasters can readily give differences in the age, growth of
the grape, and the purity of Avines, that to ordinary observers
are imperceptible.
   755. Taste as Influenced by  Smell.—Taste, as to some
substances, is dependent  on  the sense of smell.  Thus, Avith
the eyes and nostrils closed, if an  aromatic or spicy substance
be chewed it is impossible to say Avhat the substance is, except
that it is pungent,  although it may be one with Avhich the per-
son is Avell acquainted.   Yet  smell does not aid us in deter-
mining the taste of acids, alkalies,  or salts.
   756. After-Tastes.—An  important  point connected with
this sense  is  that  known as after-tastes.   Thus, frequently
after eating sweet  substances a bitter taste is left in the mouth,
and Avhen bitter substances  have   been  tasted a pleasant  and
SAveet taste is left in the  mouth.   This subject is a matter of
great importance in the art of cookery.
            THE SENSE OF  TASTE IN ANIMALS.

   757. Use  of  the Conical  Papilla;.—This sense is in all
animals confined to the tongue and inner surface of the mouth.
The sensation received from the sapid body is gained through
the papilla?, which are present on the tongue and in general
structure resemble  those  of the skin.   There are probably
four kinds in mammals, those upon  the central  part of the
tongue often being  conical, hard,  and even horny,  and those
upon the back part fungiform, or soft  and cup-shaped,  as is
seen in the tongue of the cat.   The conical papilla? seem to
act the part of a rasp, especially in the  carnivorous animals
in order to remove all the particles of meat from bones.   And

 755 Give the connection between taste and smell.  75(1. What is said of after-tastes?
7--  How many kinds of papilla- in most mammals? What are the uses of the conical
papillLTo Seating anima'ls ? How powerful an instrument do these at tunes constt-
tute? 
410
HITCHCOCK'S  ANATOMY
so efficient are these that  the skin of some of the more deli-
cate animals is removed simply by the  licking of the tongue
of one of the more powerful carnivora.
   758. Tongue  of  Birds — In  the Woodpecker  and Hum-
ming-Bird.—In birds this sense  is very feeble,  since  the
tongue is  destitute of sensitive papilla?, and is often of a hard,
horny consistence,. designed probably more for the  means of
obtaining  food than of judging of its quality.  In some birds
the tongue is furnished Avith one or more ossicles for the pur-
pose of giving stability and strength to it.   In woodpeckers
the tongue is not only long, slender, and stout, but it is armed
                           Fig. 370.
Tongue.
■  Os
Hyoides.
                     nead of the Woodpecker.
with appendages like barbs on either side, in order that it may
be thrust into narroAV crevices in trees,  to pierce and hold in-
sects upon which it lives.   (See Fig. 370.)  Humming-birds
have tongues very slender and slit at the  apex, so  that  both
sides can be formed into a sort of tube by curving them to-
gether  from the  outside, in order that the  bird may  suck
up  the  nectar  of floAvers.  And in  both  of these  birds the
tongue  can be  extended for a long  distance in front of the
body.

  759.  Tongue of Reptiles—Chameleon.—The tongue  of
most of the class of reptiles seems to be constructed for other
purposes  than  that  of  taste.   Like  that  of birds,  it is pro-
vided with one or more lingual (tongue) bones, and is desti-
 75S. How is it with the sense of taste in birds ? Describe the tongue of the woodpecker.
What is its use ? AVhat is the tongue of the humming-bird ?  IIow far can the tongue
bo protruded in either of these animals? 759. For what purpose is the tongue of rep-
tiles ? 
AND   PHYSIOLOGY.
411
tute generally of papillae.   In some of this class it is hardly
perceptible, while in  Serpents, Toads and the  Chameleon, it
is  very long and capable of rapid motion.  In Chameleons and
Serpents, Avhen the tongue is at rest, it lies in a kind of sheath
at the base  of the mouth.   That of the  latter is forked at its
apex, Avhile the former has a concave disk at its point covered
by a viscid  secretion, Avhich, by the dexterity of the animal,
can be  thrown at once against the insects flying  in the  air,
thus securing  its food.   In this  case  also the tongue seems
longer  than the body itself.
                             Fig. 371.
 Tongue of Common Fly.  a, Lobes of Lingula.  b, Portion enclosing the Lancets
formed by the Metamorphosis  of the Maxilla. C, Maxillary Palpi.  A, Portion of
one of the Metamorphosed Trachea? enlarged.
 now does the chameleon obtain his insect food ?  TfiO. Have fishes any tongue, or the
sen^e of taste' 7f.l. How well is this organ developed in some of the lower animals?
70■'" Describe the shape of the nose.  Of what is it principally composed ? 
412
niTc n cock's   ax atomy
   760. This sense in fishes appears to be very feeble.   "The
part named tongue in them consists merely of the anterior ex-
tremity of the tongue-bone covered  by mucous membrane."
If fishes possess this sense, the palate rather than the tongue
is probably its seat.

   761. Invertebrates.—Taste,  doubtless, exists  in all the
lower  animals else  how could they  select their food ?   The
seat of this sense is  not always  discoverable, as can be done
in the Cephalopoda.   But the sense exists in all, even in the
Protozoa.  Fig.  371 exhibits  the tongue of  the common fly,
which is  doubtless the seat of this sense.
SENSE   OF   SMELL.
DEFINITIONS   AND  DESCRIPTIONS.
Fig.
   762.  Anatomy of  the  Nose—The Nose which contains
the organs of smelling, is a triangular pyramid placed  upon
the face, its apex  connected Avith the forehead,  and  its base
descending nearly to a level with  the  upper lip.   It is  prin-
cipally made up of bone cartilage and integuments,  having a.
                                thin plate of bone   (the  vo-
                                mer)  and cartilage  in  the
                                middle which run in a verti-
                                cal direction, and divide  the
                                cavity into tAvo portions called
                                the nostrils.   (Fig.  372.)
 A View of the Cartilages of the Xose.
1, Tho Nasal Bones. 2, The Cartilaginous
Septum. 3, The Lateral Cartihurcs. 4,
The -Alar Cartilages. 5, The Central por-
tions of the  Alar Cartilages which consti-
tute the Columns.  C. The Appendices of
the Alar Cartilage. 7, The Nostrils.
 
AND  PHYSIOLOGY.
413
Fig. 373.
   762 a.  Use of  the  Bones.—Use  of  the  Cartilages,
and  the  Glands  in  Integuments.—The  bones  are the
tAvo nasal, which give form to the base of the  nose,  and fur-
nish a firm  attachment to  the muscles.  The  cartilage  is of
use to give form to the  nose, while  its elasticity lessens the
effects of injuries.    The integument or  skin is quite  thick
upon this organ, and aids the cartilage in giving form  to it.
It contains in its substance small glands, which secrete an oily
matter to protect the nose from extremes  of weather.   These
glands are liable to retain  dust and  other impurities in their
orifices, forming the  black specks on the nose.
   763.   Lined  wi.tli Mucous  Membrane.—The whole  cav-
ity of the nostrils  is lined with mucous membrane, which is
continuous with the  lining membrane of the fauces or throat,
with which the nostrils are in communication.
    764.   Cavities  of the
Nostrils . — Nerve   of
Smelling.—The  cavities
of the  nostrils are  very
irregular, since upon their
own outer sides are found
the  turbinal  bones  and
a similar scroll-like  por-
tion  from   the  ethmoid
bone, for the purpose  of
givjng  as large a  surface
as possible for the expan-
   A Vertical Section of the Middle Part of the Nasal Foss*, giving a Posterior View of
the Arrangement of the Ethmoidal Cells, etc. 1, Anterior Fossae of the Cranium. 2, Tho
tne Arr.iuBe                               turned up.  4, The Crista Galh
TtLTthmoidCe  TltsCHbriform Plate. 6, Its Nasal Lamella.  7, The Midd.o
of the Ethmoid isone   •           9  The 0s planum  10> Inferlor gpongy Bone.
  {"rue?»Z,  irSuperTr Maxillary Bone. 13, Its Union with the Ethmoi^ 14
 11, ine vomer    ,   i        Hi-hmorianum, covered by its  Membrane.  15, Its
 Anterior Pariete  of the An turn I , h       ^     ^^ ^ ^     ^ ^^
 wTneTs EoofftrMouUi, covered * the Mucous Membrane.  19, Section of
 ttto Sembran;  A Bristle is seen in the Orifice of the AntrumHighmor.auum.
            ',      <m „™ „ml cirtilaze in tho composition of the nose.  Ofwhatser-

 scribe tho cavities of tho nostrils.
 
414
HITCHCOCK'S  ANATOMY
sion of the nerve of smell, and at the same time furnishing such
an arrangement, that the air containing the odor can be readily
draAvn over it.   This nerve is  the Olfactory or first pair of
cranial  nerves,  which,  as  soon as  it  reaches the nostrils, is
divided into a great number of filaments, and  these  are  dis-
tributed upon the mucous  membrane—called Pituitary—al-
ready described.   The fifth pair of cranial nerves also sends
branches  to this membrane,  by means of which it is that
sneezing is effected.
   765.  Smell  under the  Control  of the  Will.—The sense
of smell is somewhat under the control of the will, since the
air containing the odoriferous particles can be carried  over the
nostrils or rejected at pleasure, and it can also be cultivated
to a great extent, although some persons are naturally more
sensitive to odors than others.    It is related that a gentleman
who had a great antipathy  to cats, could tell if there was one
in the next room by smell alone. And the blind boy Mitchell
ahvays  formed  a  favorable or unfavorable impression of a
stranger by this sense.


        THE SENSE  OF  SMELL  IN ANIMALS.

   766.  The sense  of smell is most perfectly developed in air-
breathing animals,  although many Avhich live in the water, can
distinguish odors or scents to a considerable distance.
   767.  Smell   in  Mammals.—In  Mammalia the  mucous
membrane covering the turbinal bones is  supplied with  ol-
factive  nerves.   And in carnivorous  animals,  like the Lion
and Tiger, these bones are split up into several lamina?, giving
them arborescent or tree-shaped forms, so that the membrane

  AVhy arc tho turbinal bones placed here ?  What is  the nerve of smelling?  765. To
what extent is smell under the control  of the will ?  AVhat curious facts in this connec-
tion ?  766. In what animals is this sense the most perfectly developed?  7G7. Among
what mammals do we find  this sense in the greatest perfection?  AVhat peculiarity in
the turbinal bones in the lion ? 
AND  IHYSIOLOGY.
415
may be  expanded over as great a  surface as  possible.   The
cavities in the bones of the face and skull in these animals,  as
well as also the  Horse and Deer, are  very much  developed,
and all  the  mammalia, except  the Whale  tribe,  are  supplied
with  a turbinal  bone,  the  cavities of which are lined by a
membrane which greatly aids  in  the sense of  smell.   The
sense of smell is also greatly developed in the timid grazing
animals, so that they may  in  this Avay receive notice of the
approach of their enemies and escape.   For most quadrupeds
give off a strong odor from  their bodies, in the  exhalations of
the skin.

   768.  Smell   in  Birds.—A  Nasal  Gland.—Birds possess
turbinal bones  and a large nasal cavity,  but  it is  doubted
Avhether  much  of  the poAver of  discerning  their prey de-
pends on  this  sense, or Avhether it does not entirely depend
on vision.   For the  olfactory nerve merely  ramifies  upon
a  part of the nasal cavity,  the remaining portion being sup-
plied with branches from  the fifth  pair.   There is,  how-
ever, a peculiar gland called the nasal, Avhich serves the pur-
pose of lubricating the pituitary (or mucous) membrane, which
is  probably necessary from the fact  that so much air is con-
stantly passing  over  the  nostrils  that the membrane  would
otherAvise become dry and thus impair the sense of smell.
   760.  Smell  in Reptiles.—Reptiles seem by their organiza-
tion of A'ery simple  nasal cavities, to have their sense of  smell
feebly developed.   A feAV  only have  bony  or cartilaginous
turbinal organs, and  a portion only have the cavities  lined
by a pituitary membrane ;  and from the gormandizing habits
of these animals,  we see that the sense of smell could be of
but little service to them.
   770.  Smell  in Fishes.—Fishes possess a cavity lined  by a
  What bone is the whale tribe wanting in ? now is the sense of smell in grazing ani-
mals? 76S. How well developed arc the organs of smell in birds? What is probably the
case with regard to their powers of smell ?  AVhat gland is furnished to them which pos-
sibly aids this sense?  7G9. What is said of this sense among reptiles ?  Is this sense of
any great value to them ? 
416           HITCHCOCK'S  ANATOMY

pituitary membrane and furnished Avith olfactory nerves, which
gives them a powerful organ of smell.  This cavity, hoAvever,
has no posterior  orifice, its only opening  being in  front, and
the Avater in it being continually kept  in motion by the cilia?
Avith which it is lined.   In the sharks and rays there is a mus-
cular appendage  to  keep the Avater in motion,  so that Sir
Richard Owen says these animals must actively scent (that is
search for odoriferous impressions) as Avell as smell.

   771. Articulata.—Crustaceans  have  the  sense of smell,
and the central ganglion sends off an olfactory nerve.   The
Arachnoids  can smell Avithout any  discoverable  organ.   So
also the Insects.   Probably all of the Articulates have this
sense, but perhaps Avithout special organs.

   772. Molluscs.—In Cephalopods olfactory organs are made
out, but not in the other classes.

   773. Radiata.—No distinct organs  for this sense have been
found in  these animals.   But the presumption is that it exists
Avith or Avithout special organs in them all.
   Of the Protozoa the Infusoria clearly  evince sensation and
volition; but no nervous system has been discovered in them,
and though it is quite manifest that they are sensible  to  the
contact Avith objects  and to light, yet there is no evidence that
 they have the sense of smell.  Equally probable is it  that  it
 is Avanting in the Rhizophoda.
    HYGIENIC INFERENCES IN RESPECT TO  THE  SENSES.

  7.71.—1. Moderation in  their Use Required.—All tho
organs of sensation require to be moderately employed.   If
 770. How Is it with the sense of smell in fishes?  What peculiarity among the sharks
lindrays?  771. Have articulate animals the power of smelling? Have they the organs
adapted to it?  IIow is it probable that lobsters smell?  772. Can shell-fish smell ?  773.
What of animals lower in the scale ? 
                   AND  PHYSIOLOGY.              417

the eye be  used in  too  strong light, weakness or partial pa-
ralysis of the optic nerve  may be produced; and if  the ear
receive too violent  a sound, deafness may MIoav, and so with
the other senses.   Therefore care should be taken in the use
of  the senses, for Avhen the  function  of one  of the nerves
of special sensation is gone, it is very rarely if ever restored.
   775.—2.  Sudden Extremes of Sensations to be Avoided.
—With some of the  senses, and especially that of vision, great
care must be taken to avoid, if possible, sudden transitions.
Next to very excessive use and mechanical violence, no greater
trial  can be given to the optic nerve  than a sudden  contact
Avith powerful light.   To a student  this  inference is  of great
value, and especially to those who would rise early and study
by candle-light, before  daybreak.   This practice  is  often a
source of confirmed  Aveak  eyes.   One  reason is, that during
sleep the pupil is  dilated, and when the eye is opened does
not readily contract.   This statement, hoAvever, is  not an  ar-
gument against early rising, Avhich  for other reasons has been
shown to be healthy to the student.   A good rule for students
in  sound health  during the long nights of the  year is to rise
before daybreak, and after washing the eyes in pure cold water
to  take  a  good  share of the exercise  needed  for the day.
Then, after an  early breakfast, Avhen food and exercise  are
both  obtained, he may be ready for a day's work of hard study
by the congenial light of the sun.   If, however, circumstances
are such that Ave  must  study in  the  morning by lamp-light,
we should  commence and work  moderately until the eye is
accustomed to the light.
    775. a.—S.  Cleanliness of the Organs of Sensation Nec-
essary.—Perfection of sensation requires that all the organs^
should be kept clean.  The eye needs occasional washing,  not
 774. Why do the senses all require moderation in their use? What if a nerve of spec.a
sense is destroyed 9  775. What is said of sudden extremes of sensation ?  AVhy should
 uden s esp cfauy avoid all extremes of light and darkness as far as possible ? How does
eldyrSing affect the eyes? 775. a. How does cleanliness affect  all the organs of th.
seases? 
418
HITCHCOCK'S  ANATOMY
rubbing, with cold water ;  the ear not only needs the applica-
tion of cold water, but occasionally the careful use of the ear-
pick to  remove  the  accumulations of wax which is gathered
beyond  the reach of ordinary washing.   If the nostrils are
buried by collections of snuff, how can we expect acuteness in
the sense of smell ?
   776.—4. Senses Need  Education.—The senses need edu-
cation.   No portions  of the body show so well the good effects
of discipline and practice as  do  the organs  of sense.   The
power which, by training, can be  acquired of distinguishing
the faintest shades of color, the slightest discord between mu-
sical tones, and of the quality  and  flavor of food and drinks
by the smell and taste, is so great as to astonish us.
   777.—5. Is Taste a Proper  Guide  for  the Appetite?—
The question  often arises whether  the sense of  taste can be
considered a safe guide  for  the  appetite.  As it is natural,
some  maintain that it should always  be gratified.   But even
if originally safe  to follow, how often has it been perverted by
extravagant diet,  and is at the time in a morbid condition from
a perverted state of the body ?  If such be the case, we should
be on our guard against indulging peculiar appetites, or strange
tastes.   But in some cases, of which the physician  is the best
judge, it may be safe to allow a reasonable  indulgence  in  a
desire for a peculiar article of food or drink.
   778.'—6. Our  Senses Sometimes become Sources of Mis-
ery.—In such a  world as this our senses, especially if exqui-
sitely cultivated, often become inlets of keen  suffering.   Ob-
jects  disgusting to the soul must necessarily obtrude themselves
upon every one.   Those who are afflicted with a dainty  appe-
tite  and are very nice  and particular as to their  food, often
suffer acutely ; while he who has learned to eat  only that he
may live, instead of living only that he may eat, experiences
 776. Do the senses show the good effect of education ?  777. Is taste a sufficient guida
for the appetite ? AVhat is said of peculiar appetites and tastes?  77S. Do our senses ever
give us pain ? In what way does a cultivated taste often make us wretched ? 
AND  PHYSIOLOGY.
419
gustatory enjoyment from the same food that turns the stom-
ach of another.  True, a taste for the fine arts must be culti-
vated, although the sensorium will thereby be subject to pain
from  discords in sounds, and incongruities in colors and forms.
But in respect to diet, regimen and  manners  it is  hazardous
to cultivate the sensibilities till we become disgusted with al-
most  every thing we meet, and make ourselves objects of ridi-
cule for our peculiarities.
   779.-7.  A higher  kind  of  Ilappiness than that  de-
rived from the Senses—Finally, we ought to remember that
enjoyment gained through the senses, is not the highest kind of
happiness for man.   Though it be all, or nearly so,  which the
brute can enjoy, yet the  intellectual and moral powers of man
demand of him the control of his sensual desires, and a love
for that which is far higher and purer,  For thus will all his
faculties be  engaged in their appropriate sphere,  and keep
bright till  the end  of life, and as its evening  shadows steal
upon  him, they will find him not  full of disease and Ioav de-
sires,  but peaceful  and happy, ready to make a change from
bodily to  spiritual  realities, almost Avithout  a sigh  and with
exulting anticipations.
779. Is sensual happiness superseded by no higher enjoyment? 
CHAPTER    NINTH.
 RELIGIOUS  INFERENCES FROM  ANATOMY  AND
                     PHYSIOLOGY.

  780.  Highest Use of Science.—The  highest  and most
important use of all science, is its religious applications : since
these are eternal, Avhile all its secular bearings are  only tem-
poral.
  781. Religious Value  of Anatomy  and  Physiology.—
Perhaps no sciences are so prolific of religious applications as
anatomy and physiology.  They bear especially and almost
exclusively upon Natural Religion.


    I. PROOFS  OF  THE  EXISTENCE   OF GOD.

  782. The argument for a Deity from marks of design so
obvious in nature, derives some of its most striking examples
from anatomy and physiology.
  783. The Eye,—The eye has often  been quoted as a strik-
ing instance.  Who  can mistake  its object?  And when we
examine its structure, Ave see Iioav  admirably adapted all  the
parts are—the coats,  the media, and the nerve—to secure this
object.  And it is done  far more perfectly than by the finest
optical instrument of man's construction.
  784. The Ear.—In the ear we  have another example al-
most equally striking, except that the special object of some
of its parts is not so obA'ious as in the eye.
  785.  Hands,  Lungs,  Heart,  etc.—"We  might say  the
same of the hands and  the feet, the lungs,  the muscles, the 
ANATOMY  AND  PHYSIOLOGY.       421
nerves and the heart.   If design is not manifested in their
construction,  it is difficult to see hoAV they could be mani-
fested.  The  mechanical arrangements and  operations  of the.
different parts of the system teach the same lesson.

  786.  Skeleton.—Spinal Column.—Take the bones of the
skeleton for an example.  How admirably are these arranged as
a solid framework, around Avhich the soft parts of the system
may be built up !   The vertebral  column is  not a single
straight tube, as our wisdom Avould probably think to be the
safest and best as a protection to the spinal cord  Avithin, but it
is made up of over thirty bones separated  by an elastic  sub-
stance, yet locked together and fastened by strong  ligaments,
so as in fact to be stronger than a single piece, and moreover
it is made someAvhat crooked, so that it  will  yield  a  little
when jarred,  and thus prevent the brain from being injured.

   787.  Joints.—The joints too,  hoAV admirably fitted for the
manifold movements Ave need to make!  How securely fastened
together by  numerous strong ligaments !   IIoav much  more
effectually lubricated by the synovial fluid  than  the most per-
fect engine of human construction !  Then again, how exactly
fitted to the  parts of the body, in Avhich they are placed, are
the different  kinds of joints, the ball  and socket, the hinge,
the sutures, etc. !

   788. Muscular  Arrangement—Their  Mechanical Dis-
advantage,  etc.—Contraction .—Perhaps even more striking
are the character, position, and mode of action of the muscles.
Always in pairs, except Avhere a single one is all that is needed;
bein"- antagonistic only Avhere antagonism is Avanted; being thick
where great  strength must be exerted, or some cavity must be
filled to produce symmetry of form;  being thin where wide
surfaces were to be covered, or a proper proportion could not
be secured between the different parts of the body.  Then how
wonderful that  the great mechanical disadvantage, at  which
muscles act,  which at first sight seems  so obviously a defect 
422
HITCHCOCK'S   ANATOMY
of arrangement, should on reflection be found wisely adapted
to our wants and comfort.   The mode in which  the muscles
act by mere contraction, is the simplest possible ; yet Avhen Ave
inquire how this is effected, Ave find ourselves in contact with
some of the profoundest and most  difficult  of all subjects:
there is not only design, but unfathomable wisdom here.

   789. Harmony  of Chemical and Vital Agencies.—The
conjoint operation of chemical and vital agencies  in  building
up and perfecting the system, and  freeing it from impurities,
is another  marked example of design.   These agencies, the
chemical especially, are blind, and Ave might expect  that they
would as often destroy as they Avould preserve.   But though
they are incessantly at work all over the system, as if it were
a busy laboratory, in building up the tissues,  in com-erting
elements into immediate principles, and in  separating and
casting out of the body the superfluous and deleterious mate-
rials, all goes right till Providence permits disease or accident
to disturb the harmony between  vitality and chemistry, and
from  the disastrous  effects of their morbid action, we learn
how wisely ordered was their healthy operation.

  790. Special  Arrangement exhibiting Design.—There
are some special contrivances and arrangements in the animal
frame, which strikingly show design, because it  looks  as if
the Author of Nature had  made  a modification  of his plan
to meet exigencies.   Take a few examples.

  791. Looped Muscles.—Look   at  the  looped  muscles.
There the  tendon  is fastened  by a loop,  in order  that the
direction of the force, applied  in contracting the muscle, may
be more or less changed, made in  some instances, as  in the
oblique muscle of the eye, to pull in an opposite direction ;
or at right angles, as when  the digastric muscle draws down
the chin.

  792. Anastomosis of Mood-Vessels— Then there  is the
inosculation of the  bloodvessels.   Hoav obviously this  is  in- 
AND  PHYSIOLOGY.              423
tended as  a security, when some*of the blood-vessels  are
AA'ounded and can not transmit the blood.   It then seeks those
side channels, and soon they so enlarge as to give free passage
to all the blood that is needed, eA'en though a large vessel has
been closed.  If man had constructed a machine with such an
arrangement we should have been  sure Avhat Avas  the  design.
Why  doubt the same in respect to God's work ?
   793.  Protection of Large Vessels.—Again,  the large
blood-vessels and nerves are placed deep in the system, and
where they pass  by prominent joints, grooves, or tubes, are
made for them;  or where  one side  of a joint is exposed to
injury and the other comparatively secure, the important ves-
sels are grouped together on the less exposed side, as in the
groin and arm-pit.
   794.  Annular Ligaments.—Take, for another  example,
the annular ligaments around the wrist and ankle.  Who can
doubt that they were placed there to prevent  the tendons of
the muscles from starting out of their places, when the mus-
cles are strongly  contracted and the feet and hands bent ?  If
so, who can doubt that a Being of infinite wisdom devised and
executed this arrangement ?
   795.  Nervous Power.—But all this wise disposition of the
parts of the body might have  been made and yet the whole
have  been  useless, had not  some vivifying force been added.
Therefore the nervous system was  contrived and  incorporated
with every part of the body, commencing with the brain  and
ramifying  to all the extremities.   It needed, too, a  central
power to°direct and control the nervous energy, and therefore
the mind, an immaterial and immortal principle, was enthroned
in the brain.  From thence,  as along so many conducting
wires, and doubtless by means of galvanic agency, it sends out
its orders to  originate and control every muscular movement
and keep in  play every function of the body.   The nervous
system, then, is the mysterious connecting link between mind
and matter, and the admirable manner in which it performs its 
424
HITCHCOCK'S  ANATOMY
functions and enables the "thinking principle to manifest its
astonishing powers, sIioavs the nervous system to be the most
wonderful of all the contrivances which Infinite Wisdom has
placed in the human body.   What could demand an Infinite
Deity if such a contrivance did not ?
   796.  Dependencies  of one System upon Another.—The
connection between mind  and body,  hoAvever, is only imper-
fectly understood, and therefore there  is one other thing which
exhibits more impressively than the nervous system and the
mental powers the agency of an infinitely wise  Being.   The
human body is made up of quite a number of minor systems
of organizations apparently  independent of one another, yet
all in fact mutually dependent and combined into one complete
and perfect system, with the parts all exactly adapted to one
another.   Could any thing  less than Infinite Wisdom have
accomplished so marvellous a work ?
   797.  The same Plan Exhibited  in  the whole Animal
Kingdom.—Yet if we extend our researches through the whole
animal kingdom, Ave shall find that this same mutual adapta-
tion and correlation extend through the whole series, so that
all are but parts of a mighty Avhole.  From man doAvnwards
through the hundreds of thousands of species, to  the humblest
animalcule, each occupies  a  fitting place, and every link of
the long chain is in perfect harmony with all the rest, so that
the skillful anatomist,  knowing one  part  of  the  chain, can
delineate the rest, just  as  a  single bone of an  animal often
determines the character  of its whole  frame.   What vast
reaches of thought, AA'hat wonders of Avisdom, Avhat  boundless-
ness of poAver must it have required, to Aveave together so vast
and varied a system into one golden Aveb of harmonies !


   II.  PROOFS  OT   DIVINE BENEVOLENCE

   798.  All  Organs  and  Functions  Normally Produce
Happiness.—One proof of Divine benevolence is, that all the 
AND  PHYSIOLOGY.
425
organs and their functions are adapted to promote the welfare
of the individual.  They may incidentally result in evil; but
the object Avas to produce happiness.   One  object of the  ner-
vous system aaus to guard us against  injuries  by putting us
on our guard against them.   But in case of injury or diseased
action, intense* suffering often results ; and Avhile enduring it
we are apt to forget  the grand object of the nerves of sensa-
tion, and imagine incidental to be intentional evil.   So carni-
vorous teeth and poison fangs are intended  to provide animals
with food and  the  means of defense.   But they may produce
great incidental evils by being used as animals have the power
to do, and are  sometimes incited  to do,  aside from the normal
objects for which they were given.  Indeed there is no organ
or operation Avhose leading object is not the production of hap-
piness ;  and therefore we infer the predominant disposition of
the Author of nature to be benevolent.

   799.  Pleasure  Superadded to Functions  when  not Re-
quired .—A second fact leading  to the  same conclusion is, that
often pleasure is superadded to animal  functions, Avhen it is
unnecessary to their perfect performance.   It Avas not neces-
sary to  perfect  vision  that  the colors in  nature should be
agreeable ;  that the earth,  for instance, should be green, or
that colors  in floAvers should be  harmoniously blended.  It
was not necessary for the support of the system that gusta-
tory enjoyment should accompany the reception of food; for
severe hunger would have been sufficient to impel us to eat,
eA'en though suffering folloAved.   And so in a thousand other
instances that  might be named.  On the other hand, no exam-
ple can  be  founl Avhere unnecessary pain  attends functional
operations.  The Author of such a system must  be benevolent.

   800. More Modes than One Provided  for the same Func-
tions.—A third evidence of benevolent design in the Author
of the animal  system is the provision often  made of more  than
one mode for the performance of important functions   In the
act of swallowing,  for instance, the danger is great that  par- 
426
HITCHCOCK'S  ANATOMY
tides of food may pass into the lungs.  Hence not only is the
epiglottis  provided to close upon the  glottis like a vah'e by
the very movement that carries down the food ; but the glottis
itself is endowed Avith such extreme sensibility that it instantly
closes upon the approach of a  foreign body.  The inosculation
of the blood-vessels has already been described, furnishing a
double means of circulation as a resort when one fails.  We
might also refer to the two cerebral hemispheres, two lobes to
the lungs,  two eyes, two hands, and two feet, so that the loss
of one does not obliterate the function.   All this certainly
looks like the benevolent provision of a  kind parent.
   801.  Surplus or Reserve  Power.—And  so,  in the  fourth
place, does the surplus power  given to the organs for exigen-
cies  above what is necessary exhibit benevolence.    In the
muscles there seems to be no limit to this excess of force,  save
in the ability of the fibers to endure the strain.   The digestive
organs are capable of mastering a much larger amount of food
than is necessary,  and the secretory organs at  times give out
a much larger than the normal  quantity  of their peculiar prod-
ucts.   If it were not so, life would be sacrificed in thousands
of instances where noAV the use of the  surplus power preserves
it.  If God is not benevolent  how happens it that this special
provision for exigencies should always promote the welfare of
animals ?
   802.  Vicarious PoAver.—In the fifth place, the vicarious
power given to some of  the organs teaches the same lesson.
When one or more of the senses is destroyed  or  defective, the
others can often,  in a  good  measure,  supply their  place  :
touch, for instance, the place of seeing  and hearing.  So,
also, it is said Avhen the glands appropriated to certain secre-
tions are injured or destroyed, others  Avhose normal secretion
is quite different, can elaborate the principles ordinarily given
out by the injured ones.
   803.  Adaptation of  Organs to Different Circumstances.
—The power of all the organs to adapt  themselves to different 
AND  PHYSIOLOGY.
42V
circumstances is a sixth example of benevolent intention in the
Author of nature.   The range of this power is limited ; and
yet Ave are often surprised to what Avidely different conditions
we can be accustomed, and yet be comfortable in them by new
habits.   In such a changing world  as this is, such  a poAver
seems almost  indispensable, and  yet only infinite skill could
attach it to  organs which are controlled by inflexible chem-
ical and vital laAvs.   Malevolence surely  never would have be-
stoAved it.

   804.  Recuperative Power.—The recuperative  power of
the animal system  furnishes  us  with a  seventh example  of
benevolent provision by the Creator.  However deeply acci-
dent or disease may have affected the system, if the vital pow-
ers be not destroyed, it is possible frequently to bring it back
a^ain to a state as sound and  vigorous as before.  The records
of pathology and surgery furnish  most  astonishing  cases of
such restorations.  And since  accident and disease are so com-
mon  that scarcely any adult can boast of immunity from
them, what a sad picture would society present of cripples and
invalids,  were this  recuperative power wanting.   It would be
 iust  such a picture as infinite malevolence Avould delight  in.
Its opposite therefore indicates benevolence.

»   805.  Prospective  Benevolence.—One other example only
will be fiven, and that may be called prospective benevolence.
Wasps and some other insects have an  instinct which leads
them to deposit along with their  eggs a supply of food for the
youno-  insects when they are hatched,  sufficient  to nourish
theintill they are old enough to take care of themselves.  In
other animals nature  provides a supply of milk to  be ready
just  at  the  time when  needed by  the  progeny.   The adult
man needs a firmer set  of teeth than the in ant, and so the
germs of these are placed beneath the earlier teeth,  and these
at the  proper time push their  way upward, and crowd the
first  set out of their sockets.   In such cases  the wants of
animals  were anticipated by their  Creator, just  as a be- 
428
HITCHCOCK'S   ANATOMY
nevolent parent provides beforehand for the future needs and
happiness of his children.

  806.—III.  ANATOMY  AND  PHYSIOLOGY  FURNISH  PRE-
SUMPTIVE EVIDENCE THAT THE  AVORLD IS  IN A  FALLEN
CONDITION.

  807. Benevolence blended  with Pain.—We haA-e  shown
that benevolence decidedly predominates in all the organiza-
tion and functions  of the animal system.   But it is not un-
mixed benevolence,  as Ave shall  noAV attempt to show.  There
are evils connected  Avith our physical condition, such as Ave
can not suppose Avould exist in a  paradisaical state,  and  the
inference is that these evils are  best accounted  for by the sup-
position that the Avorld is adapted  rather for a fallen  than for
a holy being.  Let  us look  at  some examples of evils which
we  can not suppose a Being  of Infinite  Benevolence and
Power Avould connect Avith a state of perfect holiness.

   808.  The Nerves much  more  Sensitive than is  neces-
sary  to Protect.—1. The nervous system produces  suffering
far beyond what is  necessary, to  put us on our guard against
accidents and injurious  agents.   To  aAvaken and  cultivate
such  prudence in  respect to these evils, seems  obviously  a
leading object of p?in and suffering: for the nerves are most
abundant  and sensitive  at the  surface of the body.    But in
many diseases the  suffering is intense.   Indeed, exasperated
and maddened nerves produce the *very  climax of  human
anguish.   But some other  object besides awakening a salu-
tary caution against evil must  be in view by such  suffering.
Now Ave knoAV, that as a matter of discipline  for a  depraved
and sinful being, it is eminently salutary.   It affords there-
fore a presumptive  proof that such is man's character.

   809. Impossibility of avoiding Accidents  and  Disease,
—2.  Man's exposure to accidents  and  diseases, which  no
human foresight can avoid, leads to the same conclusion. 
                   AND  TIIYSIOLOGY.              429

    810. That he is thus liable, we need not attempt to prove
  because all will acknowledge it.  But why should he be  so
  exposed under the government of a Being of Infinite Benevo-
  lence, if there were not something in his character which de-
  manded this severity of discipline ?  What can that be but an
  alienated, rebellious heart, which no milder means will subdue?
    811.  Evil  incidental  to  every  Function.—3.  Evil  is
  incidental to the functions of every organ in the body. Vision
  exposes us  to be witnesses of many most  unpleasant scenes
  and objects, hearing to sounds most grating, taste and smell
  to odors and solids  disgusting  and poisonous;  locomotion
  makes us liable to fatigue and bodily injuries, and disease es-
  pecially assails every organ.   We can not  conceive these in-
  cidental eAdls to be necessary in a world of perfect purity and
  happiness.    But they are wisely adapted to a fallen being, and
  therefore the presumption is that man is in such a fallen state.
   812.—Universality of Death.—4. The existence and  uni-
 versality of death lead to the same conclusion.
   813. It may indeed be made probable that in such a state
 of things as the present, death is a blessing even to  the inferior
 creatures.   But it would not be so in an unfallen paradisaical
 state.   It must be an immense drawback from  the happiness
 of such a state.  It is, however,  a fit and probably an inevit-
 able concomitant  and  consequence of sin.   Where it is uni-
 versal, therefore, the presumption is that it is a fallen  state.
   814. Condition  of  Man  not without  Bright  Prospects.
—5. But though anatomy and physiology present so many
proofs  of man's fallen condition, yet  the evidence already ad-
duced  that  benevolence vastly predominates,  affords  to  the
student of natural theology a strong presumption  that it is
not a hopeless condition.  For if there was no such thino-  as
recovery, why so many tokens  of  kindness ?   Why not give
up the offender at once into the hands of justice, and  let  the
work of retribution commence ?   How the recovery might be
effected revelation alone could show. 
430
HITCHCOCK'S   ANATOMY
  Objection.— It is said that these arguments would prove the inferior animals, even those
that lived long before man, to be in a fallen condition, since they both suffer and die.
  Answer.— The lower animals, not having a moral nature, cannot sin; but they may
suffer in consequence of their connection with sinful man. The world, from the beginning,
was adapted to him as a fallen being, and of course all other animals must be subject,
like him, to suffering and death. This sympathy of all nature with man's fallen condition
is clearly taught in Revelation.  (See Kom. viii., 18-23.)
815.--IV. ANATOMY  AND PHYSIOLOGY FURNISH PROOF OF
                    THE DIVINE UNITY.

   That  is, they show that only  one  Mind  could have been
concerned in the plan of animal organization.
   816.—1. The Conspiration of  all  the  Parts to Produce
the Same End.—This appears, in the first place,  from the
conspiration of all the tissues and organs to produce a single
result.   There  are as many as a million of parts in the hu-
man body, all of Avhich must go right to keep the system in a
healthy state.   It may worry us when some of them go wrong,
as in  case of disease;  but if many of them become deranged
death ensues.  An attentive observer of the race will see that
all these parts are originally arranged  so as to conspire in the
production of health and happiness.  There  could have been
no divided counsels in such  a work.
   817.—2. Relations  of  Different  Individuals  in  the
Animal  Kingdom .—The relations of all the branches and even
individuals of the whole animal  kingdom to one  another af-
ford a still more striking evidence of divine unity.  For  here
the objects to be compared are multiplied a thousand fold, and
the extremes  in  organization, in habits, and modes of living
are immeasurably wide.   Yet there  is  such a relation among
them all as to show them all belonging to one system, bound
together in the closest harmony.   All must, therefore, have
been  the work of one  Infinite Mind.  Or if more  than one
was concerned, each must have had the same plan ;  and the
idea is absurd  that  there can exist more  than one  infinite
mind. 
AND  PHYSIOLOGY.
431
 018.   V.  ANATOMY  AND  PHYSIOLOGY DISPROVE THE  ATHE-
     ISTIC  HYPOTHESIS THAT  THE DEVELOPMENT OF ANIMAL
     ORGANS IS THE  RESULT  OF MERE LAAV.

   819.  The Development Hypothesis.—This hypothesis sup-
 poses that the organs were not contrived and constructed by
 an intelligent mind for the uses to which they are applied, but
 that the wants of the living mass of almost amorphous matter
 led  to such efforts as ultimately to form an organ.  Thus the
 desire for  food in a mass of vitalized  jelly caused  it to pro-
 trude certain points which  ultimately  became hands, and the
 desire of locomotion  formed the feet and legs.   To form the
 organs  in this manner it would be necessary that the use  of
 parts of the living unorganized mass or body should have a
 natural tendency to produce them.  If then we can show that
 in some cases this tendency Avould be exactly the opposite, the
 hypothesis must fall.   We  need give  only a A?av examples to
 show that  such is  the case.  Take the  looped muscles, such as
 those in the back  of the eye.   Any effort of matter behind the
 eye  to move the ball must draw in a direct line, not in  the
 round about course of a loop attached  to the orbit.  Take the
 case of the annular ligaments  at  the wrist and  ankle.   The
 conatus of the muscles to  move the  fingers  and toes would
 tend to  destroy but not to form such a  ligament.   They are as
 obviously intended as any thing can be to counteract the con-
 atus of the tendons to fly off when the  muscles contract.
  820.  Such  facts so manifestly shoAV the  absurdity of the
hypothesis  under  consideration, that  examples  need not be
multiplied.  It is true of nine tenths of the  organs, that an
effort of vitality to perform their functions before their exist-
ence would have a tendency the opposite of their formation.
                           19 
432
HITCHCOCK'S  ANATOMY
 821.—VI. ANATOMY  AND PHYSIOLOGY SHOAV  THE  UNREA-
  SONABLENESS OF OBJECTING  TO MYSTEltY  IN RELIGION.

   822. Any objection against religion that Avill lie Avith equal
 force  against the constitution and course of nature is futile.
 For none but the atheist will deny that nature is the Avork of
 God,  and it  is  not reasonable  to object to  that in  religion
 Avhich Ave alloAV to  exist in nature.  But the cases of mystery
 in anatomy and physiology are more striking  than in religion.
 A few examples Avill  suffice.
   823.—1. Muscular movement.  We can see  that muscles
 contract, but the poAver that does  it is concealed.   We find
 that this power comes from the brain through  the nerves;  but
 this does not show  us Iioav the work is done.   We  find that
 electricity is concerned ;  but  Avhy should electricity contract a
 muscle more  than a Avire ?   This carries us to the end of  our
 knowledge, and still Ave know nothing; of the  nature of that
 force  by Avhich the  will is able to move a muscle.  The whole
 range of science gives not the  slightest clue to the mystery.
 It is,  in fact, as profound as  any in natural or revealed relig-
 ion, and until Ave can solve this Ave have  no right to object to
 any religious doctrine on the ground of mystery.
   824.—2. The entire connection  between mind and matter
 teaches the same lesson.   When Ave have stated the  facts as
 to their mutual influence, Ave haA'e nearly reached the limit
 of our knoAvledge  of the  subject.   There is  no physical  Liav
 or mental law either that can explain their action and reac-
 tion.   All attempts to do this amount to little more than the
 vaguest hypothesis.   Any thinking man who studies the phe-
 nomena will  be impressed by the mystery that hangs over
 them, and if  he be a true  philosopher will be  slow to reject
any doctrine of religion  because it has depths in it Avhich he
can not fathom. 
INDEX    AND   GLOSSARY.
The numbers refer to the page.
                   A.
Aboma'sum, 186,1ST.
Abdom'inal muscles, 125.
Abdom'inal aorta, 211.
Abdu'cent nerves, 329.
Acale'phi, one ot  the groups of. radiate
  animals.
Access'ory heart, 233.
Aera'tim, purifying by air.
Afferent, carrying to.
After tastes, 409.
Air, amount used in breathing, 2o3.
 "     "     of in  lungs, 256.
Albu'men, a proximate principle, 12.
Albu'minose, 12.
Algai, sea weeds.
Ambulatory, pertaining to a walk.
Amor'phowx, without shape.
Amphiarthro'sis, 66.
Anastomo'sis, 202.
Anat'oiny, definition of, 5.
    "     Comparative, definition of, 6.
An'cht/losed, grown together.
AnfrdctuoH''ities,  depressions on the brain.
An^'ioKogy, 201.
Angular motion, 68.
Animal heat, theory of, 258.
    "    kingdom, classification of, 84, 85.
Animal'cules,  minute animals.
An'nular, like a ring.
            ligaments, 132.
Antisep'tic, preventive of decay.
Aor'ta, 206.
    "    in animals, 231.
A'per,, point or summit.
Aponeuro'sis,  110.
Appendages of cells, 18.
A'queous humor, 374.
Aquiferous, water bearing.
Arach'noid membrane, 324
Ar'senic in the body, 7.
Arterialization—see Aeration.
 Arteries, 204.                ..    ___   ..„
    "    and  veins, comparative  capacity
   of, 223.
 Arthro'din, 67.
 Articula'ta, 85.
      »     skeleton of, 103.
 Artic'ulate, to make ajoint.
 Articulations, joints.
        "       varieties of, bo.
        «       anatomy of, 67.
Assimila'tion, conversion of matter  into
  the substance of the body.
Atmospheric pressure in joints, 71.
Audi'tion, hearing.
Au'ditory nerves, 329.
Au'ricles, 201.
Automat'ic, acting apparently without the
  will.
Ax'illary artery, 206.
Azot'ic, containing nitrogen.
Az'olised, containing nitrogen.

                   B.
Back Board, 144.
Basement membrane, 17, 29S.
Beaded, like a string of beads.
Belief, effect of on sensation, 30S.
Belly of muscles, 1C9.
Benevolence,  Divine, shown by  anatomy,
              424.
      "      prospective shown in organs,
              427.
      "      blended with pain, 428.
Biceps muscle, 119.
Bicus'pid teeth, 54.
Bile, 16,175.
Bill of birds, 96.189.
Birds, rate of flight, 154.
Blaste'ma, 20.
Blood, 15, 220.
   "   of articulates, 241.
   "   vessels, their use, 222.
   "      "     "  large amount, 223.
 Body, its size, 10.
 Bones, chemical composition of, Cl.
    "   mechanical structure of, 32.
    "   classes of, 35.
    "   strength of, 32.
    "  microscopic structure of, 33.
    "   intermaxillary, 89.
    "   jugal, 93.
    "   cor'acoid in birds, 90.
    "   sternal  "   '"   96.
    "   tarso-metatarsal, in birds, 97.
    "   sesamoid,        "   "    97.
    "   development of, 36.
    "   number of, 37.
    "   uses of,  74.
    "   distorted, reason of, 81.
    "   effect of wrong position on, 82.
    "   hollow in  birds, 98.
 Brachial artery, 206.
 Bra'chial plexus,  334 
434
INDEX AND
GLOSSARY.
 Brain, 318, 342.
   "   of mammals, 357.
 Breathing, object of, 253.
 Bronchi, 250.
   "     of mammals, 270.
 Bronchi'tis, inflammation of the Bronchi.
 Brunner's glands, 163.


                    C.
 Cmcal cells, closed or shut sacs.
 Csecum, 161.
 Calca'reom, hard like limestone.
 Cal'cified, made hard like limestone.
 Cal'cium in the body, 7.
 Calisthen'ics, 141.
 Callosities, 311.
 Calcutta, blackhole of, 266.
 Calorific, heat producing.
 Canalic'uli of bones, 33.
 Ca'nine teeth, 54.
 Cap'illaries, 214
 Car'apace, 99.
 Carbon in the body, 6,
   "    its  amount  given  off  from  the
  lungs, 255.
 Carbon'ie acid in the body, 10.
 Carniv'orous, flesh eating.
 Carot'id artery,  206.
 Carpus, 59, 78, 91.
 Cartilage, invertebral, 42.
 Cartildg'inous, made of cartilage.
 Ca'sein, 12.
 Caudal heart, 238.
 Cells, 18.
  "   vital force of, 21.
  "   chemical changes of, 21.
  •'   vitalization of, 21.
  "   change of form, 21.
  "   periods in the life of, 21.
 Cellular, having cells.
 Cemen'tum, 51.
 Centrip'etal and centrifugal, 349.
 Ceph'alopod, a molluscous animal.
 Cerebellum, 319, 347.
 Cer'ebral ganglia, 321, 348.
    "    hemispheres,  use of, 341
    "    nerves, 358.
 Cer'ebro-spinal center, 322.
 Cer'ebrum, 313.
     "     of mammals, 357.
 Cer'vical plexus, 334.
 Chem'ical elements of the body,  6.
 Chem'istry aud vitality combined show de-
  sign, 422.
 Chi'tine, 84, 314.
 Chit'inous, containing chitine.
 Chlorine in the body, 7.
 Cho'roid coat, 371.
 Chyla'queous fluid, 241.
 Chyle, 15, 180.
 Choles'terine, 11.
 Chyme, 175.
 Cil'icr, minute hairs.
 Cil'iary processes, 371.
 Circle of Willis, 210.
Circulation in molluscs, 242.
     "     in radiates, 243.
Circumduction, 68.
Clav'icle, 57, 78, 96.
 Cloa'ca, a sac appended to the intestines.
 Coag'ulable, capable of hardening.
 Coats of the eye, their use, 378.
 Coch'lea,  391.
 Coc'cyx, 41.
 Coeliac axis, 212.
 Colds and Coughs, 263.
 Colon, 162.
 Color blindness, 3S3.
 Compound eyes, 3S6.
 Cona'tus, attempt.
 Con'diments, their use and abnse, 184.
 Con'dyle, elevation or eminence on a bone.
 Convoluted, rolled  together like a tube.
 Coordination, working or designing to-
  gether.
 Copper in the body, 7.
 Cor'acoid  bone, 96.
 Coria'ceous, like leather.
 Co'rium, 29S,306.
 Cor'nea, 370.
 Cor'neous,  like horn.
 Cor'pora striata, 322.
 Cor'puHcles, little bodies or cells.
      "      of blood, 220, 228, 254
 Corpulence, its effect on capacity of lunga
  254.
 Corpus callosum, 319.
 Cra'nium, skull.
 Cra'nial nerves, 325-331.
 Cre'ation, 9.
 Cric'oid cartilage, 260.
 Crusta1'ceans,  animals like the crab and
  lobster.
 Ctenoi'dians, 314.
 Cubical size of the body, 10.
 Cune/iform  cartilage, 260.
 Cuta'neous, relating to the skin.
 Cu'ticle, 296.
 Cycloi'dians, 314.
 Cytogen'esis, cell production.


                   D.
Daily water bath, 310.
Daltonism, 3S3.
Death universal, 429.
 Decussation, crossing like an X,
Degluti'tion, 172.
Deity, argument for, from anatomy, 420.
Den'tine, 51.
Denti'tion,  appearance of teeth.
Den'izen,  an inhabitant.
Dermatol'ogy, science of the skin.
Dermis, skin.
Development hypothesis, argument against,

Development hypothesis, disproved by an-
  nular ligaments, 431.
Diarthro'sis, 67.
Di'aphragm, 124,150.
Dias'tole',  226.
Diet best adapted for man, 177.
Digas'tric muscle, 116.
Diges'tion, its theory, 174,175.
Dip'loo of cranium, 76.
Disassimila'tion, process of waste.
Disease not  to be avoided, 428.
   "    of circulatory organs, 228.
Dorsal vessel, 239.
Duode'nal glands, 163.
Dnode'nnm, 160.
Duplicative folding or doubling.
Dura mater, 323. 
INDEX   AND  GLOSSARY.                  435
                   E
Ear, 389.
  "  a proof of design, 420.
  "  functions of all its parts, 394, 397.
  "  of animals, 297, 399.
Eating, hygienic inferences from, 183, 1S4,
Eehin'oderms, radiate animals.
  ff'fereht, carrying away from,
  lectrical organs of fishes, 360.
Elemen'tary tissue, 14.
Emacia'tion, wasting away.
Enam'el, 51.
Enarthro'sis, 67.
En'dosmose, 17.
Epider'mis, 296.
     "     use of, 305, 306.
Epider'mic scales, 311.
Epiglottis, 261.
Epithe'lial, relating to the epithelium.
Epithe'linm, outer surface of mucous and
   other  membrane.
Esoph'agus, 157.
      "      of horse, 186.
Eustachian tube, 891.
Evil incidental hot intentional, 425.
   "     "      to every function, 429.
 Excrementi'tious, waste  or superfluous.
 Ex'osmose, 17.
 Extremities,  anterior, of quadrupeds, 92.
 Exuda'tions, 15.
 Exuvia'tion, casting off.
       "      of serpents,  313.
 Eye, anatomy of, 369.
   "  a proof of design, 420.
 Eyebrows, 876. 380.
 Eyelids, 376, 380.
 Eyes of mammals, 383.
   "  "  birds, 384.
   "  "  reptiles, 3S5.
   "  " fishes, 386.
   "  "  insects, 386.
   "  "  mollusca, 383.
   "  "  radiata,  383.
Fac'el, a little surface or face.
Face, 47.
Fa'cial nerves, 329, 351.
Fats in the body, 11.
Feathers, 312.
Fcl'on, 35.
Fem'oral  artery. 212.
Fe'mur, 63, 79, 97,100.
Fever sore, 35.
Fiber, simple, 17.
  "   muscular, 107.
Fi'bril,     "    107.
   "  in  contraction, ldT.
Fibrin,  12.
Fib'ula, 63.
Flu'orine In the body, 7.
Fol'licles, 289.
    "    of Lieberkuhn, 163.
Food, for what purposes required, 17t>.
Foram'ina of bones, 35.
Forces of blood circulation, 223, 226.
Fore arm, 58, 78.
Fright, effect of on hair, 310.

Fu°nnctioiSnthe4mode for their performance,
  425.
Fu'siform, spindle shaped.
                   G.

Gail-Bladder, 165.
Gany'lia, small knots or masses of nervous
  matter.
Ganglia, uses of, 350.
Ganoid'ians, 314.
Gastric juice, 15, 173.
   "   follicles. 159.
   "   artery, 212.
Ge'nus, a group of species.
Gills of Fishes, 274.
Gin'glymus joint, 67.
Giz'zard,'second stomach of fowls.
Glands, their anatomy, 2S9.
   "   ductless, 292.
   "   of the skin in mammals, 312.
Gliding motion, 68.
 Glob'ule, spherical particle of matter.
 Glob'ulin, 12.
 Glosso-pharyngeal nerves, 330, 351.
 Glu'ten, 12.
 Gluteus muscle, 128.
 Gompho'sis, 66.
 Granules of cells, 18.
    "     " bone, 34.
 Gymna'sia, their use, 141,144


                    H.

 Habit, effect of on sensations, 368, 402.
 Hair, number and distribution of, 803.
   "   chemical composition of, 803.
   "   constitution,  color, and properties ot,
       304
   "   rate of its growth,  305.
       variety of, in mammals, 811.
 Hamster, a rodent  animal.
 Happiness the object of all organs, 424.
 Harde'rian gland, 283.
 Harmo'nia, 66.
 Haver'sian canals, 33.
 Head of birds, 93.
 Heart of man, 201.
   "  "  mammals, 230.
   "  "  birds, 232.
   "  "  reptiles, 234
   "  "  crocodile, 236.
   "  "  fishes, 237.
   "  "  articulates, 239.
   "  "  Crustacea, 241.
 Heat producing organs, 256.
 Hem'atin, 13.
 Hepat'ic, pertaining to the liver.
      "    artery, 212.
 Herbiv'orous, vegetable eaters.
  Ilexag'onal, with six sides.
  Hippu'ric acid, 9.
  Hiss of serpents, 272.
  Histogenet/ic, tissue making.
  Histol'ogy, 14.
  llmnoge'neous,   ot  the  same character
   throughout.
  Honey comb, 187.
  Horn of rhinoceros, 311.
  Hu'merus, 57, 91, 97,100.
  Humors of the eye, 374, 378.
  Hy'drogen in the body, 6.
  Hygrol'ogy, 14
  Hyoid bone, 55. 
436
IKDEX  AND  GLOSSARY.
Ichorol'ogy, definition of, 292
Il'iac arteries, 212.
 Il'iuin, 61.
 Imbibition, 17.
 Im'bricaled, overlapping like  shingles on
   a roof.
 Imme'diate principles, 7.
 Impurities exhaled from lungs, 255.
 Inci'sor teeth, 54.
 Indian club, 145.
 Infuso'ria, microscopic animals.
 Inglu'vles, 188.
 Innominatum, 61.
 Inoscula'lion—see anastomosis.
 Inspirations compared with pulsations, 255
 Inteiartic'ular cartilage, 71.
 Intercostal muscles,  125.
 Intermaxillary bones, 89.
 Interosseous, between the bones.
 Intestinal fluid, 16.
     "     glands, 163.
 Intestine, length of, 155, 1S9, 192.
 Inver'tebrate, without internal skeleton.
 Iris, 371.
Iron in  the body, 7.
Irritability of muscular fiber. 134
Is'chium, 61.
Jeju'num, 161.
Joints, design shown in them, 421.
   "    motions of, 68.
Jugal bone, 93.
Kidneys, 171.
K.
L.
 Lab'yrinth, 391.
 Lach'rymal gland, 375,
     "      bones, 49.
 Lacteals, 169, 180, 282.
 Lacu'na;, spaces.
     "    of bone, 33.
 Lacv/nar, filled with lacuna*.
 Lamell'ce, thin layers or plates.
 Laryngeal, relating to the Larynx.
     "      pouches, 279.
 Lar'ynx, 248,  259.
    "    of birds, 279.
    "    " reptiles, 2S0.
    "    its  similarity  to  a reed instru-
  ment, 264.
 Lead in tho body, 7.
 Lens of the  eye, 374.
 Life, characteristic of organic substances. 5,
 Lig'anients, 69.
     £      annular, show  design, 423.
            used as braces, 74
 Lime, carbonate and phosphate of, 11
 liin'gual nerves, 331. 351.
 Liver, 165.
      of mammals, 189.
  "   " fishes, 193.
Lob'ules of lung, 247.
Lower jaw, 50, 89.
Lumbar arteries, 212.
 Lumbar plexus, 334.
 Lunglet, lobule of lung.
 Lungs, their liability to disease, 265.
         "   action essential for health, 266,
    "   pure air essential to, 266.
    "   capacity of, as affected by posture.
          267.
    "   capacity of may be increased, 267.
    "   of mammals, 270.
    "   " birds, 270.
    "   " reptiles, 272.
Lymph, 15.
Lymphatics, 182, 284.
      "      their function, 2S7.
      "      material absorbed by, 287.
Lymphatic hearts, 236.
     "      glands,  285.


                   M.
  Magne'sium in the body, 7.
  Malar bones, 48.
  Malle'olus, 64
  Man not without hope, 429.
  Manganese' in the body, 7.
  Man'dible, 50, 89.
  Mantle of Molluscs, 314
  Many-plies, 187.
  Marmot, a rodent or gnawing animal.
  Mass'eter muscle, 116.
  Mastication, 172.
  Me.'dia, or humors.
  Medull'a oblongata, 322, 347.
  Medu'sm, radiate animals.
  Meibo'mian glands, 377.
  Membra'na tym'pani, 390.
  Membrane, simple, 17.
  Mesenteric artery, 212.
     "      glands, 109.
 Mes'entery, 168.
 Metamor'pilosis, change,
 Metacar'pus,  60, 79, 91.
 Metatar'sus, 65.
     "      of birds, 97.
 Milk, 16.
 Mimo'sa, plant of the order leguminosa?.
 Moisture, its effect upou lymphatics, 289.
 Molar teeth, 54
 Mollusca, So.
          skeleton of, 104
 Motor, exciting motion.
    "   nerves, 336.
    "   oeuli, 326, 851.
 Mouth, 155.
 Movements of radiata, 153.
 Mu'cus, 15.
 Muscles, number of in man, 111.
     "    suspensory, 152.
     "    of birds, feathers, 152.
     "    design shown  in them, 4?1.
     "    looped, show design, 422.
     "    need use,  139.
     "      "  gradual rest, 140.
         require regular exercise, 140.
         time they may be employed, 154
    "    forms of, 110.
    "    of the fore arm, 120.
    "      "   birds,  151.
    "      "   fishes, 152.
           "   articulates  and  molluscs,

Muscular development,  141. 
INDEX  AND  GLOSSARY.                  437
Muscular strength, examples of, 137,154
    "     contraction, cause of. 135.
    "     movement, disadvantage of it, 136.
    "     contraction, its rapidity, 138.
    "          "      "  duration, 138.
    "          "      "  precision, 139.
Mus'culin, 12.
Myol'ogy, definition of, 107.
Myotility, 26, 134.
Mystery as great in physiology as in relig-
  ion, 432.
Mystery in muscular movement, 432.
    "     in connection of mind and matter,
          432.

                    N.
Nails, 277.
Nasal bones, 48.
  "  duct, 375.
Nasmyth's membrane, 53.
Neck, its length dependent on, 87.
  "   how to" bed ressed, 269.
 Nerve tubes and fibers, 317.
    "   vesicles or cells, 318.
 Nerves over sensitive, 428.
 Nervous power shows design, 423.
     "    system, its hygiene, 352.
 Neurol'ogy, definition of, 316.
 Nictitating membrane, 3SC.
 Nitrogen, 6.
 Mtrog'enou*, containing nitrogen.
 Normal, according to the standard.
 Nose, 412.
 Nostrils, 413.
     "    their use in the voice, 265.
 Nu'clear, pertaining to a nucleus.
 Uu'cleated, 18.
 Nucle'olus, 13.
 Nu'cleus, 13.
Oil, 16.
 "  glands, 299.
 "    "    use of, 307
Olein, 11.
Olfactory nerves, 325
Oma'sum, 1ST.
>, 350.
Optic nerves, 320, 3ul.
Orbicularis pal'pebrie, 114
      «     oris, 115.
Organ, definition of, 29.
Organs adapted to circumstances, 4_(>.
O^ithZryh'chus, an  animal of tho  class
  mammalia.
Os'cilliitory, vibrating.
Oss'icles, little bones.
0> quadratum,  397.
Ostein, 12.     ... o.
Osteol'ogy, definition of. 81.
Ot'oliths, bony particles of the ear.
Ovalbn'men, 12.
Ox'ygen in the  body, 6.

                    P.

Pacinian coipuscles, 336-
Pal'ate bones, 49.
Palmar arch, 209.
Pan'creas, 166.
Pancreatic fluid, 16.
Papil'lse, 295, 400, 4u8.
Par'asite of skin, 290.
Pari'etal bone, 44.
Patell'a, 63.
Paunch, 1S7.
Peeten  marsu'pium, 884.
Pedun'cle, a stalk or stem.
Pedunculated, having a stalk or peduncle.
Pelvis, bones of, 61.
Ven'niform, feather-shaped.
Pep'sin, 15,  160.
Pericar'dium,  204
Perilymph, 391.
Periosteum, 34.
Peristal'tic, moving like a worm.
Peritone'um, 16S.
Perspiration,  301.
Peyer's patches, 163.
Phalanges, 60, 65, 79, 91, 97.
Pharyn'geid, belonging to the pharynx.
Pha'rynx, 156.
Phos'phorus in the body, 7.
Physiology, definition of, 6.
Pia ma'ter,  324
Pig'ment cells, 296.
Pigmentary spots., 385.
Pigmentum ni'grum, 372.
Pinna. 339.
Pitu'itary  membrane, the  lining mem-
   brane of the nose.
Plaeoid'ians, 314.
 Plan, unity of, in animal system, 424.
 Plasma,  watery portion of the blood.
 Plastron, 99.
 Pleasure superadded to functions when not
   necessary, 425.
 Pleura, 243.
 Pleurisy, 24S.
 Plexus, 332.
 Pneumogastric nerves, 330, 351.
 Pneumonol'ogy, definition of, 244.
 Poison introduced by lymphatics, 2S8.
 Polyhe'drul, with  many ends.
 Poli/ps, radiate animals.
 Poplit'eal artery, 213.
  Pores of bones, 34.
  Portal system,  21S, 236.
  Potassium in the body, 7.
  Power reserved for exigencies, 420.
    "   vicarious in organ*, 426.
    "   recuperative in the system, 427.
  Prehen'sile, adapted for seizing.
  Prehen'sion, the act of grasping.
  Primary tissue, 14, 22.
  Principles, immediate, grouped, 8, 9.
  Prismoid, like a prism.
  Pris'tine, primary.
  Process, an  elevation on a bone.
  Processes of bones, 35.
  Protein, 13.
  Psoas muscle,  126.
  Pty'alin, 172.
  Pu'bis, 61.
  Pulsations of heart, 227.
  Pyloric appendages, 194
  P'ylo'rus, tue lower orifice of the stomach.

                      ft.
   Quad ran'gular, with 4 angles.
   Qaadrilat'eral,    "  " sides.
R.
Eu'dial artery, 203.
Uadiata, S5. 
438                INDEX  AND   GLOSSARY
Radiata, skeleton of, 106.
Radicals, organic, 8.
Ra'dius, 59.
Ram'ify, to give off branches.
Rectum, 162.
Red or Rennet, 183.
Reflex actions in articulates, 363.
Religious applications of anatomy, 420.
Respiration, process of, 252.
Respi'ratorv organs  of mammals, 270.
      "        "    "  birds, 270.
      "        "    "  reptiles, 272.
      "        "    "  fishes, 275.
      "        "'    "  articulates, 276.
      "        "    "  molluscs, 278.
      "        "    "  radiates, 279.
Retic'ulum, 1S6.
Ret'ina, 372.
Retractile, capable of being drawn back.
Ribs, 55, 96.
Rickets, cause of, 82.
Ro'dent, gnawing.
Rotation, 68.
Ru'minants, animals that chew the cud
  like the cow.
                   S.
Sac'ciform, like a sac.
Sa'cral plexus, 334.
Sa'crum, 41.
Sali'va, 16, 172.
Salivary glands, 155.
Salt in the human body, 11.
Sapona'ceous, soapy.
Sarcolem'ma, 103.
Scales of serpents, 313.
       " fishes, 314.
Scap'ula, 57.
Scepter, Indian, 145.
Schindyle'sis, 66.
Science, its highest nse, 420.
Seba'ceous glands, 299.
Sclerotica, 369.
Scle'rous, hard like bone.
Secretion, vicarious. 292.
    "     after death, 291.
    "     function of,  291.
    "      effect of emotions upon, 291.
Seg'ments, divisions.
Semicir'cular canals, 391.
Sensations, effect of habit upon, 86S, 402.
Senses often a source of misery, 418.
   "   dependent on mind, 367.
   "   effect of excessive use of, 367.
   "   development in lower animals, 367.
Sensual happiness not perfect, 419.
Seralbu'men, 12.
Serra'ti muscles, 125.
Se'rum, 15.
Ses'amoid bones, 65, 97.
Sighted, long and short, 3S1.
Silicon in the body, 7.
Si'nuses, 217.
Skeleton, design showed in, 421.
     "     human,  weight of, 32.
Skin, 295.
   "   uses of, 305.
   "   its hygienic value, 30S.
   "   attention necessary for, 3C9, 810.
   "   of mammals, 310.
   "   " birds, 312.
Skin of amphibia, 813.
  "   " ra'diates, 315.
Sleep, 342, 347.
Smell under control of the will, 414.
  "   sense of, in animals, 414, 416.
So'dium in the body,  7.
Solar plexus, 840.
Solitary glands, 163.
Sound, organs essential for, 264.
Sounds of heart, 227.
   "    " insects, 280.
   "   " mollusca, 281.
Special sense, nerves of, 363.
Sphe'noid bone, 45.
Sphincter, 111.
Spinal cord,  322, 332, 343.
      column, 42, 78, 85.
  "   nerves, 332,352, 353.
  "   accessory nerve, 330, 351.
Spi'racles of insects, 276.
Splanchnology, 155.
Spleen, 293.
Sple'nic artery, 212.
Stell'ate, star-shaped.
Stem'mata,  387.
Sternum, 55, 96, 101.
Sterno-cleido mastoid muscle, 116.
Stim'ulants,  their value and injury, 135.
Stomach, 158.
    "     of ruminants, 187.
    "     "  birds, 190.
Styloid bones, 89.
Subcla'vian artery, 206.
Sugar in the body, 11.
Sulphur "    "    7.
Superior Maxillary, 50.
Suppura'tion, forming of pus.
Suspen'sory muscle,  152.
Sutu'ra, 66.
Sutures, 46.
Sweat, 17.
   "   glands, 299.
Sympathetic system, 337,348, 353.
       "       ganglia, 339.
Sympathy between heart and lungs, 245.
Sym'physes, 67.
Synarthrosis, 66.
Synchronous, at the same time.
Syndesmol'ogy,  definition of, 66.
Syno'vial membrane, 73.
Systems of organization mutually depend-
   ent, 424
Systole, 226.

                    T.

 Tac'tile, susceptible of touch.
 Tailor's muscle, 129.
 Tapetum, CSC.
 Tarso-metatar'sus, 97.
 Tarsus, 64, 81.
 Taste, nerves of, 407.
    "   effect of education upon, 403.
    "   its connection with smell, 409.
    "   a guide  for the appetite, 418.
 Tears, 16, 380.
 Teeth, human,  51.
    "   esophage'al,  192.
    "   of reptiles, 191.
    "   of fi-dies, 102.
    "   development of, 53.
    "   names of, 54, 90.
     "    fracture of, 54. 
INDEX  AND  GLOSSARY.                 439
  Teeth, care needed for, 82.
     "   generally decay early in life, 83.
  Teg'ument of articulata, 314.
  Tegument'ary, relating to the skin.
  Tjgument'ary muscle, 150.
  lemperature of human body, 257.
  Tem'poral bone, 43.
       "     muscle, 116.
  Tendons of fingers and toes, 120.
      "    ossification of, in birds, 151.
  Tensor vag'inre fem'oris, 129.
  Tentorium, 358.
  Thal'ami optici, 322.
   Thoracic,  pertaining to the chest.
  Thoracic duct, 170.
      "     aorta, 211.
  Thy'roid cartilage, 260.
  Tibia, 63.
  Tibial artery, 213.
  Time  during which  kmuscles can  be u
     154
   Tissue, simple fibrous, 22.
      "     white fibrous, 22.
      "     yellow   "   22.
      "     areolar, 23.
      "    fihro-cellular, 23.
      "    cellular, 24.
      "    sclerous, 24.
      "    tubular, 25.
      "    muscular, 26.
      "    nervous, 28.
   Tobacco, its effect on the brain, 355.
   Tongue, human, 406.
       "    of reptiles, 191.
       "    use of, in speech, 265.
   Tonicity, muscular, 134.
   Tonsils, 155.
   Tortoise shell, 99.
   Touch, instruments of, 400.
      "    of lower animals, 403, 405.
   Tra'chea, 243.
       "   of mammals, 270.
       "    "  insects, 276.
   Transverse, crosswise.
   Transudations, 15.
   Triangle for exercise, 145.
.  Triceps muscle, 119.
   Trifa'cial nerves, 326, 351.
   Trill  of birds, 279.
   Triquet'ra ossa, 47.
   Trochanter process upon the upper
     of the femur.
   Trochlear nerves, 326.
   Tuberc'ula quadrigem'ina, 322.
   Tur'binal bone, 49.
 . Tym'panic bones, 88.
   Tym'panum, 390.
                   TJ.

Ulceration, ulcer-forming.
Ulna, 5S.
Ulnar artery, 203.
Unicellular animals, 199.
Uniformity of animal heat, 258.
Unity, Divine, proofs of from anatomy, 430.
  "     "     proved by the conspiration
  of all the parts, 430.
Unity proved by mutual relation, 430.
Urine, 16.
                   V.

Valves of the heart, 203.
Veins, 217.
  "    valves of, their discoverer, 219.
A'entral trunk, 241.
A'entricles, 202.
     "     of brain, 324.
A'entu'ri, principle of, 181.
A'ertebra,  cervical, 40, K5, 93.
           dorsal, 41, 85, 93.
     "     lumbar, 41, so.
     "     sacral,  85.
     "     caudal, 85, 93.
Arer'tebral  artery,  209.
A'ertebrata,  85.
Aressels protected, 423.
Vestibule, 391.
 Vibra'tile, susceptible of vibration.
 17///, hair-like appendages.
 Viscera, contents of an animal cavity.
 Viscid,  thick like syrup.
Aision, limits of, 3S2.
 Vitaliza'tion, the act of giving life.
A'itreous humor, 375.
A'ocal cord, 202.
A'oice, organs of, 259.
   "  its strength dependent on, 269.
Voluntary motions,  on  what  dependent;
  340.
A'o'mer, 51.

                   w.
Waste the cause   of muscular contraction,
  135.
Water in the body, 10.
   "   amount consumed  by an  adult, 11.
   »      «    discharged by the skin, 302.
Wax, 16.
AVonder nets, 231, 234.
AVounds of arteries, 229.
World fallen, proof of, from anatomy, 4J8. 
INDEX    OF    CUTS.
FIG,
  1
  2
  3
  4
  5
  6
  7
                           PAGE
Blood Crystals................   9
         "    ................  10
   "      "    ................  13
Milk...........................  16
Simple Fiber...................  17
Cells..........................  IS
  "  ...........................  18
Caudate Cells.................  19
Stellate   "  .................  19
Development op Cells........  20
     "       "   "   ........  20
                 "   ........  21
White Fibrous Tissue.........  22
A'ellow   "     "    ........  22
Areolar  Tissue.................  23
Cells of  Areolar Tissue.......  23
Adipose Tissue.................  24
Cartilaginous Tissue..........  24
Osseous         "   ..........  25
Lacun.e op Bone..............  25
Lymphatic Vessf.l.............  26
Muscular Tissue..............  26
Diagram  of Muscular Fibril..  26
Muscular Tissue...............  27
            "  ...............  27
    "       "  ...............  27
Tubular  Nerve Tissue........  2S
Vesicular  "     "   ........  2S
    "      "     "   ........  29
Fibula after Immersion in Mu-
  riatic Acid..................  32
Canaliculi of Bone...........  33
Lacuna    "   "   ..........  34
Ultimate Granules of  Bone..  34
Periosteum.....................  35
Development of Cartilage ...  37
Knee Joint....................  33
Lateral View of Spinal Col. .  38
View of Human Skeleton.....  39
Atlas..........................  40
Axis............................  40
A Dorsal Vertebra...........  41
Sacrum........................  41
fig.                           page
 43 Coccyx.........................  41
 44 A Dissected Skull.............  43
 45 Frontal Bone.................  43
 46 Temporal  "  ..................  44
 47 Parietal   "  .................  44
 48 Occipital  "  .................  45
 49 Sphenoid   "  .................  45
 50 Ethmoid  "  .................  46
 51 Vault of the Cranium........  46
 52 Front View op  the  Skull--  47
 53 Nasal Bones..................  43
 54 Malar Bone...................  48
 55 Lachrymal Bone...............  49
 56 Palate      "  ...............  49
 57 Turbinal   "  ...............  49
 58 Maxillary   "  ...............  50
 59 Mandible......................  50
 60 Vomer..........................  51
 61 Section of Human Incisor--  52
 62   "    "    "    Bicuspid....  52
 63   "    "    "    Incisor ....  52
 64   "    "    "    Molar.....  52
 65 Enamel of Tooth..............  53
 66 Permanent Teeth.............  54
 67 Hyoid Bone....................  55
 6S Sternum........................  55
 69 Upper Rib......................  55
 70 Ribs............................  56
 71 Bones of the Chest...........  56
 72 Clavicle.......................  57
 73 Scapula........................  53
 74 Humerus.......................  58
 75 Fore-Arm.......................  59
 76 Carpal Bones..................  00
 77 Bones of the Hand............  60
 78 Pelvis.........................  61
 79 Innominatum...................  62
 80 Femur.........................  62
 81 Patella........................  63
 S3 Tibia and  Fibula.............  64
 83 Bones op the Foot............  64
 84 Development of Cartilage....  69
 85 Ligaments of the Pelvis......  To 
I NDEX  OF   CUTS.
441
FIG.                            PAGE
 86 Ligaments of the Shoulder. ...  70
 87     "     "   '•  Hip.........  71
 83     "     "   "  Knee........  71
 gg     ';     "   "  Lower Jaw.  72
 90     "     "   "  A'krtebr/E
      and Ribs.....................  72
 91 Ligaments op the Elbow......  72
 92     "     "   '"  Ankle...... 73
 93     "     '•   "  Foot....... 73
 94     "     "   "  Ankle......  74
 95 Skeleton of Camel............  86
 9G     "     "  Bat...............  86
 97     "     "  Cameleopaud--  87
 93     "     "  Mole.............
 99 Head of House................
 100 Teeth  of Lion.................
 101 Teeth of an Herbivorous Ani-
      mal...........................
 102 Teeth of an  Insectivor. Animal
 103 Anterior Extremities of Dif-
       ferent Animals..............
 104 Hind Foot of Hor:
 94
 95
 95
 96
 99
100
105 Foot of Stag..................  02
106 Skeleton of Swan......'.....
107    "     •'  Gozland.........
103 Head of Eagle...............
109 Bones of Sternum & Shoulder
110 Skeleton of Tortoise........
Ill    "     "  Frog............
112    "     "  Perch............  ll'l
113 Section of the Scale of Lepi-
      dosteus.......................  1°*
114 Head of the Pike..............  102
115    "   "  "  Shark............  102
116 Microscopic Structure of
      Tooth of Eag le Ray......... 103
117 Microscopic Structure of Spine
of Hedgehog.
113 Microscopic A'iew of Shell of
Pi>
119 Microsc. View of Shell of Mya 105
19n Development of Mist cl. Fiber 107
121 Fragments
122 Muscular Fibril.............
123 Section of Fibril............
124 Myolemma....................
125 Cells of Muscular Fiber. ...
126 Radiate Muscle..............
127 Fusiform  "   ..............
123 Doubly Penniform Muscle..
129 Muscular System............
130     "      "    ............
131 Transverse Section of Neck.
132 Muscles of Face and Neck. .
133    "     "  "
      View.............
104
105
Side
108
109
H.;9
109
110
110
111
112
113
114
115

117
FIG.                           PAGE
134 Muscles of Back............... 118
135   «     " Arm................ 119
136   "     " Hand & Fore-Arm. 120
137   "     " Palm of Hand..... 121
138   "     " Pore-Arm (deep
     Layer)....................... 121
139 Muscles of Back............... 123
140 Diaphragm..................... 125
141 Muscles of Trunk (Side A'iew). 126
142   "     " Abdomen........... 127
143   "     " Thigh.............128
144   "     "   "  (Back A'iew).. 130
145   "      " Front of Leg...... 130
146   "      " Back of Leg....... 131
147   "      " Foot................ 132
14S   "      " Back of Fore-Arm. 133
 149   "      " Front of Leg..... 133
 150 Diagram of Fibrill.e.........134
 151    "      "  Disadvantage  of
      Muscular  Action............ 136
 152 Muscular Fiber Contracting.. 137
 153 Back Board...... ............. 144
 154   "      '•   in Use............. 145
 155 Indian  Club................... 145
 156 Uses of Indian Club........... 146
 157 Triangle....................... L'5
 15S Use  of Triangle................ 145
 159 Apparatus of a Gymnasium--147
 100     "      "      "      ••■• 14S
 161     «      «      «      ....119
 162 Fibrils of Pig.................. L'l
 1G3   "    " Meat Fly........... 153
 164 Insect Fasciculi................ 153
 105 Salivary Glands...............156
 166 Follicles from Tonsils........ 156
 107 Section of Mouth and Pharynx 157
 10S Esophageal Glands............ 153
 169 Human Stomach............... 158
 170 Coats of   "    ............... I59
 171 Diagr. of Stomach & Intestines 160
 172 Gastric Glands................ 160
 173 Cecum and Appendix.......... 161
 174 Human Digestive Apparatus. . 163
 175 Peyer's Patches................ 164
 176 Brunner's Gland.............. 164
 177 AtLLi of Jejunum.............164
 178 Human Liver.................. 16G
  179 Lobule of Liver............... 166
  ISO Gallbladder................... i67
  181 Pancreas and Spleen..........167
  1 s2 Peritoneum.................... 1G>*
  1S3 Chyliferous A^essels........... 169
  1S4 Thoracic Duct.................. L0
  185 Kidney......................... 1(1
  186 Diagram of Urinary Appara-
       tus.......................... ll1 
442                   INDEX  OF  CUTS.
fig.                           page
187 Diagram of Position of Thora-
     cic Duct and Jugular Vein.. 1S1
183 Principle of Venturi......... 182
189 Digestive Apparatus of Ape... 186
19.) Stomach of Sheep.............. 137
191 Interior op  "  ............... 1S7
192 Stomach of Ox................. 1SS
193 Head of Woodpecker.......... 1S9
194 Digestive Apparatus of Fowl 190
195 Head of Rattlesnake.......... 191
196 Anatomy of Snake............. 193
197 Digestive Apparatus of Beetle 194
198 AriscERA of Aplysia (Mollusc). 195
199    "    "  Star Fish.......... 195
200 Fresh Water Polyp........... 197
201 Digestive  Apparatus of  uni-
     cellular Animals............ 198
202 Human Heart.................. 201
203 Fibers of the Heart........... 202
204 Heart and Lungs..............202
205 Diagram of Heart............. 203
206 Valves of Heart.............. 204
207    "    li  Aorta............... 204
208 Arterial System................ 205
209 Middle Coat of Arteries......206
210 Heart and Arteries in Situ__ 207
211 Arteries of Neck & Shoulder . 208
212    "    " Arm and Hand___209
213 Circle of Willis............... 210
214 Abdominal Aorta..............211
215 Femoral Artery............... 212
216 Arteries of Backside of Leg... 213
217 Capillaries........---........ 214
213 A'eins of Face and Neck....... 215
219    "   "  Trunk and Neck..... 216
220 Sinuses of Brain............... 217
221 A'alves of A' kins............... 218
222 A'eins of Arm .................. 219
223    "   " Leg................... 220
224 Blood Crystals................ 221
225 Red Blood Corpuscles......... 221
226 Diagram of Heart's Contract.. 227
227 Circulation in Mammals....... 230
228 Diagram of Varieties of Aorta
     in Mammals.................. 231
229 Blood Corpuscles  of Ox....... 231
230 Blood Crystals of Guinea Pig. 232
231 Arteries of the Grebe.........233
232 Pigeon Blood Corpuscles...... 234
233 DlAGR. OF CiRCULAT. OF REPTILES 234
234 Blood Corpuscles of Frog..... 234
235 Circulat. Apparatus of Lizard 235
236 Heart of Crocodile............ 23(1
237    "    " Turtle............... 230
233 Diagram of Circulat. of Fishes 237
239 CirculatingAtesselsintheFisu 233
fig.                            page
21J Blood Corpuscles of Eel...... 239
241 Plan of Circulation in Fishes. 289
242 Circulatory Appapatus of the
     Lobster...................... 240
243 Circulat. Apparatus of Insects 240
244 Blood Corpuscles of Crab..... 241
245 Anatomy of the Snail.......... 242
246 Heart and Lungs.............. 244
247 Bronchi and A'essels in Situ. .. 245
248 Thoracic Viscera in Situ...... 246
249 Lunglet........................ 247
250 Diagramatic Section of Thora-
     cic Viscera................... 249
251 Capillaries of Human Lung... 250
252 Magnified  Section of Lung___ 250
253 Termination of Bronchus..... 251
254 Bronchial Tube laid open..... 251
255 Lateral A'iew of Larynx......259
256 Thyroid Cartilage............ 260
257 Arytenoid *  "   ............ 260
258 Cricoid      "   ............ 261
259 Epiglottis..................... 261
260 Larynx......................... 201
261     "   ....................... 262
262     "   ........................ 262
263 Larynx and Epiglottis........ 263
264 Lungs of a Bird................ 271
265 Lungs, etc., of a Pigeon....... 271
266 Lunglet of a Fowl ........... 272
207 Lungs of a Frog............... 272
263   "    " Serpents............. 273
269 Dissected Lung of Turtle..... 274
270 Gills of Eei.................... 274
271 Air Bladder of Fish........... 275
272 Trachea of AVater Scorpion... 276
273 Spiracle of Fly................ 277
274 Lymphatics..................... 282
275 Lymphatic System............. 2S3
276 Lymphatics of Axilla.......... 284
277 Thoracic and Lymphatic Ducts 285
278 Lymphatics of Abdomen........ 286
279      "      " Thigh........... 287
230 Diagram of a Gland........... 290
231 Chyliferous A'essels........... 290
282 TheSpleen..................... 203
283 Intimate Structure of Ppleen. 293
284     "        "      "     "   293
285     "        "      "     "   294
286 Papilla of Hand.............. 295
287 Epidermis of Negro............296
288 Pigment Cells.................. 296
2S9 Section of Thumb.............. 297
290 Cerumen Gland................ 299
291 Parasites of the Fat Glands.. 300
292 Skin of Palm of Hand......... 301
293 Perspiratory Gland........... 301 
INDEX  OF  CUTS.
443
"°-                            PAGE
294 Sections of Human Hair....... 302
295 Skin of Scalp..................803
296 Root of Hair.................. 304
297 Hair of Human Beard..........305
293  "   «  Sable................. 311
299  '<   " MuskDeer............311
300  "   "  Squirrel..............312
301  "   "  Pecari................ 312
302 Tubular Nerve Cells.......... 317
303 A'esicular "     "   .......... 318
304 Section of Brain, etc...........319
305   "    "    "    .............320
306 Cerebellum..................... 320
307 Base of Brain.................. 321
308 Cerebro-Spinal Axis........... 322
309 Sinuses of Brain...............323
310 Olfactory Nerves.............. 325
311 Optic Nj:rves................... 326
312 Third, Fourth, and Sixth Cra-
     nial Nerves.................. 327
313 Trifacial Nerve............... 327
314     "      "  .. ............328
315 Auditory   "  ............... 328
316 Tenth  Pair of Nerves........ 329
317 Nerves of Tongue, etc.......... 330
318 Portion of Spinal Cord........ 331
319 Diagram showing Decussation 332
320 Nervous System................ 333
321 Brachial Plexus............... 334
322 Nerves of Fore-Arm...........334
823 Ischiatio Plexus............... 335
324 Crural N erve, etc............. 335
825 Nerves of the Foot............ 336
326 Pacinian Corpuscles........... 336
327 Sympathetic Nerve............ 338
828 Union of  Spinal and Sympa-
     thetic Nerve................. 339
329 Brain of Squirrel............. 357
330   "   " Rabbit............... 357
331   "   " Buzzard...........  ..359
832   "   " Turtle............... 360
833   "   " Fishes................ 361
834 Electrical Appab. of Tobpedo. 362
FIG-                          PAGE
335- Nervous System of Articulates 362
336     "     "'   "  Beetle..... 363
337     "     "   "  Argonauta 364
338 Nervous System of Star Fish. . 365
339 Globe of the Eye............... 370
340 Plan of the Structure of the
     Eye........................... 371
341 Choroid Coat................... 371
342 The Iris....................\"\ 372
843 The Eye Dissected.............. 372
344 Microscopic Section of the Re-
     tina.......................... 373
345 Crystalline Lens, Front View 374
346      "       "   Side View..  874
347 Lens at Different Ages........ 374
348 Eyelids & Lachrymal Glands.. 375
349 Lachrymal Canals............ 376
350 A'iew of  Eye and  Append-
     ages..........................  376
351 Meibomian Glands.............377
352 A Single Meibomian Gland__  377
353 Muscles of the Eye............ 377
354 Head and Eye of the Bee......386
355 Section of one Facet.......... 380
356 Eye of Trilobite............... 3S7
357 The Left Ear..................3S9
358 External and Internal Ear .. 3S9
359 Cavity of the Tympanum.......  390
360 Membrana Tympani..*.........391
361 Ossicula Auditus..............  391
362 Labyrinth and Tympanum__392
363 Cochlea without the Nerve...  392
364 Nerve without the Cochlea...  393
365 Nerves of Extremity of Thumb 400
366 Papilla of tub Palm..........  400
367 FootofaFly..................  405
363 Human Tongue.................  406
369 Papilla of Tongue............  407
370 Head of Woodpecker..........  410
371 Tongue of Fly.................  411
372 Cartilages of  Nose............  412
373 Section of Nostrils............413