;-NRLF

I

B 3 37fl

YSIOLOG
If -.'i<'THE-

AI

V-> I!

UBRARY

PHYSIOLOGY

FOR THE

LABORATORY

BY

BERTHA MILLAED BROWN, S.B.

INSTRUCTOR IN BIOLOGY AT THE STATE NORMAL SCHOOL

AT HYANNIS, MASS., FORMERLY ASSISTANT IN

BIOLOGY AT VASSAR COLLEGE

BOSTON, U.S.A.
GINN & COMPANY, PUBLISHERS

1900

COPYRIGHT, 1900, BY
BERTHA MILLARD BROWN

ALL, BIGHTS RESERVED

PREFACE.

IT has seemed to me that there is needed a radical
change in the teaching of physiology. The old way of
teaching physiology merely from the text-book has been
outgrown in most of the best schools. Many teachers are
in the next stage of development. They use the text-
book largely, but have experiments to illustrate the text.
That is, they use first the text-book, and secondly the
experiments.

It would seem that the logical way to teach the ele-
ments of physiology, as the elements of other sciences,
would be, first, to study the specimen and then to go to
the text-book for additional facts after we have thoroughly
laid the foundation with the specimens. The text-book
should be used, but the foundation must first be laid from
the study of the actual animals in the laboratory. This
has long been the method of teaching botany, chemistry,
and the other sciences. Why should physiology be taught
so very differently ? Some have thought that the subject
was not one for experimental work in the high and normal
schools. But that can be easily disproved by visiting
some really good teaching in this subject. The student's
own body may be studied to a certain extent, and then

iii

iv PEEFA CE.

the markets furnish us with the parts of many lower ani-
mals that may be used to teach the functions of corre-
sponding parts of the human body.

The ideal way to teach physiology, of course, would be
to give the specimen to the student and expect him to
discover for himself the structure and function of all the
parts. This was Agassiz's method. But this is hardly
practicable to-day. With so much to teach and so short
a time to do it, we must necessarily help the student.
We may call his attention to the important things to be
seen and then make sure that he has found them correctly.
With a large class, the simplest way to call attention to
the main points is by clear and well-written directions to
be used in the laboratory. We can only be sure that each
one finds the parts when he shows them to us, or we exam-
ine his carefully labeled drawings. The directions should
not be too full. They should simply point the way and
not describe the parts. That is the work of the student.
If the directions are too full, or the ordinary text-book is
used in the laboratory, the beginner is tempted to study
the text-book and disregard the specimen.

Too much stress cannot be laid on the importance of
gaining the first impressions from the specimens. This
has already been too long neglected in the teaching of
physiology. We must also bear in mind that we are not
teaching this subject merely for the sake of anatomy and
physiology as sciences, but for the sake of hygiene and
better ways of living.

Finding that much time may be lost in the laboratory
unless the work is carefully planned, I have found it con-
venient, in my own classes, to use a series of directions

PREFACE. V

that may prove of service to some other teacher. All of
the experiments are simple and may be performed by
any student. Most of the apparatus is made by the
students, and no elaborate pieces are required. The other
supplies are such as may be obtained from the ordinary
market, or are similar to those found in any simple chem-
ical or physical laboratory.

I have to thank Mr. C. B. Wilson of the State Normal
School at Westfield, Mass., and Dr. Theodore Hough of
the Massachusetts Institute of Technology, for carefully
reading the manuscript and making some valuable sug-
gestions. B M B

BOSTON, MASS., April, 1900.

CONTENTS.

CHAPTER PAGE

I. GENERAL DIRECTIONS. THE MICROSCOPE . . 1

II. THE CELLS 7

III. THE BONES ^

IV. THE PREPARATION OF A SKELETON ... 16
V. THE JOINTS 18

VI. THE MUSCLES 22

VII. THE BLOOD 31

VIII. THE CIRCULATION 35

IX. RESPIRATION 49

X. THE TEETH AND THE TONGUE .... 55

XI. OTHER DIGESTIVE ORGANS 58

XII. FOODS 67

XIII. DIGESTION 77

XIV. THE KIDNEYS 87

XV. THE SKIN AND BODILY TEMPERATURE . . .89

XVI. THE BRAIN 94

XVII. THE SPINAL CORD AND OTHER NERVES . . . 106

XVIII. THE EYE AND VISION 113

XIX. THE EAR AND HEARING 125

XX. SOME DERMAL SENSATIONS 127

XXI. THE LARYNX AND THE VOICE . . . .130

XXII. BACTERIA 134

APPENDIX 147

vii

" What is the range and position of Physiological Science as a
branch of knowledge, and what is its value as a means of mental
discipline ? Its subject-matter is a large moiety of the universe ;
its position is midway between the physico-chemical and the social
sciences. Its value as a branch of discipline is partly that which it
has in common with all sciences — the training and strengthening
of common sense ; partly that which is more peculiar to itself — the
great exercise which it affords to the faculties of observation and
comparison ; and, I may add, the exactness of knowledge which it
requires on the part of those among its votaries who desire to extend
its boundaries." HUXLEY.

" The great benefit which a scientific education bestows, whether
as training or as knowledge, is dependent upon the extent to which
the mind of the student is brought into immediate contact with
facts — upon the degree to which he learns the habit of appealing
directly to Nature, and of acquiring through his senses concrete
images of those properties of things which are, and always will be,
but approximative^ expressed in human language." HUXLEY

viii

PHYSIOLOGY FOE THE LABOEATOEY,

i.

GENERAL DIRECTIONS.

THE COMPOUND MICROSCOPE.

IN studying the various parts of the human body, we
need to magnify some of them in order to see their struc-
ture. To do this, we shall need to use a compound
microscope. But, in the first place, it would be well to
study the microscope and learn how to use it properly.

A. The Parts of the Compound Microscope.

The parts of the compound microscope are the stand, the
objectives, and the eyepieces.

I. THE STAND.

The stand is the largest part of the microscope and
includes all except the objectives and the eyepieces. It
has several divisions :

a. The foot. The foot is the horseshoe-shaped part on
which the rest of the microscope stands (Fig. 1, a).

b. The pillar. This is the vertical column that is fas-
tened to the base (Fig. 1, b).

I

PHYSIOLOGY

^TJJE LABORATORY.

c. The artfu cllle arm is attached to the upper part of
the pillar and supports the parts, d and e, of the micro-

i— --mmm sc°Pe (Fi£- !» c)-

d. The body. This is the

short outer tube upheld by
the arm (Fig. 1, d).

e. The draw-tube. This is
the long tube within the body
to which the objectives and
the eyepieces are attached. It
is called the draw-tube, be-
cause in some microscopes it
can be lengthened and short-
ened to change the magnifica-
tion (Fig. 1, e).

f. The stage. This is the
part attached to the pillar,
below the body, on which the
slide that is to be examined is
placed (Fig. 1, /).

g. The diaphragm. Attached
to the lower side of the stage
is a circular piece, the dia-
phragm. It contains open-
ings of different sizes and

the

one of the desired size may
be brought under the opening in the centre of the stage

(Fig- 1, 9)-

h. The clips. These are the two small metallic pieces,
one on either side of the stage, to hold in place the slide

FIG. 1. — The compound microscope.
a, foot ; 6, pillar; c, arm ; d, body; e,
draw-tube ; /, stage ; g, diaphragm ;
h, clips ; i, mirror ; k, milled head
for fine adjustment; I, eyepiece; may be turned SO that
m, objective.

GENERAL DIRECTIONS. 6

to be examined (Fig. 1, h). These are merely for con-
venience and are not always used.

i. The mirror. The mirror is below the stage (Fig. 1, i).

k. The milled head. This is at the upper end of the
pillar (Fig. 1, A). It is the fine adjustment to raise and
lower the body of the microscope and all the parts that the
body carries. Turn the milled head slowly and notice the
motion of the body of the microscope.

II. THE OBJECTIVES AND THE EYEPIECES.

a. There are several objectives and eyepieces, but the
objectives most often used are a low power No. 3 and a
higher power No. 7. The eyepieces most often used are
a low power No. 2 and a higher power No. 4.

b. The magnifications for the Leitz microscope are
approximately as follows :

Objective 3

Eyepiece 2

Diameters 70

a

3

a

4

105

it

7

a

2

440

a

7

u

4

625

c. An object should first be examined with the low
power, and afterward studied more carefully with the
high power. The lenses must be perfectly clean, since
the least dust or cloudiness obscures the image. For
wiping the lenses use a soft cloth, first breathing upon
the glass in order to dampen it. An old handkerchief is
useful. The lenses should never be touched with the
fingers, for they are apt to make ineffaceable marks.

4 PHYSIOLOGY FOR THE LABORATORY.

B. The Use of the Microscope.

1. The stand is used with the ends of the horseshoe-foot
pointing away from the student. It is always kept in this
position, and any change in the light is overcome by a
change in the position of the mirror.

2. The light is obtained by turning the mirror so that
it will reflect the light from the sky upward through the
draw-tube ; the amount of light may be regulated by the
diaphragm. The sun should never be allowed to shine
directly on the mirror or on any other part of the microscope.

3. The proper focus is found by two adjustments.

a. The coarse adjustment is used first with both low and
high power to find the approximate focus. It is accom-
plished most easily by slowly twisting the entire draw-tube
while sliding it upward or downward with the fingers.

b. The fine adjustment is used to focus exactly, so that
the object shall be perfectly clear and distinct. It is
effected by turning the milled head on the upper end of
the pillar.

c. Never focus downward with the eye at the microscope,
as there is danger of touching the slide with the lens and
injuring both the slide and the lens.

d. If the object cannot be brought clearly into view by
the adjustment, test the illumination by changing the
position of the mirror, examine the objective to make sure
that it is not wet, and finally examine the cover-glass.

e. Learn to keep both eyes open ; the strain upon them is
far less than if one eye is closed. If the object does not

GENERAL DIRECTIONS. 5

show clearly, do not strain the eye to see it, but change
the focus by the fine adjustment.

4. Study the microscope until you are familiar with
the names and uses of the various parts.

5. Make a sketch of the microscope and carefully label
the parts.

NOTE. — The Leitz microscope and only the lenses that are most
frequently used are here described. The general description, how-
ever, would apply to any other manufacture, but each kind has its
own system of magnification.

In the microscopes made by the Bausch and Lomb Optical Co.,
the objectives and eyepieces are designated by their focal distances.
The low-power objectives range from a focal distance of 3 inches
(the lowest) to £ inch. The higher objectives range from a focal
distance of ^ inch to ^ inch (the highest). The eyepieces range from
a focal distance of 2 inches (a low power) to \ inch (a high power).

C. The Sketches and Records of Experiments.
I. SKETCHES.

All the more important observations should be recorded
by sketches.

a. The outlines may be first traced lightly.

b. When all the parts are drawn, the outlines may be
darkened with a hard pencil (H H H H) and the various parts
made clear when necessary by the use of colored crayons
or water colors.

c. Draw on a large scale and label neatly at the side of
the drawing.

d. Do not shade your drawings so as to conceal the
essential parts.

6 PHYSIOLOGY FOR THE LABORATORY.

II. THE RECORD OF EXPERIMENTS.

After performing any experiment make a record of it in
the following order :

a. The materials used.

b. The apparatus used.

c. The experiment, or what was done.

d. The observation of what occurred.

e. The inference, or explanation.

III. THE INSTRUMENTS.

Each scholar should be provided with a set of instru-
ments consisting of :

1. A pair of scissors.

2. A pair of forceps.

3. A medium-sized scalpel.

4. Two needle-holders with needles.

Care should be taken to clean the instruments after
using them, to wipe, and to keep them dry.

II.

THE CELL.
A. Simple Cells.

Material. A prepared slide showing large cells.
Apparatus. A compound microscope.

Study first with a low power and then with a high power
a prepared slide showing large cells, as the cells of the cast-
off skin of a newt, that have been stained.

Notice :

I. A SINGLE CELL.

a. Its general shape.

b. The protoplasm, lightly stained.

c. The nucleus, deeply stained.

d. The nucleolus, a dark spot in the nucleus.

e. Deeply stained loops, or chromatin loops, may be scat-
tered through the protoplasm. This is the part that is
thought to bear the hereditary characteristics.

/. The cell-wall, when present, on the outside of the cell.

II. THE ARRANGEMENT OF THE CELLS.

a. What is the general arrangement ?

b. Are there any spaces between the cells ?

c. Sketch several cells and label all the parts.

7

8 PHYSIOLOGY FOR THE LABORATORY.

B. Cells of Other Tissues.

Material. Prepared sections of skin, connective tissue, fatty tissue,
and cartilage. A section of skin from the roof of a rabbit's mouth
will show I, II, and III finely.

Apparatus. A compound microscope.

Examine, in the same way as in A, prepared sections
of the skin, connective tissue, fatty tissue, and cartilage.

Notice :

I. EPITHELIAL TISSUE.

a. Is it composed of cells or fibres ?

b. How are they arranged?

c. Notice the change in shape and structure as we pro-
ceed from the inside outward.

II. CONNECTIVE TISSUE.

a. Is it cellular or fibrous ?

b. What does its structure suggest as to its use ?

III. FATTY, OR ADIPOSE TISSUE.

a. Where is it found?

b. Compare the cells with those of epithelium.

c. Do you find any nucleus ? The protoplasm has been
changed to oil.

IV. CARTILAGE.

a. The scattered condition of cells.

b. Do you find nuclei or cell-wall?

c. The substance intervening between the cells is neither
cellular nor fibrous.

III.

THE BONES.
A. The Shapes of Bones.

Materials. A human skeleton and human vertebrae of the dorsal,
lumbar, and cervical regions. Many different kinds of bones, as the
leg and wing bones of chickens, the shoulder-blades and skulls of
dogs and horses, bones of the ankle of sheep, and the vertebrae of
chickens.

Study the bones of the human skeleton when possible,
but the corresponding bones of other animals, as the dog,
horse, and chicken, may be used for some of the experi-
ments.

Select from the bones on the table :

a. A long bone.

1. What is its general shape?

2. Compare with the human skeleton and find other

long bones.

b. A tabular or plate-like bone, as the shoulder-blade.

1. What is its general shape ?

2. Compare with the human skeleton and find other

tabular bones.

c. A short bone, as one of the wrist bones, having about
the same diameter in every direction.

9

10 PHYSIOLOGY FOR THE LABORATORY.

1. What is its general shape ?

2. Compare with the human skeleton and find other

short bones.

d. An irregular borie, such as the vertebra or any bone
except the three preceding kinds.

1. Find other irregular bones in the human skeleton.

B. The Gross Structure of a Long Bone.

Materials. A long bone, as the humerus or bone of the upper
arm ; a fresh long bone, as the bone of the leg of a sheep. This
should be sawed in halves longitudinally (lengthwise). Any butcher
will saw the bone when the material is purchased.

Study carefully any long bone, as the humerus or bone
of the upper arm. Most of the external parts may be
seen from a dried specimen. Then compare this with a
longitudinal section of a fresh bone and identify the
remaining parts.

I. THE EXTERNAL PARTS (of a long bone).
a. The shaft, or long central cylindrical portion.

1. The ridges on the surface : their use ? where do

they lead?

2. The round openings : where situated ? their use ?

3. The rough places : what is attached here ?

4. The periosteum, or covering on the fresh bone.

(1) How far does it extend ?

(2) "What is the color and appearance of its

surface ?

(3) What is its use ?

THE BONES. 11

b. The articular extremities.

1. How are these united to the shaft ? (See a bone

that has been boiled until the extremities have
separated from the shaft.)

2. The cartilage in the fresh bone.

(1) How far does it extend?

(2) What is its texture and color?

3. The large prominences or knobs : their use ?

c. Sketch and label all the external parts.

II. THE INTERNAL PARTS.

These may be seen from a longitudinal section of a fresh
bone of the leg of a sheep.

a. The hard bone on the outside.

1. Note the thickness in different parts of the bone.

2. Where is it thickest ? Why ?

3. Where is it thinnest? Why?

b. The spongy bone in the ends.

1. How far does it extend?

2. What is its color in the fresh bone? That is

due to the marrow within it.

c. The fine cavities and passages : their use?

d. The medullary cavity in the centre.

1. What is its shape ?

2. How far does it extend ?

3. Which is stronger, a solid or a hollow shaft con-

taining the same amount of material ?

4. What, then, is the use of the medullary cavity?

12 PHYSIOLOGY FOR THE LABORATORY.

e. The marrow is within the cavity. What is its color ?
What is its use to the bone ?

f. Make a sketch of the longitudinal section.

C. The Gross Structure of an Irregular Bone, a Vertebra.

Materials. A dorsal vertebra of the human skeleton or of a dog,
sheep, or other vertebrate. The axis, or second cervical vertebra, of
the human skeleton. The atlas, or first cervical vertebra, of the human
skeleton. The spinal column just taken from a fresh fish or a rabbit.

1. Examine carefully a human vertebra of the dorsal
region. If that is not possible, study the vertebra
of a cat, a dog, a bird, a sheep, or of any other of
the vertebrates. Identify the following parts when
present:

a. The centrum, or body, is the large solid part.

5. The neural arch is the bony arch on one side ; its use ?
Study the spinal column of the human skeleton and see
whether the arch is on the dorsal (back) or ventral (front)
side of the vertebral column.

c. The neural ring is formed by the neural arch and the
centrum.

d. The neural canal is the cavity within the ring. See a
fresh specimen of the spinal column of a fish and find what
is in the neural canal.

e. The spinous process is the outward projection on the
dorsal side of the neural arch.

/. The transverse processes are projections at the side.

g. The anterior articular process is the projection by which
the vertebra joins the next vertebra above towards the
head.

THE BONES.. 13

A. The posterior articular process is the projection by which
the vertebra joins the next vertebra below.

i. Is there a medullary cavity in the vertebra ?

j. Is there any spongy bone ?

k. Does an irregular bone, then, have a medullary cavity
or spongy bone ?

I. Sketch a side and an end view of a vertebra.

2. Compare with the dorsal vertebra the following :

a. The axis, or second cervical (neck) vertebra, of the
human skeleton or of a sheep. The odontoid process is the
rounded prominence upon it.

b. The atlas, or first cervical vertebra.

c. What parts are present and what parts are wanting
in each?

d. Place the axis in position on the atlas and find the
use of the odontoid process.

e. Sketch an end view of each.

D. The Chemical Composition of Bone.

Materials. A thin piece of bone about two inches long. Hydro-
chloric acid, ten per cent. Ammonium hydrate. A long, slender
bone, as a rib of a chicken.

Apparatus. A pair of Fairbanks standard scales. Bunsen burner.
A piece of wire gauze about six inches square. A tall, slender jarr
A ring-stand.

All bones are composed of animal and mineral matter.

I. THE MINERAL MATTER.

a. Weigh carefully a clean piece of bone.

b. Burn it on a piece of sheets-iron over the flame of a

14 PHYSIOLOGY FOR THE LABORATORY.

Bunsen burner until it turns white. Be very careful
neither to lose any of it nor to burn it too long.

c. What happens ?

d. Touch it ; what happens ?

e. What is its chief structure and general appearance ?
/. What have you left?

g. Weigh it.

h. Calculate the amount of mineral matter in the bone.
i. What has become^ of the animal matter?
j. Calculate the amount of animal matter in bone.
k. Place the burned bone in dilute, ten per cent, hydro-
chloric acid.

I. What happens ? Why ?

m. Add ammonium hydrate (ammonia) in excess.
n. What happens ? Why ?

The mineral matter consists of eighty-three per cent of
calcium phosphate, Ca3(PO4)2, thirteen per cent of calcium
carbonate, CaCo3, and of other salts. The animal matter
consists mainly of an albuminoid, ossein, or collagen, which
may be converted by boiling with water into gelatin.

II. THE ANIMAL MATTEK.

a. Place a. long, slender bone, such as a rib-bone, in
dilute, ten per cent, hydrochloric acid in a tall, narrow
jar, and leave it for a day or longer according to the size
of the bone. Dilute nitric acid or vinegar may also be
used.

b. Touch it ; can you bend it ?

c. What are its characteristics now?

d. What has taken place?

e. What have you left ?

THE BONES. 15

/. Where is the mineral matter ? Prove it.
g. Burn this as you did the entire bone. What previous
experiment does this verify?

E. The Microsgojnoil Structure, of Bone.

Material. A prepared slide showing a cross-section of a human
humerus.

Apparatus. A compound microscope.

Examine under the microscope a prepared cross-section
of a long bone, as the human fibula or humerus.

a. Notice with the low power :

1. The large Haversian canals that are cut across.

These are the passages for the blood-vessels.

2. The lamellae, or layers arranged concentrically

around the cajials.

3. The lacunae, or small cavities separating the

lamellae. What is their shape ? These were
once filled with living cells. Why are they
now black?

4. Sketch.

b. Notice, in addition, with high power :

1. The canaliculi, or wavy branches which run across

the lamellae .

(1) Where do they lead ?

(2) What is their use ?

2. Sketch.

IV.
THE PREPARATION OF A SKELETON.

A part of a skeleton, the wing or the leg of a fowl,
makes a good specimen to mount. This exercise may be
postponed until later, and some of the material obtained
for the study of muscles be utilized. The skeleton of an
entire animal may be prepared if each scholar will take
one part.

Materials. A leg or wing of a chicken or bones to be mounted.
Ammonium hydrate. Borax.

Apparatus. Bunsen burner. Ring-stand. A piece of wire gauze
six inches square. Granite-ware stew-pan. Fine gimlet and wire
or cardboard, needle and thread.

In preparing bones, only general directions can be given,
as the kind, size, and condition of the bones determine, to
a certain extent, the details.

a. Much of the muscle and fat may first be removed
with scissors and scalpel.

b. Place the bones and the remaining debris in water
and boil until the muscles fall readily from the bones. If
a small amount of ammonium hydrate or borax be added
to the water, the process will be facilitated. To remove
the marrow from a long bone, bore a hole in either end
and thoroughly wash out the marrow.

c. Place in clean water and remove everything from the

16

THE PREPARATION OF A SKELETON. 17

bones. Take care that none of the bones are lost, and
notice the positions of the different bones.

d. Wash the bones repeatedly in fresh water until per-
fectly clean and then place them on a board to dry.

e. Small bones may be sewed in their proper positions
on a piece of stiff cardboard. Large bones should have a
single hole bored at either end and be wired together. For
the positions of the holes, study a skeleton that has been
set up.

V.

THE JOINTS.
A. The Kinds of Joints.

Materials. The human skeleton. The student's body.

Study carefully the human skeleton and identify the
four kinds of joints.

a. A ball and socket joint, e.g. the hip-joint.

1. What are all the possible movements ?

2. What is the shape of the different parts of the joint ?

3. Find other joints of this kind.

b. A hinge joint, e.g. the knee-joint.

1. How many movements has it?

2. What is the shape of the different parts of the joint ?

3. Find other hinge joints.

c. A pivot joint, e.g. between the first and second cer-
vical vertebrae.

1. What is the motion ?

2. How is the joint formed?

3. Can you find other pivot joints ?

d. A gliding joint, e.g. between the bones of the wrist, —
the carpal bones.

1. What is their motion ?

2. Find other joints of this kind.

18

THE JOINTS. 19

B. A Ball and Socket Joint.

Material. A fresh hip-joint of an ox or sheep with the mem-
brane and muscles still attached. If the butcher saws it in halves
longitudinally, the different parts may be clearly seen.

Study carefully a large, fresh ball and socket joint, such
as the hip-joint of a sheep.
Identify :

a. The cavity, or acetabulum. What is its shape and
use?

b. The ball, or head of the long bone. What is its
shape and use ?

c. The cartilage.

1. How far does it extend?

2. Feel of it.

3. Cut it.

4. What are its properties and uses ?

d. The ligaments bind the bones together. Find the use
and the properties of each.

1. The capsular ligament is a loose bag extending

all around the joint.

2. The round ligament passes from the acetabulum

to the head of the long bone. How does the
attachment of these ligaments allow motion at
the joint?

e. The tendons attach the muscles to the bones. How
do they differ in appearance from the ligaments ?

/. The synovial membrane is a thin layer of cells extend-
ing over the ligaments and cartilage. It is too thin to be
distinguished with the naked eye.

20 PHYSIOLOGY FOR THE LABORATORY.

g. The synovial liquid is found as soon as the capsular
ligament is cut. It is secreted by the synovial membrane.

1. Rub a little between your fingers.

2. What is its use ?

A. Sketch and label all the parts.

C. Some Other Joints.

Material. The fore leg of a lamb.

The joints of the fore leg of a lamb may be studied.

1. Compare the fore leg of the lamb with the upper limb

of man and find which joint you are studying.
Describe the way in which the bones fit together at
the joint, and explain how motion in certain direc-
tions is prevented while it is allowed in others.

2. Identify the different parts of the joint that are named

under the ball and socket joint, except a and b.
Sketch.

D. The Microscopical Structure of Cartilage.

Material. A prepared slide of hyaline cartilage.
Apparatus. A compound microscope.

Study with the high power of a compound microscope a
prepared slide of a piece of hyaline cartilage.

Notice :
1. The cartilage cells.

a. What is their shape ?

b. How are they arranged?

c. What parts of the cell can you identify ?

THE JOINTS. 21

2. The homogeneous material, or matrix, in which the cells
are embedded. Sketch.

E. The Relation of Cartilage to Bone.

Materials. A prepared slide of developing bone. Foetal bones
of some young animal. (Those of the pig are usually easy to obtain
from any butcher.)

Apparatus. A compound microscope.

Study :

1. Some of the long bones of the foetus.

a. Examine them both in the centre and at the ends.
Compare in structure and density.

b. Compare them in shape with the adult form.

c. Compare them with cartilage joining the ribs to the
breast-bone and with cartilage always present at the joints.

2. Examine the prepared slide of developing bone.
Notice :

a. The enlargement and rearrangement of cartilage cells.

b. The calcification of the matrix.

c. Sketch.

VI.

THE MUSCLES.
A. The Parts of a Muscle.
Material. A chicken, pigeon, or fore leg of a lamb.

Examine the muscles of some small animal, as a chicken,
a pigeon, or the fore leg of a lamb. Dissect carefully one
entire muscle, but do not cut it away.

Notice :

a. The belly is the red central part.

1. What is its shape when contracted ?

2. What is its shape when relaxed ?

b. The tendons are attached at either end.

. 1. What is their texture ?
2. What is their use ?

c. At how many places is a muscle attached ?

d. The origin is the less movable attachment of the
muscle.

e. The insertion is the more movable attachment of the
muscle.

/. Which is the origin and which is the insertion of
the muscle that you have dissected?
g. Sketch.

22

THE MUSCLES. 23

B. The Gross Structure of a Muscle.

Material. A piece of lean corned beef about two inches long.

Some of the parts of a muscle may be seen especially
well in a piece of corned beef.

a. The perimysium, or loose sheath, is on the outside of
the entire muscle.

1. Of what is it composed?

2. What is its color?

3. What is its use ?

4. What relation does it bear to the tendons ?

5. Where do branch partitions from the perimysium

extend ?

b. A muscle is composed of many bundles of tissue or
fasciculi.

c. Smaller fasciculi unite to form a larger fasciculus.

d. The smaller fasciculi are composed of fibres. Tease
out a few fibres. Note their color, size, and shape.

e. The nerves are the fine white threads seen on the
outside and sometimes within the muscles. What is their
distribution and use?

/. The blood-vessels are the red or colorless thin-walled
vessels usually found with the nerves.
g. Is a muscle a tissue or an organ ? Why ?
h. Sketch both longitudinal and transverse views.

C. The Different Kinds of Muscles.
Material. A fowl.

In a common fowl the different kinds of muscles may
be found. The tendons of the muscles of the foot and of

24 PHYSIOLOGY FOR THE LABORATORY.

the leg of a fowl should be dissected carefully, leaving
their attachments at both ends. By pulling the upper
ends of the tendons that are attached to the muscles of
the fore leg, the toes will move as in a living fowl, and
can be made to .pick up objects.

Find as many as possible of the following kinds of
muscles.

a. A simple muscle is enlarged in the middle and tapers
towards either end.

b. A biceps muscle is divided into two parts at one end
so that it has three tendons. Find the biceps in the leg
of the fowl.

c. In a penniform muscle the tendon runs along the side
of the muscle.

d. The tendon runs down the middle of the muscle in
the bipenniform muscle. This kind may be found on the
breast of the fowl.

e. Sketch one of each kind.

D. The Microscopical Structure of Muscles.
I. STRIATED MUSCLE.

Material. A prepared slide of striated muscle.
Apparatus. A compound microscope.

Study under the compound microscope a prepared slide
of a few fibres of striated muscle that have been teased
apart. Frog's muscle shows the stria tions very plainly.

Notice :

a. A single fibre.

1. Its shape.

2. The striations that run across the cell.

THE MUSCLES. 25

3. The nuclei.

4. The sarcolemma is the thin sheath on the outside.

Look for it where the fibre has been crushed
or bent.

5. The longitudinal divisions of the fibre into many

small fibrillae are not always visible.

6. Sketch.

II. STRIATED MUSCLE. — A CROSS-SECTION.

Material. A slide showing a cross-section of striated muscle that
has been hardened in Flemming's fluid and stained in safranin.
Apparatus. A compound microscope.

Examine with the high power of a compound microscope
a cross-section of striated muscle.

Observe :

a. The arrangement of the fibres in the muscle.

b. The parts of a single fibre.

1. The polyhedral areas into which the entire fibre

is divided are the areas of Cohnheim.

2. Each area is a group of bundles of fibrillae. The

granular appearance of each area of Cohnheim
is due to the cut ends of the fibrillae. The
fibrillse are arranged in columns or bundles
which, taken together, make the fibre.

3. Surrounding each fibrilla and again around the

columns of fibrillae is a hyaline or slightly
granular substance resembling protoplasm,
called sarcoplasm.

III. PLAIN MUSCLE.

Material. A prepared slide of the fibres of plain muscle.
Apparatus. A compound microscope.

26 PHYSIOLOGY FOR THE LABORATORY.

Examine in the same way a piece of plain or non-
striated muscle. Identify the different parts of the fibre-
cell. Sketch.

E. Experiments on the Student's Body.

1. Examine carefully the back of your hand, bending and

extending the fingers one by one.

a. Find the different tendons or cords and follow them
outward. To what are they attached ?

Notice especially:

1. The arrangement at the knuckles.

2. The tendon of the little finger. How is it con-

nected with the tendon of the third finger?
Why?

b. Follow the tendons inward toward the arm.

1. Where do .they lead? Compare the tendons of

the thumb and the little finger.

2. Where are the muscles to which these tendons

are attached ? Verify by placing your fingers
on the muscles and bending the fingers as far
back as possible.

c. Sketch.

d. Compare this with a drawing of the hand showing
the muscles and tendons.

2. Notice the mass of muscles at the base of the thumb.

Grasp a book tightly between the thumb and fore-
finger. What happens ?

3. Pin a piece of paper snugly around the upper arm. Lift

a weight to the shoulder. What happens ? Why?

THE MUSCLES. 27

4. Standing with heels near together, rise on the toes
and then sink as far as possible, bending ankles
and knees. Repeat six or ten times. Explain.

F. The Way in which Muscles Act.

Materials. A frog. Ether. Cotton batting.

Apparatus. Ring-stand. Small induction coil. Battery. Wires, etc.

Etherize the frog, cut the spinal cord just back of the
head and destroy the brain with a probe. Lay bare the
gastrocnemius (calf) muscle in one hind leg with the nerve
leading to it (the sciatic nerve), and cut the several branches
of this nerve close to the backbone.

1. Stimulate the nerve, with a single shock, close to the

backbone and watch results. Does the result
follow instantaneously? Why? How long does
it take the muscle to recover its normal position ?

2. Stimulate at any point with a rapid succession of shocks.

What difference is there in the result? Call this
tetanus, and show its relation to convulsions and
cramp. How long does it take the muscle to recover?

3. Expose the muscle and nerve on the other hind leg,

cut, and repeat 1 and 2 to verify the results before
obtained, watching especially the interval which
elapses between stimulation and contraction.

4. Repeat the single shock stimuli many times at quite

short intervals, allowing the muscle to recover each
time. Note the decreasing strength of contraction
produced and the increasing length of time it takes
to recover. This is fatigue.

28 PHYSIOLOGY FOE THE LABORATORY.

G. The Work of Muscles and Bones. Levers.

Apparatus. A wooden rod about a yard long. Weights of dif-
ferent sizes. A triangular prism of wood for a fulcrum. A spring-
balance.

Arrange the different parts to show the kinds of levers.
One weight will represent the " weight," and the spring-
balance will measure the power. Change the weight and
notice the effect on the power. The power arm is the
distance from the power to the fulcrum, and the weight
arm is the distance from the weight to 'the fulcrum. Find
the relation of the product of the power and the power
arm to the product of the weight and the weight arm.

Show the three kinds of levers :

a. When the fulcrum is between the power and the
weight.

b. When the weight is between the power and the ful-
crum.

c. When the power is between the weight and the ful-
crum.

H. The Lever in the Arm.

NOTE. — These problems maybe solved arithmetically or worked
out on Dr. Fitz's lever apparatus.

1. The bones of the forearm act as a lever. Part of the
power is the biceps muscle attached on the inside
just below the elbow.

a. Where is the weight? the fulcrum?

b. What is the length of the power arm ? of the weight
arm?

G. Which kind of lever is this ?

THE MUSCLES. 29

d. How much power must be exerted to lift a weight
of twenty pounds resting on the hand, when the forearm
is in a horizontal position ?

2. The triceps muscle of the back of the arm does part
of the work of the arm. It is attached just back
of the elbow-joint.

a. Where is the weight? the fulcrum?

b. Which kind of lever is this?

c. How much power must be exerted by the triceps
muscle to make the hand push twenty pounds?

I. The Lever in the Foot and Leg.

When standing on the toes, the bones of the foot act as
a lever. The power is in the muscles of the calf of the leg.

a. Where is the weight? How much is it?

b. How long are the power and the weight arms ?

c. Which kind of lever is this ?

d. How much power is required for a person weighing
125 pounds to stand on his toes? How much is required
for you to stand on your toes ?

J. A Model of an Arm.
NOTE. — This is adapted from WoodhulPs IIome-Made Apparatus.

Apparatus. One piece of wood 4 in. x 3 in. x 1 in.
" " 9 in. x 1 in. x 1 in.

" " 4 in. x 1 in. x 1 in.

Three rubber bands. Six hooks. Four small strips of tin about an
inch long.

The general arrangement of the muscles in the arm may
be obtained from a model of wood with muscles of rubber

30

PHYSIOLOGY FOB THE LABORATORY

bands. The model consists of three pieces of wood ; the
longest represents the humerus, the smallest represents
together the radius and the ulna, and the broadest repre-
sents the shoulder-bone, or scapula. A rubber band

FIG. 2. — A model of an arm.

attached at a below the elbow-joint and at b above the
shoulder-joint represents the biceps muscle. The rubber
band attached at e and / represents the triceps muscle.

1. Adjust the three bands so that the arm hangs down

straight. Show how the muscles work in opposi-
tion to each other over the joints. How is the
joint made rigid?

2. Unfasten the band at e and/. What happens to the

arm ? What muscle causes this motion ?

3. Replace the rubber band ef and unfasten the band cd.

What happens to the arm ? What muscle does the
work?

4. If both ef and cd are unhooked, what is the position

of the arm ? What muscle causes this motion ?

5. Remove the piece of wood representing the scapula,

and readjust the muscles to represent the move-
ments of the foot.

VII.

THE BLOOD.
A. The Structure of Blood.

Materials. A drop of human blood. To obtain a drop of blood,
tie a string or wind a handkerchief tightly around the finger and
wait a few minutes until the blood has collected in. the finger.
Then with a clean needle make a prick near the nail. Let a drop
of blood fall on a glass slide. Spread out the blood very thin by
placing a second glass slide over the first and rubbing it about.
Then remove the second glass slide, place a cover-glass over the
blood and the slide is ready for examination. A prepared slide of
the blood of a frog.

Apparatus. Glass slides. Cover-glasses. Compound microscope.

I. THE HUMAN BLOOD.

Examine a drop of human blood under the microscope.
Notice :

a. The red corpuscles. What is theirshape and arrangement?

b. The white corpuscles. What is their relative size and
shape ? What is their relative number ?

c. The delicate threads of fibrin.

d. Sketch. .

II. THE FROG'S BLOOD.

Study with the microscope a slide of the blood of the frog
prepared by double staining to show the nuclei of the red
corpuscles.

31

32 PHYSIOLOGY FOR THE LABORATORY.

Notice :

a. The red corpuscles. What is their shape as shown
by a surface and an end view ? Do you find a nucleus ?

b. The white corpuscles (stained in the preparation).
What is their size and shape? What is the nature of
their contents? Have they any nucleus?

c. Sketch a corpuscle of each kind greatly enlarged.

III. THE BLOOD OF OTHER ANIMALS.

A few drops of a pigeon's or a hen's blood may be
obtained and compared with the two kinds already studied.

B. The Clotting of Blood.

Materials. Fresh blood from the market, or a frog. Chloroform.
Cotton batting.

Apparatus. Test-tube. Bell-jar.

I. THE CLOT.

Fresh blood of an animal recently killed may be had of
the butcher, or a frog may be killed and the blood col-
lected. To kill a frog, place it under a bell-jar with some
cotton batting saturated with chloroform. Wait until the
frog is stiff before dissecting. Then make an incision
along the ventral median line, cutting through the breast-
bone. Cut the blood-vessels leading to and from the heart
close to the latter, and collect the blood in a test-tube.
Pour out some of the blood into a smaller test-tube and
allow it to stand, taking care to cover it so that it cannot
dry. Watch it until changes take place. In case the
blood is obtained of the butcher, some of it should be
poured in a glass jar and allowed to coagulate.

THE BLOOD. 33

Notice :

a. The clot. What is its color, shape, size, consistency,
and position ?

b. The serum or straw-colored liquid. Where is it
found? Compare it with the clot in quantity. Remove
the serum and notice the effect on the clot.

II. FlBKIN.

Beat vigorously the remainder of the blood obtained of
the butcher, with a bundle of twigs or wires, for a few
minutes until some stringy elastic fibrin has collected upon
them. Remove the twigs with the fibrin, rinsing them as
much as possible in the whipped blood.

Notice :

a. The amount, form, and nature of the fibrin. Whence
did it come ?

b. What is its color? Rinse thoroughly under the
faucet and note again the color. To what was the former
color due? Compare with the color of clot in clotted
blood. Inferences.

c. The liquid which remains after the fibrin has been
removed. What part of the blood is it? What color
is it?

d. Allow this liquid to stand for some time. Does it
clot? To what, then, was the clotting in the other blood
due ? Compare this liquid carefully with the serum.

III. THE COMPOSITION OF BLOOD SERUM.

Material. Blood serum left after I.

Apparatus. Evaporating dish. Ring-stand. Wire gauze. Bun-
sen burner. Test-tube.

34 PHYSIOLOGY FOE THE LABORATORY.

a. Allow any corpuscles that remain in the serum to
settle and pour off some of the clear liquid. Evaporate
this slowly to dryness.

1. How much residue is left? What does this

represent ?

2. Heat this residue as you did the bone until it is

all burned. Is anything left? What kind
of matter is it?

3. Moisten a piece of paper with serum and attempt

to dry it. What must have been present in
the serum ? Whence did it come ?

4. Boil a small amount about 10 c.c. of serum in a

test-tube. What change takes place ? What
does this show?

C. The Influence of the Presence or Absence of Oxygen on
the Color of Blood.

Material. Fresh blood in a small test-tube. The blood that was
left after experiment B may be used.

Apparatus. A small test-tube. A piece of glass tubing six
inches long.

Collect a small amount of blood in a test-tube.

a. What color is the blood ?

b. Is it arterial or venous ?

c. Breathe through a glass tube into the blood.

d. What occurs ? Explain.

VIII.

THE CIRCULATION OF THE BLOOD.
A. The Heart and Related Organs.

Material. Obtain from the market the "pluck" of a sheep, pig,
or calf. This includes the heart, lungs, trachea, and diaphragm.
Care should be taken to engage it beforehand, with the request that
it be left intact, or the heart will be punctured and there will be no
pericardium.

Study the entire specimen.

Identify :

a. The lungs.

b. The trachea, or windpipe leading to the lungs.

c. The oesophagus, a thin-walled tube near the trachea,
is sometimes cut away.

d. The heart.

e. The pericardium is the thin- walled bag in which the
heart is held. Does it fit closely to the heart ? Puncture
the pericardium, if it has not already been cut.

/. The pericardial liquid is within the pericardium.

g. The diaphragm is the muscular membrane just under
the heart. What is its shape and texture? Part of it
may be cut away.

h. Sketch all the parts to show the relation of one to
another.

35

36

PHYSIOLOGY FOR THE LABORATORY.

B. The Parts of the Heart.

Materials,
removed.

The heart and lungs of a calf with the pericardium

Place the mass on the table with the heart uppermost
and with the point of the heart extending away from you.

Now you see the front of
the heart, or its ventral
surface.

u s

N

M

FIG. 3. — Diagram of the heart and large blood-
vessels. A, right ventricle ; B, left ventri-
cle ; C, right auricle ; D, left auricle ; E,
inferior vena cava ; F, superior vena cava ;

Notice :

a. The apex, or the
J point of the heart.

b. The base of the heart
is its large end.

c. The ventral surface,
or front of the heart, is
the side that is now upper-
most as it lies on the table.

d. The dorsal surface is
opposite the ventral.
Which is more convex ?

e. The right side of the

it lies on the table.

/. The left side of the

W and Bright and left ; innominate veins; heart is On your left. The
R and N, right and left subclavian veins ; J

crand x, right and left jugular veins ; G, two sides are separated by

pulmonary artery ; / and J, right and left
pulmonary veins ; H, aorta ; P, innominate
artery
arteries

ciavian arteries.

WV. 4-' " fV»*
a g^OOVC. W nat IS in tmS

y ; S and -Y.t right and left carotid PTOOVC ?
ies f T and M, right and left sub- °

g. The right ventricle is

THE CIRCULATION OF THE BLOOD. 37

the large chamber of the heart on the right side of the
heart, (A in Fig. 3.)

h. The left ventricle is the corresponding chamber on
the left side. Which ventricle has thicker walls ? Why ?
Do they both extend to the apex of the heart ? (B in
Fig. 3.)

i. The right and the left auricles are the thin-walled
pouches at the base of the heart. They may be partly
cut away in your specimen. (C and D in Fig. 3.)

j. Sketch a dorsal and a ventral view of the heart.

C. The Blood- Vessels that Open into the Heart.

Materials. The heart and lungs of a calf, neither cut nor punc-
tured in any way, but with the pericardium removed.

Apparatus. A piece of glass tubing drawn out to a point 'for a
blowpipe or a metallic blowpipe.

Identify :

a. The inferior vena cava is the large vein that comes up
from the lower part of the body and carries the impure
blood into the right auricle. Look for it on the dorsal
side of the right auricle at its extreme left where it joins
the right ventricle. With a blowpipe inflate the auricle
through the inferior vena cava. (E in Fig. 3.)

6. The superior vena cava carries the blood from the upper
part of the body into the right auricle. Look for it close
beside a, but at the part of the right auricle that is farthest
from the apex of the heart. Follow it away from the
heart, as far as you can, to its source at the union of
the two innominate veins. With the blowpipe inflate the
auricle through this vein. (F in Fig. 3.)

38 PHYSIOLOGY FOR THE LABORATORY.

c. The pulmonary artery leads from the base of the right
ventricle to the lungs. Look for it on the ventral side of
the heart between the two auricles. How far can you
trace it ? In what direction does it run ? Explain this
crossing. Does it carry arterial or venous blood ? Why
is it called an artery? (See G- in Fig. 3.)

d. The aorta is the large tube leading from the left ven-
tricle. Trace it from the heart and find the arch where it
turns to go to the lower part of the body. (See H in Fig. 3.)

e. The four pulmonary veins run from the lungs to the
left auricle. The two right pulmonary veins run close
along the dorsal surface of the right auricle. The two
left open at the extreme left of the auricle beneath the
arch of the aorta. (See I and J in Fig. 3.)

/. Indicate the openings of the blood-vessels in your
sketches of the heart.

g. Trace the path of the blood through the heart from
the superior and inferior vense cavse.

h. Indicate in your sketches of the heart the path of the
blood through it.

D. The Valves of the Heart.

Materials. The heart of the calf. Water.
Apparatus. A bulb syringe. A glass graduate.

I. THE TBICUSPID VALVE.

Cut away most of the right auricle and with a bulb
syringe inject water or allow water from a faucet to flow
into the right ventricle. Notice the action of the valves
between the auricle and ventricle at the auriculo-ventricu-
lar orifice. Press on the ventricle to imitate its contrac-

THE CIRCULATION OF THE BLOOD. 39

tion. Where does the water escape? Cut through the
wall of the ventricle from the base to the apex and spread
it open, exposing the tricuspid valve.
Notice :

a. The flaps. How many are there and how are they
arranged ?

b. How are they held in place ? The white cords are
called chordae tendinae.

c. One end of these cords is attached to the edge of the
valve. To what is the other end attached? These are
the papillary muscles. Explain how they work. Why is
something of this sort necessary?

d. Sketch.

II. THE SEMILUNAR VALVES AT THE BASE OF THE

PULMONARY ARTERY.

Find where the pulmonary artery opens into the right
ventricle. Cut away enough of the wall of the ventricle
to see the opening from below. Pour water into the
artery and watch the action of the valves.

Notice :

a. How many are there ?

b. What is their shape ?

c. What is their arrangement?

d. What effect did they have on the stream of water?

e. What effect did the water have on them ?
/. Sketch.

III. THE MITRAL OR BICUSPID VALVE.

Remove the left auricle, noticing from the inside where
the pulmonary veins open into it. Inject water into the

40 PHYSIOLOGY FOR -THE LABORATORY.

left ventricle as you did into the right and compare the
valves with those of the right ventricle.

IV. THE SEMILUNAR VALVES AT THE BASE OF THE
AOKTA.

Find the opening of the aorta into the left ventricle and
study the semilunar valves as you did those at the base
of the pulmonary artery.

E. The Valves in the Veins.

Material. The heart and blood-vessels of a calf.
Apparatus. Knitting needle.

If the veins are still attached to the specimen, try to
find the valves in them by passing down a small probe, as
a knitting needle.

a. In what direction is the blood flowing in the veins ?
In what direction do the valves prevent flow?

b. Compare their action with that of the semilunar
valves in the arteries.

Remove the heart and reserve the lungs and trachea
for study another time.

F. The Beating of the Heart.

Materials. A frog. Chloroform. 20 c.c. normal salt solution.
Apparatus. Watch crystal. Watch. Bunsen burner.

Kill a frog with chloroform, and as soon as it is dead and
the limbs are stiff make a cut along the ventral median
line, cutting through the breast-bone. Take care not to

THE CIRCULATION OF THE BLOOD. 41

cut any large blood-vessels. Cut open, carefully, the peri-
cardium and watch the action of the beating of the heart.
Observe :

a. The alternate beats of the two auricles and the ven-
tricle.

b. The synchronous beats of the two auricles.

c. The ventricle during contraction is pale, and its apex
is thrown forward and upward.

d. The pause or systole before the auricle contracts.

e. Count the beats in a minute.

f. Remove the heart from the body and place it in
normal salt solution in a watch crystal, and see if it still
beats.

g. Apply a gentle heat and watch the effect.
h. Count the number of beats.

i. Apply ice and watch the effect.
j. Count the number of beats.

G. The Circulation in the Web of the Foot of a Frog.

Material. A live frog or tadpole.

Apparatus. Glass slides. Cover-glasses. Piece of cork two inches
square. Cloth. Pins. Compound microscope.

To show the circulation in the web of the foot of the
frog, the foot should be spread out perfectly smooth and
held in place. Take a very thin piece of cork about two
inches square, and cut a hole about half an inch in diameter
in the centre of it. Lay a glass slide over the opening.
Spread out the foot on the slide over the opening, and
secure it there by pinning narrow strips of cloth across
the ends of the toes. The frog may be kept quiet by

42 PHYSIOLOGY FOR THE LABORATORY.

wrapping it in a moist cloth and then in tea-lead, leaving
one foot exposed. Cover the foot with a cover-glass, taking
care to have water beneath it.

A tadpole is often easier to manage than a frog. Lay
a tadpole on a glass slide and keep it still by winding a
piece of moist cloth loosely around both the tadpole and
slide. Cover the end of the tail with a cover-glass, tak-
ing care that there is water under the cover-glass.

Study under the microscope the circulation of blood
through the capillaries of the web of a frog's foot or the
tail of a tadpole.

Notice :

a. The capillaries, or small thin-walled blood-vessels.

b. The red corpuscles carried along in the stream. What
is their shape and color?

c. The white corpuscles. What is their movement and
position in the stream of blood?

d. At a branch in the capillaries, see how the red cor-
puscles are bent out of shape, and then resume their normal
shape.

e. The cells in the epidermis.
/. The black pigment cells.

g. What is the color of the blood in a small vein or
artery ?
h. Sketch.

THE CIRCULATION OF THE BLOOD. 43

H. Experiments on the Student's Body.
Apparatus. A watch. A rubber band, or piece of twine.

1. Find the pulse in different places.

a. In the wrist.

b. In the thumb.

c. In front of the ear, or the side of the face.

d. Under the knee. Cross one knee over the other and
watch the foot of the crossed knee. Explain.

e. On the temple.

2. Count your pulse standing, sitting, lying down, and

after running. How soon is the pulse normal after
running ?

3. Trace the veins and arteries on the back of the hand

and in the wrist. How can you distinguish between
the veins and the arteries?

4. Tie a rubber band tightly around your finger. Ex-

plain the result.

5. Press with a finger on the skin, and then lift the finger.

6. Listen for the sounds of the heart of another person.

I. The Demonstration of the Principles of Circulation.
I. UPON WHAT CIRCULATION DEPENDS.

a. The beat of the heart.

b. The peripheral resistance, or the resistance to the

flowing of the blood in the capillaries.

c. The long stretch of elastic tubing or blood-vessels.

44 PHYSIOLOGY FOE THE LABORATORY.

II. THE NORMAL FLOWING OF THE BLOOD.

Material. Water, which may be slightly colored red if preferred.
Apparatus. A small force-pump. Two wooden pails.
660 c.m. pure rubber tubing, 12 m.m. in diameter.
\% m. " « " 6 m.m. « «

560 c.m. « « " 5 m.m. " «

Three-way glass connecting tubing, F-shape. Six large size,

12 m.m. in diameter, length of one arm 90 m.m.
Eight medium size, 6 m.m. in diameter, length of one arm

65 m.m.
Two medium size, !T-shape tubing, 6 m.m. in diameter, length

of one arm 65 m.m.
Sixteen small size, 4 m.m. in diameter, length of one arm

60 m.m.

64 c.m. glass tubing 12 m.m. in diameter.
192 c.m. " " 4 m.m. « "
Two pinch-cocks.
35 c.m. of glass rod 2 m.m. in diameter, or pieces of a fine

sponge.

By means of an apparatus made of glass and rubber
tubing, the principal phenomena of the circulation of the
blood may be demonstrated. A small force-pump con-
nected with one end of the apparatus represents the action
of the heart. The large rubber tubing of one half of the
apparatus represents the arteries, and of the other half the
veins. The small passages in the sponge within the small
tubing, between the two parts, represent the capillaries
and cause the peripheral resistance. The difference in
structure between the arteries and the veins may be more
clearly shown, if the arteries are made of very elastic pure
rubber tubing, and the veins made of less elastic tubing
which has some linen fibres in its walls. The outlet at H

THE CIRCULATION OF THE BLOOD.

45

represents an injury to an artery, and a cor-
responding outlet in the other half represents
an injury to a vein.

a. Connect the pump with the large ar-
tery, and slowly force the air out of the set
of tubes, and water, slightly colored red, into
the tubes. Imitate the action of the heart
with seventy-two slight strokes a minute.
Watch the circulation of the water through
the tubing.

b. Hold in the hand a large artery and
feel and count the pulse. Feel the pulse in
a small artery. How do the two compare ?
Feel of a capillary. Is there any pulse? 4
Feel of a small vein and then a large vein
for the pulse. Where is the pulse most E
prominent? Where is it least felt?

c. Remove the stop-cock at H and con-
tinue the action of the pump. Is the out-
flow continuous or intermit-
tent ? How does the blood flow

from an injury in an artery ?

d. Remove the correspond-
ing stop-cock in the large vein,
and replace the stop-cock in
the artery. Continue the
action of the pump. Is the
outflow continuous or inter-
mittent ? How does the blood
flow from an injury in a vein ?

e. How does the flowing of

halfway g\ I | I I I II

FIG. 4. — One fourth of the apparatus
to illustrate the circulation of the
blood. 1,2, an d 3 are of the 12m .111.
rubber tubing ; 4 is of 6 m.m. rubber
tubing ; 5 and 6 are of 5 m.m. rubber
tubing ; A and E are the 12 m.m.
three-way, reshaped, connecting glass
tubing; E is a three-way, F-shaped,
glass tube ; fis the 4 m.m. three-way,
F-shaped, glass tubing ; D is a three-
way, T-shaped, connecting glass tube;
C is the connector made from 12 m.m.
glass tubing, drawn down to fit the
rubber tubing 6 m.m. in diameter ;
(j is of the 4 m.m. glass tubing, which
is filled with pieces of fine sponge,
or with pieces of glass rod 2 m.m. in
diameter.

46 PHYSIOLOGY FOR THE LABORATORY.

the blood near the pump compare with the flow in the large
tube at the opposite end of the apparatus ? What is true
of the flowing of the blood in the large arteries and veins ?

III. THE USE OF THE PERIPHERAL RESISTANCE.

Material. AYater. A small force-pump.

Apparatus. One metre of pure rubber tubing 12 m.m. in diameter.

Connect with the pump a long piece of elastic rubber
tubing, and intermittently force water through it. Is the
outflow intermittent or continuous? Compare with the
result obtained when the peripheral resistance is present as
in II c. What is the effect of the peripheral resistance ?
What is the advantage of a continuous flowing of blood
in the body ?

IV. THE USE OF THE ELASTIC WALLS OF THE TUBES.

Material. Water.

Apparatus. A small force-pump.

50 c.m. of glass tubing 12 m.m. in diameter.
6 c.m. of rubber tubing 12 m.m. in diameter.

Connect with the pump a piece of glass tubing, and
intermittently force water through it. Is the outflow in-
termittent or continuous?

J. A Model to Show the Action of the Semilunar Valves.

Material. A piece of thick manila paper, three inches by six and
a half inches, strong enough for sewing, and flexible enough to bend
easily. A piece of white cloth about the same size. Water.

Apparatus. Two glasses. Needle and thread.

A model of the base of the aorta and the semilunar
valves may be made of paper and cloth. The piece of

THE CIRCULATION OF THE BLOOD.

47

paper, rolled so that the short ends lap half an inch, repre-
sents the aorta. The three valves are nearly semicircular
in shape, like the outlines in dotted lines in Fig. 5. Each
one is two inches wide and two and a half inches deep.
These valves are left free at their upper edges, which
should be flat on the paper, and are sewed along the

FIG. 5. — A model of the semiluuar valves.

continuous line marked A A A A. After the valves are
sewed in place, roll the paper so that B comes at C and
sew. Make the model twice the size of Fig. 5.

1. Hold the model in the position corresponding to the

aorta in the body. Are the valves placed upward
or downward on the walls of the aorta?

2. Pour water through the tube to imitate the flowing

of the blood through the aorta.

a. What is the position of the valves ?

b. What is the effect of the valves on the stream of
water or blood ?

48 PHYSIOLOGY FOR THE LABORATORY.

3. Imitate in a similar manner any backward pressure
in the blood.

a. What is the effect of the water or blood on the
valves ?

b. What is the action of the valves ?

c. What is the effect of the valves on the stream of
water or blood?

d. Is your model perfect? If not, what condition of
the valves does it illustrate ?

IX.

RESPIRATION.

A. The Lungs of a Sheep.

Materials. The lungs and trachea of a sheep. A glass of water.
Apparatus. Blowpipe. Twine.

Study the lungs and trachea that have been reserved
from a former exercise.

I. THE DIFFERENT PARTS.
Notice :

a. The lungs.

1. Their shape.

2. Their size.

3. Their color.

4. Their weight as compared with water. Cut off

a small piece and place in water. Explain
its action.

b. The trachea.

1. Its shape.

2. Its size.

3. The cartilaginous rings. What is their size, shape,

and position. Do the rings reach entirely
around the trachea? Why?

4. The lining membrane.

' 49

50 PHYSIOLOGY FOR THE LABORATORY.

5. The two branches, or the right and the left bronchus.

6. Sketch both the lungs and the trachea.

c. Insert a blowpipe in the bronchus leading to the
uncut lung, and tie a stout cord around it so tightly that
no air can escape and inflate. Note the size of the lung
before and after inflation. Of what kind of tissue must
it be composed?

d. Dissect carefully one bronchus until its branches or
bronchial tubes are found. Dissect one of the large
bronchial tubes to the surface of the lung.

II. THE SUPPLY OF BLOOD.

Find where the pulmonary artery and a pulmonary vein
enter one lung, and trace them as far as possible through
the lung. Make a sketch of a portion of the lung dissected
to show a bronchial tube, a vein, and an artery.

B. The Changes in the Air during Respiration.

Materials. Lime-water, about 250 c.c. Hydrochloric acid.

Apparatus. A thermometer. A glass tumbler. A bottle con-
taining about 500 cc. A rubber stopper with two holes. Glass
tubing to fit the holes in the stopper.

I. THE CHANGE IN TEMPERATURE.

a. Take the temperature of the air in the room.

b. Take the temperature of expired air by breathing on
the bulb of a thermometer.

II. MOISTURE IN EXPIRED AIR.

a. Breathe on a cold glass.

b. What happens ? Explain.

RESPIRATION.

51

III. CARBON DIOXIDE IN EXPIRED AIR.

a. Breathe through a tube into a glass of lime-water.

b. What occurs ? Explain and write the reaction.

c. What occurs when hydrochloric acid is added ?

d. What does this prove?

IV. TEST THE AIR OF AN ORDINARY ROOM FOR CAR-

BON DIOXIDE.

Use a bottle with a rubber stopper
fitted with two pieces of glass tubing,
each bent at a right angle. One piece
of the tubing should reach nearly to
the bottom of the bottle, the other just
below the stopper. (See Fig. 6.)

a. Fill the bottle half full with lime-
water.

b. Draw the air out of the bottle
through the short tubing.

c. What happens? Why?

FlG. 6. —Apparatus for
testing ail- for car-
bon dioxide.

C. Experiments on the Student's Body.
Apparatus. A watch. A tape-measure.

I. THE NUMBER OF RESPIRATIONS.

Count the number of respirations in a minute under
ordinary conditions. Count the number after running.

II. THE SIZE OF THE CHEST DURING RESPIRATION.

Measure the chest by passing a tape across the chest
and around just under the arms to the middle of the back.

52

PHYSIOLOGY FOR THE LABORATORY.

Take a long, deep inspiration, hold the breath, and
measure again.

Give some idea of the difference in cubic capacity, which
this difference in circumference represents.

D. Models to Illustrate the Principles of Breathing.

NOTE. — Adapted from Hints for Teachers of Physiology by
Professor Bowditch.

I. THE VERTICAL ENLARGEMENT OF THE THORAX.

Apparatus. A glass bottle without the bottom, or a lamp-
chimney. A piece of rubber dam about half an inch larger than
the lower part of the chimney. A toy rubber balloon used by. small
boys, called a " squawker," or another piece of
rubber dam about six inches in diameter. A
rubber stopper, with two holes in it, to fit the
upper end of the chimney. About twelve inches
of glass tubing to fit the holes in the stopper.
A pinch-cock. Linen thread. Three inches of
rubber tubing to fit the glass tubing. A stout
rubber band.

The apparatus should be put together
very carefully, as in Fig. 7, to prevent
FIG. 7. — A model to the escape of air.

show the vertical „,

enlargement of the #• J-he chimney represents the chest

thorax.

b. With an elastic band fasten over the lower end of
the chimney a piece of rubber dam to represent the
diaphragm.

c. Into the upper end of the chimney fit the rubber
stopper containing two pieces of glass tubing, each bent at
a right angle. Attach the toy balloon (or the trachea and

RESPIRA TION.

53

lungs may be substituted in the place of the balloon) to
the inner end of one piece of the glass tubing. Slip a
piece of rubber tubing three inches long over the outer
end of the other piece of glass tubing, and put the pinch-
cock on the rubber tubing.

d. Partially exhaust the air from the bottle by sucking
through the rubber tubing, then close the pinch-cock.
This represents the condition in the thorax.

e. Lower and raise the rubber diaphragm. Notice what
occurs and explain.

II. THE DORSO-VENTRAL ENLARGEMENT OF THE
THORAX.

Apparatus. Six pieces of cardboard or thin wood six inches long
and one inch wide. Two light rubber bands. Eight fasteners.
Four hooks.

Fasten four parallel pieces of stiff cardboard at right
angles to two parallel bars so that they may be moved at
the fastenings. Place the hooks at 1, 2,
3, and 4 (Fig. 8) so that a line connecting
1 and 2 shall be at right angles to one
connecting 3 and 4. The elastic bands
shall be so short as to be put on the
stretch when placed over the hooks. The
longest piece represents the spinal col-
umn. The shortest piece represents the
sternum. The three or four pieces of
equal length, movable at either end, rep-
resent the ribs. The band 1—2, running obliquely down-
ward and forward, represents the external intercostal

FIG. 8. — A model to
show the dorso-ven-
tral enlargement of
the thorax.

54 PHYSIOLOGY FOR THE LABORATORY.

muscles. The band 3-4, running obliquely downward and
backward, represents the internal intercostal muscles.

a. Stretch a band over the hooks 1-2. What change is
there in the position of the horizontal pieces of cardboard ?
What effect does the contraction of the external intercostal
muscles have on the ribs and on the chest cavity ?

b. Remove the band from hooks 1—2 and stretch it over
hooks 3-4. What change is there in the position of the
pieces of cardboard? What is the effect of the contrac-
tion of the internal intercostal muscles?

III. THE LATERAL ENLARGEMENT OF THE THORAX.

In the body the ribs are curved, instead of being straight
as represented in Fig. 8, and as they rise during inspiration,
they also bulge outward, thus increasing at the same time
the lateral dimension of the chest cavity.

X.

THE ORGANS OF DIGESTION. — THE TEETH
AND THE TONGUE.

A. The Parts of a Tooth.

Material. A human incisor tooth.

Specimens of the different kinds of human teeth may
be obtained of a dentist.

Study an incisor tooth with reference to the different
parts.

Observe :

a. The crown is the upper part seen in the mouth.

b. The root, or fang, is the part embedded in the jaw-
bone.

c. The neck is a narrow part between the crown and
the root, embraced by the edge of the gum.

d. The hole is at the tip of the root. What is its use ?

e. Sketch a side view.

B. The Structure of a Tooth.

Material. A slide showing a longitudinal section of a human
incisor tooth.

Apparatus. A magnifying glass. A compound microscope.

1. Study with a magnifying glass a prepared microscopical
slide of a longitudinal section of an incisor tooth,
55

56 PHYSIOLOGY FOR THE LABORATORY.

Observe :

a. In the centre is the pulp cavity, which is filled during
life with a soft pulp containing blood-vessels and nerves.

b. The dentine is the hard part around the pulp cavity.

c. The enamel covers the dentine on the crown. How
far does it extend?

d. The cement covers the dentine on the root. How far
does it extend?

e. Sketch.

2. Study the same slide with the compound microscope,
and observe the structure of the different parts.

C. The Different Kinds of Teeth.
Materials. An incisor, a canine, a bicuspid, and a molar tooth.

1. Identify the following kinds of teeth :

a. The incisor with a wedge-shaped crown.

b. The canine with a pointed crown.

c. The bicuspid, or premolar, with a cuboidal crown.

d. The molar with an irregular crown.

e. Sketch one tooth of each kind.

2. Compare the parts in the different teeth.

a. How many cusps or points has each ?

b. How many fangs has each?

3. Arrange them on the table as they are in the jaw.

4. A dental formula is often used as a short method to

indicate the number of teeth. The numerator
indicates the number of teeth in one side of the

THE TEETH AND THE TONGUE. 57

upper jaw, and the denominator the number in one
side of the lower jaw; as, If, C1-. IJ indicates
that there are two incisor teeth in one side of the
upper jaw and three in one side of the lower jaw.

a. Write the formulae for the premolar and the molar
teeth.

b. What are the wisdom teeth ?

D. The Teeth of the Lower Animals.

Materials. The teeth of a horse or cow. The teeth of a cat or
dog.

1. Study the teeth of an herbivorous animal and compare

them with the human teeth.

2. Study the teeth of a carnivorous animal and compare

them with both the preceding.

E. The Tongue.
Apparatus. A hand-mirror.

With a hand-mirror examine your own tongue.
Notice :

a. The small papillae that cover most of the upper sur-
face of the tongue are the filiform papillae.

b. The larger papillse that are scattered occasionally
over the surface are the fungiform papillae.

c. The very large papillae, or the circumvallate papillae, are
situated as far back on the tongue as you can see. How
are they arranged ?

d. Sketch.

XI.
OTHER ORGANS OF DIGESTION.

The Digestive Organs of the Rabbit.
A. The General Plan of the Body — Preliminary,

Materials. A live rabbit. Chloroform. Cotton batting. Water.
Apparatus. An air-tight jar or box just large enough to hold
the rabbit.

Kill the rabbit by placing it in an air-tight box with
some cotton batting saturated with chloroform. When
ready for dissection, lift the skin of the ventral side and
make a cut along the median line from near the base of
the tail forward to the breast-bone. Cut through the
skin, and also through the body-wall. At the posterior
and anterior ends of the slit make cross-cuts extending
nearly around to the spinal column on either side and lay
back the flaps of the skin.

Notice :

a. The larger cavity at the posterior end of the body
is the abdominal cavity and contains all the visceral
organs.

6. The smaller cavity toward the anterior end of the
body is the thoracic cavity.

58

OTHER ORGANS OF DIGESTION. 59

c. The large circular muscle is the diaphragm and sepa-
rates the thoracic and the abdominal cavities.

d. Sketch.

B. The Alimentary Canal.

I. THE TEETH.

Examine the teeth and compare them with the human
teeth.

a. How many incisor teeth are there ?

1. What is peculiar about them ?

2. What is the purpose of this ?

b. How many canine teeth has the rabbit ?

c. Find the premolar teeth.

d. Are there any molar teeth ?

e. What is the dental formula of the rabbit ?

II. THE MOUTH, OK BUCCAL CAVITY.

Notice its general shape and size.

III. THE PHARYNX, OR THROAT CAVITY.

a. Can you find the nasal openings on the dorsal surface ?

1. How many are there?

b. Look carefully on the sides for the openings into
the Eustachian tubes. Pass a bristle along one tube into
the middle ear.

c. On the ventral surface of the pharynx look for the
opening into the windpipe, — the glottis. Which way
does the lid, or epiglottis, open ?

60 PHYSIOLOGY FOE THE LABORATORY.

d. Find the opening into the gullet, or oesophagus. Is
it ventral or dorsal to the glottis ?

e. Sketch.

IV. THE (ESOPHAGUS.

Trace the tube from its opening in the pharynx to the
stomach.

a. Through what cavity does it pass ?

b. Through what part of the cavity ?

c. Through what muscle does it extend?

d. Is it the same size throughout?

NOTE. — A few minutes may well be spent in identifying and
reviewing the lungs, trachea, heart, and main blood-vessels, since the
organs are here intact.

V. THE STOMACH.

The stomach will be found just beneath the diaphragm.

a. What is its shape and color ?

b. What is its position in relation to the surrounding
organs ?

c. Does the oesophagus open into the broad or the
narrow end of the stomach?

d. This opening between the oesophagus and the stomach
is the cardiac orifice, and this end of the stomach is the
cardiac end of the stomach.

1. Is it on the right or the left side of the

body?

2. Why is it called the cardiac end of the stomach ?

e. From which end of the stomach does the small intes-
tine lead? The opening between the intestine and the

OTHER ORGANS OF DIGESTION. 61

stomach is the pyloric orifice, and this is the pyloric end of
the stomach.

1. On which side of the body is this end of the

stomach ?

2. What lies between the pyloric end of the stomach

and the diaphragm ?

VI. THE SMALL INTESTINE.

The small intestine extends from the stomach to the large
intestine.

a. Is it the same size throughout?

b. What is its position in relation to the other organs ?

c. What holds it in position ?

d. What color is it?

VII. THE LAKGE INTESTINE.

The remaining part of the alimentary canal is the large
intestine. It is composed of three parts — the coecuin, the
colon, and the rectum.

a. The smaller intestine opens into the side of the large
intestine, leaving one end of the latter free in the body
cavity. This free end is the ccecum, and is much larger in
the rabbit than in man. What color is it?

l. Opening from the end of the caecum is a small
tube, the vermiform appendix. Inflammation of
this part causes appendicitis.

b. The colon begins at the opening from the small intes-
tine, and extends nearly to the end of the alimentary
canal. It is the longest part of the large intestine.

62 PHYSIOLOGY FOE THE LABORATORY.

1. What is its position in the abdominal cavity?

2. Is it the same size throughout ?

3. What color is it?

c. Near the end of the alimentary canal the colon
passes into the rectum.

VIII. THE LIVER.

There are several glands along the alimentary canal
that aid in digestion, the largest of which is the liver.

a. How many lobes has the liver?

b. Are they all of the same size ?

c. What is their position ?

IX. THE GALL BLADDER.

Raise the lobes of the liver and find the small gall bladder.
It is often green in color. Look for the common bile duct
leading from the liver and gall bladder to the small intestine.

X. THE SPLEEN.

Near the broad end of the stomach find the spleen, an
elongated dark-red body held in place by the thin mem-
brane or mesentery.

XL THE PANCREAS.

Another gland, a pale-red pancreas, lies in the mesentery
in a fold of the small intestine. Look for the opening of
the pancreatic duct on the inner wall of the intestine about
a foot from the pyloric orifice. Pass a probe into the duct.

XII. THE MESENTERY.

Spread out the intestines and notice the mesentery.

OTHER ORGANS OF DIGESTION. 63

a. What is its use ?

b. What do you find in it ?

c. Has it any connection with the peritoneum, or lining
of the abdominal cavity?

XIII. THE ENTIRE ALIMENTARY CANAL.

Remove the entire alimentary canal and straighten it
out on the table.

a. Measure the various parts.

b. How do they compare one with another?

c. How do they compare with the length of the body
cavities? -

d. Sketch.

C. A Detailed Study of the Different Organs.

Material. A dissected rabbit.
Apparatus. A magnifying glass.

With the scissors make a small cut in the walls of the
oesophagus, the stomach, the small and large intestines.
Wash out the contents.

Study :

I. THE WALL OF THE (ESOPHAGUS.

a. The muscular coat on the outside.

b. The mucous lining within.

II. THE WALL OF THE STOMACH.

a. The muscular coat on the outside.

b. The mucous coat. Look with the magnifying glass
for shallow pits over the surface of the mucous lining.
These contain the openings of the gastric glands that will

64 PHYSIOLOGY FOR THE LABORATORY.

be seen later with the compound microscope. In what
part of the stomach are they most numerous?

III. THE WALL OF THE SMALL INTESTINE.

a. The muscular coat.

b. The mucous lining.

c. Look for irregular folds running transversely around the
intestine called the valvulae conniventes. What is their use ?

d. With a magnifying glass examine carefully the sur-
face of the mucous lining, until you find small conical
elevations, or villi.

e. Sketch.

IV. THE WALL OF THE LARGE INTESTINE.

a. The muscular coat.

b. The mucous lining. What do you find on this ?
Compare with the small intestine.

D. The Microscopical Structure of the Alimentary Canal.

Materials. Microscopical slides showing cross-sections of the walls
of the stomach, the small intestine, the pancreas, and of the liver.
Apparatus. Compound microscope.

I. THE MICROSCOPICAL STRUCTURE OF THE WALL OF
THE STOMACH.

Examine with the compound microscope a cross-section
of the wall of the pyloric end of the stomach.

Notice :

a. The muscular coat.

1. Which way do the fibres extend?

2. How thick is the coat compared with the thick-

ness of the entire wall ?

OTHER ORGANS OF DIGESTION. 65

6. The mucous coat.

1. How thick is this coat?

2. Do you find the shallow pits on the surface?

3. The long tubes opening on the inner surface are

the gastric glands.

c. The submucous coat lies between the mucous and
the muscular coats. What do you find here?

d. Sketch.

II. THE MICROSCOPICAL STRUCTURE OF THE WALL
OF THE SMALL INTESTINE.

Examine with the compound microscope a cross-section
of the wall of the small intestine that has been injected.

Notice :

a. The muscular coat.

1. How thick is it?

2. Which way do the fibres extend?

b. The mucous coat.

1. Is it as thick as that of the stomach ?

2. Do you find the villi ? Notice the blood-vessels

in them. The lacteal is the large vessel in
the centre of each villus.

3. The tubular glands opening on the inner surface

are the crypts of Lieberkuhn.

c. The submucous coat is just beneath the mucous coat.
What does this contain ?

d. Sketch.

66 PHYSIOLOGY FOR THE LABORATORY.

III. THE MICROSCOPICAL STRUCTURE OF THE PAN-

CREAS.

Examine a cross-section of pancreas.
Observe :

a. The arrangement of the cells in circular groups. Each
group is a cross-section of an alveolus, or tube formed by
secreting cells.

b. A small opening, or duct, is in the centre of each alve-
olus, but is hardly visible, being filled by spindle-shaped
cells.

c. The alveoli are grouped around larger ducts to form
lobules, which in turn unite to form the lobes of the pancreas.

d. The lobes, the lobules, and the alveoli are bound
together by connective tissue carrying the blood-vessels.

e. Sketch and label the various parts.

IV. THE MICROSCOPICAL STRUCTURE OF THE LIVER.
Examine in the same way a cross-section of liver.

Observe :

a. The hepatic cells of which the liver is everywhere
composed. What parts of the cell can you distinguish?
How are they arranged?

b. An hepatic veinlet is seen in section in the centre of
each group or lobule of hepatic cells. Whither does this
blood-vessel lead?

c. Branches of the portal vein and hepatic artery may be
traced in the connective tissue between the lobules.

d. The bile ducts are small tubes lined with a single
layer of cuboidal cells. What is their use?

e. Sketch.

XII.

FOODS.

All foods consist primarily of water, proteids or protein,
fats, carbohydrates, and inorganic salts.

A. Water in Foods.

Materials. Potato. Carrot. Turnip. Cabbage. Apple.
Apparatus. Oven. Standard Fairbanks scales.

I. WATER IN POTATOES.
Experiment :

1. Wash a potato thoroughly and dry it.

2. Weigh it.

3. Heat it in an oven or on the radiator until com-

pletely dried. Take care not to burn it.

4. Weigh it again.

6. Calculate the per cent of water in potato.

II. WATER IN OTHER VEGETABLES.
Experiment :

1. In the same way examine carrot, turnip, onion,

cabbage, or apple, and calculate the per cent
of water.

2. Compare your result with a list of food com-

positions.

67

68 PHYSIOLOGY FOR THE LABORATORY.

B. Carbohydrates in Foods — Starch.

I. THE IODINE TEST FOR STARCH.

Materials. A few grains of starch. An aqueous or alcoholic
solution of iodine. Water.

Apparatus. A test-tube. Bunsen burner.

Experiment :

1. Thoroughly mix the starch with about lOc.c. of

cold water.

2. Dilute, boil, and cool.

3. Add a few c.c. of iodine solution.

4. Dilute again if the color is very dark. Boil

and cool.

II. STARCH IN POTATO.

Materials. Potato. Water. Iodine solution (either aqueous or
alcoholic).

Apparatus. Evaporating dish. Knife. Bunsen burner.

Experiment :

1. Wash thoroughly a potato and peel it.

2. Grate or slice it very thin and wash in an

evaporating dish.

3. Collect the white sediment.

4. Boil some of this with water.

5. Test for starch with iodine.

III. THE STRUCTURE OF THE STARCH GRAINS OF THE

POTATO.

Materials. A few starch grains just washed from a potato.
Apparatus. Glass slide. Cover-glass. Compound microscope.

FOODS. 69

Mount a drop of water containing a few grains of starch
and examine with the compound microscope.

Observe :

a. The shape of the grains.

b. Their concentric structure.

c. The hilum or centre of the curves.

d. Sketch.

Run a drop of iodine solution under the cover-glass and
notice the change in the grains of starch.

IV. STARCH IN OTHER FOODS.

Materials. Beans. Peas. Oatmeal. Tapioca. Farina. Rice.
Cornstarch. Sago. Barley. Indian meal. Wheat flour. Rye.
Crackers. Bread. Iodine solution.

Apparatus. Test-tubes. Test-tube rack. Filter-paper. Funnel.
Evaporating dish. Bunsen burner.

Experiment :

Examine for starch one of the following :

Beans, peas, oatmeal, tapioca, farina, rice, cornstarch,
sago, barley, Indian meal, wheat flour, rye, crackers, and
bread.

1. Make a paste by grinding and mixing with cold

water.

2. Add hot water and thoroughly mix.

3. Filter when necessary.

4. Test the nitrate for starch with the iodine test.

70 PHYSIOLOGY FOB THE LABORATORY.

Carbohydrates in Foods — The Sugars.

V. TEST FOR DEXTROSE, GRAPE SUGAR — FEHLING'S

SOLUTION.

Materials. 15c.c. of Fehling's solution, which is a solution of
alkaline potassio-tartrate of copper K2Cu(C4H4O6)2. Three grapes.
Water,

Apparatus. Test-tubes. Bunsen burner. Mortar, and pestle.
Funnel and filter-paper.

Experiment :

1. Boil 15 c.c. of Fehling's solution in a test-tube.

If no yellow color appears, the solution is in
good condition.

2. Thoroughly mix with water in a mortar three or

four grapes.

3. Filter.

4. Test the nitrate for a reducing sugar as follows :

5. Add 1 c.c. of the filtrate to the Fehlirig's solu-

tion and boil. What color is the precipitate
cuprous* oxid, Cu2O ? The sugar acts as a
reducing agent and changes the cupric salt
to a cuprous salt. This is characteristic of
dextrose, but there are other sugars, as maltose
and lactose (milk-sugar), that reduce metallic
salts, although in a less degree.

VI. TEST FOR DEXTROSE — BARFOED'S SOLUTION.

Materials. 15 c.c. of Barfoed's solution, which is a solution of
acetate of copper in water acidulated with acetic acid. 5 c.c. of a
solution of dextrose.

Apparatus. Test-tubes. Bunsen burner.

FOODS. 71

Experiment :

To the Barfoed's solution in a test-tube add the solu-
tion of dextrose and boil. What color is the precipitate?
What is it ? This test distinguishes dextrose from lactose,
maltose, and cane-sugar, which do not reduce Barfoed's
solution Avhen boiled with it for a short time.

VII. SACCHAROSE, CANE-SUGAR, AND FEHLING'S SOLU-

TION.

Materials. A few grains of cane-sugar. 15 c.c. of Fehling's solu-
tion. Water.

Apparatus. Test-tubes. Bunsen burner.

Experiment :

1. Boil the Fehling's solution in a test-tube.

2. Dissolve the sugar in 10 c.c. of water.

3. Add the solution of sugar to the Fehling's solu-

tion and boil. What happens ? Does saccha-
rose reduce Fehling's solution ?

VIII. THE ACTION OF HYDROCHLORIC ACID UPON
SACCHAROSE, CANE-SUGAR.

Materials. 100 c.c. of a strong solution of cane-sugar. 10 c.c. of
strong hydrochloric acid. 15 c.c. of Fehling's solution.

Apparatus. A glass flask. Bunsen burner. Ring-stand. Wire gauze.

Experiment :

1. To the solution of cane-sugar in the flask add

the hydrochloric acid.

2. Boil one hour or more and cool.

Caution. Never add hot caustic soda or potash to an acid.

3. Test 5 c.c. of the boiled solution for a reducing

sugar.

7:2 PHYSIOLOGY FOR THE LABORATORY.

IX. THE ACTION OF HYDROCHLORIC ACID UPON STARCH.

U A few grains of starch. 2c.c, of hydrochloric acid.

15 ex. of FeUing^s solution. Water.

Apparatus, Test-tubes. . Bunsen burner.

Experiment:

1. Mix the starch with 5 c.c. of water.

2. Add the hydrochloric acid. Boil and cool.

3. Add the Fehling's solution and boil. What

occurs? Into what has some of the starch
heen changed?

X. EXAMINE FOODS FOR DEXTROSE.

Examine maple sugar, syrup, molasses, dates, and
prunes for dextrose.

XI. THE TASTE OF THE SUGARS.

Taste a small amount of dextrose, saccharose, and lactose
and determine which is the sweetest.

C. Proteids in Foods.
I. GENERAL TESTS FOR PROTEIDS.

Egg-albumin, or the white of an egg, is a proteid. Try
the following tests for proteids upon some raw white of
egg diluted with water.

First test: Xanthoproteic Reaction.

Materials. 5c-c. of egg-albumin diluted with water. 5 ex. of
concentrated nitric add. 5 c-c. of ammonium hydrate.

Apparatus. Test-tubes. Test-tube rack. Bunsen burner.

Experiment :

Add the nitric acid to the proteid and -heat. What

FOODS. ~

happens ? Cool under the faucet and add the ammonium
hydrate. What happens ? The color is characteristic.

b. Second test : Piotrowski's Reaction.

Materials. 5c.c. of proteid solution. 10c.c- of a concentrated
solution of sodium hydrate. 2-3 drops of a one per cent solution of
cupric sulphate.

Apparatus. Test-tubes. Test-tube rack. Bunsen burner.

Experiment :

To the proteid solution add the sodium hydrate and
then the cupric sulphate. What color is obtained ? BoiL
What change is there in the color? This test detects the
smallest traces of all proteids.

c. Third test.

Materials. 5 c.c. of proteid solution. 5 c-c. of acetic acid- 3-4
drops of potassium ferrocyanide.
Apparatus. Test-tubes.

Experiment :

To the proteid solution add the acetic acid and then
the ferrocyanide. What occurs ?

II. EXAMINE MLLK FOR PROTEIDS.

10 C.C. of milk. 10 C.C- of water. 5 c-c_ of acetic
acid or vinegar. 10 c.c. of lime-water. 10 c.c- of a concentrated
solution of sodium hydrate. 2—3 drops of a dilute solution of cupric
sulphate,

Apparatus. Test-tubes. Test-tube rack. Bunsen burner. Filter-
paper. FunneL

Experiment :

l. Dilute the milk with the water and add the
acetic acid. What happens? This precipi-
tate is the proteid, casein.

74 PHYSIOLOGY FOE THE LABORATORY.

2. Filter. What is the filtrate ?

3. Add a little of the casein to water and shake.

Is the casein soluble in water?

4. Add a little of the casein to lime-water and

shake. Is it soluble?

5. Test milk by the second method above for

proteid.

6. Boil some milk. Does the casein coagulate?

Compare this result with the action of heat
upon egg-albumin.

III. TEST CHEESE FOR PROTEIDS.

Materials. A small piece of cheese. 25 c.c. of lime-water. 10 c.c.
of sodium hydrate (concentrated). 2 or 3 drops of cupric sulphate.

Apparatus. Test-tube. Filter-paper. Funnel. Bunsen burner.
Evaporating dish.

Experiment :

1. Thoroughly mix a small piece of cheese with

about 25 c.c. of lime-water.

2. Filter. Is the ' proteid in the precipitate or

filtrate ?

3. Test for proteid by the second test above.

4. From what is cheese made?

5. What proteid is in milk ?

6. What proteid is in cheese ?

IV. EXAMINE MUSCLE FOR PROTEIDS.

Materials. A piece of lean beef. 25 c.c. of 10 per cent solution
of ammonium chloride. Lime-water. 20 c.c. of a concentrated solu-
tion of sodium hydrate. 4-6 drops of cupric sulphate. Alcohol, 75
per cent solution.

Apparatus. Evaporating dish. Filter-paper. Test-tube. Bun-
sen burner. Funnel.

FOODS. 75

Experiment :

1. Thoroughly wash and mince a piece of lean

beef.

2. Save the washings and test for proteid.

3. Mix the meat with ammonium chloride. The

ammonium chloride dissolves the proteid,
myosin, in the muscle.

4. Filter. Is the myosin in the precipitate or

filtrate ?

5. Test part of the filtrate for proteids by the

second test.

6. Add alcohol to part of the filtrate until a pre-

cipitate is formed. Myosin is insoluble in
alcohol. What is the precipitate?

7. Heat in a test-tube some of the solution of

myosin. Notice what change takes place,
and compare the result with the effect of
heat upon egg-albumin and casein.

D. Fats in Foods.
I. AN EMULSION.

Materials. Water. 5 c.c. of olive oil. 2 small pieces of butter.
An egg.

Apparatus. Test-tubes. Evaporating dish. Bunsen burner.

Experiment :

1. Add 2 c.c. of oil to about 10 c.c. of water.

What occurs ? Why ?

2. Add a piece of butter to 10 c.c. of water. What

occurs ? Why ? Why does cream rise ?

3. Repeat experiment 2 with melted butter.

76 PHYSIOLOGY FOR THE LABORATORY.

4. Melt the butter and add it to the white of an
egg. Beat them together. Add the water
and beat again. Does the butter and water
mix? Why? This is an emulsion. Of what
advantage is it in digestion ?

II. THE EMULSION OF FAT IN MILK.

Materials. 1-2 c.c. of milk.

Apparatus. A glass slide. A cover-glass. Compound microscope.

Mount a drop of milk and examine under the microscope.
Notice :

a. The fat globules.

b. The liquid.

c. Sketch.

d. In what form is the fatty portion of the milk? Is
this an advantage or a disadvantage in digestion ? Why ?
Compare the results obtained from C. II, and infer what
it is that renders milk so valuable as a food.

III. THE EXTRACTION OF FAT FROM FOODS.

Materials. Indian meal. Whole wheat flour. Common flour. Benzine.
Apparatus. Evaporating dish. Filter-paper. Funnel.

Extract the fat from the Indian meal, whole wheat
flour, and common flour.
Experiment :

1. Mix the Indian meal with benzine or ether.

2. Filter and allow a drop of the filtrate to evapo-

rate on a piece of clean glass. What is left ?
Prove that this contains fat. What, then, is
one of the food constituents of Indian meal ?

3. Test in the same way the whole wheat and com-

mon flour. Which contains the most fat ?

XIII.
DIGESTION.

The Effect of the Digestive Fluids on Foods.
A. The Saliva.

I. THE MICROSCOPICAL EXAMINATION OF SALIVA.

Material. Saliva.

Apparatus. A test-tube. A glass slide and cover-glass. A com-
pound microscope.

Collect half a test-tube of saliva. Mount a drop on the
glass slide and examine with the compound microscope.

Notice :

a. The epithelial cells. Where did they come from?

b. Possibly, debris of food.

c. Forms of bacteria.

II. THE EFFECT OF SALIVA, ON STARCH.

Materials. Potato starch. Saliva.

Apparatus. Warm water-bath, or one made of a large beaker.
A Bunsen burner. A ring-stand. A piece of wire gauze six inches
square. A thermometer. Test-tubes and rack.

Prepare a warm water-bath by rilling the beaker to a
depth of three or four inches with water, and placing it
on the wire gauze on the ring-stand, over the Bunsen
burner. Stand the thermometer in the water and keep
it at a temperature of 42° C.

77

78 PHYSIOLOGY FOR THE LABORATORY.

Experiment :

1. Make a dilute starch paste of pure potato starch

and boil for a few minutes. One grain of
starch to 200 c.c. of water is sufficient.

2. Dilute 5 c.c. of saliva with 25 c.c. of water.

3. Place one of the following solutions in each of

three test-tubes :

(1) 20 c.c. of starch paste.

(2) 20 c.c. of diluted saliva.

(3) 5 c.c. of saliva and 15 c.c. of starch

paste.

4. Place in the warm bath for ten minutes and then

test each for maltose. What is the effect of
saliva on starch ? Why was the mixture kept
at a temperature of 42° C. ?

B. The Gastric Juice.
I. THE PREPARATION OF ARTIFICIAL GASTRIC JUICE.

Materials. | a gram of pepsin. 2 c.c. of strong hydrochloric

acid. 50 c.c. of water.

Apparatus. A small beaker. A warm water-bath and ther-
mometer.

The essential constituents of gastric juice are hydrochloric
acid, pepsin, and rennin. As far as we know, the action of
rennin is confined to th^ curdling of milk, so that a solution
of pepsin, slightly acidulated with hydrochloric acid, rep-
resents the action of the normal gastric juice on proteids.

Experiment :

Mix the water, the acid, and the pepsin in the beaker
and place this in a warm water-bath. Insert the ther-

DIGESTION. 79

mometer and keep the temperature at 100° F. or 42° C.
The body temperature is about J$&^ C. j>7 6 £-

II. THE ACTION OF GASTRIC JUICE ON PROTEIDS.

Materials. Egg-albumin. Artificial gastric juice. Water.
Apparatus. Evaporating dish. Glass stirring rod. Test-tubes
and rack. Warm water-bath and thermometer.

Caution. Label all of your test-tubes.
Experiment :

1. (Preliminary) Heat some water in an evaporating

dish. Into this drop a little well-shaken egg-
albumin and stir constantly.

2. Add a small piece of the coagulated albumin,

not minced, to 10 c.c. of gastric juice. Keep
it cool and still.

3. Add a small piece of the egg-albumin, minced, to

10 c.c. of gastric juice. Place it in the water-
bath but keep it still.

4. Add the same amount of minced egg-albumin

to 10 c.c. of gastric juice. Keep at 42° C., but

™" shake often to imitate the action of the stomach.

Compare the three results at the end of two

hours. What three conditions aid jdigestion
• -— — — —

III. ARE BOTH ACID AND PEPSIN NECESSARY TO

DIGESTION ?

Materials. Coagulated egg-albumin. Water. Dilute hydrochloric /
acid. Pepsin.

Apparatus. Test-tubes. Warm water-bath.

Place a small piece of coagulated egg-albumin in each
of four test-tubes.

80 PHYSIOLOGY FOR THE LABORATORY.

Experiment :

1. To the first test-tube add 10 c.c. of water.

2. To the second test-tube add 10 c.c. of dilute

hydrochloric acid.

3. To the third test-tube add 10 c.c. of pepsin and

water.

4. To the fourth test-tube add 10 c.c. of pepsin

and dilute hydrochloric acid.

5. Place all the test-tubes in the warm bath and

notice the results at the end of one or two
hours.

IV. THE ACTION OF GASTRIC JUICE ON MILK.

Materials. 10 c.c. of milk. 10 c.c. of water. A few grains of
pepsin. Rennet.

Apparatus. Test-tubes. Warm water-bath.

When the milk reaches the stomach it is first acted
upon by the rennin and then by the pepsin and hydro-
chloric acid.

Experiment :

1. The action of the rennin. (Rennin is the essen-

tial element of rennet, which is obtained from
the fourth stomach of the calf.) Add 4 or 5
drops of rennet to the milk in a test-tube,
and allow it to stand a few minutes in the
warm water-bath. What is the curd and the
whey ? What is the action of rennin on milk ?

2. The action of pepsin. Mix the curdled milk,

the pepsin, and water in a test-tube and place
it in the warm water-bath. . Look at it every
fifteen minutes. What takes place ?

DIGESTION. 81

3. The action of pepsin and hydrochloric acid. To
part of the above mixture add a few drops
of hydrochloric acid and keep it in the water-
bath. Compare the two at the end of two
or three hours. Have both the proteid and
the fat constituents been acted upon ? What
shows this? What is the action of gastric
juice on milk?

C. The Pancreatic Juice.

I. THE PREPARATION OF ARTIFICIAL PANCREATIC

JUICE.

Materials. 100 c.c. of water. 15 grains of sodium carbonate,
baking soda. 5 grains of pancreatin. ^'<\

Apparatus. A small beaker. A water-bath and thermometer.

The essential elements of pancreatic juice are trypsin,
amylopsin, steapsin, and rennin. Trypsin acts upon the
proteids, amylopsin upon the carbohydrates, and steapsin
upon the fats. The action of rennin is to coagulate what-
ever casein may have escaped coagulation by the gastric
juice.

Experiment :

In the small beaker mix the pancreatin with the aqueous
solution of sodium carbonate. Place in the water-bath
and keep it at 42° C.

II. THE ACTION OF PANCREATIC JUICE ON FATS.
Pancreatic juice acts upon fats, starch, and proteids.

Materials. 5 c.c. of olive oil. A tablespoonf ul of flour. 5 c.c.
of melted butter. 20 c.c. of artificial pancreatic juice.

82 PHYSIOLOGY FOE THE LABORATOEY.

Apparatus. Evaporating dish. Test-tubes and rack. Warm
water-bath.

Experiment :

1. Recall the experiments on fats in food.

2. Make an emulsion with olive oil, flour, and water.

3. To 10 c.c. of warm artificial pancreatic juice add

1 c.c. of olive oil. Shake.

4. To 10 c.c. of warm pancreatic juice add 1 c.c. of

melted butter. Shake and allow to stand in
the warm water-bath. What is the action
of pancreatic juice on fats as far as you can
judge from these experiments? Compare with
results in B. IV.

III. THE ACTION OF PANCREATIC JUICE ON PROTEIDS.

Materials. 15 c.c. of artificial pancreatic juice. A piece of raw
lean beef cut in small pieces.

Apparatus. Test-tube. Warm water-bath.

Experiment :

Into 15 c.c. of pancreatic juice drop the small pieces of
beef. Place the test-tube in the warm water-bath and
watch from time to time. Compare this action with that
of the gastric juice.

IV. THE ACTION OF PANCREATIC JUICE ON MILK.

Materials. 40 c.c. of milk. 20 c.c. of warm pancreatic juice.
30 c.c. of acetic acid, 5 c.c. of hydrochloric acid.
Apparatus. Test-tubes. Warm water-bath.

Experiment :

1. To 20 c.c. of milk add 5 c.c of hydrochloric acid
and shake. What is the precipitate ? Filter

DIGESTION. 83

and wash the precipitate two or three times.
Add some of this coagulated casein to 10 c.c.
of pancreatic juice and place in the warm
water-bath. Normally, what curdles the milk?
What is the effect of the pancreatic juice on
the curd?

2. Mix 20 c.c. of the milk and 10 c.c. of pan-

creatic juice. Place in the warm bath and
watch for results. After an hour what has
occurred? The precipitate is casein. Is it
in fine particles or in solid clots?

3. This experiment is to be performed after the

milk has been digested in experiment 2 for
an hour. Place in one test-tube 10 c.c. of
fresh milk and in another 10 c.c. of the milk
of experiment 2. Add to each the same
amount, about 15 c.c. of acetic acid or vinegar.
In which is the clot more firm ? Milk is often
treated with pancreatin or " peptonized " for
children and invalids. Why ?

D. Absorption of the Soluble Products of Digestion.

After the food has been acted upon by the various
digestive fluids of the alimentary canal, it is ready to
supply nourishment to the body. The products of diges-
tion, then, must in some way pass through the walls of
the alimentary canal and pass into the blood, in order to
reach the various organs of the body. Just how these
substances are able to pass through the walls of the intes-
tine has long been a question among physiologists. It is

84 PHYSIOLOGY FOR THE LABORATORY.

now thought that the epithelial membrane, composed of a
single layer of cells, takes an active part in the absorption
of the soluble, products of digestion.- The laws that
control living cells are probably different from those of
4 imbibition ' and t osmosis ' with a dead membrane. But
as these physical laws may aid in absorption they should
not be disregarded.

I. THE EPITHELIAL CELLS.

Review the microscopical slide showing a section of
the wall of the small intestine. Recall particularly the
epithelial cells, their shape, size, arrangement, and the
number of layers.

II. DIFFUSION.

Materials. 20 c.c. of water. lOc.c. of oil. 5 c.c. of ink.
Apparatus. Test-tubes.

Experiment :

1. Shake 10 c.c. of water and 10 c.c. of oil together.

Do they mix or diffuse ?

2. Shake the water and ink. Do they mix ? What

is meant by diffusion ? Why do the water and
ink diffuse while the water and oil do not?

III. OSMOSIS.

Materials. Two eggs. A cup of vinegar. Dextrose.
Apparatus. A large beaker. Tape-measure.

Experiment :

1. Measure the circumference of an egg around
the short axis and around the long axis, and
make a record of the measurements.

DIGESTION. 85

2. Place the egg in dilute acetic acid or vinegar,

and leave it a day or two until all the lime in
the shell has been dissolved.

3. Wash and place it in a solution of dextrose.

4. After a day or two measure the circumference

in the same places as before and compare
these measurements with those first taken.
What does the difference show?

5. Test the second egg for dextrose.

6. Test the egg that has been in the dextrose solu-

tion for dextrose.

7. What has taken place in the first egg ?

IV. IMBIBITION.

A. Capillary Imbibition.

Materials. Any colored solution, as red ink. Blotting-paper.
Apparatus. Glass tubing of different sizes.

Experiment :

1. Place a few pieces of glass tubing of different

sizes in a glass of red ink and note the result.

2. Suspend a strip of filter-paper or blotting-paper

so that one end dips in the red ink. Leave
'for some time. What happens? Why?

B. Molecular Imbibition.

Materials. Glue. Water.
Apparatus. A small beaker.

Experiment :

l. Soak a piece of glue in cold water for about
half an hour. Compare this with a piece of
the dry glue and explain the difference.

86 PHYSIOLOGY FOR THE LABORATORY.

2. Put a rubber cot on a finger and allow it to

remain for some time. Explain the result.

3. Explain the condition of the hands after they

have been in warm water for some time.

4. Explain the uncomfortable feeling produced by

wearing rubber shoes or boots for a long time.

XIV.

THE KIDNEYS.
A. The Kidney of a Sheep.

Material. A kidney of a sheep. This may be obtained at any
market.

Cut away most of the fat surrounding the kidney and
any other tissues that may be attached, but leave the ureter
and blood-vessels untouched.

I. THE EXTERNAL PARTS.

Notice :

a. The shape of the kidney.

b. The size.

c. The tube or ureter leading from the kidney.

d. The blood-vessels.

e. The fat. What is its use ?
/. The thin skin on the outside.

g. The hilus, or deep fissure on the inner border. Where
does it lead ?
h. Sketch.

II. THE INTERNAL PARTS.

Cut the kidney in halves longitudinally, making the
cut through the hilum and parallel to the broad side of
the kidney.

87

88 PHYSIOLOGY FOR THE LABORATORY.

Notice :

a. The pelvis is the widened end of the ureter.

b. The cups, or calices, are the smaller cavities that unite
to form the pelvis.

c. The cortical portion is the outer part of the wall of
the kidney. What is its color and structure ?

d. The medullary portion is within the cortex. It is
divided into separate pyramidal portions, called the pyra-
mids of Malpighi. How does it compare in color and
structure with the cortex?

e. Sketch.

III. THE MICROSCOPICAL STRUCTURE OF THE KIDNEY.

Material. A prepared radial section of injected kidney.
Apparatus. A compound microscope.

Examine under a low power and determine :

a. The uriniferous tubules, or small tubes, compose the
larger part of the medullary and cortical portions. Each
tube is very complicated and is composed of straight and
convoluted parts. It arises in a Malpighian body (see b)
and after passing through the cortical and medullary
portions, finally opens at the apex of a pyramid.

b. The Malpighian bodies are small spherical bodies in the
cortical portion of the kidney. Each one is composed of
a network of capillary blood-vessels, surrounded by a thin
membrane which narrows to form the beginning of a tubule.
The fluid is secreted in the capsule and in a part of the
tubules.

XV.
THE SKIN AND BODILY TEMPERATURE.

A. The Gross Structure of the Skin.

I. THE SKIN ON THE HAND.

Apparatus. A magnifying glass,

Examine with a magnifying glass the skin of the palm
of the hand.

Notice :

a. The larger furrows, or creases. What is their cause ?

b. The smaller ridges, or papillae, and the small furrows.
How are they arranged ?

c. The small openings. These are the openings of the
perspiratory, or sweat, glands. How are they arranged?

d. Sketch.

II. THE Two LAYERS OF THE SKIN.

Apparatus. A sewing needle.

Carefully insert a needle under the outer skin of your
finger.
Notice :

a. The two layers of the skin.

b. The outer, dead skin, or epidermis.

1. What is its color ?

2. Has it blood-vessels or nerves ?

89

90 PHYSIOLOGY FOR THE LABORATORY.

c. The inner, true skin, or dermis. Has it blood-vessels
or nerves ?

III. A BLISTER.

When you have a water-blister, insert a needle under
the outer skin and find the liquid that collects between
the two layers of the skin. Whence does this liquid
come ? Why does it not exude through the pores of the
sweat glands ?

IV. ATTACHMENT OF THE SKIN.

Try to lift the skin up away from the underlying tis-
sues in the following places : back of the hand, cheek,
forehead, neck, palm of hand, and fingers. What differ-
ences in the mode of the attachment in the different
places ? Why should the skin be so firmly attached to
the palms and the fingers ?

B. Finger-Prints.
Material. Printer's ink and paper.

Spread a film of thin printer's ink on a piece of paper,
glass, or a stamping pad. Place the under surface of the
last joint of a finger on the ink and then on a piece of
clean paper. Study the print and find the arrangement of
the small ridges.

a. Are they in an arch, a loop, or a whorl ? What is
their use ?

5. Make a print of all your fingers and thumbs and
compare the results with those of others.

THE SKIN AND BODILY TEMPERATURE. 91

C. The Microscopical Structure of the Skin.

Material. A microscopical slide showing a cross-section of the
skin of the head.

Apparatus. A compound microscope.

With the compound microscope examine a prepared
slide showing a cross-section of the skin of the head, and
find as many as possible of the following parts.

Notice :

a. The epidermis.

1. Its thickness.

2. The three layers of cells.

(1) The outer layer of elongated horny cells.

In which direction are they elongated ?
Have they any nuclei ? What is their
relation to dandruff?

(2) The second layer of rounded cells.

(3) The third layer of columnar cells. In which

direction are these cells elongated?
Have they any nuclei ? Compare
with the outer layer and determine
the relative amount of life in the
two layers. Inferences.

b. The dermis.

1. Its thickness.

2. Its structure.

3. The hair.

(1) The root of the hair is the part embedded
in the skin.

92 PHYSIOLOGY FOR THE LABORATORY.

(2) The stem of the hair is the part outside

of the skin. Is this stem solid or

hollow? Is it one piece or made up
of parts?

(3) The follicle is the depression in the skin

that contains the root. What relation
do the walls of the follicle bear to the
dermis and epidermis?

(4) A modified papilla is at the base of the

follicle over which the root of the
hair fits.

4. The sebaceous, or oil, glands.

(1) Their shape and size.

(2) Where do their ducts open?

5. The perspiratory, or sweat, glands are the tubular

glands.
Find:

(1) The body of the gland. What is its posi-

tion, shape, size, and structure.

(2) The gland duct. Follow its course through

the epidermis.

D. The Temperature of the Body.
I. THE NORMAL TEMPERATURE.

Apparatus. A physician's thermometer.

Place a physician's thermometer under the tongue in
the mouth. Close the lips, hold the thermometer there
for five minutes, and then read the temperature.

THE SKIN AND BODILY TEMPERATURE. 93

II. VARIATIONS IN THE TEMPERATURE.

Apparatus. A physician's thermometer.

Take the temperature at different times, when very
warm and when cold.

III. THE REGULATION OF THE TEMPERATURE.

Material. Ether or alcohol.

Pour a few drops of ether or alcohol on the hand. How
does it feel ? Why ? How do a dog and a cat cool off ?
How does a person ?

XVI.
THE NERVOUS SYSTEM.

The Brain.

The nervous tissues of the body may be divided into
several parts ; the brain, the spinal cord, the nerves, the
ganglia, and the sympathetic nerves and ganglia.

A. The Brain of a Sheep.

Materials. The head of a sheep. Cotton batting. Potassium
bichromate. Formalin or formaldehyde. A human brain if pos-
sible.

Apparatus. A meat-saw. Bone forceps. Glass jar.

The head of a sheep, a rabbit, or of some other verte-
brate may be obtained and the brain be taken from it. In
order to obtain the brain in good condition the roof of the
skull must be removed. With a meat-saw, cut across the
front of the skull just back of the eyes, and then saw,
backward along either side of the head, just above the
ears to the opening in the skull where the spinal cord
joins the brain. Carefully remove the large, nearly tri-
angular piece of bone. With the handle of a scalpel,
slowly free the brain with its coverings from the skull.
Take care not to cut the roots of the cranial nerves close
to the brain, but preserve them as long as possible. Wrap
the brain in a piece of cotton batting to prevent its weight

94

THE NERVOUS SYSTEM. . 95

from flattening it against the side of the jar while soft,
and immerse it in the following liquid to harden.

Potassium bichromate 10 grams.

Formalin or formaldehyde 40 per cent . . . 15-20 c.c.
Water 500 c.c.

Allow it to remain in this liquid two weeks, and then
remove and wash it in running water for two or three
hours. If it is not sufficiently hard, let it stand over-
night in a mixture of 350 c.c. of 5 per cent formalin and
150 c.c. of 95 per cent alcohol. If a fresh brain be placed
in this latter mixture, it will harden throughout, with no
appreciable shrinkage, to the consistency of India rubber
within thirty-six hours, but there will be no differentiation
of white and gray matter.

The potassium bichromate colors the cellular (gray)
tissue, but has no effect upon the fibrous (white) tissue,
while alcohol bleaches both tissues.

I. THE BRAIN AS A WHOLE.

a. What is its position, size, and shape ?

b. The surfaces of the brain.

1. The dorsal surface is the upper or more rounded

surface.

2. The ventral surface is the lower or flatter surface.

3. The anterior end is more rounded than the

posterior.

II. THE COVERINGS OF THE BRAIN.

a. The dura mater is the thick outer covering.

1. Is it attached to the brain ?

2. Is it close to the brain?

96 PHYSIOLOGY FOR THE LABORATORY.

3. What is its relation to the long median fissure

and to the fissure between the cerebrum and
cerebellum ?

4. What is its use ?

b. The pia mater is the thin inner membrane.

1. What is on this membrane ?

2. What is its function?

c. The arachnoid is between the two. It is a thin mem-
brane just outside the pia mater, and bridges across the
fissures.

III. THE GENERAL PARTS.

Carefully remove the dura mater, but the pia mater may
remain on the brain to protect it.

a. The cerebrum is the large anterior part of the brain.
This is the fore-brain.

b. The cerebellum or smaller division may be seen on the
dorsal surface posterior to the cerebrum. Trace it around
toward the ventral surface.

c. The pens Varolii is the band that extends across ven-
trally from one side of the cerebellum to the other.

d. The medulla oblongata, or spinal bulb, is beneath the
cerebellum, posterior to the pons Varolii. Push the cere-
bellum gently forward to find the dorsal surface of the
medulla. 5, c, and d constitute the hind-brain.

e. The crura cerebri, or peduncles of the cerebrum, are on
the ventral side, just anterior to the pons Varolii.

1. Where do their netve fibres come from ?

2. Whither do they lead?

THE NERVOUS SYSTEM. 97

/. The corpora quadrigemina are situated on the dorsal
side. Gently press backward the cerebellum and look
forward under the cerebrum for them.

1. How many parts are there?

2. What is their shape ?

3. Are they all of the same size ? e and / are in

the mid-brain.

g. Sketch larger than life-size a dorsal, a ventral, and a
lateral view of the entire brain, showing the exact relation
of the parts, and label each.

IV. A DETAILED STUDY OF THE PARTS OF THE
BRAIN.

a. The cerebrum, or fore-brain.

1. The two cerebral hemispheres, the right and the

left.

(1) Their general shape.

(2) How are they separated?

(3) How are they connected?

2. The irregular swellings are called convolutions.

(1) Is there any definite arrangement ? Com-
pare the two sides of the same specimen,
and then compare your specimen with
another.

3. The fissures are the depressions between the

convolutions. Locate the principal fissures
on each hemisphere.

(1) The median fissure lies between the two
hemispheres.

98 PHYSIOLOGY FOE THE LAB OB A TORY.

(2) The fissure of Sylvius is on the lateral sur-

face of the hemisphere. It begins about
one third the distance from the anterior
to the posterior end and runs upward
and backward.

(3) The fissure of Rolando begins at the median

fissure on the dorsal surface of the brain
and runs downward and forward in front
of the fissure of Sylvius.

(4) The parieto-occipital fissure also begins at

the median fissure, but posterior to the
fissure of Rolando, and runs across the
hemisphere.

4. Find the lobes resulting from these fissures.

(1) The frontal -lobe is at the anterior part of

the brain.

(2) The occipital lobe is at the posterior part.

(3) The parietal lobe lies between the two along

the median line.

(4) The temporal lobe is on the side below the

fissure of Sylvius. How many convo-
lutions are there in each lobe?

5. The olfactory lobes are the two small elongated

lobes on the ventral surface of the hemi-
spheres at the anterior end.

b. The hind-brain.

l. The cerebellum.

(1) Its shape. It consists of a central and
two lateral parts.

THE NERVOUS SYSTEM. 99

(2) Its structure. Are there any convolutions

and fissures ? Is it divided into hemi-
spheres ?

(3) Its relative size. Compare with the

human brain.
2. The medulla oblongata, or spinal bulb.

(1) Its shape. Raise the cerebellum, push it

gently forward, and remove the thin
epithelial covering from the dorsal side
of the medulla.

(2) The fourth ventricle is the chamber in the

medulla. What is its shape ? Where
does it open posteriorly?

(3) The diverging posterior columns, or pyramids,

are on either side of the fourth ven-
tricle.

(4) The restiform bodies, a rounded eminence

in each column. Anteriorly find where
they pass into the inferior peduncles of
the cerebellum.

(5) The superior peduncles of the cerebellum,

one on each side, proceed from the
cerebellum and pass beneath the poste-
rior corpus quadrigeminum of the same
side.

(6) On the under, or ventral, surface of the

medulla notice two cords, the anterior
pyramids. Compare them with the pos-
terior pyramids.

(7) The pons Varolii. In which direction do

its fibres run? Follow its fibres on

100 PHYSIOLOGY FOR THE LABORATORY.

each side into the middle peduncles of
the cerebellum.

c. The mid-brain.

1. The optic tracts are two bundles of fibres coming

obliquely forward over the front part of the
peduncles and meeting in the centre to form
the optic chiasma. What is the meaning of
this crossing ? What relation does it bear to
the optic nerves and the sensation of light ?

2. The tuber cinereum is the small triangular or

nearly quadrilateral area at the anterior part
of the crura cerebri in the angle of diver-
gence of the optic tracts.

3. The infundibulum extends from the tuber cinereum

to the pituitary body that may have been
torn off in removing the brain from the skull.
Notice the cavity in the infundibulum.

4. The pineal gland is the small body above the

corpora quadrigemina.

5. Sketch the details in your dorsal, ventral, and

lateral views of the brain.

B. The Motor and Sense Areas.

The surface of the cerebrum has been partly mapped
out into motor and sense regions. These are divided into
areas for the muscle-groups belonging to different members
of the body; the foot, the arm, etc. The stimulation of
a certain part of an area for the arm results in movements
of extension, the stimulation of another part of the area
results in flexion of the arm. Moreover, each area may

THE NERVOUS SYSTEM. ,, t : 101

be marked off into centres which control the motion of a
smaller group of muscles, as of a part of the arm. The
area of the arm would thus be the sum total of centres for
the various movements of which all the parts of the arm
are capable. The areas affect the movements of the
muscles of the opposite side of the body, so that stimu-
lating the area of the arm on the right cerebral cortex
will result in movements of the left arm. Locate the
main motor and sense areas from the following diagram.

Ro

Ant.

FIG. 9. — The left cerebral hemisphere. Sy is the fissure of Sylvius; 7?o, the
fissure of Rolando ; P.O., the parieto-occipital fissure ; If, the area for hear-
ing ; V, the area for vision ; S, the area for smelling.

C. The Cranial Nerves.

If the cranial nerves have been severed close to the
brain, they should be studied in the interior of the skull.
Observe carefully the points of exit of the roots of the
nerves.

a. The olfactory nerves arise from the olfactory lobes.

b. The optic nerves arise from the optic tracts just
anterior to the crura cerebri.

102 ^ PHYSIOLOGY FOR THE LABORATORY.

c. The motor oculi, or motor nerves of the eye, arise from
the inner surfaces of the crura cerebri in front of the
pons Varolii.

d. The pathetic! curve around the front edge of the
pons ; they originate a little posterior to the corpora
quadrigemina.

e. The trigeminals are large and conspicuous and arise
from the sides of the pons.

f. The abducens arise just posterior to the pons.

g. The facial nerves are seen at the lower edge of the
pons, nearly in a line with the fifth pair.

h. The auditory nerves are just outside the seventh pair,
and cling to the lateral surface of the medulla. The
glosso-pharyngeal, the pneumogastric, the spinal accessory, and
the hypoglossal, each arises by several roots which form a
line on the lateral part of the medulla. Consult a draw-
ing of the human brain.

i. Add the nerves to your ventral view of the brain.

D. The Interior of the Brain.
I. A LONGITUDINAL SECTION.

Make a median longitudinal section of the entire brain,
taking great care that it is exactly in the median line.

Identify :

a. All the parts that you have seen on the dorsal and
ventral surfaces.

b. The gray matter constitutes the outer layer, or cortex.
Is it composed of cells or fibres ? How is it arranged with
reference to the fissures ? How thick is it ?

THE NERVOUS SYSTEM. 103

c. The white substance is in the centre. Is it cellular or
fibrous ? How is it arranged ?

d. The corpus callosum, a flat, thick band of white tissue
curved under at either end and situated in the lower part
of the cerebral hemispheres.

e. The cavities of the brain, four of
which can be easily distinguished.

1. The lateral ventricles are in the

right and left cerebral hemi-
spheres. They will be found
after cutting the horizontal
sections (Fig. 10, I and II).

2. The third ventricle is dorsal to the \ " "/ "

optic tracts. (Fig. 10, III.)

3. The foramen of Monroe is the

passage from the lateral to
the third. It is I^shaped.

FIG. 10. — A diagram
(Fig. 10, F.M.) of the ventricles

4. The fourth ventricle is in the me- ofthebraiu-

dulla oblongata, and is merely covered by the
membranes of the spinal cord. (Fig. 10, IV.}

5. The aqueduct of Sylvius leads from the third to

the fourth ventricle. (Fig. 10, A.S.)
/. Sketch.

II. A HORIZONTAL SECTION.

Cut away the dorsal surface of one hemisphere in thick
horizontal sections nearly down to the corpus callosum,
noting the arrangement of white and gray matter. Make
a shallow, vertical cut into the corpus callosum, parallel
with the median fissure and about half an inch from it.

104 PHYSIOLOGY FOE THE LABORATORY.

a. Pull up the outer edge of this cut and find a hollow
space, the lateral ventricle.

b. Cut off its roof and look for the corpus striatum, pro-
jecting from the floor at the anterior end.

c. Sketch.

III. ANOTHER HORIZONTAL SECTION.

Cut off another section just below the corpus callosum
so as to pass through the corpus striatum and the optic
thalamus.

Notice :

a. The gray matter around the margin and its relation
to the convolutions. What, then, is the purpose of the
convolutions ?

b. The size and shape of the fissure of Sylvius and the
average depth of the fissures between the convolutions.

c. Sketch.

IV. A TRANSVERSE SECTION.

Cut the other hemisphere transversely halfway between
the pons and the optic chiasma.

Notice on the cut surface :

a. The shape of the fissure of Sylvius.

b. The gray matter composing the optic thalamus and
the corpus striatum.

c. Sketch.

V. THE CEREBELLUM.

Cut the peduncles of the cerebellum and remove it.
Cut one half transversely at the centre and determine the
relative number and depth of the fissures.

THE NERVOUS SYSTEM. 105

a. The white substance. How is it arranged ?

b. The gray substance. How thick is it ?

c. A gray mass, the corpus dentatum, is in the centre of
the white substance in each lateral lobe.

d. Sketch.

VI. THE MEDULLA OBLONGATA.

Make a transverse section of the medulla and note the
arrangement of the gray matter within. Make another
through the pons, and note the arrangement of the fibres
which compose it.

E. The Microscopical Structure of the Brain.

Material. A prepared section of the cerebral cortex of the human
brain.

Apparatus. A compound microscope.

Examine a prepared section of the human brain.

THE NERVE CELLS.

Note :

a. Their size, shape, and structure.

b. Protoplasmic or branched processes are called dendrites.

c. The unbranched process, or axon, is continued as the
axis cylinder of a nerve fibre. Each nerve cell with all
its processes, both dendrites and axons, is called a neuron.
Do all cells possess both kinds?

d. Draw cells showing all these parts.

e. How do nerve cells differ from epithelial and muscle
cells ?

XVII.
THE NERVOUS SYSTEM.

The Spinal Cord.
A. The Gross Structure of the Spinal Cord.

Material. The spinal cord of a calf or some large animal. This
may be easily obtained at the large markets. It is only necessary
to ask the butcher to save, when he cuts the animal for the market,
the long spinal cord that is inside the backbone.

Study the entire cord or a long piece of it.
Notice :

a. The general shape, its length and diameter. Locate
the cervical and lumbar swellings in the regions of the
neck and the lawer part of the back. What causes
them?

b. The roots, or attachments, of the spinal nerves.

1. How are they arranged ?

2. How near together are they ?

c. Sketch.

B. The Microscopical Structure of the Spinal Cord.

Material. A microscopical slide showing a cross-section of a
spinal cord.

Apparatus. A magnifying glass. A compound microscope.

106

THE NERVOUS SYSTEM. 107

I. THE SPINAL COKD SLIGHTLY MAGNIFIED.

Study with a magnifying glass a microscopical slide of
a cross-section of a spinal cord.

Notice :

a. Its general shape.

b. The anterior, ventral fissure is the deep indentation on
one side.

c. The posterior, dorsal fissure is on the opposite side.

d. The membranes around the cord. How many are there ?

e. The white substance is just within the membranes.
Distinguish the anterior, lateral, and posterior columns.

/. The gray substance is within the white substance.
What is its shape ? Find the anterior and posterior cornua.

g. The canal is in the centre of the gray substance.
What is its size?

h. The cerebro-spinal fluid was within the canal.

i. The roots of the nerves. Which roots are they, the
anterior or the posterior?

j. The blood-vessels. What is their relation to the septa
or extensions of the pia mater into the cord ?

k. Sketch.

II. THE SPINAL CORD HIGHLY MAGNIFIED.

Study the section with the high power of the com-
pound microscope.

Notice in the gray substance :
a. The nerve cells.

1. The shape.

2. The cell protoplasm.

3. The nucleus.

108 PHYSIOLOGY FOR THE LABORATORY.

4. The nucleolus.

5. The fibres leaving the cells. Is there an axon ?

Look for branching fibres.

b. The network of fibres.

c. Compare with the cells of the brain.

d. Sketch.

C. The Structure of Different Parts of the Spinal Cord.

Material. Microscopical slides showing cross-sections of the
spinal cord in the cervical, dorsal, and lumbar regions.
Apparatus. A magnifying glass.

Examine the sections of the different regions of the
spinal cord.

Notice :

a. Their comparative size and shape. Is the difference
due to the gray or white substance ? What shows this ?

b. The comparative number of cells in the anterior
cornua. What does this signify?

c. The comparative amounts of gray and white sub-
stance. To what is this due?

d. In the cervical region note the division of the pos-
terior columns into a median and lateral part separated by
connective tissue.

e. Make sketches showing typical sections from these
three regions.

D. The Spinal Nerves.

Materials. A frog. Chloroform. Formalin, 5 per cent. Cotton
batting.

Apparatus. Glass jar. Bell-jar.

THE NERVOUS SYSTEM. 109

Kill a frog and keep it in 5 per cent formalin for three
or four days. Cut open the body cavity along the ventral
surface, lay aside the intestines, and look for the spinal
nerves at the back of the body cavity.

Notice :

a. Their number and arrangement with reference to
the vertebrae.

b. Their roots, the anterior and posterior. What is the
size and structure of each ? On which is the ganglion ?

c. Their distribution. To what portions of the body do
they extend ?

E. Nerve Fibres.

Materials. A frog. Chloroform. Normal salt solution. Cotton
batting.

Apparatus. Bell- jar.

Cut off a quarter of an inch of a perfectly fresh nerve,
and put it on a slide without any liquid. Press one end
against the slide, and tease out the other end by passing
a needle lengthwise through the fibres. Spread the fibres
out like a fan, add a drop of normal salt solution, and
cover.

Notice :

a. The relative size and arrangement of the nerve fibres.

b. The connective tissue running amongst and around the
fibres.

c. The primitive sheath is a thin, transparent covering on
the outside.

d. The medullary sheath, also transparent, is inside the
primitive sheath and consists of a fatty substance.

110 PHYSIOLOGY FOB THE LABORATOBY.

e. The axon, or axis cylinder, is in the centre. Add a
drop of chloroform and look for this along the centre of
the fibres. These are called medullated or white fibres.
Distinguish from them the non-medullated or gray fibres;
where are the latter found?

/. Look for nuclei along the nerve fibre.

g. Sketch a single fibre and show all these parts.

F. A Nerve Ganglion.

Material. A prepared section of a nerve ganglion.
Apparatus. A compound microscope.

Examine a section of a nerve ganglion.
Notice :

a. The size and general shape.

b. The outer coat, its thickness and structure.

c. The nerve cells.

1. What is their size and shape ?

2. Have they any nucleus ?

3. Compare them with those seen in the brain.

d. The fibres. Do any of them join the cells ? Are
they nerve fibres?

e. Sketch.

G. The Functions of the Spinal Cord. (Reflex Action.)
I. THE KNEE-JERK.

Sit with one knee crossed over the other. With the
tips of the fingers strike the crossed knee just below the
knee pan. Notice the motion of the foot. Was the action
voluntarjr ? Trace the course of the nerve impulse.

THE NERVOUS SYSTEM.

Ill

II. THE REFLEX ACTION OF THE SPINAL CORD OF A
FROG.

Materials. A frog. Chloroform. Hydrochloric acid. Cotton batting.
Apparatus. Bell-jar. Ring-stand.

Etherize a frog, and as soon as it is unconscious sever
the brain from the spinal cord by a cut across the back of
the neck. With a probe destroy the brain and suspend

FIG. 11. — A diagram of the reflex action of the spinal cord.

the frog from an iron stand. By pinching with the
forceps, gently stimulate one foot of the frog. Give a
more vigorous stimulus and compare the result with that
previously obtained.

112 PHYSIOLOGY FOR THE LABORATORY.

Repeat the same experiment, using a small piece of
paper wet in dilute hydrochloric acid as a stimulus. Ex-
plain and give the path of the nerve impulse. Destroy
the spinal cordv by passing a needle down the spinal
column and repeat the same experiments.

By a comparison of the results obtained, infer one of
the normal functions of the spinal cord in the frog.

H. The Sympathetic System.

Material. A frog that has been in 5 per cent formalin for three
or four days. The same frog that was studied for the spinal nerves
may be used.

Lay open the body cavity and push aside the intestines
and other organs.

I. THE SITUATION OF THE SYMPATHETIC SYSTEM, AND

ITS CONNECTION WITH THE CEREBRO-SPINAL
SYSTEM.

Just back of the kidneys find a row of small nerve
fibres, which run transversely from the spinal nerves to
the . chain of pigmented, sympathetic ganglia close to the
dorsal surface and along beside the vertebrae.

II. ITS STRUCTURE.

Notice :

a. The two rows of sympathetic ganglia.

b. The nerves connecting the ganglia.

c. The sympathetic trunks which arise from the ganglia
and connecting nerves.

d. The distribution of its nerves to the digestive, circu-
latory, and excretory organs.

XVIII.
THE EYE AND VISION.

A. The Eye of an Ox.

Materials. The eye of an ox may be easily obtained at the mar-
ket. Care should be taken to obtain a fresh specimen. Potassium
bichromate, 1 per cent solution.

Apparatus. A small glass jar.

THE PARTS OF THE EYE.

a. The muscles on the outside of the eye.

1. How many do you find ?

2. Where are they attached?

3. What is the use of each ?

b. Do you find anything else on the outside of the eye ?
What is its function ?

c. Remove the muscles and fat and find the optic nerve.

1. Is it in the axis of the eye ?

2. Can you determine whether your specimen is

the right or the left eye?

d. Sketch a front and a side view.

e. The cornea is the transparent coat on the front of the
eye.

/. The sclerotic coat is the white or gray opaque coat
that is continuous with the cornea. The cornea and the
sclerotic coat form the outer covering of the eye.

118

114 PHYSIOLOGY FOR THE LABORATORY.

g. The conjunctiva is a thin membrane over the cornea.
It is a continuation of the mucous membrane lining the
eyelids. In removing the eye, the conjunctiva is cut
through where it passes from the eyelids to the sclerotic
coat.

h. The aqueous humor is found in the anterior chamber
of the eye by cutting through the cornea about a quarter
of an inch from the junction of the cornea with the
sclerotic coat.

i. Find the iris.

1. What color is it?

2. What is its shape?

3. Where is it attached?

j. The pupil, or opening.

1. How is it formed?

2. What is its shape ?

3. How does its shape change ?

Jc. At a short distance posterior to the cornea, cut
through the sclerotic coat, being careful not to cut too
deeply. The pigmented membrane beneath it is the
choroid coat. How are the sclerotic and choroid coats
connected? Remove a strip of the sclerotic coat one
quarter of an inch broad, stretching from the cornea to
the optic nerve.

1. What color is its inner surface ?

2. The pale fibres of the ciliary muscle may be seen

in the front part of the choroid close to the
cornea. Where do they arise? How far
backward do they extend?

THE EYE AND VISION. 115

I. With forceps, carefully lift the chore-id coat about
halfway between the optic nerve and the cornea and cut
through it. Beneath it the retina, a thin membrane, will
be seen. The pigment layer of the retina will probably
be torn away with the choroid.

m. The vitreous humor, which occupies the posterior cav-
ity of the eye, may be seen by tearing away a piece of the
retina. What are its characteristics ?

n. Hold the eye so that the cornea is underneath. Look
through the vitreous humor and see the longitudinal folds
of the choroid coat. These are the ciliary processes.

o. The ora serrata is the uneven line at the level of the
commencement of the ciliary processes. The retina ceases
along this line.

p. Turn the eye with the iris uppermost and cut away
the thin edge of the iris. Find the lens. Make a slit in
the membrane over the lens and remove it from its capsule.
Find how far the lens capsule extends. How is it held
in place?

q. Study the lens.

1. Its shape, size, and transparency.

2. Are its two faces alike ?

3. Lay the lens over some writing and notice the

result.

4. Place the lens in a 1 per cent solution of potas-

sium bichromate, and study the structure at
the end of a week.

r. The blind spot is the place where the optic nerve joins
the retina. It may be found by removing the posterior
half of the eye.

116 PHYSIOLOGY FOR THE LABORATORY.

s. The blood-vessels of the eye may sometimes be seen
in the choroid coat radiating from the blind spot after
removing the retina.

t. Make a diagram of a median vertical longitudinal
section, showing the position of the coats, the lens, the
chambers, and the humors of the eye.

u. Label all of the parts that are shown in your sketches.

B. The Human Eye.
Apparatus. A hand-mirror.
Study your own eyes with a hand-mirror.

a. The eyebrows.

1. Their position.

2. The direction of the hair.

3. The thickness and the color of the hair.

4. The hairless place above the bridge of the nose.

b. The eyelids.

1. Their number. Do you see the remnant of

another lid at the inner corner?

2. The union of the mucous membrane and the

skin on the edge of the eyelid.

3. The openings on the edge of the lower lid.

(1) How many are there?

(2) What is their use ?

4. The larger opening on the slight elevation near

the inner angle of the lower lid is the open-
ing into the nasal duct.

5. Do you know any animals that have three eye-

lids ? Do you know any that have no eyelids ?

THE EYE AND VISION. 117

c. The eyelashes.

1. Their position.

2. Their length and shape.

d. The sclerotic coat. What is its color ?

e. The iris.

1. What is its color ?

2. What is its shape ?

3. How does it change with a varying amount of

light?

4. What is an albino ?

/. The pupil.

1. What is it?

2. What is its shape, size, and color?

3. Compare the pupil with that of the cat, the dog,

and other animals.
g. Sketch.

C. The Formation of the Image.

Apparatus. A double convex lens on a stand. A ground glass
screen. A candle in a stand. A wooden rod on which the lens,
screen, and candle may slide.

I. THE IMAGE ON GLASS.

Arrange the lens, the candle-flame, and the screen so
that the image of the flame may fall on the screen.
Compare the image of the flame with the flame.

Notice :

a. The size of the image.

b. The position of the image.

c. The distance of the image from the lens.

118 PHYSIOLOGY FOR THE LABORATORY.

II. THE IMAGE ON THE RETINA.

Materials. The eye of an albino rabbit. Care should be taken to
have it freshly excised, with the cornea still clear, or the experiment
will fail. A piece of black paper about six inches square. A candle.

Roll the black paper into the form of a tube, and place
the rabbit's eye in it with the cornea directed forwards.
Hold the eye in front of a candle-flame, and look for the
image of the flame shining through the retina, choroid, and
sclerotic coats. Move the flame and watch the image.

D. Accommodation.

Close one eye and hold up both forefingers, the one
about six inches, the other about eighteen inches, from
the open eye. Look steadily at the nearer finger. Is the
image of it clear or indistinct? Do you see clearly the
finger farther away ? Look steadily at the finger farther
away. Is its image distinct? How is the image of the
nearer finger? Can you focus on the nearer finger with-
out an effort?

E. Defects in Vision.

Materials. Siiellen's cards of test-types including the card for
astigmatism.

I. NEAKSIGHT AND FABSIGHT.

With the aid of Snellen's test-types, examine your
own eyes and determine if they are normal. You should
be able to read type of this size ^ at a distance of
sixteen feet. ^—

What is nearsightedness, or myopia ? What is farsight-
edness, or hypermetropia ? How may each be corrected
by the use of glasses?

THE EYE AND VISION. 119

II. ASTIGMATISM.

Test your own eyes for astigmatism with a card having
lines of the same brilliancy radiating from the centre, or
with the face of the clock. Astigmatism is present if
some of the lines are more distinct or brighter than
others.

Astigmatism is usually caused by unequal curvatures
of the cornea.

F. Changes in the Iris and the Pupil.

Material. A living cat.

Apparatus. A gas-jet or lamp. A hand-mirror. A piece of
cardboard about six inches square.

I. CHANGES IN THE SIZE OF THE PUPIL.

Sit opposite a light and study the pupils of the eyes
in a hand-mirror. Place a hand over one eye and notice
the diameter of the pupil of the other. Suddenly remove
the hand from the eye while watching the pupil of the
open eye. What change do you observe?

II. THE RATE OF MOVEMENT OF THE IRIS.
a. The human eye.

Close the left eye, and with the right look through a
pin-hole in a card at a white shade of a lighted lamp.
Notice the size of the circular visual field, or the amount
of space visible at one time. Is it very bright? Open
the left eye. What change is there in the visual field?
Again close the left eye and note the change in the shape
and brilliancy of the visual field.

120 PHYSIOLOGY FOR THE LABORATORY.

b. The eye of a cat.

Study the eyes of a cat during sudden changes in the
amount of light.

G. Binocular Vision.

While holding a pencil about a foot in front of the
eyes, look at a distant object. How does the pencil
appear? Close the' right eye. What change is there?
Close the left eye and open the right.

H. The Blind Spot.
Marriott's experiment :

With the following figure find the blind spot in your
own eye. Close the right eye and hold the figure about
ten inches in front of the left eye. Look steadily at the

FIG. 12.

cross with the left eye and gradually draw the page
toward the eye. Do you find a place where the circle
disappears? The image then falls on the entrance of the
optic nerve, or the blind spot.

I. The Yellow Spot.

Clark-Maxwell's experiment:

Material. Chrome alurn, a strong solution.
Apparatus. A glass bottle with flat sides.

THE EYE AND VISION.

121

Place a clear, strong solution of chrome alum in a glass
bottle with flat sides. Close the eyes for a few minutes
and then look through the solution when held between
one eye and a white cloud. A rosy spot should be seen
in a green field of vision. The pigment in the yellow
spot on the retina absorbs the blue-green rays, and so the
remaining rays which pass through the alum give a pink
color.

J. Irradiation.

FIG. 13.

a. In Fig. 13 look at the white spot on the black
ground, and at the black spot on the white ground.
Which spot appears larger?

b. In Fig. 14 look at the four squares, two white and
two black. Which looks larger, the white or the black?
What is meant by irradiation?

K. Imperfect Visual Judgments.

a. Make three round black dots,
1, 2, and 3, of the same size and in
the same line, so that 1 and 3 are equi-
distant from 2. Make several other
dots of the same size between 1 and 2.

Which now appear to be farther apart, 1 and 2 or 2 and 3 ?

b. Make two squares of equal size with very light out-

FlG. 14.

122

PHYSIOLOGY FOR THE LABORATORY.

lines. In one draw parallel horizontal lines, and in the
other parallel vertiqal lines. How do the two squares

FIG. 15.

now compare in size and shape? Which would make a
person look taller, vertical or horizontal lines?

c. Look at the rows of letters, *, and the figures, 8.

s s s s s s s

8888888

FIG. 16.

Do the upper and the lower halves appear to be of the
same size ? Invert the page and look again.

d. ZOLLNER'S LINES. Make six parallel vertical lines.
Do they appear parallel? Draw short parallel oblique
lines across them, so that those on adjacent verticals

FIG. 17.

THE EYE AND VISION. 123

shall point in opposite directions. How do the parallel
lines now look?

e. Do the long lines appear to be of the same length in
Fig. 18? Measure them.

FIG. 18.

L. Color-Blindness.

Material. A large assortment of skeins of worsteds of different
colors, shades, and tints. A color-blind person.

Place a large assortment of the shades and tints of
different colored worsteds in a good light. Select a light
green skein and ask the person to be examined to select
all the skeins of the same color whether lighter or darker.
A color-blind person will select shades and tints of other
colors. Select a bright red skein and ask the person to
point out other skeins of the same color. The red-blind
person will select green and gray ; the green-blind person
will select red and gray. Do not ask the person to name
colors.

M. Mixing of Color Sensations.

Apparatus. Rotary apparatus for color-disks. The Bradley
Color Wheel and Maxwell Disks.

On a rotating disk place a blue and a yellow disk in
such proportions as to obtain gray or white when rotated.
Why does it not make green ? Try different combinations
of colors.

124 PHYSIOLOGY FOB THE LABORATORY.

V

N. After-images.

I. POSITIVE AFTEK-IMAGES.

Apparatus. A gas-jet with a white globe.

Rest the eyes by closing them, and then suddenly open
the eyes and look for a few seconds at the gas-jet. Now
close the eyes again and notice what you see.

II. NEGATIVE AFTER-IMAGES.

Material. Papers of different colors, as red and blue.

Experiment :

1. Look steadily for half a minute or longer at a

small white square on a black ground. Then
slip a piece of white paper over the whole
and notice the image.

2. Look steadily at a bright red square on a black

ground, and then slip a piece of white paper
over them. What color is the after-image?

3. Obtain the after-images with other colored papers.

These images are due to fatigue of the retina
and brain. What relation do the colors of
the after-images bear to the colors of the
paper.

XIX.

THE EAR AND HEARING.

A. The Ear.

Material. The ear of some animal, as a dog, or a large model of
the human ear.

Study a large model of the human ear.

Note:

I. THE EXTERNAL EAR.

a. The concha, or expansion on the outside of the head.

b. The passage leading into the head, or external auditory
meatus.

c. The drum, or tympanic membrane at the inner end of
the passage.

II. THE TYMPANUM, OR MIDDLE EAR.

a. The Eustachian tube leads from the middle ear to the
pharynx. What is its use ?

b. The three bones of the ear.

1. The malleus, or hammer, is in contact with the

drum.

2. The incus, or anvil-bone, rests against the malleus.
* 3. The stapes, or stirrup-bone, is the innermost bone.

125

126 PHYSIOLOGY FOR THE LABORATORY.

III. THE INTERNAL EAR, OR LABYRINTH.

The Internal Ear, or Labyrinth, is protected by the
temporal bone of the skull.

a. The vestibule is the middle part.

b. The semicircular canals are on one side of the ves-
tibule.

c. The cochlea, a spirally coiled tube, is on the opposite
side of the vestibule.

IV. THE PATH or THE SOUND WAVES.

Trace the path of the sound waves through the drum,
the tympanic bones, the liquids in the labyrinth to the
auditory nerve.

B. A Test for Hearing.
Apparatus. A watch.

a. Sit in a chair and have some one hold a ticking
watch at the side of one ear. How far can the watch be
carried before it ceases to be audible? Test the other
ear to see if it is equally acute.

b. Hold a ticking watch between the teeth and notice
how loud it ticks. Close both ears and notice the result.
Repeat and uncover one ear.

C. Location of Sound.
Apparatus. Two rods of iron to make a distinct sound.

Blindfold a person and see how well sounds in front,
at the back, and at the sides may be located.

XX.

SOME DERMAL SENSATIONS.

Touch, Smell, and Taste.
A. The Sense of Touch.

I. LOCATION OF TOUCH.

Close the eyes and have some one touch some part of
the body. Can you name the part touched?

II. THE SENSIBILITY OF THE SKIN.

Apparatus. A pair of dividers.

Apply the blunted points of a pair of dividers simul-
taneously to some part of the body, as the finger tips, the
back of the hand, and the back of the neck. Determine
the distance between the two points that is necessary in
order that the points may be felt as two. Compare your
results with those given in any physiology.

III. ARISTOTLE'S EXPERIMENT.

Cross the middle finger over the forefinger, and with
the crossed ends rub along the bridge of the nose. What
is the sensation felt?

B. The Sense of Temperature.

Materials. Iron rods. Pieces of fur, silk, wood, and metallic
rods. Water.

Apparatus. Bunseii burner. Large beakers or basins.

127

128 PHYSIOLOGY FOR THE LABORATORY.

I. PERCEPTION or TEMPERATURE.

a. Close the eyes and have some person touch different
parts of the body with cold and warm rods. How are the
sensations different?

b. With fur, wood, and metal of the same temperature
test the body. Which feels colder? Why?

II. ESTIMATION OF TEMPERATURE.

Plunge the hand into water of different temperatures
and so learn to judge the temperature of water. How hot
can you endure the water? Can the hands or the feet
endure warmer water? Plunge one hand into hot water,
the other in cold, and then both into warm water. What
is the sensation in each hand?

C. The Sense of Pressure.
Apparatus. Weights of different sizes.

ESTIMATION OF WEIGHTS.

a. Lift weights of different magnitude until you are
able to judge some of the more common, as a pound,
three pounds, etc.

b. Hold a pound weight in the hand. Add a few
ounces. What is the least difference that you are able
to perceive?

D. The Senses of Taste and Smell.

Materials. Sugar, vinegar, salt, pepper, apple, potato, onion,
ammonia, and cabbage.

SOME DERMAL SENSATIONS. 129

I. THE LOCATION OF THE SENSE OF TASTE.

Place a little sugar on the tip and on the back of the
tongue. Where is it sweeter? Repeat with acetic acid
or vinegar and salt, and determine where they are more
sharply tasted.

II. THE DIFFERENCE BETWEEN TASTE AND SMELL.

Close the eyes and nostrils and try to distinguish be-
tween salt and pepper, apple and potato.

Which of the following have taste, and which have
odors, — onion, sugar, salt, vinegar, carrot, dilute ammo-
nia, and cabbage?

XXI.

THE LARYNX AND THE VOICE.
A. The Larynx.

Material. The larynx of a calf or a sheep. If possible, obtain
a specimen of the larynx with the tongue and surrounding organs
still attached.

I. THE DIFFERENT ORGANS OF THE SPECIMEN.
Identify :

a. The trachea, or windpipe.

b. The larynx, or cartilaginous box, at the upper end of
the trachea.

c. The oesophagus, or gullet, a muscular walled tube run-
ning parallel with the trachea. Notice how it is attached
to the larynx.

d. The tongue. How is it held in place ?

e. The hyoid bones, at the root of the tongue, holding it
in position. Where are they attached ?

/. Some glands may be present in your specimen.
g. Sketch.

II. THE TRACHEA.

Review the structure of the trachea.

III. THE LARYNX.

Remove the fat, the blood-vessels, the lower part of the

130

THE LARYNX AND THE VOICE. 131

oesophagus, most of the tongue, the muscles of the pharynx,
and so expose the larynx.

Notice :

a. The general size and shape.

b. The front or ventral surface is easily identified by the
projection in the cartilage called the Adam's apple.

c. The epiglottis is the lid at the upper opening.

1. What is its shape ?

2. Raise it.

3. Press it down and see how it closes the opening.

4. Cut it to find its structure.

d. The vocal cords are the two elastic pads seen when
looking into the larynx. Notice them when closed and
when open.

e. The mucous membrane lines the larynx. Notice how
it also lines the oesophagus.

f. The cartilages.

1. The large cartilage on the ventral side extend-
ing backward and comprising most of the
larynx is the thyroid cartilage.

(1) What is the exact shape ?

(2) The hyoid bone is attached to its upper

dorsal corner.

(3) At the lower dorsal corner, the thyroid is

articulated with the cricoid cartilage.
Notice carefully the articulation.

(4) The Adam's apple is on this cartilage.

2. The cricoid cartilage can be found on the ventral
side just below the thyroid. It resembles one

132 PHYSIOLOGY FOR THE LABORATORY.

of the cartilaginous rings of the trachea and
might easily be mistaken for one. Move it
up and down to see that it is separate from
the thyroid and the trachea. Trace it around
to the dorsal side underneath the lower pos-
terior corner of the thyroid cartilage. How
far on the dorsal side does it extend ? What
is its exact shape? How is it articulated
with the thyroid cartilage?

3. On the dorsal side above the cricoid cartilage on
either side is an arytenoid cartilage. It is con-
cealed by the muscles and the vocal cord,
but its exact shape can be found after dis-
secting the muscles.

g. The muscles.

1. A crico-thyroid muscle is on either side of the

dorsal surface extending from the thyroid to
the corresponding cricoid cartilage.

(1) Where is it attached on each cartilage ?

(2) What is its use ?

(3) Dissect it away and find how the motion

of the thyroid is limited.

2. The posterior crico-arytenoid muscles are on the pos-

terior surface of the cricoid, one at either
side. They extend diagonally upward to
the corresponding arytenoid cartilages. Dis-
sect away the attachment on the thyroid
cartilage, pull the muscle, and note the effect
on the arytenoid cartilage and on the vocal
cord.

THE LARYNX AND THE VOICE. 133

3. The lateral crico-arytenoid stretches from the lateral

portion of the upper edge of the cricoid, up-
ward and backward to the arytenoid cartilage.
Disarticulate the thyroid and cricoid of one
side, push aside the thyroid without injury to
the muscles, and this muscle can be readily
seen. Pull the muscle and note the result.

4. The arytenoid muscle may be found by cutting

away the tissue above the cricoid cartilage at
the back of the arytenoid cartilages. Cut
through the middle and also see where it is
attached to the arytenoid cartilages. Find
where the arytenoid cartilages articulate with
the cricoid. Pull the arytenoid muscle and
find its use.

5. The thyro-arytenoid muscle extends from the ven-

tral surface of the thyroid across to the aryte-
noid. Cut it at its origin, dissect it loose,
and prove its effect on the vocal cord.

h. Sketch a dorsal, a ventral, and a lateral view of the
larynx.

i. Carefully examine from the inside the muscles of
the opposite side, showing the effect of each on the vocal
cords.

j. Remove all the muscles and find the exact shape of
the cartilages.

k. Make a paper model of the cartilages of the larynx.

XXII.
THE BACTERIA.

A. The Harmless or Non-Pathogenic Bacteria.

Materials. Nutrient gelatin made of 500 grms. of lean beef,
finely minced, 1 litre of water, 100 grms. of gold-label gelatin, 10
grms. of peptone, 5 grms. of salt, and sodium carbonate. One egg.

Apparatus. Steam sterilizer, or kettle for steaming. Hot-air
sterilizer, or oven for sterilizing with gas stove. Double boiler.
Stirring rod. Funnel. Filter-paper. Ring-stand. Bunsen burner.
Litmus paper. Cotton-batting. Two glass flasks holding 500 c.c.
each.

To make the nutrient gelatin, mix the beef with the
water and allow it to stand about twelve hours. Filter
through "cheese-cloth," and to the nitrate or meat-water
add the gelatin, peptone, and water. Mix thoroughly in
the double boiler and heat for about half an hour. Neu-
tralize by adding sodium carbonate, till red litmus paper
just turns blue. Boil for about an hour, add an egg to
clarify and settle the albuminous matter, and boil a few
minutes longer. Filter while hot through filter-paper
into sterilized flasks and plug with cotton. Care should
be taken to keep the unfiltered gelatin hot, and to wet the
filter-paper with hot water before beginning to filter.
Sterilize the gelatin in a steam generator twenty-five
minutes a day for three days in succession. If the gela-
tin is found to be acid at the beginning of filtration, it

134

THE BACTERIA. 135

should be neutralized again and boiled for fifteen minutes.
If thoroughly sterile, this nutrient gelatin should keep a
long time.

I. BACTERIA IN WATER AND ICE.

Materials. 3 c.c. of water from the faucet. 20 c.c. of nutrient
gelatin. A small piece of ice.

Apparatus. Two sterilized Petri dishes. (Caution. Keep the
dishes covered, and do not remove the cover till your materials are
ready to use.)

a. Pour the water into one of the Petri dishes, and then
add 10 c.c. of the nutrient gelatin which has been warmed
and so become liquid. Cover as soon as possible, to pre-
vent the bacteria in the air from falling into the gelatin.
Mix the gelatin and the water by gently rotating the dish.
Label the dish carefully, giving the material examined,
the date, and your name on a piece of paper placed under
the dish. Keep in a darkened place at about the tempera-
ture of 24° C. Watch from day to day, and as the colonies
of bacteria appear, study them. In performing the experi-
ments alone, several check experiments should be made,
but the results of the other members of the class will
serve as check experiments.

Notice :

1. The number of colonies. Each colony started

from a single bacterium in the water. How
many bacteria were there in the water?

2. The shape of the colonies as seen from the sur-

face and from the side. What effect do they
have on the gelatin ?

136 PHYSIOLOGY FOR THE LABORATORY.

3. The color of the colonies. What colors do you
find?

b. Ice may be examined by melting it and examining
the water obtained, as in a.

1. Should ice be placed directly in drinking water ?

Why not?

2. How may drinking water be cooled?

II. BACTERIA IN MILK.

Materials. 3 c.c. of fresh milk. 10 c.c. of nutrient gelatin.
Apparatus. A sterilized Petri dish.

Pour the milk and then the warm nutrient gelatin into
a Petri dish. Mix the water and gelatin and label the
culture. Keep in a warm, dark place and watch from day
to day for the appearance of the colonies. Compare these
colonies with those obtained from the examination of
drinking water. Study these in the same way.

III. BACTERIA IN DUST.

Materials. A little dust gathered from the floor, the top of the
door, or back of a picture. 10 c.c. of nutrient gelatin.

Apparatus. A sterilized Petri dish. A compound microscope.

a. Pour the warm nutrient gelatin into the dish and
scatter a little dust over it. Place in a warm room and
watch for the appearance of the colonies. Compare these
with the colonies obtained from the examination of water
and milk.

b. Mount a little dust in water on a glass slide and
examine with the compound microscope. What do you
find?

THE BACTERIA. 137

IV. BACTERIA IN THE AIR.

Material. 30 c.c.. of nutrient gelatin.
Apparatus. 3 sterilized Petri dishes.

a. Pour 10 c.c. of the warm nutrient gelatin into a Petri
dish, and allow it to stand for two minutes uncovered and
exposed to the air of the room. Then cover and place
with the other tests. Study the colonies as they appear.

b. Test in the same way the air of a room before and
after sweeping and compare your results.

1. Why are hardwood floors more healthful than

carpets ?

2. Which is better, a cloth or a feather duster?

Why?

V. BACTERIA IN VINEGAR.

Materials. A few c.c. of mother-of-vinegar.

Apparatus. A compound microscope, glass slide, and cover-glass.

Mount a few drops of mother-of-vinegar on a glass slide,
examine with the microscope, .and study the bacteria.

Notice :

a. Their size, shape, and motion.

6. In what are the bacteria embedded? This mass of
jelly is called a zooglea. It is formed by many individuals
whose cell-walls have become mucilaginous. If the mass
is membranous, as in the mother-of-vinegar, it is called
mycoderma, or fungus-skin.

VI. THE MICROSCOPICAL EXAMINATION OP BACTERIA.

Materials. Colonies of bacteria obtained from samples of water
and milk.

Apparatus. A compound microscope.

138 PHYSIOLOGY FOR THE LABORATORY.

Mount on a glass slide a drop of the liquid containing
bacteria. Cover with a cover-glass and examine with high
power.

Notice :

a. The size of the bacteria.

b. Their shape and motion.

B. The Pathogenic Bacteria.

Materials. Prepared slides of cultures of the bacteria that pro-
duce typhoid fever, diphtheria, consumption, and splenic fever.
Apparatus. A compound microscope.

Examine with the microscope prepared slides of bacillus
typhi abdominalis (typhoid fever), bacillus diphtherise (diph-
theria), bacillus tuberculosis (consumption), and bacillus
anthracis (splenic fever). Study as in A. VI. Do you
find any cilia?

a. What other diseases are caused by bacteria?

b. How is the body able to combat the bacteria?

c. What is susceptibility to disease?

d. What is immunity from disease ?

e. Is consumption hereditary? Explain the most com-
mon " cures " for consumption.

/. What is one method qf treatment for diphtheria?

g. What is antitoxine ? How is it obtained ?

h. What is vaccination ? Give reasons for and against
it.

THE BACTERIA. 139

C. Putrefaction.
THE CAUSE OF PUTREFACTION.

Materials. 300 c.c. of hay infusion. To make hay infusion,
pour hot water on hay, allow it to stand a few hours and then filter
through paper.

Apparatus. 3 glass flasks. Cotton-batting. Cork to fit one
flask.

Pour 100 c.c. of hay infusion into each flask and boil
for an hour. Allow the first flask to stand uncorked.
Cork the second air-tight while boiling. Plug the third
with cotton-batting while boiling. Allow the three to
stand side by side on the table and watch from day to
day. Explain the results.

a. Why will preserves keep in a thick syrup?

6. Why are pickles preserved in vinegar ?

c. Why does tripe keep in brine ?

d. Explain the conditions in canned beef.

D. Conditions Necessary for the Growth of Bacteria.
I. HEAT.

Materials. 300 c.c. of fresh milk. Ice.

Apparatus. 3 bottles. Hot water-bath. Bunsen burner.

a. Pour 100 c.c. of fresh milk in one bottle. Cork it
and place it on ice.

b. Pour 100 c.c. of the milk in another bottle. Cork it
and allow it to stand on the table.

c. Boil for an hour the other 100 c.c. of milk in the
third bottle, plug the bottle with cotton-batting and allow
it to stand on the table.

140 PHYSIOLOGY FOR THE LABORATORY,

d. Compare the three from day to day. Souring of
milk is due to the presence of certain bacteria. They
convert the milk sugar into lactic acid which gives the
sour taste and curdles the milk.

1. In which of the three bottles is the best growth

of bacteria?

2. What is the effect of extreme heat and cold

upon bacteria?

3. Why does food keep in refrigerators?

4. Does frozen beef decay? Why not?

II. MOISTURE.

Material. 10 c.c. of nutrient gelatin.
Apparatus. A Petri dish.

Pour the warm nutrient gelatin into a Petri dish and
allow it to stand uncovered for several days.

a. Do the colonies of bacteria appear ?

b. How long do they grow ?

c. What happens to them?

d. What happens to the bacteria if the disk is placed in
a windy place ?

e. Are the bacteria blown about when moist or dry?
This is a common source of infection in contagious
diseases.

/. Should infected matter from the sick room be allowed
to dry?

g. What should be done with it ? Is moisture necessary
to the growth of bacteria ?

'h. Why does ham keep?

THE BACTERIA. 141

III. LIGHT.

Materials. 10 c.c. of nutrient gelatin.
Apparatus. A sterilized Petri dish. Black paper.

Pour the liquid nutrient gelatin into the dish and expose
it two or three minutes to the air. Why? Cover and
paste a piece of black paper over half of the dish and
expose it to strong sunlight in an ordinary room. Watch
it from day to day and notice the result. Explain.

a. Is light or darkness more favorable to the growth of
bacteria ?

b. Which are more healthful, sunny or dark rooms?
Why?

c. What three conditions have you found essential to
the growth of bacteria?

E. Milk.

Since milk is a good food and furnishes proper nutri-
ment for the growth of bacteria, it becomes a serious matter
to keep milk free from bacteria.

I. THE CONTAMINATION OF MILK.

a. Sources of contamination.

b. Prevention of contamination.

c. Laws in regard to handling milk by milk-men.

d. Adulteration of milk.

1. Why is milk adulterated?

2. What chemicals are most often used?

II. THE PRESERVATION OF MILK.

a. Preservatives. Sometimes various chemicals are added
to prevent souring. What is used for this purpose ?

142 PHYSIOLOGY FOR THE LABORATORY.

b. The sterilization of milk.

1. Recall experiment D. I. How long did the
boiled milk keep sweet? How does boiling
affect the taste of milk? If the milk is
heated hot enough to kill all the infectious
germs, a scum appears on the top which is
the albumin of the milk coagulated by heat.
A boiled taste is also acquired which is
objectionable to some persons, though very
pleasant to others. Milk thus heated is a
little less digestible than fresh milk. If a
high degree of heat is used, the sugar is
scorched, and this forms a brown sediment
on the bottom of the dish.

c. The Pasteurization of milk.

Materials. Milk. Water.

Apparatus. Pasteurizing apparatus or tin pail. Thermometer.
Bunsen burner. Stand. Bottles. Cotton-batting.

The Pasteurization of milk may be easily done in any
home.

Fill one or more bottles nearly full of milk and plug
with dry, clean cotton-batting. The apparatus for Pas-
teurizing consists of a large tin pail which has a false tin
bottom perforated with holes. The cover should fit tightly
and have a thermometer held in place by a cork in an
opening. Place the bottles in an upright position in the
pail and fill the pail with enough water to rise above the
milk in the bottles. Close the pail and heat over a Bunsen
burner until the water is 155° F. (if in winter) or 180°
(in summer). Then remove the pail and keep tightly cov-

THE BACTERIA.

143

ered for half an hour. A cloth over the pail will help to
retain the heat. Take out the milk bottles, cool as quickly
as possible in cold water or on ice, and keep in a cold

1

FIG. 19. — Apparatus for Pasteurizing Milk.

place. The cotton plugs should be kept dry and not
removed until the milk is to be used.

a. Taste the milk to determine if its flavor has been
changed.

b. Keep the bottles at the ordinary temperature of the
room. How long does the milk keep before souring?

c. Is the milk germ free ? Prove it.

F. Disinfection.

By disinfection we mean killing all the bacteria and
their spores. Bacteria may be killed in several ways.

I. THE ACTION OF CHEMICALS.

Materials. 2 c.c. of a (1 to 1000) solution of corrosive sublimate.
4 c.c. of milk. 20 c.c. of nutrient gelatin.
Apparatus. Two sterilized Petri dishes.

144 PHYSIOLOGY FOB THE LABORATORY.

a. Pour 10 c.c. of the warm nutrient gelatin into a
sterilized Petri dish. Add the corrosive sublimate and
thoroughly mix it with the gelatin by rotating the dish.
Add 2 c.c. of the milk and mix it with the gelatin.

b. Pour 10 c.c. of the warm gelatin into the other Petri
dish. Add 2 c.c. of the milk. Place the two dishes
under the same conditions of heat and light and watch
for results from day to day. Explain.

1. What other chemicals are used as disinfectants ?

2. How do they disinfect?

3. What danger is there in their use ?

4. When may chemicals be safely used as disin-

fectants ?

5. When may they not be used ?

II. THE EFFECT OF HEAT.

a. Recall experiment A. I. b.
Does freezing kill bacteria?

b. Recall experiments C. I and D. I.

Does boiling or exposure for three quarters of an hour
at 100° C. by means of steam kill bacteria?

c. Some foods and liquids would be injured by exposure
for three quarters of an hour to so high a temperature as
100° C. How was the nutrient gelatin sterilized? This
method is called discontinuous sterilization. The gelatin was
subjected to a temperature of 56° C. for three or four hours
on three successive days.

1. Were all the bacteria killed on the first day?

What happened to the spores?

2. What took place on the second and third days ?

THE BACTERIA. 145

d. 1. Recall experiment E.

2. Is Pasteurized milk sterile ?

e. How were the flasks and Petri dishes sterilized?
This method is hot-air sterilization. The objects need to be
subjected to a temperature of 150° C. for three quarters
of an hour in dry air. What kind of objects are best
sterilized in this way ?

G. Purification of Water.
Read upon the following subjects : —

1. Purification of water by sand filtration. Describe

a filtration plant such as is used to filter the
drinking water of the city of Lawrence, Mass.,
or Albany, N. Y.

2. Domestic filters. Their efficiency.

3. Sterilization of water by heat.

4. Purification of water by sedimentation.

5. Purification of water by agitation with solid par-

ticles and subsequent subsidence.

6. Chemical precipitation.

7. Purification of sewage.

H. Epidemics.

Give the history of one epidemic, either of typhoid fever
or of diphtheria.

a. Its cause and extent.

b. Its means of spreading.

c. Remedies.

APPENDIX.

A LIST OF SPECIMENS NEEDED.

1. A human skeleton.

2. Pieces of bone to burn.

3. Slender (rib) bone to place in acid.

4. Long bones.

5. Tabular bones.

6. Short bones.

7. Irregular bones or vertebrae.

NOTE. — Numbers 4, 5, 6, and 7 may be obtained at the market, from
the table, or found already cleaned in the fields. Partial skeletons of a
dog, a horse, a bird, or a cow are very useful.

8. The axis and atlas.

9. A- fresh long bone sawed longitudinally.

10. Part of a skeleton to clean and mount.

11. A ball-and-socket joint of an ox, a hip-joint.

12. The fore leg of a sheep.

13. Foetal bones of some young animal, as a pig.

14. A chicken or fowl.

15. A small piece of corned beef.

16. Fresh blood.

17. The heart and lungs of a sheep.

18. Frogs.

19. Different kinds of human teeth.

20. A kidney of a sheep.

21. The brain of a sheep.

147

148 APPENDIX.

22. The spinal cord of some large animal.

23. The eye of an ox.

24. The larynx of a calf or sheep.

25. A living cat.

26. A rabbit.

27. Saliva.

28. The teeth of horse, dog, and cat.

29. A few drops of human blood.

NOTE. — The skeleton and other bones may be obtained of Ward's
Natural History Establishment, Rochester, N. Y.

A LIST OF MICROSCOPICAL SLIDES.

1. Circulation of the blood in the web of the foot of a frog.

2. Cross-section of adipose tissue.

3. " " " a human humerus bone.

4. " " " developing bone.

5. " " " the skin of the head.

6. " " " the spinal cord, cervical region.

7. " " " the spinal cord, dorsal region.

8. " " " the spinal cord, lumbar region.

9. " " " the brain.

10. " " "a nerve ganglion.

11. " " " a tooth.

12. " " " the wall of the stomach.

13. " " " the small intestine.

14. " " " the liver.

15. " " " a muscle.

16. « " " the pancreas.

17. A radial section of kidney.

18. Fresh human blood, a few drops.

19. Hyaline cartilage.

20. Milk.

APPENDIX. 149

21. Plain muscle fibres.

22. Potato starch grains.

23. Saliva.

24. Slide of bacillus typhi abdominalis.

25. " " " diphtherias.

26. " " " tuberculosis.

27. " " " anthracis.

28. Stained corpuscles of the blood of the frog.

29. Striated muscle fibres.

30. Typical cells, as the cells in the cast-off skin of a newt

or frog.

NOTE. — Numbers 1, 18, 20, 22, and 23 may be prepared before the
class exercise. The other slides may be obtained of Bausch & Lomb
Optical Company, Rochester, N. Y.

A LIST OF MODELS.

1. A manikin.

2. A model of the brain.

3. i( (i (( " eye.

4. " " " " ear.

5. " " " " heart.

6. A wooden model of the arm.

7. A model of the valves of the aorta.

8. " " " " chest to show the vertical enlargement.

9. " " to show the dorso-ventral enlargement of the

chest.

10. The circulation apparatus of glass and rubber tubing.

11. The lever apparatus.

12. A paper model of the larynx.

NOTE. — The models numbers 6, 7, 8, 9, and 12 are to be made by the
student. Most of the other models may be obtained of Ward's Natural
History Establishment, Rochester, N. Y., or of Mr. Charles H. Ward,
Rochester, N. Y.

150

APPENDIX.

A LIST OF CHEMICALS AND OTHER SUPPLIES.

1.

Acetic acid.

30.

Beans.

2.

Alcohol.

31.

Beef, lean.

3.

Ammonium chloride.

32.

Bread.

4.

Ammonium hydrate.

33.

Butter.

5.

Barfoed's solution.

34.

Cabbage.

6.

Benzine.

35.

Cane sugar or saccharose.

7.

Borax.

36.

Carrot.

8.

Chloroform.

37.

Cheese.

9.

Chrome alum.

38.

Corn meal.

10.

Corrosive sublimate.

39.

Cornstarch.

11.

Cupric sulphate, 10 per

40.

Crackers.

cent solution.

41.

Dates.

12.

Fehling's solution.

42.

Dextrose.

13.

Formalin.

43.

Eggs.

14.

Gelatin, gold label.

44.

Farina.

15.

Hydrochloric acid.

45.

Glue.

16.

Iodine.

46.

Grapes.

17.

Lime-water.

47.

Ice.

18.

Nitric acid.

48.

Indian meal.

19.

Normal salt solution.

49.

Lactose.

20.

Pancreatin, Fairchild's.

50.

Maple sugar.

21.

Pepsin, Fairchild's.

51.

Maple syrup.

22.

Peptone.

52.

Milk.

23.

Potassium bichromate.

53.

Molasses.

24.

Potassium ferrocyanide.

54.

Oatmeal.

25.

Rennet.

55.

Olive oil.

26.

Sodium hydrate.

56.

Onions.

27.

Sodium carbonate.

57.

Peas.

58.

Pepper.

28.

Apples.

59.

Potato.

29.

Barley.

60.

Prunes.

APPENDIX. 151

61. Rice. 66. Tapioca.

62. Rye. 67. Turnips.

63. Sago. 68. Vinegar and mother-of-

64. Salt. vinegar.

65. Starch. 69. Whole wheat flour.

NOTE. — " Barfoed's Solution. Make a solution of neutral acetate of
copper containing 1 part of the salt to 15 parts of water. To 200 c.c. of
this solution add 5 c.c. of a 38 per cent solution of acetic acid.

Fehling's Solution. Solution A. 34.64 grams of pure crystalline
cupric sulphate are powdered and dissolved in 500 c.c. of distilled water.
Solution B. In another vessel dissolve 173 grams of Rochelle salts
(sodio-potassium tartrate) in 100 c.c. of pure caustic soda, sp. gr. 1.34,
and add water to make 500 c.c. Keep the two solutions separate in
stoppered bottles, and mix them as required. On mixing equal quanti-
ties of A and B, a clear deep blue fluid is obtained." — Stirling's Practi-
cal Physiology.

A LIST OF APPARATUS.

1. A compound microscope giving a magnification of about

six hundred diameters.

2. A hand magnifying glass ; the tripod is convenient.

3. A set of instruments for each student, composed of —

1. One scalpel, No. 5435 (Cat., Fifteenth Edition) ;

2. One pair of scissors, No. 5585 ;

3. One pair of forceps, No. 5825 ;

4. One blowpipe, No. 5910 ;

5. Two needle holders, No. 5970.

4. Pencils, hard and medium.

5. Colored crayons, red, blue, yellow, and green.

6. Air-tight box for killing rabbit. (The crock for waste

material may be used.)

152 APPENDIX.

7. Beakers. 16. Cotton-batting.

8. Bell-jar. 17. Cotton, white.

9. Bulb syringe. 18. Cover-glasses.

10. Bunsen burner. 19. Double boiler.

11. Bone forceps. 20. Double convex lens.

12. Candle and stand. 21. Evaporating dish.

13. Cardboard. 22. Fasteners.

14. Colored paper. 23. Filter-paper.

15. Colored worsteds. 24. Force-pump.

25. Fulcrum, or triangular prism of wood.

26. Funnel.

27. Fur, a small piece.

28. Gimlet.

29. Glass bottles.

30. Glass bottle with flat sides.

31. Glass flasks, two, 500 c.c. each.

32. Glass rods, 35 c.m., of 2 m.m. in diameter.

33. Glass rods, for stirring rods.

34. Glass slides.

35. Glass tubing.

Three-way glass connecting tubing, Y-shape.

Six large size, 12 m.m. in diameter, length of one

arm, 90 m.ni.
Eight medium size, 6 m.m. in diameter, length of

one arm, 65 m.m.
Two medium size, T-shaped, 6 m.m. in diameter,

length of one arm, 65 m.m.
Sixteen small size, 4 m.m. in diameter, length of

one arm, 60 m.m.

36. Glass tubing of different sizes.

37. Glass tubing, 50 c.m. 12 m.m. in diameter.
38.- Granite-ware stew-pan.

39. Ground-glass screen.

APPENDIX. 153

40. Hot-air sterilizer or oven.

41. Knitting needle or probe.

42. Litmus paper.

43. Lamp-chimney.

44. Meat-saw.

45. Mortar and pestle.

46. Needles and thread.

47. Pair of dividers.

48. Pasteurizing apparatus or tin pail.

49. Petri dishes.

50. Pinch-cocks.

51. Pins.

52. Ring-stand.

53. Rods of wood and metal.

54. Rotary apparatus with color disks. Bradley Color Wheel

and Maxwell Disks.

55. Rubber dam.

56. Rubber tubing.

660 c.m. pure rubber tubing, 12 m.m. in diameter.
1£ metre pure rubber tubing, 6 m.m. in diameter.
560 c.m. pure rubber tubing, 5 m.m. in diameter.

57. Ruler or tape-measure.

58. Scales, Fairbanks' Standard.

59. Sheet-cork.

60. Sponge.

61. Spring-balance.

62. Steam sterilizer or kettle for steaming. May use the

Pasteurizing apparatus.

63. Test-tubes.

64. Test-tube rack.

65. Test-types for testing eyes.

66. Thermometer, chemical.

67. Thermometer, physician's.

154 APPENDIX.

68. Twine.

69. Watch-crystals.

70. Water-bath.

71. Weights of different sizes.

72. Wire, fine.

73. Wire-gauze.

74. Wooden pail.

75. Wooden rods for levers.

76. Dr. Fitz's lever apparatus.

NOTE 1. — References as to the kind of apparatus are to the catalogues
of Bausch and Lomb Optical Company.

NOTE 2. — When time permits there are other more difficult experi-
ments that may be introduced as class exercises. The apparatus for
such experiments may be obtained of the Waltham Clock Co., Waltham,
Mass.

REFERENCE BOOKS.

An American Text-Book of Physiology. W. H. Howell. W. B.

Saunders, Philadelphia.

A Text-Book of Physiology. M. Foster. The Macmillan Company.
The Human Body. The Advanced Course and the Briefer Course.

H. N. Martin. Henry Holt & Co.

Lessons in Elementary Physiology. T. H. Huxley. The Macmil-
lan Company.

Human Physiology. J. C. Dalton. Lea Brothers & Co.
Anatomy. Henry Gray. (Latest revision.) Lea Brothers & Co.
The Essentials of Histology. E. A. Schafer. Lea Brothers & Co.
Hints for Teachers of Physiology. Guides for Science Teaching,

No. XIV. H. P. Bowditch. D. C. Heath & Co.
Foods: Nutritive Value and Cost. Department of Agriculture,

Washington, D. C.
Food as a Factor in Student Life. Mrs. Ellen H. Richards and

Marion Talbot. The University of Chicago Press.
Prize-Essay. The Five Food Principles. Mrs. M. H. Abel. Henry

Lomb, Rochester, N. Y.

APPENDIX. 155

Finger Prints. Francis Galton. The Macmillaii Company.

Chemistry of Cookery. W. M. Williams. D. Appleton & Co.

The Physiology of Bodily Exercise. Fern and Lagrange. D. Apple-
ton & Co.

The Making of the Body. Mrs. S. A. Barnett. Longmans, Green
&Co.

A Course of Elementary Practical Physiology and Histology. Fos-
ter & Langley. The Macmillan Company.

Outlines of Practical Physiology. William Stirling. Blakiston,
Son & Co., Philadelphia.

A Handbook of Simple Experiments in Physiology. Charles H.
Stowell. Silver, Burdett & Co.

Practical Physiology. J. M. Callahan. A. Flanagan, Chicago.

Practical Zoology. Buel P. Colton. D. C. Heath & Co.

Home-Made Apparatus. Woodhull. E. L. Kellogg & Co., N. Y.

Laboratory Exercises in Anatomy and Physiology. J. E. Peabody.
Henry Holt & Co.

Bacteria and Their Products. S. Woodhead. Charles Scribner's
Sons.

Our Secret Friends and Foes. P. F. Frankland. E. and J. B.
Young & Co., N. Y.

The Story of the Bacteria. T. M. Prudden. G. P. Putnam's Sons.

The Story of Germ Life. H. W. Conn. D. Appleton & Co.

INDEX.

A.

Abducens, 102.
Absorption, 83, 84.
Accommodation, 118.
Acetabulum, 19.
Acetic acid, 73, 83, 85, 129.
Adam's apple, 131.
Adjustment, 3, 4.
After-images, 124.
Agitation, 145.
Air, 50, 51, 137.
Albino, 117, 118.
Albumin, 142.
Albuminoid, 14.
Alcohol, 75, 93, 95.
Alveolus, 66.
Ammonium chloride, 75.

hydrate, 14, 16, 73, 129.
Amylopsin, 81.
Animals, 117.
Antitoxine, 138.
Aorta, 38, 39.
Apex of heart, 36.
Apparatus, 151-154.
Appendix, 61, 147-155.
Apple, 67, 129.
Aqueduct of Sylvius, 103.
Arachnoid membrane, 96.
Arch, 90.
Areas, motor, 100, 101.

sense, 100, 101.

Aristotle's experiment, 127.
Arm, 2, 26, 29, 100, 101.
Artery, 38, 39, 43, 44, 50, 66.
Articular extremities, 11.

process, 12, 13.
Astigmatism, 119.
Atlas, 12, 13.
Auricles, 37, 38, 41.
Axis, 12, 13, 113.

cylinder, 105, 110.
Axon, 105, 110.

B.

Bacillus, anthracis, 138.

diphtheria, 138.

tuberculosis, 138.

typhi abdominalis, 138.
Back, 106.

Bacteria, 77, 134-145.
Baking powder (see sodium car-
bonate).
Barley, 69.
Base of heart, 36.

Bausch & Lomb Optical Co. , 5, 149.
Beans, 69.
Beats of heart, 41.
Beef, 23, 75, 82, 134, 139, 140.
Belly of a muscle, 22.
Benzine, 76.
Biceps, 24, 28.
Bicuspid, 39, 66.

157

158

INDEX.

Bile duct, 62, 66.
Binocular vision, 120.
Bipenniform, 24.
Blind spot, 115, 116, 120.
Blister, 90.
Blood, 31, 48.

arterial, 34.

circulation, 35.

clotting, 32.

color, 34.

flowing, 44.

human, 31.

of frog, 31.

of hen, 32.

of pigeon, 32.

principles of circulation, 43.

structure, 31.

venous, 34.

-vessels, 23, 37, 43, 65, 87, 88,

89, 107, 116, 130.
Bodies, restiform, 99.
Body, 26, 43, 51, 57, 58, 100, 127,
128, 138.

of the compound microscope,2.

of gland, 92.

pituitary, 100.
Bone, 9, 10, 11, 12, 13, 14, 15.

anvil, 126.

developing, 21.

hard, 11.

hyoid, 130, 131.

irregular, 9.

long, 9.

microscopical structure, 15.

short, 9.

spongy, 11, 13.

stirrup, 126.

tabular, 9.

tympanic, 126.
Books of reference, 154, 155.
Borax, 16.

Brain, 94-105, 108, 110, 111, 124.
Bread, 69.
Breathing, 52.
Brine, 139.
Bronchial tubes, 50.
Bronchus, 50.
Bulb, spinal, 96, 99.
Butter, 75, 76, 81.

C.

Cabbage, 67, 129.
Calcium carbonate, 14.

phosphate, 14.
Calf, 29, 106, 130.
Calices, 88.
Canal, 107, 126.

alimentary, 59, 63, 83.
Canaliculi, 15.
Candle-flame, 117, 118.
Cane-sugar (see saccharose).
Canine, 56, 59.
Capillaries, 42, 44.
Carbohydrates, 67, 72, 81.
Carbon dioxide, 51.
Cardboard, 16, 17.
Cardiac orifice, 60.
Card-test, 119.
Carnivorous animals, 57.
Carpal bones, 18.
Carpets, 137.
Carrot, 67, 129.
Cartilage, 8, 11, 19, 20, 21.

arytenoid, 132, 133.

cricoid, 131, 133.

thyroid, 131, 132, 133.
Casein, 73, 74, 81, 83.
Cat, 93, 117, 119, 120.
Cavity, abdominal, 58, 63.

body, 109, 112.

buccal (see mouth).

INDEX.

159

Cavity of bone, 11.

of brain (see ventricles).

thoracic, 58.
Cells, 7, 8, 15, 66, 91, 102, 103.

cartilage, 20.

epithelial, 77, 84, 105.

hepatic, 66.

muscle, 105.

nerve, 105, 107, 108, 110.
Cell-wall, 7.
Cement, 56,
Centres, 101.
Centrum, 12.

Cerebellum, 96, 97, 98, 99, 100, 104.
Cerebral hemispheres, 97, 103.
Cerebrum, 96, 97, 100.
Cervical region, 108.

swellings, 106.

Chamber of eye, 114, 115, 116.
Check experiments, 135.
Cheek, 90.
Cheese, 74.

Chemicals, 141, 143, 150, 151.
Chest, 51, 52.
Chiasma, optic, 100, 104.
Chicken, 22.

Chloroform, 108, 109, 110, 111.
Chordae tendinae, 39.
Choroid coat, 114, 115, 118.
Chromatin loops, 7.
Chrome alum, 120, 121.
Cilia, 138.
Circle, 120.

Circulation, principles of, 43.
Clark-Maxwell's experiment, 120.
Clips, 2.
Clock, 119.
Clot, 33, 83.
Cloud, 121.
Coat, 110, 116.
Cochlea, 126.

Coacum, 61.

Cohnheim, areas of, 25.

Collagen, 14.

Colon, 61.

Colonies, 135, 136, 140.

Color, 123, 136.

Color-blindness, 123.

-disks, 123.
Column, spinal (see vertebral

column).

Columns, posterior, 99, 108.
Compositions of food, 67.
Concentric structure, 69.
Concha, 125.
Conjunctiva, 114.
Consumption, 138.
^Contamination, 141.
Contents, vii.
Convolutions, 97, 104.
Cord (see tendons).
Cord, spinal, 94, 103, 106, 107, 108,

110, 111, 112.

vocal, 131, 132, 133.
Cornea, 113, 114, 115, 118, 119.
Cornstarch, 69.
Cornua, 107, 108.
Corpora quadrigemina, 97, 99, 100,

102.
Corpus callosum, 103, 104.

striatum, 104.
Corpuscles, red, 31, 42.

white, 31, 42.
Cortex, 88, 101, 102.
Cot, rubber, 86.
Coverings, 95.
Crackers, 69.
Cream, 75.
Creases, 89.
Cross, 120.
Crown of tooth, 55.
Crura cerebri, 96, 100, 101, 102.

160

INDEX.

Crypts of Lieberkuhn, 65.

Culture, 136.

Cupric sulphate, 73, 74.

Curd, 80, 83.

Curdle, 140.

D.

Dates, 72.
Debris of food, 67.
Defects in vision, 118.
Dendrites, 105.
Dentatum corpus, 105.
Dentine, 56.
Dermis, 90, 91, 92.
Dextrose, 70, 71, 72, 84, 85.
Diaphragm, 2, 4, 35, 52, 59, 61.
Diffusion, 84.
Digestion, 55-66.

organs of, 58, 76, 77-86, 112.
Diphtheria, 138, 145.
Directions, general, 1-6.
Diseases, 138, 140.
Disinfectants, 144.
Disinfection, 143.
Distribution, 109.
Dog, 93, 117, 125.
Drawings, 5.

Draw-tube of compound micro-
scope, 2, 4.
Drum, 125, 126.
Duct, 66, 92, 116.
Dust, 136.
Duster, 137.

Ear, 94, 125, 126.

Egg, 72/75, 76, 84, 85.

-albumin, 72, 74, 75, 79.
Elbow-joint, 29.

Emulsion, 75, 76.
Enamel, 56.
Epidemic, 145.
Epidermis, 42, 89, 91, 92.
Epiglottis, 59, 131.
Ether, 76, 93.
Eustachian tubes, 59, 125.
Examination of object, 3.
Experiments, records of, 6.
Extension, 100.
Eye, 4, 113-124, 129, 134.
Eyebrows, 116.
Eyelashes, 117.
Eyelids, 114, 116.
Eyepieces, 1, 3.

F.

Farina, 69.
Farsight, 118.
Fasciculi, 23.
Fat, 67, 75, 113.

globules, 76, 81, 82, 87, 130.
Fatigue, 27, 124.
Fever, splenic, 138.

typhoid, 138, 145.
Fibres, 8, 102, 103, 105, 108, 114.

medullated or white, 110.

nerve, 109, 112.

non-medullated or gray, 1 10.
Fibrillse, 25.
Fibrin, 31, 33.
Fibula, 15.
Field, visual, 119.
Figures, 122.
Filters, 145.
Filtration, 145.
Finger, 26, 90, 118, 127.

-prints, 90.
Fissure, 96, 97, 102, 104.

dorsal, 107.

INDEX.

161

Fissure, median, 103.

of Rolando, 98.

of Sylvius, 98.

parieto-occipital, 98.

ventral, 107.
Flexion, 100.
Floors, 137.
Flour, wheat, 69, 76, 81, 82.

whole wheat, 76.
Fluid, 77, 88, 107.
Focus, 4.
Foetus, 21.
Follicle, 92.
Foods, 67, 76.
Foot, 1, 29, 100, 111, 128.
Foramen of Monroe, 103.
Forearm, as lever, 28.
Fore-brain, 96.
Forehead, 90.
Fore leg of lamb, 20.
Formalin or formaldehyde, 95, 108,

109, 112.

Formula, dental, 56, 59.
Fowl, 16, 23, 24.
Frog, 27, 31, 32, 40, 41, 108, 111,

112.
Fulcrum, 28.

G.

Gall bladder, 62.
Ganglia, 94, 109, 110.
Gas-jet, 124.
Gastric glands, 63, 65.

juice, 78, 79, 80, 81, 82.
Gastrocneinius muscle, 27.
Gelatin, 14, 134, 135, 136, 137,

140, 141, 143, 144.
Germ, 142, 143.
Gimlet, 16.
Gland, 62, 63, 65, 66, 130.

Glasses, 118.
Globe, 124.
Glottis, 59, 60.
Glue, 85.
Grapes, 70.
Gullet, 130.

H.

Hair, 91, 116.

Hairless place, 116.

Ham, 140.

Hammer, 125.

Hand, 26, 43, 89, 90, 127, 128.

Haversian canals, 15.

Head of bone, 19.

Hearing, 125, 126.

Heart, 35, 36, 37, 38, 40, 43.

Heat, 143, 144.

Herbivorous animals, 57.

Hereditary characteristics, 7.

Hilum, 69.

Hilus, 87.

Hind-brain, 96, 98.

Hip-joint, 18, 19.

Humerus, 10, 15, 30.

Humor, 114, 115, 116.

Huxley, viii.

Hydrochloric acid, 13, 14, 71, 72,

78, 79, 80, 81, 82, 112.
Hypermetropia, 118.

I.

Ice, 135, 136.
Image, 117, 120, 124.
Imbibition, 84, 85.
Immunity, 138.
Impulse, nerve, 110, 112.
Incisor, 56, 59.
Incus, 125.

162

INDEX.

Infection, 140.
Infundibulum, 100.
Infusion, 139.
Ink, 84, 85, 90.
Insertion of muscle, 22.
Instruments, 6.
Intestine, 109, 112.

large, 61, 63, 64.

small, 61, 63, 64, 84.
Iodine, 68, 69.
Iris, 114, 117, 119.
Irradiation, 121.

Joints, 18-21.

ball and socket, 18, 19.

gliding, 18.

hinge, 18.

muscles of, 30.

pivot, 18.

Judgments, imperfect visual, 121,
122.

K.

Kidney, 87, 88, 112.
Knee, 110.

-jerk, 110.

-joint, 18.

pan, 110.
Knuckles, 26.

Labyrinth, 126.
Lacteal, 65.
Lactic acid, 140.
Lactose, 70, 71, 72, 140.
Lacunae, 15.
Lamb, fore leg, 22.

Lamellae, 15.
Lamp, 119.
Larynx, 130-133.
Leg, 29.

Leitz microscope, 3.
Lens, 3, 115, 116, 117.

capsule, 115.
Letters, 122.
Levers, 28, 29.
Lieberkuhn, crypts of, 65.
Ligaments, 19.

capsular, 19, 20.

round, 19.
Light, 4, 100, 141.
Lime, 85.

-water, 73, 74.
Liquid, 90, 126.
Liver, 62, 66.
Lobe, frontal, 98.

lateral, 105.

occipital, 98.

olfactory, 98.

parietal, 98.

temporal, 98.
Lobes, 66.
Lobules, 66.
Loop, 90.

Lumbar swellings, 106.
Lungs, 35, 49, 53.

Magnification, 2, 3.
Malleus, 125.
Malpighian bodies, 88.
Maltose, 70, 71, 78.
Marriott's experiment, 120.
Marrow, 11, 12.
Mater, dura, 95.
pia, 96, 107.
Matrix, 21.

INDEX.

163

Matter, gray, 102, 103, 104.

infected, 140.

mineral, 13.

white, 103.
Meal, Indian, 69, 76.
Meatus, external auditory, 125.
Medulla oblongata, 96, 99, 102,

103, 105.
Medullary cavity, 11, 13.

portion, 88.
Membrane, epithelial, 84.

mucous, 114, 116, 131.

of cord, 107.
Mesentery, 62.
Microscope, 1-5.
Mid-brain, 100.

Milk, 73, 76, 78, 80, 81, 82, 83,
136, 139, 141, 142, 143, 144, 145.
Milk-men, 141.

-sugar (see lactose).
Milled head, 3, 4.
Mirror, 3, 4.

Mitral valve (see bicuspid valve).
Model of arm, 29, 30.

chest, 52, 53, 54.

circulation, 44, 45, 46.

ear, 125.

larynx, 133.

lever, 28, 29.

valves of aorta, 46, 47.
Moisture, 140.
Molar, 56, 59.
Molasses, 72.
Motor oculi, 102.
Mouth, 59.
Mucous coat, 64, 65.
Muscles, 16, 22-30.

action of, 27.

arytenoid, 132.

ciliary, 114.

crico-arytenoid, 132.

Muscles, crico-thyroid, 132.

gross structure, 23.

groups, 100, 101.

kinds, 23.

microscopical structure, 24.

of eye, 113.

papillary, 39, 74.

simple, 24.

thyro-arytenoid, 133.
Muscular coat, 64, 65.
Mycoderma, 137.
Myopia, 118.
Myosin, 75.

N.

Nasal openings, 59.
Nearsight, 118.
Neck, 55, 90, 106, 111, 127.
Nerves, 23, 89, 94.

auditory, 102, 126.

cranial, 101.

facial, 102.

glosso-pharyngeal, 102.

hypoglossal, 102.

olfactory, 101.

optic, 100, 101, 113, 115, 120.

pneumogastric, 102.

spinal, 109, 112.

spinal accessory, 102.

sympathetic, 94, 112.

trunks of, 112.
Network, 108.
Neural arch, 12.

canal, 12.

ring, 12.
Neuron, 105.
Newt, 7.

Nitric acid, 14, 74.
Normal salt solution, 109.
Nose, bridge of, 116, 127.

164

INDEX.

Nostril, 129.

Nucleolus, 7, 108.

Nucleus, 7, 25, 31, 91, 107, 110.

0.

Oatmeal, 69.

Objectives of compound micro-
scope, 1, 3.
Odors, 129.

CEsophagus, 35, 60, 63, 130, 131.
Oil, glands, 92.

olive, 82, 84.
Onion, tf7, 129.
Openings, 10, 89, 116.
Ora serrata, 115.
Organs, 112, 130.

circulatory, 112.

digestive, 58, 112.

excretory, 112.
Origin of muscle, 22.
Osmosis, 84.
Ossein, 14.
Outflow, 46.
Ox, 113.

Oxid cuprous, 70.
Oxygen, 34.

P.

Pail, 142.

Palm of hand, 89, 90.
Pancreas, 66, 131.
Pancreatic juice, 81, 83.
Pancreatin, 81, 83.
Papers, 124.
Papilla, 57, 89, 92.
Paste, starch, 78.
Pasteurization, 142.
Pathetici, 102.
Peas, 69.

Peduncles, 96, 99, 100, 104.

Pelvis, 88.

Penniform, 24.

Pepper, 129.

Pepsin, 78, 79, 80, 81.

Peptone, 134.

Peptonized, 83.

Pericardial liquid, 35.

Pericardium, 35, 41.

Perimysium, 23.

Periosteum, 10.

Peritoneum, 63.

Person, 93, 123, 126.

Perspiratory glands, 89, 92.

Pharynx, 59.

Pickles, 139.

Pigeon, 22.

Pillar of the compound micro-
scope, 1.

Pineal gland, 100.

Piotrowski reaction, 72.

Pits, 65.

Pituitary body, 100.

Plain muscle, 25, 26.

Pluck, 35.

Pons Varolii, 96, 99, 102, 104, 105.

Potassium bichromate, 95, 113,
115.

ferrocyanide, 73

Potato, 67, 68, 129.

Pound, 128.

Power, 28.

Precipitation, 145.

Preface, iii-v.

Premolar, 59.

Preservatives, 141.

Preserves, 139.

Pressure, 128.

Process, 13, 115.

Processes, branched (seedendrites).

Products of digestion, 83.

INDEX.

165

Prominences, 11.
Proteids, 67, 72-75, 78, 81.
Protein (see proteid).
Protoplasm, 7, 8, 107.
Prunes, 72.
Pulp cavity, 56.
Pulse, 43, 45.
Pump, 45.

Pupil, 114, 117, 119.
Purification, 145.
Putrefaction, 139.
Pyloric orifice, 61.
Pyramids, 99.

of Malpighi, 88.

R.

Rabbit, 94.

Radius, 30.

Rays, 121.

Record of experiments, 5, 6.

Rectum, 61, 62.

Reducing agent, 70.

sugar, 71.

Reflex action, 110, 111, 112.
Rennet, 80.
Rennin, 78, 80, 81.
Resistance, peripheral, 43.

use of, 46.
Respiration, 49-54.

number of, 51.

Retina, 115, 116, 118, 121, 124.
Rice, 69.
Ridges, 10, 89.
Rings, cartilaginous, 49.
Rods, 128.
Rooms, 141.
Root, 91, 92.

of nerves, 101, 106, 107, 109.

of tooth, 55.
Rough places on bone, 10.

S.

Saccharose, 71, 72.

Sago, 69.

Saliva, 77, 78.

Salt, 129.

Salts, 67, 70.

Sarcolemma, 25.

Sarcoplasm, 25.

Scapula, 30.

Sclerotic coat, 113, 114, 117, 118.

Screen, 117.

Sebaceous glands, 92.

Sediment, 142.

Sedimentation, 145.

Semilunar valves, 39.

Sensations, 123, 127-129.

Septa, 107.

Serum, 33, 34.

Sewage, 145.

Shade, 119.

Shaft of a long bone, 10, 11.

Sheath, 109.

Sheep, 94, 130.

Shoes, rubber, 86.

Shoulder-blade, 9.

-bone (see scapula).

-joint, 30.

Skeleton, 9, 10, 16, 17, 18.
Sketches, 5.
Skin, 87, 89-93, 127.
Skull, 94, 100, 101.
Slides, microscopical, 148.
Smell, 127-129.
Sodium carbonate, 81, 134.

hydrate, 73, 74.

Barfoed's, 70, 71.
Solution, Fehling's, 70, 71, 72.
Sound, 126.

Souring of milk, 140, 141, 143.
Specimens, 147, 148.

166

INDEX.

Spinous process, 12.
Spleen, 62.
Spores, 143, 144.
Spot, 121.
Spring-balance, 28.
Squares, 120, 121.
Stage, 2.

Stand of the compound micro-
scope, 1, 4.
Staples, 125.

Starch, 68, 69, 72, 77, 81.
Steapsin, 81.
Stem of hair, 92.
Sterilization, 134, 142, 144, 145.
Stimulus, 111, 112.
Stomach, 60, 63, 64, 79, 80.
Striations of muscle, 24, 25.
Sublimate, corrosive, 143, 144.
Subrnucous coat, 65.
Subsidence, 145.
Substance, gray, 105, 107, 108.

white, 103, 105, 107, 108.
Sugar, cane (saccharose), 71, 72,
129.

grape (dextrose), 70, 71, 72,
85, 84.

maple, 72.

milk (lactose), 70, 71, 72, 140,
142.

reducing, 71.
Summer, 142.
Sunlight, 141.
Susceptibility, 138.
Sweat glands, 89, 90.
Sweeping, 137.
Sweet, 142.
Swellings, 106.
Synovial liquid, 20.

membrane, 19, 20.
Syrup, 72, 139.
System, cerebro-spinal, 112.

System, nervous, 94-112.

sympathetic, 112.
Systole, 41.

T.

Tadpole, 42.

Tapioca, 69.

Taste, 127-129, 142.

Teeth, 55, 59, 126.

Temperature, 50, 89-93, 127, 128.

Tendons, 19, 22, 24, 26.

Test for hearing, 126.

Test-types, Snellen's, 118.

Tetanus, 27,

Thalamus, optic, 104.

Thermometer, 142.

Thorax, 52, 53, 54.

Throat (see pharynx).

Thumb, 26, 90.

Tissue, cellular, 95.

connective, 8, 66, 108, 109.

epithelial, 8.

fatty, 8.

fibrous, 95.

nervous, 94.
Toes, 27.

Tongue, 53, 57, 129, 130, 131.
Touch, 127.

Trachea, 35, 49, 52, 130, 132.
Tracts, optic, 100, 101, 103.
Transverse processes, 12.
Triceps, 29, 30.
Trigeminals, 102.
Tripe, 139.
Trypsin, 81.
Tuber cinereum, 100.
Tubules, 88.
Turnip, 67.
Tympanum, 125.
Type, 118.

INDEX.

167

u.

Ulna, 30.
Ureter, 87, 88.
Uriniferous tubules, 88.
Use of the microscope, 4.

V.

Vaccination, 138.

Valve, 38, 39, 40, 46.

Valvulae conniventes, 64.

Vein, 38, 39, 40, 43, 44, 50.

Veinlet, hepatic, 66.

Venae cavae, 37, 38.

Ventricle, of brain, 99, 103, 104.

of heart, 36, 37, 38, 41.
Vertebra, 12, 112.
Vertebral column, 12, 112.
Vestibule, 126.
Villi, 64, 65.
Vinegar, 14, 73, 83, 84, 85, 129,

137, 139.
Vision, 113-124.
Voice, 130-133.

W.

Watch, 126.

Water, 67, 128, 135, 136, 145.

Waves, sound, 126.

Weight, 28, 128.

Whey, 80.

Whorl, 90.

Windpipe, 130.

Winter, 142.

Wire, 16.

Wisdom teeth, 57.

Worsteds, 123.

Wrist, 9, 18, 43.

Y.

Yellow spot, 120.

Z.

Zanthoproteic reaction, 72.
Zollner's lines, 122.
Zooglea, 137.

14 DAY USE

RETURN TO DESK FROM WHICH BORROWED

This book is due on the last date stamped below, or

on the date to which renewed.
Renewed books are subject to immediate recall.

--^ttfttf 1 3 IQ?fr-

NOV 5197007

.

^.ftfflT'S5 U-^/gSJnU.