-{Key for Dissection Sheets, and Abbreviations.}_

Sheet 1

Figure 1. Main facts of the Rabbit's Anatomy (diagrammatic).
an., anus.
a.ao., arch of the aorta.
au., auricle.
a.r., ad-renal body.
br., brain.
b.d., bile duct.
brch., bronchus.
cd.st., cardiac end of stomach.
co., colon.
cae., caecum.
ddnm., duodenum.
d.ao., dorsal aorta.
dia., diaphragm.
ep., epiglottis.
g.d., genital duct (either sex).
il., ileum.
in.art., innominate artery.
k., kidney.
lg., lung.
lv., liver.
l., larynx.
l.s.c., [l.c.c.] left common carotid artery.
m., mouth.
na., nasal passage.
oes., oesophagus.
p.v., pyloric valve.
p.d., pancreatic duct.
pt., peritoneal cavity.
r., rectum.
st., stomach.
[stm., sternum.]
s.r., sacculus rotundus.
s.c., spinal cord.
tr., trachea.
ur., ureter.
ur.b., urinary bladder.
v.b., a vertebral body.
v.ap., vermiform appendix.
v.v., [v.p.] velum palatium.
v., ventricle of heart.
v.c.i., vena cava inferior.
Figure 2. The Liver (diagrammatic).
g.b., the gall bladder.
r.l., r.c., l.l.., l.c., right lateral and central, and left lateral and
central, lobes respectively.
sp., the Spigelian lobe (fits into angle of stomach and oesophagus).

Sheet 2

Figure 1. The Rabbit's Circulation (see [footnote to Section 45]).
(Throughout l. indicates left, r. right.
Vessels without r. or l. prefixed are median.)
-[* The figure is inaccurate at one point; l.c.c. should
spring from the base of inn. See [Sheet 9].]-
{First Edition only text}
ao.a., aortic arch.
au., auricle.
az.v., (p.c. in Figure 2), azygos vein.
c.c., common carotid.
c.il.a., common iliac artery.
coe.a., coeliac artery.
d.ao., dorsal aorta.
e.il.v., external iliac vein.
e.ju., external jugular vein.
f., femoral artery.
h.v., hepatic vein.
inn., innominate artery.
in.j., internal jugular vein.
i.il.a., internal iliac artery.
i.il.v., internal iliac vein.
k., kidney.
lv., liver.
l.g.v., lienogastric vein (portal).
m.v., mesenteric (portal system).
p.m.a., posterior mesenteric artery.
p.v., main portal vein.
p.a. pulmonary artery.
r., rectum.
r.a., renal artery.
r.v., renal vein.
s.v., and a., spermatic (or ovarian) vein and artery (to genital
organ).
s.mes.a., superior mesenteric artery.
s.-cl.a., subclavian artery.
s.-cl.v., subclavian vein.
v.c.s., vena cava superior.
v.c.i., vena cava inferior.
v. or vn., ventricle.
Figure 2. Figure of Circulation (simplified)
illustrating certain points in development to be referred to later.
Figure 3. Respiration. See text, [Section 41].
Figure 4. Blood. See text, [Section 35].

Sheet 3
Histological Figures, 1.

{No numbers I., or II.}
Figure III. An amoeba.--
n., nucleus.
ns., nucleolus.
c.v., contractile vacuole.
Figure IV. Embryonic tissue from the blastoderm of a chick.
Figure V. Columnar epithelium.--
g.c.1, g.c.2, g.c.3, successive phases in the development of a goblet
cell.
Figure VI.
g.end., is geminating endothelium; the cells divide and apparently
drop off to become white corpuscles in the lymph current.
sq.end., squamous endothelium from the mesentery.
sq.ep., squamous epithelium (from the mucous membrane within the
cheek).
st., are opening (stomata) communicating between the lymphatics in
the mesentery and the peritoneal (coelomic) space.
Figure VII. Ciliated epithelium from the roof of the frog's mouth.
Figure VIII. Forms of glands.--
g.ep., is a gastric gland from the stomach; trs., below, is cross
section. This is one of the simplest types of gland.
s.g., a sweat gland, is also a simple tube, but convoluted below.
r.g., is a racemose gland, such as the pancreas, Brunner's or the
salivary glands.
The kidney, we shall see later, is simply an aggregate of branching
tubuli ([Sheet 7]).
Figure IX. A duodenal villus.--
lac., the lacteal.
v., the vein.
Figure X.a. Diagram of liver structure.--
b.d., the inter-lobular bile duct.
h.a., the hepatic artery, bringing blood to oxygenate and nourish the
liver tissue, and similarly distributed.
h.v., the hepatic vein taking blood from the liver to the heart, its twigs
commencing in the lobuli (intra-lobular).
lb. lb., lobuli.
p.v., the portal vein bringing blood, from which substances are to
be elaborated, into the liver, and breaking up between the lobuli
(inter-lobular).
Figure X.b. A diagram of the appearance of an injected liver
lobule as seen in section under the microscope.

Sheet 4
Histological Diagrams, 2.

Figure XI. A blood capillary. White corpuscles are migrating through
the walls into the tissues (compare [Section 66]).
Figure XII. Hyaline cartilage ([Section 64]).
Figure XIII.
c.c., connective tissue corpuscle.
w.i.f., white inelastic fibres.
y.e.f., yellow elastic fibres.
Figure XIV. Botryoidal tissue ([Section 66]).
Figure XV. Development of a fat drop.--
f.d., fat drop, in a connective tissue corpuscle; c.c., in the formation of
adipose tissue ([Section 67]).
Figure XVI. Diagrammic cross section of a long bone.--
b.c., bone corpuscle in a lacuna.
H.v., Haversian vessel (in the Haversian canal) surrounded by
concentric lamellae of bone, c.l., and together with these and zones
of bone corpuscles, called a Haversian system.
i.l., inner lamellae.
m.c., medullary canal full of yellow marrow.
o.l., outer lamellae.
p.o., periosteum.
Figure XVII. To illustrate bone development ([Section 71]).
Figure XVIII. Dentition of rabbit, incisors 2/1, canine 0/0, premolar 3/2,
molar 3/3.

Sheet 5.
Diagram of the Rabbit's Bones.

D and D' show the fore and hind limbs, to illustrate their homology.
D is in the embryonic position. The radius and tibia are, at an early
stage in development, on the anterior edge of their respective limbs;
the ulna and fibula, posterior; the former are spoken of as preaxial in
position, the latter as postaxial. But in the adult the humerus is
twisted so that the proximal end of the radius lies at the outer side of
the elbow, whence it crosses the ulna, so that its distal end is
inside, while the femur is also twisted round, so that the entire tibia
is internal.
Figures 1 and 2. -Limbs.--
a.c., acetabulum.
acr., acromion.
as., astragulus.
c., carpus.
ca., calcaneum.
co., coracoid.
[coty., cotyloid bone.]
fb., fibula.
fe., femur.
g., glenoid cavity (for head of humerus).
hd., head of femur.
hum., humerus.
i., ilium.
is., ischium.
m.c., meta-carpals.
na., navicular.
o., olecranon process of ulna.
o.f., olfactory fossa.
pb., pubis.
r., radius.
u., ulna.
Figure 3. -Sternum.--
Mb., manubrium.
r1., r2., and etc., sternal ribs.
st., sternebrae.
xi., Xiphisternum.
Figure 4. Vertebrae.--
At., Atlas.
Ax., axis.
c., [b.] centrum.
C.V., caudal vertebra.
c.v., [Cer.V.] cervical vertebra.
ep., epiphysis.
f.r., fused rib (in cervical vertebrae).
L.V., Lumbar vertebra.
m., metapophysis (of lumbar vertebra).
n.a., neural arch.
n.s., neural spine.
r., rib.
S.V., sacral vertebra.
[T.V., Thoracic.]
tr.p., transverse process.
v.a.c., vertebrarterial canal.
z., zygapophysis.

Sheet 6.
The Skull of Canis.*--
1. Dorsal. 2. Ventral. 3. Right Lateral Aspect. 4. Section a little to the
left of the nasal septum. 5. Lower jaw (smaller) 6. Hyoid apparatus.

a.n., anterior nares.
a.s., ali-sphenoid.
b.h., body of the hyoid.
b.o., basi-occipital.
b.sp., basi-sphenoid.
c., condyle of the skull.
{c.1, c.4, canines.}
c.f., condylar foramen (for XII.).
c.h., cerato-hyal.
E.f., Eustachian foramen.
e.h., epihal.
-e.n., or a.n., the anterior nares.-
e.o., exoccipital.
eth., ethmoid.
e.t., ethmo-turbinal.
f., frontal.
f.l.a., foramen lacerum anterius.
f.l.m., foramen lacerum medium.
f.l.p., foramen lacerum posterius (for IX., X., XI.).
F.M., or f.m., foramen magnum.
f.o., foramen ovale.
f.r., foramen rotundum.
{i., incisors.}
ju., jugal.
m., molars.
m.t., maxillo-turbinal.
mx., maxilla.
na., nasal.
n.t., nasal turbinal.
o.f., optic foramen.
o.s., orbito-sphenoid.
p., or pal., palatine.
pa., parietal.
p.m., pre-maxilla.
p.m.1, p.m.4, premolars.
p.n., posterior nares.
p.sp., pre-sphenoid.
pt., pterygoid.
s.h., stylo-hyal.
s.m.f., stylo-mastoid foramen (for VII.).
s.o., supra-occipital.
sq., squamosal.
s.t., sectorial tooth.
t.h. thyro-hyal.
vo., -black line indicating position of- vomer.
z.p., zygomatic process of squamosal.

Sheet 7.

Figure 1. Striated muscle fibre (of the Rabbit), ruptured to show sarcolemma.
e.p., its end plate.
K.m., membrane of Krause.
n., nucleus.
nv., nerve.
sc., sarcolemma.
s.e., sarcous elements.
Figure 2. Cardiac muscle.
Figure 3. Unstriated muscle fibres.
Figure 4. Diagram of the Skin.
b.v., blood vessel.
d., areolar tissue of the dermis (mesoblastic).
s.c., stratum corneum, and s.m., stratum mucosum of the
epidermis.
s.g., sweat gland.
t.c., tactile corpuscle.
Figure 5. To illustrate Kidney structure.--
a.b.v., and e.b.v., afferent and efferent blood-vessels, of which the
latter go to break up upon the tubli.
B.c., one of Bowman's capsules of the cortex;
ur.t., the uriniferous tubule running from it into the medulla, where
it loops and branches; around it branches a blood-vessel, of which the
latter go to break up upon the tubuli.
c., cortex.
g., glomerulus, a knot of blood-vessels in the capsule.
m., medulla.
p., pelvis.
ur., ureter.
The water of the urine is probably filtered off in the capsule, the urea
and other salts secreted by the tubuli.
{No Figure 6.}
Figure 7. The Auditory structures of the Rabbit (diagram). See text,
[Section 115].
Figure 8. The Eye (diagram). See text, [Section 111].
Figure 9. The Retina (diagram). See text, [Section 112].

Sheet 8.
The Brain of the Rabbit.--

{Figures 1-5.}
ar., arrow in the iter.
a.c., the anterior commissure, a thickening of the anterior wall of the
third ventricle.
c.c., corpus callosum.
c. cb., crura cerebri.
c.h., cerebral hemispheres.
c.q., corpora quadrigemina.
f.cbm. (right), flocculus of the cerebellum.
l.h., left cerebral hemisphere (=ch.).
l.l., lateral lobe of cerebellum.
m.c., middle commissure.
m.o., medulla oblongata.
op., optic nerve.
o.l., olfactory lobe.
o.th., (right), optic thalamus.
p.c., posterior commissure (thickening of postero-dorsal wall of the
third ventricle).
p.g., pineal gland.
pt., pituitary body.
p.V., pons Varolii.
s.c., thin roof of the fourth ventricle.
v.cbm., vermis of cerebrum.
v.l., lateral ventricle.
{Figure 4.} Nerves.--
I., Olfactory.
II., Optic.
III., Oculo-motor.
IV., Patheticus.
V., Trigeminal.
VI., Abducens.
VII., Facial (portio dura).
VIII., Auditory (portio mollis).
IX., Gustatory (glossopharyngeal.
X., Pneumogastric or vagus.
XI., Spinal Accessory.
XII., Hypoglossal.
Figure 6. The Spinal Cord in section.--
c.c., the central canal.
d.f., the dorsal fissure.
d.n., the dorsal nerve root; g., its ganglion.
v.f., the ventral fissure.
v.n., the ventral nerve root.
Note that in Figure 1 the central canal is continuous with the fourth
ventricle.
Figure 7. Histological elements.--
g.c., multipolar ganglion cell.
n., nucleus of a medullated nerve.
a.c., its axis fibre.
s.S., (sheath of Schwann), medullary sheath interrupted at intervals by
n.R., the nodes of Ranvier.
n.m.f., a non-medullated fibre.

Sheet 9.
-The Nerves of the Rabbit_.

Figure I. Rough sketch of dissection of the neck
from the left ventral aspect.--
The bands of muscle between hyoid, mandible, and
sternum, and the thymus gland carefully cleared.
lr., is the larynx, and b., the balla.
s.m.g., the right sub-maxillary gland (the left has been removed).
The nerves are numbered.
l.r.l.n., [r.r.l.n.] is the left recurrent laryngeal looping under that solid
connection between the pulmonary artery (p.a.) and ao., the aortic
arch, which was an open tube in the embryo, the ductus arteriosus.
hy., is the hyoid with its posterior cornua.
ph.n., is the phrenic nerve.
r.r.l.n., [l.r.l.n.] is the right recurrent looping under the sub-clavian.
s.c.g., is the super or cervical ganglion of the sympathetic (sym.);
s.l.n., is the left superior laryngeal, and g. the left depressor
branch of x.
z., is the ramus descendens noni of the twelfth nerve.
In early development the heart lay just beneath the pharynx in the
position of the larynx (compare Dog-fish and Frog); as the neck
elongated, the heart shifted back with its vessels, and so the long
loop of the recurrent laryngeal comes to be drawn out in this singular
way.
Figure II. Diagram of orbit to show V.1 orbit-nasal, V.2 the maxillary,
and V.3 the mandibular branch of V. In order to show these in
dissection, the malar must be cut away, and the eye and glands of
the orbit removed.
s.r., e.r. [p.r.], i.r., and a.r., cut ends of the superior, external (or
posterior), inferior, and anterior (or internal) recti muscles.
s.o., and i.o., the superior and inferior obliques.
Figure III. General diagram of the Rabbit's cranial nerves.
Figure IV. Rough sketch of dissection of the nerves and
blood-vessels dorsal to stomach.--
The stomach turned over to the animal's right, the Spigelian liver lobe
cleared from the oesophagus, the mesentery supporting spleen and
hiding solar plexus picked off, and the mesentery hiding sympathetic
cleared.
coe.art., coeliac artery, and s.m.a., superior mesenteric artery.
coe.g. coeliac, and s.m.g., superior mesenteric ganglion. The two
together form the solar plexus.
l.abd.sym., left abdominal sympathetic (in the actual dissection, the
right would also be visible).
l.a.r., left adrenal.
l.sp.n., left splanchnic nerve.
r.art., renal artery.
r.v., renal vein.
st., the stomach, and sp., the spleen.
x., the vagus on oes., the oesophagus.

Sheet 10.
-Reproductive Organs of the Rabbit_.

Figure 1. The Male.
Figure 2. The Female Organs.
(The symbols below the figures indicate the sex.)
pb., is the pubic symphysis [which has been] cut through.
R., the rectum, with r.g., the rectal gland, and a., the anus.
t., the tail.
r.ur., the right ureter.
l.ur., the left ureter.
ur.b., the urinary bladder.
In the Male
ep., the epididymis.
P., the penis.
pp., the prepuce.
scr., the scrotal sac, containing these;
r.v.d., the right vas deferens.
T., is the testis.
u.m., the uterus masculinus.
In the Female
c.ut, the left cornu uteri.
F.t., the left Fallopian tube.
ov., is the ovary, with a Graafian follicle, G.F.
V., the vagina.
v.b., the vestibule.
Figure 3. Diagram of ovary with stages in the development of a
Graafian follicle 1, 2, 3, 4, 5, see text, [Section 137]. The arrow
indicates the changes in position of the developing follicles.

Sheet 11.

Figure 1. General dissection of Frog (male).
Figure 2. The heart and great vessels laid open.
Figure 3. The circulatory system from the side.
Figure 4. Blood.
{n., nucleus.}
r.c., red corpuscle (oval and nucleated).
w.c., white corpuscle
Small figure of Frog in left-hand corner is to show position
of heel, h.
Reference Letters.
all.b., allantoic bladder (= urinary bladder).
c.ad., corpus adiposum.
cl.c., cut end of the right clavicle.
d., duodenum.
g.b., gall bladder.
il., ileum.
k., kidney.
l.au., left auricle.
l.g., lung.
l.int., large intestine.
l.s.v., longitudino-spiral valve.
L.v., Liv., liver.
pan., pancreas.
r.au., right auricle.
sp., spleen.
st., stomach.
T., testis.
t.a., truncus arteriosus.
ur., urogenital duct.
v., ventricle of heart.
Arteries (white).
ao., aorta.
c.a., carotid arch.
c.g. [c.gl.], carotid gland.
coe., coeliac.
cu., -and pa.",- cutaneous.
d.ao., dorsal aorta.
e.c., lingual artery.
[i.c., internal carotid.]
l.a.a., left aortic arch.
pa., and p., pulmonary.
p.c. [p.cu.], pulmo-cutaneous.
r.a.a., right aortic arch.
[s.cl., sub-clavian.]
t.a., truncus arteriosus.
Veins of the Caval System -(black)-.
b.v., brachial (from fore limb).
e.j., external jugular.
h.v., hepatic vein.
i.j., internal jugular.
[in.v., innominate vein.]
l.v.c.s., left vena cava superior.
p.v., cutaneous vein.
[s.cl.v., sub-clavian vein]
s.s.r., sub-scapular vein.
v.c.i., vena cava inferior.
Veins of the Portal and Renal Portal Systems -(shaded)-.
a.ad., and a.ab.v., anterior abdominal vein.
b.v., and p.v., united are called the sub-clavian vein.
l.fm., left femoral.
l.p., left pelvic.
l.r.p., (and r.p.) left renal portal.
l.sc., left sciatic.
p.v., portal vein.
-(The anterior abdominal is coloured black in Figure 1.)-
The cutaneous artery in the above figures is turned back. In dissection
it will be found to lie over and hide the dorsal-ward sweep of the aortic
arch.

Sheet 12.

Figure 1. Upper view of the Frog's brain.
Figure 2. Under view of the same.
Figure 3. The same-- median section.
Figure 4. The distribution of the Frog's nerves.
Compare [Sheet 9], Figure III.
The shaded part in 4 is the -otic capsule- [tympanum]. The hyoid
apparatus is roughly represented in black to show its relation to IX.
(dorsal to it) and sp. 1 (ventral). Compare {nerves} IX and XII in [Sheet
9]. The nerves are numbered.
cb., the cerebellum.
c.h., cerebral hemispheres.
f.t., filum terminale.
g.tr., ganglion on the fifth nerve.
l.t., lamina terminalis.
mb., mid-brain.
md., medulla oblongata.
o.l., optic lobes.
pin., pineal gland.
pit., pituitary body.
r.h., olfactory lobes (rhinencephalon).
th.c., thalamencephalon.
sp.1, first spinal nerve.
sp.2, 3, brachial plexus to fore limb.
Figure 5. The spinal column (and pelvic girdle) of the Frog.
Figure 5b. Vertebrae.
Figure 6. The pectoral girdle and limb, dorsal view.
Figure 7. The pelvic girdle and right limb from the side.
(l.h. shows the position of the right lymph hearts-- they are
paired.)
as., astragalus.
b., body.
c., calcar (?= a sixth digit).
cal., calcaneum.
cl., clavicle overlying a procoracoid cartilage.
co., coracoid.
f., fibula.
[FE., femur.]
h., humerus.
il., ilium.
is., ischium.
o.st., omosternum.
pu., pubis.
r., radius.
sc., scapula.
s.sc., supra-scapula.
s.v., sacral vertebra.
t., tibia.
t.p., transverse process.
ul., ulna.
ur., urostyle.
x., xiphisternum.
z., zygapophysis.
1, 2, and etc., first, second, and etc., digits.
D. and D'. are simplified diagrams of the limbs for comparison with the
similar ones of the Rabbit. In each girdle we have a dorsal ossification
(scapula, ilium) and two ventral parts (pubis and procoracoid cartilage,
ischium and coracoid), and at the meeting-place of the three in each
case the proximal bone of the limb (humerus, femur) articulates.

Sheet 13.
-Urogenital Organs of the Frog_.

Figure 1. The Male.
Figure 2. The Female. The oviduct removed on the animal's left,
and the ovary on its right.
Organs common to both sexes.--
al.b., allantoic bladder.
c.ad., corpus adiposum.
cl., cloaca.
int., intestine.
K., kidney.
lg., (dotted outline of) lung.
oes., oesophagus.
r.p.v., renal portal vein.
st., stomach.
In the Male.--
T., testis.
v.e., vasa efferentia.
u.g.d., urogenital duct.
p., prostate gland.
In the Female.--
adr., adrenal.
f.t., fallopian tube (anterior part of oviduct). * its opening.
o.d., oviduct (letters on [the opening] -uterine portion-).
ov., ovary.
ur., ureter.
(This would be the condition about midwinter.) In March o.d. will be
either enormously distended with eggs, or large, flabby, and empty,
and ov. will be small and brownish, without any large eggs; the ovary
gradually recovers its size through the summer.
Figure 3. Spermatozoa attached to the parent cell (g.e.) from the
lining epithelium of the testis, and one free.
fl., the flagellum.

Sheet 14.
-Skull Structure and Development of the Frog_.

Figure 1. I., II., early and late stages of the Tadpole's chindrocranium.
Diagrammatic.
Figure 2. Dorsal view of a young Frog's cranium-- the membrane
bones removed. Diagrammatic.
Figures 3 and 4. Dorsal and ventral views, respectively, of the Frog's
skull-- the lower jaw removed.
Figure 5. Side view of the Frog's skull.
Figure 6. Median section of the brain case.
Figure 7. The hyoid apparatus.
Figure 8. I., II., III., progressive stages of the Tadpole's skull from
the side. After W. K. Parker.
Figure 9. F., side and hind views of the Frog's skull. D., the same of
the Dog. Roughly diagrammatic.
N.B.--
In all cartilage is dotted, cartilage bone cross-barred, and membrane
bone, white. In Figure 4, pt., should be cross-barred;
and in 5, th.h. plain.
a.c., anterior cornu of hyoid [(= CH.)] -not lettered, in {Figure} 5-.
a.o., antorbital cartilage.
ar., angulo-splenial -(On Frog [Section 34], for Articulare read
-Angulo-Splenial_)-.
-b., parachordal part of brain box-.
b.c., brain case.
b.h., body of hyoid.
b.r., branchial arches.
CH = a.c.
c.t., cornua trabeculi.
d., dentary.
e., eye.
E.N., external nares.
e.o., exoccipital bone.
f., fenestra (membranous part of cranial wall).
-f.p., fronto-parietal.-
h.m., hyomandibular cleft = Eustachian tube and ear drum.
mb., mandible.
[M.C., Meckel's Cartilage.]
m.mk., mento-Meckelian bone.
m.p., mouth passage.
mx., maxilla.
n.c., notochord.
n.o., nasal organ.
n.p., nasal passage.
ot., or o.c., otic (auditory) capsule.
pal., palatine bone.
PAL., hard palate of Mammal.
p.c., parachordal.
p.f., [parieto-frontal] -see f.p.-
p.m., premaxilla.
P.N., internal nares.
p.o., prootic bone.
p.p., palato-pterygoid cartilage.
psph., parasphenoid bone.
pt., pterygoid bone.
q., quadrate cartilage.
q.j., quadrato-jugal.
s.e., sphenethmoid bone.
sq., squamosal.
t., trabecular part of brain box.
t.c., trabecula.
th.h., thyrohyal.

Sheet 15.

Figure 1. Dissection of -Male- [Female] Dog-Fish to show
alimentary canal, the pericardium also being opened and the
cloaca slit up. [Above is also seen the dorsal view of the head.]
Figure 2. The pelvic girdle and fin skeleton [of a male].
{No Figure 3, in First Edition.}
Figure 4. The spiral valve in the colon.
{Figure 3, in Second Edition.}
a.p., abdominal pore.
aur., -auricle- [atrium] of heart.
b.d., bile duct.
b.pt., basi-pterygium.
-cl., clasper.-
cl.c., -its- [the] supporting cartilage [of the clasper].
co., colon.
d'dnm., duodenum.
e., the eye.
g.bl., gall bladder.
g.s., gill slits.
L.Lv., left lobe of liver.
M.Lv., middle lobe of liver.
olf., olfactory opening.
[pan., pancreas.]
pcd., pericardial wall.
pel.g., the pelvic girdle.
p.p., arrow through pericardio-peritoneal canal.
r.g., rectal gland.
[R.Liv., right lobe.]
sp., spiracle.
spl., spleen.
st., the stomach.
s.v., sinus venosus.
u.g.p., uro-genital pore.
v., ventricle.

Sheet 16.

Figure 1. Circulation of the Dog-Fish.
Figure 2. Simplified and more typical fish circulation,
in which the posterior cardinals have not coalesced in the
median line. The Cuvierian veins = the vena cava superior
of the higher type; the posterior cardinal is represented by
the azygos vein in the Rabbit.
Compare [Sheet 24], Figure 7, and [Sheet 2], Figure 2.
Figure 3. Side view of the pericardium.
a.br., afferent branchial artery.
a.c.s., anterior cardinal sinus (= internal jugular vein).
au., atrium (auricle) (= the two auricles of higher forms).
b.a., bulbus arteriosus.
c.a., conus arterious.
cd. a., caudal artery.
cd.v., caudal vein.
c.s., Cuvierian sinus.
d.a., dorsal aorta.
E., eye.
e.br., efferent branchial arteries.
g.s., in position of gill slits.
h.br.a., hypobranchial artery.
H.S., hepatic sinus.
[i.j.s., inferior jugular sinus (= external jugular vein).]
K., kidney.
L.V., lateral vein.
[oe.s., ventral wall of oesophagus.]
P.C.C., pericardial cavity.
P.C.S., posterior cardinal sinus.
p.p.c., pericardio-peritoneal canal.
P.V., portal vein.
r.p.v., reno-portal vein.
s.c.v., subclavian vein.
Vn., ventricle.
-v.s.v., inferior (= external) jugular vein-.
Figure 4. Skeleton of pectoral limb, and girdle.--
g., the girdle (also in Figure 3).
m.p., meso-pterygium.
mt.p., meta-pterygium.
p.p., pro-pterygium.
sc., its dorsal portion.

Sheet 17.
-The Uro-genital Organs of the Dog-Fish_.

Figure 1. The Female, the oviduct of the left side cut away,
-and an egg case in the oviduct.-
Figure 2. The Male.
The rectum is removed in both cases, and the silvery peritoneum
dissected off from the kidneys.
Figure 3. A generalized diagram of the uro-genital organs.--
All references in text.
Ms., the mesonephros, is the epididymis in the male, and is reduced
in the female; Ms.d., its duct, is the vas deferens in the male, and
persists only as the urinary receptacle in the female.
Mt. and Mt.d., the metanephros and metanephric duct, become the
functional kidney and ureter in both sexes. G. is the gonad
(reproductive gland), and M.L. the animal's middle line (median
plane).
-Ps.-, [Pr.,] the pronephros, is never developed in the Dog-fish;
P.d., its supposed duct, is the oviduct of the female, and is
suppressed in the male.

Sheet 18.

Figure 1. The Dog-Fish Brain, dorsal view.
Figure 2. Median section of the same. To the right a
more diagrammatic figure. The nerves are numbered:--
[BR1, BR2, BR3, BR4 branches of X forking over the
second to the fifth gillslit.]
cb., cerebellum.
h.s.c., horizontal semi-circular canal of ear, exposed by
the slicing down of the otic mass.
[LAT., lateral-line branch of X.]
m.o., medulla oblongata.
oph., ophthalmic nerve (V.1+VII.1).
op.l., optic lobe.
pit., pituitary body.
pr.c., prosencephalon (cerebral hemisphere).
rh., olfactory lobe (rhinencephalon).
r.t., -its- restiform tracts [of medulla].
-st-. [S.P.G.], stalk of the pineal gland.
th., thalamencephalon.
th.c., thalamencephalon.
-ut., the utriculus, seen through the semi-transparent cartilage-.
Vid., the Vidian branch of VII.
[Visc., visceral branch of X.]
Figure 3. Diagram of the ear of a fish.
The structure of this is easily made out by clearing otic
capsule and cutting slices of the cartilage in the Dog-Fish
(e.g., Figure 1, h.s.c.).
amp., their ampullae.
a.v.c., p.v.c., h.c., anterior, posterior, horizontal canal respectively.
[amp., the ampullae.]
d.e., the ductus endo-lymphaticus.
-sac., the sacculus; c., a small outgrowth of the latter, corresponding
to the rabbit's cochlea-.
-ut., the utriculus-.
Figure 4. The cranium and branchial bars of a Dog-Fish.
The groove in the otic capsule connects the orbital and anterior
cardinal sinuses.
A.C.S., position of the anterior cardinal sinus (dotted outline).
c., the vertebral centra.
c.b., the cerato-branchial.
c.h., the cerato-hyal.
e.b., epi-branchial.
ex.b., extra-branchial.
h.M., the hyo-mandibular.
i.n.p., inter-neural plate.
M.C., Meckel's (lower jaw) bar.
Na.C., the nasal capsule.
n.p., neural plate.
n.s., neural spine.
Ot.C., the otic capsule.
ph.b., the pharyngo-branchial.
P.pt., the palato-pterygoid bar (upper jaw bar).
p.s., pre-spiracular ligament, containing a cartilaginous nodule.
r., rib.
sp., the position of the spiracle.
Figure 5. Diagrams of a vertebral centrum.-- For reference
letters, see text ([Section 9]).
{No Figure 6, in First Edition.}
[Figure 6. Diagram for comparison with Figure III., [Sheet 9].]

Sheet 19.

Figure 1. Amphioxus, seen from the right side. a----b shows the
natural size. The animal is supposed to be clarified, and mounted in
some highly refracting medium, so that it is practically transparent; I.,
II., III., and etc., refer to the section figured on [Sheet 20].
Figure 2. Amphioxus, General Dissection. (Slightly altered from a
figure by Professor E. R. Lankester.) The ventral atrial wall is
removed. The pharynx cut away from the dorsal body-wall, and with
the true ventral body-wall turned over to the (animal's) right. The arrow
a., a., passes through anus to intestine; b., b., is thrust through the
atrial pore to the atrial cavity. Note coe., the body cavity.
References to the two figures.
an., anus.
at., atrial cavity.
at.w., atrial wall.
at.p., atrial pore.
a.d., anterior dilatata of nervous system.
b.w., body-wall.
b.t.L., brown tubes of Lankester.
c.f., ciliated funnel.
coe., coelome.
c.ao., cardiac aorta.
d.ao., dorsal aorta (paired).
d.ao'., dorsal aorta median.
g., gonads (male or female genital gland).
hep., hepatic vein.
in., intestine.
i.w., intestine wall.
lv., liver.
m.f., median fin.
n.c., notochord.
p.v., portal vein.
ph., pharynx.
-p.s.-, [e.s.] pigment spot ("eye spot").
s.c., spinal cord.

Sheet 20.
-Sections of Amphioxus_.

The Roman numerals indicate the corresponding region in Figure 1,
[Sheet 19]. The lettering is identical; but note, in addition;
br.c., branchial canal.
c.f., ciliated funnel.
d.c.c., dorsal coelomic canal.
end., endostyle.
ep., epipleur.
e.s., eye spot.
h.p., hypopharyngeal grove.
h.vn., for hepatic vein.
o.c., oral cavity (or hood).

Sheet 21.
-Phases in the Development of Amphioxus_.

Figures 1, 2, 3, 4. Phases in segmentation.
Figure 5. The blastosphere.
Figure 6. The gastrula in section, anterior end to the right.
Figure 7. i. Dorsal view post gastrula stage.
Figure 7. ii. Diagrammatic section of the same in the
position indicated by the transverse line in 7, i.
Figure 8. Diagrammatic section of a later stage.
coe.p., the coelomic pouches.
n.c., the notochord.
n.p., the neural plate.
Figure 9.i. Still later section.
Figure 9. ii. Diagrammatic view of late embryo.
Figures 10, 11, 12 illustrate the formation of the atrium
as a median ventral invagination, at.

Sheet 22.
-The Development of the Frog_.

Figures 1, 2, 3. Stages in segmentation
(compare 1, 2 ,3 of {[Sheet 21]} Amphioxus).
Figure 4. Blastosphere stage (compare [5], Amphioxus). This, on a
smaller scale. The cells on the ventral side are so much larger
because distended with yolk.
Figure 5. Gastrula stage in section (compare [6], Amphioxus). The
Frog on a smaller scale than Amphioxus.
Figure 6. Dorsal view of gastrula (compare [7], Amphioxus).
Figure 7. Part of a transverse section of developing tadpole,
corresponding to [Figure 8] of Amphioxus.
Figures 8 and 9. Diagrammatic longitudinal sections of tadpoles
(compare [9. ii.] of Amphioxus). Y. represents a mass of
yolk cells.
Figure 10. Side view of young tadpole, showing external gills (e.g.)
and suckers (s.). Note the ventral bulging due to the yolk.
Figure 11. Ventral view of a later tadpole.
op., the operculum.
int., coiling intestine.
Figure 12. Head of still later tadpole in horizontal section to show
atrial chamber formed by operculum.
int.g., internal gills.
L., developing lungs.
Figure 13. Diagrammatic cross-section of the mid-dorsal part of an
embryonic vertebrate.
ao., aorta.
B.C., Bowman's capsule.
coe., coelom.
d.g., ganglion on dorsal root of spinal nerve.
gl., -its branch- [arteriole] to form glomerulus.
g.r., genital ridge.
I., intestine.
M.D., Mullerian duct.
ns. [nst.], nephrostome.
n.c., notochord; -n.s.-, [n.sh.] its sheath.
s.c., neural canal.
W.D., Wolffian duct.

Sheet 23.
-The Development of the Fowl_.

Figure 1. Diagram of the early ovum. The section below is a
small portion of the blastodermic area.
b.d., blastoderm.
y., the undivided yolk.
s.c., the segmentation between the blastoderm and yolk. Compare
s.c. in [{Sheet} 22], {Figure} 4.
Figure 2. Area pellucida about the sixteenth hour. The figure
below is the central part of the section indicated by the transverse
line, and showing the primitive streak (p.s.).
Figure 3. Area pellucida about the twenty-first hour. Two
sections through a and b below.
Figure 4. About the twenty-fifth hour; surface view; longitudinal
section to right and transverse above.
Figure 4b. Diagrammatic rendering of same stage (compare
Figure 9 of Frog and 9.ii. Amphioxus). This will be most clearly
understood if the reader look at [Sheet 22], {Figure} 9, and imagine
Y. enormously increased, and the embryo sinking into it. Epiblast,
ep., -line of dashes- [black line]. Mesoblast, dotted. Hypoblast,
-black- [line of dashes]. pp., the pleuro-peritoneal cavity.
Figure 5 and 6 illustrate formation of amnion (a.) and
allantois (all.). 6 is about the fourth day.

Sheet 24.
-The Development of the Fowl_.

Figure 1. Chick about the -fifth- [third] day. At this stage the chick
lies on its left side in the yolk. [For lettering of blood vessels, see (7)
below.]
i., the intestine.
u.v., the yolk sac.
v.v., the vitelline veins.
al., the allantois.
Figure 2. Chick about sixth day.
Figure 3. Development of heart.
Figure 4. Development of the eye.
Figure 5. Chick about the sixteenth day.
A.M. is the amnion surrounding the embryo. Note particularly how the
allantois (al.) has spread over surface of shell and how the yolk sac is
shrivelled.
Figure 6. Figures to illustrate the relative function and
importance of allantois and yolk sac in bird and mammal. In the
fowl, however, the blood-vessels of the allantois also probably absorb
the albumen of the egg, and may excrete urea into the egg-space.
Figure 7. Simplified figure of the embryonic circulation, for
comparison with the similar figures annexed to Dog-Fish and Rabbit.
{Lines from Second Edition only.}
[A.C., anterior cardinal.
Ao., Aorta.
Br4, sixth aortic arch (fourth branchial).
C.S. Cuvierian sinus.
H., the heart.
I.C., inferior cava.
P.C., posterior cardinal vein.
Tr.A., truncus arteriosus.
v.v., vitelline vein.]
Figure 8. Chick on the nineteenth day.