
HISTORY AND ANATOMY OF 
THE GOLDFISH 

tion takes place after the eggs are discharged, their outline then assuming 
a more spherical form, whereby the spermatozoa are drawn into the ova 
through minute orifices and the egg fertilized. 
g gs 
The circulation of the blood is induced by a branchial or respiratory 
heart consisting of two cavities, an auricle and a ventricle. 
Higwices Dhe 
venous blood, coming from the liver and the body generally, is taken 
rf 2 3 
FIG. 5—Diagram of the Blood cir- 
culatory systems of Fishes, Rep- 
tiles and Mammals. 
No. 1—Diagram ofa fish. 
a’ Auricle, receiving venous blood 
trom the body. 
v Ventricle, 
a Bulbus artoriosus, at the base of 
the branchial artery. 
6a Branchial artery, carrying the 
venous blood to the gills. 
c Aorta, carrying the arterial blood 
to all parts of the body. 
g Gills 
No. 2—Diagram of a Reptile, 
a Right auricle, receiving venous 
blood from the body. 
a’ Left auricle, receiving arterial 
blood from the lungs. 
wv Arterio-venous ventricle, con- 
taining mixed blood, which is 
driven by the pulmonary artery 
(p) to the lungs, and by the 
aorta (0) to the body. 
The venous system is left light, 
the arterial system is black, and 
vessels containing mixed blood 
are cross-shaded. 
No, 3—Diagram of a Mammal. 
a Right auricle. 
vw Right ventricle. 
p Pulmonary artery, carrying ven- 
ous blood to the lungs. 
pv Pulmonary veins, carrying arte- 
rial blood from the lungs. 
a’ Left auricle. 
v’ Left ventricle. 
6 Aorta, carrying arterial blood to 
the body. 
c¢ Vena cava, carrying venous 
blood to the heart. 
The arterial system is left white 
and the venous system is black. 

through the vena cava into the auricle and pro- 
pelled into the ventricle, from which arises an 
aortic arch, dilated at the base into a cavity, the 
bulbus arteriosus, which has transverse rows of 
valves, and is covered with muscular fibres for 
rhythmical contraction. The blood is driven by 
the ventricle through the branchial artery to the 
gills where it is distributed by means of the bran- 
chial laminz and subjected to the action of the 
aerated water and thereby oxygenated. The 
water is taken in at the mouth, forced to the 
branchia by muscular action, passed over the gills, 
deoxydized and then emitted from the gill slits, 
or opercular appertures, on each side of the neck. 
These gill slits are closed in front and covered 
by the operculum bones connected by bony spines 
with the hyoid arch supporting the branchiostegal 
membrane. The aerated blood is not returned 
to the heart, as in higher forms of animals, but is 
driven from the branchia through all parts of the 
body by the action both of the heart and the 
contractions of the voluntary muscles; that is, 
the arterial blood returned from the gills is pro- 
pelled through the systemic vessels of the body 
without being first sent back to the heart. The 
oxygen thus consumed is not that which forms 
the chemical constituent of water (H2O) but that 
contained in the air which is dissolved or in sus- 
pension in the water. Fishes transferred to water 
devoid of air are speedily suffocated, but gold- 
fishes are of low vitality and their absorption of 
oxygen is comparatively small, as compared with 
others; this, however, being also characteristic of 
all stillwater fishes in greater or lesser degree. 
ne. 
