334 COMPARATIVE MORPHOLOGY OF VERTEBRATES. 
branchs excepted. The gonads are roughly correlated in form to the shape of the 
body, being shortest in the anura, longest in the cecilians and urodeles. The 
ovaries are saccular (a single long sac in urodeles, a number of short ones in anura) 
and the eggs pass into the cavity and then break into the celom. The oviducts 
Fic. 334.—Male 
urogenital organs of 
Epicrium, after 
Spengel. a, anus; 5, 
urinary bladder; ci, 
cloaca; f, fat bodies; 
m, Miillerian ducts; 
mg, glandular part 
of same; #, testes; ¢I, 
longitudinal __ testi- 
cular canal; w, 
Wolffian body. 
are Miillerian ducts with ostia far forward. In the adults 
they are greatly coiled and are glandular, their walls se- 
creting the gelatinous substance which envelops the eggs. 
Usually the oviducts of the two sides open separately into 
the cloaca, but the two unite behind in Bufo. 
The testes have both the longitudinal and the testicular 
canals connecting the efferent ductules. In the gymno- 
phiona (fig. 334) the testes resemble a string of beads, each 
bead consisting of a number of seminiferous sacs, the 
string being united by the testicular canal. The efferent 
ducts pass through the mesonephros, sometimes utilizing 
the nephridial tubules, sometimes pursuing a separate course, 
the two conditions being found in different species of frog 
(Rana) in Europe. Our species have not been studied in 
this respect. 
The cloaca of the urodeles has a glandular lining and in 
the females it contains tubules which act as reservoirs of 
sperm. In the male the glands secrete a substance binding 
the spermatozoa together In many urodeles fertilization 
is internal, though thereis no intermittent organ save the 
somewhat protrusible cloacal opening. 
There are many interesting accessory reproductive rela- 
tions among the amphibia. Thus the cecilians and Am- 
phiuma lay their eggs in long strings in the soil and the 
female incubates them. The male often takes charge of the 
eggs. In Pipa each egg undergoes development in a pit in 
the skin of the back of the female and in Nototrema and 
Opisthodelphys (South America tree-toads) there is a large 
pocket in the skin of the back, opening near the coccyx, 
where the eggs are carried until partially (Nototrema) ‘or 
entirely developed. Salamandra maculosa and S. atra bring 
forth living young, the former being born with gills, the latter 
in the perfect condition. Oviposition usually occurs in the 
spring in colder climates (in the autumn with Cryptobranchus 
of America) and as the drain on the system is very consider- 
able immediately after hibernation, the substance of the 
fat body, which always is closely connected with the gonads, 
is utilized at this time. 
‘SAUROPSIDA.—The birds and reptiles agree in the broader features of the 
amniote urogenital system as outlined in the general account above. 
There is a 
general correlation between the shape of the body and that of the gonads, and often 
there is a lack of symmetry between the organs of the two sides 
Thus in snakes 
