UROGENITAL SYSTEM. 333 
mercy of the water, but a number of species (Embiotocids, Gambusia, several 
Cyprinodonts, etc.) are viviparous, the development of the eggs taking place in the 
ovary, which sometimes provides nourishment for the growing young. In the 
lophobranchs the eggs are received in a pouch between the ventral fins of the male 
and are incubated there. Other peculiar breeding habits are known. 
IG 
CAMA I i 
Fic. 332.—Relations of oviducts and pori abdominales in Coregonus, after Weber. 
a, anus; 7, intestine; ”, nephridial opening; 0, ovary; p, pore of right side; 7, opening of 
oviduct. : 
DIPNOI.—In the dipnoi more normal conditions occur. There are oviducts 
with inner ostia, resembling in structure, at least, the Miillerian ducts, and especially 
those of the amphibia, like them secreting a gelatinous substance around the eggs. 
These same ducts are also retained in the male Ceratodus and to a less extent in 
the other genera (Lepidosiren and Protopterus), The gonads are long and are cov- 
aE Caen 
MM MyM Ay wy SUMAN UNE UMD VAM MN My cv 
3 S y >, Cre, = se 
ee 
i 
WPVM pIAAAAN Aan 
Fic. 333.—Hinder part of urogenital organs of male pike, Esox lucius, after Goodrich 
a, anus; ab, air bladder; ao, aorta; d, Wolffian duct; c, cardinal vein; g, genital duct; go, 
genital opening; 7, intestine; pc, postcardinal vein; ud, urinary bladder; wo, urinary opening- 
ered on the ventral side with lymphoid tissue. The testes in Protoplerus and 
Lepidosiren contain numerous alveoli lined with sperm-forming cells. The sperm is 
carried into a longitudinal tubule (fig. 325) and from thence by one (Protopterus) 
or several efferent ductules to the Malpighian bodies of the posterior end 
of the mesonephros, the epididymis thus being posterior in position. In Ceratodus, 
which is imperfectly known, the ductules are more numerous and the epididymis 
is anterior. 
AMPHIBIA.—The amphibians are the most typical of the anamnia, the elasmo- 
