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sharks and dogfishes, there is no direct connection between 
the male and female at the breeding season. 
The generative organs are the parts of the body in 
which the spawn is formed. 
Toe Mate Fisu.—The generative organ is the testis 
or soft roe; the milt is formed in this. The milt consists 
of sperms. 
THe Femate Fisn.—The generative organ is the 
ovary or hard roe: the spawn proper is formed in this. 
The spawn consists of eges. 
Shel 
-Head-biece. 
rave. Tail—=piece 
or 
Flagellum 
se EEE 
Ss 
Microbyle 
The sperm of a fluke The egg of a fluke magnified 
magnified 1,500 dia. 30 dia. 
Fertilisation.—tThe way in which the eggs of 
a fish, such as the flounder or cod, are fertilised will be 
shewn in the hatchery. If the eggs are simply taken 
from the female fish, and allowed to remain in clear sea- 
water, no development takes place. But if the milt from 
the male is mixed with the watey in which the eggs are 
floating fertilisation takes place. One sperm enters each 
ege through the micropyle, which then closes. The 
development of the egg then begins. 
