3^ 



area at the up-; 1 ' . elow, it is not si irked 



off :' ■ yolk, but across its base exte , i,bout 



ie periblast t , c - 



.asm, section shows several vacuoles 



rig] were probabl; il ith oil, 



Brook ( 'bo) describes in the "erring a blastodisc with yolky 

 TJ is C '99 ) the U.^ in th 

 This blastodisc was found in a batch of eggs in the 

 eight- to sixteen-cel (8-12 hours). 



the geria disc i . is formed in from one to four 



Hertwig ('03 ) says formation of the germinal 



disc in the " T erring takes place in two hours . . the 



Trout from seven to eight hours, Fvidentx. - ae varies 



with the kind of fish, the : ure, and the purity of 



the water. In the Pipefish I have found it to take place 

 in fro.u four to six hours. It is noteworthy that in none 

 of the blastodiscs which were sectioned, have I ever fou 

 a nucleus, id no nuclei ii 



. after th< 'ance of - furrow, 



Two-Celled St 



As in Teleosts generally, the blastodisc e] 

 slightly before the appearance of the first furrow, and, as 



