POLARITY AND BILATERALITY OF THE ANNELID EGG. 



6 9 



band, and the distal hemisphere appears intensely yellow, and 

 packed full of yolk-granules. The surface of apposition of the 

 hyaline band and yellow hemisphere is not a plane surface, but 

 decidedly convex towards the hyaline band. 



jjys^lil^^ &c 



- 



s.a fo 



\ . .. -.-S'VrfV : : '.^-> : .-^-r'y!vi,:v^t. 



- - 



-* - . v .-;IM,';:'-.S >r ^sV^?-it?'ifi 



^ : i : 



... >. : .ry^^^^A 



' 5 'N ' "V .'^". 



.... ' ' : ^'"'.:,?3''r?" ; *?^ < ^' j vv^ 





^'..V-/ 



, ,.. !> -,-. I-N -. , .-- . > -- , 



isfsaW 



' 



FIG. 6. Section of an egg of Chatopterus centrifuged 1,150 revolutions in 31 sec- 

 onds at a radius of 13 cm. The force was not sufficient to produce a very full segre- 

 gation of the material of the gray cap. /-/, primary axis of the egg ; 2-2, secondary 

 axis, b.c., basophile cap; g.f., gray cap; h.b., hyaline band; s.a., spongy area; 

 stained in thionin and orange G. 



The gray cap is composed of fat globules, as is demonstrated 

 by staining with osmic acid (Fig. 9) ; whether or not it includes 

 the residual substance of the germinal vesicle as maintained in my 

 former paper, I am not now prepared to say. In Nereis, in place 

 of the gray cap, we have an aggregation of the large oil drops 



