596 



ANATOMY OF VERTEBRATES. 



nation at the same season are simultaneously ripened. As soon 

 as tlie germ-cell is recognisable, it is contained in a delicate ovisac, 

 and speedily exhibits several nuclei, or maculaj, fig. 418, B, ^ : it is 



417 



418 



i: 





» Q o o « *x>y-c^- 



, a o ©XW'X^ •.■.■--.-.-.--■.-.;-.-.■ 



» e V^i^JEw otoXSQ' •.•■■■.■•- ^^ ■ 

 o o o ® © sjoja 



ID Q O O O «X®X 



* » ® » •^'5Y&X'a»~ 



Jllcvupjio of Llic ovum in Osseous I'^ish. cccvTil. liatnichian ovum in liio o\isar. y^^.lli iiK'ii diam. cccTlil 



surrounded by a clear albuminous yolk fluid, vj), which gradually 

 becomes opake, and about which the yolk-granules accumulate, 

 among which is the opake or dark aggregate peculiar to Batraclna, 

 and called the yolk-nucleus, ib. vn. This body disappears as the 

 yolk-mass ajjproachcs its mature bulk, and acquires the larger 

 quadrilateral or quadrangular particles. The smooth and well- 



