which actually acts as if they are thrown out of the ovum. 

 The expression "dissolving" of the vesicle indicates the 

 disappearance of the nuclear membrane in the nucleus of 

 the ovum in the metaphase of the division of maturation. 



Baer's contention that the blastoderm develops in the 

 place of the release of the Purkinje follicle is also quite 

 correct. In the overwhelming majority of cases, the place 

 of separation of the polar bodies is close to the animal 

 pole of the ovum, i.e. to the same place where, in particular 

 in the mesoblastic ova, the first blastoderms are settled. 



Less accurate area Baer's discussions concerning the 

 nature of the Graafian follicle. He called it an ovum and 

 equated it to that follicle-shaped stage which is already 

 observed in the fallopian tube or uterus, identifying the 

 ovule as the Purkinje vesicle. However, on describing the 

 ovule, Baer mentioned in one place (p. 18) the darker central 

 and transparent peripheral parts of the ovule; in another 

 place (p. 19), he said that a central area appears in the 

 ovule which is free from granules, which remain at the 

 periphery. From these descriptions it is clear that Baer 

 had seen the nucleus in the mammalian ovum but was not 

 sure if this formation were identical to the Purkinje 

 vesicle of other animals. *■* 



12. The modern terminology was introduced by.,P. G. Svetlov 

 in a commentary on the second volume of UBER 

 ENTWICKLUNGSGESCHICHTE (note 139, pp. 476 - 480). 



299 



