The Development of the Frog 13 



chromatin, has retained practically all of the 

 cytoplasm ; so that the result of the formation 

 of the polar bodies is practically to increase the 

 cytoplasm fourfold. The objections to this 

 theory cannot be given here. 



One of the oldest and most celebrated the- 

 ories in regard to the formation of the polar 

 bodies is that of Minot. According to this 

 theory the fertilized egg-cell is said to be 

 hermaphrodite, that is, it is both male and 

 female, since it is formed by the fusion of the 

 male and female elements. When the fertilized 

 egg divides for the first time the nuclear ma- 

 terial is equally divided between the two blas- 

 tomeres that are formed, so that each of these 

 blastomeres must be hermaphrodite. If this 

 be true of the first two blastomeres, it must be 

 equally true of all the cells that are formed by 

 the repeated division of the original egg-cell : 

 hence the unfertilized egg-cell developed from 

 the original egg must also be hermaphrodite ; 

 and before it can receive additional male chro- 

 matin, in the act of fertilization, it must get rid 

 of the male chromatin that it already possesses, 

 by extruding the polar bodies. 



If this theory were true, it is evident that a 

 child could not inherit the characters of its 



