358 



ON THE NUMBER OF POLAR BODIES AND 



plasms as they are capable of containing ; and the question arises, 

 How can sexual reproduction now proceed without a doubling of 

 the quantity of germ-plasm in each germ-cell, with every new 

 generation ? 



There is only one possible answer to such a question : sexual re- 

 production can proceed by a reduction in the number of ancestral 

 germ-plasms, a reduction which is repeated in every generation. 



Father. Mother. Offspring. 



FIG. I. 



This must be so : the only question is, how and when does the 

 supposed reduction take place. 



Inasmuch as the germ-plasm is seated, according to our theory, 

 in the nucleus, the necessary reduction can only be produced by 

 nuclear division ; and quite apart from any observation which has 

 been already made, we may safely assert that there must be a form 

 of nuclear division in which the ancestral germ-plasms contained in 



