146 An Examination of Weismannism. 



produce simultaneously an acquired character in 

 the soma and a precisely identical character as 

 congenital in the germ (pp. 129-30), we are plainly 

 inviting ourselves to abandon the complex explana- 

 tion of living material in " two kinds," where one is 

 capable in all sorts of ways of communicating with 

 the other, while the possibility of any reciprocal action 

 is excluded. For the simpler hypothesis of living 

 material as all of one kind encounters no such 

 antinomies. So long as one kind of this material 

 was supposed to be as distinct from the other as a 

 parasite is distinct from its host, there was not so 

 much to choose between the theory of germ-plasm 

 and that of gemmules in this respect of simplicity. 

 But the more that the former theory has had to be 

 adjusted to facts, the greater has its complexity 

 become, until now its own author is obliged to make 

 so many additional assumptions for the purpose 

 of maintaining it, that we begin to wonder how long 

 it can continue to support the weight of its accuma- 

 lating difficulties. 



So much for the main modifications which have 

 this year been made in Weismann's postulate of the 

 perpetual continuity of germ-plasm. We must next 

 consider the changes which he has effected in his 

 companion postulate of the absolute stability of 

 germ-plasm. 



