122 An Examination of Weismannism. 



the facts of observation lent themselves equally well 

 to either interpretation, that it was very many centuries 

 before the crucial tests were forthcoming. So, in the 

 present instance, the question is as to whether the 

 carriers of heredity move from body-cells to germ- 

 cells, or vice versa ; and it is because the theory 

 which sustains the latter view has merely to invert 

 the terms of the one which takes the former, that so 

 many of the facts of observation lend themselves 

 equally well to both — as we have seen in chapter III 



(PP- 5 6 ~59)- 



Lastly, yet another reason for not considering in 



any detail Professor Weismann's intricate speculations 



on the ultimate mechanism of heredity is, that by so 



doing I should have found it impossible to avoid 



obscuring the main issues. For even Professor Weis- 



mann himself, by the extreme care which he has 



taken in fully presenting his scheme of this ultimate 



mechanism, has not found it practicable to keep 



distinctly before our view the relative insignificance 



of such details, as compared with the fundamental 



importance of his original postulates. Hence, I have 



deemed it best in the present chapter to restrict our 



attention to the changes which he has recently made 



in these the foundations of his entire system. 



For these reasons, then, I will mention only those 



main features in the ' ; architecture of germ-plasm " 



which it is necessary to understand for the purposes of 



the following criticism touching the general theory of 



germ-plasm in the most recent phase of its evolution. 



To begin with, Weismann has now seen the desira- 

 bility of ceasing to designate the ultimate " carriers of 



