II.] POSITION OP THE NEO- DARWINIANS. 65 



to throw the burden of proof upon their opponents; 

 while, at the same time, they give no proofs of their own 

 position, and confound their adversaries with verbal 

 subtleties. The burden of proof, however, lies clearly 

 upon the Neo- Darwinians, inasmuch as they, have 

 assumed to deny phenomena which were theretofore 

 considered to be established, 



A voluminous issue of polemics has arisen during the 

 last five or six years between the Neo -Darwinians and 

 the Neo - Lamarckians ; but whatever may have been its 

 effects upon the older philosophy, it is clear, to my mind, 

 that some of the attacks upon Neo -Darwinism are un- 

 answerable in any rational manner, and it is certain that 

 they have forced Weismann into a change of position 

 with reference to some of his definitions. Certain phases 

 of this discussion appeal with particular force, of course, 

 to some minds, while they exert little influence upon 

 others. My own objections to Neo -Darwinism — and I 

 admit that my bias is strong against it — seem to be 

 somewhat different from those most commonly urged in 

 opposition to it; and the three which chiefly influence 

 me I shall present very briefly. 



1. I cannot see that the non-transmissibility of 

 acquired characters is a necessary assumption to Weis- 

 mann's fundamental arguments. I have already ex- 

 plained his reasoning from the reproduction of the one- 

 celled organism. I cannot attempt any opinion of the 

 probable facts upon which the hypothesis is founded. 

 It may be said, in passing, that one of the prominent 

 objections to the fundamental basis of the theory is the 

 difficulty of deriving the mortal soma -plasm from the 

 immortal germ -plasm, a question to which, however, 

 Weismann has made a somewhat full reply. 



