II.] MERITS OF WEISMANNISM. 79 



we might also call them 'somatogenic,' because they 

 follow from the reaction of the soma under external 

 influences ; while all other characters might be contrasted 

 as 'blastogenic/ because they include all those charac- 

 ters in the body which have arisen from changes in the 

 germ, * * * We maintain that the 'somatogenic' 

 characters cannot be transmitted, or rather, that those 

 who assert that they can be transmitted must furnish 

 the requisite proofs." That is: Changes in the soma- 

 plasm are not transmitted ; acquired characters are 

 changes in the soma -plasm ; therefore, acquired char- 

 acters cannot be transmitted ! Or, to use Weismann's 

 shorter phrase, "Since the characters * * * are 

 hereditary, the term [' acquired '] cannot be rightly 

 applied to them!" Surely, Neo-Darwinism is impreg- 

 nable ! 



Weismannism has unquestionably done much to 

 elucidate some of the most intricate questions of biology, 

 and it has weeded the old hypotheses of much that was 

 ill-considered and false. It has challenged beliefs which 

 have been too easily accepted. Its value to the science 

 of heredity upon its biological side is admitted, and its 

 explanation of the meaning of sex is one of the best of 

 all contributions to the philosophy of organic nature. It 

 has suffered, perhaps, from too ardent champions, and 

 its great weakness lies in its stubborn refusal to accept 

 an important class of phenomena associated with ac- 

 quired characters, a sufficient explanation of which, it 

 seems to me, could be assumed without great violence to 

 the hypothesis. 



Most Neo - Lamarckians accept much of Weismann's 

 teaojiings. But, while there are comparatively few who 

 believe that mutilations are directly transmissible, there 



