Essays on Life 



impossibility of the transmission of acquired 

 characters, since the molecular structure of the 

 germ-plasm is already determined within the 

 embryo ; and Weismann holds that there are 

 no facts which really prove that acquired 

 characters can be inherited, although their 

 inheritance has, by most writers, been con- 

 sidered so probable as hardly to stand in need 

 of direct proof. 



" We have already seen in the earlier part 

 of this chapter that many instances of change, 

 imputed to the inheritance of acquired varia- 

 tions, are really cases of selection." 



And the rest of the remarks tend to convey 

 the impression that Mr. Wallace adopts Pro- 

 fessor Weismann's view, but, curiously enough, 

 though I have gone through Mr. Wallace's 

 book with a special view to this particular 

 point, I have not been able to find him 

 definitely committing himself either to the 

 assertion that acquired modifications never 

 are inherited, or that they sometimes are so. 

 It is abundantly laid down that Mr. Darwin 

 laid too much stress on use and disuse, and a 



residuary impression is left that Mr. Wallace 



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