Art and Science 



wall does not bring about the greater strength 

 of the stronger ; it is the consequence of this 

 last and not the cause unless, indeed, it be 

 contended that a knowledge that the weak go 

 to the wall stimulates the strong to exertions 

 which they would not otherwise so make, and 

 that these exertions produce inheritable modi- 

 fications. Even in this case, however, it would 

 be the exertions, or use and disuse, that would 

 be the main agents in the modification. But it 

 is not often that Mr. Wallace thus backslides. 

 His present position is that acquired (as dis- 

 tinguished from congenital) modifications are 

 not inherited at all. He does not indeed put 

 his faith prominently forward and pin himself 

 to it as plainly as could be wished, but under 

 the heading, " The Non-Heredity of Acquired 

 Characters," he writes as follows on p. 440 of 

 his recent work in reference to Professor 

 Weismann's Theory of Heredity : 



" Certain observations on the embryology of 

 the lower animals are held to afford direct 

 proof of this theory of heredity, but they are 

 too technical to be made clear to ordinary 



readers. A logical result of the theory is the 



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