THE DARWINIAN THEORY 



living parts grow and by disuse they atro- 

 phy. It was by constant stretching that, 

 in the course of generations the giraffe's 

 neck became so long, and likewise the legs 

 and bill of the crane as it waded in the 

 mud for its food. It was in degeneration 

 from disuse, however, that this theory had 

 its strongest arguments, just where the 

 Darwinian theory is weakest, for natural 

 selection does not account for degenera- 

 tion, because nothing would select degen- 

 eration as advantageous, while the eyeless 

 fishes in the rivers of the Mammoth Cave 

 afford direct evidence of the loss of organs 

 by disuse. The Lamarckian theory, there- 

 fore, is much simpler than the Darwinian, 

 if only it were in accord with facts, which 

 it is not, except as just stated in the case 

 of atrophies. No native tendency to 

 strong arms in the children of blacksmiths 

 is discernible. Moreover, Lamarckianism 

 depends even more than Darwinism on the 

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