70 EVOLUTION, SOCIAL AND ORGANIC 



unsupported speculation, he replies by con- 

 tending that the germ-plasm theory lives in 

 precisely the same kind of a glass house. 



However that may be, it is quite clear that 

 the germ-plasm theory completely shuts out 

 the Lamarckian factor of evolution in all cases 

 where propagation is sexual. 



"But," say the Neo-Lamarckians, "Darwin- 

 ism in itself, merely assumes variations with- 

 out attempting to explain their origin. Nat- 

 ural selection only explains the survival of 

 the fittest; it tells us nothing of what Prof. 

 Cope calls the 'Origin of the Fittest/ There 

 must be variation before selection, whence 

 then, comes this variation?" To this question 

 Weismann has a ready reply. "Variation is 

 due to the blending of two wholly different 

 kinds of germ-plasm at conception, producing 

 at birth a result that is not, and cannot be, 

 wholly like? the contributor of either." 



And now, at last, the great German is in a 

 corner. If all variations are due to congenital 

 characters only, and these, of course, are only 

 possible because of the combinations secured 

 by sexual reproduction, how do variations 

 arise among non-sexual organisms where such 

 combinations cannot exist? 



This is indeed, a poser. But any rejoicing 

 by Weismann's opponents is quite premature. 



