10 THE CASE AGAINST EVOLUTION 



the primitive type. The contrary hypothesis of a possible 

 convergence of two originally diverse types towards eventual 

 similarity Darwin rejected as an extremely improbable ex- 

 planation of the observed resemblance of organic forms, which, 

 not without reason, he thought it more credible to ascribe to 

 their assumed divergence from a common ancestral type. 



Such was the scheme of evolution elaborated by Charles Dar- 

 win. His hypothesis leaves the origin of variations an unsolved 

 mystery. It assumes what has never been proved, namely, the 

 efficacy of "natural selection." It rests on what has been 

 definitely disproved by factual evidence, namely, the inherit- 

 ability of the slight variations, now called fluctuations, which, 

 not being transmitted even, by the hereditary process, cannot 

 possibly accumulate from generation to generation, as Darwin 

 imagined. Moreover, fluctuations owe their origin to vari- 

 ability in the external conditions of life {e.g. in temperature, 

 moisture, altitude, exposure, soil, food, etc.), being due to 

 the direct influence or pressure of the environment, and not 

 to any spontaneous tendency within the organism itself. 

 Hence Darwin erred no less with respect to the spontaneity, 

 than with respect to the inheritability and summation, of his 

 "slight variations." 



The subsequent history of Lamarckian and Darwinian 

 Transformism is briefly told. That both should pass into the 

 discard was inevitable, but, thanks to repeated revisions under- 

 taken by loyal adherents, their demise was somewhat retarded. 

 In vain, however, did the Neo-Darwinians attempt to do for 

 Darwinism what the Neo-Lamarckians had as futilely striven 

 to do for Lamarckism. The revisers succeeded only in pre- 

 cipitating a lethal duel between these two rival systems, 

 which has proved disastrous to both. The controversy begun 

 in 1891 between Herbert Spencer and August Weismann 

 marked the climax of this fatal conflict. 



Spencer refused to see any value whatever in Darwin's 

 principle of natural selection, while other Neo-Lamarckians, 

 less extreme, were content to relegate it to the status of a sub- 



