16 THE CASE AGAINST EVOLUTION 



against Darwinism than it was against Lamarckism. Darwin's 

 "individual differences" or "slight variations," now spoken of 

 as fluctuations, were quite as unrepresented and unrecorded 

 in the germ cells as Lamarck's "acquired adaptations." There 

 can be no "summation of individual differences" for the simple 

 reason that fluctuations have no germinal basis and are there- 

 fore uninheritable — "We must bear in mind the fact," says 

 Prof. Edmund Wilson, "that Darwin often failed to dis- 

 tinguish between non-inheritable fluctuations and hereditary 

 mutations of small degree." (Smithson. Inst. Rpt. for 1915, 

 p. 406.) Fluctuations, as we have seen, are due to variability 

 in the environmental conditions, e.g. in access to soil nutrients, 

 etc. As an instance of fluctuational variation the seeds of 

 the ragweed may be cited. Normally these seeds have six 

 spines, but around this average there is considerable fluctua- 

 tion in individual seeds, some having as many as nine spines 

 and others no more than one. Yet the plants reared from 

 nine-spine seeds, even when similarly mated, show no greater 

 tendency to produce nine-spine seeds than do plants reared 

 from one-spine seeds. 



To meet the difiiculty presented by the non-inheritability of 

 the Lamarckian adaptation and the Darwinian fluctuation, 

 De Vries substituted for them those rare and abruptly- 

 appearing inheritable variations, which he called mutations ^ 

 and regarded as elementary steps in the evolutionary process. 

 This new version of transformism was announced by De Vries 

 in 1901, and more fully explained in his "Die Mutations- 

 Theorie" (Leipzig, 1902-1903). Renner has shown that De 

 Vries' new forms of CEnothera were cases of complex hybridi- 

 zation rather than real mutants, as the forms produced by 

 mutation are now called. Nevertheless, the work of Morgan, 

 Bateson, and others leaves little doubt as to the actual occur- 



^ The term mutation had been used long before and in a similar sense 

 by the German palaeontologist Waagen, who employed it to designate 

 the variations of a specific type that succeed one another in successive 

 strata, a thing which rarely occurs. (Cf. Waagen's Die Formenreihe des 

 AmmoTutes suhradiatus, Geognost. palaont. Beitr., Berlin, 1869.) 



