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THE AMERICAN NATURALIST [Vol. XLII 



we can do this, there will not be any use for the Breeders ' 

 Association. " . . . Mutations occur constantly, without 

 preparation and without intermediates. ' ' 6 I can not think 

 of a mutation or change in species occurring without prep- 

 aration and without intermediates. It is equivalent to 

 saying without cause. Later, one reads, "We may con- 

 fidently assume that each single mutation affects only 

 a single unit." 7 I would certainly agree with this state- 

 ment if I could conclude from the author's other state- 

 ments that he had in mind that a plant might be made up 

 of an inconceivable number of unit characters, the ulti- 

 mate nature of which may, after all, be only matters of 

 force. "In other words, the principle of adaptation, as 

 one of the main parts of the theory of evolution, should 

 be separated from the study of the geographical distri- 

 bution. ..." 8 As to this assertion, I agree that plants 

 migrate and select in the same sense that men migrate 

 and select, but I can not agree that a species never adapts 

 itself in such form as to transmit the results of adapta- 

 bility. 



"Environment has only selected the suitable forms 

 from among the throng and has no relation whatever to 

 their origin." 9 "Natural selection . . . causes survival 

 of the fittest; but it is not the survival of the fittest of 

 individuals, but that of the fittest species, by which it 

 guides the development of the animal and vegetable 

 kingdoms." 10 



These last two quotations contain sweeping assump- 

 tions and all of them taken together must be interpreted 

 as saying that evolution in plant and animal life arises 

 wholly from accidental changes, that is, from mutations 

 which are matters of accident, having no preceding 

 cause, therefore beyond us as breeders to investigate or 

 change. This would naturally deprive agriculturalists 



T Ibid., page 322. 

 •Ibid., page 345. 

 • Ibid., page 352. 

 "J&id., page 9. 



