EVOLUTION THE MASTER-KEY 



the survival of the fittest viz., the survival of 

 the unfittest, is inconceivable. 



It is impossible in a work of this scope to treat 

 all details in such complete fashion as one might 

 desire; and it is necessary, therefore, to refer the 

 reader to a volume by an expert which will suffice 

 to convince him that, in such instances as the 

 shore-crabs near Plymouth Sound and the English 

 sparrow introduced into North America, the ac- 

 tion of natural selection has been demonstrated. 

 For this purpose the reader should consult Varia- 

 tion in Animals and Plants, by Dr. H. M. Vernon, 

 of Oxford. 1 



We may take it, then, distinguished amateurs 

 notwithstanding, that natural selection, or the sur- 

 vival of the fittest, is a fact. We shall necessarily 

 recur to it when we come to consider the ethics 

 and the ethical forecast of the evolution theory. 

 Meanwhile we must briefly note the conditions 

 upon which its action depends; the primal condi- 

 tions of heredity and variation being, of course, 

 taken for granted. 



Natural selection is not an inevitable and con- 

 stant factor in the course of animal and vegetable 

 life. The popular fallacy that progress is an in- 

 variable law of nature appears to depend upon the 

 idea that natural selection is always and necessa- 

 rily in operation. But its existence was suggested, 



1 This is volume LXXXVIII. of the International Scientific 

 Series (Kegan Paul, Trench, Triibner & Co.). See especially 

 chapter xi., "The Action of Natural Selection on Variations." 



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