FIFTY YEARS OF DARWINISM 45 



this period we find numbers of letters in which he 

 expressed his disbelief in an evolution founded on 

 " sudden jumps " or " monstrosities," as well as 

 on " large," " extreme," and " great and sudden 

 variations." Out of many examples I select one 

 more because of its pecuhar interest. The Duke 

 of Argyll had criticised Darwin's theory of Nat- 

 ural Selection as though it had been a theory 

 of mutation, an interpretation repudiated by 

 Darwin. 



The Duke of Argyll in his address^ to the 

 Royal Society of Edinburgh, December 5, 1864, 

 had said: — " Strictly speaking, therefore, Mr. 

 Darwin's theory is not a theory of the Origin of 

 Species at all, but only a theory on the causes 

 which lead to the relative success and failure of 

 such new forms as may be born into the world." 

 In a letter to Lyell (January 22, 1865), Darwin 

 wrote concerning this argument of the Duke's : — 



" I demilr ... to the Duke's expression of ' new 

 births.' That may be a very goo4 theory, but it is not 

 mine, unless he calls a bird bom with a beak 1-lOOth of 

 an inch longer than usual ' a new birth ' ; but this is 

 not the sense in which the term would usually be under- 

 stood. The more I work the more I feel convinced it 

 is by the accumulation of such extremely slight varia- 

 tions that new species arise." ^ 



I desire again to state most emphatically that, 

 during the whole course of his researches and re- 

 flections upon evolution, Darwin was thoroughly 



' Scotsman, December 6, 1864. 

 ' Life and Letters, III, p. 33. 



