290 THE FITNESS OF THE ENVIRONMENT 



as philosophical naturalists exist, be Charles 

 Darwin's greatest title to glory." 1 



Recently the work of de Vries, "The Muta- 

 tion Theory," has at length set forth a num- 

 ber of trustworthy observations of the origin 

 of species in plants with which natural selec- 

 tion, in the restricted original sense at least, 

 can have nothing to do. The origin of species 

 by mutation consists in a sudden discontinu- 

 ous variation, and selection, therefore, has 

 no opportunity to operate upon a series of 

 numerous minute variations which them- 

 selves display no tendency of any sort what- 

 ever, in the manner demanded by the Darwin- 

 ian hypothesis. 2 Hence it appears certain 

 that natural selection cannot be regarded as 

 completely master of the situation; apart 

 from the origin of life there remains a lacuna 

 in biology which for the present no existing 

 mechanistic hypothesis can fill. 



Moreover, among other things, the ordinary 

 processes of regeneration and repair have 

 frequently been brought forward with some 

 success as purposeful activities inexplicable 



1 Du Bois-Reymond, "Darwin versus Galiani," "Reden," 

 Vol. I, p. 211. Quoted from Merz, "History of European 

 Thought in the Nineteenth Century," Vol. II, p. 435. To 

 the same source I am indebted for several other quotations. 



2 Hugo de Vries, "The Mutation Theory." Chicago, 2 

 vols., 1909, 1910 (trans. Farmer and Darbishire). 



