Alfred Russel Wallace 



To Sir Francis Darwin 



Broadstone, Wimborne. October 29, 1905. 



Dear Mr. Darwin, — I return you the two articles on 

 " Mutation " with many thanks. As they are both sup- 

 porters of de Vries, I suppose they put his case as strongly 

 as possible. Professor Hubrecht's paper is by far the 

 clearest and the best written, and he says distinctly that 

 de Vries claims that all new species have been produced by 

 mutations, and none by " fluctuating variations." Professor 

 Hubrecht supports this and says that de Vries has proved it ! 

 And all this founded upon a few *' sports " from one species 

 of plant, itself of doubtful origin (variety or hybrid), and 

 offering phenomena in no way different from scores of 

 other cultivated plants. Never, I should think, has such 

 a vast hypothetical structure been erected on so flimsy a 

 basis ! 



The boldness of his statements is amazing, as when he 

 declares (as if it were a fact of observation) that fluctuating 

 variability, though he admits it as the origin of all domestic 

 animals and plants, yet " never leads to the formation of 

 species " ! (Hubrecht, p. 216.) There is one point where 

 he so grossly misinterprets your father that I think you or 

 some other botanist should point it out. De Vries is said to 

 quote from ''Life and Letters," II., p. 83, where Darwin 

 refers to " chance variations " — explained three lines on as 

 " the slight differences selected by which a race or species is 

 at length formed." Yet de Vries and Hubrecht claim that by 

 ^' chance variations " Darwin meant " sports " or ^' muta- 

 tions," and therefore agrees with de Vries, while both omit 

 to refer to the many passages in which, later, he gave less 

 and less weight to what he termed " single large variations " 

 — the same as de Vries' '' mutations " ! — Yours very truly, 



Alfred R. Wallace. 

 80 



