364 GEOKGE JOHN EOMANES 1894 



you could stop here for a day on your way home, by 

 which time I shall probably have read your books, 

 and we might discuss the whole business before I 

 publish mine on the Post-Darwinian Theories. 

 With very many thanks, 



I remain yours very truly, 



G. J. Eomanes. 



Hotel Costebelle, Hyeres : February 24, 1894. 



Dear Mr. Henslow, — Nothing can be more clear 

 than are all your letters, and the last one, I take it, 

 sets at rest the only question which I had to ask. For 

 it expressly answers that, in your own view, the hypo- 

 thesis of • self-adaptation ' is a statement rather than 

 an explanation of the facts. Nevertheless, it is also to 

 some certain extent advanced as an explanation on 

 Lamarckian lines, for in your books (for which I 

 much thank you) you attribute adaptive mechanism 

 in flowers to thrusts, strains, &c. caused by insects. 

 But here, if I may say so, it does not seem to me 

 that you sufficiently deal with an obvious criticism, 

 viz. How is it so much as conceivable that proto- 

 plasm should always respond to insect irritation 

 adaptively, when we look to the endless variety and 

 often great elaboration of the mechanism ? Similarly 

 as regards the inorganic environment, Lamarck's 

 hypothesis of ^se-inheritance {i.e. mere increase and 

 decrease of parts as due to inherited efforts of greater 

 or less development by altered flow of nutrition) was 

 at least theoretically valid. But how can you extend 

 this to structures which, though useful, are never 

 active, so as to modify flow of nutrition, e.g. hard. 



