1 8 59.] DE CANDOLLE FALCONER GRAY. 217 



effect on you ; but if it should stagger you in ever so slight 

 a degree, in this case, I am fully convinced that you will 

 become, year after year, less fixed in your belief in the immut- 

 ability of species. With this audacious and presumptuous 



conviction, 



I remain, my dear Falconer, 



Yours most truly, 



Charles Darwin. 



C. Darwin to Asa Gray. 



Down, November nth [1859]. 



My DEAR Gray, I have directed a copy of my book (as 

 yet only an abstract) on the ' Origin of Species ' to be sent 

 you. I know how you are pressed for time ; but if you can 

 read it, I shall be infinitely gratified .... If ever you 

 do read it, and can screw out time to send me (as I value 

 your opinion so highly), however short a note, telling me 

 what you think its weakest and best parts, I should be ex- 

 tremely grateful. As you are not a geologist, you will excuse 

 my conceit in telling you that Lyell highly approves of the 

 two Geological chapters, and thinks that on the Imperfection 

 of the Geological Record not exaggerated. He is nearly 

 a convert to my views 



Let me add I fully admit that there are very many diffi- 

 culties not satisfactorily explained by my theory of descent 

 with modification, but I cannot possibly believe that a false 

 theory would explain so many classes of facts as I think it 

 certainly does explain. On these grounds I drop my anchor, 

 and believe that the difficulties will slowly disappear. . . . 



C. Darwin to jf. S. Henslow. 



Down, November nth, 1859. 

 My DEAR HENSLOW, I have told Murray to send a copy 

 of my book on Species to you, my dear old master in Natural 



