THE EFFICIENT CAUSE 519 



loosely much written about, often broached and attempted, 

 of transmutation by saltus ; Owen is hedging for it in his 

 review of Darwin and snub of me in Edinburgh Beview, 

 and there is a deal to be said for it ; I have often carefully 

 examined it for plants, this 15 years ; but have failed to find 

 any reasonably cumulative support in facts, and none in 

 Geog. distrib. or classification. Other views will turn up, 

 but in the present state of science, I look to an advance on 

 Darwin's general views as [the] most hopeful future. 



Ever yours affectionately, 



Jos. D. HOOKER. 



Kew : Tuesday, 1860. 



DEAR HARVEY, I sent Darwin the note of your objec- 

 tion to Nat. Selection as the efficient cause, that he might 

 clearly see that I was not singular in my view that his words 

 state far more than he means if taken in the sense you and 

 others take them. He was anxious to write to you, and I told 

 him I was sure you would be glad to hear, but not till after 

 your Lectures. Do not be dragged into a discussion of the 

 subject till you are at leisure. Thwaites has written an un- 

 conditional surrender to Darwin's view under present aspect 

 of question. 



Ever yours affectionately, 



Jos. D. HOOKER. 



DEAR HARVEY, I see you are going in for a transmuta- 

 tion doctrine after all ! and evidently the one that Owen is 

 hedging for in his review of Darwin (and snub of self) in 

 Edinburgh Review. 



I have enquired about Cowslips, etc., and will let you 

 know. The battle will now be between transmutation by 

 saltus and by slow measures. How you can deny N. S. in 

 either case is to me incomprehensible ! Every real natura- 

 list owns N. S. to be a vera causa, though few admit the 

 plenary power that Darwin gives it. In our Herb, there is 

 every intermediate between Primrose and Oxlip. 



You seem to confound variation with Nat. Selection. 

 N. S. is not itself divarication ; it no more accounts for 

 divarication than * gravity ' accounts for the motion of 

 planets. Give time, abate prejudice, and let your ideas 

 clarify, which they will assuredly do in tirp^ Kemember 



