1859.] MR. HUXLEY'S ADHERENCE. 231 



but on one or two points I enter a caveat until I can see 

 further into all sides of the question. 



As to the first four chapters, I agree thoroughly and fully 

 with all the principles laid down in them. I think you have 

 demonstrated a true cause for the production of species, and 

 have thrown the onus probandi, that species did not arise in 

 the way you suppose, on your adversaries. 



But I feel that I have not yet by any means fully 

 realized the bearings of those most remarkable and original 

 Chapters III., IV. and V., and I will write no more about 

 them just now. 



The only objections that have occurred to me are, 1st that 

 you have loaded yourself with an unnecessary difficulty in 

 adopting Natura non facit saltnm so unreservedly. . . . And 

 2nd, it is not clear to me why, if continual physical conditions 

 are of so little moment as you suppose, variation should 

 occur at all. 



However, I must read the book two or three times more 

 before I presume to begin picking holes. 



I trust you will not allow yourself to be in any way dis- 

 gusted or annoyed by the considerable abuse and mis- 

 representation which, unless I greatly mistake, is in store for 

 you. Depend upon it you have earned the lasting gratitude 

 of all thoughtful men. And as to the curs which will bark 

 and yelp, you must recollect that some of your friends, at 

 any rate, are endowed with an amount of combativeness 

 which (though you have often and justly rebuked it) may 

 stand you in good stead. 



I am sharpening up my claws and beak in readiness. 



Looking back over my letter, it really expresses so feebly 

 all I think about you and your noble book that I am half 

 ashamed of it ; but you will understand that, like the parrot 

 in the story, " I think the more." 



Ever yours faithfully, 



T. H. HUXLEY. 



