1856.] SPECIFIC CENTRES. 441 



one who believes in single centres will have to admit conti- 

 nental extensions. 



... I see from your remarks that you do not understand 

 my notions (whether or no worth anything) about modifica- 

 tion ; I attribute very little to the direct action of climate, 

 &c. I suppose, in regard to specific centres, we are at cross 

 purposes ; I should call the kitchen garden in which the red 

 cabbage was produced, or the farm in which Bakewell made 

 the Shorthorn cattle, the specific centre of these species ! And 

 surely this is centralisation enough ! 



I thank you most sincerely for all your assistance ; and 

 whether or no my book may be wretched, you have done 

 your best to make it less wretched. Sometimes I am in very 

 good spirits and sometimes very low about it. My own mind 

 is decided on the question of the origin of species ; but, good 

 heavens, how little that is worth ! . . . 



[With regard to " specific centres," a passage from a letter 

 dated July 25, 1856, by Sir Charles Lyell to Sir J. D. Hooker 

 (' Life,' ii. p. 216) is of interest : 



" I fear much that if Darwin argues that species are phan- 

 toms, he will also have to admit that single centres of disper- 

 sion are phantoms also, and that would deprive me of much 

 of the value which I ascribe to the present provinces of ani- 

 mals and plants, as illustrating modern and tertiary changes 

 in physical geography." 



He seems to have recognised, however, that the phantom 

 doctrine would soon have to be faced, for he wrote in the- 

 same letter : " Whether Darwin persuades you and me to 

 renounce our faith in species (when geological epochs are 

 considered) or not, I foresee that many will go over to the 

 indefinite modifiability doctrine." 



In the autumn my father was still working at geographical 

 distribution, and again sought the aid of Sir J. D. Hooker. 



A Letter to Sir /. D. Hooker [Sept., 1856]. 

 '* In the course of some weeks, you unfortunate wretch, 

 you will have my MS. on one point of Geographical Distribu- 



