xxiii CHAIRMANSHIP OF L.C.C. 299 



It was on this understanding of his underlying 

 assumption, that many years ago I wrote to him asking 

 what was the ground on which he made it. 



His reply was — what I described — a reference to the 

 Doctrine of Chances. 



I forget the year, but I am sure I have kept the letter 

 — although I am not sure that I know where to find it. 



If similar forms, or rather identical varieties, have 

 had separate origins, both as to time and place, a serious 

 hole would be made in his theory : but he may have 

 changed his view in later years. You do not imply 

 that he has distinctly voted in favour of Black, Yellow 

 and White Adams — originating at different places. On 

 the contrary you speak of what " you understood from 

 him to be his opinion " — which seems to refer to con- 

 versation. 



But I should like much to know whether you have 

 any written evidence that he believed in more " Adams " 

 than one. — Yours very truly, Argyll. 



39 Berkeley Square, W., 

 13 March 1890. 



My dear Duke of Argyll — I quite concur with you 

 that in Darwin's opinion each species originated in one 

 centre, but not I think from one pair. 



As I understood him external circumstances led to 

 changes eventually resulting in a new species, but these 

 circumstances in most cases affected a large number of 

 individuals. 



I have not his books or letters with me here, but when 

 I go home I will look up his letters. 



I saw him, however, so frequently that we generally 

 talked on such questions ; this being much easier than 

 writing. — Believe me, yours very truly, 



John Lubbock. 



His Grace the Duke of Argyll. 



The diary for April of this year is rather painful 

 reading, by reason of its frequent reference to his 

 sufferings from gout and struggles against it. 

 Nevertheless he managed to be in London fre- 

 quently, and to be active in scientific lecturing 

 and in business. On April 26 he is better but 



