Correspondence on Biology, etc. 



To Sir Joseph Hookeb 

 Broadstone, Wimbome. November 10, 1905. 



My dear Sir Joseph, — I am writing to apologise for a 

 great oversight. When I sent my publishers a list of persons 

 who had contributed to " My Life " in various ways, your 

 name, which should have been ^rst, was strangely omitted, 

 and the omission was only recalled to me yesterday by read- 

 ing your letters to Bates in Clodd's edition of his Amazon 

 book, which I have just purchased. I now send you a copy 

 by parcel-post, in the hope that you will excuse the omission 

 to send it sooner. 



!Now for a more interesting subject. I was extremely 

 pleased and even greatly surprised, in reading your letters 

 to Bates, to find that at that early period (1862) you were 

 already strongly convinced of three facts which are abso- 

 lutely essential to a comprehension of the method of organic 

 evolution, but which many writers, even now, almost wholly 

 ignore. They are (1) the universality and large amount 

 of normal variability, (2) the extreme rigour of Natural 

 Selection, and (3) that there is no adequate evidence 

 for, and very much against, the inheritance of acquired 

 characters. 



It was only some years later, when I began to write on 

 the subject and had to think out the exact mode of action of 

 Natural Selection, that I myself arrived at (1) and (2), and 

 have ever since dwelt upon them — in season and out of 

 season, as many will think — as being absolutely essential to 

 a comprehension of organic evolution. The third I did 

 not realise till I read Weismann. I have never seen the 

 sufficiency of normal variability for the modification of 

 species more strongly or better put than in your letters 

 to Bates. Darwin himself never realised it, and conse- 

 quently played into the hands of the " discontinuous 

 G 81 



