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 _first_, was strangely omitted, and the omission was only recalled to me yesterday by reading 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 absolutely 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 consequently played into the hands of the "discontinuous variation" and "mutation" men, by so continually saying "_if_ they vary"--"without variation Natural Selection can do nothing," etc. Your argument that variations are not caused by change of environment is equally forcible and convincing. Has anybody answered de Vries yet? F. Darwin lent me Prof. Hubrecht's review from the _Popular Science Monthly_, in which he claims that de Vries has proved that new species have always been produced from "mutations," never through normal variability, and that Darwin latterly agreed with him! This is to me amazing! The Americans too accept de Vries as a second Darwin!--Yours very sincerely, ALFRED E. WALLACE. * * * * * SIR J. HOOKER TO A.R. WALLACE _The Camp, Sunningdale. November 12, 1905._