Dear Romanes

I have read the crossing paper, which you were so kind as to send me.— It is very clear & I quite agree with it. But the point in question has not been a difficulty to me, as I have never believed in a new form originating from a single variation.—² What I have called unconscious selection by man illustrates, as it seems to me, the same principle as yours, within the same area. Man peruses the individual animals or plants which seem to him the best in any respect,—some more so & some less so—& without any matching or pairing, the breed in the course of time is surely altered³ The absence in numerous instances of intermediate or blending forms in the border country between two closely allied geographical races or close species seemed to me a greater difficulty, when I discussed the subject in the Origin.—⁴

With respect to your illustration, it formerly drove me half-mad to attempt to account for the increase or diminution of the productiveness of an organism; but I cannot call to mind where my difficulty lay.⁵ Natural selection always applies, as I think, to each individual & its offspring, such as its seeds, eggs, which are formed by the mother & which are protected in various ways.⁶ There does not seem any difficulty in understanding how the productiveness of an organism might be increased, but it was, as far as I can remember in reducing productiveness that I was most puzzled.— But why I scribble about this I know not.—

I have read your review of M^r. Allen’s book & it makes me more doubtful even than I was before whether he has really thrown much light on the subject.—⁷

I am glad to hear that some physiologists take same view as I did about your giving too much credit to H. Spencer;⁸ though Heaven knows this is a rare fault!— The more I think of your Medusa nerve work the more splendid it seems to me—.⁹

Yours very sincerely | Ch. Darwin