Pray do not let it be so. The truth will come out at last, and our difference may be the means of setting others to work who may set us both right.
After all, this question is only an episode (though an important one) in the great question of the origin of species, and whether you or I are right will not at all affect the main doctrine—that is one comfort.
I hope you will publish your treatise on Sexual Selection as a separate book as soon as possible, and then while you are going on with your other work, there will no [pg 231]doubt be found someone to battle with me over your facts, on this hard problem.
With best wishes and kind regards to Mrs. Darwin and all your family, believe me, dear Darwin, yours very faithfully,
ALFRED R. WALLACE.
Down, Bromley, Kent, S.E. October 6, 1868.
My dear Wallace,—Your letter is very valuable to me, and in every way very kind. I will not inflict a long answer, but only answer your queries. There are breeds (viz. Hamburgh) in which both sexes differ much from each other and from both sexes of G. bankiva; and both sexes are kept constant by selection.
The comb of Spanish [male symbol] has been ordered to be upright and that of Spanish [female symbol] to lop over, and this has been effected. There are sub-breeds of game fowl, with [female symbol]s very distinct and [male symbol]s almost identical; but this apparently is the result of spontaneous variation without special selection.
I am very glad to hear of the case of [female symbol] birds of paradise.