LETTER 457. A.R. WALLACE TO CHARLES DARWIN.
Holly House, Barking, E., January 27th, 1871.

Many thanks for your first volume (457/1. "The Descent of Man".), which I
have just finished reading through with the greatest pleasure and interest;
and I have also to thank you for the great tenderness with which you have
treated me and my heresies.

On the subject of "sexual selection" and "protection," you do not yet
convince me that I am wrong; but I expect your heaviest artillery will be
brought up in your second volume, and I may have to capitulate. You seem,
however, to have somewhat misunderstood my exact meaning, and I do not
think the difference between us is quite so great as you seem to think it.
There are a number of passages in which you argue against the view that the
female has in any large number of cases been "specially modified" for
protection, or that colour has generally been obtained by either sex for
purposes of protection. But my view is, as I thought I had made it clear,
that the female has (in most cases) been simply prevented from acquiring
the gay tints of the male (even when there was a tendency for her to
inherit it), because it was hurtful; and that, when protection is not
needed, gay colours are so generally acquired by both sexes as to show that
inheritance by both sexes of colour variations is the most usual, when not
prevented from acting by Natural Selection. The colour itself may be
acquired either by sexual selection or by other unknown causes.

There are, however, difficulties in the very wide application you give to
sexual selection which at present stagger me, though no one was or is more
ready than myself to admit the perfect truth of the principle or the
immense importance and great variety of its applications.