I know well it would be quite unreasonable to ask for any further information from you; but I will just mention that I am now, and shall be for a long time, writing on domestic varieties of all animals.
Any facts would be useful, especially any showing that savages take any care in breeding their animals, or in rejecting the bad and preserving the good; or any fancies which they may have that one coloured or marked dog, etc., is better than another.

I have already collected much on this head, but am greedy for facts.

You will at once see their bearing on variation under domestication.
Hardly anything in your letter has pleased me more than about sexual selection.

In my larger MS.

(and indeed in the "Origin" with respect to the tuft of hairs on the breast of the cock-turkey) I have guarded myself against going too far; but I did not at all know that male and female butterflies haunted rather different sites.