his "Ornithological Biography," 5 volumes, Edinburgh, 1831-49.) gives a
good many facts about the antics of birds during courtship, but nothing
nearly so much to the purpose as yours. I shall never be able to resist
giving the whole substance of your last note. It is quite a new light to
me, except with the peacock and Bird of Paradise. I must now look to
turkey's wings; but I do not think that their wings are beautiful when
opened during courtship. Its tail is finely banded. How about the drake
and Gallus bankiva? I forget how their wings look when expanded. Your
facts are all the more valuable as I now clearly see that for butterflies I
must trust to analogy altogether in regard to sexual selection. But I
think I shall make out a strong case (as far as the rather deceitful guide
of analogy will serve) in the sexes of butterflies being alike or differing
greatly--in moths which do not display the lower surface of their wings not
having them gaudily coloured, etc., etc.--nocturnal moths, etc.--and in
some male insects fighting for the females, and attracting them by music.

My discussion on sexual selection will be a curious one--a mere dovetailing
of information derived from you, Bates, Wallace, etc., etc., etc.

We remain at above address all this month, and then return home. In the
summer, could I persuade you to pay us a visit of a day or two, and I would
try and get Bates and some others to come down? But my health is so
precarious, I can ask no one who will not allow me the privilege of a poor
old invalid; for talking, I find by long and dear-bought experience, tries
my head more than anything, and I am utterly incapable of talking more than
half an hour, except on rare occasions.

I fear this note is very badly written; but I was very ill all yesterday,
and my hand shakes to-day.