in Edition I. (pages 89, 101) do not directly bear on the question of
protection.) If you will look at page 240 of the fourth edition of the
"Origin" you will find it very briefly given with two extreme examples of
the peacock and black grouse. A more general statement is given at page
101, or at page 89 of the first edition, for I have long entertained this
view, though I have never had space to develop it. But I had not
sufficient knowledge to generalise as far as you do about colouring and
nesting. In your paper perhaps you will just allude to my scanty remark in
the fourth edition, because in my Essay on Man I intend to discuss the
whole subject of sexual selection, explaining as I believe it does much
with respect to man. I have collected all my old notes, and partly written
my discussion, and it would be flat work for me to give the leading idea as
exclusively from you. But, as I am sure from your greater knowledge of
Ornithology and Entomology that you will write a much better discussion
than I could, your paper will be of great use to me. Nevertheless I must
discuss the subject fully in my Essay on Man. When we met at the
Zoological Society, and I asked you about the sexual differences in
kingfishers, I had this subject in view; as I had when I suggested to Bates
the difficulty about gaudy caterpillars, which you have so admirably (as I
believe it will prove) explained. (429/2. See a letter of February 26th,
1867, to Mr. Wallace, "Life and Letters" III., page 94.) I have got one
capital case (genus forgotten) of a [Australian] bird in which the female
has long tail-plumes, and which consequently builds a different nest from
all her allies. (429/3. Menura superba: see "Descent of Man" (1901),
page 687. Rhynchoea, mentioned a line or two lower down, is discussed in
the "Descent," page 727. The female is more brightly coloured than the
male, and has a convoluted trachea, elsewhere a masculine character. There
seems some reason to suppose that "the male undertakes the duty of
incubation.") With respect to certain female birds being more brightly
coloured than the males, and the latter incubating, I have gone a little