e Letter 428.) It would be a fairer
trial to cut off the eyes of the tail-feathers of male peacocks; but who
would sacrifice the beauty of their bird for a whole season to please a
mere naturalist?

LETTER 434. TO J. JENNER WEIR. Down, February 29th [1868].

I have hardly ever received a note which has interested me more than
your last; and this is no exaggeration. I had a few cases of birds
perceiving slight changes in the dress of their owners, but your facts
are of tenfold value. I shall certainly make use of them, and need not
say how much obliged I should be for any others about which you feel
confident.

Do you know of any birds besides some of the gallinaceae which are
polygamous? Do you know of any birds besides pigeons, and, as it is
said, the raven, which pair for their whole lives?

Many years ago I visited your brother, who showed me his pigeons and
gave me some valuable information. Could you persuade him (but I fear
he would think it high treason) to stain a male pigeon some brilliant
colour, and observe whether it excited in the other pigeons, especially
the females, admiration or contempt?

For the chance of your liking to have a copy and being able to find some
parts which would interest you, I have directed Mr. Murray to send you
my recent book on "Variation under Domestication."

P.S.--I have somewhere safe references to cases of magpies, of which
one of a pair has been repeatedly (I think seven times) killed, and yet
another mate was always immediately found. (434/1. On this subject see
"Descent of Man," Edition I., Volume II., page 104, where Mr. Weir's
observations were made use of. This statement is quoted from Jenner
("Phil. Trans." 1824) in the "Descent of Man" (1901), page 620.) A
gamekeeper told me yesterday of analogous case. This perplexes me much.
Are there many unmarried birds? I can hardly believe it. Or will one of
a pair, of which the nest has been robbed, or which are barren, always
desert his or her mate for a strange mate with the attraction of a nest,
and in one instance with young birds in the nest? The gamekeeper said
during breeding season he had never observed a single or unpaired
partridge. How can the sexes be so equally matched?

P.S. 2nd.--I fear you will find me a great bore, but I will be as
reasonable as can be expected in plundering one so rich as you.

P.S. 3rd.--I have just received a letter from Dr. Wallace (434/2.
See "Descent of Man," Edition I., Volume I