The Descent of Man

There is reason to believe that pigeons of both
sexes prefer pairing with birds of the same
breed; and dovecot-pigeons dislike all the highly
improved breeds. (22. 'Variation of Animals
and Plants under Domestication,' vol. ii. p. 103.)
Mr. Harrison Weir has lately heard from a
trustworthy observer, who keeps blue pigeons,
that these drive away all other coloured varieties,
such as white, red, and yellow; and from
another observer, that a female dun carrier
could not, after repeated trials, be matched
with a black male, but immediately paired with
a dun. Again, Mr. Tegetmeier had a female blue
turbit that obstinately refused to pair with two
males of the same breed, which were successively
shut up with her for weeks; but on being
let out she would have immediately accepted
the first blue dragon that offered. As she was a
valuable bird, she was then shut up for many
weeks with a silver (i.e., very pale blue) male,
and at last mated with him. Nevertheless, as a
general rule, colour appears to have little in-