The Descent of Man

lack- headed. This bullfinch was a very quiet
bird, and had never before quarrelled with any
of its comrades, including another reedbunting,
which had not as yet become blackheaded:
but the reed-bunting with a black head
was so unmercifully treated that it had to be
removed. Spiza cyanea, during the breedingseason,
is of a bright blue colour; and though
generally peaceable, it attacked S. ciris, which
has only the head blue, and completely scalped
the unfortunate bird. Mr. Weir was also obliged
to turn out a robin, as it fiercely attacked all the
birds in his aviary with any red in their plumage,
but no other kinds; it actually killed a redbreasted
crossbill, and nearly killed a goldfinch.
On the other band, he has observed that some
birds, when first introduced, fly towards the
species which resemble them most in colour,
and settle by their sides.
As male birds display their fine plumage and
other ornaments with so much care before the