Contributions to the theory of natural selection. A series of essays ... By Alfred Russel Wallace ...

216 A THEOR1Y OF BIRDS' NESTS.
quire any special protection for the female. The larger
waders are sometimes very brightly coloured in both
sexes; but they are probably little subject to the attacks
of enemies, since the scarlet ibis, the most conspicuous
of birds, exists in immense quantities in South America.
In game birds and water-fowl, however, the females
are often very plainly coloured, when the males are
adorned with brilliant hues; and the abnormal family
of the Megapodida3 offers us the interesting fact of an
identity in the colours of the sexes (which in Megacephalon and Talegalla are somewhat conspicuous), in
conjunction with the habit of not sitting on the eggs
at all.
What the Facts Teach us.
Taking the whole body of evidence here brought
forward, embracing as it does almost every group of
bright-coloured birds, it will, I think, be admitted
that the relation between the two series of facts in
the colouring and nidification of birds has been sufficiently established. There are, it is true, a few
apparent and some real exceptions, which I shall consider presently; but they are too few and unimportant
to weigh much against the mass of evidence on the
other side, and may for the present be neglected.
Let us then consider what we are to do with this
unexpected set of correspondences between groups of
phenomena which, at first sight, appear so disconnected. Do they fall in with any other groups of
natural phenomena? Do they teach us anything of the