246 A THEORY 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 Megapodide offers us the interesting fact of an 
identity in the colours of the sexes (which in Mega- 
cephalon 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 suffi- 
ciently established. There are, it is true, a few 
apparent and some real exceptions, which I shall con- 
sider 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 discon- 
nected. Do they fall in with any other groups of 
natural phenomena? Do they teach us anything of the 
