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 Megapodida; 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 



