252 A THEORY OF BIRDS’ NESTS. 
here, also, it is almost certain that the latter sits upon 
the eggs. The Turnices of India also, have the female 
larger and often more brightly coloured; and Mr. 
Jerdon states, in his ‘‘ Birds of India,” that the natives 
report, that, during the breeding season, the females 
desert their eggs and associate in flocks, while the 
males are employed in hatching the eggs. In the few 
other cases in which the females are more brightly _ 
coloured, the habits are not accurately known. The 
case of the Ostriches and Emeus will occur to many as 
a difficulty, for here the male incubates, but is not less 
conspicuous than the female ; but there are two reasons 
why the case does not apply ;—the birds are too large 
to derive any safety from concealment, from enemies 
which would devour the eggs they can defend them- 
selves by force, while to escape from their personal foes 
they trust to speed. 
We find, therefore, that a very large mass of facts 
relating to the sexual colouration and the mode of 
nidification of birds, including some of the most 
extraordinary anomalies to be found in their natural 
history, can be shown to have an interdependent re- 
lation to each other, on the simple principle of the need 
of greater protection to that parent which performs the 
duties of incubation. Considering the very imperfect 
knowledge we possess of the habits of most extra- 
European birds, the exceptions to the prevalent rule 
are few, and generally occur in isolated species or in 
small groups; while several apparent exceptions can 
be shown to be really confirmations of the law. 
