132 BOMBAY DUCKS 
insects and lizards. They also eat snakes, and hence 
are useful birds to have in the compound. 
As is known to everybody, peafowl are sexually 
dimorphic. The male only carries the gorgeous train. 
The female is by comparison a bird of sombre hues. 
Darwin explains the beauty of the male bird by the 
theory of sexual selection, the preference of the females 
for showy husbands, while they themselves are not 
similarly arrayed ; for were they thus resplendent they 
would be very conspicuous when sitting on their eggs, 
hence Natural Selection has tended to keep the plumage 
of the females of a dull, uniform colour. However, it 
seems to me that this theory fails to account for all the 
brilliant hues of the male bird, for all the wonderful 
markings on each of the feathers of his train. Nor does 
the theory of Wallace, that these are the expression of 
the great vital force, of the abundance of energy in 
which the bird rejoices. Animal colouration forms one 
of the most interesting of scientific studies, and it seems 
to me that explanations have yet to be found of not 
a few of the shades and markings which render the 
plumage of many birds so indescribably beautiful. 
The science of animal colouration is in its infancy; 
yet popular books on natural history give one to under- 
stand that the last word has been said on the subject. 
