Xu COLORATION OF EGGS 323 
fact that different species have different nesting 
habits. The eggs of the Raven, Crow, Rook, and 
Jackdaw are by no means unlike in colour. The 
Gulls are nearly allied to the Plovers, Curlews, Ruffs, 
Sand-pipers, and Avocets; and this fact, probably, 
supplies the explanation of the supposed protective 
colouring in the case of Gulls’ eggs, which require 
no protection. In the same way we can account for 
the white eggs of the Short-eared Owl. Occasionally 
we find a species whose eggs are differently coloured 
from those of its allies, without there being any 
difference of nesting habit to explain it. The Little 
Bittern, for instance, lays eggs of a dull white, while 
those of other Bitterns are of a brownish olive colour. 
It seems, in fact, that Natural Selection does not 
work either universally or very promptly upon the 
colours of eggs. If the Wood Pigeon’s eggs were of 
an inconspicuous tint, it might be a slight gain to the 
species. But the birds are so vigorous, so strong on 
the wing, and so able to find food, that a slight imper- 
fection such as the whiteness of their eggs does not 
materially reduce their numbers. The large number 
of eggs laid by the common chicken may allow for 
the destruction of a good many nests, so that con- 
cealment can be dispensed with. And it must also 
be borne in mind that when a bird lays only one or 
two eggs, sitting begins soon, so that there is more 
need for the concealment of the birds than the eggs. 
Though it may seem a paradox to say so, it is some- 
times because the eggs are many and sometimes 
because they are few that protective colouring is 
unnecessary. 
Y 2 
