Chap. XVI. 
COLOUE AND PROTECTION. 
223 
of the young of brightly-coloured species being more 
brilliantly coloured than their parents. In the fourth 
class, however, in which the young and the old resemble 
each other, there are many species (though by no means 
all) brightly-coloured, and as these form whole groups, 
we may infer that their early progenitors were likewise 
brightly-coloured. With this exception, if we look to 
the birds of the world, it appears that their beauty 
has been greatly increased since that period, of which 
we have a partial record in their immature plumage. 
On the Colour of the Plumage in relation to Pro- 
tection , — It will have been seen that I cannot follow 
Mr. Wallace in the belief 'that dull colours when con- 
fined to the females have been in most cases specially 
gained for the sake of protection. There can, however, 
be no doubt, as formerly remarked, that both sexes of 
many birds have had their colours modified for this 
purpose, so as to escape the notice of their enemies ; or, 
in some instances, so as to approach their prey unob- 
served, in the same manner as owls have had their 
plumage rendered soft, that their flight may not be 
overheard. Mr. Wallace remarks that ^^it is only 
in the tropics, among forests which never lose their 
foliage, that we find whole groups of birds, whose 
chief colour is green.” It will be admitted by every 
one, who has ever tried, how difficult it is to distinguish 
parrots in a leaf-covered tree. Nevertheless, we must re- 
member that many parrots are ornamented with crimson, 
blue, and orange tints, which can hardly be protective. 
Woodpeckers are eminently arboreal, but, besides green 
species, there are many black, and black-and-white 
kinds — all the species being apparently exposed to 
‘ Westminster Review,’ July, 1867, p. 5. 
