52 MIMICRY, AND OTHER PROTECTIVE 
that will assimilate with bark and lichen, and thus 
protect them during the day, and at the same time 
be inconspicuous in the dusk. 
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. The parrots are the most 
striking example, but we have also a group of green 
pigeons in the East; and the barbets, leaf-thrushes, 
bee-eaters, white-eyes, turacos, and several smaller 
groups, have so much green in their plumage as to 
tend greatly to conceal them among the foliage. 
Special Modifications of Colour. 
The conformity of tint which has been so far shown 
to exist between animals and their habitations is of 
a somewhat general character; we will now consider 
the cases of more special adaptation. If the lion is 
enabled by his sandy colour readily to conceal him- 
self by merely crouching down upon the desert, how, 
it may be asked, do the elegant markings of the 
tiger, the jaguar, and the other large cats agree 
with this theory? We reply that these are generally 
cases of more or less special adaptation. The tiger 
is a jungle animal, and hides himself among tufts 
of grass or of bamboos, and in these positions the 
vertical stripes with which his body is adorned must 
so assimilate with the vertical stems of the bamboo, 
as to assist greatly in concealing him from his ap-. 
proaching prey. How remarkable it is that besides — 
the lion and tiger, almost all the other large cats 
