52 
INTRODUCTION. 
the other divisions ; almost all of them are avail- 
able as a delicate and nutritious food, and the fa- 
cility of their domestication and introduction from 
one climate to another, — the ease with which they 
seem to be able to accommodate themselves to 
change of temperature or situation, afford addi- 
tional proofs of the wise adaptation of structure 
to the wants of the species, or for the purposes 
which they were intended to fill in the arrange- 
ments of nature. 
Continents containingan immense extentof forest 
and of dense cover, or stretching out into unbound- 
ed plains, are necessary for their abundance ; and 
in all the great lands of our globe, we shall find 
analogous forms marked out for their respective 
localities. In the islands, the supply becomes na- 
turally limited according to their extent ; and it 
should be recollected, that here the native inhabi- 
tants have their maintenance supplied from the 
seas, in proportion as the ruminating animals and 
rasorial birds are wanting to the land. In Europe 
and Western Asia we find the least proportion, 
the families there being now confined to the Te- 
traonidce or grouse, the bustards, and a limited 
number of pigeons. It may be remarked, at the 
same time, that these countries have been longer 
in a continued state of progressive civilization 
than any others, and that in them the greatest 
advantages have been taken of the capabilities 
which the foreign species afforded of being na- 
turalised, every other continent having been laid 
