RAPTORES. 
89 
besides this keeping in check of over production, 
by the preying of one tribe upon a weaker race, 
another provision has been considered, that of 
the removal of animal matter where heat renders 
putridity when life is extinct almost instan- 
taneous, and where there is commonly, from 
various circumstances, at the same time a great 
expense of animal life. It is thus that we find 
in the warmer climates the most abundant distri- 
bution of the vultures, which decrease as they 
reach the north, and in our own country cease, 
with the rare examples of the species with which 
our present volume commences. The Falconidae, 
again, are more universal in their proportional 
distribution, but we find the stronger or more 
typical species abounding in the temperate 
regions ; while in those countries possessing a 
greater degree of heat, and between the tropics, 
we see the forms more variously distributed, and 
a greater proportion of those small or very 
weakly formed species, which serve to keep in 
check the multitudes of small lizards and reptiles, 
with the countless hosts of insects which are 
there so extremely destructive ; and it is remark- 
able that a most formidable tribe, the Gryllidae, 
to which the locust belongs, is one of the most 
eagerly hunted after by those smaller falcons. 
The Strigidee, or owls, are also universal in their 
distribution, and prey mostly on the smaller 
