THE BAT. 24)9 
As, however, the bat itself is not rendered 
buoyant by any of the means employed in the 
internal structure of birds, and as its wings 
are themselves membranes of some strength, 
great extent of surface is required in them. 
They are not fitted for long flight, and must 
be considered as a remarkable deviation from 
the structure of the bird on one part, and 
from that of the quadruped on the other. 
The numerous species of bats are natives of 
very different regions. Three of them are 
found in Britain, several in the warmer coun- 
tries of Asia and Africa, one in the West In- 
dies, and a few in America. The smaller 
species, found in temperate climates, live 
chiefly on insects, which they catch in their 
flight, and pass the winter in a torpid state 
without food. Those of warm climates are 
usually very large, and attack birds and even 
the smaller quadrupeds. The bats are divided 
into two classes, the tailed and the tailless. 
