BATS 
(Chiroptera) 
BaTs are at once separated from all other mammals by their 
peculiar modification for flight. The fore-limbs are much elongated, 
especially the fingers, and a thin extensible membrane stretches 
over this frame-work, connecting also with the sides of the body 
and the hind legs. Another membrane stretches between the hind 
legs, known as the interfemoral membrane. 
Besides their flying apparatus, bats are peculiar in having their 
hind legs twisted around in such a way that the knee bends back- 
wards, which render it exceedingly difficult for them to walk, a 
mere flapping shuffle being the result of their best efforts. On the 
wing, however, their movements are exceedingly graceful, and they 
turn and wheel in their varied evolutions with the greatest ease. 
Other structures frequently mentioned in the description of 
bats are the peculiar leaf-like appendages to the nose and the 
elongated lobe of the ear or tragus. 
In their general anatomy and in their den- 
tition, bats show a closer relationship to the 
insectivora (shrews and moles), and may, indeed, 
be regarded as a highly specialized  off-shoot 
from that group. 
Bats are distributed in all parts of the world, 
and vary in size from the small mouse-like 
species to the big flying foxes of the Malay 
region, the expanded wings of which measure 
as much as thirty inches from tip to tip. 
These large bats and their allies are fruit 

Ear of Bat, showin ae : P : 
tragus. (d/ter Miller) eaters, but the majority of the species, including 
all our Eastern American bats, are insectivorous, and feed while 
on the wing. 
Bats are nocturnal in habits, and seem to be most active at 
dusk and early in the morning, just before dawn. The hours 
of day-time they spend at rest, hanging head downward by their 
#93 
