FOOT-HANDED AND HAND-WINGED VERTEBRATES. 41 
readily avoided these and other obstacles. Of course, 
they did this with the sense of touch alone, and that 
chiefly in their wings. They instantly knew in this way 
when they were coming near something besides air. The 
senses of smell and hearing would help them to determ- 
ine whether this something was an insect or such a thing 
as a string. 
61. The bats of temperate. climates are, like the frogs 
and toads, in a torpid state through the winter, this be- 
ing necessary simply because the insects upon which they 
live are gone. For this purpose they lodge themselves 
instinctively in some secret place where they will not be 
likely to be disturbed. 
62. The species of bats are very numerous. Some of 
the species in tropical climates are quite large animals. 
The Vampire Bat of South America, Fig. 22, measures 
CAG = = ——=S— 
aed = ——— 
Fig. 22.—Vampire Bat. 
two or three feet from tip to tip of the wings. It lives 
by sucking blood from different animals, which it does 
while they are asleep, and commonly without awaking 
them. The wound which it makes is very small, and yet 
it sucks from it quite a large quantity of blood. 
63. The most singular species of bat is found in the 
