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 



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 



