136 



SOME COMMON MA.MMAL8. 



greatly resembling in structure the ears of the long-eared 

 bat, and these also are highly sensitive. 



The most remarkable structure about the bat, however, 

 is undoubtedly the flying apparatus. Let us unfold the 

 so-called " wing." Its delicacy is remarkable ; exquisitely 

 soft to the touch and folded in innumerable creases is the 

 flying membrane stretched between the bones of the hand, 

 arm, and leg. There is also a similar membrane stretching 

 between the legs and tail. These membranes are so extra- 

 ordinarily sensitive that they are sufficient to guide the 

 bat clear of obstacles, independently of sight. So much is 

 this the case that they are credited by some observers with 

 a sixth sense. Bats fly well, and guide their movements 

 with great skill, the steering being effected 

 by the tail and its associated membrane. 



Note the large expanse of these mem- 

 branes. The length of this bat's head and 

 body is less than two inches, and if we add 

 the tail it is three and a half inches. But 

 the wing extent from tip to tip is ten 

 inches. This great expanse of wing surface 

 is brought about by the great elongation 

 of the bones of the arm and fingers, which 

 serve as supports or act as a kind of frame- 

 work upon which the flying membrane is 

 stretched. Four of the fingers are in- 

 volved as well as the arm bones. And the 

 membrane stretches across the inner bend 

 at the elbow, just as the skin is stretched 

 in the same place in a bird's wing. 



The " wing " serves not only as an organ 

 of flight, and as a sensory apparatus, but 

 is used as a wrap or mantle in which the bat sleeps and 

 in which the female holds and shelters her young. And 

 some bats use the membrane between the hind limbs as 

 a kind of sac into which they strike the moths during 

 flight. The bat's thumb is free and carries a strong claw 

 It is used in walking and in climbing, and proves service- 

 able also when bats fight, as they not uncommonly do 

 How does the bat dispose of its wings when walking ? 



Fig. 44. The Bat's 

 foot, showing the 

 toes of equal 

 length and with 

 long claws, by 

 means of which 

 the animal sus- 

 pends itself when 

 Bleeping. 



