256 BATS OR HAND-WINGED ANIMALS 



Upon examining the skeleton of the bat's wing, however, you 

 would see that there is one portion of the hand which does not form 

 part of the framework of the wing at all, and that is the thumb. 

 Although the fingers are so wonderfully lengthened, the thumb is 

 ([uite small and short, and is armed with a strong, sharp and curved 

 claw of some little size. It is by means of this claw that the bat 

 travels on level ground, for it cannot walk at all, but moves merely 

 by making use of every little crevice by which it can hitch itself, so to 

 speak, along. The reader may wonder why it is that a bat's wings 

 are so large and wide. 



The fact is, that the broader the wings the more buoyant is the 

 animal which bears them. If we look at any bird which is remark- 

 able for its powers of flight, we shall always find that its wings are 

 very large in proportion to the size of its body, while in those which 

 do not fly for very great distances they are quite small in comparison. 

 And so it is with the bat, which, being obliged to pursue and capture 

 swiftly-flying insects, must, of course, be able to skim through the air 

 with even greater speed himself. 



Thus, you will sec, nature has been most careful to suit the 

 structure of the bat in every possible way to the life which she 

 intended the animal to lead. She has given him wings which will 

 bear him swiftly through the air, and has also lightened his frame 

 to such a degree that he can continue his flight hour after hour 

 without feeling in any way fatigued. But, more than this, she has 

 also gifted him with a most wonderful power of avoiding the various 

 objects against which he might injure himself when flving after dark. 



And this she has done in a very singular manner indeed, and 

 which for many years was a great mystery to those who attempted to 

 discover it. All sorts of experiments were made without success, some 

 of them of a most cruel character, but it was not until quite of late 

 years that the true key to the secret was detected. 



The fact is, that the entire surface of the bat's wing is covered 

 with a vast number of the most delicate nerves, which can at once feel 

 the presence of any object, even though they have not come into contact 

 with it, and so warn the animal to change the direction of its flight. 

 So perfectly do these nerves perform their office, that a bat may be 



