60 Winter Holes [FOURTH WEEK 



are more nearly related to moles, shrews, and other insect- 

 eaters than they are to mice. If we look at the skeleton 

 of an animal which walks or hops we will notice that its 

 hind limbs are much the stronger, and that the girdle 

 which connects these with the backbone is composed of 

 strong and heavy bones. In bats a reverse condition is 

 found; the breast girdle, or bones corresponding to our 

 collar bones and shoulder blades, are greatly developed. 

 This, as in birds, is, of course, an adaptation to give surface 

 for the attachment of the great propelling muscles of the 

 wings. 



Although the hand of a bat is so strangely altered, yet, 

 as we shall see if we look at our captive specimen, it has 

 five fingers, as we have, four of which are very long and 

 thin, and the webs, of which we have a very noticeable 

 trace in our own hands, stretch from finger-tip to finger- 

 tip, and to the body and even down each leg, ending 

 squarely near the ankle, thus giving the creature the absurd 

 appearance of having on a very broad, baggy pair of 

 trousers. 



When thoroughly warmed up, our bat will soon start 

 on a tour of inspection of his cage. He steps rapidly from 

 one wire to another, sometimes hooking on with all five 

 toes, but generally with four or three. There seems to be 

 little power in these toes, except of remaining bent in a 

 hooked position; for when our bat stops and draws up 

 one foot to scratch the head, the claws are merely jerked 

 through the fur by motions of the whole leg, not by indi- 

 vidual movements of the separate toes. In this motion 

 we notice, for the first time, that the legs and feet grow 



