53 o THE POPULAR SCIENCE MONTHLY. 



ure to be a true tree-frog, it is difficult to imagine that this immense membrane 

 of the toes can be for the purpose of swimming only, and the account of the 

 Chinaman that it flew down from the tree becomes more credible." 



Although no existing reptile is thus furnished, there is a small 

 Asiatic lizard which is ordinarily spoken of as " flying," the Draco 

 volans. And, in fact, though this creature cannot truly fly, but only 

 flit, it has a membrane which can be extended from each side of the 

 body, and which, like the bat's wing, is supported by a number *oi 

 bony rods. These rods, however, are not, as in the bat, enormously 

 elongated fingers, but are elongated ribs, which stand out freely from 

 the body when jumping, but otherwise are folded back against the 

 flanks. 



Existing reptiles, then, present us with no close resemblance to 

 bat-structure ; but when we come to extinct reptiles reptiles which 

 flourished during and anterior to the deposition of our chalk-cliffs 

 the secondary or mesozoic period we there find reptiles to have ex- 

 isted which present the most striking analogies with existing bats in 

 all that regards their modes of locomotion, and their structure as far 

 as it is related to such modes of locomotion. 



These reptiles flew in the same way that bats do, by means of a 

 vast membrane extending from each enormously-elongated hand to 

 the adjacent side of the body. 



While, however, in the bat all the fingers of each hand are enor- 

 mously elongated (to support the alar membrane) the thumb alone re- 

 maining free in these flying reptiles only a single finger of each hand 

 was thus elongated, the others remaining short, and being provided 

 with claws like the thumb. 



With the approach of the winter season bats (like dormice) fall 

 into a peculiar state of winter sleep called hibernation. For this pur- 

 pose they generally assemble together in large numbers, in out-of-the- 

 way places, caverns, hollow trees, or the roofs of buildings, hanging 

 head downward by the claws of their feet. During this condition the 

 most important functions of life breathing and the circulation of the 

 blood are performed only with exceedingly-reduced activity, the 

 temperature of the body becoming notably diminished. 



Some of our English bats may be kept in confinement and partly 

 domesticated for a time, small pieces of raw meat being given to them 

 in lieu of their natural insect-food. Speaking of the long-eared bat, 

 Mr. Bell tells us : 



"It is more roadily tamed than any other, and may soon be brought to ex- 

 hibit a considerable degree of familiarity with those who feed and caress it. I 

 have frequently watched them when in confinement, and have observed them to 

 be bold and familiar even from the first. They are very cleanly ; not only clean- 

 ing themselves after feeding, and at other times, with great assiduity, but oc- 

 casionally assisting each other in this office. They are very playful, too, and 

 their gambols are not the less amusing from their awkwardness. Thoy run over 



