BATS. 5 



mities and development of the cutaneous system is 

 adapted to the purposes of flight, we shall find that, 

 of the diflferent parts of which it is composed, the 

 osseous basis for the support of the membrane, and the 

 membrane itself, are both applicable to other purposes 

 than those to which they may appear to be primarily 

 destined. The flying membrane is frequently used as a 

 cloak or mantle, in which not only these little creatures 

 enshroud themselves, but in which the females hold and 

 shelter their young ; the posterior portion of it, or inter- 

 femoral membrane, is also stretched forwards and ex- 

 panded, by means of the tail and thighs, during parturi- 

 tion, forming a safe and easy cradle into which the young 

 ones are received at the moment of their birth. 



But there is another, and still more important and in- 

 teresting office, which the membrane of the wings appears 

 to perform, and which deserves especial notice. Spallan- 

 zani had found that Bats, when deprived of sight, and, 

 as far as possible, of hearing and smelling also, still flew 

 about with equal certainty and safety, avoiding every ob- 

 stacle, passing through passages only just large enough 

 to admit them, and flying about places previously un- 

 known, with the most unerring accuracy, and without 

 ever coming into collision with the objects by which they 

 passed. He also stretched threads in various directions 

 across the apartment with the same result. So as- 

 tonished was he at these curious facts, that he was led 

 to attribute the phenomenon to the possession of a sixth 

 sense, unknown to us. Cuvier was the first to appreciate 

 the real value of these experiments, as afibrding a proof 

 of the existence of a vast expansion of the most exqui- 

 site sense of touch over the whole surface of the flying 

 membrane ; the naked surface and delicate structure of 

 which appear well calculated to form the seat of so im- 



