CHAPTER VTI 

 BATS. CHIROPTERA 



Bats are the only mammals that really hy. The 

 arm and hand are specially modified for the purpose, 

 the fingers being connected by a very delicate skin, 

 which is extended from the fore limb along the side 

 of the body to the hind limb, and in some cases it 

 includes the tail. This membranous skin forms the 

 wing or flying organ of the bats, and it is worked both 

 by the arms and legs. Thus the wing of the bat is 

 a very different structure from the wing of a bird, 

 and it should be carefully examined and compared 

 with a bird's wing. So specialised has the power of 

 flight become in bats that they have almost lost the 

 power of walking, and can do no more than make a 

 feeble attempt at a crawl. The thumb is short 

 and is provided with a claw ; the remaining four 

 fingers are much elongated, the third and fourth 

 being longer than the forearm. The knee is directed 

 backwards, and several bats have a spur on the 

 heels to support the membrane connecting the two 

 hind limbs. 



In all nocturnal or crepuscular animals there is 

 developed either an abnormally keen and specialised 



