^^"^ THE NEW EVOLUTION W^ 



such as ours are quite inaudible to us, though in the 

 huge oriental earthworms we can hear them easily. 



In many night-flying birds, especially in most owls, 

 the ears seem to be almost as important as the eyes. 

 To anyone familiar with owls it seems quite evi- 

 dent that the very soft plumage of most kinds which 

 gives them a ghostly almost noiseless flight is pri- 

 marily adapted to prevent any interference with ex- 

 ternal sounds coming from their prey and not so that 

 they may steal up upon their prey unheard. 



As aerial creatures feeding chiefly on insects and on 

 fruit the mammalian bats compete with birds. But 

 bats, except apparently for the large fruit-eating kinds 

 called "flying-foxes," living in the oriental regions, 

 are guided mainly by their hearing and have, at least 

 when compared with birds, very deficient sight. 

 They have, however, a high degree of sensitivity to 

 touch, well developed smell, and well developed taste. 



Bats find their way about through the analysis of 

 echoes and of all the myriads of different kinds of 

 sounds made by the insects and the foliage. As the 

 very high pitched sounds give the best indication of 

 direction, the activities of bats mainly are controlled 

 by sounds which are too high pitched for us to hear. 



Among the bats the flying-foxes correspond to the 

 owls among the birds in that their activities are con- 

 trolled after a manner differing from that of the great 

 majority of their relatives. These enormous bats are 

 to a large extent diurnal, at least in the more unsettled 

 regions. They are sometimes seen in the hottest por- 

 tions of the day circling in great numbers over open 



[il] 



