256 THE HAUNTS OF LIFE 



be carried without impeding her flight. Thus 

 the bats, though belonging to a class nearly 

 all of the members of which live on land, 

 have become thoroughly adapted to aerial life. 

 In insect-catching bats the skin is continued 

 from the hind-legs to the well-developed tail, 

 and this " inter-femoral membrane" forms a 

 very useful pouch. For when the bat has 

 caught a good-sized insect, such as a night- 

 flying beetle, the difficulty arises of crunching 

 it without letting it go from the grip of the 

 jaws. In her delightful Wild Animals of 

 Garden and Hedgerow (1920), Miss Frances 

 Pitt points out that the bat lowers its head to 

 its skin-basket and, pressing its booty against 

 that, can crunch it comfortably without risk of 

 losing what it has gained. During this process, 

 which is quickly over, the bat tumbles a little 

 in the air, but speedily recovers itself. 



FITNESSES OF BIRDS AND BATS 



Birds and bats are not in any way related to 

 one another, except that the two classes, birds 

 and mammals, may be traced back to a com- 

 mon ancestry in extinct reptiles. It is all the 

 more interesting to find that similar fitnesses or 



