256 THE HAUNTS OF LIFE 



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 with- 

 out 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 common 

 ancestry in extinct reptiles. It is all the more 

 interesting to find that similar fitnesses or 



