222 I N A G U A 



reptilian digiti-aeroplanists have been out of circulation for an 

 eon or two. 



The bat uses all its fingers except the thumb, which is free 

 and which functions as a grasping claw; the third, fourth and 

 fifth digits are longer than the remainder of the arm. If an 

 average man's fingers were produced in proportion they 

 would reach from his shoulders to the ground and would be 

 about the thickness of a lead pencil tapering to the thickness 

 of a knitting needle at the ends. These finger bones are un- 

 believably elastic and may be bent almost double before they 

 break. Yet they are so perfectly designed that they support 

 the wing tissues rigidly while in flight. 



The marvelous wing membrane, which is a very fine flexible 

 tissue, is kept well lubricated with a special grease which oc- 

 curs in the region of the nose and eyes. The care which is 

 given to the wings is as great as the attention the birds give to 

 their feathers; and a bat's wing is capable of a great many more 

 uses than the pinions of a bird. Its actual lifting surface in pro- 

 portion to bulk is much greater and is extended over a greater 

 area. Even the space between the hind legs is utilized and most 

 bats are equipped with peculiar spurs which are attached to 

 the heels to help support this inter-femoral membrane, as it 

 is termed. 



This membrane, stretching from leg to leg, and further 

 supported in some species by a flexible tail, serves a dual pur- 

 pose. It is, first of all, used as a baby-basket, for the newly 

 born young have been observed resting in its curved surface 

 as in a pouch until the parent is able to transfer them to a more 

 permanent place near her breasts. The membrane is also used 

 by certain species as a retainer for food while devouring an 

 extra large insect, such as a beetle. This in itself proves what 

 wonderful aerialists bats are, for the action of eating the beetle 

 is performed in full flight high in the evening sky. The diffi- 



