204 THE SCOTTISH NATURALIST 



one observes the speed and endurance of a bat in flight, it seems as 

 if it were no bad second to the bird, in spite of the latter's specially 

 lightened skeleton. Several distinct types of mammals have 

 developed parachute-like extensions of skin which enable them 

 to take long gliding leaps, and carry some suggestion of stages 

 in the evolution of the wing, but the bats are the only living 

 mammals which possess the power of true flight. Bats, whether 

 they be fruit- or insect-eaters, feed at night or in the dusk, and 

 they have a very highly specialised sense, apparently allied to, 

 but not actually, the sense of touch, which enables them to direct 

 their flight, at any rate, to the extent of avoiding solid objects, 

 without much aid from sight. For all bats have eyes relatively 

 small instead of the usually enlarged and very sensitive eyes of 

 nocturnal animals. The Fruit Bats spend the day sleeping. When 

 they have returned to their roosting places in the morning, each 

 bat hangs himself upside down, by one claw, to a branch, and 

 folds the membranes of his wings round his body. They group 

 together in immense numbers, so that sometimes the branches 

 of trees are broken by the weight of the bats clinging to them. 

 Towards dusk, they leave the roosting tree for their feeding ground, 

 and as they have enormous appetites, a vast quantity of fruit 

 must be destroyed by the swarms of bats. Each of the bats in 

 the Park eats about half a dozen bananas a night (and would 

 probably eat more if it were given the opportunity). When feeding 

 on growing fruit, the Fruit Bat hangs himself on to the branch 

 by one foot, and uses the claw of one thumb to steady its food. 

 The fore-limbs are, of course, modified into wings, but, unlike 

 birds, bats have retained one digit and its claw on the fore-limbs — 

 the thumb ; in the Fruit Bat this claw is a somewhat formidable 

 weapon; if the sleeping Fruit Bat be disturbed, it half extends 

 its wing, and strikes viciously at the intruder with the thumb-claw. — 

 T. H. G. 



