THE BATS 77 



developed into birds, still with the pursuit of insects as their 

 magnet. The earlier mammals no doubt were largely insecti- 

 vorous, and descendants of this type exist but little modified at 

 the present day in hedgehogs, tree-shrews, moles, shrew-mice, 

 and tenrecs. 



The earliest Insectivores were no doubt content to pursue 

 insects in and out of the herbage, into the soil, and up on the 

 trees. Once they had taken to a tree life their jumping and 

 leaping through the air after flying insects became inevitable, 

 and they learnt to do as flying squirrels even the common 

 squirrel have done : to stretch out their fingers, arms, and the 

 loose skin of the body to act as a parachute and break a fall. 

 Later on, provided with a great membrane of stretched skin (such 

 as the cobego of the Philippine Islands possesses), they strove to 

 beat the air with their webbed hands, to turn a downward swoop 

 into an upward flight, or to postpone descent. The hands, like 

 those of certain lemurs, grew more and more long and slender- 

 fingered, and the Insectivore had become a bat. 



The exact origin of the Bats is still a matter of dispute. On 

 the whole their nearest affinities in structure are with the Insecti- 

 vora rather than with the Lemurs, to which in several points 

 some of them offer misleading resemblances. Any one who in 

 Africa has possessed a galago 1 will have been struck with the 

 extraordinary resemblance in its movements which this creature 

 offers to the bat. It jumps upwards, downwards, or hori- 

 zontally through the air, starting with a tremendous spring from 

 the hind legs, but aided, no doubt, by the large outstretched hands 

 and loose skin of the fingers. The galago literally seems to fly 

 through the air from a table to a window, where with unerring 

 aim it will snap up some insect that has attracted its attention. 

 In the position of the mammae (which in all bats are reduced to 

 two and are placed on or near the breast), in some points con- 

 nected with the teeth, and, as regards the fruit-eating bats only, 

 in the superficial aspect of the head, the bats certainly offer points 



1 A species of lemur only found on the African Continent, varying in size 

 from that of a small cat to the bulk of a rat. 



