THE VAMPIRE BAT. 115 
process, the bones which thus constitute the arm and hand are marvellously elongated, 
becoming longer the farther they recede from the body. 
The two bones of the fore-arm are extreme ‘ly long, and the bone which is 
scientifically known by the name of the “ulna,” is extremely small, and in many species 
almost wholly wanting. The reason for this arrangeme nt is, that the great object of 
these two bones is, by the mode in which they are jointed to each other, to permit the 
arm to rotate with that movement which is easily shown by the simple process of turning 
the hand with its palm upwards. This latitude of motion would not only be useless to 
the Bats, but absolutely injurious, as the wing-membranes would not be able to beat the 
air with the steady strokes which are needful for maintaining flight. Therefore the 
arm is rendered incapable of rotation. 
Passing onwards from the arms to the hands, the finger-hones are strangely dispropor- 
tioned to the remainder of the body, the middle finger being considerably longer than the 
head and body together. The thumb is ve ry much short ter en any of the fingers, and 
furnished with a sharp and curved claw. By means of this claw, the Bat is enabled to 
proceed along a level surface, and to attach itself to any object that may be convenient. 
In some of the Bats the thumb is much longer than that which is here figured. 
The bones of the breast and the neighbouring parts are also formed in a peculiar 
manner, being intended to support the broad surface of the wing-membrane, and to enable 
SKELETON OF VAMPIRE BAT, 
it to beat the air with sufficient force. The collar-bones are long, considerably arched, 
and strongly jointed to the breast-bone and the shoulder-blades. In the insect-eating 
Bats, these bones are more developed than in the fruit-eaters; probably because the 
former teed a better r apparatus for the capture of their quick-winged prey, than the latter 
for seeking their vegetable food. Some species of Bat present a collar-bone which is half 
the length of the elong ated upper arm. 
The. breast-bone is very long, and is widely expanded so as to form a strong point of 
attachment for the two collar-bones. There is also a bony crest running down its centre, 
which serves as a support for the enormous breast-muscles that work the wings. The 
ribs are long and well rounded, and, indeed, seem to be much greater in proportionate 
length than those of any other mammal. 
The lower portions of the body and limbs are singularly small in proportion to the 
upper limbs. The legs are short and slender, and so arranged that the feet are rather 
turned outward, for the purpose of using their sharp claws freely. A kind of slender and 
spur-like bone is seen to proceed from the heel of each foot. When the skeleton is 
clothed with its softer textures, these curious bones run between the double membrane 
that joins the legs to the tail, and reach nearly half-way to the latter member. The 
re 
