106 THE VAMPIRE BAT. 



On reference to the figure of the Vampire Bat, it will be seen that the wide and flattened 

 membrane which supports the body in the air, connects together the whole of the limbs and 

 the tail, leaving free only the hinder feet, and the thumbs of the fore-paws. This membrane 

 is wondrously delicate, and is furnished not only with the minute blood-vessels, to which allu- 

 sion has already been made, but with a system of nerves which possess the most exquisite 

 power of sensation. 



It has been long known that bats are able to thread their way among boughs of trees and 

 other impediments with an ease that almost seems beyond the power of sight, especially when 

 the dark hours of their flight are considered. Even utter darkness seems not to impede these 

 curious animals in their aerial progress, and when shut up in a darkened place, in which 

 strings had been stretched in various directions, the bats still pursued their coiirse through 

 the air, avoiding every obstacle with perfect precision. In order to ascertain beyond doubt 

 whether this faculty were the result of a more than usually keen sight, or whether it were 

 caused by some hitherto unknown structure, Spallanzani deprived a bat of its eyes, and dis- 

 covered by this most cruel experiment, that the bat seemed as capable of directing its flight 

 among the strings without its eyes as with them. 



Whether this curious power were resident in any part of the animal's structure, or whether 

 it were the result of a sixth and unknown sense, was long an enigma to naturalists. The diffi- 

 culty, however, seems to have been solved by the investigations which have been made into 

 the formation of the bat's wing, and it is now universally allowed, that to the exquisite 

 nervous system of its wings the bat is indebted for the above-mentioned faculty. 



The Vampires are said to unite in themselves the progressive power of quadrupeds and 

 birds, and to run on the ground as swiftly as rats, while they fly through the air as easily as 

 any bird. But this accomplishment of running is by no means general among the bats, whose 

 mode of progress is awkward in the extreme, and when the animal is hurried or alarmed, 

 positively ludicrous. 



Bats are in general very much averse to the ground, and never, unless under compulsion, 

 place themselves on a level surface. Their mode of walking is grotesque and awkward in the 

 extreme ; and the arduous task of proceeding along the ground is achieved with such diffi- 

 culty, that it seems almost to be painful to the animal which is condemned for the time to 

 exchange its easy aerial course for the tardy and uncongenial crawl to which its earthly prog- 

 ress is limited. Quadrupedal in its form, although that form may be strangely modified, the 

 bat will occasionally assume quadrupedal action, and walk on the ground by the aid of all its 

 four feet. The method of advancing is as follows : 



The bat thrusts forward one of the fore-legs or " wings," and either hooks the claw at its 

 extremity over any convenient projection, or buries it in the ground. By means of this hold, 

 which it thus gains, the animal draws itself forward, raises its body partly off the earth, and 

 advances the hind leg, making at the same time a kind of tumble forward. The process is 

 then repeated on the opposite side, and thus the creature proceeds in a strange and unearthly 

 fashion, tumbling and staggering along as if its brain were reeling from the effects of disease. 

 It steers a very deviating course, falling first to one side and then to the other, as it employs 

 the limbs of either side. 



None of the bats like to raise themselves into the air from a perfectly level surface, and 

 therefore use all their endeavours to climb up some elevated spot, from whence they may 

 launch themselves into the air. 



They climb with great ease and rapidity, being able to hitch their sharp and curved claws 

 Into the least roughness that may present itself, and can thus ascend a perpendicular wall 

 with perfect ease and security. In so doing they crawl backwards, raising their bodies against 

 the tree or wall which they desire to scale, and drawing themselves up by the alternate use 

 of the hinder feet. When they have attained a moderate height they are able to fling them- 

 selves easily into the air, and to take to immediate flight. They have the power of rising at 

 once from the ground, but always prefer to let themselves fall from some elevated spot. 



The reason is now evident why the bats take their repose in the singular attitude which 

 has been already mentioned. When suspended by their hind feet, they are in the most favor- 



