118 THE VAMPIRE BAT. 
especially when the dark hours of their flight are considered. Even utter darkness seems 
not to impede these curious animals in their aérial progress, and when shut up in a 
darkened place, in which strings had been stretched in various directions, the bats still 
pursued their course 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 discovered 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 difficulty, 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 difliculty, that it seems almost to be painful to the animal which is condemned for the 
time to exchange its easy aérial course for the tardy and uncongenial crawl to which its 
earthly progress is hmited. 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 themselves 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 favourable position for taking to the air, and when they desire to fly need only to 
spread their wings, and loosing their foothold, to launch themselves into the air. 
There may be, and probably are, other reasons for the curious reversed attitude, but 
that which has already been given accounts in some measure for it. Even among the 
birds examples are found of a similar mode of repose; members of the genus Colius, an 
African group of birds, sleep suspended like the bats, clinging with their feet, and hanging 
with their heads downwards. But these birds cannot assume this attitude for the purpose 
of taking to flight, as their wings are used as readily as those of most other feathered 
