of America, but some American Bats feed chiefly upon fruits, while
many of the large essentially insectivorous species which occur there
vary their diet more or less with fruits, and also occasionally attack
and devour other vertebrate animals. Some of them--but it is still
very doubtful how many--have another habit connected with their
feeding, which renders them very decidedly objectionable, namely, that
of inflicting wounds upon birds and mammals, even including man
himself, and sucking up the blood that flows from them. This charge
has been brought against many Bats of South and Central America,
some of which have been commonly named Vampires in consequence, after
the ghostly blood-suckers, which were formerly the objects of so much
superstitious terror in Hungary and other parts of Eastern Europe; but
so far as can be made out from a consideration of the evidence, a
verdict of "not proven," at all events, must be arrived at in the case
of all but two species, which constitute a little group distinguished
by what is apparently a special organization adapting them to this
peculiar diet. These wretched little beasts, which only measure two
and a half or three inches in length, are furnished in the upper jaw
with a single pair of incisor or front teeth, but these are of great
size and strength, triangular in form, and so excessively sharp that
when the creatures are seized they can draw blood from the hand of
their captor by what seems a mere touch. This extreme sharpness of
their weapons enables them, when attacking sleeping men or animals, to
slice off a small portion of skin almost without causing any pain, and
the little oval wounds thus produced, like the similar surface-cuts
which a careless shaver sometimes inflicts upon his chin, bleed with
particular freedom. The Desmodonts, as these true Vampires are called,
will attack horses, mules, and cattle, which they generally wound on
the back, near the spine, often in the region of the withers; and they
also bite the combs of domestic fowls, and any part of the human body
that they can get at. In the case of man, however, according to most
authorities, the extremity of the great toe is the favorite part; and
some writers, perhaps possessed of a strong poetical vein, have given
wonderful descriptions of the artfulness with which these little
blood-suckers make their approaches, and keep their victim comfortably
asleep during the operation by fanning him with their wings. In fact,
the Vampire Bats had so bad a reputation from the accounts given by
travellers, that they seemed to be veritable scourges of the countries
in which they live, but so far as can be made out from the most
trustworthy reports, the mischief they cause may be summed up under
two heads, namely, weakness produced by loss of blood, which continues
to flow from the wounds long after the Bats have drunk their fill and
gone quietly home to rest, and inflammatory affections, caused either
by the irritation of the bite in the case of people of a bad habit of
body, or by the friction of the saddle or collar upon the part bitten
in the case of horses and mules, or of the shoe in the human patient.
That the Desmodonts do really feed on blood is proved by evidence of
various kinds. They have been captured in the act of blood-sucking,
when their stomachs, which are peculiarly constructed and very long,
are found filled with a black paste, which is evidently half-digested
blood; and their teeth, which are in part so well adapted for
producing the necessary wounds in other animals, are totally unfit for
the mastication of an insect prey, such as constitutes the diet of
their nearest allies.
[Illustration: THE VAMPIRE BAT.]
After all this feeding, Bats, whatever the nature of their diet, not
unnaturally find themselves inclined for repose, and as they are
active during the night or in the twilight, of course their rest has
to be taken in the daytime. To pass the period of repose in security
they seek shelter of various kinds, not only for protection against
the weather, but also for the sake of concealment from other
predaceous animals, some of which would no doubt be perfectly willing
to make a meal of them. The great Eastern Fruit Bats, trusting perhaps
to their size and strength, are content to resort to the branches of
trees, from which, after the manner of Bats in general, they suspend
themselves by the hind feet with the head downwards. From the
statements of various writers it appears that after being out all
night in search of food, the Flying Foxes and other allied Bats fly
back to their regular resting-places, where they begin to arrive about
or soon after dawn. The number resorting to the same retreat is
usually so great that the whole of the branches are loaded with them,
and in fact they are so crowded together that the settling down of the
flock into their repose is preceded by a scene of squabbling and
quarrelling of the most noisy description. Mr. Tickell, speaking of
the common Indian Flying Fox, says:--"From the arrival of the first
comer, until the sun is high above the horizon, a scene of incessant
wrangling and contention is enacted among them, as each endeavors to
secure a higher and better place, or to eject a neighbor from too
close vicinage. In these struggles the Bats hook themselves along the
branches, scrambling about hand over hand with some speed, biting each
other severely, striking out with the long claw of the thumb,
shrieking and cackling without intermission. Each new arrival is
compelled to fly several times round the tree, being threatened from
all points; and when he eventually hooks on, he has to go through a
series of combats, and be probably ejected two or three times, before
he makes good his tenure." This scene of selfish contention over, the
Fruit Bats pass some hours in profound sleep, during which they remain
suspended in rows along the branches, to which they cling by one foot
only, the other with all the lower surface of the body being
comfortably wrapped in the leathery mantle formed by the contracted
wings. In this condition, as Dr. Horsfield says of the Great Kalong,
"ranged in succession with the head downwards ... and often in close
contact, they have little resemblance to living beings, and by a
person not accustomed to their economy are easily mistaken for a part
of the tree, or for a fruit of uncommon size suspended from its
branches." In this position the head is folded down upon the breast.
Dr. Bennett and Mr. Gould ascribed very similar habits to a large
Fruit Bat common in the northern parts of New South Wales and in
Queensland, which is said to be often exceedingly destructive to the
peach and other fruit crops of the settlers in those colonies.
The European Bats, and indeed all the Bats except these Flying Foxes
and their immediate allies, seek a different kind of shelter. Their
chief natural dormitories consist of hollow trees and the caves and
fissures of rocks, to which they often resort in great numbers; but in
populous countries they also find an abundance of convenient places of
retirement in and about buildings of various kinds. Roofs, especially
when covered with tiles, or otherwise provided with apertures through
which the space immediately under the roofing is easily accessible,
outbuildings of all kinds, church towers and other similar structures,
disused chimneys, the spaces behind weather-boards and shutters which
are not often moved, in fact any dark and sheltered places about our
buildings, are readily resorted to by many species, although some few
retain their taste for unadulterated nature so strongly that no
artificial harbor will serve their turn. Thus among the British
species the Great Bat or Noctule, a generally distributed though not
abundant species throughout the southern and middle counties of
England, seems generally to retreat for its diurnal sleep to the holes
or cavities in the trunks of trees, and only to visit buildings when
there is a scarcity of such accommodation; and the Horseshoe Bats show
a decided preference for caverns and deserted quarries; but the great
majority appear to be indifferent in the matter, and to resort to any
shelter that seems convenient to them. Some, such as the Barbastelle
of the southern parts of England, are solitary in their habits,
generally retiring alone for their day's rest; others are more
sociable, reposing in larger or smaller parties in their dormitories,
whether natural or artificial, and sometimes, like the Fruit Bats,
collecting in immense numbers.
The common Bats, like the Fruit Bats, sleep in what we should consider
an exceedingly uncomfortable position, namely, with their heads
downwards, but they cling by the claws of _both_ hind feet to the
small irregularities of the stone or wood forming the walls and other
parts of the structure of their retreat. They frequent the same places
year after year, so that, where they are numerous, the ground is often
completely covered and discolored with their excrements, which in some
cases accumulate in course of time to such an amount as to have given
rise to the notion of carrying it away to be used as guano. The little
blood-sucking Vampire Bats already mentioned take up their abode in
caverns, and, according to Dr. Hensel, who observed their habits, they
discharge their excrements, which are black and pasty, near the
entrance of the cave just before starting on their evening flight, and
this substance by degrees forms quite a thick layer (one foot or more)
on the floor of the cavern. The Doctor says that a large dog which had
paid a visit of curiosity to one of these caves came out again looking
as if he had got long black boots on.
In the warmer regions of the earth's surface, where their supply of
food is constant, the activity of the Bats is not known to have any
intermission, but in cold and temperate countries they pass the winter
season in a state of torpidity. The period of this hibernation, as it
is called, varies somewhat in the different species, but few of them
are to be seen flying about, except when the weather is decidedly
mild. The commonest of all our British species, the Pipistrelle, has a
shorter winter sleep than any of its companions, it usually makes its
appearance on the wing by the middle of March, and continues active
until quite late in the year; in fact Mr. Gould has recorded the fact
of his having shot a specimen of it on a warm sunny day just before
Christmas. For the purpose of hibernation the Bats retire to their
usual resting-places, but frequently, instead of suspending themselves
by their hind feet, as when sleeping, pack themselves away in small
parties in holes and crevices, an arrangement which probably furnishes
a better protection against the inclemency of the season.
It is probably in the dormitory that the birth of the young bats takes
place--at least, so far as we know, the process is affected in a
manner which must preclude active exertions on the part of the mother
for some little time. The best account of the operation with which we
are acquainted is that given fifty years ago by Mr. George Daniell, in
a paper read before the Zooelogical Society, in which he described the
habits of some Noctules kept by him in captivity. Four out of five
died, and the survivor, a female, was observed on 23d June to become
very restless, and to continue so for about an hour, although still
suspended by the hind limbs in the attitude of repose. "Suddenly," to
use Mr. Daniell's words, "she reversed her position, and attached
herself by her anterior limbs to a cross wire of the cage, stretching
her hind limbs to their utmost extent, curving the tail upwards, and
expanding the interfemoral membrane, so as to form a perfect nestlike
cavity for the reception of the young ... which was born on its back,
perfectly destitute of hair, and blind. The mother then cleaned it,
turning it over in its nest; and afterwards, resuming her usual
position, placed the young in the membrane of her wing. She next
cleaned herself, and wrapped up the young one so closely as to prevent
any observation of the process of suckling. At the time of birth the
young was larger than a new-born mouse, and its hind legs and claws
were remarkably strong and serviceable, enabling it not only to cling
to its dam, but also to the deal sides of the cage. On the 24th the
animal took her food in the morning, and appeared very careful of her
young, shifting it from side to side to suckle it, and folding it in
the membranes of the tail and wings." Unfortunately, these
interesting observations were cut short by the death of the mother,
and the young animal, which was with some difficulty removed from the
nipple, survived only eight days, during which it was fed with milk
from a sponge, and made but little progress, its eyes being still
unopened, and its body almost hairless.
There can be no doubt that this process, varied in minor points in
accordance with differences of structure, reveals to us what takes
place in Bats generally in immediate connection with the birth of the
young. From all the observations that have been made it appears
certain that the female Bats produce only a single young one at a
birth; that this is at first blind, naked, and helpless; and that the
female nurses it carefully--a process which must be greatly
facilitated by the power of clinging to its parent possessed by the
young Bat from the first moment of its appearance in the world. The
two nipples possessed by the female are situated upon the breast,
sometimes quite at the sides under the arm-pits, a position which
renders it particularly easy for the careful mother to tend her
offspring, while she is also enabled to carry it about with her in her
evening flights, the young creature clinging firmly to its mother's
fur, and being quite out of the way of the movements of the wings.
This part of the business, of course, could not be exemplified in Mr.
Daniell's case, as the female was imprisoned in a cage, but it is a
well-known fact in the natural history of these creatures that the
mother does carry her young about with her so long as it continues
helpless. Apparently, indeed, even after the young animal becomes
capable of flying about, its mother still retains some interest in its
well-being--at least, if we may apply generally a case recorded by Dr.
Allen in his account of the Bats of North America. It relates to a
small species, the Red Bat, very common throughout the United States,
a young individual of which having been captured by a lad, "three
hours afterwards, in the evening, as he was conveying it to the museum
in his hand, while passing near the place where it was caught, the
mother made her appearance, and followed the boy for two squares,
flying around him, and finally alighted on his breast, such was her
anxiety to save her offspring. Both were brought to the museum, the
young one firmly adhering to its mother's teat. This faithful creature
lived two days in the museum, and then died of injuries received from
her captor. The young one being but half grown was still too young to
take care of itself, and died shortly after."
This little anecdote seems to set the moral character of the Bat in a
very favorable light, at any rate as regards the family affections,
and there is no doubt that the females of all the species of the group
show considerable fondness for their young. In other respects,
perhaps, they do not all shine quite so brilliantly, for, as we have
seen, the Fruit Bats squabble very selfishly for the most convenient
sleeping places, as indeed do other gregarious species of the order,
and some of the former quarrel and fight over their food. As regards
amiability of character, however, there is probably considerable
difference between different kinds of Bats; at any rate, in
confinement, they show much diversity of temper, some of them being
sullen, refusing food, and biting vigorously at their captors or the
bars of their prison, while others are easily tamed and soon become
familiar. Two of the commonest species, the Pipistrelle, and the
Long-eared Bat are among the latter. The Pipistrelle, which appears to
be abundant throughout Britain, and indeed in most of the northern
temperate regions of the eastern hemisphere, is a small reddish-brown
species, measuring little more than one inch and a half in length
without the tail, but with a spread of wing of more than eight inches.
Its regular food consists chiefly of gnats, midges, and other small
flies, in pursuit of which it often frequents the vicinity of water,
but it has a curious predilection for raw meat, and in search of this
it often makes its way into pantries, where the little thief will be
found clinging to a joint of meat, and feeding upon it with avidity.
This fondness for meat makes the Pipistrelle very easy to keep in
confinement, as it diminishes the necessity of finding it insect food,
and the little creature will in time become so tame as to take pieces
of meat from its owner's fingers. It is an active and lively little
creature, flying, running, and climbing about with great ease; in the
latter operation, according to Professor Bell, it makes use of the
extreme tip of the tail as if it was a finger.
The Long-eared Bat, so called from the great size of its ears, which
are nearly as long as the whole animal exclusive of the tail, has
perhaps a wider distribution than the Pipistrelle, but is hardly so
abundant in Britain. Its head and body measure nearly two inches long,
while its wings spread to about ten inches. This Bat generally sleeps
during the day under the roofs of houses and in church towers, and
when sleeping its long ears are carefully stowed away under the folded
wings, but the earlet or inner lobe of the ear still projects, so that
the creature appears to have a pair of short-pointed ears. The
Long-eared Bat flies very late in the evening, and indeed seems to
continue its activity throughout the night; its food appears to
consist to a great extent of the smaller moths, although other insects
are by no means disdained. This species also soon becomes very tame
and familiar; it will fly about the room, play with its fellows, and
come fearlessly to take its food from the hand. Professor Bell gives
an interesting account of one kept by Mr. James Sowerby, which, "when
at liberty in the parlor, would fly to the hand of any of the young
people who held up a fly toward it, and, pitching on the hand, take
the fly without hesitation. If the insect was held between the lips,
the Bat would then settle on its young patron's cheek, and take the
fly with great gentleness from the mouth; and so far was this
familiarity carried, that, when either of the young people made a
humming noise with the mouth, in imitation of an insect, the Bat would
search about the lips for the promised dainty." This habit of taking
its food when off the wing, would seem to be natural to the Long-eared
Bat under certain circumstances, as Mr. Tomes records his having seen
one feeding in this manner upon the myriads of small moths which
swarmed about a spindle tree in bloom.
[Illustration: LONG-EARED BAT.]
It is unnecessary to say that the creatures which display all this
activity and intelligence are well endowed with at least all the
senses possessed by the other animals of their class. The organs of
smell and hearing are well developed, and in many cases associated
with external membranous expansions of great size, as seen in the ears
of the Long-eared Bat; and the eyes, though generally of small size
except in the Fruit Bats, are bright and efficient, serving the
creatures in good stead in the rapid pursuit of their insect-prey,
which must be directed principally by sight. The common expression "as
blind as a Bat," must be taken to apply to Bats accidentally driven
from their retreats in the day-time, when it must be confessed that
they fly about in a dazed manner; but at night and in their dark
retreats they show no such imbecility of purpose, but find their way
with astonishing precision and certainty. In fact, instead of being
blind, the Bats must be especially sharp-sighted, if all their
evolutions be guided by the sense of sight, for in many cases they
habitually resort to the inmost recesses of caverns and other places
where, so far as our judgment goes, no light can possibly penetrate.
Hence it was long since suspected that some other sense than that of
sight must come to their aid when they plunge into such outer darkness
as prevails in some places through which they fly with the greatest
freedom, and more than a century ago numerous experiment were made by
a distinguished Italian naturalist, the Abbe Spallanzani, in order to
discover, if possible, what might be the secret of these curious
phenomena.
He set free, in a long passage which was bent at a right angle about
the middle of its length, a blinded Bat, which flew through the whole
of this passage, turning the corner correctly, without anywhere
touching the walls; while flying, too, it in some mysterious manner
detected a hole in the roof at a distance of eighteen inches, and
proceeded at once to ensconce itself in this shelter. In another
experiment the Abbe took two Bats, one blinded, the other not, and
placed them in a space shut off from a garden and roofed in with nets,
and with sixteen strings suspended from the top in different parts.
Both Bats flew about briskly and avoided the hanging strings equally
well, until at length the _blinded_ Bat discovered that the meshes of
the net were large enough for him to get through, when he at once made
his escape, and after flying about for a short time, went off directly
to the only roof in the vicinity, under which he disappeared. In
short, from these experiments it became perfectly clear that under
these circumstances the sense of sight was not of primary importance
in guiding the course of the Bat. Similar trials with the organs of
smell and hearing showed that they had nothing to do with it, and the
only other sense that could be appealed to was the general sense of
touch. Baron Cuvier, the great French comparative anatomist, was the
first to suggest, from the consideration of the results obtained by
the Abbe Spallanzani and others, especially by M. de Jurine, of
Geneva, that the peculiar phenomena in question might be accounted for
by the existence, especially in the great membranous expansions of the
wings, of a most delicate sensibility; and subsequent investigations
of the structure of those organs has tended to confirm this view, so
that it is now the one generally accepted. It is found that these
great membranes are traversed in all parts by numerous nerves, the
delicate terminations of which form little loops, exactly resembling
those which occur in our skin in those parts where the sense of touch
is most highly developed; and this resemblance is heightened by the
fact that the membrane is covered with rows of little points. Even the
organs of circulation in the wings are so constructed as to render it
almost certain that those organs have a quite exceptional sensibility.
Their ramifications are very numerous, and the veins as well as the
arteries have contractile walls, rendering the circulation of the
blood exceedingly active, the conditions, as Professor St. George
Mivart remarks, being almost those of a state of inflammation.
If these membranous expansions have the functions just ascribed to
them, we can easily understand that the larger they are the better,
and this will explain why the Bats generally exhibit so great a
tendency to run out into naked membranes. Thus although the ears, as
organs of hearing, have probably nothing to do with guiding the Bat
when flying in dark places, we find that in a great number of species
the external ears are exceedingly large and delicately membranous, of
which indeed we have an example in the British Long-eared Bat already
referred to. In like manner, while the nose, as a nose, may also be
left out of consideration, the development of membranous appendages of
the part of the face in which the nostrils open is one of the most
curious peculiarities of a vast number of Bats, in many of which these
singular nose-leaves almost rival the ears in size, while their
structure often renders them most grotesque. We have two Bats thus
adorned in Britain, namely, the Greater and the Lesser Horseshoe Bats,
but most of the leaf-nosed species are inhabitants of warmer regions,
and it is there that they run out into the most remarkable
eccentricities of structure. In Blainville's Bat, a small species
inhabiting South America and the West Indies, these expansions of the
skin of the face seem to have reached the utmost possible
grotesqueness, but the membranous leaves are larger and the ears much
more developed in many species allied to our own Horseshoe Bats,
especially such as the Megaderms. We can hardly imagine that these
great membranous expansions of the outer ears and the region of the
nose can have any other purpose than that of enlarging the surface of
highly sensitive skin specially adapted for the perception of external
impressions, and it is a remarkable fact, strictly in accordance with
this view, that, so far as we know, the Bats so endowed are more
decidedly nocturnal in their habits and frequent darker retreats than
their less gifted fellows. Thus our Long-eared Bat, as already stated,
continues active on the wing throughout the whole night, and the
Horseshoe Bats are distinguished as specially affecting dark caves.
HOW SNAKES EAT
(FROM SNAKES.)
BY CATHERINE C. HOPLEY.
[Illustration: HAMADRYAD SNAKE.]