THE BAT’S WINGS
“Wings, real wings, perfectly adapted to flying, are the bat’s most
striking feature. How can a mammal, an animal whose general structure
is that of a dog or a cat for example, possess the flying-apparatus of
a bird? How can two organs so entirely different be combined? In the
bat’s wing, my children, we find an admirable example of the infinite
resources at the command of the Creator, who, without adding to or
subtracting from the fundamental plan, has adapted the same organs to
the most widely different functions. The fore feet of mammals—of the
dog, or the cat we will say—are changed into wings in the bat without
the addition or the loss of a single part in this incredible
transformation. More than that, the human arms, our arms, children—are
there represented, piece by piece, bone by bone. You all look at me as
if you did not believe it, unable to understand how there can be
anything in common between our arms and a bat’s wings.”
“The fact is,” Jules confessed, “it takes all my faith in your words to
make me admit that there can be the least likeness between a man’s arm
and a bat’s wing.”
“I do not propose to make you admit it because of your faith in me; I
propose to prove it to you. Follow along your arm so as to grasp the
demonstration better.
“From the shoulder to the elbow the framework of the human arm consists
of a bone known as the humerus. From the elbow to the wrist there are
two bones of unequal size running side by side the whole length. The
larger is the cubitus, the smaller the radius. Then comes the wrist,
composed of several little bones which I will not now describe. Next is
the palm of the hand, its framework formed of a row of five bones
almost alike and each serving to support a finger. Finally, each finger
contains a succession of small bones called phalanges, of which the
thumb has two, and all the others three each. I will add that two bones
serve to attach the arm to the body. One is the shoulder-blade, a broad
triangular bone situated on the back behind the shoulder; the other is
the collar bone, slender and curved, situated in front and extending
from the shoulder to the base of the neck. Those are the collar-bones
that you can feel with your hand at the right and left above the
breast.”
While thus enumerating the parts of the arm, Uncle Paul guided the hand
of each listener and made it feel the several bones as they were named.
Emile had some difficulty with the learned terms “humerus” and
“cubitus,” which he now heard for the first time; nevertheless, by
paying close attention he found that he could easily remember them.
When the boys had all learned the name and the position of each bone in
the human arm, their uncle continued:
“Now examine with me this picture of a bat’s skeleton. The bone marked
o is the shoulder-blade. As with us, it forms the back of the shoulder,
and it is triangular, wide, and flat.”
“Then the part marked cl is the shoulder, and the bone that goes from
there to the base of the neck is the collar-bone?” queried Emile.
“Precisely.”
“I see how the rest goes,” Louis hastened to interpose. “The bone
marked h is the humerus, and the elbow is at the angle made by this
bone with the next.”
“My turn now,” put in Jules. “The two bones running side by side from
the elbow to the wrist are marked cu and r. The first is the cubitus,
the other the radius. Consequently ca is the wrist. But there I get
lost.”
“The wrist, I told you,” explained Uncle Paul, “is composed of several
small bones. That structure we find at ca, the bat’s wrist.”
“But, then, the hand?” queried Jules.
“The palm of the hand and the five fingers which it supports are
represented by the ribs of the wing and by po, which is the thumb. This
is the shortest of the five fingers, as with man. It forms no part of
the framework of the wing, but is free and is furnished with a hooked
nail which the animal uses to cling by and also in walking. Finally,
this thumb has two phalanges, as in the human thumb, and at the base is
a small bone which in man forms a part of the palm of the hand. So much
for the thumb.
“Now let us look at those four long bones that start from the wrist
(ca) and spread out through the greater part of the wing. Together with
the similar but shorter bone of the thumb they represent the series of
five bones composing the framework of the human palm. Next come the
fingers with their phalanges (ph). In short, except for a few slight
differences, the bat’s wing reproduces, piece by piece, the structure
of the human arm.”
“Yes,” Jules admitted, “it’s all there, even to the small bones of the
wrist and fingers. Is it possible that a poor bat can pattern after us
so closely? The horrid creature copies our arms to make itself wings.”
“Your pride need not suffer from this close resemblance, which you will
find in different degrees in a multitude of other animals, especially
among the mammals, our next of kin in bodily structure. In the
formation of his body man enjoys no monopoly; the dog, the cat, the
donkey, the ox—each and all of them—share with us a common stock of
organs, modified in details and suited to the kind of life of each
species. We recognize in the bat’s wings the fundamental plan of our
arms; we see it also no less plainly in the fore legs of the cat, the
dog, and many other animals, and we can trace a rude resemblance to our
hand even in the donkey’s homely hoof. I tell you these things, my
children, not to lessen in your eyes the undeniable superiority of man,
but to inspire in you a fellow feeling for animals that are formed like
us, suffer as we do, and are far too often the victims of our stupid
cruelty. Whoever needlessly causes an animal to suffer commits a
barbarous act, an inhuman act, inasmuch as he inflicts torture on flesh
like our own; he brutally misuses a body having the same mechanism as
our own and the same power of suffering. As to our superiority, it is
established preëminently by an exceptional characteristic that places
us above all comparison even with creatures that in their physical
structure most closely resemble us. This characteristic is reason, the
torch that lights us in our search for truth; it is the human soul,
which alone knows itself and enjoys the sublime privilege of knowing
its divine Author.
“In bats four of the five bones similar to those of our palm are
greatly elongated, as are also the corresponding fingers, and they
together constitute the four ribs on which is stretched the membrane of
the wing, just as silk is stretched on the ribs of an umbrella. Thus it
is at the sacrifice of what might have been a hand that the wing is
formed. Therefore the scientists call all mammals of like structure
with the bat ‘chiropters,’ meaning hand-winged creatures, from two
Greek words signifying hand and wing.
“Of the five fingers one only, the thumb, is left free in the bat, and
it is very small. It is furnished, as I said before, with a nail or
claw. The four others, destitute of nails, are lengthened to serve as
supports to the membrane of the wing. This membrane is a fold of the
skin which starts from the shoulder, stretches between the four long
fingers of the hand, and then attaches itself to the hind leg, the toes
of which are all furnished with hooked nails or claws and do not depart
from the ordinary shape of such members. By virtue of the free thumb
already described the wings are able to serve as feet in walking, when
these members are folded close to the animal’s sides. The bat grips the
ground by thrusting in first the right claw and then the left, and
pushes itself forward with its hind feet in laborious and awkward
leaps. Thus it gets over the ground at what might be called a fast
pace, but is soon tired out with the exertion; hence it does not walk
except when sure it will not be molested or when it is compelled to do
so by its position on a level surface where it cannot launch itself
into the air. Then as soon as possible it gains an elevated point, from
which it flies off. For in order to unfold the hampering membranes that
serve as wings and to throw itself into the air, the bat needs
considerable free space, which it cannot get except by hurling itself
from a height. Consequently, in the caves inhabited by bats they never
fail to secure an unimpeded drop. With the hooked talons of a hind foot
they cling to the roof, head downward. That is the way they rest, the
way they sleep. At the slightest alarm the claw lets go, the wings
spread, and the animal is off.”
“What a queer way to sleep,” Emile exclaimed, “hanging from the roof by
one foot, head downward! And do they stay that way long without getting
tired?”
“If necessary, a good half of the year.”
When he went to bed that night Emile thought again of the bat’s way of
sleeping; but he preferred his own.