History of Animals
All animals have a part analogous to the chest in man, but not
similar to his; for the chest in man is broad, but that of all other
animals is narrow. Moreover, no other animal but man has breasts in
front; the elephant, certainly, has two breasts, not however in the
chest, but near it.
Moreover, also, animals have the flexions of their fore and
hind limbs in directions opposite to one another, and in directions
the reverse of those observed in the arms and legs of man; with the
exception of the elephant. In other words, with the viviparous
quadrupeds the front legs bend forwards and the hind ones backwards,
and the concavities of the two pairs of limbs thus face one another.
The elephant does not sleep standing, as some were wont to
assert, but it bends its legs and settles down; only that in
consequence of its weight it cannot bend its leg on both sides
simultaneously, but falls into a recumbent position on one side or the
other, and in this position it goes to sleep. And it bends its hind
legs just as a man bends his legs.
In the case of the ovipara, as the crocodile and the lizard and
the like, both pairs of legs, fore and hind, bend forwards, with a
slight swerve on one side. The flexion is similar in the case of the
multipeds; only that the legs in between the extreme ends always
move in a manner intermediate between that of those in front and those
behind, and accordingly bend sideways rather than backwards or
forwards. But man bends his arms and his legs towards the same
point, and therefore in opposite ways: that is to say, he bends his
arms backwards, with just a slight inclination inwards, and his legs
frontwards. No animal bends both its fore-limbs and hind-limbs
backwards; but in the case of all animals the flexion of the shoulders
is in the opposite direction to that of the elbows or the joints of
the forelegs, and the flexure in the hips to that of the knees of
the hind-legs: so that since man differs from other animals in
flexion, those animals that possess such parts as these move them
contrariwise to man.
Birds have the flexions of their limbs like those of the
quadrupeds; for, although bipeds, they bend their legs backwards,
and instead of arms or front legs have wings which bend frontwards.
The seal is a kind of imperfect or crippled quadruped; for just
behind the shoulder-blade its front feet are placed, resembling hands,
like the front paws of the bear; for they are furnished with five
toes, and each of the toes has three flexions and a nail of
inconsiderable size. The hind feet are also furnished with five
toes; in their flexions and nails they resemble the front feet, and in
shape they resemble a fish's tail.
The movements of animals, quadruped and multiped, are crosswise,
or in diagonals, and their equilibrium in standing posture is
maintained crosswise; and it is always the limb on the right-hand side
that is the first to move. The lion, however, and the two species of
camels, both the Bactrian and the Arabian, progress by an amble; and
the action so called is when the animal never overpasses the right
with the left, but always follows close upon it.
Whatever parts men have in front, these parts quadrupeds have
below, in or on the belly; and whatever parts men have behind, these
parts quadrupeds have above on their backs. Most quadrupeds have a
tail; for even the seal has a tiny one resembling that of the stag.
Regarding the tails of the pithecoids we must give their distinctive
properties by and by animal
All viviparous quadrupeds are hair-coated, whereas man has only a
few short hairs excepting on the head, but, so far as the head is
concerned, he is hairier than any other animal. Further, of
hair-coated animals, the back is hairier than the belly, which
latter is either comparatively void of hair or smooth and void of hair
altogether. With man the reverse is the case.
Man also has upper and lower eyelashes, and hair under the
armpits and on the pubes. No other animal has hair in either of