350 BC

                               HISTORY OF ANIMALS

                                  by Aristotle

                    translated by D'Arcy Wentworth Thompson

                                 Book I

                                   1

    OF the parts of animals some are simple: to wit, all such as
divide into parts uniform with themselves, as flesh into flesh; others
are composite, such as divide into parts not uniform with
themselves, as, for instance, the hand does not divide into hands
nor the face into faces.

    And of such as these, some are called not parts merely, but limbs
or members. Such are those parts that, while entire in themselves,
have within themselves other diverse parts: as for instance, the head,
foot, hand, the arm as a whole, the chest; for these are all in
themselves entire parts, and there are other diverse parts belonging
to them.

    All those parts that do not subdivide into parts uniform with
themselves are composed of parts that do so subdivide, for instance,
hand is composed of flesh, sinews, and bones. Of animals, some
resemble one another in all their parts, while others have parts
wherein they differ. Sometimes the parts are identical in form or
species, as, for instance, one man's nose or eye resembles another
man's nose or eye, flesh flesh, and bone bone; and in like manner with
a horse, and with all other animals which we reckon to be of one and
the same species: for as the whole is to the whole, so each to each
are the parts severally. In other cases the parts are identical,
save only for a difference in the way of excess or defect, as is the
case in such animals as are of one and the same genus. By 'genus' I
mean, for instance, Bird or Fish, for each of these is subject to
difference in respect of its genus, and there are many species of
fishes and of birds.

    Within the limits of genera, most of the parts as a rule
exhibit differences through contrast of the property or accident, such
as colour and shape, to which they are subject: in that some are
more and some in a less degree the subject of the same property or
accident; and also in the way of multitude or fewness, magnitude or
parvitude, in short in the way of excess or defect. Thus in some the
texture of the flesh is soft, in others firm; some have a long bill,
others a short one; some have abundance of feathers, others have
only a small quantity. It happens further that some have parts that
others have not: for instance, some have spurs and others not, some
have crests and others not; but as a general rule, most parts and
those that go to make up the bulk of the body are either identical
with one another, or differ from one another in the way of contrast
and of excess and defect. For 'the more' and 'the less' may be
represented as 'excess' or 'defect'.

    Once again, we may have to do with animals whose parts are
neither identical in form nor yet identical save for differences in
the way of excess or defect: but they are the same only in the way
of analogy, as, for instance, bone is only analogous to fish-bone,
nail to hoof, hand to claw, and scale to feather; for what the feather
is in a bird, the scale is in a fish.

    The parts, then, which animals severally possess are diverse
from, or identical with, one another in the fashion above described.
And they are so furthermore in the way of local disposition: for
many animals have identical organs that differ in position; for
instance, some have teats in the breast, others close to the thighs.

    Of the substances that are composed of parts uniform (or
homogeneous) with themselves, some are soft and moist, others are
dry and solid. The soft and moist are such either absolutely or so
long as they are in their natural conditions, as, for instance, blood,
serum, lard, suet, marrow, sperm, gall, milk in such as have it
flesh and the like; and also, in a different way, the superfluities,
as phlegm and the excretions of the belly and the bladder. The dry and
solid are such as sinew, skin, vein, hair, bone, gristle, nail, horn
(a term which as applied to the part involves an ambiguity, since
the whole also by virtue of its form is designated horn), and such
parts as present an analogy to these.

    Animals differ from one another in their modes of subsistence,
in their actions, in their habits, and in their parts. Concerning
these differences we shall first speak in broad and general terms, and
subsequently we shall treat of the same with close reference to each
particular genus.

    Differences are manifested in modes of subsistence, in habits, in
actions performed. For instance, some animals live in water and others
on land. And of those that live in water some do so in one way, and
some in another: that is to say, some live and feed in the water, take
in and emit water, and cannot live if deprived of water, as is the
case with the great majority of fishes; others get their food and
spend their days in the water, but do not take in water but air, nor
do they bring forth in the water. Many of these creatures are
furnished with feet, as the otter, the beaver, and the crocodile; some
are furnished with wings, as the diver and the grebe; some are
destitute of feet, as the water-snake. Some creatures get their living
in the water and cannot exist outside it: but for all that do not take