History of Animals
(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
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
in either air or water, as, for instance, the sea-nettle and the
oyster. And of creatures that live in the water some live in the
sea, some in rivers, some in lakes, and some in marshes, as the frog
and the newt.
Of animals that live on dry land some take in air and emit it,
which phenomena are termed 'inhalation' and 'exhalation'; as, for
instance, man and all such land animals as are furnished with lungs.
Others, again, do not inhale air, yet live and find their sustenance
on dry land; as, for instance, the wasp, the bee, and all other
insects. And by 'insects' I mean such creatures as have nicks or
notches on their bodies, either on their bellies or on both backs
And of land animals many, as has been said, derive their
subsistence from the water; but of creatures that live in and inhale
water not a single one derives its subsistence from dry land.
Some animals at first live in water, and by and by change their
shape and live out of water, as is the case with river worms, for
out of these the gadfly develops.
Furthermore, some animals are stationary, and some are erratic.
Stationary animals are found in water, but no such creature is found
on dry land. In the water are many creatures that live in close
adhesion to an external object, as is the case with several kinds of
oyster. And, by the way, the sponge appears to be endowed with a
certain sensibility: as a proof of which it is alleged that the
difficulty in detaching it from its moorings is increased if the
movement to detach it be not covertly applied.
Other creatures adhere at one time to an object and detach
themselves from it at other times, as is the case with a species of
the so-called sea-nettle; for some of these creatures seek their
food in the night-time loose and unattached.
Many creatures are unattached but motionless, as is the case with
oysters and the so-called holothuria. Some can swim, as, for instance,
fishes, molluscs, and crustaceans, such as the crawfish. But some of
these last move by walking, as the crab, for it is the nature of the
creature, though it lives in water, to move by walking.
Of land animals some are furnished with wings, such as birds
and bees, and these are so furnished in different ways one from
another; others are furnished with feet. Of the animals that are
furnished with feet some walk, some creep, and some wriggle. But no
creature is able only to move by flying, as the fish is able only to
swim, for the animals with leathern wings can walk; the bat has feet
and the seal has imperfect feet.
Some birds have feet of little power, and are therefore called
Apodes. This little bird is powerful on the wing; and, as a rule,