or supporters, bodies covered with concave
scales, gills to supply the place of lungs for respiration, and water
for the natural element of their existence. Had mankind no other
knowledge of animals than of such as inhabit the land and breathe their
own atmosphere, they would listen with incredulous wonder, if told that
there were other kinds of beings which existed only in the waters, and
which would die almost as soon as they were taken from them. However
strongly these facts might be attested, they would hardly believe them,
without the operation of their own senses, as they would recollect the
effect produced on their own bodies when immersed in water, and the
impossibility of their sustaining life in it for any lengthened period
of time. Experience, however, has taught them, that the "great deep" is
crowded with inhabitants of various sizes, and of vastly different
constructions, with modes of life entirely distinct from those which
belong to the animals of the land, and with peculiarities of design,
equally wonderful with those of any other works which have come from the
hand of the Creator. The history of these races, however, must remain
for ever, more or less, in a state of darkness, since the depths in
which they live, are beyond the power of human exploration, and since
the illimitable expansion of their domain places them almost entirely
out of the reach of human accessibility.

200. IN STUDYING THE CONFORMATION OF FISHES, we naturally conclude that
they are, in every respect, well adapted to the element in which they
have their existence. Their shape has a striking resemblance to the
lower part of a ship; and there is no doubt that the form of the fish
originally suggested the form of the ship. The body is in general
slender, gradually diminishing towards each of its extremities, and
flattened on each of its sides. This is precisely the form of the lower
part of the hull of a ship; and it enables both the animal and the
vessel, with comparative ease, to penetrate and divide the resisting
medium for which they have been adapted. The velocity of a ship,
however, in sailing before the wind, is by no means to be compared to
that of a fish. It is well known that the largest fishes will, with the
greatest ease, overtake a ship in full sail, play round it without
effort, and shoot ahead of it at pleasure. This arises from their great
flexibility, which, to compete with mocks the labours of art, and
enables them to