And yet, for all this,

the dolphin has no organ of hearing discernible. Furthermore, when
engaged in their craft, fishermen are particularly careful to make
no noise with oar or net; and after they have spied a shoal, they
let down their nets at a spot so far off that they count upon no noise
being likely to reach the shoal, occasioned either by oar or by the
surging of their boats through the water; and the crews are strictly
enjoined to preserve silence until the shoal has been surrounded. And,
at times, when they want the fish to crowd together, they adopt the
stratagem of the dolphin-hunter; in other words they clatter stones
together, that the fish may, in their fright, gather close into one
spot, and so they envelop them within their nets.

There is no doubt

but that fishes have the sense of taste, for a
great number of them delight in special flavours; and fishes freely
take the hook if it be baited with a piece of flesh from a tunny or
from any fat fish, obviously enjoying the taste and the eating of food
of this kind. Fishes have no visible organs for hearing or for
smell; for what might appear to indicate an organ for smell in the
region of the nostril has no communication with the brain. These
indications, in fact, in some cases lead nowhere, like blind alleys,
and in other cases lead only to the gills; but for all this fishes
undoubtedly hear and smell. For they are observed to run away from any
loud noise, such as would be made by the rowing of a galley, so as
to become easy of capture in their holes; for, by the way, though a
sound be very slight in the open air, it has a loud and alarming
resonance to creatures that hear under water. And this is shown in the
capture of the dolphin; for when the hunters have enclosed a shoal
of these fishes with a ring of their canoes, they set up from inside
the canoes a loud splashing in the water, and by so doing induce the
creatures to run in a shoal high and dry up on the beach, and so
capture them while stupefied with the noise.

In some animals

the organs of sense are plainly discernible; and
this is especially the case with the eyes. For animals have a
special locality for the eyes, and also a special locality for
hearing: that is to say, some animals have ears, while others have the
passage for sound discernible. It is the same with the sense of smell;
that is to say, some animals have nostrils, and others have only the
passages for smell, such as birds. It is the same also with the
organ of taste, the tongue. Of aquatic red-blooded animals, fishes
possess the organ of taste, namely the tongue, but it is in an
imperfect and amorphous form, in other words it is osseous and
undetached. In some fish the palate is fleshy, as in the fresh-water
carp, so that by an inattentive observer it might be mistaken for a
tongue.

We now proceed to treat of the senses

for there are diversities
in animals with regard to the senses, seeing that some animals have
the use of all the senses, and others the use of a limited number of
them. The total number of the senses (for we have no experience of any
special sense not here included), is five: sight, hearing, smell,
taste, and touch.

Man, then, and all vivipara that have feet, and, further, all
red-blooded ovipara, appear to have the use of all the five senses,
except where some isolated species has been subjected to mutilation,
as in the case of the mole. For this animal is deprived of sight; it
has no eyes visible, but if the skin-a thick one, by the way-be
stripped off the head, about the place in the exterior where eyes
usually are, the eyes are found inside in a stunted condition,
furnished with all the parts found in ordinary eyes; that is to say,
we find there the black rim, and the fatty part surrounding it; but
all these parts are smaller than the same parts in ordinary visible
eyes. There is no external sign of the existence of these organs in
the mole, owing to the thickness of the skin drawn over them, so
that it would seem that the natural course of development were
congenitally arrested; (for extending from the brain at its junction
with the marrow are two strong sinewy ducts running past the sockets
of the eyes, and terminating at the upper eye-teeth). All the other
animals of the kinds above mentioned have a perception of colour and
of sound, and the senses of smell and taste; the fifth sense, that,
namely, of touch, is common to all animals whatsoever.

Furthermore,

there are some strange creatures to be found in the
sea, which from their rarity we are unable to classify. Experienced
fishermen affirm, some that they have at times seen in the sea animals
like sticks, black, rounded, and of the same thickness throughout;
others that they have seen creatures resembling shields, red in
colour, and furnished with fins packed close together; and others that
they have seen creatures resembling the male organ in shape and
size, with a pair of fins in the place of the testicles, and they aver
that on one occasion a creature of this description was brought up
on the end of a nightline.

So much then for the parts, external and internal, exceptional and
common, of all animals.

The tettix or cicada,

alone of such creatures (and, in fact, alone
of all creatures), is unprovided with a mouth, but it is provided with
the tongue-like formation found in insects furnished with frontward
stings; and this formation in the cicada is long, continuous, and
devoid of any split; and by the aid of this the creature feeds on dew,
and on dew only, and in its stomach no excretion is ever found. Of the
cicada there are several kinds, and they differ from one another in
relative magnitude, and in this respect that the achetes or chirper is
provided with a cleft or aperture under the hypozoma and has in it a
membrane quite discernible, whilst the membrane is indiscernible in
the tettigonia.

Again,

some insects have antennae in front of their eyes, as the
butterfly and the horned beetle. Such of them as have the power of
jumping have the hinder legs the longer; and these long hind-legs
whereby they jump bend backwards like the hind-legs of quadrupeds. All
insects have the belly different from the back; as, in fact, is the
case with all animals. The flesh of an insect's body is neither
shell-like nor is it like the internal substance of shell-covered
animals, nor is it like flesh in the ordinary sense of the term; but
it is a something intermediate in quality. Wherefore they have nor
spine, nor bone, nor sepia-bone, nor enveloping shell; but their
body by its hardness is its own protection and requires no
extraneous support. However, insects have a skin; but the skin is
exceedingly thin. These and such-like are the external organs of
insects.

Internally, next after the mouth, comes a gut, in the majority
of cases straight and simple down to the outlet of the residuum: but
in a few cases the gut is coiled. No insect is provided with any
viscera, or is supplied with fat; and these statements apply to all
animals devoid of blood. Some have a stomach also, and attached to
this the rest of the gut, either simple or convoluted as in the case
of the acris or grasshopper.

In addition to their other organs, flying insects are furnished
with wings. Some insects are dipterous or double-winged, as the fly;
others are tetrapterous or furnished with four wings, as the bee; and,
by the way, no insect with only two wings has a sting in the rear.
Again, some winged insects have a sheath or shard for their wings,
as the cockchafer; whereas in others the wings are unsheathed, as in
the bee. But in the case of all alike, flight is in no way modified by
tail-steerage, and the wing is devoid of quill-structure or division
of any kind.

All insects have eyes,

but no other organ of sense discernible,
except that some insects have a kind of a tongue corresponding to a
similar organ common to all testaceans; and by this organ such insects
taste and imbibe their food. In some insects this organ is soft; in
other insects it is firm; as it is, by the way, in the purple-fish,
among testaceans. In the horsefly and the gadfly this organ is hard,
and indeed it is hard in most insects. In point of fact, such
insects as have no sting in the rear use this organ as a weapon, (and,
by the way, such insects as are provided with this organ are
unprovided with teeth, with the exception of a few insects); the fly
by a touch can draw blood with this organ, and the gnat can prick or
sting with it.

Certain insects are furnished with prickers or stings. Some
insects have the sting inside, as the bee and the wasp, others
outside, as the scorpion; and, by the way, this is the only insect
furnished with a long tail. And, further, the scorpion is furnished
with claws, as is also the creature resembling a scorpion found within
the pages of books.

All insects

when cut in two continue to live, excepting such as
are naturally cold by nature, or such as from their minute size
chill rapidly; though, by the way, wasps notwithstanding their small
size continue living after severance. In conjunction with the middle
portion either the head or the stomach can live, but the head cannot
live by itself. Insects that are long in shape and many-footed can
live for a long while after being cut in twain, and the severed
portions can move in either direction, backwards or forwards; thus,
the hinder portion, if cut off, can crawl either in the direction of
the section or in the direction of the tail, as is observed in the
scolopendra.

We now proceed

to treat of insects in like manner. This genus
comprises many species, and, though several kinds are clearly
related to one another, these are not classified under one common
designation, as in the case of the bee, the drone, the wasp, and all
such insects, and again as in the case of those that have their
wings in a sheath or shard, like the cockchafer, the carabus or
stag-beetle, the cantharis or blister-beetle, and the like.

Insects have three parts common to them all; the head, the trunk
containing the stomach, and a third part in betwixt these two,
corresponding to what in other creatures embraces chest and back. In
the majority of insects this intermediate part is single; but in the
long and multipedal insects it has practically the same number of
segments as of nicks.

Of sea-nettles

there are two species, the lesser and more
edible, and the large hard ones, such as are found in the
neighbourhood of Chalcis. In winter time their flesh is firm, and
accordingly they are sought after as articles of food, but in summer
weather they are worthless, for they become thin and watery, and if
you catch at them they break at once into bits, and cannot be taken
off the rocks entire; and being oppressed by the heat they tend to
slip back into the crevices of the rocks.

So much for the external and the internal organs of molluscs,
crustaceans, and testaceans.

There is, furthermore,

the genus of the sea-nettles, peculiar in
its way. The sea-nettle, or sea-anemone, clings to rocks like
certain of the testaceans, but at times relaxes its hold. It has no
shell, but its entire body is fleshy. It is sensitive to touch, and,
if you put your hand to it, it will seize and cling to it, as the
cuttlefish would do with its feelers, and in such a way as to make the
flesh of your hand swell up. Its mouth is in the centre of its body,
and it lives adhering to the rock as an oyster to its shell. If any
little fish come up against it it it clings to it; in fact, just as
I described it above as doing to your hand, so it does to anything
edible that comes in its way; and it feeds upon sea-urchins and
scallops. Another species of the sea-nettle roams freely abroad. The
sea-nettle appears to be devoid altogether of excretion, and in this
respect it resembles a plant.