There are certain

fish that are nicknamed the epitragiae, or
capon-fish, and, by the way, fish of this description are found in
fresh water, as the carp and the balagrus. This sort of fish never has
either roe or milt; but they are hard and fat all over, and are
furnished with a small gut; and these fish are regarded as of
super-excellent quality.

Again, just as in testaceans and in plants there is what bears and
engenders, but not what impregnates, so is it, among fishes, with
the psetta, the erythrinus, and the channe; for these fish are in
all cases found furnished with eggs.

But among

insects and fishes, some cases are found wholly devoid
of this duality of sex. For instance, the eel is neither male nor
female, and can engender nothing. In fact, those who assert that
eels are at times found with hair-like or worm-like progeny
attached, make only random assertions from not having carefully
noticed the locality of such attachments. For no eel nor animal of
this kind is ever viviparous unless previously oviparous; and no eel
was ever yet seen with an egg. And animals that are viviparous have
their young in the womb and closely attached, and not in the belly;
for, if the embryo were kept in the belly, it would be subjected to
the process of digestion like ordinary food. When people rest
duality of sex in the eel on the assertion that the head of the male
is bigger and longer, and the head of the female smaller and more
snubbed, they are taking diversity of species for diversity of sex.

With regard to sex,

some animals are divided into male and female,
but others are not so divided but can only be said in a comparative
way to bring forth young and to be pregnant. In animals that live
confined to one spot there is no duality of sex; nor is there such, in
fact, in any testaceans. In molluscs and in crustaceans we find male
and female: and, indeed, in all animals furnished with feet, biped
or quadruped; in short, in all such as by copulation engender either
live young or egg or grub. In the several genera, with however certain
exceptions, there either absolutely is or absolutely is not a
duality of sex. Thus, in quadrupeds the duality is universal, while
the absence of such duality is universal in testaceans, and of these
creatures, as with plants, some individuals are fruitful and some
are not their lying still

Of all animals

man is most given to dreaming. Children and infants
do not dream, but in most cases dreaming comes on at the age of four
or five years. Instances have been known of full-grown men and women
that have never dreamed at all; in exceptional cases of this kind,
it has been observed that when a dream occurs in advanced life it
prognosticates either actual dissolution or a general break-up of
the system.

So much then for sensation and for the phenomena of sleeping and
of awakening.

Molluscs sleep

like fishes, and crustaceans also. It is plain also
that insects sleep; for there can be no mistaking their condition of
motionless repose. In the bee the fact of its being asleep is very
obvious; for at night-time bees are at rest and cease to hum. But
the fact that insects sleep may be very well seen in the case of
common every-day creatures; for not only do they rest at night-time
from dimness of vision (and, by the way, all hard-eyed creatures see
but indistinctly), but even if a lighted candle be presented they
continue sleeping quite as soundly.

They sleep

in the night-time more than during
the day; and so soundly at night that you may cast the net without
making them stir. Fish, as a general rule, sleep close to the
ground, or to the sand or to a stone at the bottom, or after
concealing themselves under a rock or the ground. Flat fish go to
sleep in the sand; and they can be distinguished by the outlines of
their shapes in the sand, and are caught in this position by being
speared with pronged instruments. The basse, the chrysophrys or
gilt-head, the mullet, and fish of the like sort are often caught in
the daytime by the prong owing to their having been surprised when
sleeping; for it is scarcely probable that fish could be pronged while
awake. Cartilaginous fish sleep at times so soundly that they may be
caught by hand. The dolphin and the whale, and all such as are
furnished with a blow-hole, sleep with the blow-hole over the
surface of the water, and breathe through the blow-hole while they
keep up a quiet flapping of their fins; indeed, some mariners assure
us that they have actually heard the dolphin snoring.

But it is from

the following facts that we may more reasonably
infer that fishes sleep. Very often it is possible to take a fish
off its guard so far as to catch hold of it or to give it a blow
unawares; and all the while that you are preparing to catch or
strike it, the fish is quite still but for a slight motion of the
tail. And it is quite obvious that the animal is sleeping, from its
movements if any disturbance be made during its repose; for it moves
just as you would expect in a creature suddenly awakened. Further,
owing to their being asleep, fish may be captured by torchlight. The
watchmen in the tunny-fishery often take advantage of the fish being
asleep to envelop them in a circle of nets; and it is quite obvious
that they were thus sleeping by their lying still and allowing the
glistening under-parts of their bodies to become visible, while the
capture is taking Place.

Apart

from the irritation caused by lice and what are nicknamed
fleas, fish are met with in a state so motionless that one might
easily catch them by hand; and, as a matter of fact, these little
creatures, if the fish remain long in one position, will attack them
in myriads and devour them. For these parasites are found in the
depths of the sea, and are so numerous that they devour any bait
made of fish's flesh if it be left long on the ground at the bottom;
and fishermen often draw up a cluster of them, all clinging on to
the bait.

The elephant

makes a vocal sound of a windlike sort by the mouth
alone, unaided by the trunk, just like the sound of a man panting or
sighing; but, if it employ the trunk as well, the sound produced is
like that of a hoarse trumpet. With regard to the sleeping and waking of animals, all creatures
that are red-blooded and provided with legs give sensible proof that
they go to sleep and that they waken up from sleep; for, as a matter
of fact, all animals that are furnished with eyelids shut them up when
they go to sleep. Furthermore, it would appear that not only do men
dream, but horses also, and dogs, and oxen; aye, and sheep, and goats,
and all viviparous quadrupeds; and dogs show their dreaming by barking
in their sleep. With regard to oviparous animals we cannot be sure
that they dream, but most undoubtedly they sleep. And the same may
be said of water animals, such as fishes, molluscs, crustaceans, to
wit crawfish and the like. These animals sleep without doubt, although
their sleep is of very short duration. The proof of their sleeping
cannot be got from the condition of their eyes-for none of these
creatures are furnished with eyelids-but can be obtained only from
their motionless repose.

Vocal sounds

and modes of language differ according to locality.
Vocal sounds are characterized chiefly by their pitch, whether high or
low, and the kinds of sound capable of being produced are identical
within the limits of one and the same species; but articulate sound,
that one might reasonably designate 'language', differs both in
various animals, and also in the same species according to diversity
of locality; as for instance, some partridges cackle, and some make
a shrill twittering noise. Of little birds, some sing a different note
from the parent birds, if they have been removed from the nest and
have heard other birds singing; and a mother-nightingale has been
observed to give lessons in singing to a young bird, from which
spectacle we might obviously infer that the song of the bird was not
equally congenital with mere voice, but was something capable of
modification and of improvement. Men have the same voice or vocal
sounds, but they differ from one another in speech or language.

Viviparous

quadrupeds utter vocal sounds of different kinds, but
they have no power of converse. In fact, this power, or language, is
peculiar to man. For while the capability of talking implies the
capability of uttering vocal sounds, the converse does not hold
good. Men that are born deaf are in all cases also dumb; that is, they
can make vocal sounds, but they cannot speak. Children, just as they
have no control over other parts, so have no control, at first, over
the tongue; but it is so far imperfect, and only frees and detaches
itself by degrees, so that in the interval children for the most
part lisp and stutter.

The dolphin

when taken out of the water, gives a squeak and moans
in the air, but these noises do not resemble those above mentioned.
For this creature has a voice (and can therefore utter vocal or
vowel sounds), for it is furnished with a lung and a windpipe; but its
tongue is not loose, nor has it lips, so as to give utterance to an
articulate sound (or a sound of vowel and consonant in combination.)

Of animals which are furnished with tongue and lung, the oviparous
quadrupeds produce a voice, but a feeble one; in some cases, a
shrill piping sound, like the serpent; in others, a thin faint cry; in
others, a low hiss, like the tortoise. The formation of the tongue
in the frog is exceptional. The front part of the tongue, which in
other animals is detached, is tightly fixed in the frog as it is in
all fishes; but the part towards the pharynx is freely detached, and
may, so to speak, be spat outwards, and it is with this that it
makes its peculiar croak. The croaking that goes on in the marsh is
the call of the males to the females at rutting time; and, by the way,
all animals have a special cry for the like end at the like season, as
is observed in the case of goats, swine, and sheep. (The bull-frog
makes its croaking noise by putting its under jaw on a level with
the surface of the water and extending its upper jaw to its utmost
capacity. The tension is so great that the upper jaw becomes
transparent, and the animal's eyes shine through the jaw like lamps;
for, by the way, the commerce of the sexes takes place usually in
the night time.) Birds can utter vocal sounds; and such of them can
articulate best as have the tongue moderately flat, and also such as
have thin delicate tongues. In some cases, the male and the female
utter the same note; in other cases, different notes. The smaller
birds are more vocal and given to chirping than the larger ones; but
in the pairing season every species of bird becomes particularly
vocal. Some of them call when fighting, as the quail, others cry or
crow when challenging to combat, as the partridge, or when victorious,
as the barn-door cock. In some cases cock-birds and hens sing alike,
as is observed in the nightingale, only that the hen stops singing
when brooding or rearing her young; in other birds, the cocks sing
more than the hens; in fact, with barn-door fowls and quails, the cock
sings and the hen does not.

But in these cases the term 'voice' is inappropriate; the more
correct expression would be 'sound'. For the scallop, when it goes
along supporting itself on the water, which is technically called
'flying', makes a whizzing sound; and so does the sea-swallow or
flying-fish: for this fish flies in the air, clean out of the water,
being furnished with fins broad and long. Just then as in the flight
of birds the sound made by their wings is obviously not voice, so is
it in the case of all these other creatures.

No mollusc

or crustacean can produce any natural voice or sound.
Fishes can produce no voice, for they have no lungs, nor windpipe
and pharynx; but they emit certain inarticulate sounds and squeaks,
which is what is called their 'voice', as the lyra or gurnard, and the
sciaena (for these fishes make a grunting kind of noise) and the
caprus or boar-fish in the river Achelous, and the chalcis and the
cuckoo-fish; for the chalcis makes a sort piping sound, and the
cuckoo-fish makes a sound greatly like the cry of the cuckoo, and is
nicknamed from the circumstance. The apparent voice in all these
fishes is a sound caused in some cases by a rubbing motion of their
gills, which by the way are prickly, or in other cases by internal
parts about their bellies; for they all have air or wind inside
them, by rubbing and moving which they produce the sounds. Some
cartilaginous fish seem to squeak.

Insects, for instance,

have no voice and no language, but they can
emit sound by internal air or wind, though not by the emission of
air or wind; for no insects are capable of respiration. But some of
them make a humming noise, like the bee and the other winged
insects; and others are said to sing, as the cicada. And all these
latter insects make their special noises by means of the membrane that
is underneath the 'hypozoma'-those insects, that is to say, whose body
is thus divided; as for instance, one species of cicada, which makes
the sound by means of the friction of the air. Flies and bees, and the
like, produce their special noise by opening and shutting their
wings in the act of flying; for the noise made is by the friction of
air between the wings when in motion. The noise made by grasshoppers
is produced by rubbing or reverberating with their long hind-legs.

Voice and sound are different from one another; and language
differs from voice and sound. The fact is that no animal can give
utterance to voice except by the action of the pharynx, and
consequently such animals as are devoid of lung have no voice; and
language is the articulation of vocal sounds by the instrumentality of
the tongue. Thus, the voice and larynx can emit vocal or vowel sounds;
non-vocal or consonantal sounds are made by the tongue and the lips;
and out of these vocal and non-vocal sounds language is composed.
Consequently, animals that have no tongue at all or that have a tongue
not freely detached, have neither voice nor language; although, by the
way, they may be enabled to make noises or sounds by other organs than
the tongue.

With regard

to sight and hearing, we cannot make statements with
thorough confidence or on irrefutable evidence. However, the solen
or razor-fish, if you make a noise, appears to burrow in the sand, and
to hide himself deeper when he hears the approach of the iron rod (for
the animal, be it observed, juts a little out of its hole, while the
greater part of the body remains within),-and scallops, if you present
your finger near their open valves, close them tight again as though
they could see what you were doing. Furthermore, when fishermen are
laying bait for neritae, they always get to leeward of them, and never
speak a word while so engaged, under the firm impression that the
animal can smell and hear; and they assure us that, if any one
speaks aloud, the creature makes efforts to escape. With regard to
testaceans, of the walking or creeping species the urchin appears to
have the least developed sense of smell; and, of the stationary
species, the ascidian and the barnacle.

So much for the organs of sense in the general run of animals.
We now proceed to treat of voice.

The cuttle-fish

the octopus, and the crawfish
may be caught by bait. The octopus, in fact, clings so tightly to
the rocks that it cannot be pulled off, but remains attached even when
the knife is employed to sever it; and yet, if you apply fleabane to
the creature, it drops off at the very smell of it. The facts are
similar in regard to taste. For the food that insects go in quest of
is of diverse kinds, and they do not all delight in the same flavours:
for instance, the bee never settles on a withered or wilted flower,
but on fresh and sweet ones; and the conops or gnat settles only on
acrid substances and not on sweet. The sense of touch, by the way,
as has been remarked, is common to all animals. Testaceans have the
senses of smell and taste. With regard to their possession of the
sense of smell, that is proved by the use of baits, e.g. in the case
of the purple-fish; for this creature is enticed by baits of rancid
meat, which it perceives and is attracted to from a great distance.
The proof that it possesses a sense of taste hangs by the proof of its
sense of smell; for whenever an animal is attracted to a thing by
perceiving its smell, it is sure to like the taste of it. Further, all
animals furnished with a mouth derive pleasure or pain from the
touch of sapid juices.

All other animals may,

with very few exceptions, be comprehended
within four genera: to wit, molluscs, crustaceans, testaceans, and
insects. Of these four genera, the mollusc, the crustacean, and the
insect have all the senses: at all events, they have sight, smell, and
taste. As for insects, both winged and wingless, they can detect the
presence of scented objects afar off, as for instance bees and
snipes detect the presence of honey at a distance; and do so
recognizing it by smell. Many insects are killed by the smell of
brimstone; ants, if the apertures to their dwellings be smeared with
powdered origanum and brimstone, quit their nests; and most insects
may be banished with burnt hart's horn, or better still by the burning
of the gum styrax.

Furthermore,

gregarious fishes, if fish washings or bilge-water be thrown
overboard, are observed to scud off to a distance, from apparent
dislike of the smell. And it is asserted that they can at once
detect by smell the presence of their own blood; and this faculty is
manifested by their hurrying off to a great distance whenever
fish-blood is spilt in the sea. And, as a general rule, if you bait
your weel with a stinking bait, the fish refuse to enter the weel or
even to draw near; but if you bait the weel with a fresh and savoury
bait, they come at once from long distances and swim into it. And
all this is particularly manifest in the dolphin; for, as was
stated, it has no visible organ of hearing, and yet it is captured
when stupefied with noise; and so, while it has no visible organ for
smell, it has the sense of smell remarkably keen. It is manifest,
then, that the animals above mentioned are in possession of all the
five senses.

The case is similar in regard to the sense of smell. Thus, as a
rule, fishes will not touch a bait that is not fresh, neither are they
all caught by one and the same bait, but they are severally caught
by baits suited to their several likings, and these baits they
distinguish by their sense of smell; and, by the way, some fishes
are attracted by malodorous baits, as the saupe, for instance, is
attracted by excrement. Again, a number of fishes live in caves; and
accordingly fishermen, when they want to entice them out, smear the
mouth of a cave with strong-smelling pickles, and the fish are Soon
attracted to the smell. And the eel is caught in a similar way; for
the fisherman lays down an earthen pot that has held pickles, after
inserting a 'weel' in the neck thereof. As a general rule, fishes
are especially attracted by savoury smells. For this reason, fishermen
roast the fleshy parts of the cuttle-fish and use it as bait on
account of its smell, for fish are peculiarly attracted by it; they
also bake the octopus and bait their fish-baskets or weels with it,
entirely, as they say, on account of its smell.

...

(Before surrounding them, then, they preserve silence, as was said; but, after
hemming the shoal in, they call on every man to shout out aloud and
make any kind of noise; for on hearing the noise and hubbub the fish
are sure to tumble into the nets from sheer fright.) Further, when
fishermen see a shoal of fish feeding at a distance, disporting
themselves in calm bright weather on the surface of the water, if they
are anxious to descry the size of the fish and to learn what kind of a
fish it is, they may succeed in coming upon the shoal whilst yet
basking at the surface if they sail up without the slightest noise,
but if any man make a noise previously, the shoal will be seen to
scurry away in alarm. Again, there is a small river-fish called the
cottus or bullhead; this creature burrows under a rock, and fishers
catch it by clattering stones against the rock, and the fish,
bewildered at the noise, darts out of its hiding-place. From these
facts it is quite obvious that fishes can hear; and indeed some
people, from living near the sea and frequently witnessing such
phenomena, affirm that of all living creatures the fish is the
quickest of hearing. And, by the way, of all fishes the quickest of
hearing are the cestreus or mullet, the chremps, the labrax or
basse, the salpe or saupe, the chromis or sciaena, and such like.
Other fishes are less quick of hearing, and, as might be expected, are
more apt to be found living at the bottom of the sea.