Thus, the windpipe of

the creature is exceptionally long, and the oesophagus is longer
still, and the windpipe commences so close to the mouth that the
tongue appears to be underneath it; and the windpipe seems to
project over the tongue, owing to the fact that the tongue draws
back into a sheath and does not remain in its place as in other
animals. The tongue, moreover, is thin and long and black, and can
be protruded to a great distance. And both serpents and saurians
have this altogether exceptional property in the tongue, that it is
forked at the outer extremity, and this property is the more marked in
the serpent, for the tips of his tongue are as thin as hairs. The
seal, also, by the way, has a split tongue.

The serpent

genus is similar and in almost all respects furnished
similarly to the saurians among land animals, if one could only
imagine these saurians to be increased in length and to be devoid of
legs. That is to say, the serpent is coated with tessellated scutes,
and resembles the saurian in its back and belly; only, by the way,
it has no testicles, but, like fishes, has two ducts converging into
one, and an ovary long and bifurcate. The rest of its internal
organs are identical with those of the saurians, except that, owing to
the narrowness and length of the animal, the viscera are
correspondingly narrow and elongated, so that they are apt to escape
recognition from the similarities in shape.

The elephant

has a gut constricted into chambers, so constructed
that the animal appears to have four stomachs; in it the food is
found, but there is no distinct and separate receptacle. Its viscera
resemble those of the pig, only that the liver is four times the
size of that of the ox, and the other viscera in like proportion,
while the spleen is comparatively small.

Much the same may be predicated of the properties of the
stomach and the gut in oviparous quadrupeds, as in the land
tortoise, the turtle, the lizard, both crocodiles, and, in fact, in
all animals of the like kind; that is to say, their stomach is one and
simple, resembling in some cases that of the pig, and in other cases
that of the dog.

There is also a difference in structure in the gut of the two
groups of animals above mentioned (those with unsymmetrical and
those with symmetrical dentition) in size, in thickness, and in
foldings.

The intestines in those animals whose jaws are unequally
furnished with teeth are in all cases the larger, for the animals
themselves are larger than those in the other category; for very few
of them are small, and no single one of the horned animals is very
small. And some possess appendages (or caeca) to the gut, but no
animal that has not incisors in both jaws has a straight gut.

All these,

then have a single stomach, and after that the gut;
but the stomach in some is comparatively large, as in the pig and
bear, and the stomach of the pig has a few smooth folds or ridges;
others have a much smaller stomach, not much bigger than the gut, as
the lion, the dog, and man. In the other animals the shape of the
stomach varies in the direction of one or other of those already
mentioned; that is, the stomach in some animals resembles that of
the pig; in others that of the dog, alike with the larger animals
and the smaller ones. In all these animals diversities occur in regard
to the size, the shape, the thickness or the thinness of the
stomach, and also in regard to the place where the oesophagus opens
into it.

Such is the stomach of those quadrupeds that are horned and have
an unsymmetrical dentition; and these animals differ one from
another in the shape and size of the parts, and in the fact of the
oesophagus reaching the stomach centralwise in some cases and sideways
in others. Animals that are furnished equally with teeth in both
jaws have one stomach; as man, the pig, the dog, the bear, the lion,
the wolf. (The Thos, by the by, has all its internal organs similar to
the wolf's.)

All the afore-mentioned

animals have a stomach, and one
similarly situated, that is to say, situated directly under the
midriff; and they have a gut connected therewith and closing at the
outlet of the residuum and at what is termed the 'rectum'. However,
animals present diversities in the structure of their stomachs. In the
first place, of the viviparous quadrupeds, such of the horned
animals as are not equally furnished with teeth in both jaws are
furnished with four such chambers. These animals, by the way, are
those that are said to chew the cud. In these animals the oesophagus
extends from the mouth downwards along the lung, from the midriff to
the big stomach (or paunch); and this stomach is rough inside and
semi-partitioned. And connected with it near to the entry of the
oesophagus is what from its appearance is termed the 'reticulum' (or
honeycomb bag); for outside it is like the stomach, but inside it
resembles a netted cap; and the reticulum is a great deal smaller than
the stomach. Connected with this is the 'echinus' (or many-plies),
rough inside and laminated, and of about the same size as the
reticulum. Next after this comes what is called the 'enystrum' (or
abomasum), larger an longer than the echinus, furnished inside with
numerous folds or ridges, large and smooth. After all this comes the
gut.

In all

animals the wind-pipe extends to the lung, and the
manner how, we shall discuss hereafter; and the oesophagus, in all
that have the organ, extends through the midriff into the stomach.
For, by the way, as has been observed, most fishes have no oesophagus,
but the stomach is united directly with the mouth, so that in some
cases when big fish are pursuing little ones, the stomach tumbles
forward into the mouth.

The spleen in all cases, when normally placed, is on the
left-hand side, and the kidneys also lie in the same position in all
creatures that possess them. There have been known instances of
quadrupeds under dissection, where the spleen was on the right hand
and the liver on the left; but all such cases are regarded as
supernatural.

Fishes in some few cases have an
oesophagus, as the conger and the eel; and in these the organ is
small.

In fishes that are furnished with an undivided liver, the organ
lies entirely on the right side; where the liver is cloven from the
root, the larger half of the organ is on the right side: for in some
fishes the two parts are detached from one another, without any
coalescence at the root, as is the case with the dogfish. And there is
also a species of hare in what is named the Fig district, near Lake
Bolbe, and elsewhere, which animal might be taken to have two livers
owing to the length of the connecting ducts, similar to the
structure in the lung of birds.

With all

animals that are furnished with these parts, the parts
are similarly situated, and with the exception of man, the heart is in
the middle; in man, however, as has been observed, the heart is placed
a little to the left-hand side. In all animals the pointed end of
the heart turns frontwards; only in fish it would at first sight
seem otherwise, for the pointed end is turned not towards the
breast, but towards the head and the mouth. And (in fish) the apex
is attached to a tube just where the right and left gills meet
together. There are other ducts extending from the heart to each of
the gills, greater in the greater fish, lesser in the lesser; but in
the large fishes the duct at the pointed end of the heart is a tube,
white-coloured and exceedingly thick.

Again,

all viviparous quadrupeds are furnished with kidneys and
a bladder. Of the ovipara that are not quadrupedal there is no
instance known of an animal, whether fish or bird, provided with these
organs. Of the ovipara that are quadrupedal, the turtle alone is
provided with these organs of a magnitude to correspond with the other
organs of the animal. In the turtle the kidney resembles the same
organ in the ox; that is to say, it looks one single organ composed of
a number of small ones. (The bison also resembles the ox in all its
internal parts).

The

callionymus, also, has the gall-bladder close to the liver, and in
no other fish does the organ attain so great a relative size. Other
fishes have the organ close to the gut, attached to the liver by
certain extremely fine ducts. The bonito has the gall-bladder
stretched alongside the gut and equalling it in length, and often a
double fold of it. others have the organ in the region of the gut;
in some cases far off, in others near; as the fishing-frog, the elops,
the synagris, the muraena, and the sword-fish. Often animals of the
same species show this diversity of position; as, for instance, some
congers are found with the organ attached close to the liver, and
others with it detached from and below it. The case is much the same
with birds: that is, some have the gall-bladder close to the
stomach, and others close to the gut, as the pigeon, the raven, the
quail, the swallow, and the sparrow; some have it near at once to
the liver and to the stomach as the aegocephalus; others have it
near at once to the liver and the gut, as the falcon and the kite.

Some animals

have a gall-bladder close to the liver, and others
have not. Of viviparous quadrupeds the deer is without the organ, as
also the roe, the horse, the mule, the ass, the seal, and some kinds
of pigs. Of deer those that are called Achainae appear to have gall in
their tail, but what is so called does resemble gall in colour, though
it is not so completely fluid, and the organ internally resembles a
spleen.

However, without any exception, stags are found to have maggots
living inside the head, and the habitat of these creatures is in the
hollow underneath the root of the tongue and in the neighbourhood of
the vertebra to which the head is attached. These creatures are as
large as the largest grubs; they grow all together in a cluster, and
they are usually about twenty in number.

In regard to the heart

there is an exceptional phenomenon
observable in oxen. In other words, there is one species of ox
where, though not in all cases, a bone is found inside the heart. And,
by the way, the horse's heart also has a bone inside it.

The genera referred to above are not in all cases furnished
with a lung: for instance, the fish is devoid of the organ, as is also
every animal furnished with gills. All blooded animals are furnished
with a liver. As a general rule blooded animals are furnished with a
spleen; but with the great majority of non-viviparous but oviparous
animals the spleen is so small as all but to escape observation; and
this is the case with almost all birds, as with the pigeon, the
kite, the falcon, the owl: in point of fact, the aegocephalus is
devoid of the organ altogether. With oviparous quadrupeds the case
is much the same as with the viviparous; that is to say, they also
have the spleen exceedingly minute, as the tortoise, the freshwater
tortoise, the toad, the lizard, the crocodile, and the frog.

All viviparous quadrupeds,

then, are furnished with an oesophagus
and a windpipe, situated as in man; the same statement is applicable
to oviparous quadrupeds and to birds, only that the latter present
diversities in the shapes of these organs. As a general rule, all
animals that take up air and breathe it in and out are furnished
with a lung, a windpipe, and an oesophagus, with the windpipe and
oesophagus not admitting of diversity in situation but admitting of
diversity in properties, and with the lung admitting of diversity in
both these respects. Further, all blooded animals have a heart and a
diaphragm or midriff; but in small animals the existence of the latter
organ is not so obvious owing to its delicacy and minute size.

As for the properties of the internal organs, these we must first
discuss in the case of the animals that are supplied with blood. For
the principal genera differ from the rest of animals, in that the
former are supplied with blood and the latter are not; and the
former include man, viviparous and oviparous quadrupeds, birds,
fishes, cetaceans, and all the others that come under no general
designation by reason of their not forming genera, but groups of which
simply the specific name is predicable, as when we say 'the
serpent,' the 'crocodile'.

Of fishes whose habitat is in the vicinity of rocks there is a
tiny one, which some call the Echeneis, or 'ship-holder', and which is
by some people used as a charm to bring luck in affairs of law and
love. The creature is unfit for eating. Some people assert that it has
feet, but this is not the case: it appears, however, to be furnished
with feet from the fact that its fins resemble those organs.

So much, then, for the external parts of blooded animals, as
regards their numbers, their properties, and their relative
diversities.

There are also sea-scolopendras, resembling in shape their land
congeners, but somewhat less in regard to magnitude. These creatures
are found in the neighbourhood of rocks; as compared with their land
congeners they are redder in colour, are furnished with feet in
greater numbers and with legs of more delicate structure. And the same
remark applies to them as to the sea-serpents, that they are not found
in very deep water.

Fishes without exception are supplied with blood. Some of them are
oviparous, and some viviparous; scaly fish are invariably oviparous,
but cartilaginous fishes are all viviparous, with the single exception
of the fishing-frog.

Of blooded animals there now remains the serpent genus. This genus
is common to both elements, for, while most species comprehended
therein are land animals, a small minority, to wit the aquatic
species, pass their lives in fresh water. There are also sea-serpents,
in shape to a great extent resembling their congeners of the land,
with this exception that the head in their case is somewhat like the
head of the conger; and there are several kinds of sea-serpent, and
the different kinds differ in colour; these animals are not found in
very deep water. Serpents, like fish, are devoid of feet.

All fishes are saw-toothed excepting the scarus; and the teeth in
all cases are sharp and set in many rows, and in some cases are placed
on the tongue. The tongue is hard and spiny, and so firmly attached
that fishes in many instances seem to be devoid of the organ
altogether. The mouth in some cases is wide-stretched, as it is with
some viviparous quadrupeds....

With regard to organs of sense, all save eyes, fishes possess
none of them, neither the organs nor their passages, neither ears
nor nostrils; but all fishes are furnished with eyes, and the eyes
devoid of lids, though the eyes are not hard; with regard to the
organs connected with the other senses, hearing and smell, they are
devoid alike of the organs themselves and of passages indicative of
them.

Again,

fishes differ from other animals in more ways than as
regards the gills. For they are not covered with hairs as are
viviparous land animals, nor, as is the case with certain oviparous
quadrupeds, with tessellated scutes, nor, like birds, with feathers;
but for the most part they are covered with scales. Some few are
rough-skinned, while the smooth-skinned are very few indeed. Of the
Selachia some are rough-skinned and some smooth-skinned; and among the
smooth-skinned fishes are included the conger, the eel, and the tunny.

Morever, with fishes furnished with gills, the gills in some
cases are simple in others duplicate; and the last gill in the
direction of the body is always simple. And, again, some fishes have
few gills, and others have a great number; but all alike have the same
number on both sides. Those that have the least number have one gill
on either side, and this one duplicate, like the boar-fish; others
have two on either side, one simple and the other duplicate, like
the conger and the scarus; others have four on either side, simple, as
the elops, the synagris, the muraena, and the eel; others have four,
all, with the exception of the hindmost one, in double rows, as the
wrasse, the perch, the sheat-fish, and the carp. The dog-fish have all
their gills double, five on a side; and the sword-fish has eight
double gills. So much for the number of gills as found in fishes.

And of those fish that are provided with gills, some have
coverings for this organ, whereas all the selachians have the organ
unprotected by a cover. And those fishes that have coverings or
opercula for the gills have in all cases their gills placed
sideways; whereas, among selachians, the broad ones have the gills
down below on the belly, as the torpedo and the ray, while the lanky
ones have the organ placed sideways, as is the case in all the
dog-fish.

The fishing-frog has gills placed sideways, and covered not
with a spiny operculum, as in all but the selachian fishes, but with
one of skin.

Fishes,

then, as has been observed, have no breasts and no
passage for the genitals visible externally. But they have an
exceptional organ in the gills, whereby, after taking the water in the
mouth, they discharge it again; and in the fins, of which the
greater part have four, and the lanky ones two, as, for instance,
the eel, and these two situated near to the gills. In like manner
the grey mullet-as, for instance, the mullet found in the lake at
Siphae-have only two fins; and the same is the case with the fish
called Ribbon-fish. Some of the lanky fishes have no fins at all, such
as the muraena, nor gills articulated like those of other fish.