by Aristotle
antagonistic to fat, for it tends to melt it.
Animals then, as a general rule, derive advantage from their kidneys
being fat; and the fat is often very abundant and extends over the
whole of these organs. But, should the like occur in the sheep,
death ensues. Be its kidneys, however, as fat as they may, they are
never so fat but that some part, if not in both at any rate in the
right one, is left free. The reason why sheep are the only animals
that suffer in this manner, or suffer more than others, is that in
animals whose fat is composed of lard this is of fluid consistency, so
that there is not the same chance in their case of wind getting shut
in and causing mischief. But it is to such an enclosure of wind that
rot is due. And thus even in men, though it is beneficial to them to
have fat kidneys, yet should these organs become over-fat and
diseased, deadly pains ensue. As to those animals whose fat consists
of suet, in none is the suet so dense as in the sheep, neither is it
nearly so abundant; for of all animals there is none in which the
kidneys become so soon gorged with fat as in the sheep. Rot, then,
is produced by the moisture and the wind getting shut up in the
kidneys, and is a malady that carries off sheep with great rapidity.
For the disease forthwith reaches the heart, passing thither by the
aorta and the great vessel, the ducts which connect these with the
kidneys being of unbroken continuity.
10
We have now dealt with the heart and the lung, as also with the
liver, spleen, and kidneys. The latter are separated from the former
by the midriff or, as some call it, the Phrenes. This divides off
the heart and lung, and, as already said, is called Phrenes in
sanguineous animals, all of which have a midriff, just as they all
have a heart and a liver. For they require a midriff to divide the
region of the heart from the region of the stomach, so that the centre
wherein abides the sensory soul may be undisturbed, and not be
overwhelmed, directly food is taken, by its up-steaming vapour and
by the abundance of heat then superinduced. For it was to guard
against this that nature made a division, constructing the midriff
as a kind of partition-wall and fence, and so separated the nobler
from the less noble parts, in all cases where a separation of upper
from lower is possible. For the upper part is the more honourable, and
is that for the sake of which the rest exists; while the lower part
exists for the sake of the upper and constitutes the necessary element
in the body, inasmuch as it is the recipient of the food.
That portion of the midriff which is near the ribs is fleshier and
stronger than the rest, but the central part has more of a
membranous character; for this structure conduces best to its strength
and its extensibility. Now that the midriff, which is a kind of
outgrowth from the sides of the thorax, acts as a screen to prevent
heat mounting up from below, is shown by what happens, should it,
owing to its proximity to the stomach, attract thence the hot and
residual fluid. For when this occurs there ensues forthwith a marked
disturbance of intellect and of sensation. It is indeed because of
this that the midriff is called Phrenes, as though it had some share
in the process of thinking (Phronein). in reality, however, it has
no part whatsoever itself in the matter, but, lying in close proximity
to organs that have, it brings about the manifest changes of
intelligence in question by acting upon them. This too explains why
its central part is thin. For though this is in some measure the
result of necessity, inasmuch as those portions of the fleshy whole
which lie nearest to the ribs must necessarily be fleshier than the
rest, yet besides this there is a final cause, namely to give it as
small a proportion of humour as possible; for, had it been made of
flesh throughout, it would have been more likely to attract and hold a
large amount of this. That heating of it affects sensation rapidly and
in a notable manner is shown by the phenomena of laughing. For when
men are tickled they are quickly set a-laughing, because the motion
quickly reaches this part, and heating it though but slightly
nevertheless manifestly so disturbs the mental action as to occasion
movements that are independent of the will. That man alone is affected
by tickling is due firstly to the delicacy of his skin, and secondly
to his being the only animal that laughs. For to be tickled is to be
set in laughter, the laughter being produced such a motion as
mentioned of the region of the armpit.
It is said also that when men in battle are wounded anywhere near
the midriff, they are seen to laugh, owing to the heat produced by the
wound. This may possibly be the case. At any rate it is a statement
made by much more credible persons than those who tell the story of
the human head, how it speaks after it is cut off. For so some assert,
and even call in Homer to support them, representing him as alluding
to this when he wrote, 'His head still speaking rolled into the dust,'
instead of 'The head of the speaker'. So fully was the possibility
of such an occurrence accepted in Caria, that one of that country
was actually brought to trial under the following circumstances. The
priest of Zeus Hoplosmios had been murdered; but as yet it had not
been ascertained who was the assassin; when certain persons asserted
that they had heard the murdered man's head, which had been severed
from the body, repeat several times the words, 'Cercidas slew man on
mam.' Search was thereupon made and a man of those parts who bore
the name of Cercidas hunted out and put upon his trial. But it is
impossible that any one should utter a word when the windpipe is
severed and no motion any longer derived from the lung. Moreover,
among the Barbarians, where heads are chopped off with great rapidity,
nothing of the kind has ever yet occurred. Why, again, does not the
like occur in the case of other animals than man? For that none of
them should laugh, when their midriff is wounded, is but what one
would expect; for no animal but man ever laughs. So, too, there is
nothing irrational in supposing that the trunk may run forwards to a
certain distance after the head has been cut seeing that bloodless
animals at any rate can live, and that for a considerable time,
after decapitation, as has been set forth and explained in other
passages.
The purposes, then, for which the viscera severally exist have now
been stated. It is of necessity upon the inner terminations of the
vessels that they are developed; for humour, and that of a bloody
character, cannot but exude at these points, and it is of this,
solidified and coagulated, that the substance of the viscera is
formed. Thus they are of a bloody character, and in substance resemble
each other while they differ from other parts.
11
The viscera are enclosed each in a membrane. For they require some
covering to protect them from injury, and require, moreover,
that this
covering shall be light. To such requirements membrane is well
adapted; for it is close in texture so as to form a good protection,
destitute of flesh so as neither to attract humour nor retain it,
and thin so as to be light and not add to the weight of the body. Of
the membranes those are the stoutest and strongest which invest the
heart and the brain; as is but consistent with reason. For these are
the parts which require most protection, seeing that they are the main
governing powers of life, and that it is to governing powers that
guard is due.
12
Some animals have all the viscera that have been enumerated;
others have only some of them. In what kind of animals this latter
is the case, and what is the explanation, has already been stated.
Moreover, the self-same viscera present differences in different
possessors. For the heart is not precisely alike in all animals that
have one; nor, in fact, is any viscus whatsoever. Thus the liver is in
some animals split into several parts, while in others it is
comparatively undivided. Such differences in its form present
themselves even among those sanguineous animals that are viviparous,
but are more marked in fishes and in the oviparous quadrupeds, and
this whether we compare them with each other or with the Vivipara.
As for birds, their liver very nearly resembles that of the
Vivipara; for in them, as in these, it is of a pure and blood-like
colour. The reason of this is that the body in both these classes of
animals admits of the freest exhalation, so that the amount of foul
residual matter within is but small. Hence it is that some of the
Vivipara are without any gall-bladder at all. For the liver takes a
large share in maintaining the purity of composition and the
healthiness of the body. For these are conditions that depend
finally and in the main upon the blood, and there is more blood in the
liver than in any of the other viscera, the heart only excepted. On
the other hand, the liver of oviparous quadrupeds and fishes inclines,
as a rule, to a yellow hue, and there are even some of them in which
it is entirely of this bad colour, in accordance with the bad
composition of their bodies generally. Such, for instance, is the case
in the toad, the tortoise, and other similar animals.
The spleen, again, varies in different animals. For in those that
have horns and cloven hoofs, such as the goat, the sheep, and the
like, it is of a rounded form; excepting when increased size has
caused some part of it to extend its growth longitudinally, as has
happened in the case of the ox. On the other hand, it is elongated
in all polydactylous animals. Such, for instance, is the case in the
pig, in man, and in the dog. While in animals with solid hoofs it is
of a form intermediate to these two, being broad in one part, narrow
in another. Such, for example, is its shape in the horse, the mule,
and the ass.
13
The viscera differ from the flesh not only in the turgid aspect of
their substance, but also in position; for they lie within the body,
whereas the flesh is placed on the outside. The explanation of this is
that these parts partake of the character of blood-vessels, and that
while the former exist for the sake of the vessels, the latter
cannot exist without them.
14
Below the midriff lies the stomach, placed at the end of the
oesophagus when there is one, and in immediate contiguity with the
mouth when the oesophagus is wanting. Continuous with this stomach
is what is called the gut. These parts are present in all animals, for
reasons that are self-evident. For it is a matter of necessity that an
animal shall receive the incoming food; and necessary also that it
shall discharge the same when its goodness is exhausted. This residual
matter, again, must not occupy the same place as the yet unconcocted
nutriment. For as the ingress of food and the discharge of the residue
occur at distinct periods, so also must they necessarily occur in
distinct places. Thus there must be one receptacle for the ingoing
food and another for the useless residue, and between these,
therefore, a part in which the change from one condition to the
other may be effected. These, however, are matters which will be
more suitably set forth when we come to deal with Generation and
Nutrition. What we have at present to consider are the variations
presented by the stomach and its subsidiary parts. For neither in size
nor in shape are these parts uniformly alike in all animals. Thus
the stomach is single in all such sanguineous and viviparous animals
as have teeth in front of both jaws. It is single therefore in all the
polydactylous kinds, such as man, dog, lion, and the rest; in all
the solid-hoofed animals also, such as horse, mule, ass; and in all
those which, like the pig, though their hoof is cloven, yet have front
teeth in both jaws. When, however, an animal is of large size, and
feeds on substances of so thorny and ligneous a character as to be
difficult of concoction, it may in consequence have several
stomachs, as for instance is the case with the camel. A similar
multiplicity of stomachs exists also in the horned animals; the reason
being that horn-bearing animals have no front teeth in the upper
jaw. The camel also, though it has no horns, is yet without upper
front teeth. The explanation of this is that it is more essential
for the camel to have a multiple stomach than to have these teeth. Its
stomach, then, is constructed like that of animals without upper front
teeth, and, its dental arrangements being such as to match its
stomach, the teeth in question are wanting. They would indeed be of no
service. Its food, moreover, being of a thorny character, and its
tongue necessarily made of a fleshy substance, nature uses the
earthy matter which is saved from the teeth to give hardness to the
palate. The camel ruminates like the horned animals, because its
multiple stomach resembles theirs. For all animals that have horns,
the sheep for instance, the ox, the goat, the deer, and the like, have
several stomachs. For since the mouth, owing to its lack of teeth,
only imperfectly performs its office as regards the food, this
multiplicity of stomachs is intended to make up for its
shortcomings; the several cavities receiving the food one from the
other in succession; the first taking the unreduced substances, the
second the same when somewhat reduced, the third when reduction is
complete, and the fourth when the whole has become a smooth pulp. Such
is the reason why there is this multiplicity of parts and cavities
in animals with such dentition. The names given to the several
cavities are the paunch, the honeycomb bag, the manyplies, and the
reed. How these parts are related to each other, in position and in
shape, must be looked for in the treatises on Anatomy and the
Researches concerning Animals.
Birds also present variations in the part which acts as a
recipient
of the food; and the reason for these variations is the same
as in the animals just mentioned. For here again it is because the
mouth fails to perform its office and fails even more completely-for
birds have no teeth at all, nor any instrument whatsoever with which
to comminute or grind down their food-it is, I say, because of this,
that in some of them what is called the crop precedes the stomach
and does the work of the mouth; while in others the oesophagus is
either wide throughout or a part of it bulges just before it enters
the stomach, so as to form a preparatory store-house for the unreduced
food; or the stomach itself has a protuberance in some part, or is
strong and fleshy, so as to be able to store up the food for a
considerable period and to concoct it, in spite of its not having been
ground into a pulp. For nature retrieves the inefficiency of the mouth
by increasing the efficiency and heat of the stomach. Other birds
there are, such, namely, as have long legs and live in marshes, that
have none of these provisions, but merely an elongated oesophagus. The
explanation of this is to be found in the moist character of their
food. For all these birds feed on substances easy of reduction, and
their food being moist and not requiring much concoction, their
digestive cavities are of a corresponding character.
Fishes are provided with teeth, which in almost all of them are of
the sharp interfitting kind. For there is but one small section in
which it is otherwise. Of these the fish called Scarus (Parrot-fish)
is an example. And this is probably the reason why this fish
apparently ruminates, though no other fishes do so. For those horned
animals that have no front teeth in the upper jaw also ruminate.
In fishes the teeth are all sharp; so that these animals can
divide their food, though imperfectly. For it is impossible for a fish
to linger or spend time in the act of mastication, and therefore
they have no teeth that are flat or suitable for grinding; for such
teeth would be to no purpose. The oesophagus again in some fishes is
entirely wanting, and in the rest is but short. In order, however,