by Aristotle
There is another two-parted limb, the leg. Of this limb the double-knobbed [5] part is the thigh, the sliding part is the knee-cap, the double-boned part is the lower leg; the front part of this latter is the shin, and the part behind it is the calf, wherein the flesh is sinewy and venous, in some cases drawn upwards towards the hollow behind the knee, as in the case of people with large hips, and in other cases drawn downwards. The lower extremity of the shin is the ankle, duplicate in either leg. The [10] part of the limb that contains a multiplicity of bones is the foot. The hinder part of the foot is the heel; at the front of it the divided part consists of toes, five in number; the fleshy part underneath is the ball; the upper part at the top is sinewy and has no particular appellation; of the toe, one portion is the nail and another the joint, and [15] the nail is in all cases at the extremity; and toes are without exception single-jointed. Men that have the inside of the foot thick and not arched, that is, that walk resting on the entire under-surface of their feet, are prone to roguery. The joint common to thigh and shin is the knee.
These, then, are the parts common to the male and the female sex. The relative position of the parts as to up and down, or to front and back, or to right and left, all [20] this as regards externals might safely be left to mere ordinary perception. But for all that, we must treat of them for the same reason as the one underlying our previous remarks; that is to say, we must refer to them in order that a due and regular sequence may be observed in our exposition, and in order that by their enumeration due attention may be subsequently given to those parts in men and other animals [25] that are diverse in any way from one another.
In man, above all other animals, the upper and lower parts are arranged in accordance with their natural positions; for in him, upper and lower are the same as in the case of the universe as a whole. In like manner the parts in front, behind, right [30] and left, are in accordance with nature. But in regard to other animals, in some cases these distinctions do not exist, and in others they do so, but in a vague way. For instance, the head with all animals is up and above in respect to their bodies; but man alone, as has been said, has, in maturity, this part uppermost in respect to the universe. [494b1]
Next after the head comes the neck, and then the chest and the back: the one in front and the other behind. Next after these come the stomach, the loins, the sexual parts, and the haunches; then the thigh and shin; and, lastly, the feet.
The legs bend frontwards, in the direction of actual progression, and [5] frontwards also lies that part of the foot which is the most effective of motion, and its bending; but the heel lies at the back, and the ankle-bones lie laterally, earwise. The arms are situated to right and left, and bend inwards: so that the convexities [10] formed by bent arms and legs are practically face to face with one another in the case of man.
As for the senses and for the organs of sensation, the eyes, the nostrils, and the tongue, all alike are situated frontwards; the sense of hearing, and the organ of hearing, the ear, is situated sideways, on the same circumference with the eyes. The [15] eyes in man are, in proportion to his size, nearer to one another than in any other animal.
Of man’s senses, touch is the most accurate; taste is second; in the others, man is surpassed by a great number of animals.
16 · The parts, then, that are externally visible are arranged in the way [20] above stated, and as a rule have their special designations, and from use and wont are known familiarly to all; but this is not the case with the inner parts. For the fact is that the inner parts of man are to a very great extent unknown, and the consequence is that we must have recourse to an examination of the inner parts of other animals whose nature in any way resembles that of man.
[25] In the first place then, the brain lies in the front part of the head. And this holds alike with all animals possessed of a brain; and all blooded animals are possessed thereof, and molluscs as well. But, taking size for size of animal, the largest brain, and the moistest, is that of man. Two membranes enclose it: the [30] stronger one is nearer the bone; the one round the brain itself is finer. The brain in all cases is bilateral. Behind this, right at the back, comes what is termed the cerebellum, differing in form from the brain as we may both feel and see.
The back of the head is with all animals empty and hollow, whatever be its size [495a1] in the different animals. For some creatures have big heads while the face below is small in proportion, as is the case with round-faced animals; some have little heads and long jaws, as is the case, without exception, among animals with bushy tails.
[5] The brain in all animals is bloodless, devoid of veins, and naturally cold to the touch; in the great majority of animals it has a small hollow in its centre. The caul around it is veined; and this brain-caul is that skin-like membrane which closely [10] surrounds the brain. Above the brain is the thinnest and weakest bone of the head, which is termed the sinciput.
From the eye there go three ducts to the brain: the largest and the medium-sized to the cerebellum, the least to the brain itself; and the least is the one situated [15] nearest to the nostril. The two largest ones, then, run side by side and do not meet; the medium-sized ones meet—and this is particularly visible in fishes,—for they lie nearer than the large ones to the brain; the smallest pair are the most widely separate from one another, and do not meet.
Inside the neck is what is termed the oesophagus (whose name, ‘gullet’ [20] (στόμαχoς), is derived from its length and narrowness), and the windpipe. The windpipe is situated in front of the oesophagus in all animals that have a windpipe, and all animals have one that are furnished with lungs. The windpipe is made up of gristle, is sparingly supplied with blood, and is streaked all round with numerous [25] minute veins; it is situated, in its upper part, near the mouth, below the aperture formed by the nostrils into the mouth—an aperture through which, when men, in drinking, choke on any of the liquid, this liquid finds its way out through the nostrils. In betwixt the two openings comes the so-called epiglottis, an organ capable of being drawn over and covering the orifice of the windpipe communicating [30] with the mouth; the end of the tongue is attached to the epiglottis. In the other direction the windpipe extends to the interval between the lungs, and hereupon bifurcates into each of the two divisions of the lung; for the lung in all animals possessed of the organ has a tendency to be double. In viviparous animals, however, the duplication is not so plainly discernible as in other species, and the duplication is [495b1] least discernible in man. And in man the organ is not split into many parts, as is the case with some vivipara, neither is it smooth, but its surface is uneven.
In the case of the ovipara, such as birds and oviparous quadrupeds, the two parts of the organ are separated to a distance from one another, so that the creatures appear to be furnished with a pair of lungs; and from the windpipe, itself single, there branch off two separate parts extending to each of the two divisions of [5] the lung. It is attached also to the great vein and to what is designated the aorta. When the windpipe is charged with air, the air passes on to the hollow parts of the lung. These parts have divisions, composed of gristle, which meet at an acute angle; from the divisions run passages through the entire lung, giving off smaller and [10] smaller ramifications. The heart also is attached to the windpipe, by connexions of fat, gristle, and sinew; and at the point of juncture there is a hollow. When the windpipe is charged with air, the entrance of the air into the heart, though imperceptible in some animals, is perceptible enough in the larger ones. Such are [15] the properties of the windpipe, and it takes in and throws out air only, and takes in nothing else either dry or liquid, or else it causes you pain until you shall have coughed up whatever may have gone down.
The gullet communicates at the top with the mouth, close to the windpipe, and [20] is attached to the backbone and the windpipe by membranous ligaments, and at last finds its way through the midriff into the belly. It is composed of flesh-like substance, and is elastic both lengthways and breadthways.
&nb
sp; The stomach of man resembles that of a dog; for it is not much bigger than the bowel, but is somewhat like a bowel of more than usual width; then comes the [25] bowel, single, convoluted, moderately wide. The lower part of the gut is like that of a pig; for it is broad, and the part from it to the buttocks is thick and short. The caul is attached to the middle of the stomach, and consists of a fatty membrane, as is the [30] case with all other animals whose stomachs are single and which have teeth in both jaws.
The mesentery is over the bowels; this also is membranous and broad, and turns to fat. It is attached to the great vein and the aorta, and there run through it a number of veins closely packed together, extending towards the region of the [496a1] bowels, beginning above and ending below.
So much for the properties of the oesophagus, the windpipe, and the stomach.
17 · The heart has three cavities, and is situated above the lung at the division of the windpipe, and is provided with a fatty and thick membrane where it [5] fastens on to the great vein and the aorta. It lies with its tapering portion upon the aorta, and this portion is similarly situated in relation to the chest in all animals that have a chest. In all animals alike, in those that have a chest and in those that have none, the apex of the heart points forwards, although this fact might possibly escape [10] notice by a change of position under dissection. The rounded end of the heart is at the top. The apex is to a great extent fleshy and close in texture, and in the cavities of the heart are sinews. As a rule the heart is situated in the middle of the chest in animals that have a chest, and in man it is situated a little to the left-hand side, [15] leaning a little way from the division of the breasts towards the left breast in the upper part of the chest.
The heart is not large, and in its general shape it is not elongated; in fact, it is [20] somewhat round in form: only it is sharp-pointed at the bottom. It has three cavities, as has been said: the right-hand one the largest of the three, the left-hand one the least, and the middle one intermediate in size. All these cavities, even the two small ones, are connected by passages with the lung, and this fact is rendered quite plain in one of the cavities. And below, at the point of attachment, in the largest cavity [25] there is a connexion with the great vein near which the mesentery lies; and in the middle one there is a connexion with the aorta.16
Passages lead from the heart into the lung, and branch off just as the windpipe does, running all over the lung parallel with the passages from the windpipe. The canals from the heart are uppermost; and there is no common passage, but the passages through their having a common wall receive the breath and pass it on to [30] the heart; and one of the passages conveys it to the right cavity, and the other to the left.
With regard to the great vein and the aorta we shall, by and by, treat of them together in a discussion devoted to them alone.
In all animals that are furnished with a lung, and that are both internally and [496b1] externally viviparous, the lung is of all parts the most richly supplied with blood; for the lung is throughout spongy in texture, and along by every single pore in it go branches from the great vein. Those who imagine it to be empty are altogether mistaken; and they are led into their error by their observation of lungs removed [5] from animals under dissection, out of which organs the blood has all escaped immediately after death.
Of the other internal organs the heart alone contains blood. And the lung has blood not in itself but in its veins, but the heart has blood in itself; for in each of its [10] three cavities it has blood, but the thinnest blood is what it has in its central cavity.
Under the lung comes the thoracic diaphragm or midriff, attached to the ribs, the hypochondria and the backbone, with a thin membrane in the middle of it. It has veins running through it; and the diaphragm in the case of man is thick in [15] proportion to the size of his frame.
Under the diaphragm on the right-hand side lies the liver, and on the left-hand side the spleen, alike in all animals that are provided with these organs in a natural and not a monstrous way; for in some quadrupeds these organs have been found in a transposed position. These organs are connected with the stomach by the [20] caul.
To outward view the spleen of man is narrow and long, resembling that of the pig. The liver for the most part and in most animals is provided with a gall-bladder; but the latter is absent in some. The liver of a man is round-shaped, and resembles that of the ox. This occurs in the case of sacrificial animals too; e.g. in a certain [25] district of the Chalcidic settlement in Euboea the sheep are devoid of gall-bladders; and in Naxos nearly all the quadrupeds have one so large that foreigners when they offer sacrifice are astounded, under the impression that this is not the animals’ nature but a sign peculiar to themselves.
Again, the liver is attached to the great vein, but it has no communication with [30] the aorta; for the vein that goes off from the great vein goes right through the liver, at a point where are the so-called portals of the liver. The spleen also is connected only with the great vein, for a vein extends to the spleen off from it.
After these organs come the kidneys, and these are placed close to the backbone, and resemble in character the same organ in the ox. In all animals that are provided with this organ, the right kidney is situated higher up than the other. It [497a1] has also less fatty substance than the left-hand one and is less moist. And this is found in all the other animals alike.
Furthermore, passages lead into the kidneys both from the great vein and from the aorta, only not into the cavity. For there is a cavity in the middle of the kidney, [5] bigger in some creatures and less in others; but there is none in the case of the seal. This latter animal has kidneys resembling those of the ox, but more solid than in any other creature. The passages that lead into the kidneys lose themselves in the substance of the kidneys themselves; and a sign that they extend no farther rests on [10] the fact that they17 contain no blood, nor is any clot found therein. The kidneys, however, have, as has been said, a small cavity.18 From this cavity in the kidney there lead two considerable passages into the bladder; and others spring from the aorta, strong and continuous. And to the middle of each of the two kidneys is attached a hollow sinewy vein, stretching right along the spine through the narrows; [15] by and by these veins are lost in either loin, and again become visible extending to the flank. And these off-branchings of the veins terminate in the bladder. For the bladder lies at the extremity, and is held in position by the ducts stretching from the kidneys, along the stalk that extends to the urethra; and pretty well all round it is [20] fastened by fine sinewy membranes, that resemble to some extent the thoracic diaphragm. The bladder in man is tolerably large.
To the stalk of the bladder the private part is attached, the endmost part of it [25] being a single united orifice; but a little lower down, one of the openings communicates with the testicles and the other with the bladder. The penis is gristly and sinewy. With it are connected the testicles in male animals, and the properties of these organs we shall discuss in our general account.
All these organs are similar in the female; for there is no difference in regard to [30] the internal organs, except in respect to the womb. The appearance of this organ can be investigated from the diagrams in the Anatomies; its position is over the bowel, and the bladder lies over the womb. But we must treat by and by of the womb of all female animals viewed generally. For the wombs of all female animals are not identical, neither do their local dispositions coincide.
These are the organs, internal and external, of man, and such is their nature [497b1] and such their local disposition.
BOOK II
1 · With regard to animals in general, some parts or organs are common to all, as has been said, and some are common only to particular genera; the parts, moreover, are identical with or different from one another on the lines already repeatedly laid down. For as a general rule all animals that are generically distinct [10] have the majority of their parts different in form; and some of them they have only analogically similar and diverse
in genus, while they have others that are alike in genus but specifically diverse; and many exist in some animals, but not in others.
For instance, viviparous quadrupeds have all a head and a neck, and all the [15] parts of the head, but they differ each from other in the shapes of the parts. The lion has its neck composed of one single bone instead of vertebrae; but, when opened up, the animal is found in all internal characteristics to resemble the dog.
The quadruped vivipara instead of arms have forelegs. This is true of all quadrupeds, but such of them as have toes have, practically speaking, organs [20] analogous to hands; at all events, they use these fore-limbs for many purposes as hands—except for the elephant.
This animal has its toes somewhat indistinctly defined, and its front legs are much bigger than its hinder ones; it is five-toed, and has short ankles to its hind feet. [25] But it has a nose of such a sort and size as to allow of its being used as a hand. For it eats and drinks by lifting up its food with the aid of this organ into its mouth, and it lifts up articles to its driver and it pulls up trees, and when walking through water it spouts the water up by means of it; and this organ bends but is not jointed, for it is [30] composed of gristle.
Of all animals man alone can learn to make equal use of both hands.
All animals have a part analogous to the chest in man, but not similar to his; for the chest in man is broad, but that of all other animals is narrow. Moreover, no other animal but man has breasts in front; the elephant, certainly, has two breasts, [498a1] not however in the chest, but near it.