Chapter XIV.

1. The heart has three cavities: it lies above the lungs, near the division of the trachea. It has a fat and thick membrane, by which it is united to the great vein and the aorta, and it lies upon the aorta near the apex; and the apex is placed in the same situation in all animals which have a chest; and in all animals, whether they have or have not a chest, the apex of the heart is forwards, though it often escapes notice by the change of position in the parts when dissected. The gibbous portion of the heart is upwards; its apex is generally fleshy and thick, and there is a sinew in the cavities.

2. In all other animals which have a chest the heart is placed in the centre; in man it is rather on the left side, inclining a little from the division of the mammæ towards the left breast in the upper part of the chest; it is not large; its whole form is not long, but rather round, except that the extremity ends in a point. It has three cavities, as I have said. The greatest is that on the right, the least on the left, the middle one is of intermediate size. They are all perforated towards the lungs. It has both the two smaller, and all of them perforated towards the lungs, and this is evident in one of the cavities downwards from its point of attachment.

3. Near the principal cavity it is attached to the great vein to which also the mesenterium is united, and in the middle it is attached to the aorta. Passages lead from the lungs to the heart, and they are divided in the same way as the trachea, following the passages from the trachea throughout the whole lungs, and the passages leading from the heart are on the upper part. There is no passage which is common to them both, but by their union they receive the breath and transmit it through the heart; for one of the passages leads to the right cavity, and the other to the left. We will hereafter speak of the great vein and the aorta in the portion of our work which treats of these parts.

4. In all animals which have lungs and are viviparous, either internally or externally, the lung has more blood than all the other parts; for the whole lung is spongy, and through each perforation branches of the great vein proceed. Those persons are deceived who say that the lungs are empty, drawing their conclusion from dissected animals, from which all the blood has escaped. Of all the viscera the heart alone contains blood, and in the lungs the blood is not in the lungs themselves, but in the veins by which they are perforated. But in the heart itself the blood is in each of the cavities, but the thinnest blood is in the middle cavity.

5. Beneath the lungs is that division of the trunk which is called the diaphragm. It is united to the ribs, the hypochondriac region, and the spine. In the centre is a smooth membranous part, and there are veins extending through it. The human veins are thick in proportion to the size of the body. Under the diaphragm, on the right side is the liver, on the left the spleen, alike in all animals which are furnished with these parts in their natural form and without monstrosity, for already there has been observed an altered order in some quadrupeds. They are joined to the abdomen near the omentum.

6. The appearance of the human spleen is narrow and long, like that of the hog. Generally speaking, and in most animals, the liver is not furnished with a gall, though this is found in some animals. The human liver is round, like that of the ox. This is the case also in animals offered for sacrifice, as in the district of Chalcis, in Eubœa, where the sheep have no gall, and in Naxos it is so large in nearly all the animals, that strangers who come to sacrifice are surprised, and think that it is ominous, and not at all natural. The liver is united with the great vein, but has no part in common with the aorta. For a vein branches off from the great vein through the liver, at the place where the gates of the liver, as they are called, are situated. The spleen also is only connected with the great vein, for a vein extends from this to the spleen.

7. Next to these are the kidneys, which lie close to the spine. In their nature they are like the kidneys of oxen. In all animals that have kidneys the right kidney lies higher than the left, and is covered with less fat, and is more dry than the left. This is the same in all animals. Passages lead from them to the great vein and to the aorta, but not to the cavity; for all animals, except the seal, have a cavity in their kidneys, though it is greater in some than in others. The human kidneys; though similar to those of oxen, are more solid than in other animals, and the passages that lead to them end in the body of the kidney; and this is a proof that they do not pass through them, that they contain no blood in the living animal, nor is it coagulated in them when dead; but they have a small cavity, as I said before. From the cavity of the kidneys two strong passages lead to the bladder, and two others, strong and continuous, lead to the aorta.

8. A hollow, sinewy vein is attached to the middle of each kidney, which extends from the spine through small branches, and disappears towards the hip, though it afterwards appears again upon the hip. The branches of these veins reach to the bladder; for the bladder is placed lowest of all, being united to the passages which proceed from the kidneys by the neck which reaches to the urethra; and nearly all round its circumference it is united by smooth and muscular membranes, very similar in form to those upon the diaphragm of the chest.

9. The human bladder is moderately large in size, and the pudendum is united to the neck of the bladder, having a strong passage above and a small one below. One of these passages leads to the testicles; the other, which is sinewy and cartilaginous, to the bladder. From this are appended the testicles of the male, concerning which we will treat in the part devoted to their consideration. These parts are the same in the female, who differs in none of the internal parts except the womb, the appearance of which may be learned from the drawings in the books on anatomy. Its position is upon the entrails. The bladder is above the uterus. In a future book we will speak of the nature of the uterus generally; for it is not alike, nor has it the same nature in them all.

These are the internal and external parts of the human body, and this is their nature and their manner.