Chapter II.

1. Of the homogeneous parts of animals, the blood is common to sanguineous animals; and so is the part in which it is contained, which is called a vein; analogous to these, in exsanguineous animals are the serum and the fibre. That which especially constitutes the body is flesh or its analogue: the bone and its analogue; the spine and the cartilage. Next to this we place the skin, membranes, sinews, hair, nails, and their analogue; after these, adeps, fat, and excrementitious matters; then are fæces, phlegm, and bile, both the yellow and the black.

2. But inasmuch as the blood and the veins seem to occupy the chief place, we will first of all speak of these, both for other reasons, and because former writers do not appear to have described them rightly. The difficulty of understanding them is the reason of their errors, for in dead animals, the nature of the principal veins is obscure, for they collapse as soon as the blood has escaped, and it pours out of them as from a vessel. No part of the body, except the veins, contains any blood, except the heart, which has a little; but it is all in the veins. In living creatures their nature cannot be distinguished, for they are internal, and out of sight; so that those who consider them only in dead and dissected animals, cannot see their principal origins. But some, by the examination of emaciated persons, have distinguished the origin of the veins, from the appearance of those which are external.

3. For Syennesis,[89] a Cyprian physician, speaks thus: "The larger veins are thus constituted. From the navel around the loins, through the back to the lungs, under the breasts; that from the right to the left, and that from the left to the right. That from the left, through the liver to the kidney and the testicle; that from the right to the spleen, the kidney, and the testicle, and from thence to the penis."

4. Diogenes[90] of Apollonia writes thus: "The veins are thus placed in man. There are two very large ones, which extend through the stomach by the spine of the back, one to the right and the other to the left, each to the leg nearest itself, and upwards to the head by the collar-bone, and through the neck. From these great veins others extend through the whole of the body, from the right to the right side, and from the left to the left side. The largest are two from the heart, surrounding the spine of the back; and others, a little higher up, through the breasts under the arm-pits, each to the hand nearest itself; and the one is called the splenetic, the other the hepatic vein.

5. "The extremity of these veins is divided, one branch goes to the thumb, and another to the wrist, and from these many small branches are extended upon each hand, and the fingers; and others, smaller still, branch off from these first veins, from the right side to the liver, from the left to the spleen and kidneys. The veins, which go to the legs, are divided near the junction, and extend through the whole thigh; but the largest of these extends to the back of the thigh, and appears thick; another, less thick, passes through the inside of the thigh, and afterwards veins extend by the knee to the leg and foot. As on the hands, they are distributed upon the tarsus of the foot, and from thence to the toes.

6. "A number of small veins are distributed on the stomach and the lungs. Those that extend to the head, through the jugular region, appear large in the neck. From the extremity of each of these many veins are distributed upon the head, some on the right side to the left, others on the left side to the right, they all end near the ear. And there is a second vein upon the neck on each side, somewhat less than the other, to which the principal veins of the neck are united. These pass inwards, through the neck, and from each of them veins pass beneath the shoulder-blade and to the hands; and near the splenetic and hepatic veins there appear others a little less, which they divide when any disease attacks the skin; but the hepatic and splenetic veins are divided for any disease in the neighbourhood of the stomach.

7. "Other veins pass from these, beneath the breasts; and there are other small ones, which proceed from each of these through the spinal marrow to the testicles, and others beneath the skin, through the flesh, reach the kidneys; in men they terminate upon the testicles, in women on the uterus. The first veins from the stomach are wider, and afterwards become smaller, until they pass over from the right to the left, and from the left to the right; these are called the spermatic veins. The thickest blood is beneath the flesh, but that which is in excess in these places becomes thin, and warm, and frothy." These are the opinions of Syennesis and Diogenes.

8. Polybus[91] writes thus: "There are four pair of veins, one from the back of the head through the neck, on the outside, near the spine on either side, as far as the thighs and the legs, afterwards through the legs to the ancles, on the outside, and to the feet. Wherefore, in complaints of the back and thigh, they divide the veins upon the poplitic region, or ancles, on the outside. Another pair of veins pass from the head, by the ears, through the neck, these are called the jugular veins; and others within, near the spine, lead by the loins to the testicles and the thighs, and through the poplitic region on the inside, and through the leg to the inner part of the ancle, and the feet; wherefore, in complaints of the loins and testicles, they bleed in the poplitic region and ancles.

9. "The third pair of veins, from the temple through the neck, and beneath the scapula, reach the lungs; those from the right to the left, under the breast, to the spleen and kidneys; and those from the left to the right side, from the lungs, under the breast, and liver, and kidney; and both end beneath the testicles. The fourth pair from the forepart of the head and the eyes, under the neck and collar-bones; from thence they extend through the humerus to the elbow, and through the cubitus to the wrist and the fingers, and through the lower part of the arm to the arm-pits, and the upper part of the lungs. The one reaches as far as the spleen, the other to the liver; afterwards they both pass over the abdomen to the pudendum."