[91] Polybus, a pupil of Hippocrates, a native of the island of Cos; he lived in the fourth century B.C. Many treatises on medical subjects are attributed to him. 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." CHAPTER III. 1. The opinions of other persons are nearly these; and there are other physiologists, but they have not treated so accurately of the veins. But all agree in placing their origin in the head and brain, in which they are incorrect. But, as I have remarked before, it is difficult to discern the course of the veins; indeed, it is impossible to understand them unless a person will examine animals which, after emaciation, have been killed by strangulation. The following is the nature of the veins: There are two veins in the interior of the chest, near the spine; the larger of these is placed forward, the smaller is behind; the larger is inclined to the right side, the smaller to the left; and this by some persons is called the aorta, from the sinewy portion which is seen in dead animals. 2. These veins have their origin in the heart, for they pass completely through the other intestines, and always preserve the character of veins. The heart is, as it were, a part of them, and especially of the more forward and larger one, for these veins are above and below, and the heart is in the middle of them. The heart of all animals contains cavities, but in the heart of very small animals the largest cavity is scarcely perceptible, in moderately sized animals the second cavity is scarcely visible, but in large animals they are all three distinct enough. And when the apex of the heart is turned forwards, as I have observed, the principal cavity is on the right side, and above it the least is on the left side, and the middle-sized one is between them; the two smaller are far less than the greater.