B. III."] THE HISTORY OP ANIMALS. 53 



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 follow- 

 ing 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 cavi- 

 ties, 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. 



3. All these are perforated towards the lungs, but im- 

 perceptibly so from the minuteness of the passage, except 

 in one place. The great vein is suspended from the upper 

 portion of the principal cavity; and on the right side ; after- 

 wards through the cavity a vein extends again, as if the 

 vein were a part of the cavity in which the blood stagnates. 

 The aorta has its origin from the middle cavity, but in a dif- 

 ferent manner from the vein, for it communicates with the 

 heart by a much narrower pasf age, and the vein is continued 



