AND THEIR FUNCTIONS. 143 



to the arm, hand, and fingers, while another extends to 

 the membranes surrounding the brain. Of the remaining 

 branches of the great blood-vessel, some pass completely 

 round the head, and others end in very delicate vessels in 

 the sensory organs and the teeth. 



It is clear, from the first part of this description, that 

 Aristotle saw what are now called the subclavian veins and 

 some of their tributaries, and that what he calls the jugulars 

 were probably the innominate veins. The blood-vessels, 

 the holding of which caused men sometimes to fall down 

 insensible, should be the internal jugulars, since Aristotle is 

 discussing branches of the great blood-vessel, but he may be 

 referring to the carotid arteries. It may be mentioned that 

 compression of the carotids to produce stupor during surgical 

 operations \vas practised by the Assyrians.* The part of 

 Aristotle s description of the blood-vessels extending as far 

 as the ears is apparently meant to refer to the internal 

 jugular veins and their tributaries, but several parts of the 

 description are incorrect, e.g., these veins have many more 

 than four tributaries, and the branching takes place at many 

 different places and not merely in the vicinity of the ears. 

 Again, the vessel which is said to pass back through the 

 neck might be one of the external jugular veins. 



Aristotle s account of the blood-vessels connected with 

 the brain will be considered when dealing with the brain 

 and spinal cord. 



The part of the great blood-vessel below the heart will 

 now be considered. Aristotle says that this passes down 

 through the diaphragm, but he adds the erroneous statement 

 that it is united to both the aorta and the spinal column by 

 loose, membranous connections. A short, thick blood-vessel 

 passes from it to the liver and breaks up therein. There 

 are also, he says, two branches of this short, thick blood 

 vessel, one ending in the diaphragm and adjacent parts, 

 and the other passing upwards and entering the right arm. 

 Therefore, he explains, when surgeons cut this blood-vessel, 

 some pains about the liver are relieved. From the left side 

 of the great blood-vessel, a short, thick blood-vessel passes 

 to the spleen, and another blood-vessel passes upward and 

 into the left arm. Other blood-vessels extend from the 

 great blood-vessel, one to the omentum, another to the 

 so-called pancreas, and many blood-vessels through the 



;;: Manual of Pharmacology, W. E. Dixon, 2nd edition, 1908, p. 51. 



