144 ARISTOTLE'S ANHOMCEOMERIA 



mesentery, but these all end in one great blood-vessel 

 extending along the intestine and stomach and as far as 

 the oesophagus. 



This practically completes Aristotle's description of the 

 great blood-vessel and its connections. The yvSby i^ which 

 he describes the downward extension of the great blood- 

 vessel suggests that he knew that what is now called the 

 ve)ia cava inferior passed somewhat centrally through the 

 diaphragm. In his description of the branches of the blood- 

 vessel passing to the liver, Aristotle is wrong ; the blood- 

 vessels from the right part of the diaphragm pass to the 

 ve7ia cava i7iferior, and those from the left part enter the 

 suprarenal vein. His statements, that another branch 

 passes upwards and enters the right arm, and that a blood- 

 vessel passes from the left side of the great blood-vessel to 

 the left arm, are of more than ordinary interest. He was 

 evidently not free from the influence of the ancient belief 

 in the existence of distinct right and left systems of blood- 

 vessels. Statements made in accordance with this belief 

 vitiated the descriptions of all ancient anatomists who dealt 

 with the arrangement of the blood-vessels, and used to 

 exercise a bad effect on surgical practice. Diogenes of 

 Apollonia, one of the best anatomists who lived before 

 Aristotle, described some of the blood-vessels of the right 

 arm and shoulder under the name " hepatitis," and some of 

 the blood-vessels of the left arm and shoulder under the 

 name " splenitis," * and said that, for some complaints, 

 surgeons practised bleeding from them.t The Ancients 

 believed, in fact, that an organ, such as the liver or spleen, 

 was connected by a blood-vessel with a distant part of the 

 body, such as one of the arms, and surgeons tried to relieve 

 pains, believed to be caused by such an organ, by bleeding 

 from the aforesaid blood-vessel. Dr. Lauth says that the 

 erroneous opinion, which even Aristotle entertained, that a 

 blood-vessel connected the liver and the right arm, and that 

 another connected the spleen and the left arm, long had a 

 bad effect on surgical practice. + 



The Chinese, who appear to have formed their ideas 

 about human anatomy without the aid of the dissecting- 

 knife, believe that there are some organs to each of which a 

 blood-vessel proceeds, such vessel having a "pulse" which 



* H. A. iii. c. 2, s. 4. f Ibid. iii. c. 2, s, 6. 



I Hist, de VAnatomie, Strasbourg, 1815, p. 77. 



