158 ARISTOTLE S ANHOMCBOMEEIA 



E. THE ALIMENTARY CANAL AND ITS CLOSELY 



CONNECTED PAETS. 



Many parts of Aristotle s statements about the alimentary 

 canal, omentum, mesentery, and diaphragm are of small 

 value, but there are some parts which describe very well a 

 few important anatomical details. He gives, e.g., good 

 descriptions of the stomach of a ruminant, the pyloric caeca 

 of fishes, and the intestinal caeca of birds, the stomach of the 

 mullet, the gizzard, proventriculus, and crop of a few 

 birds, and the stomachs or digestive cavities of some 

 invertebrates. 



After dealing with the chief terms used by Aristotle to 

 denote various parts of the alimentary canal, and briefly 

 discussing his views on digestion, the above-mentioned 

 descriptions and a few others of less importance will be 

 considered. 



In almost every instance in which he refers to the 

 oesophagus, he calls it stomachos, and in most cases he calls 

 the stomach ccelia, under which term he includes also the 

 gizzard of a bird and the digestive cavity of an invertebrate. 

 The usual term used for an lntestine is enteron, but, in many 

 passages, he uses the phrases upper ccelia and lower ccelia, 

 the former including the stomach and the latter either the 

 whole or a part of the intestines. He does not appear to 

 distinguish the small from the large intestines. 



Digestion was effected, according to Aristotle, wholly 

 or almost wholly by the action of animal heat, which he 

 believed to be different from ordinary heat, such as that 

 from a fire. The function of the mouth, he says, is not to 

 digest but to facilitate digestion by masticating the food.* 

 In the stomach and part of the intestines, digestion was 

 effected by the heat supplied, so Aristotle believed, mainly 

 by the liver, spleen, and omentum. t He says also that the 

 caeca found in most fishes serve to store up food which is 

 therein putrefied and digested, t Evidently, therefore, he 

 not only followed Hippocrates, who believed that digestion 

 was due to the action of heat, but also some who believed 

 that it was due to putrefaction. 



The nutritious matters, Aristotle says, passed into the 

 blood through numerous vessels distributed throughout the 



* P. A. ii. c. 3, 650a. f Ibid. iii. c. 7, 670a, iv. c. 3, 6776. 



} Ibid, iii, c, 14, 075a. 



