94 CONSTITUENTS OF ANIMALS, ETC. 



animals, e.g., men, birds, and fishes, to be made up of 

 anhomoeomeria. His examples of anhomoeomeria are 

 almost entirely taken from the animal kingdom, but it is 

 clear that a branch of a tree or a leaf, a wooden ball, a table, 

 or a sword would be anhomoeomeria. 



The distinction made by Aristotle between anhomoe- 

 omeria and homoeomeria corresponds, in an elementary way, 

 with the modern distinction between the organs of the body 

 and the tissues of which they consist, a distinction mainly 

 due to the labours of Bichat, who lived as late as the end of 

 the eighteenth century. Aristotle's homoeomeria, however, 

 include not only constituent parts of the organs, but also 

 matters which can be regarded as secretions and ejecta only. 



Aristotle knew but very little indeed of the structure or 

 composition of the homoeomeria. Modern anatomists 

 break up organic homoeomeria, such as fat, skin, and flesh, 

 into cells, muscle fibres, and connective and other tissues, 

 but he does not appear to have known anything of these. 

 It may be suggested that the vesicles, which he believed 

 were formed in the process of spontaneous generation, were 

 some kind of animal or vegetable cells, but there is nothing 

 to support such a suggestion in the rest of his works. The 

 following, in fact, seems to represent all he knew about the 

 structure or composition of his homoeomeria. He knew of 

 the presence of fat in the substance of the liver, in flesh, 

 and in milk, he knew also that certain fibrous structures 

 occur in flesh, and he was aware that "fibres," corresponding 

 with what is now called fibrin, could be extracted from blood, 

 after it had been drawn from the body of an animal. 



In Chapter ix. a detailed account will be given of 

 Aristotle's homoeomeria. 



