148 ARISTOTLE S ANHOMCEOMERIA 



CHAPTEK XI. 



AKISTOTLE S ANHOMCEOMEEIA AND THEIK 

 FUNCTIONS (continued). 



C. LUNGS, GILLS, AND THE LIKE. 



MANY interesting statements are made by Aristotle about 

 the lungs, gills, and the structures which, according to him, 

 take their place in some animals, but his views on their 

 functions were quite different from those accepted to-day. 

 He believed that these organs mainly served to cool the 

 animals to which they belonged. Not only did he not 

 understand the respiratory function of the water passing 

 through the gill chambers,* but he also held that air could 

 not exist in the water, t He says that insects and other 

 animals belonging to his Entoma cannot respire,! and, in 

 support of this statement, he says that many of the Entoma 

 live when divided into two or more parts, and that flies and 

 bees swim about for a long time in water, unless this is very 

 cold or hot. For him, respiration had a limited meaning. 

 Unlike Diogenes, Anaxagoras, Democritus, and many other 

 philosophers, he denied that animals without lungs could 

 respire, |1 and, even in animals with lungs, the air taken in 

 and expelled served merely to cool the blood and the heart, 

 which was the chief centre of heat. II 



Such were his views on the functions of lungs, gills, and 

 the like. Further information about these views will be 

 given in the following discussion of his statements about the 

 structure and arrangement of these organs. 



Aristotle says that the lung is usually double, but this 

 is not so evident in viviparous animals, and least of all 

 in Man, and that the human lung is not divided into many 

 lobes, as in some animals, nor is it smooth, but irregular.** 

 In oviparous animals, he says, such as birds and oviparous 



* De Respir. c. 16. f Ibid. c. 2. 



I H. A. i. c. 1, s. 7. De Eespir. cc. 3 and 9. 



|| Ibid. cc. 1 and 2. IT Ibid. cc. 16 and 21. 



** H. A. i. c. 13, s. 6. 



