AND THEIE FUNCTIONS. 133 



d. Hair. — Aristotle gives a long description of the hair of 

 animals, chiefly in H. A. iii. c. 10, and, although including 

 many erroneous statements, such description seems to have 

 been, for many centuries, the best. 



He says that the thickness, fineness, and length of hairs 

 vary with their positions and the nature of the skin,* that 

 animals with coarse hair become softer-haired, and animals 

 with soft hair become coarser-haired, by good feeding, and 

 that men living in warm localities have harsh hair, while 

 those living in cold localities have soft hair.f He adds that 

 straight hairs are soft, but curly hairs are harsh, t 



Many other conditions, besides the nature of their 

 food, affect the qualities of the hair, but the nature of the 

 food has an important effect, e.g., when the Angora goats of 

 Asia Minor have a variety of good food their hair is finer 

 and in better condition than when their food is coarse. Why 

 Aristotle states that animals with soft hair become coarser- 

 haired by good feeding is not clear. It seems to be,v 

 however, an example of his fondness for laying down a 

 proposition and then stating its converse. 



When speaking about the hair of men living in warm 

 and in cold localities, he seems to rely on a comparison 

 between the Europeans, with hair fairly straight or moder- 

 ately curled, and the Negroes, with frizzly hair. It is not 

 clear what he means by softness and harshness, as applied 

 to hair, but he seems to suggest that straightness and 

 curliness respectively are meant. There are important ex- 

 ceptions, however, to his general statements, e.g., the 

 Mongols, whether living in warm countries, like Siam or 

 the Malay Archipelago, or in cold countries, like Siberia, 

 have cylindrical, straight hair, and the degree of frizziness 

 or curliness of the hair of Negroes depends very much on 

 the degree of ellipticity or flatness of the hair in cross 

 section. 



Aristotle says that hair becomes grey from the tip, and 

 that, during the course of some complaints, the hair turns 

 grey and falls off but grows again and is of its original 

 colour. § Hair commonly becomes grey from the roots, 

 sometimes from the tips, and occasionally at intervals along 

 the hairs. Aristotle's statement about the recovery of the 

 hair after illness was probably taken from Hippocrates, and 



* H. A. iii. c. 10, s. 1. f Ihid. iii. c. 10, s. 2. 



I Ibid. § Ihid. iii. c. 10, s. 5. 



