AND THEIR FUNCTIONS. 131 



neath. Probably, a similar thing happens in some other 

 animals, which are said to lose their canines only." * 



The true molars are not shed, and the Greek word used 

 by Aristotle, viz., gomphioi, certainly includes these, but, on 

 account of the ambiguity of his statements, both here and 

 elsewhere, it cannot be asserted that he refers to true 

 molars only. His assertion that pigs do not shed their teeth 

 is incorrect, but is still believed by some. One breeder, in 

 fact, informed me that pigs do not shed their teeth, or, at 

 most, only the canines. Aristotle's interesting statements 

 about the shedding of the teeth of dogs are correct, as far 

 as they go, for the milk teeth are shed and, although there 

 are great variations with respect to time and order of 

 shedding in different dogs, the permanent teeth are usually 

 well-developed before the milk teeth are shed. Before me 

 is the skull of a dog with well-developed upper canines, 

 third upper premolars, and third and fourth lower premolars, 

 all projecting well beyond the bone ; the corresponding milk 

 teeth, however, are still in position but in process of being 

 gradually pushed out of their sockets by the permanent 

 teeth. 



He states, erroneously, that horns, referring particularly 

 to those of ruminants, are more closely connected with the 

 skin than with the bones, and attempts to explain in this 

 way why certain cattle in Phrygia and other places moved 

 their horns like ears.t This passage gives a wrong im- 

 pression of the value of his knowledge of these structures. 

 He knew that the horns of ruminants are closely connected 

 with the bones. In H. A. iii. c. 9, s. 2, he says that most 

 horns are hollow from their bases and sm-round an inner 

 bone growing from the head, but are solid at the tip and 

 unbranched, and, m H. A. ii. c. 2, s. 11, he says that the 

 hollow parts are produced mainly from the skin, and the 

 hard parts from the bone ; in both passages he says that 

 the horns of deer are the only ones which are solid through- 

 out. The supposed close connection between horns and 

 skin caused him to believe that the colours of these cor- 

 respond, dark horns being found with dark skins or hair, 

 and light horns with light skins or hair, and he believed 

 that the same was true for nails, claws, and hoofs, t There 

 are many animals for which these statements are not true, 



* H. A. ii. c. 3, ss. 11 and 12. j Ihid. iii. c. 9, s. 3. 

 I Ihid. iii. c. 9, s. 1. 



