AND THEIR FUNCTIONS. 129 



than the females,*' and this statement has often been used 

 against him by critics. He also misunderstood the ar- 

 rangement of the teeth of camels. He says that they have 

 no front teeth in their upper jaws.t In young camels there 

 are three pairs of incisors in the upper jaw, and in adult 

 camels the pair of incisors next the canines persists. 



He also says that all fishes, except the parrot-wrasse, 

 have sharp, interlocking teeth. I This statement does not 

 appear to be an interpolation, and yet it is difficult to 

 understand why Aristotle should have made it. The parrot- 

 wrasse has many flat pharyngeal teeth and a parrot-like 

 beak formed by the coalescence of many of its teeth, but 

 Aristotle was well acquainted with the gilt-head, which has 

 some strong, blunt front teeth and many rounded teeth, 

 embedded like peas or beans along the sides of and within 

 its mouth, and he probably knew the eagle ray and the 

 female thornback skate, which have flat teeth. 



On the other hand, he makes many interesting state- 

 ments, substantially or quite correct, about the teeth of 

 many other animals. He says that the elephant has four 

 teeth on each side, for grinding down its food, that it has 

 teeth as soon as it is born, but that its tusks are not visible at 

 birth. § This is true as regards the teeth on each side except 

 in old elephants, which usually have only two teeth left on 

 each side of the mouth. The elephant usually has, during 

 its whole life, twelve cheek teeth on each side of its mouth. 

 They are developed gradually and move forwards along the 

 jaws at the same rate as the front ones are worn away. 

 The milk tusks of male elephants are not visible at birth, 

 but project beyond the gum between the fifth and seventh 

 months, according to Owen, who also says that the first 

 molars of the Asiatic elephant are in place and in use at 

 three months.il 



Aristotle correctly points out how old and young dogs 

 may be distinguished by means of their teeth, those of 

 young dogs being white and sharp, while those of old dogs 

 are dark and worn. IT He was also aware of what is called 

 the " mark " in the incisor teeth of horses, for he says that 

 horses differ from other animals in that their teeth become 

 whiter with age, while those of other animals become 



* H. A. ii. c. 3, s. 13. 



t H. A. ii. c. 2, s. 6, ii. c. 8, s. 8 ; P. A. iii. c. 14, 674a. 

 I H. A. ii. c. 9, s. 5 ; P. A. iii. c. 1, 662a. § H. A. ii. c. 3, s. 15. 

 Ii Anat. Vertehr. iii. 1868, pp. 360 and 362. •! H. A. ii. c. 3, s, 12. 



K 



