THE TEETH 



435 



Second Lower Premolar ( -}. The only abnormality 



\pm 21 



observed in tins tooth is its occasional oblique insertion in the jaw 

 (Fig. 363). 



Lower Molar (-- ). Size. The lower sectorial varies in size as 



\in / 



the upper sectorial varies. In only one specimen of very many 

 studied was there evidence of an additional fang. This was shown 

 in the presence of a small alveolus in the interval between the two 

 normal alveoli, but on the outer side of the jaw (right). This is not 

 an uncommon variation in the lower milk sectorial (Fig. 364). 



FIG. 364. 



ABNORMAL LOWER MILK MOLARS. 



Number. I have no record of the absence of the lower sectorial. 

 Supernumerary lower molars are occasionally seen. Hensel notes two 

 such cases : in one the additional tooth was a small one placed internal 

 to the middle of the lower sectorial and divided into two cusps, hence 

 it was a copy of the normal tooth ; in the other case the abnormal tooth 

 was placed internal to the lower end of the sectorial, but it was not so 

 distinctly divided into two cusps. Wyman 1 gives a case of "super- 

 numerary permanent molar in the lower jaw." No cases of additional 

 lower molars of a tubercular kind like the small upper molar have 

 been recorded as occurring in the cat, although Hensel, Bateson, 

 Schlegel, 2 and Magitot 3 have seen them in other of the Felidse. 



HUMAN TEETH. 



Man has normally thirty-two teeth, comprising on each side, 

 above and below, two incisors, one canine, two premolars, and three 



21 23 

 molars. The dental formula therefore is i ^ c -> pm -, m - = 32. The 



Zi L ' A O 



canines are sometimes called the cuspids, the eye teeth, and the stomach 



1 Proc. Boston N. H. S., v. p. 160. 2 Proc. Zool. Soc., 1866, p. 419. 



3 Anom. Syst. Dent., p. 103. 



