120 



ELEMENTS OF MAMMALIAN ANATOMY. 



most numerous and thickly set over the entire dorsal 

 aspect; and the fungiform, which are blunt and located 

 more thickly on the sides and near the tip of the tongue 



(Fig. 55)- 



The Teeth.- -During the first year the cat develops 

 twenty-six teeth, known as the deciduous or temporary 

 set, as they are later replaced by a permanent set. The 

 three parts of a tooth are the crown, neck, and fang (Fig. 

 57). The crown may be divided into several portions 

 called cusps. A tooth split longitudinally presents the 



following four features (Fig. 56) : the 

 enamel, a hard glistening substance 

 covering the entire crown of the tooth 

 down to the neck; the cement, a bony 

 substance investing the fang ; the den- 

 tine, forming the interior hard portion 

 of the tooth ; and the pulp cavity, con- 

 taining in the recent state the nerve- 

 and blood-vessels. The enamel con- 

 sists mostly of the phosphate of lime. 

 It is the covering which when broken 

 permits the tooth to decay. 



In an adult cat there are in each 



half of the upper jaw three incisors, one canine, three pre- 

 molars, and one molar (Fig. 57). In each half of the lower 

 jaw there are three incisors, one canine, two premolars, 

 and one molar. The permanent dentition of the cat is 

 therefore expressed by the formula i -|, c \, pm J, m -J-. 



The upper incisor teeth are small and undivided both 

 as to root and crown. They are scarcely one-third as 

 long as the canine and are planted in the alveoli or 

 sockets of the premaxillary. The remaining teeth of 

 this jaw are in the maxilla. The canine or eye tooth 

 is the longest and likewise is undivided as to root and 



FIG. 56. - - LONGITU- 

 DINAL SECTION OF 

 THE CANINE TOOTH. 



c, Crown ; cr, cement ; 

 d, dentine; c, en- 

 amel; /, fang; m, 

 pulp-cavity ; n, neck. 



