132 ELEMENTS OF MAMMALIAN ANATOMY 



Each half of the mandible holds three incisors, one canine, 

 two premolars, and one molar. The incisors and canine are 

 so similar to the upper ones that they need no further descrip- 

 tion. The first premolar presents a princii)al cusp or proto- 

 conid, a lower small cusp or motaconid, and a projection, on 





Fig. 64. — Lateral Aspect of the Permanent Dentition of the Cat. 

 i\, 12, 13, First, second, and third incisors of the uppet jaw; c, canine; pi. Pi, 

 and p3, first, second, and third premolars; m, molar; i, 2, 3, the incisors of the 

 lower jaw; 4, canine; 5 and 6, first and second premolars; 7, molar; c, cingulum; 

 d, deutrocone; m, metaconid; m, molar; pt, protoconid; re, protocone; td, talonid; 

 /, talon; tr, triticone. 



the posterior side of the base, known as the talonid. A cingulum 

 or encircling ridge is also present at the base of the tooth. 

 The root consists of two fangs. 



The second premolar is very similar to the first except that 

 it is larger and presents an anterior basal cusp in addition to 

 the others. The lower molar, sometimes called the sectorial, 

 because it shears against the upper sectorial or carnass al pre- 

 molar, presents two nearly equal cusps, the protoconid and 

 the paraconid. The root consists of two fangs, the anterior 

 of which is the larger. • 



The deciduous or milk teeth begin to appear above the gums 

 when the kitten is two weeks old. The incisors and the canine 

 appear first, then second and third molars. The first upper 

 molars do not appear till the kitten is about six weeks old. 

 According to Jayne, the deciduous dentition is complete at 



