ORGANS OF DIGESTION 13I 



In each half of the lower jaw there are three incisors, one 

 canine, two premolars, and one molar. The permanent denti- 

 tion of the cat is therefore expressed by the formula i M, c l{, 

 pm M, m Yi. 



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 pre- 

 maxillary. 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 crown. The next three teeth are known as the 

 premolars. They vary much in size. The 

 anterior one is the smallest, being about the 

 size of the incisors. Its crown is usually 

 simple, although occasionally there is seen 

 a small posterior cusp, called triticone, in 

 distinction to the main cusp or protocone. 

 The root is usually composed of only one 

 fang. The second premolar is much larger Fig. 63.— Longitu- 



° ^ ^ DiNAL Section of 



than the first. Its crown presents a large the Canine Tooth. 



T , i-i c, crown; cr, ce- 



median cusp, or protocone; a very small ^^^t; d, dentine; e. 

 cusp, triticone, on the posterior side of the enamel; /, fang; m, 



pulp-cavity; n. neck. 



protocone half-way between its base and 



apex; and a basal cusp, the talon, on the 



posterior side of the base of the tooth. The prominent ridge 



encircling the tooth at its base is the cingulum. The root is 



composed of two fangs. 



The third premolar or carnassial tooth is fully twice as large 

 as the second premolar. Its protocone is the large central 

 cusp, posterior to which is the large triticone. At the median 

 anterior angle is the deuterocone. The small projection at 

 the lateral anterior angle is the protostyle. The root of the 

 tooth usually consists of three fangs. The posterior tooth in 

 the maxilla is called the molar, since it is the only one not pre- 

 ceded by a milk tooth. It is very small and its crown presents 

 a grinding surface instead of a cutting one. Its root consists 

 of two fangs. 



