ORGANS OF DIGESTION. 109) 
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 premolars, and one molar 
(Fig. 58). In each half of the lower 
jaw there are three incisors, one ca- 
nine, two premolars, and one molar. 
The permanent dentition of the cat is 
therefore expressed by the formula 
176 Zi: PEL YO, Tm A, 
The upper incisor teeth are small and 
Fic.- 57. Loneitru- 
undivided both as to root and crown. DINAL SECTION OF 
They are scarcely one-third as long THE CANINE TooTH. 
re i oes 1 ee | c, Crown; cr, cement; 
as the canine and are planted in the d, dentine; e, en- 
alveoli or sockets of the premaxillary. amel; f, fang; m, 
ao is ae : pulp-cavity ; , neck. 
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 dis- 
tinction to the main cusp or protocone. The root is usually 
composed of only one fang. The second premolar is much 
larger than the first. Its crown presents a large median 
cusp, or protocone; a very small cusp, triticone, on the 
posterior side of the 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 
