CHAP. ii. ] THE CATS GENERAL FORM, 29 



notched at its middle. Behind the third premolar is an exceedingly 

 small tooth, which is called a true molar. It has two small fangs 

 and a flattened crown, the greatest breadth of which (Fig. 86) is 

 from without inwards. The common term molars is often used to 

 denote all the teeth which are neither incisors nor canines ; it "being 

 sometimes convenient to speak of such teeth as one whole, without 

 distinguishing between premolars and true molars. In the lower 

 jaw, at its anterior end, there is also a transverse row of six small 

 incisors. The three of each half of the jaw increase in size from 

 within outwards, as do those of the upper jaw ; but they are all smaller 

 than the upper incisors, especially the third, or posterior, one, which is 

 not conical, like the corresponding tooth above. Then comes, with- 

 out any interspace, a large, strong, pointed canine, so placed as (when 

 the jaws are closed) to bite in front of the upper canine, passing up 

 in the interspace between the upper incisors and canines. The lower 

 canine resembles the upper canine in shape, save that it is somewhat 

 shorter and more curved its anterior and posterior margins being 

 rather strongly convex and concave respectively. Next to the lower 

 canine follow two premolars and one molar, separated however from 

 the canine by a wide diastema. The first premolar corresponds with 

 the second upper premolar, and bites in front of the latter. It has 

 two fangs, while its crown (like that of its analogue above) has one 

 large central lobe, at the base of which are two small cusps behind, 

 with one in front. 



The second premolar has also two fangs, and is like its pre- 

 decessor, save that it is larger. The lower molar is very unlike 

 the upper one, having a more completely trenchant form than any 

 other tooth. It is called the lower sectorial tooth. It has two 

 fangs, whereof the anterior is much the larger. Its crown consists 

 of two nearly equal lobes, each ending in a point, the points di- 

 verging. At the base of the hinder side of the hinder lobe there is 

 a minute, scarcely perceptible, indication of a posterior tubercle or 

 "talon." On its inner side, the crown is deeply excavated between 

 the lobes ; but externally the surface is equably convex, save that 

 a fissure descends vertically from the apex of the notch dividing the 

 two lobes. The adjacent edges of each lobe are very sharp, so that 

 the tooth presents an exceedingly trenchant margin, which bites 

 against the similarly trenchant cutting edge above described as 

 connecting the middle and hindmost external lobes of the upper 

 sectorial. Thus these two trenchant margins act together like two 

 blades of a pair of ivory scissors. 



17. The teeth of the adult cat are preceded by a somewhat 

 different set, forming its milk-teeth or deciduous dentition. There 

 are on each side of the upper jaw three deciduous incisors, one 

 deciduous canine and three deciduous molars, and the same on each 

 side of the lower jaw, save that there is one deciduous molar less. 

 There are thus twenty-six milk-teeth in all. The deciduous incisors 

 appear when the kitten is between two and three weeks old, then 

 follow the canines and molars, all appearing by the end of the sixth 



