28 THE CAT. [CHAP. n. 



they form (with their three fellows of the opposite side) a row of six 

 teeth arranged in the same transverse line. Each tooth has a single, 

 conical fang. The first, or innermost of the three teeth of this 

 kind on each side is the smallest, and the outermost considerahly 

 the largest. The innermost, when quite unworn, has its crown 

 indented by a transverse furrow, while the part anterior to the 

 furrow is produced into three points or cusps, whereof the middle 

 one is the largest. The next tooth is similar, save that the outer- 

 most of the three cusps is larger and the innermost one smaller 

 than in the tooth first described. In the third tooth there is no 

 innermost cusp, and the outer one is much smaller, while the inner 

 one (corresponding with the middle cusp of the two preceding 

 teeth) is very much larger, forming almost all the crown of the 

 tooth. This is the condition of these teeth only when quite unworn ; 

 very soon there can only be distinguished a slight transverse pos- 

 teriorly placed furrow, with, a prominence in front of it, which is 

 more or less irregular in outline. These three teeth are called 

 incisors, and thus there are altogether six incisors in the upper jaw. 



The next tooth, which is separated from the outermost incisor by a 

 considerable interval or diastema, is a very large, strong conical tooth 

 called a canine, with a fang generally much thicker and larger than 

 its crown. The crown is somewhat curved, and is sharply pointed 

 with a strongly marked vertical groove on its outer surface, and a 

 less marked groove on the surface which is turned towards the inside 

 of the mouth. On its hinder margin is a more or less distinct 

 vertical ridge. 



The next tooth (separated from the canine by an interspace) is a 

 very small one, and, like the tw r o which come behind it, is called 

 a premolar. It has an obtuse conical crown with a single fang. 



The next tooth, or second premolar, is very much larger, and has 

 two diverging fangs, one in front of the other. Its crown is com- 

 pressed or flattened from within outwards, and consists of one large 

 triangular pointed cusp, at the base of which there is in front a 

 small single tubercle, while, posteriorly, there are two small ones 

 juxtaposed, one behind the other. The third premolar is yet larger 

 the largest of all the cat's teeth and from its trenchant shape (so 

 well adapted to cut flesh) is called the upper sectorial tooth. It has 

 three fangs, two smaller in front (placed one within the other on the 

 same transverse line) and one much larger, placed posteriorly. 



Its crown consists of three external lobes (or cusps), separated by 

 two notches, and of one internal tubercle. Of the external cusps 

 the first is the smallest, and the second, which is backwardly 

 directed, is the largest. A ridge from the first and second extends 

 inwards to meet at the internal tubercle (Fig. 29), which projects 

 downwards but little. A very slight horizontal prominence or 

 ridge (the external cingulum] connects the bases of the three external 

 cusps on the outer surface of the tooth. When this tooth is viewed 

 from within, a sharp ridge is seen to connect the middle and hind- 

 most of the external lobes, forming a very cutting blade, deeply 



