Teeth] 2 %9 [Teeth 



immediately behind the incisors are called the 

 tusks or canines, and behind those are the 

 molars. 



Each tooth is divided into three parts. The 

 free, or part that is seen when looking into the 

 mouth, is called the crown ; then there is the 

 neck or constricted part, which is encircled by the 

 gum, and divides the crown from the fang or root, 

 which is inserted in a cavity (the Alveolus) in the 

 jaw-bone. 



Each tooth is made up of three different 

 structures. The external, or enamel, which 

 gives the new tooth its beautiful white appear- 

 ance, and consists only of a somewhat thin layer, 

 and covers the crown of the tooth only. Im- 

 mediately underneath the enamel, is situated 

 the ivory or dentine, of which the tooth, 

 including the fang, principally consists. In the 

 centre of the fang is a foramen, or small cavity, 

 containing the pulp, consisting of a membrane 

 nerve and small blood-vessels to supply nourish- 

 ment, etc., to the tooth. 



The incisors, twelve in number, both in the 

 temporary as well as in the permanent set, are 

 for distinction divided into nippers, which are 

 the two centre ones ; the intermediates are those 

 situated between the nippers and corners, the 

 latter being placed next to the tusks. 



The crown of an incisor tooth presents three 

 prominences — a middle, which is the strongest, 

 and two lateral. On the internal surface of the 

 tooth is noticed a slope, somewhat resembling 

 that found in an ox's or sheep's tooth. The root 



