INCISORS. 



11 



-ever, in the place where they will appear later, we sometimes 

 find small, rudimentary teeth with no defined shape. We again 

 sometimes find, both in the young and in the adult animal, 

 a more or less rudimentary premolar tooth, commonly known 

 as the wolf tooth, which raises the number in the adult animal 

 to forty-four. 



INCISORS. 



INCISORS OF FIRST DENTITION. 



The milk-teeth, known also as deciduous or foetal teeth, are 

 twelve in number, — six in each jaw, three on each side. The 



Fig. 2. 

 A milk-tooth. A, posterior face ; B, anterior face ; C, profile. 



middle ones are known as pincher teeth, the next as the inter- 

 mediate teeth, and the outside ones as the corner teeth. They 

 are at first imbedded in the body of the bone, and cohered by 

 the gum ; but when they have protruded from the alveolar 

 cavities they form a half-circle, convex in front. Compared 

 with the permanent teeth, they are shorter ; they have a con- 

 striction in the centre which is known as the neck, which 

 divides them into a free portion or crown, and an imbedded por- 

 tion or root (Fig. 2). They are dead white, milky, or yellowish 

 white in color. The anterior face of these teeth is convex in 

 both directions and roughened by little parallel, longitudinal 

 ridges and depressions, which, however, become worn off, and 



