CHARACTERS OF TEETH. 



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mainly concerned in grasping and biting off the food: these are 

 called incisors. In mammals which, like the pig (fig. 1), possess 

 the primitive number of teeth, there are three of these on either 

 side in both upper and lower jaws. Behind these come the 



Fig. 4. 



Diagrammatic section of various teeth, 



I. Section of tusk of elephant, a permanently growing tooth. II. Section 

 of a young human incisor still growing, the root not yet fully formed. 



III. Section of human incisor fully formed, the root being complete. 



IV. Section of human molar showing the low-crowned (brachyodont) 

 condition, the cusps being rounded tubercles (bunodont). V. Section of 

 the molar of an ox, showing the high (hypsodont) complexly folded 

 crown. In the figures the enamel is black, the pulp white, the 

 dentine represented by horizontal lines, the cement by dots. 



canines, one on each side above and below ; these are generally 

 more or less pointed teeth, serving chiefly for fighting or defence. 

 Behind these again are the cheek-teeth, which have to do mainly 



