CHARACTERS OF INDIVIDUAL TE-ETE. 



135 



molars, arranged in a definite order in each jaw. Begin- 

 ning at the middle line we meet in each half of each jaw, 

 successively, with two incisors, one canine, and two mo- 

 lars in the milk set; making twenty altogether in the two 

 jaws. The teeth of the permanent set are thirty-two in 

 number, eight in each half of each jaw, viz. beginning at 

 the middle line two incisors, one canine, two bicuspids, 

 and three molars. The bicuspids of the permanent set 

 replace the molars of the milk set, while the permanent 

 molars are new teeth added on as the jaw grows, and not 

 substituting any of the milk teeth. The hindmost perma- 

 nent molars are often called the wisdom teeth. 



Characters of Individual Teeth. The incisors or cutting 



Fia. 45. 



FIG. 42. An incisor tooth. 



FIG. 43. A canine or eye tooth. 



FIG. 44. A bicuspid tooth seen from its outer side; the inner cusp is accord- 



ly not visible. 



FIG. 45. A molar tooth. 



teeth (Fig. 42) are adapted for cutting the food. Their 

 crowns are chisel-shaped and have sharp horizontal cutting 

 edges which become worn away by use, so that they are 

 beveled off behind in the upper row and in the opposite 



Enumerate the milk teeth in order. How many are there alto- 

 gether? Number of permanent teeth? Enumerate in order. What 

 permanent teeth replace the milk molars? What permanent teeth 

 replace no milk teeth? Which are the wisdom teeth? 



Describe an incisor tooth. 



