78 NATURE STUDY. 



teeth, toward the end or side of the jaws. Use made 

 by children of incisors and grinding teeth. 



Examine teeth of cat or dog. Incisor teeth readily 

 seen, but grinding teeth somewhat difficult to see. 

 Great length of canine or dog teeth. Used and fitted 

 for seizing and tearing animals and meat. 



Examine teeth of rabbit, comparing with teeth of 

 child, and of cat or dog. Back teeth will probably have 

 to be studied from a skeleton, or picture of skeleton of 

 head, or the teacher may have to tell pupils about them. 

 Note the two long sharp incisor teeth in the front of. 

 each jaw, and the space at either side of these without 

 any teeth. From a skeleton of the rabbit's head can 

 be seen the two additional very small teeth back of and 

 hidden by the incisors in the upper jaw (found only in 

 rabbits and hares), and the five or six flat grooved 

 grinding teeth in the ends of the jaws, each with a 

 transverse ridge of enamel, so that it appears to be 

 composed of two halves. 



The provision made for keeping the incisor teeth 

 sharp, and for replacing the parts worn away by gnaw- 

 ing, has been already given in Lesson III. 



The character and number of the teeth are very im- 

 portant in classification ; hence pains should be taken 

 to have them thoroughly understood as a basis for the 

 next lesson on classification. 



Adaptation. See also Lesson III. The rabbit belongs 

 to a group or order of animals called " gnawers." How 

 is it adapted for gnawing? By cleft upper lip, free 

 movement of lower jaw, and position, shape, size 



