MOLARS OF SECOND DENTITION PERMANENT MOLARS. 



35 



covered witli ridges and cavities, but the external border oi' iiw 

 superior teeth and the internal border of the inferior teeth arc 

 always longer than the opposite border, so that they present 

 two oblique planes, -which become more marked as the teeth 

 wear down. As the animal becomes older the molars wear 

 down till they are reduced (Figs. 23 and 24) to little thin plates. 



Fig. 22. 

 The three inferior temporarx molar,- (right side). F J. internal face ; F E, external face. 



which fit close to, or cap. as it were, the crowns of the replacing 

 molars, by which they are finally forced out from the jaw-. 



MOLARS OF SECOND DENTITION PERMANENT MOLARS. 



These are twenty-four in number, — twelve in each jaw, six 

 on each side. They are designated numerically from in front 

 to behind, as the first, second, etc. The thn^e first, which 



