VETERINARY DENTAL SURGERT. 141 



alveoli during the entire life of the animal to replace 

 the surface worn off by friction." 



If we combine the essential points of the last two 

 statements we will see that the tooth ceases to grow 

 at some period of life (just when, we are left in 

 doubt), and that its free surface above the gums is 

 maintained after the growth of the tooth ceases, by 

 being pushed upwards from the alveolar cavity and 

 the gums closing around it. 



I formerly held the same opinion as that expressed 

 by Professor Clark, that the teeth continued to grow 

 throughout life, but since have had so many proofs 

 of its erroneousness that I have very materially 

 modified my views. 



The following cut, Fig. 31, shows the fourth 

 upper molar which has projected just one inch 



FIG. 31. 



Molar teeth of the horse, showing a projecting fourth 

 molar. 



