76 J 'E 'I' Elf IX. 1 /,' r DENTAL S URGER I '. 



which influence the color of the decayed part, but 

 just what they are is not easy to determine. 



The study and investigation of the phenomena 

 attending caries of the teeth of domestic animals, is 

 a difficult problem and one not easily solved. Pro- 

 fessor Williams says: "Caries, dental gangrene or de- 

 cay, is almost exclusively confined to the molar teeth, 

 although I have seen the incisors in that condition. 



*Caries of the molars may commence primarily 

 with the fang, neck or crown of the tooth. 



"Caries of the fang arises from inflammation of the 

 pulp, and may be caused by a constitutional predis- 

 position or external injury. Inflammation of the pulp 

 -does not always cause caries. I have seen several 

 cases on record where the fangs were enlarged from 

 a periodental deposit, with abcesses surrounding 

 the fangs without caries. Caries commencing at the 

 fang may be due to obliteration of the pulp cavity 

 at an age when the vitality of the tooth depends 

 upon the integrity of the pulp. I need scarcely re- 

 mind the professional readers that the integrity 

 of the teeth depends upon due supply both as to 

 quantity and quality of nutritive materials. On the 

 fangs of the recently cut tooth but little crusta-pe- 

 trosa is met with, compared with that which exists 

 in old teeth. As age advances the crusta increases 

 .and the tooth grows from the outside. 



* Williams. 



