ANIMAL DENTISTRY. 



33 



to communicate freely. This arrangement of the enamel 

 organ is due to the fact that its infolds are lateral and not 

 superior. That is, the enamel does not dip deeply into the 

 table end, but folds inwards into great rufHes along each 

 side. They each have two roots, each of which is pierced at 

 the apex with the foramen for the entrance of the vessels and 

 nerves. 



i 

 Fig. i8. 



Longitudinal Section 



Through a Molar. 



1, I. Infundibulum. 



2. Dentine. 



3, Crusta petrosa and 

 enamel. 



4. Internal enamel. 



Fig. 19. 



An Inferior Molar, 



Buccal Surface. 



Fig. 20. 

 An Inferior Molar, Lin- 

 gual Surface, with 

 Measurement. 



The superior arcades are prominently convex on the 

 external or buccal surface, and concave on the internal or 

 lingual surface. The width of the arcade is uniform through- 

 out the entire length, with the exception of the extremities 

 which taper to a narrow border anteriorly and a blunted one 



