212 MANUAL OF MODERN FARRIERY. 



wliicli is distinguished by the first appearance of the incisory 

 teeth, and by the wearing out -of their external cavity. We 

 have then the one characterized by the wear of the dental 

 funnel. During this period the table of the incisor teet^ 

 contains in its middle the central enamel, and the funnel at 

 first traverses from one side to the other, and becomes suc- 

 cessively triangular, oval, and round. In the third period, 

 the wear of the portion of the tooth next the root indicates 

 It. After the central enamel becomes obliterated, the table 

 shows a coloured point, which disappears before the wear of 

 the funnel is completed, and takes difierent shades of colour 

 as well as shapes ; and in very old teeth the root is super- 

 seded by a small black cavity. 



In the early stages of their formation, the incisor teeth 

 of the horse resemble a cellular body whose sides are soft 

 and membraneous, and quickly become hard and thickened, 

 and are then reflected at the side of the table. From this 

 primary dental production emanate two cavities that have 

 no communication with each other, and which are essentially 

 difierent, the largest being situated next the root. (See 

 T)late V. fig. 11.) This contains the pulpy substance. The 

 other cavity is open at the side next the table, and forms a 

 reflected funnel. This dental production is soon trans- 

 formed into enamel, which is quickly surrounded with the 

 bony substance on both its surfaces ; the latter incrusts 

 itself in greater quantity on the side next the root, but 

 never completely fills the funnel, the cavity of which is 

 never obliterated except through the effect of wear. This 

 funnel, as has just been mentioned, is formed by the reflec- 

 tion of the elementary membrane of the tooth, and forms a 

 true partition, acquiring a certain length, and terminating 

 in a rounded blind pouch. 



Through wear, the enamel of the incisors is divided 



