212 
MANUAL OF MOUERN FARRIERT. 
which is distinguished by the first appearance of the incisorv 
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 teeth 
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 different 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 
different, the largest being situated next the root. (See 
olate 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 
»n a rounded blind pouch. 
Through wear, the enamel of the incisors is divided 
