402 
Dentition as indicative of the Age 
The moutli of the horse at two years and a half has a very 
characteristic appearance, especially when viewed in the front, 
by separating the lips. The four permanent central incisors 
are seen in position about half grown, with deep cavities or 
infundibula extending across each tooth, presenting a striking 
contrast to the worn temporary teeth on each side of them. 
The new permanent teeth ar this age are not more than halfway 
up, and there is consequently a considerable space between 
the upper and lower teeth when the temporary teeth are in 
apposition. 
When the horse has reached the age of two years and nine 
months, the four permanent incisors will be in actual contact, 
at least in regard to their anterior edges when the mouth is 
closed ; but, on examining the tables, it is apparent that no wear 
has taken place, and the posterior edges of the teeth are not yet 
level with the anterior. 
At three years old the central permanent incisors are fully 
developed, and the anterior edges show a narrow line of worn 
surface. The posterior edges are level with the anterior, but 
are not worn to the same extent. 
These appearances are shown in the next illustration (Fig. 10), 
which was taken from the mouth of a colt at the completion of 
the third year. 
During the development of the central permanent incisors in 
the course of the third year, an important change is going on in 
the first and second molars, the fangs of which are gradually 
absorbed as the permanent teeth push their way up underneath 
them. 
At two years and a half old, one or two of the permanent molars 
may be in the mouth. Sometimes the second in position is cut 
before the first, and a careful examination will show that the 
crowns of the first and second temporary molars which yet 
remain are only retained in their position by a slight attach- 
ment to the gum, and very little force is required to dislodge 
them. 
The succeeding drawing (Fig. 11, p. 404) shows the condition 
of the molar teeth soon after two years and a half. A permanent 
tooth, the first in position, is seen occupying the place of the 
temporary molar which has fallen, and the second permanent 
tooth is pushing its way up under the second temporary molar, 
which is only held in its place by small portions of the fangs 
which have not yet been absorbed. The fifth molar, which 
was up at two years old, is fully developed, and is quite clear 
from the angle of the jaw. 
At three ^ears old the first and second permanent molars are 
well up, and the top and bottom teeth are in contact when the 
