408 
Dentition as indicative of the Age 
line of worn surface surrounds the central cavity, exoeptinj; a 
small point where the corners touch the lateral incisors. The 
line of wear is broader at the anterior than at the posterior edge, 
and the cavity is still of considerable depth. 
In the lateral incisors the cavity (or mark) is shallow, and 
much smaller than that of the corner incisors. The figure 
described by the central enamel is approaching an oval. The 
cavity in the central incisor is almost worn out, but its 
boundaries are distinctly marked by the central enamel which 
surrounds it, forming an elliptical figure which extends almost 
across the tooth in the direction of its long diameter, and is 
nearer to the posterior than to the anterior edge. 
The tusks are usually well developed, but their points are not 
worn, and the hollows on their inner surfaces are well defined. 
rig. 15. — Incisors of Horse at six years. 
All the above characters are shown in the illustration 
(Fig. 15) of the lower incisors of a six-year-old horse. 
