of the Animals of the Farm. 
409 
At seven years old the tables of the corner teeth are perfectly' 
formed, and the cavity in each tooth is very shallow. The 
central enamel, however, is well defined and forms an elliptical 
figure, which is nearer to the posterior than to the anterior 
edge of the tooth. In the lateral incisors the central enamel 
forms a figure which is nearer to the oval than to the elliptical, 
and the mark, which is very shallow, does not extend so far 
across the table of the tooth as it does at six years old. These 
teeth are also deeper from front to back than they were at six 
years. 
The central incisors at seven years old have their sides 
elongated, so that the table approaches the figure of a triangle. 
The mark is very close to the posterior edge of the tooth, and 
the central enamel forms an oval^vith flattened sides in place of 
the elliptical figure, which is shown in the drawing of the six- 
year-old mouth. The tusks are somewhat blunted at their 
points. 
Fig. IG. — Incisors cf Horse at seven years. 
The illustration (Fig. 16) represents the above described 
characters of the seven-year-old mouth. 
