130 DADD’S VETERINARY MEDICINE AND SURGERY. 
mode of obtaining the one or the other makes considerable differ- 
ence in the wear and tear of the same, consequently we must 
bear in mind that the popular theory of “age” is sometimes more 
arbitrary than truthful, and allowances for the same must be 
made. At the age of two, or a few months over, the front perma- 
nent tecth ought to appear, and, consequently, at the age of three, 
varying a few months, the middle teeth are up. At fous, varying 
as in the preceding cases, the corner teeth begin to show them- 
selves, and are not up square with the others until the fifth year 
The animal now emergcs from colthood, and is known as a horse, 
As regards the female, during her minority she is termed “ fil/y;” 
at five she enters the adult stage, and, consequently, is denomi- 
Fig. 10 
A YOUNG HORSE'S MOUTH. 
nated a mare. Supposing the horse to have a full set of nippers, 
or incisors, at the age of five, the marks, or black incrustation, 
will have so worn away at six as to leave a faint brown mark 
At seven, similar appearances have taken place in the two next, 
or middle, teeth. At eight the marks, or rather the cavities, of 
the two next, or corner teeth, are now about obliterated, and the 
face of the teeth are nearly level, and the central enamel is nearer 
the inward than the outward border. After the marks have all 
disappeared in the lower jaw, the exact age can not clearly be 
shown. At the age of nine the front teeth appear somewhat 
rounded; the middle and corner ones contract their oval faces, 
and the central enamel diminishes and approaches the inward 
border. At ten the middle incisors resemble those at nine, and 
the central enamel has approximated the inward border and is 
rounded. At eleven the middle teeth resemble ‘hose at ten, and 
