ON THE TEETH OF CATTLE, AS INDICATING THE AGE. 209 
may be easily extracted. They are the wolves’ teeth of the horse, 
which are the milk grinders, pushed out of their places, and 
although not expelled by the new molars, reduced by their pres¬ 
sure to a very little size, and yet sometimes exceedingly trouble¬ 
some. 
A beast of six years has all the incisor teeth fully grown. 
The edges of these teeth have, however, been gradually wearing 
down. Even at three years the edge of the central incisors is 
taken off. At four years, a dark waving line, shewing the bone 
beneath, begins to appear. At five, this is seen in the four cen¬ 
tral ones; and at six it has extended over the whole set. At 
seven it is becoming broader and more irregular in them all, with 
a second, and broader and more circular mark appearing within 
the former one, and which, at eight, has extended over the six 
middle teeth. 
At nine, the process of diminution which was observed in the 
milk teeth is beginning to appear in the permanent ones, and 
the two central teeth are evidently smaller than their neighbours; 
and the two dark marks in all except the corner teeth are rubbed 
into one, of a triangular shape. At ten, the four central incisors are 
diminished, and the mark is becoming smaller and fainter. At 
eleven, it is so with the six central ones; and at twelve, all are 
much diminished ; but not to the extent to which the diminution 
of the milk teeth was carried, and therefore these teeth are much 
closer together than the milk teeth of the eighteen-month steer 
were. The mark is now very faint, or nearly obliterated, except in 
the corner teeth, and the inner edge is worn down to the gum. 
It is seldom that the animal is suffered to live beyond this 
period, because he is materially decreasing in value ; but some 
favourite bulls have been retained until they were more than 
twenty years old. Cattle usually begin to lose condition, and 
sometimes rapidly, at twelve, and the reason is evident—the teeth 
are not only blunt and flat, but small and far apart, and the 
animal has much difficulty in cropping sufficient nutriment. 
The author of the “ Illustrations of Natural History,” who is 
always interesting and generally correct, gives a very strange ac¬ 
count of the process of dentition in cattle, page GO. “The age 
of the ox is known by the teeth and horns. The animal is fur¬ 
nished with eight cutting teeth in the lower jaw; at the age of 
ten months the two middlemost of these fail out, and are re¬ 
placed by others that are not so white but broader. At the age 
of sixteen months the two next milk-white teeth fall out likewise, 
and others come up in their room : thus, at the end of every six 
months, the creature loses and gains Till he arrives at the age of 
three years; when all the cutting teeth are renewed, and then 
VOL. III. 1 f 
