328 
On the Teeth of the Ox, Sheep, and Piy, 
this, but both they and our other breeds furnish some cases of the 
same kind. I have only met with about half a dozen cases where 
the second pair of incisors was cut before two years and tliree 
months, and tliese were in animals certified to be tico years and 
two months old. 
More prizes are now offered than formerly for the best 
bulls and heifers under two years old, and it is therefore of 
great importance to ascertain what is the state of the mouth 
at two, and a little after it ; — the limit in fact which belongs 
to the cutting of these teeth. At a recent Agricultural 
meeting a heifer was exhibited in this class, to which an 
objection was taken. The examination sliowed that there 
were four incisors, all well up. Satisfactory proof of the cor- 
rectness of the certificate was therefore called for, which having 
failed to be given, the animal Avas disqualified. According 
to the authority quoted in these pages, and the prevailing opinion 
of Agriculturists, this animal's mouth indicated three years of 
age, whereas she was probably but two and a quarter. An 
animal three months over age miglit be sent to compete in the 
"young class," but this cannot be supposed of a three-years-old. 
The existence of four permanent incisors, as a general rule, 
may be said to indicate two years and a half old, tliere being, 
however, some oxen that do not cut the second pair until after this 
time. Such animals come under our second table of dentition, 
which gives the average periods of the changes, when breed and 
other ?i;davourable causes are in operation. The case just cited, 
when contrasted with the latter named fact, not only confirms the 
propriety of classifying dentition under two heads, but proves 
the absolute necessity for so doing. 
At about txco years and a half the two anterior molars are also 
shed, and their places occupied by the permanent. These two 
teeth vary as to the order of their fall ; occasionally the 
first in position is changed before the second, but generally the 
second gives place to its permanent successor before the first. 
This irregularity of renewal is even greater in the sheep than in 
the ox, for in that animal, as will be hereafter explained, the third 
temj^orary molar will sometimes be the first to disappear. 
From two and a half to three years, the third molar of the ox 
falls, and the permanent one fills its place, thus completing the 
series of changes in these teeth. 
Annexed we have two illustrations of the molar teeth, the 
first of which, fig. 30, shows that the third temporary molar is 
unchanged at two years and a half, Avhen the first and second 
permanent are in their place, the second, fig. 31, that at three years 
the third permanent molar is also in situ. 
The difference in general form between the third permanent 
