340 
On the Teeth of the Ox, Sheep, and Pir/, 
An engraving (fig. 38) of the front part of the jaw of a ycar- 
okl sheep from a specimen of early teething, exhibits the central 
^ p,air of incisors, marked 1, 1, giving evi- 
' dence, when compared with the height 
i i and size of the temporary teeth, of having 
been very recently put up. The frequency 
of the cutting of the first pair of per- 
I manent incisors at a year old, by sheep 
of all breeds, has led to my taking this as 
one of the standards of comparison in the 
table of carhj dentition which is attached 
hereto. 
It will be found that the majority of sheep 
do not cut these teeth till they are about 
fifteen months old. The chief object of a 
tabular arrangement would, however, have 
been defeated, even if fourteen months 
had been fixed upon as the average time. The judge at a cattle- 
show might hesitate to award the prize, if he found a twelve or 
thirteen months' old sheep with two " broad teeth." The varia- 
tions in the teething of sheep, as in the ox, have required that 
they should be reduced to two standards of comparison rather 
than one, and therefoi'e in the first table the times of the earliest 
dentition are given as I have found them, taking one breed with 
another. 
At fifteen months, Avhen, as just remarked, the greater number 
of sheep cut their first permanent incisors, it must be remem- 
bered that the animal has five molars on either side of the jaws, 
and that tico of these are permanent. As this is an important 
period in the history of the dentition of the sheep, I add, as with 
the ox and pig, a view of one half of the lower jaw, dissected to 
show the true condition of both incisors and molars. In this 
illustration one of the first pair of permanent incisors (marked 1, 
fig. 39) is well up, and one of the second pair, 2, so far developed 
as to Ije soon cut. The other two incisors are as yet very small, 
and are situated, as seen in the figure, a little above the second 
incisor. The three anterior permanent molars are lying in their 
capsules at the roots of the corrcs])onding temporary teeth, each 
occupying about" the same height in the jaw ; a circumstance 
Avhich explains the fact that the temporary molars, as in sorne 
other animals, are changed nearly all together. 4 and 5 are per- 
manent teeth ; the first of them was cut at three months, and the 
second at nine. At this time (fifteen months) they greatly ex- 
ceed the others in size, but when the anterior molars are fully 
* Fig. 38. Front part of the lower jaw of a sheep, one year old, showing two 
permanent incisors, 1,1. Natural size, seen from above. 
