342 On the Teeth of the Ox, Sheep, and Pirj, 
stones of 1-i lbs. each, the largest over shown there of that breed, and that he 
had not one of his jjcrmancnt teeth. There are also irregularities in the times 
of renewing the teeth, not to be accounted for by either of these circumstances ; 
in fact, not to be accounted for by any known circumstances relating to the 
breed or the keeping of the sheep." 
Mr. Youatt follows up these remarks by quoting some cases of 
irregular dentition ; but to comment on them would draw me 
Pi„ 45 , too far from my subject. At 
eighteen months most slipep 
will cut the sixth molar tooth, 
another important stage in den- 
tition. Many animals, however, 
at this date are still without the 
second pair of permanent inci- 
sors. If, on the contrary, these 
teeth should be in the mouth 
and nearly on a level with the 
first pair, and the sixth molar 
not cutting but well up, such 
would be a proper case for in- 
vestigation, if the animal were 
certified to be only eighteen 
months old. Figure 40 repre- 
sents the cutting of the sixth 
molar, and also the general state 
of the mouth at this time in a 
case of early dentition. It will 
•be noticed that the second pair 
of permanent incisors is of 
small size, and the anterior 
molar teeth all temporary ones. 
As with the first pair of 
" broad teeth," so with the se- 
cond, many sheep do not put 
tht-m up until three months 
after others. A year and three 
quarters is the average time 
when sheep will cut their se- 
cond pair of permanent inci- 
sors. But instances are not 
wanting of sheep being nearly 
two years old before these teeth 
are in the mouth. In fig. 41 
is shown the appeai'ance of the 
teeth under ordinary circum- 
* Fig. 40. One half of the lower jaw at 18 months, representing the cutting of 
the last molar tooth. Natural size,. 
