320 
On the Teeth of the Ox, Sheep, and Fig, 
Fig. 23. * 
kind of molars v.liich occupy the mouth. It may be added that 
the form of this tooth beautifully adapts it to its oflTice, for in the 
act of mastication its pro- 
jections intersect those of 
the corresponding inolar 
in the upper jaw, and thus 
effectually grind down the 
food which is submitted 
to their action. 
The putting up of the 
temporary incisors and 
molars at al)out a month, 
completes " first denti- 
tion," and as there are 
now a given number of 
teeth, so any addition to 
them will mark an import- 
ant stage in the further 
process of teething. When 
this addition takes place, 
the temporary teeth, 
merely by their number, 
cannot avail in our inqui- 
ries, nor can they be said 
materially to do so up to 
that period by the slight 
wear they may have un- 
dergone. The general ap- 
pearance of the young 
animal, for the first few 
months, suffices to foi'm 
a fair estimate of its age. 
As the temporary inci- 
sors agree in number with 
the permanent, but the 
temporary molars are but 
a moiety of the whole, of 
these teeth, so the addi- 
tion is necessai'ily made 
to the latter. Inquirers 
into the age of the ox 
have assigned very differ- 
ent dates for the appear- 
* Fig. 23. Side view of one half of the lower jaw of a six-mouths-old calf, 
showing that the fourth molar tooth, 4 P. M., is cut. Reduced one fourth from the 
natural size. 
