286 
Oji the Teeth of the Ox, Sheep, and Pig, 
preceded by deciduous teeth. Appearing above the gums, usu- 
ally between the fourth and fifth years of his age, should they 
fall by accident they are not renewed. 
Tlie part of the tush which protrudes above the gum is more 
or less cone-shaped in all animals. Sometimes it terminates in 
a tolerably sharp point, at others its apex is rounded, as is more 
particularly- the case with the upper tush of the pig. The em- 
bedded portion frequently is but a continuation of the pro- 
truding ar, to form, and consequently vi^hen the tooth is fully 
developed, its larsrest part is that which is embraced by tlie 
gum. In the pig and his congeners, the greater portion of the tush 
which is implanted in the jaw is but a prolongation of the base 
of the cone.* The deeper or further the tooth extends, until its 
final length is nearly acquired, the larger does it become. When 
its dimensions, however, have been fully reached, we have then a 
slight diminution of the end of the fang, approaching again the 
conical form. The height of the protruding part Avill often give 
but a very imperfect idea of the entire length of the tush. In a 
specimen now before me, from a pig of ten months of age, the 
tooth measures more than three inches and a half long, while the 
portion which had penetrated the gum is less than half an inch 
in length. This explains how it is tliat the tush in time so far 
exceeds the otlier teeth in the height it attains. It is also to be 
remembered that, long after the period of the animal's life which 
has been named, the tush continues to grow, from its persistent 
dentinal pulp. To provide for this increasing length, the tooth 
is curved so as to form the segment of a circle, having its em- 
bedded part lying below the fangs of the anterior molar teeth, 
and occupying thereby far less space in the jaw than otlierwise it 
would do. 1 pass to a general description of the molar teeth. 
The molars, or, as they are commonly called, the grinders, are 
placed at the back part of the mouth. In the ox and sheep, the 
permanent molars, when completed, are 24, as in most animals, 
arranged in sets of six on either side of the upper and lower 
jaws, as seen in fig. 35.t The temporary molars are only 12 ; 
they occupy a like situation, giving place in due time to an equal 
number of permanent teeth, 12 being added to complete the set. 
Occasionally, in all animals, supernumerary molars are present. 
These are always placed, one on either side, in front of their re- 
spective rows, and are very small compared with the other teeth. 
So frequently do these additional teeth exist in both jaws of the 
* It is necessary to state that these remarks apply especially to the tushes of the 
t This figure is referred to simply to show the relative position of the molar 
teeth. It represents the skull of a three months old lamb, and as such, but four 
molars are seen above and below. 
