OF DOMESTICATED ANIMALS. 593 
with the permanent ones, whether in the adult animal, or one 
of the age of three years. 
The protrusion and wear of the incisors and tushes. —At its 
birth, the pig generally has the corner teeth and the tushes in 
both jaws ; and at the expiration of three or four months, all the 
milk teeth are cut. 
At six months^ the corner teeth of the lower jaw are shed, and 
the permanent ones appear at the expiration of a few days. 
At this time the pincers and the middle teeth are worn on their 
upper surface. 
At ten months, the supernumerary incisor of the upper jaw 
gives place to the permanent tooth, and its fall is followed or 
accompanied by that of the inferior supernumerary incisor. 
At some period between eight and eleven months, the milk 
tushes are lost, and the permanent ones speedily follow, consi¬ 
derably stronger and larger. 
In the course of from twenty months to two years, the pincers 
of both jaws are replaced by the permanent ones. 
From two years and a half to three years, the middle teeth 
undergo the same changes, and the hog will then have acquired 
all his permanent teeth. He is then said to have a perfect 
mouth. 
All the incisor teeth, and the inferior tushes, become blunted 
and rounded, and there is a gradual obliteration of the cavity 
on their surface: but these various alterations, complicated 
with the loss of some teeth and the breaking of others, 
and particularly of the corner ones, have not been observed with 
sufficient accuracy to afford any exact indication of the age. 
Section II.— The Molar Teeth. 
The molars of the hog are seven in number on each side, above 
and below. They increase gradually in size from the first to the 
last; the last is always the largest, and it is of the form of a 
triple crown. The first of these teeth, the supernumerary molar, 
is not renewed, and which continues only until a certain age. 
The inferior supernumerary molar, larger than that above, is 
analogous to the supernumerary incisor of that jaw. It has the 
form of a fleur-de-lis, and is isolated between the tush and the 
real molar. The supplementary tooth of the superior jaw touches 
the molar next to it, and seems to assist it in the mastication of 
the food. The three inferior molars, behind the sujiplementary 
one (avant molaires)f are depressed laterally ; their surface is 
elongated from before backwards, and divided at several irregular 
points. 
The back molars (arrierc molaires), larger than the front ones, 
