2i6' Mr. Corse's Observations on the 
the same manner, to the one next it, till the whole are thus 
gradually joined, and form a grinder or case of teeth. 
As soon as the anterior part of the grinder is thus firmly 
united, the fangs or roots are next added : these, at first, appear 
in the form of a thin curtain or lamella of bone, extending 
backwards, along some of the anterior laminae, at their lower 
edges. (Tab. VI. VII. VIII. and XI.) A fang common to the 
three anterior teeth, first begins to be formed (Tab. VII. and 
XI. ) by the ossification shooting across from each side, in a 
circular direction, at the anterior portion of the first, and the 
posterior part of the third lamina. These join and become 
longer, assuming a conical shape : the hollow is gradually filled 
up by successive layers of the substance of the tooth, as the 
fang lengthens, till at last it becomes solid. (Tab. XII.) This, 
however, does not happen, till the three layers to hich the 
fang is attached are nearly worn away. When its ossificat on is 
almost completed, another process begins to take place, which 
is, the absorption of the fang from its external surface. (Tab. 
VII. and XII.) 
By the time that the anterior layers of the grinders are com- 
pletely worn down, both the fangs and the alveolar processes 
begin to be absorbed. (Tab. VII. X. and XII.) Their places are 
gradually supplied by the next laminae of the grinder, and 
their fangs, coming forward in a constant succession. When 
the last tooth of a grinder has advanced sufficiently in the 
jaw, to supply the place of its predecessor, the anterior tooth 
of the next succeeding grinder comes forward, to supply its 
place. 
From the peculiar manner in which the grinders are supplied 
from behind, but never from beneath, a preceding grinder, (as is 
