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HO HUNTER ON THE TEETH.

at that part so well, as at the side of the Jaw ; and, instead of
the grinding motion, which would be useless, where there are
no Grinders ; they bruise their food rather by a simple motion
of the Jaw upwards and downwards.
It is from the want of Teeth in both those ages, that the
face is shorter in proportion to its breadth. In an old person,
after the Teeth are gone, the face is shorter, while the mouth
is shut, by almost the whole lengths of the Teeth in both Jaws
;
that is, about an inch and an half.
From the want of Teeth too, at both those ages, the cavity
of the mouth is then smaller ; and the tongue seems too large
and unmanageable, more especially in old people. In these
last we observed also, that the chin projects forwards, in pro-
portion as the mouth is shut ; because the basis of the Lower-
Jaw (which is all that now remains) describes a wider circle
than the Alveolar Process in younger people. The Jaws do
not project so much forwards in a child, as in an adult ; hence
the face is natter, especially at the lower part. In proportion
as the last Grinders are produced, the sides of the curve formed
by the Jaws become longer, and push forward the fore-part,
none of the additional part passing backwards. The fore-part
also continues nearly of the same size, so that the whole Jaw
is longer in proportion to its breadth, and projects farther
forwards.

OF THE FORMATION OF THE ALVEOLAR PROCESS.
Having considered the Alveolar Processes in their adult, or
perfect state, we shall next examine and trace them from their
beginning.
"We observe the beginning of the Alveolar Process at a very
early period. In a fcetus of three or four months it is only a
longitudinal groove, deeper and narrower forwards, and becom-
ing gradually more shallow and wider backwards: instead of
bony partitions, dividing that groove into a number of sockets,
there are only slight ridges across the bottom and sides, with
intermediate depressions, which mark the future Alveoli.