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10

SECTION III

OF THE ARTICULATION OF THE LOWER JAW."

Just under the beginning of the zygomatic process of
each temporal bone, before the external meatus auditorius,
an oblong cavity may be observed ; in direction, length and
breadth, in some measure corresponding with the condyle of
the lower jaw. Before, and adjoining to this cavity, there is an
oblong eminence, placed in the same direction, convex upon
the top, in the direction of its shorter axis, which runs from be-
hind forwards ; and a little concave in the direction of its lon-
ger axis, which runs from within outwards. It is a little
broader at its outer extremity, as the outer corresponding end
of the condyle describes a larger circle in its motion than the
inner. The surface of the cavity, and eminence, is covered
with one continued smooth, cartilaginous crust, which is
somewhat ligamentous ; for, by putrefaction, it peels off like
a membrane with the common periosteum. Both the cavity
and eminence serve for the motion of the condyle of the
lower jaw. The surface of the cavity is directed down-
ward ; that of the eminence downward and backward,
in such a manner that a tranverse section of both would
represent the italic letter S. Though the eminence may
on a first view of it, appear to project considerably be-
low the cavity, yet a line drawn from the bottom of
the cavity to the most depending part of the eminence,
is almost horizontal, and therefore nearly parallel with
the line made by the grinding surfaces of the teeth in the
upper jaw : and when we consider the articulation farther,

* Hunter, page 9—11.