(The extrinsic muscles of the tongue (p. 228, and Figs. 67 and 96) may
be dissected at this point, if desired. (_a_) The styloglossus; (_b_)
the genioglossus; (_c_) the hyoglossus. They need not be cut.)
11. The masseter (p. 108, and Fig. 65, _a_). Cut the superficial and
middle layers near their insertions by incisions parallel to the border
of the jaw. Cut the deep layer near its origin. Look for the origin of
fibres of the temporal muscle from the inner surface of the middle
layer.
12. The temporal (p. 110, and Fig. 63, _n_). Clear its outer surface
completely. Cut the temporal fascia transversely and reflect it toward
the insertion of the muscle, with the superficial portion of the muscle.
Cut through the zygomatic arch at its two ends and remove it, dissecting
the fibres of the temporal free from their origin on its inner surface.
Then examine the insertion of the temporal.
(The muscles of the pharynx (p. 232) may be dissected at this point; for
directions, see page 451.)
13. The ceratohyoid (p. 115). To uncover this, the middle constrictor of
the pharynx (Fig. 67, _j_) must be cut and reflected.
Cut the mylohyoid, geniohyoid, genioglossus, and the mucosa of the floor
of the mouth free from the mandible on both sides, so that the tongue
and the floor of the mouth may be drawn ventrad and turned out of the
way, exposing the roof of the mouth (as in Fig. 66, p. 112). Cut through
one side of the pharynx near the ventral surface and turn the tongue
toward the uncut side.