THE PERIPHERAL NERVOUS SYSTEM. 375 
J. N. alveolaris inferior (Fig. 154, @).— This passes 
toward the mandibular foramen, but before reaching it gives 
off a branch to the mylohyoid and digastric muscles. It then 
enters the foramen, passes through the mandibular canal, and 
gives numerous inferior dental branches to the teeth. At the 
mental foramen (or foramina) it passes out of the canal and 
divides into several mental nerves, to the chin, lower lip, and 
mucosa of the lower jaw. 
g. N. lingualis (Fig. 154, 4).—The lingual nerve passes 
between the internal and external pterygoid muscles, and two 
or three millimeters from its origin it receives the chorda tym- 
pani nerve (c), a communicating branch from the facial (see 
page 376). It passes onto the ventral surface of the external 
pterygoid, thence onto the side of the tongue, beneath the 
mylohyoid. On the side of the tongue it divides into branches 
which enter the tongue and are distributed to its mucous mem- 
brane. One branch passes to the mucosa of the pharynx. 
Just before entering the tongue a branch is given off to the 
sublingual and submaxillary glands. 
VI. N. ABDUCENS.—The sixth nerve, the abducens, arises 
from the medulla, as already described (Fig. 138, V/, and page 
347). It passes into the orbit through the orbital fissure, then 
extends obliquely cranioventrad along the medial surface of 
the lateral rectus muscle (Fig. 154, #). At about the middle 
of the length of the muscle it divides into two or three branches 
which enter at once into the lateral rectus and supply it. 
VII. N. FACIALIS (Fig. 155).—The seventh or facial nerve 
arises from the trapezium at the caudal margin of the pons, 
craniad of the origin of the eighth nerve, as described in the 
account of the brain (Fig. 138, V//). It passes into the 
internal auditory meatus, traverses the facial canal through the 
petrous bone, and emerges at the stylomastoid foramen. 
Within the facial canal the nerve bears an enlargement, 
the ganglion geniculi. It gives off within the canal a branch 
to the stapedius muscle, and the superficial petrosal and 
chorda tympani nerves. 
The superficial petrosal (N. petrosus superficialis major) 
nerve passes into the hiatus facialis, through the canal which 
