THE PERIPHERAL NERVOUS SYSTEM. 377 
zygomatic process of the temporal, and joins the lingual nerve 
(Fig. 154, 4) (branch of the third division of the fifth nerve). 
On emerging from the stylomastoid foramen the facial 
nerve (Fig. 155, a) gives off at once a small branch (4) to the 
digastric muscle (1), and.a larger branch, N. auricularis 
posterior (c), which passes dorsocaudad about the base of the 
ear, supplying some of its muscles. Another small branch (d) 
pierces the cartilaginous external ear and is distributed to its 
inner surface. The facial nerve then curves craniad about the 
proximal part of the cartilaginous external ear, and divides five 
or six millimeters from its emergence into two main branches, 
which may be designated as the dorsal (/) and ventral (e) 
rami. A third small branch may also rise from the point of 
union of the two; it is usually, however, a twig from the dor- 
sal ramus, and passes to M. submentalis. 
The dorsal ramus (/) sends two or three small branches 
to the cheek (including the one just mentioned), and divides 
into the temporal (g) and the zygomatic (%) branches. The 
former (g) passes along the cranial margin of the external ear, 
supplying the superficial muscles, and extends into the tem- 
poral region, where it lies deeper than the terminal branches 
of the lachrymal nerve (m) (from the fifth cranial). The 
zygomatic branch (/) passes across the malar bone to the 
caudal angle of the eye, sends branches into both eyelids, 
anastomoses with twigs from the lachrymal branch (yz) of the 
fifth nerve, and passes along the medial side of the eye to the 
lateral surface of the nose, where it ramifies. 
The ventral ramus (¢) gives off a minute branch (z) to the 
stylohyoid muscle (2), then proceeds toward the angle of the 
mouth and divides into superior (£) and inferior (7) buccal 
branches, the former to the muscles of the upper lip and the 
contiguous regions, the latter to those of the lower lip and 
chin. 
The seventh nerve thus supplies most of the muscles of the 
head except those of mastication, and of these it supplies the 
digastric. 
VIII. N. acusticus.—The eighth or auditory nerve takes 
origin (Fig. 138, V//7) from the floor of the fourth ventricle, 
