The Nervous System 137 
by different paths, to the inner skin of the 
mouth; (b’) the second twig divides into four 
parts—two leading to the mylohyoid muscle 
and to the integument at the corner of the 
mouth, one to the integumental glands at the 
corner of the mouth, and one to the floor of 
the mouth cavity. 
VI. The abducens nerve leads to the retractor 
oculi muscle and to the muscle for the nictitating 
membrane. 
VII. The facial nerve gives off three main 
branches: (1) the first divides again into three 
twigs—(a) connecting with a branch of the trigemi- 
nal nerve, (b) and (c) connecting with the trigem- 
inal and also leading to the palate; (2) the second 
branch divides into two twigs that connect with 
the glossopharyngeal nerve; (3) the third branch 
divides into two parts, a muscular twig, and the 
chorda tympani. 
VIII. The auditory or acoustic nerve leads, of 
course, to the sensory regions of the ear. 
IX. The glossopharyngeal nerve divides into 
four main branches, as follows: (1) to the larynx, 
(2) to the cesophagus, (3) to the hyomaxillary 
and sterno-maxillary muscles, and (4) to the tongue. 
There are also certain communicating twigs with 
the facial and vagus nerves. 
X. The vagus or pneumogastric nerve gives 
off four branches: (1) and (2) communicate with 
each other and supply the pharynx, larynx, cesoph- 
