SEVENTH PAIR- — POETIO DUEA, OK FACIAL. 



497 



SIXTH PAIR ABDUCENS. 



This is a nerve of motion, has its apparent origin close behind 

 the pons Varolii, at its junction with the inferior pyramids, and 

 its fibres can be traced to the inferior pyramids and lateral bundles 

 of the medulla. From its origin it passes forwards through the 

 foramen lacerum orbitale, in company with the third and the 

 ophthalmic branch of the fifth nerves, and is distributed to the 

 abductor oculi, or external rectus, and the external portion of the 

 retractor oculi muscles. 



Fig. 18S. 

 Left side of the face— showing the distribution of the facial portions of the fifth and the seventh 

 nerves, a, Infraorbital; h, Masseter ; c, Superior ; d, Inferior branch of subzygomatic ; e, An- 

 terior : /, Middle ; g, Posterior auricular ; h h. Posterior temporal ; i, Cervical branch ; k, Styloid ; 

 I I I, Parotid branches ; m. Facial; n n' n", ltd superior portion ; o. Its inferior portion. 



SEVENTH PAIR PORTIO DURA, OR FACIAL. 



This nerve has its apparent origin in a depression in the 

 medulla oblongata between the olivary and restiform bodies : its 

 deep origin can be traced to the floor of the fourth ventricle and 

 olivary fasciculus. From its origin it passes outwards, in company 

 with the eighth nerve, along with which it enters the meatus 

 auditorius internus, and thence into the aqueduct of I'allopius, 



2 K 



