826 THE NERVES. 



column, and that portion of the restiform body which is continuous with the 

 large root of the fifth pair. Arrived near the floor of the foui'th ventricle, the 

 facial nerve separates into two fasciculi. The less important goes to a nucleus 

 confounded with that of the external motores oculorum ; the other passes back- 

 wards, and forms a prominence (fasciculus teres) on the floor of the fourth 

 ventricle ; then it is suddenly inflected outwards and forwards, forming a bend 

 (the geniculate ganglion, genu facialis (Fig. 452, TT) described by Deiters, 

 Vulpian, etc., and terminates in a nucleus {posterior or inferior nucleus) situated 

 in the lateral parts of the medulla oblongata, on the prolongation of the inferior 

 cornua of the spinal cord (Fig. 452, Fi). The cells of the nucleus are multi- 

 polar, pigmented, and larger than those of the anterior nucleus. In the Cat, 

 the principal fasciculus has no bend or genu. 



Course. — Scarcely has the facial nerve left the medulla oblongata, than it is 

 directed outwards, to pass into the internal auditory meatus, along with the 

 auditory nerve, which lies in contact with it behind. It afterwards enters the 

 aqueduct of Fallopius, courses along it, and follows its inflections, which results 

 in its forming a bend forward at a short distance from the internal opening of 

 the canal, and a curve with concavity anterior, on its passage behind the cavity 

 of the tympanum. On leaving the aqueductus Fallopii by the stylo-mastoid 

 foramen, it is hidden beneath the deep face of the parotid gland, and continues 

 to be inflected forward — passing between that gland and the guttural pouch — and 

 reaches the posterior border of the inferior maxilla, where it issues from beneath 

 the anterior margin of the parotid to become superficial and place itself on the 

 masseter muscle, immediately beneath the temporo-maxillary articulation. There 

 it terminates in two or three branches, which anastomose with those of the super- 

 ficial temporal nerve from the fifth pair, thus forming the facial or subzygomatic 

 plexus {pes anserinus) (Fig. 168). 



Distribution. — a. In its interosseous course, the facial nerve successively 

 furnishes — 



1. The, great superficial petrosal nerve {nervus petrosus superficialis major). 



2. The small superficial petrosal nerve {nervus petrosus superficialis minor). 



3. The filament of the stapedius muscle {tympanic branch). 



4. The chorda tympani. 



It communicates, besides, with the pneumogastric nerve, by means of a 

 voluminous filament described as — \ 



5. The anastomotic branch of the pneumogastric. 



b. The branches it emits on its course beneath the parotid gland arise either 

 from its superior or inferior border ; they are — 



6. The occipito-styloid nerve. 



7. The stylo-hyoid nerve. 



8. The digastric nerve. 



9. The cervical ramuscule. 



10. Filaments to the guttural pouch and parotid gland. 

 The superior branches comprise : — 



11. The posterior auricular nerve. 



12. The middle auricular nerve. 



13. The anterior auricular nerve.^ 



■ It Is necessary to add to these branches, those which go to the parotid gland, the 

 stimulation of which excites its secretion. Moussu believes at present, that these excito 

 secretory branches do not really come from the seventh, but from the ninth pair. 



