722 THE NEEVES. 



immediately beneath the temporo-maxillary articulation. There it ter- 

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

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

 plexus (pes anserinus, Fig. 110). 



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

 furnishes : 



1. The great superficial petrous nerve (nervus petrosus superficialis major). 



2. The small superficial petrous 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. 



6. 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 ctrvical 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. 



c. To this collection of collateral ramuscules are added the terminal 

 branches, formed by their anastomoses with the superficial temporal nerve : 



14. The subzygomatic plexus. 



A. COLLATERAL BRANCHES. 1. GREAT SUPERFICIAL PETROUS NERVE. 

 This is a very remarkable ramuscule, which is detached from the bend of 

 the facial nerve to proceed to Meckel's ganglion. The importance of the 

 peculiarities attaching to the study of this nerve requires us to call special 

 attention to its origin, course, and termination; though the details into 

 which we are about to enter may be omitted by the student. 



Origin. Ganglion geniculare. The manner in which the great super- 

 ficial petrous nerve comports itself at its origin is yet an obscure and 

 controverted fact, on which however light is beginning to be thrown. The 

 following is the most general opinion : This nerve arises from a small grey 

 enlargement, the genicular ganglion (or intumescentia gangliformis), placed 

 on the course of the facial nerve, at the summit of the angle which that 

 nervous trunk describes after its entrance into the aqueduct of Fallopius ; and 

 the presence of this small ganglion on the seventh pair should assimilate the 

 facial to a mixed nerve, whose sensitive root would be represented by the 

 portio intermedia of Wrisberg a thin filament comprised between the seventh 

 and eighth pair, and which emanates directly from the medulla oblongata to 

 pass into the posterior part of the ganglion geniculare. 



We have constantly .found this ganglion in the domesticated animals. 

 There exists, in fact, on this angle or elbow of the facial nerve, a very slight, 

 grey, conical prominence, composed of ganglionic corpuscles which a micro- 

 scopical examination readily reveals, and giving origin on its apex to the 

 great superficial petrous nerve. This prominence, which, we repeat, is very 



