NERVUS FACIALIS OF ALBINO MOUSE 121 



spinal V tract, this tract being considered as a tract whose 

 nucleus is generally cutaneous in function. 



Van Gehuchten ('98) found that a few cells of the geniculate 

 ganglion degenerate after cutting the facial nerve at its exit from 

 the facial canal. In an abstract of an article by DeGaetani ('06) 

 sensory fibers in the ramus temporofacialis are. mentioned. 

 Weigner ('05) describes fibers of small caliber, presumably in- 

 termedins fibers, in the facial nerve of man distal to the origin 

 of the chorda tympani. 



The chief clinical evidence for the presence of such fibers in 

 the facial nerve has been presented by Hunt ('15). By a method 

 which he calls the herpetic method and which is based on the fact 

 that herpetic vesicles on the skin are caused by pathological proc- 

 esses involving the ganglion from which the cutaneous fibers 

 arise, he attributes the supply of certain parts of the auricle, 

 including the concha, to the facial nerve. One of the probable 

 pathways to the skin for these fibers which he mentions is through 

 the auricular branch of the vagus. In the different cases reported 

 the areas showing the herpetic eruption vary to some extent. If 

 homologous conditions are found in man to those here reported 

 in the mouse this variation can probably be accounted for by the 

 mixing of the vagus and facial fibers at the point of the anastomosis. 



In the mouse there is no evidence that either the inner or 

 middle ear receive fibers from the facial nerve. A communicating 

 branch from the facial nerve to the tympanic plexus is not 

 present in any of my series. 



5. Nervus auricularis posterior and the nerves to the stylohyoid and 



digastric muscles 



The posterior auricular nerve arises from the lateral side of 

 the facial nerve just distal to the origin of the ramus cutaneus 

 (figs. 11 and 12, R.Aur.P.) . It passes dorsally behind the auricle 

 and is distributed to the muscles posterior to and along the 

 cranial side of the auricle. It is composed of fibers from the 

 motor part of the facial and is a purely motor nerve. A similar 

 area of skin of the auricle is supplied by sensory fibers from the 

 second and third cervical nerves. 



