THE RAMUS LATERALIS VAGL II9 



X. — The Ramus Lateralis Vagi. 



The ramus lateralis at its ganglion turns abruptly out- 

 ward under the dorsal musculature and soon turns caudad. 

 Its branches will be described from before backward. 



/. — Ramus Siiprateinporalis Vagi. 



This nerve arises from the dorsal surface of the lateralis 

 ganglion and runs cephalad under the dorsal musculature 

 and external to the auditory capsule. About two-thirds 

 of its fibres are of the coarse lateralis variety, the re- 

 mainder being finer fibres probably in part derived from 

 the anastomosing communis root from the IX nerve, and 

 representing the vagal root of the r. lateralis accessorius. 

 About .3 mm. from the ganglion it gives off a branch 

 which passes dorsad and caudad to the single canal organ 

 of the occipital commissure, which lies in the same trans- 

 verse plane as the lateralis ganglion. This branch, though 

 mainly coarse-fibred, draws off a few fine fibres {a. r. VII. 2 

 of Fig. 4) which, instead of turning back to the canal 

 organ, go directly dorsad to the skin, under which they 

 pass dorsad and then cephalad to join the r. lateralis 

 accessorius near the median line (600, Fig, 3). 



The remainder of the r. supra-temporalis (partly coarse 

 and partly fine fibres) continues cephalad along the dorsal- 

 surface of the squamosal bone, being crowded laterally 

 and dorsally by the projecting ear capsule. At 620 the 

 coarse fibres separate and enter the canal organ (Fig. 5, 

 in. I.) of the main canal between the mandibular and 

 infra-orbital canals. The finer fibres continue cephalad 

 for a time along the squamosal bone just dorsally of the 

 bony canal, gradually passing laterally to the skin under 

 which they continue cephalad to 550. Here they divide, 

 the larger portion turning directly laterally to supply a 



