1912.] 



Temporal Bone not hitherto Described. 



325 



of its course. The auricular branch of the pneumogastric nerve passes 

 upwards from the jugular fossa through the bone towards the ganglion 

 (Plate 6, fig. 1, a.p.). 



The general position of the ganglion having now been described, it remains 

 to give a few details concerning its finer structure. This can only be done 

 from a series of microscopic sections. Such a series was made, but the 

 decalcification process was too energetic, and in some of the sections portions 

 of the bone and even portions of the ganglion itself have been washed away. 



The ganglion is A r ery irregular in shape, and is surrounded on all sides by 

 bone. As a result of this irregularity in shape different portions of the 

 structure come into view in different portions of the same section, so that 

 at first sight it would appear that there are two or more ganglia. But 

 when the series is studied carefully it is found that this appearance is merely 

 due to the presence of outlying semi-detached portions of one ganglion. 



The name which I propose to give to the structure is "the Stapedial 

 Ganglion." It is situated close to the lowest point of the stapedius muscle 

 in man, and the name suggested is, perhaps, as appropriate as any. 



The first section (fig. 2) passes through the anterior portion of the 

 ganglion. Considerable portions both of the bone and of the ganglion itself 

 have been lost in the course of preparation, but the upper and lower parts 

 of the latter are seen, g.g. The posterior semicircular canal is seen to the 

 left of the uppermost portion of the ganglion, and the jugular fossa is shown 

 in the left lower part of the photograph. A bundle of fibres derived from 

 Arnold's nerve runs in the direction of the gang-lion. 



Fig. 2. 



/". facial nerve ; p. posterior semicircular canal ; g.g. ganglion ; j. jugular fossa ; 

 a. auricular branch of vagus nerve. 



