256 Journal of Comparative Neurology. 



"mandibularis externus" and "hyoideus, " for example, because 

 our present knowledge does not seem to warrant the applica- 

 tion of these latter terms to nerves of Urodela without exten- 

 sive and precise limitations in each instance. Such limitations 

 would elucidate nothing, and would ultimately tend to confusion. 



/. — TJie Roots and Ganglia. 



In his description of the roots and ganglia of the fifth and 

 seventh nerves in Amblystoma, Strong ('95, p. 132) states 

 that the communis VII root arises dorsally of the VIII root. 

 These results differ from mine. In a projection on the sagittal 

 plane the communis VII root is plainly shown to arise dorsally 

 of the ventral VIII but anteriorly (cephalad) of the dorsal 

 VIII root. 



Kingsbury ('95) and Bowers ('00), also, described the 

 communis VII root as emerging dorsally of the VIII root in 

 Necturus and Spelerpes. It should be noticed, however, that 

 these two authors do not distinguish two acustic roots. It is 

 possible that the auditory nerve of Spelerpes and Necturus 

 differ in this regard from the auditory nerve of Amblystoma, 

 but the peripheral relations of the acusticus will scarcely sup- 

 port such an hypothesis. Moreover, Strong's statement con- 

 cerning Amblystoma suggests that the relative position of the 

 communis root in Urodela has been misinterpreted. Indeed any 

 transverse section of the medulla through the communis root 

 at its origin will show acustic fibers emerging ventrally of the 

 communis root. But when projected upon the sagittal plane, 

 the auditory fibers are seen to emerge also caudally of the com- 

 munis root. Excepting the point just mentioned, Necturus 

 and Spelerpes do not seem to differ from Amblystoma with 

 regard to the roots and ganglia of the fifth and seventh nerves. 

 The description of these parts in Desmognathus by Fish ('95), 

 however, shows some irregularities. Fish says, "from the 

 common trunk" (evidently referring to the common root of the 

 facial and auditory nerves) "there passes a good sized branch 

 towards the dorsal surface of the Gasserian ganglion." This 

 branch, he maintains, "probably corresponds to the palatinus 



