82 'Journal of Comparative Neurology and Psychology. 



Ixxv, Plate V; Gadus, Fig. xciii, Plate VI) a small part of the 

 fibers pass in a frontal direction, but a much larger part caudad 

 at the outer margin of this region under the cerebellar crest (Figs. 

 Ixxvii, xcv.) 



The descending fibers ma 7 be followed as far as the place where 

 the ascending fibers of the radix lateralis posterior end, the two 

 roots mingling and thus constituting a proof of the functional 

 relation between the posterior root which enters with ,the glosso- 

 pharyngeus and the anterior root entering with the octavus. In 

 the young Lophius the anterior root enters as one root, and this is 

 the case with Gadus morrhua also, as already stated by Cole, 

 and C. J. Herrick. 



The part of the oblongata where the nervus lateralis ends is 

 covered by the cerebellar crest, which we know from the investi- 

 gations of ScHAPER, Haller (telcosts and selachians), Johnston 

 (ganoids) and others to contain cells related to and very similar 

 to those of the molecular layer and Purkinje layer of the cere- 

 bellum, of which it is a continuation. Under, and in, this layer 

 the nervus lateralis probably sends its final ramifications. I 

 cannot state for certain w^hether the ascending fibers of the lateral 

 nerves reach the cerebellum, as Johnston states for Acipenser; 

 in any case they reach as far as the cerebellum and it is more than 

 probable that between the ascending cerebellar tracts of this 

 region there are also direct cerebellar connections with the lateralis 

 system, as is evident for the acusticus. The number of the bun- 

 dles going in a backward direction is much larger, but I could not 

 follow them as far as the nucleus Rolandi either in Lophius or in 

 Gadus, in which they end in the posterior part of the tuberculum 

 acustico-laterale. 



In recent times this radix anterior lateralis has generally been 

 considered as belonging to the facialis, as it leaves the brain in its 

 immediate neighborhood. But two arguments contrary to this 

 opinion may be mentioned: (i) its terminal region, which in the 

 teleosts is identical with the terminal region of the acusticus; 

 (2) the function of this radix lateralis, which, like the posterior 

 root of the ner\ais lateralis, accords with that of the labyrinth. 

 In my opinion it is better to treat the radices laterales separately, 

 or to consider them to belong to the eighth nerve, especially the 

 vestibular root. 



Authors are in general agreement on the character and origin 



