Kingsbury, Brain of Nectmus. 183 



ectad of the endyma, causing a slight elevation. In this position 

 they run cephalad to just caudad of the exit of the eighth where 

 they turn laterad and ventrad, in two (or three) bundles, to 

 leave the oblongata as the motor roots of the seventh nerve, 

 and immediately unite with the issuing fibers of the eighth. 

 The origin of these roots in urodeles, and the recognition of 

 them as homologous with the facial of higher forms, have been 

 involved in a great deal of obscurity. Stieda ('75, p. 302) 

 recognized this bundle in the floor of the oblongata as belong- 

 ing to the facial and describes its exit to form that nerve ; he 

 could not, however, discover the origin. Osborn ('88), in his 

 study of the oblongata of CryptobrancJms, regarded this as be- 

 longing to the eighth instead of the seventh, and derived the 

 fibers of VII^*^ from the posterior longitudinal fasciculus. He 

 was not, however, certain of the correctness of the homology, 

 and in note 3 in the appendix to his paper, seemed inclined to 

 doubt the relation of the fibers to the posterior longitudinal 

 bundle. He was influenced in his view of this tract by the 

 close relation of the posterior longitudinal fasciculus and the 

 eighth nerve in the papers of Fulliquet and Ahlborn, the last 

 of whom his misquotes, however. The ventral division of 

 what is here termed the dorsal VH was considered by him 

 motor and to represent the root which would otherwise be 

 wanting. Burckhardt ('91) following Osborn, named these 

 roots, Vni, 3 and 4, and found them composed " mostly of 

 Miillerian fibers." He also regarded the ventral root of the 

 " dorsal seventh " as representing the facial. His VHI, 3 and 

 4 in Protoptenis ('92) are the same, and these he derives "in 

 part from the posterior longitudinal fasciculus, and in part from 

 a motor nidus." Strong did not attempt a solution of the 

 question but regarded the source of these fibers as partly from 

 the posterior longitudinal fasiculus and partly from the trigem- 

 inal motor nidus. 



In view of the importance of the matter, and the confusion 

 with regard to this nerve in Amphibia, a somewhat extended 

 comparative discussion seems desirable ; especially since the 

 mode of origin of this nerve is so nearly constant in widely 



