600 



however, but little separated from the rest of the V. As to the large 

 [b) cutaneous fibres, they can be traced caudad in the ascending Tri- 

 geminal tract to the posterior columns of the cord and are thus con- 

 tinuous with the large fibres found in these columns. 



Facial. — Some of the most interesting discoveries have been 

 made in connection with this nerve. 



The Facial of the Amphibia is divisible into two parts, very dif- 

 ferent from each other: a ventral part which persists in the higher 

 Vertebrates and corresponds, in part at least, to the Facial of Mamma- 

 lia; and a dorsal part, representing in ChoropJiihis and tadpoles the 

 diminished remnant of a nerve, or group of nerves, which are much 

 more important in the Urodela and remaining Ichthyopsida. 



a) The ventral VII., or Facial of the higher Vertebrata, using 

 the former term for clearness, is given off close beneath the Auditory. 

 It arises by two roots : a fine-fibred root, VII. a a, from the Fasciculus 

 communis 1 of O shorn and a coarse-fibred root, VII. «5. more ventral 

 which appears to be connected with a nucleus similar to that of the 

 minor Trigeminus. The root apparently corresponding to this in Uro- 

 dela, however, Osborn has ascertained to be derived from the pos- 

 terior longitudinal fasciculus. It may, perhaps, have a double 

 origin . 



After its exit, the ventral VII. (VII. a) proceeds forwards, is reën- 

 forcedby one-half the coarse-fibred dorsal VII. (VII. 5, see bcloAv) and 

 just before coming in contact with the Gasserian ganglion, divides into 

 two parts, a coarse and a fine-fibred. The latter breaks up in the ven- 

 tral part of the Gasserian ganglion and emerges as the fine-fibred 

 Palatine. It is reënforced here by fibres of the Sympathetic and also 

 contains a considerable number of ganglion cells somewhat smaller 

 than those of the Gasserian ganglion. In Ecker's «Anatomy of the 

 Frog« this is spoken of as if mainly a branch of the Ophthalmicus 

 trigemini reënforced by the Facial (3, p. 1G9). I believe, rather, that the 

 majority, if not all, of its fibres are from the Facial and not from the 

 Trigeminus, wliich opinion is further supported by the fiict that this 



1 Sec lUj. This tract first becomes conspicuous in the posterior horn of the 

 medulla shortly eephalad of the opening of the IV. ventricle. It is fine-fibred and con- 

 tributes to the X., IX. and VII. or VIII. nerves in Urodela accordin}^ to the obser- 

 vations of Osborn which are confirmed by those of M ill er (10 and 11). I have veri- 

 fied these in Anura but have shown that it goes to the VII. and not the VIII. 

 Koppen (8) seems to have observed this tract but fallen into the error of assigning 

 it to the V. instead of the VII. It is probably identical with the tract described by 

 Gorono witsch (7) as found in the Lobus vagi of Acipcnscr. 



