76 yournal of Comparative Neurology and Psychology. 



The sensory fibers of the trigeminus enter at the same level as 

 the motor, but only a very small part of them end there. Nearly 

 all of the fibers of the sensory quintus remain in a ventral situation 

 and go backward as a compact bundle accompanied as far as the 

 lobi glossopharyngeo-vagales by the secondary communis tract 

 (secondary vago-trigeminus tract of Mayser) behind which the 

 bundle continues and is soon divided into two parts. One part 

 which is always situated most dorsally in the posterior vagus 

 region turns upward and enters the nucleus Rolandi (Fig. Ixxxi) 

 where it ends. I have already mentioned that this region is very 

 large in the teleosts, especially in Lophius piscatorius. Accord- 

 ingly, Kingsbury, who examined many species, rightly says, 

 "the enlargement of the metatela produces corresponding ectal 

 swellings resembling the clavas of the mammalian brain; and from 

 this the spinal fifth root can be traced." 



This, however, is not the only terminus of the tr. descendens 

 nervi quinti. A considerable part goes farther backward under 

 the nucleus of Rolando between the posterior funicles of the 

 medulla spinalis beyond which it cannot be separately followed 

 (Figs. Ixxix to Ixxxii, Plate V). This last part is by no means 

 small, but is about one-third of the whole tr. descendens and 

 between the entrance of the sensory root and the nucleus Rolandi 

 it always lies ventrallv of the fibers destined for this nucleus. 



I am of the same opinion as C. J. Herrick and Van Gehuch- 

 TEN about the so-called radix ascendens of the trigeminus and 

 must differ from most other investigators. Haller (teleosts), 

 Edinger and Mayser (teleosts) and Goronowitsch (ganoids) 

 agree that such an ascending root is quite well developed, but I 

 must, after careful and repeated examination deny that such a 

 root exists, though at first I felt rather inclined to consider such a 

 bundle present. This was due to the fact that from the nucleus 

 lateralis cerebelli (or secondary vagus nucleus) I followed fibers 

 down to the level of the trigeminus where they lie at the side of the 

 sensory root of this nerve and seemed to be a true radix ascendens. 

 But this is contradicted not only by the fact that in following these 

 fibers more carefully it could be determined with certainty that 

 they go farther caudad accompanying the tr. descendens and end 

 in the lobi glossopharyngei et vagi but by the further fact that this 

 secondary communis tract is not yet developed in the young 

 Lophius so that here there was no trace of the supposed radix 



