( 389 ) 



perhaps it may l>c of very threat iiiipovtance. Othoi' methods of investi- 

 gatio]i will 1)0 more etilleieiit in hringiiig this pi'oi)lem nearer to its 

 solnlioii. Ill (ig. 19 and 20 this gi'amdalioii is represented, as it 

 appeared in a cat after a central lesion of the 4*^'' dorsal segment 

 (fig. 3). Yet I think I am fnlly jnstilied in concluding from my 

 preparations to the existence of long ascending fibres, thai ha\e their 

 origin proltal)ly soine\yliere near the central canal. In the spinal 

 cord tliese fibres then continue their course in the anlei'ior fascicle, 

 part of them also in the anterolateral ffiscicle (fig. 12;. The former 

 ones turn more cent rahyard at the origin of the medulla oblongata, 

 and issue in the fasciculus longitudinalis dorsalis. The second 

 ones take a l)ont near the most caudal root of the hypoglossus, 

 and proceed along the course of that root centrahvard to the 

 fasciculus longitudinalis (fig. 13, 14 and 25). These asceiidijig fibres 

 are still found eyen in the nucleus of the N. oeulimotorius, as is 

 shown in fig. 26. 



Ramon y Ca.tal also assumes the existence of these fibres, y. Gkhlt'htkn 

 howeyer has found ascending degeneration oidy after a lesion of 

 the nucleus of Deiter, but he does not. mention whether he has made 

 observations on sections obtained after central lesions of the spinal 

 cord. In the laboratory of yAN Gehuchten similar experiments \vere 

 made by rjunouscniNE, by the injection of a drop of water. But 

 it was his purpose to destroy part of the posterior horn in order 

 to trace the origin of the anterolateral fascicle. He found this fas- 

 cicle to be degenerated, but there did not exist any degeneration of 

 tlie fasciculus longitudinalis, because the central portion of the spinal 

 cord remained uninjured. 



After the hemisoction near the origin of the medulla oblongata, 

 there apjiearod also degeneration of the fractus bulbo-cerebellaris, 

 which lakes its course from the oliyary body towards the periphery 

 of the corpus restiforme as fibrae arcuafae internae and externae. 

 The greater [)art of these fibres are ci'ossed, still a few of them 

 originate on the same side. 



Besides these fibres there are found in the basal portion of the 

 formatio reticularis a great number of degenerated fibres, ascending 

 longitudinally and probably belonging to the secondary sensible tract 

 (Hg. 7 — ']]). Part of these fibres transgress the median line and seek 

 the median ribbon (laqueus medialis) of the non-injured side, the rest of 

 them are united near the oliya superior and continue their course in the 

 laqueus lateralis more centrahvard than the fibres of the fascicle of 

 GowERS. They may be traced into the corpus quadrigeminum posterius. 



The significance of the grannlation in the corpus trapezoides, which 



