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tliat SiU'li eiTei'ciil lihrc^^ (Icsccinliiiu- iii llic cord, sliuiild s|triiiLi- fi'oiii 

 (this part ai Icasl of) llic dciilalc iiiiclciis. 



Regai'dii^u' llic asccndiim' douviioi-atioii iii llic diU'creiil ()[)L'raU'(l 

 animals the inosl coiiiplclc accordaiico is Ibiiiid. Two luiiidiesarc found 

 in all snccessfid cases, xcrv cleariv and in exacllv (lic same place ot" 

 the ci'Oss-seclions and Itodi liiid in tlie same re.uion (»!' llie ccrchnnn 

 their end, vi/. in tlie reuio ^idillialaniica. In tlic lir^t place lliesu[»e- 

 rior cerebellar peduncle heiiiii' llie most \'oluminous Itundlc, where 

 we lind lihres of lica\ v calilxT. 'J'liis dcLi-eneratioii shows cs|»cciallv 

 *>'ross tibres, coni[)ai'cd witli llie line deuenei'ations. found elsewhere 

 in the rabbit, 'i'lie (k\ueneralion is found es[)eciallv in the middle 

 third pail of the superior cerebellar ])ednncle, whereas the medial 

 and lateral thirds arc nearly cnlircly free from deu'cnerate fibres. 

 Arrived about at the posterior (piadriueminal body, the degenerate 

 fibres cnrNc do\vn\vard in a nearly riühtangle, as this is repre- 

 sented In the aiitli(u-s. building the AxcUUnown |)cdnncnlar decussa- 

 tion, (^nlv a tcw' s{>clions s(>paralc the commeiiciMiieiit and the 

 tinish (»l' the decussation in the sections. In the substantia reticularis 

 the direction is auain |nirely longitudinal to the long axis of the 

 cerebral stem, where as in the region of the rvtl nucleus it becomes 

 clear, that es|tecially the \-enlral part of the wd nucleus comes in 

 contact ^^ ith the crossed peduncle. This crossed connection is, as tar 

 as the flocculus is concerned com])lele. Here it may be recalled, that 

 Probst has shown, thai after extirpation of more tlorsally situated 

 cerebellar parts of llie cat also ]ion-crossed tibres run to the subtha- 

 lamic region. 



Hesides this most important n|)ward degenerating bnndle, there 

 is another tract up lo now only descrilied as far as I am aware by 

 Phobst, which is constituted of liner fibres than the first bnndle, takes 

 its course by the substantia reticularis, of the contra-lateral side, 

 and joins the first tract about its arri\al in the red nucleus. Both 

 together run frontalwards, and end in the ventral j)art of the 

 nucleus ventralis thalami. Tht^ sections leave no doubt, that no fibres 

 from the tloccnlns arrive in the thalamic region uncrossed, but all 

 decussate either in the decussation of llie sui)erior [)eduncle or as far 

 as the second bnndle is concei-ned in the ])ontine region, right near 

 its emergence trom the flocculus. Also Thomas has designed this 

 degeneration, but he thiidcs, that here we have to deal with descending 

 collaterals of the frontal cei'ebellar peduncle, which leave the principal 

 bundle after the decussation of this peduncle. Probst on the other 

 hand thinks, that these fibres arise from the dentate nucleus, pass 

 directly through the region of the vestibular nuclei, to the substantia 



