( 3«7 ) 



animals used in llie experiments : a full-grown rabbit, in wliich a 

 liemisection was made at the origin of the medulla oblongata (fig. 1) 

 and three young cats, on which lesions were produced in different 

 portions of the spinal coi'd (fig. 2, 8 and 4), indicated by C^ 0^ and D*. 



The central nervous system of these animals was treated by the 

 JVlARCHi-method, and afterwards cut into serial sections 25 n thick. 



Tn all these animals a plainly visible degeneration was found after 

 the operation in the traetus spino-cerebellaris anterior or the fascicle 

 of GowKRs. In the dorso-lateral fasciculus there is likewise found a 

 certain degree of degeneration, but far less intense, excepting only in 

 the first animal on which the liemisection was made near the origin 

 of the medulla oblongata. For in this latter case there is found a 

 very compact degeneration of the corpus restiforme, being caused 

 however not only by spino-cerebellar fibres, but likewise and for a 

 gi-eat part by bulbo-cerebellar fibres, that were injured when the 

 lesion was produced ^). 



Figures 5 — 11 represent the degeneration as observed in my 

 preparations. In the first sections we see the dorsal and the ventral 

 spino-cerebellar system still undivided and taking a longitudinal 

 course. Gradually the fibres of the dorso-lateral portion are deviating 

 from the longitudinal direction, whilst the \enli'al portion still 

 continues to follow it. In a slow spiral-line the dorsal fibres run 

 towards the corpus restiforme ; consequently by and by several 

 important portions of the medulla oblongata arc found to be encom- 

 passed between the two parts of the lateral fasciculi ad cerebellum. 

 This fact becomes most plainly evident in fig. XV, taken from the 

 first cat, on which an almost complete section had been made at 

 C'. There being no degeneration of the olivo-cerebellar tract in this 

 case, the demarcation between corpus restiforme and antero-lateral 

 fascicle is much more distinct. 



I have represented from both these animals the radiation of the 

 corpus restiforme into the cei-ebellum (dorsal portion of the lateral 

 fasciculi to the cerel)eilum), and that of the fascicle of Gowers 

 (.antero-lateral portion of the lateral fasciculi to the cerebellum) : 

 fiu'. JO and 11, 17 and 18. The first radiation is produced through 

 the pedunculus ad cerebellum inferior, that, of the fascicle of Gowkrs 

 through the pedunculus ad cerebellum superior. 



In order to reach this latter the fibres of the traetus spino-cerebei- 



^) To understand this riglitly, the exact place of lesion must be more accurately 

 circumscribed. The lesion was made just underneath the most caudal root of the 

 hypoglossus, and directed somewhat obliquely upward. Haemorrhage was still to 

 be traced in those sections where the olivary body shows the largest profile. 



