( 819 ) 



Anatomy. "Anatomical Research about cerebellar connections." 



(Third communication). By Dr. L. J. J. Muskens (Communi- 

 cated by Prof. C. Winkler). 



(Communicated in the meeting of March 30, 1907). 



The ventral cerebello-thalamlc bundle. 



Whereas it is nowadays generally accepted, that the direction of 

 conduction in the superior crus cerebelli is cerebellofugal, there is 

 no uniformity of opinion attained yet by the authors regarding the 

 bundle, which is found degenerated in the predorsal region in the 

 pons after cerebellar lesions. After Pellizzi and van Gehuchten, 

 Thomas, Orestano, Cayal and Lewandowsky this bundle is built up 

 by fibres, which take their origin from the superior crus after it 

 has crossed the raphe in Wernekinck's commissure, the direction of 

 conduction being rubro-fugal. Probst however, describes this bundle 

 as the ventral cerebello-thalamic bundle, conducting nervous impulses 

 from the cerebellar basal nuclei upward towards the red nucleus. 



The problem of this bundle really has to deal with two questions ; 

 1 st . which are the two nerve centres, which are connected by means 

 of this bundle and 2 nd . what is the direction of conduction of impulses 

 in the same. 



Cats appear to be more suitable for these experiments. In two 

 animals different parts of the cerebellar cortex, with the adjacent 

 part of the basal nuclei, were removed, except the flocculus. In these 

 animals there was hardly any degeneration at all in the ventral 

 cerebello-thalamic bundle, whereas in 3 other cats in which with 

 other parts also the flocculus was removed there was very extensive 

 degeneration of this bundle. That these (ibres do not take their origin 

 from the cortical gray matter of the flocculus is proved by the fact, 

 that in another cat in which the cortex of the formatio vermicu- 

 laris cerebelli was injured, no degeneration of the said bundle was 

 found. 



In two cats (XXIII and LXI) a lesion was effected in the mid- 

 brain, by passing a curved knife in front of the lobus simplex 

 cerebelli in such a way, that the predorsal region on the right side 

 was cut, distally from the red nucleus. In none of these animals 

 any degeneration was found in the ventral bundle. If Cayai/s sup- 

 position were correct, certainly a great many of the descending col- 

 laterals of the superior crus ought to have been found degenerated . 



In one cat (LVIII) a longitudinal lesion was effected in the teg- 



