1097 



raents ^), then it is the following. VII : swaying movement of the 

 bodj, with the coxa as resting-point. 



The animal sits on its hind part, while tlie front part, resting 

 on the fore legs, constant ij' tosses to the right or to I lie left, exactly 

 as the pendtilinn of a clock. This movement is, as 1 suppose, the 

 same as described in sub II, althongli more intensitied, because not 

 only the head, but nearly the whole of the body participates in it. 



As all these symptoms were Jiever found in one and the same 

 animal experimented on, but changed according to the parts which 

 were excochleated, and totally in accordance with the view of Bolk, 

 I supposed that in the new experiments some of them would come 

 to the foreground. 



The aim of the operation^) therefore was to leave only unsectioned 

 a part of the afferent cerebellar tracts. For this purpose the connec- 

 tions between the medulla spinalis and the cerebellum were to be 

 sectioned in first instance, and as soon as the animal should have 

 overcome the disturbances of gait, resulting from it and thus walked 

 well again, then the vestibular apparatus was destroyed unilateraUy. 



By this method still some afferent tracts should reach the cere- 

 bellum and in this way a partial lesion of its cortex should be imitated. 



Referring to the first part of the experimental operation, we know, 

 that from the funiculi posteriores, through the interposition of the 

 nuclei of Gou, and Burdach, stimuli still reach the restiform body 

 and the cerebellum along the fibrae arcuatae ext. post, et anter. It 

 should be of importance not only to section the spino-cerebellar 

 tracts, but also the funicular posterior tracts. 



The ideal place for this would be above the I'^f cervical root, 

 because there all the medullary fibres going to the cerebellum can 

 be sectioned. The endeavours applied for this purpose failed however, 

 as all the cats died during the operations. Therefore I resolved to 

 perform the section on a lower level, i.e. between c, and c,. For 

 this purpose the dorsal part of the secund arcus vertebrae cervicalis 

 was cut off, the dura was opened and between c, and c, in the 

 first place both the posterior funiculi were transsectioued and later 

 on with a small curved knife the lateral edge of the medulla was 

 cut in. By microscopical examination it was stated, that it had not 



1) Cerebellar ataxia Experimental reseaches. Psych. Neurol. Bl. 1909. 

 Cerebellar functions in correlation of their localisation. Id. 1915. 



2) Prof. B. Magnus and his temporary substitute Dr. W. Stoem van Leeuwen, 

 had the kindness to let me operate in the pharmacological laboratory, for which 

 opportunity I am greally indebted to them. 



71* 



