110.3 



have to bring more eleaiMiess. Now 1 will only point out the con- 

 tradiction which I saw, and which with the aid of the well-known 

 facts at oni' disposal cannot yet be explained. 



SUMMARY. 



1. By experimental operation extra cerei)ellars, i. e., by transsectinp; 

 the tracts of Golt,, Burdaoh, Fi.kchsig and Gowkk and the fibi-es 

 of the vestibniar organ, it is possible to call forth cerebellar ataxia. 



2. The hypothesis which I made and described in my previous 

 communication, on account of clinical experimental reports, that 

 sensory cerebellar ataxia appears through interruption, in the 

 cei-ebeilum, of the sub I mentioned tracts, is proved by experiments 

 on animals. 



PROTOCOL. 



Cat No. 1. Tianssection of the tracts of Goll and Burtlach and of the spino- 

 cerebellar funicular tracts, on the right as well as on the left. After the animal 

 had totally recovered from this operation the vestibular organ and the vestibular 

 nerve on the rigid side w^ere destroyed. 



After awakening from the aether narcosis, the head was seen to hang to trie 

 right and downwards; therefore it showed turning of the head. No head-nystagmus 

 was I erceived. The Irias of sympathetic palsy, resulting from Iransseclion of the 

 postganglional nerve fibre in the mid-ear, i.e. narrowing of the eye-lid. was present 

 on the right. Moreover eye-nystagmus towards the sound side, therefore towards 

 the kft. All the symptoms, which one sees after destroying the vestibular organ 

 and the vestibular nerve, were present except the head-nystagmus. The day follow- 

 ing the operation, there appeared a strongly pronounced circus gait to the left, 

 therefore to the sound side. This was so intensified, that when a piece of meat 

 was laid down on the right side of the cat, the animal had to turn around its 

 tail to get at the food. Was the meat put down at a distance in front of the 

 cat, then we saw the curved gait line, as indicated in fig. 1. if the cat was lying 

 in rest, then it turned its head to the right as well as to the left. 



After a few days the circus gait — to the left — had greatly diminished, to 

 slowly continue in a deviation to the left, which was still distinctly seen while 

 walking, ll was clearly visible that the anim.al, when it walked aimlessly around, 

 leaned with the left side, i.e. the sound side, against the wall and that it walked 

 on along the wall. 



Eight days after the operation the animal was killed for examination. Prof. 

 VViNKLKR, who had the kindness to prepare the central nervous system and to dif- 

 ferentiate it afler the Marchi method, found: distaUg from the field of operation, 

 lying between c, and c^ degeneration of the pyramidal lateral funicular tract, 

 especially in its lateral part and further degeneration in the ventral white field, 

 at the level of the peripheral border, where in man') the tectospinal tract is found. 

 The distally lying degeneration is on the left side far less pronounced than on the 



C. Winkler, Handboek der Neurologie, bl. 259. Haarlem, Erven Bohn. 1917. 



