38 C. WINKLER. THE CENTRAL COURSE 



and both lower extremities are atonic in the highest degree. 



Gradually the rolling ceases. Permanently however the animal 

 bears its head obliquely , the eyes retain their deviated position , 

 changing with the position of the head. If this latter is put straight, 

 the deviation of the eyes attains again its maximal degree. Briefly, 

 an animal in wich has been produced a succesful dorsal section 

 is not greatly different from one in wich the labyrinth has been 

 removed in toto. Here also the difference is only in degree. Yet 

 the a'.ony is more evident. It exists on both sides and especially 

 in both lower extremities it is stronger than after removal of the 

 labyrinth. After this latter operation the atony of the lower 

 extremity on the operated side often has to be sought for. It can 

 only be demonstrated by comparing it carefully with the extre- 

 mity on the other side. After the dorsal section both lower extre- 

 mities, that on the opposite side also, are hanging helplessly down 

 like inert masses. Though the atony is strongest in the extremities 

 of the operated side, in the opposite legs it is still very important. 

 It prevails in the lower extremities, so much that during the first 

 days after the operation we might believe in paralysis of the hind- 

 part of the body. But if the animal is left to itself, we find that 

 it draws its hindlegs again under the body, though with some 

 difficulty. As soon as it is frightened and changes its place, the 

 lax lower extremities remain behind. 



This appears to me being the cause that the rolling of the 

 animal is performed with less vigour than after removal of the 

 labyrinth. Generally it is confined to one single revolution, where- 

 as after extirpation of the labyrinth several revolutions may take 

 place, and do so as a rule. 



This also seems the reason of a symptom , that rabbits present 

 sometimes as a permanent symptom after the sectioning of the 

 dorsal tracts. 



It is the motion of the animal on the outline of a circle the 

 centre of which is found on the operated side. In rabbits with 

 one-sided removal of the labyrinth this manege-gait is not observed. 

 I believe the cause from this fact to be that after the latter operation 

 the atony in both lower extremities is never so much marked, 

 that the hind-part of the body does no longer follow the fore-part 

 of it. The fore-part during the gait , is deviating toward the side 

 of the operation. This is also the case after the removal of the 

 labyrinth. But after the sectioning of the dorsal secnndary tract of- 

 the N. VIII, the weakness of the lower extremities is the cause 

 that they remain on their place (the animal then moves as the 



