44 C. WINKLER. THE CENTRAL COURSE ETC. 



upon these animals, whilst every precaution had been taken to 

 prevent air-shakes. Without doubting in the least degree the cor- 

 rectness of the observations of such an investigator as EWALD, I 

 believe that such observations go beyond the limits assigned to 

 our judgment on the sense-perception of animals. I have believed 

 to observe that rabbits, whose cochlea was destroyed, still did 

 hear, but I wish expressly to leave this question undecided. 



For the same reason I will only just recall the fact that the 

 animal, chosen preferably to all others for demonstrating the degene- 

 ration of the labyrinth as the cause of disturbances of motion , the 

 dancing Japanese mouse is at the same time deaf. I know of no 

 instance wherein dancing mice have been described that could hear 

 and I can assure that they have lost completely the primary nuclei 

 of the N. VIII. As to deaf- and dumb creatures, whether they 

 present disturbances of motion or not, it is my belief that the 

 question whether in their case it is only the cochlea or the whole 

 of the labyrinth that is damaged, is not yet resolved. 



In this paper I carefully avoid to communicate anatomical investi- 

 gations on the periferical endings of the eighth nerve. I prefer main- 

 taining it between its proper limits. Therefore also I neglect experi- 

 ments on sound-perceptions. I only have to study the influence 

 that the N. octavus exerts on the motion of the animal. 



That, what I wish to state here, is that the disturbances of 

 functions, observed after removal of the cochlea and after extir- 

 pation of the labyrinth, show only a difference in degree, and 

 that they leave room for the conception that there need not be 

 assumed an essential difference in the mode of distribution in the 

 central organ of the N. cochlearis and the N. vestibularis. This 

 opinion is supported by the anatomical course of both nerves in 

 the central nerve-system. 



