42 C. WINKLER. THE CENTRAL COURSE 



The rabbit, whose labyrinth has been removed on one side, is 

 an animal with a one-sided disturbance of innervation , a disturbance 

 being at its maximum at the onset, and up to a certain degree 

 compensated and corrected afterwards. 



7. Conclusions concerning the disturbances of motion found after 

 extirpations of the labyrinth. 



The disturbances of motion, observed after extirpation of the 

 labyrinth, may without any exception be considered as phenomena 

 of ,,loss of function." It is not at all necessary to presume symp- 

 toms of irritation in order to explain them. In this respect I have 

 nothing to add to the conceptions of EWALD. This opinion is proved 

 irrefutably by the effect of the double-sided operation , that of all 

 apparent symptoms of irritation, of all the spasms and forcibly 

 assumed attitudes does leave nothing but only a most extensive 

 muscular atony. All this may be demonstrated on the rabbit with 

 still greater evidence than on the pigeon. 



The identical disturbances of motion are shown further, though 

 in a far feebler degree, after removal of the cochlea. They are 

 then of the same kind as after removal of the entire labyrinth , and 

 there is such a striking accordance between both cases, that we may 

 only speak of a difference in degree, not of an essential difference. 

 This fact may be explained in two different ways. 



In the first place we may believe that the N. cochlearis, serving 

 for the perception of sound , does not exert any influence on the 

 muscular system. As in removing the cochlea, to all probability 

 the contents of the vestibulum will be damaged in some measure 

 by discharge of endolymph , it is to be expected that some slight 

 disturbance of motion will occur. In that case the motion-symptoms 

 would be dependent on the peripherical endings of the N. vestibu- 

 laris. The Nervus cochlearis should have no influence on motion ; 

 the two nerves would be quite different nerves. 



It is indeed not rare to find that, without any obvious cause, 

 the far graver disturbances of motion , peculiar to destruction of 

 the whole labyrinth , are gradually developing likewise after remo- 

 val of the cochlea, and as in such cases the possibility of infection 

 is excluded, this degeneration must originate in a slow secundary 

 destruction of the vestibular endings. 



This conception would be in accordance with the current opinions 

 concerning the physiological signification of the cochlea for hearing and 

 of the ampullae and maculae acusticae for the perception of equilibration. 



