OF THE NEEYUS OCTAVOS. 43 



But there may be given still another possible explanation of this 

 fact. Leaving aside the specific perceptive functions belonging hypothe- 

 tically to both terminal organs , it may still be imagined that both the 

 N. cochlearis and the N. vestibularis should extend their fibres into the 

 central nerve-system in a similar way , and are distributed in the same 

 manner in relation to the motor nuclei situated there. Such being 

 the case, the same disturbances of motion, that are manifested 

 completely when the entire terminal organ is extirpated, would 

 likewise be occasioned in a lesser degree (but still in quite the 

 same way) by the incomplete removal of the terminal organ, as is 

 done by destruction of the cochlea. As to the influence on motility , 

 this conception is only seeing a quantitative difference between the 

 two nerves. The N. cochlearis has an influence on motility in the 

 same way, but not so intense as the N. vestibularis. 



This conception may be argumented by the course of both 

 nerves, because both are degenerating central wards as a result of 

 the lesion, and it is greatly supported in that way; but still it is 

 not quite in accordance with the current opinion, that N. cochlearis 

 and N. vestibularis are two nerves of entirely separate functions. 

 A discussion about these opinions here however would lead me 

 far beyond the limits put to this treatise , besides its being useless 

 for my purpose. 



For I think it is not proved, either that the vestibular-endings 

 does not participate in the. perception of sound, or that the cochlea 

 may be neglected as being without any signification w.hen investi- 

 gating the causes of the spasms, the forced attitudes and the rol- 

 lings. I doubt if a decisive argument may be given that hearing 

 is not supported by the N. vestibularis, or that the N. cochlearis 

 should have no influence on motion. 



The animal, in which the cochlea has been destroyed on both 

 sides, does not react on the violent sound-impressions of a Galton- 

 whistle, blown above its head, as it did before the operation. It 

 does not roll, but it always has in a slight degree the charac- 

 teric deviations of head, neck and eyes. 



But as soon as the experiments are made to aim directly at the 

 solution of the question whether a remnant of sound-perception may 

 still exist after removal of the cochlea, there arise such enormous 

 difficulties, that I dare not draw any conclusion whatever from 

 those experiments. 



I will only just recall to mind that after the opinion of EWALD , 

 pigeons whose labyrinth has been destroyed on both sides, still 

 hear , i. e. that they reacted on sound-impressions , brought to act 



