160 C. WINKLER. THE CENTRAL COURSE 



be? are all merely psychological questions, and they are treated 

 here to a certain degree conform whith the hypothesis defended 

 by JAMES, LANGE a. o. in regard to the origin of psychical emotions 

 in general. 



But their elucidation may win nothing by treating here quite 

 another question, which is often mixed up with them, but that in 

 reality only regards the modus of stimulation of the periferical 

 endings of the N. octavus. 



Many sagacious reasonings have been used in trying to analyze 

 the modus of stimulation of the cells found in the maculae and 

 at the cristae ampullarum, since GOLTZ has called attention to the 

 position of the semicircular channels and to the possibility that 

 changes in the pression of the endolymph may act as a stimulus. 

 Rotation-experiments initiated long ago by PURKINJE, repeated 

 by BREUER, CRUM-BROWN, MACH a. o., extended by YVES DELAGE, 

 KREIDL a. o. have worked out the ingenious presumptions of GOLTZ 

 to a serious hypothesis. But rotation-experiments are experiments 

 suited to study an irritation of the here analysed function. Inte- 

 resting as they may be, they neither have a direct relation with 

 the loss of function of the endings of the N. octavus as it is produced 

 by the removal of the labyrinth, nor are they very well suited to 

 study the perception of equilibration or the origin of vertigo. 



They may teach that irritation of the end-organs alters their motor 

 innervation in a distinct way , and what is of far more importance , 

 they may prove the existence of mechanical stimuli adaequate to 

 the ciliated cells in the vestibulum of another origin than sound-waves. 



For instance, nobody may doubt that the loss of otoliths in lower 

 animals (VERWORN, LOEB a. o.) may produce distinct motor disorders, 

 comparable with those after removal of the labyrinth. Rotation now 

 may perhaps prove that a dislocation of otoliths in a definite 

 direction is the cause to irritation of distinct octavo-motor inner- 

 . vations, and even rotation-experiments may defend the existence of 

 a definite direction of sliding of the otoliths in the maculae sacculi 

 et utriculi. In that case I willingly accept, that the motion of the 

 otoliths in the supposed definite direction is a stimulus adaequate 

 to the cells in the maculae. But I only see in this modus of 

 stimulation, the beginning of impulses given to octavus-fibres and 

 conducted by them to the centre. Motor innervations are following 

 these impulses. They are the cause of motor disorders, but there 

 is not a single argument compelling us to accept, the changes in 

 motion, seen in such cases, to be a consequence of altered perception. 



In the same way the results of rotation-experiments may be 



