575 



very diftiinilt and the results were unsafisfactory, or rather they 

 agreed perf'eclly wiih tliose nf Guyénoï. 



The becond way resembles much that of Guyenot. Sideways behind 

 the head a longitudinal cut was made in the ranscles just where 

 the Tripus is situated. I reached the fossa auditoria of Weber, felt 

 my way by means of a thin hook until I felt the Tripus move, 

 then I caught firmly hold of it, detached it earefidiy from its 

 connection with the air-bladder on one side and the other bones of 

 Weber on the other, and removed it from the body. Of course this 

 was done on either side. 



The connection was now entirely removed. 



The results of these experiments are very striking. Whenever the 

 removal of the connection had been effected without giving rise to 

 liemorrha<ie daring the operation, the [ir^ssnre-decrease required to 

 bring about an emission of air-bubbles rons no greater or hardly any 

 greater than before the operation. Only when the geuei-al condition 

 of the fish was a bad one, and immediately, after the operation, 

 a retardation was to be observed. Sometimes indeed, a retardation 

 could be observed in fishes which had only been submitted to a 

 beginning of an operation, which, moreover, had nothing to do with 

 the organ of Weber, or the muscles innervating the sphincter. If, 

 besides, we keep in view how long the retardation of the reflex 

 manifested itself after narcosis or after tlie recovery from the effect 

 of an electric current, we may be sure that Guyenot's results must 

 be due to the shock. 



Hence we conclude that the experiment of Güyénot cannot be 

 adduced in support of the theory of U..\ssv.c. s. regarding the f miction 

 of the air-bladder and the organ of Weber. 



To obtain greater certainty I also interrupted the hypothetical 

 reflex course in another spot. 



If the sphincter-reflex is affected by the elimination of the organ 

 of Weber, this must also be the case if the connection between 

 brain and labyrinth is destroyed. Therefore I twice attempted to cut 

 the nervus octavus in tenches on one side and twice on both sides. 

 Technically this operation presented few difficulties. The fishes 

 remained alive for many days after the operation. Autopsy proved 

 that the operation had succeeded. In none of these cases the emission 

 of air-bubbles had been retarded after the operation. The function 

 of the ductus-sphincter is entirely independent of the intact state of 

 the labyrinth. 



Hence the afferent jiart of the inhibitory reflex course is not found 

 in the organ of Wkber. It will |)r()bably have to be looked for in 



