160 STATIC FUNCTIONS OF LABYRINTH 



Simple and plausible as Breuer's a priori conception appears no 

 one has ever been able to confirm it by direct experiment. Lee/ for 

 example, states that: "Stimulation of the otolithic parts of the ear 

 has not been entirely satisfactory. The results were found exceed- 

 ingly variable." Experiments by pressure on the otoliths or epithe- 

 lium have usually been described as unconvincing or contradictory. 

 As will be seen they are consistently contradictory to Breuer's views 

 so commonly held. 



I have now found that it is possible to stimulate mechanically the 

 otolith organ of the recessus and to get results just as clear and con- 

 sistent as those obtained from stimulation of the ampullae. I quote 

 the following record of an experiment. 



"July 16, 1920. Large dogfish (Galeus). 



Opened both ears and removed all six ampullae. 



Using a stiff bristle tipped with wax and the wax covered by a thin layer of 

 absorbent cotton, applied pressure to various parts. 



Right ear. 



Pressed on right (lateral) side of otoHth (of recessus utriculi) ; right eye depressed, 

 left eye elevated. 



Pressed on left side of otolith; left eye depressed, right eye elevated. 



Repeated several times with uniform results. Otolith soon disintegrated: no 

 more response. 



Left ear. 



Pressed on left side of otolith; left eye depressed, right eye elevated. 



Pressed on right side (median) of otolith; right eye down, left eye up. 



Repeated several times with same result." 



Experiments made in this way gave fairly constant results, but it 

 was not possible to repeat the observation many times without injury 

 to the otolith organ. A new and very simple method was later 

 found which permitted repetition of the stimulation many times 

 before serious damage was done to the otolith and which gave abso- 

 lutely constant results. The experiment is performed as follows: 



A small mass of absorbent cotton is formed into a tiny cushion about 

 the size of the otolith of the recessus and is cautiously placed on top 

 of that otolith. The cotton is then grasped with the points of a fine 



* Lee, F. S., A study of the sense of equilibrium in fishes. I, /. Physiol., 1894, 



xv,3n. 



