HELMHOLTZ IN BONN 



the base of the stapes, on the amplitude of the ex- 

 cursions of the vibratile bodies in the cochlea, and 

 on the degree of stimulus given to the nerve. 



The base of the stapes is chiefly opposite the 

 utricle, although it partly abuts against the saccule. 

 On the wall of the utricle, immediately in front, 

 there are no nerve-endings or modified epithelium, 

 but on the back wall we find a ridge called the crista 

 acoustica, on which are long cells having bristle-like 

 points which are directed towards the base of the 

 stapes. In front of these bristle cells lies a mass of 

 otoliths, or ear stones, consisting of carbonate of lime. 

 The pressures must be communicated, in the first 

 instance, to the, otoliths, and by them to the bristle 

 cells. As the bristle cells are fixed, while the otoliths 

 are capable of moving backwards and forwards in a 

 fluid, it is clear that one impulse from the base of the 

 stapes may cause the otoliths to oscillate, and, by thus 

 making a series of impacts on the points of the bristle 

 cells produce in them a more or less prolonged ex- 

 citation. This was the opinion of Johannes Miiller. 

 Helmholtz, on the contrary, considered the matter 

 from the physical point of view, and his opinion was 

 that the thin membrane, bearing the bristle cells, 

 will readily move to the impacts of the stapes, and 

 the heavy otolithic mass, by virtue of its inertia, will 

 move more slowly at first, but it will continue to 

 oscillate, and thus keep up stimulation. The long 

 and extremely light bristles also appeared to him to 

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