HELMHOLTZ IN BONN 



unpleasant, indicating, in the opinion of Helmholtz, 

 4 that the vibrating parts of the ear are not damped with 

 sufficient force and rapidity to allow of successfully 

 effecting such rapid alternation of tone. It is there- 

 fore highly probable that a damping mechanism exists.' 



The next step was to attempt to explain how the 

 cochlea, in which the nerve-endings exist in the form 

 of the remarkable organ of Corti, can analyse tone, 

 and with the development of this theory, however 

 much it may have to be modified as time goes on, 

 the name of Helmholtz will be imperishably con- 

 nected. There are only three ways in which the nerve- 

 endings may be affected. Either (i) small vibratile 

 bodies may exist so as to transmit the pressures sent 

 to the filaments of the auditory nerve, each vibra- 

 tile body having a frequency period of its own ; or 

 (2) individual nerve fibres may be directly excited 

 by waves of a definite period, that is to say, there 

 may be differences in the nerve fibres, so that they 

 have a selective action ; or (3) the organ may be 

 affected as a whole, all the nerve fibres being affected 

 by any variations of pressures, and thus the power 

 of analysis, which is admitted, would be relegated 

 from the peripheral to the cerebral organs. 



The first hypothesis seems a priori to be probable, 

 for the following reasons: (i) The existence of 

 such bodies would give a natural explanation of many, 

 if not all, of the phenomena ; (2) the evidence of 

 comparative physiology points to gradually-increasing 



