ACTION OF THE TECTORIAL MEMBRANE 511 



arising and falling in intensity and, more rarely, the result was 

 actually intermittent while the sounding of the note by the 

 horn was continuous. (2) With some of the low notes em- 

 ployed, while a low intensity would result in a continuous buzzing 

 at all regions, if the intensity was greatly increased, certain 

 regions of the membrane seemed to 'buckle' or be lifted away 

 from contact of the platinum wire with the copper plate. Or, 

 in some other cases the current remained made in a region, 

 indicating that the membrane in the region had been forced in 

 closer contact than the adjustment made for a make and break 

 of the current. Ewald and Jaderholm ('06), experimenting with 

 an apparatus producing sounds of known vibration frequency, 

 formulated the conclusion that "all intermittent noises give 

 intermittent tones." This conclusion I think is necessarily 

 correct, but also, could the construction of the model be trusted, 

 the above would suggest that there may be evenly continuous 

 forms of vibration (noises) which can give sensations of inter- 

 mittent tones. Obviously also the manifestations of rise and 

 fall of intensity or throbs in the buzzing of the telephone suggest 

 the phenomena described as beats and perhaps overtones as well. 

 As is known, the vibrations of the tongue of the organ reed do 

 not give pure tones. 



Tinnitus aurium could be produced by a region of the tectorial 

 membrane being so forced down upon the hairs of the hair cells 

 as to remain adherent to them temporarily, or for a long period 

 as sometimes happens, after very violent auditory stimulation. 

 In origin, the tectorial membrane is directly analogous to the 

 otolithic membranes. These latter are nonnally loaded with 

 calcarious deposits. Under pathological conditions and with 

 advancing age the tectorial membrane may become so loaded, 

 as are other tissues of the body. A light load or a load in a part 

 of the membrane, increasing its inerita, might give rise to 'tone 

 islands' among the higher pitches; a heavier load equally dis- 

 tributed could contribute to the 'failing ears' of old age. 



It is not intended here to claim that the tectorial membrane 

 is the only possibly vibratory structure in the cochlea, but, that 

 it is the most adapted in every way and must be the chief vibra- 



