508 IRVING HARDESTY 



cells, while regions both above and below it may not so vibrate. 

 In other words, the regions immediately adjacent to that vibrat- 

 ing in resonance, having nearly the same natural periods, might 

 be agitated but to a degree less effective and decreasing as the 

 distance from the region most affected increases. Or, again, 

 since loading a vibrating body lowers its natural period or pitch, 

 if the load be uniformly distributed, the vibration frequency of 

 all its components will be lowered, but if the load be placed at 

 one end of the vibrating body then one of the complications 

 resulting would be a lowering of the natural vibration frequency 

 of that end more than the other. If the tectorial membrane 

 may be considered as a vibrating body with a load gradually 

 increasing till the load carried by its apical end becomes 40 times 

 that of its basal end, then it may at least be assumed that the 

 natural period of its different regions must be lowered as the apical 

 end is approached and sound waves imparted to the endolymph 

 may act upon it accordingly. Several waves, of course, may be 

 transmitted in the same du'ection simultaneously through a 

 medium. 



Results with the model, however, show that sounds of lower 

 vibration frequency throw the entire tectorial membrane into 

 effective vibration. 



It may be mentioned that in line with the above a possible 

 suggestion of resonance with the higher sounds was offered by 

 the model. In three cases a note seemed to produce stronger 

 and more evenly continuous vibration of one region of the arti- 

 ficial membrane than in any other of the six regions. For ex- 

 ample, the note a (220 vibrations per second), while causing 

 vibrations in all regions except region 6, seemed to cause a more 

 definite and more evenly continuous buzz of the signal-marker 

 and telephone at region 4 than in other regions. In region 2, 

 the indication in both signal-marker and telephone was more or 

 less intermittent in contrast, regardless of the amphtude given 

 the note. The note d, above a, gave the same in region 1, and, 

 less to be expected, the note g below a gave the same in region 4, 

 the same region as that in which the note a gave it. The fact 

 that a and g gave the evidence in the same region leads to the 



