22 UNIVERSITY OF MISSOURI STUDIES 



drawing can occur in the fluid below the Reissner membrane. 

 The fluid here can only move up and down, pushing or pull- 

 ing the organ of Corti into its limit of displacement. No fric- 

 tion of the kind above referred to, which might do injury to 

 the delicate tissues of the organ of Corti, can therefore take 

 place, and the problem of protection from friction is thus 

 solved. We shall, however, in order to make our language as 

 simple as possible, restrict the term partition to the organ of 

 Corti, neglecting the membrane of Reissner, since this mem- 

 brane, aside from the important protection which it offers to 

 the tissues below, does not seem to possess any function 

 whatever. 



We saw on a previous page that an imaginary partition 

 which is able to yield to the pressure of the fluid only within 

 certain limits would be exposed to the dan- 

 The safety valve ger of breaking whenever an extraordina- 

 rily powerful external force tended to 

 cause a movement of the stirrup which would displace more 

 fluid than the yielding partition could make room for, and 

 that this danger might be avoided or at least greatly lessened 

 by an opening of communication between the two divisions at 

 the end of the tube. It is interesting to learn from the re- 

 searches of the anatomists that such an opening — a safety 

 valve, as we may call it — actually exists at the extremity of 

 the tube of the cochlea. 



We may now, after making ourselves familiar with the 

 structural elements of the inner ear and their physical prop- 

 erties, enter into a discussion of the actual function of the 

 organ. 



