132 Irving Hardesty 



Lowenberg, "64, thought that the membrane consisted of layers, one 

 above the other; Gottstein, '72. pictured it as structureless, and many 

 others after these failed to comprehend its character. Most of the 

 physiological and theoretical papers giving it any attention assume 

 rather than study its anatomy. All the more recent anatomical studies 

 admit the membrane to be fibrous. Shambaugh, '07, assumed the mem- 

 brane to be constructed of an immense number of delicate lamellfe, and 

 on the basis of this, propounds a very interesting theory of tone percep- 

 tion. Coyne and Cannieu, '85, were, I think, the first to make tangential 

 sections of the cochlea, passing through the membrane transverse to its 

 fibers, and to picture the transverse sections of the fibers as fine dots, 

 as shown here also in Fig. 9. They also tried to analyze the course 

 and arrangement of the fibers, and, with Barth, ^89 ; Dupuis, '94, and 

 Kishi, '07, made, I think, a mistake in describing the fibers as coursing 

 from the labium vestibulare in two layers, one on the upper surface and 

 one on the under, with a less compactly assembled layer of fibers between 

 the two. They probably mistook the peripheral condensation, explained 

 above, as due to the action of the reagents, as special upper and loAver 

 layers of fibers. 



Seen from the upper surface, the fibers appear to course from the 

 attached or inner zone outward, but, instead of coursing radially, they 

 always slant from the labium vestibulare toward the apex of the cochlea. 

 This slant is greater in the region of the inner zone, and deviates 

 slightly toward the radius in the outer zone as shown in Fig. 4, tlie 

 general course showing a slight tendency toward the shape of the letter 

 >S^. This general course was also noted by Dupuis, '94, in his prepara- 

 tions. Kishi notes an oblique direction tending toward the apex in the 

 animals he studied, and A^on Ebner states that the inclination is about 

 45° from the radius. 



Kishi claims to have noted fibers of varying size and length, and 

 Kolmer, '07, states that the fibers have a thicloiess of 14 micron. 

 From casual observation the impression is very readily obtained that 

 the fibers course individually across the entire width of the membrane, 

 but closer study of the membrane of the pig under higher power con- 

 vinces that they are far more numerous than first supposed, and tliat 

 they are too fine to be followed individually or to be measured by the 

 ordinary means. 



Comparing the surface view with the transverse section (Figs. 2, 6 

 and 4) shows that, instead of all the fibers extending from the labium 



