34 IRVING HARDESTY 



the membrane {PC, figs. 1 to 3) and explained it as representing, 

 on the apical surface, the product of the first activities of the 

 then young producing cells, and on the basal surface as the last 

 product of the then declining activities of the producing cells. 

 That it appears condensed as compared with main body of the 

 membrane, I thought due to the different actions of the reagents 

 upon these superficial and less completely formed products of 

 the beginning and waning functions of the cells. As noted by 

 Held for his homogeneous layer, the peripheral condensation is 

 not so noticeable along the axial side of the basal surface. Here 

 the maturely active cells are probabl}^ torn from their product 

 more suddenly than from the thicker part of the outspanning 

 zone. Also, as noted b}^ Held, the very thin extreme axial 

 edge of the attached axial zone appears dense in the preparations. 

 This edge corresponds to only the earlier product of the activities 

 of the cells, for here production of the membrane ceases in the 

 early fetus and the cells sink back into inactive form while the 

 remaining are still forming the 'peripheral condensations.' I 

 have called attention to sections of the apical surface cut parallel 

 to it, showing a coarse reticular arrangement and have sug- 

 gested that the reticulum in these sections represented the first 

 formed ends of the fibers of the membrane, not so adequately 

 embedded in matrix as in the main body, washed together and 

 cohering in anastomosing bundles. In the transverse sections, 

 these form part of the peripheral condensation. If this sug- 

 gestion is possible, it could explain Held's Decknetz of the 

 apical surface. 



Held did little more than look over the figures given in jny 

 paper. He kindly gives a 'Zusatz' at the end of his paper in 

 which he states that he did not know of my paper till after his 

 manuscript had been closed, and that he thought some of my 

 figures defective, two of them 'artificial monstrosities' of the 

 tectorial membrane resulting from swelling. Held had never 

 studied the tectorial membrane of the hog, which I think is sim- 

 ilar to the human. All the drawings of the present paper are 

 intentionally made from projections of sections of cochleae 

 fixed and prepared for sectioning according to the identical 



