136 Irving Hardesty 



preparations examined from the ventral surface, by transmitted light, 

 show it to be fibrous and to be largely composed of a dense linear 

 series of the intercrossing ends of the fibers approaching each other iu 

 the ventral surface from the two directions. In fact, the stripe occupies 

 approximately the position of the dividing line between the fibers 

 coursing in this surface from the two directions. It is most probably 

 distinguishable because it is a linear accumulation of these intercrossing 

 ends which, as such, behave toward the light differently from the other 

 regions. For the same reason, it was distinguishable in my preparations 

 by reflected light, that is, when viewed over a black surface, as well as by 

 transmitted light. It is strong enough to appear quite distinctly through 

 the membrane when studied from the upper surface. 



Von Ebner, '02, notes that Hensen's stripe may show from the upper 

 surface, and thinks that it is produced by a thickening or bunching of 

 the substance of the membrane, and he accepts the statements of others 

 that it lies over the line of the inner hair cells of the organ of Corti. 

 He, Coyne and Cannieu, '85, and Dupuis, '94, state that it is absent in 

 some animals. The latter notes that it varies in different species, and 

 that it may be modified by pressure of the cover glass, not leaving one 

 to feel positive that the stripe is ever normally absent. Hensen himself 

 thought the stripe a line of connection with the inner hair cells, and 

 Shambaugh, '07, describes it as "a sort of fascet where, normally, 

 the membrane is attached to the supporting cells just internal to the 

 inner row of hair cells." The latter description is based upon the 

 appearance of the membrane in sections, largely one section, manifestly 

 distorted. In none of the sections of the pig's cochlea used here was it 

 possible to locate Hensen's stripe by any means as positively as Dr. 

 Shambaugh was able to do with his sections. It is of necessity always 

 involved in the peripheral condensation. Denser, or more condensed, 

 spots were often seen cut across in the under surface, but these were 

 too numerous and too variously placed to be interpreted as other than 

 sections of crimps in the peripheral condensation produced by the further 

 shrinkage of the membrane during the preparation for sectioning. 



In removing two of the preparations used here from cochleae fixed 

 and decalcified in Zenker's fluid, the tectorial membrane was found to 

 be stuck down to the organ of Corti in the regions of the first and 

 second turns of the spiral. By careful use of the needle one of these 

 was freed, and, though finally broken, the pieces were stained in fuchsin 

 and mounted, under surface upward. Though disappointing and practi- 



