THE ORGAN OF HEARING. 



449 



coils. The free extremity of each cell supports some 

 twenty hair-like processes, while the outer extremity 

 reaches half-way to the basilar membrane and is in 

 contact with nerve arborizations. 



3. Deiters 1 supporting cells alternate with the rows 

 of the outer hair cells. Their lower ends expand 

 upon the basilar membrane, and the upper end tapers 



Fig. 309. Section of Corti's organ from guinea-pig's cochlea: ST, 

 scala tympani; TC, tunnel of Corti; a, bony tissue or spiral lamina; b, b, 

 fibrous tissue covering same continued as substantia propria of basilar 

 membrane; c, c, protoplasmic . envelope of Corti's pillars (e, e,); d, 

 endothelial plates; /, heads of pillars containing oval areas; g, head 

 plates of pillars; h, h f , inner and outer hair cells; m, membrana retic- 

 ularis; k, I, cells of Hensen and Claudius; n, n, nerve fibers; i, cells of 

 Deiters (after Piersol). 



and extends to the free surface of the hair cells. 

 Each cell has a nucleus near its middle and contains 

 a bright thread-like structure, called the supporting 

 fiber. 



4. The cells of Hensen are outer supporting cells and 

 consist of several rows just outside of Deiters' cells, 

 where they form a well-marked elevation on the floor 

 29 



