222 HISTOLOGY 



to form an almost continuous cover. These supporting cells are known 

 as the Deiter's cells. This cover is interrupted at regular intervals to 

 permit the tops of the short outer auditory cells or outer cells to form 

 a part of the surface in the row. These short cells do not reach to the 

 basement membrane, but are supported in their elevated position by 

 the three rows of Deiter's cells. 



The next cells appear in two rows, which are composed of the tallest 

 cells of all. They spring from broad bases wide apart and lean toward 

 each other at an angle with narrow bodies which touch and merge by 

 a wide, curved contact at the top. The first of these two rows are the 

 outer and the second the inner pillar cells. The round tube-like space 



FIG. 198. Section of the organ of Corti of a young Guinea pig, Cavia. d.c., cells of Claudius; 

 h.c., Hensen's cells; d.c., Deiter's cells or supporting cells of the sensory epithelium; 

 aud.c., auditory cells or hair cells (outer) ; p.c., outer and inner pillar cells; i.aud.c., inner 

 auditory cell or hair cell; n.fi., nerve fibrils; m.t., membrane tectoria; s.s.c., cells lining 

 the sulcus spiralis. 



that runs between them is the tunnel of Corti. The greater part of the 

 cell body is a specialized product of the cytoplasm. 



Next to the inner pillar cells is found a single row of hair cells, the 

 inner hair cells, or, as we shall call them, the inner auditory cells. They 

 are followed by a portion of simple epithelium that lines a groove 

 called the sulcus spiralis. This epithelium is thicker than that which is 

 continued over the remainder of the septum and across as the free mem- 

 brane veslibularis to the outer bony wall and thence to the point at 

 which we began, the cells of Claudius. 



The nerve supply consists of the different processes of neurons lying 

 in a ganglion that is found in the immediate neighborhood. These 

 fibers pass along through the bony septum which is called the lamina 

 spiralis and send naked fibrils in a bundle to the hair cells. Some of these 

 fibrils form perceptory end-plates on the inner hair cells and the rest 

 cross the tunnel of Corti, and, passing into the spaces between the sus- 

 tentacular cells and under the hair cells, end in the same way on the outer 

 hair cells. 



