chap, xu.] THE INTERNAL EAR. 331 



in the shape of a horseshoe in the outer part of the 

 free surface of the cell. 



Four, and even five, rows of hair-cells (Waldeyer), 

 arranged in an alternating manner, are found in 

 man. 



The outer hair-cells are also called the cells of 

 Corti ; they are conical, and more or less firmly con- 

 nected with a nucleated spindle-shaped cell the cell 

 of Deiters. The two cells are more or less fused 

 together in their middle part (Nuel). The cell of 

 Corti is fixed by a branched process to the membrana 

 basilaris, while the cell of Deiters sends a process 

 towards the surface, where it joins the membrana 

 reticularis (see below). 



482. Farther outwards from the last row of outer 

 hair-cells are columnar epithelial cells, called the outer 

 supporting cells of Hensen ; they form the transition 

 to the epithelium lining the outer angle of the scala 

 media, i.e., to the cells of Claudius. 



In the guinea-pig, the outer supporting ceiis in- 

 clude fat globules. 



483. The medullated nerve-fibres, which we 

 traced in a former page to the margin of the lamina 

 spiralis ossea, make rich plexuses in this, and pass 

 through holes in it, in order to reach the organ of 

 Corti on the membrana basilaris. Looking from the 

 surface on this part, we notice a row of holes the 

 habenula perforates of Kblliker a little to the inside 

 of the region of the inner hair-cells. Numerous 

 primitive fibrillse pass there among small nucleated 

 cells situated underneath the inner hair-cells : these 

 are the granular cells. Some of these nerve-fibrilla? 

 the inner bundle of spiral nerve-fibres become con- 

 nected with the inner hair-cells ; while others the 

 three outer bundles of spiral fibrils (Waldeyer) pass, 

 between the inner rods of Corti, right through the 1 , 

 tunnel ; and, further, penetrating hotweon the outer 



