Chap. XLI.] THE INTERNAL EAR. 329 



there is also a hyaline basement membrane. The 

 endothelial cells covering this on the tympanic surface 

 have been mentioned above. 



477. The organ of Corti (Fig. 164). Passing 

 outwards from the epithelium lining the sulcus spiralis, 

 we meet with small polyhedral epithelial cells in the 

 region of the termination of the lamina spiralis ossea, 

 next which are columnar-looking cells the inner 

 supporting cells; next to these is the inner hair-cell 



Fig. 164. Organ of Corti of the Cochlea of a Guinea-pig. 



o, Outer rod or pillar of Corti ; 6, inner rod or pillar of Corti ; c, tunnel of Corti'8 

 arch ; d, outer hair-cells ; e, inner hair-cell ; /, outer supporting cells contain- 

 ing fat globules ; Dinner supporting cells; h, cells of Claudius; i, epithelial 

 cells lining the sulcus spiralis internus;/, ncrvc-flbres; *, part of crista 

 spiralis. (Atlas.) 



a columnar, or conical, epithelial cell, with a bundle 

 of stiff hairs, or rods, extending beyond the surface. 

 The inner hair-cells form a single file along the whole 

 extent of the two and a half turns of the scala media. 

 478. Next to the inner hair-cell is the inner rod, or 

 inner pillar, of Corti, and next to this the outer rod, 

 or older pillar, of Corti. Each forms a single file for 

 the whole extent of the tw> and a half turns of the 

 scala "media. The two fods are inclined towards one 

 another, and "in contact wifch-their" upper extremity, or 

 hea^ ; whe*reas their opposite extremj^;, the^ .fodt, 

 rests under an acute angle on the membrana basilaris, 

 on which it is firmly fixed The rest of the rod is a 

 slender, more or tefes cylindrical, piece the body. The 



