288 THE ESSENTIALS OF HISTOLOGY. 



manner, but rest by their larger end upon the basilar membrane, and 

 are prolonged above into a cuticular process which is attached to the 

 reticular lamina (cells of Deiters, fig. 321, z). 



4. The inner hair-cells (fig. 321, i), placed internal to the rods of 

 Corti. They form a single series of columnar cells surmounted by 

 auditory hairs, lying in close apposition to the inner rods. 



The rest of the epithelium-cells have no important characteristics. 

 They are long and columnar next to the outer hair-cells, but soon 

 diminish in size, becoming cubical, and in this form they are continued 

 over the outer wall of the cochlear canal. Here they cover a very vas- 

 cular membrane (stria vascularis, fig. 319, str. v.), which is frequently 

 pigmented : its capillary blood-vessels penetrate between the epithelium- 

 cells. Internal to the inner hair-cells the epithelium also soon becomes 

 cubical ; it is prolonged in this form over the limbus of the spiral 

 lamina. The epithelium of Reissner's membrane is of the pavement 

 variety. 



The membrana tectoria (fig. 319, M.t.) is a soft, fibrillated structure, 

 which is attached along the upper surface of the limbus, and lies like a 

 pad over the organ of Corti. It thins out towards the distal margin, 

 here becoming somewhat reticular, and, according to Retzius, it is 

 attached to the lamina reticularis. In sections it usually appears raised 

 a short distance above the auditory hairs, but it is probable that it 

 always rests upon them during life. 



FIG. 324. GENERAL VIEW OF THE MODE OF DISTRIBUTION OF THE COCHLEAE NERVE, 



ALL THE OTHER F;ARTS HAVING BEEN REMOVED. 



The fibres of the cochlear branch of the auditory nerve enter the base 

 of the columella, and run in canals through its substance, being gradu- 

 ally deflected outwards as they pass upwards into the spiral lamina, 

 at the base of which they swell out into a ganglionic cord (spiral 



