[Hearing receptor of the white rat]

The cochlea of albino rats was studied on the fresh and fixed but not dehydrated specimens, as well as on radial sections of Epon embedded material, and by scanning electron microscopy. Obtaining sections of the non-dehydrated tectorial membrane made it possible to reconstruct its shape and position with respect to the organ of Corti and sulcus spiralis. The quantitative description of geometry of the tectorial membrane is given in addition to that of the surface of the organ of Corti and of bundles of stereocilies of both outer and inner hair cells. The three parts of the cochlea are shown (apical, medial and basal) to manifest characteristic gradients of the analyzed parameters.