Abstract
The light microscopic structures of the basilar membrane and its adjacent areas of the experimental animal cochlea were studied by the surface preparation technique combined with a silver staining, which demonstrated the following characteristics:
1. The mesothelial cells, which cover the basilar membrane on the side of the scala tympani, are of elongated, spindle-like shape and are arranged in a spiral direction from the base to the apex of the cochlea.
2. Near the apex, however, the mesothelial cells show a radial arrangement running parallel to the fibers of the pars pectinata.
3. The mesothelial cells become narrower toward the base of the cochlea and laterally toward the spiral ligament in the basal turn, lying tightly side by side or overlapping with each other.
