Abstract
The light microscopical structure of Reissner's membrane was studied in the cat. The epithelial cells facing the endolymphatic space are smaller on the inner (modiolus) side and they become larger towards the outer (spiral ligament) side of Reissner's membrane. The epithelial cells on the inner side of the membrane are more vulnerable to post-mortem changes. The mesothelial cells facing the perilymphatic space are very elongated and fusiform in shape with a regular arrangement from the inner to the outer side of Reissner's membrane. Post-mortem changes of the mesothelial cells consisted in separation of cell junctions or detachment from the basement membrane.
