| Abstract: | The ultrastructure of the round window membrane of the cat was investigated. Three distinct layers were recognised and described. It was established that the outer epithelial layer is non-ciliated, but often contains microvilli. The middle layer, under the basement membrane, contains a large amount of collagen and elastic fibres in addition to fibrocytes. The inner layer is a continuation of the epithelial layer of the perilymphatic space. The thickness of the membrane has been measured as being 15--20 micrometer. The latest human audiological and clinical observations concerning the function and rupture of the round window membrane emhasise the importance of the electron microscopic study of this membrane. |
