In fixed materials variations in size, shape, position and apparent structure of the so-called cupula are found. The cupula does not exist as a definitely formed structure in the living ampulla. A substance which contains many minute, shining particles, found distal to the crista, when acted upon by fixing reagents, coagulates upon the crista to form the so-called cupula. The analogy between the cupula and the tectorial membrane indicates that this membrane may be a coagulation product also.