For the purpose of studying the sectional curve of the tympanic membrane cut by a perpendicular to its basic plane (Fig. 2), authors made moulds of the figures of tympanic membranes (Fig. 1 B), by pouring paraffin into the eternal auditory meatus and taking photographs of side-figures of them, using fresh temporal bones of the Japanese cadavers for materials. After measuring the figures of the paraffin moulds and photographs, we determined the sectional curve of the membrane; it was similar to a witch of Agnesi. Stiffness of the middle point and the periphery of the tympanic membrane were deduced to be greater then that of the intermediate part.
