The membrana tympani though recognized by the anatomist to be a structure admirably adapted to play an important part in the mechanism of sound conduction, has not, until recently, received from the neurologist the attention it would appear to merit. At present the description of the nerve distribution in this membrane in mammals, with the exception of man, may be said to be in the main satisfactory. In man the account is not only meagre but lacking in many essential details. It is contained in the work of Kessel published in 1872, when the technic for nerves and nerve endings was less satisfactory than it now is. So far as I know, excepting a drawing by Kessel, believed both by Jacques and myself to be inaccurate, there have not appeared any illustrations of the nerve distribution. It is difficult to account for this indifference. While it may be due in some small measure to a lack of appreciation of the importance of this membrane, it is mainly to be accounted for by the difficulty of the technic inherent in its structure. I n a former paper ('07a) I described the mode of distribution and the varieties of endings found in the membrana tympani of the rabbit, dog, cat and monkey; in this paper I propose to extend these investigations to the membrana tympani of man.
1 The drawings have been made by Herr β¬1. Schilling of Freiburg, and Miss Kill of the University of Chicago, t o whom I wish to express my sincere thanks.