Otosclerosis is the most important cause for severe deafness coming on in early or middle adult life. The pathology, the clinical picture, the diagnosis and the prognosis of the disease and its relative frequency were accurately described by Bezold, who in 1885 was the first to show that the characteristic clinical picture is due to bony ankylosis of the stapes. The acceptance of these facts, however, particularly concerning the frequency of otosclerosis, has been slow, especially in this country where histologic examination of temporal bones was until recently limited to a very few investigators. Seeing is believing; and, as the microscopic study of temporal bones is being carried out more extensively and in more places, the accuracy of the observations of Bezold, Siebenmann and others that otosclerosis is a very common disease is beginning to be appreciated.
Knowledge of the etiology of this very important cause for progressive deafness has