In the past year Lange 1 has given the results of his study of the early pathologic changes in otosclerosis. The material used consisted of sixty-six temporal bones from forty-five patients. The site of the foci was noted as follows: oval window alone, twenty-two; both windows, seven, and round window alone, four. In only two of the forty-five cases were the windows free. Of the twentyone cases in which both sides were examined, twenty showed symmetrical areas of disease on both sides. For the study of the early stages, Lange chose not the manifest foci on the promontory, but other smaller areas in the rest of the labyrinth capsule. He stated that in the latter situation the process differs considerably from that on the promontory, as at the windows hypertrophy is a prominent feature. The enchondral bone here is very thin and receives a better supply of blood from the