The material for this report consists of four temporal bones from three cases of otosclerosis. The first temporal bone described was from a woman, aged 37, whose case was reported in the ARCHIVES OFOTOLARYNGOLOGY for July, 1929. The published report dealt only with the infectious condition. There was extensive infection of the middle ear, surrounding the stapes and round window, with invasion of the pneumatic spaces. Otitis media and mastoiditis of the right side had developed. Later sinus thrombosis, cerebellar abscess and meningitis developed. With these complications the patient died thirty-three days after the onset of the infection. The original hospital record was lost, but so far as could be ascertained there was no history of previous deafness or ear trouble. No history of family deafness was obtained.
Horizontal sections of the right ear, from above down, revealed a focus of pathologic change (fig. 1) which began at