Tuberculosis of the middle ear, with caries and necrosis of the temporal bone, is comparatively frequent, especially in the phthisical. Habermann, Haug and others have described, in detail, the pathologic changes produced by tuberculosis of the middle ear. Many of the authors refer to the extension of the process to the dura mater, which has been found either perforated or covered, both externally and internally, by tuberculous granulation tissue and caseous nodules. An interesting instance of tuberculous otitis with a secondary tumorlike protuberance into the cranial cavity is described by Piffl1. The process was observed in a case of extensive pulmonary tuberculosis. It is assumed that the infection reached the middle ear by way of the Eustachian tube, although two remaining routes of infection, namely the circulating blood and the external auditory canal, could not be definitely excluded. From the middle ear the process had spread to the mastoid cells,