Since our student days we have been familiar with the fact that molds may at times be pathogenic in their action. Attention had been called to this pathogenicity even before Virchow's work in 1856 describing the infectious process and identifying the organism. Baumgarten in his "Mykologie," published in 1890, describes the lesions resulting from experimental injections of Aspergillus niger and discusses very fully the pathologic changes and the microscopic observations.
Myers and Dunn1 reported a case of aspergillosis in which the infection was located on the dorsal aspect of the hand of a farmer. The lesion was in the nature of a granuloma.
Most often this infection is seen in the auditory canal and in the lungs. In the lung it may run a very chronic course and defy accurate diagnosis for a long time. In the auditory canal it is a question whether the mold acts as a