The pathology of the middle turbinate is in general the pathology of the other intranasal structures. It is subject, as they are, to infectious inflammations, both of determined and undetermined etiology, to the progressive and regressive disturbances of nutrition, and to various processes of degeneration and atrophy. I assume, however, that your committee in assigning to me this subject had in mind that I should treat of those pathologic alterations of the middle turbinate which, from the situation and anatomic structure of the bone, assume here certain definite peculiarities. I shall leave out of consideration, therefore, the pathology of hay fever, of acute rhinitis of other infections and of benign and malignant tumors. We have left those processes which may be grouped under the head of chronic inflammation with tendency to hypertrophy. In association with these conditions are found histologic evidences of degeneration in the mucous membrane and glands.