In this, the last of a series of articles devoted to the study of epitheliomas, the same general plan has been followed as in the preceding papers.1 The cases of epithelioma have been divided into eight groups from the standpoint of location: (1) the tongue; (2) the inside of the cheeks and lips, gums, floor of mouth, and so forth; (3) the tonsil; (4) the pharynx, and hard and soft palate; (5) the larynx; (6) the esophagus; (7) the inside of the nose, accessory nasal sinuses, nasopharynx and mucous membrane of orbit, and (8) cases in which the primary lesion could not be located. In grading the degree of malignancy in this series of cases as in my previous cases, cell differentiation plays the important part; that is, if about three-fourths of the epithelioma was differentiated epithelium and one-fourth undifferentiated, it was graded 1; if the differentiated and undifferentiated