The author has observed in one case of hyperplasia following the correction of a saddle nose, that the area injected presented no unusual appearance for six months, when the nose at its middle third began to enlarge slowly until it resembled a marked Roman shape, the enlargement extending laterally and as far down as the nasogenian furrows at the end of nine months. The injection used was a cold, semisolid paraffin mixture, and only sufficient to barely correct the defect was injected, the skin being thoroughly flexible at the time of operation. No reason can, therefore, be given for this unusual result, except, perhaps, a peculiar idiosyncrasy of the tissues, that may be compared, somewhat, with the external tissue changes in hypertrophic or keloidal scars, especially noted in the wounds of negroes—a condition for which we have, as yet, found no attributable cause. While we cannot definitely prevent such a result, following an injection of a hydrocarbon, we may at least be sure that hyperinjection is not the cause. The hyperplasia as exhibited in these cases is one of true fibromatosis. The microscopical examination may show the retention of paraffin in small, round, pearllike masses lying in cells of varying size, but with specimens of such tissue removed after a number of years’ standing does not show the paraffin _in situ_. In a specimen taken from a chin five years after the injection of paraffin the Lederle Laboratory makes the following report accompanied by microphotographs of sections taken from the fibromatous area as shown in Figs. 288_a_ and 288_b_: “ANATOMIC DIAGNOSIS.—The specimen consists of several pale, tough masses of tissue removed from the chin covered on the outside by normal skin. “HISTOLOGIC DIAGNOSIS.—The various layers of the epidermis—i. e., the strata corneum, lucidum, and granulosum—are unthickened and practically normal. In the corium the papillary and reticular layers are apparently normal, showing no thickening nor round-cell infiltration. “The glandular elements in this area and the hair follicles appear normal. “Toward the deeper layers and the subcutaneous connective tissues appear isolated areas of round-cell infiltration separated by masses of fibrous connective tissue, much of which is of new formation, as indicated by the nucleated character of the elongated cells. There are areas of diffuse round-cell infiltration. “In this portion of the corium there is also to be found a large number of vacuolated areas varying very greatly in size, and which are surrounded by membranous fibrous-tissue elements, much of which is likewise of new formation, as indicated by the character of its cells. “These vacuoles doubtless represent the areas containing the masses of paraffin which have been split up by the new formation of fibrous tissue. Between the vacuolated areas can be seen actual infiltration by true fat cells.