In presenting this name for a distinct type of tumors of the thyroid gland, I am actuated by a desire to emphasize the clinical importance of these tumors, and to bring them in stronger contrast with the nodulations of old colloid goiters, erroneously called adenomas. If the term "adenoma" can be eliminated from the nomenclature of goiters, it will be easier to attain a true perspective of the pathogenesis of goiters in general. The foregoing designation is, of course, equivalent to the old term "fetal adenoma." The point that it is necessary to emphasize is that they begin as masses of thyroid tissue which has never reached an adult stage. The designation, "mixed tumor," while a strained one, is, in a measure, justified by the life history of the tumor. They have many points in common with the mixed tumor of the parotid and, more particularly, those of the submaxillary