It has long been agreed that the various forms of xanthomatosis are of general medical interest and not simply the expression of a local change in the skin. In many cases deposits of the same structure as that of the cutaneous deposits occur in internal organs. In 1878 Quinquaud advanced the idea that xanthoma is due to changes in the blood, hypercholesteremia, and more recent investigations have established the fact that it does concern a disturbance of lipoid metabolism. Other forms of lipoidosis, such as Gaucher's disease and Niemann-Pick disease, will not be considered at this time; neither will the xanthomatous manifestations in diabetes, myxedema, pregnancy and disease of the liver with icterus be discussed. The constitutional nature of "essential" xanthomatosis is shown clearly by its hereditary occurrence. Török1 observed xanthomatosis as a hereditary manifestation in several families, and this has since been confirmed by others. The localization of