THE CLINICAL phenomena associated with venous stasis in the lower extremities and the sequelae thereof are among the commonest of entities seen in the practice of medicine. It has been estimated1 that 10 to 17 per cent of the population are afflicted with varicose veins and their complications. That there is an important relation between chronic venous insufficiency and the subsequent (or concomitant) development of cutaneous changes in adjacent or overlying areas of skin or both has not been questioned, but the mode of development of such changes has long been a matter of much conjecture. The purpose of this investigation was to determine what, if any, pathologic changes occurred in the blood vessels of the skin of the lower extremities in patients who showed clinical manifestations of chronic insufficiency of the venous return of blood from these areas. CHRONIC VENOUS INSUFFICIENCY Definition.—Chronic venous insufficiency has