Until recently most of the knowledge regarding the lymphatics of the human skin was based on anatomic preparations which at best represented fixed changes in the tissues. These histologic studies showed that the lymphatic vessels, especially the smaller ones, are minute and delicate structures closely associated with but independent of the blood vessels. It was also known that the lymphatic vessels change their size and shape, depending on intrinsic and extrinsic differences in pressure and chemical reactions. The number of active lymphatic capillaries in the living skin probably varies under diverse conditions. Krogh1proved that blood capillaries vary in size and number under changing conditions. It is a common experience to find numerous dilated and engorged lymphatic vessels in sections taken from various inflammatory lesions of the skin, such as those of erysipelas and cellulitis. Sections of skin taken from a great variety of cutaneous lesions show similar variations