Crude soybean lecithin was rubbed on the skin of the inner side of the rightear of the rabbit once every other day for a period of two months or longer.The other ear, for control, was also rubbed mechanically without lecithin. Aconspicuous increase in size, number and activity of the macrophages in thesubcutaneous tissue of the treated ear was demonstrated by means of vital stain-ing through intravenous injection with Trypan blue.