Like mechanical stimulation, electrical stimulation can nearly always activate lipolysis, as evidenced by increased blood glycerol and NEFA. The interpretation of this phenomenon is discussed and importance is attached to catecholamine mediation, since administration of a beta-blocking agent is sufficient to cause a significant reduction in the extent of the phenomenon. Other mechanisms can possibly be sought in the muscle fibres present in subcutaneous tissue, whose contraction induces increases blood lymph flow. While electrical stimulation of adipose tissue fragments in vitro gave no appreciable results, it is still possible that electrical impulses act even more intimately by means of direct physical modification of the more elementary metabolic mechanisms.