Abstract
A review of the historical development and present status of the problem, with 167 citations. The vaginal smear technique, which has been found best, has brought out 4 phases in the [female] sex cycle throughout the mammalia; but the menstruation phenomenon in primates has not received final interpretations. The endocrinal basis of the cycle is not yet completely worked out. Effects of the female sex rhythm upon other phenomena have been determined in varying degrees of agreement: body temp., metabolic rate, sensory functions, spontaneous activity, intensity of the sex drive and of sex desire, all seem to show some effect; while cardiovascular changes, reflex actions, muscular strength, motor coordination, motor learning, and psychomotor efficiency have each been studied with conflicting results.