TEMPORARY CONTINENCE. Many married couples who are desirous of preventing too-frequent conception, or conception following too soon after the birth of the youngest child, practice the method of refraining from the marital sexual relations during certain periods in which conception is most likely to occur. This custom is said to be favored by those acting under the advice of their religious instructors, and who regard all methods of birth-control other than continence as sinful. Even the most orthodox objectors to birth-control as a general principle seem to regard this particular method as free from objection, providing that the married couple do not seek to entirely escape parenthood in this manner. This plan is based upon the well-known, and well-established physiological principle that THE TIME IMMEDIATELY BEFORE THE MENSTRUAL PERIOD, AND STILL MORE, IMMEDIATELY AFTER THE PERIOD IS THE MOST FAVORABLE TO CONCEPTION. Impregnation is most likely to occur just after the menstrual period; while from about two weeks after the beginning of the period, to a few days before the beginning of the next period, is the time of comparative sterility when impregnation and conception are the least likely to occur. Consequently, the authorities hold that the period of from ten to fifteen days after the END of the menstruation is one peculiarly free from the probability of impregnation and conception. This plan of temporary continence, continuing during the period in which conception is most probable, and terminating when that period has passed each month, until the new period approaches, is followed by many married couples with the full approval of the conscience and their religious guides. In many cases the result fulfills the expectations, though as there is a considerable variation observed among different women there is no absolute certainty to the plan considered as a birth-control method--at the best it is but taking advantage of the law of probabilities, the chances being in favor of the result sought. Semi-Continence. Semi-Continence (in the sense in which the term is employed herein) consists of the abstinence from the exercise of the procreative functions, while there is a partial manifestation of the sexual relation. Under various fanciful names, backed by as many curious theories, this birth-control method is practiced by very many married couples in this and other countries.