In the years between ten and twelve every child should learn from a parent or other adult confidant some general facts regarding their approaching puberty. This is especially important in the case of girls, for many a girl has been physically and mentally injured because a prudish mother has procrastinated too long the giving of information regarding the first menstrual period. The facts in the first thirty pages of W.S. Hall's "Life Problems" should be known by many girls of eleven and by the great majority before thirteen. Some books for young girls are defective in that they avoid reference to the coming changes. I see no excuse for a sex-hygiene book for girls who are too young to be trusted with the simplest knowledge regarding menstruation. Such children should be interested in nature studies and perhaps the elements of general hygiene, but certainly not in books with curiosity-stimulating titles. [Sidenote: Special needs of boys.] Since boys entering puberty pass through no such sharply defined beginning as girls do, the information they need in advance is not so specific. At the same time, we must recognize that the average boy under twelve years picks up more information regarding sexual life than a girl does, and so the problem of teaching self-control comes earlier, although the average girl enters puberty a year or two before the boy. Parents and teachers must recognize the fact that sexual tendencies come to many boys several years before puberty, and masturbation and even premature sexual intercourse are possible problems with many boys long before the twelfth year. The boy's early gathering of sexual information is not without advantage, for it becomes possible for parents and other adult confidants to explain many important truths as to the proper use of his sex organs and as to his conduct towards girls. All this can be done with the average boy of eleven or twelve and with hundreds of even nine and ten without any fear of giving information that is startlingly new and without any danger of giving a nervous shock. [Sidenote: Cautious teaching of girls.] It is not so with average girls of equal ages, if we may accept the opinion of many women who are trained in science and medicine. Specific information as to the functional relationships of the two sexes is said by many educated women to have been absolutely new and startling to them at twenty and twenty-five years. Evidently there is a special reason for gradual and cautious teaching of girls, and so it is probably best, as many parents urge, that in pre-adolescent years the girl's instruction in social-sexual lines be training in modest deportment and a proper reserve towards boys. This ought to be sufficient for the girl's protection until gradually in adolescent years she learns the whole story of life, probably several years later than her boy friends whose natural leadership in sexual activity makes their early information desirable as a protection to both sexes.