The next information and guidance needed by our boys and girls concerns the influence of sex upon their own development. The objection is continually raised that it is not well for little children to have sex thoughts emphasized in their minds. But at present no boy or girl grows up and plays among other children, or hears talk on the streets, or goes to work in factory or store, without hearing these facts emphasized day by day, emphasized unhealthily and distorted shamefully. We propose simply to have the emphasis shifted and lightened for it will be lightened if the facts are given truly and in right relations. Boys and girls should learn, at the same time they are learning facts of nutrition, excretion, respiration, and circulation of the blood, those facts regarding sex which are most important for healthy growth of mind and body. They should know that the organs of reproduction have a definite relation to the natural and healthful development of the full powers of their bodies in future years; that internal secretions of these organs coming into the blood help to build up bones and muscles, help to make their nerve fibers active and vigorous, help to form their brains, and help to equip them for manly strength and womanly grace in the years that are to come. These are very simple matters. These facts of sex can be conveyed by just a few sentences of clear, considerate, wise information at the right time, in relation to the other facts of bodily development. Considering now the period of puberty, we find additional needs, for no boy or girl reaches puberty, under ordinary conditions, without knowing that it brings the possibility of fatherhood and motherhood, brings the possibility of that process that we call fertilization, in which the life of plants and animals begins. The boy or girl who reaches this age has a right to know what fertilization means, and what fertilization implies; has a right to the simple biological facts which will tell him the relation between the life of the parents and the life of the child, the mysterious relation in body and mind that we call heredity. The beginning of the socializing of sex energy and sex power depends upon recognition of the fact that this power that develops in the young man and young woman at puberty is not to be used for selfish gratification, is not primarily a source of pleasure, but has a very direct relation to the health, intelligence, and happiness of others. This relation may be enforced by a simple study of succeeding generations of flowers and the ways in which forms, colors, and sizes originate and are handed down from generation to generation in wonderful variety. Or it may be illustrated from an observation of the beginnings of sex in infusoria; how tiny animals in stagnant water grow to full size and each divides simply into two to form a new generation; how this simple asexual process continuing for several