With a feeling of reverence for ourselves we now take up the subject of special physiology to learn what makes us women. In the study of general physiology we find very few physical differences in the sexes, but when we come to investigate what is called the reproductive system we find entire difference of structure and of function. Boys and girls in early childhood are much alike in their inclinations. They both love activity--to run, to climb, to shout, to laugh, to play. If left to themselves one sees not much more difference between boys and girls than between different individuals of the same sex. But as they grow and develop they begin to take on characteristics that indicate the evolution of sex. The boy grows rapidly in height, his voice breaks, the signs of a moustache appear, he seems constrained and embarrassed in society, and yet he begins to show more politeness towards women and more of an inclination to be gallant to girls. He is becoming a man, and assumes manlike airs. Often, too, he becomes restless and willful, hard to govern, self-assertive, with an assumption of wisdom that provokes laughter from his elders. The boy is passing through a serious crisis and needs much wise and loving care. There are inner forces awakening that move him strangely; he does not understand himself, neither do his friends seem to understand him. Sometimes they snub and nag him, sometimes they tease and make fun of him. In either case he does not find home a happy place, and frequently leaves it to seek more sympathetic companionship elsewhere.