She most likely has received her sexual information from some one else, and the mother is astonished at the stubborn silence on the part of her daughter. She fails to realize that some one else has that confidence which belongs to her and which she should have gained many years earlier. There is a strong tie between the adolescent girl and her sexual informant. The influence of an older girl over a younger, between whom there are confidences regarding sex, is surprisingly great. The mind at this age is very susceptible to influences of any kind, and the ideals instilled into a girl's mind are of paramount importance. These are only a few of the disturbances of the adolescent girl. But they are sufficient for us to know that at the bottom of all these disturbances is the mysterious influence of sex gradually unfolding itself and finally claiming its own. At the time these emotions are in full sway along comes a newer and deeper one. The boy with whom she has played for the past several years, run races, played house, ball and games, one day looks into her eyes—and something happens. Perhaps that look was accompanied by a pull at her hair, a pinch on her arm, or a hit with an apple core, but the glance was one which awakened within her a new instinct; the consciousness of sex, and upon her horizon man appears. Those who have investigated boy and girl love affairs seem to be of the opinion that they are invariably of short duration. Out of 100 high school girls interrogated, two had married while at school, and one of these had received a divorce shortly after. This goes to prove that the boy a girl is willing to elope with, or even starve for at 18, is quite forgotten at the age of 25. When girls marry between the ages of 19 and 20—the years when they are developing in body, mind and character, they are at a loss to understand themselves, because they are ignorant of the fact that the wonderful instinct of sex is making itself felt. For thousands of years this instinct has been in the germ of life. When they have reached that age nature is preparing them to proclaim its right, to perform their natural functions, to propagate. As the knowledge of the sex functions is one of the most important to the health and happiness of the girl, we shall now consider the girl in the period when nature has developed and prepared her to carry out its plan, in the Age of Puberty. CHAPTER III. PUBERTY—PART I.