Its results--Causes--Lack of cleanliness--Pin-worms--All functions attended with pleasure--Sex not low--Its development accompanied by increased power--How overcome the bad habit?--Remove causes of pelvic congestions--Train the senses--Study clouds, leaves, shapes, birds, etc. 151 CHAPTER XX. BE GOOD TO YOURSELF. What is real fun--The effects of a wrong idea of fun--Flirtations--Familiarities--Criticism of girls by young men--Class of girls who are most respected--Responsibility of girls--The conduct of a pure woman the safeguard of man. 159 CHAPTER XXI. FRIENDSHIP BETWEEN BOYS AND GIRLS. The meaning of friendship--Mother the girl's wisest confidante--Kissing--Friendship between brothers and sisters--Platonic friendships--The value of noble companionship. 169 CHAPTER XXII. FRIENDSHIP BETWEEN GIRLS. Gushing girls--Manly friendships--The highest type of friendship--To love truly is to grow strong by true giving. 177 CHAPTER XXIII. EXERCISES. Correct dressing--To overcome curvature--Round shoulders--To strengthen the back--To develop the chest--Abdominal muscles--To restore displaced organs. 181 CHAPTER XXIV. RECREATIONS. Walking--Running--Riding--Skating--Rowing--Cycling--Tennis-- Swimming--Skipping--Dancing--Card-playing--Theatre-going. 187 PART III. CHAPTER XXV. LOVE. Different ideas of different people--Much that is called love is selfishness--Love at first sight--Present conditions of society unnatural--Parents unwilling to teach their children, yet permit flirtations, etc.--What is love?--One word to express different phases of regard--Love of man and woman--Love should include mental congeniality, spiritual sympathy and physical attraction--Young people should have opportunity to get acquainted--Comradeship of young people--Love is a growth. 199 CHAPTER XXVI. RESPONSIBILITY IN MARRIAGE. Who is the young man?--What are his antecedents, his talents, his habits?--What sort of a family does he belong to?--The wife marries her husband's family--Girls should know this--A mother's privilege. 209 CHAPTER XXVII. THE LAW OF HEREDITY. A strange will--Should study the law of inheritance--Plant heredity--Race heredity--National characteristics--Individual inheritance--We are composite photographs--The law of heredity a beneficial law--Transmission of evil a warning--Bad tempers inherited--Atavism. 215 CHAPTER XXVIII. HEREDITARY EFFECTS OF ALCOHOL, TOBACCO, ETC.