Living beings--Animals and vegetables--Life force--Reproduction-- Spontaneous generation--Simplest form of generation--Hermaphrodism-- Sex in plants--Sex in animals--Other sexual differences--Men and women differ in form--Modern mania for female pedestrianism--3,000 quarter miles in 3,000 quarter hours--A female walking-match--The male and female brain--Vital organs of man and woman--Woman less muscular, more enduring--A pathological difference--Why a woman does not breathe like a man--The reproductive elements--Sexual organs of plants-- Polygamous flowers--The female organ of flowers--Sexual organs of animals--The spermatozoon--The ovum--Fecundation--Fecundation in flowers--Union of the ovum and zoosperm--Curious modes of reproduction--Human beings are developed buds--Fecundation in hermaphrodites--Development--Unprotected development--Partial protection of the ovum--Development in the higher animals and in man-- The uterus--Uterine gestation--The primitive trace--Curious relations to lower animals--Simplicity of early structures--The stages of growth-- Duration of gestation--Uterine life--How the unborn infant breathes-- Parturition--Changes in the child at birth--Nursing--Anatomy of the reproductive organs--Male organs--The prostate gland--Female organs-- Puberty--Influence of diet on puberty--Brunettes naturally precocious-- Remarkable precocity--Premature development occasions early decay-- Early puberty a cause for anxiety--Changes which occur at puberty-- Menstruation--Nature of menstruation--A critical period--Important hints--Menorrhagia--Dysmenorrhoea--Amenorrhoea and chlorosis-- Hysteria--Prevention better than cure--Extra-uterine pregnancy--Twins-- Monsters--Hybrids--Law of sex--Heredity--Ante-natal influences--Law universal--A source of crime--Circumcision--Castration . . . . . . . 25 _THE SEXUAL RELATIONS_. Sexual precocity--Astonishing ignorance--Inherited passion--Various causes of sexual precocity--Senile sexuality--Marriage--Time to marry--Application of the law of heredity--Early marriage--Mutual adaptation--Disparity of age--Courtship--Long Courtships-- Flirtation--Youthful flirtations--Polygamy--Polyandry--Divorce-- Who may not marry--Do not be in a hurry. . . . . . . . . . . . . . . 116 _CHASTITY_. Mental unchastity--Amativeness--Unchaste conversation--Causes of unchastity--Early causes--Diet vs. chastity--Clerical lapses--Tobacco and vice--Bad books--Idleness--Dress and sensuality--How young women fall--Fashion and vice--Reform in dress needed--Round dances--Physical causes of unchastity--Constipation--Intestinal worms--Local uncleanness--Irritation of the bladder--Modern modes of life . . . . 174 _CONTINENCE_. Continence not injurious--Does not produce impotence--Difficulty of continence--Helps to continence--The will--Diet--Exercise--Bathing-- Religion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205 _MARITAL EXCESSES_.