"I don't believe in teaching my boys and girls any facts concerning sex. I prefer to keep them innocent until they have grown up." In these decisive words a prominent woman closed a statement of her firm conviction that the world-wide movement for the sex-instruction of young people is a stupendous mistake. Poor deluded mother! How does she expect to keep her children ignorant of the world of life around them? Is she planning to transplant them to a deserted island where they may grow up innocently? Or is she going to keep the children in some cloister within whose walls there will be immunity from the contamination of the great busy world outside? Or is she going to have them guarded like crown princes, and if so, where are absolutely safe guards to be found? Such are the questions which rush into the minds of those who have studied the problem of keeping children ignorant of the most significant facts of life. It is usually an easy matter to protect children against smallpox and typhoid and some other diseases, but no parent or educator has yet found out how we may be sure to keep real live children ignorant of sex knowledge. They seem to absorb such forbidden facts as naturally and as freely as the air they breathe. Ask any large group of representative men--ministers, or doctors, or teachers, or men of business, or the world's toilers--whether any of them knew the essential facts of sexual life before they were twelve years of age, and ninety-seven in every hundred will answer quickly in the affirmative. Ask any large group of women, excepting those whose girlhood has been guarded with exceptional care, and the overwhelming majority will acknowledge that they knew the essential facts before they were fifteen years old. Once more, ask these same men and women whether their early knowledge of sex came from pure and reliable sources or from vulgar playmates and depraved servants; and with rare exceptions it is found that vulgarity made the strongest impression in the first lessons concerning the great facts of life. Such being the truth, it is nonsense for parents to sit in complacency because they feel sure that their children are safely protected against any vulgar first lessons concerning sex; for no one can know that children are safely guarded from others who may corrupt their innocent minds. As an illustration, a few years ago the mothers of a group of little girls in one of the best-managed private schools felt that with careful supervision both in school and home there was no danger of forbidden knowledge reaching the children. But one day a new pupil innocently exhibited to her mother a miniature notebook with unprintable notes on sexual topics. The resulting investigation revealed a secret club organized by the pupils for the purpose of passing to each member through notebooks all newly acquired information, which had a peculiar value because it must be kept secret from teachers and parents. That