=How to proceed.=--This is not a difficult problem to the young father who is fairly well informed and who has strong convictions of his duty. He can start with his son, as soon as he asks about his origin, and tell him the stories of life, six months or a year apart, and continue to give him such information as his developing boyhood and manhood demand. But to the uninformed father, out in middle life, aroused for the first time to the great need of this teaching and to his personal responsibility to his boys ranging from five to twenty years old, this is not an easy problem. In this case I would suggest that, if possible, he should avail himself of hearing a good course of lectures, and buy for himself a practical and complete book on sex for himself and smaller books adapted to the age and sex of his children. If he has a boy from five to eight years old, begin by telling him the story of how plants are brought into the world. If he has a boy ten to fifteen, I would advise that he put in his hands a book containing stories of life from plants to man and encourage him to read it. If there is real companionship between the father and son, a better plan would be for them to read the book together and talk with each other. When this is done and a few days have passed the father should give him a book containing such information as a boy from ten to fourteen should know. And if proper companionship exists, they should read this book and talk over its revelations together. When this is done the boy should be encouraged to talk over any personal problem he may have. It would be well for the father to inquire of his son, if he has any irritation or soreness in his sexual organs, if the prepuce is capable of passing back and if the frenulum is too short. The boy should understand that he will be welcomed at any time to return with his problems and to ask for information. If he has a boy over fifteen he should be presented with a book that covers the problems of a young man. If there is a companionable relation between the father and his son, it would be well for them to read and talk over the revelations of this book. The son should be encouraged to ask questions and to talk about his personal problems. =When should a boy be informed of the secret sin?=--In no case should this be postponed until a boy is twelve. Out of one thousand of the young men who have read “Perfect Manhood” and in that way were lead to write me about their troubles not one in twenty-five learned the habit after he was twelve, many commenced when they were eight and ten, a few when five and six, one stating that so far as he knew he was born practicing the vice.