Sexual knowledge : the knowledge of self and sex in simple language : for the instruction of young people, young wives and young husbands, fathers and mothers, teachers and nurses, and all who feel a need of reliable information on the best way and the best time to impart sexual knowledge to boys and girls / by Winfield Scott Hall, Ph.D. (Leipzig), M.D. (Leipzig), professor of physiology, Northwestern University Medical School, Chicago, President of the Child Conservation League of America, etc. author of "Reproduction and sexual hygiene," "From youth to manhood," "Text-book of physiology," "Manual of experimental physiology," etc. ; assisted by Jeannette Winter Hall, author of "Life's story," "The first five hundred days of a child's life," "New century series of physiology," etc