Nature's secrets revealed : scientific knowledge of the laws of sex life and heredity, or, eugenics : vital information for the married and marriageable of all ages ... together with important hints on social purity, heredity, physical manhood and womanhood by noted specialists, embracing the story of life and how to tell it, also a department on ethics of the unmarried / by T.W. Shannon ; introduced by Samuel Fallows ; medical department by W.J. Truitt.