In this little book Dr. Marie Stopes deals with subjects which are generally regarded as too sacred for an entirely frank treatment. Some earnest and delicate minds may feel apprehensive that such frankness in details is "dangerous," because the effect on prurient minds might be to give them food for their morbid fancies. It is just such a fear which has been largely responsible for the silence and mystery which have for so long been wrapped round the sacred rites of mating.