These words written by a poet to his young son express the longing which has at times seized all of us, to guard youth from the mass of difficulties which may be traced to the obscure manifestation of that fundamental susceptibility of which we are all slow to speak and concerning which we evade public responsibility, although it brings its scores of victims into the police courts every morning. At the very outset we must bear in mind that the senses of youth are singularly acute, and ready to respond to every vivid appeal. We know that nature herself has sharpened the senses for her own purposes, and is deliberately establishing a connection between them and the newly awakened susceptibility of sex; for it is only through the outward senses that the selection of an individual mate is made and the instinct utilized for nature's purposes. It would seem, however, that nature was determined that the force and constancy of the instinct must make up for its lack of precision, and that she was totally unconcerned that this instinct ruthlessly seized the youth at the moment when he was least prepared to cope with it; not only because his powers of self-control and discrimination are unequal to the task, but because his senses are helplessly wide open to the world. These early manifestations of the sex susceptibility are for the most part vague and formless, and are absolutely without definition to the youth himself. Sometimes months and years elapse before the individual mate is selected and determined upon, and during the time when the differentiation is not complete--and it often is not--there is of necessity a great deal of groping and waste.