of sex and the processes of reproduction.  If nothing is said on such subjects, which in the nature of things are bound to excite a lively interest and curiosity in the minds of older children, evil results are apt to follow.  Because parents have never mentioned these subjects to their child, they must not conclude that he is ignorant of all knowledge concerning them.  It is not unlikely that the question has often occupied his thoughts, and that his speculations have led him to conclusions which are, on the whole, true, although perhaps incorrect in matters of detail.  Most children, unable to ask their mother or father direct questions upon matters which they feel instinctively are taboo, have pieced together, from their reading and observation, a faulty theory of sexual life.  The pursuit of such knowledge, in secret, is not a healthy occupation for the child.  His parents’ silence has given him the feeling that the unexplored land is forbidden ground.  In satisfying his curiosity he is most certainly fulfilling an uncontrollable impulse, but he has been forced to be secretive, and to look upon the information he has acquired as a guilty secret.  So far even the best of children will go upon, the dangerous path.  If training has been good, and if the child has responded well to it, he will go no further.  Though he can hardly be expected to refrain from constructing theories and from testing them in the light of any chance information which may come his way, he will instinctively feel that the subject is one best left alone.  He will not talk of it with other boys—­not even with those who are older than himself and whose superior knowledge in all other matters he is accustomed to respect.  We need not be surprised, however, that the majority of children do not attain to this high standard of conduct, and that the interest and excitement of exploring the unknown and the forbidden proves too great.  Children will consult with each other about such matters, and knowledge of evil may spread rapidly from the older to the younger.  In some schools, as is well known, there may grow up with deplorable facility an unhealthy interest in sexual matters.  On the surface of school life all may seem fair enough, but beneath, hidden from all recognised authority, lies much that is unspeakable.  If the boy has not been taught to have clean thoughts upon matters which are essentially clean, if he has not learned to know evil that he may avoid it, he may not escape great harm.  The fault in us which kept him in ignorance will recoil upon our own heads.  He will maintain the barrier which was erected in the first place by our own unhappy reticence, and we may find it a hard task to penetrate behind it and prevent his constant return to secret thoughts and imaginings or secret habits and practices.  Certain physiological processes come to have for him an unclean flavour which is yet perniciously attractive.  He knows little of the real meaning of sexual processes or of the great purpose for which they are designed.  It is only that an unhealthy interest becomes attached to all subjects which are scrupulously avoided in general conversation.  In secret he develops a wrong attitude to all these matters.