Having thus considered the general significance of sexual enlightenment, we have next to ask what are the grounds on which such enlightenment is thought to be desirable. These will have become partly apparent from what has been said regarding the importance of the sexual life of the child; but this does not exhaust the matter, for the sexual enlightenment of the child may also comprise instruction concerning the entire subsequent development of the sexual life. The reasons for sexual enlightenment may be classified under various heads; the chief of these are reasons of health, of social life, of law, morality, education, and the intellectual development. To consider first the matter of intellectual development, we have here to think, not so much of a limitation of the intellectual growth in consequence of the sexual thoughts of the child, as of the fact that instruction in the nature of sexual processes, at least as far as the objective field is concerned, promotes the general culture. The degree to which even adults are ignorant about such matters, is hardly credible. There are persons who believe that every egg laid by a hen will develop into a chicken if incubated by the mother, or if kept for the proper time in an artificial incubator; there are persons who do not know what the hard roe and soft roe of fishes are, who do not understand the nature of the spawning process, and are, in fact, quite uninstructed concerning the process of reproduction in fishes. I have conversed with adults who did not know wherein a wether differs from a ram, or a bullock from a bull; and who were even ignorant, as regards great groups of the animal kingdom, whether they reproduced their kind by means of eggs or living young. But on such matters as these, every cultured person should be sufficiently informed, and should not be capable of being shamed by the superior knowledge of an uneducated child from the country. On one occasion, I even saw a married woman, actually twenty-eight years of age, who had been examined by a gynecologist, and for whom the latter had recommended the operative division of the hymen; but the lady confused this operation with oophorectomy, and it was by no means an easy matter to make her understand the difference between the two. It will readily be understood that every grown man and woman ought ultimately to be fully informed concerning all such matters. In part, such instruction will take place at school, and more especially in the case of processes in the vegetable and lower animal world; these things will be explained in connexion with instruction in natural history and biology. But information about the human reproductive organs cannot be given in the school, unless to children of a considerable age; for these matters, direct personal instruction at home is more suitable.