Civilization has changed all this, and has developed two castes of women, the old maids and the prostitutes. The latter satisfy the appetites of men in an artificial and unhealthy manner, while marriage and family cares only bring them labor and burdens instead of riches. Owing to the promiscuous polyandry of prostitution, man can always obtain enough women, while woman can with difficulty obtain a suitable husband. These circumstances have more and more developed the art of flirtation, coquetry and advances on the part of girls, and we can now see, especially in the United States, that advances come more and more from the female side, if not in principle, at any rate in fact. This is not a question of a phylogenetic or hereditary transformation of the sexes among civilized peoples, but an unhealthy effect resulting from abnormal circumstances, that is the non-satisfaction of the sexual desires of woman, together with the satiety of those of men. Woman makes advances from the fear of remaining celibate; she will cease to do so when the unnatural causes which have produced this state of things have been done away with. As a rule, a normal and adaptable man will conduct himself in sexual matters as in others according to the prevailing fashion. He will most often succeed in accommodating his sentiments to those of his conjoint. On the other hand, this average representative of normal mediocrity easily becomes the slave of routine and incapable of new ideas. However normal he may be, he has less faculty of adaptation or mental plasticity and less liberty, than a man of higher nature independent of prejudices. ONTOGENY OF SEXUAL LIFE The first striking fact in the ontogeny of sexual life is the following: All the sexual organs, both external and internal, remain in an embryonic and non-functional state, not only in the embryo but for a long time in the child. The organs and their elements exist, but they are still small, imperfectly developed, and in a state of rest. At the time of puberty, which varies in different individuals, the sexual glands and the other copulatory apparatus enlarge and begin to functionate. In the European races puberty occurs between the age of twelve and seventeen years in girls, and between fourteen and nineteen in boys; it is generally earlier in the South and later in the North. It is curious to note that the correlative irradiations of the sexual appetite in the human mind develop much earlier than the organs, or even the sexual appetite. Again, the sexual appetite often appears before the normal development of the genital organs. In other rare cases the sexual appetite is absent in the adult, even when the corresponding organs are well-developed. (Vide Chapter VIII.) Such irregularities of the sexual appetite belong to the domain of pathology.