Adolf Gerson, in a somewhat similar spirit, argues ("Die Ursache der Prostitution," _Sexual-Probleme_, September, 1908) that "prostitution is one of the means used by Nature to limit the procreative activity of men, and especially to postpone the period of sexual maturity." Molinari considers that the social benefits of prostitution have been manifested in various ways from the first; by sterilizing, for instance, the more excessive manifestations of the sexual impulse prostitution suppressed the necessity for the infanticide of superfluous children, and led to the prohibition of that primitive method of limiting the population (G. de Molinari, _La Viriculture_, p. 45). In quite another way than that mentioned by Molinari, prostitution has even in very recent times led to the abandonment of infanticide. In the Chinese province of Ping-Yang, Matignon states, it was usual not many years ago for poor parents to kill forty per cent. of the girl children, or even all of them, at birth, for they were too expensive to rear and brought nothing in, since men who wished to marry could easily obtain a wife in the neighboring province of Wenchu, where women were very easy to obtain. Now, however, the line of steamships along the coast makes it very easy for girls to reach the brothels of Shang-Hai, where they can earn money for their families; the custom of killing them has therefore died out (Matignon, _Archives d'Anthropologie Criminelle_, 1896, p. 72). "Under present conditions," writes Dr. F. Erhard ("Auch ein Wort zur Ehereform," _Geschlecht und Gesellschaft_, Jahrgang I, Heft 9), "prostitution (in the broadest sense, including free relationships) is necessary in order that young men may, in some degree, learn to know women, for conventional conversation cannot suffice for this; an exact knowledge of feminine thought and action is, however, necessary for a proper choice, since it is seldom possible to rely on the certainty of instinct. It is good also that men should wear off their horns before marriage, for the polygamous tendency will break through somewhere. Prostitution will only spoil those men in whom there is not much to spoil, and if the desire for marriage is thus lost, the man's unbegotten children may have cause to thank him." Neisser, Näcke, and many others, have pleaded for prostitution, and even for brothels, as "necessary evils."