However common the concubinate may be, nowhere do we find it so wisely combined as in ancient Mexico, where four sorts of sexual association were recognised--monogamic marriage, consecrated by law and religion; semi-legitimate marriage; free and durable union with a legitimable concubine; and lastly, free love, escaping all regulation. I shall proceed soon to take an estimate of these customs, so different from our own, but it still remains for me to speak of the concubinate among the superior races, the yellow and the white. The Mongols of Tartary are monogamous in principle, in the sense of having one sole legitimate wife; but the rich and noble have by the side of this matron or chief wife, concubines or lesser wives, subject to the former, who has precedence and rules over them, who governs the household, and whose children are considered legitimate and have hereditary rights.[477] In China, the concubinage of the Mongols has been carefully regulated, like everything else; it is naturally, as elsewhere, the privilege of the rich and great, who sometimes keep a veritable harem, and people it by purchasing pretty girls, scarcely arrived at puberty, from their parents (Macartney, _Hist. Univ. des Voy._, t. xxxiii. 473).[478] According to the current morality of China, the concubinate is blamed unless the legitimate wife remains sterile for ten or twelve years.[479] Formerly an attempt was made to restrain it, by only tolerating it for the mandarins and childless quadragenarians;[480] but these severe measures have fallen into desuetude.