I have no longer to prove that morality is variable and perfectible, that it results from social life, and is only to be taken together with the other needs, desires, and necessities of the struggle for existence. Our moral sentiments are simply habits incarnate in our brain, or instincts artificially created; and thus an act reputed culpable at Paris or at London may be and frequently is held innocent at Calcutta or at Pekin. In order to judge impartially of polyandric marriage we must remember these elementary truths. Not, certainly, that polyandry is rare amongst us, but it is censured, counted as criminal, and obliged to hide itself. The legal and regulated possession, publicly acknowledged, of one woman by several men, who are all husbands by the same title, shocks our feelings and morality extremely in the present day.
Nevertheless, human societies, small or large, must and will live, and it is an imperious condition which imposes the polyandric régime, namely, a considerable inequality between the number of men and that of women. Now, this disproportion may result from divers causes. In the first place, it may be natural, as it is among certain animal species. Among the lepidoptera, for example, nine hundred and thirty-four males have been counted as against seven hundred and sixty-one females.[169] Although smaller, the disproportion is not less real amongst mankind. As a general rule, and in nearly all countries where it has been possible to ascertain it, the relation between masculine and feminine births gives a certain excess of boys. This relation has been found in Europe to be 106 for 70 million of births; but our great masculine mortality re-establishes the equilibrium in the early years of life. The proportion of births, besides, is far from being identical in all the countries of Europe, and we even find oscillations in a given country. In England it is generally 104.5, in France 106.3, in Russia 108.9, at Philadelphia 110.5. In certain ethnic or social categories the proportion of masculine births notably augments. It rises to 113 for the Jews of Russia, to 114 for those of Breslau, to 120 for the Jews of Livonia. More singular still, the proportion of masculine to feminine births augments for certain professions; it is, for example, higher amongst the English clergy.[170] It is even seen to vary spontaneously. In the year 1886, during several months, the proportion of feminine births rose at Paris. In France, for a period of forty-four years, it has happened five times in one department, and six times in another, that the female births have been in excess. At the Cape of Good Hope, among the whites, for several years there have been ninety to ninety-nine masculine births. The reason or reasons of these spontaneous oscillations in the proportion of the sexes still escapes us. We verify it only, and we are warranted in concluding that the production of sex in the embryo depends on some relatively second causes. It is sure, for example, that the clergy of England are not of a special race. If, however, they have more male children than the other inhabitants of England, the fact can only depend on intimate particulars of their kind of life. This reminds us of certain biblical precepts relative to conjugal life, and the too neglected theory of M. Thury (of Geneva) on the influence of the degree of ovular maturity on the production of the sexes.
But spontaneous oscillations in the proportion of the sexes are always feeble; even the matrimonial type does not seem to influence them, for in the harems of Siam the sexual relation of births is the same as in Europe.[171] On the other hand, it is proved that race-horses, which are very polygamous, since they serve as stallions, have male and female descendants in exactly equal proportions.[172]
It is the social actions of men which produce the most profound disturbances in the proportion of the sexes. To begin with, in savage or barbarous countries, where violent death has become an ordinary occurrence for men, the number of adult females much exceeds that of adult males. Thus, at Bantou, when the Dutch established themselves there, they found ten women to one man.[173] In La Soñora, at the end of a civil war, there were seven women to one man. In spite of all moral and legal precepts, such conditions unfailingly result in polygamy, disguised or not.
On the contrary, a custom very widely spread in savage countries, that of the infanticide of girls, not less necessarily engenders polyandry, if the equilibrium in the numerical proportion of the sexes is not re-established in another manner. In reality, the infanticide of girls has been largely practised in nearly all polyandrous countries. It seems also that the custom of sacrificing the female children influences in the long run the natural production of the sexes. Thus the polyandrous Todas, who formerly killed their girls, have actually a sexual proportion of 133.3 for adults, and of 124 for the children.[174]
In Polynesia, where the infanticide of girls was so largely practised, the sexual relation to-day is altogether in favour of male births.
In New Zealand the proportion of the sexes in 1858 was 130.3 for adults, and 122.2 for non-adults.[175]
In 1839, in the Sandwich Islands, the numerical proportion was 125.08 for adults, and 125.75 for non-adults.
In 1872 a general census of all the Sandwich Islands gave for the numerical proportion of the sexes 125.36.
But there is more than one way of falsifying the proportion of the sexes. It is not necessary to kill nearly all the female children, as was the custom among the Gonds of Bengal, where in many villages Macpherson did not see a single girl;[176] it suffices to sell them. It is even the sale of girls which in many countries has at first restrained the savage practice of feminine infanticide. Girls became a merchandise negotiated by the parents, and afterwards redeemed by the men, because they could not do without them; but then it happened, in various countries and among various races, that men joined together to lighten the expense, and that several of them contented themselves with one wife in common, became polyandrous.