To resume, monogamy is by far the most widespread form of marriage. This is explained by the relative number of men to women. It has often been stated that the number of individuals of the two sexes is nearly the same, and this has been used as an argument in favor of monogamy. But this statement is incorrect; sometimes it is the men, but more often the women, who predominate. Among the natives of Oregon there are seven hundred men to eleven hundred and eighty-five women. Among the Punkas and other races the number of women is two or three times greater than that of the men. In Kotcha-Hamba there is only one man to five women. Among other races there are, on the contrary, more men than women, especially in Australia, Tasmania, and Hayti. In the latter island there is only one woman to five men. In Cashmere there are three men to one woman. Among the negroes, on the contrary, the women predominate, sometimes in the proportion of three to one, but more generally as three to two.
In Europe, more boys than girls are born on the average, but from the age of fifteen to twenty the numbers become equal, and after twenty the women predominate. This is due to the greater mortality among men, owing to war, the greater danger of masculine occupations, and also to alcoholism. In the fifteen largest towns in Switzerland alcoholism is the direct or indirect cause of death in 10.5 per cent. of men above the age of twenty.
Among savages the women often take part in war, for instance the Amazons of Dahomey. Drinking habits are also the same or absent in both sexes, which equalizes matters. When the men predominate in these people, this is often due to infanticide committed on young girls, and also to overwork of the women. With the Cingalese the natality of boys is greater than that of girls, while in Asia Minor two girls, in Arabia even four girls, are born to one boy. The Arab says, "Allah has given us more women than men; it is, therefore, clear that polygamy is a divine commandment."
Production of Sexes at Will.—I will say a few words on the question of the causes of production of the sexes. There is no want of hypotheses, assertions, nor even of experiments on this subject; but, we are obliged to admit that up to the present we know nothing certain. No one has yet succeeded in producing experimentally in animals males or females at will. According to one theory, which has created much impression, overfeeding produces females and underfeeding males. Although this appears to be true in certain cases among some animals, it is in no way proved in a positive manner.
It has also been suggested that selection produces the sex which is deficient in numbers; but here again proofs are wanting. It has been maintained that crossing tends to breed females, while consanguineous marriages produce males; in other words, that mongrel races show an excess of female births, while races in which marriages are very consanguineous, and polyandrous tribes show an excess of males. It is much better to leave this question alone till science has furnished us with conclusive proofs. Certain results obtained with the lower animals give hope that the future may shed some light on this point.
Again, marriage customs are not always in relation to the excess of one of the sexes. Races in which men predominate are not always polyandrous, and those in which women are in excess are not always polygamous; sometimes even the contrary exists. Polygamy is thus not always due to a surplus of female births, or to the death of many men, but often to religious prescripts, as among the Islamites and Mormons. In polyandry, poverty often plays a greater part than consanguineous marriages or surplus of male births. Religious prescription of the husband's continence during his wife's menstrual periods, pregnancy, and even the period of nursing, a period which often lasts from two to four years in savages, is an important cause of polyandry. At Sierra Leone, coitus of the husband with his wife before the last-born child can walk is regarded as a crime.
Although very advantageous to the wife's health this custom is entirely based on religious ideas and superstitions. Many savages consider that every woman is impure and bewitched during her monthly periods, during pregnancy and suckling. If we add to this the fact that, being usually treated as beasts, the women soon grow old, we can easily understand that the men are inclined to polygamy. It is remarkable with what rapidity the savage woman grows old. She is only fresh from thirteen to twenty years; after twenty-five she is old and sterile, and a little later she has the aspect of an old sorceress. This premature senility is not so much due to early sexual intercourse as to the terribly hard work they undergo, and also to the prolonged period of suckling.
Another cause of polygamy is man's natural desire for change. The negroes of Angola exchange wives. The instinct of procreation, love of glory and riches coöperate with the sterility of many women in propagating polygamy. Certain races only tolerate it when the woman is sterile, or has only daughters, which clearly proves that it is based on the fear of remaining without male descendants.
On the whole, savage women are less fecund than civilized, owing to their long continence during the two or four years nursing of each child. If we add to this the high infant mortality, we can understand how polygamy becomes among these people a means of reproduction in the struggle for existence, and even in African races a natural law. A native of Central Africa may have a hundred wives, who also act as servants and retainers. In this case polygamy is the expression of pomp and wealth. It is especially developed in agricultural peoples owing to the value of the woman's labor. On the other hand it is impossible among nomadic tribes. In Dahomey the king had thousands of wives, the nobility hundreds, the simple citizen a dozen and the soldier none at all.
Jealousy and rivalry among the wives is not always the rule in polygamous families. In equatorial Africa the wives themselves incline to polygamy and regard a rich man who restricts the number of his wives as miserly. Livingstone relates that the women of Makololo declared they would not live in monogamous England, for any respectable man should prove his wealth by the number of his wives. We must not forget that among most savages the moral conception of good and evil are confounded with that of riches and poverty. In reality, the supernumerary wives bought by a polygamist are simply slaves. His power and authority do not easily allow jealousy among them; nevertheless suicide sometimes occurs among the old wives who have been passed over in favor of younger ones. Sometimes they kill their children at the same time. Among the Indians of Terra del Fuego a hut containing three or four women often resembles a battlefield. We have already pointed out the way in which jealous Fiji women cut off the noses of their rivals. Among the Islamites and Hindus intrigue and jealousy are common with the women; the same in Abyssinia, among the Hovas of Madagascar and the Zulus. The Hova term for polygamy is rafy, which signifies adversary. To prevent the jealousy of his wives the polygamous man often places them in separate houses; this is common among the South American Indians.