Dr. Düsing has, moreover, inferred that incest is less common in proportion as the number of males is great. The more males, he says, the farther off they have to go from their birthplace to find mates. Incest is injurious to the species; hence incestuous unions have a tendency to produce an excess of male offspring.[3002] Thus, according to Dr. Nagel, certain plants, when self-fertilized, produce an excess of male flowers. According to Dr. Goehlert’s statistical investigation, in the case of horses, the more the parent animals differ in colour, the more the female foals outnumber the male.[3003] Among the Jews, many of whom marry cousins, there is a remarkable excess of male births. In country districts where, as we have seen, comparatively more boys are born than in towns, marriage more frequently takes place between kinsfolk. It is for a similar reason, says Dr. Düsing, that illegitimate unions show a tendency to produce female births.[3004]
The evidence given by Dr. Düsing for the correctness of his deduction is, then, exceedingly scanty—if, indeed, it can be called evidence. Nevertheless, I think his main conclusion holds good. Independently of his reasoning, I had come to exactly the same result in a purely inductive way. There is some ground for believing that mixture of race produces an excess of female births. In his work on the ‘Tribes of California,’ Mr. Powers observes, “It is a curious fact, which has frequently come under my observation, and has been abundantly confirmed by the pioneers, that among half-breed children a decided majority are girls.... Often I have seen whole families of half-breed girls, but never one composed entirely of boys, and seldom one wherein they were more numerous.”[3005] When I mentioned this statement to a gentleman who had spent many years in British Columbia and other parts of North America, he replied that he himself had made exactly the same observation. Mr. Starkweather has found that, according to the United States statistical tables of the sex of mulattoes born in the Southern States, there is an excess of from 12 to 15 per cent. of female mulatto children, whilst, taking the whole population together, the male births show an excess of 5 per cent.[3006] In Central America, according to Colonel Galindo, “an extraordinary excess is observable in the births of white and Ladino females over those of the males, the former being in proportion to the latter as six, or at least as five, to four: among the Indians the births of males and females are about equal.”[3007] Mr. Stephens asserts that, among the Ladinos of Yucatan, the proportion is even as two to one.[3008] Taken in connection with the fact mentioned by Mr. Squier, that the whites in Central America are as one to eight in comparison with the mixed population,[3009] these statements accord well with the following observation of M. Belly as regards Nicaragua:—“Ce qui me paraît être le fait général,” he says, “c’est que dans les villes où l’élément blanc domine, il se procrée en effet plus de filles que de garçons.... Mais dans les campagnes et partout où la race Indienne l’emporte, c’est le contraire qui se produit, et dès lors la prépondérance du sexe masculin se maintient par la prépondérance de l’élément indigène. Le même phénomène avait déjà été observé au Mexique.”[3010]
Concerning the proportion of the sexes at birth among the mixed races of South America, I have unfortunately no definite statements at my disposal. But Mr. J. S. Roberton informs me, from Chañaral in Chili, that in that country, with its numerous mongrels, more females are born than males. According to the list of the population of the capitaina of São Paulo, in the year 1815, given by v. Spix and v. Martius—a list which includes more than 200,000 persons,—the proportion between women and men is, among the mulattoes, 114·65 to 100; among the whites, 109·3 to 100; among the blacks, 100 to 129.[3011] But this last proportion is of no consequence, as we have no account of the number of negro slaves annually imported into the capitaina. Sir R. F. Burton found, from the census returns of 1859 for the town of São João d’El Rei, where there is a large intermixture of the white race with the coloured women, an excess of nearly 50 per cent. of women as compared with men.[3012] A census of the population in the Province of Rio, taken in the year 1844, also shows a considerable excess of women, not only, however, among the mixed population, but among the Indian and negro creoles as well;[3013] and M. de Castelnau was astonished at the disproportionately large number of females in Goyaz.[3014]
In the northern parts of the United States, according to Kohl, female children predominate in the families of the cross-breeds arising from the intercourse of Frenchmen with Indian women.[3015] This statement is very much like Graf v. Görtz’s, that the families of the offspring of Dutchmen and Malay women in Java (Lipplapps) consist chiefly of daughters.[3016] A census taken in the eighteenth century, given by Süssmilch, proves also that among these mongrels there is a great excess of women over men.[3017] From Stanley Pool in Congo, Dr. Sims writes to me, “It is the subject of general remark here, that the half-caste children are generally girls; out of ten I can count, two only are boys.” At the same time he states that, among the native Bateke people, no disproportion between the sexes is observable. Mr. Cousins informs me that, in the western province of Cis-Natalian Kafirland, in the “Karoo” district from Caledon up to Mossel Bay, there is a half-caste or mixed race called “Bruin Menschen,” generally known as bastards, among whom more females than males are born. Dr. Felkin found that, among the foreign women imported to Uganda, the excess of females in the first births was enormous, viz., 510 females to 100 males, as compared with 102 females to 100 males in first births from pure Waganda women; whilst in subsequent pregnancies of these imported women the ratio was 137 females to 100 males. As a matter of fact, in the families of the poorer classes of Uganda, who “do all in their power to marry pure Waganda women,” the sexes are as evenly balanced as in Europe, whereas this is certainly not the case among the children of chiefs and wealthy men who have large harems supplied mainly with foreign wives. “I found,” says Dr. Felkin, “that of the women captured by the slave-raiders in Central Africa, and brought down to the East Coast, either near Zanzibar or through the Soudan to the Red Sea, those who had been impregnated on the way usually produced female children. Hence the Soudan slave-dealers, instead of having only one slave to sell, have a woman and a female child.”[3018] Dr. Felkin suggests, as an explanation of this excess of female births, that the temporarily superior parent produces the opposite sex; but the facts stated seem strongly to corroborate the theory that intermixture of race is in favour of female births. Very remarkable are two statements in the Talmud, that mixed marriages produce only girls.[3019] Mr. Jacobs informs me that his collection of Jewish statistics includes details of 118 mixed marriages; of these 28 are sterile, and in the remainder there are 145 female children and 122 male—that is, 118·82 to 100 males.
We must not, of course, take for granted that what applies to certain races of men holds good for all of them; but it should be observed that the cases mentioned refer to mongrels of very different kinds. It is indeed scarcely probable that anything else than the crossing can be the cause of this excess of females, as facts tend to show that unions between related individuals or, generally, between individuals who are very like each other, produce a comparatively great number of male offspring.
In all the in-and-in bred stocks of the Bates herd at Kirklevington, according to Mr. Bell, the number of bull calves was constantly very far in excess of the heifers.[3020] Of the in-and-in bred Warlaby branch of short-horns, Mr. Carr says that it “appears to have a most destructive propensity to breed bulls.”[3021] Dr. Goehlert’s statement as regards horses, just referred to, is corroborated by Crampe’s investigations, which included more than two thousand different cases, all tending to prove that female foals predominate in proportion as the parent animals differ in colour.[3022]
We have seen that the Todas of the Neilgherry Hills are probably the most in-and-in bred people of whom anything is known, and we have also seen how, among them, the disproportion between male and female births is strikingly in favour of the males. Among the Badagas, a neighbouring people, who, like the Todas, have numerous subdivisions of caste, each of which differs in some social or ceremonial custom,[3023] and all of which, probably, are endogamous, there is also a considerable surplus of men.[3024] Now it is very remarkable that in another tribe inhabiting the same hill ranges, the Kotars, who do not intermarry with the inhabitants of their own village, but always seek a wife from another “kotagiri,” women are not so scarce as among the Todas and the Badagas.[3025] Among the endogamous Maoris, the men outnumber the women. So also among the Sinhalese, who consider marriage between the father’s sister’s son and the mother’s brother’s daughter the most proper union. Among the polyandrous Arabs mentioned by Strabo, marriage between cousins was the rule. The polyandrous mountaineer of South Africa, in almost every case, marries a daughter of his father’s brother.[3026] And with the Jews, among whom cousin marriages occur perhaps three times as often as among the surrounding populations,[3027] the proportion of births is probably more in favour of the males than among the non-Jewish population of Europe.[3028] All these facts, taken together, seem to render it probable that the degree of differentiation in the sexual elements of the parents exercises some influence upon the sex of the offspring, so that, when the differentiation is unusually great, the births are in favour of females; when it is unusually small, in favour of males.
We certainly cannot, from the numerical proportion of the sexes, especially at birth, draw any inference as to the form of marriage characteristic of the species. Among birds living in a state of nature, polyandry is almost unheard of, though, according to Dr. Brehm, the males are generally more numerous than the females.[3029] As for man, there are several non-polyandrous peoples among whom the men are considerably in excess of the women; whilst among other peoples polygyny is forbidden, though the women are in excess of the men. Nevertheless, the form of marriage depends to a great extent upon the proportion between the male and female population. Polyandry, as already said, is due chiefly to a surplus of men, though it prevails only where the circumstances are otherwise in favour of it. And, as regards polygyny, I cannot agree with M. Chervin that it is quite independent of the proportion between the sexes.[3030] It has been observed that, in India, polyandry occurs in those parts of the country where the males outnumber the females, polygyny in those where the reverse is the case.[3031] Indeed, in countries unaffected by European civilization, polygyny seems to prevail wherever women form the majority.
Thus the causes which determine the proportion of the sexes exercise some influence also upon the form of marriage. Among the Eskimo, for instance, who, according to Armstrong, take more than one wife when the women are sufficiently numerous,[3032] polygyny results chiefly from the dangerous life the men have to lead in order to gain their subsistence. Among the Indians of North America, it is, to a large extent, due to the wars which destroy many of the male population. In certain countries it seems to be furthered by physiological conditions leading to an excess of female births. As for polyandry, we have some reason to believe that it is due, on the one hand, to poor conditions of life, on the other to close intermarrying. As a matter of fact, the chief polyandrous peoples either live in sterile mountain regions, or are endogamous in a very high degree.