Paul Broca - On the Phenomena of Hybridity in the Genus Homo

But when the intermixture of races is effected in nearly equal proportions, or if it be the result, not of one invasion, but of a constant and abundant immigration, the case is altogether different, and the fusion of the ethnological elements gives rise to a hybrid population, in which the number of individuals of a pure race is constantly diminishing, so that at the termination of a few centuries the representatives of the two primitive types become the exceptions. In a long Memoir “On the Ethnology of France,” which I lately read before the Anthropological Society of Paris, I have shown to what extent intermixture may modify the physiognomy of a people. Examining in the first place the records of history on hand, the origin of the populations of our departments, and appreciating as much as possible the proportion of the elements which we find in combination; determining, also, for each region the principal and the accessory stocks, I have been enabled to find in the present French nation, in the midst of the innumerable variations of stature, complexion, hair, eyes, cephalic shapes, etc., which may everywhere be expected in mixed races; I have been able to detect, I repeat, the characters of these different races, and to recognise the more or less marked and dominant impress of the Celts, Kimris, Romans, and Germans. I was even enabled, on the statistics of recruiting, to give to my inquiries, in regard to stature, a rigorous precision. I cannot in this place enter into any details: I am obliged to refer the reader to the Memoir, which is published by the Anthropological Society. In point of fact, it was merely because eminent men have for some years doubted the existence of eugenesic hybridity in mankind, that it became necessary to demonstrate so evident a proposition, that the population of France in at least nineteen-twentieths of our territory, presents in unequal degrees the characters of mixed races.

This single example might suffice; but I have no doubt that by examining in a similar manner the historical origin and the actual condition of the peoples of Northern Italy, Southern Germany, Great Britain – not to speak of the United States, where the fusion of blood is probably inexplicable – it might be demonstrated with equal certainty, that these different races have given birth, by their intermixture, to ethnological modifications still recognisable. In all these countries is the instability of anthropological characters in contrast with the fixity which is the mark of pure races; and we might say, without fear of error, that the greater part of Western Europe is inhabited by mixed races.

Moreover, the authors who have denied the existence of mixed races, have not denied that there are in Europe and elsewhere, numerous vivacious populations, formed by the intermixture of two or several distinct races. They merely asserted that mongrel breeds, whatever their origin, were necessarily inferior in reference to fecundity to individuals of pure blood, and that their direct descendants would become extinct after a few generations, unless they contracted new alliances with the mother races, or at least with one of them. If we object to this, that the mixed populations possess everywhere, as those of France and Great Britain, a vitality and fecundity which leaves nothing to be desired, they reply that this proves nothing; that the cross breeds are prolific in a collateral line, as is observed in cases of paragenesic hybridity, and they add that two cases may present themselves:

1. If among the two primitive races these obtain a very large numerical inequality, the predominant race soon absorbs the other. After two or three generations, the less numerous race counts scarcely one representative, and the cross-breeds are fused in the more numerous race. The latter thus returns to a state of original purity. The mixed race has only a transitory duration, and leaves no trace of its existence.

2. If, on the contrary, the two races, though numerically unequal, are in sufficient proportion that neither can absorb the other, both persist indefinitely beside each other upon the same soil. The hybrid race which they engender, seems also to persist indefinitely; but only in appearance, for they constantly intermarry with the pure races, while the latter marry between themselves. The mixed race gains thus, in every generation, a contingent equal to what it loses, those which represent it at present are not the descendants of those who represented the mixed race five or six generations back. It is not maintained by itself: existing only under the condition of being sustained by the races from which it is issued, and if there arrived a time when it is completely isolated from these two races, and reduced to its own forces, it would necessarily become extinct after a few generations.

I might urge some objection against the first point, for it does not seem to me to be demonstrated, that in a mixture of very unequal proportions, the less numerous race exercises no influence upon the other race. I acknowledge, however, that this influence, if it exists, is sufficiently slight to be set aside.

The second point is much more serious, for if accepted without restriction, we must admit that eugenesic hybridity does not exist in mankind, and that all cross-breeds, whatever their origin, whether they are issued from nearly approaching or distant races, not merely the descendants of whites and negroes, but also of Celts and Kimris, are incapable of engendering a durable posterity. For my part, I believe that such is actually the case with certain mongrel-breeds; I believe that in the genus Homo , there are very unequal degrees of eugenesic hybridity; but after having recognised that eugenesic hybridity does exist between dog and wolf, hare and rabbit, goat and sheep, camel and dromedary, I am permitted to say that it also exists between certain races of men.

Among the facts quoted to prove the sterility of human cross-breeds, some are of great value: and we shall examine them in the sequel; others have been wrongly interpreted, while some are far from being exact. I have already pointed out a cause of error which was not taken into account, and which occurs frequently: it is the change of climate which alone is capable of sterilising a race transplanted into the midst of another race. Before attributing a defect of fecundity to the mixed descendants of an immigrant race, we must see whether in the same country the individuals of this race are more prolific in their direct alliances. It is known, for instance, that the Mamelukes, originating from the region of the Caucasus, have never taken root in Egypt, where, nevertheless, from 1250, the epoch of their advent, until 1811, the period of their extermination, their caste has always formed a notable part of the population. They could only maintain themselves by reinforcements which they annually received from the native country, and though not half a century has elapsed since the great massacre of Cairo, there remains no trace of them on the borders of the Nile. Such being the fact, it was concluded therefrom, that the descendants of the Mamelukes and the Egyptians were hybrids of little or no fecundity. Gliddon has thus interpreted it, and Pouchet has accepted that interpretation. 21This, however, is not the real cause of the sterility of the Mamelukes in Egypt, and Volney, who, towards the end of the last century, has carefully observed and studied this race, offers the following remarks on them: “Seeing that they have existed in Egypt for centuries, one would be apt to believe that they have reproduced themselves by the ordinary process of breeding; but if their first settlement is a curious fact, their perpetuation is not less so. For five centuries there have been Mamelukes in Egypt, yet not one of them has left a subsisting line: there exists not one family of the second generation, all their children perish in the first or second generation. The Ottomans are nearly in the same condition