We must regard hybridity in a double point of view, as being able or unable to give an indication of the real value of different human races, as compared with the acknowledged natural groups in the greater number of zoological classifications; and on the other hand, we must study hybridity, belonging, as has been asserted, to the creation of new races.
It has been said, we repeat, that all men being able to reproduce one with another, the genus homo only constitutes one single family. That this argument should hold good, it was necessary to be proved that among animals (for thence it was that it was borrowed) two well acknowledged species, more different even than two human races, should never be prolific one with the other. Now, this is far from being the case. Isidore Geoffroy Saint-Hilaire, who has treated this subject in a masterly manner in his Histoire Naturelle Générale, acknowledges that animals belonging to two different genera can, by a union, produce a mixed breed, which, consequently he calls bigenerate hybrids.
So we will not give ourselves the trouble of contesting, as some polygenists have done, the universality of reproduction between all races of mankind; we will not ask if every degree of combination has been observed,—the union, for instance, of an Esquimaux with a Negro, an American with an Australian, a Tartar with a Bosjesman. Let us admit, what is, perhaps, hardly the truth, that all races produce one with another,—we will admit all this; and yet it will prove nothing in favour of the monogenists who have brought forward this fact, since we henceforth know that there is no basis in this universality of reproduction for a serious argument,—since we know that two distinct species, two genera, in fact, can produce cross-breeds. This faculty of reproduction has had too much importance given to it,—it is only a function, that is to say, a physiological character quite improper for classification; the existence of bigenerate hybrids shows this sufficiently. It is a bad characteristic, because it is not a constant one; because either the man or the animal does not bear it in him, and that a given uniformity of circumstances is necessary in order to reveal this characteristic to an observer. It is the same with animal forms, which do not countenance in any manner such an observation; it is sufficient to recall the alternating generations of the invertebrata. Where shall we place all these agamous animals? how shall we class these proscolex and scolex, which have no sex, and which will never have one? Instead of the idea of fecundity, which is insufficient to characterise a species, we must substitute another, that of the development of the produce. If everything shows us that zoosperms, proceeding from very different animals, can equally fecundate any given ovum,—if we even admit that we have no good reason for rejecting the theory that each ovum can be impregnated by different kinds of zoosperms, it is very easy, on the contrary, to account for the fact that offspring will have no chance of life, except so far as the two parents show a sufficient identity, but which we cannot regard as fit to characterise species.
As the produce of two organisms, a descendant ought always to be considered as the result of two united halves fitted together, and combined one with the other. If the two halves are identical, the animal is like its progenitors in everything. If the two beings, who have endeavoured to unite themselves, are too dissimilar, the two forces cannot combine, and there is either no produce, or it is arrested in its development from the first moment of its embryo life. If the two forces, or the sum of the two forces, have a certain amount of common direction, they can produce a new being, but an imperfect one, and which will not have all the conditions of existence like its parents; it will not have genital power, and consequently will not be fitted to become the founder of a series of individuals similar to itself, succeeding it through time, “naturally, regularly, and indefinitely.”[246]
Putting on one side the power of reproduction, we must attend solely to the union of different human races with regard to vitality of produce, and let us see what observation will teach us on this subject.
Jacquinot states, that “one can scarcely quote any cross between Australians and Europeans.” When the ancient inhabitants of Van Diemen’s Land, reduced to the number of two hundred and ten, were taken from Flinder’s Island, not only had the union of the women with the unscrupulous convicts been unable to form a distinct race, but only two adults were found who were the produce of these unions.[247]
“The Mulattoes,” says Nott, “are the shortest-lived of any of the branch races; when they unite amongst themselves, they are less prolific than if united to one or other of the branches.[248]” This assertion is especially true concerning the cross-breeds born of Negroes and inhabitants of the north of Europe. At Java, crosses between Malays and Dutch appear not to be able to reproduce beyond the third generation.[249] “The half-caste of India,” says Warren, “comes to a premature end, generally without reproduction; and if there are any offspring, they are always wretched and miserable.”[250]
We must say another word about Isidore Geoffroy Saint-Hilaire’s opinion on the important question of cross-breeding in mankind. After having reproached Cuvier, and with reason, with having often, in the interest of particular views, admitted, as regards mankind, a flagrant contravention of the biological laws which his genius proclaimed for other animals, Isidore Geoffroy seems to us to have, in his turn, fallen into a contradiction of the same kind. He especially calls hybrids the crosses which occur from the cross of two different species, and he remarks, besides, that hybrids have generally tolerably decided characteristics, which are partly those of the father and partly those of the mother; so that the offspring, he adds, can resemble one more than the other, but not exclusively either of them: the cross is always to be found in it. On the contrary, it is not always so with the cross between two varieties of the same species; the produce has often the characteristics of both its parents, but very frequently, also, it resembles one of them exclusively.
For these beings who are the offspring of two varieties of the same species, and who very frequently reproduce entire the type of one of their parents to the exclusion of the other, Isidore Geoffroy reserved the name of homoïdes. Well, we ask him this,—in taking, as an example, the offspring of a union between a white and a black, shall we find in it the characteristics of a homoïd cross? Will it never resemble exclusively one of the two founders? Are not the characteristics of the Mulatto perfectly represented, perfectly defined, and always medium? Are not exceptions, if any can be quoted, of extreme rarity?[251] In the name of this consistency, ought not Isidore Geoffroy to have seen in a Mulatto something besides a homoïd mongrel, and to doubt even more that the different races of mankind constituted only varieties of the same species?
However, let us examine into hybridity so far as it may serve to produce new, or modify existing races, as Blumenbach and Flourens have admitted.[252] Let us only remark that these two authors, like most monogenists, in placing hybridity, as the modifying cause, in the same rank as climate or medium, commit a great error. Hybridity, even in giving it the creative power which some have desired, goes entirely into the second rank, for it supposes a pre-existing plurality. It can only act, in the end, by weakening differences, by creating a middle term to two extremes. It cannot of itself produce variety of origin, it is the consequence of it, and we shall see that the part it takes on this matter is extremely restricted.