The advocates for the plurality of races, being met with so many objections, good as well as bad, have attempted to enlarge the circle of their arguments, and, ceasing to make the skull their only study, have proceeded to the examination of the entire individual. They have rightly shown that the differences do not exist merely in the aspect of the face and formation of the skull, but, what is no less important, they exist also in the shape of the pelvis, the relative proportion of the limbs, and the nature of the pilous system.
Camper and other naturalists had long since perceived that the pelvis of the negro presented certain peculiarities. Dr. Vrolik extended his researches further, and observed that in the European race the differences between the male and female pelvis are much less distinctly marked, while the pelvis of the negro, of either sex, partakes in a very striking degree of the animal character. The Amsterdam savant, starting from the idea that the formation of the pelvis necessarily influences that of the fœtus, concludes that there must be difference of origin.[134]
Mr. Weber has attacked this theory with but little success. He was obliged to allow that certain formations of the pelvis occur more frequently in one race than in another; and all he could do, was to show that the rule is not without exceptions, and that some individuals of the American, African, or Mongol race presented the forms common among the European. This is not proving a great deal, especially as it never seems to have occurred to Mr. Weber that these exceptions might be owing to a mixture of blood.
The adversaries of the unity doctrine pretend that the European is better proportioned. They are answered that the excessive leanness of the extremities among those nations which subsist principally on vegetable diet, or whose alimentation is imperfect, is not at all surprising; and this reply is certainly valid. But a much less conclusive reply is made to the argument drawn from the excessive development of bust among the mountaineers of Peru (Quichuas) by those who are unwilling to recognize it as a specific characteristic; for to pretend, as they do, that it can be explained by the elevation of the Andes, is not advancing a very serious reason.[135] There are in the world many mountain populations who are constituted very differently from the Quichuas.[136]
The color of the skin is another argument for diversity of origin. But the opposite party refuse to accept this as a specific characteristic, for two reasons: first, because, they say, this coloration depends upon climatic circumstances, and is not permanent—which is, to say the least of it, a very bold assertion; secondly, because color is liable to indefinite gradations, by which white insensibly passes into yellow, yellow into black, so that it is impossible to find a line of demarcation sufficiently decided. This fact simply proves the existence of innumerable hybrids; an observation to which the advocates for unity are constantly inattentive.
With regard to the specific differences in the formation of the pile, Mr. Flourens brings his great authority in favor of the original unity of race.[137]
I have now passed rapidly in review the more or less inconsistent arguments of the advocates of unity; but their strongest one still remains. It is of great force, and I therefore reserved it for the last—the facility with which the different branches of the human family produce hybrids, and the fecundity of these hybrids themselves.
The observations of naturalists seem to have well established the fact that half-breeds can spring only from nearly related species, and that even in that case they are condemned to sterility. It has been further observed that, even among closely allied species, where fecundation is possible, copulation is repugnant, and obtained, generally, either by force or ruse, which would lead us to suppose that, in a state of nature, the number of hybrids is even more limited than that obtained by the intervention of man. It has, therefore, been concluded that, among the number of specific characteristics, we must place the faculty of producing prolific offspring.
As nothing authorizes us to believe that the human race are exempt from this law, so nothing has hitherto been able to shake the strength of this objection,[138] which, more than all the others, holds the advocates for plurality in check. It is, indeed, affirmed that, in certain portions of Oceanica, indigenous women, after having brought forth a half-breed European child, can no longer be fecundated by compatriots. If this assertion be admitted as correct, it might serve as a starting point for further investigations; but at present it could not be used to invalidate the admitted principles of science upon the generation of hybrids—against the deductions drawn from these it proves nothing.