We must return to the subdivision proposed by Charles Bonaparte,—a family. Man constitutes a simple family in the Order of Quadrumana, distinguished by characteristics precisely equal in importance to those which make a difference between other similar groups in the class of mammalia, that which even comes to the assistance of the adversaries of the human kingdom, and the partisans of the zoological system. For want of positive characteristics taken from the extremities, which could never,—in the eyes of true naturalists, as we have just said,—favour a serious distinction between man and other quadrumana, a characteristic in dentition has been discovered, remarkable for its constancy even in the most degraded and animal-like races, and which, first and foremost, distinguishes man from the group which immediately follows him in the zoological series. This characteristic, upon which Professor Owen has, in many places, insisted,—like the two Cuviers,—but with an entirely new vigour,[106] is the contiguity of the teeth and the continuity of their crowns, not one of which ever extends beyond the level of the others.[107]
Thus it is for man, like the rest of the mammalia; it is the dental system which gives us the best characteristic. A new proof that the study of mankind and that of animals ought to be conducted in one and the same manner; a proof, indeed, that these two studies are two parallel branches, intimately united, of one and the same science.
CHAPTER IV.
ANATOMICAL, PHYSIOLOGICAL, AND PATHOLOGICAL VARIETIES.
We have endeavoured to prove in the preceding pages the specific unity of the biological phenomena in each Order, which are to be found among the superior animals and man. This unity has led us necessarily to another, that of method; and we have just seen that man forms simply a family, that is to say, a very secondary division in the zoological series.
But we have only taken the first step of the path in which we have to travel. The genus homo shows many varieties, and many dissimilarities. We must try to estimate their value, and to find out what the divisions to be established between what we commonly call races of men may be worth. Now, the only rule to be followed here is naturally that which is applied by all zoologists to the other individuals composing the animal series. The only way to arrive at such a goal will be, first of all, the study of the physical differences, the necessary basis of a rational classification. Thus we shall, at least, have important, and what is more, comparable results.
The anatomy of races has been largely written about, and yet we may even now offer this subject to the serious study of anthropologists; perhaps, also, in carrying their attention farther than the skin, the encephalic mass and the skeleton, which have been nearly the sole objects of study up to the present time, they will find in all systems dissimilarities of the same order, and as clearly defined.[108] These differences and varieties are such that they are obvious, and at once appreciated even by ignorant persons,[109]—they are such that the most eminent monogenists agree in regarding them as everywhere sufficient to make a difference in species, or even in genus itself.
They refer to every point of organisation, and we shall see farther on that they are found to be as decided and as palpable both in the mind and in the natural constitution. We do not pretend to speak of all of them in this place, not even to enumerate them; we shall merely quote the principal points, or those which appear to deserve some special remark. The number of those which exist, or which are believed to exist,—for this is a necessary restriction,—is immense; in fact, if we are the first to admit that there is an infinite variety of differences, considerable in themselves, between the various kinds of men, we also wish to avoid falling into the errors which are so often committed, and which happen from the small number of facts which have been observed, the investigators having often given the value of general facts to individual observation.
We find more than one example of these hasty opinions in the history of anthropological studies. Towards the end of the last century, when the colour of the Negro had already been for a hundred years the dominant study of the scientific world of Europe,[110] a certain Kluegel affirmed (in the Encyclopédie de Berlin, 1782) that the lips of the Ethiopian were of a fine red colour. A great commotion arose; Sömmering himself was roused; he wrote everywhere, sought for information, and demanded fresh intelligence, which, quite naturally, was found to be contrary to the opinion expressed by Kluegel. In fact, we know that in the Negro the colouring matter extends to most of the mucous membranes whose structure resembles that of the skin.