The most important of the several prognathisms is that arising from the portion of the maxillary bone situated below the nose, and comprising the alveoli of the incisors and canines. This is the sub-nasal-alveolar prognathism, or the superior maxillary prognathism. It is this trait of the Negro which is opposed to the orthognathism of the White. This character suggests remarks similar to those which I have already made so often. It is the evident result of the following summary, which I borrow almost verbatim from M. Topinard’s work.
All races and all individuals are more or less prognathous. As a rule, in European races it is only slight; it is much more marked in the Yellow and Polynesian races, and more strongly marked still in Negro races. Let us remark, however, that even mean indices place the Tasmanians (76°·28) above the Finns and Esthonians (75°·53), and very near the Merovingians (75°·54).
The minimum prognathism, or maximum orthognathism, is found in the Guanches (81°·34), and the opposite extreme in the Namaquois and Bosjesmans (59°·88). The means establish limits between the various sub-divisions of the great fundamental races. Individual variations, however, in this case, as in others, obliterate these distinctions. In all races there are exceptions, Negroes in whom prognathism is no more marked than in Whites, and Whites in whom it is very pronounced. M. Topinard regards these exceptional cases as examples of crossing, atavism, or as pathological phenomena. There is certainly some truth in this view. I have long referred the prognathism, sometimes so curiously marked in certain Parisian women, to atavism. But we must also take into consideration these oscillations of characters, which we everywhere meet with in races not subject to selection with any special aim.
In any case we cannot consider cessation of development as explaining the existence of a most striking prognathism in certain individuals of incontestably pure white race. In fact, far from diminishing with age, like the preceding characters, it rather increases. Even in the European, the child is manifestly more orthognathous than the adult. With regard to Negroes, Pruner Bey observed some time ago, and I have myself proved, that the child presents scarcely any trace of that feature, so characteristic in the parents. It is not till the period of puberty that it appears, and is rapidly developed. The forward projection of the maxillary bone is, therefore, in both races a fact of normal evolution, merely more marked in the one than in the other. Far from being the result of a cessation, prognathism betrays an excess of development.
The absolute theory of Serres, which would treat the Negro merely as a White, subjected to a cessation of general development, is then here at fault. The truth is, that in the black race, organic evolution is less advanced than the general type of white race in some respects, and more so in others. This is a fact upon which I have long insisted in my lectures at the Museum, and which is confirmed, as we now see, by the more exact work of later years.
We see, also, that, in order to account for the differences separating the Negro from the White, it is by no means necessary to have recourse to phenomena of atavism as exhibited by animals. Simple oscillations, above or below the mean in the normal evolution of man, are sufficient to explain it. I feel myself, therefore, still more strongly justified in opposing the human evolution theory to the simian evolution theory.
The zygomatic arches, the malar bone, the superior and inferior maxillary bones also furnish the anthropologist with several more or less essential characters which sometimes acquire, in reference to a given race, a value superior to that which they have elsewhere. Such is the slight elevation of the palatine vault in the Lapps. But I cannot here enter into these details, and refer the reader to special books and memoirs.
IV. Characters drawn from the skull considered as a whole. When, instead of studying the face or cranium alone, we consider them in their reciprocal relations, we see new traits appearing, furnishing a number of characters, some of which are of real importance.
Let us, in the first place, remark that there may be either harmony or dysharmony between these two great regions. The skull is harmonic in the Negro, whose cranium and face are equally long, and in the Mongol, who unites the two contrary characters; it is dysharmonic, as we have seen, in the old man of Cro-Magnon, and in the man of La Truchère, but for contrary reasons.