CHAPTER VI.
INTERCROSSING AND FUSION OF CHARACTERS IN ANIMAL
RACES; APPLICATION TO MAN.
Without even quitting the ground of morphology, it will be easy to prove which theory is most probably the correct one.
We know that naturalists consider that all individuals which pass from one to another by invisible shades belong to the same species, however different the extremes may be. All great museums contain examples of this fact.
The grounds for this conclusion are much stronger when there exists an intercrossing of characters. This intercrossing exists when a very decided and apparently exclusive character reappears in one or several individuals differing widely in other respects, and undoubtedly belonging to distinct groups. It is a case of intercrossing again, when the same character varies in such a manner as to lead, if considered apart, to the division of a natural group, and to the separation of the fractions into very different groups.
Now there is no animal species which presents these essentially morphological characters in a higher degree than man. When the human groups are studied in some detail, the difficulty does not consist in finding resemblances, but in clearly defining the differences. The more carefully they are considered, the more they disappear and become obliterated. We then understand the accounts given by most trustworthy travellers, such as d’Abbadie, of countries where the Negro and the White live side by side. In their extremes these two types are certainly very distinct. But in Abyssinia, for example, where they have long lived in contact, and intermingled, the Negro is no longer characterised by either colour, features, or hair, but simply by the exaggerated protuberance of the heel. This character in its turn, however, loses its value on the Eastern coast of Africa, where whole Negro tribes have the heel formed like ours.
This is an example of intercrossing, and they could easily be multiplied. I have already observed how closely the Aryan or Dravidian Hindoos, African or Melanesian Negroes and manifestly Semitic populations may resemble each other in colour. The following is a still more striking example. Desmoulins regarded the perforation of the olecranon process as one of the most decided characters of his Austro-African species of man. Now this perforation reappears in Egyptian and Guanche mummies, in a large number of European skeletons of the neolithic period, the crania of which moreover, exhibit no other relations with those of the Bosjesmans, and even in some Europeans of the present epoch.
The intercrossing of characters between human groups becomes still more evident from the comparison of numerical data taken from a number of different groups. I shall confine myself for the moment to giving the results arrived at by the study of the stature when the representative numbers are placed in order. We shall presently meet with other examples.
I here reproduce the table published in the Voyage of the Novara, by Dr. Weisbach. I have added to the figures of the Austrian savant a few data relating especially to the smallest races. I have also given the maxima and minima where I have been able to procure them, so as to make the extent of the variation more appreciable than is possible from the average alone:
STATURE OF DIFFERENT HUMAN RACES.
We here see what strange relations and what a singular confusion rise from a consideration of the stature. Numbers given in the same order, representing the size of the skull, the cephalic indices, the weight of the brain, will give the same striking result.
We must also observe that there is a great majority of means in this table. Now we see that the discrepancies between these means are less than the discrepancies between the maximum and minimum of a single race, so much so that races widely distinct from each other intervene between them.
Now let us mentally compare instead of these groups, the individuals of which they are composed. Is it not clear that if they were placed according to height, we should pass from one to the other with scarcely the difference of a millimetre; but is it not also clear that the confusion would become much greater than it appears even in the table?
I ask anyone who possesses even the smallest knowledge of zoology and zootechny whether it would be in a collection of species that he would expect to find the most evident affinities destroyed by the application of this method? Would it not be rather in a collection of races that similar facts would be met with, as, for example, in canine races, where the mastiff and its young, the greyhound of Saintonge and the Italian greyhound, the large and the small carriage dog would be separated from each other by a number of other races if stature alone were taken into account.
The intercrossing and fusion of characters, so marked between human groups, are inexplicable if we consider these groups as species, unless we admit that the morphological relations between these human species are of an entirely different nature to the relations established between animal species. But this hypothesis makes an exception of man; we have, therefore, the right to regard it as false.
If, on the contrary, we look upon these groups as nothing more than races of a single species, all these facts of intercrossing and fusion agree with what may be observed in plants and animals and replace man under the dominion of general laws.
Thus, without quitting morphological considerations, which correspond to the idea of resemblance contained in the definition of species, we are justified in concluding in favour of monogenism. To confirm this conclusion, however, we must turn our attention to other facts which correspond to the idea of filiation, and consider the teachings of physiology concerning the phenomena of generation.