Chapter V

EXTENT OF VARIATIONS IN ANIMAL AND VEGETABLE RACES; APPLICATION TO MAN.

I. The question to which this chapter is devoted is one of those which I shall treat most fully in this course. In fact, it has a special importance. Nearly all the polygenistic arguments are included in the following:—“The difference between the Negro and the White is too great for them to belong to the same species.” These types are the two extremes in the human series. Therefore, if it can be shown that between the two extremes, the limits of variation are almost always greater in plants and animals than in man, we shall have undermined the foundation of the whole polygenistic doctrine.

Now, even if we leave plants out of the question, and there can be little doubt in respect to them; if we merely compare man and animals, organ for organ, function for function, we shall have no great difficulty in arriving at the conclusion, that this is really the case; so much so that we shall be led to ask the question, why the variability is less in man than in animals. The complete demonstration of this general fact would require more extended treatment than I am able to give. I shall, therefore, confine myself to citing some examples.

II. The colouring of the skin is one of the most striking characteristics, and one which is most apparent to the eye. This has given rise to the expressions White, Yellow, and Black, which are most improperly used to designate the three fundamental groups of mankind. We will first prove that these names possess the grave inconvenience of giving rise to ideas which are entirely erroneous. Amongst the _Whites_ there are entire populations, whose skin is as black as that of the darkest Negro. I shall only quote the Bishareen and other tribes inhabiting the African coasts of the Red Sea, the black Moors of Senegal, etc. On the other hand, there are yellow _Negroes_, as the Bosjesmans, who are the colour of light mahogany, or of café au lait, as Livingstone tells us.

It is no less true that colour is by far the most variable characteristic in man, and when we place the _coal black Negro_ side by side with the _fair White_ with his pinkish complexion, the contrast is striking. But this contrast is repeated in several races of animals, in the dog, for example, whose skin is generally blackish, but white in the white poodle. It is the same among horses, a fact which was known even to Herodotus, who pronounces white horses with a black skin as superior to all others.

The races of our domestic fowls alone present the three extreme colours observed in man. The French fowl has a white skin; in the cochin-china it approaches to yellow; it is black in _black fowls_. Sometimes they present a peculiarity similar to that which I mentioned in reference to the horse: a dark skin accompanying a white plumage as in the _silk hen_ of Japan.

These same _black fowls_ possess several interesting peculiarities from our present point of view. In Europe, melanism appears from time to time in our poultry-yards, and would infallibly spread if the fowls attacked by it were not destroyed. It is perhaps from want of this precaution that black fowls have been developed in various parts of the globe, among others in the Philippines, in Java, in the Cape Verd Islands, and upon the plateau of Bogota, all of which have been derived from European stocks. Melanism appears moreover, in groups of fowls which differ most strikingly in other respects, in the silk hen as well as in our ordinary races.

We see that _black fowls_ are in no sense a distinct species, and that the appearance of the black colour is merely an accidental character, which may be produced in races very dissimilar in other respects, and afterwards propagated by heredity. Why then admit that it has been otherwise in man?

Again, melanism is more highly developed in fowls than in man. It has long been held as a recognised fact that the skull of the Negro is more darkly coloured than that of the White. The fact is true. But M. Gubler has proved that the skull of a very dark-complexioned White was coloured exactly in the same manner as that of the Negro, and that this peculiarity was sometimes individual, and sometimes hereditary in certain families. In fowls also, melanism penetrates to the interior; but it is not only the meninges which present peculiarities similar to those presented by the _black man_. With them all the mucous, fibrous, and aponeurotic membranes, even to the muscular sheaths, possess the same colouring. The flesh also assumes a repugnant appearance, and it is for this reason that the propagation of black fowls is prevented as much as possible.

The difference in colouring is easily explained. We now know beyond a doubt that the skin of the Negro is exactly the same in composition as that of the White. We find the same layers in both; the _dermis_, the _mucous layer_ and the _epidermis_ present exactly the same structure. The layers are merely thicker in the Negro. In these two great races, the mucous layer, situated between the other two, is the seat of colour. It is formed of cells which are of a pale yellow colour in the _fair White_, of a more or less brownish yellow in the _dark White_, and of a blackish brown in the Negro. External causes have, moreover, an influence upon the organ and modify the coloured secretion. Simon has shown that freckles are nothing more than spots upon the skin of the _White_ presenting the characteristics of the skin of the Negro, and we know that an unusual exposure to the sun in the men and women of our race, and pregnancy in the latter, is sufficient to determine the formation of these spots.

Why, then, should it be thought strange that a number of circumstances, a constant heat, a bright light, &c., should influence the whole body and perpetuate those modifications which in us are only circumscribed and transitory. In treating of the formation of the human races we shall have to bring forward facts which will clearly prove that this is not merely hypothesis.

Finally, the colour of the skin depends upon a simple secretion which is subject to modification under a number of circumstances, as is the case with many others. There is, therefore nothing strange in the fact that some human groups, differing widely in other respects, should resemble each other in the matter of colour. This is the reason why the Hindoo (_Aryan_), the Bisharee and the Moor (_Semitic_), although belonging to the _White race_, assume the same, and even a darker hue than the _true Negro_. It also explains the fact that the colour of the Negro approximates in certain cases, to that of peoples belonging to the white stock who are more or less of a brown colour, or assumes a hue which exactly recalls that of the yellow races.

Thus, in man, as in animals, the aphorism is verified which was formulated by Linnæus in regard to plants:—_nimium ne crede colori_.

III. I shall not dwell at any length upon the modifications of the hair and villosities. They are much more apparent than real in man. Whether fair or black, fine and of a woolly appearance, as in the Negro, or coarse and stiff, as in the yellow and red races; whether the transverse section is circular as in the Yellow race, oval, as in the White, or elliptic, as in the Negro, _the hair remains hair_. The woolly fleece of our sheep, on the contrary, is in part of Africa, replaced by a short and smooth hair. In America the same is the case with the sheep of the Madeleine whenever they are left unshorn; and on the other hand, in the high plains of the Andes, the wild boars acquire a kind of coarse wool.

The practice of certain natives of shaving off all hair has made some travellers believe in the existence of human races which are entirely hairless; the error has however been recognised. All men possess hair in the normal places. Hairless dogs and horses are, however, known to exist. In America, where the oxen have a European origin, the hair commences with becoming very fine and few in number with the _pelones_, and disappears entirely with the _calongos_; and if the latter do not increase in number, it is due to their being systematically destroyed from an idea that they are a degenerate race.

It is evident that in these several respects the variations are more extensive in animals than in man.

IV. This fact becomes more evident when it is possible to substitute exact measurements for merely general ideas, and to compare figures. The variations in size present this advantage, and it is interesting to compare from this point of view the extremes of some animal races with the extremes admitted in human groups.

+-----------+--------------+-----------------+----------------+------+
| SPECIES. | RACE. | | DIFFERENCE. |RATIO.|
+-----------+--------------+-----------------+----------------+------+
| | | m. ft. in. m. ft. in. | |
|Dogs | Small Spaniel| 0·305 1 } | |
| (length) | St. Bernard | 1·328 3 4·27 } 1·025 2 4·27 | 0·2 |
|Rabbits | Niçard | 0·20 7·87 } | |
| (length) | Bélier | 0·60 1 11·62 }0·40 1 3·74 | 0·3 |
|Horse | Shetland | 0·76 2 5·92 } | |
| (height) | Dray Horse | 1·80 5 10·85 } 1·04 3 4·94 | 0·4 |
|Sheep | | 0·325 1 0·79 } | |
| (height) | | 1·040 3 4·94 }0·715 2 4·15 | 0·3 |
|Man (mean | Bosjesman | 1·37 4 5·93 } | |
| height) | Patagonian | 1·72 5 8·11 } 0·35 1 2·18 | 0·8 |
+-----------+--------------+-----------------+----------------+------+

We see that the variation between races is in the horse twice as great as in man, nearly three times in the sheep and rabbit, and four times as much in the dog. The difference is perhaps even more striking in the goat and ox, judging from the terms of comparison used by several travellers.

If, after having studied the various dimensions of the body, we compare the differences in proportion presented on the one hand by animals and on the other by human groups, we shall arrive at similar results. Without, however, entering into details it will be sufficient to mention the greyhound and the beagle.

V. One of the most singular external characters, and one which has often been insisted upon as being necessarily a character of species, is that presented by the Bosjesman women. It is generally known that at the lower extremity of the loins they develop a fatty mass which sometimes increases to a considerable protuberance, as may be seen in the _Hottentot Venus_, the model of which is in the Paris Museum. This _steatopygia_ reappears however in certain tribes situated much further north than the Houzouana races, while Livingstone states that certain women of the Boors, incontestably of Dutch origin, had begun to be affected by it. From this fact alone, this exaggerated development of the adipose tissue loses the value which many wished to attach to it.

If, however, the steatopygia were to exist only among the Houzouanas we could not, on that account, regard it as a character of species, for it has been proved in animals where it is only a character of race. Pallas has proved this fact in certain sheep of Central Asia. In these animals the tail disappears and is reduced to a simple coccyx, to the right and left of which are situated two hemispherical fatty masses weighing from twenty to thirty pounds each. Here, again, the variation is proportionally greater than in the Bosjesman woman.

We cannot regard these sheep as a different species, for when the Russians removed the same animals from the country in which they were born, the steatopygia disappeared in a few generations. It is, therefore, merely a character of race which can only be preserved in the place where it was developed, as may be seen in a number of other cases.

VI. It is evident that the preceding character is just as much internal as external; it is also evident that neither the size, nor the proportions of the trunk and limbs, can vary, unless the skeleton and the accompanying muscles experience corresponding modifications. The anatomical characters change then with the race in animals, as well as external characters. There are, however, certain facts which relate more directly to anatomy. I will quote a few cases.

A dog’s fore-paw possesses normally five well-formed toes, while the hind-paws have only four with a rudimentary fifth. This latter disappears in some races, mostly of a diminutive size. In certain large races, on the contrary, it is developed, and becomes equal to the other four. There must be then a formation of bone corresponding to the tarsus and metatarsus.

Something analogous to the appearance we have just remarked may be observed in the pig, complicated, however, by a fresh phenomenon. Here the normal foot bears two small rudimentary lateral toes, and two medial toes, each with its own hoof. Now in certain races, already known to the ancients, a third medial toe is developed, and the whole is enveloped in a single hoof. Instead of being _cloven-footed_, which is the normal type of the _species_, the race becomes _solidungulate_.

Nothing of this kind is ever seen in man. In every race the feet maintain their ordinary composition, in the Bosjesman as in the Patagonian. Some teratological exceptions with a tendency to heredity are nevertheless occasionally displayed, of which we shall speak in another chapter.

VII. The vertebral column is, so to speak, the fundamental portion of the skeleton, and yet it does not vary the less on that account. I shall not insist upon the differences presented by its caudal portion, merely remarking that there are races of dogs, sheep, and goats, in which the tail is so reduced as to be nothing more than a short coccyx.

The central portions themselves are known to be liable to change. Philippi tells us that the oxen of Piacentino had thirteen ribs instead of twelve, and, consequently, an extra dorsal vertebra. In the pig Eyton has observed the dorsal vertebræ vary from thirteen to fifteen, the lumbar from four to six, the sacral from four to five, and the caudal from thirteen to twenty-three, so that the total is forty-four in the African pig and fifty-four in the English pig.

In man, the presence of one extra vertebra has occasionally been observed. These have always been isolated cases, except in one Dutch family, quoted by Vrolich. But it does not approximate to a constant character in any human group, and if such a group did exist, it is evident that the variation would here again be less than in animals, for without even reckoning the tail, it is three times stronger in the latter.

Of course, I do not take into consideration what has been so often said of men asserted to have tails. We now know better how much credit to attach to this statement. But the variations which take place in the caudal region among animals teaches us that even a considerable elongation of the coccyx in a human group, and the multiplication of the vertebræ which compose it, must not be considered _à priori_ as a specific character.

VIII. It might have been expected that the head would have escaped modifications, on account of the importance of the organs which belong to it. But such is not the case, and here again the modifications are much greater in animals than in man. Blumenbach remarked long ago that there was more difference between the head of a domestic pig and the wild boar than between that of the White and the Negro. There are no domestic species to which the same remark cannot be applied. But I shall only remind the reader of the heads of the bull-dog, greyhound and spaniel.

The extent to which the modifications of the head can be carried is nowhere more plainly shown than in the _niata_ cattle of Buenos Ayres and La Plata. This ox exhibits the modifications of the specific characters similar to those which the bull-dog presents among dogs. All the forms are shortened and thickened, the head in particular seeming to have experienced a general movement of concentration. The inferior maxillary bone, although itself shortened, so far exceeds the superior in length that the animal is unable to browse the trees. The cranium is as much deformed as the face; not only are the forms of the bones modified, but also their relations, not one of which, according to Professor Owen, has been strictly preserved. This race, though perfectly established, is not therefore necessarily of less recent origin; for, as I remarked above, all the American oxen are descended from European stocks. It is already represented in the New World by two sub-races, one of which, that of Buenos Ayres, has preserved the horns, while that of Mexico has lost them.

It is scarcely necessary to remark that no human group presents anything at all analogous to this.

IX. The several facts which I have here enumerated seem to me sufficient to justify the proposition which I asserted at the commencement of the chapter, namely:—that the limits of variation are almost always more extensive between certain races of animals than between the most distant human groups.

Consequently, however great the differences existing between these human groups may be, or may appear to be, to consider them as _specific characters_ is a perfectly arbitrary estimation of their value. It is, to say the least, quite as rational, quite as scientific, to consider these differences only as _characters of race_, and even on that account to refer all the human groups to a single species.

The legitimacy of this conclusion is incontestable. Now, I repeat, that this conclusion is sufficient to destroy the very foundation of the polygenistic theory. In reality this theory rests entirely upon _morphological_ considerations. Its partisans, struck only by the material differences presented by the human groups, have thought it impossible to account for them, except by the admission of the existence of several species. By showing that facts of this nature can be equally well interpreted under the hypothesis of the Unity of the Species, monogenism and polygenism are, so to speak, placed on an equal footing.