When, too, we cross from Central Europe to Central Africa, we see that these two extreme types of mankind are linked together by all the intervening shades between fair and dark. In Southern Europe the skin and hair become more pigmented ; in Northern Africa the skin is dark brown or black. Whenever we find an intermediate series which carries us from one extreme to the other, we believe that those extremes may have arisen from a common stock. We see, too, how the inhabitants of the same country or even of the same parish, may show many shades of pigmentation ---but for each country there is a certain average, and the variation in shade is bounded by definite limits. When we wish to explain why the Central European is fair and the Central African is black, we are brought at once to a dead stop by our ignorance. We do not know what service pigment performs in the human body. We cannot suppose it to be a useless substance. It is true that it is most developed in those who live in hot climates, yet the ancient Tasmanians, the natives of a very temperate climate, were black. There is no definite proof that negroes become less black in temperate countries, nor that fair men become more pigmented in tropical lands. Yet it seems most reasonable to suppose that the pigment of the skin does protect the body from certain rays of the sun.
Anthropologists have always presumed that the primitive human stock must have been dark-skinned. Certainly the degree of pigmentation seen amongst the great anthropoids lends support to this theory. The gorilla is black ; there are various races or varieties of chimpanzee, and all of them show a degree of black pigmentation. In one variety the skin becomes totally black; in another, pigmentation of the face and of other parts is delayed until late in life ; in others the face never becomes absolutely black. The skin of the orang is also deeply pigmented, but the black granules are masked by the presence of a red element. The evidence supplied by anthropoids points to a common stock with dark pigmented skins. It is very possible, however, that in the progress of evolution, the degree of pigmentation has somewhat increased in the pure negro races, while in the Central European it has become greatly diminished. One is led to form such an opinion from the skin colour of the natives of Australia. They have so many primitive features in the structure of their bodies that it is also possible that their skin colour is likewise primitive. Their skins are not so deeply pigmented as in the typical negro. On the whole, the evidence points to the stock from which human races have arisen as having had brown pigmented skins. The very black African and very fair European races may represent comparatively recent products in the evolution of modern races.
We must return to the consideration of the African and European types of mankind now standing before us. We shall admit, I think, that in character of skull and of brain, and in colour of skin, the negro shows the older type, but in the character of his hair this is not so. The woolly hair, coiled naturally into little isolated locks, is unlike the hair of ape or man. It is a feature of the negro or negroid races, and was evolved with them. The straight black or wavy brown hair of the European appears to be more primitive in character. There are two other features of the negro's face which appear to be specializations or departures from the primitive type. The thick everted lips are very different from the thin straight lips of the anthropoid apes. The thin European lips seem a more primitive type, and yet when sections are made of the lips of Europeans and Africans certain features are seen which make us hesitate to endorse this opinion. Then, again, there are the characters of the forehead. It is true that in the West Coast of Africa we meet natives with prominent supraorbital ridges and receding foreheads. In the typical African negro this is not the case ; the forehead as a rule is high, narrow, often prominent or bulging, and the supraorbital ridges are moderately or slightly developed—distinctly less prominent than in the European. There is not a shadow of doubt that the stock from which modern man is descended had great supraorbital ridges. They are still to be found in a fairly primitive form in native Australians, but to see them at their best one must examine the skulls of those ancient Europeans—the Neanderthal race. In the gorilla especially, and also in the chimpanzee, these supraorbital ridges form prominent bony ledges or shelves above their sunken eyes. The typical negro is destitute of great supraorbital ridges, which are primitive features.
When we compare the negro and European nose it may be a question as to which is the more primitive. Neither the one nor the other is like the nose of the anthropoid, and yet of the two, the sharp, narrow, prominent nose of the European, with its high bridge and compressed wings, must be admitted to be the more specialized type. If, however, we leave the Congo Valley and make our way to Egypt along the Valley of the Nile, we shall meet with various negro tribes in whom the nose is narrow and prominent and almost European in shape.
We have reason to believe that the shape of the nose does depend to a considerable degree on the development of the teeth and jaws. A long, prominent and narrow nose is usually part of a face in which the palate is narrow or contracted and in which the jaws have grown in length rather than in width and strength. In the ancient inhabitants of Europe we find the jaws and teeth well and regularly developed and the nose of fair width. In modern Europeans, especially in those with long heads, we find a tendency to an irregular development of the jaws and to an elongation and narrowing of the face, with the result that the nose also is rendered sharper and more prominent. The jaws and cheeks have retreated and left the nose as a narrow prominent organ on the face of the typical European. In Central Africa we find other tendencies at work ; the teeth are big, white, and regularly set in well-developed jaws. The face is broad rather than long. The jaws may be so well grown as actually to give the individual the appearance of having a muzzle. The nose is correspondingly flat and wide. In brief, I conceive it possible that the nose of the negro might assume a European form were his teeth and jaws to undergo those changes which are apparently occurring amongst the civilized peoples of Europe and America.