The deviations from the national type, which occur sporadically, have been considered the result of disease, and can, as Professor Waitz observes, “but rarely become permanent, as the national type is always that which harmonizes with the soil and the climate, and the external relations in which the respective peoples live.”[1583] We must assume that a certain kind of constitution is best suited for certain conditions of life, and that every considerable deviation from this must perish in the struggle for existence in a state in which natural selection is constantly at work and physical qualities are of the first importance. We know from Isidore Geoffroy’s investigations that persons who deviate much, with regard to the length of body, from the common standard—they may be dwarfs or giants—are, as a rule, abnormal in other respects also, being deficient in intelligence as well as in the power of reproduction, and being especially liable to premature death.[1584] Sir W. Lawrence, too, remarks that the strength of men who have considerably exceeded the ordinary standard has by no means corresponded to their size, and that “there are very few instances of what we can deem healthy, well-made men, with all the proper attributes of the race, much below the general standard.”[1585] If, among civilized peoples, such deviations indicate some disturbance of the vital functions, and, as a consequence, are unfavourable to existence, this must be even more the case with savage tribes, all the members of which are subject to nearly the same conditions of life. Abnormal characteristics may sometimes flourish in a highly civilized society, but they are doomed to perish in communities among whom the struggle for existence is far more severe.

It may at first sight seem strange that all the characteristics, however slight, in which the various races of men differ from each other, should harmonize with particular conditions of life to the exclusion of others. But it must be remembered that, if we had fuller knowledge, characteristics which seem to us useless, or even hurtful, might be seen to be useful. We know the utility of some special characteristics, and that of others may, at least provisionally, be assumed. It is certain that the physiological functions of most persons who quit their native land and settle in a wholly different region, must undergo a considerable change if the new conditions are not to have injurious effects. Moreover, many bodily structures are so intimately related, that when one part varies others vary also, though, in most instances, we are quite unable to assign any reason why this should be the case.

Savage men are generally distinguished for relatively large jaws, which, no doubt, are of use in a state of nature, where food is often hard and tough, where the jaws have to perform the functions of knife and fork, and where the teeth occasionally serve as implements. This racial peculiarity, being in fact only a mark of low civilization, is thus easily accounted for by the law of natural selection. The less man, with advancing civilization, was in want of large and strong jaws, the greater was the chance for individuals born with smaller jaws to survive; hence a race with comparatively small jaws gradually arose. Indeed, Professor Virchow has shown that the prognathous type of face is inconsistent with the full development of the brain.[1586]

Another peculiarity which characterizes the lower races of men is the lateral jutting-out of the cheek-bones. But, as Mr. Spencer observes, this excessive size of the cheek-bones is only an accompaniment of large jaws. Other peculiarities of feature—depression of the bridge of the nose, forward opening of the nostrils, wide-spread alæ, and a long and large mouth—constantly coexist with large and protuberant jaws and great cheek-bones, alike in uncivilized races and in the young of civilized races;[1587] hence we cannot believe that the connection is merely accidental.

Professor Schaaffhausen has noticed that many peculiarities of the skull are coincident with arrested cerebral development and correlated to each other:—“The characters observed in the skulls of the lower races, namely, a narrow and low frontal bone, a short sagittal suture, a low temporal squama, a short occipital squama, the upper margin of which forms a flat arch, are therefore to be considered as approximations to the animal form, and they stand to each other in organic connection.”[1588] It seems as if stature and muscular force were in some way connected with the dolichocephalic and the brachycephalic forms of the skull, for Welcker found that short men and short races incline more to the latter, tall men and tall races to the former. Again, according to Fick, the muscles exercise a remarkable influence on the form of the bones in general, and particularly upon some cranial bones.[1589]

The process of acclimatization affords opportunities for the study of the connection between organic structures and functions on the one hand, and surrounding nature on the other. At present, however, our knowledge of the subject is exceedingly scanty. It has been asserted that the curly hair of the European becomes straight in America,—like the hair of an Indian; that in North America, as in New South Wales, children of European parents are apt to become tall and lean, whilst there is a tendency among European colonists at the Cape to grow fat,—which reminds us of the steatopygy of the native women.[1590] Almost all that we know with certainty is that, in the process of acclimatization, man has to undergo a change, and that this change is often too great to be endurable. As Dr. Felkin observes, Europeans are almost incapable of forming colonies in the tropics;[1591] and, with few exceptions, they have been unable to rear a sound progeny there in marriage with white women.[1592] Colonel Hadden, who has spent sixteen years in India, informs me that it is a prevalent opinion among British officers in that country that an English regiment of a thousand men would, within thirteen years, from climate, disease, or other casualties, almost wholly die out. This statement well agrees with Professor Sprenger’s, that a regiment consisting of eight hundred men loses within ten years more than seven hundred.[1593] It is also, according to Colonel Hadden, a common report that, of a third generation of pure Europeans in India, children only are, occasionally, met with, and that they never reach the age of puberty.[1594] English parents, as a rule, send their children to Europe when five or six years old, as otherwise they would succumb.[1595] According to Mr. Squier, it is the concurrent testimony of all intelligent and observing men in Central America that the pure whites are there not only relatively but absolutely decreasing in numbers, whilst the pure Indians are rapidly increasing, and the Ladinos more and more approximating to the aboriginal type.[1596]

The colour of the skin is justly considered one of the chief characteristics of race. Now it is quite impossible to assign any definite reason why one race is white, another black, brown, or yellow. Nobody has yet been able to prove that the colour of the skin is of any direct use to man, and it certainly is not the immediate result of long exposure to a certain climate. But we know that there exists an intimate connection between the colour of the skin and bodily constitution. “Les colorations diverses,” says M. Godron, “qui distinguent les différentes variétés de l’espèce humaine, tiennent beaucoup moins aux agents physiques, qu’aux phénomènes les plus intimes de l’organisation qui dans l’état actuel de la science, nous échappent et resteront peut-être toujours couverts d’un voile impénétrable.”[1597] Thus the alteration in the customary physiological functions called acclimatization, seems often to be connected with some change of colour not directly depending upon the influence of the sun. Dr. Mayer observed that a European at the tropics loses his rosy complexion, the difference in colour between arterial and venous blood being strikingly diminished on account of the smaller absorption of oxygen, which results from the feebler process of combustion.[1598] According to Dr. Tylor, it is asserted that the pure negro in the United States has undergone a change which has left him a shade lighter in complexion;[1599] whilst a long medical experience at New Orleans showed Dr. Visinié that the blood of the American negro has lost the excess of plasticity which it possessed in Africa.[1600] A negro boy brought to Germany by Gerhard Rohlfs, changed his colour after a residence of two years, from deep black to light brown.[1601] Klinkosch mentions the case of a negro who lost his blackness and became yellow; and Caldani declares that a negro, who was a shoemaker at Venice, was black when brought, during infancy, to that city, but became gradually lighter, and had the hue of a person suffering from a slight jaundice.[1602] In the ‘Philosophical Transactions,’ there is even a record of a negro who became as white as a European.[1603] On the other hand, we are told of an English gentleman Macnaughten by name, who long lived the life of a native in the jungle of Southern India, and acquired, even on the clothed portions of his body, a skin as brown as that of a Brahman.[1604] These statements, if true, certainly refer to exceedingly exceptional cases, but their accuracy cannot be à priori denied. We know that certain organisms are much better able than others to undergo the change which constitutes acclimatization, and we have no positive reason to doubt that this power may, in abnormal cases, be extraordinarily great. At any rate, it is beyond doubt that a close connection exists between the colour of the skin and the physiological functions of the body, on the one hand, and between these and the conditions of life on the other. Disease is commonly accompanied by a change of colour. Mr. Wallace observes that, in many islands of the Malay Archipelago, species of widely different genera of butterflies differ in precisely the same way as to colour or form from allied species in other islands.[1605] The same thing occurs to a less degree in other parts of the world also. And Agassiz has pointed out that, in Asia and Africa, the large apes and the human races have the same colour of the skin.[1606]

We may thus take for granted that racial peculiarities stand in some connection with the external circumstances in which the various races live. It may perhaps be objected that we meet with native tribes of various types on the same degree of latitude, and under the same climatic conditions.[1607] But we must remember that it is often impossible to decide whether the conditions of life are exactly the same; that intermixture of blood has caused a great confusion of racial types; and that all peoples have arrived at their present localities after more or less extensive migrations. We may be sure that some characters have been preserved from earlier times when the race lived in other circumstances, and that the higher its degree of civilization the less likely it would be to lose the stamp impressed upon it.[1608]

It is, however, exceedingly doubtful whether racial differences are so directly the result of external influences as anthropologists generally believe,—that is, whether they are the inherited effects of conditions of life to which previous generations have been subject. Professor Weismann, as is well known, thinks that acquired characters are not transmitted from parent to offspring. “It has never been proved,” he says, “that acquired characters are transmitted, and it has never been demonstrated that, without the aid of such transmission, the evolution of the organic world becomes unintelligible.”[1609] Man has from time immemorial mutilated his body in various ways, and there is not a single well-founded case of these mutilations having been inherited by the offspring.[1610] The children of accomplished pianists do not inherit the art of playing the piano. Facts show that children of highly civilized nations have no trace of a language, when they have grown up in a wild condition and in complete isolation.[1611] Change in colour influenced by sun and air is obviously temporary. The children of the husbandman, or of the sailor, are just as fair as those of the most delicate and pale inhabitant of a city; and, although the Moors, who have lived in Africa since the seventh century, are generally in mature life very sunburnt, their children are as white as those born in Europe, and “restent blancs toute leur vie, quand leurs travaux ne les exposent pas aux ardeurs du soleil.”[1612]

Such facts are certainly not in favour of the prevalent theory that the differences of race are due to direct adaptation. Whether Professor Weismann’s theory proves to be well founded or not, we manifestly cannot assume that the heredity of acquired characters suffices to explain the origin of the human races. It seems most probable that, at the very earliest stages of human evolution, mankind was restricted to a comparatively small area, and was then homogeneous, as every animal and vegetable species is under similar conditions. In the struggle for existence the intellectual faculties of man were developed, and before the breaking away of isolated groups he may have invented the art of making fire, and of fabricating the simplest implements and weapons. This mental superiority made it possible for man to disperse, enabling him to exist even under conditions somewhat different from those to which he was originally adapted. His organism had to undergo certain changes, but we are not aware that these modifications were transmitted to descendants. All that we know is, that the children born were not exactly like each other, and that those who happened to vary most in accordance with the new conditions of life as a rule survived, and became the ancestors of following generations. The congenital characters which enabled them to survive were of course transmitted to their offspring, and thus, through natural selection,[1613] races would gradually arise, the members of each of which would have as hereditary dispositions the same peculiarities as those which, to a certain extent, may be acquired through acclimatization, but then only for the individual himself, not for his descendants. We can thus understand how the children of a negro are black[1614]—even if they are born in Europe[1615]—as the black colour is the correlative of certain physiological processes favourable to existence in the country of their race. They survive, whilst the children of Europeans who have emigrated to the tropics are carried off in great numbers, even though their parents have succeeded in undergoing the functional modifications which accompanied the change of abode.