CHAPTER I.

_SOMATIC CHARACTERS._

DISTINCTIVE CHARACTERS OF MAN AND APES.

Monkeys and anthropoid apes--Erect attitude--Curvature of the spine--Brain--Skull--Teeth--Other characters--Differences less accentuated in the fœtus and the young than in the adult.

DISTINCTIVE MORPHOLOGICAL CHARACTERS OF HUMAN RACES.

_Stature_: Individual limits--Dwarfs and giants--Average stature of different populations--Influence of environment--Differences according to sex--Reconstitution from the long bones--_Teguments_: Skin--Hair of head and body--Four principal types--Microscopic structure--Correlation between the hair of the head and the pilosity of the body--_Pigmentation_: Colouring of the skin, the eyes, and the hair--Changes in the pigment.

_Distinctive Characters of Man and Apes._

The physical peculiarities distinguishing man from the animals most nearly allied to him in organisation, and those which differentiate human races one from another, are almost never the same. I shall in a few words point out the former, dwelling at greater length on the latter, which have a more direct connection with our subject.

From the purely zoological point of view man is a placental or _Eutherian_ mammal, because he has breasts, because he is more or less covered with hair, because his young, nourished in the womb of the mother through the medium of the placenta, come fully formed into the world, without needing to be protected in a pouch or fold of skin, as in the case of the marsupial mammals (implacentals or _Metatherians_), or completing their development in a hatched egg, as in the case of the monotremata or _Prototherians_.

In this sub-class of the placental mammals, man belongs to the order of the _Primates_ of Linnæus, in view of certain peculiarities of his physical structure--the pectoral position of the breasts, the form, number, and arrangement of the teeth in the jaw, etc.

The order of the Primates comprises five groups or families: the Marmosets (_Hapalidæ_), the _Cebidæ_, the _Cercopithecidæ_, the anthropoid apes (_Simidæ_), and lastly, the _Hominidæ_.[9] Putting aside the first two groups of Primates, which inhabit the New World, and which are distinguished from the three other groups by several characters, let us concern ourselves with the apes of the Old World and the _Hominians_. Let us at the outset remember that the monkeys and the anthropoid apes exhibit the same arrangement of teeth, or, as it is termed, the same “dental formula,” as man. This formula, a character of the first importance in the classification of mammals, is summed up, as we know, in the following manner: four incisors, two canines, four premolars, and six molars in each jaw.

The _Cercopithecidæ_ walk on their four paws, and this four-footed attitude is in harmony with the structure of their spine, in which the three curves, cervical, dorsal, and lumbar, so characteristic in man, are hardly indicated; thus the spine seems to form a single arch from the head to the tail. As to this last appendage, it is never wanting in these monkeys, which are also provided with buttock or ischiatic callosities, and often with cheek-pouches.

The _anthropoid apes_ form a zoological group of four genera only. Two of these genera, the gorilla and the chimpanzee, inhabit tropical Africa; the two others, the orang-utan and the gibbon, are confined to the south-east of Asia, or, to be more precise, to Indo-China, and the islands of Sumatra and Borneo. We can even reduce the group in question to three genera only, for many naturalists consider the gibbon as an intermediate form between the anthropoid apes and the monkeys.[10] The anthropoids have a certain number of characters in common which distinguish them from the monkeys. Spending most of their life in trees, they do not walk in the same way as the macaques or the baboons. Always bent (except the gibbon), they move about with difficulty on the ground, supporting themselves not on the palm of the hand, as do the monkeys, but on the back of the bent phalanges. They have no tail like the other apes, nor have they cheek-pouches to serve as provision bags. Finally, they are without those callosities on the posterior part of the body which are met with in a large number of _Cercopithecidæ_, attaining often enormous proportions, as for instance, among the _Cynocephali_. The gibbon alone has the rudiments of ischiatic callosities.

If we compare man with these apes, which certainly of all animals resemble him most, the following principal differences may be noted. Instead of holding himself in a bending position, and walking supported on his arms, man walks in an erect attitude--the truly biped mode of progress. In harmony with this attitude, his vertebral column presents three curves, cervical, dorsal, and lumbar, very definitely indicated, while they are only faintly marked in the anthropoids, and almost absent in the monkeys. This character, moreover, is graduated in man; in civilised man the curvature in question is more marked than among savages. There is no need, however, to see in that any “character of superiority.” It is quite simply an acquired formation; it is more marked in civilised man just because it is one of the conditions of the stability of the vertebral column, a stability so essential in sedentary life, while a curvature less marked gives much more flexibility to the movements, at once so numerous and varied, of the savage.[11]

But to what does man owe this erect and biped attitude? Professor Ranke has put forward on this subject a very ingenious hypothesis.[12] According to him, the excessive development of the brain, while conducive to enlargement of the skull, would at the same time determine the change of attitude in a being so imperfectly and primitively biped as was our progenitor. In this way would be assured the perfect equilibrium on the vertebral column of the head, made heavy by the brain. Without wishing to discuss this theory, let me say that several peculiarities in the anatomical structure of man, compared with those of anthropoid apes and other mammals, give it an air of plausibility.

In fact, while with the majority of mammals the equilibrium of the head is assured by very powerful _cervical ligaments_, and with anthropoid apes by very strong muscles, extending from the occiput to the spinous processes of the cervical vertebræ, twice as long as those of man (Figs. 1 and 2, _a_), which prevent the massive muzzle from falling upon the chest and pressing on the organs of respiration,[13] we see nothing of a similar kind in the genus _Homo_--no cervical ligament, and no powerful muscles at the nape of the neck. The very voluminous brain-case of man suffices to counterbalance the weight of the much reduced maxillary part, almost without the aid of muscles or special ligaments, and the head balances itself on the vertebral column (Fig. 2).

This equilibrium being almost perfect, necessitates but very thin and flexible ligaments in the articulation of the two occipital condyles of the skull on the atlas. The slight muscles to be found behind the articulation are there only to counterbalance the trifling tendency of the head to fall forward.

In connection with this point, we must remember that Broca and several other anthropologists see, on the contrary, in the biped attitude, one of the conditions of the development of the brain, as that attitude alone assures the free use of the hands and extended range of vision. Somewhat analogous ideas have lately been put forward by men of science of the first rank like Munro and Turner.[14]

In any case, let us remember in regard to this point, that at birth man still bears traces of his quadrupedal origin; he has then scarcely any curves in the vertebral column. The cervical curve only shows itself at the time when the child begins to “hold up its head,” in the sitting posture to which it gradually becomes accustomed--that is to say about the third month. On the other hand, as soon as the child begins to walk (the second year), the prevertebral muscles and those of the loins act upon the lower regions of the spine and produce the lumbar curve.

Thus, perhaps, the chief fact which determines the erect attitude so characteristic of man is the excessive development of his brain, and the consequent development of the brain-case.

It is in this excessive development of the brain that the principal difference between man and the anthropoid apes must be sought. We know in fact from the researches of numerous anthropologists (see Chapter II.) that the average weight of a man’s brain in European races (the only races sufficiently known in this respect) is 1360 grammes, and that of a woman’s is 1211 grammes. These figures may rise to 1675 grammes in certain instances, and fall to 1025 in others.[15] Brains weighing less than 1000 grammes are generally considered as abnormal and pathological.

On the other hand, the brains of the great anthropoid apes (gorilla, chimpanzee, and orang-utan), the only ones comparable to man in regard to weight of body, have an average weight of 360 grammes. This weight may rise to 420 grammes in certain isolated cases, but never exceeds this figure. And even in these cases, with the orang-utan, for example,[16] it only represents one half per cent. of the total weight of the body, while with European man the proportion is that of at least three per cent., according to Boyd and Bischoff.[17]

The excessive development of the brain and of the brain-case which encloses it is correlative, in the case of man, with the reduction of the facial part of the skull. In this respect the difference is also appreciable between him and the animals. In order to convince ourselves of this we have only to compare the human skull with that of any ape whatever, placing both in the same horizontal plane approximately parallel to the line of vision.[18]

Viewed from above, or by the _norma verticalis_, as the anthropologists say, the bony structure of the human head leaves nothing of its facial part to be seen (Fig. 11); at the very most may be observed, in certain rare instances, the lower part of the nasal bones, or the alveolar portion of the upper jaw (Fig. 10). On the other hand, with apes, anthropoid or otherwise, almost all the facial part is visible. Examined in profile (_norma lateralis_), the bony structure of the heads of man and monkeys presents the same differences.

With the anthropoid apes, the facial portion forming a veritable muzzle rises, massive and bestial, _in advance_ of the skull, while with man, very reduced in size, it is placed _below_ the skull. The facial angle, by means of which the degree of protuberance of the muzzle may, to a certain point, be measured, exhibits notable differences when the skulls of man and animals are compared in this particular. On continuing the examination of the profiles of the bony structures of the two heads in question, we notice also the slight development of the facial part of the malar bone in man, as compared with its temporal part, and the contrary in the ape; as well as the difference in the size of the mastoid processes, very strong in man, very much diminished proportionately to the dimensions of the head in the anthropoid apes.

Seen from the front (_norma facialis_), the human skull presents a peculiarity which is not observed in any anthropoid skull, namely, that the top of the nasal opening is always situated higher than the lowest point of the lower edge of the orbits (Fig. 12); while in the anthropoid apes it is always found below this point. Lastly, if the skulls in question, always placed on the horizontal plane, are compared from behind (_norma occipitalis_), it will be noted that on the human skull the occipital foramen is not seen at all; on the skulls of monkeys it is plainly visible, if not wholly, at least partly.[19]

All the other characters which distinguish man from the anthropoid apes are only the consequences of the great enlargement of his brain-case, at the expense of the maxillary part of the face, and of the erect attitude and biped progression.

Let us take, for instance, those enormous crests which give an aspect at once so strange and horrible to the skulls of the adult males of the gorilla and the chimpanzee. These projections are due to the extreme development of the masticatory muscles which move the heavy jaws and of the cervical muscles, ensuring the equilibrium of the head. Not having found sufficient room for their insertion on the too small brain-case, they have, so to speak, compelled the bony tissue in the course of development to deposit itself as an eminence or crest at the point where the two lines of insertion meet on the crown of the head. The best proof of this is that the young have no crests, and that on their skulls the distance between the temporal lines marking the insertion of the temporal muscles is almost as great as it is in man. In the gorillas, it is the same with the enormous spines of the cervical vertebræ, to which are fixed the muscular masses of the nape of the neck. These crests and these processes being less developed in the orang-utan, its head is not so well balanced, and its heavy muzzle falls on its chest. So one may suppose that the laryngeal sacs, considerably larger than those of the gorilla, serve him as air-cushions to lessen the enormous weight of the jaw resting on the trachea. The gibbon, better adapted to biped progression, and having a less heavy jaw, has no skull-crests. Further, with it, the ventricles of Morgagni, that is to say, the little pouches situated behind the vocal cord in the larynx, never develop (except in one species, _Hylobates syndactylus_) into enormous air-sacs as in the orang-utan. In this respect, the gibbon approaches much nearer to man than the other anthropoids, but it is also more distinguished from him than the others by the excessive length of the arms, or, to be more exact, of the pectoral limbs. It holds itself erect and walks almost as well as man, aided by the long arms and hands which touch the ground even when the animal is standing quite upright, and which he uses as a pendulum when walking. In the case of three other anthropoids, which bend forward in walking, the pectoral limb is shorter than in the gibbon but longer than in man.

The first toe, opposable in the anthropoid apes and unopposable in man, the relative length of the toes and fingers generally, etc., only constitute modifications correlative to the erect attitude and biped movement of man, and to his terrestrial habitat as opposed to the arboreal habitat of the anthropoid apes, and to their biped movement necessitating the support of the hands.

The differences in the form and size of the teeth are also the consequence of the inequality of the development of the maxillary part of the face in man, and in the apes in general.

The size of the teeth in proportion to that of the body is less in man than in the apes (Figs. 1 and 2). Putting aside the incisors and the canines, the size of the molars and the premolars of these animals is larger in relation to the length of the facial portion of the skull. The “dental index” of Flower, that is to say the centesimal relation of the total length of the row of molars and premolars to the length of the naso-basilar line (from the nasal spine to the most advanced point of the occipital foramen), is always greater in the anthropoid apes than in man; in the latter it is never above 47.5, while it is 48 in the chimpanzee, 58 in the orang, and 63 in the gorilla.

As to the arrangement of the teeth on the alveolar arch, with man they are in a compact line forming a continuous series without any notable projection of any one tooth above the common level; while in all the apes is observed an interval (_diastema_) between the canines and the lateral incisors of the upper jaw, and between the canines and the first premolars of the lower jaw. These gaps receive in each jaw the projecting part of the opposite canine.

Like the anthropoid apes, man has five tubercles in the lower molars, while the monkeys have in general only four. This rule admits, however, of numerous exceptions: very often the fifth posterior tubercle is wanting in the two last molars in man; on the other hand, it is regularly found in the last molar in certain kinds of monkeys (_Cynocephali_, _Semnopitheci_). As to the wisdom tooth, in certain pithecoid apes (_Cynocephali_, _Semnopitheci_) it is greater in size than the anterior molars; whilst in certain others, like the _Cercopitheci_, it is much less than the two first molars. With the anthropoid apes this tooth is of the same size as the other molars or a little smaller, and it is generally the same with man, though in somewhat frequent cases it is entirely wanting. The dental arch is different as regards form in man and in apes. In man it has a tendency towards the parabolic and elliptical form, whilst in apes it usually takes the form of U.

It should be noted that all the characters that distinguish man from the anthropoid apes have a tendency to become more marked with the development of civilisation and life in a less natural environment, or artificially modified, as we have already seen in regard to the curves of the vertebral column. Thus the absence of the fifth tubercle in the lower molars has been more often noted in European races (29 times out of 51, according to Hamy) than with Negroes and Melanesians. The wisdom tooth seems to be in a state of retrogressive evolution among several populations. Especially in the white races it is nearly always smaller than the other molars; the number of the tubercles is reduced to three instead of four or five; very often in the lower jaw it remains in its alveola and never comes through.

In the same way the little toe tends, in the higher races (perhaps owing to tight boots), to become atrophied and formed of but two phalanges instead of three. Pfitzner has noted this reduction in thirty feet out of a hundred and eleven that he examined.[20]

It is perhaps in similar retrogressive evolutions due to the “social environment” that we must seek the explanation of a great number of characters of “inferiority” and “superiority,” so called, of certain races.

The difference between man and the ape in regard to teguments is not so appreciable as might be thought. Man comes into the world covered almost entirely with _lanugo_ or short fine hair. This hair is afterwards replaced in early infancy by permanent hair which only occupies certain parts of the body. Primitive man, it may be presumed, was entirely covered with hair, except perhaps on the front part of the trunk, where natural selection in the struggle with parasites (infesting that warm part of the mother’s body in contact with the young when being suckled) would soon cause the disappearance of the hair from that place, as indeed we see in apes.[21] It is curious to observe in this respect that the disposition of the hair of the arms in man is far from recalling that of the anthropoid apes, as Darwin thought, but rather resembles the disposition observed among the monkeys. In fact, instead of being directed upwards towards the bend of the elbow, this hair is turned downwards towards the wrist in the higher half of the arm, and transversely in its lower half. The anthropoid apes being accustomed to cover the head with their arms, or to keep them above their head so as to cling to the branches of the trees on which they spend their life, the hairs may have taken in this case an opposite direction to that of the primitive type of the Primates by the simple effect of gravity.[22]

Space does not permit us to pass in review several other characters distinguishing man from the anthropoid apes: absence of certain muscles (_acromiotrachelian_, etc.) in the former, simplicity of the cerebral folds in the latter, the absence of the lobulation of the liver and that of the penile bone in the former and their presence in some of the anthropoid apes, etc.

Let me say in conclusion that all these distinctions are only very marked when adult individuals are compared, for they become accentuated with age. The fœtus of the gorilla at five months bears a very close resemblance to the human fœtus of the same age. A young gorilla and a young chimpanzee, by their globular skull, by their not very prominent muzzle, and by other traits, remind one of young Negroes. In comparing the skulls of gorillas, from the fœtal state through all the stages of growth to the adult state, we can follow step by step the transformation of a face almost human into a muzzle of the most bestial aspect, as a result of the excessive development of the face in front and below in the anthropoid ape, and the growth of the skull upward and behind in man, as if these parts moved in different directions in relation to a central point in the interior of the skull near to the _sella turcica_.[23]

_Distinctive Characters of Human Races._

In treatises on anthropology, anatomy, and physiology will be found all the information wished for on the different somatic characters of man, as well as on their variations according to sex, age, and race. It would be exceeding the limits of our subject were I to describe here, one by one, all the anatomical or morphological characters drawn from the bony, muscular, nervous, and other systems of which the human body is composed. We shall only pass in review the characters which possess a real importance in the differentiation of races. These are much less numerous than is generally supposed, and belong for the most part to the category of characters that are observed in the living subject. It is generally believed that the sole concern of anthropology is the description of skulls. This is one of the common errors of which there are so many current among the general public on scientific subjects. To be sure, the skull, and especially the head, of the living subject furnish the principal characters which differentiate races, but there exist several others, without a knowledge of which it is difficult to direct one’s steps in the midst of the diversity of forms presented by the human body according to race. We distinguish in general two kinds of somatic characters: (1) those dealing with the form and structure of the body--morphological characters; and (2) those which are connected with its different functions--physiological characters, with which we will include psychological and pathological characters.

We shall first examine the morphological characters, beginning with those furnished to us by the body as a whole--the stature, the nature of the tegument (the skin and hair), and its colouring. We shall afterwards pass to an examination of the morphology of the head, and the different parts of the body, with their bony framework (skull and skeleton). We shall complete this brief account by a glance at the internal organs, muscles, brain, viscera.

_Stature._--Of all the physical characters which serve to distinguish races, stature is perhaps that which has hitherto been regarded as eminently variable. It has been said that not only does stature change with age and sex, but that it varies also under the influence of external agencies. These variations are unquestionable, but it must be remarked that they are produced in a similar way in all races, and cannot exceed certain limits imposed by race.

Even from birth stature varies. Setting aside individual variations, the new-born are on an average a little taller, for example, in Paris (499 millim. for boys) than in St. Petersburg (477 millim.). Unfortunately we have hardly any data in regard to this important question for the non-European populations. Here in a tabulated form is the average height of the new-born of different populations, so far as information has been obtainable.

AVERAGE STATURE.

-----------------+----------------+----------------+------------ | /Boys/. | /Girls/. | /Populations/. +-------+--------+-------+--------+ /Name of/ |Millim.|Inches. |Millim.|Inches. | /Observer/. -----------------+-------+--------+-------+--------+------------ Annamese | 474 | 18.49 | 464 | 18.10 | Mondière. Russians of | | | | | St. Petersburg | 477 | 18.60 | 473 | 18.45 | Mies. Germans | | | | | of Cologne | 486 | 18.95 | 484 | 18.88 | Mies. Americans | | | | | of Boston | 490 | 19.27 | 482 | 18.80 | Bowditch. English | 496 | 19.35 | 491 | 19.31 | C. Roberts. French | | | | | of Paris | 499 | 19.52 | 492 | 19.35 | Mies. -----------------+-------+--------+-------+--------+------------

According to this table there would also be from the time of birth an inequality of stature of the two sexes; boys exceed girls by a figure which varies from 2 to 10 millim., that is to say on an average half a centim. (less than a quarter of an inch). The data relating to different races are insufficient; it may be remarked, however, that with people very low in stature, like the Annamese (1 m. 58, or 5 feet 2 inches), on the average the new-born are also shorter than those of people of greater stature, as, for instance, the English or the inhabitants of the United States. The French (average height 5 feet 5 inches) appear to be an exception to this rule.

We shall examine at greater length in Chapter IV. increase of stature in connection with all the phenomena of growth. Let me for the present say that as regards man, the age of 18 to 25 years, according to race, may be considered as the practical limit of this growth. In order to make a useful comparison of statures of different populations, we should only take, then, adults above these ages.

It must be said on this point that the greater part of the reliable information which we possess concerning stature relates solely to men, and among these, more especially to conscripts or soldiers. And it has often been objected that the figures in documents furnished in connection with the recruiting of armies do not represent the true height of any given population, for the conscripts, being in general from 20 to 21 years of age, have not yet reached the limit of growth.

This is true in certain cases; for example, when we have the measurements of all conscripts, who, in fact, grow from 1 to 2 centimetres during their military service; but when we have only the measurements of those enrolled, that is to say only of men above the standard height (and that is most frequently the case), the question presents a different aspect. The average height of this picked section of the population, higher by 1 to 2 centimetres than that of men of their age in general, may be considered (as I have elsewhere shown[24]) to represent the average stature of the whole number of adult males of any given population. We may then, while making certain reservations, take the height of those enrolled (but not that of all the conscripts) as representing the height of the adults of any given population.

The individual limits between which the height varies are very wide. It is admitted in general that the limits of height in the normal man may vary from 1 m. 25 (4 feet 1 inch) to 1 m. 99 (6 feet 6-3/4 inches). Below 1 m. 25 begins a certain abnormal state, often pathological, called Dwarfism. Above 2 m. we have another corresponding state called Giantism. Dwarfs may be 38 cent. high (15 inches), like the little feminine dwarf Hilany Agyba of Sinai (Joest), and giants as high as 2 m. 83 (9 feet 5 inches), like the Finn Caïanus (Topinard).[25]

Dwarfism may be the result of certain pathological states (microcephaly, rickets, etc.), as it may be equally the result of an exceeding slowness of growth.[26] In the same way giantism is often seen associated with a special disease called acromegaly, but most frequently it is produced by an excessive growth. In any case, exceptional statures, high or low, are abnormal phenomena, the acknowledged sterility of dwarfs and giants being alone sufficient to prove this.

Extreme statures which it is agreed to call normal, those of 1 m. 25 and 1 m. 99, are very rare. One might say that, in general, statures below 1 m. 35 and above 1 m. 90 are exceptions. Thus in the extensive American statistics,[27] based on more than 300,000 subjects, but one giant (above 2 m.) is met with out of 10,000 subjects examined, and hardly five individuals in 1000 taller than 1 m. 90 (75 inches). Again, in the statistics of the Committee of the British Association,[28] which embrace 8,585 subjects, only three individuals in a thousand have been found taller than 1 m. 90. Yet in these two cases, populations of a very high stature (1 m. 72 on an average) were being dealt with. If we turn to a population lower in stature, for instance the Italian, we find only one subject 1 m. 90 or above in height in 7000 examined, according to the statistics of Pagliani.[29] In the same way, low statures under 1 m. 35 (53 inches) are met with only once in every 100,000 cases among the subjects examined by the American Commission, and not once among 8,585 inhabitants of the United Kingdom; even in a population low in stature, like the Italians, only three such in every 1000 subjects examined are to be found. We do not possess a sufficient number of figures to be able to affirm that among all the populations of the globe the instances of all these extreme statures are exceptional, but what we know leads us to suppose that it is so, and that the limits of normal stature in man are between 1 m. 35 and 1 m. 90.

The figures of individual cases are much less interesting than the averages of the different populations, that is to say the height obtained by dividing the sum of the statures of individuals by the number of subjects measured. On comparing these averages it becomes possible to form a clear idea of the difference existing among the various peoples. But here there is an observation to make.

The data of this kind published up to the present in the majority of books may often lead to error. In fact, as a general rule they give only the average height without stating the number of subjects measured. Very often it is only the rough guess of a traveller who has not even measured at all the populations of which he speaks. In other cases we have averages drawn from the measurements of two, three, or four subjects, which are evidently insufficient for a standard which varies so much in one individual and another, and even in the same individual according to the hour of the day.

We know, in fact, that man measures one or two centimetres more on rising in the morning than on going to bed at night, when the fibro-cartilaginous discs situated between the vertebræ are compressed, more closely packed, and the vertebral column is more bent. Unscrupulous conscripts whose stature is near the regulation limit know perfectly well that if the day before the official examination they carry heavy loads, they compress their intervertebral discs so that their height is sometimes diminished by three centimetres.

It is necessary then, in order to avoid error, not only to have measurements taken from adult subjects, but also from several series containing a great number of these subjects. Calculation and inference have shown us that it is necessary to have at least a series of one hundred individuals to guarantee the exact figure of the height of a population but slightly blended. Series of 50 to 100 individuals may still furnish occasionally good indications, and series of 25 to 50 individuals an approximation; but with series under 25 individuals doubt begins and the figures are often most deceptive.

I have brought together and grouped in the table at the end of this volume (Appendix I.) average statures calculated in series of twenty-five individuals or more. These series have been based on the collation of hundreds of documents, of which limits of space prevent a full enumeration.

An examination of our table shows that the extreme averages of different populations fluctuate, in round figures, from 1 m. 38 (4 ft. 6 in.) with the Negrillo Akkas, to 1 m. 79 (5 ft. 10.5 in.) with the Scots of Galloway.[30] But if we set aside the pigmy tribe of the Akka, quite exceptional as regards stature, as well as the Scots of Galloway, and even the Scots of the north in general (1 m. 78), who likewise form a group entirely apart, we arrive at the extreme limits of stature, varying from 1465 mm. with the Aeta or Negritoes of the Philippines, and 1746 mm. with the Scots in general. In round figures, then, we can recognise statures of 1 m. 46 (4 feet 9.5 inches) and 1 m. 75 (5 feet 9 inches) as the extreme limits of averages in the different populations of the globe. The medium height between these extremes is 1 m. 61, but if we put on one side the exceptional group of Negritoes (Akka, Aeta, Andamanese, and Sakai), we shall note that the rest of mankind presents statures which ascend by degrees, almost uninterruptedly, from millimetre to millimetre between 1 m. 54 and 1 m. 75, which makes the average 1 m. 65 (5 feet 5 inches), as Topinard has discovered.[31] Topinard has likewise proposed the division of statures, since universally adopted, into four categories, viz.: short statures, under 1 m. 60; statures under the average, between 1 m. 60 and 1 m. 649; statures above the average, between 1 m. 65 and 1 m. 699; and lastly, high statures, 1 m. 70 and over.

Our table shows conclusively that there are many more populations (almost double the number) whose stature is above or under the average, than populations of a short or high stature.

Short stature is rare in Africa, being found only among the Negrillo pigmies and Bushmen; in South America a few tribes of low stature are also met with; but the true home of low stature populations is Indo-China, Japan, and the Malay Archipelago. In the remaining portion of Asia this low stature is only met with again in Western Siberia, and among the tribes called Kols and Dravidians in India.

Statures under the average predominate in the rest of Asia (with the exception of the populations to the north of India and anterior Asia) and in Eastern and Southern Europe, while statures above the average comprise Irano-Hindu populations, the Afrasian Semites, the inhabitants of Central Europe, as well as the Melanesians and Australians.

Thus high stature is plainly limited to Northern Europe, to North America, to Polynesia, and especially to Africa, where it is met with as well among Negroes as among Ethiopians.

What is the influence of environment on stature? This is one of the most controverted questions. Since the time of Villermé the statement has been repeated in a variety of ways that well-being was favourable to growth and increase in stature, and that hardship stunted growth. There are facts which seem to prove this. In a population supposed to be formed of a mixture of many races, the well-fed upper classes appear to possess a higher stature than the lower classes; thus, while the English of the liberal professions are 69.14 inches (1757 mm.) in height, the workmen of the same nation are only 65.7 inches (1705 mm.).[32] But can we not likewise adduce here the influence of race? That predominating in the aristocracy and well-to-do classes does not, perhaps, predominate in the working classes. Beddoe[33] and others have remarked that the stature of miners is lower than that of the population around them; in the same way, workmen in shops and factories are inferior in height to those who labour in the open air, and this in Belgium (Houzé) as well as in England (Beddoe, Roberts) or Russia (Erisman, Anuchin).[34] According to Collignon,[35] the populations of Normandy and Brittany living in the neighbourhood of railways and high-roads are superior in height to those living in out-of-the-way places. He concludes from this that the material conditions of life being improved since the formation of roads, the stature of the population has increased. According to Ammon and Lapouge, the population of the towns in France and Southern Germany are taller in stature than those of the country, because of the migration towards urban centres of the tall dolichocephalic fair race which they call _Homo Europeus_. However, Ranke observed just the opposite, and there are other objections to be raised against this theory, based on the data of recruiting. These town-dwellers of high stature are perhaps only conscripts too quickly developed; town life accelerates growth, and town-dwellers have nearly reached the limit of their height while dwellers in villages have not finished growing. This is so true that in countries where statistics have been taken of the civic population, as in England for example, the population of the towns is shorter in stature than that of the country. Beddoe explains this fact by the bad hygienic conditions in towns, the want of exercise and drinking habits of dwellers in cities.[36]

To conclude, the influence of environment cannot be denied in many cases: it may raise or lower stature, especially by stimulating or retarding and even arresting growth; but it is not demonstrated that such a change can be perpetuated by hereditary transmission and become permanent. The primordial characteristics of race seem always to get the upper hand, and the modifications produced by environment can alter the stature of the race only within very restricted limits. Thus miners of a high stature like the Scotch, for example, while shorter than the Scotch of the well-to-do classes, will be still taller than the individuals of the well-to-do classes in, for example, Spain or Italy, and much more so than those of Japan (1 m. 59). Stature is truly then a character of race, and a very persistent one.

So far I have spoken only of the height of men. That of women (as regards adult women of seventeen to twenty-three years of age, according to race) is always lower than the height of men, but by how much? Tentatively, Topinard gave the figure 12 centimetres as the general difference between the stature of the two sexes in all races. The data for the height of women being very scarce, I have only been able to bring together thirty-five series of measurements of women comprising each more than fifteen individuals, for comparison with series of measurements of men.

It follows from this slight inquiry that in twenty cases out of thirty-five, that is to say, almost two-thirds, the difference in height between the two sexes in any given population hardly varies more than from 7 to 13 centimetres (3 to 5 inches); fourteen times out of thirty-five it only varies from 11 to 13 centimetres (4.5 to 5 inches), so that the figure of 12 centimetres (5 inches) may be accepted as the average. Besides, the difference does not appear to change according to the average stature, more or less high, of the race: it is almost the same for the Tahitians and the Maricopas, who are tall, as it is for the Samoyeds and the Caribs, who are short.[37]

Thus, then, in a general way, the categories of statures--tall, short, etc.--for women will be comprised within the same limits already indicated for man, only reduced by 12 centimetres for each category. Thus, high statures for women will begin at 1 m. 58 instead of 1 m. 70; short statures under 1 m. 48 instead of 1 m. 60.

The stature of a living man is naturally higher than that of his skeleton, but what the difference is is not exactly known. It can hardly, however, exceed 2 or 3 centimetres, according to Topinard, Rollet, and Manouvrier.

By means of measurements of the long bones of the limbs (femur, humerus, etc.), the height of the skeleton of which they form part may be approximately calculated. For this purpose we make use of Rollet’s formula,[38] according to which the length of the femur must be multiplied by 3.66 for the height of man, and by 3.71 for the height of woman, or multiply the length of the humerus by 5.06 or by 5.22, according to sex. But this formula is only applicable to subjects whose stature is near the average, 1 m. 65. In the generality of cases we must substitute for it more exact calculations by the help of Manouvrier’s tables.[39] It is by this means that Rahon[40] has been able to determine approximately the height of the prehistoric populations of France, which will be dealt with in Chapter IX.

_Teguments: The Skin._--The human skin is essentially composed of two parts, the corium (Fig. 3, /D/) and a superficial epidermis; the latter is formed in its turn of two cellular layers, the horny layers (Fig. 3, _c.c._), the quite shallow cells of which are freely exposed to the air, and Malpighi’s layer situated beneath it, with granules of pigment in more or less quantity in its lower range of cells (Fig. 3, _c.p._). In certain places the epidermis is modified so as to form either a mucous membrane, as, for instance, on the lips, or a horny substance, sometimes transparent (as the cornea of the eye) and sometimes only translucent and more or less hard (the nails).

There is little to say about the differences in the nature and structure of the skin according to race. Its colouring, of which I shall speak later on (see _Pigmentation_), is more important. Attention has been drawn to the hardness of the corium and the velvety softness of the skin in the negro; the latter quality is probably due to the profusion and size of the sebaceous glands which accompany the hair. Bischoff has made an interesting observation on the relative rarity of the sweat glands (which are found in the thickness of the corium, Fig. 3, _g.su._) among the Fuegians,[41] but comparative studies on this subject have not been pursued in regard to other races. The disposition of the papilla ridges on the tips of the fingers, so well studied by Galton,[42] is of great interest as regards the identification of the individual; but from this fact alone, that it is a good characteristic of the individual, it loses all its value as a characteristic of race.

_Hair of the Head and Body._--The most important horny product of the skin, as regards the differentiation of races, is undoubtedly the hair of the head and body. The general structure and number of the hairs (about 260 to each square centimetre) hardly show any difference between race and race; on the other hand, the length of the hair of the head, the relation of this length in one sex to that in the other, the nature of the hair, its consistence, its transverse section, its form, its colour, vary much according to race.

The body hair has its origin in a layer of the epidermis, deeply imbedded in the corium as though it were in a little sac or follicle (Fig. 3, _fo._); from the bottom of this sac, and covering by its root a little papilla (Fig. 3, _pa._) filled with vessels designed to nourish it, each hair rises and pushes its way to the outside; it is always accompanied by a little muscle which can move it (Fig. 3, _m.r._), and by a sebaceous gland (Fig. 3, _g.s._) designed to lubricate it.

Four principal varieties of hair are usually distinguished in anthropology, according to their aspect and their nature--straight, wavy, frizzy, and woolly. It is easy to form a clear idea at first sight of the differences which are presented by these varieties, but the most careful examination shows that the differences are deeper, and can be pursued even into the microscopic structure of the hair.

_Straight and smooth hair_ (_droit_ or _lisse_ in French, _straff_ or _schlicht_ in German) is ordinarily rectilinear, and falls heavily in bands on the sides of the head; such is the hair of the Chinese, the Mongols, and of American Indians (Fig. 4). Straight hair is ordinarily stiff and coarse, but it is sometimes found tolerably fine; for example, among the western Finns. It is true that in this case it has a tendency to become wavy. _Wavy hair_ (_ondé_ in French, _wellig_ in German) forms a long curve or imperfect spiral from one end to the other (Figs. 5 and 6). It is called curly when it is rolled up at the extremity (Fig. 7). The whole head of hair when wavy produces a very pleasing effect; I will merely cite as examples certain fair Scotchwomen. The type is very widespread among Europeans, whether dark or fair. The frizzy type (_frisé_ in French, _lockig_ in German) is that in which the hair is rolled spirally, forming a succession of rings a centimetre or more in diameter (Fig. 8). Such is the hair of the Australians (Figs. 21 and 22), the Nubians, of certain Mulattos, etc. Lastly, the type of woolly hair (_crépu_ in French, _kraus_ in German) is characterised by spiral curves exceedingly narrow (from 1 millimetre to 9 millimetres as the maximum); the rings of the spiral are very near together, numerous, well rolled, and often catch hold of each other, forming tufts and balls, the whole result recalling in appearance sheep’s wool (Fig. 9). The type admits of two varieties. When the hair is relatively long and the spirals sufficiently broad, the whole head looks like a continuous fleece, as with certain Melanesians (Fig. 153), or the majority of Negroes (Figs. 9 and 47). In his classification of the human races, Haeckel[43] has taken this type as characteristic of the group of _eriocomes_. But when the hair is short, consisting of very small spirals, it has a tendency, when tangled, to form little tufts, the dimensions of which vary from the size of a pea to that of a pepper-corn; these tufts are separated by spaces which appear bald (pepper-corn hair). This type (called _lophocome_ by Haeckel) is very widespread among Hottentots and Bushmen, but the majority of Negroes have it in their infancy, and even at adult age, especially towards the temples, on the forehead--briefly, in all the places where the hair remains very short (Fig. 9). We must not think that the disposition of which I have just spoken is due to the hair being stuck in the skin of the head like the bristles of a brush, for the mode of insertion is the same in all races, with Bushmen as with Europeans or Mongols. At the most it may be noted that the rows of hair in Negroes are more irregular, and are closer together in certain places, leaving in other rows intervals between them of two or three millimetres. Only, as a consequence of the shortness and the excessive twisting, the hair gets entangled and the spirals catch hold of each other, so forming glomerules or tufts.

Does there exist any difference of form between straight, waved, frizzy, or woolly hair? The microscopical examination of transverse sections of the hair allows us to reply affirmatively to this question. This examination, already applied to the hair in 1822 by Heusinger, then successively by Blower (of Philadelphia), Kölliker, Pruner-Bey, Latteux, and Waldeyer,[44] has yielded results which have been vigorously discussed, and are still debatable if we cling to the individual and absolute figures, comparing sections made according to defective methods, or carried out on different levels of the hair. But if we calculate the _index_--that is to say, the relation of the breadth to the length (= 100) of the section (and that in a great number of individual cases)--we obtain satisfactory results, as Topinard and Ranke[45] have shown in general, as also Baelz in the case of the Japanese, and Montano in the case of the races of the Malay Archipelago.[46]

If we consider a great number of microscopical sections, all obtained from the same level of the hair, we note that straight hair gives a circular section, whilst woolly hair gives one in the form of a lengthened ellipse. This ellipse is less extended, a little more filled out, in the sections of wavy hair. If the major axis of the ellipse be supposed to equal 100, the minor axis will be represented by figures varying from 40 to 50 for the woolly hair of the Bushmen and the Hottentots, from 50 to 60 for that of the Negroes, while the straight hair of the Eskimo will have this axis = 77, that of the Thibetans = 80, that of the Japanese = 85, etc. The hair of Europeans represents an elliptical section in which the major axis being = 100, the minor axis will be represented by figures varying from 62 to 72 (Topinard). It can be said to-day with certainty, after the work of Unna,[47] that the woolly hair of Negroes rolls up into a compact spiral precisely because of the flattened shape of this elliptical section, and of the special form of the follicle and papilla. In fact, in the Negro the follicle, instead of being straight, as in the European (Fig. 3, A), is curved inward in the form of a sabre, or even of the arc of a quarter of a circle (Fig. 3, B); further, the papilla is flattened instead of being round. One would say that the hair has encountered in its development so much resistance on the part of the dermis (which is so hard, in fact, among the Negroes), that it would be twisted, as it were, from the first. Emerging from an incurvated mould, it can only continue to roll up outside, given especially its flattened shape; it rolls up into a spiral, the plane of which, at the beginning, is perpendicular to the surface of the skin.[48] As to the thickness of the hair, it appears that in general it is greater in straight hair than in woolly; however, the hair of the western Finns is straight and fine at the same time.

A certain correlation appears to exist between the nature of the hair and its absolute and relative length. Thus straight hair is at the same time the longest--Chinese, Americans, Indians (Fig. 4), while woolly hair is shortest, from 5 to 15 centimetres (Fig. 9); wavy hair occupies an intermediate position. Moreover, the difference between the length of the hair of men and women is almost inappreciable in the two extreme divisions. In certain straight-haired races the hair of the head is as long with men as with women; one need but to call to mind the plaits of the Chinese, or the beautiful heads of hair of the Red Indians, which may attain in certain cases a length of even two metres (Catlin). In frizzy-haired races the hair of the head, on the contrary, is equally short in the two sexes; the hair of the head of women among the Bushmen, Hottentots, and even Negroes, is not appreciably longer than among the men. It is only in the categories of wavy and in part of frizzy hair, that the differences are appreciable. With European men the length of the hair rarely exceeds 30 or 40 centimetres, while with the women it averages 65 to 75 centimetres, and may attain in exceptional cases to 2 metres (as in the case of an Englishwoman, according to Dr. D. Watson).

Another fact to be noted is that the general development of the pilose system on the face, as on the rest of the body, seems also to be in relation to the nature of the hair of the head.

Straight-haired races are ordinarily very glabrous, the men have hardly a rudimentary tuft of beard--American Indians (Fig. 4), Mongols (Fig. 20), Malays; while in the wavy or frizzy-haired races, the development of the pilose system is considerable--Australians, Dravidians, Iranians (Fig. 22), Ainus (Fig. 117), etc. The woolly-haired races are not, however, included in this rule; glabrous types (Bushmen, western Negroes) are found side by side with rather hairy types (Melanesians, Akka, Ashanti). There appears to be a certain likeness between the abundance of hair on the head and on the body. Thus, according to Hilgendorf, the Japanese who are glabrous have from 252 to 286 hairs to each square centimetre on the head, whilst the hairy Ainus have only 214. Negroes and white men do not appear, however, to present the same differences (Gould). Even baldness results largely from the nature of the hair. According to Gould, baldness is ten times less frequent among Negroes than among Whites, between 33 years and 44 years, and thirty times less so between 21 and 32. Among Mulattos it is more frequent than among the Negroes, but less than among Whites. Lastly, among Red Indians it seems to be still more rare than among Negroes. White hair follows almost the same rule.[49]

In the mass, the human races may be divided according to the character of their hair as follows:--

_Woolly Hair._--Bushmen, Negro, and Melanesian races.

_Frizzy Hair._--Australian, Ethiopian, Beja, Fulbé, etc., and Dravidian.

_Wavy Hair._--The white races of Europe, of Northern Africa, and Asia (Melanochroi or the dark-complexioned Whites, and Xanthochroi or pale Whites).

_Fine, straight, or lightly-waved Hair._--Turco-Tatars, Finns, Ainus, and Indonesians (Dyaks, Nagas, etc.); lastly,

_Coarse straight Hair._--Mongolians and American races, with some exceptions. It must be noted that, in the manifold blendings of races, characteristics of the hair amalgamate. Thus the half-breeds between Negroes and American Indians have, most frequently, the hair frizzy or wavy. But there are also frequent reversions to the primitive type, almost always, however, a little weakened.

There are no races of _hairy men_. Everything that has been said of different “hairy savages” in the interior of Africa or Indo-China resolves itself into the presence of a light down (probably the remains of embryonic lanugo) in the case of the Akkas of the Upper Nile, or to the fortuitous existence of one or two families of hairy men and women from Burma exhibited some years ago in Europe and America. Other “phenomena” have been shown, like the famous Julia Pastrana or the “Dog-men” of Russia. All these subjects are only particular cases of atavism, or of a reversion to the probable primordial condition of man or of his precursor at the period when he was as hairy as, for instance, the anthropoid apes of to-day; they are by no means the representatives of a hairy race.

The beard is, as we know, one of the sexual characteristics of man, although many fine ones are found among certain women, notably among the Europeans of the south, and especially among Spanish women. The more hairy the body, the thicker as a rule is the beard. In the glabrous races (Mongols, Malays, Americans) a few straggling hairs are all that can be seen at the corners of the mouth and on the chin (Figs. 20 and 168); in the very hairy races, like the Ainus, the Iranians, certain Semites, the Todas, the Australians, the Melanesians, the beard is strong and abundant on the lips, the chin, and the cheeks, where it reaches sometimes to the cheek-bones (Fig. 22); in the Negro and Bushmen races neither the moustache nor the beard can attain to great dimensions, because of the curly nature of the hair (Figs. 140 and 143). The eyelashes and the eyebrows are likewise much developed in races having an abundant beard, and this is the case in both sexes; we have only to recall the thick and joined eyebrows of the Persian women. On the other hand, among the Mongolians we note the small development of the eyelashes in relation to the particular structure of their eye (see p. 77).

_Pigmentation._--The distribution of the pigment which gives the colouring to the skin, to the hair, to the iris, varies much according to race, and forms, along with the nature of the hair, a good distinctive characteristic. As I have already stated above, the pigment is accumulated principally in the lowest layers of the rete Malpighii (Fig. 3, _c.p._), but it is also met with in small quantities in the horny layer, and even in the dermis.[50] According to race, the microscopic granules of pigment of a uniform brown are very unequally distributed around the nuclei of the cells, to which they give the most varied tones from pale yellow to dark brown, almost black. As the pigment exists in all races, and in all parts of the body, it is to its more or less plentiful accumulation in the cells that the colouring of the skin and its derivatives is due. Further, there must be added, for certain races at least, the combination with the tint of the blood of the vessels, as seen through the skin.

Every one knows that our white races become tanned in the sun; the cause of this is the pigment, developing abundantly and being deposited in the cells under the combined action of air, heat, and light; the congestion of the vessels has also something to do with it. In the same way, persons living a long time in dense forests or in dark though airy places end by becoming paler, in consequence of the loss of the pigment, but recover colour immediately on re-exposure to the sun. But the modifications produced by the action of air and sun vary even among Europeans according to the colouring peculiar to their race.

Thus among the fair races of Northern Europe the skin, burnt by the sun, becomes red, as if swollen; on the other hand, among the dark-coloured peoples of the Mediterranean, it takes a bronze tint. There are thus between these two races notable differences, if not in the chemical nature of the pigment, which is scarcely likely, at least in regard to its quantity. It is the same with other races generally, and ten principal shades of colour at least can easily be distinguished. In the first place, among Whites, three shades: 1st, pale white; 2nd, florid, or rosy, peculiar to the Scandinavians, English, Dutch, etc.; 3rd, brownish-white, peculiar to Spaniards, Italians, etc. In the races called Yellow, three varieties of colour can likewise be distinguished: 4th, yellowish-white, a sickly hue the colour of wheat, as, for example, among certain Chinese; 5th, olive-yellow, the colour of new portmanteau leather, as among the majority of South American Indians, Polynesians, and Indonesians; 6th, dark yellow-brown, dark olive, or the colour of dead leaves, as among certain Americans, Malays, etc. In the dark-skinned races, four shades at least must be distinguished: 7th, red, copper-coloured, as, for example, among the Bejas, Niam-Niam, Fulbé; 8th, reddish-brown, chocolate, as among the Dravidians, the Australians, certain Negroes and Melanesians; lastly, 9th, sooty black, and 10th, coal-black, for example, among the different Negro populations.

In order to avoid an arbitrary designation of colours, anthropologists make use of chromatic tables, in which examples of the chief variations of colour are marked by numbers. The best table, almost universally adopted, is that of Broca, of thirty-four shades.[51] The Anthropological Institute of Great Britain and Ireland has published a very practical and simplified edition of it,[52] which contains only the ten numbers of principal shades proposed by Topinard, namely, those I have just enumerated.

The pigment is not uniformly distributed, as I have said, through the whole body, and this is so with the Whites as well as with the darkest races. In all of them the parts of the body most deeply coloured are the nape of the neck, the back (as with animals), the back part of the limbs, the arm-pits, the scrotum, and the breasts; the belly (as with animals), the insides of the hands, the soles of the feet, are among the most lightly coloured. The parts covered by garments are less coloured among white and yellow races than the parts uncovered; it is affirmed, but without reliable proofs, that the contrary takes place among the dark and black populations.

In the iris, the pigmentation assumes a particular character. As we know, this perforated diaphragm of the eye is composed, histologically, of three layers: an anterior epithelial one; a middle one, the “stroma,” with muscular fibres, designed to enlarge or reduce the pupil; and lastly, a posterior layer, called the pigmental layer. But it must not be thought that this layer is the only repository of the pigment of the iris. It is also found accumulated in the thickness of the stroma, and between the muscular fibres. In both places the granules of the pigment have the same brown colour as in the rest of the body, but the pigment of the posterior or pigmental layer is only seen through the stroma and appears blue or grey, more or less light or dark, according to its quantity, just as the black veins of the blood appear to us blue through the skin. On the contrary, the pigment accumulated in the stroma or between the muscular fibres of the iris exhibits its natural yellow, brown, or almost black colouring, according to the quantity of it, under the form of a trail radiating very clearly from the pupil towards the periphery of the eye occupying one-third, two-thirds, or even the whole of the iris.

Seen at a certain distance, irises without pigment in their stroma appear blue or grey; those having the whole or the greater part of this charged with pigment appear brown, dark brown, or almost black, according to the quantity of this pigment. But irises having a blue or grey foundation strewn with yellowish spots of pigment appear green, yellow, yellowish-grey, greenish-grey, etc.

There are thus distinguishable only three fundamental shades of the iris, or, as is commonly said, of the colour of the eyes: light (blue or grey); dark (bright or dull brown or black); and intermediate shades (green, yellow, yellowish-grey, greenish-grey, etc.). This classification is entirely based on the quantity of pigment in the iris.

It is only in fair European races that blue or grey eyes are found, perhaps also in the Turco-Ugrian races; light-brown eyes are met with among some Mongolians. In all the other populations of the earth the eyes are dark-brown or black. It is the same with the colouring of the hair. It varies appreciably among the wavy-haired races, much less so among the straight and frizzy-haired races, and remains always black among the woolly-haired races. Four principal shades can be distinguished in the hair--black, dark-brown, chestnut-brown (_châtain_ in French), and fair. In this last shade, golden must be separated from flaxen and dull grey-reddish hair. Red hair of all shades is only an individual anomaly, accompanied besides, almost always, by freckles (_ephelides_) on the face and neck. There are no red-haired races, but light and chestnut hair may have a reddish reflection in it. Red hair is very common in countries where several white-coloured races (brown or fair) are intermixed. In these crossed races there are found heads of hair of all colours--black, brown, fair, reddish-brown, dull-grey, chestnut, etc. This is the natural result of the intermixture of blood. Among a dark-haired people, which has remained free from intermixture, or has only intermingled with dark-haired races, an exceptional red-haired individual constitutes a pathological condition, called “erythrism” by Broca. Erythrism can only manifest itself in certain races; at least, until now no example has been instanced among the Negroes; on the other hand, erythrism is somewhat common among the Jews of Europe, and among such Jews it is most frequently associated with frizzy hair.[53]

The colouring of the hair depends not only on the pigment, but on the more or less quantity of air in the medulla of the hair, which blends the white and grey tones with the general tint given by the pigment. In the air, the hair fades, becomes less highly coloured, duller. Certain acids of the perspiration render the hair reddish-brown, as for instance, under the arm-pit.

At birth pigment is found in the body in less quantity than in the adult state. Every one knows that the hair of children, often light-coloured at birth and in early years, becomes darker as they grow up. Almost all our European children are born with blue eyes, and the pigment only begins to increase in the iris, transforming the eyes into grey, brown, or black at the end of some weeks, or even months after birth. New-born Chinese, Botocudos, Malays, Kalmuks, are much less yellow than the adults of these people, and, lastly, Negroes at birth are of a reddish-chocolate or copper colour, which only becomes darker at the end of three or four days, beginning in certain places, such as the nape, nipples, scrotum, etc.

The presence of temporary spots of pigment noticed among new-born Japanese by Grimm and Baelz, among the Chinese by Matignon, among the Tagals of the Philippines by Collignon, and among the Eskimo by Sören-Hansen,[54] is more puzzling. These are somewhat large blue, grey, or black spots, situated in the sacro-lumbar region and on the buttocks, which disappear about the age of two, three, or five years. The existence of these spots, like that of the ephelides in the European child, would prove rather the migration of pigmental granules to the places selected than a general increase of them. In most races women appear to have clearer skin than men; in that respect, as in many other characters, they have a closer resemblance to children. It is thought by some that the hair of women is lighter than that of men among European races.[55]

Among Negroes the pigment is visible not only on the skin, in the hair, and the iris, but also in the sclerotic, in the mucous membrane of the lips, the mouth, the genital organs, etc.; the internal organs, even, are not free from it; the suprarenal capsules, the mesentery, the liver, the spleen, are often coloured with black spots of pigment, and even the brain contains numerous pigmented points in its envelopes and in its grey matter. Such an abundance of pigment would become a danger to the White, as is proved by certain diseases, melanism, for example, in which the pigment especially invades the viscera, or Addison’s disease, in which, on the contrary, there is an over-production of pigment in the skin and the mucous membranes.

The total absence of pigment, which may occur with the Negro as with the White, is termed albinism. This may be accompanied, if complete (that is to say, when, besides the white skin and hair, the iris is also deprived of pigment, and appears red), by somewhat serious affections of the eyesight. But, in every respect, albinos are weakly, and probably not fertile amongst themselves.

In considering from all points of view the nature of hair and pigmentation in general, we cannot help noticing a certain correlation between these two characters. In fact, to the white colouring of the skin corresponds, in a general fashion, wavy hair, the colouring of which varies often in accord with the colour of the eyes and the shades of the skin (white, fair, brown races); to the yellow colouring corresponds straight, smooth hair; to the reddish-brown skin, frizzy hair; and to the black, woolly hair.