the power of moving the various limbs, and securing the activity of the whole frame. These muscles are adapted to the special need of the system; and although, in the power these muscles possess over the movement of the body, man may not appear to have so great advantages as many animals in running, climbing, leaping, and flying, yet in his intelligence he possesses a power of controlling these muscles: this enables him fearlessly to contend with the strongest animals, and to subdue them to his own wants and requirements. The structure and position of the heart, and the distribution of the great blood-vessels, have all reference to the erect posture in man. This is seen remarkably in the form of the blood-vessels which enter the head, and which are so constructed as to allow of a free passage of blood to the brain. It is on this account that a long-continued stooping posture is so injurious to man, and frequently ends in an attack of apoplexy, arising from the too great facility with which the blood in this position enters the head. The great nervous mass called the brain is larger in man, in those portions devoted to the exercise of the functions of the intellect, and the convolutions are deeper and larger, than in any of the lower animals. This large brain is connected with the development of those higher mental powers which, after all, constitute the most remarkable distinction between man and the brutes. As a power under the direct control of his intelligence, voice is one of the distinguishing characters of man. Although many animals may have the power of producing sounds through their larynx, and these may be indications to others of certain feelings, or even mental conditions, there is nothing corresponding with human language amongst them. At any rate, they have no power of indicating by signs these sounds, and thus of handing down from generation to generation the knowledge they have previously acquired. With this power in man we find remarkably connected his capacity for progress. He accumulates his knowledge, and each generation, as it passes away, leaves the world richer in facts, thoughts, and ideas than it found it: thus the habits of man become changed as successive generations of his race pass away. But this is not the case with of the lower tribes of animals; they are probably the same to-day as they were when their first progenitors appeared upon the earth. The dog, the pig, the monkey, the elephant, are not conscious of a history, and we have every reason to believe that they are guided by the same instincts, and ruled by the same laws, now as they ever have been.

any

The slow growth of man, and the great age he attains, in comparison with his size, are both points in his economy which are remarkably characteristic of his race. He is not able to procure food for himself until he is at least more than three years old; but long after this period he requires the constant attention of his parents. This long dependence of the offspring upon the care of its parents gives rise to those social relations which last through life, and which afford so much happiness to man, but little of which exists amongst any of the brute creation. As far as can be ascertained, man lives much longer than any of the kinds of animals with which we are at present acquainted; for, although his average period of existence does not exceed between thirty and forty years, and many instances are known of animals living so long, yet there is abundant evidence to prove that man lives sometimes to the age of a hundred years, and that, were his attention more directed to the removal of the causes of death, and the

abolition of the practice of war, he might extend the average of his life to sixty or seventy years.

We shall not enter here into any detail of the contrast between the mental powers of man and the lower animals, but merely refer to man's capacity of reasoning from effect to cause, and his powers of proceeding to recognize, in all that exists around him, a great First Cause-omnipotent, omniscient, and omnipresent-whom he worships as his Creator, from whom he has proceeded, and to whom he hopes in spirit to return-for the most convincing argument of man's essential distinction from the rest of the animal kingdom, and his dignified position in the world in which he is placed.

CHAPTER IV.

ON THE SKIN, HAIR, EYES, AND BONES OF THE SKULL, AS LIABLE TO VARIETY IN THE DIFFERENT RACES OF MEN.

In the preceding chapters we have seen that however numerous may be the points of agreement between man and the lower animals, he is clearly distinguished from them by characters that are unmistakable in all circumstances in which he may be found. Yet numerous as are the features which distinguish man from the highest monkeys, at first sight they do not appear to be more decided than the differences which exist between the various races of men. How many are the characters, for instance, by which an individual of the black races of Africa is distinguished from one of the white races of Europe! The black skin, the curly hair, the retreating forehead, the projecting jaw, the whole frame of the one-how strongly it contrasts with the fair complexion, the long hair, the prominent brain, the retreating jaw of the other! Yet, when we come to examine accurately the differences between the various races of men, we shall find that every recorded dissimilarity may be comprised within limits very much narrower than any that distinguish man from the lower animals. Thus, although we find considerable variety in the form and length of the foot in man, we never find anything approaching the difference that exists between man and the orang-outang. We might thus take up every individual character of difference between man and man, and show that whatever may be its extent amongst the human races, it is much greater between man and the lower animals. There is, in fact, no one physical feature characteristic of the degradation of the lowest races of men in which man does not more closely resemble the highest specimens of his race than he does the most highly developed forms of the mammalia.

Let us, then, now proceed to examine some of these differences in the appearance and structure of man, and the agencies to which they have been ascribed as causes.

One of the most obvious, although perhaps not the most constant, differences between the races of men is the colour of the skin. This varies in all possible shades amongst the different varieties of mankind-from the fairest blondes of the European races to the deep ebony of those of Africa. All the observed varieties of shade appear to depend on the presence or absence of a peculiar set of cells in the skin. In order, however, that this may be un

derstood, we must speak a little in detail of the structure of the skin. Although apparently very simple in its structure, the skin is nevertheless a very compound organ; and when we consider the important functions it performs, and its relations to the rest of the body, we shall not be surprised at this. It is not only the seat of common sensation, but, by means of the vapour it constantly emits in the form of perspiration, it becomes the great regulator of the heat of the body. For these purposes it is supplied with nerves, blood-vessels, and glands.

On examining a portion of skin from the palm of the hand or sole of the foot, from without inwards, we find that externally it presents a number of furrows, or lines, which are tolerably constant in particular parts of the body. On the elevations between these lines are seen a number of minute openings (Fig. 4, b b), which are the terminations of the glands (dd d) that yield perspiration. These furrows and pores are in the upper layer of the skin, called epidermis (e c), or scarf skin. This membrane is in some parts very thin, not exceeding 4th part of an inch in thickness, whilst in others, as in the sole of the foot and the palm of the hand, it is at least th of an inch thick. It is this portion of the skin which is elevated when what are called blisters are formed. When examined with the microscope, it is found to consist of minute flat cells, which have been formed below, and are gradually thrust upwards. Below this, but for the most part continuous with it, is another series of layers of cells (c c), and which were called, at one time, by the name rete mucosum, as it was supposed to be a separate membrane. The real nature of these layers of cells is, that they are all secreted on the surface of a tough fibro-vascular membrane, called the corium, or true skin (h h). The cells of the lower layer, called the rete mucosum, are softer and much less compressed than those which form the epidermis. It is amongst these cells that a certain set are found which are termed pigment cells. When separated they have a very distinct form, and are easily distinguished from all the other cells by their dark colour. This dark colour is dependent on the presence, in the cells, of a number of flat, rounded, or oval granules, not more than the both of an inch in diameter. Now, it is found that these cells are always present in the skin of the darkcoloured races of mankind, and also in those parts of the skin of fair races which are of a dark colour. It is, then, to the presence or absence of these cells that the skin is indebted for its white or black colour. Where they are very abundant, the skin has a black colour; and in proportion to their diminution are the various shades called red, yellow, brown, brunette, which are observed amongst the various races of mankind.

Fig. 4.*

It has always been a question of interest to the ethnologist as to whether

Diagram of the structure of the skin :-a Epidermis. bb Pores. cc Layers of epidermis and rete mucosum. or true skin. d d d Bulbs of sudoriferous glands opening in the pores, bb. ef Inhalant vessels. g g Papilla of the skin. h h Corium,

the presence of these pigment cells could be traced to any external influence. As far as inquiries have extended at the present day, it appears that the tendency to form these cells is dependent in some measure on the exposure of the skin to light. As a rule, it is found that where the sun's rays are most direct-in other words, where there is the greatest amount of lightthe skins of human beings exhibit the greatest tendency to develope these cells. The darkest-skinned races are inhabitants of the tropics.

This is not a mere concidence; for when the laws of light are studied, we find that its influence on organic beings is such that we are led to the conclusion that light is capable of affecting the organic constitution of bodies which are exposed to its action. In the vegetable world the most brilliant colours, the most powerful scents, and the most poisonous secretions are all produced under the agency of intense light. That exposure to light has an influence in the development of the colour of the skin is also supported by the fact that the children of all dark races are born fair, and do not become black till they have been exposed to the light of the sun.

At the same time that there exists this evidence to support generally the position that the light of the sun developes the dark colour of the skin, there are many facts to show that the growth of these cells at all is under the control of circumstances over which this external agent has no influence. Thus occasionally there are born amongst the black races individuals in whom these pigment cells are not developed, and they remain white through-out their lives. In certain parts of the body these cells are found in fair races, as in the hair and the eyes, but even amongst these races such individuals are born. They are known by the name of Albinos, and are remarkable for white hair, and the absence of pigment cells in the eyes, which gives the interior of these organs a red colour, from the blood-vessels reflecting the colour of the blood. This occurrence is also not unfrequent amongst domesticated animals. From these facts we must regard the dark colour of the skin as due to the constant action of light upon a system in which there is a natural tendency to develope the pigment cells.

Although colour so remarkably and evidently distinguishes human beings from one another, yet we find that throughout nature it is one of the least permanent marks of distinction between one animal and another, and even one plant and another. It will be well to bear this in mind, for when we come to speak of the great question as to whether there is more than one species of man—whether God has created two or more kinds of men, with different characters, habits, and destinies-we shall find it important to form a just estimate of the individual characters which distinguish man.

Closely connected with the colour of the skin are the appearance and colour of the hair. With the dark black skin the hair is black, crisp, and woolly; whilst with the red or yellow colour of the skin the hair is seldom woolly, or even curly, but is black, lank, and straight. On the other hand, with the fair skin the hair is never woolly, and frequently of a light colour.

The hair is an appendage of the skin, and is formed in little depressions of this organ, which are called hair follicles (Fig. 5, a). These follicles extend to various depths of the corium, and are always lined with cells of the same nature as those found in the epidermis. It is through the secretions of these cells that the hair (b) is first formed in the follicle, and then gradually thrust out from below, upwards, so that what is called the growth of the hair is secured. The hair is not a living part of the body; it has no bloodvessels or nerves, and is similar in its organic nature to the epidermis itself.

On examining a hair under the microscope, it is found to consist of three parts-first, of a coating of finely-imbricated scales, the projecting edges of which give to the hair a serrated appearance; secondly, a fibrous substance, made up of straight, rigid, longitudinal fibres, flattened and pointed at each end, and broad in the middle. These fibres are the result of the cells of which we have before spoken, formed in the interior of the follicle, and which, as they pass upward to form the shaft of the hair, are submitted to a considerable amount of compression in the upper part of the follicle. It is

d

in these fibres of the hair that the colouring matter exists which gives the peculiar colour to the hair. This depends on the presence of the same kind of cells in the follicle which we before found giving colour to the skin. When the pigment cells are numerous in the hair follicle, the hair is black; and it is of varying shades of lightness according as these cells are d absent. It is the perfect absence of these cells that gives to the hairs of the Albino and the aged their silvery white appearance. The same cause produces the colour of the hairs of the skins of various animals. The white hairs are destitute of the pigment cells, whilst in coloured hairs they are present in various proportions. In some hairs there is a third portion, called the medulla, or pith. It consists of little masses of granular particles and corpuscles, which form a dark line in the middle of the hair. It is not, however, an essential part of the hair, as it is found very frequently absent. In the skin are a number of small glands, whose function it is to secrete oily matter, which is thrown out on the surface, and in most cases it is found that these sebaceous glands open into the hair follicles (Fig. 5, d d). Their function is probably to facilitate the projection of the hair from its follicle, as well as to supply it with the oily matter which is necessary to its healthy condition.

Fig. 5.*

2

From these facts we may arrive at the obvious conclusion that the hair is influenced by the same external agents as the skin; and we have this confirmed by the occurrence of the particular kinds and colour of hair with special conditions of the skin. At the same time we see here again that conditions of the hair come on independently of the influence of heat and light. The children of fair parents are sometimes born with black curly and almost woolly hair. In animals -for instance, the sheep-where the hair is normally white, we constantly find the occasional occurrence of a lamb that is perfectly black. Another instance of the colour of the

Fig. 6.†

hair being independent of climatal and hereditary tendencies is seen in

*Diagram of a hair follicle and hair. a Follicle. b Hair. c Epidermis. dd Sebaceous glands, opening into hair follicle.

+ Caucasian eye.