University of Virginia Library

Chapter 15
The Law of Evolution continued

§116. Changes great in their amounts and various in their kinds, which accompany those dealt with in the last chapter, have thus far been ignored; or, if tacitly recognized, have not been avowedly recognized. Integration of each whole has been described as taking place simultaneously with integration of each of the parts into which it divides itself. But how comes the whole to divide itself into parts? This is a transformation more remarkable than the passage of the whole from an incoherent to a coherent state; and a formula which says nothing about it omits more than half the phenomena to be formulated.

This larger half of the phenomena we have now to treat. Here we are concerned with those. secondary re-distributions of matter and motion which go on along with the primary re-distribution. We saw that while in very incoherent aggregates, secondary redistributions produce but evanescent results, in aggregates that reach and maintain a certain medium state, neither very incoherent nor very coherent, results of a relatively persistent kind are produced — structural modifications. And our next inquiry must be — What is the universal expression for these structural modifications?

Already an implied answer has been given by the title — Compound Evolution. Already in distinguishing as simple Evolution, that integration of matter and dissipation of motion which is unaccompanied by secondary re-distributions, it has been tacitly asserted that where secondary re-distributions occur complexity arises; the mass, instead of remaining uniform, must have become multiform. The proposition is an identical one. To say that along with the primary re-distribution there go secondary re-distributions, is to say that along with the change from a diffused to a concentrated state, there goes a change from a homogeneous state to a heterogeneous state. The components of the mass while becoming integrated have also become differentiated.

This, then, is the second aspect under which we have to study Evolution. In the last chapter we contemplated existences of all orders as displaying progressive integration. In this chapter we have to contemplate them as displaying progressive differentiation.

§117. A growing variety of structure throughout our Sidereal System, is implied by the contrasts which indicate aggregation throughout it. We have nebulae that are diffused and irregular, and others that are spiral, annular, spherical. We have groups of stars the members of which are scattered, and groups concentrated in all degrees down to closely-packed globular clusters. We have these groups differing in the numbers of their members, from those containing several thousand stars to those containing but two. Among individual stars there are great contrasts, real as well as apparent, of size; and from their unlike colours, as well as from their unlike spectra, many contrasts among their physical states are inferable. Beyond which heterogeneities in detail there are general heterogeneities. Nebulae are numerous in some regions of the heavens, while in others there are only stars. Here the celestial spaces are almost void of objects, and there we see dense aggregations, nebular and stellar together.

The matter of our Solar System during its integration has become more multiform. The concentrating gaseous spheroid, dissipating its contained molecular motion, acquiring more marked unlikeness of density and temperature between interior and exterior, and leaving behind from time to time annular portions of its mass, underwent differentiations which increased in number and degree, until there was evolved the existing organized group of Sun, planets, and satellites. The heterogeneity of this is variously displayed. There are the immense contrasts between the Sun and the planets, in bulk and in weight; as well as the subordinate contrasts of like kind between one planet and another, and between the planets and their satellites. There is the further contrast between the Sun and the planets in respect of temperature; and there are indications that the planets differ from one another in their proper heats, as well as in the heats which they receive from the sun. Bearing in mind that they also differ in the inclinations of their orbits, the inclinations of their axes, in their specific gravities, and in their physical constitutions, we see how decided is the complexity wrought in the Solar System by those secondary redistributions which have accompanied the primary redistribution.

§118. Passing from illustrations, which, as assuming the nebular hypothesis, must be classed as more or less hypothetical, let us descend to evidence less open to objection.

It is now agreed among geologists that the Earth was once a molten mass. Originally, then, it was comparatively homogeneous in consistence; and, because of the circulation which takes place in heated liquids, must have been comparatively homogeneous in temperature. It must, too, have been surrounded by an atmosphere consisting partly of the elements of air and water, and partly of those various other elements which assume gaseous forms at high temperatures. Cooling by radiation must, after an immense time, have resulted in differentiating the portion most able to part with its heat; namely, the surface. A further cooling, leading to deposition of all solidifiable elements contained in the atmosphere, and then to precipitation of the water, leaving behind the air, must thus have caused a second marked differentiation; and as the condensation commenced on the coolest parts of the surface-namely, about the poles there must so have resulted the first geographical distinctions.

To these illustrations of growing heterogeneity, inferred from known laws, Geology adds an extensive series that have been inductively established. The Earth' s structure has been age after age further complicated by additions to the strata which form its crust; and it has been age after age made more various by the increasing composition of these strata; the more recent of which, formed from the detritus of the more ancient, are many of them rendered highly complex by the mixtures of materials they contain. This heterogeneity has been vastly augmented by the actions of the Earth's nucleus on its envelope; whence have resulted not only many kinds of igneous rocks, but the tilting up of sedimentary strata at all angles, the formation of faults and metallic veins, the production of endless dislocations and irregularities. Again, geologists teach us that the Earth's surface has been growing more varied in elevation — that the most ancient mountain-systems are the smallest, and the Andes and Himalayas the most modern; while, in all probability, there have been corresponding changes in the bed of the ocean. As a consequence of this ceaseless multiplication of differences, we now find that no considerable portion of the Earth's exposed surface, is like any other portion, either in contour, in geologic structure, or in chemical composition.

There has been simultaneously going on a gradual differentiation of climates. As fast as the Earth cooled and its crust solidified, inequalities of temperature arose between those parts of its surface most exposed to the Sun and those less exposed; and thus in time there came to be the marked contrasts between regions of perpetual ice and snow regions where winter and summer alternately reign for periods varying according to the latitude, and regions where summer follows summer with scarcely an appreciable variation. Meanwhile, elevations and subsidences, recurring here and there over the Earth's crust, and producing irregular distributions of land and sea, have entailed various modifications of climate beyond those dependent on latitude; while a yet further series of such modifications has been caused by increased differences of height in the surface, which in sundry places have brought arctic, temperate, and tropical climates to within a few miles of one another. The general results are, that every extensive region has its own meteorological conditions, and that every locality in each region differs more or less from others in those conditions: as also in its structure, its contour, its soil.

Thus between our existing Earth, the phenomena of whose varied crust neither geographers, geologists, mineralogists, nor meteorologists have yet enumerated, and the molten globe out of which it was evolved, the contrast in heterogeneity is striking.

§119. The clearest, most numerous, and most varied illustrations of the advance in multiformity that accompanies the advance in integration, are furnished by living bodies. Distinguished as these are by the great quantity of their contained molecular motion, they exhibit in an extreme degree the secondary re-distributions which contained motion facilitates. The history of every plant and every animal, while it is a history of increasing bulk, is also a history of simultaneously-increasing differences among the parts. This transformation has several aspects.

The chemical composition which is almost uniform throughout the substance of a germ, vegetal or animal, gradually ceases to be uniform. The several compounds, nitrogenous and non-nitrogenous, which were homogeneously mixed, segregate by degrees, become diversely proportioned in diverse places, and produce new compounds by transformation or modification. In plants the albuminous and amylaceous matters which form the substance of the embryo, give origin here to a preponderance of chlorophyll and there to a preponderance of cellulose. Over the parts that are becoming leaf-surfaces, certain of the materials are metamorphosed into wax. In this place starch passes into one of its isomeric equivalents, sugar; and in that place into another of its isomeric equivalents, gum. By secondary change some of the cellulose is modified into wood; while some of it is modified into the allied substance which, in large masses, we call cork. And the more numerous compounds thus arising, initiate further unlikenesses by mingling in unlike ratios. The yelk, or essential part of an animal-ovum, having components which are at first evenly diffused among one another, chemically transforms itself in like manner. Its protein, its fats, its salts, become dissimilarly proportioned in different localities; and multiplication of isomeric forms leads to further mixtures and combinations that constitute minor distinctions of parts. Here a mass darkening by accumulation of hematine, presently dissolves into blood. There fatty and albuminous matters uniting, compose nerve-tissue. At this spot the nitrogenous substance takes on the character of cartilage; and at that, calcareous salts, gathering together in the cartilage, lay the foundation of bone. All these chemical differentiations slowly become more marked and more numerous.

Simultaneously arise contrasts of minute structure. Distinct tissues take the place of matter that had previously no recognizable unlikenesses of parts; and each of the tissues first produced undergoes secondary modifications, causing sub-species of tissues. The granular protoplasm of the vegetal germ, equally with that which forms the unfolding point of every shoot, gives origin to cells that are at first alike. Some of these, as they grow, flatten and unite by their edges to form the outer layer. Others lengthen, and at the same time join together in bundles to lay the foundation of woody-fibre. Before much elongating, certain of these cells show a breaking-up of the lining deposit, which, during elongation, becomes a spiral thread, or a reticulated framework, or a series of rings; and by the longitudinal union of cells so lined, vessels are formed. Meanwhile each of these differentiated tissues is re-differentiated: instance that constituting the essential part of a leaf, the upper stratum of which is composed of chlorophyll-cells remaining closely packed, while the lower stratum becomes spongy. Of the same general character are the transformations undergone by the fertilized ovum, which, at first a cluster of similar cells, quickly reaches a stage marked by dissimilarity of the cells. More frequently recurring fission of the superficial cells, a resulting smaller size of them, and subsequent union of them into an outer layer, constitute the first differentiation; and the middle area of this layer is rendered unlike the rest by still more active processes of like kind. By such modifications upon modifications, many and various, arise the classes and sub-classes of tissues which, intricately combined one with another, compose organs.

Equally conforming to the law are the changes in general shape and in the shapes of organs. All germs are at first spheres and all limbs are at first buds or mere rounded lumps. From this primordial uniformity and simplicity, there take place divergences, both of the wholes and of the leading parts, towards multiformity of contour and towards complexity of contour. Remove the compactly-folded young leaves that terminate every shoot, and the nucleus is found to be a central knob bearing lateral knobs, one of which may grow into either a leaf, a sepal, a petal, a stamen, or a carpel: all these eventually — unlike parts being at first alike. The shoots themselves also depart from their primitive unity of form; and while each branch becomes more or less different from the rest, the whole exposed part of the plant becomes different from the imbedded part. So, too, is it with the organs of animals. One of the Arthropoda, for instance, has limbs that were originally indistinguishable from one another — composed a homogeneous series; but by continuous divergences there have arisen among them unlikenesses of size and form, such as we see in the crab and the lobster. Vertebrate creatures equally exemplify this truth. The wings and legs of a bird are of similar shapes when they bud-out from the sides of the embryo.

Thus in every plant and animal, conspicuous secondary re-distributions accompany the primary re-distribution. A first difference between two parts; in each of these parts other differences which presently become as marked as the first; and a like multiplication of differences in geometrical progression, until there is reached that complex combination constituting the adult. This is the history of all living things whatsoever. Pursuing an idea which Harvey set afloat, it has been shown by Wolff and Von Baer, that during its development each organism passes from a state of homogeneity to a state of heterogeneity. For a generation this truth has been accepted by biologists.

§120. When we pass from individual forms of life to life at large, and ask whether the same law is seen in the ensemble of its manifestations — whether modern plants and animals have more heterogeneous structures than ancient ones, and whether the Earth's present Flora and Fauna are more heterogeneous than the Flora and Fauna of the past, — we find the evidence so fragmentary that nearly every conclusion is open to dispute. Three-fifths of the Earth's surface being covered by water; a great part of the exposed land being inaccessible to, or untravelled by, the geologist; the most of the remainder having been scarcely more than glanced at; and even familiar portions, as England, having been so imperfectly explored that a new series of strata has been added within these few years; it is clearly impossible to say with any certainty what creatures have, and what have not, existed at any particular period. Considering the perishable nature of many of the lower organic forms, the metamorphosis of many beds of sediment, and the gaps that occur among the rest, we shall see further reason for distrusting our deductions. On the one hand, the repeated discovery of vertebrate remains in strata previously supposed to contain none — of reptiles where only fish were thought to exist, and of mammals where it was believed there were no creatures higher than reptiles; renders it daily more manifest how small is the value of negative evidence. On the other hand, the worthlessness of the assumption that we have found the earliest, or anything like the earliest, organic remains, is becoming equally clear. That the oldest known aqueous formations have been greatly changed by igneous action, and that still older ones have been totally transformed by it, is becoming undeniable. And the fact that sedimentary strata earlier than any we know have been melted up, being admitted, it must also be admitted that we cannot say how far back in time this destruction of sedimentary strata has been going on. For aught we know to the contrary, only the last chapters of the Earth's biological history may have come down to us.

Most inferences must thus be extremely questionable. If a progressionist argues that the earliest known vertebrate remains are those of Fishes, which are the most homogeneous of the Vertebrata; that Reptiles, which are more heterogeneous, are later; and that later still, and more heterogeneous still, are Mammals and Birds; it may be replied that the Palaeozoic deposits, not being estuary deposits, are not likely to contain the remains of terrestrial Vertebrata, which may nevertheless have existed. A like answer may be made to the argument that the vertebrate fauna of the Palæozoic period, consisting, so far as we know, entirely of Fishes, was less heterogeneous than the modern vertebrate fauna, which includes Reptiles, Birds and Mammals, of multitudinous genera; while a uniformitarian may contend with great show of truth, that this appearance of higher and more varied forms in later geologic eras, was due to progressive immigration — that a continent slowly upheaved from the ocean at a point remote from pre-existing continents, would necessary be peopled from them in a succession like that which our strata display. At the same time the counter-arguments may be proved equally inconclusive. When, to show that there cannot have been a continuous evolution of the more homogeneous organic forms into the more heterogeneous ones, the uniformitarian points to the breaks which occur in the succession of these forms, there is the sufficient answer that current geological changes show us why such breaks must occur, and why, by subsidences and elevations of large areas, there must be produced breaks so immense as those which divide the great geologic epochs. Or again, if the opponent of the development hypothesis cites the facts set forth by Professor Huxley in his lecture on "Persistent Types" — if he points out that "of some two hundred known orders of plants, not one is exclusively fossil," while "among animals, there is not a single totally extinct class; and of the orders, at the outside not more than seven per cent are unrepresented in the existing creation" — if he urges that among these some have continued from the Silurian epoch to our own day with scarcely any change and if he infers that there is a much greater average resemblance between the living forms of the past and those of the present, than consists with the hypothesis; there is still a satisfactory reply, on which in fact Prof. Huxley insists; namely, that we have evidence of a "pre-geologic era" of unknown duration. And, indeed, when we remember that the enormous subsidences of the Silurian period show the Earth's crust to have been approximately as thick then as it is now — when we conclude that the time taken to form so thick a crust, must have been immense as compared with the time which has since elapsed — when we assume, as we must, that during this comparatively immense time the geologic and biologic changes went on at their usual rates; it becomes manifest, not only that the palaeontological records which we find do not negative the theory of evolution, but that they are such as might rationally be looked for.

Moreover, though the evidence suffices neither for proof nor disproof, yet some of its most conspicuous facts support the belief, that the more heterogeneous organisms and groups of organisms, have been evolved from the less heterogeneous ones. The average community of type between the fossils of adjacent strata, and especially the community found between the latest tertiary fossils and creatures now existing, is one of these facts. The discovery in some modern deposits of such forms as the Pataeotherium and Anaplotherium, which, according to Prof. Owen, had a type of structure intermediate between some of the types now existing, is another of these facts. And the comparatively recent appearance of Man, is a third fact of this kind, which possesses still greater significance. Hence we may say that though our knowledge of past life upon the Earth is relatively small, yet what we have, and what we continually add to it, support the belief that there has been an evolution of the simple into the complex alike in individual forms and in the aggregate of forms.

§121. Advance from the homogeneous to the heterogeneous is clearly displayed in the progress of the latest and most heterogeneous creature — Man. While the peopling of the Earth has been going on, the human organism has grown more heterogeneous among the civilized divisions of the species; and the species, as a whole, has been made more heterogeneous by the multiplication of races and the differentiation of them from one another. In proof of the first of these statements may be cited the fact that, in the relative development of the limbs, civilized men depart more widely from the general type of the placental mammalia, than do the lowest men. Though often possessing well-developed body and arms, the Papuan has very small legs: thus reminding us of the man-like apes, in which there is no great contrast in size between the hind and fore limbs. But in the European, the greater length and massiveness of the legs has become marked — the fore and hind limbs are relatively more heterogeneous. The greater ratio which the cranial bones bear to the facial bones, illustrates the same truth. Among the Vertebrata in general, evolution is marked by an increasing heterogeneity in the vertebral column, and especially in the components of the skull: the higher forms being distinguished by the relatively larger size of the bones which cover the brain, and the relatively smaller size of those which form the jaws, etc. Now this trait, which is stronger in Man than in any other creature, is stronger in the European than in the savage. Moreover, from the greater extent and variety of faculty he exhibits, we may infer that the civilized man has also a more complex or heterogeneous nervous system than the uncivilized man; and, indeed, the fact is in part visible in the increased ratio which his cerebrum bears to the subjacent ganglia. If further elucidation be needed, every nursery furnishes it. In the infant European we see sundry resemblances to the lower human races; as in the flatness of the alae of the nose, the depression of its bridge, the divergence and forward opening of the nostrils, the form of the lips, the absence of a frontal sinus, the width between the eyes, the smallness of the legs. Now as the developmental process by which these traits are turned into those of the adult European, is a continuation of that change from the homogeneous to the heterogeneous displayed during the previous evolution of the embryo; it follows that the parallel developmental process by which the like traits of the barbarous races have been turned into those of the civilized races, has also been a continuation of the change from the homogeneous to the heterogeneous. The truth of the second statement is so obvious as scarcely to need illustration. Every work on Ethnology, by its divisions and subdivisions of races, bears testimony to it. Even were we to admit that Mankind originated from several separate stocks, it would still remain true that as, from each of these stocks, there have sprung many now widely different tribes, which are proved by philological evidence to have had a common origin, the race as a whole is more heterogeneous than it once was. Add to which that we have, in the Anglo-Americans, an example of a new variety arising within these few generations; and that, if we may trust to the descriptions of observers, we are likely soon to have another such in Australia.

§122. On passing from Humanity under its individual form to Humanity as socially embodied, we find the general law still more variously exemplified. The change from the homogeneous to the heterogeneous is displayed equally in the progress of civilization as a whole, and in the progress of every tribe or nation; and it is still going on with increasing rapidity.

Society in its first and lowest stage is a homogeneous assemblage of individuals having like powers and like functions: the only marked difference of function being that which accompanies difference of sex. Every man is warrior, hunter, fisherman, tool-maker, builder; every woman performs the same drudgeries; every family is self-sufficing, and, save for purposes of companionship, aggression, and defence, might as well live apart from the rest. Very early, however, in the course of social evolution, we find an incipient differentiation between the governing and the governed. Some kind of chieftainship soon arises after the advance from the state of separate wandering families to that of a nomadic tribe. The authority of the strongest and cunningest makes itself felt among savages, as in a herd of animals or a posse of schoolboys: especially in war. At first, however, it is indefinite, uncertain; is shared by others of scarcely inferior power; and is unaccompanied by any difference in occupation or style of living: the first ruler kills his own game, makes his own weapons, builds his own hut, and, economically considered, does not differ from others of his tribe. Along with conquests and the massing of tribes, the contrast between the governing and the governed grows more decided. Supreme power becomes hereditary in one family; the head, first military and then political, ceasing to provide for his own wants, is served by others; and he begins to assume the sole office of ruling. At the same time there has been arising a co-ordinate species of government — that of Religion. Ancient records and traditions show that the earliest conquerors and kings came to be regarded as divine personages. The maxims and commands they uttered during their lives were held sacred after their deaths, and were enforced by their divinely-descended successors; who in their turns were promoted to the pantheon of the race, there to be worshipped and propitiated along with their predecessors. For a long time these connate forms of government — civil and religious — remain closely associated. For many generations the king continues to be the chief priest, and the priesthood to be members of the royal race. For many ages religious law continues to contain more or less of civil regulation, and civil law to possess more or less of religious sanction; and even among the most advanced nations these two controlling agencies are by no means completely differentiated from each other. Having a common root with these, and gradually diverging from them, we find yet another controlling agency — that of Manners or ceremonial usages. Titles of honour were originally the names of the god-king; afterwards of God and the king; still later of persons of high rank; and finally came, some of them, to be used between man and man. Forms of complimentary address were at first expressions of propitiation from prisoners to their conqueror, or from subjects to their ruler, either human or divine — expressions that were afterwards used subordinate authorities, and slowly descended into ordinary intercourse. Modes of salutation were once signs of subjection to a victor, afterwards obeisances made before the monarch and used in worship of him when dead. Presently others of the god-descended race were similarly saluted; and by degrees some of the salutations have become the due of all. Thus, no sooner does the originally homogeneous social mass differentiate into the governed and the governing parts, than this last exhibits an incipient differentiation into religious and secular-Church and State; while at the same time or still earlier there begins to take shape, that less definite species of government which rules our daily intercourse — a species of government which, as we may see in heralds' colleges, in books of the peerage, in masters of ceremonies, is not without a certain embodiment of its own. Each of these kinds of government is itself subject to successive differentiations. In the course of ages, there arises, as among ourselves, a highly complex political organization of monarch, ministers, lords and commons, with their subordinate administrative departments, courts of justice, revenue offices, etc., supplemented in the provinces by municipal governments, county governments, parish or union governments — all of them more or less elaborated. By its side there grows up a highly complex religious organization, with its various grades of officials from archbishops down to sextons, its colleges, convocations, ecclesiastical courts, etc.; to all which must be added the ever-multiplying independent sects, each with its general and local authorities. And simultaneously there is developed a complicated system of customs, manners, and temporary fashions, enforced by society at large, and serving to control those minor transactions between man and man which are not regulated by civil and religious law. Moreover, it is to be observed that this increasing heterogeneity in the governmental appliances of each nation, has been accompanied by an increasing heterogeneity in the governmental appliances of different nations. All peoples are more or less unlike in their political systems and legislation, in their creeds and religious institutions, in their customs and ceremonial usages.

Meanwhile there has been going on a differentiation of a more familiar kind; that, namely, by which the mass of the community has been segregated into distinct classes and orders of workers. While the governing part has undergone the complex development above indicated, the governed part has undergone a more complex development, which has resulted in that minute division of labour characterizing advanced nations. It is needless to trace out this progress from its first stages, up through the caste-divisions of the East and the incorporated guilds of Europe, to the elaborate producing and distributing organization existing among ourselves. Political economists have long since described the industrial progress which, through increasing division of labour, ends with a civilized community whose members severally perform different actions for one another; and they have further pointed out the changes through which the solitary producer of any one commodity, is transformed into a combination of producers who, united under a master, take separate parts in the manufacture of such commodity. But there are yet other and higher phases of this advance from the homogeneous to the heterogeneous in the industrial organization of society. Long after considerable progress has been made in the division of labour among the different classes of workers, there is relatively little division of labour among the widely separated parts of the community: the nation continues comparatively homogeneous in the respect that in each district the same occupations are pursued. But when roads and other means of transit become numerous and good, the different districts begin to assume different functions, and to become mutually dependent. The calico-manufacture locates itself in this county, the woollen-manufacture in that; silks are produced here, lace there; stockings in one place, shoes in another; pottery, hardware, cutlery, come to have their special towns; and ultimately every locality grows more or less distinguished from the rest by the leading occupation carried on in it. Nay, more, this subdivision of functions shows itself not only among the different parts of the same nation, but among different nations. That exchange of commodities which free-trade promises so greatly to increase, will ultimately have the effect of specializing, in a greater or less degree, the industry of each people. So that beginning with a primitive tribe, almost if not quite homogeneous in the functions of its members, the progress has been, and still is, towards an economic aggregation of the whole human race; growing ever more heterogeneous in respect of the separate functions assumed by separate nations, the separate functions assumed by the local sections of each nation, the separate functions assumed by the many kinds of producers in each place, and the separate functions assumed by the workers united in growing or making each commodity. And then, lastly, has to be named the vast organization of distributers, wholesale and retail, forming so conspicuous an element in our town-populations, which is becoming ever more specialized in its structure.

§123. Not only is the law thus exemplified in the evolution of the social organism, but it is exemplified in the evolution of all products of human thought and action, whether concrete or abstract, real or ideal. Let us take Language as our first illustration.

The lowest form of language is the exclamation, by which an entire idea is vaguely conveyed through a single sound; as among the lower animals. That human language ever consisted solely of exclamations, and so was strictly homogeneous in respect of its parts of speech, we have no evidence. But that language can be traced down to a form in which nouns and verbs are its only elements, is an established fact. In the gradual multiplication of parts of speech out of these primary ones — in the differentiation of verbs into active and Passive, of nouns into abstract and concrete - in the rise of distinctions of mood, tense, person, or number and case — in the formation of auxiliary verbs, of adjectives, adverbs, pronouns, prepositions, articles — in the divergence of those orders, genera, species, and varieties of parts of speech by which civilized races express minute modifications of meaning; we see a change from the homogeneous to the heterogeneous. And it may be remarked that it is more especially because it has carried this subdivision of functions further than any other language, that the English language is structurally superior. Another process throughout which we may trace the development of language, is the differentiation of words of allied meanings. Philology early disclosed the truth that in all languages words may be grouped into families having each a common ancestry. An aboriginal name, applied indiscriminately to each member of an extensive and ill-defined class of things or actions, presently undergoes modifications by which the chief divisions of the class are expressed. These several names springing from the primitive root, themselves become the parents of other names still further modified. And by the aid of those systematic modes, which presently arise, of making derivatives and forming compounds expressing still smaller distinctions, there is finally developed a tribe of words so heterogeneous in sound and meaning, that to the initiated it seems incredible they should have had a common origin. Meanwhile, from other roots there are being evolved other such tribes, until there results a language of a hundred thousand different words, signifying as many different objects, qualities, acts. Yet another way in which language advances from the homogeneous to the heterogeneous, is by the multiplication of languages. Whether, as Max Müller and Bunsen think, all languages have grown from one stock, or whether, as some philologists say, they have grown from two or more stocks, it is clear that since large families of languages, as the Indo-European, are of one parentage, there have arisen multiplied kinds through a process of continuous divergence. The diffusion over the Earth's surface which has led to differentiation of the race, has simultaneously led to differentiation of its speech: a truth which we see further illustrated in each country by the dialects found in separate districts. Thus linguistic changes conform to the general law, alike in the evolution of languages, in the evolution of families of words, and in the evolution of parts of speech. If in our conception of language we include not its component words only but those combinations of them by which distinct ideas are conveyed — namely sentences — we have to recognize one more aspect of its progress from homogeneity to heterogeneity which has accompanied the progress in integration. Rude speech consists of simple propositions having subjects and predicates indefinitely linked; and anything like a complex meaning is conveyed by a succession of such propositions connected only by juxtaposition. Even in the speech of comparatively developed peoples, as the Hebrews, we find very little complexity. Compare a number of verses from the Bible with some paragraphs from a modern writer, and the increase in heterogeneity of structure is very conspicuous. And beyond the fact that many of our ordinary sentences are by the supplementary clauses, secondary propositions, and qualifying phrases they contain made relatively involved, there is the fact that there is great variety among the sentences in a page: now long, now short, now formed in one way, now in another, so that a double progress in heterogeneity in the style of composition is displayed.

On passing from spoken to written language, we come upon several classes of facts, having similar implications. Written language is connate with Painting and Sculpture; and at first all three are appendages of Architecture, and have a direct connexion with the early form of settled government — the theocratic. Merely noting the fact that sundry wild races, as the Australians and the tribes of South Africa, are given to depicting personages and events on the walls of caves, which are probably regarded as sacred places, let us pass to the case of the Egyptians. Among them, as also among the Assyrians, we see mural paintings used to decorate the temple of the god and the palace of the king (which were, indeed, originally identical); and as such they were governmental appliances in the same sense that stage-pageants and religious feasts were. Further, they were governmental appliances in virtue of representing the worship of the god, the triumphs of the god-king, the submission of his subjects, and the punishment of the rebellious. And yet again they were governmental, as being the products of an art reverenced by the people as a sacred mystery. From the constant use of this pictorial representation, there grew up the but slightly-modified practice of picture-writing — a practice which was found still extant among the Mexicans at the time they were discovered. By abbreviations analogous to those still going on in our own language, the most familiar of these pictured figures were successively simplified; and ultimately there grew up symbols, most of which had but distant resemblances to the things for which they stood. The inference that the hieroglyphics of the Egyptians thus arose, is confirmed by the fact that the picture-writing of the Mexicans was found to have given birth to a like family of ideographic forms; and among them, as among the Egyptians, these had been partially differentiated into the kuriological or imitative, and the tropical or symbolic: which were, however, used together in the same record. In Egypt, written language underwent a further differentiation, resulting in the hieratic and the epistolographic or enchorial: both derived from the original hieroglyphic. At the same time for proper names, which could not be otherwise expressed, phonetic symbols were employed; and though the Egyptians never achieved complete alphabetic writing, yet it can scarcely be doubted that among other peoples phonetic symbols, occasionally used in aid of ideographic ones, were the germs out of which alphabetic writing arose. Once having become separate from hieroglyphics, alphabetic writing itself underwent numerous differentiations — multiplied alphabets were produced: between most of which, however, connexions can still be traced. And in each civilized nation there have now grown up, for the representation of one set of sounds, several sets of written signs, used for distinct purposes. Finally, through a yet more important differentiation came printing; which, uniform in kind as it was at first, has since become multiform.

§124. While written language was passing through its earlier stages of development, the mural decoration which formed its root was being differentiated into Painting and Sculpture. The gods, kings, men, and animals represented, were originally marked by indented outlines and coloured. In most cases these outlines were of such depth, and the object they circumscribed so far rounded, as to form a species of work intermediate between intaglio and bas-relief. In other cases we see an advance upon this: the spaces between the figures being chiselled out, and the figures themselves appropriately tinted, a painted bas-relief was produced. The restored Assyrian architecture at Sydenham exhibits this style of art carried to greater perfection: the persons and things represented, though still barbarously coloured, are carved with more truth and in greater detail; and in the winged lions and bulls used for the angles of gateways, we see advance towards a completely sculptured figure; which, nevertheless, is still coloured and still forms part of the building. But though in Assyria the production of a statue proper seems to have been little, if at all, attempted, we may trace in Egyptian art the gradual separation of the sculptured figure from the wall. While a walk through the collection in the British Museum will afford an opportunity of observing transitions, it will bring into view much evidence that the independent statues were derived from bas-reliefs: newly all of them not only display that lateral attachment of the arms with the body which is a characteristic of bas-relief, but have the back of the statue united from head to foot with a block which stands in place of the original wall. Greece repeated the leading stages of this progress. As in Egypt and Assyria, these twin arts were at first united with each other and with their parent, Architecture; and were aids of Religion and Government. On the friezes of Greek temples, we see coloured bas-reliefs representing sacrifices, battles, processions, games — all in some sort religious. On the pediments we see painted sculptures partially united with the tympanum, and having for subjects the triumphs of gods or heroes. Even when we come to statues that are definitely separated from the buildings to which they pertain, we still find them coloured; and only in the later periods of Greek civilization, does the differentiation of painting from sculpture appear to have become complete. In Christian art there occurred a parallel re-genesis. All early paintings and sculptures throughout Europe were religious in subject — represented Christs, crucifixions, virgins, holy families, apostles, saints. They formed integral parts of church architecture, and were among the means of exciting worship: as in Roman Catholic countries they still are. Moreover, the early sculptures of Christ on the cross, of virgins, of saints, were coloured; and it needs but to call to mind the painted madonnas and crucifixes still abundant in continental churches, to perceive the significant fact that painting and sculpture continue in closest connexion with each other, where they continue in closest connexion with their parent. Even when Christian sculpture become separate from painting, it was still at first religious and governmental in its subjects — was used for tombs in churches and statues of saints and kings; while, at the same time, painting, where not purely ecclesiastical, was applied to the decoration of palaces, and after representing royal personages, was almost wholly devoted to sacred legends. Only in modern times have painting and sculpture become entirely secular arts. Only within these few centuries has painting been divided into historical, landscape, marine, architectural, animal, still-life, etc., and sculpture grown heterogeneous in respect of the variety of real and ideal subjects with which it occupies itself.

Strange as it seems then, all forms of written language, of painting, of sculpture, have a common root in those rude drawings on skins and cavern-walls by which savages commemorated notable deeds of their chiefs, and which, during social progress, developed into the politico-religious decorations of ancient temples and palaces. Little resemblance as they now have, the bust that stands on the console, the landscape that hangs against the wall, and the copy of The Times lying upon the table, are remotely akin. The brazen face of the knocker which the postman has just lifted, is related not only to the woodcuts of the Illustrated London News which he is delivering, but to the characters of the billet-doux which accompanies it. Between the painted window the prayer-book on which its light falls, and the adjacent monument, there is consanguinity. The effigies on our coins, the signs over shops, the figures that fill every ledger, the coat-of-arms outside the carriage-panel, and the placards inside the omnibus, are, in common with dolls, blue-books, and paper-hangings, lineally descended from the sculpture-paintings and picture-writings in which the Egyptians represented and recorded the triumphs and worship of their god-kings. Perhaps no example can be given which more vividly illustrates the multiplicity and heterogeneity of the products that in course of time may arise by successive differentiations from a common stock.

The transformation of the homogeneous into the heterogeneous thus displayed in the separation of Painting and Sculpture from Architecture and from each other, and in the greater variety of subjects they embody, is further displayed in the structure of each work. A modern picture or statue is of far more complex nature than an ancient one. An Egyptian sculpture-fresco represents all its figures as on one plane — that is, at the same distance from the eye; and so is less heterogeneous than a painting that represents them as at various distances. It exhibits all objects as similarly lighted; and so is less heterogeneous than a painting which exhibits different objects, and different parts of each object, as in different degrees of light. It uses scarcely any but the primary colours, and these in their full intensities; and so is less heterogeneous than a painting which, introducing the primary colours but sparingly, employs an endless variety of intermediate tints, each of heterogeneous composition, and differing from the rest not only in quality but in strength. Moreover, these earliest works manifest great uniformity of conception. In ancient societies the modes of representation were so fixed that it was sacrilege to introduce a novelty. In Egyptian and Assyrian bas-reliefs, deities, kings, priests, attendants, winged-figures and animals, are in all cases depicted in like positions, special to each class, holding like implements, doing like things, and with like expression or non-expression of face. If a palm-grove is introduced, all the trees are of the same height, have the same number of leaves, and are equidistant. When water is imitated, each wave is a counterpart of the rest; and the fish, almost always of one kind, are evenly distributed. The beards of the Assyrian kings, gods, and winged-figures, are everywhere similar; as are the manes of the lions, and equally so those of the horses. Hair is represented throughout by one form of curl. The king's beard is built up of compound tiers of uniform curls, alternating with twisted tiers placed transversely and arranged with perfect regularity; and the terminal tufts of the bulls' tails are represented in exactly the same manner. Without tracing out analogous traits in early Christian art, in which, though less striking, they are still visible, the advance in heterogenity will be sufficiently manifest on remembering that in the pictures of our own day the composition is endlessly varied; the attitudes, faces, expressions, unlike; the subordinate objects different in size, form, position, texture. Or, if we compare an Egyptian statue, seated upright on a block, with hands on knees, fingers outspread and parallel, eyes looking straight forward, and the two sides perfectly symmetrical, with a statue of the advanced Greek or the modern school, which is asymmetrical in respect of the position of the head, the body, the limbs, the arrangement of the hair, dress, appendages, and in its relations to neighbouring objects, we see the change from the homogeneous to the heterogeneous clearly manifested.

§125. In the co-ordinate origin and gradual differentiation of Poetry, Music, and Dancing, we have another series of illustrations. Rhythm in speech, rhythm in sound, and rhythm in motion, were in the beginning, parts of the same thing. Among existing barbarous tribes we find them still united. The dances of savages are accompanied by some kind of monotonous chant, the clapping of hands, the striking of rude instruments: there are measured movements, measured words, and measured tones; and the whole ceremony, usually having reference to war or sacrifice, is of governmental character. The early records of the historic races similarly show these three forms of metrical action united in religious festivals. In the Hebrew writings we read that the triumphal ode composed by Moses on the defeat of the Egyptians, was sung to an accompaniment of dancing and timbrels. The Israelites danced and sung "at the inauguration of the golden calf. And as it is generally agreed that this representation of the Deity was borrowed from the mysteries of Apis, it is probable that the dancing Was copied from that of the Egyptians on those occasions." There was an annual dance in Shiloh on the sacred festival; and David danced before the ark. Again, in Greece the like relation existed: the original type being there, as probably in other cases, a simultaneous chanting and mimetic representation of the achievements of the god. The Spartan dances were accompanied by hymns; and in general the Greeks had "no festivals or religious assemblies but what were accompanied with songs and dances" — both of them being forms of worship used before altars. Among the Romans, too, there were sacred dances: the Salian and Lupercalian being named as of that kind. Even in the early Christian church, dances in the choir at festivals, occasionally led by bishops, were among the forms of worship, and in some places continued down to the 18th century. The incipient separation of these once united arts from each other and from religion, was early visible in Greece. Probably diverging from dances partly religious, partly warlike, as the Corybantian, came the war-dances proper, of which there were various kinds; and from these resulted secular dances. Meanwhile Music and Poetry, though still joined, came to have an existence separate from dancing. The primitive Greek poems, religious in subject, were not recited but chanted; and though at first the chant of the poet was accompanied by the dance of the chorus, it ultimately grew into independence. Later still, when the poem had been differentiated into epic and lyric — when it became the custom to sing the lyric and recite the epic-poetry proper was born. As, during the same period, musical instruments were being multiplied, we may presume that music came to have an existence apart from words. And both of them were beginning to assume other forms than the religious. Facts having like implications might be cited from the histories of later times and peoples: as the practices of our Anglo-Saxon "gleemen" and Celtic bards, who sang to the harp heroic narratives versified by themselves to music of their own composition: thus uniting the now separate offices of poet, composer, vocalist, and instrumentalist. The common origin and gradual differentiation of Dancing, Poetry, and Music is thus sufficiently manifest.

Besides being displayed in the separation of these arts from one another and from religion, growing heterogeneity is also displayed in the multiplied differentiations which each of them afterwards undergoes. Just referring to the numberless kinds of dancing that have, in course of time, come into use, and to the progress of poetry, as seen in the development of the various forms of metre, of rhyme, and of general organization, let us confine our attention to music as a type of the group. As argued by Dr. Burney, and as implied by the customs of extant savages, the first musical instruments were percussive-sticks, calabashes, tom-toms — and were used simply to mark the time of the dance. So, too, the vocal music of various semi-civilized races consists of simple phrases endlessly reiterated. In this constant repetition of the same sounds we see music in its most homogeneous form. The Egyptians had a lyre with three strings. The early lyre of the Greeks had four, constituting their tetrachord. In course of some centuries lyres of seven and eight strings came to be employed. And, by the expiration of a thousand years, they had advanced to their "great system" of the double octave. Through all which changes of course arose a greater heterogeneity of melody or rather recitative. Simultaneously came into use the different modes — Dorian, Ionian, Phrygian, AEolian, and Lydian — answering to our keys; and of these there were ultimately fifteen. As yet, however, there was but little heterogeneity in the time of their music. Instruments being used merely to accompany the voice, the vocal music being completely subordinated to words, — the singer being also the poet, chanting his own compositions and making the lengths of his notes agree with the feet of his verses — there unavoidably arose a tiresome uniformity of measure which, as Dr. Burney says, "no resources of melody could disguise." Lacking the complex rhythm obtained by our equal bars and unequal notes, the only rhythm was that produced by the quantity of the syllables, and was of necessity monotonous. And further, the chant thus resulting being like recitative, was much less differentiated from ordinary speech than is our modern song. Nevertheless, considering the extended range of notes in use, the variety of modes, the occasional variations of time consequent on changes of metre, and the multiplication of instruments, we see that music had, towards the close of Greek civilization, attained to considerable heterogeneity: not indeed as compared with our music, but as compared with that which preceded it. As yet, however, there existed nothing but serial combinations of notes (for so we must call them since they were not melodies in our sense): harmony was unknown. It was not until Christian church-music had reached some development, that music in parts was evolved; and then it came into existence through an unobtrusive differentiation. The practice which led to it was the employment of two choirs singing alternately the same air. Afterwards it became the habit (possibly first suggested by a mistake) for the second choir to commence before the first had ceased: thus producing a fugue. With the simple airs then in use, a partially harmonious fugue might not improbably result; and a very partially harmonious fugue satisfied the ears of that age, as we know from still preserved examples. The idea having once been given, the composing of airs productive of fugal harmony would naturally grow up; as in some way it did grow up out of this alternate choir-singing. And from the fugue to concerted music of two, three, four, and more parts, the transition was easy. Without pointing out in detail the increasing complexity that resulted from introducing notes of various lengths, from the multiplication of keys, from the use of accidentals, from varieties of time, from modulations and so forth, it needs but to contrast music as it is with music as it was, to see how immense is the increase of heterogeneity. We see this also if, looking at music in its ensemble, we enumerate its many different genera and species — if we consider the divisions into vocal, instrumental, and mixed; and their subdivisions into music for different voices and different instruments — if we observe the many forms of sacred music, from the simple hymn, the chant, the canon, motet, anthem, etc., up to the oratorio; and the still more numerous forms of secular music, from the ballad up to the serenata, from the instrumental solo up to the symphony. Again, the same truth is seen on comparing any one sample of aboriginal music with a sample of modern music — even an ordinary song for the piano; which we find to be relatively very heterogeneous, not only in respect of varieties in the intervals and in the lengths of the notes, the number of different notes sounding at the same instant in company with the voice, and the variations of strength with which they are sounded and sung, but in respect of the changes of key, the changes of time, the changes of timbre of the voice, and the many other modifications of expression. While between the old monotonous dance-chant and a grand opera of our own day, the contrast in heterogeneity is so extreme that it seems scarcely credible that the one is the ancestor of the other.

§126. Many further illustrations of the general law throughout social products might be detailed. Going back to the time when the deeds of the god-king, chanted and mimetically represented in dances before his altar, were further narrated in picture-writings on the walls of temples and palaces, and so constituted a rude history, we might trace the development of Literature through phases in which, as in the Hebrew Scriptures, it presents in one work, theology, cosmogony, history, biography, civil laws, ethics, poetry; through other phases in which, as in the Iliad, the religious, martial, historical, the epic, dramatic, and lyric elements are similarly commingled; down to its present heterogeneous development, in which its divisions and subdivisions are so numerous and varied as to defy complete classification. Or we might track the unfolding of Science; beginning with the era in which it was not yet differentiated from Art, and was, in union with Art, the handmaid of Religion; passing through the era in which the sciences were so few and rudimentary, as to be simultaneously cultivated by the same philosophers; and ending with the era in which the genera and species are so multitudinous that few can enumerate them, and no one can adequately grasp even one genus. Or we might do the like with Architecture, with the Drama, with Dress. But doubtless the reader is already weary of illustrations, and my promise has been amply fulfilled. The advance from the simple to the complex through successive modifications upon modifications, is seen alike in the earliest changes of the Heavens to which we can reason our way back, and in the earliest changes we can inductively establish; it is seen in the geologic and climatic evolution of the Earth, of every individual organism on its surface and in the aggregate of organisms; it is seen in the evolution of Humanity, whether contemplated in the civilized man, or in the assemblage of races; it is seen in the evolution of Society, in respect alike of its political, its religious, and its economical organization; and it is seen in the evolution of those countless concrete and abstract products of human activity, which constitute the environment of our daily life. From the remotest past which Science can fathom, up to the novelties of yesterday, an essential trait of Evolution has been the transformation of the homogeneous into the heterogeneous.

§127. So that the general formula arrived at in the last chapter needs supplementing. It is true that Evolution, under its primary aspect, is a change from a less coherent state to a more coherent state, consequent on the dissipation of motion and integration of matter; but this is far from being the whole truth. Along with a passage from the coherent to the incoherent, there goes on a passage from the uniform to the multiform. Such, at least, is the fact wherever Evolution is compound; which it is in the immense majority of cases. While there is a progressing concentration of the aggregate, caused either by the closer approach of the matter within its limits, or by the drawing in of further matter, or by both; and while the more or less distinct parts into which the aggregate divides and subdivides are also severally concentrating; these parts are simultaneously becoming unlike — unlike in size, or in form, or in texture, or in composition, or in several or all of these. The same process is exhibited by the whole and by its members. The entire mass is integrating, and at the same time differentiating from other masses; while each member of it is also integrating and at the same time differentiating from other members.

Our conception, then, must unite these characters. As we now understand it, Evolution is definable as a change from an incoherent homogeneity to a coherent heterogeneity, accompanying the dissipation of motion and integration of matter.

NOTES