In 1886, Professor Romanes p.r.o.nounced as follows:[236]

"At present it would be impossible to find any working naturalist who supposes that survival of the fittest is competent to explain all the phenomena of species-formation."

As to the actual position now occupied in Scientific opinion by Mr.

Darwin's hypotheses, we may content ourselves with the declaration of Professor S. H. Vines in his Presidential address to the Linnean Society, May 24, 1902.

1. It is established that Natural Selection, though it may have perpetuated species, cannot have originated any.

2. It is still a mystery why Evolution should tend from the lower to the higher, from simple to complex organisms.

3. The facts seem to admit of no other interpretation than that variation is not [as Darwin supposed] indeterminate, but that there is in living matter an inherent determination in favour of variation in the higher direction.

That is to say, Darwin's _Origin of Species_ does not explain the Origin of Species; and as to the laws which govern Evolution we can be sure only that they are not those which he a.s.signed.

In like manner, Sir Oliver Lodge p.r.o.nounces:[237]

Take the origin of species by the persistence of favourable variations; how is the appearance of these same favourable variations accounted for? Except by artificial selection not at all. Given their appearance, their development by struggle and inheritance and survival can be explained; but that they arose spontaneously, by random changes without purpose, is an a.s.sertion which cannot be made.

We are thus in a position to form our own judgment as to the claim made on behalf of Mr. Darwin, with which we started this chapter--namely, that he has eliminated all mystery from the organic world by the discovery of natural mechanical laws by which all its operations are governed. It is, indeed, difficult to understand how Darwinists themselves can suppose their system to make any such claim, for, as M.

Paul Vignon truly observes,[238] "La science darwinnienne s'imaginait avoir triomphe du Sphinx, alors qu'elle avait simplement decompose le probleme dans une monnaie d'enigmes moins rebarbatives en apparence." As has been said, it is far more on account of the vast consequences professedly based upon it, as a sure foundation stone, than for its own sake, that it has seemed advisable to devote so much attention to the study of Darwinism, quite apart from which the whole question of organic Evolution still demands consideration.

It seems far more just to conclude with M. Fabre:[239]

Let us acknowledge that in truth we know nothing about anything, so far as ultimate truths are concerned. Scientifically considered nature is a riddle to which human curiosity can find no answer.

Hypothesis follows hypothesis, the ruins of theories are piled one on another, but truth ever escapes us. To learn how to remain in ignorance may well be the final lesson of wisdom.[240]

XVI

THE FACTS OF EVOLUTION

Leaving the field of speculation and "aetiology," we have now to enquire, not to what causes organic Evolution may be attributable, but how far it can be shewn to have actually occurred. This can be learnt only from the history of life upon earth as disclosed by the evidence of palaeontology, or the geological record, and we are thus brought to the investigation of that evidence, by which alone, as Professor Huxley agrees, can the truth about Evolution be scientifically or satisfactorily established.

In his address recently mentioned on occasion of the twenty-first birthday of the _Origin of Species_, having spoken of various advances of our knowledge, as in comparative anatomy and embryology, which had helped to win acceptance for transformist doctrines, he thus continued:

But all this remains mere secondary evidence. It may remove dissent, but it does not compel a.s.sent. Primary and direct evidence in favour of evolution can be furnished only by palaeontology. The geological record, so soon as it approaches completeness, must, when properly questioned, yield either an affirmative or a negative answer; if evolution has taken place, there will its mark be left; if it has not taken place, there will be its refutation.

This is common sense. Evolution can claim to be a scientific truth, only so far as clear evidence is forthcoming that Evolution there has been.

If the geological record be sufficiently complete to prove or disprove its claims, the question is settled for ever. If, on the other hand, the record be not complete enough for a conclusive verdict, it is, at least, hard to understand the grounds of such a statement as that the doctrine of Evolution has long since pa.s.sed beyond the stage of discussion among scientific thinkers;[241] or that of Professor Marsh, that to doubt Evolution is to doubt Science; or of Professor Huxley himself[242]--"So far as the animal world is concerned, Evolution is no longer a speculation, but a matter of historical fact."

This historical enquiry is accordingly all-important, and it is one which should be easy to undertake without any prepossessions, for it is hard to see upon what _a priori_ grounds these could rest. That there has been Evolution in one sense of the term is obvious,--that is to say, development of organic types from lower to higher forms, from the sea-weed or fungus to the oak or the rose, from the star-fish or the coral-insect, to the eagle or to man. The question is, not whether there has been such a progressive succession of forms, but whether one form has proceeded from another _genetically_, being produced in the same manner as individuals of a species now are. That this has been the case, as Professor Huxley tells us in the same address, is the cornerstone of evolutionary teaching. He appears indeed to restrict Evolution within the limits of cla.s.ses and groups, but such restriction is so contrary to all his principles that the words which seem to imply it can scarcely be taken as having any definite significance. Should the appearance of different cla.s.ses and groups require to be severally accounted for, we should be landed back in the system of separate creations against which he is never tired of inveighing.

The fundamental doctrine of all forms of the theory of evolution applied to biology [he says] is that the innumerable species, genera, and families of organic beings with which the world is peopled have all descended, each within its own cla.s.s or group, from common parents, and have all been modified in the course of descent.

And, holding as he does that palaeontology furnishes the necessary evidence, he thus continues:

And, in the view of the facts of geology, it follows that all living animals and plants are the lineal descendants of those which lived long before the Silurian epoch.

Here is a plain issue, and one, as has been said, to be discussed without prejudice. That the innumerable forms of organic life should thus have been genetically derived one from another, is no more difficult to conceive than that they should have come into existence at all. Moreover, it appears to our minds almost a first principle that natural law must suffice to account for the phenomena of nature from beginning to end, and that any system is self-condemned which finds anywhere in these phenomena evidence of a non-natural, or supernatural, interposition. Has not such a theologian as Suarez, following St.

Augustine, laid it down as an axiom[243] that G.o.d does not directly interfere with the operations of Nature, when He can effect His purposes through natural causes? Undoubtedly, too, it is difficult for our minds to imagine in what way, except through genetic evolution, the successive production of more and more developed types could be effected.

But, as has before been observed, what seems to us probable is not therefore proved to be true. What we want are facts, and by facts we must be ready to abide. At the same time, it is not very easy to understand the supreme importance which evolutionists generally appear to attach to the descent of all living creatures from some _one_ original, and their abhorrence of the idea that the power, whatever it was, which first produced life, may have operated repeatedly, at different epochs, to repeat the production. It seems to be a.s.sumed that this must imply "miracle" and interruption of the continuity of Nature, to admit which is irrational and unscientific. But since life did unquestionably once originate somehow, which Science makes no attempt to deny, why should it be so improper to suppose that it originated more than once, at various times and in various forms, and that, consequently, genetic descent with modification, or "Evolution," is not the explanation of typic development? As Sir J. W. Dawson writes[244]

concerning the oyster tribe, whereof two species are found in the Coal Measures (one European and the other American), and a continuous succession of species ever since:

All these species may have proceeded from one origin, by descent with modification, or, on the other hand, the same causes which led to their origination in the Carboniferous may have operated again and again.

It must, however, be remembered that, if the theory of genetic descent with acc.u.mulation of minute modifications be the true explanation of the production of new forms, it necessarily follows, that could a complete record be forthcoming of the ancestry of any actual species, there would be found in that pedigree no distinction of species or genera, for no sharply marked lines of limitation would be discoverable. It would be like the case of a man who had been photographed every hour of his life from birth to old age;--immense though the difference might be between the two extremes, the gradations of change would at all points pa.s.s as imperceptibly into one another as do the phases of the moon. This consideration is both fundamental and obvious, yet it would seem to be almost universally ignored. It appears to be thought that, in order to demonstrate the fact of evolution, all that is needed is to find a form here and there, in some sense intermediate between others,--like the reptilian birds already mentioned. This would imply that the course of Evolution must be like that of an army, making long marches from point to point, and traceable only by the remains of its camp-fires: whereas it should be as that of a glacier continuously creeping on, and leaving its tracks at one point as much as another. What are wanted, therefore, as evidence for Evolution, are not isolated specific forms uniting some characteristics of those which they are supposed to connect,--as Nelson's men-of-war form a stepping-stone between the vessels of the Nors.e.m.e.n and the ironclads of the present day,--but a series sufficient to show, or at least to indicate, that all changes have been gradual and insensible, without the introduction at any point of a new element. To pursue the ill.u.s.tration, such a new element would be gunpowder or steam in the evolution of the battle-ship, for by no mere development could bows or javelins produce a cannon, or sailing ships a steamboat.

Therefore, in proportion as the geological record approaches completeness, its testimony,--if it is to be in favour of Evolution--must tend more and more in this direction, and unless, in some instance at least, clear evidence be discoverable of the melting of one form into another, it cannot possibly be said that we have sufficient proof that such a process ever occurred. Mere graduated resemblance of isolated forms does not necessarily imply such trans.m.u.tation, as we see for example in the methodical progression of shape, exhibited by various crystals, and even more remarkably in the affinities which we can recognize among what we know as elementary substances.

There is another important point to be borne in mind. According to the teaching of Evolutionists such as Darwin or Haeckel,[245] every Species has originated from a single ancestor,--or, as they should rather say, from a single pair.

If this were so, it would necessarily follow that every new form, originating in some particular spot of earth, would very gradually spread thence to other regions, fighting its way along. As Mr. Darwin acknowledges,[246] "The development by this means (i.e. Natural Selection) of a group of forms, all of which are descended from some one progenitor, must have been an extremely slow process; and the progenitors must have lived long before their modified descendants."

Of this gradual spread of new types there should, at least in some cases, be some palaeontological evidence.

It is likewise by no means easy to understand how species thus generated could stand solitary and isolated from kindred forms in the records of the earth. The pair of individuals which started a new persistent group,--its members all stamped with the same specific characters, while all around were in a state of flux and divergence,--differed from their immediate ancestors, as we have seen, only infinitesimally. They can have differed no more from many of their contemporaries, for all the lines of descent must ramify afresh in each generation, and so form a web rather than anything like a line. It is not very easy to understand how a pair here and there struck root and founded a species, while the thousands which jostled them round about failed to do so, for the others which survived longest must be supposed to have resembled them most nearly, and therefore to have partic.i.p.ated in their advantages. At least, we should expect to find around them the debris of the mult.i.tude they vanquished in the struggle for existence.

We are told, moreover, that, with hardly an exception, the organic forms found in a fossil state must be supposed to be the last of their special line of development, which terminated in them; so that neither can they be claimed as the direct ancestors of any other forms, fossil or living, nor can any others which are actually known be claimed as their progenitors. The genealogies supplied for almost all known species, extinct or existing, are admittedly conjectural, and as in the most famous instance of all, namely the supposed common ancestor of simians and men, the links are persistently "missing." Thus M. de Quatref.a.ges, speaking of the human pedigree as set forth by Professor Haeckel, writes thus:[247]

All species, existing or extinct, are said to have been preceded by _ancestral forms_ which have disappeared without leaving the slightest vestige behind them. The _amphioxus_ itself, which more than any other realizes the type of the group it represents, was preceded, according to Haeckel, by the _provertebrate_, which no man has ever seen, but of which, nevertheless, the Jena professor gives us a figure, and describes the anatomy.

Thus the number of forms postulated by the theory of genetic Evolution, must have been enormous beyond conception, in comparison with those belonging to the numerically insignificant groups which formed the mere extremities of branches on the genealogical tree.

This being premised, we must ask what Geology has to tell us on the subject, and it will be well to begin by briefly recalling the main features of the geological record.

The stratified rocks comprising the crust of the earth, in which fossil plants and animals are found embedded, have evidently been formed at successive periods, chiefly by the agency of water, each formation having begun as a sediment like the mud or ooze at the bottom of our oceans and seas. Geological investigation has proved that the chronological order of the strata thus deposited can be satisfactorily determined, and they are found to divide themselves, in respect of the organisms they contain, into three great series, lying above the _Azoic_ (or lifeless) rocks, older than them all.

These series, beginning from the bottom, in which order we shall have to trace their history, are most conveniently named _Primary_, _Secondary_, and _Tertiary_, otherwise termed respectively, _Palozoic_ ("ancient life"), _Mesozoic_ ("middle life"), and _Kainozoic_ ("recent life").

Each of these again, contains various formations, or as we may call them volumes of its chronicle, each of which has its fixed place in order of sequence.

Thus, always proceeding from below upwards, in the _Primary_ series, commencing with the _Laurentian_, we find successively the _Huronian_, _Cambrian_, _Silurian_, _Devonian_ or _Old Red Sandstone_, _Carboniferous_, and _Permian_.

In the _Secondary_, the lowest formation is the _Tria.s.sic_ or _New Red Sandstone_, followed by the _Jura.s.sic_ or _Oolite_, and the _Cretaceous_ or _Chalk_.

Finally the _Tertiary_ has three main divisions; the _Eocene_, or "dawn of the recent," _Miocene_, or "less recent," and _Pliocene_, or "more recent."

Above these comes the series now in progress, variously called, _Quaternary_, _Post-Tertiary_, and _Pleistocene_, or "most recent."

It seems advisable to begin our investigation with the vegetable kingdom, as its cla.s.sification being comparatively simple, the essential points of its development are easily followed. We cannot do better than start with the summary of its main divisions furnished by Mr.

Carruthers.[248]

The vegetable kingdom is divided into sections, according to the simplicity or complexity of structure. a.s.sociated with plants of simple structure we find, as a rule, more elementary organs of reproduction. Linnaeus made two great divisions, of flowering (_Phanerogams_) and flowerless plants (_Cryptogams_).... The higher group have flowers, with their stamens and pistils, which produce seeds, while the lower group are without flowers and bear spores, which are much simpler bodies than seeds. There are seven main groups of spore-bearers--the _algae_ or water-weeds; the _fungi_ or mushroom family; the _lichens_, which cover old walls and rocks with patches of coloured vegetation; the _mosses_ with their green leaves and urn-shaped fruit; the _ferns_ with their large and usually much-divided leaves, on the back or edges of which the spores are borne; the _horsetails_, found in wet places, having jointed hollow stems and spores produced in little cones; and the _club-mosses_, upright or creeping leafy plants found on our mountains. These seven groups may be arranged in two divisions, according to the tissues of which they are formed. In the first four the whole plant is composed of _cells_, while in the last three a firm _vascular skeleton_ is present. These characters are of great importance to the student of fossil plants.... The flowering plants are more complex in their structure, and in their organs of reproduction. The lowest group of these plants is the _Gymnosperms_, or naked-seeded plants, like our yews and pines. The other flowering plants (_Angiosperms_) have their seeds in a closed fruit. These are divided into two sections from characters derived from the embryo plant in the seed, depending on whether this minute plant has one seed-leaf (_cotyledon_) or two, and so we have _Monocotyledons_ and _Dicotyledons_. The higher group, or dicotyledons, have been arranged into three divisions, according to the complexity of the flower. In one large group (_Apetalae_) the pistil and stamens are not surrounded by petals, e.g. in the oak and the stinging nettle: superior to them are the plants (_Monopetalae_) in which the petals form a cup, as the blue-bell[249] and the gentian, while the highest group (_Polypetalae_) have all the petals separate, as the b.u.t.tercups and roses.[250]