A common furnace will sometimes exemplify the operation of forces which have produced the Giant's Causeway; and in a sloping ploughed field after rain we may often observe, at the lower end of a furrow, a handful of washed and neatly deposited mud or sand, capable of serving as an ill.u.s.tration of the way in which Nature has produced the deltas of the Nile and Ganges. In the ripple-marks on sandy beaches of the present day we see Nature's exact repet.i.tion of the operations by which she impressed similar features on the sandstones of the carboniferous era.

Even such marks as wind-slanted rain would in our day produce on tide-deserted sands have been read upon tablets of the ancient strata.

It is the same Nature--that is to say, G.o.d through or in the manner of Nature--working everywhere and in all time, causing the wind to blow, and the rain to fall, and the tide to ebb and flow, inconceivable ages before the birth of our race, as now. So also we learn from the conifers of those old ages that there were winter and summer upon earth, before any of us lived to liken the one to all that is genial in our own nature, or to say that the other breathed no airs so unkind as man's ingrat.i.tude. Let no one suppose there is any necessary disrespect for the Creator in thus tracing His laws in their minute and familiar operations. There is really no true great and small, grand and familiar, in Nature. Such only appear when we thrust ourselves in as a point from which to start in judging. Let us pa.s.s, if possible, beyond immediate impressions, and see all in relation to Cause, and we shall chastenedly admit that the whole is alike worshipful.

The Creator, then, is seen to have formed our earth, and effected upon it a long and complicated series of changes, in the same manner in which we find that he conducts the affairs of Nature before our living eyes; that is, in the manner of natural law. This is no rash or unauthorised affirmation. It is what we deduce from the calculation of a Newton and a Laplace on the one hand, and from the industrious observation of facts by a Murchison and a Lyell on the other. It is a point of stupendous importance in human knowledge; here at once is the whole region of the inorganic taken out of the dominion of marvel, and placed under an idea of Divine regulation.

_III.--The History of the Earth's Life_

Mixed up, however, with the geological changes, and apparently as final object connected with the formation of the globe itself, there is another set of phenomena presented in the course of our history--the coming into existence, namely, of a long suite of living things, vegetable and animal, terminating in the families which we still see occupying the surface. The question arises: In what manner has this set of phenomena originated? Can we touch at and rest for a moment on the possibility of plants and animals having likewise been produced in a natural way, thus a.s.signing immediate causes of but one character for everything revealed to our sensual observation; or are we at once to reject this idea, and remain content, either to suppose that creative power here acted in a different way, or to believe unexaminingly that the inquiry is one beyond our powers? Taking the last question first, I would reply that I am extremely loth to imagine that there is anything in Nature which we should, for any reason, refrain from examining. If we can infer aught from the past history of science, it is that the whole of Nature is a legitimate field for the exercise of our intellectual faculties; that there is a connection between this knowledge and our well-being; and that, if we may judge from things once despaired of by our inquiring reason, but now made clear and simple, there is none of Nature's mysteries which we may not hopefully attempt to penetrate. To remain idly content to presume a various cla.s.s of immediate causes for organic Nature seems to me, on this ground, equally objectionable.

With respect to the other question the idea has several times arisen that some natural course was observed in the production of organic things, and this even before we were permitted to attain clear conclusions regarding inorganic nature. It was always set quickly aside as unworthy of serious consideration. The case is different now, when we have admitted law in the whole domain of the inorganic.

Otherwise, the absurdities into which we should be led must strike every reflecting mind. The Eternal Sovereign arranges a solar or an astral system, by dispositions imparted primordially to matter; he causes, by the same means, vast oceans to join and continents to rise, and all the grand meteoric agencies to proceed in ceaseless alternation, so as to fit the earth for a residence of organic beings. But when, in the course of these operations, fuci and corals are to be, for the first time, placed in these oceans, a change in his plan of administration is required. It is not easy to say what is presumed to be the mode of his operations. The ignorant believe the very hand of Deity to be at work.

Amongst the learned, we hear of "creative fiats," "interferences,"

"interpositions of the creative energy," all of them very obscure phrases, apparently not susceptible of a scientific explanation, but all tending simply to this: that the work was done in a marvellous way, and not in the way of Nature.

But we need not a.s.sume two totally distinct modes of the exercise of the divine power--one in the course of inorganic nature and the other in intimately connected course of organic nature.

Indeed, when all the evidence is surveyed, it seems difficult to resist the impression that vestiges, at least, are seen of the manner and method of the Creator in this part of His work. It appears to be a case in which rigid proof is hardly to be looked for. But such evidences as exist are remarkably consistent and harmonious. The theory pointed to consorts with everything else which we have learned accurately regarding the history of the universe. Science has not one positive affirmation on the other side. Indeed, the view opposed to it is not one in which science is concerned; it appears as merely one of the prejudices formed in the non-age of our race.

For the history, then, of organic nature, I embrace, not as a proved fact, but as a rational interpretation of things as far as science has revealed them, the idea of progressive development. We contemplate the simplest and most primitive types of being as giving birth to a type superior to it; this again producing the next higher, and so on to the highest. We contemplate, in short, a universal gestation of Nature, like that of the individual being, and attended as little by circ.u.mstances of a miraculous kind as the silent advance of an ordinary mother from one week to another of her pregnancy.

Thus simple--after ages of marvelling--appears organic creation, while yet the whole phenomena are, in another point of view, wonders of the highest kind, being the undoubted results of ordinances arguing the highest attributes of foresight, skill and goodness on the part of their Divine Author.

If, finally, we study the mind of man, we find that its Almighty Author has destined it, like everything else, to be developed from inherent qualities.

Thus the whole appears complete on one principle. The ma.s.ses of s.p.a.ce are formed by law; law makes them in due time theatres of existence for plants and animals; sensation, disposition, intellect, are all in like manner sustained in action by law.

It is most interesting to observe into how small a field the whole of the mysteries of Nature thus ultimately resolve themselves. The inorganic has been thought to have one final comprehensive law--gravitation. The organic, the other great department of mundane things, rests in like manner on one law, and that is--development. Nor may even these be after all twain, but only branches of one still more comprehensive law, the expression of a unity flowing immediately from the One who is first and last.

_IV.--The Future and its Meaning_

The question whether the human race will ever advance far beyond its present position in intellect and morals is one which has engaged much attention. Judging from the past, we cannot reasonably doubt that great advances are yet to be made; but, if the principle of development be admitted, these are certain, whatever may be the s.p.a.ce of time required for their realisation. A progression resembling development may be traced in human nature, both in the individual and in large groups of men. Not only so, but by the work of our thoughtful brains and busy hands we modify external nature in a way never known before. The physical improvements wrought by man upon the earth's surface I conceive as at once preparations for, and causes of, the possible development of higher types of humanity, beings less strong in the impulsive parts of our nature, more strong in the reasoning and moral, more fitted for the delights of social life, because society will then present less to dread and more to love.

The history and const.i.tution of the world have now been hypothetically explained, according to the best lights which a humble individual has found within the reach of his perceptive and reasoning faculties.

We have seen a system in which all is regularity and order, and all flows from, and is obedient to, a divine code of laws of unbending operation. We are to understand from what has been laid before us that man, with his varied mental powers and impulses, is a natural problem of which the elements can be taken cognisance of by science, and that all the secular destinies of our race, from generation to generation, are but evolutions of a law statuted and sustained in action by an all-wise Deity.

There may be a faith derived from this view of Nature sufficient to sustain us under all sense of the imperfect happiness, the calamities, the woes and pains of this sphere of being. For let us but fully and truly consider what a system is here laid open to view and we cannot well doubt that we are in the hands of One who is both able and willing to do us the most entire justice. Surely, in such a faith we may well rest at ease, even though life should have been to us but a protracted malady. Thinking of all the contingencies of this world as to be in time melted into or lost in some greater system, to which the present is only subsidiary, let us wait the end with patience and be of good cheer.

GEORGES CUVIER

The Surface of the Globe

Georges Cuvier was born Aug. 24, 1769, at Montbeliard, France. He had a brilliant academic career at Stuttgart Academy, and in 1795, at the age of twenty-six, he was appointed a.s.sistant professor of comparative anatomy at the Museum d'Histoire Naturelle in Paris, and was elected a member of the National Inst.i.tute. From this date onwards to his death in 1832, his scientific industry was remarkable. Both as zoologist and palaeontologist he must be regarded as one of the greatest pioneers of science. He filled many important scientific posts, including the chair of Natural History in the College de France, and a professorship at the Jardin des Plantes. In 1808 he was made member of the Council of the Imperial University; and in 1814, President of the Council of Public Instruction. In 1826 he was made grand officer of the Legion of Honour, and five years later was made a peer of France. The "Discours sur les Revolutions de la Surface du Globe," published in 1825, is essentially a preliminary discourse to the author's celebrated work, "Recherches sur les Oss.e.m.e.ns fossiles de Quadrupedes." It is an endeavour to trace the relationship between the changes which have taken place on the surface of the globe and the changes which have taken place in its animal inhabitants, with especial reference to the evidence afforded by fossil remains of quadrupeds. "It is apparent," Cuvier writes, "that the bones of quadrupeds conduct us, by various reasonings, to more precise results than any other relics of organised bodies." The two books together may be considered the first really scientific palaeontology.

_I.--Effects of Geological Change_

My first object will be to show how the fossil remains of the terrestrial animals are connected with the theory of the earth. I shall afterwards explain the principles by which fossil bones may be identified. I shall give a rapid sketch of new species discovered by the application of these principles. I shall then show how far these varieties may extend, owing to the influence of the climate and domestication. I shall then conceive myself justified in concluding that the more considerable differences which I have discovered are the results of very important catastrophes. Afterwards I shall explain the peculiar influence which my researches should exercise on the received opinions concerning the revolutions of the globe. Finally, I shall examine how far the civil and religious history of nations accords with the results of observation on the physical history of the earth.

When we traverse those fertile plains, where tranquil waters cherish, as they flow, an abundant vegetation, and where the soil, trod by a numerous people, adorned with flourishing villages, rich cities, and superb monuments, is never disturbed save by the ravages of war, or the oppression of power, we can hardly believe that Nature has also had her internal commotions. But our opinions change when we dig into this apparently peaceful soil, or ascend its neighboring hills. The lowest and most level soils are composed of horizontal strata, and all contain marine productions to an innumerable extent. The hills to a very considerable height are composed of similar strata and similar productions. The sh.e.l.ls are sometimes so numerous as to form the entire ma.s.s of the soil, and all quarters of the globe exhibit the same phenomenon.

The time is past when ignorance could maintain that these remains of organised bodies resulted from the caprice of Nature, and were productions formed in the bosom of the earth by its generative powers; for a scrupulous comparison of the remains shows not the slightest difference between the fossil sh.e.l.ls and those that are now found in the ocean. It is clear, then, that they inhabited the sea, and that they were deposited by the sea in the places where they are now found; and it follows, too, that the sea rested in these places long enough to form regular, dense, vast deposits of aquatic animals.

The bed of the sea, accordingly, must have undergone some change either in extent or situation.

Further, we find under the horizontal strata, _inclined_ strata. Thus the sea, previously to the formation of the horizontal strata, must have formed others, which have been broken, inclined, and overturned by some unknown causes.

More than this, we find that the fossils vary with the depth of the strata, and that the fossils of the deeper and more ancient strata exhibit a formation proper to themselves; and we find in some of the strata, too, remains of terrestrial life.

The evidence is thus plain that the animal life in the sea has varied, and that parts of the earth's surface have been alternately dry land and ocean. The very soil, which terrestrial animals at present inhabit has a history of previous animal life, and then submersion under the sea.

The reiterated irruptions and retreats of the sea have not all been gradual, but, on the contrary, they have been produced by sudden catastrophes. The last catastrophe, which inundated and again left dry our present continents, left in the northern countries the carca.s.ses of large quadrupeds, which were frozen, and which are preserved even to the present day, with their skin, hair and flesh. Had they not been frozen the moment they were killed, they must have putrefied; and, on the other hand, the intense frost could not have been the ordinary climatic condition, for they could not have existed at such low temperatures. In the same instant, then, in which these animals perished the climate which they inhabited must have undergone a complete revolution.

The ruptures, the inclinations, the overturnings of the more ancient strata, likewise point to sudden and violent changes.

Animal life, then, has been frequently disturbed on this earth by terrific catastrophes. Living beings innumerable have perished. The inhabitants of the dry land have been engulfed by deluges; and the tenants of the water, deserted by their element, have been left to perish from drought.

Even ancient rocks formed or deposited before the appearance of life on the earth show signs of terrific violence.

It has been maintained by some that the causes now at work altering the face of the world are sufficient to account for all the changes through which it has pa.s.sed: but that is not so. None of the agents Nature now employs--rain, thaw, rivers, seas, volcanoes--would have been adequate to produce her ancient works.

To explain the external crust of the world, we require causes other than those present in operation, and a thousand extraordinary theories have been advanced. Thus, according to one philosopher, the earth has received in the beginning a uniform light crust which caused the abysses of the ocean, and was broken to produce the Deluge. Another supposed the Deluge to be caused by the momentary suspension of the cohesion of minerals.

Even accomplished scientists and philosophers have advanced impossible and contradictory theories.

All attempts at explanation have been stultified by an ignorance of the facts to be explained, or by a partial survey of them, and especially by a neglect of the evidence afforded by fossils. How was it possible not to perceive that the theory of the earth owes its origin to fossils alone? They alone, in truth, inform us with any certainty that the earth has not always had the same covering, since they certainly must have lived upon its surface before they were buried in its depths. If there were only strata without fossils, one might maintain that the strata had all been formed together. Hitherto, in fact, philosophers have been at variance on every point save one, and that is that the sea has changed its bed; and how could this have been known except for fossils?

From this consideration I was led to study fossils; and since the field was immense I was obliged to specialise in one department of fossils, and selected for study the fossil bones of quadrupeds. I made this selection because only from a study of fossil quadrupeds can one hope to ascertain the number and periods and contents of irruptions of the sea; and because, since the number of quadrupeds is limited, and most quadrupeds known, we have better means of a.s.suring ourselves if the fossil remains are remains of extinct or extant animals. Animals such as the griffin, the cartazonon, the unicorn, never lived, and there are probably very few quadrupeds now living which have not been found by man.

But though the study of fossil quadruped be enlightening, it has its own special difficulties. One great difficulty arises from the fact that it is very rare to find a fossil skeleton approaching to a complete state.

Fortunately, however, there is a principle in comparative anatomy which lessens this difficulty. Every organised being const.i.tutes a complete and compact system with all its parts in mutual correspondence. None of its parts can be changed without changing other parts, and consequently each part, taken separately, indicates the others.

Thus, if the intestines of an animal are made to digest raw flesh, its jaws must be likewise constructed to devour prey, its claws to seize and tear it, its teeth to rend it, its limbs to overtake it, its organs of sense to discern it afar. Again, in order to enable the jaw to seize with facility, a certain form of condyle is necessary, and the zygomatic arch must be well developed to give attachment to the ma.s.seter muscle.

Again, the muscles of the neck must be powerful, whence results a special form in the vertebrae and the occiput, where the muscles are attached. Yet again, in order that the claws may be effective, the toe-bones must have a certain form, and must have muscles and tendons distributed in a certain way. In a word, the form of the tooth necessitates the form of the condyle, of the shoulder-blade, and of the claws, of the femur, and of all the other bones, and all the other bones taken separately will give the tooth. In this manner anyone who is scientifically acquainted with the laws of organic economy may from a fragment reconstruct the whole animal. The mark of a cloven hoof is sufficient to tell the form of the teeth and jaws and vertebrae and leg-bones and thigh-bones and pelvis of the animal. The least fragment of bone, the smallest apophysis, has a determinative character in relation to the cla.s.s, the order, the genus, and species to which it may belong. This is so true that, if we have only a single extremity of bone well preserved, we may, with application and a skilful use of a.n.a.logy and exact comparison, determine all those points with as much certainty as if we were in possession of the entire animal. By the application of these principles we have identified and cla.s.sified the fossil remains of more than one hundred and fifty mammalia.

_II.--What the Fossils Teach_

An examination of the fossils on the lines I have indicated shows that out of one hundred and fifty mammiferous and oviparous quadrupeds, ninety are unknown to present naturalists, and that in the older layers such oviparous quadrupeds as the ichthyosauri and plesiosauri abound.

The fossil elephant, the rhinoceros, the hippopotamus, and the mastodons are not found in the more ancient layers. In fact, the species which appear the same as ours are found only in superficial deposits.