ANTIQUITY OF MAN.

I do not propose to bestow any large amount of space upon the enumeration of the palÆontological evidence of the antiquity of man. The works of the various eminent authors who have devoted themselves to the special consideration of this subject exhaust all that can be said upon it with our present data, and to these I must refer the reader who is desirous of acquainting himself critically with its details, confining myself to a few general statements based on these labours.

In the early days of geological science when observers were few, great groups of strata were arranged under an artificial classification, which, while it has lost to a certain extent the specific value which it then assumed to possess, is still retained for purposes of convenient reference. Masters of the science acquired, so to say, a possessive interest in certain regions of it, and the names of Sedgwick, Murchison, Jukes, Phillips, Lyell, and others became, and will remain, inseparably associated with the history of those great divisions of the materials of the earth’s crust, which, under the names of the Cambrian, Silurian, Devonian, Carboniferous, and Tertiary formations, have become familiar to us.

In those days, when observations were limited to a comparatively small area, the lines separating most of these formations were supposed to be hard and definite; forms of life which characterized one, were presumed to have become entirely extinct before the inauguration of those which succeeded them, and breaks in the stratigraphical succession appeared to justify the opinion, held by a large and influential section, that great cataclysms or catastrophes had marked the time when one age or formation terminated and another commenced to succeed it.

By degrees, and with the increase of observers, both in England and in every portion of the world, modifications of these views obtained; passage beds were discovered, connecting by insensible gradations formations which had hitherto been supposed to present the most abrupt separations; transitional forms of life connecting them were unearthed; and an opinion was advanced, and steadily confirmed, which at the present day it is probable no one would be found to dispute, that not all in one place or country, but discoverable in some part or other of the world, a perfect sequence exists, from the very earliest formations of which we have any cognizance, up to the alluvial and marine deposits in process of formation at the present day.[71]Correlatively it was deduced that the same phenomena of nature have been in action since the earliest period when organic existence can be affirmed. The gradual degradation of pre-existing continents by normal destructive agencies, the upheaval and subsidence of large areas, the effusion from volcanic vents, into the air or sea, of ashes and lavas, the action of frost and ice, of heat, rain, and sunshine—all these have acted in the past as they are still acting before our eyes.

In earlier days, arguing from limited data, a progressive creation was claimed which confined the appearance of the higher form of vertebrate life to a successive and widely-stepped gradation.

Hugh Miller, and other able thinkers, noted with satisfaction the appearance, first of fish, then of reptiles, next of birds and mammals, and finally, as the crowning work of all, both geologically and actually, quite recently of man.

This wonderful confirmation of the Biblical history of creation appealed so gratefully to many, that it caused for a time a disposition to cramp discovery, and even to warp the facts of science, in order to make them harmonize with the statements of Revelation. The alleged proofs of the existence of pre-historic man were for a long time jealously disputed, and it was only by slow degrees that they were admitted, that the tenets of the Darwinian school gained ground, and that the full meaning was appreciated of such anomalies as the existence at the present day of Ganoid fishes both in America and Europe, of true PalÆozoic type, or of Oolitic forms on the Australian continent and in the adjacent seas.

But step by step marvellous palÆontological discoveries were made, and the pillars which mark the advent of each great form of life have had to be set back, until now no one would, I think, be entirely safe in affirming that even in the Cambrian, the oldest of all fossiliferous formations, vestiges of mammals, that is to say, of the highest forms of life, may not at a future day be found, or that the records contained between the Cambrian and the present day, may not in fact be but a few pages as compared with the whole volume of the world’s history.[72]It is with the later of these records that we have to deal, in which discoveries have been made sufficiently progressive to justify the expectation that they have by no means reached their limit, and sufficiently ample in themselves to open the widest fields for philosophic speculation and deduction.

Before stating these, it may be premised that estimates have been attempted by various geologists of the collective age of the different groups of formations.[73] These are based on reasonings which for the most part it is unnecessary to give in detail, in so much as these can scarcely yet be considered to have passed the bounds of speculation, and very different results can be arrived at by theorists according to the relative importance which they attach to the data employed in the calculation.

Thus Mr. T. Mellard Reade, in a paper communicated to the Royal Society in 1878, concludes that the formation of the sedimentary strata must have occupied at least six hundred million years: which he divides in round numbers as follows:—

He estimates the average thickness of the sedimentary crust of the earth to be at least one mile, and from a computation of the proportion of carbonate and sulphate of lime to materials held in suspension in various river-waters from a variety of formations, infers that one-tenth of this crust is calcareous.

He estimates the annual flow of water in all the great river-basins, the proportion of rain-water running off the granitic and trappean rocks, the percentage of lime in solution which they carry down, and arrives at the conclusion that the minimum time requisite for the elimination of the calcareous matter contained in the sedimentary crust of the earth, is at least six hundred millions of years.

A writer in the Gentleman’s Magazine[74] (Professor Huxley?), whose article I am only able to quote at second-hand, makes an estimate which, though much lower than the above, is still of enormous magnitude, as follows:—

Mr. Darwin, arguing upon Sir W. Thompson’s estimate of a minimum of ninety-eight and maximum of two hundred millions of years since the consolidation of the crust, and on Mr. Croll’s estimate of sixty millions, as the time elapsed since the Cambrian period, considers that the latter is quite insufficient to permit of the many and great mutations of life which have certainly occurred since then. He judges from the small amount of organic change since the commencement of the glacial epoch, and adds that the previous one hundred and forty million years can hardly be considered as sufficient for the development of the varied forms of life which certainly existed towards the close of the Cambrian period.

On the other hand, Mr. Croll considers that it is utterly impossible that the existing order of things, as regards our globe, can date so far back as anything like five hundred millions of years, and, starting with referring the commencement of the Glacial epoch to two hundred and fifty thousand years ago, allows fifteen millions since the beginning of the Eocene period, and sixty millions of years in all since the beginning of the Cambrian period. He bases his arguments on the limit to the age of the sun’s heat as detailed by Sir William Thompson.

Sir Charles Lyell and Professor Haughton respectively estimated the expiration of time from the commencement of the Cambrian at two hundred and forty and two hundred millions of years, basing their calculations on the rate of modification of the species of mollusca, in the one case, and on the rate of formation of rocks and their maximum thickness, in the other.

This, moreover, is irrespective of the vast periods during which life must have existed, which on the development theory necessarily preceded the Cambrian, and, according to Mr. Darwin, should not be less than in the proportion of five to two.

In fine, one school of geologists and zoologists demand the maximum periods quoted above, to account for the amount of sedimentary deposit, and the specific developments which have occurred; the other considers the periods claimed as requisite for these actions to be unnecessary, and to be in excess of the limits which, according to their views, the physical elements of the case permit.Mr. Wallace, in reviewing the question, dwells on the probability of the rate of geological changes having been greater in very remote times than it is at present, and thus opens a way to the reconciliation of the opposing views so far as one half the question is concerned.

Having thus adverted to the principles upon which various theorists have in part based their attacks on the problem of the estimation of the duration of geological ages, I may now make a few more detailed observations upon those later periods during which man is, now, generally admitted to have existed, and refer lightly to the earlier times which some, but not all, geologists consider to have furnished evidences of his presence.

I omit discussing the doubtful assertions of the extreme antiquity of man, which come to us from American observers, such as are based on supposed footprints in rocks of secondary age, figured in a semi-scientific and exceedingly valuable popular journal. There are other theories which I omit, both because they need further confirmation by scientific investigators, and because they deal with periods so remote as to be totally devoid of significance for the argument of this work.

Nor, up to the present time, are the evidences of the existence of man during Miocene and Pliocene times admitted as conclusive. Professor Capellini has discovered, in deposits recognised by Italian geologists as of Pliocene age, cetacean bones, which are marked with incisions such as only a sharp instrument could have produced, and which, in his opinion, must be ascribed to human agency. To this view it is objected that the incisions might have been made by the teeth of fishes, and further evidence is waited for.

Not a few discoveries have been made, apparently extending the existence of man to a much more remote antiquity, that of Miocene times. M. l’AbbÉ Bourgeois has collected, from undoubted Miocene strata at Thenay, supposed flint implements which he conceives to exhibit evidences of having been fashioned by man, as well as stones showing in some cases traces of the action of fire, and which he supposes to have been used as pot-boilers. M. Carlos Ribeiro has made similar discoveries of worked flints and quartzites in the Pliocene and Miocene of the Tagus; worked flint has been found in the Miocene of Aurillac (Auvergne) by M. Tardy, and a cut rib of Halitherium fossile, a Miocene species, by M. Delaunay at PouancÉ.

Very divided opinions are entertained as to the interpretation of the supposed implements discovered by M. l’AbbÉ Bourgeois. M. Quatrefages, after a period of doubt, has espoused the view of their being of human origin, and of Miocene age. “Since then,” he says, “fresh specimens discovered have removed my last doubts. A small knife or scraper, among others, which shows a fine regular finish, can, in my opinion, only have been shaped by man. Nevertheless, I do not blame those of my colleagues who deny or still doubt. In such a matter there is no very great urgency, and, doubtless, the existence of Miocene man will be proved, as that of Glacial and Pliocene has been, by facts.” Mr. Geikie, from whose work—Prehistoric Europe—I have summarized the above statements, says, in reference to this question: “There is unquestionably much force in what M. Quatrefages says; nevertheless, most geologists will agree with him that the question of man’s Miocene age still remains to be demonstrated by unequivocal evidence. At present, all that we can safely say is, that man was probably living in Europe near the close of the Pliocene period, and that he was certainly an occupant of our continent during glacial and interglacial times.”

Professor Marsh considers that the evidence, as it stands to-day, although not conclusive, “seems to place the first appearance of man [in America] in the Pliocene, and that the best proofs of this are to be found on the Pacific coast.” He adds: “During several visits to that region many facts were brought to my knowledge which render this more than probable. Man, at this time, was a savage, and was doubtless forced by the great volcanic outbreaks to continue his migration. This was at first to the south, since mountain chains were barriers on the east,” and “he doubtless first came across Behring’s Straits.”

I have hitherto assumed a certain acquaintance, upon the part of the general reader, with the terms Eocene, Miocene, and Pliocene, happily invented by Sir Charles Lyell to designate three of the four great divisions of the Tertiary age. These, from their universal acceptation and constant use, have “become familiar in our mouths as household words.” But it will be well, before further elaborating points in the history of these groups, bearing upon our argument, to take into consideration their subdivisions, and the equivalent or contemporary deposits composing them in various countries. This can be most conveniently done by displaying these, in descending order, in a tabular form, which I accordingly annex below. This is the more desirable as there are few departments in geological science which have received more attention than this; or in which greater returns, in the shape of important and interesting discoveries relative to man’s existence, have been made.

Comparatively recent—comparatively, that is to say, with regard to the vast Æons that preceded them, but extending back over enormous spaces of time when contrasted with the limited duration of written history,—they embrace the period during which the mainly existing distribution of land and ocean has obtained, and the present forms of life have appeared by evolution from preceding species, or, as some few still maintain, by separate and special creation.

THE TERTIARY OR CAINOZOIC AGE.

PLIOCENE.

MIOCENE.

EOCENE.

The subdivisions of the Eocene have been worked out in great detail in Britain, France, and America. Those of most other countries have either not yet been fully studied or their exact equivalence remains undetermined.

We learn, both from the nature of these deposits and from their organic contents, that climatic oscillations have been passing during the whole period of their deposition over the surface of the globe, and inducing corresponding fluctuations in the character of the vegetable and animal life abounding on it. A complete collation of these varying conditions at synchronous periods remains to be achieved, but the study of our own country, and those adjacent to it, shows that alternations of tropical, boreal, and temperate climate have occurred in it; a remarkable series of conditions which has only lately been thoroughly and satisfactorily accounted for.

Thus, during a portion of the Eocene period a tropical climate prevailed, as is evidenced by deposits containing remains of palms of an equatorial type, crocodiles, turtles, tropical shells, and other remains attesting the existence of a high temperature. The converse is proved of the Pleistocene by the existence of a boreal fauna, and the widespread evidences of glacial action. The gradations of climate during the Miocene and Pliocene, and the amelioration subsequent to the glacial period, have resulted in the gradual development or appearance of specific life as it exists at present.

Corresponding indications of secular variability of climate are derived from all quarters: during the Miocene age, Greenland (in N. Lat. 70°) developed an abundance of trees, such as the yew, the Redwood, a Sequoia allied to the Californian species, beeches, planes, willows, oaks, poplars, and walnuts, as well as a Magnolia and a Zamia. In Spitzbergen (N. Lat. 78° 56') flourished yews, hazels, poplars, alders, beeches, and limes. At the present day, a dwarf willow and a few herbaceous plants form the only vegetation, and the ground is covered with almost perpetual ice and snow.

Many similar fluctuations of climate have been traced right back through the geological record; but this fact, though interesting in relation to the general solution of the causes, has little bearing on the present purpose.Sir Charles Lyell conceived that all cosmical changes of climate in the past might be accounted for by the varying preponderance of land in the vicinity of the equator or near the poles, supplemented, of course, in a subordinate degree by alteration of level and the influence of ocean currents. When, for example, at any geological period the excess of land was equatorial, the ascent and passage northwards of currents of heated air would, according to his view, render the poles habitable; while, per contrÂ, the excessive massing of land around the pole, and absence of it from the equator, would cause an arctic climate to spread far over the now temperate latitudes.

The correctness of these inferences has been objected to by Mr. James Geikie and Dr. Croll, who doubt whether the northward currents of air would act as successful carriers of heat to the polar regions, or whether they would not rather dissipate it into space upon the road. On the other hand, Mr. Geikie, though admitting that the temperature of a large unbroken arctic continent would be low, suggests that, as the winds would be stripped of all moisture on its fringes, the interior would therefore be without accumulations of snow and ice; and in the more probable event of its being deeply indented by fjords and bays, warm sea-currents (the representatives of our present Gulf and Japan streams, but possessing a higher temperature than either, from the greater extent of equatorial sea-surface originating them, and exposed to the sun’s influence) would flow northward, and, ramifying, carry with them warm and heated atmospheres far into its interior, though even these, he thinks, would be insufficient in their effects under any circumstances to produce the sub-tropical climates which are known to have existed in high latitudes.

Mr. John Evans[75] has thrown out the idea that possibly a complete translation of geographical position with respect to polar axes may have been produced by a sliding of the whole surface crust of the globe about a fluid nucleus. This, he considers, would be induced by disturbances of equilibrium of the whole mass from geological causes. He further points out that the difference between the polar and equatorial diameters of the globe, which constitutes an important objection to his theory, is materially reduced when we take into consideration the enormous depth of the ocean over a large portion of the equator, and the great tracts of land elevated considerably above the sea-level in higher latitudes. He also speculates on the general average of the surface having in bygone geological epochs approached much more nearly to that of a sphere than it does at the present time.

Sir John Lubbock favoured the idea of a change in the position of the axis of rotation, and this view has been supported by Sir H. James[76] and many later geologists.[77] If I apprehend their arguments correctly, this change could only have been produced by what may be termed geological revolutions. These are great outbursts of volcanic matter, elevations, subsidences, and the like. These having probably been almost continuous throughout geological time, incessant changes, small or great, would be demanded in the position of the axis, and the world must be considered as a globe rolling over in space with every alteration of its centre of gravity. The possibility of this view must be left for mathematicians and astronomers to determine.

Sounder arguments sustain the theory propounded by Dr. Croll (though this, again, is not universally accepted), that all these alterations of climate can be accounted for by the effects of nutation, and the precession of the equinoxes. From these changes, combined with the eccentricity of the ecliptic from the first, it results that at intervals of ten thousand five hundred years, the northern and southern hemispheres are alternately in aphelion during the winter, and in perihelion during the summer months, and vice versÂ; or, in other words, that if at any given period the inclination of the earth’s axis produces winter in the northern hemisphere, while the earth is at a maximum distance from that focus of its orbit in which the sun is situated, then, after an interval of ten thousand five hundred years, and as a result of the sum of the backward motion of the equinoxes along the ecliptic, at the rate of 50' annually, the converse will obtain, and it will be winter in the northern hemisphere while the earth is at a minimum distance from the sun.

The amount of eccentricity of the ecliptic varies greatly during long periods, and has been calculated for several million years back. Mr. Croll[78] has demonstrated a theory explaining all great secular variations of climate as indirectly the result of this, through the action of sundry physical agencies, such as the accumulation of snow and ice, and especially the deflection of ocean currents. From a consideration of the tables which he has computed of the eccentricity and longitude of the earth’s orbit, he refers the glacial epoch to a period commencing about two hundred and forty thousand years back, and extending down to about eighty thousand years ago, and he describes it as “consisting of a long succession of cold and warm periods; the warm periods of the one hemisphere corresponding in time with the cold periods of the other, and vice versÂ.”

Having thus spoken of the processes adopted for estimating the duration of geological ages, and the results which have been arrived at, with great probability of accuracy, in regard to some of the more recent, it now only remains to briefly state the facts from which the existence of man, during these latter periods, has been demonstrated. The literature of this subject already extends to volumes, and it is therefore obviously impossible, in the course of the few pages which the limits of this work admit, to give anything but the shortest abstract, or to assign the credit relatively due to the numerous progressive workers in this rich field of research. I therefore content myself with taking as my text-book Mr. James Geikie’s Prehistoric Europe, the latest and most exhaustive work upon the subject, and summarizing from it the statements essential to my purpose.

From it we learn that, long prior to the ages when men were acquainted with the uses of bronze and iron, there existed nations or tribes, ignorant of the means by which these metals are utilized, whose weapons and implements were formed of stone, horn, bone, and wood.

These, again, may be divided into an earlier and a later race, strongly characterized by the marked differences in the nature of the stone implements which they respectively manufactured, both in respect to the material employed and the amount of finish bestowed upon it. To the two periods in which these people lived the terms PalÆolithic and Neolithic have been respectively applied, and a vast era is supposed to have intervened between the retiring from Europe of the one and the appearance there of the other.

PalÆolithic man was contemporaneous with the mammoth (Elephas primigenius), the woolly rhinoceros (Rhinoceros primigenius), the Hippopotamus major, and a variety of other species, now quite extinct, as well as with many which, though still existing in other regions, are no longer found in Europe; whereas the animals contemporaneous with Neolithic man were essentially the same as those still occupying it.

Fig. 19.—Engraving by PalÆolithic Man on Reindeer Antler.[79]

(The two sides of the same piece of antler are here represented.)

The stone implements of PalÆolithic man had but little variety of form, were very rudely fashioned, being merely chipped into shape, and never ground or polished; they were worked nearly entirely out of flint and chert. Those of Neolithic man were made of many varieties of hard stone, often beautifully finished, frequently ground to a sharp point or edge, and polished all over.

PalÆolithic men were unacquainted with pottery and the art of weaving, and apparently had no domesticated animals or system of cultivation; but the Neolithic lake dwellers of Switzerland had looms, pottery, cereals, and domesticated animals, such as swine, sheep, horses, dogs, &c.

Implements of horn, bone, and wood were in common use among both races, but those of the older are frequently distinguished by their being sculptured with great ability or ornamented with life-like engravings of the various animals living at the period; whereas there appears to have been a marked absence of any similar artistic ability on the part of Neolithic man.

Fig. 20.—Reindeer engraved on Antler by PalÆolithic Man. (After Geikie.)

Again, it is noticeable that, while the passage from the Neolithic age into the succeeding bronze age was gradual, and, indeed, that the use of stone implements and, in some parts, weapons, was contemporaneous with that of bronze in other places, no evidence exists of a transition from PalÆolithic into Neolithic times. On the contrary, the examination of bone deposits, such as those of Kent’s Cave and Victoria Cave in England, and numerous others in Belgium and France, attest “beyond doubt that a considerable period must have supervened after the departure of PalÆolithic man and before the arrival of his Neolithic successor.” The discovery of remains of PalÆolithic man and animals in river deposits in England and on the Continent, often at considerable elevations[80] above the existing valley bottoms, and in LÖss, and the identification of the Pleistocene or Quaternary period with Preglacial and Glacial times, offer a means of estimating what that lapse of time must have been.[81]Skeletons or portions of the skeletons of human beings, of admitted PalÆolithic age, have been found in caverns in the vicinity of Liege in Belgium, by Schmerling, and probably the same date may be assigned those from the Neanderthal Cave near DÜsseldorf. A complete skeleton, of tall stature, of probable but not unquestioned PalÆolithic age, has also been discovered in the Cave of Mentone on the Riviera.

These positive remains yield us further inferences than can be drawn from the mere discovery of implements or fragmentary bones associated with remains of extinct animals.

The Mentone man, according to M. RiviÈre, had a rather long but large head, a high and well-made forehead, and the very large facial angle of 85°. In the Liege man the cranium was high and short, and of good Caucasian type; “a fair average human skull,” according to Huxley.

Other remains, such as the jaw-bone from the cave of the Naulette in Belgium, and the Neanderthal skeleton, show marks of inferiority; but even in the latter, which was the lowest in grade, the cranial capacity is seventy-five cubic inches or “nearly on a level with the mean between the two human extremes.”

We may, therefore, sum up by saying that evidences have been accumulated of the existence of man, and intelligent man, from a period which even the most conservative among geologists are unable to place at less than thirty thousand years; while most of them are convinced both of his existence from at least later Pliocene times, and of the long duration of ages which has necessarily elapsed since his appearance—a duration to be numbered, not by tens, but by hundreds of thousands of years.

Fig. 21.—Engraving by PalÆolithic Man on Reindeer Antler.