These several heads include, I think, all the really material evidence of a geological character. It is evidence of a kind not easily reducible into definite dates, but there can be no doubt that its nature, and the rapid accumulation of facts within a small number of years, have created a deep and widespread conviction among geologists and archæologists that we must relegate the origin of man to a much more remote antiquity than that sanctioned by history or by the Biblical chronology. I shall first review the character of this evidence, and then state a number of geological facts which bear in the other direction, and have been somewhat lost sight of in recent discussions. Of the facts above referred to, the most important are those which relate to caverns, peat-bogs, and river-gravels. We may, therefore, first consider the nature and amount of this evidence.
That the reader may more distinctly understand the geological history of these more recent periods of the earth's history which are supposed to have witnessed the advent of man, in Western Europe at least, I quote the following summary from Sir Charles Lyell of the more modern changes in that portion of the world. These are:
"First, a continental period, toward the close of which the forest of Cromer flourished; when the land was at least 500 feet above its present level, perhaps much higher. * * * The remains of Hippopotamus major and Rhinoceros etruscus, found in beds of this period, seem to indicate a climate somewhat milder than that now prevailing in Great Britain. [This was a Preglacial era, and may be regarded as belonging to the close of the Pliocene tertiary.]
"Secondly, a period of submergence, by which the land north of the Thames and Bristol Channel, and that of Ireland, was generally reduced to * * * an archipelago. * * * This was the period of great submergence and of floating ice, when the Scandinavian flora, which occupied the lower grounds during the first continental period, may have obtained exclusive possession of the only lands not covered with perpetual snow. [This represents the Glacial period; but according to the more extreme glacialists only a portion of that period.]
"Thirdly, a second continental period, when the bed of the glacial sea, with its marine shells and erratic blocks, was laid dry, and when the quantity of land equalled that of the first period. * * * During this period there were glaciers in the higher mountains of Scotland and Wales, and the Welsh glaciers * * * pushed before them and cleared out the marine drift with which some valleys had been filled during the period of submergence. * * * During this last period the passage of the Germanic flora into the British area took place, and the Scandinavian plants, together with northern insects, birds, and quadrupeds, retreated into the higher grounds. * * *
"Fourthly, the next and last change comprised the breaking up of the land of the British area once more into numerous islands, ending in the present geographical condition of things. There were probably many oscillations of level during this last conversion of continuous land into islands, and such movements in opposite directions would account for the occurrence of marine shells at moderate heights above the level of the sea, notwithstanding a general lowering of the land. * * * During this period a gradual amelioration of temperature took place, from the cold of the glacial period to the climate of historical times." [134]
The second continental period above referred to is that which appears on the best evidence to have been the time of the introduction of man; but such facts as that of the Settle Cave, and the implements of the breccia in Kent's Cave, if rightly interpreted, would make man preglacial or "interglacial."
The deposits found in caverns in France, Switzerland, Germany, Belgium, and England have afforded a large proportion of the remains from which we derive our notions of the most ancient prehistoric men of Europe. From the Belgian caves, as explored by M. Dupont, we learn that there were two successive prehistoric races, both rude or comparatively uncivilized. The first were men of Turanian type, but of great bodily stature and high cerebral organization, and showing remarkable skill in the manufacture of implements and ornaments of bone and ivory. These men are believed to have been contemporary with the earlier postglacial mammals, as the mammoth and hairy rhinoceros, and to have lived at a time when the European land was more extensive than at present, stretching far to the west of Ireland, and connecting Great Britain with the Continent. The skeletons found at Cro-Magnon, Mentone, and elsewhere in France fully confirm the deductions of Dupont as to this earliest race of Palæocosmic, Palæolithic, or antediluvian man. This grand race seems to have perished or been driven from Europe by the great depression of the level of the land which inaugurated the modern era, and which was probably accompanied by many oscillations of level as well as by considerable changes of climate. They were succeeded by a second race, equally Turanian in type, but of small stature, and resembling the modern Lapps. These were the "allophylian" peoples displaced by the historical Celts, and up to their time the reindeer seems to have existed abundantly in France and Germany. These two successive prehistoric populations have been termed respectively men of the "mammoth" age and men of the "reindeer" age. The Bible record would lead us to regard the earlier and gigantic men as antediluvian, and the smaller or Lappish race as postdiluvian. We may therefore, having already at some length considered the postdiluvian age, take up the mode of occurrence of the remains of the earlier of the two races—that of the mammoth age.
The caverns themselves may be divided into those of residence, of sepulture, and of driftage, though one cavern has often successively assumed two at least of these characters. In the caverns of residence large accumulations have been formed of ashes, charcoal, bones, and other débris of cookery, among which are found flint and bone implements, the general character of which, as well as that of the needles, stone hammers, mortars for paint, and other domestic appliances, are not more dissimilar from those of the Red Indian and Esquimau races in North America than these are from one another, and in many things, as in the bone harpoons, the resemblance is very striking indeed. In tendency to imitative art, and in the skill of their delineations of animals, the prehistoric men seem to have surpassed all the American races except the semi-civilized mound-builders and the more cultivated Mexican and Peruvian nations. With regard to the residence of these men of the mammoth age in caverns, several things are indicated by American analogies to which some attention should be paid.
It is not likely that caverns were the usual places of residence of the whole population. They may have been winter houses for small tribes and detached families of fugitives or outlaws, or they may have been places of resort for hunting parties at certain seasons of the year. The large quantities of broken and uncooked bones of particular species, as of the horse and reindeer, in some of the caverns, would farther indicate a habit of making great battues, like those of the American hunting tribes, at certain seasons, and of preparing quantities of pemmican or dried meat preserved with marrow and fat for future use. The number of bone needles found in some of the caves would seem to hint that, like the Americans, they sewed up their pemmican in skin bags. The multitude of flint flakes and of rude stone implements applicable to breaking bones certainly indicates a wholesale cutting of flesh and preparation of marrow. In the "Story of the Earth," I have suggested in connection with this that there may have been towns or villages of these people unknown to us, and which would afford higher conceptions of their progress in the arts. This anticipation appears recently to have been realized in the discovery of such a town or fortified village of the mammoth age at Soloutre, in France, and which seems to afford evidence that these ancient people had already domesticated the horse, using it as food as well as a beast of burden, in the manner of the Khirgis and certain other Tartar tribes of Central Asia. [135] This, with the undoubtedly high cerebral organization indicated by the skulls of the mammoth age, notably raises our estimate of the position of man at this early date.