One of the most widely-known examples was that of Trenton, on the Delaware, where there was a bed of gravel alleged to be pleistocene, and which seemed to contain enough of 'palæolithic' implements to stock all the museums in the world. The evidence of age was not satisfactory from a geological point of view, and Holmes, with the aid of a deep excavation made for a city sewer, has shown that the supposed implements do not belong to the undisturbed gravel, but merely to a talus of loose débris lying against it, and to which modern Indians resorted to find material for implements, and left behind them rejected or unfinished pieces. This alleged discovery has therefore no geological or anthropological significance. The same acute and industrious observer has inquired into a number of similar cases in different parts of the United States, and finds all liable to objections on similar grounds, except in a few cases in which the alleged implements are probably not artificial. These observations not only dispose, for the present at least, of palæolithic man in America, but they suggest the propriety of a revision of the whole doctrine of 'palæolithic' and 'neolithic' implements as held in Great Britain and elsewhere. Such distinctions are often founded on forms which may quite as well represent merely local or temporary exigencies, or the débris of old work-shops, as any difference of time or culture.
CHIPPED QUARTZITES, MODERN AMERICAN (after Holmes)
Upper line (1 to 6), unfinished and rejected pieces.
Lower line (7 to 18), progress of development from the unfinished oval form to finished lance and arrow-heads.
For the present, therefore, we may afford to pass over with this slight notice the alleged occurrence of miocene and pliocene man, and this the rather since, if such men ever existed in the northern hemisphere, the cold and submergence of the pleistocene must have cut them off from their more modern successors in such a way that man must practically have made a new beginning at the close of the glacial age.
I do not refer here to the finds of skulls and implements in the auriferous gravels of Western America. Some of these, if genuine, might go back to the pliocene age, but in so far as the evidence now available indicates, they all belong to the modern races of Indians, and, in one way or another, by fraud or error, have had assigned to them a fabulous antiquity.
There still seems reason to believe that remains of man and his works exist in beds which are overlaid by boulders and gravel, implying a cold climate. These may indicate the last portion of the glacial period proper, in which case the beds with human remains may be called inter-glacial, or they may indicate a partial relapse to the cold conditions occurring after the glacial age had passed away, and in the early part of the modern period. My own view is, that it is most natural to draw the boundary line of the pleistocene and anthropic or modern at the point where the earliest certain evidences of man appear, and that the anthropic age will be found to include not only an early period of mild climate succeeding the glacial age, but a little later a return of cold, not comparable with that of the extreme glacial period, but sufficient seriously to affect human interests, and which almost immediately preceded those physical changes which carried away palæocosmic man, or the man of the earliest period, and many of his companion animals, and introduced the neanthropic or later human age. We shall find facts bearing on this in the sequel.
In the meantime, we may consider it as established beyond cavil that man was already in Europe immediately after the close of the glacial period, and was contemporary with the species of animals, many of them large and formidable, which at that time occupied the land. He must have entered on the possession of a world more ample and richer in resources than that which remains to us. The early post-glacial age was, like the preceding pliocene, a time of continental elevation, in which the dry land spread itself widely over the now submerged margins of the sea basins. In Europe, the British Islands were connected with the mainland, and Ireland was united to England. The Rhine flowed northward to the Orkneys, through a wide plain probably wooded and swarming with great quadrupeds, now extinct or strange to Europe. The Thames and the Humber were tributaries of the Rhine. The land of France and Spain extended out to the hundred-fathom line. The shallower parts of the Mediterranean were dry land, and that sea was divided into two parts by land connecting Italy with Africa. Possibly portions of the shallower areas of the Atlantic were so elevated as to connect Europe and America more closely than at present.
Connected with this elevation of the continents out of the sea was a great change of climate, whereby the cold of the pleistocene age passed away and a milder climate overspread the northern hemisphere, while the newly-raised land and that vacated by snow and ice became clothed with vegetation, and were occupied by a rich quadrupedal fauna, including even in the northern parts of Europe, Asia, and America, species of elephant, rhinoceros, and other genera now confined to the warmer climates. This new and noble world was the rich heritage of primeval man.