CHAP. XI. AGE OF THE NATCHEZ DEPOSIT. 203 was obtained by Dr. Dickeson of Natchez, in whose collection I saw it. It appeared to be quite in the same state of preservation, and was of the same black colour as the other fossils, and was believed to have come like them from a depth of about thirty feet from the surface. In my 'Second Visit to America,' in 1846,* I suggested, as a possible explanation of this association of a human bone with remains of a mastodon and megalonyx, that the former may possibly have been derived from the vegetable soil at the top of the cliff, whereas the remains of extinct mammalia were dislodged from a lower position, and both may have fallen into the same heap or talus at the bottom of the ravine. The pelvic bone might, I conceived, have acquired its black colour by having lain for years or centuries in a dark superficial peaty soil, common in that region. I was informed that there were many human bones, in old Indian graves in the same district, stained of as black a dye. On suggesting this hypothesis to Colonel Wiley, of Natchez, I found that the same idea had already occurred to his mind. No doubt, had the pelvic bone belonged to any recent mammifer other than Man, such a theory would never have been resorted to; but so long as we have only one isolated case, and are without the testimony of a geologist who was present to behold the bone when still engaged in the matrix, and to extract it with his own hands, it is allowable to suspend our judgment as to the high antiquity of the fossil. If, however, I am asked whether I consider the Natchez loam, with land-shells and the bones of mastodon and megalonyx, to be more ancient than the alluvium of the Somme containing flint implements and the remains of the mammoth and hyæna, I must declare that I do not. Both in Europe and America the land and freshwater shells accompanying the extinct pachyderms are of living species, and I could detect no shell in the Natchez loam so foreign to the * Vol. ii. p. 197. 204 GREAT ANTIQUITY OF NATCHEZ LOAM. CHAP. XI. basin of the Mississippi as is the Cyrena fluminalis to the rivers of modern Europe. If, therefore, the relative ages of the Picardy and Natchez alluvium were to be decided on conchological data alone, the fluvio-marine beds of Abbeville might rank as a shade older than the loess of Natchez. My reluctance in 1846 to regard the fossil human bone as of postpliocene date arose in part from the reflection that the ancient. loess of Natchez is anterior in time to the whole modern * delta of the Mississippi. The table-land, de, fig. 26, p. 200, was, I believe, once a part of the original alluvial plain or delta of the great river before it was upraised. It has now risen more than two hundred feet above its pristine level. After the upheaval, or during it, the Mississippi cut through the old fluviatile formation of which its bluffs are now formed, just as the Rhine has in many parts of its valley excavated a passage through its ancient loess. If I was right in calculating that the present delta of the Mississippi has required, as a minimum of time, more than one hundred thousand years for its growth, it would follow, if the claims of the Natchez man to have coexisted with the mastodon are admitted, that North America was peopled more than a thousand centuries ago by the human race. But even were that true, we could not presume, reasoning from ascertained geological data, that the Natchez bone was anterior in date to the antique flint hatchets of St. Acheul. When we ascend the Mississippi from Natchez to Vicksburg, and then enter the Ohio, we are accompanied everywhere by a continuous fringe of terraces of sand and gravel at a certain height above the alluvial plain, first of the great river, and then of its tributary. We also find that the older alluvium contains the remains of mastodon everywhere, and in some places, as at Evansville, those of the megalonyx. As in the valley of the Somme in Europe, those old post-pliocene gravels often occur *See Principles of Geology. CHAP. XI. AGE OF NATCHEZ FOSSIL MAN. 205 at more than one level, and the ancient mounds of the Ohio, with their works of art, described at p. 39, are newer than the old terraces of the mastodon period, just as the GalloRoman tombs of St. Acheul or the Celtic weapons of the Abbeville peat are more modern than the tools of the mammoth-bearing alluvium. In the first place, I may remind the reader that the vertical movement of two hundred and fifty feet, required to elevate the loess of Natchez to its present height, is exceeded by the upheaval which the marine stratum of Cagliari, containing pottery, has been ascertained by Count de la Marmora to have experienced, p. 177. Such changes of level, therefore, have actually occurred in Europe in the human epoch, and may therefore have happened in America. In the second place, I may observe that, if, since the Natchez mastodon was embedded in clay, the delta of the Mississippi has been formed, so, since the mammoth and rhinoceros of Abbeville and Amiens were enveloped in fluviatile mud and gravel, together with flint tools, a great thickness of peat has accumulated in the Valley of the Somme; and antecedently to the first growth of peat, there had been time for the extinction of a great many mammalia, requiring, perhaps, as shown at p. 144, a lapse of ages many times greater than that demanded for the formation of thirty feet of peat, for since the earliest growth of the latter there has been no change in the species of mammalia in Europe. Should future researches, therefore, confirm the opinion that the Natchez man coexisted with the mastodon, it would not enhance the value of the geological evidence in favour of Man's antiquity, but merely render the delta of the Mississippi available as a chronometer, by which the lapse of post-pliocene time could be measured somewhat less vaguely than by any means of measuring which have as yet been discovered or rendered available in Europe. 206 CHRONOLOGICAL RELATIONS CHAP. XI. CHAPTER XII. ANTIQUITY OF MAN RELATIVELY TO THE GLACIAL PERIOD AND TO THE EXISTING FAUNA AND FLORA. CHRONOLOGICAL RELATION OF THE GLACIAL PERIOD, AND THE EARLIEST FREQU REQUENT allusions have been made in the preceding pages to a period called the glacial, to which no reference is made in the Chronological Table of Formations given at p. 7. It comprises a long series of ages, chiefly of posttertiary date, during which the power of cold, whether exerted by glaciers on the land, or by floating ice on the sea, was greater in the northern hemisphere, and extended to more southern latitudes than now. It often happens that when in any given region we have pushed back our geological investigations as far as we can, in search of evidence of the first appearance of Man in Europe, we are stopped by arriving at what is called the boulder clay' or 'northern drift.' This formation is usually quite destitute of organic remains, so that the thread of our inquiry into the history of the animate creation, as well as of man, is abruptly cut short. The interruption, however, is by CHAP. XII. OF THE GLACIAL AND HUMAN PERIODS. 207 no means encountered at the same point of time in every district. In the case of the Danish peat, for example, we get no farther back than the recent period of our Chronological Table (p. 7), and then meet with the boulder clay; and it is the same in the valley of the Clyde, where the marine strata contain the ancient canoes before described (p. 47), and where nothing intervenes between that recent formation and the glacial drift. But we have seen that, in the neighbourhood of Bedford (p. 165), the memorials of Man can be traced much farther back into the past, namely, into the post-pliocene epoch, when the human race was contemporary with the mammoth and many other species of mammalia now extinct. Nevertheless, in Bedfordshire as in Denmark, the formation next antecedent in date to that containing the human implements is still a member of the glacial drift, with its erratic blocks. If the reader remembers what was stated in the Eighth Chapter, p. 144, as to the absence or extreme scarcity of human bones and works of art in all strata, whether marine or fresh-water, even in those formed in the immediate proximity of land inhabited by millions of human beings, he will be prepared for the general dearth of human memorials in glacial formations, whether recent, post-pliocene, or of more ancient date. If there were a few wanderers over lands covered with glaciers, or over seas infested with ice-bergs, and if a few of them left their bones or weapons in moraines or in marine drift, the chances, after the lapse of thousands of years, of a geologist meeting with one of them must be infinitesimally small. It is natural, therefore, to encounter a gap in the regular sequence of geological monuments bearing on the past history of Man, wherever we have proofs of glacial action having prevailed with intensity, as it has done over large parts of Europe and North America, in the post-pliocene period. As |