The lowest, that is, the oldest, deposit on the eastern coast in which any relics of human industry are claimed to have been found, is that known as the Columbian gravel. This is considered by geologists to have been formed in the height of the first glacial period. From its undisturbed layers have been exhumed stones bearing the marks of rough shaping, so as to serve the purpose of rude primitive weapons.12
During the first or main Inter-glacial Period was deposited the modified drift. In a terrace of this material on the Mississippi, near Little Falls, Minnesota, Miss Babbitt found numerous quartz chips regarded by competent archæologists as artificial products.13 They represent the refuse of an early workshop near the quartz veins in that vicinity, and were cast aside by the pristine implement-maker when the Minnesota glacier was receding for the last time, but still lifted its icy walls five or ten miles above the present site of Little Falls.
The extensive beds of loess which cover many thousand square miles in the Central United States are referred to the second Glacial Epoch. Professor Aughey reports the finding of rudely chipped arrowhead in this loess as it occurs in the Missouri Valley. They lay immediately beneath the vertebra of an elephant, an animal, I need scarcely add, long since extinct. Another proof of mans presence about that date is a primitive hearth discovered in digging a well along the old beach of Lake Ontario. According to that competent geologist, Professor Gilbert, this dated from a period when the northern shore of that body of water was the sheer wall of a mighty glacier, and the channel of the Niagara river had not yet begun to be furrowed out of the rock by the receding waters.14 Other finds which must be referred to about this epoch are those by McGee of a chipped obsidian implement in the lacustrine marls of western Nevada; and that of a fragment of a human skull in the westernmost extension of the loess in Colorado.15
More conclusive than these are the repeated discoveries of implements, chipped from hard stones, in deposits of loess and gravels in Ohio and Indiana, which deposits, without doubt, represent a closing episode of the last Glacial Epoch. There may be some question about the geologic age of the former finds, but about these there is none. They prove beyond cavil that during the closing scenes of the Quaternary in North America, man, tool-making, fire-using man, was present and active.16 This decision is not only confirmed, but greatly extended, by the researches of Dr. C. C. Abbott and others in the gravels about Trenton, on the Delaware. These were laid down contemporaneously with the terminal moraine in Ohio and Indiana, from which the palæoliths were exhumed. Abbotts discoveries include several hundred stone implements of the true palæolithic or Chelléen type, and some fragments of human skeletons.17 They reveal to us not only the presence of man, but a well defined stage of culture strictly comparable to that of the river drift men of the Thames and the Somme in western Europe, which has been so ably described by De Mortillet.18
Such discoveries have not been confined to the northern portion of the continent. Barcena reported the relics of man in a quaternary rock in the valley of Mexico.19 The geologists of the Argentine Republic describe others which must be referred to a very remote age. The writers who have given the most information about them are Ameghino and Burmeister. They found bone and stone implements of rude form and the remains of hearths associated with bones of the extinct horse, the glyptodon, and other animals now unknown. The stratigraphic relations of the finds connected them with the deposits of the receding Austral glacier.20
Such facts as these place it beyond doubt that man lived in both North and South America at the close of the Glacial Age. It is not certain that this close was synchronous in both the northern and southern hemispheres, nor that the American glacier was contemporary with the Ice Age of Europe. The able geologist, Mr. Croll, is of opinion that if there was a difference in time, the Ice Age of America was posterior to that of Europe. In any case, the extreme antiquity of man in America is placed beyond cavil. He was here long before either northern Asia or the Polynesian islands were inhabited, as it is well known they were first populated in Neolithic times.
The question naturally arises, did he not originate upon this continent? The answer to this is given by Charles Darwin in his magistral statementOur progenitors diverged from the catarhine stock of the anthropoids; and the fact that they belonged to this stock clearly shows that they inhabited the Old World.21 In fact, all the American monkeys, whether living or fossil, are platyrhine, have thirty-four teeth, and have tails, characteristics which show that none of the higher anthropoids lived in the New World.
We are obliged, therefore, to look for the original home of the American glacial man elsewhere than in America. Some interesting geological facts throw an unexpected light upon our investigations. I have already remarked that in the various recent oscillations of the earths crust, there occurred about the middle and later Glacial Epoch an uplift of the northern part of the continent and also of the northern Atlantic basin. In the opinion of Professor James Geikie this amounted to a vertical elevation of three thousand feet above the present level, and resulted in establishing a continuous land connection between the higher latitudes of the two continents, which remained until the Post-glacial period.22 Dr. Habernicht also recognizes this condition of affairs and places it during the old stone age in Europe,23 which corresponds to the position assigned it by McGee.
Very recently, Professor Spencer has summed up the evidence in favor of the elevation of the northern portions of America and the north Atlantic, about the early Pliocene times, and considers that it proves beyond a doubt that it must have reached from 2000 to 3000 feet above the present level.24
Further testimony to the existence of this land bridge is offered by the glacial striæ on the rocks of Shetland, the Faroe Islands, Iceland and south Greenland. These are in such directions and of such a character that Mr. James Croll, a high authority, maintains that they must have been produced by land ice, and that the theory of a land connection between these localities can alone explain all the facts.25 A comparison of the flora and fauna in the higher latitudes of the two continents reveals marked identities which require some such theory to explain them. Thus, certain species of land snails occur both in Labrador and Europe, and the flora of Greenland, although American in the north, is distinctly European in the south.26
Again, in certain very late Pliocene formations in England, known as the Norwich crag and the red crag of Suffolk, no less than eighteen species of American mollusca occur, only seven of which still live on the Scandinavian coast, the remainder being confined to North America. In consequence of such facts the most careful English geologists of to-day hold that the land communication, which certainly existed between Europe and North America in Eocene times by way of Iceland and Greenland, which was then a part of the American continent, continued to exist through the Miocene and Pliocene Epochs. This land bridge formed a barrier of separation between the Arctic and Atlantic oceans, so that the temperature of the higher latitudes was much milder than at present.27
Again, in certain very late Pliocene formations in England, known as the Norwich crag and the red crag of Suffolk, no less than eighteen species of American mollusca occur, only seven of which still live on the Scandinavian coast, the remainder being confined to North America. In consequence of such facts the most careful English geologists of to-day hold that the land communication, which certainly existed between Europe and North America in Eocene times by way of Iceland and Greenland, which was then a part of the American continent, continued to exist through the Miocene and Pliocene Epochs. This land bridge formed a barrier of separation between the Arctic and Atlantic oceans, so that the temperature of the higher latitudes was much milder than at present.27
The evidence, therefore, is cumulative that at the close of the last Glacial Epoch, and for an indeterminate time previous, the comparatively shallow bed of the North Atlantic was above water; and this was about the time that we find men in the same stage of culture dwelling on both its shores.
The attempt has often been made by geologists to calculate the remoteness in time of the close of the Ice Age, and of these vestiges of human occupation. The chronometers appealed to are the erosion of river valleys, especially of the gorge of Niagara, the filling of lake beds, the accumulation of modern detritus, etc. Professor Frederick Wright, who has studied the problem of the Niagara gorge with especial care, considers that a minimum period of twelve thousand years must have elapsed since its erosion began.28 But as Professor Gilbert justly remarks, whatever the age of the great cataract may be, the antiquity of man in America is far greater, and reaches into a past for which we have found no time-measure.29
The same may be said for Europe. De Quatrefages and many other students of the subject consider that the evidence is sufficient to establish the presence of man near the Atlantic coast in the Pliocene Epoch; and excellent English geologists have claimed that the caves in the valley of the River Clwyd, in north Wales, whose floors contain flint implements, had their entrance blocked by true glacial deposits, so that man was there present before the Great Ice Age began.
From this brief presentation of the geologic evidence, the conclusion seems forced upon us that the ancestors of the American race could have come from no other quarter than western Europe, or that portion of Eurafrica which in my lectures on general ethnography I have described as the most probable location of the birth-place of the species.30
Scheme of the Age of Man in America.
Many difficulties present themselves in bringing these periods into correspondence with the seasons of the Quaternary in Europe; but after a careful study of both continents, Mr. W. J. McGee suggests the following synchronisms:31
Of course it would not be correct to suppose that the earliest inhabitants of the continent presented the physical traits which mark the race to-day. Racial peculiarities are slowly developed in certain areas of characterization, but once fixed are indelible. Can we discover the whereabouts of the area which impressed upon primitive American manan immigrant, as we have learned, from another hemispherethose corporeal changes which set him over against his fellows as an independent race?
I believe that it was in the north temperate zone. It is there we find the oldest signs of mans residence on the continent; it is and was geographically the nearest to the land-areas of the Old World; and so far as we can trace the lines of the most ancient migrations, they diverged from that region. But there are reasons stronger than these. The American Indians cannot bear the heat of the tropics even as well as the European, not to speak of the African race. They perspire little, their skin becomes hot, and they are easily prostrated by exertion in an elevated temperature. They are peculiarly subject to diseases of hot climates, as hepatic disorders, showing none of the immunity of the African.32 Furthermore, the finest physical specimens of the race are found in the colder regions of the temperate zones, the Pampas and Patagonian Indians in the south, the Iroquois and Algonkins in the north; whereas, in the tropics they are generally undersized, short-lived, of inferior muscular force and with slight tolerance of disease.33
These facts, taken in connection with the geologic events I have already described, would lead us to place the area of characterization of the native American east of the Rocky Mountains, and between the receding wall of the continental ice sheet and the Gulf of Mexico. There it was that the primitive glacial man underwent those changes which resulted in the formation of an independent race.
We have evidence that this change took place at a very remote epoch. The Swiss anatomist, Dr. J. Kollmann, has published a critical investigation of the most ancient skulls discovered in America, as the one I have already referred to from Calaveras county, California, one from Rock Bluff, Illinois, one from Pontimelo, Buenos Ayres, and others from the caverns of Lagoa Santa, Brazil, and from the loess of the Pampas. All these are credited with an antiquity going back nearly to the close of the last glacial period, and are the oldest yet found on the continent. They prove to be strictly analogous to those of the Indians of the present day. They reveal the same discrepancy in form which we now encounter in the crania of all American tribes. The Calaveras skull and that from Pontimelo are brachycephalic; those from Lagoa Santa dolichocephalic; but both possess the wide malar arches, the low orbital indices, the medium nasal apertures and the general broad faces of the present population. Dr. Kollmann, therefore, reaches the conclusion that the variety of man in America at the close of the glacial period had the same facial form as the Indian of to-day, and the racial traits which distinguish him now, did also at that time.
The marked diversity in cranial forms here indicated is recognizable in all parts of the continent. It has frustrated every attempt to classify the existing tribes, or to trace former lines of migration, by grouping together similar head-measurements. This was fully acknowledged by the late Dr. James Aitken Meigs, of Philadelphia, who, taking the same collection of skulls, showed how erroneous were the previous statements of Dr. Morton in his Crania Americana. The recent studies of Virchow on American crania have attained the same conclusion.34 We must dismiss as wholly untenable the contrary arguments of the French and other craniologists, and still more peremptorily those attempted identifications of American skulls with Mongolian or Mongoloid types. Such comparisons are based on local peculiarities which have no racial value.
Yet it must not be supposed from this that carefully conducted cranial comparisons between tribes and families are valueless; on the contrary, the shape and size of the skull, the proportion of the face, and many other measurements, are in the average highly distinctive family traits, and I shall frequently call attention to them.
The lowest cephalic index which I have seen reported from an American skull is 56, which is that of a perforated skull from Devil river, Michigan, now in the medical museum at Ann Arbor university;35 the highest is 97, from a Peruvian skull, though probably this was the result of an artificial deformity.