will follow the order of Sir Charles Lyell's work, and merely state the leading facts which geological investigations have brought to light.

In the Danish islands there are deposits of peat from ten to thirty feet thick, formed in the hollows or depressions of the northern drift or bowlder formation. These beds of peat have been examined to the bottom, and they reveal the history of vegetation in those localities, and the contemporaneous history of human progress. Beginning at the top, the explorer finds the first layers to contain principally the trunks of the beech tree, along with implements and tools of wood and iron. Below these is a deposit of oak trunks, with implements mainly of bronze. Farther down still he finds the trunks of the Pinus sylvestris, or Scotch fir, together with implements of stone. This clearly indicates that in the lapse of centuries the pine was supplanted by the oak, and the oak by the beech, and that man advanced contemporaneously from the knowledge and use of stone implements to those of bronze and iron. Now the known fact is that in the time of the Romans, as now, the Danish isles were covered by magnificent beech forests, and that eighteen centuries have done little or nothing toward changing the character of the vegetation. How many centuries must have elapsed to enable the oak to supplant the pine, and the beech to supplant the oak, can only be vaguely conjectured. Yet the evidence is clear that man lived in those old pine forests—leaving his implements of stone behind him, as he did his tools of bronze and iron in the succeeding periods. Along the coast of Denmark, also, are found shell mounds mixed with flint knives, hatchets, etc., but never any tools of bronze or iron, showing that the rude hunters and fishers who fed on the oyster, cockle, and other mollusks, lived in the period of the Scotch fir, or, as it has been called, the 'age of stone.'

In many of the Swiss lakes are found ancient piles driven into the bottom, on which were once erected huts or villages, the lacustrine abodes of man. This use of them is proved by the abundance of flint implements and fragments of rude pottery, together with bones of animals, which have been dredged up from among the piles. The implements found belong to the 'age of stone,' or the period of the Scotch fir in Denmark, and the bones of animals are all, with one exception, those of living species.

Passing over the fossil human remains and works of art of the 'recent' period, as found in the delta and alluvial plain of the Nile, in the ancient mounds of the valley of the Ohio, in the mounds of Santos in Brazil, in the delta of the Mississippi, in which, at the depth of sixteen feet from the surface, under four buried forests, superimposed one upon the other, was found, a few years ago, a human skeleton, estimated by Dr. B. Dowler to have been buried at least fifty thousand years—in the coral reefs of Florida, in which fossil human remains were found, estimated by Professor Agassiz to have an antiquity of ten thousand years—in the recent deposits of seas and lakes, in the central district of Scotland, which bears clear traces of an upheaval since the human period, and in the raised beaches of Norway and Sweden—passing over these for want of space for minute detail, we go back to the post-pliocene period, and find the bones of man and works of art in juxtaposition with the fossil remains of extinct mammalia.

In the cavern of Bize, in the south of France, and in the caves of Engis, Engihoul, Chokier, and Goffontaine, near Liége, human bones and teeth, together with fragments of rude pottery, have been found enveloped in the same mud and breccia, and cemented by stalagmite, in which are found also the land shells of living species and the bones of mammalia, some of extinct, and others of recent species. The chemical condition of all the bones was found to be the same. Quite a full account is given of the researches of MM. Journal and Christol in the Bize cavern, and of Dr. Schmerling in the Liége caverns, and every effort made, apparently, by the author, to weigh candidly and honestly the evidence for and against the contemporaneous existence and deposition of the human and mammalian remains. And while he admits that at one time he was strongly inclined to suspect that they were not coeval[3], yet he has been compelled by subsequent evidence, especially in view of the fact that he has had convincing proofs in later years that the remains of the mammoth and many other extinct species, very common in caves, occur also in undisturbed alluvium, imbedded in such a manner with works of art as to leave no room for doubt that man and the extinct animals coexisted, to reconsider his former opinion, and to assign to the proofs derived from caves of the high antiquity of man a much more positive and emphatic character.

In chapter fifth we have a minute and interesting account of such fossil human skulls and skeletons as have been found in caves and ancient tumuli, and a careful endeavor made to estimate their approximate age. In 1857, in a cave situated in that part of the valley of the Düssel, near Düsseldorf, which is called the Neanderthal, a skull and skeleton were found, buried beneath five feet of loam, which were pronounced by Professor Huxley and others to be clearly human, though indicating small cerebral development and uncommon strength of corporeal frame. In the Engis caves, near Liége, portions of six or seven human skeletons were found, imbedded in the same matrix with the remains of the elephant, rhinoceros, bear, hyena, and other extinct quadrupeds. In an ancient tumulus near Borrely, in Denmark, a human skull was discovered which was adjudged by its surroundings to belong to the 'stone period' of Denmark, or the era of the Scotch fir. The careful anatomical examination and comparison to which these skulls have been subjected, have led to important discussions, not only as to their age, but also as to their relation to existing races.

Next comes an extended account of the flint implements and other works of art, found so abundantly in juxtaposition with the bones of extinct mammalia, in various localities—in a cave at Brixham, near Torquay, in Devonshire; in the alluvium of the Thames valley; in the gravel of the valley of the Ouse, near Bedford; in a fresh-water deposit at Hoxne in Suffolk; in the valley of the Lach at Icklingham; in a cavern in Somersetshire; in the caves of Gomer in Glamorganshire, in South Wales; and especially in the gravel beds of Abbeville and Amiens, in France, and various localities of the valley of the Somme. As to these flint implements, they are chiefly knives, hatchets, and instruments of that sort, and they have been found in such large numbers, and such diverse localities, and so uniformly in close proximity with the remains of the same species of extinct mammalia, that the evidence derived from them is, to say the least, of a very weighty character, and in the opinion of Sir Charles Lyell clearly establishes the fact that Elephas primigenius, Elephas antiquus, Rhinoceros tichorrhinus, Ursus spelœus, and other extinct species of the post-pliocene alluvium, coexisted with man.

Attempts have been made to throw doubt upon these implements, first upon their nature, and next upon their genuineness; but we think no one who weighs the evidence candidly and carefully, can award to these doubts the merit of respectability. That they are works of art and not native forms, is, we think, as fully established as human observation can establish anything; and though frauds have been recently detected, it would be no more absurd to attribute the whole phenomena of fossil remains to fraudulent manufacture, than to refer to the same