stone were frozen into their lower surfaces, scooped out grooves in the subjacent solid strata. Thirdly, after the surface of the rocks had been smoothed and grated upon by the passage of innumerable icebergs, the clay, gravel, and sand of the Drift were deposited; and occasionally fragments of rock, both large and small, which had been frozen into glaciers, or taken up by coast-ice, were dropped here and there at random over the bottom of the ocean, wherever they happened to be detached from the melting ice. Finally, the period of re-elevation arrived, or of that intermittent upward movement in which the old coast lines were excavated and the ancient sand bars or osars laid down.' Such are the conclusions at which Sir Charles Lyell arrived a few years since respecting the Canadian Lake District; and he states, in the note to which I have referred, that he has ever since been applying them to Scotland. Our country, during the chill and dreary period of the boulder-clay, seems to have been settling down into the waves, like the vessel of some hapless Arctic explorer struck by the ice in middle ocean, and sinking by inches amid a wild scene of wintry desolation.

There are a few detached localities in Scotland where the remains of beds of stratified sand and gravel have been detected underlying the boulder-clay; and in some of these in the valley of the Clyde, Mr. Smith of Jordanhill found on a late occasion shells of the same semi-arctic character as those which occur in the clay itself. And with these stratified beds the record in Scotland closes; whereas in England we find it carried interestingly onward from the Pleistocene period, first into the newer, and then into the older, Pliocene ages. I stated incidentally in my former address, that some of the mosses of the sister kingdom, unlike those of our own country, are older than the Drift period; and, from the existence of these under the Drift gravels and brown clay, it has been inferred by Mr. Trimmer, that as the trees which enter into their composition grew

D

upon the surface of what is now England, where they now lie, previous to the period of the boulder-clay, and as the boulder-clay is, as shown by its remains, decidedly marine, it must have been deposited during a period of depression, when what had been a forest-bearing surface was lowered beneath the level of the sea. None of the trees of these ancient pre-glacial forests seem to be of extinct species: the birch and Scotch fir are among their commonest forms, especially the fir. I find it stated, however, as a curious fact, that along with these, the Abies Excelsa, or Norwegian spruce-pine, is found to occur,--a tree which, though introduced by man into our country, and now not very rare in our woods, has not been of indigenous growth in any British forest since the times of the boulder-clay. Though the species continued to live in Norway, it became extinct in Britain; and it has been suggested, that as it was during the Drift period that it disappeared, it may have owed its extirpation to the depression of the land, while its contemporaries the birch and fir were preserved on our northern heights. When this Norwegian pine flourished in Britain, the island was inhabited by a group of quadrupeds now never seen associated, save perhaps in a menagerie. Mixed with the remains of animals still native to our country, such as the otter, the badger, and the red deer, there have been found skeletons of the Lagomy, or tail-less hare, now an inhabitant of the cold heights of Siberia, and horns of the rein-deer, a species now restricted in Europe to Northern Scandinavia, and those inhospitable tracts of western Russia that border on the Arctic Sea. And with these boreal forms there were associated, as shown by their bones and tusks, the elephant, the rhinoceros, and the hippopotamus, all, however, of extinct species, and fitted for living under widely different climatal conditions from those essential to the well-being of their intertropical congeners.1 Scotland,

1 The true mammoth, with the tichorine rhinoceros and the musk buf

though it has proved much less rich than England in the remains of the early Pleistocene mammals, has furnished a few well-attested elephantine fossils. In the summer of 1821, in the course of cutting the Union Canal, there was found in the boulder-clay near Falkirk, on the Clifton Hall property, about twenty feet from the surface, a large portion of the tusk of an elephant, three feet three inches in length and thirteen inches in circumference; and such was its state of keeping when first laid open, that it was sold to an ivory-turner by the labourers that found it, and was not rescued from his hands until a portion of it had been cut up for chessmen. Two other elephants' tusks were found early in 1817 at Kilmaurs1 in Ayrshire, on a property of the Earl of Eglinton,-one of them so sorely decayed that it could not be removed; but a portion of the other, with the rescued portion of the Falkirk tusks, may be seen in the Museum of our Edinburgh University, which also contains, I may here mention, the horn of a rhinoceros, found at the bottom of a morass in Forfarshire, but which, in all probability, as it stands alone among the organisms of our mosses, had been washed out of some previously formed deposit of the Drift period. Scotland seems to have furnished several other specimens of elephantine remains; but as they were brought to light in ages in which comparative anatomy was unknown, and men believed that the human race had been of vast strength and stature in the primeval ages, but were fast sinking into dwarfs, they were regarded as the remains of giants. Some of the legends to which the

falo, are the leading types of the mammalian fauna of the Glacial Drift epoch. The remains of hippopotamus would be washed out of older beds.-W.S.

1 At a later period (December 1829), similar elephantine tusks were found thirty-four feet beneath the surface, in boulder-clay overlying the quarry of Greenhill, also in Kilmaurs parish; and they may now be seen in the Hunterian Museum, Glasgow.

bones of these supposed giants served to give rise in England occupy a place in the first chapter of the country's history, as told by the monkish chroniclers, and have their grotesque but widely-known memorials in Gog and Magog, the wooden giants of Guildhall our Scottish legends of the same class are less famous ; but to one of their number, -charged with an argument in behalf of the temperance cause of which our friends the teetotallers have not yet availed themselves,-I may be permitted briefly to refer, in the words of one of our elder historians. 'In Murray land,' says the believing Hector Boece, is the Kirke of Pette, quhare the bones of Litell Johne remainis in gret admiration of pepill. He hes bene fourtene feet of hicht, with squaire membres effering thairto. Six yeirs afore the coming of this work to licht (1520) we saw his henche bane, as meikle as the haill banes of ane manne; for we schot our arme into the mouthe thairof; be quhilk appeirs how strang and squaire pepill greu in oure regeoun afore thay were effeminat with lust and intemperance of mouthe.'

Under these pre-glacial forests of England there rests a marine deposit, rich in shells and quadrupedal remains, known as the Norwich or Mammaliferous Crag; and beneath it, in turn, lie the Red and Coralline Cragsmembers of the Pliocene period. In the Mammaliferous Crag there appear a few extinct shells, blent with shells still common on our coasts. In the Red Crag the number of extinct species greatly increases, rising, it is now estimated, to thirty per cent. of the whole; while in the Coralline Crag the increase is greater still, the extinct shells averaging about forty per cent.1 In these deposits some of our best-known molluscs appear in creation for the first time. The common edible oyster (Ostrea edulis) occurs in

1 The known species of shells in the Coralline Crag amount to three hundred and forty. Of these, seventy-three are living British species. See Woodward's Manual, part iii. p. 421.-W.S.

the Coralline Crag, but in no older formation, and with it the great pecten (Pecten maximus), the horse mussel (Modiola vulgaris), and the common whelk (Buccinum undatum). Other equally well-known shells make their advent at a still later period; the common mussel (Mytilus edulis), the common periwinkle (Littorina littorea), and, in Britain at least, the dog-whelk (Purpura lapillus), first appear in the overlying Red Crag, and are not known in the older Coralline formation. By a certain very extended period, represented by the Coralline Crag, the edible oyster seems to be older than the edible mussel, and the common whelk than the common periwinkle; and I call your special attention to the fact, as representative of a numerous class of geological facts that bear on certain questions of a semi-theological character, occasionally mooted in the religious periodicals of the day. There are few theologians worthy of the name who now hold that the deductions of the geologists regarding the earth's antiquity are at variance with the statements of Scripture respecting its first creation, and subsequent preparation for man. But some of them do seem to hold that the scheme of reconciliation, found sufficient when this fact of the earth's antiquity was almost the only one with which we had to grapple, should be deemed sufficient still, when science, in its onward progress, has called on us to deal with this new fact of the very unequal antiquity of the plants and animals still contemporary with man, and with the further fact, that not a few of them must have been living upon the earth thousands of years ere he himself was ushered upon it,-facts of course wholly incompatible with any scheme of interpretation that would fix the date of their first appearance only a few natural days in advance of that of his own. We have no good reason to hold that the human species existed upon earth during the times of the boulder-clay: such a belief would conflict, as shown by the antiquity of the ancient and existing coast lines, with our