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Show 232 DARWINIAN A. Asia as well as of Atlantic North America, but all wan;ing in California ; one J uglans like the walnut of the Old World, and another like our black walnut; two or three grapevines, one near our Southern fox grape or muscadine, another near our Northern frostgrape; a Tilia, very like. our basswood of t~e Atl~ntic States only; a Liqmdambar; a magnolia, whiCh recalls our M. grandi:f:lora ; a Liriodendron, sole representative of our tulip-tree; and a sassafras, very like the living tree. Most of these, it will be noticed, have their nearest or their only living representatives in the Atlantic States, and when elsewhere, mainly in Eastern Asia. Several of them, or of species like them, have been detected in our tertiary deposits, west of the Mississippi, by Newberry and Lesquereux. I-~erbacem:s plants .as it happens, are rarely preserved m a fossil state ~lse they would probably supply additional testimo~ y to the antiquity of our existing vege~a~ion, its wide diffusion over the northern and now :frigid zone, and its enforced migration under changes of climate.1 Concluding, then, as we must, that our exis~ing vegetation is a continuation of that of the tertiary . . ' - 1 There is, at least, one instance so opportune to the present argu-ment that it should not pass unnoticed, although I had overlooked t~e record until now. Onoclea sensibilis is a fern peculiar to the AtlantiC United States (where it is common and wide-spread) a~d to Ja~an. Prof. N ewbeny identified it several years ago in a colle~twn, ob~am~d by D;-. Hayden of miocene fossil plants of Dakota Terntory, whiCh IS far . beyond it ~resent habitat. He moreover regards it as probably identical with a fossil specimen "described by the late Prof. E. Forbes, under the name of Filicites Hebridicus, and obtained by the Duke of Argyll from the i-sland of Mull." SEQUOIA AND ITS HISTORY. 233 period, may we suppose that it absolutely originated then? Evidently not. The preceding Cretaceous period has furnished to Carruthers in Europe a fossil fruit like that of the Sequoia gigantea of the famous groves, associated with pines of the same character as those that accompany the present tree; has furnished to Heer, from Greenland, two more Sequoias, one of them identical with a tertiary species, and one nearly allied to Sequoia Langsdorfii, which in turn is a pro bable ancestor of the common Californian redwood; has :furnished to New berry and Lesquereux in North America the remains of another ancient Sequoia, a Glyptostrobus, a Liquidambar which well represents our sweet-gum-tree, oaks analogous to living ones, leaves of a plan·e-tree, which arealso in the Tertiary, and are scarcely distinguishable from our own Platanus oooidentalis, of a magnolia and a tulip-tree, and "of a sassafras undistinguishable from our living species." I need not continue the enumeration. Suffice it to say that the facts justifiy the conclusion which Lesquereux -a scrupulous investigator-has already announced: that" the essential types of our actnal flora are marked in the Cretaceous period, and have come to us after passing, without notable changes, through the Tertiary formations of our continent." According to these views, as regards plants at least, the adaptation to successive times and changed conditions has been maintained, not by absolute renewals, but by gradual modifications. I, for one, cannot doubt that the present existing species are the lineal successors of those that garnished the earth in the old time before them, and that they were as well adapted to |