in California, and which our trustworthy paleontological botanist has not yet had time to examine, we may expect to find evidence of the early arrival of these two redwoods upon the ground which they now, after much vicissitude, scantily occupy. Differences of climate, or circumstances of migration, or both, must have determined the survival of Sequoia upon the Pacific; very similar would seem to have been the fate of a more familiar gymnospermous tree, the ginko or salistiria. It is now indigenous to Japan only. Its ancestor, as we may fairly call it, since, according to Heer, "it corresponds so entirely with the living species that it can scarcely be separated from it," once inhabited Northern Europe and the whole arctic region round to Alaska, and had even a representative farther south in our Rocky Mountain district. For some reason, this and glystrophobes survived only on the shores of Eastern Asia. Libocearus, on the other hand, appears to have cast in its lot with the Sequoias. Two species, according to Heer, were with the ancient ones in Spitzbergen. Of the two now living, one L. decurrens—the incense-cedar—is one of the noblest associates of both the present redwoods; the other is far south in the Andes of Chili. The genealogy of the torreyas is more obscure; yet it is not unlikely that the yew-like trees, named taxides, which flourished with the Sequoias in the Tertiary arctic forests, are the remote ancestors of the three species of torreya, now severally in Florida, in California, and in Japan. As to the pines and firs, these were more numerously associated with the ancient Sequoias of the polar forests than with their present representatives, but in different species, apparently more like those of Eastern than of Western North America. They must have encircled the whole polar zone then as they encircle the present temperate zone now.
I must refrain from all enumeration of the angiospermous or ordinary deciduous trees and shrubs, which are now known by their fossil remains to have flourished throughout the polar regions when Greenland better deserved its name, and enjoyed the present climate of New England and New Jersey. Then Greenland and the rest of the north abounded with oaks, representing the several groups of species which now inhabit both our eastern and western forest districts; several poplars are very like our balsam-poplar or balm-of-Gilead-tree; more beeches than there are now, a hornbeam, and a hop-hornbeam, some birches, a persimmon, and a plane-tree, near representatives of those of the Old World, at least of Asia, as well as of Atlantic North America, but all wanting in California; one juglans, like the walnut of the Old World; two or three grape-vines are near our Southern fox-grape or muscadine, the other near our Northern frost-grape; a tilia, very like our basswood of the Atlantic States, only a liquidamber; a magnolia, which recalls our Magnolia grandiflora; a liriodendron, sole representative of our tulip-tree; and a sassafras very like the living tree. Most of these, it will be noticed, have
