Again, no traces of northern drift are found in California, which is surrounded by high mountains, in some of which fragments of glaciers are found even to this day.[3] According to Foster, the Drift did not extend to Oregon; and, in the opinion of some, it does not reach much beyond the western boundary of Iowa. Nor can it be supposed that the driftless regions of Siberia, Northwestern America, and the Pacific coast are due to the absence of ice upon them during the Glacial [1. "Report of the Geological Survey of Wisconsin," vol. i, p. 114. 2. "The Great Ice Age," p. 465. 3. Whitney, "Proceedings of the California Academy of Natural Sciences."] {p. 32} age, for in Siberia the remains of the great mammalia, the mammoth, the woolly rhinoceros, the bison, and the horse, are found to this day imbedded in great masses of ice, which, as we shall see, are supposed to have been formed around them at the very coming of the Drift age. But there is another difficulty: Let us suppose that on all the continents an ice-belt came down from the north and south poles to 35° or 40° of latitude, and there stood, massive and terrible, like the ice-sheet of Greenland, frowning over the remnant of the world, and giving out continually fogs, snow-storms, and tempests; what, under such circumstances, must have been the climatic conditions of the narrow belt of land which these ice-sheets did not cover? Louis Figuier says: "Such masses of ice could only have covered the earth when the temperature of the air was lowered at least some degrees below zero. But organic life is incompatible with such a temperature; and to this cause must we attribute the disappearance of certain species of animals and plants--in particular the rhinoceros and the elephant--which, before this sudden and extraordinary cooling of the globe, appeared to have limited themselves, in immense herds, to Northern Europe, and chiefly to Siberia, where their remains have been found in such prodigious quantities."[1] But if the now temperate region of Europe and America was subject to a degree of cold great enough to destroy these huge animals, then there could not have been a tropical climate anywhere on the globe. If the line of 35° or 40°, north and south, was several degrees below zero, the equator must have been at least below the frost-point. And, if so, how can we account for the survival, [1. "The World before the Deluge," p. 462.] {p. 33} to our own time, of innumerable tropical plants that can not stand for one instant the breath of frost, and whose fossilized remains are found in the rocks prior to the Drift? As they lived through the Glacial age, it could not have been a period of great and intense cold. And this conclusion is in accordance with the results of the latest researches of the scientists:-- "In his valuable studies upon the diluvial flora, Count Gaston de Saporta concludes that the climate in this period was marked rather by extreme moisture than extreme cold."