With these astounding facts before us, due wholly to the transference of a portion of the warm currents of the Atlantic to the shores of Europe, even with all the disadvantages of an icy sea to the north-east and ice-covered Greenland to the north-west, how can we doubt the enormously greater effect of such a condition of things as has been shown to have existed during the Tertiary epoch? Instead of _one_ great stream of warm water spreading widely over the North Atlantic and thus losing the greater part of its store of heat _before_ it reaches the Arctic seas, we should have _several_ streams conveying the heat of far more extensive tropical oceans by comparatively narrow inland channels, thus being able to transfer a large proportion of their heat _into_ the northern and Arctic seas. The heat that they gave out during the passage, instead of being widely dispersed by winds and much of it lost in the higher atmosphere, would directly ameliorate the climate of the continents they passed through, and prevent all accumulation of snow except on the loftiest mountains. The formation of ice in the Arctic seas would then be impossible; and the mild winter climate of the latitude of North {87} Carolina, which by the Gulf Stream is transferred 20deg northwards to our islands, might certainly, under the favourable conditions which prevailed during the Cretaceous, Eocene, and Miocene periods, have been carried another 20deg north to Greenland and Spitzbergen; and this would bring about exactly the climate indicated by the fossil Arctic vegetation. For it must be remembered that the Arctic summers are, even now, really hotter than ours, and if the winter's cold were abolished and all ice-accumulation prevented, the high northern lands would be able to support a far more luxuriant summer vegetation than is possible in our unequal and cloudy climate.[26]