The line of perpetual snow may naturally be expected to descend lower and lower on advancing to the pole, and hence many mountainous regions or elevated plateaux, such as the interior of Spitzbergen, of Greenland, of Nova Zembla, etc., which in a more temperate clime would be verdant with woods or meadows, are here covered with vast fields of ice, from which frequently glaciers descend down to the verge of the sea. But even in the highest northern latitudes, no land has yet been found covered as far as the water’s edge with eternal snow, or where winter has entirely subdued the powers of vegetation. The reindeer of Spitzbergen find near 80° N. lichens or grasses to feed upon; in favorable seasons the snow melts by the end of June on the plains of Melville Island, and numerous lemmings, requiring vegetable food for their subsistence, inhabit the deserts of New Siberia. As far as man has reached to the north, vegetation, when fostered by a sheltered situation and the refraction of solar heat from the rocks, has everywhere been found to rise to a considerable altitude above the level of the sea; and should there be land at the North Pole, there is every reason to believe that it is destitute neither of animal nor vegetable life. It would be equally erroneous to suppose that the cold of winter invariably increases as we near the pole, as the temperature of a land is influenced by many other causes besides its latitude. Even in the most northern regions hitherto visited by man, the influence of the sea, particularly when favored by warm currents, is found to mitigate the severity of the winter, while at the same time it diminishes the warmth of summer. On the other hand, the large continental tracts of Asia or America that shelve toward the pole have a more intense winter cold and a far greater summer’s heat than many coast-lands or islands situated far nearer to the pole. Thus, to cite but a few examples, the western shores of Nova Zembla, fronting a wide expanse of sea, have an average winter temperature of only -4°, and a mean summer temperature but little above the freezing-point of water (+36½°), while Jakutsk, situated in the heart of Siberia, and 20° nearer to the Equator, has a winter of -36° 6’, and a summer of +66° 6’.