tinuous belt, stretching through three parts of the world, in a breadth of from 15° to 20°, even the woods of the Amazon, which cover à surface fifteen times greater than that of the United Kingdom, shrink into comparative insignificance. Unlike the tropical forests, which are characterized by an immense variety of trees, these northern woods are almost entirely composed of coniferæ, and one single kind of fir or pine often covers an immense extent of

ground. The European and Asiatic species differ, however, from those which grow in America.

Thus in the Russian empire and Scandinavia we find the Scotch fir (Pinus sylvestris), the Siberian fir and larch (Abies sibirica, Larix sibirica), the Picea obovata, and the Pinus cembra; while in the Hudson's Bay territories the woods principally consist of the white and black spruce (Abies alba and nigra), the Canadian larch (Larix canadensis, and the gray pine (Pinus banksiana). In both continents birch-trees grow farther to the north than the coniferæ, and the dwarf willows form dense thickets on the shores of every river and lake. Various species of the service-tree, the ash, and the elder are also met with in the Arctic forests; and both under the shelter of the woods. and beyond their limits, nature, as if to compensate for the want of fruit-trees, produces in favorable localities an abundance of bilberries, bogberries, cranberries, etc. (Empetrum, Vaccinium), whose fruit is a great boon to man and beast. When congealed by the autumnal frosts, the berries frequently remain hanging on the bushes until the snow melts in the following June, and are then a considerable resource to the flocks of water-fowl migrating to their northern breeding-places, or to the bear awakening from his winter sleep.

Another distinctive character of the forests of the high latitudes is their apparent youth, so that generally the traveller would hardly suppose them to be more than fifty years, or at most a century old. Their juvenile appearance increases on advancing northward, until suddenly their decrepit age is revealed by the thick bushes of lichens which clothe or hang down from their shrivelled boughs. Farther to the south, large trees are found scattered here and there, but not so numerous as to modify the general appearance of the forest, and even these are mere dwarfs when compared with the gigantic firs of more temperate climates. This phenomenon is sufficiently explained by the shortness of the summer, which, though able to bring forth new shoots, does not last long enough for the formation of wood. Hence the growth of trees. becomes slower and slower on advancing to the north; so that on the banks of the Great Bear Lake, for instance, 400 years are necessary for the formation of a trunk not thicker than a man's waist. Toward the confines of the tundra, the woods are reduced to stunted stems, covered with blighted buds that have been unable to develop themselves into branches, and which prove by their numbers how frequently and how vainly they have striven against the wind, until finally the last remnants of arboreal vegetation, vanquished by the blasts of winter, seek refuge under a carpet of lichens and mosses, from which their annual shoots hardly venture to peep forth.

A third peculiarity which distinguishes the forests of the north from those of the tropical world is what may be called their harmless character. There the traveller finds none of those noxious plants whose juices contain a deadly poison, and even thorns and prickles are of rare occurrence. No venomous snake glides through the thicket; no crocodile lurks in the swamp; and the northern beasts of prey-the bear, the lynx, the wolf—are far less dangerous and blood-thirsty than the large felidæ of the torrid zone.

The comparatively small number of animals living in the Arctic forests corresponds with the monotony of their vegetation. Here we should seek in vain for that immense variety of insects, or those troops of gaudy birds which in the Brazilian woods excite the admiration, and not unfrequently cause the despair of the wanderer; here we should in vain expect to hear the clamorous voices that resound in the tropical thickets. No noisy monkeys or quarrelsome parrots settle on the branches of the trees; no shrill cicadæ or melancholy goat-suckers interrupt the solemn stillness of the night; the howl of the hungry wolf, or the hoarse screech of some solitary bird of prey, are almost the only sounds that ever disturb the repose of these awful solitudes. When the tropical hurricane sweeps over the virgin forests, it awakens a thousand voices of alarm; but the Arctic storm, however furiously it may blow, scarcely calls forth an echo from the dismal shades of the pine-woods of the north.

In one respect only the forests and swamps of the northern regions vie in abundance of animal life with those of the equatorial zone, for the legions of gnats which the short polar summer calls forth from the Arctic morasses are a no less intolerable plague than the mosquitoes of the tropical marshes.

Though agriculture encroaches but little upon the Arctic woods, yet the agency of man is gradually working a change in their aspect. Large tracts of

forest are continually wasted by extensive fires, kindled accidentally or intentionally, which spread with rapidity over a wide extent of country, and con

tinue to burn until they are extinguished by a heavy rain. Sooner or later a new growth of timber springs up, but the soil, being generally enriched and saturated with alkali, now no longer brings forth its aboriginal firs, but gives birth to a thicket of beeches (Betula alba) in Asia, or of aspens in America.

FOREST CONFLAGRATION.

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 (+364°), 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'.

The influence of the winds is likewise of considerable importance in determining the greater or lesser severity of an Arctic climate. Thus the northerly winds which prevail in Baffin's Bay and Davis's Straits during the summer months, and fill the straits of the American north-eastern Archipelago with ice, are probably the main cause of the abnormal depression of temperature in that quarter; while, on the contrary, the southerly winds that prevail during summer in the valley of the Mackenzie tend greatly to extend the forest of that favored region nearly down to the shores of the Arctic Sea. Even in the depth of a Siberian winter, a sudden change of wind is able to raise the thermometer from a mercury-congealing cold to a temperature above the freezingpoint of water, and a warm wind has been known to cause rain to fall in Spitzbergen in the month of January.

The voyages of Kane and Belcher have made us acquainted with the lowest temperatures ever felt by man. On Feb. 5, 1854, while the former was wintering in Smith's Sound (78° 37' N. lat.), the mean of his best spirit-thermometer showed the unexampled temperature of -68° or 100° below the