There are many proofs that a milder climate once reigned in the northern regions of the globe. Fossil pieces of wood, petrified acorns and fir-cones have been found in the interior of Banks’s Land by M’Clure’s sledging-parties. At Anakerdluk, in North Greenland (70° N.), a large forest lies buried on a mountain surrounded by glaciers, 1080 feet above the level of the sea. Not only the trunks and branches, but even the leaves, fruit-cones, and seeds have been preserved in the soil, and enable the botanist to determine the species of the plants to which they belong. They show that, besides firs and sequoias, oaks, plantains, elms, magnolias, and even laurels, indicating a climate such as that of Lausanne or Geneva, flourished during the miocene period in a country where now even the willow is compelled to creep along the ground. During the same epoch of the earth’s history Spitzbergen was likewise covered with stately forests. The same poplars and the same swamp-cypress (_Taxodium dubium_) which then flourished in North Greenland have been found in a fossilized state at Bell Sound (76° N.) by the Swedish naturalists, who also discovered a plantain and a linden as high as 78° and 79° in King’s Bay--a proof that in those times the climate of Spitzbergen can not have been colder than that which now reigns in Southern Sweden and Norway, eighteen degrees nearer to the line. We know that at present the fir, the poplar, and the beech grow fifteen degrees farther to the north than the plantain--and the miocene period no doubt exhibited the same proportion. Thus the poplars and firs which then grew in Spitzbergen along with plantains and lindens must have ranged as far as the pole itself, supposing that point to be dry land. In the miocene times the Arctic zone evidently presented a very different aspect from that which it wears at present. Now, during the greater part of the year, an immense glacial desert, which through its floating bergs and drift-ice depresses the temperature of countries situated far to the south, it then consisted of verdant lands covered with luxuriant forests and bathed by an open sea. What may have been the cause of these amazing changes of climate? The readiest answer seems to be--a different distribution of sea and land; but there is no reason to believe that in the miocene times there was less land in the Arctic zone than at present, nor can any possible combination of water and dry land be imagined sufficient to account for the growth of laurels in Greenland or of plantains in Spitzbergen. Dr. Oswald Heer is inclined to seek for an explanation of the phenomenon, not in mere local terrestrial changes, but in a difference of the earth’s position in the heavens. [Illustration: 11. ARCTIC MOONLIGHT.]