Careful and pains-taking observation has lain at the beginning of most great discoveries; the busy miner, not the careless idler, finds the gold. A course of accurate study in some particular department of science has often opened up new views, and afforded new data in some very different and equally important subject. Thus diligent investigations in the flora and fauna of various countries have not only revealed facts connected with plants and animals, but have unfolded new chapters in the history of earth-building. A very minute study of the plant and animal life of Australia, New Zealand, South America, and some of the South Pacific islands has made clear the fact that certain types are common to all those localities, and are not found elsewhere. Does some one say, “What is curious about that? That is nothing!” To the ardent disciple of science, whose mind is keenly at work on the problems of nature, this fact means much. The first deduction from such a fact is that these lands must once have been very nearly united, while widely separated from the rest of the world, and that over them plants and animals have spread from a common centre. Following the hint thus given, it has been concluded after more extended observation, that at some former time there was around the South Pole a great Antarctic continent, or a vast archipelago with its islands closely strewn upon the South Polar sea, which then was not a desolate waste of ice-floes, diversified by glittering icebergs, but was mild and beautiful as the Pacific. We have seen that once the North Polar lands enjoyed a temperate climate and abundant vegetation. No doubt the South Polar regions were blessed with a similar golden age. Since this Antarctic continent stretched out to join, or nearly join, Australia, New Zealand, South America, and certain of the South Pacific islands, its fruits, flowers, birds, beasts, and fresh-water fishes were distributed among all these countries. When climatic changes came to the Antarctic land; when, perhaps, much of its shores were submerged; when deep and icy waters flowed where reefs and shallows had been; when whole islands sank beneath the waves never to rise again,--then Australia and New Zealand were for long ages parted from the rest of the world. The attention of explorers has been directed to the Arctic, rather than to the Antarctic regions; thrilling adventures at the north have provoked ardent minds to seek adventures yet more thrilling. The search for sperm whales and for a Northwest Passage has diverted interest from the Antarctic land, where marvels as great and rewards as rich, no doubt, await the explorer. Now that interest in these unknown regions has been roused it may not be long before we learn the secrets hidden for ages in ice-caskets in the south.