Together with these developed creatures, the atmosphere contains countless germs of future formations; eggs of insects, and seeds of plants, which, by means of hairy or feathery crowns, are borne forward on their long autumnal journey. Even the vivifying pollen scattered abroad by the male blossoms, is carried by winds and winged insects over sea and land, to the distant and solitary female plant[74]. Thus, wheresoever the naturalist turns his eye, life or the germ of life lies spread before him. But if the moving sea of air in which we are immersed, and above whose surface we are unable to raise ourselves, yields to many organic beings their most essential nourishment, they still require therewith a more substantial species of food, which is provided for them only at the bottom of this gaseous ocean. This bottom is of a twofold kind: the smaller portion constituting the dry earth, in immediate contact with the surrounding atmosphere; the larger portion consisting of water,—formed, perhaps, thousands of years ago from gaseous matters fused by electric fire, and now incessantly undergoing decomposition in the laboratory of the clouds and in the pulsating vessels of animals and plants. Organic forms descend deep into the womb of the earth, wherever the meteoric rain-waters can penetrate into natural cavities, or into artificial excavations and mines. The domain of the subterranean cryptogamic flora was early an object of my scientific researches. Thermal springs of the highest temperature nourish small Hydropores, Confervæ and Oscillatoræ. Not far from the Arctic circle, at Bear Lake, in the New Continent, Richardson saw flowering plants on the ground which, even in summer, remains frozen to the depth of twenty inches. It is still undetermined where life is most abundant: whether on the earth or in the fathomless depths of the ocean. Ehrenberg’s admirable work on the relative condition of animalcular life in the tropical ocean and the floating and solid ice of the Antarctic circle, has spread the sphere and horizon of organic life before our eyes. Siliceous-shelled Polygastrica and even Coscinodiscæ, alive, with their green ovaries, have been found enveloped in masses within twelve degrees of the Pole; even as the small black glacier flea, _Desoria Glacialis_, and Podurellæ, inhabit the narrow tubules of ice of the Swiss glaciers, as proved by the researches of Agassiz. Ehrenberg has shown that on some microscopic infusorial animalcules (_Synedra_ and _Cocconeis_), other species live parasitically; and that in the Gallionellæ the extraordinary powers of division and development of bulk are so great, that an animalcule invisible to the naked eye can in four days form two cubic feet of the Bilin polishing slate.