are mouldering into soil; seas are filling up; rivers and streams are continually shifting their outlines; and lakes are converted into fertile meadows and the sites of luxuriant forests, by means of the vast armies of Nature's pioneers. Hard inorganic matters are reduced to impalpable atoms; waters and gases are decomposed and moulded into new forms and substances having new properties, by vegetable growth. Minute as these plants are, they are intimately related to the giant forms of the universe. It has been observed that as the great whole is indissolubly connected with its minutest parts, so the germination of the minutest lichen and the growth of the simplest moss are directly linked with the grandest astronomical phenomena; nor could the smallest fungus or conferva be annihilated without destroying the equilibrium of the universe. It is with organic Nature as with the body politic or the microcosm of the human frame, if "one member suffer all the members suffer with it," and the loss of one class or order would involve that of another, till all would perish. Our comfort and health, nay our very existence, more or less immediately depend on the useful functions which they perform. Before we can have the wheat which forms our daily bread, or the grass which yields us, through the instrumentality of our herds, our daily supply of animal food, or the cotton and lint which form our clothes, countless generations of lichens and mosses must have been at work preparing a soil for the growth of the plants which produce these useful materials. And as on the dry land, so in the great waters, this wonderful chain of connection exists in all its complexity. Before the reader can peruse these pages by the light of the midnight lamp, or the gay party can indulge their revels under the brilliant glare of spermaceti tapers, myriads of minute diatoms and Confervœ, floating in the waters of the sea, must have formed a basis of subsistence for the whales and seals whose oil is employed for these purposes. Man's own structure is nourished and built up by the particles which these active plants have rescued from the mineral kingdom, and which once circulated through their simple cells; and thus the highest and most complex creature, by a vital sympathy and a close physical relation, is connected with the lowest and simplest organism, to teach him humility, and inspire him with a deep interest in all the works of his Maker!
"Nothing in this world is single;
All things, by a law divine,
In one another's being mingle."
It may be asked by a class of individuals, unfortunately too numerous, What is the use of these minute plants? In the business language of the world things are called useful when they promote the profit, convenience, or comfort, of every-day life; and useless when they do not promote, or when they hinder, either of these desired ends. But this definition is extremely partial and one-sided. There are
