secret resources of Nature's laboratory, amid so many convulsions of the globe, are now buried deep in the bowels of the earth, packed into solid sandstone cases, and under huge shady covers, and stored up in the smallest compass by the mighty pressure of ponderous rock-presses, constituting the chief source of our domestic comfort, and of nearly all our commercial greatness. A coal-bed is, in fact, a hortus siccus of extinct cryptogamic vegetation, bringing before the imagination a vista of the ancient world, with which no arrangement of landscape or combination of scenery can now be compared; and, gazing upon its dusky contents, our minds are baffled in aiming to comprehend the bulk of original material, the seasons of successive growth, and the immeasurable years or ages which passed while decay, and maceration, and chemical changes, prepared the fallen vegetation for fuel. If the specimens of plants, thus strangely preserved, teach us one truth more than another, it is this, that size and development are terms of no meaning when applied to a low or a high type of organization. The Cryptogamia of the Old World, the earliest planting in the new-formed soil, are in bulk, as well as in elegance and beauty of form, unrivalled by the finest specimens of the modern forest. The little and the great, the recent and the extinct, were equally the objects of Nature's care, and were all modelled with a skill and finish that left nothing to be added.
And as in early geological epochs they occupied so conspicuous a position, so now in the annals of physical geography they are entitled to a prominent place. With the exception of the grasses—Nature's special favorites—they are the most abundant of all plants, possessing inconceivable myriads of individual representatives in every part of the globe, from which unfavorable conditions exclude all other vegetation; and thus they contribute, far more than we are apt from a superficial observation to imagine, to the picturesque and romantic appearances exhibited by scenery, and to the formation of that richly-woven and beautifully-decorated robe of vegetation which conceals the ghastly skeleton of the earth, and hides from our view the rugged outlines and primitive features of Nature. They are the first objects that clothe the naked rocks which rise above the surface of the ocean; and they are the last traces of vegetation which disappear under degrees of heat and cold fatal to all life. Their structure is so singularly varied and plastic, that they are adapted to every possible situation. In every country they form an important element in the number of plants, the proportion to flowering plants decreasing from and increasing toward the poles. Taking them as a whole, and in regard to their size, they occupy a larger area of the earth's surface than any other kind of vegetation. There are immense forests of trees here and there in different countries, realizing Cowper's wish for "a boundless contiguity of shade;" there are vast colonies of flowering plants; but the range of the most ubiquitous tree or flower is vastly inferior to that of
