The plants whose growth and decay originally furnished the materials of which our black coal[[63]] is composed, flourished in that far distant period when as yet no bird or mammalian quadruped had made its appearance, when even the gigantic Ichthyosaurus was not yet born, and the progress of organic life had not advanced beyond the creation of some uncouth reptiles or strangely formed fishes. From the vast space of time which separates us from the carboniferous age, it may easily be imagined that the state of the vegetable world was then extremely different from that now prevailing. The vegetable remains which constitute coal have generally been so transformed as to afford no trace of their original texture; yet the distinct plants found here and there preserved in the mass, and which amount to about five hundred species, plainly bear the character of a swampy vegetation, and show that they must have grown in submerged, or at least extremely humid, situations. They consist chiefly of ferns, of Lepidodendra, allied to the club-mosses of the present day, of a few coniferous trees, the woody structure of some of them showing that they were related to the Araucarian division of pines, more than to any of our common European firs; of some large ‘horsetails,’ and of Sigillariæ and Calamites, that seem to have been distinct from all tribes of now existing plants. Scanty as are these relics of an extinct world, they yet allow the fancy to reconstruct the forests of which they formed a part, and to wander through those dismal woods where generations after generations of arborescent ferns and moor-plants flourished and decayed for the use of beings that were to appear millions of years later upon the stage of life.
LEPIDODENDRON ELEGANS.
ASTEROPHYLLITES COMOSA.
SIGILLARIA OCULATA.
CALAMITES NODOSUS.
The following description by Hugh Miller will assist our fancy in roaming among the primeval thickets from which coal was formed: ‘We have before us a low shore, covered with a dense vegetation. Huge trees of wonderful form stand out far into the water. There seems no intervening beach. A thick hedge of reeds, tall as the masts of pinnaces, runs along the deeper bays, like water-flags at the edge of a lake. A river of vast volume comes rolling from the interior, darkening the water for leagues with its slime and mud, and bearing with it to the open sea reeds and ferns and cones of the pine, and immense floats of leaves, and now and then some bulky tree undermined and uprooted by the current. We near the coast, and now enter the opening of the stream. A scarce penetrable phalanx of reeds, that attain to the height and wellnigh to the bulk of forest trees, is ranged on either hand. The bright and glossy stems seem rodded like Gothic columns; the pointed leaves stand out green at every joint, tier above tier, each tier resembling a coronal wreath, or an ancient crown with the rays turned outwards, and we see atop what may be either large spikes or catkins. What strange forms of vegetable life appear in the forest behind! Can that be a club-moss that raises its slender height for more than fifty feet from the soil? Or can these tall palm-like trees be actually ferns, and these spreading branches mere fronds? And then these gigantic reeds! are they not mere varieties of the common horsetail of our bogs and marshes, magnified some sixty or a hundred times? Have we arrived at some such country as the continent visited by Gulliver, in which he found thickets of weeds and grass tall as woods of twenty years’ growth, and lost himself amid a forest of corn fifty feet in height? The lesser vegetation of our own country, its reeds, mosses, and ferns, seems here as if viewed through a microscope, the dwarfs have sprung up into giants, and yet there appears to be no proportional increase in size among what are unequivocally its trees. Yonder is a group of what seem to be pines—tall and bulky, ’tis true, but neither taller nor bulkier than the pines of Norway and America. There is an amazing luxuriance of growth all around us. Scarce can the current make way through the thickets of aquatic plants that rise thick from the muddy bottom; and though the sunshine falls bright on the upper boughs of the tangled forest beyond, not a ray penetrates the more than twilight gloom that broods over the marshy platform below. The rank steam of decaying vegetation forms a thick blue haze, that partially obscures the underwood. Deadly lakes of carbonic acid gas have accumulated in the hollows; there is a silence all around, uninterrupted save by the sudden splash of some reptile fish that has risen to the surface in pursuit of its prey, or when a sudden breeze stirs the hot air, and shakes the fronds of the giant ferns, or the catkins of the reeds. The wide continent before us is a continent devoid of animal life, save that its pools and rivers abound in fish and mollusca, and that millions and tens of millions of the infusory tribes swarm in the bogs and marshes. Here and there, too, an insect of strange form flutters among the leaves. It is more than probable that no creature furnished with lungs of the more perfect construction could have breathed the atmosphere of this early period and have lived.’