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Page:Popular Science Monthly Volume 18.djvu/639

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A PIECE OF COAL.

organization since then has come about through the unfolding and development of the possibilities, the carrying out of the promises, and the fulfillment of the prophecies that were woven into every tissue of the old ferns and club-mosses. The types that lay latent in the oldest vegetation have simply been separated and perfected; progressive development has been gradually led along a series of intricate but constantly diverging lines that lead out and up, and finally terminate in the endless graded ranks and profuse varieties which constitute the grand flora—the grandest the world has ever seen—that annually buds and blooms, and bears its wealth of leaf and fruit for you and me, provided only we appreciate it all. Indeed, the whole world, past and present, is ours, but only so far as mind and soul can lay bold of and possess its wondrous beauty, and still more wondrous meaning; beyond that it belongs to the dull ox as muck as to us.

But life has never been the exclusive property of plants, at least not since the geological record accessible to us began. Neither have plants monopolized the significant facts from which we may draw interesting conclusions regarding the laws of Nature and of being. In our study of the coal, we catch glimpses of animals that are worthy of notice. Their remains are left, along with the remains of plants, imbedded in the coal itself, or in the strata that limit the coal-seam above and below. Time will permit us to notice only a few examples. We must omit all description of the large, clear-winged insects that flitted in and out among the calamites and ferns, as well as of the curious spiders that laid snares for them in all available places; and we can only mention the scorpions and cockroaches that hid in the chinks and crevices of the fallen pines and club-mosses. All these would be interesting enough if time allowed, and interesting too would be the centipeds and land-snails that Dawson found in hollow Sigillarian stumps of the coal-measures of Nova Scotia. All would tend to enforce the lesson that the world in the Carboniferous age was controlled and operated very much as at present. Trees germinated and grew to perfection and died, and the hollow stumps became the refuge of myriads of creeping things, that found safety from hungry enemies only in complete concealment.

It is to the animals of higher rank that we must give attention. Let us remember that the Carboniferous age comes just after that which witnessed the introduction of fishes—the earliest as well as the lowest of animals having brains, and heads, and spinal columns. It lies, therefore, very near the focus toward which all the genealogical lines of our present vertebrates converge, and hence every structural feature in the higher Carboniferous animals becomes invested with a peculiar interest. Of true fishes there were none—they are a much later product—but, of creatures that combined in the most unthought-of ways the characters of both fish and reptile, the seas seem to have