The course of creation

by John Anderson

It will excite no surprise, therefore, should we remark that the various beds of old red sandstone now so disjoined, or appearing only as patches, once covered the greater part of the district traced above, extending from the Ochils across the Sidlaws to the Grampians. Nor can there be difficulty in finding an adequate cause for their up-break, especially in the upper members of the group. Consider not merely the constant waste arising from aqueous abrasion and meteroic influences, but also the tearing effects occasioned by the convulsive throes and elevatory movements of the Grampian, Sidlaw, and Ochil ranges, either singly, or, as it may have happened, in combination, when the overlying rocks must have been shattered and broken in every direction, and rendered capable of easy transportation. Although belonging to a posterior geological epoch, these hillocks of gravel and sand are thus the collected records of primeval times, attesting that mighty agencies have been at work in rending the globe, re-adjusting its materials, and preparing them for future combinations.

How speedily, in these first days of creation, does geology make us acquainted with the liability to change and mutation stamped upon all earthly things! The mountains are raised up, and their earliest struggles are to get down again. Nor is it the law of matter, if we may use the expression, to rise. The waters seek the hollows of the earth, because they are material. The rocks, more solid, are subject to the same principle of gravitation, and their course is downward, and their natural place the bottom of the waters. When the rocks were separated from and elevated above the waters, it was not by any virtue or power in themselves to assume these positions. The separation as well as the elevation were the results of direct arrangement; both certainly provided for in the original plan, and yet not the less brought about against their own material tendencies by a special agency. Geology thereby establishes the fact, that the mountains were raised up and the dry land commanded to appear. And now, decomposing and wasting down, we see them seeking back to their old places, to be there re-constructed, and to subserve other purposes.

The Organic Remains, which fall next to be described, are confined to three of the beds, as enumerated above. The first of these, in the order of superposition, is the micaceous flagstone of Carmylie and Arbroath, likewise extending along the south bank of the Tay, and distinguished by the vegetable culmiferous impressions with which it abounds. These, in some places, are so numerous, as to cover the entire surface of the rock. The idea of an ancient marsh is immediately called up in the mind, as one sees stone after stone split up, and all the interstices mottled and streaked over with the stems and leaves of the plants which were fed by its waters. While we write, every pond, and every lake in the neighborhood has crept quietly under its carpeting of ice, a congelation of the living with the dead. How beautiful and distinctly delineated the culms and leaves of the chara locked in its crystal embrace; the flower of the juncus yet lingers on the stalk; and there, how gracefully float the long broad continuous stems of the scirpus lacustris! The pike and perch, both typified in the olden rocks, may be seen motionless as a stone, or softly buoyant as the down, in the clear depths below. Not so brightly, but now as fixedly set, and as minutely preserved, are the fragments of the flora of the Devonian age: if blackened and jetty in their hoary antiquity, these films of mica give light and relief to the darker background of the picture; and shapes, too, were there sporting in the waters,—the seraphim and buckler-headed cephalaspis,—which painter never conceived, nor poet feigned.

These fossils are not in a state of petrifaction, but generally consist in the form of an easily-separated film of carbonaceous matter, or more frequently as a simple coaly marking. Sometimes, but very rarely, the plant is found betwixt the slaty layers, as it were in a dried state, and still perfectly flexible; and the impressions not unfrequently resemble the narrow striated leaves of the alopecurus geniculatus, the floating foxtail-grass, with its knotted culms. There are other specimens, that look like the bark of trees, or the branches of the gnarled oak, ribbed and jointed crosswise. The round dotted patches, varying from the size of a garden pea to an inch in diameter, not unlike, in shape and appearance, the form of a compressed strawberry, are very plentiful. Dr. Fleming, in Cheek’s “Edinburgh Journal” for February, 1831, has figured this organism in connection with the stem, which thereby forms a graceful and well-defined flowering plant, while Sir Charles Lyell considers these berry-shaped forms to be the relics of the ova of some gasteropoda of the period. But at Wormit and Parkhill they are so uniformly, and in such numbers, associated with the culmiferous and leaf impressions, as most strongly to vindicate their claim to a vegetable origin. We have in our collection several specimens, with this organism separated certainly from the culm, but still in such closeness and proportionate size, as, with little aid from the imagination, to infer their former connection, and assign to them a place among the phanerogamous and seed-yielding plants. If so, we cannot too highly prize these relics, regarding them, as they undoubtedly are, among the oldest of organic substances—the first of the green herbs that sprung from the earth—the fragile flower, that withers often in a day, there to attest the mandate of primeval creation. How many seasons have returned; how many seed-times and harvests have covered the fields; what revolutions and changes over all these hills and plains, since that flinty rock formed the soil, and these vegetables sprung from its fertility! They are not admitted among the economic order of the gramineæ; nor whether of marine, semi-marine, or lacustrine origin, have geologists been able to determine.

Of the Animal Remains of fishes belonging to the gray sandstone, the Cephalaspis Lyellii was one of the earliest discovered, as it still constitutes one of the most remarkable of these fossil relics. The head of this creature, and hence the name buckler-headed, is large in proportion to the body, forming nearly one-third of its length. The outline is rounded in the form of a crescent, the lateral horns inclining slightly toward each other, while the anterior or central parts project considerably outward; this peculiarity of structure is occasioned by the intimate anchylosis of all the plates which compose the cranium. The body resembles in appearance an elongated spindle, swelling out on the ridge of the back, and narrowing to the extremity of the tail, which terminates in a long slender point. How like, peradventure, the very dagger with which the murderous Thane of Glammis threatened to render—

“The multitudinous seas incarnadine,

Making the green one red!”

The sanguineous fluid, in those days, was not indeed very plentiful; but the sharp-horned orthoceræ, and the swift predaceous nautili were cotemporaries; and hence, either for protection or attack, we find that, while the head of the Cephalaspis was one entire plate of enameled bone in the upper division, the body was wrapped in a closely woven net-work of bony scales, of peculiar form, and differing from the scales of every other genus of ganoids. The scales along the center of the sides are so high, that their breadth exceeds their length eight or ten times, occupying more than half the height of the animal. Everywhere meshed in smaller but equally impervious nettings, there are of the larger scales, from twenty-six to thirty covering the sides, thereby completing a mail-clad figure of a singularly warlike aspect, and bidding defiance, like his great anti-type, to all his foes,—“let fall thy blade on vulnerable crests”—but now, like Banquo’s ghost, “the bones are marrowless.”

These curious fossils were first detected in the quarries at Glammis, by Sir Charles Lyell, and from their striking resemblance to the cephalic shield of certain trilobites, were supposed, for a time, to belong to the class of crustaceans. The beds of Carmylie and Balruddery, yield these organisms in the greatest abundance. One solitary specimen, a fragment of two inches in length, of the smaller scaly net-mesh, has been obtained by me in the gray rock, on the south bank of the Tay. The heads are uniformly in the best state of preservation; indeed hundreds of these lie entire, where no part of the body has left the trace of an impression. M. Agassiz assigns, as the reason of this, the great difference that exists in the structure of these two parts, and especially in the disproportion of their dimensions and forms, which would offer a distinct resistance to the pressure to which the animals must have been exposed. “If, on the other hand,” he adds, “the heads usually present their superior surface to us, it is because their inferior surface, the cavity of the mouth, the branchial arch and sinuosities of the inferior bones of the cranium, are points of support comparatively more solid, and more adapted for sustaining the matter which has filtered into them, than a larger surface slightly convex, which would naturally be detached from the rock wherever a separation was found in it.”