The Testimony of the Rocks

Chapter 16

Prev List Next

The belief that fossil remains had never entered into the composition of living organisms, but had been formed in the rocks just as we find them, gradually gave place, during the seventeenth century, to the belief that they were the debris of the Noachian Deluge, and evidences, as they occurred in almost every known country, and were found on the top of lofty hills, of at once its universality and the height to which its waters had prevailed. And this hypothesis, like the others, has been reproduced by some of the anti-geologists of the present day. The known fact,--a result of modern science,--that the several formations (always invariable in their order of succession) have their groups of organisms peculiar to themselves, has, however, interposed a difficulty from which the earlier cosmogonists were exempt. It has become necessary to show that the Noachian cataclysm was strangely selective, in burying in the beds which it is held by the cla.s.s to have formed, now one group of plants and animals, now quite another group, and anon yet another and different group still; and all this many times repeated with such nice care and discrimination, that not a single organism of the lower beds is to be detected in the middle ones, nor yet a single organism of either the middle or lower in the beds that lie above. Even this task, however, just a little lightened by here and there a suppression of the facts, has been attempted by the redoubtable Dean of York.[38] Fire and water were, he conceives, equally agents in the great catastrophe that destroyed the old world,--a circ.u.mstance which, if true, would have furnished with an admirable apology the cla.s.s of persons who, according to the wit, would have cried out "Fire, fire," at the deluge. The dean conceives that at the commencement of the Flood, when torrents of rain were falling upon the land, numerous submarine volcanoes began to disgorge their molten contents into the sea, destroying the fish, and all other marine productions, by the intensity of the heat, and at the same time locking them up in strata formed of the erupted matter. This process took place ere the land floods, laden with the spoils of island and continent, and the accompanying mud and sand, could arrive at the remoter depths; which, however, they ultimately reached, and formed a second formation, overlying the first. There were thus two formations originated,--a marine formation below, and a terrestrial or fresh water formation above; but as these two deposits could not be made to include all the geological phenomena with which even the dean was acquainted, he had nicely to parcel out the work of his volcanoes on the one hand, and that of his land floods on the other, into separate fits or paroxysms, each of which served to entomb a distinct cla.s.s of creatures, and originate a definite set of rocks. Thus, the first work of his volcanoes was to form the Transition series of strata. As a commencement of the whole, the internal fire blew up from the bed of the ocean, in tremendous explosions, vast quant.i.ties of pulverized rock mixed with clay, which, slowly subsiding, and covering up, as it sank, sh.e.l.ls, stone-lilies, and trilobites, formed the Silurian rocks. A second explosion brought up the vents of the volcanoes to the level of the ocean; and while the Old Red Sandstone, thus produced, and charged with fish killed by the heat, was settling on their flanks, they themselves, as if seized by black vomit, began to disgorge in vast quant.i.ties, coal in the liquid state. Very opportunely, just ere it cooled, enormous quant.i.ties of vegetables, washed out to sea by the extraordinary land floods, were precipitated immediately over it; and, sticking in its viscid surface, or sinking into its substance through cracks formed in it during the cooling, they became attached to it in such considerable ma.s.ses, as to lead long after to the very mistaken notion that coal itself was of vegetable origin. Then there ensued another deposit of red sand, with salt boiled into it; and then a deposition of lime and clay.

The land floods still continuing, the great Sauroid reptiles which had haunted the rivers and lower plains began to yield to their force, and their carca.s.ses, floating out to sea, sank amid the slowly subsiding lime and clay, now known as the Lias. The volcanoes too were still very active; and the lighter sh.e.l.ls, ammonites, and the like, which had been previously bobbing up and down on the boiling surface, now sank by myriads; for the viscid argillaceous mud thrown up by the fiery ebullitions from beneath stuck fast to them, and dragged them down. Then came the formation of the Oolite, rolled into little egg-like pellets by the waves; and last of all, the Green sand and Chalk; after which the waters ran off, and sank into the deep hollow which now forms the bed of the ocean, but which previous to the cataclysm had been the place of the land. The dean, as he went on, fell into some little confusion regarding the true place of some of his animals, such as the megatherium, which arrived in his arrangement a little too soon. He spoke, too--if a newspaper report is to be credited--of a heavy creature soon overtaken and drowned by the rising waters, which he termed the _pterogactylus_, and which does not seem to have turned up, either in the body or out of it, since it was lost on that memorable occasion. Nor did he make any provision in his arrangement for the formation of the various Tertiary deposits. But then all these are slight matters, that could be very easily woven into his hypothesis. As the flood rose along the hill sides, first such of the weightier animals would perish as could not readily climb steep acclivities; and then the oxen, the horses, the deer, and the goats, with the lighter carnivora, who, as they would die last,--some of them not until the final disappearance of the hill-tops,--would of course be entombed in the upper deposits. Such is the hypothesis of the Dean of York,--a hypothesis of which it may be justly affirmed, that it is well nigh as ingenious as the circ.u.mstances of the case permit, and against which little else can be urged than that it must seem rather c.u.mbrous and fanciful to the cla.s.s who do not know geology, and, on the whole, somewhat inadequate to the cla.s.s who do.

The Flood, however, is not left to do the whole geologic work, by even such of the anti-geologists as a.s.sign to it the largest share. A great unrecorded convulsion which accompanied the Fall is held by some of their number to have greatly a.s.sisted, by laying down the older formations of the fossiliferous rocks; and very much is said to have been done during the extended antediluvian period that succeeded it. One of perhaps the most amusing though least known of the writers that take this special view is a Scotchman, resident in a secluded provincial town, who for the last twelve or fifteen years has been printing ingenious little books against the infidel geologists, and getting letters of similar character inserted in such of our country newspapers as are ambitious of rendering their science equal to their literature.

And from the great trouble which he has taken with the writings of the individual who now addresses you, he seems to regard them as peculiarly unsolid and dangerous. According to this profound cosmogonist, the world before the Fall was rather more than twice its present size, and very artificially constructed.[39] It was a hollow ball, supported inside by a framework of metal wrought into hexagonal reticulations, somewhat like the framework of the great iron bridge over the river Wear at Sunderland; and which had an open s.p.a.ce in its centre, occupied by a vast tubular furnace lying direct south and north, which threw out huge volumes of flame towards the poles. Over the reticulated framework there rose a great, thick _firmament_ of metal, which formed the inner sh.e.l.l of the globe; over the metal there lay a considerably thicker sh.e.l.l of granite; and over the granite, a thinner sh.e.l.l of a substance not specified, perhaps not known, but which, from its being completely water-tight, served the purpose of the layer of asphalt or _terra cotta_ which the architect spreads over his flat roofs, or on the tops of his sloping terraces, afterwards to be covered with soil and laid out into gardens. Such, it seems, was that portion of the framework of our great globe which corresponded to the hollow lath and plaster framework of the little globes used in schools; while its uppermost layer,--correspondent with the slips of the map which the geographer pastes on the model and then varnishes,--was formed of earth and water, economically laid out into "most useful and tasteful configurations,"--the earth into pretty little rising grounds and valleys, and the water into seas and lakes of no great extent, but which formed, from their very handsome combinations, "a terraqueous surface all over PERFECTLY PARADISAICAL."

Over this exquisitely neat earth there lay an enveloping atmosphere, greatly thinner and less dense than the air at present is, and incapable, in consequence, of being agitated by storms; while directly over the northern and southern extremities of the world the polar auroras, now so fitful and broken, extended in a permanent arch, and gave light, during the long dark winters, to the regions lying below.

And as warmth was as necessary to the paradisaical perfection of these districts as light, they received the necessary heat from the great double-acting furnace in the interior, which, belching out flames at both ends, acted powerfully against the polar portions of the metallic crust or sh.e.l.l, and thus maintained the necessary glow in the absence of the sun, on the principle on which a frying-pan or Scotch _girdle_ is heated when placed by the cookmaid over the fire. And such, according to this excellent world-fashioner and very zealous man, was the construction of that unblighted and unbroken earth which was of old p.r.o.nounced to be "very good." The Fall, however, produced a most remarkable and singularly disastrous change. The earth was somehow partially crushed and broken, contemporaneously with the event,--like a strong fishing basket when it accidentally falls from a coach-top under the wheel; and, from a most interesting colored copperplate that ill.u.s.trates one of the author"s treatises (for he draws as well as he writes), the exact damage which it received can be minutely estimated.

The interior network was compressed into all sorts of irregular polygons; the iron firmament was broken into great fragments,--some of which may be seen in the print hanging down into the hollow interior, like patches of broken plaster dangling from a ceiling, suspended by the hairs originally employed to give the necessary tenacity to the lime.

The great granitic sh.e.l.l was also broken, but broken so nicely, on the principle of the arch, that the pieces remained in nearly their original places. Finally, vast rents are seen to occur in the cement and soil of the outer crust; and these great rents, which must have formed enormous gulfs and deep interminable ravines, were destined, it would seem, to perform a most important part in the future geology of the globe.

Forming impa.s.sable lines of demarcation between the several portions into which they broke up the earth"s surface, they imprisoned the recently created animals in separate groups, kept as completely from mixing together as the fallow-deer of one loftily-walled park are kept from mixing with the white oxen of another loftily-walled park, or as the kangaroos or duck-billed quadrupeds of Australia are kept by the surrounding ocean from mixing with the tigers of Sumatra or the tortoises of Madagascar. I employ the writer"s own happy ill.u.s.tration:--"In some places these fragments" of the earth"s crust "would be piled more or less above each other, and in others quite detached and isolated, like fragments of ice on the bank of a river after a thaw." They would of course be on very different levels, each having, as I have said, a distinct group of animals of its own; and when, after the lapse of nearly two thousand years, the great catastrophe of the Flood came on, it would necessarily find, as it rose along the levels, and submerged platform after platform in succession, a different and yet different set of creatures to kill. To borrow from the description of this ingenious cosmogonist, "those on the lower fragments would be first engulphed, and their races completely extinguished from off the surface, and deposited in the earth; then those on higher and higher upwards, till the whole became submerged. And we have only to suppose that man, with the present survivors, were those that occupied one of the higher table-lands when the Flood commenced (and of course in that case Noah could collect into the ark only out of those of his own country); then the result would be, that man and his present contemporaries would be among the last overwhelmed. This will sufficiently account for the fact of his and their remains not being found deep in the earth....

"The two most interesting geological facts therefore, namely, that distinct organisms are to be found in distinct formations respectively; and secondly, _that no remains of man, and few or none of the other races at present surviving, are to be found in any but comparatively recent formations,_--these two grand facts of geology, we say, instead of pointing back to vast cycles of ages before the creation, seem to point merely to the peculiar physical circ.u.mstances of the fallen planet in the interval between those two eventful stages in its history, the Fall and Flood, and the natural consequences of these circ.u.mstances in causing distinct divisions, and some of these of different elevations, among the organic living creatures, during the interval." One other circ.u.mstance completes this really original and beautiful hypothesis.

The cosmogonist holds that the Flood,--no mere tranquil rising of the waters, as some suppose,--was accompanied by terrible convulsions, which reduced to utter ruin the already shattered earth. The granitic dome fell inwards upon the central furnace; and the fires, bursting outwards under the enormous pressure, found vent at the surface, and made the volcanoes. And this collapsed and diminished world,--scarce half the bulk of the old one,--with no heating furnace under its polar regions, nor aught save the merest tatters of an aurora flitting occasionally over them,--greatly too dense in itself, and surrounded by a greatly too dense atmosphere,--with its huge mountains, vast oceans, wide steppes, and arid deserts, with its snows, its frosts, its drenching rains, its horrible tempests, its terrible thunder storms, and devastating earthquakes,--all alike frightful defects, not in the original plan,--is not only unlike the primeval world, not very good, or, unlike the antediluvian world, tolerably good, but not good at all. "On taking a bird"s-eye view of the geographical and hydrographical features or superficies of the globe," says this bold writer, "any unprejudiced person must at once admit, that in either of these departments there is scarce a trace of that beautiful, tasteful, and economical design which we have a right to expect from the admitted qualities of the great Author, and his avowed object in the structure and report of it when newly finished." It is added, however, that "its _present object_, as the _Siberia_--the penal settlement--of expatriated rebels, it is in its _present state_ well calculated to fulfil."

It may be worth mentioning, that the writer who sets himself after a fashion so peculiar to a.s.sert and justify the ways of Providence against the geologists resides in one of the loveliest districts in Scotland,--a district, however, s.h.a.ggy with rock, and overshadowed by great mountains, and occasionally visited by earthquake tremors, and both snow and thunder storms, and so, with all its wild beauty to other eyes, merely, I must suppose, one of the rougher districts of the penal Siberia in his. He is, indeed, particularly severe upon mountains; though not, as he tells us, wholly devoid of a lurking prejudice in their favor. But what weak prejudice might palliate or plead for, his better judgment condemns. "See," says this judicious writer, "vast districts of the globe disfigured by tremendous ma.s.ses of rugged and almost barren mountains.... What, cry some, would you bury as deformities the lofty peak and rugged mountain brow, nature"s palaces,--generally the grandest and most sublime objects in natural scenery! We cordially a.s.sure the reader we are by no means prejudiced against these grand objects; _for if prejudice we have on the subject, it is rather on the other side_. It is therefore the force of evidence alone makes us,--reluctantly we admit,--give up these to rank among the derangements and deformities of nature. She, according to her usual _taste_ and _economy_, would never be at the expense of rearing, and that upon ground _that might have otherwise been much better occupied_, such unwieldy, useless ma.s.ses of matter, merely for the sake of gratifying the taste for grandeur and sublimity in a few of her sons, nor, indeed, for any other use we ever heard ascribed to them....

According to _our_ test, a rich and gently undulatory surface, intersected with rivulets and sheets of water, in the places taken up by these elevations, would be far better, as combining in the highest degree the _utile c.u.m dulce_."[40] To such of my audience as are familiar with Dr. Thomas Burnet"s "Sacred Theory of the Earth" (1684), that revolution in the cycle of hypothesis to which I have referred, and through which the visionaries of the later ages return to the dreams which had occupied the visionaries of an earlier time, must be sufficiently apparent in this pa.s.sage. For not only does Burnet speak after the same manner of hills and mountains, but also of an idle, ill-founded prejudice entertained in their favor. We find him thus summing up a general survey of the mountains of the globe:--"Look upon these great ranges: in what confusion do they lie! They have neither form nor beauty, nor shape, nor order, no more than the clouds in the air. Then, how barren, how desolate, how naked are they! How they stand neglected by nature! Neither the rains can soften them, nor the dews from heaven make them fruitful. I give this short survey of the mountains of the earth _to help to remove that prejudice we are apt to have_, or that conceit that the present earth is regularly formed....

There is nothing in nature," adds this writer, "more shapeless and ill-figured than an old rock or a mountain."

I leave it to my audience to determine how far this depreciatory view,--whether regarded as that of Dr. Burnet or of the modern anti-geologist,--agrees with the estimate of the higher minds, or whether it manifests the proper respect for the adorable Being who, in his infinite wisdom, made our world what it is. Let me next show that some of even the abler and more respectable anti-geologists exhibit no very profound veneration for the letter of Scripture, when, instead of bearing, as they think, against the deductions of their opponents, they find it directly opposed to fancies of their own. It is held by not a few among them, that at the Deluge the sea and land changed places. When the waters receded, it was found, they allege, that the old land had become ocean, and the old ocean had become land; and as there are certain rivers which are described in Scripture as flowing beside Eden, and which, judging by the names given them, still exist, it has become imperative on the a.s.sertors of the hypothesis to show that the rivers which now drain tracts of what they hold was then sea, and that fall into seas which they hold were then land, could not by any possibility have formed the boundaries of the old Adamic garden. Let us mark how Mr.

Granville Penn,--certainly one of the most extensively informed of his cla.s.s,--deals with this difficulty.[41] There are, he argues, certain great corruptions of Scripture. What had been at first written as marginal notes by uninspired men, and were in some cases very erroneous and absurd, came in the course of transcription to be transferred, wholly by mistake, from the side of the page into the body of the text; and thus, in at least a few places, the Scriptures were vitiated, and now declare, instead of Divine truth, what is neither sense nor fact.

And on this very general, and certainly most perilous ground, he goes on to argue, unsupported by a single ancient ma.n.u.script, and solely on what he terms internal evidence, that the verses in Genesis which conflict with his hypothesis must be regarded as mere idle glosses, ignorantly or surrept.i.tiously introduced into the text by the ancient copyists. "In the second chapter of Genesis," we find him saying, "_there appears an internal critical evidence_ of an insertion of the 11th, 12th, 13th, and 14th verses, similar to that of the 4th verse of the 5th chapter of St.

John, and const.i.tuting, in a similar manner, a _parenthesis_ intersecting the thread of the narrative, and introduced solely for a similar purpose of ill.u.s.tration. It does not wear the character of the simple narrative in which it appears, but _of the surcharge of the gloss or note of a later age, founded upon the fanciful traditions then prevailing with respect to the situation of the ancient Paradise_." This certainly is cutting the knot; and, if erected into a precedent by the geologist, would no doubt greatly facilitate the labor of reconciliation. It would, however, be perilous work for _him_. "A wolf,"

says Plutarch, "peeping into a hut where a company of shepherds were a.s.sembled, saw them regaling themselves with a joint of mutton. "Ye G.o.ds!" he exclaimed, "what a clamor these men would have raised if they had caught _me_ at such a banquet."" I need scarcely add, that the hypothesis in whose behalf Scripture is thus divested of its authority, and recklessly cast aside, is entirely a worthless one; and that the various continents of the globe, instead of all dating from one period little more than four thousand years back, are of very various ages,--some of them comparatively modern, though absolutely old in relation to human history; and some of so h.o.a.r an antiquity, that the term since man appeared upon earth might be employed as a mere unit to measure it by.

It need not surprise us that a writer who takes such strange liberties with a book which he professes to respect, and which he must have had many opportunities of knowing, should take still greater liberties with a science for which he entertains no respect whatever, and of whose first principles he is palpably ignorant. And yet the wild recklessness of some of his explanations of geological phenomena must somewhat astonish all sufficiently acquainted with the science to know that the place and relations of its various formations have been long since determined, and now as certainly form the regulating data of the practical miner, as the places and relations long since determined by the geographer form the regulating data of the practical navigator or engineer. It is as certain, for instance, that the Oolitic system underlies the Green Sand and the Chalk, with all the various formations of the Tertiary division,--Eocene Miocene, Pliocene, and Pleistocene,--as that York is situated to the south of Edinburgh, or that both these cities lie very considerably to the north of London and Paris. And the anti-geologist who would argue, in the heat of controversy, that the Oolite and the Pleistocene were contemporaneous deposits, would be no more worthy of reply than the anti-geographer who would a.s.sert, in order to serve some argumentative purpose, that the North Cape lies in the same lat.i.tudinal parallel as South California, or that Terra del Fuego is but a day"s sailing from Iceland. And yet such, as I intimated on a former evening, is the line taken up by Mr.

Granville Penn, in dealing with the difficulties of the Kirkdale Cave, so remarkable for its acc.u.mulations of gnawed bones of the Pleistocene ages,--especially for its bones of hyaenas, tigers, bears, wolves, rhinoceroses, and elephants. The cave occurs in the moorlands of Yorkshire, in a limestone rock of that Oolitic division to which the Oxford Clay and the Coral Rag belong, and contains corals and sh.e.l.ls that had pa.s.sed into extinction long even ere the Tertiary period began; while in the cave itself, mixed with bones of the extinct mammals of the geologic age in immediate advance of the present one, there have been found the contemporary remains of animals that still live in our fields and woods, such as the hare, the rabbit, the weasel, and the water rat.

And we find Mr. Penn a.s.signing both the Oolitic rock in which the cave is hollowed, and the mammalian remains of the cave itself, equally to the period of the deluge. The limestone existed at that time, it would seem, as a soft calcareous paste, into which the animal remains, floated northwards from intertropical regions on the waters of the Flood, were precipitated in vast quant.i.ties, and sank, and then, fermenting under the putrefactive influences, the gas which they formed blow up the yielding lime and mud around them into a long narrow cave, just as a gla.s.s-blower blows up a bottle, or as a little yeast blows up into similar but greatly smaller cavities a bit of leaven. And the stalact.i.tes and stalagmites which encrust the Kirkdale Cave are, Mr.

Penn holds, simply the last runnings of the lime that exuded after the general ma.s.s had begun to set. Certainly any one disposed to take such liberties with the Bible on the one hand, and with geologic science on the other, as those taken in the given instances by this most formidable of the anti-geologists, could have but little difficulty in making either Scripture as geological or geology as Scriptural as he had a mind. His chief danger would be that of making the sounder theologians just a little angry, and of escaping, unless quoted for the joke"s sake, the notice of the geologists altogether. In truth, the extreme absurdity of our later anti-geologists in virtually contending, in the controversy, that _their_ ignorance of an interesting science, founded on millions of determined facts, ought to be permitted to weigh against the knowledge of the men who have studied it most thoroughly, forms their best defence. It secures them against all save neglect. As, however, some of their number are well meaning men, who would not be ridiculous if they could help it, and only oppose themselves to the geologists because they deem them mischievous and in error, it may be worth while showing them, by an example or two, the ludicrous nature of the positions which in their honest ignorance they permit themselves to occupy, and the real scope and bearing of the arguments which they unwittingly permit themselves to use. I shall adduce two several instances of reasoning, directed by the anti-geologists _against_ their antagonists (as they themselves believed), but which, from their ignorance of the true state of the argument, and of the bearing of the facts with which they dealt, in reality made out for these antagonists as strong a case as they could possibly have made out for themselves.

And I am sure that, rather than be found siding with their opponents, the anti-geologists would be content even to acquire a little geology.

I shall select my first instance from the records of the annual controversy which used to rage some ten or fifteen years ago, in sermons, newspapers, and magazines, immediately after every meeting of the British a.s.sociation. A religious Dublin newspaper,--the "Statesman and Record,"--since extinct, took always an active part in these discussions on the anti-geological side, and boldly affirmed, as in a number now before me, that geology had the devil for its author. A learned correspondent of the paper, who was, however, somewhat more charitable, thought that at least the _facts_ of the science might be exempted from a condemnation so sweeping; nay, that, well interpreted, they might be found decidedly opposed to at least the more mischievous deductions of the geologists; and in ill.u.s.trating the point, we find him thus arguing, from certain appearances in the valley of the Nile, that the globe which we inhabit cannot possibly be more than six thousand years old.[42] "The valley of the Nile," says this writer, "is known to be covered with a bed of slime which the river has deposited in its periodical inundations, and which rests on a foundation of sand, like that of the adjacent desert. The French savans who accompanied Bonaparte in his Egyptian expedition made several experiments to ascertain the thickness and depth of this superinc.u.mbent bed. They dug about two hundred pits, and carefully measured the thickness in the transversal section of the valley, where the deposit had been free from obstacles, and had not been materially increased or lessened by local causes. They found the mean of all these measurements to be six and a half metres, or rather more than twenty feet. M. Gironde endeavored to determine the quant.i.ty of slime deposited in a century; and he found that the elevation of soil in that period was rather less than four inches and a half! Dividing the total thickness of the bed by the centenary elevation, he found the quotient 56.50; whence it followed that the inundations had commenced 5650 years before the year 1800, when the experiments were made,--a number which only differed 159 years from the Mosaic date. The difference is not very important, when it is considered that the most trifling error, whether in the measure of the entire superinc.u.mbent bed, or in the valuation of the quant.i.ty of slime deposited in a century, affects the final results. Notwithstanding this, the coincidence between the sacred historian and the computations of science is remarkable, and furnishes one proof more of the harmony existing between nature and revelation. An honest experimentalist was constrained to arrive at this conclusion at a period when the infidel school of our continental neighbors was in high feather. I am sorry to add, that the result of his own calculation had not that effect on the philosopher himself, or his free-thinking a.s.sociates, which, for their own sakes, was desirable; but it is no less valuable to us on that account; for we know that an unwilling witness to the truth is worth a score of evidences already prejudiced in its favor."

Now, this is clear, distinct statement; and nothing can be more evident than that the theologian who makes it holds he is reasoning with conclusive effect in behalf of what may be termed the short chronology,--not in its legitimate connection with the recent introduction of the human species, but in its supposed bearing on the age of the earth. And in doing so he commits himself to the apparent positive fact, determined on what may be regarded as geologic data, that the river Nile has been flowing over its bed for about as many years as have elapsed, according to the Hebrew chronology adopted by Usher, since the creation of man, and no more. To the integrity of this inference he pledges himself, as an inference to which the infidel ought to have yielded, as conclusive in its bearing on the question of the earth"s age, and as of singular value to the believer who sets himself to deal with the evidences of his faith. Now, without referring to the circ.u.mstance that the data on which the French savans under Napoleon founded have since been challenged by geologists, such as Lieutenant Newbold and Sir G. Wilkinson, who have carefully surveyed the rocks and soils of Egypt with the a.s.sistance of clearer light than existed at the commencement of the century, let us, for the argument"s sake, hold the inference to be quite as good as this theologian regards it. And see, we urge upon him, that you yourself do not suffer it to drop should you find that it commits you to the other side of the argument. Be at least as fair and honest as you say the infidels ought to have been. The six and a half metres of silt and slime,--representative, let us hold, of from five to six thousand years,--rest, you say, on "a foundation of sand like that of the adjacent desert." But have you ascertained on what the sand rests? I know nothing of that, replies the theologian; I had not even thought of that. But the geologist has thought of it, we reply; and has spent much time under the hot sun in ascertaining the point. For nearly three hundred miles,--from the inner boundaries of the delta to within a few hours" journey of the cataracts,--the silt and sand rest on what is known as the "marine" or nummulitic limestone,--a formation of great extent, for it runs into the Nubian desert on the one hand, and into the Libyan desert on the other; and which, though it abounds in the animalcules of the European chalk, is held to belong, in at least its upper beds, which are charged with nummulites, to the earlier Eocene.

Over this marine limestone there rests a newer formation, of later Tertiary age, which contains the casts of sea sh.e.l.ls, and whole forests of dicotyledonous trees, converted into a flint-like chert; and over all repose the sands and gravels of the desert. Underneath the silt of the river, then, and the sand of the desert, lie these two formations of the Tertiary division. The lower, which is of great thickness, must have been of slow formation. It is composed almost exclusively, in many parts, of microscopic animals, and abounds in others in fossil sh.e.l.ls,--nautili, ostreadae, turritella, and nummulites, with corals, sponges, the remains of crustacea, and the teeth of fishes. And between the period of its deposition and that of the formation which rests upon it the surface of what is now Egypt must have been elevated over the surface of the sea, to be covered, in the course of ages, by great forests, which, ere the land a.s.sumed its present form and level, were submerged by another oscillation of the surface, and petrified amid beds of a siliceous sand at the bottom of the ocean. Nor is the underlying marine limestone by any means the oldest of the sedimentary rocks of Egypt. It rests on a sandstone of Permian or Tria.s.sic age; the sandstone rests, in turn, on the famous Breccia de Verde of Egypt; and the Breccia on a group of Azoic rocks, gneisses, quartzes, mica schists, and clay slates, that wrap round the granitic nucleus of Syene. The formations of Egypt const.i.tute a well-determined part of that great series of systems which compose the upper portion of the earth"s crust: its silt is by far the most inconsiderable of its deposits; and if five thousand six hundred and fifty years were exhausted in laying down layer after layer of the twenty feet which form _its_ average thickness, what enormous periods must we not demand in addition for the laying down of the forest formation, of the marine limestone formation, of the New Red Sandstone formation, of the Breccia de Verde formation, and, in short, for the some ten miles of fossiliferous rock of which those deposits form such definite, well-determined portions; besides the time necessary for the production of the enormously developed Azoic rocks which lie under all!

The theologian, in this instance, instead of reasoning, as he himself supposed, in behalf of the short chronology, has been making out a very formidable case for the long one; and all that the geologist can have to urge upon him in the circ.u.mstances is simply that he should act as he holds the infidel ought to have done, and yield to the force of evidence. I may mention in the pa.s.sing, that some of the most ancient buildings of Egypt are formed of the Tertiary marine limestones of the country; the stones of the pyramids are charged with nummulites, known to the Arabs as "Pharaoh"s beans;" and these organisms stand out in high relief on the weathered portions of the Great Sphinx. Some of the oldest things in the world in their relation to human history,--erections, many of which had survived the memory of their founders even in the days of Herodotus,--are formed of materials so modern in their relation to the geologic epochs, that they had no existence as rock until after the Palaeozoic and Secondary ages had gone by. Not only the Carboniferous sandstone of the High Church and Parliament House of Edinburgh, but even the Oolitic (that is, Portland stone) of Somerset House and St. Paul"s, are of an antiquity incalculably vast compared with the stone out of which the oldest of the pyramids were fashioned.

[Ill.u.s.tration: Fig. 116.

NUMMULITES LaeVIGATA.

(_Pharaoh"s Beans._)]

The second example which I shall adduce is one with which many of my auditors must be already familiar. The Falls of Niagara are gradually eating their way through an elevated tract of table-land, upwards towards Lake Erie, at the rate of about fifty yards in forty years; and it has been argued by Sir Charles Lyell, that as they are now seven miles distant from Queenston, where the elevation of the plateaux begins, they must have taken about ten thousand years to scoop out their present deep channel through that s.p.a.ce.[43] Ten thousand years ago the Falls were, he infers, at Queenston; and the grounds on which he reasons are exactly those on which one would infer that a laborer who had cut a ditch two hundred yards long at the rate of ten yards per day, and was still at work without pause or intermission, had begun to cut it just twenty days previous. A reverend anti-geologist takes up Sir Charles;[44] and, after denouncing the calculation as "a stab at the Christian religion," seeing it involves the a.s.sertion that the "Falls were actually at Queenston four thousand years before the creation of the world according to Moses," he brings certain facts, adduced both by other writers and Sir Charles himself, to bear on the calculation, such as the fact that the deep trench through which the Niagara runs is much narrower in its lower than in its upper reaches, and that the river must have performed its work of excavation, when the breadth was less, at a greatly quicker rate than now. And thus the work of excavating the trench is brought fairly within six thousand years. Nor is the principle of the reasoning bad. In our ill.u.s.tration of the ditch excavated by the laborer we of course take it for granted that it is a ditch of the same depth and breadth throughout, and excavated in the same sort of soil; for if greatly narrower and shallower at one place than at another, or dug in a greatly softer mould, the rate of its excavation at different times might be very different indeed, and the general calculation widely erroneous, if based on the ratio of progress when it went on most slowly, taken as an average ratio for the whole. But the anti-geologist provokes only a smile when, in his triumph, he exultingly exclaims, "It is on grounds such as these that the most learned and voluminous among English geologists disputes the Mosaic history of the Creation and Deluge,--a strong proof that even men of argument on other subjects often reason in the most childish and ridiculous manner, and on grounds totally false, when they undertake to deny the truth of the Holy Scriptures." Now, it must be wholly unnecessary to remark here, that it is surely one thing to "undertake to deny the truth of the Holy Scriptures," and quite another and different thing to hold that the Niagara Falls may have been at Queenston ten thousand years ago; or further, that it seems not in the least wise to stake the truth of Revelation on any such issue. Let me request you, however, to observe, that in one important respect this writer resembles the former one. The former, ignorant of the various phenomena exhibited by the great deposits of Egypt, exhausted all his five thousand six hundred years of available time in accounting for the formation of one of the least of them,--the silt of the Nile; and the latter, though he bids down Sir Charles some four thousand four hundred years or so in the one item of scooping out the bed of the St. Lawrence, at least expends the remainder of the ten thousand,--his five thousand six hundred years,--in that work of excavation alone, and leaves himself no further sums to set off against the various geologic processes that may have preceded it.

In this case, as in the other, let us grant, for the argument"s sake, all the facts. Let us admit that the trench through which the St.

Lawrence now flows has been cut by the river in somewhat less than six thousand years. But through what, let us ask, has it been cut? There can exist no doubt on the subject: it has been cut through an ancient graveyard of the Upper Silurian system, charged with the peculiar fossils characteristic of what are known as the Clinton and Niagara groups, and common, many of them, to the Upper Silurian of our own country and of the European continent. _Leptaena depressa_ and _Pentamerus oblongus_, two of the most frequent sh.e.l.ls of the deposit, occur also in equal abundance in the Dudley and Caradoc formations of England; its prevailing encrinite, _Ichthyocrinus laevis_, is scarce distinguishable from an encrinite which I have often picked up in the quarries of the "Wren"s Nest" (_Ichthyocrinus pyriformis_); while its prevailing trilobite, _Phacops limulurus_, seems to be but a transatlantic variety of our well known _Asaphus (Phacops) caudatus_.

Further, the sequence of the various formations both above and below the Niagara group, is shown with remarkable distinctness in that part of the world along the sh.o.r.es of the great lakes. They may be traced downward, on the one hand, along the Lower Silurian deposits, to the non-fossiliferous base on which the system rests, and upwards, on the other, through the Old Red Sandstone and the Carboniferous Limestone, to the workable Coal Measures. Both stratigraphically and palaeontologically the place in the scale of the Niagara graveyard can be definitely determined; and a superficial deposit on the heights in its immediate neighborhood shows that the river did not begin its work of excavation among its long extinct sh.e.l.ls, trilobites, and corals, until after not only the great Palaeozoic, but also the Secondary and Tertiary divisions had been laid down, and the recent period ushered in. The superficial sh.e.l.ls of the adjacent heights belong to the Pleistocene age, and show that in even that comparatively modern time the lower lands of Upper Canada were submerged beneath the level of the ocean, and that a series of deep seas, connected by broad sounds, occupied the place of the great lakes. Not until the last upheaval of the land was the river now known as the St. Lawrence called into existence, to begin its work of excavation; and ere that event took place, fully ten miles of fossiliferous rock had been deposited on the earth"s surface, charged with the remains of many succeeding creations. The deposit through which the St. Lawrence is slowly mining its way is older than the river itself by the vast breadth of the four Tertiary periods, by that of all the Secondary ages,--Cretaceous, Oolitic, and Tria.s.sic,--by the periods, too, of the Permian system, of the Carboniferous system, of the Old Red system, and of the uppermost beds of the Upper Silurian system. But a simple ill.u.s.tration may better serve to show the true character of the conclusion urged here by the opponent of Sir Charles, than any such line of statement as that which I employ, however clear to the geologist. In the year 1817, Prince"s Street, in Edinburgh, was opened up to the Calton Hill, and the Calton burying-ground cut through to the depth of many feet by the roadway. Let us suppose that when the excavation has been carried a hundred yards into the cemetery, a geologist, finding the laborers cutting on the average about a yard per day, simply intimates as his opinion that the laborers have been a hundred days at work. "No,"

replies a controversialist on the anti-geological side; "for the first fifty yards, so soft was the subsoil, and so shallow the covering of mould, that the laborers must have cut at the rate of two yards a day; it has been merely for the last fifty yards that they have been excavating at the present slow rate: they cannot have been more than seventy-five days at work. I marvel exceedingly at the absurdity of geological reasoners: _palpably the burying-ground of the Calton is only seventy-five days old._" Now, such, in no exaggerated, but, on the contrary, greatly modified form, is the argument that would limit the age of the earth to the period during which the St. Lawrence has been scooping out a channel for itself, from Queenston to Niagara, through an ancient Silurian burying-ground. Both arguments alike confound the age of the ancient burying-grounds with the date of the modern excavations opened up through them; but in order to render the argument of my ill.u.s.tration equally absurd with the other, it would be not only necessary to infer that the Calton cemetery was only seventy-five days old, but also that the rock on which it rested was no older.

But enough of follies such as these! I had marked a good many other pa.s.sages of similar character in the writings of the recent anti-geologists, and would have little difficulty in filling a volume with such; but it would be a useless, though mayhap curious work, and is much better exhibited by specimen than as a whole. A little folly is amusing, but much of it fatigues. There is a time coming, and now not very distant, when the vagaries of the anti-geologists will be as obsolete as those of the geographers of Salamanca, or as those of the astronomers who upheld the orthodoxy of Ptolemy against Galileo and Newton; and when they will be regarded as a sort of curious fossils, very monstrous and bizarre, and altogether of an extinct type, but which had once not only life, but were formidable. It will then be seen by all what a n.o.ble vestibule the old geologic ages form to that human period in which moral responsibility first began upon earth, and a creature destined to immortality antic.i.p.ated an eternal hereafter. There is always much of the mean and the little in the worlds which man creates for himself, and in the history which he gives them. Of all the abortions of the middle ages which have come down to us, I know not a more miserable one,--at once ludicrous and sad,--than that heavens and earth of Cosmas _Indicopleustes_, the monk, which I ill.u.s.trated by diagrams in my last lecture (Figs. 114, 115). They are just such heavens and earth as a monk might have made, and made too at a sitting. The heavens, represented as a solid arch raised on tall walls, resemble, as a whole, the arch which figures in the middle of a freemason"s ap.r.o.n, or, more homely still, the section of a wine cellar; while the earth lies beneath as a great plain or floor, with a huge hill in the distance, behind which the sun pa.s.ses when it is night. And yet this scheme gave law to the world for more than six centuries, and lay like a nightmare on physical discovery, astronomic and geographical. The anti-geologists have been less mischievous, for they live in a more enlightened age; and we already see but the straggling remains of the body, and know that the time cannot be far distant when it will be as completely extinct as any of the old faunas. The great globe, ever revolving on itself, and journeying in s.p.a.ce round the sun, in obedience to laws which it immortalized a Newton to discover and demonstrate, is an infinitely more sublime and n.o.ble object than the earth of Cosmas the monk, with its conical mountain and its crypt-like firmament; nor can I doubt that its history throughout the long geologic ages,--its strange story of successive creations, each placed in advance of that which had gone before, and its succeeding organisms, vegetable and animal, ranged according to their appearance in time, on principles which our profounder students of natural science have but of late determined,--will be found in an equal degree more worthy of its Divine Author than that which would huddle the whole into a few literal days, and convert the incalculably ancient universe which we inhabit into a hastily run-up erection of yesterday.

LECTURE ELEVENTH.

ON THE LESS KNOWN FOSSIL FLORAS OF SCOTLAND.[45]

PART I.

Scotland has its four fossil floras,--its flora of the Old Red Sandstone, its Carboniferous flora, its Oolitic flora, and that flora of apparently Tertiary age of which his Grace the Duke of Argyll found so interesting a fragment overflown by the thick basalt beds and trap tuffs of Mull. Of these, the only one adequately known to the geologist is the gorgeous flora of the Coal Measures,--probably the richest, in at least individual plants, which the world has yet seen. The others are all but wholly unknown; and the a.s.sociation may be the more disposed to tolerate the comparative meagreness of the few brief remarks which I purpose making on two of their number,--the floras of the Old Red Sandstone and the Oolite,--from the consideration that that meagreness is only too truly representative of the present state of our knowledge regarding them; and that if my descriptions be scanty and inadequate, it is only because the facts are still few. How much of the lost may yet be recovered I know not; but the circ.u.mstance that two great floras,--remote predecessors of the existing one,--which once covered with their continuous mantle of green the dry land of what is now Scotland, should be represented by but a few coniferous fossils, a few cycadaceous fronds, a few ferns and club mosses, must serve to show what mere fragments of the past history of our country we have yet been able to recover from the rocks, and how very much in the work of exploration and discovery still remains for us to do. We stand on the further edge of the great floras of by-past creations, and have gathered but a few handfuls of faded leaves, a few broken branches, a few decayed cones.

The Silurian deposits of our country have not yet furnished us with any unequivocal traces of a terrestrial vegetation. Professor Nicol of Aberdeen, on subjecting to the microscope the ashes of a Silurian anthracite which occurs in Peeblesshire, detected in it minute tubular fibres, which seem, he says, to indicate a higher cla.s.s of vegetation than the algae; but these may have belonged to a marine vegetation notwithstanding. I detected some years ago, in the Trilobite-bearing schists of Girvan, a.s.sociated with graptolites of the Lower Silurian type, a vegetable organism somewhat resembling the leaf of one of the pond weeds,--an order of plants, some of whose species, such as Zostera, find their proper habitats in salt water. I have placed beside this specimen a fragment of the same graptolite-bearing rock, across which I have pasted part of a leaf of _Zostera marina_, the only plant of our Scottish seas which is furnished with true roots, bears real flowers inclosed in herbaceous spathes, and produces a well formed farinaceous seed. It will be seen, that in the few points of comparison which can be inst.i.tuted between forms so exceedingly simple, the ancient very closely resembles the recent organism. It is not impossible, therefore, that the Silurian vegetable may have belonged to some tribe of plants allied to Zostera; and if so, we can easily conceive how the Silurian anthracite of our country may be altogether of marine origin, and may yet exhibit in its microscopic tubular fibres vestiges of a vegetation higher than the algae.

[Ill.u.s.tration: Fig. 117.

_a_, SILURIAN ORGANISM. _b_, GRAPTOLITE. _c_, PORTION OF THE LEAF OF ZOSTERA MARINA.]

[It were well, in dealing with the very ancient floras, in which equivocal forms occur that might have belonged to either the land or the sea, to keep in view those curious plants of the present time, the habitats of which are decidedly marine, but which are marked by many of the peculiarities of the seed-bearing plants of the land. The superiority of Zostera to the common sea weeds of our coasts appears to have struck in the north of Scotland eyes very little practised in such matters, and seems to have given rise, in consequence, to a popular myth. _Zostera marina_ abounds on a series of sand banks, partially uncovered by the larger stream tides, which lie directly opposite the town of Cromarty, near the spot pointed out by tradition as the site of an earlier town, which was swept away some two or three hundred years ago by the encroachments of the sea. And these banks, with their thick covering of green Zostera, used to be pointed out by the fishermen of the place, in my younger days, as the _meadows_ of the old town, still bearing their original coverings of vegetation,--a vegetation altered no doubt by the "sea change" that had come over it, but still essentially the same, it was said, as that which had smiled around the old burgh, and not at all akin to the brown kelp or tangle that every storm from the boisterous north-east heaps along the sh.o.r.e. It was virtually affirmed that the luxuriant terrestrial gra.s.ses of ancient Cromarty had made a virtue of necessity in their altered circ.u.mstances; and that, settling down into gra.s.ses of the sea, they remained to testify that an ancient Cromarty there had _once been_. _Zostera marina_, like most plants of the land, ripens its seeds towards the close of autumn; and I have seen a smart night"s frost at this season, when coincident with a stream tide that laid bare the beds, nip its seed-bearing stems by thousands; and have found them strewed along the beach a few days after, with all their gra.s.s-like spikes fully developed, and their grain-like seeds charged with a farinaceous substance, which one would scarce expect to find developed in the sea. In the higher reaches of the Cromarty Firth, the Zostera beds, which are of great extent, are much frequented, during the more protracted frosts of a severe winter, by wild geese and swans, that dig up and feed upon the saccharine roots of the plant. The Zostera of the warmer lat.i.tudes attain to a larger size than those of our Scottish seas. "A southern species," says Loudon, "_Zostera oceanica_, has leaves a foot long and an inch broad. It is used as a thatch, which is said to last a century; bleaches white with exposure; and furnishes the rush-like material from which the envelops of Italian liquor flasks are prepared." The simple rectilinear venation of ribbon-like fronds, usually much broken, that occurs in the Lower Old Red Sandstone, has often reminded me of that exhibited by this exotic species of Zostera.]

[Ill.u.s.tration: Fig. 118.

FUCOID.]

[Ill.u.s.tration: Fig. 119.

FUCOIDS.]

a.s.sociated with the earliest ichthyic remains of the Old Red Sandstone, we find vegetable organisms in such abundance, that they communicate often a fissile character to the stone in which they occur. But, existing as mere carbonaceous markings, their state of keeping is usually so bad, that they tell us little else than that the antiquely-formed fishes of this remote period swam over sea bottoms darkened by forests of algae. The prevailing plant was one furnished with a long, smooth stem, which, though it threw off, in the alternate order, numerous branches at least half as stout as itself, preserved its thickness for considerable distances without diminution,--a common fucoidal characteristic. We find its remains mixed in the rock, though sparingly, with those of a rough-edged plant, k.n.o.bbed somewhat like the thong-like receptacles of _Himanthalia lorea_, which also threw off branches like the other, but diminished more rapidly. A greatly more minute vegetable organism of the same beds, characterized by its bifid partings, which strike off at angles of about sixty, somewhat resembles the small-fronded variety of _Dictyota dichotoma_, save that the slim terminations of the frond are usually bent into little hooks, like the tendrils of the pea just as their points begin to turn. Another rather rare plant of the period, existing as a broad, irregularly cleft frond, somewhat resembling that of a modern _Cutleria_ or _Nitophyllum_, betrays at once, in its outline and general appearance, its marine origin; as does also an equally rare contemporary, which, judging from its appearance, seems to have been a true fucus. It exists in the rock as if simply drawn in Indian ink; for it exhibits no structure, though, as in some of the ferns of the Coal Measures, what were once the curls of its leaflets continue to exist as sensible hollows on the surface. It broadens and divides atop into three or four lobes, and these, in turn, broaden and divide into minor lobes, double or ternate, and usually rounded at their terminations. In general appearance the plant not a little resembles those specimens of _Fucus vesiculosus_ which we find existing in a diminutive form, and divested of both the receptacles and the air vessels, at the mouth of rivers. Of two other kinds of plants I have seen only confused ma.s.ses, in which the individuals were so crowded together, and withal so fragmentary and broken, that their separate forms could not be traced. In the one the general appearance was such as might be produced by compressed and tangled ma.s.ses of _Chorda filium_, in which the linear and even tubular character of the plant could be determined, but not its continuous, cord-like aspect; in the other, the fragments seemed well nigh as slim as hairs, and the appearance was such as might be produced by branches of that common ectocarpus, _E.

littoralis_, which may be seen on our rocky coasts roughening at low water the stems of laminaria. When highly magnified, a mesial groove might be detected running along each of the hair-like lines. With these marine plants we occasionally find large rectilinear stems, resolved into a true coal, but retaining no organic character by which to distinguish them. As I have seen some of these more than three inches in diameter, and, though existing as mere fragments, several feet in length, they must, if they were also plants of the sea, have exceeded in size our largest laminaria.[46] And such are the few vegetable organisms, of apparently aquatic origin, which I have hitherto succeeded in detecting in the Lower Old Red Sandstone of Scotland.[47] Their individual numbers, however, must have been very great, though, from the destructible character of their tissues, their forms have perished in the stone. The immensely developed flagstones of Caithness seem to owe their dark color to organic matter mainly of vegetable origin. So strongly bituminous, indeed, are some of the beds of dingier tint, that they flame in the fire like slates steeped in oil.

[Ill.u.s.tration: Fig. 120.]

The remains of a terrestrial vegetation in this deposit are greatly scantier than those of its marine plants; but they must be regarded as possessing a peculiar interest, as, with the exception of the spore cases of the Ludlow rocks, the oldest of their cla.s.s, in at least the British islands, whose true place in the scale can be satisfactorily established. In the flagstones of Orkney there occurs, though very rarely, a minute vegetable organism, which I have elsewhere described as having much the appearance of one of our smaller ferns, such as the maidenhair-spleenwort, or dwarf moonwort. It consists of a minute stem, partially covered by what seems to be a small sheath or hollow bract, and bifurcates into two fronds or pinnae, fringed by from ten to twelve leaflets, that nearly impinge on each other, and somewhat resemble in their mode of arrangement the leaflets of one of our commonest Aspleniums,--_Asplenium trichomanes_. One of our highest authorities, however, in such matters (Professor Balfour of Edinburgh) questions whether this organism be in reality a fern, and describes it from the specimen on the table, in the Palaeontological chapter of his admirable Cla.s.s Book, simply as "a remarkable pinnate frond." (Fig. 13, p. 56.) We find it a.s.sociated with the remains of a terrestrial plant allied to lepidodendron, and which in size and general appearance not a little resembles one of our commonest club mosses,--_Lycopodium clavatum_.[48]

It sends out its branches in exactly the same style,--some short and simple, others branched like the parent stem,--in an arrangement approximately alternate; and is everywhere covered, stem and branch, by thickly set scale-like leaflets, that, suddenly narrowing, terminate in exceedingly slim points. It has, however, proportionally a stouter stem than Lycopodium; its leaves, when seen in profile, seem more rectilinear and thin; and none of its branches yet found bear the fructiferous stalk or spike. Its resemblance, however, to this commonest of the Lycopodia,--a plant that may be gathered by handfuls on the moors by which the flagstones are covered,--is close enough to suggest a new reading of the familiar adage on the meeting of extremes. Between the times of this ancient fossil,--one of the oldest of land plants yet known,--and those of the existing club moss that now scatters its light spores by millions over the dead and blackened remains of its remote predecessor, many creations must have intervened, and many a prodigy of the vegetable world appeared, especially in the earlier and middle periods,--Sigillaria, Favularia, Knorria, and Ulodendron,--that have had no representatives in the floras of latter times; and yet here, flanking the immense scale at both its ends, do we find plants of so nearly the same form and type, that it demands a careful survey to distinguish their points of difference. Here, for instance, to ill.u.s.trate the fact, is there a specimen of _Lycopodium clavatum_, from one of these Caithness moors, that agrees branch for branch, and both in the disposition of its scales and in general outline, with the specimen in the stone. What seems to be an early representative of the Calamites occurs in the same beds. Some of the specimens are of large size,--at least from nine inches to a foot in circ.u.mference,--and retain their thickness, though existing as fragments several feet in length, with but little diminution throughout. They resembled the interior casts of Calamites in being longitudinally furrowed; but the furrows are flatter, and are themselves minutely striated lengthwise by lines as fine as hairs; and, instead of presenting any appearance of joints, there run diagonally across the stems, interrupted and very irregular lines of k.n.o.bs. These I find referred to by Dr. Joseph Hooker, in describing a set of ma.s.sive but ill preserved remains of the same organism detected in South Ness quarry, near Lerwick, by the Hon. Mr. Tuffnell, as taking, in two of the specimens, "the appearance of transverse k.n.o.bs and bars (mayhap spirally arranged) that cross the striae obliquely. But though the k.n.o.bs," he adds, "may perhaps indicate a peculiar character of the plants, they have more probably been caused by pressure during silicification." As, however, they also occur in the best preserved fragment of the plant which I have yet seen,--a Thurso specimen which I owe to my friend Mr. d.i.c.k,--I deem it best to regard them, provisionally at least, as one of the characteristics of the plant. I may mention, that while I disinterred one of my specimens from the Thurso flagstones, where it occurred among remains of Dipterus and Asterolepis, I derived another specimen from the great overlying formation of pale Red Sandstone to which the lofty hills of Hoy and the tall mural precipices of Dunnet Head belong; and that this plant is the only organism which has yet been found in this uppermost member of the Lower Old Red, to at least the north of the Moray Firth. Another apparently terrestrial organism of the lower formation, of, however, rare occurrence, very much resembles a sheathing bract or spathe. It is of considerable size,--from four to six inches in length, by from two to three inches in breadth,--of a broadly elliptical and yet somewhat lanceolate form, deeply but irregularly corrugated, the rugae exhibiting a tendency to converge towards both its lower and upper terminations, and with, in some instances, what seems to be the fragment of a second spathe springing from its base. Another and much smaller vegetable organism of the same beds presents the form of a spathe-enveloped bud or unblown flower wrapped up in its calyx; but all the specimens which I have yet seen are too obscure to admit of certain determination. I may here mention, that curious markings, which have been regarded as impressions made by vegetables that had themselves disappeared, have been detected during the last twelvemonth in a quarry of the Lower Ol

Prev List Next