“And it is not merely the small, but the large islands also, not merely the islands, but the continents which can be lifted up together with the sea; and, too, the large and small tracts may subside, for habitations and cities, like Bure, Bizona, and many others, have been engulfed by earthquakes.”[75]
But it was not until eighteen centuries later that this doctrine, under the teachings of Playfair, Leopold von Buch, and Élie de Beaumont (1829–30) became generally accepted. In 1845 Humboldt remarked, “It is a fact to-day recognized by all geologists, that the rise of continents is due to an actual upheaval, and not to an apparent subsidence occasioned by a general depression of the level of the sea” (Cosmos, i). Yet as late as 1869 we have an essay by H. Trautschold[76] in which is a statement of the arguments which can be brought forward in favor of the doctrine that the increase of the land above sea level is due to the retirement of the sea.[77]
As authentic and unimpeachable proofs of the former existence of the sea where now it is absent, Lamarck cites the occurrence of fossils in rocks inland. Lamarck’s first paper on fossils was read to the Institute in 1799, or about three years previous to the publication of the Hydrogéologie. He restricts the term “fossils” to vegetable and animal remains, since the word in his time was by some loosely applied to minerals as well as fossils; to anything dug out of the earth. “We find fossils,” he says, “on dry land, even in the middle of continents and large islands; and not only in places far removed from the sea, but even on mountains and in their bowels, at considerable heights, each part of the earth’s surface having at some time been a veritable ocean bottom.” He then quotes at length accounts of such instances from Buffon, and notices their prodigious number, and that while the greater number are marine, others are fresh-water and terrestrial shells, and the marine shells may be divided into littoral and pelagic.
“This distinction is very important to make, because the consideration of fossils is, as we have already said, one of the principal means of knowing well the revolutions which have taken place on the surface of our globe. This subject is of great importance, and under this point of view it should lead naturalists to study fossil shells, in order to compare them with their analogues which we can discover in the sea; finally, to carefully seek the places where each species lives, the banks which are formed of them, the different beds which these banks may present, etc., etc., so that we do not believe it out of place to insert here the principal considerations which have already resulted from that which is known in this respect.
“The fossils which are found in the dry parts of the surface of the globe are evident indications of a long sojourn of the sea in the very places where we observe them.” Under this heading, after repeating the statement previously made that fossils occur in all parts of the dry land, in the midst of the continents and on high mountains, he inquires by what cause so many marine shells could be found in the explored parts of the world. Discarding the old idea that they are monuments of the deluge, transformed into fossils, he denies that there was such a general catastrophe as a universal deluge, and goes on to say in his assured, but calm and philosophic way:
“On the globe which we inhabit, everything is submitted to continual and inevitable changes, which result from the essential order of things: they take place, in truth, with more or less promptitude or slowness, according to the nature, the condition, or the situation of the objects; nevertheless they are wrought in some time or other.
“To nature, time is nothing, and it never presents a difficulty; she always has it at her disposal, and it is for her a means without limit, with which she has made the greatest as well as the least things.
“The changes to which everything in this world is subjected are changes not only of form and of nature, but they are changes also of bulk, and even of situation.
“All the considerations stated in the preceding chapters should convince us that nothing on the surface of the terrestrial globe is immutable. They teach us that the vast ocean which occupies so great a part of the surface of our globe cannot have its bed constantly fixed in the same place; that the dry or exposed parts of this surface themselves undergo perpetual changes in their condition, and that they are in turn successively invaded and abandoned by the sea.
“There is, indeed, every evidence that these enormous masses of water continually displace themselves, both their bed and their limits.
“In truth these displacements, which are never interrupted, are in general only made with extreme and almost inappreciable slowness, but they are in ceaseless operation, and with such constancy that the ocean bottom, which necessarily loses on one side while it gains on another, has already, without doubt, spread over not only once, but even several times, every point of the surface of the globe.
“If it is thus, if each point of the surface of the terrestrial globe has been in turn dominated by the seas—that is to say, has contributed to form the bed of those immense masses of water which constitute the ocean—it should result (1) that the insensible but uninterrupted transfer of the bed of the ocean over the whole surface of the globe has given place to deposits of the remains of marine animals which we should find in a fossil state; (2) that this translation of the ocean basin should be the reason why the dry portions of the earth are always more elevated than the level of the sea; so that the old ocean bed should become exposed without being elevated above the sea, and without consequently giving rise to the formation of mountains which we observe in so many different regions of the naked parts of our globe.”
Thus littoral shells of many genera, such as Pectens, Tellinæ, cockle shells, turban shells (sabots), etc., madrepores and other littoral polyps, the bones of marine or of amphibious animals which have lived near the sea, and which occur as fossils, are then unimpeachable monuments of the sojourn of the sea on the points of the dry parts of the globe where we observe their deposits, and besides these occur deep-water forms. “Thus the encrinites, the belemnites, the orthoceratites, the ostracites, the terebratules, etc., all animals which habitually live at the bottom, found for the most part among the fossils deposited on the point of the globe in question, are unimpeachable witnesses which attest that this same place was once part of the bottom or great depths of the sea.” He then attempts to prove, and does so satisfactorily, that the shells he refers to are what he calls deep-water (pélagiennes). He proves the truth of his thesis by the following facts:
1. We are already familiar with a marine Gryphæa, and different Terebratulæ, also marine shell-fish, which do not, however, live near shore. 2. Also the greatest depth which has been reached with the rake or the dredge is not destitute of molluscs, since we find there a great number which only live at this depth, and without instruments to reach and bring them up we should know nothing of the cones, olives, Mitra, many species of Murex, Strombus, etc. 3. Finally, since the discovery of a living Encrinus, drawn up on a sounding line from a great depth, and where lives the animal or polyp in question, it is not only possible to assure ourselves that at this depth there are other living animals, but on the contrary we are strongly bound to think that other species of the same genus, and probably other animals of different genera, also live at the same depths. All this leads one to admit, with Bruguière,[78] the existence of deep-water shell-fish and polyps, which, like him, I distinguish from littoral shells and polyps.
“The two sorts of monuments of which I have above spoken, namely, littoral and deep-sea fossils, may be, and often should be, found separated by different beds in the same bank or in the same mountains, since they have been deposited there at very different epochs. But they may often be found mixed together, because the movements of the water, the currents, submarine volcanoes, etc., have overturned the beds, yet some regular deposits in water always tranquil would be left in quite distant beds.... Every dry part of the earth’s surface, when the presence or the abundance of marine fossils prove that formerly the sea has remained in that place, has necessarily twice received, for a single incursion of the sea, littoral shells, and once deep-sea shells, in three different deposits—this will not be disputed. But as such an incursion of the sea can only be accomplished by a period of immense duration, it follows that the littoral shells deposited at the first sojourn of the edge of the sea, and constituting the first deposit, have been destroyed—that is to say, have not been preserved to the present time; while the deep-water shells form the second deposit, and there the littoral shells of the third deposit are, in fact, the only ones which now exist, and which constitute the fossils that we see.”
He again asserts that these deposits could not be the result of any sudden catastrophe, because of the necessarily long sojourn of the sea to account for the extensive beds of fossil shells, the remains of “infinitely multiplied generations of shelled animals which have lived in this place, and have there successively deposited their débris.” He therefore supposes that these remains, “continually heaped up, have formed these shell banks, become fossilized after the lapse of considerable time, and in which it is often possible to distinguish different beds.” He then continues his line of anti-catastrophic reasoning, and we must remember that in his time facts in biology and geology were feebly grasped, and scientific reasoning or induction was in its infancy.
“I would again inquire how, in the supposition of a universal catastrophe, there could have been preserved an infinity of delicate shells which the least shock would break, but of which we now find a great number uninjured among other fossils. How also could it happen that bivalve shells, with which calcareous rocks and even those changed into a silicious condition are interlarded, should be all still provided with their two valves, as I have stated, if the animals of these shells had not lived in these places?
“There is no doubt but that the remains of so many molluscs, that so many shells deposited and consequently changed into fossils, and most of which were totally destroyed before their substance became silicified, furnished a great part of the calcareous matter which we observe on the surface and in the upper beds of the earth.
“Nevertheless there is in the sea, for the formation of calcareous matter, a cause which is greater than shelled molluscs, which is consequently still more powerful, and to which must be referred ninety-nine hundredths, and indeed more, of the calcareous matter occurring in nature. This cause, so important to consider, is the existence of coralligenous polyps, which we might therefore call testaceous polyps, because, like the testaceous molluscs, these polyps have the faculty of forming, by a transudation or a continual secretion of their bodies, the stony and calcareous polypidom on which they live.
“In truth these polyps are animals so small that a single one only forms a minute quantity of calcareous matter. But in this case what nature does not obtain in any volume or in quantity from any one individual, she simply receives by the number of animals in question, through the enormous multiplicity of these animals, and their astonishing fecundity—namely, by the wonderful faculty they have of promptly regenerating, of multiplying in a short time their generations successively, and rapidly accumulating; finally, by the total amount of reunion of the products of these numerous little animals.
“Moreover, it is a fact now well known and well established that the coralligenous polyps, namely, this great family of animals with coral stocks, such as the millepores, the madrepores, astrææ, meandrinæ, etc., prepare on a great scale at the bottom of the sea, by a continual secretion of their bodies, and as the result of their enormous multiplication and their accumulated generations, the greatest part of the calcareous matter which exists. The numerous coral stocks which these animals produce, and whose bulk and numbers perpetually increase, form in certain places islands of considerable extent, fill up extensive bays, gulfs, and roadsteads; in a word, close harbors, and entirely change the condition of coasts.
“These enormous banks of madrepores and millepores, heaped upon each other, covered and intermingled with serpulæ, different kinds of oysters, patellæ, barnacles, and other shells fixed by their base, form irregular mountains of an almost limitless extent.
“But when, after the lapse of considerable time, the sea has left the places where these immense deposits are laid down, then the slow but combined alteration that these great masses undergo, left uncovered and exposed to the incessant action of the air, light, and a variable humidity, changes them gradually into fossils and destroys their membranous or gelatinous part, which is the readiest to decompose. This alteration, which the enormous masses of the corals in question continued to undergo, caused their structure to gradually disappear, and their great porosity unceasingly diminished the parts of these stony masses by displacing and again bringing together the molecules composing them, so that, undergoing a new aggregation, these calcareous molecules obtained a number of points of contact, and constituted harder and more compact masses. It finally results that instead of the original masses of madrepores and millepores there occurs only masses of a compact calcareous rock, which modern mineralogists have improperly called primitive limestone, because, seeing in it no traces of shells or corals, they have mistaken these stony masses for deposits of a matter primitively existing in nature.”