Principles of Geology, by Charles Lyell

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CHAPTER 15

Imbedding of organic remains in subaqueous deposits – Division of the subject – Phenomena relating to terrestrial animals and plants first considered – Wood sunk to a great depth in the sea instantly impregnated with salt-water – Experiments of Scoresby – Drift timber carried by the Mackenzie into Slave Lake and into the sea – Cause of the abundance of drift timber in this river – Floating trees in the Mississippi – In the Gulf stream – Immense quantity thrown upon the coast of Iceland, Spitzbergen, and Labrador – Imbedding of the remains of insects – Of the remains of reptiles – Why the bones of birds are so rare in subaqueous deposits – Imbedding of terrestrial quadrupeds – Effects of a flood in the Solway Firth – Wild horses annually drowned in the savannahs of South America – Skeletons in recent shell marl – Drifting of mammiferous and other remains by tides and currents

WE have treated hitherto of the imbedding of organic remains in deposits formed upon the emerged land, and we shall next consider the including of the same in deposits formed under water.

It will be convenient to divide this branch of our subject into three parts; considering first, the various modes whereby the relics of terrestrial species may be buried in subaqueous formations; secondly, the modes whereby the animals and plants inhabiting fresh-water may be so entombed; thirdly, the manner in which marine species may become preserved in new strata.

The phenomena which we are now about to notice demand a fuller share of attention than those previously examined, since the deposits which originate upon the dry land are insignificant in thickness, superficial extent, and durability, when contrasted with those of subaqueous origin. At the same time, the study of the latter is beset with greater difficulties, for we are here concerned with the results of processes much more removed from the sphere of ordinary observation. There is, indeed, no circumstance, as we before remarked, [1] which more seriously impedes the acquisition of just views in the etiology of our science, than an habitual disregard of the important fact, that the reproductive effects of the principal agents of change are confined to another element, -- to that larger portion of the habitable globe, from which, by our very organization, we are almost entirely excluded.

Imbedding of Terrestrial Plants.

When a tree falls into a river from the undermining of the banks, or from being washed in by a torrent or flood, it floats on the surface, not because the woody portion is specifically lighter than water, but because it is full of pores containing air. When soaked for a considerable time, the water makes its way into these pores, and the wood becomes water-logged and sinks. The time required for this process varies differently in different woods, but several kinds may be drifted to great distances, sometimes across the ocean, before they lose their buoyancy.

If wood be sunk to vast depths in the sea, it may be impregnated with water suddenly. Captain Scoresby informs us, in his Account of the Arctic Regions, [2] that on one occasion a whale, on being harpooned, ran out all the lines in the boat, which it then dragged under water, the men having just time to escape to a piece of ice. When the fish returned to the surface "to blow," it was struck a second time, and soon afterwards killed. The moment it expired it began to sink, -- an unusual circumstance, which was found to be caused by the weight of the sunken boat which still remained attached to it. By means of harpoons and ropes the fish was prevented from sinking until it was released from the weight by connecting a rope to the lines of the attached boat, which was no sooner done than the fish rose again to the surface. The sunken boat was then hauled up with great labour, for so heavy was it, that although before the accident it would have been buoyant when full of water, yet it now required a boat at each end to keep it from sinking. "When it was hoisted into the ship, the paint came off the wood in large sheets; and the planks, which were of wainscot, were as completely soaked in every pore as if they had lain at the bottom of the sea since the Flood! A wooden apparatus that accompanied the boat in its progress through the deep, consisting chiefly of a piece of thick deal, about fifteen inches square, happened to fall overboard, and, though it originally consisted of the lightest fir, sank in the water like a stone. The boat was rendered useless; even the wood of which it was built, on being offered to the cook for fuel, was tried and rejected as incombustible." [3]

Captain Scoresby found that by sinking pieces of fir, elm, ash, &c., to the depth of four thousand and sometimes six thousand feet, they became impregnated with sea-water, and when drawn up again, after immersion for an hour, would no longer float. The effect of this impregnation was to increase the dimensions as well as the specific gravity of the wood, every solid inch having increased one-twentieth in size and twenty-one twenty-fifths in weight. [4]

When timber is drifted down by a river, it is often arrested by lakes, and becoming water-logged it may sink and be imbedded in lacustrine strata, if any be there forming: sometimes a portion floats on till it reaches the sea. In the course of the Mackenzie River we have an example of vast accumulations of vegetable matter now in progress under both these circumstances.

In Slave Lake in particular, which vies in dimensions with some of the great fresh-water seas of Canada, the quantity of drift-timber brought down annually is enormous. "As the trees," says Dr. Richardson, "retain their roots, which are often loaded with earth and stones, they readily sink, especially when water-soaked, and, accumulating in the eddies, form shoals, which ultimately augment into islands. A thicket of small willows covers the new-formed island as soon as it appears above water, and their fibrous roots serve to bind the whole firmly together. Sections of these islands are annually made by the river, assisted by the frost; and it is interesting to study the diversity of appearances they present according to their different ages. The trunks of the trees gradually decay until they are converted into a blackish brown substance resembling peat, but which still retains more or less of the fibrous structure of the wood; and layers of this often alternate with layers of clay and sand, the whole being penetrated, to the depth of four or five yards or more, by the long fibrous roots of the willows. A deposition of this kind, with the aid of a little infiltration of bituminous matter, would produce an excellent imitation of coal, with vegetable impressions of the willow roots. What appeared most remarkable was the horizontal slaty structure that the older alluvial banks presented, or the regular curve that the strata assumed from unequal subsidence.

"It was in the rivers only that we could observe sections of these deposits, but the same operation goes on on a much more magnificent scale in the lakes. A shoal of many miles in extent is formed on the south side of Athabasca Lake, by the drift-timber and vegetable debris brought down by the Elk River; and the Slave Lake itself must in process of time be filled up by the matters daily conveyed into it from Slave River. Vast quantities of drift timber are buried under the sand at the mouth of the river, and enormous piles of it are accumulated on the shores of every part of the lake." [5]

The banks of the Mackenzie display almost everywhere horizontal beds of wood coal, alternating with bituminous clay, gravel, sand, and friable sandstone; sections, in short, of such deposits as are now evidently forming at the bottom of the lakes which it traverses.

Notwithstanding the vast forests intercepted by the lakes, a still greater mass of drift-wood is found where the Mackenzie reaches the sea, in a latitude where no wood grows at present except a few stunted willows. At the mouths of the river the alluvial matter has formed a barrier of islands and shoals, where we may expect a great formation of coal at some distant period.

The abundance of floating timber on the Mackenzie is owing, as I am informed by Dr. Richardson, to the peculiar direction and to the length of the course of this river, which runs from south to north, so that the sources of the stream lie in much warmer latitudes than its mouths. In the country, therefore, where the former are situated, the frost breaks up at an earlier season, while yet the waters in the lower part of its course are ice-bound. Hence the current of water, rushing down northward, reaches a point where the thaw has not begun, and finding the channel of the river blocked up with ice, it overflows the banks, sweeping through forests of pines, and carrying away thousands of uprooted trees.

We have already observed [6] that the navigation of the Mississippi is much impeded by trunks of trees half sunk in the river. On reaching the Gulf of Mexico many of them subside and are imbedded in the new strata which form the delta, but many of them float on and enter the Gulfstream. "Tropical plants, (says M. Constant Prevost,) are taken up by this great current, and carried in a northerly direction, till they reach the shores of Iceland and Spitzbergen uninjured. A great portion of them are doubtless arrested on their passage, and, probably, always in the same inlets, or the same spots on the bottom of the ocean; in fact, wherever an eddy or calm determines their distribution, which, in this single example, extends over a space comprehended between the equator and the eightieth degree of latitude-an immense space, six times more considerable than that occupied by all Europe, and thirty times larger than France. The drifting of various substances, though regular, is not continual; it takes place by intermittance after great inundations of rivers, and in the intervals the waters may only carry sand or mud, or each of these alternately, to the same localities." [7]

The ancient forests of Iceland, as Malte-Brun observes, have been improvidently exhausted; but, although the Icelander can obtain no timber from the land, he is supplied with it abundantly by the ocean. An immense quantity of thick trunks of pines, firs, and other trees, are thrown upon the northern coast of the island, especially upon North Cape and Cape Langaness, and are then carried by the waves along these two promontories to other parts of the coast, so as to afford sufficiency of wood for fuel and for constructing boats. Timber is also carried to the shores of Labrador and Greenland; and Crantz assures us that the masses of floating wood thrown by the waves upon the island of John de Mayen often equal the whole of that island in extent. [8]

In a similar manner the bays of Spitzbergen are filled with drift-wood, which accumulates also upon those parts of the coast of Siberia that are exposed to the east, consisting of larch trees, pines, Siberian cedars, firs, and Fernambucco and Campeachy woods. These trunks appear to have been swept away by the great rivers of Asia and America. Some of them are brought from the Gulf of Mexico, by the Bahama stream, while others are hurried forward by the current which, to the north of Siberia, constantly sets in from east to west. Some of these trees have been deprived of their bark by friction, but are in such a state of preservation as to form excellent building timber. [9] Parts of the branches and almost all the roots remain fixed to the pines which have been drifted into the North Sea, into latitudes too cold for the growth of such timber, but the trunks are usually barked.

The leaves and lighter parts of plants are seldom carried out to sea, in any part of the globe, except during tropical hurricanes among islands, and during the agitations of the atmosphere which sometimes accompany earthquakes and volcanic eruptions. [10]

It will appear from these observations, that although the remains of terrestrial vegetation, borne down by aqueous causes from the land, are chiefly deposited at the bottom of lakes or at the mouths of rivers, yet a considerable quantity is drifted about ill all directions by currents, and may become imbedded in any marine formation, or may sink down, when waterlogged, to the bottom of unfathomable abysses, and there accumulate without intermixture of other substances.

It may be asked whether we have any data for inferring that the remains of a considerable proportion of the existing species of plants will be permanently preserved, so as to be hereafter recognizable, supposing the strata now in progress to be at some future period upraised? To this inquiry we may reply that there are no reasons for expecting that more than a small number of the plants now flourishing in the globe will become fossilized, since the entire habitations of a great number of them are remote from Jakes and seas, and even where they grow near to large bodies of water, the circumstances are quite accidental and partial which favour the imbedding and conservation of vegetable remains. Those naturalists, therefore, who infer that the ancient flora of the globe was, at certain periods, less varied than now, merely because they have as yet discovered only a few hundred fossil species of a particular epoch, while they can enumerate more than fifty thousand living ones, are reasoning on a false basis, and their standard of comparison is not the same in the two cases.

Imbedding of the Remains of Insects.

I HAVE observed the elytra and other parts of beetles in a band of fissile clay, separating two beds of recent shell-marl, in the Loch of Kinnordy. Amongst these, Mr. Curtis recognized Elater lineatus and Atopa cervina, species still living in Scotland. 1."hese, as well as other remains which accompanied them, appear to belong to terrestrial, not aquatic species, and must have been carried down in muddy water during an inundation. In the lacustrine peat of the same locality, the elytra of beetles are not uncommon; but in the deposits of drained lakes gene.. rally, and in the silt of our estuaries, the relics of this class of the animal kingdom are extremely rare. In the blue clay of very modern origin of Lewes Levels, Mr. Mantell has found the Indusia, or cases of the larvae of Phryganea, in abundance, with minute shells belonging to the genera Planorbis, Limnea, &c., adhering to them. [11]

When speaking of the migrations of insects, we pointed out that an immense number are floated into lakes and seas by rivers, or blown by winds far from the land; but they are so buoyant that we can only suppose them, under very peculiar circumstances, to sink to the bottom before they are either devoured by insectivorous animals or are decomposed.

Remains of Reptiles.

As the bodies of several crocodiles were found in the mud brought down to the sea by the river inundation which attended an earthquake in Java in the year 1699, we may imagine that extraordinary floods of mud may stifle many individuals of the shoals of alligators and other reptiles which frequent lakes and the deltas of rivers in tropical climates. thousands of frogs were found leaping about among the wreck carried into the sea by the late inundations in Morayshire t; and it is evident that whenever a sea-cliff is undermined, or land is swept by other violent causes into the sea, land reptiles may be carried in.

Remains of Birds.

WE might have anticipated that the imbedding of the remains of birds in new strata would be of very rare occurrence, for their powers of flight insure them against perishing by numerous casualties to which quadrupeds are exposed during floods; and if they chance to be drowned, or to die when swimming on the water, it will scarcely ever happen that they will be submerged so as to become preserved in sedimentary deposits. For in consequence of the hollow tubular structure of their bones and the quantity of their feathers, they are extremely light in proportion to their volume, so that when first killed they do not sink to the bottom like quadrupeds, but float on the surface until the carcass either rots away or is devoured by predaceous animals. To these causes we may ascribe the absence of any vestige of the bones of birds in the recent marl formations of Scotland; although these lakes, until the moment when they were artificially drained, were frequented by a great abundance of water-fowl.

Imbedding of Terrestrial Quadrupeds.

RIVER inundations recur in most climates at very irregular intervals, and expend their fury on those rich alluvial plains where herds of herbivorous quadrupeds congregate together. These animals are often surprised, and being unable to stem the current, are hurried along until they are drowned, when they sink immediately to the bottom. Here their bodies are drifted along, together with sediment, into lakes or seas, and may then be covered by a mass of mud, sand, and pebbles, thrown down upon them. If there be no sediment superimposed, the gases generated by putrefaction usually cause the bodies to rise again to the surface about the ninth, or at most the fourteenth day. The pressure of a thin covering would not be sufficient to retain them at the bottom, for we see the putrid carcasses of dogs and cats, even in rivers, floating with considerable weights attached to them, and they would be still more buoyant in sea-water.

In cases where the body is so buried in drift-sand, or mud accumulated upon it, as never to rise again, the skeleton may be preserved entire; but if it comes again to the surface while in the process of putrefaction, the bones commonly fall piecemeal from the floating carcass, and may in that case become scattered at random over the bottom of a lake, estuary, or sea, so that a jaw may afterwards be found in one place, a rib in another, a humerus in a third -- all included, perhaps, in a matrix of fine materials, and where there may be evidence of very slight transporting power in the current, or even of none, but simply of some chemical precipitate.

A large number of the bodies of drowned animals, if they float into the sea or a lake, especially in hot climates, are instantly devoured by sharks, alligators, and other carnivorous beasts, which may have power to digest even the bones. But during extraordinary floods, when the greatest number of land animals are destroyed, the waters are commonly so turbid, especially at the bottom of the channel, that even aquatic species are compelled to escape into some retreat where there is clearer water, lest they should be stifled. For this reason, as well as the rapidity of sedimentary deposition at such seasons, the probability of some carcasses becoming permanently imbedded is considerable.

One of the most memorable floods of modern date, in our island, is that which visited part of the southern borders of Scotland, on the 24th of January, 1794, and which spread particular devastation over the country adjoining the Solway Frith.

We learn from the account of Captain Napier, that the heavy rains had swollen every stream which entered the Frith of Solway, so that the inundation not only carried away a great number of cattle and sheep, but many of the herdsmen and shepherds, washing down their bodies into the estuary. After the storm, when the flood subsided, an extraordinary spectacle was seen on a large sand-bank, called "the beds of Esk," where there is a meeting of the tidal waters, and where heavy bodies are usually left stranded after great floods. On this single bank were found collected together the bodies of nine black cattle, three horses, one thousand eight hundred and forty sheep, forty-five dogs, one hundred and eighty hares, besides a great number of smaller animals, and, mingled with the rest, the corpses of two men and one woman. [12]

In those more recent floods in Scotland, in August 1829, whereby a fertile district, six hundred miles in length, became a scene of dreadful desolation, a vast number of animals and plants were washed from the land, and found scattered about after the storm, around the mouths of the principal rivers. An eye-witness thus describes the scene which presented itself at the mouth of the Spey, in Morayshire. "For several miles along the beach, crowds were employed in endeavouring to save the wood and other wreck with which the heavy rolling tide was loaded; whilst the margin of the sea was strewed with the carcasses of domestic animals, and with millions of dead hares and rabbits. Thousands of living frogs, also, swept from the fields, no one can say how far off, were observed leaping among the wreck." [13]

We are informed by Humboldt, that during the periodical swellings of the large rivers in South America, great numbers of quadrupeds are annually drowned. Of the wild horses, for example, which graze in immense troops in the savannahs, thousands are said to perish when the river Apure is swollen, before they have time to reach the rising grounds of the Llanos. The mares, during the season of high water, may be seen, followed by their colts, swimming about and feeding on the grass of which the top alone waves above the waters. In this state they are pursued by crocodiles; and their thighs frequently bear the prints of the teeth of these carnivorous reptiles. "Such is the pliability," observes the celebrated traveller, "of the organization of the animals which man has subjected to his sway, that horses, cows, and other species of European origin, lead, for a time, an amphibious life, surrounded by crocodiles, water-serpents, and manatees. When the rivers return again into their beds, they roam in the savannah, which is then spread over with a fine odoriferous grass, and enjoy, as in their native climate, the renewed vegetation of spring." [14]

We find it continually stated, by those who describe the Ganges and Burrampooter, that these rivers carry before them, during the flood season, not only floats of reeds and timber, but dead bodies of men, deer, and oxen. [15]

We have already referred to the effects of a flood which attended an earthquake in Java in 1699, when the turbid waters of the Batavian river destroyed all the fish except the carp; and when drowned buffaloes, tigers, rhinoceroses, deer, apes, and other wild beasts, were brought down to the seacoast by the current, with several crocodiles which had been stifled in the mud. [16]

On the western side of the same island, in the territory of Goulongong, in the regencies, a more recent volcanic eruption (1821) was attended by a flood, during which the river Tjetandoy bore down hundreds of carcasses of rhinoceroses and buffaloes, and swept away more than one hundred men and women from a multitude assembled on its banks to celebrate a festival. Whether the bodies reached the sea, or were deposited, with drift matter, in some of the large intervening alluvial plains, we are not informed. [17]

We might enumerate a great number of local deluges that have swept through the fertile lands which border on large rivers, especially in tropical countries, but we should surpass the limits of this work. We may observe, however, that the destruction of islands, in rivers, is often attended with great loss of lives. Thus, when the principal river in Virginia rose, in 1771, to the height of twenty-five feet above its ordinary level, it swept entirely away Elk Island, on which were seven hundred head of quadrupeds,-horses, oxen, sheep, and hogs,-and nearly one hundred houses. [18]

The reader will gather, from what we have said in a former volume respecting the deposition of sediment by aqueous causes, that the greater number of the remains of quadrupeds drifted away by rivers must be intercepted by lakes before they reach the sea, or buried in fresh-water formations near the mouths of rivers. If they are carried still farther, the probabilities are increased of their rising to the surface in a state of putrefaction, and, in that case, of being there devoured by aquatic beasts of prey, or of subsiding into some spots whither no sediment is conveyed, and, consequently, where every vestige of them will, in the course of time, disappear.

In some instances, the skeletons of quadrupeds are met with abundantly in recent shell-marls in Scotland, where we cannot suppose them to have been imbedded by the action of rivers or floods. They all belong to species which now inhabit, or are known to have been indigenous in Scotland. The remains of several hundred skeletons have been procured within the last century, from five or six small lakes in Forfarshire, where shell-marl has been worked. Those of the stag (Cervus elaphus) are most numerous, and if the others be arranged in the order of their relative abundance, they will follow nearly thus: the ox, the boar, the horse, the sheep, the dog, the hare, the fox, the wolf, and the cat. The beaver seems extremely rare, but it has been found in the shell-marl of Loch Marlie, in Perthshire, and in the parish of Edrom, in Berwickshire.

In the greater part of these lake deposits there are no signs of floods, and the expanse of water was originally so confined, that the smallest of the above-mentioned quadrupeds could have crossed, by swimming, from one shore to the other. Deer, and such species as take readily to the water, may often have been mired in trying to land, where the bottom was soft and quaggy, and, in their efforts to escape, may have plunged deeper into the marly bottom. Some individuals, we suspect, of different species, have fallen in when crossing the frozen surface in winter, for nothing can be more treacherous than the ice when covered with snow, in consequence of the springs, which are numerous, and which, always retaining an equal temperature, cause the ice, in certain spots, to be extremely thin, while, in every other part of the lake, it is strong enough to bear the heaviest weights.

As the bones of mammalia are often so abundantly preserved in peat, and in such lakes as we have just described, the encroachments of a sea upon a coast may sometimes throw down the imbedded skeletons, so that they may be carried away by tides and currents, and entombed in subaqueous formations. Some of the smaller quadrupeds, also, which burrow in the ground, as well as reptiles and every species of plant, are liable to be cast down into the waves by this cause, which must not be overlooked, although we believe it to be of comparatively small importance amongst the numerous agents whereby terrestrial organic remains may be included in submarine strata.

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Notes:

1. Vol. i., p. 81.

2. Vol. ii. p. 191.

3. Account of the Arctic Regions, vol. ii. p. 193.

4. Ib. p. 202.

5. Dr. Richardson's Geognost. Obs. on Capt. Franklin's Polar Expedition.

6. Vol. i. p. 245.

7. Mem. de la Soc. d'Hist. Nat. de Paris, vol. iv. p. 84.

8. Malte-Brun, Geog. vol. v. part i. p. 112. -- Crantz, Hist. of Greenland, tome i. pp.50-54.

9. Olafsen, Voyage to Iceland, tome i. Malte-Brun's Geog. vol. v. part i. p. 112.

10. De la Beehe, Geol. Manual, p. 477.

11. Trans. Geol. Soc. vol. iii. part i. p. 201, Second Series.

12. Sir T. D. Lauder's Account, Second Ed., p. 312.

13. Treatise on Practical Store Farming, p.25.

14. Sir T. D. Lauder's Account of the Great Floods in Morayshire, August 1829, p. 312, Second Ed.

15. Humboldt's Pers. Narr., vol. iv., pp. 394-396.

16. Malte-Brun, Geog., vol. iii., p. 22.

17. See ante, vol. i., p.444.

18. This account I had from Mr. Baumhauer, Director-General of Finances in Java.

19. Scots Mag., vol. xxxiii.

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CHAPTER 16

Imbedding of the remains of man and his works in subaqueous strata – Drifting of bodies to the sea by river-inundations – Destruction of bridges and houses – Burial of human bodies in the sea – Loss of lives by shipwreck – Circumstances under which human corpses may be preserved under a great thickness of recent deposits – Number of wrecked vessels – Durable character of many of their contents – Examples of fossil skeletons of men – Of fossil canoes, ships, and works of art – Of the chemical changes which certain metallic instruments have undergone after long submergence – Effects of the subsidence of land in imbedding cities and forests in subaqueous strata – Earthquake of Cutch in 1819 – Submarine forests – Berkely's arguments for the recent date of the creation of man – Concluding remarks

WE shall now proceed to inquire in what manner the mortal remains of man and the works of his hands may be permanently preserved in subaqueous strata. Of the many hundred million human beings which perish ill the course of every century on the land, every vestige is usually destroyed in the course of a few thousand years, but of the smaller number that perish in the waters, a considerable proportion must frequently be entombed, under such circumstances, that parts of them may endure throughout entire geological epochs.

We have already seen how the bodies of men, together with those of the inferior animals, are occasionally washed down during river- inundations into seas and lakes, of which we shall now enumerate some additional examples.

Belzoni witnessed a flood on the Nile in September, 1818, where, although the river only rose three feet and a half above its ordinary level, several villages, with some hundreds of men, women, and children, were swept away. [1] We mentioned in a former volume that a rise of six feet of water in the Ganges in 1763, was attended with a much greater loss of lives. In the year 1771, at the time of the bursting of the Solway moss before alluded to, when the inundations in the north of England appear to have equalled the recent floods in Morayshire, a great number of houses and their inhabitants were swept away by the rivers Tyne, Can, Wear, Tees, and Greta; and no less than twenty-one bridges were destroyed in the courses of these rivers. At the village of Bywell the flood tore the dead bodies and coffins out of the churchyard, and bore them away, together with many of the living inhabitants. During the same tempest an immense number of cattle, horses, and sheep, were also transported to the sea, while the whole coast was covered with the wreck of ships. Four centuries before (in 1338), the same district had been visited by a similar continuance of heavy rains followed by disastrous floods, and it is not improbable that these catastrophes may recur periodically. As the population increases, and buildings and bridges are multiplied, we must expect that the loss of lives and property will rather augment. [2]

If to the hundreds of human bodies committed to the deep in the way of ordinary burial, we add those of individuals lost by shipwreck, we shall find that, in the course of a single year, a great number of human remains are consigned to the subaqueous regions. We shall hereafter advert to a calculation by which it appears that more than five hundred British vessels alone, averaging each a burden of about one hundred and twenty tons, are wrecked, and sink to the bottom, annually. Of these the crews for the most part escape, although it sometimes happens that all perish. In one great naval action several thousand individuals sometimes share a watery grave.

Many of these corpses are instantly devoured by predaceous fish, sometimes before they reach the bottom; still more frequently when they rise again to the surface and float in a state of putrefaction. Many decompose on the floor of the ocean where no sediment is thrown down upon them, but if they fall upon a reef where corals and shells are becoming agglutinated into a solid rock, or subside where the delta of a river is advancing, they may be preserved for an incalculable series of ages in these deposits.

Often at the distance of a few hundred feet from a coral reef there are no soundings at the depth of many hundred fathoms Here if a ship strike and be wrecked, it may soon be covered by calcareous sand and fragments of coral detached by the breakers from the summit of a submarine mountain, and which may roll down to its base. Wrecks are known to have been common for centuries near certain reefs, so that canoes, merchant vessels, and ships of war may have sunk and have been enveloped in these situations in calcareous sand and breccia. Suppose a volcanic eruption to cover such remains with ashes and sand, and that over the tufaceous strata resulting from these ejections, a current of lava is afterwards poured, the ships and human skeletons might then remain uninjured beneath the superincumbent rock, like the houses and works of art in the subterranean cities of Campania. That cases may have already occurred where human remains have been thus preserved in a fossil state beneath masses more than a thousand feet in thickness, is by no means improbable, for in some volcanic archipelagos a period of thirty or forty centuries might well suffice for such an accumulation of matter.

We stated that at the distance of about forty miles from the base of the delta of the Ganges, there is a circular space about fifteen miles in diameter where soundings of a thousand feet sometimes fail to reach the bottom. As during the flood season the quantity of mud and sand poured by the great rivers into the Bay of Bengal, is so great that the sea only recovers its transparency at the distance of sixty miles from the coast, this depression must be gradually shoaling, especially as during the monsoons the sea, loaded with mud and sand, is beaten back in that direction towards the delta. Now if a ship or human body sink down to the bottom in such a spot, it is by no means improbable that it may become buried under a depth of three or four thousand feet of sediment in the same number of years.

Even on that part of the floor of the ocean whither no accession of drift matter is carried, (a part which we believe to constitute, at any given period, by far the larger proportion of the whole submarine area,) there are circumstances accompanying a wreck which favour the conservation of skeletons. For when the vessel fills suddenly with water, especially in the night, many persons are drowned between decks and in their cabins, so that their bodies are prevented from rising again to the surface. The vessel often strikes upon an uneven bottom and is overturned, in which case the ballast consisting of sand, shingle, and rock, or the cargo, frequently composed of heavy and durable materials, may be thrown down upon the carcasses. In the case of ships of war, cannon, shot, and other warlike stores, may press down with their weight the timbers of the vessel when they decay, and beneath these and the metallic substances the bones of man may be preserved.

When we reflect on the number of curious monuments consigned to the bed of the ocean in the course of every naval war from the earliest times, our conceptions are greatly raised respecting the multiplicity of lasting memorials which man is leaving of his labours. During our last great struggle with France, thirty-two of our ships of the line went to the bottom in the space of twenty-two years, besides seven fifty-gun ships, eighty-six frigates, and a multitude of smaller vessels. The navies of the other European powers, France, Holland, Spain, and Denmark, were almost annihilated during the same period, so that the aggregate of their losses must have many times exceeded that of Great Britain. In every one of these ships were batteries of cannon constructed of iron or brass, whereof a great number had the dates and places of their manufacture inscribed upon them in letters cast in metal. In each there were coins of copper, silver, and often many of gold, capable of serving as valuable historical monuments; in each were an infinite variety of instruments of the arts of war and peace, many formed of materials, such as glass and earthenware, capable of lasting for indefinite ages when once removed from the mechanical action of the waves. and buried under a mass of matter which may exclude the corroding action of sea- water.

But the reader must not imagine that the fury of war is more conducive than the peaceful spirit of commercial enterprise to the accumulation of wrecked vessels in the bed of the sea. From an examination of Lloyd's lists from the year 1793, to the commencement of 1829, it has appeared that the number of British vessels alone lost during that period amounted, on an average, to no less than one and a half daily, [3] a greater number than we should have anticipated, although we learn from Moreau's tables that the number of merchant vessels employed at one time in the navigation of England and Scotland, amounts to about twenty thousand, having one with another a mean burden of one hundred and twenty tons. [4] Out of five hundred and fifty-one ships of the royal navy lost to the country during the period above mentioned, only one hundred and sixty were taken or destroyed by the enemy, the rest having either stranded or foundered, or having been burnt by accident, [5] a striking proof that the dangers of our naval warfare, however great, may be far exceeded by the storm, the hurricane, the shoal, and all the other perils of the deep.

Millions of dollars and other coins have been sometimes submerged in a single ship, and on these, when they happen to be enveloped in a matrix capable of protecting them from chemical changes, much information of historical interest will remain inscribed and endure for periods as indefinite as have the delicate markings of zoophytes or lapidified plants in some of the ancient secondary rocks. In almost every large ship, moreover, there are some precious stones set in seals, and other articles of use and ornament composed of the hardest substances in nature, on which letters and various images are carved-engravings which they may retain when included in subaqueous strata, as long as a crystal preserves its natural form.

It was a splendid boast, that the deeds of the English chivalry at Agincourt made Henry's chronicle

--- as rich with praise
As is the ooze and bottom of the deep
With sunken wreck and sumless treasuries;

for it is probable that a greater number of monuments of the skill and industry of man will, in the course of ages, be collected together in the bed of the ocean, than will be seen at one time on the surface of the continents.

If our species be of as recent a date as we suppose, it will be vain to seek for the remains of man and the works of his hands imbedded in submarine strata, except in those regions where violent earthquakes are frequent, and the alterations of relative level so great, that the bed of the sea may have been converted into land within the historical era. We do not despair of the discovery of such monuments whenever those regions which have been peopled by man from the earliest ages, and which are at the same time the principal theatres of volcanic action, shall be examined by the joint skill of the antiquary and the geologist.

There can be no doubt that human remains are as capable of resisting decay as are the harder parts of the inferior animals; and we have already cited the remark of Cuvier, that "in ancient fields of battle the bones of men have suffered as little decomposition as those of horses which were buried in the same grave." [6] In the delta of the Ganges bones of men have been found in digging a well at the depth of ninety feet; [7] but as that river frequently shifts its course and fills up its ancient channels, we are not called upon to suppose that these bodies are of extremely high antiquity, or that they were buried when that part of the surrounding delta where they occur was first gained from the sea.

Several skeletons of men, more or less mutilated, have been found in the West Indies, on the north-west coast of the mainland of Guadaloupe, in a kind of rock which is known to be forming daily, and which consists of minute fragments of shells and corals, incrusted with a calcareous cement resembling travertin, which has also bound the different grains together. The lens shows that some of the fragments of coral composing this stone, still retain the same red colour which is seen in the reefs of living coral which surround the island. The shells belong to species of the neighbouring sea intermixed with some terrestrial kinds which now live on the island, and among them is the Bulimus Guadaloupensis of Ferussac. The human skeletons still retain some of their animal matter, and all their phosphate of lime. One of them, of which the head is wanting, may now be seen in the British Museum, and another in the Royal Cabinet at Paris. According to Mr. Konig, the rock in which the former is inclosed is harder under the mason's saw and chisel, than statuary marble. It is described as forming a kind of glacis, probably an indurated beach, which slants from the steep cliffs of the island to the sea, and is nearly all submerged at high tide.

Similar formations are in progress in the whole of the West Indian archipelago, and they have greatly extended the plain of Cayes in St. Domingo, where fragments of vases and other human works have been found at a depth of twenty feet. In digging wells also near Catania, tools have been discovered in a rock somewhat similar.

When a vessel is stranded in shallow water, it usually becomes the nucleus of a sand bank, as has been exemplified in several of our harbours, and this circumstance tends greatly to its preservation. About fifty years ago, a vessel from Purbeck, laden with three hundred tons of stone, struck on a shoal off the entrance of Poole harbour and foundered; the crew were saved, but the vessel and cargo remain to this day at the bottom. Since that period the shoal at the entrance of the harbour has so extended itself in a westerly direction towards Peveril Point in Purbeck, that the navigable channel is thrown a mile nearer that Point. [8] The cause is obvious; the tidal current deposits the sediment with which it is charged around any object which checks its velocity. Matter also drifted along the bottom is arrested by any obstacle, and accumulates round it just as the African sand-winds, before described, raise a small hillock over the carcasses of every dead camel exposed on the surface of the desert.

We alluded, in the former volume, [9] to an ancient Dutch vessel, discovered in the deserted channel of the river Rother, in Sussex, of which the oak wood was much blackened, but its texture unchanged. The interior was filled with fluviatile silt, as was also the case in regard to a vessel discovered in a former bed of the Mersey, and another disinterred where the 81. Catherine Docks are excavated in the alluvial plain of the Thames. In like manner many ships have been found preserved entire in modern strata, formed by the silting up of estuaries along the southern shores of the Baltic, especially in Pomerania. Between Bromberg and Nakel, for example, a vessel and two anchors in a very perfect state were dug up far from the sea. [10]

At the mouth of a river in Nova Scotia, a schooner of thirty-two tons, laden with live stock, was lying with her side to the tide, when the bore, or tidal wave, which rises there about ten feet in perpendicular height, rushed into the estuary and overturned the vessel, so that it instantly disappeared. After the tide had ebbed, the schooner was so totally buried in the sand, that the taffrel or upper rail of the deck was alone visible. [11] We are informed by Leigh, that, on draining Martin Meer, a lake eighteen miles in circumference, in Lancashire, a bed of marl was laid dry, wherein no fewer than eight canoes were found imbedded. In figure and dimensions they were not unlike those now used in America. In a morass about nine miles distant from this Meer, a whetstone and an axe of mixed metal were dug up. [12] In Ayrshire also, three canoes were found in Loch Doon some few years ago; and during the present year (1831) four others, each hewn out of separate oak trees. They were twenty-three feet in length, two and a half in depth, and nearly four feet in breadth at the stern. In the mud which filled one of them, was found a war club of oak and a stone battle-axe.

The only examples of buried vessels to which we can obtain access, are in such situations as we have mentioned, but we are unable to examine those which have been subjected to great pressure, at the bottom of a deep ocean. It is extremely possible that the submerged wood-work of ships which have sunk where the sea is two or three miles deep, has undergone greater chemical changes in an equal space of time, for the experiments of Scoresby before mentioned show that wood may at certain depths be impregnated in a single hour with salt-water, so that its specific gravity is entirely altered.

It may often happen that hot springs charged with carbonate of lime, silex and other mineral ingredients, may issue at great depths, in which case every pore of the vegetable tissue may be injected with the lapidifying liquid, whether calcareous or siliceous, before the smallest decay commences. The conversion also of wood into lignite is probably more rapid under such enormous pressure. But the change of the timber into lignite or coal would not prevent the original form of a ship from being distinguished, for as we find in strata of the carboniferous era, the bark of the hollow reed-like trees converted into coal, and the central cavity filled with sandstone, so might we trace the outline of a ship in coal, and in the indurated mud, sandstone, or limestone filling the interior, we might discover instruments of human art, ballast consisting of rocks foreign to the rest of the stratum, and other contents of the ship.

Many of the metallic substances which fall into the waters, probably lose, in the course of ages, the forms artificially imparted to them; but under many circumstances these may be preserved for indefinite periods. The cannon inclosed in a calcareous rock, drawn up from the delta of the Rhone, which is now in the museum at Montpellier, might probably have endured as long as the calcareous matrix; but even if the metallic matter had been removed and had entered into new combinations, still a mould of its original shape would have been left, corresponding to those impressions of shells which we see in rocks, from which all the carbonate of lime has been subtracted. About the year 1776, says Mr. King, some fishermen sweeping for anchors in the Gull stream, (a part of the sea near the Downs,) drew up a very curious old swivel gun, near eight feet in length. The barrel, which was about five feet long, was of brass; but the handle by which it was traversed, was about three feet in length, and the swivel and pivot on which it turned were of iron. Around these latter were formed incrustations of sand converted into a kind of stone, of an exceeding strong texture and firmness; whereas round the barrel of the gun, except where it was near adjoining to the iron, there was no such incrustation, the greater part of it being clean and in good condition, just as if it had still continued in use. In the incrusting stone, adhering to it on the outside, were a number of shells and corallines, "just as they are often found in a fossil state." These were all so strongly attached, that it required as much force to separate them from the matrix, " as to break a fragment off any hard rock." [13]

In the year 1745, continues the same writer, the Fox man-of-war was stranded on the coast of East Lothian and went to pieces. About thirty-three years afterwards a violent storm laid bare a part of the wreck, and threw up near the place several masses" consisting of iron, ropes and balls," covered over with ochreous sand concreted and hardened into a kind of stone. The substance of the rope was very little altered. The consolidated sand retained perfect impressions of parts of an iron ring, "just in the same manner as impressions of extraneous fossil bodies are found in various kinds of strata." [14]

After a storm in the year 1824, which occasioned a considerable shifting of the sands near St. Andrew's, in Scotland; a gun barrel of ancient construction was found, which is conjectured to have belonged to one of the wrecked vessels of the Spanish armada. It is now in the museum of the Antiquarian Society of Scotland, and is encrusted over by a thin coating of sand, the grains of which are cemented by brown ferruginous matter. Attached to this coating are fragments of various shells, as of the common cardium, mya, &c.

Many other examples are recorded of iron instruments taken up from the bed of the sea near the British coasts, incased by a thick coating of conglomerate, consisting of pebbles and sand, cemented by oxide of iron.

Dr. Davy describes in the Philosophical Transactions; [15] a bronze helmet of the antique Grecian form, taken up in 1825, from a shallow part of the sea, between the citadel of Corfu and the village of Castrades. Both the interior and exterior of the helmet were partially encrusted with shells, and a deposit of carbonate of lime. The surface generally, both under the incrustation and where freed from it, was of a variegated colour, mottled with spots of green, dirty white, and red. On minute inspection with a lens, the green and red patches proved to consist of crystals of the red oxide and carbonate of copper, and the dirty white chiefly of oxide of tin.

The mineralizing process, says Dr. Davy, which has produced these new combinations, has in general penetrated very little into the substance of the helmet. The incrustation and rust removed, the metal is found bright beneath, in some places considerably corroded, in others very slightly. It proves on analysis to be copper alloyed with 18.5 per cent. of tin. Its colour is that of our common brass, and it possesses a considerable degree of flexibility: --

"It is a curious question," he adds, "how the crystals were formed in the helmet, and on the adhering calcareous deposit. There being no reason to suppose deposition from solution, are we not under the necessity of inferring, that the mineralizing process depends on a small motion and separation of the particles of the original compound? This motion may have been due to the operation of electro-chemical powers which may have separated the different metals of the alloy."

Effects of the Submersion of Land by Earthquakes.

We have -hitherto considered the transportation of plants and animals from the land by aqueous agents, and their inhumation in lacustrine or submarine deposits, and we may now inquire what tendency the subsidence of tracts of land by earthquakes may have to produce analogous effects. Several examples of the sinking down of buildings and portions of towns near the shore to various depths beneath the level of the sea, during subterranean movements, were enumerated in a former volume, when we treated of the changes brought about by inorganic causes. The events alluded to were comprised within a brief portion of the historical period, and confined to a small number of the regions of active volcanos. Yet these authentic facts, relating merely to the last century and a half, gave indications of considerable change which must have taken place in the physical geography of the globe. If, during the earthquake. of Jamaica in 1692, some of the houses in Port Royal subsided, together with the ground they stood upon, to the depth of twenty-four, thirty-six and forty-eight feet under water, we are not to suppose that this was the only spot throughout the whole range of the coasts of that island or the bed of the surrounding sea which suffered similar depressions. If the quay at Lisbon sank at once to the depth of six hundred feet in 1755, we must not imagine that this was the only point on the shores of the peninsula where similar phenomena might have been witnessed.

If during the short period since South America has been colonized by Europeans we have proof of alterations of level at the three principal ports on the western shores, Callao, [16] Valparaiso, and Conception, we cannot for a moment suspect that these cities so distant from each other have been selected as the peculiar points where the desolating power of the earth· quake has expended its chief fury. "It would be a knowing arrow that could choose out the brave men from the cowards," retorted the young Spartan, when asked if his comrades who had fallen on the field of battle were braver than he and his fellow prisoners; we might in the same manner remark that a geologist must attribute no small discrimination and malignity to the subterranean force, if he should suppose it to spare habitually a line of coast many thousand miles in length, with the exception of those few spots where populous towns have been erected. If then we consider how small is the area occupied by the sea-ports of this disturbed region, -- points where alone each slight change of the relative level of sea and land can be recognized, and reflect on the proofs in our possession of the local revolutions that have happened on the site of each port, within the last century and a half, our conceptions must be greatly exalted respecting the magnitude of the alterations which the Andes may have undergone even in the course of the last six thousand years.

We cannot better illustrate the manner in which a large extent of surface may be submerged, so that the terrestrial plants and animals may become imbedded in subaqueous strata, than by referring to the earthquake of Cutch, in 1819, alluded to by us in a former volume. [17] We shall enter somewhat more fully into details concerning that catastrophe than the immediate subject of the present chapter might require, in order to lay before the reader the information obtained during the recent survey of Cutch.

The published account of Lieutenant A. Burnes, [18] who examined that portion of the delta of the Indus in 1826 and 1829, confirms the facts before enumerated by us, and furnishes the following important particulars. The tract around Sindree, which subsided during the earthquake in June, 1819, was converted from dry land into sea in the course of a few hours, the new-formed mere extending for a distance of sixteen miles on each side of the fort, and probably exceeding in area the lake of Geneva. Neither the rush of the sea into this new depression, nor the movement of the earthquake, threw down the small fort of Sindree, the interior of which is said to have become a tank, the water filling the space within the walls, and the four towers continuing t6 stand, so that on the day after the earthquake the people in the fort who had ascended to the top of one of the towers saved themselves in boats. Immediately after the shock the inhabitants of Sindree saw, at the distance of five miles from their village, a long elevated mound, where previously there had been a low and perfectly level plain. To this uplifted tract they gave the name of "Ullah bund," or "the Mound of God," to distinguish it from an artificial barrier previously thrown across an arm of the Indus.

It is already ascertained that this newly raised country is upwards of fifty miles in length from east to west, running parallel to that line of subsidence before mentioned, which caused the grounds around Sindree to be flooded. The range of this elevation extends from Puchum island towards Gharee; its breadth from north to south is conjectured to be in some parts sixteen miles, and its greatest ascertained height above the original level of the delta is ten feet, an elevation which appears to the eye to be very uniform throughout.

For several years after the convulsion of 1819, the course of the Indus was very unsettled, and at length in 1826, the river burst its banks above Sinde, and forcing its way in a more direct course to the sea, cut right through the "Ullah bund," whereby a natural section was obtained. In the perpendicular cliffs thus laid open, Lieutenant Burnes found that the up raised land consisted of beds of clay filled with shells. The new channel of the river, where it intersected the" bund," was eighteen feet deep, and during the swells in 1826, it was two or three hundred yards in width, but in 1828 the channel was still further enlarged. The Indus, when it first opened this new passage, threw such a body of water into the new lake or salt lagoon of Sindree, that it became fresh for many months, but it had recovered its saltness in 1828, when the supply of river-water was less copious, and finally it became more salt than the sea, in consequence, as the natives suggested to Lieu tenant Burnes, of the saline particles with which "the Runn of Cutch" is impregnated.

Besides Ullah bund, there appears to have been another elevation south of Sindree, parallel to that before mentioned, respecting which, however, no exact information has yet been communicated. There is a tradition of an earthquake, which, about three centuries before, upheaved a large area of the bed of the sea; and converted it into land in the district now called "the Runn," so that numerous harbours were laid dry and ships were wrecked and engulphed; in confirmation of which account it was observed in 1819; that in the jets of black muddy water thrown out of fissures in that region, there were cast up numerous pieces of wrought iron and ship nails.

We must not conclude without alluding to a moral phenomenon connected with this tremendous catastrophe, which we regard as highly deserving the attention of geologists. The author above cited states that "these wonderful events passed unheeded by the inhabitants of Cutch," for the region convulsed, though once fertile, had for a long period been reduced to sterility by want of irrigation, so that the natives were indifferent as to its fate. Now it is to this profound apathy, which all but highly civilized nations feel in regard to physical events, not having an immediate influence on their worldly fortunes, that we must ascribe the extraordinary dearth of historical information concerning changes of the earth's surface, which modern observations show to be by no means of rare occurrence in the ordinary course of nature.

It is stated that, for some years after the earthquake, the withered tamarisks and other shrubs protruded their tops above the waves, in parts of the submerged tract around Sindree; but after the flood of 1826 they were seen no longer. Every geologist will at once perceive that forests sunk by such subterranean movements, may become imbedded in subaqueous deposits both fluvatile and marine, and the trees may still remain erect, or sometimes the roots and part of the trunks may continue in their original position, while the current may have broken off, or levelled with the ground, their upper stems and branches.

But although a certain class of geological phenomena may be referred to the repetition of such catastrophes, we must hesitate before we call in to our aid the action of earthquakes, to explain what have been termed submarine forests, observed at various points around the shores of Great Britain. We have already hinted that the explanation of some of these may be sought in the encroachments of the sea, in estuaries, and the varying level of the tides, at distant periods on the same parts of our coast. [19] After examining, in 1829, the so called submarine forest of Happisborough in Norfolk, I found that it was nothing more than a tertiary lignite of the "Crag" period, which becomes exposed in the bed of the sea as soon as the waves sweep away the superincumbent strata of bluish clay. So great has been the advance of the sea upon our eastern shores within the last eight centuries, that whenever we find a mass of submerged timber near the sea side, or at the foot of the existing cliffs which we cannot suppose to be a mere accumulation of drift, vegetable matter, we should endeavour to find a solution of the problem, by reference to any cause rather than an earth. quake. For we can scarcely doubt that the present outline of our coast, the shape of its estuaries, and the formation of its cliffs are of very modern date, probably within the human era, whereas we have no reason whatever to imagine that this part of Europe has been agitated by subterranean convulsions, capable of altering the relative level of land and sea, at so extremely recent a period.

Some of the buildings which have at different times subsided beneath the level of the sea, have been immediately covered up to a certain extent with strata of volcanic matter showered down upon them. Such was the case at Tomboro in Sumbawa, in the present century, and at the site of the Temple of Serapis, in the environs of Puzzuoli, probably in the 12th century. The entrance of a river charged with sediment in the vicinity, may still more frequently occasion the rapid envelopement of buildings in regularly stratified formations. But if no foreign matter be introduced, the buildings when once removed to a depth where the action of the waves is insensible, and where no great current happens to flow, may last for indefinite periods, and be as durable as the floor of the ocean itself, which may often be composed of the very same materials. There is no reason to doubt the tradition mentioned by the classic writers, that the submerged Grecian towns of Bura and Helice were seen under water; and I am informed by an eye-witness that eighty-eight years after the convulsion of 1692, the houses of Port Royal were still visible at the bottom of the sea. [20]

We cannot conclude this chapter without recalling to the reader's mind a memorable passage written by Berkely a century ago, in which he inferred, on grounds which may be termed strictly geological, the recent date of the creation of man. "To anyone," says he, "who considers that on digging into the earth such quantities of shells, and in some places bones and horns of animals are found sound and entire, after having lain there in all probability some thousands of years; it should seem probable that guns, medals and implements in metal or stone might have lasted entire, buried under ground forty or fifty thousand years if the world had been so old. How comes it then to pass that no remains are found, no antiquities of those numerous ages preceding the Scripture accounts of time; that no fragments of buildings, no public monuments, no intaglias, cameos, statues, basso-relievos, medals, inscriptions, utensils, or artificial works of any kind are ever discovered, which may bear testimony to the existence of those mighty empires, those successions of monarchs, heroes, and demi-gods for so many thousand years? Let us look forward and suppose ten or twenty thousand years to come, during which time we will suppose that plagues, famine, wars and earthquakes shall have made great havoc in the world, is it not highly probable that at the end of such a period, pillars, vases, and statues now in being of granite, or porphyry, or jasper, (stones of such hardness as we know them to have lasted two thousand years above ground, without any considerable alteration) would bear record of these and past ages? Or that some of our current coins might then be dug up, or old walls and the foundations of buildings shew themselves, as well as the shells and stones of the primeval world, which are preserved down to our times ?" [21]

That many signs of the agency of man would have lasted at least as long as "the shells of the primeval world," had our race been so ancient, we are as fully persuaded as Berkely; and we anticipate with confidence that many edifices and implements of human workmanship, and the skeletons of men, and casts of the human form, will continue to exist when a great part of the present mountains, continents, and seas have disappeared. Assuming the future duration of the planet to be indefinitely protracted, we can foresee no limit to the perpetuation of some of the memorials of man, which are continually entombed in the bowels of the earth or in the bed of the ocean, unless we carry forward our views to a period sufficient to allow the various causes of change both igneous and aqueous, to remodel more than once the entire crust of the earth. One complete revolution will be inadequate to efface every monument of our existence, for many works of art might enter again and again into the formation of successive eras, and escape obliteration even though the very rocks in which they had been for ages imbedded were destroyed, just as pebbles included in the conglomerates of one epoch often contain the organized remains of beings which flourished during a prior era.

Yet it is no less true, as a late distinguished philosopher has declared, "that none of the works of a mortal being can be eternal." [22] They are in the first place wrested from the hands of man, and lost as far as regards their subserviency to his use, by the instrumentality of those very causes which place them in situations where they are enabled to endure for indefinite periods. And even when they have been included in rocky strata, when they have been made to enter as it were into the solid framework of the globe itself, they must nevertheless eventually perish, for every year some portion of the earth's crust is shattered by earthquakes or melted by volcanic fire, or ground to dust by the moving waters on the surface. "The river of Lethe," as Bacon eloquently remarks, "runneth as well above ground as below." [23]

_______________

Notes:

1. Narrative of Discovery in Egypt, &c. London, 1820.

2. Scots Mag., vol. xxxiii. 1771.

3. I am indebted to my friend Captain W. H. Smyth, R. N., for this information.

4. Caesar Moreau's Tables of the Navigation of Great Britain.

5. I give these results on the authority of Captain W. H. Smyth, R. N.

6. Vol. i. p. 154.

7. Hoff., vol. i. p. 379.

8. This account I received from the Honourable A. Harris.

9. Vol. i. p. 278.

10. Hoff., vol. i. p. 368.

11. Silliman's Geol. Lectures, p. 78, who cites Penn.

12. Leigh's Lancashire, p. 17, A. D. 1700.

13. Phil.. Trans., 1719.

14. Phil. Trans., vol.1xix., 1779.

15. 1826, part ii; p. 55.

16. It is well known that during the great earthquake of Lima, in 1746, part of the promontory south of Callao sank down, and it is a common story at Lima that its former termination became the present isle of San Lorenzo, between which and the main land there is now a navigable channel. The submerged arches of a church, and the present position of other buildings, are said to indicate that the site of Callao underwent, during the earthquakes, a change of level; an interesting fact, the evidences of which we hope will soon be examined by some of our naval officers, and other intelligent persons frequenting that port.

17. Vol. i. p. 405.

18. Now in the Library of the Royal Asiatic Society.

19. Vol. i. p. 270.

20. Admiral Sir Charles Hamilton frequently saw the submerged houses of Port Royal in the year 1780, in that part of the harbour which lies between the town and the usual anchorage of men-of-war. Bryan Edwards also says in his History of the West Indies, (vol. i. p. 235, oct. ed. 3 vols., 1801,) that in 1793 the ruins were visible in clear weather from the boats which sailed over them. I regret to see that Mr. De la Beche, in his valuable Manual of Geology, (p. 130,) has evinced so much scepticism in regard to the accuracy of the evidence collected by Sir Hans Sloane, respecting the catastrophe of Port Royal, a town with which Sir H. was well acquainted. To me the original documents collected immediately after the event, appear to bear the intrinsic stamp of truth. The objection against the fact alleged by several eye-witnesses, "that the chimney tops alone of many houses were seen after the shocks, as well as the masts of vessels just projecting above the waves," is quite futile. Perhaps the chimneys in Port Royal might in 1692, have been confined to low kitchens, as Mr. De la Beche says they now are, and they might only have been fifteen or twenty feet in height, still the same subsidence which reduced them to the level of the water might cause the ships which were previously floating to disappear entirely, with the exception of the tops of their masts. Besides, we infer from the various narratives, that the subsidences were very unequal at different neighbouring points. I have great pleasure in stating, that on my requesting Mr. De la Beche to send me more exact particulars, respecting the present state of the harbour of Port Royal, he has ordered a survey to be made.

21. Alciphron, or the Minute Philosopher, vol. ii. pp. 84, 85. 1732.

22. Davy, Consolations in Travel, p. 276.

23. Essay on the Vicissitude of Things.

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CHAPTER 17

Imbedding of aquatic species in subaqueous strata – Inhumation of freshwater plants and animals – Shell marl – Fossilized seed-vessels and stems of Chara – Recent deposits in the American lakes – Fresh-water species drifted into seas and estuaries – Lewes levels – Alternations of marine and freshwater strata, how caused – Imbedding of marine plants and animals – Cetacea stranded on our shores – Their remains should be more conspicuous in marine alluvium than the bones of land quadrupeds – Liability of littoral and estuary testacea to be swept into the deep sea – Effects of a storm in the Frith of Forth – Burrowing shells secured from the ordinary action of waves and currents – Living testacea found at considerable depths

WE have hitherto treated of the imbedding of terrestrial plants and animals, and of human remains in the deposits that are now forming beneath the waters, and we come next to consider in what manner aquatic species may be entombed in strata, formed in their own element.

Imbedding of Fresh-water Plants and Animals.

The remains of species belonging to those genera of the animal and vegetable kingdoms, which are more or less exclusively confined to fresh-water, are for the most part preserved in the beds of lakes or estuaries, but they are oftentimes swept down by rivers into the sea, and there intermingled with the exuviae of marine races. The phenomena attending their inhumation in lacustrine deposits, may be sometimes revealed to our observation by the drainage of small lakes, such as are those in Scotland which have been laid dry for the sake of obtaining shell marl for agricultural uses.

In these recent formations, as seen in Forfarshire, two or three beds of calcareous marl are sometimes observed separated from each other by layers of drift peat, sand, or fissile clay. The marl often consists almost entirely of an aggregate of shells of the genera limnea, planorbis, valvata, and cyclas, with some few others, species of all which now exist in Scotland. A considerable proportion of the testacea appear to have died very young, and few of the shells are of a size which indicates their having attained a state of maturity. The shells are sometimes entirely decomposed, forming a pulverulent marl; sometimes they are in a state of good preservation. They are frequently intermixed with stems of charm and other aquatic vegetables, which are matted together and compressed, forming laminae often as thin as paper.

As the chara is an aquatic plant, which occurs frequently fossil in formations of different eras, and is often of much im portance to the geologist in characterizing entire groups of strata, we shall describe the manner in which the recent species have been found in a petrified state. They occur in one of the lakes of Forfarshire, inclosed in nodules, and sometimes in a continuous stratum of a kind of travertin.

The seed-vessel of these plants is remarkably tough and hard, and consists of a membranous nut covered by an integument (fig. d diagram No. 2,) both of which are spirally striated or ribbed. The integument is composed of five spiral valves, of a quadrangular form (fig. g). In Chara hispida which abounds in the lakes of Forfarshire, and which has become fossil in the Bakie Loch, each of the spiral valves of the seed-vessel turns rather more than twice round the circumference, the whole together making between ten and eleven rings. The number of these rings differs greatly in different species, but in the same appears to be very constant.


(No.2.): Seed-vessel of Chara hispida
(a) Part of the stem with the seed-vesssel attached. Magnified.
(b) Natural size of the seed-vessel.
(c) Integument or the Gyrogonite, or petrified seed-vessel of Chara hispida, found in the Scotch marl-lakes. Magnified.
(d) Section showing the nut within the integument.
(e) Lower end of the integument to which the stem was attached.

The stems of charre occur fossil in the Scotch marl in great abundance. In some species, as in Chara hispida, the plant when living contains so much carbonate of lime in its vegetable organization, independently of calcareous incrustation, that it effervesces strongly with acids when dried. The stems of Chara hispida are longitudinally striated, with a tendency to be spiral. These striae, as appears to be the case with all charae, turn always like the worm of a screw from right to left, while those of the seed-vessel wind round in a contrary direction. A cross section of the stem exhibits a curious structure, for it is composed of a large tube surrounded by smaller tubes, (diagram No. 3. fig. b, c,) as is seen in some extinct, as well as recent species. In the stems of several species, however, there is only a single tube. [1]


(No.3.): Stem and branches of Chara hispida.
(a) Stem and branches of the natural size.
(b) Section of the stem magnified.
(c) Showing the central tube surrounded by two rings of smallertubes.

The valves of a small animal called cypris (C. ornata Lam.) occur completely fossilized like the stems of charae, in the Scotch travertin above mentioned. This cypris inhabits the lakes and ponds of England where it is not uncommon. Species of the same genus also occur abundantly in ancient fresh-water formations.

The recent strata of lacustrine origin above alluded to are of very small extent, but analogous deposits on the grandest scale have been formed in the great lakes of North America. By the subsidence of the waters of Lakes Superior and Huron, occasioned probably by the partial destruction of their barriers at some unknown period, beds of sand one hundred and fifty feet thick are exposed, below which are seen beds of clay, inclosing shells of the very species which now inhabit the lake. [2]

But no careful examination appears as yet to have been made of recent fresh-water formations within the tropics, where the waters teem with life, and where in the bed of a newly drained lake the remains of the alligator, crocodile tortoise, and perhaps some large fish might be discovered.

Imbedding of Fresh-water Species in Estuary and Marine Deposits.

We have sometimes an opportunity of examining the deposits which within the historical period have silted up some of our estuaries; and excavations made for wells and other purposes, where the sea has been finally excluded, enable us to observe the state of the organic remains in these tracts. The valley of the Ouse between Newhaven and Lewes is one of several estuaries from which the sea has retired within the last seven or eight centuries; and here it appears from the researches of Mr. Mantell, that strata of thirty feet and upwards in thickness have accumulated. At the top, beneath the vegetable soil, is a bed of peat about five feet thick, enclosing many trunks of trees. Next below is a stratum of blue clay containing fresh-water shells of about nine species, such as now inhabit the district. Intermixed with these was observed the skeleton of a deer. Lower down, the layers of blue clay contain with the above-mentioned fresh-water shells several marine species well known on our coast. In the lowest beds, often at the depth of thirty-six feet, these marine testacea occur without the slightest intermixture of fluviatile species, and amongst them the skull of the narwal, or sea-unicorn (Monodon monoceros), has been detected. Underneath all these deposits is a bed of pipe-clay, derived from the subjacent chalk. [3]

If we had no historical information respecting the former existence of an inlet of the sea in this valley, and of its gradual obliteration, the inspection of the section above described would show, as clearly as a written chronicle, the following sequence of events. First, there was a salt-water estuary peopled for many years by species of marine testacea identical with those now living, and into which some of the larger cetacea occasionally entered. Secondly, the inlet grew shallower, and the water became brackish, or alternately salt and fresh, so that the remains of fresh-water and marine shells were mingled in the blue argillaceous sediment of its bottom. Thirdly, the shoaling continued until the river water prevailed, so that it was no longer habitable by marine testacea, but fitted only for the abode of fluviatile species and aquatic insects. Fourthly, a peaty swamp or morass was formed where some trees grew, or, perhaps, were drifted during floods, and where terrestrial quadrupeds were mired. Finally, the soil being only flooded by the river at distant intervals, became a verdant meadow.

We have stated when speaking of the delta of the Ganges, that on the sea-coast there are eight great openings, each of which has evidently, at some ancient periods, served in its turn as the principal channel of discharge. Now as the base of the delta is two hundred miles in length, it must happen that as often as the great volume of river-water is thrown in by a new mouth, the waters of the sea will at one point be converted from salt to fresh, and at another from fresh to salt; for, with the exception of those parts where the principal discharge takes place, the salt-water not only washes the base of the delta, but enters far into every creek and lagoon. It is evident then that repeated alternations of beds containing fresh-water shells, with others filled with corals and marine exuviae, may here be formed, and each series may be of great thickness, as the sea on which the Gangetic delta gains, is of considerable depth, and intervals of centuries elapse between each alteration in the course of the principal stream.

It is evident that analogous phenomena must sometimes be occasioned by such alternate elevation and depression of the land as was shown in. the last chapter to be taking place in the delta of the Indus. But the subterranean movements affect but a small number of the deltas formed at one period on the globe; whereas, the silting up of some of the arms of great rivers and the opening of others, and the consequent variation of the points at which the chief volume of their waters enters the sea, are phenomena common to almost every delta.

The variety of species of testacea contained in the recent calcareous marl of Scotland, before mentioned, is very small, but the abundance of individuals is extremely great, a circumstance which characterizes fresh-water formations in general as compared to marine j for in the latter, as is seen on sea-beaches, coral reefs, or in the bottom of seas examined by dredging, wherever the individual shells are exceedingly numerous there rarely fails to be a vast variety of species.

Imbedding of the Remains of Marine Plants and Animals.

Marine Plants. -- We have alluded to the large banks of drift sea-weed which occur on each side of the equator in the Atlantic, Pacific, and Indian oceans. [4] These when they subside may often produce considerable beds of vegetable matter. In Holland submarine peat is derived from fuci, and on parts of our own coast from Zostera marina. In places where algae do not generate peat, they may nevertheless leave traces of their form imprinted on argillaceous and calcareous mud, as they are usually very tough in their texture.

Cetacea. -- It is not uncommon for the larger cetacea, which can only float in a considerable depth of water, to be carried during storms or high tides into estuaries, or upon low shores, where, upon the retiring of high water, they are stranded. Thus a narwal (Monodon monoceros) was found on the beach near Boston, in Lincolnshire, in the year 1800, the whole of its body buried in the mud. A fisherman going to his boat saw the horn and tried to pull it out, when the animal began to stir itself. [5] An individual of the common whale (Balaena mysticetus), which measured seventy feet, came ashore near Peterhead, in 1682. Many individuals of the genus Balaenoptera have met the same fate. We may content ourselves with referring to those cast on shore near Burnt Island, and at Alloa, recorded by Sibbald and Neill. The other individual mentioned by Sibbald, as having come ashore at Boyne, in Banffshire, was probably a Razor-back. Of the genus Catodon (Cachalot), Ray mentions a large one stranded on the west coast of Holland in 1598, and the fact is also commemorated in a Dutch engraving of the time of much merit. Sib. bald, too, records that a herd of Cachalots, upwards of one hundred in number, were found stranded at Kairston, Orkney. [6] The dead bodies of the larger cetacea are sometimes found :floating on the surface of the waters, as was the case with the immense whale exhibited in London in 1831. And the carcass of a sea-cow or Lamantine (Halicora) was, in 1785, cast ashore near Leith. We might enumerate many more examples de- rived from foreign as well as British shores, but the facts above cited will suffice to show that such occurrences are not rare.

To some accidents of this kind, we may refer the position of the skeleton of a whale seventy-three feet long, which was found at Airthrey, on the Forth near Alloa, imbedded in clay twenty feet higher than the surface of the highest tide of the river Forth at the present day. From the situation of the Roman station and causeways at a small distance from the spot, it is concluded that the whale must have been stranded there at a period prior to the Christian era. [7]

Other fossil remains of this class have also been found in estuaries, known to have been silted up in recent times, one example of which we have already mentioned near Lewes, in Sussex. When we reflect on the facility with which these marine mammalia are thus shown to run aground upon shoals, even when there have been no great convulsions, such as hurricanes or earthquakes extending under the ocean, but merely such disturbances as the tides and storms of our seas may cause, we may be better enabled to form a sound opinion, in regard to the probability of certain geological theories, which have acquired no small share of popularity. It has been suggested, that if the ocean, displaced by the sudden upheaving of some great mountain-chain, such as the Andes, should make a transient passage over the land, a covering of alluvium might be left strewed over the hills and valleys, and that, in this alluvium, might be contained the remains of mammalia exclusively terrestrial. The skeleton of the gigantic whale, the long horn of the narwal (harder than ivory), the strong grinders of the lamantine, these and other marine relics of the era

Omne cum Proteus pecus egit altos
Visere montes,

might, we are told, be entirely wanting. Not one of them would be conspicuous amongst the refuse of the " bated and retiring flood," but instead of them we should discover the bones, tusks, and teeth of the elephant or rhinoceros, the hip popotamus, ox, and horse, with occasionally, perhaps, some intermixture of terrestrial and lacustrine shells! Such, we are taught, would be the memorials of a marine deluge sweeping over our continents! We are, however, willing to admit that they who invent causes without reference to known analogies, are guilty of no inconsistency when they claim some license in the use which they make of their extraordinary agents. If we allow them to "call spirits from the vasty deep" to do their bidding, and to uplift colossal chains, like the Andes, suddenly within the historical era, we must not complain that the effects of such mighty powers are not always such as the analogy of the ordinary laws of Nature would have led us to anticipate.

Marine Tesiacea. -- The aquatic animals and plants which inhabit an estuary are liable, like the trees and land animals which people the alluvial plains of a great river, to be swept from time to time far into the deep. For as a river is perpetually shifting its course, and undermining a portion of its banks with the forests which cover them, so the marine current alters its direction from time to time, and bears away the banks of sand and mud, against which it turns its force. These banks may consist in great measure of shells peculiar to shallow, and sometimes brackish water, which may have been accumulating for centuries, until at length they are carried away and spread out along the bottom of the sea, at a depth at which they could not have lived and multiplied. Thus littoral and estuary shells are more frequently liable even than freshwater species, to be intermixed with the exuviae of pelagic tribes.

After the late storm of February 4, 1831, when several vessels were wrecked in the estuary of the Forth, the current was directed against a bed of oysters with such force, that great heaps of them were thrown alive upon the beach, and remained above high-water mark. Many of these oysters, as also the common whelks (buccina), which were thrown up with them, in a living state, were worn by the long attrition of sand which had passed over them as they lay in their native bed, and which had evidently not resulted from the mere action of the tempest by which they had been cast ashore.

From these facts we may learn that the union of the two parts of a bivalve shell does not prove that it may not have been transported to a certain distance; and when we find shells worn, and with all their prominent parts rubbed off, they may still have been imbedded where they grew.

It sometimes appears extraordinary when we observe the violence of the breakers on our coast, and see the strength of the current in removing cliffs and sweeping out new channels, that many tender and fragile shells should inhabit the sea in the immediate vicinity of this turmoil. But a great number of the bivalve testacea, and many also of the turbinated univalves burrow in sand or mud. The solen and the cardium, for example, which are usually found in shallow water near the shore, pierce through a soft bottom without injury to their shells; and the pholas can drill a cavity through mud of' considerable hardness. The species of these and many other tribes can sink, when alarmed, with considerable rapidity, often to the depth of several feet, and can also penetrate upwards again to the surface if a mass of matter be heaped upon them. The hurricane, therefore, may expend its fury in vain, and may sweep away even the upper part of banks of sand or mud, or may roll pebbles over them, and yet these testacea may remain below secure and uninjured.

We have already stated that at the depth of nine hundred and fifty fathoms between Gibraltar and Ceuta, Captain Smyth found a gravelly bottom, with fragments of broken shells carried thither probably from the comparatively shallow parts of the neighbouring straits, through which a powerful current flows. Beds of shelly sand might here, in the course of ages, be accumulated several thousand feet thick. But, without the aid of the drifting power of a current, shells may accumulate in the spot where they live and die, at great depths from the surface, if sediment be thrown down upon them; for, even in our own colder latitudes, the depths at which living marine animals abound is very considerable. Captain Vidal ascertained, by soundings lately made off Tory island, on the north. west coast of Ireland, that crustacea, star-fish, and testacea, occurred at various depths between fifty and one hundred fathoms; and in the tropics testacea and zoophytes have been found still deeper.

During the survey of the west coast of Africa, now in progress, Captain Belcher found, by frequent soundings between the twenty-third and twentieth degrees of north latitude, that the bottom of the sea at the depth of from twenty to about fifty fathoms, consists of sand, with a great intermixture of shells often entire, but sometimes finely comminuted. Between the eleventh and ninth degrees of north latitude, on the same coast, at soundings varying from twenty to about eighty fathoms, he brought up abundance of corals and shells mixed with sand. These also were in some parts entire, and in others worn and broken.

In all these cases it is only necessary that there should be some deposition of sedimentary matter, however minute, such as may be supplied by rivers or currents preying on a line of cliffs, and stratified formations, hundreds of feet in thickness, will result in the course of ages, containing throughout organic remains, in a more or less perfect state of preservation.

_______________

Notes:

1. Geol. Trans., vol. ii., second series, p. 73: On Fresh-water Marl, &c. By C. Lyell, Esq.

2. Dr. Bigsby's Journal of Science, &c. No. 37, pp. 262, 263.

3. Mantell, Geol. of Sussex, p. 285; also Catalogue of Org. Rem., Geol. Trans., v. iii., part 1, p. 201. Second Series.

4. Page 78.

5. Fleming's Brit. Animals, p. 31; in which work may be seen many other cases enumerated.

6. [omitted by publisher]

7. Quart. Journ. of Lit. Sci., &c. No. 15, p. 172. Oct. 1819.

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CHAPTER 18

Formation of coral reefs – They are composed of shells as well as corals – Conversion of a submerged reef into an island – Extent and thickness of coral formations – The Maldiva isles – Growth of coral not rapid – Its geological importance – Circular and oval forms of coral islands – Shape of their lagoons – Causes of their peculiar configuration – Openings into the lagoons – Why the windward side both in islands and submerged reefs is higher than the leeward – Stratification of coral formations – Extent of some reefs in the Pacific – That the subsidence by earthquakes in the Pacific exceeds the elevation due to the same cause – Elizabeth, or Henderson's Island – Coral and shell limestones now in progress, exceed in area any known group of ancient rocks – The theory that all limestone is of animal origin, considered – The hypothesis that the quantity of calcareous matter has been and is still on the increase, controverted

THE powers of the organic creation in modifying the form and structure of those parts of the earth's crust, which may be said to be undergoing repair, or where new rock-formations are continually in progress, are most conspicuously displayed in the labours of the coral animals. We may compare the operation of these zoophytes in the ocean, to the effects produced on a smaller scale upon the land, by the plants which generate peat. In the case of the Sphagnum, the upper part vegetates while the lower portion is entering into a mineral mass, where the traces of organization usually remain, but in which life has entirely ceased. In the corals, in like manner, the more durable materials of the generation that has passed away, serve as the foundation on which living animals are continuing to rear a similar structure.

The calcareous masses usually termed coral reefs, are by no means exclusively composed of zoophytes, but also a great variety of shells; some of the largest and heaviest of known species contributing to augment the mass. In the south Pacific, great beds of oysters, mussels, pinnae marinae, and other shells, cover in great profusion almost every reef; and, on the beach of coral islands, are seen the shells of echini and the broken fragments of crustaceous animals. Large shoals of fish also are discernible through the clear blue water, and their teeth and hard palates are probably preserved, although a great portion of their soft cartilaginous bones may decay.

Of the numerous species of zoophytes which are engaged in the production of coral banks, some of the most common belong to the genera Meandrilla, Caryophyllia and Astrea, but especially the latter.

The reefs, which just raise themselves above the level of the sea, are usually of a circular or oval form, and are surrounded by a deep and often unfathomable ocean. In the centre of each, there is usually a comparatively shallow lagoon where there is still water, and where the smaller and more delicate kinds of zoophytes find a tranquil abode, while the more strong species live on the exterior margin of the isle, where a great surf usually breaks. When the reef, says M. Chamisso, a naturalist who accompanied Kotzebue, is of such a height that it remains almost dry at low water, the corals leave off building. A continuous mass of solid stone is seen composed of the shells of molluscs and echini, with their broken off prickles and fragments of coral, united by the burning sun, through the medium of the cementing calcareous sand, which has arisen from the pulverization of shells. Fragments of coral limestone are thrown up by the waves, until the ridge becomes so high, that it is covered only during some seasons of the year by the high tides. The heat of the sun often penetrates the mass of stone when it is dry, so that it splits in many places. The force of the waves is thereby enabled to separate and lift blocks of coral, frequently six feet long and three or four in thickness, and throw them upon the reef. "After this the calcareous sand lies undisturbed, and offers to the seeds of trees and plants cast upon it by the waves, a soil upon which they rapidly grow, to overshadow its dazzling white surface. Entire trunks of trees, which are carried by the rivers from other countries and islands, find here, at length, a resting-place after their long wanderings: with these come some small animals, such as lizards and insects, as the first inhabitants. :Even before the trees form a wood, the sea-birds nestle here; strayed land-birds take refuge in the bushes; and, at a much later period, when the work has been long since completed, man also appears, builds his hut on the fruitful soil formed by the corruption of the leaves of the trees, and calls himself lord and proprietor of this new creation." [1]

The Pacific ocean throughout, a space comprehended between the thirtieth parallel of latitude on each side of the equator, is extremely productive of coral. The Arabian gulf is rapidly filling with the same, and it is said to abound in the Persian gulf. Between the coast of Malabar and that of Madagascar, there is also a great sea of coral. Flinders describes an unbroken reef three hundred and fifty miles in length, on the east coast of New Holland; and, between that country and New Guinea, Captain P. King found the coral formations to extend throughout a distance of seven hundred miles, interrupted by no intervals exceeding thirty miles in length.

The chain of coral reefs and islets, called the Maldivas, situated in the Indian ocean to the south-west of Malabar, form a chain four hundred and eighty geographical miles in length, running due north and south. It is composed throughout of a series of circular assemblages of islets, the larger groups being from forty to fifty miles in their longest diameter. Captain Horsburgh, whose chart of these islands is subjoined, informs me that outside of each circle or atoll, as it is termed, there are coral reefs sometimes extending to the distance of two or three miles, beyond which there are no soundings at immense depths. But in the centre of each atoll there is a lagoon from fifteen to twenty fathoms deep. In the channels between the atolls, no soundings have been obtained at the depth of one hundred and fifty fathoms.

The Laccadive islands run in the same line with the Maldivas, on the north, as do the isles of the Chagos Archipelago, on the south, so that these may be continuations of the same chain of submarine mountains, crested in a similar manner by coral limestone. It would be rash to hazard the hypothesis. that they are all the summits of volcanos, yet we might imagine, that if Java and Sumatra were submerged, they would give rise to a somewhat similar shape in the bottom of the sea; for the volcanos of those islands observe a linear direction, and are often separated from each other by intervals, corresponding to the atolls of the Maldivas; and as they rise to various heights, from five to ten thousand feet above their base, they might leave an unfathomable ocean in the intermediate spaces.


No. 4.: Maldiva Isles

In regard to the thickness of the masses of coral, MM. Quoy and Gaimard are of opinion, that the species which contribute most actively to the formation of solid masses do not grow where the water is deeper than twenty-five or thirty feet. But the branched madrepores, which live at considerable depth, may form the first foundation of a reef, and raise a platform on which other species may build, [2] and the sand and broken fragments washed by the waves from reefs may, In time, produce calcareous rocks of great thickness.

The rapidity of the growth of coral is by no means great, according to the report of the natives to Captain Beechey. In an island west of Gambier's group, our navigators observed the Chama gigas (Tridacna, Lam.) while the animal was yet living, so completely overgrown by coral, that a space only of two inches was left for the extremity of the shell to open and shut. [3] But conchologists suppose, that the chama may require thirty years or more to attain its full size, so that the fact is quite consistent with a very slow rate of increase in the calcareous reefs. In the late expedition to the Pacific no positive information could be obtained, of any channel having been filled up within a given period, and it seems established that several reefs had remained for more than half a century, at about the same depth from the surface.

The increase of coral limestone, however, may vary greatly according to the sites of mineral springs, for these we know often issue in great numbers at the bottom of the sea in volcanic regions, as in the Mediterranean, for example, where they sometimes cause the sea at great depths to be fresher than at the surface, a phenomenon also declared by the South Sea islanders to be common in the Pacific.

But when we admit the increase of coral limestone to be slow, we are merely speaking with relation to the periods of human observation. It often happens, that parasitic testacea live and die on the shells of the larger slow-moving gasteropods in the South Seas, and become entirely inclosed in an incrustation of compact limestone, while the animal, to whose habitation they are attached, crawls about and bears upon his back these shells, which may be considered as already fossilized. It is, therefore, probable, that the reefs increase as fast as is compatible with the thriving state of the organic beings which chiefly contribute to their formation; and if the rate of augmentation thus implied be called, in conformity to our ordinary ideas of time, gradual and slow, it does not diminish, in the least degree, the geological importance of such calcareous masses.

Suppose the ordinary growth of coral limestone to amount to six inches in a century, it will then require three thousand years to produce a reef fifteen feet thick; but have we any ground for presuming that, at the end of that period, or of ten times thirty centuries, there will be a failure in the supply of lime, or that the polyps and molluscs will cease to act, or that the hour of the dissolution of our planet will first arrive, as the earlier geologists were fain to anticipate?

Instead of contemplating the brief annals of human events, let us turn to some natural chronometers, to the volcanic isles of the Pacific, for example, which shoot up ten or fifteen thousand feet above the level of the ocean. These islands bear evident marks of having been produced by successive volcanic eruptions; and coral reefs are sometimes found on the volcanic soil, reaching for some distance from the sea-shore into the interior. When we consider the time required for the accumulation of such mountain masses of igneous matter according to the analogy of known volcanic agency, all idea of extenuating the comparative magnitude of coral limestones, on the ground of the slowness of the operations of lithogenous polyps, must instantly vanish.

The information collected during the late expedition to the Pacific throws much additional light on the peculiarities of form and structure of coral islands. Of thirty-two of these, examined by Captain Beechey, the largest was thirty miles in diameter, and the smallest less than a mile. They were of various shapes, all formed of living coral, except one, which, although of coral formation, was raised about eighty feet above the level of the sea, and encompassed by a reef of living coral. All were increasing their dimensions by the active operations of the lithophytes which appeared to be gradually extending and bringing the immersed parts of their structure to the surface. Twenty- nine of the number had lagoons in their centres, which had probably existed in the others, until they were filled, in the course of time, by zoophytic and other substances.

In the above-mentioned islands, the strips of dry coral encircling the lagoons when divested of loose sandy materials heaped upon them, are rarely elevated more than two feet above the level of the sea; and were it not for the abrupt descent of the external margin which causes the sea to break upon it, these strips would be wholly inundated. "Those parts of the strip which are beyond the reach of the waves are no longer inhabited by the animals that reared them, but have their cells filled with a hard calcareous substance, and present a brown rugged appearance. The parts which are still immersed, or are dry at low water only, are intersected by small channels, and are so full of hollows that the tide, as it recedes, leaves small lakes of water upon them. The width of the plain or strip of dead coral, in the islands which fell under our observation, in no instance exceeded half a mile from the usual wash of the sea to the edge of the lagoon, and in general was only about three or four hundred yards." [4] Beyond these limits the sides of the island descend rapidly, apparently by a succession of inclined ledges, each terminating in a precipice. The depth of the lagoons is various; in some entered by Captain Beechey, it was from twenty to thirty-eight fathoms.

In the annexed cut (No. 5), one of these circular islands is represented just rising above the waves, covered with the cocoa-nut and other trees, and inclosing within, a lagoon of tranquil water.


No. 5: View of Whitsunday Island. [5]

The accompanying section will enable the reader to comprehend the usual form of such islands. (No. 6.)


No. 6.: Section of a Coral Island.
(a a) Habitable part of the island, consisting of a strip of coral, inclosing the lagoon.
(b b) The lagoon.

The subjoined cut (No. 7) exhibits a small part of the section of a coral island on a larger scale.


No. 7.: Section of part of a Coral Island.
(a b) Habitable part of the island.
(b e) Slope of the side of the island, plunging at an angle of forty-five to the depth of fifteen hundred feet.
(c c) Part of the lagoon.
(d d) Knolls of coral in the lagoon, with over-hanging masses of coral, resembling the capitals of columns.

The circular or oval forms of the numerous coral isles of the Pacific, with the lagoons in their centre, naturally suggest the idea that they are nothing more than the crests of submarine volcanos, having the rims and bottoms of their craters overgrown by corals. This opinion is strengthened by the conical form of the submarine mountain, and the steep angle at which it plunges on all sides into the surrounding ocean. It is also well known that the Pacific is a great theatre of volcanic action, and every island yet examined in the wide region termed Eastern Oceanica, consists either of volcanic rocks or coral limestones.

It has also been observed that, although within the circular coral reefs, there is usually nothing discernible but a lagoon, the bottom of which is covered with coral, yet within some of these basins, as in Gambier's group, rocks composed of porous lava and other volcanic substances, rise up, resembling the two Kameni's, and other eminences of igneous origin, which have been thrown up within the times of history, in the midst of the Gulf of Santorin. [6]

We mentioned that in volcanic archipelagos there is generally one large habitual vent, and many smaller volcanos formed at different points and at irregular intervals, all of which have usually a linear arrangement. Now in several of the groups of Eastern Oceanica there appears to be a similar disposition, the great islands, such as Otaheite, Owhyhee, and Terra del Spirito Santo, being habitual vents, and the lines of small circular coral isles which are dependent on them being very probably trains of minor volcanos, which may have been in eruption singly and at irregular intervals.

The absence of circular groups in the West Indian seas, and the tropical parts of the Atlantic, where corals are numerous, has been adduced as an additional argument, inasmuch as volcanic vents, though existing in those regions, are very inferior in importance to those in the Pacific and Indian seas. [7] It may be objected that the circles formed by some coral reefs or groups of coral islets, varying as they do from ten to thirty miles and upwards in diameter, are so great as to preclude the idea of their being volcanic craters. In regard to this objection we may refer to what we have said in a former volume respecting the size of the so-called craters of elevation, many of which, we conceive, may be the ruins of truncated cones. [8]

There is yet another phenomenon attending the circular reefs, to which we have not alluded, viz., the deep narrow; passage which almost invariably leads from the sea into the lagoon, and is kept open by the efflux of the sea at low tides. It is sufficient that a reef should rise a few feet above low-water mark to cause the waters to collect in the lagoon at high tide, and, when the sea falls, to rush out violently at one or more points where the reef happens to be lowest or weakest. At first there are probably many openings; but the growth of the corals tends to obstruct all those which do not serve as the principal channels of discharge, so that their number is gradually reduced to a few, and often finally to one. This event is strictly analogous to that witnessed in our estuaries, where a body of salt-water accumulated during the flow, issues with great velocity at the ebb of the tide, and scours out or keeps open a deep passage through the bar, which is almost always formed at the mouth of a river.

When we controverted in our first volume Von Buch's theory of "elevation craters," we suggested that the single gorge leading from the central cavity to the sea, may have been produced by a stream of water issuing from a lake filling the original crater, and which had in process of time cut a deep channel; [9] but we overlooked the more probable cause, the action of the tides, which affords, we think, a most satisfactory explanation. Suppose a volcanic cone, having a deep crater, to be at first submarine, and to be then gradually elevated by earthquakes in an ocean where tides prevail, a ravine cannot fail to be cut like that which penetrates into the Caldera of the isle of Palma. The opening would at first be made on that side where the rim of the crater was originally lowest, and it would afterwards be deepened as the island rose, so as always to descend somewhat lower than the level of the sea. Captain Beechey's observations, therefore, of the effect of the tides on the coral islands, corroborate the opinion which we offered respecting the mode of formation of islands having a configuration like Palma; whereas the theory of the sudden upheaving of horizontal strata into a conical form, affords no explanation whatever of the single ravine which intersects one side of these circular islands.

In the coral reefs surrounding those volcanic islands in the Pacific which are large enough to feed small rivers, there is generally an opening or channel opposite the point where the stream of fresh water enters the sea. The depth of these channels rarely exceeds twenty- five feet, and they may be attributed, says Captain Beechey, to the aversion of the lithophytes to fresh water, and to the probable absence of the mineral matter of which they construct their habitations. [10]

But there is yet another peculiarity of the low coral islands, the explanation of which is by no means so obvious. They follow one general rule in having their windward side higher and more perfect than the other. "At Gambier and Matilda islands this inequality is very conspicuous, the weather side of both being wooded, and of the former inhabited, while the other sides are from twenty to thirty feet under water, where, however, they might be perceived to be equally narrow and well defined. It is on the leeward side also that the entrances into the lagoons occur; and although they may sometimes be situated on a side that runs in the direction of the wind, as at Bow Island, yet there are none to windward." These observations of Captain Beechey accord perfectly with those which Captain Horsburgh and other hydrographers have made in regard to the coral islands of other seas. Thus the Chagos Isles in the Indian Ocean are chiefly of a horse-shoe form, the openings being to the north-west; whereas the prevailing wind blows regularly from the south-east. From this fortunate circumstance ships can enter and sail out again with ease, whereas, if the narrow inlets were to windward, vessels which once entered might not succeed for months in making their way out again. The well-known security of many of these harbours, depends entirely on this fortunate peculiarity in their structure.

In what manner is this singular conformation to be accounted for? The action of the waves is seen to be the cause of the superior elevation of some reefs on their windward sides, where sand and large masses of coral rock are thrown up by the breakers; but there are a variety of cases where this cause alone is inadequate to solve the problem; for reefs submerged at considerable depths, where the movements of the sea cannot exert much power, have, nevertheless, the same conformation, the leeward being much lower than the windward side. [11]

I am informed by Captain King, that on examining the reefs called Rowley Shoals, which lie off the north-west coast of Australia, where the east and west monsoons prevail alternately, he found the open side of one crescent-shaped reef, the Imperieuse, turned to the east, and of another, the Mermaid, turned to the west; while a third oval reef, of the same group, was entirely submerged. This want of conformity is exactly what we should expect, where the winds vary periodically.

It seems impossible to refer the phenomenon now under consideration to any original uniformity in the configuration of submarine volcanos, on the summits of which we may suppose the coral reefs to grow; for although it is very common for craters to be broken down on one side only, we cannot imagine any cause that should breach them all in the same direction. But, if we mistake not, the difficulty will be removed if we call in another part of the volcanic agency-subsidence by earthquakes. Suppose the windward barrier to have been raised by the mechanical action of the waves to the height of two or three yards above the wall on the leeward side, and then the whole island to sink down a few fathoms, the appearances described would then be presented by the submerged reef. A repetition of such operations by the alternate elevation and depression of the same mass (an hypothesis strictly conformable to analogy) might produce still greater inequality in the two sides, especially as the violent efflux of the tide has probably a strong tendency to check the accumulation of the more tender corals on the leeward reef, while the action of the breakers contributes to raise the windward barrier.

The calcareous formations of the Pacific are probably all stratified, although single beds may sometimes attain a great thickness. The occasional drifting of sand from the exposed parts of a reef into the lagoon or the surrounding sea, would suffice to form occasional lines of partition, especially during violent tempests which occur annually among the South-Sea islands. The decomposition of felspathic lavas may supply the current which washes and undermines the cliffs of some islands with fine clay, and this may be carried to great distances and deposited in distinct layers between calcareous masses, or may be mingled with them and form argillaceous limestones. Other divisions will arise from the arrangement of different species of testacea and zoophytes, which inhabit water of various depths, and which succeed each other as the sea deepens by the fall of the land during earthquakes, or grows shallower by elevation due to the same cause, or by the accumulation of organic substances raising the bottom.

To these causes of minor subdivision must be added another of great importance,-the ejection of volcanic ashes and sand, often carried by the wind over wide areas, and the flowing of horizontal sheets of lava, which may interrupt suddenly the growth of one coral reef, and afterwards serve as a foundation for another. An example of this kind is seen in the isle of France, where a bed of coral, ten feet thick, intervenes between two currents of lava, [12] and in the West Indies, in the island of Dominica, Maclure observes that "a bed of coral and madrepore limestone, with shells, lies horizontally on a bed of cinders, about two or three hundred feet above the level of the sea, at Rousseau, and is covered with cinders to a considerable height." [13]

The reefs in the Pacific are sometimes of great extent: thus the inhabitants of Disappointment Islands, and those of Duff's Group, pay visits to each other by passing over long lines of reefs from island to island, a distance of six hundred miles and upwards. When on their route they present the appearance of troops marching upon the surface of the ocean. [14]

A reference to our :first volume will show that a series of ordinary earthquakes might, in the course of a few centuries, convert such a tract of sea into dry land; and it is, therefore, a remarkable circumstance that there should be so immense an area in eastern Oceanica, studded with minute islands, without one single spot where there is a wider extent of land than belongs to such islands as Otaheite, Owhyhee, and a few others, which either have been or are still the seats of active volcanos. If an equilibrium only were maintained between the upheaving and depressing force of earthquakes, large islands would very soon be formed in the Pacific; for, in that case, the growth of limestone, the flowing of lava, and the ejection of volcanic ashes, would combine with the upheaving force to form new land.

Suppose the shoal which we have described as six hundred miles in length, to sink fifteen feet, and then to remain unmoved for a thousand years; during that interval the growing coral may again approach the surface. Then let the mass be re-elevated fifteen feet, so that the original reef is restored to its former position: in this case the new coral formed since the first subsidence, will constitute an island six hundred miles long. An analogous result would have occurred if a lava-current fifteen feet thick had overflowed the submerged reef. The absence, therefore, of more extensive tracts of land in the Pacific seems to show that the amount of subsidence by earthquakes exceeds in that quarter of the globe at present the elevation due to the same cause.

We mentioned that one of the thirty-two islands examined by our navigators in the late expedition, was raised about eighty feet above the level of the sea. [15] It is called Elizabeth or Henderson's Island, and is five miles in length by one in breadth. It has a flat surface, and on all sides except the north, is bounded by perpendicular cliffs about fifty feet high, composed entirely of dead coral, more or less porous, honeycombed at the surface, and hardening into a compact calcareous mass, which possesses the fracture of secondary limestone, and has a species of millepore interspersed through it. These cliffs are considerably undermined by the action of the waves, and some of them appear on the eve of precipitating their superincumbent weight into the sea. Those which are less injured in this way present no alternate ridges or indication of the different levels which the sea might have occupied at different periods, but a smooth surface, as if the island, which has probably been raised by volcanic agency, had been forced up by one great subterraneous convulsion. [16]


No. 8: Elizabeth or Henderson's Island.


No. 9: Enlarged view of part of Elizabeth or Henderson's Island.

At the distance of a few hundred yards from this island, no bottom could be gained with two hundred fathoms of line. It will be seen from the annexed sketch, communicated to me by Lieutenant Smyth, of the Blossom, that the trees come down to the beach towards the centre of the isle, a break which at first sight resembles the openings which usually lead into lagoons: but the trees stand on a steep slope and no hollow of an ancient lagoon was perceived. The reader will remark that such a mass of limestone represents exactly those horizontal cappings of calcareous strata which we sometimes find on hills which have tabular summits.

As we have at present no proof that Henderson's Island has been upheaved within the historical period, we deviate somewhat from our plan when we describe it in the present chapter; but, as earthquakes are now felt from time to time in this part of the Pacific, and as indications of very recent changes of level are not wanting, [17] it is by no means improbable that the era of the elevation of this island may not be very remote.

The calcareous masses which we have now considered, constitute, together with the associated volcanic formations, the most extensive of the groups of rocks which can be demonstrated to be now in progress. The space in the sea which they occupy is so vast, that we may safely infer that they exceed in area any group of ancient rocks which can be proved to have been of contemporaneous origin. We grant that each of the great archipelagos of the Pacific are separated by unfathomable abysses, where no zoophytes may live and no lavas flow, where not even a particle of coral sand or volcanic scoriae may be drifted: we confine our view to the extent of reef ascertained to exist, and assume that a certain space around each volcanic or coral isle has been covered with ejections or matter from the waste of cliffs, and it will then be seen that the space occupied by these formations may equal, and perhaps exceed in area that part of our continents which has been accurately explored by the geologist.

That the increase of these calcareous masses should be principally, if not entirely, confined to the shallower parts of the ocean, or, in other words, to the summits of submarine ranges of mountains and elevated platforms, is a circumstance of the highest interest to the geologist; for, if parts of the bed of such an ocean should be upraised, so as to form large continents, mountain-chains might appear, capped and flanked by calcareous strata of great thickness, and replete with organic remains, while in the intervening lower regions no rocks of contemporary origin would ever have existed.

A modern writer has attempted to revive the theory of some of the earlier geologists, that all limestones have originated in organized substances. If we examine, he says, the quantity of limestone in the primary strata, it will be found to bear a much smaller proportion to the siliceous and argillaceous rocks than in the secondary, and this may have some connexion with the rarity of testaceous animals in the ancient ocean. He farther infers that in consequence of the operations of animals. " the quantity of calcareous earth deposited in the form of mud or stone is always increasing; and that as the secondary series far exceeds the primary in this respect1 so a third series may hereafter arise from the depths of the sea, which may exceed the last in the proportion of its calcareous strata." [18]

If these propositions went no farther than to suggest that every particle of lime that now enters into the crust of the globe, may possibly in its turn have been subservient to the purposes of life by entering into the composition of organized bodies, we should not deem the speculation improbable; but when it is hinted that lime may be an animal product combined by the powers of vitality from some simple elements, we can discover no sufficient grounds for such an hypothesis; and many facts which militate against it.

If a large pond be made, in almost any soil, and filled with rain water, it may usually become tenanted by testacea, for carbonate of lime is almost universally diffused in small quantities. But if no calcareous matter be supplied by waters flowing from the surrounding high grounds or by springs; no tufa or shell-marl are formed. The thin shells of one generation of molluscs decompose, so that their elements afford nutriment to the succeeding races; and it is only where a stream enters a lake, which may introduce a fresh supply of calcareous matter, or where the lake is fed by springs, that shells accumulate and form marl.

All the lakes in Forfarshire which have produced deposits of shell-marl, have been the sites of springs which still evolve much carbonic acid, and a small quantity of carbonate of lime. But there is no marl in Loch Fithie, near Farfar; where there are no springs, although that lake is surrounded by these calcareous deposits, and although, in every other respect, the site is favourable to the accumulation of aquatic testacea.

We find those charae which secrete the largest quantity of calcareous matter in their stems, to abound near springs impregnated with carbonate of lime. We know that if the common hen be deprived altogether of calcareous nutriment, the shells of her eggs will become of too slight a consistency to protect the contents, and some birds eat chalk greedily during the breeding season.

If on the other hand we turn to the phenomena of inorganic nature, we observe that, in volcanic countries, there is an enormous evolution of carbonic acid, mixed with water or in a gaseous form, and that the springs of such districts are usually impregnated with carbonate of lime in great abundance. No one who has travelled in Tuscany, through the region of extinct volcanos and its confines, or who has seen the map recently constructed by Targioni to show the principal sites of mineral springs, can doubt for a moment, that, if this territory was submerged beneath the sea, it might supply materials for the most extensive coral reefs. The importance of these springs is not to be estimated by the magnitude of the rocks which they have thrown down on the slanting sides of hills, although of these alone large cities might be built, nor by a coating of travertin that covers the soil in some districts for miles in length. The greater part of the calcareous matter passes down in a state of solution to the sea; and a geologist might as well assume the mass of alluvium formed in a few years in the bed of the Po, or the Ganges, to be the measure of the quantity deposited in the course of centuries in the deltas of those rivers, as conceive that the influence of the carbonated springs in Italy can be estimated by the mass of tufa precipitated by them near their sources.

It is generally admitted that the abundance of carbonate of lime given out by springs, in regions where volcanic eruptions or earthquakes prevail, is referrible to the solvent power of carbonic acid. For, as the acidulous waters percolate calcareous strata, they take up a certain portion of lime and carry it up to the surface where, under diminished pressure in the atmosphere, it may be deposited, or, being absorbed by animals and vegetables, may be secreted by them. In Auvergne, springs charged with carbonate of lime rise through granite, in which case we must suppose the calcareous matter to be derived from some primary rock, unless we imagine it to rise up from the volcanic foci themselves.

We see no reason for supposing that the lime now on the surface, or in the crust of the earth, may not, as well as the silex, alumine, or any other mineral substance, have existed before the first organic beings were created, if it be assumed that the arrangement of the inorganic materials of our planet preceded in the order of time the introduction of the first organic inhabitants.

But if the carbonate of lime secreted by the testacea and corals of the Pacific, be chiefly derived from below, and if it be a very general effect of the action of subterranean heat to subtract calcareous matter from the inferior rocks, and to cause it to ascend to the surface, no argument can be derived in favour of the progressive increase of limestone from the magnitude of coral reefs, or the greater proportion of calcareous strata, in the more modern formations. A constant transfer of carbonate of lime from the inferior parts of the earth's crust to its surface, would cause throughout all future time, and for an indefinite succession of geological epochs, a preponderance of calcareous matter in the newer, as contrasted with the older formations.

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Notes:

1. Kotzebue's Voyages, 1815-18, vol. iii. p. 331-3.

2. Journ. of Geograph. Soc. of London, 1831, p. 218.

3. Beechey's Voyage to the Pacific, &c. p. 157.

4. Captain Beechey, part i. p. 188.

5. This plate and the section which follows are copied, by permission of Captain Beechey, from the illustrations of his valuable work before alluded to.

6. See vol. i. p. 386.

7. De la Beche, Geol. Man. p. 141.

8. See vol. i. p. 388.

9. Vol. i., p. 395.

10. Voyage to the Pacific, &c., p. 194.

11. Voyage to the Pacific, &c., p. 189.

12. De la Beche, Geol. Man. p. 142. Quoy and Gaimard, Ann. des Sci. Nat. tome vi.

13. Observations on the Geology of the West Indian Islands, Journal of Science, &c., No. X., p. 318.

14. Malte-Brun's Geog. vol. iii. p. 401.

15. According to some accounts between sixty and seventy feet.

16. Beechey, ib. p. 46.

17. See Captain Beechey's Voyage to the Pacific, &c., pp. 159 and 191.

18. Macculloch's Syst. of Geol., vol. i. p. 219.

[admin]

DESCRIPTION OF THE PLATES AND MAP

FRONTISPIECE.

View of part of the Valley del Bove, on the East side of the great Cone of Etna.

THIS valley is a cavity of immense depth, commencing at a short distance below the summit of Etna, and descending through that zone of the mountain where lateral eruptions are frequent. The general dip of the volcanic beds in the precipices surrounding this valley is towards the sea, but exceptions occur where lateral cones have been buried in the manner described in the first volume (p. 868). The stupendous precipices surrounding this great amphitheatre vary from 600 to nearly 8000 feet in height, and they are traversed on all-sides by innumerable vertical walls or dikes of compact lava, which cut through the sloping beds of lava, sand, and scoriae, of which the great cone is formed. These dikes, which will be described in the next volume, seem all to have been produced by ancient lateral eruptions on the flanks of Etna.

The causes which have produced this great depression in the otherwise symmetrical cone of the volcano will be discussed in the third volume, and we shall merely state here, that we consider the conformation of the rocky barrier encircling the cavity, as entirely at variance with an hypothesis recently proposed, that the hollow was a crater of eruption from whence the scoriae of the surrounding heights have proceeded.

We have introduced two colours into the plate, the grey to express that part of the mountain which may have been formed before the origin of the "Val del Hove," the red to indicate the part which has resulted from eruptions subsequent to the formation of the valley. The great lava currents of 1819 and 1811, described in the first volume (p. 367), are seen pouring down from the· higher parts of the valley, overrunning the forests of the great plain, and rising up in the foreground on the left with a rugged surface, on which small hillocks and depressions are seen, such as often characterize a lava-current immediately after its consolidation.

The small cone, No. 7, was formed in 1811, and was still smoking when I saw it in 1828. Immediately in front of it is seen another cone, formed during the same eruption. The other small volcano to the left, from which vapour is issuing, was formed, I believe, in 1819.

This sketch, which forms part of a panoramic drawing which I made in November 1828, is merely intended to assist the reader, in comprehending some geological details into which we shall hereafter enter, on the structure of the older portion of Etna, but it will give no idea of the extraordinary geological interest, still less of the picturesque grandeur of this magnificent scene of desolation. Nor is the view sufficiently extensive to exhibit the entire form of the vast amphitheatre, part only of the northern, and scarcely any of the southern boundary of which is included.

MAP

Shewing the extent of Surface in Europe which has been covered by Water since the Deposition of the older Tertiary Strata. (St-rata of the Paris and London Basins, &c.)

[Constructed chiefly from M. Amie Boue's Geological Map of Europe.]

This map will enable the reader to perceive at a glance the great extent of change in the physical geography of Europe, which can be proved to have taken place since some of the older tertiary strata were deposited. The most ancient part of the period to which the map refers cannot be deemed very remote, considered geologically, because the deposits of the Paris and London basins, of Auvergne, and many other districts belonging to the older tertiary epoch, are newer than the greater part of the sedimentary rocks of which the crust of the globe is composed. The species, moreover, of marine and fresh-water testacea, of which the remains are found in these formations, are not entirely distinct from such as now live; a proportion of about three in a hundred of the fossil species having been identified with species now living. Yet, notwithstanding the comparatively recent epoch to which the retrospect is carried, the variations in the distribution of land and sea depicted on the map, form only a part of those which must have taken place during the period under consideration. Some approximation has merely been made to a correct estimate of the amount of sea converted into land in that part of Europe best known to geologists, but we cannot determine how much land has become sea during the same period; and there may have been repeated interchanges of land and water in the same places, mutations of which no account is taken in the map, and respecting the amount of which little accurate information can ever be obtained by geologists.

[In the original publication, the map on the following two pages was printed as a fold-out and hand painted in two colors. We have adapted the colors to shading in order to print the map in black and white.]


MAP shewing the extend of surface in EUROPE, which has been covered by Water since the commencement of the deposition of the older TERTIARY strata (strata of the Paris & London Basins &c & c. Constructed chiefly from the Geological Map of Europe by M.A. Beur

The proofs of submergence, during some part of the tertiary period, throughout the districts distinguished by ruled lines, are of a most unequivocal character; for the area thus described is now covered by deposits, containing the remains of aquatic animals belonging to tertiary species. We have, indeed, extended the sea in two or three instances beyond these limits, because other geological data have been obtained for inferring the submergence of these tracts subsequently to the commencement of the deposition of the tertiary strata. Thus we shall explain, in the next volume, our reasons for concluding that part of the chalk of England, (the north and south downs, for example, together with some other adjoining secondary tracts,) continued beneath the sea until the older tertiary beds had begun to accumulate.

It is possible also that a considerable part of Caernarvonshire might with propriety have been represented as sea, it our information respecting the geology of that country had been more full and accurate; for marine shells have been found in sand and gravel at the height of one thousand feet above the level of the sea, on the summit of Moel Tryfane, between Snowdon and the Menai Straits. The species are apparently recent, but certainly are newer than the older tertiary epoch. [1]

The introduction of a small bay where the river Ribble enters into the sea in Lancashire, is warranted by the newly discovered deposit of tertiary shells covering an area of about thirty miles square in that region. [2]

A portion also of the primary district in Brittany is divided into islands, because it has been long known to be covered with patches of marine tertiary strata; and when I examined the disposition of these, in company with my friend Captain S. E. Cook, R.N., in 1830, I was convinced that the sea must have covered much larger areas than are now occupied by these small and detached deposits.

The former connexion of the White Sea and the Gulf of Finland is proved by the fact that a broad band of tertiary strata extends throughout part of the intervening space. We have represented the channel as somewhat broader than the tract now occupied by the tertiary formation, because the latter is bordered on the north-west by a part of Finland, which is extremely low, and so thickly interspersed with lakes as to be nearly half covered with fresh-water.

Certain portions of the north-western shores or Norway have been left blank, because the discovery by Von Buch, Brongniart, and others, of deposits of recent shells along the coast of Norway and Sweden, at several places and at various heights above the level of the sea, attest the comparatively recent date of the elevation of part of the gneiss and other primary rocks in that country, although we are unable as yet to determine how far the sea may have extended.

On the other hand, a considerable space of low land along the shores of the Gulf of Bothnia, in the Baltic, is represented as sea, because the growth of deltas on that coast, and the shallowing of the water by sedimentary deposits during the historical era, leave no room for doubt that the extent of the gulf must have been very much greater at some periods since the older tertiary epoch.

The low granitic steppe coloured red, to the north of the Black Sea has not been represented as having been under water during the tertiary period, although, from the quantity of marine tertiary strata in the surrounding districts, it is far from improbable that it has recently emerged.

We were anxious, in the observations annexed to the title of this map, to guard the reader against the supposition that it was intended to represent the state of the physical geography of part of Europe at anyone period. It is not a restoration of a former condition of things, but a view of the change which a certain amount of surface has undergone within a given period, an alteration so complete, that not one of the species of organic beings which now inhabit the large space designated by ruled lines, beyond the borders of the existing seas, can have lived there during some other period subsequent to the commencement of the tertiary era.

We have stated, in the first volume, [3] that the movements of earthquakes occasion the subsidence as well as the upraising or the surface; and that, by the alternate rising and sinking of particular spaces, at successive periods, a great area may have been entirely covered with marine deposits, although the whole may never have been beneath the waters at one time; nay, even though the relative proportion of land and sea may have continued unaltered throughout the whole Period. We believe, however, that since the commencement of the tertiary period, the dry land in the northern hemisphere has been continually on the increase, not only because it is now greatly in excess beyond the average proportion which land generally bears to water on the globe, but because the comparison of the secondary and tertiary strata implies a passage throughout the space now occupied by Europe, from the condition of an ocean interspersed with islands to that of a large continent.

But if it were possible to represent all the vicissitudes in the distribution of land and sea that have occurred during the tertiary period, and to exhibit not only the actual existence of land where there was once sea, but also the extent of surface now submerged, which may once have been land, the map would still fail to express all the important revolutions in physical geography, which have taken place within the epoch under consideration. The oscillations of level have not merely been such as to lift up the land from below the waters to a small height above them, but in some cases a rise of several thousand feet has been effected. Thus the Alps have acquired an additional altitude of from 2000 to 4000 feet, and even in some places still more; and the Apennines owe a great part of their height (from 1000 to 2000 feet and upwards) to subterranean convulsions which have happened within the tertiary epoch.

On the other hand, some mountain chains may have been lowered, during the same series of ages, in an equal degree, and shoals may have been converted into deep abysses.

It would be superfluous to point out in detail the bearing of the facts exhibited in this map, on the theories proposed in a former part of this volume, respecting the migrations of animals and plants, and the extinction of species; and it would be equally unnecessary to enlarge on the variations in local climate, which must have accompanied such vicissitudes in physical geography.

But the general temperature, also, of the habitable surface of the globe, as well as the local climates, may have been considerably modified by such extraordinary revolutions. The alteration in climate, implied by a comparison of the organic remains of the older tertiary strata, and the species of living animals and plants, does not appear to be so great as would be produced if the temperature of our tropics were now transferred to the temperate zone, and the temperature of the latter to the arctic. We do not, therefore, anticipate that the reader, who has duly studied the arguments explained by us in the 6th, 7th, and 8th chapters of the first volume, will object to the adequacy of the cause proposed, on the score of the small quantity of geographical change during the time in question.

But if there be good reason to conclude that the change would be fully adequate, in point of the magnitude of its effects, this cause, we conceive, ought to supersede every other of a purely speculative nature, until some argument can be adduced to prove that the change has not acted in the right direction. [4]

Some persons, but slightly acquainted with the present state of geology, have objected, that the lands in high northern latitudes have not been recently elevated. If they had reflected that every year we are making some new discoveries respecting the periods when tracts in the immediate neighbourhood of the great European capitals emerged from the deep, and had they sufficiently considered that the antiquity of a group of rocks has no necessary connexion with the date of its elevation, they would probably have seen the futility of such arguments. As far as we can conjecture, from the very scanty information which we possess of the geology of the arctic region, there is no want of proofs of comparatively recent alterations of level.

In conclusion, we may remark that the portion of Europe distinguished in this map by colours and ruled lines, comprises the greater part of the globe now known to geologists -- almost all at least that is known in such a manner as to entitle anyone to speculate on the mutations in physical geography which have taken place during the tertiary period. In regard to other parts of the world, we have no reason for inferring, from any data hitherto obtained, that during an equal lapse of the ages which immediately preceded our times, an equal amount of alteration of surface may not have taken place.

LIST OF WOOD-CUTS.

1. Eggs of fresh-water Molluscs, p. 111.
2. Seed-vessel of Chara hispida, p. 273.
3. Stem and branches of ditto, p. 274.
4. Chain of coral islets, called the Maldivas, p. 286.
5. View of Whitsunday Island, p. 289.
6. Section of a coral island, p. 290.
7. Ditto of part of a coral island, p. 290.
8. Elizabeth, or Henderson's Island, p. 297.
9. Enlarged view of part of ditto, p. 297.

_______________

Notes:

1. Joshua Trimmer, Esq., Proceedings or the Geological Society or London, No. 22, 1831. The shells were exhibited at the Geological Society when the memoir was read.

2. See an abstract of a memoir read by Mr. Murchison, Pres. Geol. Soc., Proceedings or York meeting, 183l.

3. Page 126.

4. See Mr. Herschell's remarks on a change of climate. -- Disc. on the Study of Nat. Phil., pp. 146 and 148.

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PART 1 OF 2

INDEX

VOL. II.

ACQUIRED habits of animals rarely
transmissible, page 48.
Adige, its delta increased by the system
of embankment, 203.
lElian, on the breeding of elephants in
captivity, 46.
Africa, devastations caused by locusts
in, 137.
-- many species probably annihilated
by the advance of the sands of, 166.
-- dried carcasses of camels imbedded
in the deserts of, 235.
-- strata now forming off the coast
of, 282.
African desert, its area as compared to
the Mediterranean, 166.
Airthrey, a fossil whale found at, 279.
Algre, great depths at which some
species live, 72.
- may leave traces of their form in
calcareous mud, 278.
Alloa, whale cast ashore at, 278;
-- fossil whale found near, 279.
Alluvium, stalagmite found alternating
with in French caves, 222.
-- imbedding of organic remains
in, 228.
Alps, have been greatly raised during
the tertiary epoch, 308.
Alternations of marine and fresh-water
strata, how formed, 277.
America, specific distinctness of the animals
in, and those of the Old World,
66, 87.
__ domesticated animals have run
wild in, 28, 153.
-- rapid multiplication of domestic
quadrupeds in, 152.
-- number of plants common to the
Old World, and, 69.
-- number of square miles of useful
soil in, 155.
Andes, may have undergone great
changes of level in the last 6000
years, 265.
-- effects which it is said would result
from their sudden elevation, 279
Animal kingdom, theory of the uninterrupted
succession in the, 2.
Animal origin of limestone theory considered,
298.
Animal remains in caves and fissures
219.
Animals, Lamarck's theory of the production
of new organs in, 7.
-- imported into America have run
wild, 28.
-- aptitude of some kinds to domestication,
38.
-- hereditary instincts of, 39.
-- domestic qualities soon developed
in some, 47.
-- some of their qualities given with
a view to their connexion with man,
41, 44, 47.
-- their acquired habits rarely transmissible,
48.
-- changes in the brain of the feotus
in vertebrated, 62.
-- their agency in diffusing plants, 78.
-- their geographical distribution, 87.
-- different regions of indigenous, 88.
-- in islands, 90.
-- their powers of swimming, 92.
-- migrations of, 94.
-- their power of crossing the sea
very limited, 96.
-- causes which determine the stations
of, 130, 140.
-- influence of society in altering the
distribution of, 149.
-- migratory powers indispensable
to, 159.
-- manner in which they become
preserved in peat, 216.
-- remains of those most common in
peat mosses, 218.
-- most abundantly preserved where
earthquakes prevail, 230.
-- imbedded by floods in Scotland, 230.
-- imbedded by river inundations,
247·
-- found imbedded in Scotch marl
lakes, 251.
Animate creation, changes now in progress
in the, 1.
Antagonist powers, synchronism of their
action, 196.
Antiseptic property of peat, whence derived,
216.
Ants, their ravages in Grenada, 137.
Apennines, have been a vegetable centre
whence species diffused themselves, 178.
-- in great part elevated during the
tertiary epoch, 308.
Aphides, White's account of a shower
of, 114.
__ their rapid multiplication, 135.
-- ravages caused by, 136.
Aphonin, on the diffusion of man over
the globe, 117.
Apure, river, wild horses drowned in
great numbers by the annual floods of
the, 249.
Aquatic and terrestrial species, their reciprocal
influence, 138.
Aquatic species, imbedding of their remains
in subaqueous strata, 272.
Aqueous lavas ill Campania, seven persons
destroyed by, 236.
Arabian Gulf, rapidly filling with coral,
285.
Arctic region, on alterations of level in
the, 309.
Ass, the, has run wild in Quito, 153.
-- wild, account of their migrations
in Tartary, 95.
Astrea, genus, instrumental in the formation
of coral, 284.
Athabasca Lake, large shoal formed by
drift-wood in. 242.
Atlantic, absence of circular coral groups
in the, 291.
Aubenas, fissures filled with breccia
near, 220.
Augustin, St., on a plague caused by
locusts in Africa, 137.
Australia, the kangaroo and emu giving
way in, 1~0.
-- vegetation of, 178.
-- extent of coral reefs off the coast
of, 285.
Auvergne, tertiary deposits of, 304.

Baboon of Sumatra, trained to ascend
trees, 47.
Bacon, Lord, on the vicissitudes of
things, 271.
Baffin's Bay, marine animals found at
great depths in, 181.
Bakewell, Mr., on the formation of
soils, 188.
-- his account of the fall of Mount
Grenier, 229.
Bakie loch, charae found in a fossil state
in, 274.
Ballard, M., on changes which some
human bones have undergone, in
fourteen or fifteen centuries, 225.
Banks formed by drift sea-weed, 277.
Barbadoes, rain diminished by the felling of forests in, 200.
Barriers to the distribution of species,
remarks on, 172.
Barrow, Mr., his account of a bank
formed in the sea by the bodies of
locusts, 138.
Barton, Mr., on the agency of insects in
the fructification of plants, 54.
-- on the geography of plants, 67.
Baumhauer, Mr., his account of a violent
river-flood in Java, 250.
Bears, once numerous in Wales, 149.
-- black, migrate in great numbers, 94.
Beaver, once an inhabitant of Scotland
and Wales, 149.
-- remains of the, found in shell·
marl, in Perthshire, 251-
Bee, number of instincts of the, 58.
Beechey, Captain, on the drifting of
canoes in the Pacific, 120.
-- on the buried temple of Ipsambul,
234.
-- on the rate of the growth of coral
in the Pacific, 287.
-- on the situation of the channels
into the lagoons of coral islands, 293.
-- on the superior height of the
windward side of coral islands, 293.
-- his description of Elizabeth or
Henderson's Island, 297.
__ on recent changes of level in the
Pacific, 298.
Belcher, Captain, on the strata now
forming in the 8ea off the coast of
Africa, 282.
Belzoni, on the buried temple of Ipsambul,
234.
-- his account of a flood on the Nile,
253.
Berkely, on the recent origin of man,
270.
Bewick, on the great geographical range
of some birds, 101.
-- on the distribution of the bustard
in England, 150.
Bhooi, volcanic eruption at, during
Cutch earthquake, 238.
Bigsby, Dr., on the North American
lakes, 275.
Birds, diffusion of plants by, 80.
-- geographical distribution of, 100.
-- some species very local, 100.
-- their powers of diffusion, 101.
-- periodical migrations of, 101.
-- great range of some species, 101.
-- rate of the flight of, 102.
-- frequently overtaken by hurricanes,
102.
-- their agency in the distribution of
fish, 106.
-- many species of, unremittingly
persecuted, 149.
Birds, recent extermination of some
species of, 150.
-- bones of in Gibraltar breccia, 223.
-- rarity of their remains in Dew
strata, 246.
Bisons, immense herds of, in the Mississippi valley, 93.
Bize, human remains found mixed with
extinct mammalia in a cave at, 224.
Black cattle, their rapid multiplication
in South America, 152.
Black Sea, marine tertiary strata found
near the, 307.
Blavier, M., on the peat at the mouth
of the Loire, 211.
Bloomfield, bursting of a peat moss
near, 218.
Blown sand, imbedding of organic remains,
&c. in, 234.
Boa constrictor, account of one conveyed
to St. Vincent's on drift-wood,
104.
Boates, Dr., on Irish peat-bogs, 211.
Boblaye, M., on the formation termed
ceramique, in the Morea, 233.
Bog iron ore, whence derived, 214.
Bonaparte, C., on the birds common to
Rome and Philadelphia, 101.
Bonelli, Professor, on the migrations of
the painted lady butterfly, 113.
Bonpland, on the plants common to the
old and new world, 69.
Bordeaux, timber destroyed by a beetle
introduced by commerce at, 122.
Borneo, the orang-outang taught to
ascend trees by the inhabitants of, 47.
Boston, a narwal found buried in mud
on the beach near, 278.
Botanical geography, 67.
Botanical provinces, their number, 71.
-- how caused, 125.
-- why not more blended together, 127.
Bothnia, gulf of, its extent formerly
much greater, 307.
Boyne, a large whale stranded at, 278.
Brand, Rev. J. F., on the birth-place of
man, 117.
British vessels, average number wrecked
annually, 254, 257.
-- durable nature of many of their
contents, 256, 257.
British coasts, cetacea frequently stranded
on the, 278.
Brittany, a village in, buried under
blown sand, 235.
-- marine tertiary strata of, 305.
Brocchi, his remarks on the extinction
of species, 128.
Broderip, Mr., on the agency of Ianthina
fragilis, in disseminating other
species, 108.
Broderip, Mr., some large bulimi restored
to life after twenty months'
abstinence, by, 109.
Bromberg, a vessel and two anchors dug
up near, 260.
Brongniart, M., his discovery of recent
shells at considerable heights in
Sweden, 306.
Brown, Mr., on the plants common to
Africa, Guiana, and Brazil, 76.
-- on the vegetation of New Holland,
178.
Buckland, Dr., on animal remains in
caves, 219.
-- on the remains of recent quadrupeds
in fissures, 220.
-- on stalagmite of caves, 222.
-- on human remains in caves, 223.
-- on the organic remains in the cave
of Paviland, 223.
Buffaloes destroyed in great numbers
by a river flood in .Java, 250.
Buffon, on the want of specific identity
in the animals of the Old and New
World, 66.
-- on the geographical distribution of
animals, 87.
-- on the check which the increase of
one animal offers to that of another,
154.
-- his remarks on the gradual extinction
of species, 176.
Buildings submerged without being
thrown down, examples of, 266, 269.
Bura and Helice, submerged Grecian
towns, 269.
Burckhardt, buried temple of Ipsambul,
discovered by, 234.
-- his account of the carcasses of
camels in the Libyan sands, 235.
Burnes, Lieut. A., his account of the
effects of the earthquake of Cutch,
1819, 266.
Burnt island, whale cast ashore near, 278.
Burrampooter, bodies of men, deer, &c.,
conveyed to the sea by the floods of
the, 250.
Burringdon, human remains found in a
cave at, 223.
Burrowing shells secure from the ordinary
action of the waves, 280.
Bustards recently extirpated in England,
150.
Bywell, bodies washed out of the
churchyard of, by floods, 254.

Cabbages, examples of deviation from
a common type shown ill different
races of, 33.
Cachalots, a herd of stranded at Kairston,
in Orkney, 278.
Caemarvonshire, recent discovery of
tertiary strata in, 305.
Calabria, animals how preserved in alluvium
in, 230.
-- animals engulphed in fissures in,
231.
Calcareous marl of the Scotch lakes,
shells found in the, 272.
Calcareous formations of the Pacific,
probably all stratified, 294.
-- their great extent, 298.
Calcareous matter, the theory that it is
on the increase controverted, 300.
Caldera of the isle of Palma, ravine in
the, how formed, 292.
Callao, recent changes of level caused by
earthquakes in, 265.
Camels, the carcasses of imbedded in
drift-sand, 235.
Campania, people destroyed by aqueous
lavas in, 236.
Campbell, Mr., on the migration of
quaggas in South Africa, 95.
Camper, on the gradation in intellect as
shown by the facial angle, 60.
Cannon inclosed in calcareous rock
taken up from the delta of the Rhone,
262.
- account of one taken up near the
Downs, 262.
Canoes full of men and women drifted
to great distances, 119.
-- eight found in draining Martin
Meer, Lancashire, 260.
-- several found in Loch Doon, 261.
Cape Langaness, drift-wood abundant
at, 244.
Carcasses of camels in ~rift-sand, 235.
Caryophyllia, coral formed by the genus,
284.
Caspian, on the level of the, 163.
Caspian and Black Sea formerly connected
by straits, 100.
Castle, Mr., on the ravages of ants in
Grenada, 137.
Catalonia, devastation caused by torrents
in, 199.
Catania, part of the town of overflowed
by lava, 236.
-- tools discovered in digging a well
at, 259.
Catastrophes, remarks on general, 161.
Caterpillars, ravages caused by some
kinds, 136.
Catodon, Ray's account of a large one
stranded in Holland, 278.
-- a herd of them stranded in Orkney,
278.
Caverns, organic remains in, may, in
some cases, have fallen through fissures,
221.
Caves, organic remains in, 219.
-- preserved by sediment introduced
by land-floods, 221.
-- alternations of sediment and stalagmite in some, 222.
-- Dr. Buckland on human remains
in, 223, 227.
-- marine and terrestrial shells of
eatable species found in, 224.
Caves, works of art found at a depth of
twenty feet at, 259.
Central India, buried cities in, 237.
Ceramiqne, account of the formation
termed, 233.
Cetacea, their geographical range, 91.
-- migrations of the, 99.
-- identity of those found in the
Mediterranean and Caspian Seas, 99.
-- imbedding of their remains in
recent strata, 278.
-- often stranded on low shores
during storms, 278.
-- their remains should be more frequent
in marine alluvium than those
of land quadrupeds, 279.
Chagos isles, their linear direction, 286.
-- openings into them in the opposite
direction to the prevailing wind, 293.
Chalk of the north and south downs
elevated after the commencement of
the tertiary era, 305.
Chama gigas, time which it requires to
attain its full growth, 287.
-- found in the Pacific completely
overgrown by coral, 287.
Chamisso, M., on the formation of coral
islands, 284.
Channel into the lagoons of coral
islands, how formed, 292.
Chara hispida, it. structure described,
see wood-cuts, No.2 and 3, 273, 274.
Charae, fossilized in the lakes of Forfarshire,
273.
Chockier, three alterations of stalagmite
and alluvium in a cave at, 222.
Christol, M. de, on human remains, &c.
in caves, with extinct quadrupeds,
224.
Climate, its influence on the distribution
of plants, 68.
-- effect of alterations in, on the distribution
of species, 169.
-- its influence in causing one species
to give way before another, 172.
-- influence of vegetation on, 200.
-- on the alteration which changes in
physical geography may have caused
in, 308.
Coal, formation of, at the mouths of the
Mackenzie, 242.
Coiron, land shells in breccia at, 220.
Colebrooke, Major R. H., on the formation
of new islands in the Ganges, 203.
Columella, on the breeding of elephants
in captivity, 46.
Conception, changes of level caused by
earthquakes at, 265.
Cones formed on Etna in 1819 and
1811 (see frontispiece), 304.
Conservative influence of vegetation,
198.
Cook, Captain, on the diffusion of nutmeg
seeds by pigeons, 80.
-- on the drifting of canoes to great
distances, 119.
Cook, Captain S. E., examined Brittany
with the author, 306.
Coral, rate of the growth of, in the
Pacific, 287.
-- its growth probably varies according to
the sites of mineral springs, 287.
-- found between two lava currents
in the West Indies, 294.
Coral animals, their action compared to
plants which generate peat, 283.
-- MM. Quoy and Guimard on the
depth at which they live, 286.
Coral islands, formation of, 284.
-- linear direction of, see wood-cut
No. 4, 286.
-- origin of the form of, 288.
-- two sections explaining their form,
see diagrams Nos. 6 and 7, 290.
-- many probably the crests of submarine
volcanos. 290.
-- their windward side higher and
more perfect than the other, 293.
Coral reefs, formation of, 283.
-- great beds of oysters, &c., found
on, in the Pacific, 283.
-- genera of zoophytes by which they
are constructed, 284.
-- their extent, 285, 295, 298.
-- linear direction of, 286.
-- rapidity of the growth of, 287.
-- the most extensive formation now
in progress, 298.
Cornwall, ruins of buildings found in
the drift-sand of, 235.
Corse, Mr., on the habits, &c.of the elephant,
46.
Cowslip, Linnaeus on the varieties of
the, 34.
Crantz, on the drift-wood of the North
Sea, 244.
Creation, supposed centres, or foci, of
126.
Crocodile taken in the Rhone, 104.
Crocodiles imbedded by a river inundation
in Java, 246.
Currents, distribution of drift-timber
by, 245.
Curtis, Mr., on the ravages caused by
aphides, 136.
Curtis, Mr. John, on the power of the
tipulae to cross the sea, 116.
-- on insects in marl, 245.
Cutch, effects of the earthquake of, in
1819, 265.
Cuvier on the variability in the same
species, 25.
-- on the varieties of the dog, 27.
-- on identity of Egyptian mummies
with living species, 30.
-- on the migrations of the Springbok, 95.
-- on the extinction of the Dodo, 151.
-- on the durability of the bones of
men, 258.
Cuvier, M. F., on the aptitude of some
animals to domestication, 38.
-- on the influence of domestication,
41.
Cypris found completely fossilized in
Scotch marl lakes, 275.
-- not uncommon in ponds in England,
275.

Dangerfield, Captain F., on buried cities
in Central India, 238.
Daubeney, Dr., his discovery of nitrogen
in mineral springs, 189.
Davy, Sir H., on the occurrence of gypsum
in peat, 210.
-- his objection to the theory of the
gradual civilization of man, 117.
-- on the perishable nature of the
works of man, 27t.
Davy, Dr., on the changes which a
helmet taken up from the sea near
Corfu had undergone, 263.
Decandolle, his opinion respecting hybrid
plants, 56.
-- on the distribution of plants, 68, 71.
-- on the agency of man in the dispersion
of plants, 82.
-- On the causes of stations of plants,
131.
-- on the barriers which separate distinct
botanical provinces, 177.
Decandolle, M. Alph., on the number of
botanical provinces, 71.
Deer, their powers of swimming, 92.
-- formerly very abundant in Scotland,
149.
-- abundance of their remains in the
Scotch marl lakes, 251.
Deguer on remains of ships, &c., in the
Dutch peat mosses, 219.
Degradation of land, caused by rain,
199.
De la Beche, M., on the action of rain
in the tropics, 200.
De la Beche, M., on the drifting of the
lighter parts of plants to sea by hurricanes,
244.
-- his remarks on the subsidence at
Port Royal, 269.
-- on the coral formations of the West
Indian seas, 291.
-- on the alternation of coral and lava
in the Isle of France, 295.
Delametherie, speculative views of, 11.
Delille, wheat found in the Egyptian
tombs by, 31.
-- on the native country of the common
wheat, 31.
Delta of the Ganges, alternations of marine
and fresh-water strata formed in
the, 277.
-- of the Indus, recent elevation and
depression of the, 277.
-- of the Rhone, cannon inclosed in
calcareous rock taken up from the,
262.
De Luc on the conversion of forests into
peat mosses, 214.
Denudation caused by rain, 199.
Desert of Africa, its area as compared
to that of the Mediterranean, 166.
Desjardin, M., bones of the dodo found
fossil under lava by, 151.
Dikes numerous in the Val del Hove,
Etna, 303.
Disappointment Islands, connected with
Duff's group by coral reefs, 295.
Dislocations of strata, ancient and modern,
remarks on, 195.
Distribution of species, effect of changes
in physical geography on the, 160.
-- effect of changes in climate on,
169.
Dodo, on the recent extinction of the,
150.
Dog, varieties of the, 26.
-- its distinctness from the wolf, 27.
-- hybrids between the wolf and, 51.
Dogs, Lamarck on the numerous races
of, 7.
__ examples of acquired instincts becoming
hereditary in, 39.
-- have run wild in America, 153.
-- goats in Juan Fernandez destroyed
by, 154.
Domestic qualities soon developed in
some animals, but wholly denied to
others, 47.
Domestication, aptitude possessed by
some animals to, 38.
-- influence of, 41.
Dominica, a bed of coral found between
two lava currents in, 294.
Downham, part of the town of, overwhelmed
by blown sand, 235.
Downs, account of a cannon taken up
from the sea near the, 262.
Drift sea-weed, large banks formed by,
277.
Drift wood, a boa constrictor conveyed
to St. Vincent's on, 104.
-- on the imbedding of, 241.
-- abundant in the North Sea, 244.
-- conveyed in all directions by cur·
rents, 245.
Drumlanrig forest overturned by the
wind in 1756, 212.
Duff's group, these islands connected
with Diappointment islands by coral
reefs, 295.
Dulverton, pigs found entire in digging a
well at, 216.
Duncombe Park, bones of recent quadrupeds
found in a fissure in, 220.
Dureau de la Malle, M., on the changes
caused by man in different races of
dogs, 2ft
-- on the aptitude of some animals to
domestication, 38.
Dutch peat-mosses, remains of ships,
&c., found in, 219.
Dutch vessel found in the old channel of
the river Rother, 260.

Earth's surface, effects produced by the
powers of vitality on the, 185.
-- permanent modifications produced
by the action of animal and vegetable
life on the, 209.
Earthquakes, animals most abundantly
preserved where they prevail, 230.
-- ravages caused by the waves of the
sea on low coasts during, 232.
-- in Sicily, 1693, several thousand
people entombed at once in caverns,
during, 232.
-- effects of the submersion of land
by, 264.
-- their effects often unheeded, 267.
-- their effects in imbedding cities
and forests, 268.
-- in the Pacific, 297.
Edrom, remains of the beaver found
in the parish of, 251.
Edwards, his account of the destruction
of the town of Savanna la Mar, 233.
Egypt, cities and towns buried under
drift sand in, 234.
Egyptian mummies identical with species
still living, 28.
Eider-ducks destroyed by a fox drifted
on ice to the island of Vidoc, 145.
Ekmark, on the diffusion of plants by
birds, 80.
Elephants, their sagacity not attributable
to their intercourse with man, 46.
Elephants will breed in captivity, 46.
-- their powers of swimming, 92.
Elevation, effects which would result in
some places from partial, 163.
-- recent, in the delta of the Indus,
266.
-- and subsidence, effects of alternate,
307.
Elizabeth, or Henderson's Island described-
see wood-cuts No. 8 and 9,
296, 297.
Elk Island, with 700 quadrupeds, swept
away by a river-flood in Virginia, 250.
Emu in Australia will become exterminated,
150.
Equilibrium among plants kept up by
insects, 132.
Eschscholtz's bay, cliffs consisting of ice
and vegetable mould in, 194.
Escrinet, Pass of, conglomerate now
forming at, 221.
Estuaries, imbedding of fresh-water
species in, 275.
-- description of the manner in which
they become filled up, 276.
Etna, fourteen towns and villages covered
at once by the lava of, 236.
-- general dip of the volcanic beds of,
303.
-- lava currents of 1819 and 1811,
on, 304.
-- recent cones formed on, 304.
Extermination of species, no prerogative
of man, 156.
Extinction of species, successive, part of
the economy of nature, 168, 176.

Facial angle, on the gradation in intellect, as shown by the, 60.
Ferussac on the distribution of fresh.
water molluscs, 108.
Finland, Gulf of, its connexion with the
White Sea, 306.
Fish, their geographical distribution,
105.
-- migrations of, 106.
-- agency of birds and water-beetles
on their distribution, 106.
Fissures, preservation of organic remains
in, 220, 231.
-- on their communication with caverns,
221.
Fleming, Dr., on the rapid flight of
birds, 102.
__ his account of turtles taken on the
coast of England, 104.
-- on the changes in the animal kingdom,
caused by the increase of human
population, 148.
-- his account of the stranding of cetacea
on the British coasts, 278;
Flinders, a reef of coral 350 miles long,
described by, 285.
Floating islands within the tropics, animals
transported by, 97.
Floods in Scotland, 1794, 248.
-- 1829, 249.
Forests, degradation of land increased
by their destruction, 198.
-- rain diminished by the felling of,
200.
-- of America, cause of their position,
201.
-- sites of many ancient ones now
covered by peat, 206, 211.
-- sometimes overturned by storms,
212.
-- in Germany destroyed by insects,
206.
-- submarine, remarks on their formation,
268.
Forfarshire Lakes, shell marl deposits,
how formed in the, 272, 299.
-- charae found fossilized in the-see
wood-cuts No.2 and 3, 273, 274.
-- skeletons of animals numerous in
the, 251.
Formation of coral reefs, 283.
Fort of Sindree, subsidence of, in 1819,
266.
-- not thrown down by the earthquake,
266. .
Forth, effects of a storm in its estuary,
Feb. 1831, 280.
Fourcroy on the occurrence of iron in
all compact woods, 215.
Fox man-of-war, changes which some
articles, thrown up from the wreck of
the, had undergone in 33 years, 262.
France, human bones and works of art
found with extinct quadrupeds, in
the south of, 224.
-- number of ships of war lost during
the last war with, 256.
Franklin, on a whirlwind in Maryland,
74.
Fresh-water formations, recent, not yet
examined, in the tropics, 275.
-- the variety of species of testacea
but small in, 277.
Fresh-water and marine strata, alternations
of, how formed in the delta of
the Ganges, 277.
Freshwater plants and animals, imbedding
of their remains in subaqueous
strata, 272, 275.
Fries, on the dispersion of cryptogamic
plants, 76.
Frisi, on the conservative influence of
vegetation, 198.
Frogs, conveyed to the sea in great numbers by floods, in Morayshire, 246.
Frontispiece described, 303.

Gaimard, M., on the depth at which
the zoophytes, that form coral, live,
286.
Gambier Island, its windward side highest,
293.
Gambier's group, rate of the growth of
coral in, 287.
-- volcanic rocks found in the lagoons
of, 291.
Gamma moth, ravages caused by the caterpillars
of the, 136.
Ganges, islands formed by the, 203.
-- bodies of men, deer, and oxen conveyed
to the sea by the floods of the,
250.
-- bones of men found in the delta of
the, 258.
-- alternations of marine and freshwater
strata, how formed in its delta,
277.
Gases, two of different gravities, will become
uniformly diffused, 188.
Genera, Linnaeus on their real existence,
19.
Geographical distribution of specie~, on
the laws which regulate the, 66.
Geographical distribution of plants, 67.
-- of animals, 87.
-- of cetacea, 91.
Geography of plants, 67.
Geological causes divisible into two great
classes, 209.
Gerard, M., on the peat of the valley of
the Somme, 219.
Germany, forests destroyed by insects
in, 206.
Gibraltar, birds' bones found in breccia
at, 223.
-- and Ceuta, shelly strata forming
at great depths between, 281.
Gmelin on the agency of birds in the
distribution of fish, 106.
Goats, rapid multiplication of, in South
America, 153.
-- in Juan Fernandez, destroyed by
dogs, 154.
Godman on the migrations of the reindeer,
97.
Graves, Lieut., some bulimi brought to
England by, recovered after twenty
months' abstinence, 109.
-- on the diffusion of insects by the
wind, 115.
Graves, Mr., on the distribution of the
bustard, 150.
Greenland, timber drifted to the shores
of, 244.
Grenada, sugar-canes destroyed by ants
in, 137.
Greville, Dr., on some remarkable accumulations
of drift sea-weed, 78.
Guadaloupe, human skeletons imbedded
in calcareous rock in the island of,
259.
Guilding, Rev. L., his account of the
arrival of a boa constrictor in St. Vincent's,
on drift wood, 104.
Guldenstadt, on the distinctness of the
dog and wolf, 28.
Gulf of Bothnia, its extent formerly
much greater, 307.
Gulf of Finland, its geological connexion
with the White Sea, 306.
Gulf-stream, great area over which
plants are drifted by the, 76, 243.
Gull-stream, account of a cannon taken
up in the, 262.
Gun-barrel, with shells attached, found
in the sands near St. Andrew's, 263.
Gypsum, Sir H. Davy on its occurrence
in peat, 210.
Gyrogonite, or petrified seed-vessel of
charae, described-see wood-cut No.2,
273.

Habitations of plants described, 69.
Habits of animals, when acquired rarely
transmissible, 48.
Hamilton, Sir Charles, on the submerged
buildings of Port Royal, 269.
Happisborough, remarks on the so-called
submarine forest of, 268.
Harris, Hon. A., on the effects of the
foundering of a vessel off Poole harbour,
260.
Hatfield moss, trees of vast size found
in, 213.
Helice and Bura, submerged Grecian
towns, 269.
Helix, extensive range of some species
of, 109.
-- some species of very local, 109.
Helmet, changes which one taken up
from the sea near Corfu, had undergone,
263.
Henderson on the drifting of the polar
bear to Iceland, 143.
Henderson's Island described-see woodcuts
No. 8 and 9, 296, 297.
Henslow, Rev. Prof., his experiments
on the cowslip, 35.
-- on the diffusion of plants by birds, 80.
Herbert, Hon. Mr., on some remarkable
varieties in plants, from a common
stock, 34.
-- his experiments on the cowslip, 34.
-- on hybrid plants, 56.
Herschell, Mr., his remarks on a change
of climate, 309.
Hilaire. M. Goof. St., on the uninterrupted succession in the animal kingdom,
2.
Hoff, M. Von, on human remains in the
delta of the Ganges, 258.
-- his account of a buried vessel between
Bromberg and Nakel, 260.
Hogs, rapid multiplication of, in South
America, 153.
Holland, the teredo navalis brought by
ships to, 122.
-- submarine peat found in, 278.
- a large cachalot stranded on the
west coast of, in 1598, 278.
Hooker, Dr., on the drifting of a fox on
ice, 145.
Horsburgh, Capt., his description of the
Maldiva Islands, 285.
-- on the situation of the channels
into the lagoons of coral islands, 293.
Horses, the amble hereditary in some,
44.
-- numerous, in a wild state in Mississippi
valley, 152.
-- wild, annually drowned in great
numbers in South America, 249.
Horsfield, Dr., on the distribution of the
Mydaus meliceps in Java, 95.
Horticulture, changes in plants produced
by, 32.
Human bones, changes which some have
undergone in fourteen or fifteen centuries,
225.
Human remains in peat mosses, 215.
-- in caves, 223.
- their durability, 258.
-- found in the delta of the Ganges,
258.
-- found in calcareous rock at Guadaloupe,
259.
Humboldt on the training of monkeys
to ascend trees, 47.
-- on the distribution of species, 67.
-- on the plants common to the Old
and New World, 69.
-- on the distribution of animals, 88.
-- on the periodical migrations of American water-fowl, 102.
-- on the drifting of insects by the
wind in the Andes, 114.
-- on the rapid multiplication of domestic
quadrupeds in America, 152.
-- on the comparative size of the
African desert and the Mediterranean,
166.
-- origin of beings said by him not to
belong to zoological geography, 179.
-- his account of the annual drowning
of wild horses in South America,
by river floods, 249.
Humming-birds peculiar to the New
World, 100.
Humming-birds, found by Captain King
in the Straits of Magellan, in the
depth of winter, 100.
-- some species very local, 100.
Hunter, John. on mule animals, 50.
-- on the identity of the dog, wolf,
and jackal, 50.
Hunter, Mr., his account of the buried
city of Oujein, 237.
Huron, Lake, strata containing recent
shells, found on the shores of, 275.
Hurricanes, many of them connected
with submarine earthquakes, 232.
-- leaves of plants drifted out to sea
by, 244.
Huttonian theory, remarks on the,
196.
Hybrid races, Lamarck on the origin of,
10.
Hybrids, phenomena of, 49.
-- sometimes prolific, 49.
-- John Hunter's opinion on, 50.
-- not strictly intermediate between
the parent species, 51.
-- between the dog and wolf, 51.
-- among plants prolific through several
generations, 52.
-- rare among plants in a wild state,
54.
-- difficulties attending their propagation,
59.
Hydrangea hortensis, influence of soil
on the colour of its petals, 34.
Hydrophytes, distribution of, 72, 78.

Ianthina fragilis, its extensive range,
108.
-- an active agent in disseminating
other species, 108.
Icebergs, plants transported by, 77.
Ice-floes, drifting of animals on, 97.
Iceland, the polar bear frequently drifted
from Greenland to, 143.
-- rein-deer imported into, 154.
Igneous action, remarks on its intensity
at different epochs, 194.
Igneous causes, the real antagonist power
to the action of running water, 194.
Imbedding of organic remains in deposits
on emerged land, 209.
-- in peat mosses, 215.
-- in caves and fissures, 219.
-- in alluvium, and the ruins caused
by landslips, 228.
-- in volcanic formations on the land,
236.
-- in subaqueous deposits, 239.
-- by river inundations, 247.
-- in recent marl-lakes in Scotland,
251.
Imperieuse, coral reef, 294.
Imrie, Major, on the Gibraltar breccia,
223.
India, buried cities in Central, 237.
Indians of North America will become
exterminated, 175.
Indus, recent alterations of level in its
delta, 265, 277.
Inorganic causes, their influence in
changing the habitations of species,
158.
Insects, the fructification of plants
greatly assisted by, 54.
-- geographical distribution of, 112.
-- migrations of, 113.
-- certain types of, distinguish particular
countries, 114.
-- diffused by the wind, 115.
-- disseminated by animals, birds,
river-floods, &c., 116.
-- power of some kinds of to cross the
sea, 116.
-- destructive to timber, introduced
by commerce, 122.
-- parasitic, 122.
-- their numbers kept down by other
insects, 133.
-- peculiarity of their agency in preserving
an equilibrium of species, 134.
-- rapid propagation of some kinds of,
135.
-- imbedding of the remains of, 245.
-- only preserved under peculiar circumstances,
246.
Instincts of the bee, fi8.
Instincts, migratory, occasional development
of in animals, 93.
-- new ones, which have become hereditary
in some animals, 39.
-- modified by domestication, 44.
Ipsambul, buried temple of, 234.
Ireland, tradition of the destruction of
the reptiles of, by St. Patrick, 103.
-- its flora but little known, 103.
-- area covered by peat in, 211.
-- trees of great size found in the peat
of, 212.
-- human body found in peat in, 215.
-- cattle lost in great numbers in the
bogs of, 217.
-- testacea found living at great
depths off the N. W. coast of, 282.
Iron, common in all compact woods,
215.
-- ore in peat, whence derived, 214.
-- instruments, account of some taken
up from the bottom of the sea, incased
in conglomerate, 262.
Islands, vegetation of, 70, 227.
-- the migration of plants aided by,
77.
-- animals found in, 90.
Islands of the Pacific, animals found in,
90.
-- coral, manner in which they are
formed, 284.
-- of drift wood, with trees growing
on them, discovered at sea, 98.
Isle of France, alternation of coral and
lava seen in the, 295.
Isthmus of Sleswick, action of the sea on
the, 165.
-- effects which would result from its
destruction, 165.
Italian peninsula, in great part elevated
since present marine species were in
being, 178.

[admin]

PART 2 OF 2

Jamaica, seeds drifted to Europe from,
76.
-- subsidence in the harbour of Port
Royal in, 161, 264.
-- rain diminished in, by the felling
of forests, 200.
-- a town in, swept away by the sea,
233.
James, Mr., on the herds of bisons in the
Mississippi Valley, 93.
Java, imbedding of the remains of reptiles
in, 246.
-- animals destroyed by river-floods
in, 250.
John de Mayen, drift wood on the
island of, 244.
Juan Fernandez, goats destroyed by
dogs in, 154.

Kamtschatka, migrations of rats in, 94.
Kangaroo is giving way before the progress
of society in Australia, 150.
Keith on the dispersion of seeds by rivers
and torrents, 76.
King, Mr., on the number of cattle lost
in bogs in Ireland, 217.
-- his account of a cannon taken up
from the Downs, 262.
King, Capt. P., on the coral reefs of
New Holland, 285, 294.
Kinnordy, Loch of, remains of insects
found in marl in the, 245.
Kirby, Rev. Mr., on the instincts of the
bee, 58.
-- on the distribution of insects, 113.
-- on the dissemination of insects by
river-floods, 116.
-- on the rapid propagation of some
insects, 135.
-- on the devastations caused by ants
in Grenada, 137.
Knight, Mr., on the wearing out of garden
varieties of fruit, 33.
Kolreuter, his experiments on hybrids,
between two species of tobacco, 52.
Konig, Mr., on the rock in which the
human skeletons from Guadaloupe are
imbedded, 259.
Kotzebue, his account of a canoe drifted
1500 miles, 119.
-- on the formation of coral islands,
284.
Krantz on the migrations of seals, 99.

Labrador, drift timber carried to the
shores of, 244.
Laccadive Islands, their linear direction,
285.
Lacepede on identity of Egyptian mummies
with living species, 30.
Lagoons of coral islands, volcanic rocks
sometimes found in them, 291.
-- cause of the narrow opening into
the, 291.
-- the entrances into them always on
the leeward side, 293.
Lake, formed by subsidence in the delta
of the Indus, 1819, 266.
-- has become more salt than the sea,
267.
Lakes of North America, animals inhabiting
them would be destroyed if
they were drained, 168.
-- strata containing recent shells
formed by the, 275.
Lamantine cast ashore near Leith, 278.
Lamarck, his definition of the term species, 3.
-- his theory of the transmutation of
species, 3.
-- on the origin of the cultivated
wheat, 6.
-- on the numerous races of dogs,
7.
-- on the production of new organs
in animals, 7.
-- on the origin of hybrid races, 10.
-- his theory of progressive development,
11.
-- his definition of Nature, 13.
-- on the conversion of the orangoutang
into the human species, 14.
__ on identity of Egyptian mummies
with living species, 30.
-- answer to his objection as to the
native country of wheat, 31.
-- on the power of species to modify
their organization, 169, 173.
-- on the abundance of polyps in the
ocean, 181.
Lamouroux on the distribution of hydrophytes,
72.
Lancashire, eight canoes found in draining a lake in, 260.
-- recent discovery of a bed of tertiary shells in, 306.
Land has increased in the northern hemisphere
since the commencement of
the tertiary era, 307.
Landslips, imbedding of organic remains
in the ruins caused by, 229.
-- villages and their inhabitants buried by, 229.
Lapland, migrations of squirrels in, 94.
Latham on the great geographical range
of some birds, 101.
Latreille on the geographical distribution of insects, 112.
Lauder, Sir T. D, his account of pigs
swimming to great distances, 92.
-- his account of the number of frogs
carried down to the sea by the floods
in Morayshire, 246, 249.
-- on the imbedding of animals by
floods in Scotland, 230.
Lava currents, of 1819 and 1811, of
Etna, described - see Frontispiece,
304.
Lawrence on the causes which enable
man to live in all climates, 62.
Leigh, his account of canoes found in
draining Martin Meer, 260.
Lemings of Scandinavia migrate in vast
numbers, 94.
Lesley on the former abundance of deer
in Scotland, 149.
Lesueur on the geographical distribution
of fish, 105.
-- on the distribution of zoophytes,
111.
Lewes, state of some human bones found
in a tumulus near, 225.
-- estuary of the Ouse recently filled
up near, 275.
-- Levels, indusia found in the blue
clay of, 245.
Lichens, height at which they can grow,
75.
Lignite, wood probably converted into,
more rapidly under great pressure,
261.
Limestone, the theory that it is all of
animal origin, considered, 298.
Lindley on the dispersion of cryptogamic
plants, 75.
Linear direction of coral islands, 286.
Linnaeus on the constancy of species, 3.
-- on the real existence of genera in
nature, 19,
-- on the distribution of seeds by animals,
79.
-- on the diffusion of plants by man,
83.
-- on the original introduction of
species, 123.
Lisbon, subsidence of the quay at, 19r,
264.
Lloyd's lists, number of vessels wrecked
between 1793 and 1829, as shown by,
257.
Loch Doon, seven canoes found in, 261.
Loch Fithie, why no marl formed in,
299.
Loch Marlie, remains of the beaver found
in, 251.
Loch of Kinnordy, remains of insects
found in marl in the, 245.
Locusts, devastations caused by, 137.
-- a great bank formed in the sea by
their dead bodies, 138.
London basin, tertiary deposits of the,
305.
Louch, M., on the migration of the
painted lady butterfly, 114.
Lowe, Mr., on the land-mollusca of
Madeira and Porto Santo, 109.
Lybian sands, caravans overwhelmed by
the, 235.
Lyon, Capt., on the imbedding of the
carcasses of camels in the African
sands, 235.

Macculloch, Dr., on the gradation from
peat to coal, 211.
-- on the occurrence of tannin in
peat, 216.
-- his theory that all limestone is of
animal origin considered, 298.
Mackenzie, Sir G., on the importation
of the rein-deer into Iceland, 154.
Mackenzie river, accumulation of vegetable
matter in, 241.
-- beds of wood-coal found on its
banks, 242.
-- cause of the abundance of drift
timber in, 243.
Maclaren on the quantity of useful soil
in America, 155.
-- on the position of the American
forests, 201.
Maclure, Mr., on the alternation of coral
and lava in the 'Vest Indies, 294.
Madagascar, great extent of coral near,
285.
Majendie, M., on the faculty of the retriever,
40.
Malabar, a great sea of coral near, 285.
Malcolm, Sir J., on the buried cities in
central India, 238.
Maldivas, description of the chain of
coral islands called the, see Wood-cut,
No.4, 285, 286.
Malte-Brun on the verdant rafts of the
Mississippi, 98.
-- his account of a crocodile taken in
the Rhone, 104.
-- on the geographical distribution of
fish, 106.
Malte-Brun on the diffusion of man,
119.
-- on destructive insects introduced
by commerce, 122.
-- on the level of the Caspian, 163.
-- on the destruction of villages by
landslips, 229.
-- on the burying of villages under
blown sand, 235.
-- on the abundance of drift wood in
the North Sea, 244.
_ on the drifting of bodies to the sea
by the Ganges, 250.
-- on the coral reefs of the Pacific,
295.
Mammalia, different regions of indigenous,
88.
Man, Lawrence on the causes which
enable him to live in all climates, 62.
-- his agency in the dispersion of
plants, 82.
-- geographical distribution and diffusion
of, 116.
-- speculations on the probable birth..
place of, 116.
-- his involuntary influence in dif.
fusing animals and plants, 121.
-- changes caused by, 146.
-- recent origin of, 155, 270.
-- effects of the diffusion of, 155.
-- power of exterminating species no
prerogative of, 156.
-- his influence in modifying the
physical geography of the globe, 202.
-- imbedding of the remains of, and
his works, in subaqueous strata,
253.
-- circumstances under which his remains
may be preserved in recent deposits,
255.
-- perishable nature of the works of,
271.
Mantell, Mr., on the superior solidity of
human bones from a Saxon tumulus
to those in a recent skeleton, 225.
-- remains of insects found in Lewes
levels by, 245.
-- his description of the recent strata
in the valley of the Ouse, 275.
Map, explanation of the, 304.
Marine and fresh-water strata, alternations
of, how formed in the delta of
the Ganges, 277.
Marine deposits, imbedding of freshwater
species in, 275.
Marine formations contain in general
a great variety of species, 277.
Marine plants and animals, imbedding
of the remains of, 277.
Marine testacea, imbedding of the remains
of, 280.
Marine testacea, great depths at which
they have been found living, 281.
Marine vegetation, 71, 78.
Marl lakes of Scotland, animals imbedded
in the, 251.
-- charae found fossilized in the, 273.
Martin Meer, eight canoes found in
draining, 260.
Martius on the changes which man will
produce in Brazil, 148.
Maryland, account of a whirlwind in,
74.
Matilda island, its windward side highest,
293.
Meandrina, coral formed by the genus,
284.
Mediterranean, its area as compared to
the African desert, 166.
Melville Island, annual migrations of
animals into, 97.
Men, on the extermination of savage
tribes of, by civilized colonies, 175.
-- more than 100 swept away by a
river flood in Java, 250.
-- several hundreds swept away by
the Nile, 253.
-- durability of the bones of, 258.
-- bones of, found in the delta of the
Ganges, 258.
Mendip hills, sediment deposited during
floods in the caves of the, 221.
Mermaid, coral reef, 294.
Mersey, a vessel discovered in its former
bed, 260.
Metallic substances, changes which some
taken up from the bottom of the sea
have undergone, 262.
Mhysir, a buried city in central India,
238.
Migrations, of animals, 94.
-- of cetacea, 99.
-- of birds, 101.
-- of fish, 106.
-- of insects, 113.
Migratory powers indispensable to animals to enable them to keep their
ground, 159.
Mississippi, floating islands in the, 98.
_ imbedding of terrestrial plants in
its delta, 243.
-- valley, wild horses very numerous
in parts of the, 152.
Mpi liere overflowed by lava in 1669,
237.
Monkeys trained to ascend trees, 47.
Morayshire, animals conveyed to the
sea by floods in, 249.
Morea, description of the formation
termed Ceramique in the, 233.
Moreau, Caesar, his tables of the navigation
of Great Britain, 257·
Montoire, great size of the peat moss of
211.
Mount Conto, town buried by the fall
of part of, 229.
Mount Grenier, five villages buried by
the fall of part of, 229.
Mountain chains, remarks on the theory
of their sudden elevation, 197.
Mules sometimes prolific, 49.
Murchison, Mr., on the 'ecent conglmerate of Escrinet, 221:
-- on the tertiary strata of Lancashire,
306.

Nakel, a vessel and two anchors dug up
near, 260.
Napier, Capt., his account of the animals
destroyed by floods in Scotland, 1794,
248.
Narwal found buried in mud on the
beach near Boston, 278.
-- skull of the, found in recent strata
in the valley of the Ouse, 276.
Nature, as defined by Lamarck, 13.
Necker supposed species could not be annihilated,
128.
Neill, his account of whales stranded
at Alloa, &c., 278.
Nerbuddah river, its channel cut
through columnar basalt, 238.
Newfoundland, cattle often mired in the
bogs of, 216.
Newhaven, valley of the Quse recently
filled up near, 275.
New Holland, mammiferous quadrupeds
of, 89.
-- its native inhabitants will become
extinct, 175.
-- extent of coral reefs off the coast
of, 285.
Nice, formation of breccias near, 221.
Nightingale, extraordinary range of the,
101.
Nile, cities and towns buried under
blown sand near the, 234.
-- several hundred men swept away
by a flood on the, 253.
Nitrogen common in mineral springs,
189.
North American lakes, animals inhabiting
them would be destroyed by their
drainage, 168.
-- strata containing recent shells
formed by the, 275.
North Cape, abundance of drift wood
thrown on, 244.
Nova Scotia, account of a vessel over..
turned by the bore or tidal wave in,
260.
Norway, on the comparatively recent
elevation of part of, 306.
Olafsen, on the abundance of drift wood
on the Coast of Siberia, 244.
Orang-Outang, Lamarck on its conversion into the human species, 14.
-- taught to climb trees by the inhabitants
of Borneo, 47.
Organic remains, imbedded in deposits
on emerged land, 209.
-- in peat, 210, 215.
-- in caves and fissures, 219.
__ in alluvium and the ruins caused
by landslips, 228.
-- in blown sand, 234.
-- in volcanic formations on the land,
236.
-- in subaqueous deposits, 239.
Osseous breccias, remarks on the formation
of, 232.
Otaheite, an habitual volcanic vent, 291.
Oujein, account of the buried city of,
237.
Ouse, its estuary recently filled up, 275.
-- section of the beds formed in its
estuary, 276.
Owhyhee, an habitual volcanic vent, 291.
Oysters, &c., thrown alive on the Leach
by a storm in the Forth, 280.
Pacific, animals found in the islands of
the, 90.
-- volcanic islands of the, 288.
-- a great theatre of volcanic action,
290.
-- all the islands yet examined in the,
are formed of coral or volcanic rocks,
290.
-- the calcareous formations of the,
probably all stratified, 294.
-- subsidence greater than elevation
in the, 296.
-- earthquakes felt from time to time
in the, 297.
-- recent changes of level in the, 297.
-- calcareous formations in the, the
most extensive now in progress, 298.
-- beds of oysters, &c., found on the
coral reefs of the, 283.
-- coral very abundant in the, 285.
Panama, effects which would follow the
sinking down of the isthmus of, 162.
Parasitic testacea, 287.
Paris basin, tertiary deposits of the,
305.
Paroxysmal convulsions, remarks on,
196.
Parrot tribes, their geographical distribution,
100.
Parry, Capt., on the swimming of the
Polar bear, 97.
-- on the animals of Melville Island,
97.
Paviland cave, human skeleton found
in, 223, 226.
Peat, its formation has not always a
conservative tendency, 193.
-- on its growth and the preservation
of organic and other remains in
it, 210.
-- abundant in hot and humid climates, 211.
-- area in Europe covered by, 211.
-- site of ancient forests now occupied
by, 206, 214.
-- human remains found in, 215.
-- its antiseptic property, whence
derived, 216.
-- mosses, accounts of the bursting
of, 217.
-- cattle mired in, 217.
-- animal remains in, 218.
-- submarine, 218, 278.
Penco uplifted 25 feet in 1750, 161.
Pennant on the distribution of animals,
89.
-- his account of the migrations of
rats in Kamtschatka, 94.
Peron on the geographical distribution
of fish, 105.
-- on the distribution of zoophytes,
111.
Persian Gulf, coral said to abound in
the, 285.
Peterhead, a large whale cast ashore
near, in 1682, 278.
Physical geography, effect of changes in,
on the distribution of species, 160, 308.
-- changes which have taken place
in, since the deposition of the older tertiary
strata, (see map,) 304.
-- effects of changes in, on climate,
308.
Pigs, fortuitous acquirements of some
not hereditary, 42.
-- instances of their swimming to
great distances, 92.
-- the carcasses of some found entire
at Dulverton in digging a well, 216.
Piz, fall of the mountain of, 229.
Plants, varieties in, produced by
culture, 32.
-- extent of variation in, 33.
-- influence of soil on the colour of
the petals of, 34.
-- agency of the wind in the fructification of. 55.
-- their geographical distribution, 67.
-- effect of climate, &c., on their distribution, 68.
-- number common to the old and
new world, 69.
-- distinct provinces of indigenous,
69.
Plants, in islands, 70, 127.
-- agency of the winds in the dispersion
of, 73.
-- form of the seeds of some freshwater,
75.
-- on the dispersion of cryptogamic,
75.
-- agency of rivers and torrents in
the dispersion of, 76.
-- absence of liquid matter in the
seeds of, 77.
-- their migrations aided by islands,
77·
-- agency of animals in the distribution
of, 78.
-- diffused by birds, 80.
-- agency of man in the dispersion of,
82.
-- causes which determine their stations,
131.
-- equilibrium among, kept up by insects,
132.
-- elements found in, 188.
-- which contribute to the formation
of peat, 210.
-- imbedding of the remains of terrestrial
in subaqueous deposits, 240.
-- drifted from the tropics to Iceland
by the gulf stream, 243.
-- their lighter parts drifted out to
sea by hurricanes, 244.
-- on the number that are now becoming
fossilized, 245.
-- freshwater, imbedding of the remains
of, in subaqueous strata, 272.
__ marine, imbedding of the remains
of, 277.
Playfair on the formation of vegetable
soil, 188.
Pleurs, town of, and its inhabitants
buried by a landslip, 229.
Po, its delta rapidly increased by embankments,
203.
Pointer, its stand probably a modification
of the instinct of a wild race, 40.
Polar bears, drifted from Greenland to
Iceland, 97.
-- Scoresby on their numbers, 97.
-- Capt. Parry on their power of
swimming, 97.
-- effects which may have followed
their first entrance into Iceland, 144.
Pomerania, several ships found entire in
the recent formations of, 260.
Pondres, human remains and extinct
animals found in a cave at, 225.
Poole harbour, effects of the foundering
of a vessel near its entrance, 259.
Population, human, of the globe, 148.
-- changes caused by the progress of,
Port Royal, suhsidence of, in 1692, 264.
Port Royal, Mr. De la Beche's remarks
on the subsidence of, 269.
-- Sir C. Hamilton on the submerged
buildings of, 269.
Prevost, M. Constant, his division of
geological causes, 209.
__ on the drifting of plants by the
gulf stream, 243.
Pre-occupancy the most powerful barrier
against emigration, 167, 168.
Prichard, Dr., on the distinct origin of
the dog and wolf, 27.
-- on the unequal transmissibility of
colour, &c. 52.
-- on hybrid races, 52.
-_ on the facial angle, 61.
-- on the geographical distribution of
animals, 88.
-- on animals found in islands, 90.
-- on the distribution of the parrot
tribes, 100.
-- his account of Linnaeus's theory of
the introduction of species, 124.
Progressive development, Lamarck's
theory of, 11.
Pursh on the phanerogamic plants of
the United States, 69.

Quadrupeds, domestic, their rapid multiplication
in America, 152.
-- imbedding of the remains of terrestrial,
247.
Quaggas, their migrations in South
Africa, 95.
Quoy, M., on the depth at which zoophytes
that form coral live, 286.

Raffles, Sir S., on the training of the
Sumatra baboon to ascend trees, 47.
Rain, remarks on the action of, 199.
-- diminished by the destruction of
forests, 200.
Rats migrate in great numbers in
Kamtschatka, 94.
-- involuntarily introduced by man
into America, 121.
Ray, the green lizard found in Ireland
according to, 103.
Reaumur on the rapid propagation of
the Aphis, 135.
-- on the ravages of the Gamma
moth, 136.
Rein-deer, geographical range of the, 94.
-- migrations of the, 97.
-- imported into Iceland, 154.
Remains, human, and extinct animals
found in a cave at Pondres, 225.
-- found in Wokey Hole, 224.
Rennie, Rev. Dr., on the seeds of fresh..
water plants, 75.
Rennie, Rev. Dr., on the formation of
peat, 210.
-- on the recent origin of some peatmosses,
212.
-- on the destruction of European
forests by the Romans, 214.
-- on the occurrence of iron-ore in
peat-mosses, 215.
-- on the preservation of human
remains in peat, 215.
-- on sub-marine peat, 219.
Reptiles, their geographical distribution,
103.
-- distinct regions of indigenous, 103.
-- their powers of diffusion, 103.
- in Ireland, legend of their destruction
by St. Patrick, 103.
-- imbedding of the remains of, in
subaqueous deposits, 246.
Retriever, M. Majendie on the faculty
of the, 40.
Rhinoceroses, hundreds swept away by
a river flood in Java, 250.
Rhone, a cannon imbedded in calcareous
rock taken up from its delta,
262.
Richardson, Dr., on the rocky mountain
sheep, 45.
-- on the imbedding of drift timber
in Slave Lake, 241.
-- on the cause of the abundance of
drift wood in the Mackenzie, 243.
River inundations, animals imbedded by,
247, 248, 253.
Rocks, their antiquity may have no connexion
with the period of their elevation,
309.
Rocky mountain sheep, Dr. Richardson
on the, 45.
Rolander on the balance of power among
species, 133.
Roman coins, &c., discovered in peat, 213.
Rossberg, 800 people destroyed by the
slide of the, 229.
Rother, a Dutch vessel found buried in
its old channel, 260.
Roulin, M., on acquired instincts which
have become hereditary in dogs, 39.
Rousseau, alternation of coral and volcanic
cinders at, 295.
Runn of Cutch, ship nails, &c., thrown
out of fissures in the, 267.
Running water, igneous causes the antagonist
power to the action of, 194.

Sand, drift, imbedding of organic remains,
&c. in, 234.
-- cities and towns in Egypt buried
under, 234.
-- carcasses of camels imbedded in,
236.
San Lorenzo, isle of, said to have been
formed by the subsidence of the promontory
of Callao, 265.
Santorin, gulf of, volcanic rocks in the
lagoons of Gambier's group like those
in the, 291.
Sardinia, its flora but little known, 103.
Savanna la Mar, town of, swept away
by the sea, 233.
Scotland, peat mosses of, 213.
-- cattle often mired in them, 217.
-- animals imbedded by floods in, 248.
-- quadrupeds found imbedded in the
marl lakes of, 251.
-- shell marl obtained from some
small lakes in, 272.
-- charae found fossil in the marl lakes
of, 273.
-- but few species in the marls of, 277.
Scoresby, Capt., his experiments on the
impregnation of wood by sea-water,
240, 261.
Sea, its ravages on low coasts during
earthquakes, 232.
-- sometimes fresher at great depths
than at the surface, 287.
-- estimate of the amount of, converted
into land since the deposition
of the tertiary strata, 305.
Sea-cow cast ashore near Leith, 278.
Seals, their migration, 99.
Sea-weed, large banks formed by drift,
78, 277.
Sections of coral islands, see diagrams,
No. 6 and 7, 290.
Sedgwick, Professor, his theory of the
antagonist power of vegetation controverted, 190.
-- on eras of paroxysmal convulsion,
197.
__ on the preservation of organic re.
mains in fissures, 220.
Selside, great fissure in limestone at,
220.
Serres, E. R. A., on the changes in the
brain of the foetus in vertebrated animals,
62.
Serres, M. Marcel de, on the changes
which some human bones have under·
gone in fourteen or fifteen centuries,
225.
-- on human remains in French
caves, 224.
Sheep, great multiplication of in South
America, 153.
Shell marl, on the formation of, in the
lakes of Scotland, 272, 299.
Shells found in the calcareous marl of
the Scotch lakes, 272.
Shifts or faults, ancient and modern
compared, 195.
Ships, British, number annually wrecked,
254, 257.
Ships of war, number lost during the
French war, 256.
-- several found buried in recent
strata, 219, 260.
Sibbald on a turtle taken in the Orkneys, 104.
-- his account of whales stranded at
Burnt island, &c., 278.
Siberia, drift timber accumulated On the
east coast of, 244.
Sicily, several thousand people entombed
at once by an earthquake in, 232.
Silliman, Professor, his account of a
vessel overturned by the bore or tidal
wave in Nova Scotia, 260.
Sindree, a new salt lake formed by subsidence
in the delta of the Indus near,
266.
-- the fort of, subsided without falling, 266.
-- elevation of Ullah Bund near, 266.
Sipparah, river, its course changed,
238.
Skeleton, human, imbedded at Guadaloupe,
259.
-- found in Paviland cave, 223, 226.
Slave Lake, accumulation of drift timber
in, 241.
Sligo, bursting of a peat moss in, 218.
Sloane, Sir H., on the dispersion of
seeds by the gulf stream, 76.
Smith, Sir J., on the propagation of
plants by buds, grafts, &c., 32.
-- on the distribution of seeds by
birds, 80.
Smyth, Capt. W. H., On floating islands
of drift wood, 98.
-- on the drifting of birds by a gale
of wind in the Mediterranean, 102.
-- on the diffusion of insects by the
wind, Il5.
-- on the average number of British
merchant vessels lost daily, 257.
-- on the number of men of war lost
from 1793 to 1829, 257.
-- found broken shells at great depths
between Gibraltar and Ceuta, 281.
Smyth, Lieutenant, his account of Henderson's
Island, 297.
Soil, its influence on the colours of the
petals of plants, 34.
Soils, on the formation of, 188.
Solway moss described, 217.
-- a man and horse, in armour,
found in, 217.
-- account of the bursting of, 217.
Solway Frith, animals washed by river
floods into, 248.
Somme, peat-mosses in the valley of the,
219.
Sortino Vecchio, several thousand people entombed at once in caverns at,
282.
South America, wild horses annually
drowned in great numbers in, 247.
-- recent changes of level in, 265.
Souvignargues, human remains found
with extinct animals in a cave at, 225.
Spallanzani On the effects of heat On the
seeds of plants, 77.
-- on the flight of birds, 102.
Species, definition of the term, 2.
-- Linnaeus on the constancy of, 3.
-- Lamarck's theory of the transmutation of, 3.
__ insufficiency of the arguments in
favour of the transmutation of, 18.
-- causes of the difficulty of discriminating, 21.
-- causes of variability in the same,
24.
-- extent of known variability in, 26.
-- variability of a, compared to that
of an individual, 36.
-_ extent of change in, 37.
-- inferences as to their reality in nature, 64.
-- laws which regulate their geographical
distribution, 66.
-- theories respecting their first introduction,
123.
-- proposal of an hypothesis as to
their first introduction, 124.
-- effects which would result from the
introduction of single pairs of each,
126.
-- Brocchi on the extinction of, 128.
-- Rolander on the balance of power
among, 133.
-- reciprocal influence of aquatic and
terrestrial, 138.
-- their successive destruction part
of the order of nature, 141.
-- effect of the extension of the range
of, 142.
-- power of exterminating them no
prerogative of man, 156.
-- influence of inorganic causes in
changing their habitations, 158.
-- effect of changes in physical geography
on their distribution, 160, 308.
-- their successive extinction part of
the economy of nature, 168, 176.
-- effect of changes of climate on their
distribution, 169, 308.
-- influence of climate in causing One
to give way before another, 172.
-- barriers which oppose their distribution, 172.
-- remarks on the conversion of one
into another, 174.
-- their local distribution, 176.
Species, their recent origin, or antiquity,
may be equally consistent with their
distribution, 177.
-- speculations on the appearance of
new, 179.
-- on the time which might be required
for the extinction of one mammiferous, 182.
Specific character, permanence of the, 18.
Spence, Mr., on the number of instincts
of the common bee, 58.
-- on the distribution of insects, 113.
-- on the rapid propagation of some
insects, 135.
-- on the devastation caused by ants
in Grenada, 137.
Spitzbergen, bays filled with drift wood
in, 244.
Spix, M., on the changes which man
will produce in Brazil, 148.
Springbok, or Cape antelope, migrates
in vast herds, 95.
Springs, mineral, in the Mediterranean,
287.
Squirrels, migrations of the common, in
Lapland, 94.
St. Andre destroyed by a landslip, 229.
St. Andrew'ls a gun barrel found in the
sands near, with shells attached to it,
263.
St. Domingo, fragments of vases, &c.,
found at a depth of twenty feet in,
269.
St. Katherine Docks, a vessel found
buried in excavating them, 260.
St. Patrick, tradition of the destruction
of the Irish reptiles by, 103.
St. Vincent, account of the arrival of a
Boa-constrictor on drift wood in the
island of, 104.
Stalagmite alternating with alluvium in
French caves, 222.
Stations, of plants, description of, 69.
-- of animals, circumstances which
constitute them are changeable, 141.
-- of animals and plants, causes by
which they are determined, 130.
Staveren, isthmus burst through, 165.
Storm of February, 1831, in the estuary
of the Forth, effects of, 280.
Stratton, Mr., his account of buried
temples in Egypt, 234.
Subaqueous strata, imbedding of aquatic
species in, 272.
Subaqueous vegetation, 72, 78.
Submarine forests, remarks on the formation of, 266.
Submarine peat, found in Holland, 278.
--formed on the English coast, 278.
Submersion of land by earthquakes,
effects of the, 264.
Subsidence, effects which would result
from, in some places, 162.
-- of Port Royal in Jamaica, 264,
269.
-- of the quay at Lisbon, 264.
-- of part of the promontory of Callao,
265.
-- in the delta of the Indus, 266.
-- in Sumbawa, 269.
-- of the North American lakes, 275.
-- greater than elevation in the Pacific,
296.
-- and elevation, effects of alternate,
307.
Subterranean action, our knowledge of
it yet in its infancy, 195.
Sumbawa, subsidence in, 269.
Superior, lake, strata containing recent
shells formed by, 275.
Sweden, shells of recent species found
at great heights in, 306.
Switzerland, towns destroyed by landslips
in, 229.


Tannin, its occurrence in peat, 216.
Temples in Egypt buried under blown
sand, 234.
Teredo navalis, introduced into Holland
on the bottoms of ships, 122.
Terra del Spirito Santo. the island of,
an habitual volcanic vent. 291.
Terrestrial species, imbedding of the
remains of in subaqueous deposits,
239.
Tertiary strata. changes which have
taken place in physical geography
since their deposition-see Map, 304.
Testacea, their geographical distribution,
107.
-- causes which limit the extension
of many species, 108.
-- great range of some speeies of, 108.
-- some kinds capable of existing
without air or nourishment for long
periods, 100.
-- their powers of diffusion-see Diagram, No. 1, 111.
-- but few species of in fresh-water
formations, 277.
-- burrowing, secured from the ordi
nary action of the waves and currents,
280.
-- marine, depths at which they have
been found living, 281.
-- parasitic, 287.
Thames, a vessel found buried in the
alluvial plain of the, 260.
Thunder-storm in Spain, devastation
caused by a 109.
Tide, channels into the lagoons of coral
islands kept open by the, 291.
Tides and currents, drifting of the
remains of animals by, 252.
Tieddemann on the changes in the
brain in the foetus of vertebrated animals,
62.
Timber destroyed by insects introduced
by commerce, 122.
Tjetandoy, river, effects of a recent flood
of the, in Java, 250.
Tobacco, hybrids between two species
of, 52.
Toomer, Mr., a pig trained to hunt by, 42.
Torrents in Catalonia, devastation
caused by, 199.
Tory island, testacea found living at great
depths off, 282.
Tournal, M., human teeth and fragments
of pottery found in a cave by,
224.
Towns destroyed by landslips, 229.
Travertin formed in Forfarshire lakes,
273.
-- charae found fossil in, in Scotland,
273.
-- cypris found fossilized in, 275.
Trimmer, Mr., his discovery of tertiary
strata in Wales, 306.
Tropics, recent fresh-water formations
of the, not yet examined, 275.
Turtles migrate in droves, 104.
-- sometimes taken on the English
coast, 104.
Turton on the drifting of wolves out to
sea on ice, 97.
-- his account of a turtle taken in
the Severn, 104.

Ullah Bund elevated in 1819 in the delta
of the Indus, 266.
-- section which it exhibited when
cut through by the river, 267.
Ulloa on the multiplication of the ass in
Quito, 153.
-- on the destruction of goats in Juan
Fernandez, by dogs, 154.
Universal formations, remarks on, 196.
Universal ocean, theory of, disproved,
124.

Val d'Arno, effect of the destruction of
forests in the upper, 198.
Valley del Bove, description of the-
(see Frontispiece, ) 303.
-- dikes numerous in the, 303.
-- dip of the volcanic beds in the, 303.
Valparaiso, recent alterations of level
caused by earthquakes at, 265.
Variability, cause of, in the same species,
24.
Variation in plants produced by horticulture, extent of, 33.
Vegetable soil, why it does not increase
on the surface, 188.
-- formed in part by absorption from
the atmosphere, 189.
Vegetation, centres of, discordance of
the opinions of botanists concerning,
177.
-- no counterpoise to the levelling
power of water, 190.
-- force which it exerts compared to
the action of frost, 193.
-- its conservative influence, 198.
-- its influence on climate, 200.
Vermont, timber imbedded by the bursting
of a lake in, 228.
Vernon, Mr., on organic remains found
at North-Cliff, Yorkshire, 226.
Vessel, effects of the foundering of one
off the mouth of Poole Harbour, 259.
-- account of one overturned by the
bore or tidal wave, in Nova Scotia,
260.
Vessels, several found buried in recent
formations, 260.
-- manner in which they may become
preserved in subaqueous strata,
261.
Vesuvius, people destroyed by volcanic
alluvions on, 236.
Vicissitudes in the distribution of land
and sea since the commencement of
the tertiary era, 305.
Vicramaditya, Rajah, cities in Central
India overwhelmed in the time of
the, 237.
Vidal, Captain, testacea found living at
great depths by, 282.
Villages and their inhabitants buried by
landslips, 229.
Ville Deux, breccia with land shells
now forming at, 220.
Virginia, account of the destruction of
Elk island by a river flood in, 250.
Vitality, effects produced on the earth's
surface by the powers of, 185.
-- these most extensive in subaqueous
regions, 186.
Volcanic beds of Etna, their general
dip, 304.
-- cones, their perfect state no proof
of their relative age, 199.
-- formations, imbedding of organic
and other remains in, 236.
-- islands of the Pacific, 288.
Von Buch, his discovery of deposits of
recent shells in Norway, 306.
Vultures, some species true cosmopolites,
101.

Walker, Dr., on the overturning of
forests by wind, 212.
West Indian seas, absence of circular
coral reefs in the, 291.
West Indies, a bed of coral found between
two lava currents in the, 294.
Whales often stranded on low shores by
storms, 278.
Wheat, Lamarck on the origin of the
cultivated, 6.
-- answer to Lamarck's objection as
to its native country, 31.
-- found in the Egyptian tombs, 31.
Whirlwinds, dispersion of seeds by, 74.
White, Mr. eh., on the regular gradation
in man, &c., 61.
White, Rev. Mr., on a shower of
Aphides, 114.
White Sea, its connexion with the Gulf
of Finland, 306.
'Whitsunday Island, description of-see
wood-cut, No. 5, 289.
Wiegmann on hybrids between the dog
and wolf, 51.
-- on hybrid plants, 53.
Wilcke on the agency of birds in the
diffusion of plants, 80.
-_ on the manner in which an equilibrium
is kept up among plants, 132.
Willdenow on the diffusion of plants by
man, 83.
-- on centres of vegetable creation,
177.
Wind, forests sometimes overturned by
the, 212.
Winds dispersion of seeds by the, 73.
-- their velocity, 74.
Windward side of coral reefs, on the
cause of the superior height of the,
294.
Wokey Hole, human remains found in,
224.
Wolf and dog distinct species, 27.
-- hybrids between the, 51.
Wolves frequently drifted out to sea on
floating ice, 97.
-- extirpated in great Britain, 149.
Wood. Mr., on the migrations of the
wild ass, 95.
Wood instantly impregnated with salt
water when sunk to a great depth,
240.
-- on the imbedding of drift, 241.
-- probably converted into lignite
more rapidly under great pressure,
261.
Wood-grouse extirpated in England
within fifty years, 150.
Wreck, changes which some articles
thrown up from a, had undergone in
thirty-three years, 262.
Wrecks, average number of per year,
254, 257.
-- manner in which they may be preserved
in subaqueous strata, 255.

Zoological provinces, how formed, 125.
-- why not more blended together,
127.
Zoophytes, their geographical distribution,
111.
__ their powers of diffusion, 112.
-- engaged in the construction of coral
reefs, 284.
-- their operations compared to plants
which generate peat, 283.
Zostera marina, submarine peat formed
from the, 278.

[admin]

View of the Volcanoes around Olot in Catalonia

PRINCIPLES OF GEOLOGY, BEING AN ATTEMPT TO EXPLAIN THE FORMER CHANGES OF THE EARTH'S SURFACE, BY REFERENCE TO CAUSES NOW IN OPERATION.

BY CHARLES LYELL, ESQ., F.R.S.,
FOR. SEC. TO THE GEOL. SOC., PROF. OF GEOL. TO KING'S COLL., LONDON

IN THREE VOLUMES.

VOL. III.

LONDON: JOHN MURRAY, ALBEMARLE-STREET.
MDCCCXXXIII.

LONDON:
PRINTED BY WILLIAM CLOWES.
Stamford Street.

TO RODERICK IMPEY MURCHISON, ESQ., F.R.S.,
&c. &c. &c.
LATE PRESIDENT OF THE GEOLOGICAL SOCIETY.

My DEAR MURCHISON,

I HAVE great pleasure in dedicating this volume to you, as it contains the results of some of our joint labours in the field, in Auvergne, Velay, and Piedmont -- results which had not yet been communicated to the public through any other channel.

When we quitted England together for a tour on the continent. in May, 1828, the first sketch only of my 'Principles of Geology' was finished. Since that time you have watched the progress of the work with friendly interest, and, as President of the Geological Society, have twice expressed in your Anniversary Addresses, your participation in many of my views, which were warmly controverted by others. The eulogy which you have lately pronounced from the chair, on the last part of my work, (whether I attribute your approval to the exercise of an unbiassed judgment or to the partiality of a friend,) could not fail to be most gratifying to my feelings, and I trust that you will long enjoy health and energy to continue to promote with enthusiasm the advancement of your favourite science.

Believe me, my dear Murchison,

Yours, &c. &c.

CHARLES LYELL.

PREFACE

THE original MS. of the 'Principles of Geology' was delivered to the publisher at the close of the year 1827, when it was proposed that it should appear in the course of the year following, in two volumes octavo. Since that time many causes have concurred to delay the completion of the work, and, in some degree, to modify the original plan. In May, 1828, when the preliminary chapters on the History of Geology, and some others which follow them in the first volume, were nearly finished, I became anxious to visit several parts of the continent, in order to acquire more information concerning the tertiary formations. Accordingly, I set out in May, 1828, in company with Mr. Murchison, on a tour through France and the north of Italy, where we examined together many districts which are particularly mentioned in the body of this work. We visited Auvergne, Velay, Cantal, and the Vivarais, and afterwards the environs of Aix, in Provence, and then passed by the Maritime Alps to Savona, thence crossing to Piedmont by the Valley of the Bormida.

At Turin we found Signor Bonelli engaged in the arrangement of a large collection of tertiary shells obtained chiefly from the Italian strata; and as I had already conceived the idea of classing the different tertiary groups, by reference to the proportional number of recent species found fossil in each, I was at pains to learn what number Signor Bonelli had identified with living species, and the degree of precision with which such identifications could be made. With a view of illustrating this point, he showed us suites of shells common to the Subapennine beds and to the Mediterranean, pointing out that in some instances not only the ordinary type of the species, but even the different varieties had their counterparts both in the fossil and recent series. The same naturalist informed us that the fossil shells of the hill of the Superga, at Turin, differed as a group from those of Parma and other localities of the Subapennine beds of northern Italy; and, on the other hand, that the characteristic shells of the Superga agreed with the species found at Bordeaux and other parts of the South of France.

I was the more struck with this remark, as Mr. Murchison and myself had already inferred that the highly-inclined strata of the Valley of the Bormida, which agree with those of the Superga, were older than the more horizontal Subapennine marls, by which the plains of the Tanaro and the Po are skirted.

When we had explored some parts of the Vicentin together, Mr. Murchison re-crossed the Alps, while I directed my course to the south of Italy, first staying at Parma, where I studied, in the cabinets of Signor Guidotti, a beautiful collection of Italian tertiary shells, consisting of more than 1000 species, many of which had been identified with living testacea. Signor Guidotti had not examined his fossils with reference to their bearing on geological questions, but computed, on a loose estimate, that there were about 30 per cent. of living species in the Subapennine beds. I then visited Florence, Sienna, and Rome, and the results of my inquiries respecting the tertiary strata of those territories will be found partly in the body of the work, and partly in the catalogues given in Appendix II.

On my arrival at Naples I became acquainted with Signor O. G. Costa, who had examined the fossil shells of Otranto and Calabria, and had collected many recent testacea from the seas surrounding the Calabrian coasts. His comparison of the fossil and living species had led him to a very different result in regard to the southern extremity of Italy, from that to which Signors Guidotti and Bonelli had arrived in regard to the north, for he was of opinion that few of the tertiary shells were of extinct species. In confirmation of this view, he showed me a suite of fossil shells from the territory of Otranto, in which nearly all the species were recent.

In October, 1828, I examined Ischia, and obtained from the strata of that island the fossil shells named in Appendix II., p. 57. They were all, with two or three exceptions, recognized by Signor Costa as species now inhabiting the Mediterranean, a circumstance which greatly astonished me, as I procured some of them at the height of 2000 feet above the level of the sea (Vol. iii. p. 126).

Early in November, 1828, I crossed from Naples to Messina, and immediately afterwards examined Etna, and collected on the flanks of that mountain, near Trezza, the fossil shells alluded to in the third volume (p. 79, and Appendix II., p. 53). The occurrence of shells in this locality was not unknown to the naturalists of Catania, but having been recognized by them as recent species, they were supposed to have been carried up from the sea-shore to fertilize the soil, and therefore disregarded. Their position is well known to many of the peasants of the country, by whom the fossils are called 'roba di diluvio.'

In the course of my tour I had been frequently led to reflect on the precept of Descartes, C that a philosopher should once in his life doubt every thing he had been taught;' but I still retained so much faith in my early geological creed as to feel the most lively surprise, on visiting Sortino, Pentalica, Syracuse, and other parts of the Val di Noto, at beholding a limestone of enormous thickness filled with recent shells, or sometimes with the mere casts of shells, resting on marl in which shells of Mediterranean species were imbedded in a high state of preservation. All idea of attaching a high antiquity to a regularly stratified limestone, in which the casts and impressions of shells alone were discernible, vanished at once from my mind. At the same time, I was struck with the identity of the associated igneous rocks of the Val di Noto with well known varieties of 'trap' in Scotland and other parts of Europe, varieties, which I had also seen entering largely into the structure of Etna. I occasionally amused myself with speculating on the different rate of progress which Geology might have made, had it been first cultivated with success at Catania, where the phenomena above alluded to, and the great elevation of the modern tertiary beds in the Val di Noto, and the changes produced in the historical era by the Calabrian earthquakes, would have been familiarly known.

From Cape Passaro I passed on by Spaccaforno and Licata to Girgenti, where I abandoned my design of exploring the western part of Sicily, that I might return again to the Val di Noto and the neighbourhood of Etna, and verify the discoveries which I had made. With this view I travelled by Caltanisetta, Piazza, Caltagirone, Vizzini, Militello, Palagonia, Lago Naftia, and Radusa, to Castrogiovanni, and from thence to Palermo, at which last place I procured the shells named in Appendix II. p. 55. The sections on this new route confirmed me in my first opinions respecting the Val di Noto, as will appear by the 6th, 8th, and 9th chapters of the third Volume.

When I again reached Naples, in January, 1829, I found that Signor O. G. Costa had examined the ter tiary fossils which I had sent to him from different parts of Sicily, and declared them to be for the most part of recent species. I then bent my course homeward, seeing at Genoa, Professor Viviani and Dr. Sasso, the last of whom put into my hands his memoirs on the strata of Albenga (see vol. iii. p. 166) in which I found, that, according to his list of shells, the tertiary formations at the foot of the maritime Alps contained about 50 per cent. of recent species.

I next re-visited Turin, and communicated to Signor Bonelli the result of my inquiries respecting the tertiary beds of the south of Italy, and of Sicily, upon which he kindly offered to review his fossils, some of which had been obtained from those countries, and to compare them with the Subapennine shells of northern Italy. He also promised to draw up immediately a list of the shells characteristic of the green-sand of the Superga, and common to that locality and Bordeaux, that I might publish it at the end of my second volume; but the death of this amiable and zealous naturalist soon afterwards deprived me of the benefit of his assistance.

I had now fully decided on attempting to establish four sub-divisions of the great tertiary epoch, the same which are fully illustrated in the present work. I considered the basin of Paris and London to be the type of the first division; the beds of the Superga, of the second; the Subapennine strata of northern Italy, of the third; and Ischia and the Val di Noto, of the fourth. I was also convinced that I had seen proofs, during my tour in Auvergne, Tuscany and Sicily, of volcanic rocks contemporaneous with the sedimentary strata of three of the above periods.

On my return to Paris, in February, 1829, I communicated to M. Desnoyers some of the new views to which my examination of Sicily had led me, and my intention to attempt a classification of the different tertiary formations in chronological order, by reference to the comparative proportion of living species of shells found fossil in each. He informed me, that during my tour he had been employed in printing the first part of his memoir, not yet published, 'on the Tertiary Formations more recent than the Paris basin,' in which he had insisted on the doctrine 'of the succession of tertiary formations of different ages.' At the end of the first part of his memoir, which was published before I left Paris, [1] he annexed a note on the accordance of many of my views with his own, and my intention of arranging' the tertiary formations chronologically, according to the relative number of fossils in each group, which were identifiable with species now living.

At the same time I learned from M. Desnoyers, that M. Deshayes had, by the mere inspection of the fossil shells in his extensive museum, convinced himself that the different tertiary formations might be arranged in a chronological series. I accordingly lost no time in seeing M. Deshayes, who explained to me the data on which he considered that the three ter tiary periods mentioned in the Tables, Appendix I., might be established. I at once perceived that the fossils obtained by me in my tour would form but an inconsiderable contribution to so great a body of zoological evidence as M. Deshayes had already in his possession. I therefore requested him to examine my shells when they arrived from Italy, and expressed my great desire to obtain his co-operation in my work, in which, as will appear in the sequel, I was fortunate enough to succeed.

The preparation of my first volume had now been suspended for nine months, and was not resumed until my return to London in the beginning of March, 1829. Before the whole was printed another summer arrived, and I again took the field to examine 'the Crag,' on the coasts of Essex, Norfolk, and Suffolk. The first volume appeared at length in January, 1830, after which I applied myself to perfect what I had written on 'the changes in the organic world,' a subject which merely occupied four or five chapters in my original sketch, but which was now expanded into a small treatise. Before this part was completed another summer overtook me, and I then set out on a geological expedition to the south of France, the Pyrenees, and Catalonia.

On my return to Paris, in September, 1830, I studied for six weeks in the museum of M. Deshayes, examining his collection of fossil and recent shells, and profiting by his instructions in conchology. As he had not yet published any of the general results deducible from his valuable collection, I requested him to furnish me with lists of those species of shells which were common to two or more tertiary periods, as also the names of those known to occur both in some tertiary strata and in a living state. This he engaged to do, and we agreed that the information should be communicated in a tabular form. After several modifications of the plan first proposed for the Tables, we finally agreed upon the manner in which they should be constructed, and the execution was left entirely in the hands of M. Deshayes, in whose name they were to appear in my second volume.

The tables were sent to me in the course of the following spring (1831), and additions and corrections several months later. They contained not only the information which I had expected, but much more, for the names of several hundred species were added, as being common to two or more formations of the same period, whereas it was originally proposed to insert those only which were known to be common to two or more distinct periods. Thus, for example, more than 50 shells are now included in the tables, on the ground that they are common to the tertiary strata both of the London and Paris basins, although they only occur in the Eocene period to which the strata of those basins belong. The names thus added will increase the value of the tables, and give a more complete view of the point to which fossil conchology has now reached; at the same time, it must be admitted that tables of shells cannot be perfected on this plan, as the science advances from year to year, without soon outgrowing the space which could reasonably be allotted to fossil conchology in a work on geology, for they would soon embrace the names of the greater number of known shells, nearly all of these being common to different groups of strata of the same period. Some of the catalogues which I have given in Appendix II., of fossil shells from the neighbourhood of the Red Sea, and from some other localities, may illustrate this remark, as they lead us to anticipate that, at no distant time, we may find a large proportion of all the Recent species in a fossil state.

In treatises on fossil conchology, such as I trust M. Deshayes will soon publish, we cannot have too complete a catalogue of all the species which have been found fossil in every locality, together with their synonyms; but in geological works we can only illustrate the more important theoretical points by catalogues of those shells which are either characteristic of particular periods, as being exclusively confined to them, or which show the connexion of two periods, by being common to each. For this purpose we must select certain normal groups which do not approximate too closely to each other, and enumerate by name the species common to more than one of these. Thus, for example, we might omit in our tables the Newer Pliocene formations altogether, and enumerate the shells common to the Recent and Older Pliocene beds.

I have arranged the tertiary formations in four groups, as I had determined to do before I was acquainted with M. Deshayes; and in his tables he has referred the shells to three periods, according to which he had classed them before he had any communication with me. No confusion, however, will arise from this want of conformity between the tables and my classification, since I have named two of my periods (the Newer and Older Pliocene) as subdivisions of one of his; and by reference to the Synoptical Table, at p. 61, the reader will see which localities mentioned in M. Deshayes's Tables belong to the Newer and which to the Older Pliocene period.

In the summer of 1831 I made a geological excursion to the volcanic district of the Eifel, and on my return I determined to extend my work to three volumes, the second of which appeared in January, 1832. The last volume has been delayed till now by many interruptions, among which I may mention a tour, in the summer of 1832, up the valley of the Rhine, when I examined the loess (vol. iii. p. 151), and a visit, on my way home through Switzerland, to the Valorsine, where I had an opportunity of verifying the observations of M. Necker on the granite veins and altered stratified rocks of that district. I may also mention the time occupied in the correction of the second edition of the first and second volumes, and the delivery of a course of Lectures in May and June, 1832, at King's College, London, on which occasion I had an opportunity of communicating to the scientific world a great part of the views now explained in my last volume.

London, April, 1833.

TABLE OF CONTENTS:

• Front Matter
• Chapter 1: Connexion between the subjects treated of in the former parts of this work and those to be discussed in the present volume – Erroneous assumption of the earlier geologists respecting the discordance of the former and actual causes of change – Opposite system of inquiry adopted in this work – Illustrations from the history of the progress of Geology of the respective merits of the two systems – Habit of indulging conjectures respecting irregular and extraordinary agents not yet abandoned – Necessity in the present state of science of prefixing to a work on Geology treatises respecting the changes now in progress in the animate and inanimate world
• Chapter 2: Arrangement of the materials composing the earth's crust – The existing continents chiefly composed of subaqueous deposits – Distinction between sedimentary and volcanic rocks – Between primary, secondary, and tertiary – Origin of the primary – Transition formations – Difference between secondary and tertiary strata – Discovery of tertiary groups of successive periods – Paris basin – London and Hampshire basins – Tertiary strata of Bordeaux, Piedmont, Touraine, &c. – Subapennine beds – English crag – More recent deposits of Sicily, &c.
• Chapter 3: Different circumstances under which the secondary and tertiary formations may have originated – Secondary series formed when the ocean prevailed: Tertiary during the conversion of sea into land, and the growth of a continent – Origin of interruption in the sequence of formations – The areas where new deposits take place are always varying – Causes which occasion this transference of the places of sedimentary deposition – Denudation augments the discordance in age of rocks in contact – Unconformability of overlying formations – In what manner the shifting of the areas of sedimentary deposition may combine with the gradual extinction and introduction of species to produce a series of deposits having distinct mineral and organic characters
• Chapter 4: Chronological relations of mineral masses the first object in geological classification – Superposition, proof of more recent origin – Exceptions in regard to volcanic rocks – Relative age proved by included fragments of older rocks – Proofs of contemporaneous origin derived from mineral characters – Variations to which these characters are liable – Recurrence of distinct rocks at successive periods – Proofs of contemporaneous origin derived from organic remains – Zoological provinces are of limited extent, yet spread over wider areas than homogeneous mineral deposits – Different modes whereby dissimilar mineral masses and distinct groups of species may be proved to have been contemporaneous
• Chapter 5: Classification of tertiary formations in chronological order – Comparative value of different classes of organic remains – Fossil remains of testacea the most important – Necessity of accurately determining species – Tables of shells by M. Deshayes – Four subdivisions of the Tertiary epoch – Recent formations – Newer Pliocene period – Older Pliocene period – Miocene period – Eocene period – The distinct zoological characters of these periods may not imply sudden changes in the animate creation – The recent strata form a common point of departure in distant regions – Numerical proportion of recent species of shells in different tertiary periods – Mammiferous remains of the successive tertiary eras – Synoptical Table of Recent and Tertiary formations
• Chapter 6: Newer Pliocene formations – Reasons for considering in the first place the more modern periods – Geological structure of Sicily – Formations of the Val di Noto of newer Pliocene period – Divisible into three groups – Great limestone – Schistose and arenaceous limestone – Blue marl with shells – Strata subjacent to the above – Volcanic rocks of the Val di Noto – Dikes – Tuffs and Peperinos – Volcanic conglomerates – Proofs of long intervals between volcanic eruptions – Dip and direction of newer Pliocene strata of Sicily
• Chapter 7: Marine and volcanic formations at the base of Etna – Their connexion with the strata of the Val di Noto – Bay of Trezza – Cyclopian isles – Fossil shells of recent species – Basalt and altered rocks in the Isle of Cyclops – Submarine lavas of the bay of Trezza not currents from Etna – Internal structure of the cone of Etna – Val di Calanna – Val del Bove not an ancient crater – Its precipices intersected by countless dikes – Scenery of the Val del Bove – Form, composition, and origin of the dikes – Lavas and breccias intersected by them
• Chapter 8: Speculations on the origin of the Val del Bove on Etna – Subsidences – Antiquity of the cone of Etna – Mode of computing the age of volcanos – Their growth analogous to that of exogenous trees – Period required for the production of the lateral cones of Etna – Whether signs of Diluvial Waves are observable on Etna
• Chapter 9: Origin of the newer Pliocene strata of Sicily – Growth of submarine formations gradual – Rise of the same above the level of the sea probably caused by subterranean lava – Igneous newer Pliocene rocks formed at great depths, exceed in volume the lavas of Etna – Probable structure of these recent subterranean rocks – Changes which they may have superinduced upon strata in contact – Alterations of the surface during and since the emergence of the newer Pliocene strata – Forms of the Sicilian valleys – Sea cliffs – Proofs of successive elevation – Why the valleys in the newer Pliocene districts correspond in form to those in regions of higher antiquity – Migrations of animals and plants since the emergence of the newer Pliocene strata – Some species older than the stations they inhabit – Recapitulation
• Chapter 10: Tertiary formations of Campania – Comparison of the recorded changes in this region with those commemorated by geological monuments – Differences in the composition of Somma and Vesuvius – Dikes of Somma, their origin – Cause of the parallelism of their opposite sides – Why coarser grained in the centre – Minor cones of the Phlegraean Fields – Age of the volcanic and associated rocks of Campania – Organic remains – External configuration of the country, how produced – No signs of diluvial waves – Marine Newer Pliocene strata visible only in countries of earthquakes – Illustrations from Chili – Peru – Parallel roads of Coquirnbo – West-Indian archipelago – Honduras – East-Indian archipelago – Red Sea
• Chapter 11: Newer Pliocene fresh – water formations – Valley of the Elsa – Travertins of Rome – Osseous breccias – Sicily – Caves near Palermo – Extinct animals in newer Pliocene breccias – Fossil bones of Marsupial animals in Australian caves – Formation of osseous breccias in the Mores – Newer Pliocene alluviums – Difference between alluviums and regular subaqueous strata – The former of various ages – Marine alluvium – Grooved surface of rocks – Erratic blocks of the Alps – Theory of deluges caused by paroxysmal elevations untenable – How ice may have contributed to transport large blocks from the Alps – European alluviums chiefly tertiary – Newer Pliocene in Sicily – Loss of the Valley of the Rhine – Its origin – Contains recent shells
• Chapter 12: Geological monuments of the older Pliocene period – Subapennine formations – Opinions of Brocchi – Different groups termed by him Subapennine are not all of the same age – Mineral composition of the Subapennine formations – Marls – Yellow sand and gravel – Subapennine beds how formed – Illustration derived from the Upper Val d'Arno – Organic remains of Subapennine hills – Older Pliocene strata at the base of the Maritime Alps – Genoa – Savona – Albenga – Nice – Conglomerate of Valley of Magnan – Its origin – Tertiary strata at the eastern extremity of the Pyrenees
• Chapter 13: Crag of Norfolk and Suffolk – Shown by its fossil contents to belong to the older Pliocene period – Heterogeneous in its composition – Superincumbent lacustrine deposits – Relative position of the crag – Forms of stratification – Strata composed of groups of oblique layers – Cause of this arrangement – Dislocations in the crag produced by subterranean movements – Protruded masses of chalk – Passage of marine crag into alluvium – Recent shells in a deposit at Sheppey, Ramsgate, and Brighton
• Chapter 14: Volcanic rocks of the older Pliocene period – Italy – Volcanic region of Olot in Catalonia – Its extent and geological structure – Map – Number of cones – Scoriae – Lava currents – Ravines in the latter cut by water – Ancient alluvium underlying lava – Jets of air called 'Bufadors' – Age of the Catalonian volcanos uncertain – Earthquake which destroyed Olot in 1421 – Sardinian volcanos – District of the Eifel and Lower Rhine – Map – Geological structure of the country – Peculiar characteristics of the Eifel volcanos – Lake craters – Trass – Crater of the Roderberg – Age of the Eifel volcanic rocks uncertain – Brown coal formation
• Chapter 15: Miocene period – Marine formations – Faluns of Touraine – Comparison of the Faluns of the Loire and the English Crag – Basin of the Gironde and Landes – Fresh-water limestone of Saucats – Position of the limestone of Blaye – Eocene strata in the Bordeaux basin – Inland cliff near Dax – Strata of Piedmont – Superga – Valley of the Bormida – Molasse of Switzerland – Basin of Vienna – Styria – Hungary – Volhynia and Podolia – Montpellier
• Chapter 16: Miocene alluviums – Auvergne – Mont Perrier – Extinct quadrupeds – Velay – Orleanais – Alluviums contemporaneous with Faluns of Touraine – – Miocene fresh – water formations – Upper Val d'Arno – Extinct mammalia – Coal of Cadibona – Miocene volcanic rocks – Hungary – Transylvania – Styria – Auvergne – Velay
• Chapter 17: Eocene period – Fresh-water formations – Central France – Map – Limagne d'Auvergne – Sandstone and conglomerate – Tertiary Red marl and sandstone like the secondary 'new red sandstone' – Green and white foliated marls – Indusial limestone – Gypseous marls – General arrangement and origin of the Travertin – Fresh-water formation of the Limagne – Puy en Velay – Analogy of the strata to those of Auvergne – Cantal – Resemblance of Aurillac limestone and its flints to our upper chalk – Proofs of the gradual deposition of marl – Concluding remarks
• Chapter 18: Marine formations of the Eocene period – Strata of the Paris basin how far analogous to the lacustrine deposits of Central France – Geographical connexion of the Limagne d'Auvergne and the Paris basin – Chain of lakes in the Eocene period – Classification of groups in the Paris basin – Observations of M. C. Prevost – Sketch of the different subdivisions of the Paris basin – Contemporaneous marine and fresh-water strata – Abundance of Cerithia in the Calcaire grossier – Upper marine formation indicates a subsidence – Part of the Calcaire grossier destroyed when the upper marine strata originated – All the Parisian groups belong to one great epoch – Microscopic shells – Bones of quadrupeds in gypsum – In what manner entombed – Number of species – All extinct – Strata with and without organic remains alternating – Our knowledge of the physical geography, fauna, and flora of the Eocene period considerable – Concluding remarks
• Chapter 19: Volcanic rocks of the Eocene period – Auvergne – Igneous formations associated with lacustrine strata – Hill of Gergovia – Eruptions in Central France at successive periods – Mont Dor an extinct volcano – Velay – Plomb du Cantal – Train of minor volcanos stretching from Auvergne to the Vivarais – Monts Domes – Puy de Côme – Puy Rouge – Ravines excavated through lava – Currents of lava at different heights – Subjacent alluviums of distinct ages – The more modern lavas of Central France may belong to the Miocene period – The integrity of the cones not inconsistent with this opinion – No eruptions during the historical era – Division of volcanos into ante-diluvian and post-diluvian inadmissible – Theories respecting the effects of the Flood considered – Hypothesis of a partial flood – Of a universal deluge – Theory of Dr. Buckland as controverted by Dr. Fleming – Recapitulation
• Chapter 20: Eocene formations, continued – Basin of the Cotentin, or Valognes – Rennes – Basin of Belgium, or the Netherlands – Aix in Provence – Fossil insects – Tertiary strata of England – Basins of London and Hampshire – Different groups – Plastic clay and sand – London clay – Bagshot sand – Fresh-water strata of the Isle of Wight – Palaeotherium and other fossil mammalia of Binstead – English Eocene strata conformable to chalk – Outliers on the elevated parts of the chalk – Inferences drawn from their occurrence – Sketch of a theory of the origin of the English tertiary strata
• Chapter 21: Denudation of secondary strata during the deposition of the English Eocene formations – Valley of the Weald between the North and South Downs – Map – Secondary rocks of the Weald divisible into five groups – North and South Downs – Section across the valley of the Weald – Anticlinal axis – True scale of heights – Rise and denudation of the strata gradual – Chalk escarpments once sea-cliffs – Lower terrace of 'firestone,' how caused – Parallel ridges and valleys formed by harder and softer beds – No ruins of the chalk on the central district of the Weald – Explanation of this phenomenon – Double system of valleys, the longitudinal and the transverse – Transverse how formed – Gorges intersecting the chalk – Lewes Coomb – Transverse valley of the Adur
• Chapter 22: Denudation of the Valley of the Weald, continued – The alternative of the proposition that the chalk of the North and South Downs were once continuous, considered – Dr. Buckland on the Valley of Kingsclere – Rise and denudation of secondary rocks gradual – Concomitant deposition of tertiary strata gradual – Composition of the latter such as would result from the wreck of the secondary rocks – Valleys and furrows on the chalk how caused – Auvergne, the Paris basin, and south-east of England one region of earthquakes during the Eocene period – Why the central parts of the London and Hampshire basins rise nearly as high as the denudation of the Weald -- Effects of protruding force counteracted by the levelling operations of water – Thickness of masses removed from the central ridge of the Weald – Great escarpment of the chalk having a direction north-east and south-west – Curved and vertical strata in the Isle of Wight – These were convulsed after the deposition of the fresh-water beds of Headen Hill – Elevations of land posterior to the crag – Why no Eocene alluviums recognizable – Concluding remarks on the intermittent operations of earthquakes in the south-east of England, and the gradual formation of valleys – Recapitulation
• Chapter 23: Secondary formations – Brief enumeration of the principal groups – No species common to the secondary and tertiary rocks – Chasm between the Eocene and Maestricht beds – Duration of secondary periods – Former continents placed where it is now sea – Secondary fresh-water deposits why rare – Persistency of mineral composition why apparently greatest in older rocks – Supposed universality of red marl formations – Secondary rocks why more consolidated – Why more fractured and disturbed – Secondary volcanic rocks of many different ages
• Chapter 24: On the relative antiquity of different mountain-chains – Theory of M. Elie de Beaumont – His opinions controverted – His method of proving that different chains were raised at distinct periods – His proof that others were contemporaneous – His reasoning why not conclusive – His doctrine of the parallelism of contemporaneous lines of elevation – Objections – Theory of parallelism at variance with geological phenomena as exhibited in Great Britain – Objections of Mr. Conybeare – How far anticlinal lines formed at the same period are parallel – Difficulties in the way of determining the relative age of mountains
• Chapter 25: On the rocks usually termed 'Primary' – Their relation to volcanic and sedimentary formations – The 'primary' class divisible into stratified and unstratified – Unstratified rocks called Plutonic – Granite veins – Their various forms and mineral composition – Proofs of their igneous origin – Granites of the same character produced at successive eras – Some of these newer than certain fossiliferous strata – Difficulty of determining the age of particular granites – Distinction between the volcanic and the plutonic rocks – Trappean rocks not separable from the volcanic – Passage from trap into granite – Theory of the origin of granite at every period from the earliest to the most recent
• Chapter 26: On the stratified rocks usually called 'primary' – Proofs from the disposition of their strata that they were originally deposited from water – Alternation of beds varying in composition and colour – Passage of gneiss into granite – Alteration of sedimentary strata by trappean and granitic dikes – Inference as to the origin of the strata called 'primary' – Conversion of argillaceous into hornblende schist – The term 'Hypogene' proposed as a substitute for primary – 'Metamorphic' for 'stratified primary' rocks – No regular order of succession of hypogene formations – Passage from the metamorphic to the sedimentary strata – Cause of the high relative antiquity of the visible hypogene formations – That antiquity consistent with the hypothesis that they have been produced at each successive period in equal quantities – Great volume of hypogene rocks supposed to have been formed since the Eocene period – Concluding remarks
• Relative Ages of Different Formations
• Deshay's Table of Shells
• General Results
• Fossil Shells Collected by the Author
• Glossary
• Index

Table I. Showing the relations of the various classes of rocks, the Alluvial, the Aqueous, the Volcanic, and the Hypogene, of different periods

Table II. Showing the order of superposition of the principal European groups of sedimentary strata mentioned in this work

Notes in explanation of the Tables of fossil shells in Appendix I.

Appendix I. Tables of fossil shells by Monsieur G. P. Deshayes

Appendix II. Lists of fossil Shells chiefly collected by the author in Sicily and Italy, named by M. Deshayes

Glossary, containing an explanation of geological and other scientific terms used in this work

Index

LIST OF PLATES AND WOOD-CUTS IN THE THIRD VOLUME.

PLATES.

Frontispiece. View of the volcanos around Olot, in Catalonia. See p. 186. This view is taken from a sketch by the author; an attempt is made to represent by colours the different geological formations of which the country is composed. The blue line of mountains in the distance are the Pyrenees, which are to the north of the spectator, and consist of primary and ancient secondary rocks. In front of these arc the secondary formations~ described in chap. xiv., coloured purplish-grey of different tints, to express different distances. The flank of the hill, in the foreground, called Costa di Pujou, is composed partly of secondary rocks, which are seen to the left of a small bridle- road, and partly of volcanic, the red colour expressing lava and scoriae.

Several very perfect volcanic cones, chiefly composed of red scoriae, and having craters on their summits, are seen in the immediate neighbourhood of Olot, coloured red. The level plain on which that town stands has clearly been produced by the flowing down of many lava-streams from those hills into the bottom of a valley, probably once of considerable depth, like those of the surrounding country, but which has been in a great measure filled up by lava.

The reader should be informed, that in many impressions of this plate Montsacopa is mis-spelt 'Montescopa,' and Mount Garrinada is mis-spelt 'Gradenada.'

Plate 1. The shells represented in this plate have been selected by M. Deshayes as characteristic of the Pliocene period of the Tables, Appendix I. The greater part of them are common both to the older and newer Pliocene periods of this work. Eight of the species, Nos. 1, 3, 5, 6, 7, 9, 13, and 14, are now living, but are given as being also found in the Older Pliocene formations. Fusus crispus is not found either recent or in the Miocene or Eocene formations, but occurs both in the Newer and Older Pliocene strata. Mitra plicatula has been found only in the older Pliocene deposits. The Turbo rugosus was considered as exclusively Pliocene when selected by M. Deshayes, but M. Boue has since found it in the Miocene strata at Vienna and Moravia (see Tables, Appendix I. p. 26). Buccinum semistriatum is also a Miocene shell, but was inserted as being peculiarly abundant in the Pliocene strata.

Plate II. All the shells figured in this plate, except Cardita Ajar, are very characteristic of the Miocene formations; that is to say, they are found in that period and no other. Cardita Ajar is also very common in the Miocene strata, but is also a Recent species. It has not yet been observed in any Pliocene deposit.

Plate III. The species of shells figured in this plate are characteristic of the Eocene period, as being exclusively confined to deposits of that period, and for the most part abundant in them.

Plate IV. The microscopic shells of the order Cephalopoda, figured in this plate, are characteristic of the Eocene period, and are distinct from the microscopic shells of the Older Pliocene formations of Italy. The figures are from unpublished drawings by M. Deshayes, who has selected some of the most remarkable types of form. The reader will observe, that the minute points, figures 4, 8, 11, 14, and 18, indicate the natural size of the species which are represented. (For observations on these shells see p. 251.)

Plate V. Geological Map of the south-east of England, exhibiting the Denudation of the Weald. This map has been compiled in great part from Mr. Greenough's Geological Map of England, and Mr. Mantell's Map of the south-east of England. (Illustrations of Geol. of Sussex, and fossils of Tilgate Forest, 1827.) The eastern extremity of the 'denudation' is reduced from Mr. Murchison's Map of that district. (Geol. Trans., 2nd series, vol. ii. part i. plate 14.) The object of this map is fully explained in chapters xxi. and xxii. of this volume.

LIST OF WOOD-CUTS.

1. Diagram showing the order of succession of stratified masses

2. Diagram showing the relative position of the Primary, Secondary, and Tertiary strata

3. Diagram showing the relative age of the strata of the Paris basin, and those of the basin of the Loire, in Touraine

4. Diagram showing the same in the strata of Suffolk and Piedmont

5. Diagram containing sections in the Val di Noto, Sicily

6 & 7. Horizontal sections of dikes near Palagonia

8. Section of horizontal limestone in contact with inclined strata of Tuff in the hill of Novera, near Vizzini

9. Section of calcareous grit and peperino, east of Palagonia, south side of the pass

10. Section of the same beds on the north side of the pass

11. Outline view of the cone of Etna from the summit of the limestone platform of Primosole

12. Section from Paterno by Lago di Naftia to Palagonia

13. Section of beds of clay and sand capped by columnar basalt and conglomerate at La Motta, near Catania

14. View of the Isle of Cyclops, in the Bay of Trezza

15. Diagram showing the contortions in the newer Pliocene strata of the Isle of Cyclops

16. Horizontal section showing the invasion of the newer Pliocene strata of the Isle of Cyclops by lava

17. Wood-cut showing the great valley on the east side or Etna

18. Diagram explanatory of the origin of the Valleys of Calanna and St. Giacomo, on Etna

19. View of dikes at the base of the Serre del Solfizio, Etna

20. View of tortuous dikes or veins of lava, Punto di Guimento, Etna

21. View of the rocks Finochio, Capra, and Musara, in the Val del Bove

22. View from the summit of Etna into the Val del Bove

23. View of the Valley called Gozzo degli Martiri, below Melilli

24. Diagram showing the manner of obliteration of successive lines of sea-cliff

25. View of dikes or veins of lava at the Punto del Nasone, on Somma

26. Diagram showing the superposition of alluvium and cave deposits containing extinct quadrupeds to a limestone containing recent shells

27. Diagram showing the position of the Cave of San Ciro, near Palermo

28. Diagram showing the position of Tertiary strata at Genoa

29. Section from Monte Calvo to the sea by the Valley of Magnan, near Nice

30. Diagram showing the manner in which the Crag may be supposed to rest on the chalk

31. Section of shelly crag near Walton, Suffolk

32. Section at the light-house near Happisborough

33. Section of Little Cat Cliff, showing the inclination of the layers of quartzose sand in opposite directions

34. Lamination of shelly sand and loam, near the Signal-House, Walton

35. Diagram illustrative of the successive deposition of strata

36. Section of ripple marks caused by the wind on loose sand

37. Bent strata of loam in the cliffs between Cromer and Runton

38. Folding of the strata between East and West Runton

39. Section in the cliffs east of Sherringham

40. Section east of Sherringham, Norfolk

41. Side view of a promontory of chalk and crag, at Trimmingham, Norfolk

42. Northern protuberance of chalk, Trimmingham

43. Map of the volcanic district of Catalonia

44. Section of volcanic sand and ashes in a valley near Olot

45. Section above the bridge of Cellent

46. Section at Castell Follit

47. Superposition of rocks in the volcanic district of Catalonia

48. Map of the volcanic district of the Lower Rhine

49. View of the Gemunden Maar

50. Section of the same and other contiguous lake-craters

51. Section of tertiary strata overlying chalk near Dax

52. Section explaining the position of the Eocene strata in the Bordeaux basin

53. Section of Inland cliff near Dax

54. Position of the Miocene alluviums of Mont Perrier (or Boulade)

55. Section of the fresh-water formation of Cadibona

56. Map of Auvergne, Cantal, Velay, &c.

57. Section of Vertical marls near Clermont

58 & 59. Superposition of the formations of the Paris basin

60. Section of the Hill of Gergovia near Clermont

61. Lavas of Auvergue resting on alluviums of different ages

62. Map of the principal tertiary basins of the Eocene period

63. Section from the London to the Hampshire basin across the Valley of the Weald

64. Section of the country from the confines of the basin of London to that of Hants, with the principal heights above the level of the sea on a true scale

65. View of the chalk escarpment of the South Downs, taken from the Devil's Dike, looking towards the west and south-west

66. Chalk escarpment as seen from the hill above Steyning, Sussex. The castle and village of Bramber in the foreground

67. Section of lower terrace of firestone

68. Diagram explanatory of anticlinal and synclinal lines

69 & 70. Sections illustrating the gradual denudation of the Weald Valley

71. Section from the north escarpment of the South Downs to Barcombe

72. Section of cliffs west of Sherringham

73. View of the transverse valley of the Adur in the South Downs

74. Supposed section of a transverse valley

75. View of Lewes Coomb

76. Section of a fault in the cliff-hills near Lewes

77. Hypothetical section to illustrate the question of the denudation of the Weald Valley 304

78. Ground plan of the Valley of Kingsclere

79. Section across the Valley of Kingsclere from north to south

80. Section of the Valley of Kingsclere with the heights on a true scale

81. Hypothetical section illustrating the denudation of the Weald Valley and the contemporaneous origin of the Eocene strata

82 & 83. Diagrams illustrative of the relative antiquity of mountain-chains

84. Diagram showing the relative position of the Hypogene sedimentary and volcanic rocks

85. Granite veins traversing stratified rocks

86. Granite veins traversing gneiss at Cape Wrath in Scotland

87. Granite veins passing through hornblende slate, Carnsilver Cove, Cornwall

88. View of the junction of granite and limestone in Glen Tilt

89. Lamination of clay-slate, Montagne de Seguinat, near Gavarnie, in the Pyrenees

90. Junction of granite with jurassic or oolite strata in the Alps

91. Diagram showing the different order of position in the Plutonic and Sedimentary formations of different ages

92. Diagram to explain the meaning of the term 'fault,' Glossary

93. Diagram to explain the term' salient angle,' Glossary

ERRATA.

Page 89, line 11 from the top, for vivid, read livid.
-- 103, line 10 from the top, for newer, read older.
-- 104, line 9 from the top, for Colosseum, read Coliseum.
-- 110, No. of wood-cut, for No. 22, read No. 23.
-- 111, Ditto, for No. 23, read No. 24.
-- 192, line 10 from the bottom, for with, read without.
-- 193, line 2 from the bottom, for Von Oyenhausen, read Von Oeynhausen.
-- 193, line 3 from the bottom, for M. Noeggerath, read M. Noeggerath.
-- 197, line 19 from the top, for Moseberg, read Mosenberg.


Plate 1. The shells represented in this plate have been selected by M. Deshayes as characteristic of the Pliocene period of the Tables, Appendix I. The greater part of them are common both to the older and newer Pliocene periods of this work. Eight of the species, Nos. 1, 3, 5, 6, 7, 9, 13, and 14, are now living, but are given as being also found in the Older Pliocene formations. Fusus crispus is not found either recent or in the Miocene or Eocene formations, but occurs both in the Newer and Older Pliocene strata. Mitra plicatula has been found only in the older Pliocene deposits. The Turbo rugosus was considered as exclusively Pliocene when selected by M. Deshayes, but M. Boue has since found it in the Miocene strata at Vienna and Moravia (see Tables, Appendix I. p. 26). Buccinum semistriatum is also a Miocene shell, but was inserted as being peculiarly abundant in the Pliocene strata.


Plate II. All the shells figured in this plate, except Cardita Ajar, are very characteristic of the Miocene formations; that is to say, they are found in that period and no other. Cardita Ajar is also very common in the Miocene strata, but is also a Recent species. It has not yet been observed in any Pliocene deposit.


Plate III. The species of shells figured in this plate are characteristic of the Eocene period, as being exclusively confined to deposits of that period, and for the most part abundant in them.


Plate IV. The microscopic shells of the order Cephalopoda, figured in this plate, are characteristic of the Eocene period, and are distinct from the microscopic shells of the Older Pliocene formations of Italy. The figures are from unpublished drawings by M. Deshayes, who has selected some of the most remarkable types of form. The reader will observe, that the minute points, figures 4, 8, 11, 14, and 18, indicate the natural size of the species which are represented. (For observations on these shells see p. 251.)


[In the original publication, Plate V was hand painted in six colors. We have adapted the colors to shading in order to print the map in black and white.]
Plate V. Geological Map of the south-east of England, exhibiting the Denudation of the Weald. This map has been compiled in great part from Mr. Greenough's Geological Map of England, and Mr. Mantell's Map of the south-east of England. (Illustrations of Geol. of Sussex, and fossils of Tilgate Forest, 1827.) The eastern extremity of the 'denudation' is reduced from Mr. Murchison's Map of that district. (Geol. Trans., 2nd series, vol. ii. part i. plate 14.) The object of this map is fully explained in chapters xxi. and xxii. of this volume.

_______________

Notes:

1. Ann. des Sci. Nat., tome xvi. p. 214.

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CHAPTER 1

Connexion between the subjects treated of in the former parts of this work and those to be discussed in the present volume – Erroneous assumption of the earlier geologists respecting the discordance of the former and actual causes of change – Opposite system of inquiry adopted in this work – Illustrations from the history of the progress of Geology of the respective merits of the two systems – Habit of indulging conjectures respecting irregular and extraordinary agents not yet abandoned – Necessity in the present state of science of prefixing to a work on Geology treatises respecting the changes now in progress in the animate and inanimate world

HAVING considered, in the preceding volumes, the actual operation of the causes of change which affect the earth's surface and its inhabitants, we are now about to enter upon a new division of our inquiry, and shall therefore offer a few preliminary observations, to fix in the reader's mind the connexion between two distinct parts of our work, and to explain in what manner the plan pursued by us differs from that more usually followed by preceding writers on Geology.

All naturalists, who have carefully examined the arrangement of the mineral masses composing the earth's crust, and who have studied their internal structure and fossil contents, have recognized therein the signs of a great succession of former changes; and the causes of these changes have been the object of anxious inquiry. As the first theorists possessed but a scanty acquaintance with the present economy of the animate and inanimate world, and the vicissitudes to which these are subject, we find them in the situation of novices, who attempt to read a history written in a foreign language, doubting about the meaning of the most ordinary terms; disputing, for example, whether a shell was really a shell, -- whether sand and pebbles were the result of aqueous trituration, -- whether stratification was the effect of successive deposition from water; and a thousand other elementary questions which now appear to us so easy and simple, that we can hardly conceive them to have once afforded matter for warm and tedious controversy.

In the first volume we enumerated many prepossessions which biassed the minds of the earlier inquirers, and checked an impartial desire of arriving at truth. But of all the causes to which we alluded, no one contributed so powerfully to give rise to a false method of philosophizing as the entire unconsciousness of the first geologists of the extent of their own ignorance respecting the operations of the existing agents of change.

They imagined themselves sufficiently acquainted with the mutations now in progress in the animate and inanimate world, to entitle them at once to affirm, whether the solution of certain problems in geology could ever be derived from the observation of the actual economy of nature, and having decided that they could not, they felt themselves at liberty to indulge their imaginations, in guessing at what might be, rather than in inquiring what is,. in other words, they employed themselves in conjecturing what might have been the course of nature at a remote period, rather than in the investigation of what was the course of nature in their own times.

It appeared to them more philosophical to speculate on the possibilities of the past, than patiently to explore the realities of the present, and having invented theories under the influence of such maxims, they were consistently unwilling to test their validity by the criterion of their accordance with the ordinary operations of nature. On the contrary, the claims of each new hypothesis to credibility appeared enhanced by the great contrast of the causes or forces introduced to those now developed in our terrestrial system during a period, as it has been termed, of repose.

Never was there a dogma more calculated to foster indolence, and to blunt the keen edge of curiosity, than this assumption of the discordance between the former and the existing causes of change. It produced a state of mind unfavourable in the highest conceivable degree to the candid reception of the evidence of those minute, but incessant mutations, which every part of the earth's surface is undergoing, and by which the condition of its living inhabitants is continually made to vary. The student, instead of being encouraged with the hope of interpreting the enigmas presented to him in the earth's structure, -- instead of being prompted to undertake laborious inquiries into the natural history of the organic world, and the complicated effects of the igneous and aqueous causes now in operation, was taught to despond from the first. Geology, it was affirmed, could never rise to the rank of an exact science, -- the greater number of phenomena must for ever remain inexplicable, or only be partially elucidated by ingenious conjectures. Even the mystery which invested the subject was said to constitute one of its principal charms, affording, as it did, full scope to the fancy to indulge in a boundless field of speculation.

The course directly opposed to these theoretical views consists in an earnest and patient endeavour to reconcile the former indications of change with the evidence of gradual mutations now in progress; restricting us, in the first instance, to known causes, and then speculating on those which may be in activity in regions inaccessible to us. It seeks an interpretation of geological monuments by comparing the changes of which they give evidence with the vicissitudes now in progress, or 'which may be in progress.

We shall give a few examples in illustration of the practical results already derived from the two distinct methods of theorizing, for we have now the advantage of being enabled to judge by experience of their respective merits, and by the relative value of the fruits which they have produced.

In our historical sketch of the progress of geology, the reader has seen that a controversy was maintained for more than a century, respecting the origin of fossil shells and bones -- were they organic or inorganic substances? That the latter opinion should for a long time have prevailed, and that these bodies should have been supposed to be fashioned into their present form by a plastic virtue, or some other mysterious agency, may appear absurd; but it was, perhaps, as reasonable a conjecture as could be expected from those who did not appeal, in the first instance, to the analogy of the living creation, as affording the only source of authentic information. It was only by an accurate examination of living testacea, and by a comparison of the osteology of the existing vertebrated animals with the remains found entombed in ancient strata, that this favourite dogma was exploded, and all were, at length, persuaded that these substances were exclusively of organic origin.

In like manner, when a discussion had arisen as to the nature of basalt and other mineral masses, evidently constituting a particular class of rocks, the popular opinion inclined to a belief that they were of aqueous, not of igneous origin. These rocks, it was said, might have been precipitated from an aqueous solution, from a chaotic fluid, or an ocean which rose over the continents, charged with the requisite mineral ingredients. All are now agreed that it would have been impossible for human ingenuity to invent a theory more distant from the truth; yet we must cease to wonder, on that account, that it gained so many proselytes, when we remember that its claims to probability arose partly from its confirming the assumed want of all analogy between geological causes and those now in action.

By what train of investigation were all theorists brought round at length to an opposite opinion, and induced to assent to the igneous origin of these formations? By an examination of the structure of active volcanos, the mineral composition of their lavas and ejections, and by comparing the undoubted products of fire with the ancient rocks in question.

We shall conclude with one more example. When the organic origin of fossil shells had been conceded, their occurrence in strata forming some of the loftiest mountains in the world, was admitted as a proof of a great alteration of the relative level of sea and land, and doubts were then entertained whether this change might be accounted for by the partial drying up of the ocean, or by the elevation of the solid land. The former hypothesis, although afterwards abandoned by general consent, was at first embraced by a vast majority. A multitude of ingenious speculations were hazarded to show how the level of the ocean might have been depressed, and when these theories had all failed, the inquiry, as to what vicissitudes of this nature might now be taking place, was, as usual, resorted to in the last instance. The question was agitated, whether any changes in the level of sea and land had occurred during the historical period, and, by patient research, it was soon discovered that considerable tracts of land had been permanently elevated and depressed, while the level of the ocean remained unaltered. It was therefore necessary to reverse the doctrine which had acquired so much popularity, and the unexpected solution of a problem at first regarded as so enigmatical, gave perhaps the strongest stimulus ever yet afforded to investigate the ordinary operations of nature. For it must have appeared almost as improbable to the earlier geologists, that the laws of earthquakes should one day throw light on the origin of mountains, as it must to the first astronomers, that the fall of an apple should assist in explaining the motions of the moon.

Of late years the points of discussion in geology have been transferred to new questions, and those, for the most part, of a higher and more general nature; but, notwithstanding the repeated warnings of experience, the ancient method of philosophising has not been materially modified.

We are now, for the most part, agreed as to what rocks are of igneous, and what of aqueous origin,-in what manner fossil shells, whether of the sea or of lakes, have been imbedded in strata,-how sand may have been converted into sandstone, and are unanimous as to other propositions which are not of a complicated nature; but when we ascend to those of a higher order, we find as little disposition, as formerly, to make a strenuous effort, in the first instance, to search out an explanation in the ordinary economy of Nature. If, for example, we seek for the causes why mineral masses are associated together in certain groups; why they are arranged in a certain order which is never inverted; why there are many breaks in the continuity of the series; why different organic remains are found in distinct sets of strata; why there is often an abrupt passage from an assemblage of species contained in one formation to that in another immediately superimposed,-when these and other topics of an equally extensive kind are discussed, we find the habit of indulging conjectures, respecting irregular and extraordinary causes, to be still in full force.

We hear of sudden and violent revolutions of the globe, of the instantaneous elevation of mountain chains, of paroxysms of volcanic energy, declining according to some, and according to others increasing in violence, from the earliest to the latest ages. We are also told of general catastrophes and a succession of deluges, of the alternation of periods of repose and disorder, of the refrigeration of the globe, of the sudden annihilation of whole races of animals and plants, and other hypotheses, in which we see the ancient spirit of speculation revived, and a desire manifested to cut, rather than patiently to untie, the Gordian knot.

In our attempt to unravel these difficult questions, we shall adopt a different course, restricting ourselves to the known or possible operations of existing causes; feeling assured that we have not yet exhausted the resources which the study of the present course of nature may provide, and therefore that we are not authorized, in the infancy of our science, to recur to extraordinary agents. We shall adhere to this plan, not only on the grounds explained in the first volume, but because, as we have above stated, history informs us that this method has always put geologists on the road that leads to truth,-suggesting views which, although imperfect at first, have been found capable of improvement, until at last adopted by universal consent. On the other hand, the opposite method, that of speculating on a former distinct state of things, has led invariably to a multitude of contradictory systems, which have been overthrown one after the other, -- which have been found quite incapable of modification, -- and which are often required to be precisely reversed.

In regard to the subjects treated of in our first two volumes, if systematic treatises had been written on these topics, we should willingly have entered at once upon the description of geological monuments properly so called, referring to other authors for the elucidation of elementary and collateral questions, just as we shall appeal to the best authorities in conchology and comparative anatomy, in proof of many positions which, but for the labours of naturalists devoted to these departments, would have demanded long digressions. When we find it asserted, for example, that the bones of a fossil animal at OEningen were those of man, and the fact adduced as a proof of the deluge, we are now able at once to dismiss the argument as nugatory, and to affirm the skeleton to be that of a reptile, on the authority of an able anatomist; and when we find among ancient writers the opinion of the gigantic stature of the human race in times of old, grounded on the magnitude of certain fossil teeth and bones, we are able to affirm these remains to belong to the elephant and rhinoceros, on the same authority.

But since in our attempt to solve geological problems, we shall be called upon to refer to the operation of aqueous and igneous causes, the geographical distribution of animals and plants, the real existence of species, their successive extinction, and so forth, we were under the necessity of collecting together a variety of facts, and of entering into long trains of reasoning, which could only be accomplished in preliminary treatises.

These topics we regard as constituting the alphabet and grammar of geology; not that we expect from such studies to obtain a key to the interpretation of all geological phenomena, but because they form the groundwork from which we must rise to the contemplation of more general questions relating to the complicated results to which, in an indefinite lapse of ages, the existing causes of change may give rise.

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CHAPTER 2

Arrangement of the materials composing the earth's crust – The existing continents chiefly composed of subaqueous deposits – Distinction between sedimentary and volcanic rocks – Between primary, secondary, and tertiary – Origin of the primary – Transition formations – Difference between secondary and tertiary strata – Discovery of tertiary groups of successive periods – Paris basin – London and Hampshire basins – Tertiary strata of Bordeaux, Piedmont, Touraine, &c. – Subapennine beds – English crag – More recent deposits of Sicily, &c.

GENERAL ARRANGEMENT OF THE MATERIALS COMPOSING THE EARTH'S CRUST.

WHEN we examine into the structure of the earth's crust (by which we mean the small portion of the exterior of our planet accessible to human observation), whether we pursue our investigations by aid of mining operations, or by observing the sections laid open in the sea cliffs, or in the deep ravines of mountainous countries, we discover everywhere a series of mineral masses, which are not thrown together in a confused heap, but arranged with considerable order; and even where their original position has undergone great subsequent disturbance, there still remain proofs of the order that once reigned.

We have already observed, that if we drain a lake, we frequently find at the bottom a series of recent deposits disposed with considerable regularity one above the other; the uppermost, perhaps, may be a stratum of peat, next below a more compact variety of the same, still lower abed of laminated shell marl, alternating with peat, and then other beds of marl, divided by layers of clay. Now if a second pit be sunk through the same continuous lacustrine deposit, at some distance from the 6rst, we often meet with nearly the same series of beds, yet with slight variations; some" for example, of the layers of sand, clay, or marl may be wanting, one or more of them having thinned out and given place to others, or sometimes one of the masses, first examined, is observed to increase in thickness to the exclusion of other beds. Besides this limited continuity of particular strata, it is obvious that the whole assemblage must terminate somewhere; as, for example, where they reach the boundary of the original lake-basin, and where they will come in contact with the rocks which form the boundary of, and, at the same time, pass under all the recent accumulations.

In almost every estuary we may see, at low water, analogous phenomena where the current has cut away part of some newly-formed bank, consisting of a series of horizontal strata of peat, sand, clay, and, sometimes, interposed beds of shells. Each of these may often be traced over a considerable area, some extending farther than others, but all of necessity confined within the basin of the estuary. Similar remarks are applicable, on a much more extended scale, to the recent delta of a great river, like the Ganges, after the periodical inundations have subsided, and when sections are exposed of the river-banks and the cliffs of numerous islands, in which horizontal beds of clay and sand may be traced over an area many hundred miles in length, and more than a hundred in breadth.

Subaqueous deposits. The greater part of our continents are evidently composed of subaqueous deposits; and in the manner of their arrangement we discover many characters precisely similar to those above described; but the different groups of strata are, for the most part, on a greater scale, both in regard to depth and area, than any observable in the new formations of lakes, deltas, or estuaries. We find, for example, beds of limestone several hundred feet in thickness, containing imbedded corals and shells, stretching from one country to another, yet always giving place, at length, to a distinct set of strata, which either rise up from under it like the rocks before alluded to as forming the borders of a lake, or cover and conceal it. In other places, we find beds of pebbles, and sand, or of clay of great thickness. The different formations composed of these materials usually contain some peculiar organic remains; as, for example, certain species of shells and corals, or certain plants.

Volcanic rocks. Besides these strata of aqueous origin, we find other rocks which are immediately recognized to be the products of fire, from their exact resemblance to those which have been produced in modern times by volcanos, and thus we immediately establish two distinct orders of mineral masses composing the crust of the globe-the sedimentary and the volcanic.

Primary rocks. But if we investigate a large portion of a continent which contains within it a lofty mountain range, we rarely fail to discover another class, very distinct from either of those above alluded to, and which we can neither assimilate to deposits such as are now accumulated in lakes or seas, nor to those generated by ordinary volcanic action. The class alluded to, consists of granite, granitic schist, roofing slate, and many other rocks, of a much more compact and crystalline texture than the sedimentary and volcanic divisions before mentioned. In the unstratified portion of these crystalline rocks, as in the granite for example, no organic fossil remains have ever been discovered, and only a few faint traces of them in some of the stratified masses of the same class; for we should state, that a considerable portion of these rocks are divided, not only into strata, but into laminae, so closely imitating the internal arrangement of well-known aqueous deposits, as to leave scarcely any reasonable doubt that they owe this part of their texture to similar causes.

These remarkable formations have been called primitive, from being supposed to constitute the most ancient mineral productions known to us, and from a notion that they originated before the earth was inhabited by living beings, and while yet the planet was in a nascent state. Their high relative antiquity is indisputable; for in the oldest sedimentary strata, containing organic remains, we often meet with rounded pebbles of the older crystalline rocks, which must therefore have been consolidated before the derivative strata were formed out of their ruins. They rise up from beneath the rocks of mechanical origin, entering into the structure of lofty mountains, so as to constitute, at the same time, the lowest and the most elevated portions of the crust of the globe.

Origin of primary rocks. Nothing strictly analogous to these ancient formations can now be seen in the progress of formation on the habitable surface of the earth, nothing, at least, within the range of human observation. The first speculators, however, in Geology, found no difficulty in explaining their origin, by supposing a former condition of the planet perfectly distinct from the present, when certain chemical processes were developed on a great scale, and whereby crystalline precipitates were formed, some more suddenly, in huge amorphous masses, such as granite; others by successive deposition and with a foliated and stratified structure, as in the rocks termed gneiss and mica-schist. A great part of these views have since been entirely abandoned, more especially with regard to the origin of granite, but it is interesting to trace the train of reasoning by which they were suggested. First, the stratified primitive rocks exhibited, as we before mentioned, well-defined marks of successive accumulation, analogous to those so common in ordinary subaqueous deposits. As the latter formations were found divisible into natural groups, characterized by certain peculiarities of mineral composition, so also were the primitive. In the next place, there were discovered, in many districts, certain members of the so-called primitive series, either alternating with, or passing by intermediate gradations into rocks of a decidedly mechanical origin, containing traces of organic remains. From such gradual passage the aqueous origin of the stratified crystalline rocks was fairly inferred; and as we find in the different strata of subaqueous origin every gradation between a mechanical and a purely crystalline texture; between sand, for example, and saccharoid gypsum, the latter having, probably, been precipitated originally in a crystalline form, from water containing sulphate of lime in solution, so it was imagined that, in a former condition of the planet, the different degrees of crystallization in the older rocks might have been dependent on the varying state of the menstruum from which they were precipitated.

The presence of certain crystalline ingredients in the composition of many of the primary rocks, rendered it necessary to resort to many arbitrary hypotheses, in order to explain their precipitation from aqueous solution, and for this reason a difference in the condition of the planet, and of the pristine energy of chemical causes, was assumed. A train of speculation originally suggested by the observed effects of aqueous agents, was thus pushed beyond the limits of analogy, and it was not until a different and almost opposite course of induction was pursued, beginning with an examination of volcanic products, that more sound theoretical views were established.

Granite of igneous origin. As we are merely desirous, in this chapter, of fixing in the reader's mind the leading divisions of the rocks composing the earth's crust, we cannot enter, at present, into a detailed account of these researches, but shall only observe, that a passage was first traced from lava into other more crystalline igneous rocks, and from these again to granite, which last was found to send forth dikes and veins into the contiguous strata in a manner strictly analogous to that observed in volcanic rocks, and producing at the point of contact such changes as might be expected to result from the influence of a heated mass cooling down slowly under great pressure from a state of fusion. The want of stratification in granite supplied another point of analogy in confirmation of its igneous origin; and as some masses were found to send out veins through others, it was evident that there were granites of different ages, and that instead of forming in all cases the oldest part of the earth's crust, as had at first been supposed, the granites were often of comparatively recent origin, sometimes newer than the stratified rocks which covered them.

Stratified primary rocks. The theory of the origin of the other crystalline rocks was soon modified by these new views respecting the nature of granite. First it was shown, by numerous examples, that ordinary volcanic dikes might produce great alterations in the sedimentary strata which they traversed, causing them to assume a more crystalline texture, and obliterating all traces of organic remains, without, at the same time, destroying either the lines of stratification, or even those which mark the division into laminae. It was also found, that granite dikes and veins produced analogous, though somewhat different changes; and hence it was suggested as highly probable, that the effects to which small veins gave rise, to the distance of a few yards, might be superinduced on a much grander scale where immense masses of fused rock, intensely heated for ages, came in contact at great depths from the surface with sedimentary formations. The slow action of heat in such cases, it was thought, might occasion a state of semi-fusion, so that, on the cooling down of the masses, the different materials might be re-arranged in new forms, according to their chemical affinities, and all traces of organic remains might disappear, while the stratiform and lamellar texture remained.

May be of different ages. According to these views, the primary strata may have assumed their crystalline structure at as many successive periods as there have been distinct eras of the formation of granite, and their difference of mineral composition may be attributed, not to an original difference of the conditions under which they were deposited at the surface, but to subsequent modifications superinduced by heat at great depths below the surface.

The strict propriety of the term primitive, as applied to granite and to the granitiform and associated rocks, thus became questionable, and the term primary was very generally substituted, as simply expressing the fact, that the crystalline rocks, as a mass, were older than the secondary, or those which are unequivocally of a mechanical origin and contain organic remains.

Transition formations. The reader may readily conceive, even from the hasty sketch which we have thus given of the supposed origin of the stratified primary rocks, that they may occasionally graduate into the secondary; accordingly, an attempt was made, when the classification of rocks was chiefly derived from mineral structure, to institute an order called transition, the characters of which were intermediate between those of the primary and secondary formations. Some of the shales, for example, associated with these strata, often passed insensibly into clay slates, undistinguishable from those of the granitic series; and it was often difficult to determine whether some of the compound rocks of this transition series, called greywacke, were of mechanical or chemical origin. The imbedded organic remains were rare, and sometimes nearly obliterated; but by their aid the groups first called transition were at length identified with rocks, in other countries, which had undergone much less alteration, and wherein shells and zoophytes were abundant.

The term transition, however, was still retained, although no longer applicable in its original signification. It was now made to depend on the identity of certain species of organized fossils; yet reliance on mineral peculiarities was not fairly abandoned, as constituting part of the characters of the group. This circumstance became a fertile source of ambiguity and confusion; for although the species of the transition strata denoted a certain epoch, the intermediate state of mineral character gave no such indications, and ought never to have been made the basis of a chronological division of rocks.

Order of succession of stratified masses. All the subaqueous strata which we before alluded to as overlying the primary, were at first called secondary; and when they had been found divisible into different groups, characterised by certain organic remains and mineral peculiarities, the relative position of these groups became a matter of high interest. It was soon found that the order of succession was never inverted, although the different formations were not coextensively distributed; so that, if there be four different formations, as a, b, c, d, in the annexed diagram (No. 1), which, in certain localities, may be seen in vertical superposition, the uppermost or newest of them, a, will in other places be in contact with c, or with the lowest of the whole series, d, all the intermediate formations being absent.


No. 1

Tertiary formations. After some progress had been made in classifying the secondary rocks, and in assigning to each its relative place in a chronological series, another division of sedimentary formations was established, called tertiary, as being of newer origin than the secondary. The fossil contents of the deposits belonging to this newly-instituted order are, upon the whole, very dissimilar from those of the secondary rocks, not only all the species, but many of the most remarkable animal and vegetable forms, being distinct. The tertiary formations were also found to consist very generally of detached and isolated masses, surrounded on all sides by primary and secondary rocks, and occupying a position, in reference to the latter, very like that of the waters of lakes, inland seas, and gulfs, in relation to a continent, and, like such waters, being often of great depth, though of limited area. The imbedded organic remains were chiefly those of marine animals, but with frequent intermixtures of terrestrial and freshwater species so rarely found among the secondary fossils. Frequently there was evidence of the deposits having been purely lacustrine, a circumstance which has never yet been clearly ascertained in regard to any secondary group.

We shall consider more particularly, in the next chapter, how far this distinction of rocks into secondary and tertiary is founded in nature, and in what relation these two orders of mineral masses may be supposed to stand to each other. But before we offer any general views of this kind, it may be useful to present the reader with a succinct sketch of the principal point, in the history of the discovery and classification of the tertiary strata.

Paris Basin. The first series of deposits belonging to this class, of which the characters were accurately determined, were those which occur in the neighbourhood of Paris, first described by MM. Cuvier and Brongniart. [1] They were ascertained to fill a depression in the chalk (as the beds d, in diagram No. 2, rest upon c), and to be composed of different materials, some- times including the remains of marine animals, and sometimes of freshwater. By the aid of these fossils, several distinct alternations of marine and freshwater formations were clearly shown to lie superimposed upon each other, and various speculations were hazarded respecting the manner in which the sea had successively abandoned and regained possession of tracts which had been occupied in the intervals by the waters of rivers or lakes. In one of the subordinate members of this Parisian series, a great number of scattered bones and skeletons of land animals were found entombed, the species being perfectly dissimilar from any known to exist, as indeed were those of almost all the animals and plants of which any portions were discovered in the associated deposits.


No.2.
a, Primary rocks.
b, Older secondary formations.
c, Chalk.
d, Tertiary formation.

We shall defer, to another part of this work, a more detailed account of this interesting formation, and shall merely observe in this place, that the investigation of the fossil contents of these beds forms an era in the progress of the science. The French naturalists brought to bear upon their geological researches so much skill and proficiency in comparative anatomy and conchology, as to place in a strong light the importance of the study of organic remains, and the comparatively subordinate interest attached to the mere investigation of the structure and mineral ingredients of rocks.

A variety of tertiary formations were soon afterwards found in other parts of Europe, as in the south-east of England, in Italy, Austria, and different parts of France, especially in the basins of the Loire and Gironde, all strongly contrasted to the secondary rocks. As in the latter class many different divisions had been observed to preserve the same mineral characters and organic remains over wide areas, it was natural that an attempt should first be made to trace the different subdivisions of the Parisian tertiary strata throughout Europe, for some of these were not inferior in thickness to several of the secondary formations that had a wide range.

But in this case the analogy, however probable, was not found to hold good, and the error, though almost unavoidable, retarded seriously the progress of geology. For as often as a new tertiary group was discovered, as that of Italy, for example, an attempt was invariably made, in the first instance, to discover in what characters it agreed with some one or more subordinate members of the Parisian type. Every fancied point of correspondence was magnified into undue importance, and such trifling circumstances, as the colour of a bed of sand or clay, were dwelt upon as proofs of identification, while t1le difference in the mineral character and organic contents of the group from the whole Parisian series was slurred over and thrown into the shade.

By the influence of this illusion, the succession and chronological relations of different tertiary groups were kept out of sight. The difficulty of clearly discerning these, arose from the frequent isolation of the position of the tertiary formations before described, since, in proportion as the areas occupied by them are limited, it is rare to discover a place where one set of strata overlap another, in such a manner that the geologist might be enabled to determine the difference of age by direct superposition.

ORIGIN OF THE EUROPEAN TERTIARY STRATA AT SUCCESSIVE PERIODS.

We shall now very briefly enumerate some of the principal steps which eventually led to a conviction of the necessity of referring the European tertiary formations to distinct periods, and the leading data by which such a chronological series may be established.

London and Hampshire Basins. -- Very soon after the investigation, before alluded to, of the Parisian strata, those of Hampshire and of the Basin of the Thames were examined in our own country. Mr. Webster found these English tertiary deposits to repose, like those in France, upon the chalk or newest rock of the secondary series. He identified a great variety of the shells occurring in the British and Parisian strata, and ascertained that, in the Isle of Wight, an alternation of marine and fresh-water beds occurred, very analogous to that observed in the basin of the Seine. [2] But no two sets of strata could well be more dissimilar in mineral composition, and they were only recognized to belong to the same era, by aid of the specific identity of their organic remains. The discordance, in other respects, was as complete as could well be imagined, for the principal marine formation in the one country consisted of blue clay, in the other of white limestone, and a variety of curious rocks in the neighbourhood of Paris had no representatives whatever in the south of England.

Subapennine Beds. -- The next important discovery of tertiary strata was in Italy, where Brocchi traced them along the Banks of the Apennines, from one extremity of the peninsula to the other, usually forming a lower range of hills, called by him the Subapennines. [3] These formations, it is true, had been pointed out by the older Italian writers, and some correct ideas, as we have seen, had been entertained respecting their recent origin, as compared to the inclined secondary rocks on which they rested. [4] But accurate data were now for the first time collected, for instituting a comparison between them and other members of the great European series of tertiary formations.

Brocchi came to the conclusion that nearly one-half of several hundred species of fossil shells procured by him from these Subapennine beds were identical with those now living in existing seas, an observation which did not hold true in respect to the organic remains of the Paris basin. It might have been supposed that this important point of discrepancy would at once have engendered great doubt as to the identity, in age, of any part of the Subapennine beds to anyone member of the Parisian series; but, for reasons above alluded to, this objection was not thought of much weight, and it was supposed that a group of strata, called 'the upper marine formation,' in the basin of the Seine, might be represented by all the Subapennine clays and yellow sand.

English Crag. -- Several years before, an English naturalist, Mr. Parkinson, had observed, that certain shelly strata, in Suffolk, which overlaid the blue clay of London, contained distinct fossil species of testacea, and that a considerable portion of these might be identified with species now inhabiting the neighbouring sea. [5] These overlying bedsm which were provincially termed 'Crag,' were of small thickness, and were not regarded as of much geological importance. But when duly considered, they presented a fact worthy of great attention, viz., the superposition of a tertiary group, inclosing, like the Subapennine beds, a great intermixture of recent species of shells, upon beds wherein a very few remains of recent or living species were entombed.

Mr. Conybeare, in his excellent classification of the English strata, [6] placed the crag as the uppermost of the British series, and several geologists began soon to entertain an opinion that this newest of our tertiary formations might correspond in age to the Italian strata described by Brocchi.

Tertiary Strata of Touraine. -- The next step towards establishing a succession of tertiary periods was the evidence adduced to prove that certain formations, more recent than the uppermost members of the Parisian series, were also older than the Subapennine beds, so that they constituted deposits of an age intermediate between the two types above alluded to. Mr. Desnoyers, for example, ascertained that a group of marine strata in Touraine, in the basin of the Loire (e, diagram No. 3), rest upon the uppermost subdivision of the Parisian group d, which consists of a lacustrine formation, extending continuously throughout a platform which intervenes between the basin of the Seine and that of the Loire. These overlaying marine strata, M. Desnoyers assimilated to the English crag, to which they bear some analogy, although their organic remains differ considerably, as will be afterwards shown.


No. 3.
c, Chalk and other secondary formations.
d, Tertiary formation of Paris basin.
e, Superimposed marine tertiary beds of the Loire.

A large tertiary deposit had already been observed in the south-west of France, around Bordeaux and Dax, and a description of its fossils had been published by M. de Basterot. [7] Many of the species were peculiar, and differed from those of the strata now called Subapennine; yet these same peculiar and characteristic fossils reappeared in Piedmont, in a series of strata inferior in position to the Subapennines (as e underlies f, diagram No. 4.)


No.4.
c, Chalk and older formations.
d, London clay, (old tertiary).
e, Tertiary strata of same age as beds of the Loire.
f, Crag and Subapennine tertiary deposits.

This inferior group, e, composed principally of green sand, occurs in the hills of Mont Ferrat, and beds of the same age are seen in the valley of the Bormida. They also form the hill of the Superga, near Turin, where M. Bonelli formed a large collection of their fossils, and identified them with those discovered near Bordeaux and in the basin of the Gironde.

But we are indebted to M. Deshayes for having proved, by a careful comparison of the entire assemblage of shells found in the above- mentioned localities, in Touraine, in the south-east of France, and in Piedmont, that the whole of these three groups possess the same zoological characters, and belong to the same epoch, as also do the shells described by M. Constant Prevost, as occurring in the basin of Vienna. [8]

Now the reader will perceive, by reference to the observations above made, and to the accompanying diagrams, that one of the formations of this intervening period, e, has been found superimposed upon the highest member of the Parisian series, d; while another of the same set has been observed to underlie the Subapennine beds, f. Thus the chronological series, d, e, f, is made out, in which the deposits, originally called tertiary, those of the Paris and London basins, for example, occupy the lowest position, and the beds called 'the Crag,' and 'the Subapennines,' the highest.

Tertiary Strata newer than the Subapennine. -- The fossil remains which characterize each of the three successive periods above alluded to, approximate more nearly to the assemblage of species now existing, in proportion as their origin is less remote from our own era, or, in other words, the recent species are always more numerous, and the extinct more rare, in proportion to the low antiquity of the formations. But the discordance between the state of the organic world indicated by the fossils of the Subapennine beds and the actual state of things is still considerable, and we naturally ask, are there no monuments of an intervening period? -- no evidences of a gradual passage from one condition of the animate creation to that which now prevails, and which differs so widely?

It will appear, in the sequel, that such monuments are not wanting, and that there are marine strata entering into the composition of extensive districts, and of hills of no trifling height, which contain the exuviae of testacea and zoophytes, hardly distinguishable, as a group, from those now peopling the neighbouring seas. Thus the line of demarcation between the actual period and that immediately antecedent, is quite evanescent, and the newest members of the tertiary series will be often found to blend with the formations of the historical era.

In Europe, these modern strata have been found in the district around Naples, in the territory of Otranto and Calabria, and more particularly in the Island of Sicily; and the bare enumeration of these localities cannot fail to remind the reader, that they belong to regions where the volcano and the earthquake are now active, and where we might have anticipated the discovery of emphatic proofs, that the conversion of sea into land had been of frequent occurrence at very modern periods.

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Notes:

1. Environs de Paris, 1811.

2. Webster in Englefield's Isle of Wight and Geol. Trans., vol. ii. p. 161.

3. Conch. Foss. Subap., 1814.

4. See vol. i. p. 51, for opinions of Odoardi, in 1761.

5. Geol. Trans., vol. i. p. 324. 1811.

6. Outlines of the Geology of England and Wales, 1822.

7. Mem. de la Soc. d'Hist. Nat. de Paris, tome ii., 1825.

8. Sur la Constitution, &c. du bassin de Vienne, Journ. de Phys., Nov. 1820.