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fresh-water from a bursting lake, or unusual land flood, is often fatal to large numbers of the inhabitants of the waters thus respectively interchanged.*

The greater number of fossil fishes present no appearance of having perished by mechanical violence; they seem rather to have been destroyed by some noxious qualities imparted to the waters in which they moved; either by sudden change of temperature,† or an admixture of carbonic acid, or sulphuretted hydrogen gas, or of bituminous or earthy matter in the form of mud.

The circumstances under which the fossil fishes are found at Monte Bolca seem to indicate that they perished suddenly on arriving at a part of the then existing seas, which was rendered noxious by the volcanic agency, of which the adjacent basaltic rocks afford abundant evidence. The skeletons of these fish lie parallel to the lamina of the strata of the calcareous slate; they are always entire, and so closely packed on one another, that many individuals are often contained in a single block. The thousands of specimens which are dispersed over the cabinets of Europe, have nearly all been taken from one quarry. All these fishes must have died suddenly on this fatal spot, and have been speedily buried in the calcareous sediment then in the course of deposition. From the fact that certain individuals have even preserved traces of colour upon their skin, we are certain that they were entombed before decomposition of their soft parts had taken place.‡

* See account of the effects of an irruption of the sea into the fresh-water of the lake of Lowestoffe, on the coast of Suffolk. Edinburg Philosophical Journal, No. 25, p. 372.

M. Agassiz has observed that a sudden depression to the amount of 15° of the temperature of the water in the river Glat, which falls into the lake of Zurich, caused the immediate death of thousands of Barbel.

The celebrated fish (Blochius longirostris) from this quarry, described as petrified in the act of swallowing another fish (Ithiolitologia Veronese, Tab. XII.) has been ascertained by M. Agassiz to be a deception, arising from the accidental juxta-position of two fishes. The size of the head of the

The fishes of Torre d'Orlando, in the Bay of Naples, near Castelamare, seem also to have perished suddenly M. Agassiz finds that the countless individuals which occur there in Jurassic limestone, all belong to a single species, the Pyenodus rhombus. Tetragonolepis. An entire shoal seems to have been destroyed at once, at a place where the waters were either contaminated with some noxious impregnation, or overcharged with heat.*

In the same manner also, we may imagine deposites from muddy water, mixed perhaps with noxious gases, to have formed by their sediments a succession of thick beds of marl and clay, such as those of the Lias formation; and at the same time to have destroyed, not only the Testacea and lower orders of animals inhabiting the bottom, but also the higher orders of marine creatures within the regions thus invaded. Evidence of the fact of vast numbers of fishes and saurians having met with sudden death and immediate burial, is also afforded by the state of entire preservation in which the bodies of hundreds of them are often found in the Lias. It sometimes happens that scarcely a single bone, or scale, has been removed from the place it occupied during life; this condition could not possibly have been retained, had the uncovered bodies of these animals been left, even for a few hours, exposed to putrefaction, and to the attacks of fishes and other smaller animals at the bottom of the sea.t

smaller fish supposed to be swallowed, in such as never could have entered the diminutive stomach of the putative glutton; moreover it does not enter within the margin of its jaws.

*The proximity of this rock to the Vesuvian chain of volcanic eruptions, offers a cause sufficient to have imparted either of these destructive powers to the waters of a limited space in the bay of Naples, at a period preceding those intense volcanic actions which prevailed in this district during the deposition of the Tertiary strata, and which are still going on there.

+ Although it appears from the preservation of these animals, that certain parts of the Lias were deposited rapidly, there are also proofs of the lapse of much time during the deposition of other parts of this formation. See Notes in future Chapters on Coprolites and fossil Loligo.

Another celebrated deposite of fossil fishes is that of the cupriferous slate surrounding the Hartz. Many of the fishes of this slate at Mansfeldt, Eiselebon, &c., have a distorted attitude, which has often been assigned to writhing in the agonies of death. The true origin of this condition, is the unequal contraction of the muscular fibres, which causes fish and other animals to become stiff during a short interval between death and the flaccid state preceding decomposition. As these fossil fishes maintain the altitude of the rigid stage immediately succeeding death, it follows that they were buried before putrefaction had commenced, and apparently in the same bituminous mud, the influx of which had caused their destruction. The dissemination of Copper and Bitumen through the slate that contains so many perfect fishes around the Hartz, seems to offer two other causes, either of which may have produced their sudden death.*

From what has been said respecting the general history of fossil organic Remains, it appears that not only the relics of aquatic, but also those of terrestrial animals and plants, are found almost exclusively in strata that have been accumulated by the action of water. This circumstance is readily explained, when we consider that the bones of all dead creatures that may be left uncovered upon dry land, are in a few years entirely destroyed by various animals and the decomposing influence of the atmosphere. If we

Under the turbulent conditions of our planet, whilst stratification was in progress, the activity of volcanic agents, then frequent and intense, was probably attended also with atmospheric disturbances affecting both the air and water, and producing the same fatality among the then existing Tribes of fishes, that is now observed to result from sudden and violent changes in the electric condition of the atmosphere. M. Agassiz has observed that ra pid changes in the degree of atmospheric pressure upon the water, affect the air within the swimming bladders of fishes, sometimes causing them to be distended to a fatal degree, and even to burst. Multitudes of dead fishes, that have thus perished during tempests, are often seen floating on the sur face, and cast on the shores of the lakes of Switzerland.

except the few bones that may have been collected in caves, or buried under land slips, or the products of volcanic eruptions, or in sand drifted by the winds, it is only in strata formed by water that any remains of land animals can have been preserved.

We continually see the carcasses of such animals drifted by rivers in their seasons of flood, into lakes, estuaries, and seas; and although it may at first seem strange to find terrestrial remains, imbedded in strata formed at the bottom of the water, the difficulty vanishes on recollection that the materials of stratified rocks are derived in great part from the Detritus of more ancient lands. As the forces of rains, torrents, and inundations have conveyed this detritus into lakes, estuaries, and seas, it is probable that many carcasses. of terrestrial and amphibious animals, should also have been drifted to great distances by currents which swept such

* Captain Lyon states, that in the deserts of Africa, the bodies of camels are often dessiccated by the heat and dryness of the atmosphere, and become the nucleus of a sand-hill, which the wind accumulates around them. Be neath this sand they remain interred like the stumps of palm trees, and the buildings of ancient Egypt.

In a recent paper on the geology of the Bermudas (Proceedings of Geol. Soc. Lond. Ap. 9, 1834,) Lieutenant Nelson describes these islands as composed of calcareous sand and limestone, derived from comminuted shells and corals; he considers great part of the materials of these strata to have been drifted up from the shore by the action of the wind. The surface in many parts is composed of loose sand, disposed in all the irregular forms of drifted snow, and presents a surface covered with undulations like those produced by the ripple of water upon sand on the sea-shore. Recent shells occur both in the loose sand and solid limestone, and also roots of the Palmetto now growing in the island. The N. W. coast of Cornwall affords examples of similar invasions of many thousand acres of land by Deluges of sand drifted from the sea-shore, at the villages of Bude and Perran Zabulo; the latter village has been twice destroyed, and buried under sand, drifted inland during extraordinary tempests, at distant intervals of time. See Trans. of Geol. Soc. of Cornwall, vol. ii. p. 140, and vol. iii. p. 12. See also De la Beche's Geological Manual, 3d edit. p. 84, and Jameson's Translation of Cuvier's Theory of the earth, 5th edit. Note G.

enormous quantities of abraded matter from the lands; and accordingly we find, that strata of aqueous formation have become the common repository not only of the Remains of aquatic, but also of terrestrial animals and vegetables.

The study of these Remains will form our most interesting and instructive subject of inquiry, since it is in them that we shall find the great master-key whereby we may unlock the secret history of the earth. They are documents which contain the evidences of revolutions and catastrophes, long antecedent to the creation of the human race; they open the book of nature, and swell the volumes of science, with the Records of many successive series of animal and vegetable generations, of which the Creation and Extinction would have been equally unknown to us, but for recent discoveries in the science of Geology.

CHAPTER XIII.

Aggregate of Animal Enjoyment increased, and that of Pain diminished, by the existence of Carnivorous Races.

BEFORE we proceed to consider the evidences of design, discoverable in the structure of the extinct carnivorous races, which inhabited our planet during former periods of its history; we may briefly examine the nature of that universal dispensation, whereby a system of perpetual destruction, followed by continual renovation, has at all times tended to increase the aggregate of animal enjoyment, over the entire surface of the terraqueous globe.

Some of the most important provisions which will be presented to us in the anatomy of these ancient animals, are found in the organs with which they were furnished for the

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