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... he destruction of the animals of which the remains are now so curiously preserved, has been something of sudden and instantaneous operation. Of this, however, we do not think that the proof is quite satisfactory; and though the thing may be true in some instances, we believe that in far the greater number it cannot be admitted. The rhinoceros, of which the skeleton with some parts of the muscles and the hide, was found near the banks of the Lena, must no doubt have been frozen soon after its death, otherwise the fleshy parts could not have escaped corruption. the same may be said of the great carcass recently discovered, included in a mass of ice on the shores of the Frozen Ocean. Some local catastrophe may have overwhelmed these, and perhaps a great number of other animals; but we cannot suppose that it has extended to those of which the remains are found in the alluvial beds all over the world.
These are so numerous, they are so far scattered, and have so little to do with the effects of ice as a preservative, that we cannot suppose the cases to be similar. The quantity of the fossil bones, is in many instances too great to proceed from the animals of one generation; and must have been supplied from those of many ages, which have fed successively on the banks of the great rivers, and of which the bones have been buried in the mud and sand, thrown out by these rivers on their banks. That local inundations, or catastrophes, have been very frequent, will be easily admitted, if we ascribe them to the depression of the land, rather than the rising of the sea. The change of the level of the sea, infers a change of level over the whole of its surface; that of the land extends no farther than a particular country.
The latter is, of the two, the hypothesis far the best calculated to resolve the enigmas of the mineral kingdom. The next object, is to show that there is little probability of discovering any new species among the larger quadrupeds now living. It is shown, also, that the larger animals of the old continent, were all well known to the ancients: the observations on this subject, as well as on the fabulous animals of antiquity, are highly interesting, and full of learning and ingenuity. CUVIER treats next of the means of distinguishing the genera and species of the fossil bones of quadrupeds. He observes, "that, the parts of the animal system are so tied together from their nature, that the most certain rules may be deduced by a careful study of the parts, and by accurate and repeated observation.
Any one, " says he, "who observes the print of a cloven hoof, may conclude that it has been left by a ruminating animal; so that a single footmark may clearly indicate to the observer, the forms of the teeth, of the jaws, of the vertebrae, of the leg-bones, thighs, shoulders, & c. of the animal which left the mark. "From the mere comparison of observations, where theory is unable to direct, we also procure astonishing results; insomuch, that when we find merely the extremity of a well preserved bone, we are able, by careful examination, assisted by analogy and exact comparison, to determine the species to which it once belonged, as certainly as if we had the entire animal before us. Before venturing to put entire confidence in this method of investigation, I have very frequently tried it with portions of bones belonging to known animals; and always with such complete success, that I now entertain no doubt with regard to the results which it affords. "In this matter, we have ascertained and classified the fossil remains of 78 different quadruped in the viviparous and oviparous classes. Forty-nine of these are distinct species, hitherto entirely unknown to naturalists. Eleven or twelve others have such entire resemblance to species already known, as to leave no doubt whatever of their identity; and the remaining 16 or 18, have considerable traits of resemblance to known species: But the comparison has not yet been made with such precision, as to remove all uncertainty. Of the 49 new, or hitherto unknown species, 27 belong to 7 new genera; while the other 22 new species belong to 16 genera or subgenera already known.
The whole number of genera and subgenera, to which the fossil remains of quadruped, hitherto investigated, are referable, are 36, including those belonging both to known and unknown species. In order to connect these remains with the natural history of the globe itself, it would be desirable to ascertain the particular strata in which each species was found, and to inquire if there were any general laws which connected their position among the strata, with their resemblance to the species actually living on the surface of the earth. " On this subject, CUVIER has made the following observation: "It seems, in the first place, clearly ascertained, that the remains of oviparous quadrupeds belong to more ancient strata than those of viviparous quadrupeds. The crocodiles of Honfleur and of England are underneath the chalk. The lizards of Thuringia are still more ancient, if the slate in which they are contained is to be placed, as some mineralogists suppose, among the most ancient of the secondary formations. "The earliest appearance of fossil bones seems to indicate, that dry land and fresh water existed before the formation of the chalk strata. But it is not till we arrive at strata of a far more recent date, that we come to the fossil remains of mammiferous land quadrupeds.
We begin, indeed, to discover the bones of mammiferous sea animals, such as the Lamantin and the seal, in the shell limestone which immediately covers the chalk in the neighborhood of Paris; but no bones of mammiferous land animals are to be found in that formation, nor till we come to those which lie over this limestone stratum; after which the bones of land quadrupeds are discovered in great abundance. "Thus we are led to conclude, that the oviparous quadrupeds began to exist along with the fishes, at the commencement of the period which produced the secondary formations, and that the land quadrupeds did not appear till long afterwards. "There is also a determinate order observable in the disposition of the bones of this latter kind, with respect to the strata in which they are found. The genera, which are now unknown; as the palaeotheria, anaplotheria, & c. are found in the most ancient of the formations of which we now speak, or those which are directly over the coarse limestone. They are chiefly what occupy the regular strata deposited from the fresh water. Along with them are found some lost species of known genera, but in small numbers. "The most remarkable of the unknown species belonging to known genera, as the fossil elephant, rhinoceros, and mastodon ton, are never found along with those more ancient genera, but are contained in alluvial formations of a later date, and never in the regular rocky strata. "Lastly, the bones of species apparently the same with those now living on the earth, are never found, except in the very latest alluvial depositions, such as are either formed on the sides of rivers, or at the bottoms of ancient lakes or marshes now dried up.
These bones, though the most recent of all, from being nearest to the surface, are the worst preserved. " These are the laws, as far as our author's observations extend, which connect the unknown species with the strata in which they are lodged. It is curious to remark a kind of convergence, if we may call it so, both in the animals that inhabited the earth, and in the superficies of the earth itself, to the state in which they are now found. As the land came nearer to its resent form, its inhabitants approached nearer to their present condition. Can it be doubted, that a vast number of ages was necessary for bringing about such important changes?
It must, however, be observed, that the extent to which these observations reach is not considerable: IT is to the chalk country round Paris, and perhaps only to a part of it -- no other tract on the earth's surface having yet been subjected to the same scrupulous and elaborate examination. CUVIER, indeed, gives the preceding results with that degree of diffidence which suits so new an inquiry, and one where the conclusions have not yet been verified by corresponding observations. He goes on, after this, in another article, to show, that the extinct species of quadrupeds are not varieties of the species presently existing; and he proves, in a very satisfactory manner, that the distance between these fossil species and the living species, to which they have the greatest affinity, is much greater than is ever found among the varieties of the same species. The conclusion of this article is highly deserving of notice. "When I endeavored to prove, " says he, "that the rocky strata contain the remains of several genera, and the loose strata those of several species which have now entirely disappeared from the face of our globe, I do not pretend that a new creation was necessary for calling the present races into existence; I only urge, that they did not anciently occupy the same places. Let us suppose, that a prodigious inroad of the sea were now to cover the continent of New Holland with a coat of earth: this would necessarily bury the carcasses of many animals belonging to the genera of Kangaroo, & c. and would entirely extinguish all the species of these genera, as not one of them is to be found in any other country.
Were the same revolution to lay dry the numerous narrow strengths which separate New Holland from New Guinea, the Indian islands, and the continent of Asia, a road would be open for the elephants, rhinoceroses, and all the other Asiatic animals, to occupy a land in which they are hitherto unknown. Were some future naturalist, after becoming well acquainted with the living animals of the country in this new condition, to search below the surface, he would then discover the remains of races quite different. What New Holland would then be, Europe, Siberia, and a large portion of America, actually are at present. Perhaps hereafter, when other countries shall be examined, and New Holland among the rest, they may be found to have undergone similar revolutions, and to have made equal changes of their animal productions. " This is the reflection of a man of great general views, who had deeply considered the subject before him, and discovered what is probably the true relation between the strata of the mineral kingdom, and the fossil remains which they contain. For the productions of the such local catastrophes as are here supposed, the rising and falling of the level of the land is a cause much better accommodated than a similar change in the level of the sea. It is here observed, that among the bones found in a fossil state, those of the human species have never been discovered.
Several of those specimens which passed for being remains of the latter kind, CUVIER himself has carefully examined; and the judgment of so able a naturalist must be held as decisive. The fossil bones which SPALLANZANI brought from the island of Cargo, are of that number; and our author has no difficulty of affirming, that not a single fragment among them ever belonged to a human skeleton. He pronounces the same sentence on the specimen which Scheuchzer called Homo diluvium testis. The next article undertakes to prove, that the population of the world is but recent, and that its present surface is by no means of very ancient formation. In the proof of the last of these propositions, we do not think that our author has been successful, and shall take the liberty of stating our objection to his reasoning. "By a careful examination, " says he, "of what has taken place on the surface of the globe since it has been laid dry for the last time, and its continents have assumed their present form, at least in such parts as are somewhat elevated above the level of the ocean, it may be clearly seen that this last revolution, and consequently the establishment of our existing societies, could not have been very ancient. This result is one of the best established, and least attended to in rational zoology; and it is so much the more valuable, as it connects natural and civil history together in one uninterrupted series. " The argument by which CUVIER endeavors to establish a result which he considers as so certain and important, is, in its form and intention, perfectly logical.
To judge of the time in which a certain work has been accomplished, we must ascertain the rate of working, or the quantity of work done in a given time; and if we then can measure also the whole work that has been performed, we may be enabled to calculate the time of the performance with some tolerable exactness. This is the method followed by our author; but in the manner of ascertaining his data, we think great errors have been introduced. These errors affect both the things to be determined, viz. the rate of working, and the total effect produced. The first is made much too great, and the latter much too small; on which account, the time taken up by the action must fall vastly short of the truth. "It must be, " says CUVIER, "since the last retreat of the waters, that the acclivities of our mountains have begun to disintegrate, and to form slopes of the debris at their bottoms and upon their sides; that our rivers have begun to flow in their present courses, and to form alluvial depositions. " Now, in these words, since our rivers have begun to flow in their present courses, we conceive that a great error is concealed. Whether the land was laid dry by the sea retiring to a lower level, or by the land itself rising to a higher level, is not material to the present question.
While the surface was covered by water to a great depth resting above it, there was no physical agent whatever that could be supposed to cut out or to prepare for the rivers any thing like the courses in which they now flow and discharge themselves into the sea. There is, indeed, no where any physical agent by which this operation, or this great system of operations, can have been effected. Great original inequalities were no doubt left behind by the sea when it retired; but that there should be any system of lines or canals connecting all these inequalities, with a declivity nearly uniform from the one end to the other, it were altogether unreasonable to suppose. No agent having the least tendency to produce this effect could act on a surface deeply immersed under a fluid, and where the pressure of that fluid tended to reserve an equilibrium in all directions. Chance, or the cooperation of acid...
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Research essay sample on Rivers Have Begun Flow In Their Present Courses Species
