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As the bones of all these animals found in the earliest series of the tertiary deposites are accompanied by the remains of reptiles, such as now inhabit the fresh waters of warm countries, e. g. the Crocodile, Emys, and Trionyx (see Pl. 1, Figs. 80, 81, 82,) and also by the leaves and prostrate trunks of palm trees (Pl. 1, Figs. 66, 67, 68, and Pl. 56,) we cannot but infer that the temperature of France was much higher than it is at present, at the time when it was occupied by these plants and reptiles, and by Mammalia allied to families which are natives of some of the warmest latitudes of the present earth, e. g. the Tapir, Rhinoceros, and Hippopotamus.
The frequent intrusion of volcanic rocks is a remarkable accompaniment of the tertiary strata of the Eocene period, in various parts of Europe; and changes of level, resulting from volcanic agency, may partially explain the fact, that portions of the same districts became alternately the receptacles of fresh and salt water.
The fresh-water calcareous deposites of this period are also highly important, in relation to the general history of the origin of limestone, from their affording strong evidence of the sources whence carbonate of lime has been derived.* Mammalia of the Miocene Period. The second or Miocene System of Tertiary Deposites, contains an admixture of the extinct genera of lacustrine mammalia, of the first or Eocene series, with the earliest
ture. Hence there is no doubt that the Sivatherium was invested with a trunk like the Tapir, Its jaw is twice as large as that of a Buffalo, and larger than that of a Rhinoceros. The remains of the Sivatherium were ac. companied by those of the Elephant, Mastodon, Rhinoceros, Hippopotamus, several Ruminantia, &c.
It is stated that there is a wider distance between the living Genera of the Order Pachydermata than between those of any other Order of Mammalia, and that many intervals in the series of these animals have been filled up by extinct Genera and Species, discovered in strata of the Tertiary series. The Sivatherium forms an important addition to the extinct Genera of this intermediate and connecting character. The value of such links with reference to considerations in Natural Theology will be alluded to elsewhere.
* We see that thermal springs, in volcanic districts, issue from the earth, so highly charged with carbonate of lime, as to overspread large tracts of country with beds of calcareous tufa, or travertino, The waters
that flow from the Lago di Tartaro, near Rome, and the hot springs of San Filippo, on the borders of Tuscany, are well-known examples of this phenomenon. These existing operations afford a nearly certain explanation of the origin of extensive beds of limestone in fresh-water lakes of the tertiary period, where we know them to have been formed during seasons of intense volcanic activity. They seem also to indicate the probable agency of thermal waters in the formation of still larger calcareous deposites at the bottom of the sea, during preceding periods of the secondary and transition series,
It is a difficult problem to account for the source of the enormous masses of carbonate of lime that compose nearly one-eighth part of the superficial crust of the globe. Some have referred it entirely to the secretions of marine animals; an origin to which we must obviously assign those portions of calcareous strata which are composed of comminuted shells and corallines : but, until it can be shown that these animals have the power of forming lime from other elements, we must suppose that they derived it from the sea, either directly, or through the medium of its plants. In either case, it remains to find the source whence the sea obtained, not only these supplies of carbonate of lime for its animal inhabitants, but also the still larger quantities of the same substance, that have been precipitated in the form of calcareous strata.
We cannot suppose it to have resulted, like sands and clays, from the mechanical detritus of rocks of the granitic series, because the quantity of lime these rocks contain, bears no proportion to its large amount among the de. rivative rocks. The only remaining hypothesis seems to be, that lime was continually introduced to lakes and seas, by water that had percolated rocks through which calcareous earth was disseminated.
Although carbonate of lime occurs not in distinct masses among rocks of igneous origin, it forms an ingredient of lava and basalt, and of various kinds of trap rocks. The calcareous matter thus dispersed through the substance of these volcanic rocks, seems to afford a magazine from which percolating water, charged with carbonic acid gas, may, in the lapse of ages, have derived sufficient carbonate of lime to form all the existing strata of limestone, by successive precipitates at the bottom of ancient lakes and seas. Mr. De la Beche states the quantity of lime in granite composed of two-fifths quartz, two-fifths felspar, and one-fifth mica, to be 0.37; and in greenstone, composed of equal parts of felspar and homblende, to be 7.29. (Geol. Researches,
forms of genera which exist at the present time. This admixture was first noticed by M. Desnoyers, in the marine formations of the faluns of Touraine.* Similar admixtures have been found in Bavaria,t and near Darmstadt.I Many p. 379.)—The compact lava of Calabria contains 10. of carbonate of lime, and the basalt of Saxony 9, 5.
We may in like manner, refer the origin of those large quantities of silex, which constitute the chert and flint beds of stratified formations, to the waters of hot springs, holding siliceous earth in solution, and depositing it on exposure to reduced degrees of temperature and pressure, as silex is deposited by the hot waters that issue from the geysers of Iceland.
* Here, the remains of Palæotherium, Anthracotherium, and Lophiodon, which formed the prevailing genera in the Eocene period, are found mixed with bones of the Tapir, Mastodon, Rhinoceros, Hippopotamus, and Horse: these bones are fractured and rolled, and sometimes covered with flustra, and must have been derived from carcasses drifted into an estuary, or sea. Annales des Sciences Naturelles. Février, 1828.
+ Count Munster and Mr. Murchison have discovered, at Georgensgemünd, in Bavaria, the bones of Palætherium, Anoplotherium, and Anthracotherium, mixed with those of Mastodon, Rhinoceros, Hippopotamus, Horse, Ox, Bear, Fox, &c.; and several species of land shells.
A very interesting detailed description of the remains found at this place has been published by Hermann von Meyer Frankfurt, 1834, 4to. with 14 plates,
We learn from the excellent publication of Professor Kaup, of Darmstadt, that at Epplesheim, near Altzey, about twelve leagues south of Mayence, remains of the following animals have been found, in strata of sand, referable to the second or Miocene period of the tertiary formations. These are preserved in the Museum at Darmstadt.
Gigantic Herbivorous Animals fifteen
s and eighteen feet long.
. . 3. · Hog.
..4.. Large Cats, some as large as a Lion. Machairodus . .1. , Allied to Bear. Ursus Cultridens. Gulo
. .l. . Glutton.
of these animals, also indicate a lacustrine or swampy condition of the regions they inhabited : one of them, the Dinotherium giganteum (gigantic Tapir of Cuvier,) is calculated to have been eighteen feet in length, and was much the largest of all terrestrial Mammalia yet discovered, exceeding even the largest fossil elephant.
The Dinotherium will be described in a subsequent chapter.
Mammalia of the Pliocene Periods.
The third, and fourth, or Pliocene devisions of the tertiary fresh-water deposites, contain no more traces of the extinct lacustrine genera of the Palæotherian family, but abound in extinct species of existing genera of Pachydermata, e. g. Elephant, Rhinoceros, Hippopotamus, and Horse, together with the extinct genus Mastodon. With these also occur the first abundant traces of Ruminantia, e. g. Oxen and Deer. The number of Rodentia becomes also enlarged; and the carnivora assume a numerical importance commensurate with the increased numbers of terrestrial herbivora.
The seas, also, of the Miocene and Pliocene periods, were inhabited by marine Mammalia, consisting of Whales, Dolphins, Seals, Walrus, and the Lamantin, or Manati, whose existing species are chiefly found near the coasts and mouths of rivers in the torrid zone (see Pl. 1, Figs. 97 to 101.) The presence of the Lamantin adds another argument to those which arise from the tropical character of many other animals, even of the latest tertiary strata, in favour of the opinion, that the climate of Europe maintained a high, though probably a gradually decreasing temperature, even to the latest periods of tertiary formations.
We have many sources of evidence whereby the history of the Pliocene periods is illustrated: First, we have the remains of terrestrial animals, drifted into estuaries or seas, and preserved together with marine shells; such are the Subapennine marine formations, containing the remains of Elephant, Rhinoceros, &c. and the Crag of Norfolk.* .
Secondly, we have similar remains of terrestrial quadrupeds, mixed with fresh-water shells, in strata formed during the same epoch, at the bottom of fresh-water lakes and ponds; such as those which occur in the Val D'Arno, and in the small lacustrine deposite at North Cliff, near Market Weighton, in Yorkshire. (See Phil. Mag. 1829, vol.. vi. p. 225.)
Thirdly, we have remains of the same animals in caverns: and fissures of rocks, which formed parts of the dry land during the more recent portions of the same period. Such are the bones collected by Hyænas, in the caves of Kirkdale, Kent's Hole, Lunel, &c.; and the bones of Bears in caverns of the limestone rocks of central Germany, and the Grotte d'Osselles, near Besançon.. Such also are the bones of the osseous breccia, found in fissures of limestone rocks on the northern shores of the Mediterranean, and in similar fissures of limestone at Plymouth, and in the Mendip Hills in Somerset. These are derived chiefly from herbivora which fell into the fissures before they were partially filled with the detritus of a violent inundation.
Fourthly, we have the same remains contained in deposites of diluvial detritus, dispersed over the surface of formations of all ages.
As I have elsewhere (Reliquiæ Diluvianæt) entered into
• In the museum at Milan, I have seen a large part of the skeleton of a Rhinoceros, from the Sub-appennine formation, having oyster shells attached to many of its bones, in such a manner as to show that the skeleton must have remained undisturbed for a considerable time at the bottom of the sea. Cuvier also states that in the museum at Turin there is the head of an elephant, to which shells of the same kind were similarly attached, and fitted to the form of the bones.
+ The evidence which I have collected in my Reliquiæ Diluvianæ, 1823, shows, that one of the last great physical events that have affected the surface of our globe, was a violent inundation, which overwhelmed