in proportion to the quantity and the size of the bones that have to be broken; and these conditions of structure will necessarily influence the development and form of the several parts that contribute to move the jaws.

The strength of the claws, in like manner, and the mobility of the paws and toes, have a necessary relation to the forms of the bones in the feet, and the distribution of the muscles and tendons by which they are moved. As the bones of the forearm are articulated with the humerus, no change can be made in the form and structure of the former without occasioning correspondent changes in the form of the latter. The shoulder-blade also, or scapula, requires a correspondent degree of strength in all carnivorous animals, while the play and action of the several parts are dependent on the muscles which set them in motion, and the impressions formed by these muscles still further determine the forms of all these bones. Again, the shape and structure of the teeth regulate the forms of the condyle, of the scapula, and of the claws, in the same manner as the equation of a curve regulates all its other properties; and, as in regard to any particular curve, all its properties may be ascertained by assuming each separate property as the foundation of a particular equation, in the same manner a claw, a shoulder-blade, a condyle, a leg or arm bone, or any other bone separately considered, leads to the discovery of the characters of teeth to which they have belonged; and reciprocally from the teeth we are enabled to discover the structure and forms of the other bones.

Thus, conducting his investigations by a careful survey of the bones and organs individually and separately, the skillful anatomist was enabled to reconstruct the whole animal to which they severally had belonged. The orders likewise and subdivisions of herbivorous, ruminant, hoofed, and cloven-hoofed animals, he determined with equal precision, and found to result from the same constant laws of organization. By employing the method of observation, where theory was no longer able to direct his views, Cuvier was furnished with other astonishing results. The smallest fragment of bone, even the most apparently insignificant apophysis, he found to possess a fixed and determinate character, relative to the class, order, and genus of the animal to which it

elonged; insomuch that, when he observed merely the articulatng extremity of a well-preserved bone, he could at once ascertain he species as certainly as if the entire animal had been before im. Proceeding after this method, assisted by analogy and exact comparison, Cuvier has been enabled to determine the fossil remains of seventy-eight different quadrupeds, in the viviparous and oviparous classes. Of these, forty-nine are distinct species hitherto unknown, twenty-seven of which are referable to seven new genera, and the other twenty-two new species belong to sixteen genera, or sub-genera, already known; while the whole number of genera and sub-genera, to which the fossil remains of quadrupeds investigated belong, are thirty-six, including those both of known and unknown species; some hoofed animals not ruminant, and some ruminant-others gnawers and others carnivorous-two, of the sloth genus, toothless and two, amphibious animals, of two distinct genera.

Such are the triumphs of science, which always lead to a profounder admiration of the works of Nature, in the immensity and constancy of those laws that have prevailed through all time, and where her wisdom and foresight are demonstrated by a series of systematic contrivances and mutual adaptations to which she invariably adheres. In the remote invisible depths of space, slight oscillations have from time to time been detected, and following up the researches, astronomy, as announced beforehand, is rewarded by the discovery of a new planet. The earth gives up its dead, entombed for ages in its stony matrix. At the bidding of science their figures are restored, their habits determined, their very food ascertained, their characters for ferocity or otherwise brought to light, and they are all, each after their kind, called by their names. What a mastery in all this over the extinct forms of organic nature, as Newton manifested in a different way in his wonderful deductions and calculations respecting the molecules of inorganic nature and the physical heavens!

III. The Paris basin, which consists of the lower or eocene series of the tertiary system, is inclosed nearly on all sides by the middle or miocene group of strata. These, however, are most

fully developed along the district of the Loire and its tributaries, as the former are chiefly confined to the water-shed of the Seine and the environs of Paris. We thus advance a step upward in the Course of Creation, while so far as geology has been able to mark the progress, the last stages of the stupendous work, prior to the introduction of its noblest inhabitant, are to be discovered in the PLEIOCENE deposits that immediately succeed, stretching over the western shores from Bordeaux to Bayonne.

THE BASIN OF THE LOIRE. The rocks which compose these upper layers of the earth's crust, have all a family resemblance to the tertiaries already described. In the district of the Loire the miocene beds consist generally of quartzose sand, gravel, and broken shells, mostly loose and earthy, but in many places agglutinated by a calcareous or ferruginous cement, so as to be fit for building purposes. The "faluns," as they are provincially termed, resemble the crag of England, abounding in shells, and mammiferous remains incrusted with serpulæ, flustra, and balani. The deposit is seldom above seventy feet in its greatest thickness. Betwixt Sologne and the sea, patches are found to rest successively upon gneiss, clay slate, the coal-measures, Jura limestone, greenstone trap, chalk, and the upper beds of the eocene series. The pleiocene beds are not materially different in their lithological characters from those of the miocene group: blue clays, marls, and osseous breccias are among the prevailing strata; and siltings of sand and gravel, only distinguishable by their organic remains from the alluvia and superficial drifts of the current era. Volcanic products are often largely mixed up with these pleiocene beds, and in districts where, in addition to the fossil evidence, they clearly establish that they belong to the class of extinct volcanoes, as the sedimentary deposits are themselves determined to belong to the pleiocene age.

The interesting peculiarity connected with these two groups of the tertiary system is, that here all animal as well as vegetable life approaches a step nearer to the existing family types. Analogous species of molluscs are more numerous, the testacea in many instances being identical with those of our modern seas. The mammalia are likewise more akin to those of our domesti

ated tribes, where the horse is strikingly prefigured in the hipotherium, the dog in the agnotherium, and the cat in feline forms s large as lions. The glutton and the bear have also their comeers, nor are the fox, hare, and mouse, without their represenatives. But the marvel of the formation is the DINOTHERIUM or gigantic tapir, whose dimensions in every organ and member are

stupendous. The dinotherium was seemingly possessed of powers which enabled him at once to exercise the digging propensities of the mole and amphibious habits of the walrus, a trunk projecting nearly as long as that of the elephant, and two enormous tusks depending from the lower jaw. This animal was partly terrestrial and partly aquatic, and hence, says Dr. Buckland, the tusks may also have been applied to hook on the head to the bank, with the nostrils sustained above the water, so as to breathe securely during sleep, while the body remained floating at ease beneath the surface. Thus would he repose, moored to the margin of a lake or river-the huge body, of eighteen feet in length, with a corresponding thickness, indolently basking in the sun-beams, or quietly cooling after exertion in the limpid wave- and these enormous tusks, ready to release him at a bound, when attacked by the enemy beneath. The dinotherium existed during the miocene period, and constitutes an intermediate link between the

tapir and the mastodon. It has left abundant remains in the basin of the Rhine, in Bavaria and Austria, and in several districts of the formation in France.

This

The tertiaries have a wide geographical distribution, and cover a vast extent of superficial area. Stretching from the Rhone to the Danube, they are found in every part of central and southern Europe, along the Julian Alps, and over the interior of Italy, from Ancona to Turin. The eocene group is ascertained, from the character of its fossils, and especially by its nummulites and echinoderms, to extend from the Mediterranean, through Egypt, AsiaMinor, and Persia, to Hindostan, and there to occupy large regions forming the western and northern limits of British India. enormous mass of tertiary strata was drifted into lakes or estuaries, whereby the mind is carried back to a period when Europe was chiefly lacustrine, and all these countries eastward were as yet submerged in their waters. What explanation can geology give of their elevation to the surface? A scene of volcanic agency, now and before the modern epoch extinct, remains to be noticed, which in part at least will furnish a probable solution of the changes then in operation or completed.

CENTRAL FRANCE, consisting of the districts of Auvergne, Velay, and Viverais, is universally admitted by geologists to be of volcanic origin. The most cursory glance at the dome-shaped hills, the basalt, trachyte, and scoriaceous ingredients of which they are composed, at once satisfies the student of nature as to the class of rocks among which he here treads. This region lies upon the river Rhone, nearly in the angle formed by it with the Mediterranean, and covers an area of forty or fifty leagues in diameter. Here are associated, perhaps, the earliest and the latest products of Plutonic action, the primary granites, and the basaltic lavas of comparatively recent times. The granite is flanked on the south and west by immense overliers of gneiss. It may be described as the highlands of the country, whence all the great rivers, the Seine, the Loire, the Gironde, and their principal feeders, take their rise. The mountains, though not remarkable for elevation, now that we are approaching true Alpine peaks, reach the height of four, five, and six thousand, and the Aurillac