We must yet notice another hypothesis on the question of climate, which has been proposed for explaining the subject of fossils supposed to have been once tropical beings, in cold climates. This is a former sate of the globe, in which its temperature was higher than it is at present ; an opinion that has been entertained by geologi cal theorists for the purposes of explaining many other phenomena besides this one. That opinion, as promul gated on different grounds, and with different views gene rally, by Baron, 1)e Luc, Breislak, and others, rests, how ever, so little on facts, and involves such a mass of spe culative reasoning on the subject of heat, on an imaginary former state of the globe, and on the general theory of the earth, that it does not admit of examination in a discus sion of this nature, without wandering into the endless and obscure wilds of geological hypothesis. A discussion of the chemical questions alone that are implied in this hy pothesis would occupy in itself an essay; nor are we aware that any advantages could be derived from a laborious in vestigation of possibilities for the purpose of explaining or establishing what may never have existed. At any rate, such inquiries are inadmissible in an essay of this nature, and we must therefore refer our readers to the au thors who have entered on this field, and whose writings will convey both amusement and instruction, although they should fail in establishing this point. Should such a former state of the earth be either proved, or rendered probable, it will then be time enough to inquire how it bears on the question at issue, that relates to the climate under which fossil plants and animals lived.
On the Transportation of Fossil Remains It will not now be necessary to say much respecting the transportation of fossil remains, as the chief arguments which relate to it have been already in a great measure anticipated. However true it may be, that, in particular cases, such fossils have actually been brought from dis tant places to those where they are now found, the opinion has been unwarrantably extended to many others, obvi ously as an hypothesis, for the purpose of explaining these imaginary transportations.
'When the general deluge was resorted to as affording an explanation of the existence of fossil shells at their present enormous elevations above the level of the sea, it became necessary that they should also have been trans ported to those situations by the motion of the waters. Other writers, unwilling to admit the elevation of the strata, or actuated by a love of their own inventions, have adopted tides, currents, and incomprehensible revolutions of other kinds, to effect that, which they did not choose to attribute to the Mosaic deluge. \Ve shall hereafter ex amine these general questions, as far as it is possible and necessary to do so, in our future article on THEORIES OF THE EARTH ; and it is only requisite here to ask, whether these fossil shells do exhibit the marks of transportation or not ? It was already shown, for other purposes, that these shells were frequently found so perfect, even in the most tender parts, as to preclude all possibility of a distant transportation in their loose or separate state. The same
argument applies, in the same or a greater degree, to plants, which are often preserved, even when most deli cate, as they would have been in the Hortus siccus of a botanist, although still found separated, or in detached parts only. \Ve need scarcely make the same remark on fishes, which, from their softness and destructibility, could not have admitted of transportation. But the case of Monte Bolca has already been considered ; and it is only necessary here to add, that, if in a less degree, still the same conclusion may be drawn from those whose impres sions, if not themselves, are found in the limestones and schists. Though the animal itself may have vanished, it is equally certain that it was originally imbedded in the place where it died, without undergoing any transference after death, until long after it was consolidated in its bed, and protected from injury.
It was also shown that, in many cases, the different species were found unmixed, or in separate colonies, as living shells arc now found tinder the sea ; offering a proof that they are now imbedded in the same earths in which they had lived, although these had been indurated to the state of a rock This is very remarkable in the case of the Cerithium formerly mentioned, in that of the Milio lites of Mont Rouge, in the Nummulites, and in numer ous other instances, which it is quite superfluous to quote. Even where more species than one are found together, it does not vitiate this argument ; because the same occurs in living animals of the same tribes at present. It is almost unnecessary to add to these arguments the fact, that these shells are disposed in the same manner towards the planes of stratification of the rocks in which they are found, as they were in the original beds of earth, wher ever their forms are of such a nature as to admit of such a choice of position. But it will not be denied, at the same time, that in some cases there are marks of transportation in fossil shells, indicated by their fractured and imperfect state, by their intermixture, and by other circumstances too obvious to require mention. Examples of this exist in the oolites, formerly noticed, and conspicuously in the Purbeck stone.
But even to produce such effects, no distant transpor tation, by means of diluvian or other currents, or by general deluges, is necessary. At this moment, the sound ings of mariners show that fragments of various shells are found intermixed at the bottom of the sea. On certain coasts, similar fragments of various species are accumula ted in the shape of sand. These are the probable germs of future rocks; but the transportation has, in these cases, as probably in most others of the ancient ones, been limited to that small motion which is the result of the daily and incessant action of the winds and waves. If there have been transportations of shells produced in former times by diluvian currents, or by actions, of whatever kind, of a more extensive nature than the ordinary movements of the sea, it is to be feared that we are scarcely in a con dition to prove them.