COLIJBER.
Only one instance is mentioned of the occurrence of bones of serpents in a fossil state. This is in the calcare ous breccia of Montpelier, which resembles that of Dal matia, and the fragments are thought by Cuvier to be like those of the common snake, or C. Natrix.
MAN.
We have had occasion to notice, in another place, the presence of human skeletons in a calcareous rock, in Guadaloupe. There is a specimen in the British Museum, from which our figure has been taken; and it requires no particular notice here, as we have mentioned the nature of the rock in which it is inclosed elsewhere. This skeleton is very imperfect. It is described at great length by Mr. Konig in the Philosophical Transactions; but the figure will supersede the necessity of any description in this place.
Of the Fossil Organic Deposits found in Fissures.
We mentioned, in rather a general manner, in another part of this article, the calcareous conglomerates, gene rally belonging to fissures, which eontain fossil remains ; but, for the illustration of some of the preceding observa tions, it will be convenient to bring them together here somewhat more particularly.
The general position of these conglomerates is in the fissures or caves of different calcareous rocks, the geo logical relations of which are not all known, and which, in this case, indeed, are of no importance. The pheno mena in question are quite independent of the date of the rocks themselves. The fragments are always angu lar, and generally adhere by means of calcareous infil trations, the solidifying power of which is assisted by the smaller sand and fragments. These rocks are, therefore, in the proper sense of the word, alluvial ; since it is of no mo ment, as far as the mere alluvium itself is concerned, whether it is spread out on a plain, or included in a casual receptacle. All that can be said is, that they are local and partial alluvia, indurated, in consequence of their peculiar nature and position, to the state of rocks. As to other minor particulars, namely, the presence of vesicles, or unfilled spaces in them, or that of veins, they are evident ly mere casualties, possessed of no kind of interest as far as the main question is concerned.
Now, it appears to us utterly vain, as we have else where slightly observed, to attempt to draw any general conclusion of a geological nature respecting these sub stances ; to refer them all to some one date, or, at any rate, to recent ones. and then to make use of these in rea soning upon epochas respecting different kinds of fossil animals. Assuredly, no one will deny that they have not
been formed either by a tranquil sea or by any sudden inundations. Nor can any geologist be so inconsiderate as to imagine that they had been formed under the sea, or to expect to find in them sea shells, or marine remains of any sort. As little could any person, with the slightest knowledge of geology, expect to find them covered with stratified rocks. Consequently, and without the necessi ty of any circuitous reasonings on the subject, every one must conclude that they are the produce of fragments which have fallen into fissures formed in the open day, and have there been consolidated, just as such operations are now hourly going on in all calcareous cavities.
Thus far is abundantly simple, but what follows is by no means so obvious. We will admit, if Cuvier pleases, that these rocks are modern when compared with the seconda ry rocks, but it does not necessarily follow that they are so with respect to all the alluvia also ; or rather, that there is no one of them which is not more modern than the most ancient alluvium that contains the remains of lost animals. This proposition is indeed, in some measure, contradicted by his own statement, that the breccias of Corsica contain the remains of unknown animals. Neither do we see any reason for, or any advantage in, admitting that no such rocks are formed at the present day. Those very precise rocks could not be ; but similar formations are daily going on wherever there are open fissures into which fragments can fall, and calcareous matter by which they can be agglutinated. Not to mention the very fami liar and parallel cases of cavities and fissures in calcareous racks, we can refer to such recent conglomerates in the fissures of gneiss, of slate, and of trap ; in Glen Shiel, in Lewis, in the Isle of Man, and in Bute. Our conclu sion, therefore, so far differs from Cuvier's as to be this, that such breccias may be of any possible date from the time at which the sea no longer covered the rocks, and that they may thus be of the same antiquity as the most ancient alluvia, unless a terrestrial alluvium an be pointed out, that was deposited where it now lies, while the land was still beneath the ocean. At the same time, like all other alluvia of a loose and horizontal disposition, they may be of any more recent date down even to the present time.