Such marine remains are the fragments of ancient or ganic limestones, deposited by the ordinary processes of waste in the form of alluvia ; and among these the bones, or other remains of far more recent origin, are also neces sarily found, if they exist at all in such alluvia. To prove, in such cases, a simultaneous origin and consequent trans portation, the marine remains, like the bones, should be in their natural state; whereas in the supposed circum stances, it is plain that they belong to far different times and places, and that their union is merely casual.
The other case is that of Italy, which, for various pur poses, has so often already come under review. Here the difficulty at first sight seems greater, as the remains of the marine bodies are contiguous to those of land animals, are often intermixed with them, and are, at the same time, not in a petrified state. The peculiar circumstances un der which the bottom of the sea appears here to have been elevated, were formerly explained; and thus, without the necessity or even the possibility of transportation, when the integrity of the remains is considered, have the re mains of land animals existing in after times become ap proximated to those of marine ones.
Thus the greater part of the questions that presume on the transportation of alluvial organic remains are cleared away ; but it must still be admitted, that partial and limit ed transportations of this nature may have actually taken place. Occasional floods do, at the present day, carry to the sea not only the bones but the entire carcasses of land animals; and of these, one very noted instance, just al luded to, occurred in Scotland in the year 1794, when, after a severe storm of snow, upwards of 2000 bodies of sheep, horses, cows, and smaller animals, were deposited in the Solway Firth. Here, therefore, was the foundation of a considerable deposit of alluvial, organic, and terrestrial remains, and which would, in this case, have been mixed with marine ones. That similar events must have taken place in ancient times, often, perhaps, from causes of a more extensive and violent nature, and so as to have pro duced deposits of far greater importance, is more than probable. Such cases, whenever they occur, will admit of explanation on this ground, by duly attending to all the collateral circumstances, without rendering it necessary to adopt that hypothesis more universally.
It is unnecessary here to seek to point out such ex amples among the recorded instances of alluvial fossil de posits, because, without an accurate detail of all the par ticulars, it is impossible to be certain respecting those which have had such an origin. But it is probable, that the cases of the fresh-water deposits, and particularly of those portions where marine and terrestrial remains are intermixed in one stratum or one alluvium, are examples of this kind of limited transportation. Thus we may ac
count for the numerous nuts or fruits found in the upper English clay together with marine remains; these being also substances which might easily have undergone such a transportation without injury. That such substances may be transported to great distances by the currents of the ocean, is proved by the fruits and seeds which the gulf stream and its consequences throw on the western coasts of Scotland; but the effects of these have probably been always too limited to produce phenomena likely to come under the review of a geologist.
On the Origin of the Remains found in Caverns.
The remains of animals that have been found, not in alluvial strata, but in caverns or fissures, or disposed in some other irregular manner, have been mentioned in a former part of this article, but some of the general re marks to which they are subject were reserved to this place, as particularly connected with these general geo logical considerations. It is a subject unconnected with those modes of disposition already mentioned and discus sed, and independent of the reasonings to which they are open. It stands, in fact, as a separate branch of the his tory of fossil remains; but as it refers to the former in habitants of the globe, it is interesting, although not much connected with geological reasonings or theories. That these appearances have sometimes been injudiciously con founded with others of a more general nature, is an addi tional reason for bestowing a transient attention on them.
It has already been questioned, whether the bones found in fissures in Dalmatia do not belong to this class of par-, tial and peculiar deposits. Those of Gibraltar assuredly do. In both these cases, some of the bones are said to belong to hares, and other herbivorous animals already described ; but many also are unknown. Similar collec tions, as we have shown, are found near Montpellier and Nice, and in Corsica. Those of the latter spot are said to be particularly obscure; but, respecting others, it is thought that the bones of animals still existing in the neighbouring countries have been traced in them. It does not appear that any rational explanation of these singular collections has yet been offered; and if the con. glomerate rocks in which they are involved are not of very remote origin, we are not at any rate aware, that such are now in the act of forming. Yet the antiquity of these collections must be less than that of the last considerable revolutions of the earth's surface, on account of their oc cupying fissures that must have been formed in the rocks, not before those events at least, if it is not more probable that they were produced long after.