would wash them into caves and form an òssiferous deposit like that in the caves of Franconia. There can be, however, no general explanation for all bonebearing caves. We must examine all the evidence in each case, and then form our opinion as to how a particular bonebed was formed. Buckland's view seems to me to be in most cases the correct one. So are caves formed and modified, and filled and swept clean and filled again, and we must bear all these facts in mind when we attempt to read the story of a cave from the deposits which we find in it. Broken-up stalagmitic floors are not evidence of the action of the sea, but, on the contrary, must generally be referred to land floods. Laminated clays are not evidence of glacial action, but only of alternations of muddy and clear water, such as follow rainy and fair weather. Some of the most interesting caves, in respect of their contents and the light they throw on the history of primæval man, are only rock-shelters-abris—such as are seen in the Dordogne district.* They are sometimes longitudinal sections of parts of subterranean watercourses, but are more commonly due to the weathering away of soft rock between two harder beds. It does not always require a stream or direct rainfall to wet the surface of a rock sufficiently to let the frost act upon it. The travelling moisture of the air, condensed in and on the cold rock, is enough, and is probably the chief agent in case of a rock undercut so far that the rain cannot touch it, just as Rendut explains the film of ice upon the snow at high elevation not by the melting and refreezing of the snow, but by the condensation of the little moisture left in the air which comes in contact with the snow in those high regions. The carbonate of lime of the limestone is removed by the water and carbonic acid; but whither does it go, and what becomes of the earthy residuum which forms so large a part of some limestones? These can also be traced, and furnish us with evidence of another kind that this subterranean chemical denudation is going on. When the acidulated water falls upon chalk, for instance, and, instead of being collected into rivulets, acts over the whole surface, we find a great mass of red clay, full of flints which have been weathered out. A great part of this red clay is the insoluble portion of the chalk. All limestones have a good deal of iron *Lartet, Christy, and Jones, Reliquiæ Aquitanicæ, 1876. + Rendu, Théorie des Glaciers. 1 in them. When the limestone is weathered away and the iron is oxydised, it colours the earthy residuum red. So cave deposits are often red. When the same process has been carried on at a considerable depth, as, for instance, over the surface of the chalk where covered by the lower Tertiary deposits, the residuum is unoxidised and green.* The carbonate of lime has been carried away in solution, making the spring and river water hard, lining all kettles and boilers with fur. At the mouth of a cave or a spring-head in a limestone district, where the water first gives off part of its carbonic acid, down goes the carbonate of lime which the water can no longer carry, and coats the moss and grass, and anything on which it can collect; and thus we see in petrifying springs only a proof that the chemical waste, which, under certain conditions, forms caves, is going on continually. The quantity of travertine thrown down in some districts is enormous. A great part of Rome is built of this, the Lapis tiburtinus, so named from Tivoli. In caves, as the water gets towards the outlet, the carbonate of lime is precipitated round the edge of a pendent drop or on the margin of some tranquil pool, or, instead of the water eating away the walls of the cave, it coats it over with stalactite, and so protects it from further waste. In doing so it frequently closes up altogether the fissures through which the water once ran. So it grows here, stops growing there; is laid on thickly in one place favourable for its rapid precipitation,-as, for instance, where the water is splashed over the surrounding stones and aërated at a waterfall,-while it takes ages to form a thin film in another adjoining chamber. When the great storm of 1872 broke up the floors at the mouth of Ingleborough Cave, I saw modern ginger-beer bottles which had been buried a foot deep in the stalagmite. On the other hand, Pengelly records that names cut on the walls of Kent's Cavern as far back as the beginning of the seventeenth century† are only just varnished over, as it were, with a thin stalagmitic coating. From the nature of the case this travertinous deposit must be of extremely irregular accumulation, and it is of no value as a measure of the age of the deposits which it covers. On the spray-moistened blades of grass or moss evaporation is rapid, and the travertine soon forms a thick Q. J. G. S. 1866, p. 402. † Pengelly, Brit. Assoc. Reports. Kent's Cavern Committee, 10th and 11th Report, 1874, 1875. porous mass; and inside the caves there is a difference in the quantity of water that trickles over different parts, a difference in the amount of carbonate of lime in solution in the water, and a difference in the rate of evaporation and giving-off of the acid gas. Most of the leading facts with regard to caves and cavedeposits were noticed by Dr. Buckland, and clearly told in his interesting book, the Reliquiæ Diluviana. We must remember, of course, that he wrote that work to support a theory, and so, when he gets to the description of the gravels, &c., associated with the cave-deposits, either in or near the caverns, he sees in them the evidence of a short and transient, but universal, flood. But he quite realised the long sojourn of the beasts of prey in the caves, and the many generations of animals that furnished them with food. He says that he had estimated that in some of the German caverns the bones found indicated ten times the number of individuals that could in the flesh have been crammed into the cave. He spared no pains in gathering information as to the habits of the modern representatives of the hyæna and other animals whose remains occur in the deposits; and his graphic description leaves little to be added. It is interesting to read his ingenious inquiries into the cause of the polished and worn bones which are found in these old hyæna-dens, which he refers to the trampling of the animals on the fragments as they lay partly imbedded in the muddy floor; pointing out, by way of illustration, how some objects of reverence, in stone or metal, have been rubbed down by the touch of devotees. He probably had in his mind the toe of the bronze statue of St. Peter in Rome, which has been polished and worn by the lips of the faithful. Buckland's view, that the deposits of the celebrated Kirkdale Cave, and other similar caves which he refers to, would be connected with a great submergence, which he identified with Noah's Flood, was not, however, so wild as we are sometimes inclined to think, in our eagerness to assert the independence of such inquiries from all preconceived ideas or theological tenets. There certainly is evidence in many places along our coasts of small depressions since the occupation of those districts by man, and it is extremely probable that the land had not, at any rate, recovered its present elevation in this country after the greater submergence that followed on the Glacial age, before man appeared on the scene. There is a great deal of evidence of torrent-action in these caves. There are marine shells washed into them and buried in the same earth as Paleolithic man and the extinct mammals. Buckland's view was, as I believe, far more nearly in accordance with facts than the views of those who have argued for the pre-Glacial age of some of these caverns, which contain only the later group of early Pleistocene mammals. It agrees with the view that there has been a great submergence since the occupation of some of the known Pleistocene caves, but is less wild than the theory that the deposits of that submergence are Glacial because they contain a large percentage of material derived from older Glacial deposits. I have already combated the view that the contents of the Victoria Cave* were pre-Glacial, and I have recently+ examined the evidence upon which the theory that the contents of the caves of Ffynon Beuno were pre-Glacial because they were anterior to the submergence which followed the Glacial age. This view was far more untenable than that of Dr. Buckland, for its advocates held that if the sea of the last submergence washed the mouth of these caves after they had received the deposits containing the Paleolithic remains now. found in them, that in itself would constitute a proof that those remains were pre-Glacial. 1 It is a very curious thing that, although we find such abundant evidence of Paleolithic man in caves as well as in river deposits, there should be so few remains of his bones. Perhaps it was because such little care was taken of the dead that all traces of them were soon destroyed by beasts of prey. However, the fact remains; and, therefore, it is of great importance to inquire into any alleged occurrence of human bones of Paleolithic date. One such announcement was made some years ago, when it was reported that a whole human skeleton had been found with the remains of the mammoth and other extinct animals in a cave on the coast near Mentone. The skeleton was brought to Paris, where I saw it. In a photograph which was shown to me soon after the discovery there were two Neolithic implements lying beside the body, but these were not exhibited with it in Paris. The body was lying on its side in a red earth, with few fragments of any kind in it. There was a quantity of oxide of iron about the head, which might have been the remains either of ornaments in pyrites or of a pigment formed of reddle. Some years afterwards I had an opportuity of examining the place where it was said to have been found, and of con * Trans. Vict. Inst. March, 1879, vol. xiii. p. 316. versing about it with M. Bomfils, who was there at the time it was discovered. The cave is one of several which occur east of Mentone in the Limestone Rocks, known as Baousse Rousse, the Red Rocks. The cave was partly filled with cave earth and angular fragments of limestone fallen from the roof and sides. In this the skeleton was found, as far as I could gather, interred. I learned that the implements which I noticed in the photograph had not been found with it, but had been put in to make a better picture. It appeared that, though found with the bones of the extinct mammalia, it was not Paleolithic, but buried among them, and so it may have been of any subsequent date. The evidence, however, which appeared to assign its more probable age to it,—namely, Neolithic,-was unfortunately of no value, as the implements were not found with the skeleton, but only placed by it to make a more interesting photograph. Some caves, like that of Adelsberg, about twenty-six miles east of Trieste, open out into grand halls draped with stalagmite and sparkling with crystalline incrustations. One of the chambers measures 665 × 640 × 100 feet, and in another, on every Whit-Monday, a great ball is given. The work of excavation is still going on here, for a river empties itself into the cavernous rock below the entrance to these grottoes, and is heard roaring in the deep recesses far within the cave. In other cases, instead of such vast halls, we find a more immense extent of galleries, as in the Mammoth Cave of Kentucky. Both suggest a great lapse of time. In this it is estimated that there are about 150 miles of underground passages. All the drainage of that area drops into great swallow-holes which join the general network of subterranean channels. In them a uniform earth temperature of 54 deg. Fahr. is maintained. No frost and thaw aid the denudation there. As long as the area drained has been unchanged and the amount of acid in the water has not varied, the rate of waste has probably been the same; and though we cannot offer any numerical estimate of the time it has taken to remove so much rock in this way, we cannot help feeling that it must have been very long. If we turn to the fauna of this cave, we get a peep at Nature carrying on some of her most mysterious work. Here we find animals modified to accord with their surroundings, organs unused being atrophied and lost. Where there was no light, they could not see. So many of the insects, crustaceans, and fish are blind. The wild spring and headlong flight of the grasshopper would be dangerous in those dark recesses. The poor insect would dash against the rock or |