obviously showing the results of the very long continued action of subterranean streams, that one is puzzled as to what has occurred there, and at a loss to connect what is seen with those great bodies of water which may through the weathering of the limestone, have washed everything out. There no boulders are to be seen-nothing but the most beautifully fine dolomitic sand and crystallised lead ores, sometimes showing in large masses, like sides of bacon. In the Forest of Dean there are similar openings, where a valuable iron ore is found, the other materials in these caves also being almost entirely dolomitic. I should like to hear from Professor Hughes whether he has observed anything of the kind at Ingleborough. Here let me say that I think one of the most important lessons we have to learn is, the great caution that ought always to be observed in seeing that our observations are made with scientifically systematic precision; and, in the next place, in only accepting statements that are made as to these matters when they are founded on exact work of this kind, undertaken by experienced persons, well qualified to judge of the mode in which cave-openings have been formed as well as of the mode in which they have been filled. Mr. J. STALKARTT.-I should like, in saying a few words on this subject, to know whether the history of the tigers and hyenas, whose remains are found in the caverns. spoken of, is different from that of the tigers and hyænas now existing in different parts of the world? Ordinarily, when a tiger or hyæna kills any animal he does not drag it into a cave, but eats it where it has been seized; it is only when it has young to feed that it drags the carcass to its den. A lion does not carry its prey up a mountain side; it lies in wait near the track of the animal it kills, and there takes its fill The hyæna might drag its prey down a hill, but would hardly drag it uphill. We know that in India these animals kill and eat their prey on the spot, only sometimes carrying their prey a short distance. They may quarrel over the remains, and drag pieces hither and thither; but, for the most part, they eat where they kill; that which they leave is chiefly the head. Suppose a bullock that has died a natural death is found: the jackals quarrel over it; a leg is drawn here, and another there, but the greater portion of the carcass is left, and the head, which they cannot gnaw, invariably remains. Therefore, I am not inclined to believe that these caves were the resort of hyenas in the manner alleged. I think we ought to inquire into the fact whether the hyænas referred to by geologists had habits differing from those of similar animals at the present day. Mr. S. R. PATTISON, F.G.S.-I take it that the hyenas spoken of as found in caves were not only inhabitants of those recesses, but made incursions in search of prey. In Somersetshire the existence of the lion is too well attested to admit of any doubt, and the fair inference from the bones found in the caves is that they were dragged there. It is, however, by no means certain that all the hyæna and other bones found in caverns were those of animals dragged in: doubtless many of them are those of animals that died a natural death where they are found. I am sure we ought to be thankful that Professor Hughes, during his Ingleborough explorations, was able to escape being made a martyr to science; for I can understand, having travelled those moors myself, how easily an accident of a serious nature might have occurred. As to the paper this evening, it fully bears out Professor Hughes's promise to tell us all about the operations of nature in forming and filling these rocky caves; and not only has he kept his word in this respect, but he has given us a graphic and picturesque account of the exceptional meteorological circumstances which sometimes act as factors in these transactions. With regard to the glacial period, it may be gathered that there was first of all a glacial period; then a pluvial period which has been slightly referred to as that of a Deluge ; then the period in which there was the final subsidence of the land and the accumulation of modern gravels which we now behold. The controversy arises as to whether the animals whose bones are found in the caves lived before the glacial period or afterwards. What I have to say on this point is that the glacial period is really a sort of sliding scale. Its effects may have been felt at one spot and not at another at the same time, so that there must have been constant wasting at one time and place and constant accumulation at another; the result being that life may have made its appearance, and then its evidences may have been mechanically covered up by the changes. The subject is one of extreme difficulty, and I should say it is impossible, as far as dogmatic assertion goes, to say much more than this. I quite agree with Sir Warington Smyth that these matters should be dealt with by geologists with the utmost caution, especially with regard to the conditions of life during the glacial period. With regard to the animals found in the Kentucky Cave, Professor Hughes thinks that certain of the features to which he refers in the case of those creatures have been modified by their surroundings; but the fact is that there is no trace of modification, for, as far as our knowledge goes, the features there remarked have always been the same,-the long antennæ and absence of wings in the insects he alludes to having been constant. Consequently, I cannot see the force of producing these as proofs of evolution. Then, as to the mushrooms in the fairy rings, which, it is said, are prevented from growing inside through the material being exhausted, so that there the species become extinct; I submit that the species does not become extinct. The individual dies, but not the species; and, although it may be speculated on as a theory, we have no instance of a species dying out in that way. I will not now enter into any argument upon the point, but simply claim to enter a caveat against it. Mr. D. HOWARD, V.P.C.S.--It seems to me that the paper to which we have just listened is one of exceptional value, not merely on account of the inherent interest of the subject, but from the very useful and sound method of study it puts before us. It was, I think, a most fortunate accident that led Professor Hughes to Ingleborough at the time of the great storm, the effects of which he has described, because a more accurate and valuable account of that catastrophic incident could not have been furnished. The subject is one of very great importance in many ways. The more we are struck with the continuity of causation, the more must we guard against circumstances which carry the idea too far, especially in regard to questions connected with chemistry, which afford abundant examples of the danger of carrying this theory beyond its legitimate scope. We have many examples of stalagmites forming with perfect regularity, and we assume that the process has been going on from endless time. I have twice seen the Ingleborough Cave. The first occasion was during a very wet summer, when a vast deal of water came down, not in torrents, but with a very rapid formation of stalagmite. The autumn following was very dry, and the stalagmitic formation not so rapid, and I could not help thinking how utterly impossible it must be to form anything like an accurate judgment of the speed of formation when the process was shown to be going on at two different rates. It is not merely the action of carbonic acid in the destruction of the rock that strikes one, but the wonderful way in which the solvent process goes on hollowing out the lime and disintegrating the stone, until some flood occurs and washes away vast quantities of the broken up débris. This is specially the case in the carbonated rocks, where you get a more rapid solution than in other cases; because the rock is honeycombed and cut to pieces in a wonderful manner, so that it goes to pieces with a comparatively small rush of water. Throughout the whole of this question you must bear in mind that a very slight alteration in the balance, whether of the carbonic acid produced by the surface vegetation, or in the proportion of water to carbonic acid, may make a very wide difference in the result. The presence of a little more or less silica in the water may make a vast difference in the mode in which the travertine is deposited. Any one who has had experience in connexion with steam boilers knows full well that you may have it deposited in an exceedingly hard scale if there be a sufficient amount of silica to cement it together; or, if this is not the case, it may exist as an exceedingly soft powder, which blows away directly the blow-off cock of the boiler is opened; in the same way it is not merely the percentage of carbonate of lime that is dissolved and set free by the evaporation of the carbonic acid, but whether there is sufficient cementing action going on to form a solid mass to resist the inflow of the water. One cannot help being struck with the amount of careful knowledge displayed by the author of this paper. He goes back to the most minute forms of things. This is what Lord Bacon did many years ago; but the lesson is one that has not been fully learned yet, although it is refreshing to find that it has been acquired and put in practice by Professor Hughes. Sir WARINGTON W. SMYTH-(taking up from the table a pipe encrusted with stalagmitic deposit) asked how long it had taken to produce that result. Professor HUGHES said he was unable to say. Sir WARINGTON W. SMYTH.-I have seen a pipe as large as this filled up in two years. Professor HUGHES then replied, saying :-A question has been raised by Sir Warington Smyth as to how the bones got into the caverns. That, question is one that ought to be asked with regard to each cave separately. There is, first, the suggestion that the bones may have been washed in from above. I have discussed this point (p. 90). Or the bones may have been carried in by animals that inhabited the caves; and then we have to consider whether these caves were ever hyæna dens, whether the beasts of the present day behave in the same way as those whose remains are found in the caves appear to have done. Dr. Buckland found that they do. He examined carefully the bones of the animals gnawed by hyænas, and found the marks of teeth on the bones so dealt with, and that those bones which had marrow in them or some little flesh adhering to them have had splinters torn away, or are altogether broken up. Thus, it is clear, from the accumulation of evidence, that hyænas were there, and had dragged in the remains of many of the larger animals which are found lying about. In some cases we find, instead of a mass of broken bones, the bones lie whole upon the floor of the cave. This seems to have been the case where the remains of bears are found; it is different when we have a hyæna den. It is evident that, in determining these questions, a great many things have to be taken into account. As to the way in which the carcasses are dealt with, we must remember that, when the larger animals have done with them, the smaller ones come in,—the foxes, the rats, and the mice,—all of them pulling the bones about. We trace them by the marks of their little teeth. Thus, you may find the bones drawn up into crevices into which they could not have been carried by the larger animals. Once, at Cambridge, I was shown a set of bones that ought not to have been in the gravels, from which they were said to have been obtained. I went and asked the workmen where they got them. They showed me the place, and told me they were in a sort of hole stretching from one point to another across the corner of the pit. I cleared out and examined the hole, and noticed in it a series of claw-marks, showing that the place had been used by badgers and foxes. Thus we had another example of the way by which the bones were conveyed into places where the larger animals could not have taken them nor water have washed them. Or, again, the bones may be those of animals which died in the cave —bears, for instance. In one case the bats were described as furnishing, in the shape of their own bones, a large portion of the deposit. Thus, it will be seen, we have to go from one thing to another to arrive at the true explanation. Those animals came there, lived there, and died there, and the remains of bats covered the whole of the bottom of the cave. Owls and other birds of prey also bring in remains of animals, as I pointed out in the case of Cave Ha. The same kind of thing has been noticed in America, where in the upper layers of cave-deposits are, in a number of cases, found the pellets of owls, and lower down the bones of small animals, packing Therefore, it is necessary that in every case we should all the interstices. Therefore, it consider how the bones found in a particular cave got there. Mr. J. STALKARTT.—They do not eat in caves. We find in India that the tiger will not go into a cave where he has a wilderness or jungle at hand. This is so in the case of the tigers close by the Himalayas ; but another tiger, which is rather smaller, and is found on the other side of the Ganges, does go into caves, and has there been shot in the most plucky manner by British officers. If you get evidence from those caves of such a deposit of bones as has been described, then, doubtless, the inference which has been drawn will hold good. It may be that the hyænas spoken of may have gnawed the bones before they got into the caves. When a lion or a tiger has killed an ox or other large animal, and sucked the blood or eaten part of the flesh, the jackals go to the carcass and finish the work, or the vultures assemble and tear it to pieces. Professor HUGHES.-We have not found traces of the tigers behaving otherwise than according to their ordinary habits at the present time. We do, however, find remains of hyænas in the caves, and, as we are informed, the hyænas of to-day do leave their marks on the bones of the animals they eat, and other traces, just such as are found in the caves, and that, I think, is sufficient. With regard to the glacial epoch, I have confined myself to what has happened in one particular valley, and asked what is the order of events found there, for the glacial conditions found in another hemisphere can make no difference as far as this particular matter is concerned. The record of intermediate forms is exceedingly rare. If we could find in any of these caves a set of deposits representing every stage in the growth of cavern-deposits, we should possibly get all the various developments of the intermediate forms of life; but, not having these, we say that the remains we find are those of creatures which do suit their surroundings, and differ from the nearest allied forms by modifications such as might be carried out according to the laws of evolution as worked out and observed within the limits of our lives. It is one of those cases in which you have an hypothesis founded in the first place on one bit of evidence, and then supported by the comparison of that with another bit of evidence, until you get more and more data added to what was at first insufficient and the foundation of a tentative hypothesis only, and in the end you come to the conclusion that nothing but that hypothesis will fit in with all the observations made. With regard to what has been said about the fairy rings, what I meant was that the plant became locally extinct within the circle, and, if its possible area of growth were limited, and it were pushed to the margin, it might, in the same way, become totally extinct. As to species having died out, I need only mention the sea-cow, the dodo, and the auk. Mr. PATTISON.-I did not mean it in that way. All we have to do is to show |