tumuli, that had been all opened. Urburhill, which reaches out to the sea, lay upon the right hand, and, on advancing farther over the plain, you see the dwelling-house of Howkelie, at a little distance to the right, in a valley which stretches up into the hill. At the upper end this sandy plain was bounded by a glacier-dike or rampart, which extended across the whole valley. As this glacier dike is remarkable, and, so far as I know, the only one of its kind lying close to the level of the sea, in a district where you find only a few heaps of perpetual snow in hollows of the mountains, where it slopes to the north-east, at the height of from two to three thousand Rhenish feet above the sea, I must be a little more particular in describing it. Its length across the valley, from mountain to mountain, is 2250 feet, its perpendicular height above the plain 100. At one of the ends where it approaches to the mountain, it is broken through, so that there the highest part of its brink is not above twelve feet higher than the plain. This opening or breach is not above 200 feet broad. The dike itself consists of coarse gravel and sand, mixed with a great number of immense blocks of gneiss, which is the prevailing kind of rock in the mountain. We find this gravel and sand not only heaped up across the valley, but pushed up in great quantity on the opposite side of the dike, to the length of 1400 feet towards the mountain. The whole bottom of the valley is covered with a lake, which is called Howkelie Water, of the same breadth as the length of the dike, and extending about ten thousand feet up the valley. The people in the neighbourhood say that it is one hundred fathoms deep. As the surface of the lake is only ten feet higher than the plain on the other side of the dike, and as this, therefore, where it is lowest, is two feet higher than the surface of the lake, there can be no run from it on this quarter. The water has its outgate at the other end, by a fall of a few feet, into a similar lake, and from this again, by a little fall at Vasbotten, it passes into a larger lake, called Ejewater, from which it soon after runs into Lyseford. These three lakes lie in a semicircle. From this description it will be easy to see that this dike * By observations I made, Stavanger Church lies in Lat. 58° 57′ 56′′. could have been formed only by masses of ice, which must have filled up the whole valley, and, by their spreading and pressure, have hollowed out its bottom. In all probability the water of the melted ice, at a late period, burst through the dike, and for a while had its issue through the opening, and its present outlet either did not then exist, or was filled up with ice and gravel. On the plain below we find not a trace of the gravel carried down from the dike, a thing of course not to be expected, when we think of a torrent 200 feet in breadth rushing out with violence. Not only the dike itself, but the whole horizontal surface, exhibits proofs that there has been a glacier here, for the plain exactly resembles those which I found adjoining to the glaciers presently existing between Londfiord and Lomb, in Guldbrandsdal, where I had likewise occasion to travel last summer. The resemblance is so striking, that every one who has an opportunity of making the comparison, must form the same opinion. As a proof of this I may mention, that Mr O. Tank, a skilful young mineralogist, who visited with me the dike of which I have given the description, and afterwards accompanied me to the glaciers, I have just mentioned, on seeing the latter, without having heard a hint on the subject from me, he immediately exclaimed that the dike we had seen at Stavanger must be a glacier dike,* As I think that what I have stated will be sufficient to prove that the Norwegian mountains have been covered with ice down to the level of the sea, and therefore that the sea itself must have been frozen, we may from this find the reason why the Norwegian mountains in general are so steep, I may say perpendicular, on the sides which hang over the valleys, not only in the valleys which are high above the level of the sea, but in those from the bottom of which the waters run into the Norwegian Fiords (Firths). Ice, or glaciers, by their immense expanding powers, must, beyond doubt, have produced this change in their original form, from this circumstance, that they were continually sliding The principal glacier in the valley of Boredhus descends from 3000 feet above the sea to 1400, with a moraine or dike, of earth and stones, in front, from 6 to 800 feet broad.-EDIT. + Our English geographers use Frith from fretum, instead of the correct word Firth, from the Danish Fiòrd.-EDIT. downwards from the higher mountains to the lower districes, and, by this progressive motion, carried with them the masses of stone which they had torn from the mountains. It is easy to explain why no trace of these masses thus separated is to be found immediately below the precipices thus formed. As these mountain precipices are often from three, four, to five thousand feet high, and the valleys over which they hang are likewise several thousand feet in breadth, it must be a matter of astonishment to think of such valleys being filled with ice to the extent of several miles. This ice in lower districts must have stretched a long way out into the sea, and, on its thawing, large masses must have broke loose, and gone out to sea, as we find takes place now in the polar regions. I have no hesitation in affirming this, when I survey the effects of immense masses of ice, where there is no room to be mistaken. I shall further mention the supposed effects of glacier ice in another part of Norway, at the level of the sea. Last summer I went by sea from Bergen to Söndfiord and Nordford, on the outside of the Scars (the rocks which lie along the shore), to examine the petrifactions which Pontoppidan talks of in his Natural History of Norway, as to be found in Steensund, in the island of Gulé, at the beginning of the 61° of north latitude. I went on shore at different places; and although I carefully examined every place around, I found not a trace of petrifaction.* On the contrary, I found that the part of the continent separated from it by the Sound, and the island of Inner or Easter Lulé, consisted of a solid conglomerate, composed of boulders, from the size of a pea to that of a man's head. These boulders consisted chiefly of gneiss, quartz, and clayslate, which were involved and bound together in a mass so solid, that it was difficult to find out what the binding medium was, as the interstices between the large stones were completely filled up with small boulders. On closer examination, at particular spots, I found that this binding medium was chlo rite and hard clay. * Professor Rathke, who had formerly been at the same place, and found none, recommended to me to make this examination. On this rock there seemed to me proofs of the powerful operation of ice. I found that the precipices on the side of the mountain next the Sound were several feet in height, and perfectly perpendicular; and though they were composed, as I have mentioned, of boulders cemented together, they were perfectly even and smooth. If these precipices had been the effect of rents, attended with successive masses tumbling down, then the boulders adjoining the rent must have been found adhering sometimes to the one and sometimes to the other of the separated masses, (those which have fallen into the sea are no more to be seen); and, in that case, the boulders left in one mass must have left a mark of itself in the corresponding one. This, however, was by no means the case, as the rock which remained was perfectly smooth, and had the appearance as if these boulders had been cut across by a sharp knife. I can explain this phenomenon in no other way than by supposing, that large masses of ice pressing through the Sound, have cut these precipices lying parallel to the direction of the Sound. I could give other proofs of the conclusion I have sought here to establish, but, to persons capable of judging of the matter, I consider these as sufficient. The result of what I have said I may state in the following particulars. 1. That, in the beginning, the earth existed in a fluid state. 2. That, during the long period it required to assume its proper composition and form, it has alternately been, at one time, at such a distance from the sun, that all the water upon it must have necessarily been converted into ice; at another so near it, that not only the solid earth and minerals underwent a change, but also the fluid substance which held them in solution was decompounded and changed. How deep these changes went into the body of the earth we have yet no means of ascertaining. By comparing the phenomena of burning volcanoes with the combus tion of the metalloids, kalium, natrium, silicium, calcicum, we may conclude, that, deep in the bowels of the earth, there is to be found a multitude of specific metalloids, the combustion of which is the cause of the eruptions of volcanoes. 3. That organisation did not begin till this long period was completed, which the earth required to the full development of its own constitution; that, after it began, it proceeded by successive steps from the less to the more perfect formations, ending with man as the head of the whole. Observations on the Structure and Functions of the Sponge. By R. E. GRANT, M. D., F. R. S. E., F. L. S., M. W. S., THE silicious and calcareous spicula above described are grouped into strong fasciculi, which are disposed around the internal canals of the sponge, in the order best calculated to defend these passages from compression, and from the entrance of extraneous bodies, and likewise to form between the canals certain interstitial spaces for the development and exit of the ova. Like the hard parts composing the skeleton in other animals, these earthy spicula are maintained in their relative situations by a tough ligamentous matter, distinct from the other soft parts of the sponge. In the horny species, however, where the axis is composed of cylindrical tubular horny fibres, ramified and continuous throughout the whole body, this connecting cartilaginous matter appears to be unnecessary, and, from the examination of dried specimens, it appears to be altogether wanting. The examination of the living properties of the axis in the horny species forms a subject of curious and interesting inquiry, which must be left to those who have opportunities of observing them alive in warmer latitudes, as they do not seem to inhabit the British shores. The dried filaments of the S. fistularis, Lam. when viewed through a powerful microscope, appear to consist of one continuous ramified tube, whose central cavity (Pl. II. Fig. 19. b) is entirely filled with a dark opaque granular matter, which does not consist of spicula, while the sides of the tube (a) are transparent and amber coloured like common cat gut. In the S. officinalis, where the filaments are much finer, the sides of the tube (Fig. 20. a) have the same colour and homogeneous appearance, but the central cavity (b) appears empty. Mr Ellis states, |