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now; for the great glaciers that filled the larger valleys issued out upon and overflowed these low-lying river-gravels, and deposited their moraines above them, only in part scooping them away, apparently because the glaciers did not endure long enough of sufficient size to complete their destruction. No better proof could be required that in great part the valleys of the Alps were approximately as deep before the glacial epoch as they are at present; and I believe, with the Italian geologists, that all that the glaciers as a whole effected was only slightly to deepen these valleys."—Phil. Mag., Nov. 1862, p. 379.

This passage was, I presume, intended to upset the doctrines of Dr. Tyndall, and it did so, conclusively, as far as the mouth of the Valley of Aosta was concerned. It struck almost as severely at the opinions of its author. Indeed, there is scarcely anything more damaging to be found in the whole of the remarks which the publication of his original memoir called forth. At the mouth of the Valley of Aosta, during the glacial epoch, the whole of the conditions were found which Professor Ramsay requires for the formation of lake-basins. There was a vast glacier that issued out upon a plain, and which, in consequence of retardation, worked with unusual effect (?). It is demonstrable that it existed upon the plain for an enormous length of time; it is certain that it was extraordinarily thick; and the particular area upon which it worked was undoubtedly favourable for excavation. Yet the Professor is obliged to confess that the ice was unable to remove loose river-gravel lying upon the surface (indeed, that the glacier actually left another stratum of drift upon the gravel), and that the solid rock beneath did not experience any excavation whatever! There are many other places at which the same thing is known to have occurred, and so far from there being any especial tendency to excavate towards the snouts of glaciers, well-established facts lead rather to the opposite conclusion. A glacier which is bearing moraines always has those moraines brought together, jumbled together, towards its snout. Much of this moraine-matter falls down the sides of the glacier, and gets wedged between the ice and the bed-rock; much more falls over the terminal face of ice, and forms a stratum over which the glacier has to pass. This continually happens as the