therefore _remaniés_--the relics of the bottom-moraine of the North Channel _mer de glace_ rearranged and redistributed. And this is why they and other Irish rocks are so comparatively rare in the glacial accumulations of the west of England. [X] _Trans. Edin. Geol. Soc._, vol. ii., 1874. Thus all the instances of intercrossings adduced by Mr. Mackintosh as favouring the iceberg theory, and condemning its rival, I would cite as proving exactly the opposite. So far from presenting any real difficulty to an upholder of the land-ice theory, they, in point of fact, as I have already remarked, lend that view additional support. It is not my purpose to criticise all the arguments and reasons advanced by Mr. Mackintosh in favour of his special views, but I may be allowed a few remarks on the somewhat extraordinary character of the agents which, according to him, were mainly instrumental in producing the drift-phenomena of western England. Before doing so, however, I may point out that, in ascribing the transport of erratics in that region (and, by implication, the formation of the boulder-clays, etc., with which most of these erratics are associated) to floating-ice and sea-currents, Mr. Mackintosh has failed to furnish us with any "fossil evidence" to show that western England was under water at the time the boulder-clays and erratics were being accumulated. He speaks of cold and warm currents, but where do we find any traces of the marine organisms which must have abounded in those waters? Where are the raised sea-beaches which must have marked the retreat of the sea? Where do we encounter any organic relics that might help us to map out the zones of shallow and deep water? The sea-shells, etc., which occur in the boulder-clays are undeniably _remaniés_; they are erratics just as much as the rock-fragments with which they are associated. Similar assemblages of organic remains are met with in the till of Caithness, where shallow-water and deep-sea shells, and shells indicative of genial and again of cold conditions, are all confusedly distributed throughout one and the same deposit. The same or analogous facts are encountered in the _Blocklehm_ of some parts of Prussia, marine and freshwater shells occurring commingled in the boulder-clay. Nay, even in the _moraine profonde_ of the ancient Rhone glacier, broken and well-preserved shells of Miocene and Pliocene species appear enclosed in the tumultuous accumulation of clay, sand, and erratics. And precisely similar phenomena confront us in the glacial deposits of the neighbourhood of Lago Lugano. Mr. Mackintosh refers to the so-called "stratification" of the boulder-clay, as if that were a proof of accumulation in water. But a rude kind of bedding, generally marked by differences of colour, and sometimes by lines of stones, was the inevitable result of the sub-glacial formation of the boulder-clay. The "lines of bedding" are due to the shearing of the clay under great