It will be remarked by all who have followed the discussions respecting the transportation of loose materials over great distances from the spot where they occurred primitively, that the most minute and the most careful investigations have been made by those geologists who have attempted to establish a new theory of their transportation by the agency of ice. The part of those who claim currents as the cause of this transportation has been more generally negative, inasmuch as, satisfied with their views, they have generally been contented simply to deny the new theory and its consequences, rather than investigate anew the field upon which they had founded their opinions. Without being taxed with partiality, I may, at the outset, insist upon this difference in the part taken by the two contending parties. For, since the publication of Sefstroem's paper upon the drift of Sweden, in which very valuable information is given respecting the phenomena observed in that peninsula, and the additional data furnished by De Verneuil and Murchison upon the same country and the plains of Russia, the classical ground for erratic phenomena has been left almost untouched by all except the advocates of the glacial theory. I need only refer to the investigations of M. de Charpentier, Escher, Von Derlinth and Studer, and more particularly to those extensive and most minute researches of Professor Guyot in Switzerland, without speaking of my own and some contributions from visitors,--as the Martins, James Forbes, and others, to justify my assertion, that no important fact, respecting the loose materials spread all over Switzerland, has been added by the advocates of currents since the days of Sanssure, De Luc, Escher and Von Buch; whilst Professor Guyot has most conclusively shewn that the different erratic basins in Switzerland are not only distinct from each other, as was already known before, but that in each the loose materials are arranged in well-determined regular order, shewing precise relations to the centres of distribution, from which these materials originated; an arrangement which agrees in every particular with the arrangement of loose fragments upon the surface of any glacier, but which no cause acting convulsively could have produced.[46] Footnote 46: A comparison of the maps, shewing the arrangement of the moraines upon the glacier of the Aar, in my _Système Glaciaire_, with the maps which Professor Guyot is about to publish of the distribution of the erratic boulders in Switzerland, will shew more fully the identity of the two phenomena. The results of these investigations are plainly that the boulders found at a distance from the Central Alps, originated from their higher summits and valleys, and were carried down at different successive periods in a regular manner, forming uninterrupted walls and ridges, which can be traced from their starting-point to their extreme peripheric distribution.