This would be the proper place to consider the formation of the lakes of Switzerland, as well as their preservation by the agency of glaciers. But this subject is so intricate, and has already given rise to so many controversies which could not be overlooked in this connection, that I prefer to pass it over altogether in silence. Suffice it to say that not only are most of the lakes of Switzerland hemmed in by transverse moraines at their lower extremity, but the lakes of Upper Italy, at the foot of the Alps, are barred in the same way, as are also the lakes of Norway and Sweden, and some of our own ponds and lakes. Strange as it may seem to the traveller who sails under an Italian sky over the lovely waters of Como, Maggiore, and Lugano, it is, nevertheless, true, that these depressions were once filled by solid masses of ice, and that the walls built by the old glaciers still block their southern outlets. Indeed, were it not for these moraines, there would be comparatively few lakes either in Northern Italy or in Switzerland. The greater part of them have such a wall built across one end; and but for this masonry of the glacier, there would have been nothing to prevent their waters from flowing out into the plain at the breaking up of the ice-period. We should then have had open valleys in place of all these sheets of water which give such diversity and beauty to the scenery of Northern Italy and Switzerland, or, at least, the lakes would be much fewer and occupy only the deeper depressions in the hard rocks.