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190 some at the Bosco di Gaudianella. When we have explained the relation of arrangements between the neptunian rocks of the third series and the volcanic, it will not be difficult to understand how they came there. Lastly, among the districts in which numerous pebbles of rock crystal are observed, we must enumerate the vicinity of Pietraroia, remarkable for the great variety which is found there. Before we had observed the granites enclosed in the limestone of the Fontana delle Rose, we referred the blocks of the same kind found at Monte Vergine, and Pietraroia to the doubtful series of masses of similar rocks, sometimes of enormous size, called by geologists (erratici massi) erratic blocks. We now class them in another group of rocks, and assert that their origin is not at all different from that of the minute grains of quartz, of which the Macigno of the fucoidal rocks is composed; the grains as well as the spangles of mica which are frequently seen in clay, being minute particles of granite, or of some other crystalline rock. The greater number if not all the varieties of granite found in isolated blocks among the sedimentary rocks of the Apennines, resemble, in the most minute particulars of their sensible properties, the rocks of the same kind which we observed in their primitive arrangement in Calabria. If this is sufficient to assure to us that they owe their origin to the granitic mountains of Calabria, it will follow, that we must hold, that at least the greater part of the materials which form these rocks of the second series, was derived from these mountains; for, it is indubitable that the elements of which they are formed, must have been transported from regions many miles distant from the places where they are deposited, and the mountains of Calabria from which they might have been taken, are the nearest. As to the inquiry into the origin of such impetuous and extensive torrents of water, possessing the force necessary for carrying down so large a quantity of waste material, this, we must admit, is a difficult question, and perhaps the consideration of the manner in which this transport was effected is still more difficult.

Allowing every one to conceive the events of such remote epochs,