Where alternations of quartzite and mica-schist occur, irregularities of the surface are readily maintained. Heather climbs upon the yellow soils furnished by the schist, and trees may gather in its hollows; but the quartzite stands out bare and dominant. In some cases the upturned beds of the latter weather out like dykes across the country. Worn-down plateaus of ancient gneiss, the mere residues of mountain-land, may be seen in the storm-swept levels of the Outer Hebrides, and in the hummocky country, a swelling sea of bare grey rock and peat-filled hollows, that borders all the west of Sutherland. The irregular weathering of mica-schist, and the readiness with which it can be carved by streams, control the bold landscapes of the highlands from the Trossachs to Lough Ness, and thence away again to the northern sea. Here and there, great domes of intrusive granite rise amid the broken moorlands; at times, a white cone of quartzite catches the eye with a gleam like that of snow. We may traverse this country as an introduction to the high glacial plateaus and deeply notched seaward slopes of the metamorphic lands of Norway; or to the contrasts of jagged schists and resisting gneisses that meets us as we near the Alpine core. REFERENCES (_The numbers of volumes are given throughout in thick type; the dates are between brackets, and the page-references follow in ordinary figures._) [Footnote 1: Cordier, "Mémoire sur les substances dites en masse, qui entrent dans la composition des Roches Volcaniques," Journ. de Physique, =83= (1816), 135, 285, and 352.] [Footnote 2: On specific gravity of mineral grains see especially W. J. Sollas, Nature, =43= (1891), 404.] [Footnote 3: Sorby, Q. Journ. Geol. Soc. London, =14= (1858), 453.] [Footnote 4: Katzer, "Geologischer Führer durch Bosnien," IX internat. Geologencongress (1903), 190.] [Footnote 5: A. W. Rogers, "Geology of Cape Colony," ed. 2 (1909), 401.] [Footnote 6: Linck, "Die Bildung der Oolithe u. Rogensteine," Neues Jahrb. für Min., =16= (1903), 495.] [Footnote 7: Daly, "The Limeless Ocean," Amer. Journ. Sci., Ser. 4, =23= (1907), 104, and "Evolution of the Limestones," Bull. Geol. Soc. Amer. =20= (1909), 153.] [Footnote 8: A. R. Horwood, Geol. Mag. (1910), 173; and Cole and Little, _ibid._ (1911), 49, with references to literature.] [Footnote 9: "The Atoll of Funafuti," Roy. Soc. London (1904).] [Footnote 10: M. Ogilvie (Gordon), "Coral in the Dolomites," Geol. Mag. (1894), 1 and 49, and later papers.] [Footnote 11: Gardiner and Reynolds, "The Portraine Inlier (Co. Dublin)," Q. Journ. Geol. Soc., =53= (1897), 532.] [Footnote 911: Walther, "Einleitung in die Geologie als historische Wissenschaft"; 3ter. Theil, "Lithogenesis der Gegenwart" (1894), 707.] [Footnote 12: See Nichols, Field Columbian Museum, Geology, =3= (1906).]