Mica-schist and gneiss are often found in the same region, and are the materials of which most of the highest peaks in Europe are composed. We find them abounding in the district of Mont Blanc; and all the monarch's attendant _aiguilles_, with the splintered ridges enclosing the great snowfields in the heart of the chain, consist mostly of these two rocks. The Matterhorn, Weisshorn, Monte Viso, the Grand Paradis, the Aiguille Verte and Aiguille du Dru are examples of the wonderful forms produced by the breaking up and decay of these two rocks. The different varieties of slate split in a very marked way. Slates are often associated with the schists, and exert their influence in modifying the scenery. Limestone ranges, though less striking in the outlines of their crests than those composed of slates and crystalline schists, and not reaching to such heights, are nevertheless not at all inferior in the grandeur of their cliffs, which frequently extend for miles along the side of a valley in vast terraces, whose precipitous walls are often absolutely inaccessible. The beauty of limestone mountains is often enhanced by the rich pastures and forests which clothe their lower slopes. The dolomitic limestone of the Italian Tyrol, being gashed by enormous vertical joints and at the same time having been formed in rather thin layers which break up into small blocks, produces some very striking scenery. But wild as these mountainous ridges may be, their forms can never be confounded with those of the crystalline schists; for however sharp their pinnacles may appear at first sight, careful examination will always show that their outline is that of ruined masonry, suggesting crumbling battlements and tottering turrets, and not the curving, flame-like crests and splintered peaks of the crystalline schists.[30] [30] Bonney. It has already been explained that all sedimentary rocks have been formed under water in layers or strata, and it must be obvious that the stratification of such rocks has an important influence on scenery; and very much depends on whether the strata have been left undisturbed, with perhaps just a slight slope, or whether they have been folded and crumpled; for the position of the strata, or "bedding," as it is called,--whether flat, inclined, vertical, or contorted,--largely determines the nature of the surface. Undoubtedly the most characteristic scenery formed by stratified rocks is to be seen in those places where the "bedding" is horizontal, or nearly so, and the strata are massive. A mountain constructed of such materials appears as a colossal pyramid, the level lines of stratification looking like great courses of masonry. The joints that cut across the strata allow it to be cleft into great blocks and deep chasms; so that, as in the case of the dolomitic limestone above mentioned, we find a resemblance to ruined buildings.