Over the lower bed of conglomerate, which here, as on the east coast, is of great thickness, we find a bed of gray stratified clay, containing a few calcareo-argillaceous nodules. The conglomerate cliffs to the north of the village present appearances highly interesting to the geologist. Rising in a long wall within the pleasure-grounds of Dunolly castle, we find them wooded atop and at the base; while immediately at their feet there stretches out a grassy lawn, traversed by the road from the village to the castle, which sinks with a gradual slope into the existing sea-beach, but which ages ago must have been a sea-beach itself. We see the bases of the precipices hollowed and worn, with all their rents and crevices widened into caves; and mark, at a picturesque angle of the rock, what must have been once an insulated sea-stack, some thirty or forty feet in height, standing up from amid the rank grass, as at one time it stood up from amid the waves. Tufts of fern and sprays of ivy bristle from its sides, once roughened by the serrated kelp-weed and the tangle. The Highlanders call it M'Dougal's Dog-stone, and say that the old chieftains of Lorne made use of it as a post to which to fasten their dogs,--animals wild and gigantic as themselves,--when the hunters were gathering to rendezvous, and the impatient beagles struggled to break away and begin the chase on their own behalf. It owes its existence as a stack--for the precipice in which it was once included has receded from around it for yards--to an immense boulder in its base--by far the largest stone I ever saw in an Old Red conglomerate. The mass is of a rudely rhomboidal form, and measures nearly twelve feet in the line of its largest diagonal. A second huge pebble in the same detached spire measures four feet by about three. Both have their edges much rounded, as if, ere their deposition in the conglomerate, they had been long exposed to the wear of the sea; and both are composed of an earthy amygdaloidal trap. I have stated elsewhere ["Old Red Sandstone," Chapter XII.], that I had scarce ever seen a stone in the Old Red conglomerate which I could not raise from the ground; and ere I said so I had examined no inconsiderable extent of this deposit, chiefly, however, along the eastern coast of Scotland, where its larger pebbles rarely exceed two hundred weight. How account for the occurrence of pebbles of so gigantic a size here? We can but guess at a solution, and that very vaguely. The islands of Mull and Kerrera form, in the present state of things, inner and outer breakwaters between what is now the coast of Oban and the waves of the Atlantic; but Mull, in the times of even the Oolite, must have existed as a mere sea-bottom; and Kerrera, composed mainly of trap, which has brought with it to the surface patches of the conglomerate, must, when the conglomerate was in forming, have been a mere sea-bottom also. Is it not possible, that when the