It is not uncommon to find fossils in the pebbles of a conglomerate rock showing lines of a dislocating fracture filled with spar. The fossil shell or coral once had an inhabitant. We must allow time for its life and death. Its vacant tabernacle must then have become filled with extraneous matter. This must have required time to harden into rock. While that rock was still in the mass, some cause must have operated to fracture it, and such causes are not of every-day operation. After this, more time was needed to fill up the divisional line with spar; more time to break off the fragment containing the shell from the general mass of the rock; more time to roll it into a pebble; more time to imbed it hard and fast in a conglomerate rock; more time to raise the rock high out of the waters; and, lastly, one more vast addition of time for the crumbling away of the conglomerate formation, so as to expose the tall sea-cliff from which human hands might gather this memorial relic of untold ages. The same tale is told by the coal-measures. Dr. Dawson, of Montreal, has drawn out the argument from the carboniferous formation[57] with extraordinary force and a convincing plainness that leaves nothing to be desired, for the benefit of any one who will read his great work on Acadian geology. The formation of coal depends on sub-aërial growths, affected by sub-aqueous action. The trees and plants, out of which coal is formed, for the most part could not possibly have grown under water. The mud, the sand, the stone which cover seams of coal, could not have been laid over them without the agency of water to bring them down, and spread them out in regular layers of stratification. When the hollow bark of a tall tree is found erect upon its roots, with those roots still permeating the clay from which they once drew nourishment, it is evident that time must be allowed for the growth of the tree, for the almost complete decay which left nothing of it but its bark and roots, and for the slow accumulation of sediment which has encased without overthrowing it. A complete alteration must have taken place in the conditions of the ground in the interval between the time when the tree began to grow, and the time when a length of seven or eight feet of its upright stem was buried in mud. Layers, indeed, of sand and mud may be spread out over small areas by storms and inundations with comparative speed; but if above the sands we come to thicknesses of limestone composed almost entirely of animal remains, such as those of shells and fish, not only are we forced to admit a long period for the successive generations of those creatures, but we are forced to observe the products of the ocean lying actually above the products of the dry land, as though, according to the old poetical extravagance, the stag and doe had taken to the waters and the fishes been building in the tree-tops. The conclusion is inevitable, that what was once dry