to the Lammermuirs, and that another stratified formation has to be intercalated in this district, between the oldest existing strata and the parent rock, whence the sediment was derived. This opinion is founded chiefly on the circumstance, that in none of the beds have there ever been observed any fragments of granite, or the associated crystalline gneiss and schists, while fragments of clay-slate and graywacke are not uncommon amongst the conglomerate or coarser varieties. But, admitting the truth of the statement, does it warrant the inference deduced? The clay-slates and graywacke of the Highlands are equally destitute of the inclosed granitoid portions so abundant in the superimposed conglomerates of the old red; and, upon the supposition of an intensely but unequally heated sea-bottom, and partial outbursts of irruptive matter, these appearances in the Lammermuirs, where certain strata contain included fragments of similar consolidated rock, receive an intelligible and less extravagant explanation. We more willingly accede to the conclusion of Mr. Nicol, that we have still here much of the original shape and contour of this ancient land; that the rivers and valleys are all in their olden places, and that since the elevation of the group there has been no important change in their general character and physical outline. The Lammermuirs, too, connected as they are with the great silurian deposits of England, Wales, and Ireland, lend confirmation to the theory, repeatedly adverted to, that these mountains, as well as those of the preceding epoch, formed the land on which grew part at least of the exuberant vegetation entombed in the coal formations of Great Britain. It may have been a peninsula projecting into a sea, whose waves washed the Grampians on the north, covered all the midland and eastern districts of England on the south, and were bounded by the primary and silurian girdle of rocks on the west. Through these depths roamed the successive races of holoptychius, palæoniscus, gyracanthus, and megalichthys; the shallows and bottom teemed with swarms of molluscs, trilobites, cephalaspes, pamphracti; while the dense forests of ferns, palms, and pines, which clothed the shores and uplands, have been distributed among the various basins of the coal-measures.