CHAPTER III.
How the boulder came to be one—"Crag and tail"—Scenery of central Scotland: Edinburgh—"Crag and tail" formerly associated in its origin with the boulder-clay—This explanation erroneous—Denudation an old process—Its results—Illustration from the Mid-Lothian coal-field—The three Ross-shire hills—The Hebrides relics of an ancient land—Scenery of the western coast—Effects of the breakers—Denudation of the Secondary strata of the Hebrides—Preservative influence of trap-rocks—Lost species of the Hebrides—Illustration—Origin of the general denudation of the country—Illustrative action of streams—Denudation a very slow process—Many old land-surfaces may have been effaced—Varied aspect of the British Islands during a period of submergence—Illustration,
CHAPTER IV.
Interior of the boulder—Wide intervals of Geology—Illustration—Long interval between the formation of the boulder as part of a sand-bed, and its striation by glacial action—Sketch of the intervening ages—The boulder a Lower Carboniferous rock—Cycles of the astronomer and the geologist contrasted—Illustration—Plants shown by the boulder once grew green on land—Traces of that ancient land Its seas, shores, forests, and lakes, all productive of material aids to our comfort and power—Plants of the Carboniferous era—Ferns—Tree-ferns—Calamites—Asterophyllites—Lepidodendron—Lepidostrobus—Stigmaria—Scene in a ruined palace—Sigillaria—Coniferæ, Cycadeæ—Antholites, the oldest known flower—Grade of the Carboniferous flora—Its resemblance to that of New Zealand,
CHAPTER V.
Scenery of the carboniferous forests—Contrast in the appearance of coal districts at the present day—Abundance of animal life in the Carboniferous era—Advantages of palæontology over fossil-botany—Carboniferous fauna—Actiniæ—Cup-corals—Architecture of the present day might be improved by study of the architecture of the Carboniferous period—Mode of propagation of corals—A forenoon on the beach—Various stages in the decomposition of shells—Sea-mat—Bryozoa—Fenestella—Retepora—Stone-lilies—Popular superstitions—Structure of the stone-lilies—Aspect of the sea-bottom on which the stone-lilies flourished—Sea-urchins—Crustacea, their high antiquity—Cyprides—Architecture of the Crustacea and mollusca contrasted—King-crabs,