specimens are probably thousands of years old, and are still growing; why should they ever die? They have never been disturbed by a breath of moving air, and, balanced exactly on their succulent, pedestal-like stems, surrounded by an atmosphere of dead nitrogen, vapor, and other gases, with their roots imbedded in carbonates and minerals, they have food at command, nutrition inexhaustible."
"Still I do not see why they grow to such mammoth proportions."
"Plants adapt themselves to surrounding conditions," he remarked. "The oak tree in its proper latitude is tall and stately; trace it toward the Arctic circle, and it becomes knotted, gnarled, rheumatic, and dwindles to a shrub. The castor plant in the tropics is twenty or thirty feet in height, in the temperate zone it is an herbaceous plant, farther north it has no existence. Indian corn in Kentucky is luxuriant, tall, and graceful, and each stalk is supplied with roots to the second and third joint, while in the northland it scarcely reaches to the shoulder of a man, and, in order to escape the early northern frost, arrives at maturity before the more southern variety begins to tassel. The common jimson weed (datura stramonium) planted in early spring, in rich soil, grows luxuriantly, covers a broad expanse and bears an abundance of fruit; planted in midsummer it blossoms when but a few inches in height, and between two terminal leaves hastens to produce a single capsule on the apex of the short stem, in order to ripen its seed before the frost appears. These and other familiar examples might be cited concerning the difference some species of vegetation of your former lands undergo under climatic conditions less marked than between those that govern the growth of fungi here and on surface earth. Such specimens of fungi as grow in your former home have escaped from these underground regions, and are as much out of place as are the tropical plants transplanted to the edge of eternal snow. Indeed, more so, for on the earth the ordinary fungus, as a rule, germinates after sunset, and often dies when the sun rises, while here they may grow in peace eternally. These meandering caverns comprise thousands of miles of surface covered by these growths which shall yet fulfill a grand purpose in the economy of nature, for they are destined
