The calcareous districts, which form the great portion of the region west of the Alleghanies, present certain tracts entirely divested of trees, which are called _barrens_, though capable of being rendered productive. The cause of this peculiarity has not been accurately examined. Those parts of this region which are elevated three or four hundred feet, and lie along deeply depressed beds of rivers, are clothed with the richest forests in the world. The Ohio flows under the shade of the plane and the tulip tree, like a canal dug in a nobleman’s park; while the _lianas_, extending from tree to tree, form graceful arches of flowers and foliage over branches of the river. Passing to the south, the wild orange tree mixes with the odoriferous and the common laurel. The straight silvery column of the papaw fig, which rises to the height of twenty feet, and is crowned with a canopy of large indented leaves, forms one of the most striking ornaments of this enchanting scene. Above all these, towers the majestic magnolia, which shoots up from that calcareous soil to the height of more than one hundred feet. Its trunk, perfectly straight, is surmounted with a thick and expanded head, the pale green foliage of which affects a conical figure. From the centre of the flowery crown which terminates its branches, a flower of the purest white rises, having the form of a rose, and to which succeeds a crimson cone. This, in opening, exhibits rounded seed of the finest coral red, suspended by delicate threads six inches long. Thus, by its flowers, its fruit, and its gigantic size, the magnolia surpasses all its rivals of the forest. The following excellent description of the prairie country is from the pen of Mr. James Hall. ‘That these vast plains should be totally destitute of trees, seems to be an anomaly in the economy of nature. Upon the mind of an American, especially, accustomed to see new lands clothed with timber, and to associate the idea of damp and silent forests with that of a new country, the appearance of sunny plains, and a diversified landscape, untenanted by man, and unimproved by art, is singular and striking. Perhaps if our imaginations were divested of those associations, the subject would present less difficulty; and if we could reason abstractly, it might be as easy to account for the existence of a prairie as of a forest.