875. The pine lands in the southern states have generally old oak grubs, which, by reason of the periodical fires, are prevented from becoming trees; notwithstanding, they still continue alive; and when land is turned out (that is, when the cultivation of land is relinquished), pines, being by nature unproductive of suckers, are consequently killed in toto; while the oak, now sole possessor of the soil, starts up and grows vigorously. On the other hand, land which had been solely occupied by oaks previously to its cultivation, is invariably of a superior quality to what is termed pine lands, and naturally is a longer period under cultivation before it is turned out; by which means the roots of the oaks are completely eradicated, while it is in a state of cultivation. The pine seeds, being winged, and thereby easily carried by the wind to a considerable distance, if the ground is free from the roots of other trees, are the first to establish themselves; and being of a free and rapid growth, they take the lead of all other species of timber, and become the principal occupiers of the land ; but when the roots of the oaks are not destroyed, they will take the lead, and resist the pine and other trees. All pine lands which originally had no oaks will invariably produce pines again, whether they have been under cultivation for a long or a short period.