‘It is natural to suppose that the first covering of the earth would be composed of such plants as arrived at maturity in the shortest time. Annual plants would ripen, and scatter their seeds many times before trees and shrubs would acquire the power of reproducing their own species. In the mean time, the propagation of the latter would be likely to be retarded by a variety of accidents――the frosts would nip their tender stems in the winter――fire would consume, or the blasts would shatter them――and the wild grazing animals would bite them off, or tread them under foot; while many of their seeds, particularly such as assume the form of nuts or fruits, would be devoured by animals. The grasses, which are propagated both by the root and by seed, are exempt from the operation of almost all these casualties. Providence has, with unerring wisdom, fitted every production of nature to sustain itself against the accidents to which it is most exposed, and has given to those plants which constitute the food of animals, a remarkable tenacity of life; so that although bitten off, and trodden, and even burned, they still retain the vital principle. That trees have a similar power of self protection, if we may so express it, is evident from their present existence in a state of nature. We only assume that in the earliest state of being, the grasses would have the advantage over plants less hardy, and of slower growth; and that when both are struggling together for the possession of the soil, the former would at first gain the ascendancy; although the latter, in consequence of their superior size and strength, would finally, if they should ever get possession of any portion of the soil, entirely overshadow and destroy their humble rivals.