One of the most interesting of these struggles between grassland and woody vegetation in a region climatically able to produce both, is in Natal. Large sections of that country are grasslands or veld, as the people there call it. Scattered through the veld are various species of acacia trees, locally called thorn, with feathery compound leaves. These do not shut out enough light to prevent the development of grasses directly under their shade, yet the annual firing of the veld prevents, except accidentally, the production of the acacias. But the seeds of this tree, whether from long usage to this burning or not, are actually hastened in their germination by the firing, and it is a common practice in that country to roast or partly boil the seeds of the tree to hasten germination. The presence of the climatically favorable environment for both trees and grassland results in the latter being the dominant type of vegetation over large tracts of the country, largely because fires destroy tree seedlings, and yet the tree seeds, by a quite extraordinary fitness for their peculiar environment, offer a measure of insurance against the total destruction of woody vegetation by the grassland. The pampas of the Argentine have been vividly described by P. G. Lorentz, who, in writing of the drier parts of it, says: “Viewed from a distance, these grasses seem to form a close grassy covering, and the pampa presents the appearance of extensive grassy tracts whose coloring varies with the seasons: coal black in the spring, when the old grass has been burned; bright green, the color of the mature grass; finally--at flowering time--when the silvery white spikes overtop the grass, over wide tracts it seems like a rolling, waving sea of liquid silver. “After the Gramineæ (grasses), the family of plants that is represented in the pampas by the greatest number of individuals is that of Compositæ (daisy family); usually twiggy undershrubs with inconspicuous flowers, a bright yellow _Solidago_ (golden-rod) alone gleams out from among the others.” Here, as in the other grasslands of the world, if a local water supply above the general requirements of the grass exists, there is always a small element of woody plants, low, thick-leaved shrubs usually, but where water is more plentiful, trees, as in the region in Natal, already mentioned, and in many other parts of the world, notably parts of Australia, China, Brazil, and many sections of the western part of the United States.