[Illustration: Fig. 127. Planted White Pine, Fifty Years Old, Bridgewater, Mass. _U. S. Forest Service._] IMPROVEMENT. Besides utilization and preservation, the third main object of forestry is the improvement of the forest. It is not an uncommon mistake to suppose that the virgin forest is the best forest for human purposes. It is a comparatively new idea, especially in America, that a forest can be improved; that is, that better trees can be raised than those which grow naturally. Lumbermen commonly say, "You never can raise a second growth of white pine as good as the first growth." As if this "first growth" were not itself the successsor of thousands of other generations! There is even a legend that white pine will not grow in its old habitat. Says Bruncken, Many people probably imagine that a primeval wood, "by nature's own hand planted," cannot be surpassed in the number and size of its trees, and consequently in the amount of wood to be derived from it. But the very opposite is true. No wild forest can ever equal a cultivated one in productiveness. To hope that it will, is very much as if a farmer were to expect a full harvest from the grain that may spring up spontaneously in his fields without his sowing. A tract of wild forest in the first place does not contain so many trees as might grow thereon, but only so many as may have survived the struggle for life with their own and other species of plants occupying the locality. Many of the trees so surviving never attain their best development, being suppressed, overshadowed, and hindered by stronger neighbors. Finally much of the space that might be occupied by valuable timber may be given up to trees having little or no market value. The rule is universal that the amount and value of material that can be taken from an area of wild forest remains far behind what the same land may bear if properly treated by the forester. It is certain, therefore, that in the future, when most American forests shall be in a high state of cultivation, the annual output of forests will, from a much restricted area, exceed everything known at the present day. (Bruncken, _North American Forests and Forestry_, pp. 134-135.) It is probable that the virgin forest produces but a tithe of the useful material which it is capable of producing. (Fernow, p. 98.)