... little study of the roots of trees is practicable, some knowledge of their forms, varieties, and parts is important The great office of the roots of all plants is the taking in of food from the soil ... chance for the constant growth of the trunk The different kinds of trees are readily known by the appearance of the bark of the trunk, due to the many varieties of surface caused by the allowance for ... acquainted with all the useful and ornamental woods used in a region; the differences in the color of the heart-wood, the character of the annual layers, and the size and the distribution of the medullary...