And, it MUST DO SO or pharmacy will either expire of inaction, or be shattered into fragments by the encroachments of invading sciences. Let us next consider a typical plant-for example, a tree. There are varieties of trees, ranging from tall trees with mighty trunks to treelike shrubs, in untold number of grades. These may be bushy or slender, drooping like the beech, or tufted like the cocoa- nut. There are trees with smooth bark, as the birch, and trees whose bark is rough or coarse, as the hemlock, or shaggy, as the hickory.
Barks vary to infinity.
We cannot define the tree by any one feature involved in descriptions such as these, nor yet by the leaf. The tree, be it large or small, is, however, only one form of plant. There are herbaceous plants and woody plants. There are land plants and marine plants. The mistletoe, that grows from the bark of the oak or honey locust tree, is typical of vegetable vam- pires.