root, rote

[Icel. rót; Sw.rot; Dan. rod. The 3492 (5) Ground, basis, foundation. "Remove the root of his opinion." Shakesp.: Winter's Tale, ii. 3. (6) Foundation, basis, support. "With a courage of unshaken root . " Cowper: Table Talk , 15. 7. A primitive word from which other words are formed. II. Technically : 1. Anat .: That part of any organ or appendage of the body which is buried in another part. Thus the root of a nail is the portion covered by the skin: the root of a tooth, the base of it whien is lodged in a socket. †2. Astron. The moment from which one begins to calculate the time of revolution of a planer. 3. Bot . The radix or descending axis of a plant. The tendency downward is very powerful. Unlike the symmetrically placed branches of the stem, the ramifications of the roots look irregular as if they arose from any part of the surface. There is in them, however, a certain Rhizotaxis (q. v.). The roots of Dicotyledons are exorhizal, those of Monocotyledons endorhizal, and those of Acotyledons heterohizal. A root has no perfect bark, true pith, medullary sheath, or true leaves, and only a thin epidermis, a few stomata, and very rarely leaf-buds. Its growth is chiefly at the lower extremity. The body of a root is called the caudex, its minute subdivisions the fibrils or radicles, and their ends the spongioles. A primary root is one formed by the downward elongation of the axis of the embryo, and is, therefore, in a line with the stem; secondary or lateral roots, like those of ivy, spring laterally from the stem and from the primary root. When the primary root is thicker than the branches which proceed from it, it is called a tap root, when it is no thicker than its ramifications, which conceal it from view, the root is said to be fibrous. Other forms of roots are conical, fusiform, napiform, rotund, nodose or coralline, moniliform, tuberose, or (finally) premorse. Most roots are terrestrial, a few are aërial, and a few aquatic. The chief functions of the root are to anchor the plant firmly in the ground, and to transmit upward to the stem and leaves absorbed IMG:content-0726.png:[blocks in formation] Zool .: Arvicola economus , a large species, ranging from the Obi to Kamschatka. It is migratory, like the Lemming (q. v.).