English: Fig. 29.—A small piece of one annual ring of old oak wood (magnified twenty diameters): a, boundary of the autumn wood of the preceding (older) ring; b, that between the zone shown and the next youngest ring. In the annual ring shown the spring wood begins with large vessels, c and d, some with tyloses, d, in them, and passes gradually into autumn wood, with smaller vessels, e, e, and more tracheids and fibers, g. Only small medullary rays, i, are shown. (Hartig.)