Abstract
Microscopic observations have revealed that the crop plants tolerant against the injury of excessive soil moisture are characterized with a highly developed ventilating system and that the reverse is true for those susceptible. The ventilating system may furnish the crop root with sufficient oxygen transported from the top. In the illustration figures of the present report the following abbreviations are used: Ab, axillary bud; ae, aerenchyma ; ca, cavity; ck, cork; co, cortex; cr, crown root; en, endodermis; ep, epidermis; ls, leaf-sheath; ly, lysigenic air space; pa, partition, pe, pericycle; pm, primary meristem; rv, reinforced vascular bundle; sm, secondary meristem; sp, sieve portion; St, stipula; sv, separated vascular bundle; va, vascular bundle; wp, wood portion.
