| Popis: |
1. The scutellum in maize, oats, and wheat is the cotyledon. The "ventral scale" of the cotyledon, when present, may be interpreted as its ligule. The epiblast, when present, cannot be considered a rudimentary cotyledon; it probably has little morphological significance. These interpretations hold also for other grasses examined, including barley, rye, and rice. 2. The coleoptile is homologous with a foliage leaf, and is the second leaf of the plant, the leaf distal to it being the third leaf of the plant. 3. In maize and oat seedlings, the elongated structure between the cotyledon and the coleoptile is the first internode of the axis. The term "mesocotyl" as applied to this structure is meaningless. In wheat, the corresponding structure, although not elongated, is likewise the first internode of the axis. This holds true for other Gramineae that develop similarly to maize, such as oats and rice, and those that develop like wheat, such as barley and rye. The principal elongating structure in the young whe... |
