GROWTH AND DEVELOPMENT AS INFLUENCED BY FRUIT AND SEED FORMATION

Some years ago Briggs, Kidd, and West (3) summarized the very extensive data which had been accumulated at a much earlier time by U. Kreisler and his co-workers on the growth of several field crop plants, especially Zea mays (14, 15). The data had been lying more or less dormant and neglected up to that time. When the weekly percentage increases in dry weight (growth rate) and leaf area per unit dry weight (leaf -area ratio) were plotted against time, curves were obtained from these old records which could be roughly reduced to a generalized form (fig. 1). The similarity in the direction of the two schematic curves thus secured suggests that the growth rate (percentage increase in dry weight) is a function of the leaf area and that it is quite constant during the life cycle of the plant. There are, however, two quite noticeable discrepancies. Growth seems to be independent of the leaf area early in the development of the plant when the seedling is still drawing on the food reserves of the