In any growth stage, there is a progressive decrease in % of N in the complete plant and its separate parts in the following order: leaves, complete plant, stems, and roots. There is a progressive increase in % of cellulose and lignin in the order: leaves, complete plant, stems, roots. The carbohydrate % in the plant and its parts was rather constant. This resulted in a narrow ratio between total N and carbohydrates and cellulose for the leaves, which gradually widened in the complete plant, stems, and roots, respectively. The accumulation of nitrates following the incorporation of the complete plant or any of its parts was most rapid from the leaves, progressively decreasing from the complete plant, stems, and roots in the order named, except with the leaves in the late fall stage, which varied little from that of the complete plant. The stems and roots show a utilization of the nitrate N of the soil in the early stages of decomposition. There is relatively little variation in the % of N and carbohydrates in the leaves of the plant through the successive growth stages but there is some increase in the % of lignin and cellulose as the plant approaches maturity. There is little variation in the rapidity of the nitrification of the N added as leaves, with the exception of the leaves in the late fall growth stage, where desiccation occurred. With the complete plant through the successive growth stages, there is a progressive increase in % of lignin and cellulose with a corresponding decrease in % of N, whereas the % of the carbohydrates remains rather constant. There is a progressive decrease in rapidity of nitrification of the N added to the soil from the complete plant through the successive stages of growth, i.e., succulent, bloom, seed pod, and late fall, in decreasing order. In the first 2 growth stages (succulent and bloom) there is little variation in % of N, cellulose, and lignin in the stems and roots, whereas during the 2 latter growth stages there is an increase in % of cellulose and lignin and a decrease in % of N. The carbohydrates were rather constant in % for all growth stages. There is only a slight variation in the course of nitrification of N added to the soil as stems in the succulent and bloom stages. This course showed a more rapid accumulation of nitrates from these stems than from the stems of the seed pod and late fall stages. The time required for a positive accumulation of nitrates after the incorporation of the stems was shorter for the succulent and bloom stage stems than for the seed pod and late fall stems. Similar results were obtained with the roots.