“…In the normal plants there were a number of the long type of nodules, which are simply large nodules, while the largest number were of the round t-ype, or small nodules. When the nitrogen sources were added, this distribution was changed as was noted for nitrate in a previous publication (9). Even in the lowest concentration (2 mg. of N) of KNO3, (NH4)2S0, urea, and asparagin, the nodules were found, not principally on the tap-root but almost exclusively on the secondary roots.…”