Abstract
1. The nodule bacteria of azuki bean are rod-shaped and remain unchanged during the stage of bacteroid. Sometimes, during the stage of bacteroid 10 or more bacteria unite together forming a small spherical group. 2. The numbers of bacteria contained in a cell of bacteroidal tissue are 20, 000∼40, 000 in round figures. 3. Sometimes, a sylindrical cell is found in a layer of cells in the nodule cortex. The sylindrical cell may protect the nodule from external invaders and at the same time terminate the hypertrophy of the cells of bacteroidal tissue. 4. The nodule bacteria usually enters the host plant through the root hairs and according to this investigation the spead of infection is as follows; No. of bacteria found in root hairs (Average)[table]
