Abstract
1. In soy bean, the nodule bacteria do not transform their shape during the stage of bacteroid, and always remain in rod-form. Sometimes, in the stage of bacteria are found to unite into small spherical groups each of which contains 1O or more bacteria. 2. As the result of infection, the cells of bacteroidal tissue show hypertrophy and become 2∼3 times larger in diameter. 3. As roughly estimated, each bacteroidal cell containes 20, 000∼60, 000 bacteria. 4. A conspicuous layer of sclerenchyma cells develop in the cortical parenchyma between the epidermis and the bacteroidal tissue of the soy bean nodule. This layer of sclerenchyma cells may protect the nodule from external invaders such as injurious insects or microbes, and at the same time it may also terminate the hypertrophy of the cells of bacteroidal tissue.
