抄録
Protoplasmic streaming is a phenomenon of particle movement in living cell. The particles were contained the cellular organelles and other particles called mitochondria and chloroplasts. We want to know the role of protoplasmic streaming in living plant cell. In this study we observed two types of protoplasmic streaming of Nitella and Tradescantia. The vesicle of moving speed and size were measured by microscopic observation. The cell division time was estimated from the volume of vesicle and cell, the moving speed and distribution of vesicles. As a result, the tradescantia cell division time was about 3.47×10^<17> hours. It was found that the protoplasmic streaming of Tradescantia was contributed 1.64×10^<-15>% for cell volume expansion
