Abstract: In the pollen germinated for more than 4 hours, many cytoplasmic fibrils can be observed under optical microscope. These fibrils which form a network are always in motion, being rigid and flexible to a certain extent, defined as moving cytoplasmic fibril network in the present paper. The network fibrils are different from cytoplasmic streaming, because they not only, move vertically but also horizontally. Furthermore, they restrict the transportation of cytoplasmic particles. Electron micrographs show that the fibrils are composed of many parallel microfilaments with 5–7 nm in diameter, and at the joint of two microfilaments there are arrowheaded compounds in the same direction and the same distance about 420 A. They may be the force “motor” and the “viscous cluch” formed by the directional arrangement of myosin which is necessary to the movement of both fibrils and cytoplasmic particles.

Key words: Germinated pollen, Cytoplasmic fibril network: The movement of cytoplasmic particles