Since CORTI (1774) observed for the first time a streaming in plant cells, a history oJ mnre than 180 years has already elapsed in the study of proto plasmic streaming. Durling this period of time, many experiments have been conducted and various discussions have been made nn prntoplasmic streaming, each of them within the limits of the knowledge and techniques of its own times and mnre or less under the influence of the ideas that pre vailed then. With such a long history of research, in spite of all the interest and efforts that have been devoted to it by many, the mechani'sm of this in triguing and complicated binlogical phenomenon is still left far from clear. It is an undeniable fact that one important factor stood in the way in analysing this phenomenon, that is, the limitations in the techniques ap plicable to thi,s research. Another factor lay in the fact that we still have not enough knowledge about the protoplasm regar1ding its structural organisation, mechanochemistry, energetics, rheology, etc., all of which con stitute basic problems in understanding the nature of the streaming.

Inhalt
I. Introduction.- II. Types of Streaming.- 1. General survey.- 2. Change in streaming type.- III. Rate and Intensity.- 1. Intracellular velocity distribution.- 2. Rate.- 3. Course and direction of rotational streaming.- 4. Transport-volume and intensity of flow.- IV. Motive Force Responsible for the Protoplasmic Streaming.- 1. Motive force of the rotational streaming.- 2. Motive force of the protoplasmic streaming in myxomycete Plasmodium.- V. Rhythmicity.- 1. Rhythm of motive force generation in the Plasmodium.- 2. Rhythmicity of the protoplasmic motion in plant cells.- VI. Energetics of Protoplasmic Streaming.- 1. Oxygen tension.- 2. Metabolic inhibitors.- 3. The role of ATP in the protoplasmic flow.- 4. Availability of ATP.- VII. Influences of External Factors.- 1. Temperature.- 2. Light.- 3. Ultraviolet rays and other radiations.- 4. Osmotic pressure.- 5. Plasmolysis.- 6. Hydrostatic pressure.- 7. Mechanical pressure.- 8. Gravity.- 9. Centrifugal force.- 10. Electric current.- 11. Action current.- 12. Magnetic field.- 13. Hydrogen ions.- 14 Carbon dioxide.- 15. Salts.- 16. Auxins.- 17. Fat solvents.- 18. Miscellaneous substances.- VIII. Biology and Function of Protoplasmic Streaming.- 1. Inducement of protoplasmic streaming.- 2. Transport of substances.- 3. Locomotion.- 4. Correlation with some physiological activities and seasonal variations.- IX. Experimental Approaches to the Mechanism of Protoplasmic Streaming.- 1. Seat of the motive force in rotational streaming.- 4. Moving fibrils in protoplasm.- 5. The phenomenon of shifting occurring in the plasmagel.- 6. Causal relation between potential difference and the motive force of the protoplasmic streaming.- 7. The mechanochemical system of the protoplasmic streaming.- X. Theories.- 1. Rotational streaming.- 2. Streaming in transvacuolar protoplasmic strand.- 3. Streaming in myxomycete plasmodium.- 4. Independent motion of protoplasmic particles.- XI. Concluding Remarks.- Acknowledgements.- Author Index.