THE ONSET OF RHYTHMIC STREAMING IN THE PHYSARUM-PLASMODIUM - COOPERATIVE HIERARCHICAL ORGANIZATION OF A MULTI-NUCLEATE CELL

Usually the large amoeboid cell of the Physarum plasmodium becomes ind efinitely large, but we found that the plasmodium broke temporarily in to pieces which contained only several nuclei at low temperatures. It is well known that the large plasmodium exhibits regular shuttle strea ming, but we found that the shuttle streaming emerged only when the si ze exceeded a certain critical size. Thus, the plasmodium does not org anize its multi-nucleate system directly from a single cell, but hiera rchically from units which are larger than the nucleus, gaining higher levels of organization step by step.