Cell-nuclear migration during the amoebo-flagellate transformation of Physarum polycephalum is mediated by the centrosome. The centrosome is expected to be strongly connected to the cell nucleus. An electron micrograph of a thin section of intact amoeba cell suggested that one of the structures consisting centrosome complex, mtoc, was directly attached to the outer membrane the of cell nucleus without any intervening microtubules. To analyze the fine details of the centrosome perimeter, and especially the space between the cell nucleus and mtoc, we used 0.1% Triton X-100 and different concentrations of NaCl to remove obstructive cytoplasm around the centrosome and the cell nucleus. The centrosome complex was shown to be composed of 2 centrioles, mtoc, link, ppks, extension, crown and lattice. With 100mM NaCl, the connection between the centrosome complex and the cell nucleus remained intact and was visible as a cell-nuclear appendage even by light microscope. This linkage was maintained even when 2mM Ca²⁺ ion was added to the samples to depolymerize and eliminate the effects of microtubules. This shows that the structure which connects the centrosome complex to the cell nucleus is mtoc, not microtubules. Electron micrography using whole mounts and thin sections of the treated amoeba cells demonstrated that the cell nucleus retained traces of its outer and inner membranes, and that the mtoc of the centrosome complex was directly connected to the outer membrane of the cell nucleus.