Scanning electron microscopy of spherules of Physarum polycephalum

The ultrastructure of starvation-induced sclerotic and mannitol-induced spherules was studied by a scanning electron microscope (SEM). Each spherule in the berry-like sclerotium is not rounded and has lobe-like forms, whereas the separate spherules are significantly bigger and rounded. Bead-like granules were observed inside and on the spherules. Broken spherules observed in the SEM show ultrastructure of cell wall, cytoplasm, vacuoles and granules, nuclei and nucleoli.