Observations on cell growth, mitosis, and division in the fungus Basidiobolus ranarum.

The paper describes the forward streaming, growth, and division of the vegetative cell of Basidiobolus ranarum. The cell is several hundred microns long and has a single large nucleus. Mitosis is invariably followed by cell division. Both processes have been studied in the living cell by ordinary and phase contrast microscopy. Mitosis is accompanied by a temporary coarsening of the organisation of the cytoplasm and a considerable slowing down of the rate of growth of the cell wall tube. Fixed and stained preparations have shown that there is a large number of small chromosomes and that the mitotic spindle is formed from the nucleolus. Basidiobolus appears suitable for observations on the cell duplication cycle and the physiology of mitosis.