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C F ROBINOW

Publications and source records attributed to C F ROBINOW.

15 recordsLinked to original sources

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.

Cell Cycle↗

Observations with the electron microscope on the fine structure of the nuclei of two spherical bacteria.

The nuclei of two spherical bacteria have been examined in electron micrographs of thin sections of specimens prepared by the method of Ryter and Kellenberger (1958). The nuclei appear to consist of the same fine fibers in a matrix of low density which have already been seen in many other bacteria prepared by the same procedure. They are worth a separate description because their constituent fibers are arranged in patterns of uncommon orderliness. In the nuclei of one of the two bacteria this is seen at all times, in the nuclei of the other one only at the beginning of the growth cycle. In some places the diameter of the nuclear fibers is close to that of the DNA molecule in the model of Watson and Crick (1953).

Bacteria↗

Mitosis in the yeast Lipomyces lipofer.

A study of mitosis in Lipomyces has been carried out because preliminary observations by Ganesan and Roberts, 1959 (9), had indicated that the nucleus of this yeast might be unusually favourable for morphological observations. This impression has proved correct. The chromosomes of Lipomyces are visible as separate, countable bodies for the greater part of mitosis. The pattern of mitosis differs from the common one in that in Lipomyces the proper distribution of sister chromosomes is accomplished without the help of a spindle apparatus. At the end of prophase sister chromosomes are found in pairs which align themselves parallel to one another to form a palisade or stack whose long axis coincides with the axis of the impending division. At anaphase-telophase the stack of paired chromosomes fuses into a seemingly homogeneous cord which divides by constriction.

Anaphase↗