. The cytology and life-history of bacteria. Bacteria. 74 THE CYTOLOGY AND LIFE-HISTORY OF BACTERIA It was shown by Witkin (1951) that if bacteria which produce easily recognisable variant colonies are irradiated at a stage of growth when the majority of cells have a single chromosome, then complete variant colonies are produced. If they have two or four chromosomes then sectored colonies, with half or quarter variant sectors respectively, are produced. The segregation of the variant character, produced by alteration of an irradiated chromosome, takes place after a delay of two vegetative divi

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. The cytology and life-history of bacteria. Bacteria. 74 THE CYTOLOGY AND LIFE-HISTORY OF BACTERIA It was shown by Witkin (1951) that if bacteria which produce easily recognisable variant colonies are irradiated at a stage of growth when the majority of cells have a single chromosome, then complete variant colonies are produced. If they have two or four chromosomes then sectored colonies, with half or quarter variant sectors respectively, are produced. The segregation of the variant character, produced by alteration of an irradiated chromosome, takes place after a delay of two vegetative divisions, representing the process. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Bisset, Kenneth Alexander. Baltimore : Williams and Wilkens

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Keywords: ., bookcentury1900, bookcollectionbiodiversity, booksubjectbacteria