. The cytology and life-history of bacteria. Bacteria. THE BACTERIAL NUCLEUS 69 redistributed in the filament, and the latter then fragments into nidividual bacteria, each containing two pairs ot chrcMiiosomes. Thus each chromosome of the original six becomes the parent of the entire complement of two pairs in one daughter bacterium. The occurrence ot the fusion process has now been confirmed by genetic studies (Section G, below). ^ ^ /n r\ <j ^. {Reproduced front the Journal of Hygiene.) Fig. 30 VEGETATIVE REPRODUCTION IN BACTERIUM The trinucleate cell precedes the fusion cell wit
. The cytology and life-history of bacteria. Bacteria. THE BACTERIAL NUCLEUS 69 redistributed in the filament, and the latter then fragments into nidividual bacteria, each containing two pairs ot chrcMiiosomes. Thus each chromosome of the original six becomes the parent of the entire complement of two pairs in one daughter bacterium. The occurrence ot the fusion process has now been confirmed by genetic studies (Section G, below). ^ ^ /n r\ <j ^. {Reproduced front the Journal of Hygiene.) Fig. 30 VEGETATIVE REPRODUCTION IN BACTERIUM The trinucleate cell precedes the fusion cell with its three pairs of chromosome complexes. Within the fusion cell there is one nuclear division. The six chromosome pairs are re- distributed in the growing filament. There is a second nuclear division and the filament fragments into six daughter cells, each with the full complement of two pairs of chromosome complexes. In streptococci only three daughter cells are formed. Notliing has been recorded of the process by which the fusion cell which inaugurates this series of changes attains its form and nuclear complement. Bacteria occur which are probably the precursors of the fusion cells, as they contain three pairs of chromosomes, arranged in a more normal manner, with one pair at each end and one in the centre of the bacterium. But how these are derived from a bacterium with two pairs is not easy to understand. ana some un detected process of reduction may be 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
