Archive image from page 72 of The cytology and life-history of. The cytology and life-history of bacteria cytologylifehist00biss Year: 1955 ACTERIAL NUCLEUS 57 The nuclei of mycobacteria were described as Feulgcn-positive granules, regularly arranged along the length of the bacillus, before it was realised that the bacillus is multicellular, and that each granule was a cell nucleus. Some confusion has also resulted from identification of these granules with those Fig. 21 EFFECTS OF HYDROLYSIS ON THE SPORE NUCLEUS a. Spore with nucleus in natural position. b. The ' crescentic nucleus.' The
Archive image from page 72 of The cytology and life-history of. The cytology and life-history of bacteria cytologylifehist00biss Year: 1955 ACTERIAL NUCLEUS 57 The nuclei of mycobacteria were described as Feulgcn-positive granules, regularly arranged along the length of the bacillus, before it was realised that the bacillus is multicellular, and that each granule was a cell nucleus. Some confusion has also resulted from identification of these granules with those Fig. 21 EFFECTS OF HYDROLYSIS ON THE SPORE NUCLEUS a. Spore with nucleus in natural position. b. The ' crescentic nucleus.' The nuclear material forms a pool between the cytoplasm and spore coat. c, d. The ' peripheral nucleus.' The spore coat is bulged outwards by the ejected nuclear material. e. Complete ejection of nuclear material. which appear in the well-known granular or beaded effect seen in heat-fixed preparations of M. tuberculosis. The latter arc, in fact, merely the shrunken cell contents. The metachromatic granules of C. diplitlieria' have also been identified with nuclei by some workers, and disproved by others. They are not seen except in dried preparations, and are artefacts consisting of an aggregate of stainable material within the larger, terminal cells of the bacillus. Fig. 20 MICROCYSTS OF BACTERIACEM The appearance of the resting cell and resting nucleus may be very distincti\e, even in bacteria of which the vegetative stages are similar. Acid-Giemsa, < 3000. (1, 2) Bacterium coli. Small, oval cells with an eccentrically staining nucleus. Proteus and most Salmonella are similar. (3, 4) Bacterium aerogenes, much larger, with a small, central nucleus. ((4) is stained by methylene-blue-eosin). (5-7) The large microcysts of 5. typhi. < (8) Shigella schmitzii, large oval cells with a central nucleus.
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