Archive image from page 35 of The cytology and life-history of. The cytology and life-history of bacteria cytologylifehist00biss Year: 1955 THE CYTOLOGY AND LIFE-HISTORY OF BACTERIA SECTIONS OF BACTERIA Diagrams drawn from electron micrographs of Bacillus cereus are compared. Diagram A is taken from the study by Chapman and HilUer, and B from material prepared in this laboratory. The former has been treated with 2°,, osmium tetroxide which has had the effect of rendering the cell wall very clearly visible but may also have coagulated the softer structures. Section B has been accorded mini
Archive image from page 35 of The cytology and life-history of. The cytology and life-history of bacteria cytologylifehist00biss Year: 1955 THE CYTOLOGY AND LIFE-HISTORY OF BACTERIA SECTIONS OF BACTERIA Diagrams drawn from electron micrographs of Bacillus cereus are compared. Diagram A is taken from the study by Chapman and HilUer, and B from material prepared in this laboratory. The former has been treated with 2°,, osmium tetroxide which has had the effect of rendering the cell wall very clearly visible but may also have coagulated the softer structures. Section B has been accorded minimal treatment before embedding. The cell envelopes are much less clearly seen, but the arrangement of the various structures is in closer accordance with that seen in stained preparations. A—the cell wall has an outer (A) and an inner {A) layer ; the latter may or may not correspond to the cell membrane. The cross-walls are seen complete (B) and developing by ingrowth {B) ; an important observation. The material (C) between the inner boundaries of the developing cross-wall, and (C) at an early stage of their formation, corresponds to the basophilic septum which precedes the true cross-wall. Its present appearance may well be an artefact arising from the coagulation of a much thinner, continuous structure across the cell. Similarly, the extension of the matrix (/->'), in which the nuclei (D) are embedded now extends across the former cell boundaries, at {B) and (C). B—The cell wall (E) and cross-walls (F) have thickenings (G) at their junctions, such as can be observed by phase-contrast by the method of Tomcsik, and in some stained pre- parations. The cross-walls are indistinct but continuous ; their mode of development cannot be discerned. The matrix (H) of the nuclear bodies (//) does not extend across the cell boundaries where these have remained complete.
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Keywords: 1950, 1955, archive, bacteria, baltimore_williams_and_wilkens, bisset_kenneth_alexander, book, bookauthor, bookdecade, bookpublisher, booksubject, bookyear, drawing, historical, history, illustration, image, page, picture, print, reference, vintage
