Volume 1

A system of surgery / edited by C.C. Choyce ; pathological editor J. Martin Beattie.

Date:
1912-1914
Catalogue details

Licence: Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)

Credit: A system of surgery / edited by C.C. Choyce ; pathological editor J. Martin Beattie. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

    34/1097 (page 5)
    STRUCTURE OF BACTERIA 3 Rounded organisms (Cocci) Straight RODS (Bacilli) Curved rods PROVISIONAL CLASSIFICATION OF BACTERIA ( Monococcus : Single organisms separating after division. Diplococcus : Remaining in pairs after division. Tetragenus : Dividing in two directions at right angles to each other, tlius giving rise to an arrangement in fours. Sarcina : Dividing in three directions mutually at right angles, thus giving rise to packets of eight. Streptococcus : Dividing in one direction only, the new organisms remaining in contact to form chains. Staphylococcus : Dividing in all directions, the organisms are masssd together in irregular clusters. Ascococcus : Dividing like the staphylococcus, the clusters ]:irii- duced are enclosed within a membrane and form a nodulated mass. (Monohacillus : Single organisms, separating after division. [ Diplobacilliis : Remaining in pairs after division. ! StreptohacUlus : Remaining connected and fc)rming chains or I threads. Vibrio : Curved single or paired organisms. {Spirillum : Remaining connected after division and forming ! wavy threads. I Spiroch(vtc : Single uniform screw-like threads, more sharply 1^ bent than tlie spmlla. Of the liiglier bacteria, or filamentous forms, tlie only group at present of surgical interest is that of the Streptothricia;, in which the filaments exhibit branching. To this group belong the ray fungus (the actinomyces) and the Streptothrix nutdurce. 4. STRUCTURE AND CONSTITUTION The bacteria are highly refractile, sharply-contoured, colourless or more or less pigmented masses of protoplasm, which may be regarded as individual cells, but which exhibit staining properties more akin to those of nuclei than of cell protoplasm in general. The closer study of their intimate structure has been pursued in the main by three chief methods, viz. the artificial production of plas- molysis, staining with aniline dyes, and chemical or microchemical analysis. Plasmolysis is produced by placing the cells in question in salt solutions of higher concentration than that normal to the cells them- selves. This causes the cell protoplasm to become shrunken up within the envelope, leaving a space between, since the protoplasm is of a more fluid character than the envelope, and therefore is more markedly affected by the loss of Avater. The bacterial cell consists of (i) an envelope, (ii) a cell protoplasm containing vacuoles and granules, and exhiljiting in certain cases what