Modern surgery, general and operative . to a number of daughter-cells, which are calledarthrospores. Organisms which when active multiply by fission take on spore-formation when subjected to certain conditions. Spore-formation tends to occur when bacilh are about to die for want ofnourishment or when there is an excess of oxygen present. The spore has adense envelope or covering which is very resistant to destructive agents. Soresistant is the covering that twice the amount of heat is necessary to kill aspore as to kill an active adult cell. Spores when placed under conditionsimfavorable for d
Modern surgery, general and operative . to a number of daughter-cells, which are calledarthrospores. Organisms which when active multiply by fission take on spore-formation when subjected to certain conditions. Spore-formation tends to occur when bacilh are about to die for want ofnourishment or when there is an excess of oxygen present. The spore has adense envelope or covering which is very resistant to destructive agents. Soresistant is the covering that twice the amount of heat is necessary to kill aspore as to kill an active adult cell. Spores when placed under conditionsimfavorable for development may remain inactive for an indefinite period, justas seeds remain inactive when unplanted. Drying, even drying for years, maynot destroy them. A dry temperature of nearly 300° F. destroys the spores ofanthrax, but only after acting for three hours. Steam or boiling water killsmost spores in a few minutes. Some spores are able to withstand the actionof live steam for several or perhaps for many hours. Direct sunlight quickly. Fig. 13.—Sporulation (after De Bary). 24 Bacteriology / destroys spores (Clinical Bacteriology, by Levy and Klemperer). Whenspores encounter favorable conditions, they develop very rapidly into adultcells, just as seeds develop when planted. It seems probable that spores occa-sionally remain dormant in the human body for long periods, and finally awakeninto activity because of injury or disease of the tissue in which they lie. Chemical Composition of Bacteria.—The protoplasm of bacteria consistsof water, salts, albimiinous material, extractives soluble in alcohol, and extrac-tives soluble in ether. Life=conditions of Bacteria.—In order to grow and to multiply,bacteria require a suitable soil and the favoring influences of heat and soil demanded consists of highly organized compounds rather than crudesubstances, and slight modifications in it may prove fatal to some forms ofbacterial Hfe, but highly advantageous to others. Some
Size: 1639px × 1525px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, bookpublishe, booksubjectsurgery
