. A manual of determinative bacteriology. Bacteria. BACTERIOLOGY. In tubercle bacilli this beaded appearance is common, and the unstained spaces are considered by A. Coppen Jones to be of the nature of vacuoles. It is doubtful whether this is correct; on the contrary, it is more probable that the beaded structure rep- resents a fragmentation of the protoplasm, which is a phase in all cellular de- generation. According to Biitschli, in Bad. lineola, the central body is surrounded by an envelope of protoplasm corresponding to the cyto- plasm of other cells. If such a cytoplasmic layer -exists in
. A manual of determinative bacteriology. Bacteria. BACTERIOLOGY. In tubercle bacilli this beaded appearance is common, and the unstained spaces are considered by A. Coppen Jones to be of the nature of vacuoles. It is doubtful whether this is correct; on the contrary, it is more probable that the beaded structure rep- resents a fragmentation of the protoplasm, which is a phase in all cellular de- generation. According to Biitschli, in Bad. lineola, the central body is surrounded by an envelope of protoplasm corresponding to the cyto- plasm of other cells. If such a cytoplasmic layer -exists in other species of bacteria, it is too thin to be differen- tiated from the outer capsule. Whether the central body is a true nucleus or not cannot be positively decided, but there is no good reason to beheve that it is. That the central body is a distinct structure from the outer capsule is demonstrated by the phenomenon of plasmolysis. Thus when bacteria are placed in a per cent potassium nitrate or a i per cent sodium chloride solution, the central body contracts, and separates itself in places from the capsule, .as shown in Fig. i, D. The bacterial plasma in certain species may show the pres- ence of granular bodies, as in B. butyricus, Vibrio bugula, and Bact. Pasteurianum, which stain bluish or violet-black' with iodine; the so-called granulose reaction. The exact nature of granulose is not known. It may be identical with starch, or, at .any rate, is a closely related carbohydrate. Fig. I. — Showing structure of bacterial cell. -A. Bact. lineola after Biitschli, a capsule, b proto- plasmic layer, c nuclear body. B. Bact. oxyla- ticum after Migula, a capsule, b central body, c vacuole, d metachromatic granules. C-D. plasmolysis of bacterial cell. E. bacilli, show- ing metachromatic 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
Size: 1730px × 1443px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, bookpublishernewyo, bookyear1901
