A text-book of pathological anatomy and pathogenesis / by Ernst Ziegler ; tr. and ed. for English students by Donald MacAlister.

  • Ernst Ziegler
Date:
1887
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Licence: Public Domain Mark

Credit: A text-book of pathological anatomy and pathogenesis / by Ernst Ziegler ; tr. and ed. for English students by Donald MacAlister. Source: Wellcome Collection.

Provider: This material has been provided by the Francis A. Countway Library of Medicine, through the Medical Heritage Library. The original may be consulted at the Francis A. Countway Library of Medicine, Harvard Medical School.

    358/1132 (page 324)
    i 324 A TEXT-BOOK OF PATHOLOGICAL AISTATOMY. Lichtheim, Berl. klin. Woch., 9, 1882 ; Leber, Griife's Arch., xxv., and Berl. klin. Woch., 19, 1883; Duclaux, Ferments et Maladies, Paris, 1882 ; Koch, Berl. klin. Woch., 52, 1881 ; Kaufmann, Lyon medicale, 1882.] 220. The action of the mould-fungi on the nutrient soil on which they grow is slow, and limited in extent. Thus the mouldy covering which forms on preserved fruit extends only to a slight depth below the surface. Mouldy articles of food acquire a peculiar, unpleasant, musty taste. If the mycelium of a fungus gains access to an apple, for instance, the apple becomes rotten ; i.e., a process of change and decay sets in ac- companied by purely chemical decompositions. Timber in which mould- fungi develop becomes soft and brittle, and breaks down into a dry mouldering dust. Fungi which are specifically distinct may give rise to similar or identical decompositions in articles of food, timber, etc. The mycelium of Merulius lacrhnans (dry-rot) destroys the wood-work of houses. Moulds may likewise attack living plants, i.e., they may thrust their niycelia into living vegetable tissue. The changes they occasion are va- rious. Sometimes they seem to exert no disturbing influence on the nor- mal development of the tissue. In others they induce abnormal growths. The so-called witches' brooms of the silver fir are produced by the set- tlement in the tree of the Aecidiimi elatinum. Often the cell-contents become altered ; thus starch and cellulose may be converted into turpen- tine. Hartig thinks the moulds may also act as organized ferments. Not infrequently the fungi destroy altogether the plants they attack. Thus the O'ldiuin Tuckeri (vine-mildew) seizes on the green parts of the vine, and destroys it. If the spores of Peronospora infestans reach the tubers of the potato-plant, they drive their germinal hyphge into their substance, form a mycelium there, and so ruin the potato (De Bary) ; this constitutes the potato-disease. The leaf-rust which destroys fruit-trees is likewise due to a fungus {Moestelia cancellata).. [References : Sachs, Text-book of Botany, 1882 ; De Bary, Die gegenwartig herrschende Kartoffelkrankheit, Leipzig, 1861, Journ. of Botany, 1876, Botan. Zeitung, 1881 ; Hartig, Ueber die durch Filze bedingten Pflanzenkrankheiten, Munich, 1881.] 221. Pathological significance. The mould-fungi do not act as producers of disease to anything like the same extent as the bacteria. \ The fact that they require abundance of oxygen and flourish best at tem-i peratures below that of the body hinders their development within it. i Moreover, their growth and reproduction are much slower than in thai case of the bacteria, and this also is a hindrance to the invasion of living: tissues by them. Lastly, they do not usually find in living tissues their proper nutriment. At the same time the products of the decompositions