Two monographs on malaria and the parasites of malarial fevers / I. Marchiafava and Bignami, II. Mannaberg.

  • New Sydenham Society
Date:
1894
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Licence: Public Domain Mark

Credit: Two monographs on malaria and the parasites of malarial fevers / I. Marchiafava and Bignami, II. Mannaberg. Source: Wellcome Collection.

Provider: This material has been provided by The University of Leeds Library. The original may be consulted at The University of Leeds Library.

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    being always coloured, indeed, it is very often completely trans- parent and colourless (Plate IV, figs. 63, 64 ; Plate I, figs. 57—66). Further proofs for the existence of a true investing membrane round these bodies will be given subsequently. Even under high powers no proof of structure in the membrane is obtainable. Lastly, it must be mentioned that Antolisei sometimes observed a double contour in the spores of the quartan parasites, and that the same author is of opinion that the spores in general have an investing membrane. {b) Plasmic bodies and their contents.—Each hsematozoon possesses a plasmic body which occupies a different amount of space in relation to the whole parasite ; relatively it is least in the quite immature forms, because in them the size of the nucleus much predominates, whereas in the fully-developed parasite the relative size of the two is generally reversed. The bulk of the cytoplasm is excentrically situated with reference to the nucleus, as is seen in the illustration (see Plate III). In the living parasites, especially in all immature forms, it is generally impossible to differentiate the plasma from the nucleus. Both constituents apparently form a homogeneous mass, and this explains why it was so long before the difference was made out. In stained preparations the more or less markedly stained plasmic body projects itself quite clearly from the unstained vesicle which forms the nucleus (see Plate III). As the amoeboid processes of the immature forms proceed from the plasma, it is natural that in the stained preparation all possible forms are presented. In the Protozoa, to which, indeed, the malarial parasite belongs, two layers of the plasmic body are in general distinguished, the inner and the outer layers of protoplasm (Entocyte and Sarcocyte). These layers are found clearly separated from one another in many developed Protista ; the granules of the Entocyte especially present a marked difference in comparison with the hyaline con- struction of the Sarcocyte. In the malarial parasites it is not always possible to accomplish such a division of the protoplasm into two accurately differentiated layers, just as little as it can be done in a large number of the Rhizopoda, in the small single Grregarinida and the Coccidia. Celli and Guarnieri [46] were the first to use for the malarial parasites the expressions Ecto- and Endo-plasm, but they caused some confusion because they designated Endoplasm the unstained part of the hgematozoa,—that part which represents the nucleus and which has, therefore, nothing to do with the protoplasm.