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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    I observed, as did Grassi and Feletti, that in immature para- sites the melanin granules are chiefly found in the external part of the protoplasm, whereas the inner, the part next the nucleus, contains little or no pigment. I have therefore suggested that the distinction of the two layers should be based upon this fact. In many of the illustrations in the plates the reader will notice the conditions mentioned well marked. As, however, especially in the larger forms, the opposite condition is also to be observed, or certainly no considerable difference in the distribution of the pigment is appreciable, I think that we shall do best in the mean- time to consider the protoplasm of the malarial parasites as a body without any distinct differentiation. I must distinctly deny Romanowsky's [48] opinion that in healthy parasites, which have not been influenced by quinine, the marginal layer is always left free from pigment. A glance at the illustrations shows that just the opposite is the case; in young lively amoeboid bodies, and, therefore, certainly in perfectly vigorous bodies, I have very often observed that the very few pigment granules which are present are found at the extreme periphery of the parasite (Plate II, figs. 12—14). Danielewsky finds that also in the blood parasites of birds pigment forms in the outer layer. It is interesting to notice that this behaviour presents a contrast to the known fact that in the other Protozoa it is the inner proto- plasmic layer (Entoplasma) which contains the granules, products of digestion, &c., while the outer layer (Ektoplasma) is free from them. The protoplasmic substance appears to be chiefly homogeneous and hyaline, but in fully developed parasites it not infrequently shows a thick granulated appearance, which is made up of slight refractile granules. These granules also take part in the peculiar motion in which the pigment granules are found. The most important protoplasmic contents are formed of melanin granules, the malarial pigment. It has already been mentioned in the introductory chapter that Heinrich Meckel was the first to see this pigment in the blood, and that Virchow first recognised the importance of the fact in regard to malaria. Virchow, as well as Meckel, then assumed that the pigment originates in the spleen and from there makes its way into the circulation of the blood, while Planer first thought of the possibility of the origination of pigment in the blood itself. Later observers divided themselves chiefly into two groups, one of which represented the view started by Virchow, for instance Frerichs [63], who, placing the principal source of pigment in the spleen, regarded the liver as a secondary