Page:Popular Science Monthly Volume 50.djvu/654

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POPULAR SCIENCE MONTHLY.

been traced by Golgi and others, and results in the formation of a number of bodies arranged in the form of a rosette, with a mass of pigment granules at the center (see Fig. 2). The growth of the plasmodium seems to be at the expense of the hæmoglobin of

Fig. 2.—Intracorpuscular Development of the Parasite of Tertian Intermittent Fever: 1, 2, young hyaline forms; 3, 4, more advanced pigmented forms; 5, fully grown parasite; 6, 7, 8, 9, segmentation and production of free spores (10).

the infected red blood-corpuscle, and the pigment granules are probably to be regarded as an excrementitious product. The segments of the rosette, which represents the final stage of intracorpuscular development, are finally set free by a breaking down of the remains of the corpuscle, and are supposed to correspond with the elementary body which invaded the corpuscle in the first instance. The periodicity of this class of fevers is believed to depend upon the fact that a certain time is required for the intracorpuscular development of the plasmodium, and that successive crops of these elementary bodies are set free at regular intervals. We have also in the blood of malarial-fever patients certain pigmented bodies which are believed to represent different stages in the development of the same parasite, or of a nearly related parasite, which is concerned in the ætiology of a different type of malarial fever. The form most frequently encountered is associated with the so-called "æstivo-autumnal" malarial fevers which prevail in the vicinity of Rome and elsewhere. The bodies characteristic of this type of fever are crescentic in form and contain black pigment granules, usually centrally located (see Fig. 3). These crescentic bodies are not usually found in the blood of persons suffering from intermittent fever of the tertian or quartan type. Golgi, who has made very extended studies of the blood of malarial patients, asserts that each intermittent paroxysm is associated with the segmentation of a group of intracorpuscular organisms—that is to say, that the paroxysm corresponds with the