Page:An Address on the Hæmatozoa of Malaria.pdf/2

 more general interest in the question was aroused by the publications of Marchiafava and Celli, who found in the blood of malarial patients at Rome the bodies described by Laveran. They figured carefully the alterations of the organism in the interior of the red corpuscles to which they gave the name Plasmodium malariæ. Councilman, of Baltimore, has more recently confirmed these observations. The pigment granules so numerous in the interior of the red corpuscles in cases of "comatose pernicious fever," and which appear to be included in a hyaline mass are, according to Marchiafava and Celli, and Councilman (who had previously described them ) these amœboid parasites deeply laden with altered hæmoglobin.

Technical Details.—The finger pad from which the blood drop is taken should be thoroughly cleansed, and, if the examination is made during a paroxysm, the sweat which may exude after the friction and drying should be removed. Attention to these, apparently trivial, details will secure specimens of blood free from small particles of dirt, and facilitate considerably the search for pigmented bodies. The layer of blood beneath the top cover should be very thin and uniform, the corpuscles, as far as possible, isolated and not aggregated in clumps or in rouleaux. It is well to surround the cover with paraffin if the examination is prolonged. No reagent of any kind should be added. Cover-glass preparations may be made and stained in methyl blue or fuchsin, and mounted in balsam. Osmic acid preparations may also be employed. Although these bodies may be seen with a power of 500 to 600 diameters, it is essential for the satisfactory study of the changes to use higher powers. I have uniformly worked with the ??? homo. immersion of Zeiss, and the ?? im. of Reichert. Stricker's warm stage will be found useful.

1. The Forms which Exist within the Red Corpuscle.—(a) The most common alteration in the blood of malarial patients is presented by a pigmented structure inside the red corpuscle. The attention of the observer will most likely be first attracted by the presence of a few dark grains in the stroma, and a careful study of a suitable specimen will soon lead to the conviction that these are not scattered loosely, but are enclosed in a finely granular or hyaline body in the interior of the corpuscle (Fig. 1). The red discs in which

they occur are usually larger, look flat, and are very often paler than normal; they may, indeed, exist only as colourless shells. The number of corpuscles so affected varies extremely in different cases. In some instances they are readily found after a search of a moment or two, but, in other cases, a prolonged examination may be necessary. Only one is usually present in each corpuscle, but two or three, or even four, may occupy the stroma. They vary greatly in size, the smaller ones not occupying a fourth of the corpuscle, while the larger ones may almost fill it. A delicate contour line can usually be seen separating the body from the stroma; at times this is very indistinct, particularly if the illumination is very bright. The substance appears hyaline, or very finely granular, and the pigment grains are scattered irregularly in it. They may be very numerous, and give a dark aspect to the body, or they may be scanty. They frequently present rapid Brownian movements. Occasionally a vacuole may be seen in the interior of the body. In several instances the bodies appeared to be enclosed in a clear space—vacuole—in the stroma. When first seen they are more or less spherical, but, as already stated, the outline may be indistinct. The pigment granules may be seen to alter their position in relation to each other. If the margin of the body is carefully observed, slow changes can be seen, which gradually bring about alterations in shape. These movements, which appear to be amœboid in character, can often be traced with great ease. They are well represented at Fig.1, and, better still, at Fig.2. Changes in position of the body in the corpuscle result from them. They are decidedly slower than the amœboid movement of the colourless corpuscle. I have not seen any evidence of migration from the corpuscle. In dry preparations

these bodies stain deeply with gentian violet or fuchsin,and present a granular stroma, in which the pigment grains are imbedded. (Fig. 3.)

(b) In seven cases peculiar hyaline structures existed in the interior of the red corpuscles, which differ from the bodies just described, in the absence of pigment and in the much greater activity of the changes. Fig. 4 illustrates the appearance and the alterations in outline. These

bodies are devoid of structure, and the corpuscles in which they are present are not so pale as those with the pigmented forms. Marchiafava and Celli, who have given an excellent plate of these bodies, regard them as the initial forms of the pigmented bodies. One does occasionally see appearances indicative of commencing pigmentation, but they have not, as a rule, the solid aspect of the pigmented bodies. In three cases I have seen the following remarkable changes. The hyaline body, while actively changing shape, suddenly burst from the stroma, and disappeared, or formed only a few granules. Thus, in a red corpuscle, there were, at 3.40, two hyaline, irregular-shaped bodies, which were changing rapidly in outline. The alterations were so marked that the physicians present at the time had no difficulty in seeing them. The stroma of the corpuscle was of full colour. At 3.50, as I was carefully watching these forms, the corpuscle suddenly ruptured, and gave exit to two distinct masses, which quickly broke up into ten or twelve spherical bodies. No change took place in these after twelve hours, except that they became pale and indistinct. The stroma of the corpuscle became quite colourless. On two other occasions a similar phenomenon was witnessed, but in one no trace could be seen of the extruded material. This is evidently a physical change, and I think these very pale hyaline bodies must be carefully distinguished from the pigmented forms, though possibly associated with their early development.