. Animal parasites and human disease. Medical parasitology; Insects as carriers of disease. 152 MALARIA explains the occasional distinct projection of the parasites at the periphery or edge of the corpuscles (Fig. 44); and it accounts for the ease with which the parasites may be distorted in making blood smears. Another argument in favor of this theory as opposed to the intracorpuscular theory is that the haemoglobin in the corpuscles is believed to be in a more or less solid state, and would therefore make it difficult for the parasites, if situated inside, to indulge in such O active movemen
. Animal parasites and human disease. Medical parasitology; Insects as carriers of disease. 152 MALARIA explains the occasional distinct projection of the parasites at the periphery or edge of the corpuscles (Fig. 44); and it accounts for the ease with which the parasites may be distorted in making blood smears. Another argument in favor of this theory as opposed to the intracorpuscular theory is that the haemoglobin in the corpuscles is believed to be in a more or less solid state, and would therefore make it difficult for the parasites, if situated inside, to indulge in such O active movements as they do. The majority of protozoologists, however, have not accepted B Mrs. Johnson's conclusions. As the parasite develops there is a distinct Fig. 44. Blood tendency for the affected corpuscles to clump corpuscles showing . . * malaria parasites together, thus clogging the tiny capillaries which at periphery. B are iaro-e enough to allow the passage of only a shows two para- ° ° . t. , sites resting one single corpuscle at a time. In this way the above the other. capmaries of such organs as brain, spleen, bone (Sketches from mi- ^ t crophotographs by marrow and others may be obstructed to a Mary Lawson f t x degree. Three-fourths of the life cycle of [Mrs. Johnsonj.) & . J the parasites is usually passed in the plugged capillaries so that only during one-fourth of their cycle can they be found readily in the circulating blood. After about forty hours the nucleus of the parasite divides into a variable number of fragments, usually from ten or 15 to as many as 32, , under favorable conditions it may split five times, into two, four, eight, 16, and 32 parts. The rest of the body divides itself into portions, one surrounding each fragment of the nucleus, thus forming a little heap of " spores " (Fig. 43E) ready to burst apart and leave the corpuscle on which the parent parasite had been feeding. In the center of the heap can be found a little mass of coa
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectmedical, bookyear1918
