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of life beloiifring lu tlip spDi-uzoa and is most commonly known under 

 the name of Plasmodium malariae. To detect this parasite in the blood 

 is the crucial test for malarial fever in these days of laboratory methods 

 of investigating and diagnosing diseases; once found, the application of 

 the remedy for the disease is clearly indicated— this is quinine or one 

 of the allialoids of the cinchona group. Quinine is a pi'otoplasmic poison 

 to the malarial parasite. 



The Plasmodium malariae lives in and at the expense of the red 

 blood corpuscles of human beings afflicted with the disease. It appears 

 first as a minute speck in the corpuscles, gradually enlarges, and about 

 the time the cell is consumed it undergoes a segmentation, each segment 

 being a new and independent being which at once seeks a new host, a 

 fresh corpiiscle. Segmentation keeps up the species in the body of 

 the host. 



Under suitable conditions a higlier development of the parasite can 

 be seen. It is a process of differentiation into gametes, or males and 

 females, and the resulting offspring are concerned in the transmission 

 of the species, and of the disease, be it noted, into a new host. 



The role of the mosquito in carrying the disease from one person to 

 another has been worked out during the past two years. The prevailing 

 view of how this is done may be outlined in this wise: When the 

 Anopheles mosquito bites a human being afflicted with malaria, the 

 parasites in the blood are taken into the insect's stomach and here and 

 in the intestines they undergo a certain cycle of existence, or evolution, 

 lasting about a week or ten days, and sporozoids — corresponding to the 

 eggs of higher animals or to the seeds of plants— are formed, and these 

 get into the salivary gland, and when the mosquito bites ag^in they are, 

 along with the saliva, injected into the wound. Once in the human system 

 these sporozoa seek and occupy the red blood corpuscles; gradually they 

 increase in numbers by sporulation, and in the course of a few days, or 

 after one or more weeks, evidence of malaria manifests itself. In this 

 way malaria is transmitted to a new individual. 



The life history, or the development of the parasite, can be followed: 



First. In the blood of a malaria fever patient by taking a drop of 

 the blood at variable intervals and examining it under a high power of 

 magnification. This will show the sporulating generation. 



Second. In blood kept for some time under suitable conditions — 

 warmth and loss of fluid by evaporation— under the microscope. 



