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POPULAR SCIENCE MONTHLY. 



enter, and in which they repeat the cycle, thus bringing about auto- 

 infection. 



Another Italian naturalist, Golgi, in 1889, showed that the spore- 

 formation of the parasites and the well-known pyrexial attacks on the 

 part of the patient occur at the same time, and the phenomena were 

 interpreted as cause and effect. The direct cause of the attack was 

 then found to be the liberation into the blood plasm of the melanin 



Fig. 2. Life Cycle of Coccidium. [Schaudinn.] 



The sporozoites penetrate epithelial cells {«) and grow to adult size. When 

 ready to sporulate, they are free in the lumen of the organ. The nucleus divides 

 repeatedly (&) and each of the ultimate sub-divisions becomes the nucleus of a 

 merozoite (c). These re-enter epithelial cells (a) and repeat the cycle. After 

 five or six days the merozoites have a different fate. Some (d — g) enlarge and 

 form egg-cells; others (h — ;) form minute flagellated male cells, or microgametes. 

 One of these fuses with one egg cell, (g — k), and the copula then forms spores 

 (fc), each of which form, in turn, two sporozoites (/). In this condition the 

 organism is taken into a new host and the process is tlicn repeated. 



granules, which, acting like a poison, throw the entire system into 

 disorder. In different types of malaria, the attacks sometimes occur 

 every 72 hours, sometimes every 48 hours, and in some cases at 

 irregular intervals. These different effects are produced by slightly 

 different forms of the malaria organism. One form, known as 

 Plasmodium malarice, sporulates every 72 hours; another, Plasmodium 



