THE MALARIA-GERM. 



195 



■m'«a', every 48 hours. Amitlici- form, giviiii;' risi; to a more malignant 

 type of malaria, is Laverania m.alarice, which prohably sporulates every 

 4S hours. Tn some types of tlu' disease it is supposed that two or more 



Fig. o. LiFK Cycle of the Malaria-Organism. [Partly After Koss and Fielding-Ould.] 



The young sporozoites {(i) penetrate red blood corpuscles and grow at the 

 expense of the hsemaglobin (b — (/). Spores (c — f) are finally formed and the 

 growth products (melanin) are liberated. These spores, or merozoites, enter new 

 blood cells and repeat the process (auto-infection). When taken into the stomach 

 of the mosquito Anopheles, the parasites become much larger, some develop 

 ]nale gametes (0, j), q) on the Polymitus form {p) ; others, female gametes 

 (r — u). These conjugate (v) in the stomach of Anopheles, and the copula (ic) 

 penetrates the epithelial lining of the stomach and ultimatel}' lies suspended in 

 tlip body cavity (x — zz). When mature, the parasite forms spores (A), which 

 f<iriii. in turn, naked sporozoites (B). The sporozoites are liberated into the body 

 cavity, and finally penetrate the salivary gland of the mosquito (C), from 

 which they are emptied out witli tlie fiuid from the gland into the blood of a 

 human host. 



species may be present at the same time, and, sporulating at different 

 intervals, may give rise to irregular attacks. 



Until 1896, the life history of the parasite, as outlined above, was 

 regarded as incomplete because of the perplexing form discovered in 



