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Chapter XXII 



THE RELATION OF SPECIES OF ANO; 

 PHELINAE TO MALARIAL ENDEMICITY 



Species undoubtedly play an important part 

 in the development of blood parasites in the 

 mosquito. 



Proteosoma, for instance, develops in certain 

 species of Culex, e.g., C. nemovusiis was used by 

 Koch in Europe. It does not, however, develop 

 in certain species of Taeniorhynchus (S. P. James). 



The malaria parasite does not develop in 

 species of Culex, Taeniorhynchus, Stegomyia, or 

 other blood-sucking flies, e.g., Phlebotomus, Simu- 

 lium, etc. In tl^ie case of Culex fatigans placed 

 under absolutely identical conditions with Ano- 

 pheles, no sign of zygote formation occurs on the 

 second or third day. 



Similarly with regard to filaria, it is only in 

 certain species of Culicidae that certain species of 

 filaria will develop, thus Ce. argyrotarsis is an 

 efficient host for F. nocturna, but inefficient for 

 F. demar quail. 



The malarial endemicity or endemic index may 

 be defined as the percentage of infected children 

 (under ten years of age) in any district, and repre- 

 sents the liability of immigrants to contract 

 malaria. 



