X 



THE MOSQUITO: MALARIA, YELLOW 

 FEVER, FILARIASIS 



\A7 ITHIN the last few years, it has been proved 

 * * that the mosquito is an intermediate host, 

 between man and man, of malaria, yellow fever, and 

 filariasis (elephantiasis). # Just as the grosser 

 parasites, the tape-worms, must alternate between 

 man and certain animals, and cannot otherwise go 

 through their own life-changes and reproduce their 

 kind, so the micro-parasites that are the cause of 

 malaria, etc., alternate between man and the 

 mosquito, having the mosquito as an intermediate 

 host. These organisms, once they get into the 

 mosquito, pick out certain structures, and there 

 carry out a definite cyclical phase of their lives, 

 whereby their progeny make their way into the 

 stylets of the mosquito, and so get back to man, 

 who is their " definitive host." Thus, malaria is 

 not, strictly speaking, a disease of man ; it is one 

 phase in man of micro-organisms that have another 



* For Dr Graham's recent experiments at Beyrout, which 

 seem to prove that the mosquito can also convey dengue or 

 dandy-fever, see the New York Medical Record, 8th February 

 1902. 



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