Mosquitoes and Yellow Fever ; Mosquitoes 

 and Filiariasis 



IN 1881, Dr. Carlos Finlay, of Havana, noticed a cor- 

 respondence between the abundance of mosquitoes 

 and a period of increase of yellow fever in the 

 autumn, while during- the summer yellow fever had been 

 scarce and mosquitoes also scarce. This sug"g"ested to 

 him the idea that mosquitoes are responsible for the 

 transfer of the disease, and he conducted certain experi- 

 ments in which he claimed to have transmitted the 

 disease by the bites of the mosquitoes which had previ- 

 ously sucked the blood of persons suffering' with the 

 disease. Carrying on his idea further he proposed a 

 plan of inoculating non-immunes by the bites of infected 

 mosquitoes, on the theory that a mild type of the disease 

 would be produced which would afterward be protective 

 against reinfection of a more severe character. 



Dr. Finlay's theory w^as received with interest by phy- 

 sicians and investigators, but with a very pronounced 

 g-eneral incredulity. His experimental work did not 

 seem to have been definite enough to attract confidence 

 to his conclusions, nor was there enough of it. It is 



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