Mosquitoes and Yellow Fever ; Mosquitoes 

 and Flliariasis 



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 sugrg-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 hy ph}^- 

 sicians and investigators, but with a very pronounced 

 general incredulity. His experimental work did not 

 seem to have been definite enoug'h to attract confidence 

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



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