FIGHTING THE PANAMA MOSQUITO WITH Oil, 



These sanitary drip-barrels automatically spread oil, drop by drop, over pools, streams, 

 and marshy places, thereby preventing the mosquito from breeding in the water. _ "He (Ross) 

 proved beyond any peradventure that the Anopheles mosquito is the intermediate host, and 

 that no one can contract malaria except he be bitten by a mosquito which has previously 

 bitten a person suffering from that disease" (see page 347). 



blame upon the mosquito, and charged 

 that it introduced a poison similar to 

 snake venom into the human system 

 through the biting process. 



Step by step a closer approach to the 

 truth was made, and in 1883 Sir Patrick 

 Manson demonstrated that the mosquito 

 was the intermediate host of the blood 

 parasite filaria. 



But it was not until Sir Ronald Ross 

 arrived upon the scene with his investi- 

 gations that the real truth of the prin- 

 ciple of insect-borne diseases came to be 

 understood. Prior to this Laveran had 

 succeeded in isolating the germ of ma- 

 laria ; and, building upon this foundation, 

 Ross labored to ascertain the exact rela- 

 tion between man and the mosquito. 



346 



