60 MOSQUITOES 



villag-e had from one to five persons sick with chills and 

 fever, and other malarial tronbles ; doctors in constant at- 

 tendance. In the summer of 1900 there were only two spo- 

 radic cases of chills, both caused by neglig-ence or in- 

 attention to ordinary caution. Everyone in the village 

 seems quite free from malaria since July 10th." 



In Cuba, as a result of the mosquito- extermination work, 

 which will be mentioned in the chapter on " Yellow Fever 

 and Mosquitoes," Colonel J. R. Keane, U. 8. A., Surg-eon- 

 in-Charg-e at Havana, wrote me, January 12, 1901, that in 

 his opinion there had been a very marked reduction of 

 malaria at the military posts in w^estern Cuba. 



The principal arguments in favor of the idea that mal- 

 aria may also enter the human system in some other way, 

 are that there is malaria where there are no mosquitoes, 

 and that there are many mosquitoes in localities where 

 there is no malaria. These points are adduced by per- 

 sons wdio, while admitting- that it has been proved that 

 Anopheles transmits malaria, and that possibly this is the 

 only method Avhich has been proved, still insist that there 

 may be, and even that there must be, other methods. As 

 a matter of fact, it is practically impossible to prove that 

 there is local malaria Avhere there are no Anopheles. The 

 bite and method of attack of Anopheles is so insidious that 

 these mosquitoes attract very little a'iention where they 

 are not especially numerous. One may be bitten by them 

 while asleep at night almost without realizing it. Anoph- 

 eles may be present wdiere there is no malaria, since it 

 wdll always remain uninfected unless some vertebrate ani- 

 mal suffering- with the disease comes to its neighborhood. 



