60 3/<JS(ji:rJVh's 



villa^-e had from one to fivo persons sick with chills and 

 fever, and other nialaiial troubles ; doctors in constant at- 

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

 radic cases of chills, both caused by negligence or in- 

 attention to ordinary caution. Everyone in the village 

 seems quite free from malaria since July lOtli." 



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

 which will be mentioned in the cha])ter on " Yellow Fever 

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

 in-Charge at Havana, wrote me, January 12, li)01, that in 

 his opinion there had been a very marked reduction of 

 malaria at the military posts in western 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. Thesis points are adduced by yor- 

 sons who, while admitting that it has b(>en jn'oved that 

 Anopheles transmits malaria, and that possibly this is the 

 only method which 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 where there are no Anopheles. Tlie 

 bite and method of attack of Anopheles is so insidious that 

 these nioscpiitoes attract very litth^ attention wlnn^e tliey 

 are not especially nunun-ous. One may be l)itten by them 

 while asleep at night almost without realizing it. Anoph- 

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

 will always remain uninfected unless some vcu'tebrate ani- 

 mal suffering with the disease comes to its neighborhood. 



