MALARIA 227 



found. Animals are not susceptible to human malaria. 

 Monkeys may be artificially infected. No antiserum 

 or vaccine treatment is possible now. Quinine is a 

 specific, and if properly used will cure all cases. The 

 spread of malaria is checked by preventing the propa- 

 gation of mosquitoes. These insects lay their eggs on 

 the surface of quiet water. The young remain at the 

 surface of the water when they require air. Oil is 

 spread upon the surface of the water and all marshes 

 are drained. No increase of the insects can go on if 

 these two things are done. 



