20 The Control of Mosquitoes 



over the ground and sometimes did not return to 

 the lower part of the ditch. In addition, the foot 

 of the hill formed the shore line of an extensive 

 swamp. - These adverse conditions, and wet areas 

 covered with vegetation, encouraged Anopheles. 

 A more prolific source would be hard to imagine. 



The number of adult Anopheles present in the 

 hospital wards and buildings corresponded with 

 the numerous favorable propagation areas on and 

 near the hillside. At night, comfort was impos- 

 sible and mosquito bars indispensable. Not a 

 single building was screened. The malaria and 

 yellow fever patients had been accessible to 

 Anopheles and Aedes calopus, and the other patients 

 were near them. The patients in wards were 

 located according to nationality instead of accord- 

 ing to the nature of their illness. Had it been 

 intended to spread yellow fever and malaria with 

 the greatest rapidity among the patients as soon 

 as they arrived, no better plan could have been 

 adopted. Similar conditions have existed in other 

 tropical countries; in fact, were customary in past 

 years. • 



Before sanitary work was fairly under way, with 

 one or two exceptions, the small hospital sanitary- 

 force was down with malaria. During the first 

 year of work, all the force suffered. At one time 



