The Isthmus in 1904 21 



it became necessary for the sanitary inspectors 

 to be employed all night in clerical work. The 

 Anopheles were so numerous that night work had 

 to be done in relays; one set of men using fans to 

 protect those working. We were two thousand 

 miles from the source of supplies and had to wait 

 for screening, its installation, necessary supplies, 

 etc. 



When the hospital was first opened and treat- 

 ment given without charge to employees, the 

 native laborers who had known of the suffering 

 and deaths in previous years at Ancon refused 

 to go to the hospital, stating that they "preferred 

 to die at home." We could readily sympathize 

 with their ideas, knowing what had happened in 

 the past. No attempt was made to approximate 

 the number of Anopheles present. The prevailing 

 species was Anopheles albimanus. Inside one of 

 the buildings near the hospital, fifty-four adult 

 Anopheles were noted on the upper panel of a 

 screen door. 



It was desirable to know the time of the day 

 or night when the Anopheles would take blood. 

 In July of 1904, men were dressed in white clothing 

 and dark coats and made to lie on cots in an un- 

 screened ward at Ancon. They were furnished 

 with pill-boxes and a clock. Each time a mos- 



