MALTA FEVER, MALARIA, YELLOW FEVER 



from yellow-fever patients. These experiments 

 went on for 21 days. The men took no harm. 

 When they had thus disproved the old belief that 

 the fever can be transmitted by contagion, they 

 exposed themselves to the mosquitoes, and all of 

 them got the fever. 



Thus, by 1901, the case against the mosquito 

 was complete. As Anopheles maculipennis con- 

 veys malaria from man to man, so Stegomyia 

 calopus conveys yellow fever from man to man. 

 Therefore, to keep down malaria and yellow fever, 

 keep down these mosquitoes. The eggs are laid 

 on stagnant water : " ponds, swamps, puddles, 

 roadside ditches, tanks, cisterns ; and all such 

 chance receptacles of rain-water as rain-barrels, 

 pots and pans and broken bottles and old biscuit- 

 tinsall the rubbish of the backyard." The larvae 

 live in the water, coming to the surface to breathe 

 through their air-tubes. It is easy, therefore, to 

 deal with them. " Pools and ditches are drained, 

 or stocked with minnows, or filmed with kerosene 

 to kill the larvae ; broken crockery and the like 

 debris are carted away ; cisterns and wells and 

 rain-barrels are covered ; everywhere, the surface- 

 soil is tidied up ; and all collections of stagnant 

 water are cleared out." 



By this labour, much of it unskilled, we know 

 what great victories have been won over malaria 



