INSECTS AND HUMAN DISEASE 113 



of 460. Other campaigns have been carried out in Hon- 

 duras, Brazil, and the West Indies with equally gratifying 

 results, and, most striking and dramatic of all, in the 

 Panama Canal zone. 



The Panama Canal forms the centre of a strip of land 

 10 miles wide by 45 miles long ; its population consists of 

 some 50,000 labourers and their families, scattered over an 

 area of 500 square miles. As in Havana, so in Panama, 

 the inhabitants depend on rain-water for domestic pur- 

 poses, with the result that, adjacent to every house, there 

 is some vessel for catching and storing water. The climate 

 is favourable for continued breeding of mosquitoes all the 

 year round, and by Stegomyia fasciata, the yellow fever 

 mosquito, some domestic utensil containing a little water 

 is the most favoured breeding place. Small wonder, 

 then, that this district was once a hotbed of yellow fever 

 and malaria, and the failure of the Canal work, during 

 the French occupation, was largely due to the enormous 

 mortality of Europeans in the zone. In 1904, the American 

 Sanitary Department took upon its shoulders the seemingly 

 impossible task of rendering the Canal zone healthy and 

 habitable. The whole region was divided into districts, 

 bodies of men worked at mosquito extinction in each 

 district, and an inspector was put in charge of each of 

 these bodies, to see that the work was carried out in a 

 scientific manner. Primarily, operations were directed 

 against the yellow fever mosquito, but the malaria mos- 

 quito did not by any means escape from the campaign 

 unscathed. It is impossible to detail all the antimalarial 

 measures that were undertaken in the zone all the 

 breeding places of the mosquitoes were destroyed as far as 

 possible ; bottles, old cans, etc., in which Stegomyia might 

 breed were cleaned up, and ditches, etc., within a hundred 

 yards of any dwelling were cleared so as not to afford a 

 home to Anopheles larvae; protection for the adult mos- 

 quitoes in the shape of rank grass was also burned or 



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