436 



MOSQUITOES OF NORTH AMERICA 



The later developments of the work in the Mexican Eepublic under Doctor 

 Lieeaga's leadership have been remarkable. In the American Journal of Public 

 Hygiene, new series, volume vi, No. 1 (February, 1910), is published Doctor 

 Lieeaga's " Annual Eeport on Yellow Fever in the Mexican Eepublic, from Au- 

 gust 16, 1908, to date," a paper read before the American Public Health Asso- 

 ciation at Eichmond, Va., October, 1909. The following paragraphs concluding 

 this report will give an idea of the excellent results which have followed the 

 work of the sanitary oflBcials in Mexico : 



" The campaign against Yellow Fever, which commenced in the Mexican 

 Eepublic in the year 1903, has continued uninterrupted up to this date, without 

 even suspending it during the Winter months as is done in other countries ; that 

 the war on the mosquitoes is so efficacious that there are none left in Veracruz, 

 and consequently, there are no stegomyas, as demonstrated by the reports ren- 

 dered by the physician of the Public Health and Marine Hospital Service of the 

 United States, who is resident in that Port. 



" The cases which have been observed in Merida and surrounding villages, 

 arise from the existence in that city of over thirty thousand water tanks which 

 could not be so easily and securely watched as those of Veracruz. 



" In the entire section which was formerly devastated by Yellow Fever we 

 continue to canalize the deposits of standing water and to fill up the hollows, as 

 well as to spread oil on all those ponds which cannot be otherwise filled in or 

 covered. 



" We continue to fumigate the dwelKng houses, workshops, schools, etc., in 

 which we have encountered either cases of Yellow Fever or any suspected cases. 



" We continue the surveillance over the passengers who travel by rail in any 

 part of the region which formerly suffered from Yellow Fever, and this service 

 is especially active along the line of the Tehuantepec Eailroad. 



" In the ports of Coatzacoalcos, on the Gulf Coast and Salina Cruz on the 

 Pacific, it is nearly four years since a single case of Yellow Fever was observed.'' 



WORK IN JAPAN. 



Work in Japan, under Surgeon Major Tsuzuki, as early as 1901, confirmed 

 experimentally the malarial relations of Anopheles, and later a large-scale ex- 

 periment was carried on among the Japanese troops occupying Formosa, which, 

 on account of its large scale, served to set at rest any doubts which had previously 

 existed as to the value of mosquito protection. Portions of Formosa are mala- 

 rious, and the following table indicates the conditions existing among the troops 

 from 1897 to 1900, before there had been any control work in the modem sense : 



From the 21st of September, 1901, to the 38th of February, 1903, work based 

 on the mosquito theory was carried on by order of the Governor of Formosa, 



