430 MOSQUITOES OF NORTH AMERICA 
drawn. Every house in Havana, on the average, has a cesspool, the liquid con- 
tents generally seeping into the soil. The inspector on each visit had from four 
to six ounces of petroleum poured into the cesspool, and where this was not 
accessible it was poured into all closets connected with the cesspool. All recep- 
tacles containing fresh water that did not conform to the law were emptied, 
and, on a second offence, destroyed. If the owner was an old offender, he was 
prosecuted under the law and fined. 
The result of this work of the so-called “ stegomyia brigade” was that, while 
in January, 1901, there were 26,000 fresh-water receptacles containing mosquito 
larve, in January, 1902, there were less than 400 such receptacles containing 
larvee ; mosquitoes had rapidly decreased, and were entirely absent in many parts 
of the city. The result of this work, thoroughly done, was to wipe out yellow 
fever in Havana. 
The “anopheles brigade” was organized for work along the small streams, 
irrigated gardens and similar places in the suburbs, and numbered from fifty to 
three hundred men. No extensive drainage, such as would require engineering 
skill, was attempted, and the natural streams and gutters were simply cleared of 
obstructions and grass, while superficial ditches were made through the irrigated 
meadows. Among the suburban truck gardens Anopheles bred everywhere in the 
little puddles of water, foot-prints of cattle and horses, and similar depressions 
in grassy ground. Little or no oil was used by the “ anopheles brigade,” since it 
was found in practice a simple matter to drain these places. At the end of the 
year it was very difficult to find water containing mosquito larve anywhere in 
the suburbs, and the effect upon the malarial statistics was striking. In 1900, 
the year before the beginning of the mosquito work, there were 325 deaths from 
malaria; in 1901, the first year of mosquito work, 151 deaths; in 1902, the 
second year of mosquito work, 77 deaths. Since 1902 there has been a gradual, 
though slower decrease, as follows: 1903, 51; 1904, 44; 1905, 32; 1906, 26; 
1907, 23. 
WORK AT THE ISTHMUS OF PANAMA. 
The United States government has very properly used the services of Colonel 
Gorgas, who was in charge of the eminently successful work at Havana, by 
appointing him Chief Sanitary Officer of the Canal Zone during the digging of 
the Canal. In 1904 active work was begun, and Colonel Gorgas was fortunate 
in having the services of Mr. J. Le Prince, who has been chief of his mosquito 
brigades in Havana, and therefore was perfectly familiar with anti-mosquito 
methods. In Panama, as in Havana, the population had depended principally 
upon rain-water for domestic purposes, so that every house had cisterns, water- 
barrels and such receptacles for catching and storing rain-water. The cities of 
Colon and Panama were divided up into small districts with an inspector in 
charge of each district. This inspector was required to cover his territory at 
least twice a week and report upon each building with regard to the breeding- 
places of mosquitoes. Al] the cisterns, water-barrels and other water receptacles 
in Panama were covered, and in the water-barrels spigots were inserted so that 
