Even if the dangers had been as great as they were under the French, and the deaths as numerous, I believe we would have found a sufficient number of men who were willing to go to the Isthmus, just as did the French. There is always a certain element which is attracted by danger and adventure, and to whom exposure to risk is a sufficient reward for their labor. This characteristic I have always found particularly strong among the Americans. But if we had lost from disease thirty-five hundred of our Americans every year (for the French lost in about this ratio), I am inclined to think that public opinion would not have backed any work involving such loss of life, and that Congress would not have made the appropriations for continuing the work. CHAPTER XII YELLOW-FEVER WORK AT THE ISTHMUS At the same time that yellow-fever work was commenced, an attack was also made upon malaria. Mr. Joseph L. Le Prince, who was in charge of similar work in Havana, was placed in charge of this work. The anti-malarial work in the towns of Colon and Panama was exactly similar to that in the city of Havana. But the country along the line of the Canal between the two termini, Colon and Panama, was entirely different, and the problem was much more extensive than it had been in Havana. The anopheles, the malarial mosquito, is peculiarly a country mosquito. In general, he likes clear, fresh water in which grass and algæ are plentiful, such as is found along the banks of the small mountain streams of Panama, or the fresh water ponds and pools. The grass and algæ give protection to the larvæ from the fish. Wherever the small fish can easily gain access, there mosquitoes cannot breed. For the purpose of looking after malaria along this fifty miles of country district, the region was divided into twenty-four sanitary districts, known as Panama, La Boca, Ancon, Corozal, Miraflores, Pedro Miguel, Paraiso, Culebra, Empire, Las Cascadas, Bohio, Matachin, Gorgona, Juan Grande, San Pablo, Tabernilla, Frijoles, Largarto, Lion Hill, Gatun, Mount Hope, Colon, Nombre de Dios and Toro Point. Some years after, when the railroad was being relocated, we had an additional sanitary district, embracing the town of Lirio and a working force in that neighborhood for several miles up and down the road. Later, a quarry was established at the old city of Porto Bello, for the purpose of getting stone for the Gatun locks, and here we had another sanitary district.