It did not matter that in four months there were only 47 deaths on the Isthmus from yellow fever as compared with 108 from malaria in the same period--men do not stop to study mortality tables and to compare the relative fatalities of diseases when yellow fever stares them in the face. But after all, the yellow fever panic of 1905 served a good purpose, for if the mosquito thereby secured a reopening of its case, it stirred the United States Government to give to the sanitary officers of the Canal Zone the powers they needed, and the means required to prove finally and forever in the court of last resort, the guilt of the mosquito, and to establish for once and all the method of combating its stealthy work. The whole world recognizes the remarkable results in sanitary work that have been achieved at Panama. While it must be remembered that the population of the Canal Zone is made up largely of able-bodied men, and that, therefore, the death rate naturally would be lower than under like conditions with a normal population of infancy and old age, the fact remains that sanitary science has converted the Zone from a mosquito paradise of swamp and jungle into a region where mosquitoes have all but disappeared, and where men are as free from danger of epidemic diseases as in the United States itself. The sanitary statistics of the Canal Zone, and of the cities of Panama and Colon, were based for several years upon an erroneous assumption of population. The Department of Sanitation estimated the population of the Canal Zone by deducting the recorded emigrants from the recorded immigrants and assumed that the difference represented a permanent addition to the Zone's population. Under this method of estimating population a serious error crept in, since hundreds of people came into Panama from the Panaman outports and were recorded as arrivals, but who, departing in small sailing vessels and launches at night after the port officers had gone home, were not recorded as having departed. In this way the sanitary department estimates of population in the Canal Zone reached a total of 93,000 in 1912. The census taken that year showed only 62,000 population in the Zone. This served to make the death rate given out by the Department of Sanitation 50 per cent lower than was justified by actual population conditions. But one does not need to consider figures to realize what has been accomplished at Panama. Anyone who goes there and sees the remarkable evidence of the success of the efforts to conquer the disease of the tropical jungles, finds a lesson taught that is too impressive to need the confirmation of medical statistics.