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some do nothing. We have, however, pretty well learned now 

 from which communities results can be obtained, and don't lose 

 much time on the others. We did not know at first. 



Some of these consultations have been in connection with 

 rather extensive drainage projects, so as to control malaria as 

 much as possible while rendering the land suitable for agricul- 

 ture. Some have been in connection with rice culture, a most 

 difficult problem in some places. Some with people contemplat- 

 ing the construction of hydro-electric plants, so as to minimize 

 the amount of malaria — hence damage suits — caused by the re- 

 sulting pond. This last, too, is a difficult problem sometimes 

 and involves much work, but is exceedingly important, and I 

 am sure profitable, from a sanitary standpoint. 



There isn't time to tell you of the research work we have done 

 on this problem ; of the statistics of morbidity we have gathered, 

 the gathering of which have been a factor in inducing some 

 States to make malaria a reportable disease; of the blood index 

 work to determine the degree and the nature of the infection of 

 communities; of the problems which have come up from time 

 to time the solution of which was necessary to progress. I do 

 not need to tell you, who have worked with mosquitoes, how 

 many problems of botany, of entomology, of agriculture — yes, 

 and of geology and meter ology — come up in the working out the 

 control of mosquitoes. We have all these and others, in human 

 pathology and the action of drugs in man and on parasites in 

 man, because the control of mosquitoes is only one of the methods 

 of controlling malaria. Yet I think I must mention the determi- 

 nation of Mitzmain, of this Service, that the parasites of malaria 

 did not live through winter in the mosquitoes which hibernate in 

 central Mississippi. This determination rendered logical the de- 

 monstration undertaken by the Rockefellers in that State which 

 otherwise has been illogical. That all three of the common 

 varieties of Anopheles in the east of the United States were 

 infected with and can convey malaria has been shown by King, 

 of the Entomological Bureau, and Mitzmain — a most important 

 thing, and one which we did not know before. 



