The twelfth session of the Assembly of the World Health Organization (WHO) was held in Geneva, from May 12 to May 29, I959. In his inaugural address, the President of the Assembly, Sir John Charles, spoke of the tasks of the individual worker and of WHO in the field of medical research, stating that the task of the former ended with the presentation of his information, thereby enabling WHO to enter the field of medical research through its contribution—just as important and quite apart from its own research in fields such as tuberculosis and the virus diseases—in the way of coordination and communication. The Director-General, introducing his report on the work of WHO during 1958, observed that, as 1958 had marked the tenth anniversary of the organization, it was natural that the year's activities had been viewed in the light of progress made during the entire decade. He recalled that great strides had been taken in the eradication of malaria and smallpox, but stressed the fact that WHO's goal could not be accomplished without world-wide eradication: as long as malaria or smallpox survived in a single country it constituted a danger for all. He also spoke of the intensified international program of medical research, in which the WHO fellowship program was playing an important role, and of the problem of environmental sanitation, with regard to which WHO had failed in its attempt to arouse public interest.