16 by the Laboratory of Radiation Biology, University of Washington, between March 1954 and March 1959, and two collections by the Naval Radiological Defense Laboratory, February 1955 and February 1956. Analyses of some of the samples were made by the Health and Safety Laboratory of the Atomic Energy Commission. In addition, teams of medical experts have been conducting periodic medical examinations of the Rongelapese. toring The soils and biological moni- data through 1956 have been summarized by Dunning (1957). It was recognized that while monitoring of the biota for radioactive contamination is essential to an immediate estimate of potential hazards, application. the information so gained is limited in Understanding of the processes involved in the movement of radioisotopes throughout the physical and biological system of the atoll is essential if it is hoped to arrive at basic conclusions of broader applicability. From such basic conclusions it might then be possible to predict the consequences of future contamination of similar areas and possibly the development of practical methods of reducing radioisotopic levels in foods of the area. It was also recognized that the total ecology of the area should eventually be understood in as great detail as possible in order to understand the processes by which the radioisotopes move from the soil to plants and probably to the sea, lagoon bottom to the marine life and sea birds, the land. from the thence back to Obviously this is an ambitious concept involving many