-17- The per cent of activity remaining on the filters in those samples filtered at date of collection (August 8 - 14, 1958) 1s 5 to 170 times that found in the samples filtered January 13, 1959. Thus a considerable amount of leaching occurred during the intervening period. After wi85 was detected and identified in the samples of plankton from the Collett survey, at Eniwetok, Bikini, Rongelap, Atolls in the Marshall Islands, Caroline Islands, other specimens collected Ujelang, Utirik and Wotho Kapingamarangi Atoll in the Tarawa Atoli in the Gilbert Islands, and Kusaie and Ponape Atolls in the Senyavin Islands were examined by gamma spectrometry for the photopeak (0.055 MEV) of wi85. The isotope was found only in samples from Eniwetok, Bikini, Rongelap and Ujelang Atolls. Eniwetok Atoll Samples Chemical separations were made on Scaevola leaves from Belle Island by ion-exchange and precipitation methods. [In the anions from the ion-exchange column only the peaks of energy represented by wi85 and Zr?9-Nb?> were observed in the gamma spectra. RulO3+106_py103+106 yere driven off by heat in the ashing process. In the precipitation separation, specific for tungsten, which is only the 0.055 MEV photopeak and the 0.03