-38- (Table 6) show that the plant tissues concentrated the longlived isotopes e337? and Sr 90 amounts in the soil. in the soil, which were present Cel44_ py 144 | present in high accounted for only a small radioactivity in the plant samples. in low amounts percentage of the Analyses were not made of the radioisotopes later shown to be present commonly in plant gamples 2x25 -Nb?>, from this Ryt06~ pp 106 | area. These isotopes, Co? 7, 69 and Zn©? , such as may account for the radioactivity that was not determined in the analyses. Radioactive decay curves of individual samples of these tissues show that the radioactivity was decaying at a very slow rate. radiochemical data, and ¢csi37 This observation is in accord with the since both sr?° (half life 27 years) (half life 28 years) accounted for the major portion of the radioactivity analyzed. DISCUSSION Previous studies to evaluate the recovery and rein- vasion of the flora at the Eniwetok Proving Ground, mately fifteen months after Operation Sandstone, in 1949 by St. John (22) and Biddulph (©) , approxi- were made They reported morphological abnormalities in ten species of plants growing