Analysis by Species. Because of the incompleteness of the collections and the great variation within species, it is not reasonable to attempt to determine whether significant differences in the amount of activity exist between species. From the data available, it appears that bunch grass, Lepturus repens, had the highest activity of the plants collected at Rigili and Rojoa after the shot. On the other hand, Mycena, a fungus, was among the highest at Rigili, but lowest at Igurin. Because of inconsistencies of this nature conclusions as to species differences are not justifiable. Analysis by organs. No specific conclusions can be made regarding radioactivity in the organs of the land plants collected before and after the Mike shot because of the inconsistencies encountered. At some collecting areas the roots had the highest activity, at others the lowest. leaves were highest. In general the An insufficient number of flower and fruit samples were assayed from the post Mike series to warrant comparison. Radiochemical analyses. Radiochemical analyses of post Mike soils from Rigili, Rojoa, and Runit and of post Mike plants from Engebi were made in order to determine the identity and relative amounts of fission products present. By comparing the relative percentages of specific fission products in plants with those found in the soil, and knowing the solubility of these fission products in water, it is possible to estimate which tso- topes have entered the plant via the normal processes of mineral - 59 -