ir If the number of disintegrations per second for one curle is 367 x 10*9 and this value is corrected for conversion to minutes and then the equation above is converted to millimicrocuries the resulting value 1s the 2.2 that appears in the denominator of the equation. The per cent error in counting was insignificant because of the relatively high rate of disintegration. Discussion of Results The data recorded in Table I indicates an appreciable uptake of active material by aquatic forms collected about one and one-fourth miles north of Runit Island on the day following the test. The fish material ashed and counted during late May, based on seven specimens, had the greatest concentration of active materials in the gut, where an average of 51,800 millimicrocuries per kilogram of material was found. The counts in the liver of 3810 mpc/kg indicate that absorption is taking place. Surface contamination with the material possibly adhering to the mucous cover of the body is indicated by the 2150 mjuc/kg found as an average count in the skin. The gills (1670 maic/kg), the bone (1540) and the mscle (201) had decreasing amounts of activity. Fish material ashed and counted during mid-June, late dugust and early September had counts with about the same distribution of activity in the various tissues but with reduced amounts sugpesting a rapid rate of activity decay. Reduction of Activity by Decay Selected samples of the May 16 collection from Eniwetok were used to determine the rate of activity decay. Counting started on some of this S Y ARCLILVE UNIVERSIT IES R A R WArL. LIDA UNI OF