pyroid containingsredoainantty2, I mentioned in the weston on birds. Te Among the 23 plates counted most often ( 10 ~- 73 times) and presumed to be counted frequently enough toe detect the existence z ef a linear semt~log relationship, only one other sample was : more nearly linear by semiwlog than by log-log plot. This wes the gastric mill ofa ereb, Grapsus8 grapsus, taken March 26, 41954, at Kabelle. The ‘staph (Figure 11) was sufficiently curved _to indicate the presence of, moré than one isotope. The early portion 50 « 300 days gave-a halfelife of 78 days, and the portion. 300. = 439 days gave ahalf-life of 107 days. A section of “the curve of another sample, manele of sea cucumber (Figure 11), / Was typleal of gent-1og linearity+ the, radioactivity of this sample decayed over the period from 50 te nearly 200 days with a half-life of “about 75 days, but more slowly later, Although a’ single isotope displays a domwardly soncave curvilinear plot by log-log presentation, a mixture of ae few as two taotopes with half-lives of similar ordersof magnitude, guch as eet and ceh*4 of 30- and 280- day half-lives, may appear almost Linear on & logelog plot over the period. ar 7S to 500 days. , Most decays were beat suited to log-log Plottingas seen in the seven ousimpleis4 dn1Fagures 2 12 and. 13. Although acme appear slightly curved, straight lines warefisted and slopes were sealed graphically eM a oFGEEGomes te “Deftattion.of.the.gurves ‘requires‘evaluation’notnlyof FR rerpartarene: Ob Sta. Seti poreice: