28 in other soils, presumably because smaller particles have been eroded away since fallout occurred. Old Soil A radiocautograph of a core from the old soil (Fig. 12) shows that the radioactivity extends to a greater depth and is more diffusely distributed than in the young soils. The surface litter contains little radioactivity compared with the soil surface. Horizontal Movement There is evidence of localized horizontal movement of radionuclides in the soil, at least near the surface, which in turn may affect vertical distribution. Fig. 14 is a photograph and radioautograph of a section of a soil core collected in old soil on Kabelle Islet. There is a darkened funnel-shaped area at the top center of the radioautograph and a corresponding darker area of high organic content in the core section. The amount of activity in the stem of the "funnel" appears to be too great to be accounted for by leaching from the surface directly above. Either a depression was filled with radioactive organic matter after fallout, or the depression was filled before fallout and the radionuclides were adsorbed when surface runoff water filtered through the funnel of organic matter. The latter interpretation seems more probable since gamma-ray spectra of por