Pish. In fish a fairly even distribution of active mater- ial is seen in muscle, liver, gut, and to some extent in bone. Most of the activity was in the gut and liver as indicated by counts as well as by autoradiographs. The activity is less evenly distributed on or in the skin, in that more“specks" were in evidence in this tissue.. In some fish a concentration of activ- ity was noted in the gills (Fig. 23) or in the teeth (surgeon fish, Fig. 24). Carnivores and omnivores showed striking dif- ferences in the amount within the body cavity (Fig. 24). Land plants. Washing with running tap water removed 10 to 20 percent of the activity on the land plants in most cases, although a much higher percentage of the “speck” contamination was removed by this method from the leaves of a grass collected at Engebi (Fig. 25). The remainder of the radioactivity was partly spotty and partly homogeneous in distribution. The spotty activity was probably due to material that was not washed from the external surfaces of the plants, and the homogeneous activ- ity was the result of dissolved radioactive material that had been actively absorbed and metabolized by the plant. In leaves radioactivity was highest in the veins, the conductors of absorbed materials throughout the leaves. 4.9.2 Other Surface Contamination The general problem of surface contamination from indirect sources is illustrated by specific examples such as the contamination found on the carapace of a crab, - 9% - on the shell of a clam,