Anslysis by Tissues or Organs. The data for the analysis of tissues or organs are summarized in Tables 12 and 13, in which the d/m/g wet weight of tissues is compared by islands and by feeding habits. Part of the material has been discussed on the preceding pages. Generally, in both pre-shot and post shot fish, the greatest amount of activity was found in the gut with liver, skin, bone, and muscle having lesser amounts in descending order of magnitude. Exceptions to this sequence were most numerous in skin and bone counts, in which the disintegration rates were about the same. Omnivores usually had slightly more activity in the bone than in the skin, whereas the reverse was generally true in the carnivores. Other exceptions occurred in most of the fish at Japtan and in the pre-shot samples from Igurin, where the activity in the livers was usually lower than in other tis- sues, while muscle radioactivity was comparatively high in proportion to other tissues and when compared with other stations. Counts in skin and bone averaged about twice muscle in pre-shot omnivores and carnivores. In post shot omnivores the skin and bone counts were about 5 times muscle and in carnivores about 2 to 3 times muscle. Differences between these three tis- seemed to be greatest at Rigili, Engebi, and Aaraanbiru sues’ in post shot fish. Aside from the exceptions at Japtan and Igurin mentioned above, the liver was usually much more radioactive than skin, bone, and muscle. The average for all fish livers combined - §3 -