- 360 - (skin elasticity and looseness, hair greyness; accommodation, visual acuity, and arcus senilis of the eyes; hearing loss; nervous and neuromuscular function and vibration sense, light extinction test, rapid movement test, and hand grip strength; systolic blood pressure, blood cholesterol level, and body potassium (4°K)). Analysis of variance was used to determine correlation with age and the data for each criterion were weighted according to this correlation factor, Combined scores for all criteria gave a measure of "physiological" age as compared with chronological age on an individual and group basis. Most of the criteria showed good correlation with age on a group basis, less so on an individual basis. Between 20 and 40 years of age the criteria showed less change than after that age. No significant differences were noted between the exposed and unexposed groups. It was postulated that if there were ageing effects from the dose of radiation received by this population more sensitive tests would be necessary to show them. Longitudinal studies of individuals and groups in this Marshallese population might be more rewarding in the FOES RESIS TES SREY SCATARI SW YASetA IMIRCTAt pm ae future,