-10- organisms resulting in hyperimmunization. in the Marshallese. Such a situation may be present | | The increased gamma globulin levels would seem to be incompatible with decreased immunological reactions in the aged. It has been suggested that the increased globulin levels may be partly related to the development of autoantibodies with age. Blumenthal and Berns (1964) state that “while antibodies to exogenous antigens decrease with age there may be an age-related increase in gamma globulins, presumably containing antibodies to endogenous substances.'' On the other hand the changes may be of a compensatory nature. Perhaps in older people there is a greater conservation of immunoglobulins _ by some mechanisms which would decrease catabolism or excretion. might be increased activity of those cells: antibodies. Or there still capable of producing If it had been possible to study age-related integrity of plasma cells and other lymphatic and reticuloendothelial tissues in these people, further light might have been shed on the problem. Finally, no attempt was made in the studies to separate "normal" older people from those with various . morbid changes (if that is possible). Therefore some of the age-correlated .. changes may be associated with such morbid processes, processes part of aging? But are not these (it will be interesting in future studies of this population, to see if longitudinal changes on an individual basis agree with the cross~sectioned results. ~ A Let us now consider the differences noted in the exposed population as compared with the unexposed. phenomenon. Radiation-indyced aging is a poorly understood It is generally considered to be a late effect of radiation, a manifestation of non-reparable injury since such aging effects are usually