‘same -10- dose of radiation received by their smaller glands. Though the pathological changes in the nodules are similar to those seen in iodine deficiency goiter there is no reason to suspect such causal relationship in the Marshallese cases since dietary iodine is normal, urinary excretion of iodine is in the normal range and there are no known goitrogenic foods. The radiation induction of such changes in the thyroid could conceivably result from injury to the thyroid gland reducing the hormone output and thus calling on the pituitary to secrete a greater amount of TSH. This would give the thyroid picture of hypertrophy in those follicles capable of responding to such hormone and the presence also of atrophic follicles incapable of responding. In addition the occurrence of radiation induced mutations would enhance the possible development of malignancy in these Such a possible development in the Marshallese subjects must be borne in mind, This is particularly true in the case of the children since ‘many retrospective and prospective studies have shown a casual relationship of irradiation of the neck region in infants with the later development of thyroid cancer. It is of course not possible to prove the causal relationship of irradiation in the case of cancer of the thyroid in the exposed Marshallese woman but in view of the low incidence of such malignancies in the Marshallese this possibility must be seriously considered. The causal relationship of thyroid deficiency and growth retardation in the children in the more heavily exposed group seems reasonably well established and it is hoped that thyroid hormone treatment will enhance their growth and development. 5004291 Sy glands.