In times past there was much discussion of such questions as the differences between exophthalmic goiter and toxic nodular goiter. More recently it has been generally agreed that the differences in the history and the pathologic picture of these variations of hyperthyroidism are probably due to such factors as the age of the patient, the duration of the disease, the number of times acute exacerbations have occurred and the history with respect to intake of iodine, etc. From the functional point of view, most students of such disease have been content to differentiate between hyperthyroidism and hypothyroidism, and have bent their efforts toward elucidation of the causation and the physiologic manifestations of these abnormal functional states.
A salient fact in physiology of the thyroid has been the influence of iodine on the function of the gland. This relationship has not been easy to interpret. It seemed fairly certain that the