Abstract
THE usual clinical and experimental presumption has been that exophthalmos is due to an excess of a pituitary substance. Exophthalmos has been produced repeatedly in the thyroidectomized guinea pig by pituitary preparations (1 and 2). Desiccated thyroid (2) and thyroxine (1) are reported not to produce exophthalmos in this animal. Exophthalmos has also been produced b}’ pituitary extract in Fundulus heteroclitus (3). The present studies were designed with the above background to test the clinical assumption that additional thyroid would antagonize the exophthalmos which occurred during treatment of thyrotoxicosis. However, the results were at variance with the above work.