THERE have been numerous clinical reports of the beneficial effect of pituitary adrenocorticotropic hormone (ACTH) and cortisone on inflammatory ocular disease in humans. However, when the present study was begun, relatively little work had been reported on the results of cortisone or ACTH treatment of experimental uveitis. The intraocular injection of horse serum has been found to be a satisfactory method of producing a granulomatous type of uveitis in rabbits, 1 probably on the basis of an anaphylactic type of hypersensitivity. In view of the fact that ACTH and cortisone suppress many forms of systemic hypersensitivity, including cardiovascular lesions in rabbits induced with horse serum, 2 it might well be expected that these substances would be effective in horse serum uveitis. Since the present work was begun, Woods 3 has reported the dramatic effects of ACTH and cortisone on experimentally produced ocular inflammation in rabbits, including the injection of horse