The current conception of the etiology of chronic inflammation of the uveal tract includes chiefly the theory of focal infection and its ramifications. The specific organisms of syphilis1and tuberculosis2have been isolated from the eye in cases of disease of the uveal tract. Likewise, organisms have been cultured in cases of metastatic intraocular inflammation.3This suggests the possibility of the dissemination of organisms in so-called nonspecific uveitis. Proponents of this view argue that there is a circulation from a focus of the actual organisms, organisms with a predilection or specificity for uveal tissue, or of the toxin of organisms to the eye. An attempt has been made to analyze this view and to test its various aspects experimentally. When an organism enters the eye, it must meet existing conditions portrayed by the aqueous and vitreous, intra-ocular tissue and the intra-ocular portion of the blood stream.