A new interest concerning the importance of Toxoplasma as an etiological agent in granulomatous uveitis followed the microscopic discovery of Toxoplasma organisms in eyes removed from 41 patients by Wilder in 1952.1 The diagnostic methods which were subsequently developed for the detection of Toxoplasma antibodies include the complement-fixation test by Warren and Sabin in 1942,2 the dye test by Feldman and Sabin in 1948,3 and the skin test by Feldman and Sabin in 1949.4 In 1954 Jacobs5 and his co-workers adapted the hemagglutination test for Toxoplasma from Boyden's (1951)6 technique using tanned antigen-coated erythrocytes. This latter assay is the most sensitive test which has been devised. It is unfortunate, however, that the hemagglutination test has the disadvantage of being time consuming and of requiring freshly sensitized cells which cannot be stored satisfactorily for more than a few days. Following the suggestion of Flick,7