THE FORMATION OF humoral antibodies in response to homotransplantation is a well-established phenomenon; both hemagglutinins and cytotoxins have been quantitated.1 In previous work from this department, antibodies accompanying homograft rejection were studied by means of skin tests (local inverse anaphylaxis)2-3 and mixed agglutination in tissue cultures.4 Although the relationship of humoral antibodies to graft destruction has not been established, evidence is accumulating which suggests that the role of these antibodies is quite important.5-9 This increases the need for various serologic methods of studying these antibodies. This paper describes the application of the antiglobulin consumption test to the study of humoral antibodies produced as a result of skin homografts in the rabbit. Materials and Methods Operative Procedure.— Adult rabbits of several varieties were used, some colored and some albino. Full-thickness skin grafts were transplanted in various sex and color combinations under local anesthesia. Thirteen pairs of rabbits