1. An attempt was made to repeat and extend various tests which have been presumed to demonstrate specific antigens and antibodies in rheumatic fever.
2. The "phase reaction" appears to be an inconstant phenomenon probably related to a colloidal abnormality of the serum, rather than to a specific antigen-antibody system.
3. No specific autoantibodies to human tissue extracts were demonstrable by complement fixation or by the collodion particle technique. Variable results were noted with the same test sera on different occasions, and positive reactions with control tissues and control sera were observed.
4. The possibility should be considered that autoantibodies are not necessarily specific for rheumatic fever but may be manifestations of the occurrence of a type of reaction similar to a biologically false positive Wassermann reaction.