Whether these blood culture strains produce symptoms because of ectotoxins, and if such be the case, the possibility of creating a satisfactory antitoxin to combat these manifestations, are questions which are still being investigated.
Although the present series is not sufficiently large, and the present stage of the work not sufficiently far advanced to permit the deduction of definite conclusions, the submitted experimental data seem to further emphasize the following theories:—First, that the main primary cause of chronic rheumatoid arthritis seems to be a highly selective group of streptococci. Second, that in the symptom complex of chronic rheumatoid arthritis a secondary rôle may be played by diphtheroid bacilli, bacilli of the paracolon group, and staphylococcus aureus.
Some of the diphtheroid baciffi isolated from the blood stream of arthritic patients exhibited such protean properties as to make us wonder if they are not a transition stage between cocci and bacilli.