526 INFECTION AND IMMUNITY. 



endocarditis, etc., in rabbits. Similar observations 

 have been made by Westphal, Wassermann and 

 Malkoff, Poynton and Paine. Beaton and Walker 

 and others, and the possibility of producing lesions 

 characteristic of rheumatic fever by the inocula- 

 tion of pure cultures into rabbits has been well es- 

 tablished. Although the organism was called a 

 diplococcus by the discoverers, it can not be dis- 

 tinguished from the ordinary streptococcus pyo- 

 genes by cultural tests. These discoveries do not, 

 however, put this particular streptococcus on a 

 satisfactory basis as the cause of the disease, since 

 streptococci from various sources are able to cause 

 experimental arthritis in rabbits (Cole, Harris). 

 It seems that virulent streptococci from whatever 

 source have a predilection for serous surfaces. This 

 is apparent from the frequency with which the 

 joints, endocardium, etc., are involved in strepto- 

 coccus septicemia in man. The view of Singer 

 and of Menzer that "acute rheumatism is simply 

 one of the many manifestations of streptococcus 

 invasion" (Harris), finds some justification in 

 the streptococcus tonsillitis with which the dis- 

 ease usually begins, the recovery of streptococci 

 from the lesions and the production of these lesions 

 in rabbits by the injection of pure cultures. Tun- 

 nicliff found that the opsonic indices for M. rlieu- 

 maticus (Beattie, Poynton and Paine) for Strep- 

 tococcus viridans from the throat of a patient with 

 rheumatism and for Streptococcus pyogenes fol- 

 low the same course during attacks of rheu- 

 matism. In cases with joint symptoms and 

 high temperature the index was subnormal and 

 with improvement in clinical symptoms it 



