366 APPLICATION OF METHODS OF BACTERIOLOGY 



In appropriately high dilutions the members of one group 

 did not react with the serum homologous for either of the 

 other groups. 



A fourth group, containing only 22 cultures, gave such 

 irregularities that no final attempt was made at subgrouping. 



However, of the total of 292 strains examined, 93 per cent, 

 could be definitely arranged by specific reactions into these 

 groups; while 7 per cent., constituting a fourth group, was 

 not conclusively investigated. The four strains of hemo- 

 lytic streptococci thus established grouped themselves about 

 the various normal and pathological conditions from which 

 the individual cultures were obtained according to the 

 following table: 



GROUPING OF 292 STRAINS OF HEMOLYTIC STREPTOCOCCI 



(HAVENS). 



From this, Havens suggests that healthy carriers may be 

 the source of supply for all hemolytic streptococci causing 

 disease. 



