These results were checked by triplicate determinations. 



The above detailed tabulation may be summarized as follows:- 



Note: A "fast" strain is one which reacts alike to the blood of all species. 



This table indicates definitely the probable source for many discrep- 

 ancies. It indicates, too, that a very decided advance in the systematic 

 study of the streptococci may be made by instituting definite standards 

 of procedure. 



The group of organisms used for analytical material included two "fast 1 ' 

 strains of each type. 



(b) Immunity reactions: These reactions were studied in order to 

 demonstrate that the chosen organisms were biologically distinct. To 

 prove this point, the agglutinative capacity of each antiserum against 

 each of the antigens was determined. The method of producing the 

 immune sera and the technique for conducting the titrations was that 

 used by Dochez, Avery and Lancefield (53). 



The results obtained (as may be seen from the table) show no duplica- 

 tion in the strains used. 



Immune Serum 



Note: The numbers under "immune serum" designate the highest dilutions of the 

 antiserum which showed definite specific clumping of the organisms. 



(c) Other biochemical reactions: Although our choice of the experi- 

 mental strains depended almost entirely on the blood reactions yet a 

 complete characterization of the organisms must include the description 

 of their ability to (i) ferment various carbohydrates and related sub- 

 stances (33, 34); (2) coagulate milk (33, 34); (3) coagulate inulin-serum- 

 water (53, 54); (4) liquefy gelatin (34); (5) dissolve in bile (55). 



The test substance (10 c.c.) in each series (except 5) was inoculated 

 with 0.05 c.c. culture from the seed tubes. In series (5) 0.3 c.c. bile 

 was mixed with 3 c.c. culture. All except series (3) were incubated at 

 37 C. for 24 hours. Series (3) was incubated for 6p hours. The follow- 

 ing tabulation lists the reactions given by the experimental cultures: 



n 



