BIOCHEMISTRY OF STREPTOCOCCUS HEMOLYTICUS 



221 



broth were used in the tests. To 0.5 cc. of the corpuscular 

 suspension were added amounts of culture varying from 0.005 

 cc. to 0.5 cc. The volume was then made up to a total of 1 cc. 

 with broth, after which the mixture was incubated at 37° for 

 two hours. During the first hour of incubation the tubes were 

 frequently shaken to insure thorough mixing. At the end of 

 the incubation period the degree of hemolysis was observed, 

 and expressed as follows : 



100 per cent of corpuscles hemolyzed + +++ 

 90 per cent of corpuscles hemolyzed + + + =b 

 75 per cent of corpuscles hemolyzed + + + 

 50 per cent of corpuscles hemolyzed + + 

 25 per cent of corpuscles hemolyzed + 

 per cent of corpuscles hemolyzed — 



Experiment II. The "protein sparing^ ^ action of Streptococcus 



hemolyticus 



Bacto beef broth, Ph 7.2, served as the basis of the combina- 

 tions used in the experiment. The inoculum for each 10 cc. of 

 broth consisted of 0.4 cc. of an eighteen-hour, glucose broth 

 culture. The ammonia determinations were made after seventy 

 hours incubation. The results are incorporated in table 4. 



The results show that in the presence of little or no free carbo- 

 hydrate, as in (2) and (4) of the table, the ammonia output is 

 slightly increased over that found in the presence of 1 per cent 

 glucose. If protein material in the form of horse serum be 

 present the ammonia output is distinctly higher. This is shown 



