EXAMINATION FOR STREPTOCOCCI 



155 



finose, mannite, lactose, and salicin broths for determination of 

 acidity, in milk for coagulation, and to blood agar plates for 

 haemolysis. A virulence test is also desirable, but in considering 

 the results obtained due regard must be given to the dosage and 

 method of inoculation. A quantity of broth that is sufficient to 

 kill the test animal in three days when injected intravenously 

 might not produce more than local symptoms when given sub- 

 cutaneously, and similar conditions apply to the dosage. For 

 guinea pigs 1 c.cm. of a forty-eight hour broth culture and for 

 mice 0.5 c.cm. of a twenty-four hour culture have been found 

 to give satisfactory results when injected into the peritoneal 

 cavity. 



The biochemical characteristics should be determined 

 quantitatively by Winslow's method 39 if the best results are to 

 be secured. 



TABLE LIX 



BIOCHEMICAL CHARACTERS OF PRINCIPAL TYPES OF 

 STREPTOCOCCI. (BROADHURST) 



X indicates that test substance is fermented with production of acid and without 

 gas formation. 



indicates that test substance is occasionally fermented. 



