156 



than saccharose. (3) They reatlily ferment dextrose, lactose, and saccha- 

 rose at 20 C. On the other hand, throat streptococci (1) seldom yield 

 over 2.5% acid in any substance. (2) Over 40% of the cultures yield 

 over 1.2% acid in either salicin or raffinose. (3) At 20 C they almost never 

 attack any of the seven test substances. 



