Reaction to 



Strain Whole Blood 



1159 G 



1161 I 



I2IO H 



1220 G 



1221 



1232 



1236 



1239 



1279 G 



1286 I 



1293 G 



682 I 



684 I 



688 I 



703 G 



720 



725 I 



746 



748 



770 I 



O = No solution of organisms by bile. ^ 



I = Indifferent to blood cells. 

 H =Hemolysis of blood cells. 

 G = Green-producing action on blood cells. 



5. STOCK CULTURES: After isolation, each organism was planted in 

 2 c.c. defibrinated sheep blood, incubated for four hours at 37 C. and 

 then stored in the ice-chest at 10 C. Some of the strains were used after 

 several days isolation, others after several months of cultivation. 



6. SEED CULTURE: Two days before a specific culture had to be used, 

 a loopful (platinum loop, 4mm. in diameter) from the stock blood culture 

 was planted in i% glucose broth (9.5 c.c. sugar-free broth plus 0.5 c.c. 

 sterile 20 per cent glucose solution and incubated for 18 hours at 37 C. 

 Then 0.05 c.c. of this subculture was inoculated into plain infusion broth 

 (not made sugar-free) and incubated for the same period. This is desig- 

 nated as a seed culture. 



In order to insure uniformity in the number of organisms transplanted 

 from such seed cultures to the test media it was necessary to estimate 

 the amount of growth. The cultures were well shaken and diluted to 

 equal opacity by matching in a comparator block (the kind used in the 

 colorimetric determination of hydrogen-ion concentration). Then the 

 accuracy of this procedure was verified by the results obtained from 

 plating definite amounts of the matched cultures and counting the colonies 

 after 18 hours incubation at 37 C. For all comparative tests these 

 matched cultures served as the seeds. 



7. BIOCHEMISTRY AND BIOLOGY: 



(a) Reaction on blood medium: The significance of this reaction may 

 be clearly brought out by a brief review of the literature on the classi- 

 fication of the streptococci. At the very outset investigators attempted 

 to differentiate these organisms according to morphological characters. 

 Thus arose the groups (i) Streptococcus longus and (2) Streptococcus 

 brevis (29, 30) . Such a distinction between types could be nothing more 

 than tentative and therefore was short-lived. 



Collateral with this grouping, but of more lasting influence, there 

 existed another that based on source of origin. We refer here to such 

 groups as Streptococcus erysipelas (31, 32), Streptococcus equinus, 

 Streptococcus pyrogenes, Streptococcus salivarans, etc. (33, 34, 35). 

 This scheme too, could have but little value for there would be as many 



8 



