152 RELATIONSHIPS OF THE COCCACE^ 



distinguished by growth in blood media. The first, 

 which he called Sir. longus pyo genes sen erysipelatos 

 when grown in blood-broth, changed its color to a bur- 

 gundy red, and on blood-agar its colonies were surrounded 

 by a clear zone. The second, Str. mitior seu viridans, 

 produced a brownish color in blood-broth, and on blood- 

 agar formed greenish colonies without hemolysis. The 

 former were generally more pathogenic, occurred in longer 

 chains, produced sediment instead of turbidity in broth, 

 and more generally failed to coagulate milk. The cap- 

 sulated streptococcus and D. pneumonia behaved like Str. 

 mitior in blood-agar. Rieke (1904) studied, with some 

 care, the hemolytic power of the streptococci, which 

 underlies Schottmuller's test; and found that twenty-five 

 cultures, all of the Str. longus type, produced essentially 

 the same change in blood-bouillon. All dissolved the 

 blood cells and set free oxyhemoglobin, giving the bur- 

 gundy-red coloration, which, according to Schottmuller, 

 is characteristic of Str. longus; later, in all cultures, the 

 oxyhemoglobin was changed to neutral methemoglobin, 

 giving the brownish-red color supposed to be charac- 

 teristic of Str. mitior. 



Boxer (1906) studied the behavior of a considerable 

 series of cultures of diplococci and streptococci on blood- 

 agar. Thirty-six of the 47 streptococci showed char- 

 acteristic decolorized areas around the colonies, due, as 

 shown by microscopic examinations, to hemolysis. None 

 of the others showed the green color of Str. mitior. 



