THE GENUS STREPTOCOCCUS 163 



5. Streptococcus anginosus (Andrewes and Horder). 

 This type is a pathogenic long-chained form, allied 

 in other respects to Str. salivarius, and bearing to it 

 much the same relation which Str. pyogenes bears to Str. 

 mitis. It occurs most commonly in cases of scarlatinal 

 and other forms of sore throat. It is long-chained and 

 produces a flocculent deposit in broth. It generally fails to 

 grow on gelatin at 20 degrees, and is markedly hemolytic. 

 Like Str. salivarius, on the other hand, it clots milk, reduces 

 neutral red, and forms acid in saccharose, lactose, and 

 raffinose. 



6. Streptococcus mcalis (Andrewes and Horder). 

 This type is specially characteristic of the human 

 intestine. It is short-chained and renders broth uni- 

 formly turbid. It grows readily at 20 'degrees and forms 

 sulphureted hydrogen in broth cultures. It has no hemo- 

 lytic power and little virulence, but produces a positive 

 reaction to all of Gordon's tests except raffinose and inulin. 

 That is, it clots milk, reduces neutral red, and ferments 

 saccharose, lactose, salicin, coniferin, and mannite. The 

 mannite reaction is specially characteristic of this intestinal 

 type. 



The seventh of Andrewes and Horder' s types is the 

 pneumococcus, which we have placed in the genus Diplo- 

 coccus. It is characterized by the presence of a capsule 

 under proper cultural conditions. It occurs in pairs or 

 short chains. It is virulent, and fails to grow on gelatin 

 at 20 degrees. It fails to act on neutral red, or to ferment 



