280 A MANUAL OF BACTERIOLOGY 



Holm an 's classification thus gives sixteen principal varieties of 

 streptococci met with in man and animals. In the following 

 summary the figure appended indicates the relative frequency 

 of the form, being the number of times it was met with by certain 

 observers (Holman). 



8. infrequens (132). Frequent in the throat in scarlet 

 fever. 



8. pyogenes (762). The largest group. The commonest 

 streptococcus of pyogenic conditions. 



8. anginosus (162). Common in the throat, tonsils and nose. 

 Occurs in endocarditis. 



8. hcemolyticus I. (5), II. (5), and III. (2). All rare. 



8. equi. Rare in man. Met with in " strangles " (horse). 



8. subacidus (131). Met with in the throat, abscesses, blood 

 infections and endocarditis. 



8. fcBcalis (298). The streptococcus of human faeces. Also 

 occurs in the blood, in endocarditis and in wounds. 



8. non-hcemolyticus I. (7), II. (10), and III. (2). AU rare. 



8. mitis (395). Commonest of the non-hsemolytic strains. Met 

 with in the throat and occasionally in the blood and in endo- 

 carditis. 



8. salivarius (309). Common in the throat and mouth, occa- 

 sionally met with in the blood and in endocarditis. 



8. equinus (42). In horse and human faeces ; derived from 

 horse manure. 



8. ignavus (71). The most inactive form. Varieties of S. 

 fcecalis, equinus, non-hcemolyticus II. and III., ferment inulin. 



8. viridans, isolated by Major and others from cases of sub- 

 acute endocarditis and characterised by the formation of greenish 

 colonies on blood-agar, belongs to two or three of Holman's 

 varieties of non-haemolytic streptococci, particularly 8. salivarius. 

 They cause chronic infections and have a high invasive power for 

 damaged tissues. Death results from infections by them only 

 after a prolonged course or repeated infections. 8. lacticus of 

 milk belongs to this group but is non-pathogenic. 



Broadhurst found that human throat strains usually fail to 

 ferment mannite and that raffmose fermenters are common in 

 the human throat and in bovine faeces, but are strikingly lacking 

 in milk. 



Rosenow maintains the essential identity of the members of the 



