GENUS STREPTOCOCCUS 191 



the author thought applicable to the entire genus. He 

 worked very largely, however, with the streptococci from the 

 human mouth and throat. 



The classification of Kurth* Kurth worked largely with 

 the streptococci from cases of scarlatina. His system is prac- 

 tically the same as that of von Lingelsheim, with the exception 

 that he does not include pathogenesis as necessarily belonging 

 to either group. The divisions are as follows : 



(a) Streptococcus rigidi Streptococci growing in short 

 chains, imparting a uniform turbidity to bouillon. 



(b) Streptococcus fleoc-uosi Streptococci which grow in 

 long interlacing chains forming flocculi in bouillon, leaving 

 the liquid clear. 



The classification of Pasquale. 4 Pasquale worked with 

 thirty-three streptococci, including nearly all of the then 

 known species. His work was quite exhaustive, but he had to 

 deal with cultures of various generations. He divides them 

 into four groups, as follows : 



(a) Short saphrophytic streptococci. 



(b) Long non-virulent streptococci. 



(c) Long pathogenic streptococci. 



(d) Short highly infectious streptococci. 



Group (d) pertains largely to bacteria which are no 

 longer recognized as streptococci, for example, the diplococcus 

 (Micrococciis lanceolatus) of pneumonia. It is now known 

 that streptococci which grow in short chains are often virulent. 

 This is especially true of the pyogenic forms. 



Classification of Andrews and Harder. These authors 

 divide the genus into seven main types or species. 



1. Streptococcus equinus. This type of streptococcus 

 appears to be characteristic of the herbivora. It is abundant 

 in horse dung and is the commonest form in the air of London. 

 It forms chains of medium length, grows feebly, if at all, at 



3 Kurth. Arbeiten a. d. Kaiserlichen Gesundheitsamte, Bd. VII 

 (1891) p. 389. 



4 Pasquale. Beitrage zur path. Anat. u. zur allgemeinen Path- 

 ologie, Bd. XII (1893) p. 433. 



