142 RELATIONSHIPS OF THE COCCACE^ 



tives of this genus (Cohn, 1875); but his descriptions 

 are too incomplete for identification. The first clearly 

 defined species was the Streptococcus erysipelatos of 

 Fehleisen (1883). In the next year Rosenbach (1884) 

 described a similar organism as the cause of wound infec- 

 tions, under the name Str. pyogenes. Similar strepto- 

 cocci have been found in a multitude of pathological 

 conditions, — in diseases of the skin and of the joints, in 

 sore throats and lung infections, in intestinal and puer- 

 peral diseases, in secondary infections, and in general 

 septicaemias; and others have been described as the spe- 

 cific agents in scarlet fever, small-pox, and rheumatic fever. 

 Some bacteriologists have held that each of these types 

 was a specific entity; others have maintained with equal 

 vigor that all were variants of a single unit-form. 



Streptococci are also frequently associated with dis- 

 eased conditions in animals, and have been studied with 

 special care by veterinarians in connection with inflam- 

 mations of the cow's udder. The large volume of litera- 

 ture upon this subject has been admirably summarized 

 by Steiger (1904), with the addition of original observa- 

 tions of his own upon a considerable series of organisms. 

 None of the cocci of bovine disease appear to differ 

 from organisms previously described from the human 

 body or from air, under other names. Streptococcus 

 mastitidis sporadicce and Str. agalactia contagiosa^ are 

 forms of Str. pyogenes; and here, as in the human 

 subject, long-chained and short-chained varieties have 



