144 RELATIONSHIPS OF THE COCCACE^ 



same species, — a species which includes Streptococcus 

 lacticus, Bacterium Giintheri, and Bacterium lactis acidi, 

 and is identical with Streptococcus pyogenes. He notes 

 that cultures from faeces, with feebler growth and acid 

 production, showed a higher pathogenicity. Heinemann 

 (1906) has recently shown that the organisms which 

 ordinarily cause the lactic acid fermentation of milk are 

 two, a bacillus and a streptococcus; and that the latter, 

 Sir. lacticus of Kruse, is identical in morphological and 

 cultural properties with the streptococci isolated from 

 the normal and diseased human body. The same ob- 

 server has found (1907) that pathogenicity offers no 

 distinction between Str. lacticus and Str. pyogenes. It 

 appeared in his experiments that five passages through 

 rabbits would produce a high degree of virulence in the 

 former organism. 



Numerous streptococci isolated from cheese by Henrici 

 (1897) are indistinguishable from Str. pyogenes according 

 to the author's descriptions. Macchiati (1899) found 

 similar organisms in macaroni, as did Prescott (1906) 

 on various grains, including wheat, buckwheat, rye, 

 barley, and oats. It is possible that these organisms, 

 like B. coli, may live in a semi-parasitic fashion on plants, 

 as well as on animals. 



In none of the investigations cited did the streptococci 

 isolated from other sources differ in any constant way from 

 those found on or in the human body. In cultures of 

 either human or animal origin differences existed; but 



