THE GENUS STREPTOCOCCUS 159 



the polysaccharide, inulin. Three-quarters of the cul- 

 tures produced diffuse turbidity in broth, and about the 

 same proportion showed short chains under the micro- 

 scope. One hundred and seventy-two streptococci iso- 

 lated by the same observer (Houston, 1905, b) from cow's 

 milk showed somewhat different average characters. 

 As compared with the faecal strains, a larger proportion 

 of the milk streptococci had medium or long chains (31 

 per cent), and a smaller proportion (only 46 per cent) 

 formed diffuse turbidity in broth. Positive reactions 

 were rarer in salicin (60 per cent), in raffinose (19 per 

 cent), and in neutral red broth (20 per cent); but more 

 common with inulin (21 per cent), kctose (97 per cent), 

 and litmus milk (70 per cent). In the next year Hous- 

 ton (1906) studied one hundred streptococci from cow 

 dung and found marked differences between their proper- 

 ties and those of the human intestine in three reactions. 

 Mannite was fermented by 24 per cent of the human 

 cultures and by none of the bovine strains; raffinose was 

 fermented by 32 per cent of the human and by 74 per 

 cent of the bovine cultures; neutral red was reduced by 

 39 per cent of the human strains and by none of those 

 from cow dung. 



Gordon's tests completely demolished the "Einheit" 

 of the streptococci. As he and Houston left the matter, 

 however, the group was in a state of "Vielheit" so com- 

 plex as to be appalling. The enormous series of vari- 

 ants which the fermentation tests revealed required 



