PLATE 15. 



, 



r 



SEWAGE STREPTOCOCCUS, from Effluent. (Houston.) 



j From broth culture, 48 hours at 38 C. Stained by 

 Gram's method, x 1000. 



Streptococcus pyogenes. 



Film culture from broth culture. Stained by Gram 

 method, x 1000. 



SEWAGE STREPTOCOCCUS, from Crude Sewage. (Houston.) 



From broth culture, 48 hours at 38 C. Stained by Gram's method, 

 x 1000. 



[To face page 156. 



