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BACTERIOLOGICAL METHODS 



Fig. 40. — Streptococcus (Staphylococcus) pyogenes and 5. aureus. There are 

 three principal species of Streptococci (S. pyogenes albus, S. pyogenes aureus and 5. 

 pyogenes citreus), similar in form and appearance, concerned in pus formation, as in 

 wound infection. These organisms are very widely distribvited in soil and air. 



Note the chain form arrangement of the cocci in ^ . B is a smear preparation. — 

 [Stitt (A) andPittfield (B).) 



