Demonstrating phagocytosis of various bacteria as observed in the determina- 

 tion of the opsonic index. 1, Staphylococcus; 2, Micrococcus candicans; 3, Strepto- 

 coccus pyogenes; 4, Colon bacillus; 5, Gonococcus; 6, Tubercle bacillus. {See p. 234.) 



