3511. Non-pathogenic Bacteria. 22 Color Photomicrographs. 1. Streptococcus lactis, milk souring 2. Sarcina lutea, Gram stained 3. Gaffkya tetragena, occurring in tetrads 4. Bacillus subtilis, hay bacillus, bacilli and spores 5. Bacillus mycoides, large so