ILLUSTRATIONS 



PAGE 



Mold Colony, Showing Mycelium and Spore Clusters 

 Common Mold (Penicillium), Showing Masses of Spores 



Frontispiece 



Fine Needle, a Bit of Dust and Bacteria 2 



Colonies of Bacteria Growing on Gelatin 3 



Shapes of Bacteria 4 



Flagella 5 



Spores 7 



Size of Yeasts, Mold Spores and Bacteria 8 



Common Yeast 9 



Yeast in Fermenting Cider 9 



Common Mold, Penicilliwn 10 



Common Mold, Aspergillus 11 



Mold Showing Threads of the Mycelium 12 



Mold Colony on a Gelatin Plate 13 



A Sarcina Type 14 



Varieties of Bacterium lactis acidi 27 



Varieties of Bacterium lactis acidi 28 



Colonies of Bacterium lactis acidi in Litmus Gelatin . . . 30 



Gelatin Stab Cultures of Bact. aerogenes and Bact. lactis acidi 31 



Effect of Different Bacteria on Milk 33 



Types of Bacterial Growth on Agar Slants 34 



Production of Gas in Fermentation Tube Produced by Bact. 



lactis aerogenes 35 



Liquefaction of Gelatin by Enzyme-forming Bacteria . . 39 



Bacteria of Butyric Acid .^ . . 43 



Effect of Slimy Milk Bacteria upon Milk 45 



Bacterium lactis viscosus, the Common Cause of Slimy Milk 46 



Coccus, Producing Bitter Milk 48 



Torula amari, Producing Bitter Milk and Cheese .... 49 



Kefir Grains 51 



Bacterium eyano genes 53 



Oidium lactis from a Surface Colony on Gelatin .... 56 



Structure of Cow's Udder 59 



Filthy Condition of Cow's Hindquarters 63 



Proper Condition for Cow's Hindquarters 64 



