LIST OF ILLUSTRATIONS. 



FIGURE FACE 



Various kinds of bacteria . . . Frontispiece 



1. General shapes of bacteria 18 



2. Method of multiplication of bacteria. ... 19 



3. Micrococci 19 



4. Streptococci 19 



5. Sarcina 2O 



6. Separate rods showing variations in size ... 20 



7. Rod-forms united to form chains .... 20 



8. Various types of spiral bacteria 21 



9. Various shaped rods 23 



10. Bacteria surrounded by capsules .... 23 



11. Various types of bacteria "colonies" ... 24 



12. Endogenous spores 26 



13. So-called arthrogenous spores 27 



14. Formation of spores in unusual forms (Crenothrix) . 28 



15. Bacteria provided with flagella 29 



16. Internal structure of bacteria 30 



17. Threads of Oscillaria 32 



1 8. Bacillus acetieum, of vinegar ..... 53 



19. Bacillus acidi lactici, of sour milk . . . . 7 1 



20. Dairy bacterium producing red milk .... 73 



21. Dairy bacterium producing pleasant flavours in butter 80 



22. Dairy bacterium producing pleasant aroma in butter 81 



23. Dairy bacterium producing pleasant flavour in butter 83 



24. Dairy bacterium producing " swelled " cheese . . 92 



25. Diagram illustrating Nature's food cycle ... 99 



7 



