FIG. i. 



. i. i. Coccus. 2. Streptococcus. 3. Staphylococcus. 4. Capsulated diplo- 

 coccus. 5. " Biscuit "-shaped coccus. 6. Tetrads. 7. Sarcina form. 8. Types 

 of bacilli (1-8 are diagrammatic). 9. Non-septate spirillum X 1000. 10. Ordinary 

 spirillum (a) comma-shaped element ; (b) formation of spiral by comma-shaped 

 elements X 1000. u. Types of spore formation. 12. Flagellated bacteria. 13. 

 Changes in bacteria produced by plasmolysis (after Fischer). 14. Bacilli with 

 terminal protoplasm (Hutschli). 15. (a) Bacillus composed of five protoplasmic 

 meshes ; (b~) protoplasmic network in micrococcus (Biitschli). 16. Bacteria con- 

 taining metachromatic granules (Ernst, Neisser) some contain polar granules. 

 17. Beggiatoa alba. Both filaments contain sulphur granules one is septate. 18. 

 Thiothrix tenuis (Winogradski). 19. Leptothrix innominata (Miller). 20. Clado- 

 thrix dichotoma (Zopf). 21. Streptothrix actinomyces (Bostrom), (a) colony 

 under low power ; (/>) filament showing true branching ; (c) filament containing 

 coccus-like bodies ; (d) filament with club at end. 



