Fig. 6. Spiral bacteria. 1, 2, and 3. Spirochtcee apis; X 2,000. (Maassen.) 

 4. Spirillum undula; X 1,300. (Flugge.) 5. Spirillum cholera Asiaticoe; 

 X 3,000. (Hewlett.) 6. Spirillum volutans.; X 1,300. (Cohn.) l.Thio- 

 spirillum Winogradskii; X 300. (Omelianski.) 



