6^ 1^ 



a. 





Fig. 42. a. Escherichia coli, F-3412. Peritrichous flagella of normal shape. 

 The flagellation of Escherichia strains tends to be rather poor. Coiled and ir- 

 regularly curved flagella are common. Strains with curly flagella are occasion- 

 ally encountered. 



b. Paracolon type (Bethesda), F-364. This shows a normal flagellum ex- 

 tending out from the somatic pole and four nicely coiled flagella. The organ- 

 isms of the paracolon group have much the same type of flagellation as the 

 typical Escherichia. 



c. Paracolon type ( Arizona ) . Peritrichous flagella of normal curvature. 



d. e. E. freundii, F-360. In d is illustrated the normal peritrichous flagella. 

 In e is shown a filamentous form with curly flagella. Curly flagella, of course, 

 are also found on nonfilamentous individuals. 



(See p. 101 for Table VIII.) 



99 



