Diameter of colonies 

 Parent strain no. 1 



4: 0-1 mm. } 



Fig. 9. Histocrram showing rates of growth of colonies from 

 single cells of Escherichia coli grown under anaerobic condi- 

 tions. Measurements of colony diameter made after 3 hr. 

 incubation at 37°. Re-selection of the subcultures indicated 

 by arrows. (Hughes, W.H. {1955 a), J. gen. Microbiol., 12,205.) 



