138 THE CYTOLOGY AND LIFE-HISTORY OF BACTERIA 



< i' 



ABC 



F G 



{Reproduced from the Journal of Pathology and Bacteriology.) 



Fig. 60 

 STAGES IN THE GROWTH OF A MEDUSA-HEAD COLONY 



A. Original bacillus. 

 B, C. Elongation and looping. 



D. Primary coil. 



E. Further growth, against the friction of the medium cau.ses infolding of the coil. 



F. Secondary infolding of the coil. 



G. Continued growth of all parts of the colonj' causes complex folding and convolution. 



