76 



MORPHOLOGIC VARIATION 



mode, there would not occur distinct bimodality such as is apparent 

 here. If, however, out of the inoculated cells, one group started to 

 grow, while the others remained dormant, bimodality, with a new 

 mode growing at the expense of the old one, would result. 



Further studies were made in broth cultures, and these were run 

 in parallel series with varying sizes of seeding, in order to deter- 



iOn 



1 T 



Culture II 



Culture III 



J L 



5 

 Hours. 



10 



Fig. 



18. Influence of Size of Seeding on Length of Cells of B. mega- 

 therium: Cultures II and III. 



mine more clearly the influence of the rate of growth upon the size 

 of the cells. The first series, marked Cultures II and III, were 

 inoculated simultaneously from a seven-hour agar slant culture, again 

 after transplanting every twelve hours for several days to get rid 

 of spores. Culture III being seeded with one-tenth as many cells as 

 Culture II. Since this culture started from a very young one, no 

 pronounced lag phase was noted. The experiment was therefore 

 repeated in Cultures IV, V, and VI, using a twenty-hour broth 



