114 



MORPHOLOGIC VARIATION 



by the density of the population in relation to the concentration 

 of foodstuff in the medium. It appears earlier in the heavily seeded 

 cultures and in the more dilute media, because those cultures do 

 not have so long a period of vegetative reproduction; that is, because 

 the resting phase of the culture appears earlier. This is quite con- 



100^ 



60^ 



kC^ 



20^ 



T f 



1 I I r^ 



Heavy Inoculum 



Full S trength Medium 



Light Inoculum 



Full Strength Medium 



Heavy Inoculum 

 Dilute Medium 



Light Inoculum 

 Dilute Medium 



12 18 



v^ 3t kk 56 9+ bO bb 72 

 Hours. 



Fig. 32. 



Influence of Size of Seeding and Concentration of Nutrients 

 ON Rate of Spore Formation in B. cohaerens. 



trary to the results obtained by Migula, and I cannot help but 

 believe that his' observations were in error. 



If we are to consider the large, deeply stained cells free of 

 granules as comparable with the embryonic cells of a growing plant 

 or animal, as has been proposed in Chapter V, then conversely we 

 must look upon those cells with which we are most familiar, the 



