[VoL. 7 
78 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
In constructing the graphs the curves were plotted in the 
normal manner, with the amounts of dextrose on the Y axis 
and time on the X axis for the first ten days of the incubation 
period. In order to make the curves for cultures II and IV 
continuous and harmonie, the Y ordinate is shifted for these 
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Fig. 1 
cultures at the end of 10 days so that the 2000-mgm. point is 
on the original X axis. The dotted curve in the insert is the 
Duclaux curve for increase in number of cells, while the solid 
line represents the type of curve predicted on the assumption 
that carbohydrate consumption is a simple function of cell 
multiplication. 
The results show that the rate of carbohydrate consumption 
in Azotobacter cultures does not proceed in a manner similar to 
