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MINNESOTA BOTANICAL STUDIES 



plants more nearly show actual conditions, by smoothing over any 

 individual variations which are certain to occur in all biological ex- 

 periments, these data are combined with those of the preceding and 

 shown in figure 3. Here the solid line gives the transpiration of 

 twelve healthy plants and the broken line that of 16 rusted plants 



I'ig. 4. (Graphs showing relative transpiration rates be- 

 tween 11 control and 14 diseased wheat 

 I)lants. 



with an average pustular area 0.9 per cent of the transpiring surface. 

 It may be mentioned that an analysis of the second battery here in- 

 cluded gave results very similar to those shown in figure 2, but with 

 a closer agreement between the graphs representing the transpira- 

 tion of the diseased plants. 



On March 7 the first weighing was made on another battery of 



