28 



Levi Otto Gratz 



and constituted the second series. The weak point in the system was 

 the mercury valve. The pull increased as the plants became larger, 

 and occasionally this resulted in the pulling-over of the mercury into the 

 cup. In order not to have the pots flooded, the intake was placed in a 



Per cent of 

 damping-off 



20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 

 Hours after transplanting 



Figure 1. influence of different soil temperatures and soil moistures on 

 rate of damping-off of cabbage seedlings caused by corticium vagum 



(TABLE 9, TRIAL i) 



Soil moistures are given as percentages 



