PoRoiTs Ci.AY Cup for Automatic Watering. 



223 



Pot V constituted the control, without automatic watering ap- 

 ])aratus. 



The cuj s in the first four pots were connected by means of 

 a s-.nall lead tube to separate glass bottles of one liter capacity. At 

 each observation the bottles were filled to a file mark on the nar- 

 row neck, record being made of the amount of water necessary 

 for filling. The reservoirs were so placed that the water surface 

 when they were filled, was 40 cm. below the base of the corres- 

 ponding pot. 



Figure 2. 



Four soaked seeds were planted in each pot on Feb. 2, 1910, 

 A considerable variation in the time recjuirement for germination 

 could not be directly related to the conditions of soil moisture, 

 neither could the failure of several seeds to germinate be related 

 to any external condition, and so, on Feb. 23 (20 days after 



