MISCELLANEOUS EXPERIMENTS 



185 



zontally over the seeds at right angles to the row, and about 3 or 4 

 mm. above them, was the Welsbach mantle, style "Yusia," No. 

 189, purchased in the market (Figure 46). 



Control, with no mantle, and both cultures placed in the dark 

 room, in a moist chamber. 



Fig. 46. Experiment 65. Method of exposing germinating Seeds to the Rays of 

 Thorium from a Welsbach Gas Mantle. 



June 13, 10 A, M. 



The control seeds are evenly germinated. 



The exposed seeds have germinated about the same amount as 

 those of the control, except directly under the mantle, where there is 

 only a very slight germination. 



June 14, 10 A. M. 



The seedlings in both cultures have grown since yesterday, but 

 the relative conditions remain as then. Both cultures were placed in 

 the light and illuminated only from above. 



June 16, 10 A. M. 



Retardation following the exposure is still evident, and the cul- 

 tures were photographed (figure 47). 



