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EFFECTS OF EXPOSING SEEDS 



Experiment 28 



To ascertain the effect of exposing dry seeds for short periods of 

 time to radium of strong activity, the following experiment was made. 



Five sets of eight dry seeds of Lufimis albus each were exposed 

 respectively to the rays of radium of 1,500,000 activity by having the 

 sealed glass tube of the radium bromide (10 mg.) placed in contact 

 with their hilum-edges. The duration of exposures was 2, 3, 4, 6, 

 and 14 hrs., respectively. 



Fig. 21. Activity of Radium, 1,800,000. 



April 17, II A. M. 



The exposed seeds, together with eight control seeds, were 

 planted in soil, in similar pots. 



April 21, 2 P. M. 



No marked difference could be observed in the six cultures. No 

 measurements were taken. 



April 23, 10 : 30 A. M. 



Average lengths of the hypocotyls above the surface of the soil : 



14 hrs. 6 hrs. 4 hrs. 3 hrs. 2 hrs. Control 



14.50 mm. 15.87 mm. 14.70 mm. 18.28 mm. 17.70 mm. 15.12 mm. 



