EFFECTS OF EXPOSING SEEDS 



87 



were planted in separate jars and placed in the propagating-house to 



germinate. 



April 25. 



(Record taken by the gardener.) 



All the seeds in the control culture have broken the soil, save one 

 that decayed. 



None of the radiated seeds have yet come up. 

 April 27. 



Two of the radiated seeds have come up. 

 April 28. 



Seventeen more of the radiated seeds are just breaking through, 

 the surface of the soil. The average height of the control seedlings 

 from the surface of the soil to the tip of the first leaf, is 60.40 mm. 



On April 29 the cultures were photographed (figure 3), and up 

 to May 5 there had been no appreciable growth of the radiated seeds 

 since they were photographed, and the experiment was closed. 



R^^^^ ^^^^^c 



Fig. 3. Experiment 3. Germination of Oats Retarded by Exposure, while Dry, to 



Radium Rajs. 



Experiment 4 

 May 6, 9:35 A. M. 



Eight dry seeds of Phaseolus (Henderson's " Long Yellow Six 

 Weeks ") were placed with their hilum-edges touching the radium- 

 coated rod (25,000 X ) four seeds on each side of the rod. 

 May 12, 5 P. M. 



After an exposure of 145 hours the rod was removed from the 

 seeds, and six hours after its removal the seeds were planted in soil 

 (pot R), with the control seeds (pot C) in an adjacent pot in the 

 propagating house. 



