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EXPOSED WATER AND FRESHLY FALLEN RAIN 



July 4, lo A. M. 



Zea Mays 



Lupinus 



Julys, II A. M. 



Zea Mays 



Lupinus 



July 6, 10: 30 A. M. 



Zea Mays 



Radium 

 72.00 mm. 

 82.00 

 65.00 

 30.00 



249.00 mm. 

 62.25 ™n^' 



Control 

 179.00 mm. 

 172.00 

 199.00 

 185.00 



735.00 mm. 

 183.75 "^'^• 



Lupinus 



Radium 

 63.00 mm. 

 60.00 

 45.00 

 60.00 



228.00 mm. 

 57.00 mm. 



Control 

 27.00 mm. 

 22.00 

 46.00 

 65.00 



160.00 mm. 

 40.00 mm. 



The plants were kept growing and watered as described above 

 until July 25, when the relative differences in height were the same 

 as on July 6, and the experiment was closed. On July 4 the cultures 

 were photographed (figures 37 and 38 ; also figures 39 and 40). 



On July 8 one plant was removed from each culture, dried, and 

 tested with the electroscope to see if the dry substance of the tissues 

 was radioactive. Neither plant was radioactive. This was the result 

 to be expected under the conditions of the experiment. 



