effects of exposing seeds io3 



Experiment 20 



Six seeds of Liifintis albus were soaked in water for 17 hours, 

 and the seed-coats were removed from over the hypocotyls. The 

 seeds were then placed in a Zurich germinator in two rows, with the 

 hypocotyls facing each other, and the glass tube of RaBrg (5 mg., 

 1,500,000 X ) was placed over the seeds in contact with the hypocotyls. 



Control of six seeds similarly treated except that an empty glass 

 tube was used instead of the radium-tube. 



November 26, 8 : 30 A. M. 



All seeds have begun to germinate, and an ink mark was placed 

 on each radicle as a reference mark in measuring. 



November 27, 4 : 30 P. M. 



Increase in length of the radicles in the past 32 hours as follows : 



Control 



3.00 mm. 



8.00 



8.00 



10.00 



5-50 

 11.00 



25.00 mm. 

 Average, 4.16 mm. 



November 28, 3 : 30 P. M. 

 Radium 

 7.00 mm. 



54.50 mm. 77-50 "1"^- 



Average, 9.08 mm. Average, 15.50 mm. 



The radicles of the control seeds have elongated almost twice as 

 rapidly as those exposed to the radium. 



Experiment 21 

 November 28, 4 : 30 P. M. 



Twenty-four seeds of hnc\!.vfhQ2ii{Fagopyrum esculenttcm), soaked 

 in water for 24 hours, were divided into two groups, R and C, of 12 



