EFFECTS OF EXPOSING SEEDS 



85 



Radui7n 

 lo.oo mm. 

 7.00 

 8.50 

 9.00 

 6.00 

 5.00 



Control 

 10.00 mm. 

 21.00 

 12.00 

 18.00 

 24.00 

 00.00 



45.50 mm. Total. 

 Average height, 7.58 + mm. 



85. 00 mm. Total. 

 Average height, 14.16 + mm. 



February 16, 12 M. 



Radiujn 

 12.50 mm. 



4-50 



7-50 

 12.50 

 12.50 



7.00 



56.50 mm. Total. 



Average height, 9.41 mm. 



The cotyledons are not reflexed, 

 and the epicotyl has begun to elongate 

 in only one seedling. 



Length of Hypocotyls 



Control 

 26.00 mm. 

 29.00 

 24.50 



23-50 

 20.50 

 20.50 



144.00 mm. Total. 



Average height, 24.00 mm. 



The cotyledons are well reflexed, 

 and the epicotyls are elongating w^ith 

 leaves well expanded. 



February 22. 



The plants were carefully removed from the pots and the soil 

 washed from the roots. The roots of the radiated plants are very 

 short, and secondary roots are only slightly, and in two specimens 

 not at all, developed. 



The roots of the control plants are several times as long as those 

 of the radiated specimens, and with secondary roots well developed. 



The radiated plants did not lose the nyctitropic movements of 

 the leaves, and measurements of the length of the stomata in the two 

 showed no difference between the normal and the radiated plants. 



Experiment 2 

 February 2, 4 P. M. 



Four seeds of Lupimis albtis^ after having lain for four days in a 

 cylinder lined with Lieber's " radium coating," were planted in soil 



