t*1 



EXPERIl EUTS WITH HELIOTROPE. 



The experiments were made on seedling plants 

 of the common florists' variety of Heliotropium 



eruvianum grown in a soil of one half loam and one half 

 sand, "by volume. The technique was the same in all par- 

 ticulars as that described for Coleus. The plants were 

 practically mature when tested. Two plants were treated 

 by replacing the normal soil atmosphere with nitrogen. 

 In both cases the plant wilted, much as happened in the 

 case of Goleus, the wilting beginning to be visible 

 approximately 25 and 33 hours respectively, after the 

 soil atmosphere was replaced. He-supply of oxygen to 

 the roots did not induce recovery. In both cases the 

 wilting progressed rapidly and the plants died within 

 a few days. Sae cessation of water- intake which ac- 

 companied the wilting of Coleus did not occur with 

 Heliotrope until the plants were completely wilted and 

 nearly all of the leaves were black and entirely dead. 

 However, a slight decrease in the amount of water taken 

 in occurred coincidently, or nearly so, with the beginning 

 of wilting and the amount of water-intake decreased 

 gradually thereafter until the final stoppage. Ex.- - 

 ination of the roots showed that the root systems were 

 entirely dead and badly disintegrated, but this exam- 

 ination was not made until after the complete death of 



the aerial portions. No roots were examined soon after 



