PHYSIOLOGICALLY ACTIVE GASES 



145 



Figure 54. Ethylene-induced epinasty of leaves. All plants sealed in Wardian cases 

 for the periods and in the concentrations of gases mentioned below and photographed 

 immediately after removal from the cases: 1. Fuchsia, check; 2. Fuchsia in 500 ppm of 

 ethylene for 24 hours; 3. Buckwheat, 1 part to 10,000 of Yonkers gas, equivalent to 

 3 ppm of ethylene, for 72 hours; 4. Sunflower, 1 part to 10,000 of Yonkers gas, 48 hours; 

 5. Paper White narcissus, 1 part to 10,000 of Yonkers gas, 96 hours. 



