studies With C'-labeled Ethylene 



loS 



Fig. 1. Radioautograms of cotton and Coleus leaves after absorption of ethylene- 

 C". Film exposed for 30 days, negative print (light areas indicate radioactivity). 



Entire cotton plants at the six true leaf stage were enclosed for 

 a period of 5 hrs. in an atmosphere of about 625 p.p.m. of ethyl- 

 ene-Ci4. During the treatment period the plants were subjected to 

 500 foot candles of light. The leaves were harvested and oven-dried at 

 50° C. for 8 hrs. Following grinding the dry leaf powder was pressed 

 at 15,000 pounds per square inch for 3 min. into smooth 6.6 cm.2 

 briquettes of uniform texture. The briquettes were counted in a 

 Nuclear Measurement Model PC-3 proportional-gas-flow counter. 

 The leaves contained a total of 2,600 c.p.m. with a specific activity of 

 2.0 cpm/mg of dry tissue. 



