1915] 



HARVEY— ETHYLENE 



199 



A. CHEMICAL ANALYSIS 



i. General procedure 

 At the close of the culture period, the epicotyls of the seedlings 

 were collected, their wet weight determined, and preserved in 



Fig. 2.— Sections of the sweet pea epicotyl at the stage corresponding to fig. 1 : 

 A and B, normal; C and D, ethylene treated; X50. 



85 per cent alcohol 2 (redistilled). Both the ethylene treated and 

 the untreated samples usually weighed 100-150 gm. Soon after 



2 Enough 95 per cent alcohol was added to make the final concentration 85 per cent ' 

 allowing for water in the tissue, which was about 92 per cent. 



