1,000- 



o 



X 

 UJ 



5 



X 

 UJ 



li. 



LlI 



< 



LlI 



o 



500 



Fig. 5. Separation of an inhibitory principle from a growth-stimulating one by 

 partitioning tomato juice between ethyl acetate and \\'ater. The fractions were 

 tested on Gauthcret's strain of habituated Scorzonera hispanica without (C) and 

 with 5 X 10'' M indole-3-acetic acid (A). TJ = whole tomato juice (10 per cent, 

 v/v). EA ^ ethyl acetate fraction. W ^ aqueous fraction. The numl)ers on top of 

 the bars give the exact growth increments. (From 25) 



Fig. 6. Aspect of the cultures of Srorzoiwrn liispaiiiai (hai)ituaicd stiain) giown for 

 11 weeks on the media indicated in Fissure 5. 



