SKOOG AND TSUI 



275 





u 25 



u 



q: 



LU 

 Q. 



Q 

 UJ 



q: 

 o 



2 

 m 



o 



10 20 30 40 

 TIME IN DAYS 



Figure 7. Relative activities of different purine derivatives and uracil on 

 bud formation in tobacco stem segments. Exp. #69 started 3/15/49. Initial 

 pH 4.0, KH2PO4 12.5 mg./l. Curves: i. adenine sulfate; 2. guanine; 3. adenylic 

 acid; 4. nucleic acid; 5. adenosine; 6. xanthine; 7. uracil; and 8. control. 

 All substances added in 0.00025 n^ol^r cone, except nucleic acid which was 

 85 mg./l. 



