A. W. (RALSTON AND RAVINDAR KAUR 



691 



120 



100 



■5. 80 



60 



r 40 



20 • 



Green 



2 3 4 



5 10 



Original Length of Section (mm) 



— »• 

 20 



Fig. 2. Effect of the initial length on the percentage increase in length of 

 etiolated and green pea stem sections in the presence of indole acetic acid. 



significantly protruding (C) . The growth data for sections excised 

 from these various types of plants are presented in Table 2. It can be 

 seen that no major growth differences appear. In general, response 

 to auxin in etiolated plants was best in condition A and in green 

 plants in conditions B and C. These configurations were therefore 

 selected as standards in further studies. 



E[Ject of in tern ode length on growth. Sections may obviously be 

 derived from internodes of varying length. Table 3 demonstrates that 

 etiolated internodes less than 15 mm long are inferior to longer 



200 



.? 150 



5 



100 



50 



12 3 4 5 10 



Original Length of Section (mm) 



20 



Fig. 3. Effect of the initial lengtli on the percentage increase in fresh weiglit of 

 etiolated and green pea stem sections in the presence of indole acetic acid. 



