250 



Z 



o 

 tr 

 o 



I- 



Z 

 UJ 



o 



40 



LOG lAA 

 G./ML. 



Fig. 4. Growth responses of segments from roots grown in 2,4-dichloroanisole (DCA) 

 (10-=^ g/ml). (A) Total extension in 48 hrs. of normal (open circles) and DCA-grown 

 (solid circle) segments. Response to lAA. Vertical lines indicate the least significant 

 difference (5 per cent) between means. B and C. Epidermal cell length distribution 

 before and after 48 hrs. of extension. (B) Normal segment responses to lAA. (C) 

 DCA-grown segment responses to lAA. Open parallel lines-segments immediately 

 after excision. Blacked-in parallel lines— segments after 48 hrs. in 0.5 per cent 

 sucrose solution. These lines are plotted at distance of <r/VN above and below 

 the respective mean of successive groups of cells. 



