Growth Measurements 



179 



Fig. 48. Tip of excised tomato root grown for one week in a 

 complete nutrient to which were added 3 x 10~ G g. of indole acetic 

 acid per ml. of nutrient. Failure of the axis to elongate has 

 crowded the branch-primordia which are usually scattered over 

 many centimeters of root into a few millimeters giving the appear- 

 ance of a "rooting" response, x 25. 



