Abstract
Young internodes of C. blumei are known for their sizable amount of acropetal IAA movement. Plants of the same clone, under improved growing conditions, now show almost absolute basipetal polarity of 14C-IAA, as measured by liquid scintillation counting of 14C in the receiver cylinders of agar. The ratio of basipetal to acropetal movement is now as much as 85:1, instead of the 3:1 ratio found years ago under conditions providing slower growth.