Pea seeds were allowed to germinate om paper soaked with distilled water for 3 days at room temperature. Roots of approximately equal length were then selected and cut in two fragrments: the tip, and a fragment immediately above the tip. It was found that the specific activity of acid DNase is much higher in the tip than im the other part of the root; the shorter the tip fragment, the higher the specific activity. Neutral DNase is also higher in the tip, but the difference between the two fragments is less marked than for the acid enzyme. Thus, the acid DNase seems linked to the process of growth in pea roots. (P.C.H.)