IT was stated in an earlier communication1 that if 4-mm. portions of the broad bean radicle were assayed for vitamin C, the ninth portion from the tip contained an average of 112.96 mgm. of the vitamin per 100 gm. of fresh weight. This amount was thought to be present within the region of maximum growth. Following this statement, J. Read pointed out to us in a private communication that the accepted region of maximum growth occurs at a distance of 5–7 mm. from the tip. He suggested that analysis of one-millimetre portions should therefore be undertaken.