Regeneration of Root Cuttings as Influenced by Plant Hormones

ROOT cuttings (thongs) of sea-kale ( Crambemaritima ) under suitable conditions produce, whichever way up they are inserted in the rooting medium, buds and roots at the morphological apex (proximal end) and base (distal end) respectively (Fig. C ). This phenomenon of polarity has been explained by Went and Thimann in terms of the polar transport of auxin—“polarity can now be expressed quantitatively as a function of the transport of a known substance in the tissues” 1 .