The introduction of kinetin in the axillary tissues of isolated nodes of Cress cuttings induces a momentary stop in the growth of all the organs of the axillary "radicular plate". After this interruption, a more or less rapid growth of the long roots sets in again, while in the younger roots morphological modifications occur which lead to the formation of a bud at the tip of the root, whatever the age of the axil which bears these roots.This results is possible only up to a certain stage of root development (corresponding to a maximum length of 0.4 mm). Beyond this length the inversion of the direction of organogenesis does not occur.