Etude du fonctionnement des zones organogènes du gamétophyte du Gymnogramme calomelanos L. (Pteridophytes, Filicinées)

Abstract

Studies on correlations of growth in the elementary system constituted by the young gametophyte of the Fern: Gymnogramme calomelanos have shown prominent part played by the apical regions on the branching of the protonema. In addition, double way connections, which are probably induced by an acropete transfer of nutritional materials, have been demonstrated. In the branching phenomena the first and most important events take place in the wall of the future apical cell in which there appears a bulge which precedes the nuclear division. During the gametophyte's growth, apical zones become less and less sensitive to luminous shocks and, consequently, can more easily exert their dominance effects on the orther parts of the gametophytic tissues.