The development of the female gametophyte and floss in Bombax malabaricum D.C.

Abstract

The paper gives an account of the development of the female gameto-phyte and floss inBombax malabaricum. 1. The ovules are anatropus and bitegmic. Both the integuments take part in the formation of the micropyle which is somewhat zig-zag. 2. The archesporial cell is hypodermal in origin. Two megaspore mother cells have been noted in many preperations. A normal linear tetrad of megaspores is produced of which the lowermost one becomes functional and produces a seven-nucleate embryo-sac of the normal angiospermous type. The antipodals are ephemeral. The development of the embryo is very much delayed. Endosperm development is of the nuclear type. 3. The floss develops from the cells of the epidermal layer of the inner carpellary wall of the boll. All the cells, however, do not develop. The 'non-fibre' cells as also some of the fibre cells divide anticlinally during the early stages of the development of the fibre. The growth of the latter seems to be arrested after division. The mature fibres are uninucleate and have an unconstricted base.