Title: Cytochemical Studies on the Integument and Integumentary Tapetum in<i>Linaria Bipartita</i>(Vent.) Willd.
Abstract: SUMMARYThe distribution of insoluble polysaccharides, DNA, RNA, total proteins and histones have been studied in the developing ovule of Linaria bipartita. The distribution of the above metabolites has been observed in the nucellus, integument and integumentary tapetum with a view to understand the role played by these tissues. The cytochemical details of the nucellus show that the nucellar cells in tenuinucellate ovules do not have a significant role in providing nutrition to the embryo sac. In the absence of a vascular supply to the funiculus, a group of elongated and thin-walled cells seems to be transporting food materials from the placenta to the chalaza. Cytochemical details of the integumentary tapetum assign a high metabolic activity to this tissue. It is possible that a part of the nutrients from the chalaza of the ovule is transported to the micropylar end of the embryo sac, through the integumentary tapetum. Therefore, the present study indicates that the nutrients are supplied to the embryo sac both at the micropylar and chalazal ends. The possible pathways of nutrition to the embryo sac before and after fertilization is depicted diagramatically.