and Leptadenia were studied for its taxonomic and phylogenetic significance. Epicarp is single layered in Calotropis, Ceropegia and Leptadenia, while in Marsdenia, Wattakaka, Tylophora and Gymnema it is multilayered. Mesocarp is parenchymatous possessing aerenchymatous tissue in all the genera studied. Endocarp is multilayered and lignified. Dehiscence of the follicle is marginicidal. Factors responsible for dehiscence are also discussed.

Colleters are found on the adaxial basal part of the stipule and calyx of <em>Gardenia lucida</em>. They secrete a yellow transparent resinous substance commonly known as "Dikamali gum". They develop on both the stipule and calyx from a group of epidermal and hypodermal initials. A mature colleter consists of a central core of elongated parenchymatous cells surrounded by a palisade-like secretory epidermis. Druses type crystals of calcium oxalate are frequent in the colleters. At the time of senescence the central cells show lignification and the presence of tannin.

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The present article describes various subcellular changes occurring during development and maturation of the mesocarp of Asclepias curassavica follicle. The ground tissue of the ovary wall consists of dense cytoplasm containing cell organelles like mitochondria, endoplasmic reticulum, chloroplast, ribosomes etc. Mesocarp developing from the ground tissue is differentiated into three zones on the basis of cell shape and degree of vacuolation. Chloroplasts possess starch grains which have a central electron translucent area and a peripheral electron opaque boundary. In the mature fruit the mesocarpic cells are highly vacuolated with a peripheral layer of cytoplasm. The cytoplasm seems to be loose or less denser than that of the developing mesocarpic cells, but contains all the cell organelles that are present in the developing mesocarp.

Anatomy of the fruit wall of Calotropis, Tylophora, Gymnema, Marsdenia, Wattakaka, Ceropegia and Leptadenia were studied for its taxonomic and phylogenetic significance. Epicarp is single layered in Calotropis, Ceropegia and Leptadenia, while in Marsdenia, Wattakaka, Tylophora and Gymnema it is multilayered. Mesocarp is parenchymatous possessing aerenchymatous tissue in all the genera studied. Endocarp is multilayered and lignified. Dehiscence of the follicle is marginicidal. Factors responsible for dehiscence are also discussed.