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SUMMARYThe relationship between anther dehiseenee and dehydration of the filament tip and the connective tissue were followed in Gasteria verrucosa (Mill.) H. Duval, Allium cepa L. and Lilium hybrida ev. ' Enehantment' using various mieroseopical techniques, including direct observations of living tissues in the SEM.In G. verrucosa anther dehiseenee immediately follows anthesis, with concomitant dehydration and shrivelling of the filament tip. In L. hybrida the filament tip dehydrates and shrivels before anthesis. The anthers start to dehisce immediately after anthesis. In A. cepa the filament tip dehydrates and shrivels slowly after anthesis and dehiseenee, which may take up to several days, correlates with the rate of extension of the filament.The attenuated period of dehiseenee in A. cepa may be related to the absence of stomata on the anther. Experiments on xylem conductivity and transpiration reveal that the presence of continuously open stomata on the anthers sets the time of dehiseenee after anthesis in G. verrucosa and L. hybrida.The shrinking filament tip in all three species functions as a hinge which suspends the dangling anther after dehiseenee. The uniformly thickened epidermal cell walls on the anthers opposite the filament prevent the outwardly bending locule walls from embracing the filament.

The pistil of Lilium longiflorum secretes two forms of exudate, one from the stigma surface and the other from the canal cavity. Electrophoretic studies of these exudates have revealed quantitative and qualitative differences in protein profiles. The exudatic components which are transferred to the cell wall by endoplasmic reticulum and Golgi vesicles, are stored within the cell wall of the secretive tissues and secreted from the cell walls directly. The cell wall structure of these secretive tissues differs. The canal cell wall has thick characteristic ingrowths that are supplied mainly from Golgi vesicles, while the papilla cell wall of the stigma is thinner, lacks ingrowths, and is supplied from ER vesicles.

The development of the lower part of the stamen of Gasteria verrucosa (Mill.) H. Duval, the filament, was investigated using interference contrast, transmission and scanning electron microscopy, and was related to the development of the anther.The filament extends during its entire development, in the younger stages mainly in the basal region, in the older stages in the tip. Up to maturity the solidity is gradually improved by the progressive thickening of the tangential epidermal wall and the cuticle from the tip to the base of the filament and the increasing turgidity of the epidermis.The amount of tracheary elements increases up to maturity as does the starch content of the epidermis and the parenchyma. Starting at the pollen mitosis stage, a progressive cytoplasmic degeneration can be observed from the tip to the base and from the central parenchyma to the epidermis. At anther dehiscence the filament tip shrivels and the starch has disappeared from the entire filament. Both the latter phenomenon and the cytoplasmic degeneration may be due to redistribution of substances to other floral parts. The presence of prominent intercellular spaces may be important for the supply of gas to the maturating locule.