Ultrastructure of Central Cell before and after Fertilization in Sugar Beet (Beta vulgaris) Isolation of Embryo Sac Cells of Lettuce (Lactuca sativa) Single-Pair Fusion of Various Combinations Between Female Gametoplasts and Other Protoplasts in Nicotiana tabacum AN ULTRASTRUCTURAL STUDY ON THE DEVELOPMENT OF CENTRAL CELLS IN RICE EMBRYO SAC THE CYTOCHEMICAL CHANGES OF IN VIVO AND IN VITRO DEVELOPED UNFERTILIZED CENTRAL CELLS IN NICOTIANA TABACUM Gamete Recognition in Higher Plants: An Abstruse but Charming Mystery The First Record of Dynamics of Male-Female Nuclear Fusion in Viable Tobacco Central Cell During in Vitro Fertilization Ultrastructures of the Egg Apparatus and the Central Cell of Calystegia hederacea (Convolvulaceae) Before and After Fertilizati on In Vitro Divisions of Unfertilized Central Cells and Other Embryo Sac Cells in Nicotiana tabacum var macrophylla Formation and Development of Archegonium in the Fern Ceratopteris thalictroides(L.)Brongn Ultrastructural Aspects of the Female Germ Unit in Pelargonium hortorum Quantification of Mitochondrial DNA Copies in Central Cells of Antirrhium majus