Megasporogenesis, formation and development of embriosac and embryo in Coffea Dewevrei de Wild Et Th. DurThe embryo sac development in Coffea Dewevrei De Wild et Th. Dur. is a slower process than in the other diploid species C. canephora and still slower than in the tetra-ploid species C. arábica. First divisions of functional megaspore begin on the day the flowers open. Very few complete embryo sacs are found in the next day; in general, the embryo sac is complete on the eighth day and from the tenth day on most of them present fused polar nuclei whether fertilization has taken place or not. Fertilization was observed on the sixth day but was more frequently seen about the tenth day. Divisions of primary nucleus of the endosperm could be seen from the tenth day on. The endosperm is of "non-cellular" type, its transformation into "cellular" occurring from 22 till 107 days after flower opening. Oosphere maintains itself undivided; its first division was observed on the 142th day, but probably occurred before, aince at that time multicellular pro-embryos were also seen. After fertilization the ovule increases rapidly in volume, and becomes 1500 times larger on the 142th day. Meanwhile the endosperm develops very slowly, its volume increasing 230 times. Even when fertilization does not occur, the ovule grows during the first 30 days; the embryo sac, however, does not grow and desintegrates rapidly. Afterwards, the ovule tissues also degenerate and the ovary falls down.