Abstract:Embryological studies on Convallaria majalis L. revealed that: 1. The anther was four sporangiate. The development of anther walls conformed to the monocotyledonous type. The tapetum, of which each cell contained two or many nuclei in the later stages, was of glandular type. Meiosis of the microspore mother cells was accompanied by successive cytokinesis, which resulted in the formation of isobilateral and tetrahedral tetrads. The mature pollen grains were of the 2-celled type. 2. The ovary was trilocular. The placentation was axile, but placentas were not fully fused in the center of the ovary. The ovule was bitegminous, crassinucellate and anatropous. The micropyle was formed by the inner integument. 3. The development of the embryo sac was of the Allium type and Endymion type. 4. Raphides were observed in the ovary wall, the funiculus and the outer integument after fertilization. 5. The development of the embryo was similar to the Caryophyllad type, but the basal cell was vertically divided into two cells. 6. The development of the endosperm was of the nuclear type. However, the gigantic endosperm nucleus was formed at the chalazal end.