Abstract
1. The megasporocyte of Lilium philippinense is derived by the enlargement of subepidermal cell of the nucellus. The megasporocyte nucleus develops directly into an embryo-sac without any previous divisions.
2. The microsporocyte remains for a short time in the resting stage and immediately proceeds into heterotypic and homoeotypic divisions.
3. The haploid number of the chromosomes is twelve and the diploid number is twenty-four.
4. The four daughter nuclei resulting from the homoeotypic division are of the Same size and contain the Same number of chromosomes. Three of these four nuclei are closely arranged in the chalazal end, and the remaining one moves towards the micropylar end. Following this arrangement the four nuclei divide simultaneously. The spindles of the three nuclei become united forming a multipolar spindle which ultimately develop into a bipolar one.
5. Of the four resulting nuclei from this division, the two in the micropylar end have smaller dimension and contain twelve chromosomes each, while the two at the chalazal end are more voluminous and contain thirty-six chromosomes each.
6. The two pairs of nuclei resulting from the last division divide almost simultaneously forming an eight-nucleate embryo-sac. Two of the nuclei move towards the micropylar end and become synergids, one becomes into an egg, and the other moves towards the middle part of the embryo-sac and fuses with one of the chalazal nuclei, forming the polar nuclei. The three remaining chalazal nuclei move towards the extremity of the embryo-sac and become the antipodal nuclei.
