Abstract
Nuclei of lily microsporocytes in meiotic prophase were sub-j ected to two-dimensional spreading and stained with silver nitrate. This method made it possible to observe the behavior of synaptonemal complexes with light microscopy. Axial cores of homologous chromosomes, which had been formed at the leptotene stage, were paired during the zygotene stage, consequently being integrated into the synaptonemal complexes. During the middle zygotene stage, a number of paired segments were observed as heavily stained stretches in the spread nuclei, thus indicating the multiple initiation of pairings along sets of homologous chromosomes.
