Microstructural Observations and Cytochemical Studies on the Archegonial Development and Oogenesis of Marchantia polymorpha STUDY ON THE MORPHOLOGY AND DEVELOPMENT OF THE ARCHEGONIUM AND ANTHERIDIUM OF THE FERN OSMUNDA CINNAMOMEA Primary Study on the Archegonium Formation and Oogenesis in the Fern Phymatosorus hainanensis Enzymatic Isolation of Archegonium of Pinus Yunnanensis Fr. and Observations on the Proembryo Development Formation and Development of Archegonium in the Fern Ceratopteris thalictroides(L.)Brongn Female Gametophyte Development and Endangered Mechanism Research in Isoetes yunguiensis