Abstract: The blepharoplast, an elliptical, compact spherical body ranging 0.5～0.6 /μm in diameter, appears in the cytoplasm of the sperm mother cell during the sperm development of Lygodium japonicum (Thunb.) Sw. It consists of cartwheel tubular subunits arranged in radiant pattern and amorphous material. Numerous microtubules extended from the blepharoplast into cytoplasm. In the process of sperm cell development, the blepharoplast became loose, and the centrioles originated from the subunits separated from each other and dispersed towards the surface, with the amorphous material in the center. Accompanying the differentiation of the centrioles, muhilayered structure with the spline ( i. e. microtubular band) and lamella strata came into existence, with one end attaching to the amorphous material in the center. Then the muhilayered structure (MIS) associated with a mitochondrion and moved towards the nucleus, and a dent facing the MIS is formed in the nucleus. A cotton-like structure consisting of amorphous material and dardyed small tubular structure appeard in late stage of spermatogenesis. Microtubules were seen protruding from the surface of the cotton-like structure. It is suggested that this structure might be relevant to the origin of the blepharoplast.

Key words: Lygodium japonicum, Sperm cell, Blepharoplast, Muhilayered structure