The electron microscopic technique was adopted to study spermatocyte and spermatozoid ultra-structures of Dryopteris crassirhizoma Nakai. The spermatocytes were polygonal and contained many commonly-observed organelles such mitochondria, plastids, endoplasmic reticula, Golgi bodies; in their cytoplasm some concentric membrane-like structures were seen to stand near the plasmalemma or corner areas. The concentric structures consisted of self-encircled double-layer membrane covered by a single-layer unit membrane. There formed segregating cavities between spermatocyte cell-wall and spermogonium cell-wall and osmiophillic layers outside spermatocyte cytoplasmalemma, which indicated that the spermatocytes had begun to gradually break away from the male gametophytes and embark on independent development. Although osmiophillic layers also developed between spermatocyte and gametophytes, they were interrupted by pores for substance and signal exchanges. Mature gametophytes, wrapped by a transparent membrane, contained spermatozoids and spiral-shape bodies composed of ring-shape organelles that encircle themselves in 3～4 folds; the ring-shaped organelles included multi-layer structures, microtubule ribbon, megamitochondria, flagellum bands, a long dolichomorphic concentrated nucleus. At the back end of the spermatozoids there existed some vacuolated cytoplasm that contained residual mitochondria, amyloplasts and some big vesicles. When mature spermatids released from the antheridia, the spermatozoids overcame the binding of the transparent membrane and broke away from the vesicles at the back end to become free. In addition, the ultra-structures of Dryopteris crassirhizoma Nakai. were compared with those of other ferns.%应用电镜技术对蕨类植物绵马鳞毛蕨(Dryopteris crassirhizoma Nakai)精母细胞和游动精子的超微结构特征进行了研究.精母细胞为多边形,细胞质内含有丰富的线粒体、质体、内质网、高尔基体等常见的细胞器,在细胞质中还可见到一些同心圆膜状结构,位于质膜的附近或精母细胞的角偶.同心圆膜状结构由双层膜环绕构成,外被1层单位膜.精母细胞与精子器的璧细胞之间形成了分离腔,在精母细胞质膜外形成了嗜锇层,这些结构的形成说明精母细胞已经开始与雄配子体逐渐分离,进入独立发育的阶段.尽管精母细胞之间也有嗜锇层的形成,但嗜锇层是不连续的,其上有一些空隙,精母细胞之间可通过空隙进行物质和信息的交流.成熟的精子细胞外被1层透明的薄膜,里面为游动精子,螺旋状,由环状细胞器环绕3～4圈构成,这些环状细胞器包括多层结构、微管带、巨大线粒体、鞭毛带和1个长形浓缩的细胞核.游动精子的后端为一些泡囊化的细胞质,其中包括一些残存的线粒体、造粉质体及大的囊泡等.当成熟的精子细胞排出精子器后,其内的游动精子挣脱透明质膜的束缚,摆脱后端的囊泡,成为1条游动精子.本文还对绵马鳞毛蕨和其它蕨类植物精子的超微结构特征进行了比较.
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