1927 年 41 巻 483 号 p. 172-180
1. The stem of Diplazium esculentum, a Polypodiacean treefern, has the dictyostele with medullary bundles. The petiole has double bundles which fuse into one at a higher part.
2. The construction of the stelar ring, the mode of parting of leaf- and root-traces, the presence of brown sclerenchymatous masses and the histological structure of the vegetative organs show the normal Polypodiacean type.
3. There are two types of origin of the medullary bundles, the one originating independently in the pith and the other by internal thickening of the meristele. In both cases their upper ends join with the leaf-traces. The former type is normally found in the adult plant and the latter in the young, indicating that the former type or the Cyatheacean type has been derived from the latter type or the Polypodiacean type.