Takakia lepidozioides Hatt. et Inoue was studied by microtome sections, and the followings were revealed: 1. The apical cell at shoot apex is tetrahedral and has three cutting faces. Three cells cut off from the apical cell are all of the equal size (Fig. 1, A-C). 2.At shoot apex the leaves are in three vertical rows corresponding to the three cutting faces of the apical cell of stem. Later, however, the leaves displace and lose their arrangement in three ranks. The leaf primordia often divide and a pair of leaves develops (Fig. 2 A-F). 3. The venter of archegonium has the wall of 2-3 cells thick, and neck cells arrange in 6 vertical rows. The archegonium is of the same origin with a leaf, and it has a few chloroplasts in the cells (Fig. 1, F-K, and Fig. 2, A). 4. Branches are originated from the cortical cells, which become meristematic (Fig. 1, E, and Fig. 2, G-K). 5. The structures of shoot apex and of archegonium are largely similar to those of Musci.