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dichotomons, and the cells are short when young, but they become 

 much elongated when fully grown, as it is the case with many other 

 plants of this family. In the growing portion of frond the: formation 

 of a hair-leaf from its basal cell is well observed. One of the young 

 pericentral cells cut off from an axial cell is divided by a horizontal 

 partition into 2 cells, the upper one of which is clifferenciatecl into the 

 hair-leaf. The latter is protruded beyond the surface of frond, and 

 now, a transverse partition is formed in this cell at the same level 

 with surface of that part. By this way, this cell is divided into two, 

 of which the upper one becomes the mother cell of a hair-leaf, while 

 the lower, its basal cell. In the solid portion of frond there is no hair- 

 leaf present. 



Mode of growth of the frond is monopodial. Toward the apex 

 of frond, cells of the axial column become much shortened into disc- 

 shaped segments and the apical cell which is slightly prominent is cut 

 off by a horizontal partition. 



Each pericentral cell in the swollen portion is plainly connected at 

 its extremity with 4 larger cells which form the innermost layer of 

 the wall of the cavity (Fig. r i ), Every one of the latter also cuts off 4 

 similar but smaller cells which give rise to other 4, and so on. By 

 succession, a thick wall of the cavity is formed in 3 or 4 layers of 

 .cells. Near the bottom ot the cavity the pericentral cells enlarge 

 toward their extremities in clavate manner and form the innermost 

 layer ot the wall, and then give rise to 4 subcortical cells as in the 

 ； remaining portion. In the globular portion, the longitudinal axis 

 ■never sends out a branch. ； but in solid part, the axis often gives off 

 .branches. Advciuitious branches arise from the sides as well as from 

 :th じ harmed ends ot rliizomes and pedicels of balls. In the most part 

 .of the globular portion pericentral cells are almost horizontally 

 .stretclied out ； but as they approach toward the apex they are 

 j.urved downward alone;' the iimtr wail ot the cavity. .. ' . : 



