7 



and two-to-three-celled prominences are seen along the growing margin, 

 hi Ktichidia, i.e. specially tran.-fornied hrauchlets hearing tetraspore-. only 

 one terminal cell has been obverved in a shallow terminal notch, with 

 similarly incurved arrangement of cortical cells. This is due to the special 

 growth (into stichidia) of dichotomous branches developed from originally 

 dichotomous, terminal cells of a short. 



Tetraspores are produced either in stic'nidia-like branches (having one 



-peeiali/.ed shoots (having two apical cells). They are at first regularly 

 arranged in b.th transvorst and imigiiudinal rows ])resenting three or four 

 in surface view, and are formed in a vertieillate manner around the central 

 axes, becoming more numerous and irregular afterwards. Sporiferous branches 

 are often aggregated and are sometimes proliferated from the under-surface 

 of frond. 



often heaping together, and Ire provided with some" nine involucres. In- 

 volucres are compressed and either naked or provided with 2-3 celled teeth- 

 like processes. Neuclei are few or numerous. 



In cutting a cross-section of frond, a transverse row of cells having a 



For the sake of convenience, I call this row the middle layer. Outside of 

 this is occupied by similar but smaller cells which become gradually smaller 

 outward -and pass to the cortical cells. Surrounding the axial cell there are 

 six cells, which were taken by .Mr. Falkenberg for pericentral cells, having 

 been numbered by him in five. They are not, however, those comparable 



the adpressed portion of frond shows unequal thickness of cortex above and 

 beneath the middle layer; but a section cut from the free portion shows 

 radial structure, so that the plant does not possess a dorso-ventral organisa- 

 tion, as Mr. Falkenberg considered. On cutting a longitudinal section parallel 

 to the flat surface, the middle layer is found to be composed of a chain 

 of larger and roundish cells, arising obliquely and opjwsitely from the central 

 cell. These chains lye in parallel to each other, keeping regularity and 

 firmly coalesce together. Cells in the chain are gradually smaller toward 

 the margin and they branch off minor ones towards both surfaces which 

 give rise to cortex. A section cut through the plane pependicular to the 

 surface presents a similar appearence differiug only in the shorter length 

 of the chain of cells arising from the axial cell. They cut off minor cells 

 towards surface and so form cortex. 



