87 



to the peripheral cells, as in all normal antheridia chlorophyll 

 is quite absent from the central cell. 



In G. fiabellata and G. rupesteris Rauwenhoff found that there 

 were only three or four cells in the walls of the antheridia 

 aside from the stalkcell. Indeed they differ from the antheridia 

 of the Polypodiaceae merely in the fact that the lower ring- 

 formed cell may divide into two by a vertical wall. In G. 

 pectinata the number of cells is very much greater. No com- 

 plete ringcells are found, although he first wall may be very 

 much curved or horseshoe-shaped (PL XI, Fig. 71 ~-73), and this is 

 also the case in the other species examined. From a careful 

 study of many sections taken in all directions the following 

 seems to be the succession of divisions. After tw^o or three 

 basal (stalk-) cells have been cut off, extending half way or 

 more around the antheridium, the central cell is separated by 

 the first periclinal wall, which forms a dome-shaped cell above 

 the central cell of the antheridium. It is not quite certain 

 what is the next division, l)ut it is probably the separation of 

 a cap-cell, as in the species described by Rauwenhoff. The sub- 

 sequent divisions in the wall-cells are not absolutely uniform, but 

 in the main follow the same plan. Where a series of sections of 

 the antheridium are examined (PI. X, Fig. 69; PI. XI, Figs. 74 

 and 90) it will usually be found that the arrangement of the cells 

 on the opposite sides of the antheridium is quite different. On one 

 side the position of the walls is horizontal, following the lines 

 of the first formed wall, and forming partial ring-shaped cells 

 which, however, are later divided by vertical walls. On the 

 opposite side, probably corresponding to the last formed of the 

 basal sei'ies of segments, there are also vertical walls running 

 to the apex of the antheridium. The latter is occupied by the 

 primary cover-cell, which is often more or less lateral in 

 position, and this cover-cell also undergoes certain divisions. 

 These divisionwalls are arranged spirally, the last division 

 resulting in the formation of a small opercular cell {o) like 

 that found in Osmumhi and the eusporangiate ferns. While the 

 number of cells forming the wall of the antheridium in G. 



