PSILOTUM 



49i 



V. This is a little more advanced; the whole of the cells are now fill- 

 ed with a cellular mass, all cells equal, adhering together, less grume. 



These cells under £ present the appearance of an inner cavity, the 

 walls of which are studded with granules, and probably besides filled with 

 grumous matter. 



VI. The next stage the capsule is hardened, perfectly walled out 

 with furrows, indicating the incomplete valvation. 



The cells appear now filled with large bags, each with many globular 

 nuclei, within each is a distinct membrane. 



Each of these becomes afterwards divisable into farinaceous grains by 

 division. 



There are also many smaller grumous bodies without any distinct 

 membrane. All sorts of stages are seen, the smaller grumous bodies 

 are perhaps the young grains, although their shape is different. 



VII. The next stage, sporules have their mature form. They are 

 shaped like a narrow grain of wheat, looking very different according to 

 the aspect. No membrane visible under 1-10, although the sporules pre- 

 serve their grouping in a marked manner, no membrane visible in iodine ; 

 amylaceous (violetted) granules plenty, invisible in the field, mixed with the 

 usual molecules, many are about this period loose: (a, side view, b, back.) 



VIII. Cells occupied by irregular groups of hispid looking cells, all 

 sorts of cells are seen, from simple large ones, with adhering granules, to 

 compound with nuclei as the simple small nucellar, without obvious 

 membranes ; in the large earlier simple ones, a remarkable aggregation 

 of the granules occurs. 



Young sporules are evidently contained in parent cells, while those 

 near the walls of the capsule present the appearance of aggregate oppo- 

 site, without any distinct membrane. The appearances at this stage are 

 otherwise uniform. 



IX. Tolerably uniform, irregular masses of cells without any com- 

 mon membrane, with a cavity, or one forming ; in some with a distinct 

 nucleus in the cavity. This may be considered next to IV. 



Nitric acid shews these to be of a distinct nucleus, with a beautiful 

 hyaline membrane. 



X. Mature sporules subreniform, apex filled with globules containing 

 grume. Appearances of teguments, probably three, the outer teguments, 

 quite hyaline, only seen along the concave edge, and by the aid of pressure. 



XI. Slight traces under 1-16 (in the perfectly distinct one) of a proper 

 integument, also of nucleus on a transverse section, many nucleary disks 

 with nucelli will be seen also, these from examination, I take to be es- 

 caped young sporules. 



These often burst, discharging a grume in the parent cell, exactly as 

 in Isoetes. 



I have not seen a division of the parent cell before separation of the 



