50 
however, not to keep the ground soaking wet, or else there is 
danger of the prothallia rotting. © 
The young male prothallia are small, and often of irregular 
form (Fig. 1), the antheridia (av.) arising from the marginal, 
or sometimes the terminal cells. They arise as papillae, resem- 
bling very much at this stage, the young root hairs, but soon be- 
come distinguished by their denser contents, and more regularly 
hemispherical form (Fig. 2, an.) 
The young antheridium now becomes cut off from the cell of 
the prothallium by a wall, and is seen to contain a distinct cen- 
tral nucleus, around which the contents are more granular than in 
the peripheral portions of the cell. Among the granules are 
some chlorophyll bodies, but these are smaller than those of the 
other cells of the prothallium. 
The first wall formed within the antheridium is funnel-shaped 
in most cases, the broad portion being directed upward, and the 
point in contact with the wall by which the antheridium was cut 
off from the cell of the prothallium (Fig. 3, 2-7). Sometimes 
before this is differentiated a wall is formed parallel to the latter, 
thus making a pedicel, but this was quite exceptional. In some 
cases the point of the funnel-shaped wall does not reach to the 
base of the antheridium, or the wall may even be nearly flat. 
The second wall (Fig. 3, 4) is much less variable, being ap- 
proximately hemispherical, and parallel to the outer wall of the 
antheridium. 
Finally a third wall is formed, resembling the first one in 
form, and cutting off the covering cell of the antheridium (Figs. 
4, 8.) 
The antheridium now consists of four cells, three parietal and 
a central cell. The two lower parietal cells are annular in form, 
the upper one flat. They all are nucleated and contain a num- 
ber of small chlorophyll granules. The central cell appears 
pentagonal when seen from the side, and is characterized by a 
large nucleus and dense, granular and highly refractive proto- 
plasm. 
The division of the central cell begins either before, or imme- 
diately after the formation of the covering cell. The first wall 
(Figs. 3, 8) is nearly vertical, and is soon followed by a second 
