128 
MORPHOLOGY 
antheridium development resembles closely the eusporangiate method 
of sporangium development, and is always associated with it. It is 
interesting to note that only the Anthocerotales among bryophytes 
approach this method of antheridium formation in the fact that the 
inner cell following 
the periclinal division 
gives rise to the sper- 
matogenous tissue. 
The sperms are re- 
markable among 
pteridophytes in be- 
ing biciliate, a char- 
acter which belongs 
to the sperms of 
bryophytes (fig. 282). 
Archegonium. 
The archegonium 
also resembles that of 
the Anthocerotales in 
being an embedded 
structure. The out- 
line of its develop- 
ment is as follows: 
It begins as a super- 
ficial cell, which 
divides by a trans- 
verse wall (fig. 283), 
the outer cell being 
the primary neck cell, 
the inner one the 
inner cell. The inner 
cell divides by a 
transverse wall, re- 
sulting in a row of 
three cells (fig. 284), 
FIG. 276. Section of gametophyte of Lycopodium com- a Condition of the 
planatum, showing crown (g) bearing antheridia (a) and archegonium Very 
archegonia (a') (in one, e, the embryo sporophyte has de- ' 
veloped), and the tuberous region (c) with highly different!- ( 
ated tissues. After BRUCHMANN. ginning with the 
