BRYOPHYTA 379 
archegonia and the antheridia are similiar to those of the two 
previous orders. The fertilized eggs develop into a sporophyte 
(Fig. 414) similar to that of the Marchantiales in that it con- 
sists of a sporangium, a foot, and a stalk. 
The sporophyte of the Jungermanniales is more complex than 
that of the Ricciales, but the simplest thalli found among the 
Hepaticae occur in some of the | 
thallus members of this order. 
ORDER ANTHOCEROTALES 
The thallus of the Antho- 
cerotales is simple, but the 
sporophyte is more compli- 
cated than that of any other 
order. Anthoceros (Fig. 415) 
may be taken as an example. 
In this genus the sporophyte 
(Fig. 417) consists of a basal 
absorbing organ, the foot, 
and a terminal club-shaped 
sporangium. Near the base 
there is a meristematic region, 
the activity of which causes 
the sporangium to increase 
in length. The outer part of 
the sporangium consists of . 
sterile cells, and in the center there is a column of sterile 
cells, the columella. The spores are formed between these 
two sterile regions. As the spores in the tip of the spo- 
rangium reach maturity the upper part of the sporangium 
splits and the spores are liberated (Hig. 415). As more spores 
mature the sporangium continues to split. In this way the 
sporangium is continually liberating spores, while new spores 
are being produced as the result of the activity of the basal 


_ Fra. 418. Gametophyte of a moss, show- 
ing a group of antheridia and archego- 
nia at the tip. (x 7) 
meristem. 
