416 BRYOPHYTES (MOSS PLANTS) 
Thus as compared with the Marchantiales, the Jungermaniales 
have gametophytes more differentiated in form but less in struc- 
ture, and have sporophytes characterized by a greater sterilization 
of sporogenous tissue. 
Anthoceros. — Anthoceros is a representative of the Antho- 
eerotales which is a very small group of inconspicuous Liverworts. 
Anthoceros and its allied forms are the most interesting of all 
Liverworts, because their structure suggests the steps by which 
Pteridophytes, the Fern group, could have originated from the 
Bryophytes. Anthoceros grows spread out like some of the 
Riccias and is common on moist 
soil in north temperate regions 
(Fig. 871). The gametophyte is 
a simple thallus, much simpler 
than that of the Marchantias. 
The sex organs develop in sunken 
areas on the top surface of the 
thallus. 
The remarkable feature is the 
sporophyte, which differs in a 
number of ways from the spo- 
rophytes of other Liverworts. 
Fig. 371. — Anthoceros, showing Tn the first place the sporo- 
a gametophyte (g) bearing sporo- Phyte is green, which means that 
phytes (s). x about 2. it is supplied with chloroplasts 
and is thereby able to make 
food for itself, although it has to depend upon the gameto- 
phyte for water and mineral salts. This feature suggests the 
independent sporophyte of the Pteridophytes. The epidermis 
of the sporophyte even contains stomata for allowing the air 
to reach the green tissues beneath as in the leaves of higher 
plants. Evidently, if this sporophyte had roots, it could live 
independently of the gametophyte. In the second place there 
is a core or central axis of sterile tissue called columella extend- 
ing lengthwise through the sporophyte, and bands of spore- 
forming tissue alternate with bands of sterile tissue around this 
columella. The columella is a characteristic feature of Moss 
sporophytes, and in this way the Anthocerotales relate the 
Liverworts to Mosses. If one imagines the bands of sterile 
tissue which alternate with the bands of spore-forming tissue 
