380 A TEXTBOOK OF GENERAL BOTANY 
While the thalli of the Anthocerotales are simple, the sporo- 
phytes are the most complex found in the Hepaticae. They 
resemble the sporophytes of the Muse, and 
also those of the Pteridophyta and Spermato- 
phyta, in having stomata and assimilating tissue 
with chlorophyll. Owing to the presence of 

Fig. 419. A single 
archegonium of a 
moss. (150) 
chlorophyll the  sporo- 
phyte is only partially 
dependent on the game- 
tophyte. If the foot. of 
the sporophyte of Antho- 
ceros were developed into 
a root, the sporophyte 
would be an independent 
plant. 
CLASS MUSCI 
Life history. The mosses 
are a large group of small 
plants which, like the 
liverworts, are charac- 
terized by an alternation 
of a gametophyte and a 
sporophyte. 
The gametophyte is a 
leafy plant(Fig. 418). In 
most cases the stem con- 
tains conducting tissue 
and the leaf a midrib. 
The gametophytes bear 
archegonia (Fig. 419) 
and antheridia (Fig. 420), which may be 
on the same or on different plants. They 
occur in groups at the tips of the stems (Figs. 418, 421). 
The fertilized egg develops and produces a sporophyte 
(Fig. 422), which usually, like those of most liverworts, consists 

Fig. 420. A single an- 
theridium of a moss. 
(x 155) 
