MARCHANTIA 
331 
brown or gray on the under 
side. In the middle of the 
thallus is a midrib. On the 
upper surface are diamond¬ 
shaped markings, each of which 
has an opening which leads to 
an air chamber below. On the 
under side are rhizoids, which 
attach the plant loosely to the 
soil. 
The liverworts, which are 
well represented by marchantia, 
are adapting themselves to a 
life on land, but they are still 
dependent upon water. Their reproductive habits are like 
those of the mosses (Figures 300 and 301), but the sporophyte 
generation is less conspicuous. 
LABORATORY STUDY 
OF MARCHANTIA 
Examine pieces of the plant 
and identify the thallus, mid¬ 
rib, rhizoids and markings. 
Examine the umbrella¬ 
shaped, upright branches 
which bear the antheridia or 
male reproductive organs, the 
branches with slender projec¬ 
tions which bear the arche- 
gonia or female reproductive 
organs. With a microscope 
examine a cross section of the 
thallus, and observe the open¬ 
ings and air chambers. 
SUMMARY 
Mosses are much more 
complex than algae and 
Figure 302.—A Common Liver¬ 
wort. 
Plant with antheridial branches. 
