LIVERWORTS 173 
of small, often crowded leaves (Fig. 168, B\ There are 
really three rows of leaves, but the third is against the 
substratum and is usually so much changed in appearance 
as not to resemble the other rows. 
There is, of course, the same alternation of generations as 
in the A/archantia forms, but the sporophyte is more than 
a spore-case. It develops a distinct stalk or stem that 
bears a spore-case at its summit, and therefore the sporo- 
phyte has become more complex. Besides, the spore-case 
does not burst open somewhat irregularly, as in the Mar- 
chantia forms, but splits into four pieces that spread apart 
and expose the spores. 
99. Anthoceros forms.—This group contains compara- 
tively few forms; but they are of great interest, since many 
suppose that they are the liverworts that approach most 
nearly the higher plants. The 
thallus body is very simple, not 
becoming so thick as are the 
Marchantia bodies, nor becoming 
leafy bodies as are those of the 
leafy liverworts. 
The important feature of the 
group is the sporophyte. At the 
“fruiting” period the thallus be- 
comes more or less covered by 
structures that look like small, 
erect grass-blades (Fig. 169). 
Each of these blade-like bodies 
is a sporophyte that has devel- 
oped from an odspore lying 
within an archegonium. The sporophyte has a large 
bulbous base embedded in the simple thallus, and above 
this base there arises a long pod-like spore-case. The 
cells forming the wall of tkis spore-case contain chloro- 
plasts, so that the sporophyte is able to make food for itself, 
Fic. 169. — Anthoce- 
ros: A, thallus with 
spore - cases (spor- 
ophytes); B, a sin- 
gle spore-case, hav- 
ing split for the dis- 
charge of spores. 
