76 TYPES OF BRITISH PLANTS 
surface of the ground, with small scale-like leaves upon 
the under side asa rule. The most picturesque of these 
is the Marchantia, which you will recognise at once by 
the curious branches that spring up from the main stem 
on the ground, and look like open umbrellas. Upon these 
are developed the sexual organs, and 
the “fruit-plant” is based upon 
them in the same way as the “ fruit- 
plant” of the moss. Another Liver- 
wort, or rather a group of them, 
gives an interesting case of joint 
house-keeping. At the base of the 
leaves there are small cups, in each 
of which may often be found a tiny 
animal called a Rotifer, which draws 
into the cup, and devours the minute 
animalculz that are contained in the 
moisture surrounding the plant. So 
far as is known, the plant gets no advantage from the 
partnership, but these little cups are not produced, as one 
might think, by the Rotifer, as galls are made by the 
gall-fly. They are to be found in just as fine a develop- 
ment when no Rotifer is present, but no use has been yet 
suggested for them, so far as the plant is concerned. 
Now we may take another step upward and reach the 
Ferns. 
LIVERWORT. 
