66 TYPES OF BRITISH PLANTS 
tioned of spreading its race, that of vegetative reproduc- 
tion. Part of the thin fungal threads, or hyphe, roll 
themselves up into a ball of felt, as it were, with a few 
algal cells twined among: the filaments. These appear 
first below the surface, but shortly push their way up 
above and’ come out on the top as buds. Their casing 
splits, and the swarm is carried away, on just the same 
principle as a swarm of bees from a hive. 
Lichens are classified according to the families of the 
funguses which control them, and they are again sub- 
divided according to the fashion of their growth. The 
three divisions are the encrusting Lichens (Crustaceous), 
the leaf-like Lichens (Folose), and the branching Lichens 
(Fruticose). 
The first are the commonest of all, and we see them 
clinging in patches and circles to rocks and walls and 
smooth trees, so closely that they cannot be torn away 
without injury, and slowly eating a way into the hard rock 
by their acid sap, and etching the outline of their shape. 
Each plant is insignificant enough, but by their number 
they often give a touch of colour which adds wonderful 
beauty to wild rock scenery, such as you may see even in 
England in the Lake District, in the Wastwater and 
Scafell region. 
The leafy lichens, though still adhering to their homes, 
and spreading over them in ribbon-like strips, can be 
detached easily enough. Amongst them are the bright 
yellow lichens that you may see on rough bark, and the 
leafy green lichen that is to be found among mosses in 
_ damp parts of a wood. 
But the most beautiful lichens by far are the branching 
group. The fantastic shapes give a grace to decaying 
wood and to the damp banks, which otherwise have too 
