126 THROUGH GLADE AND MEAD. 
While the conspicuous flowers have not yet made 
their appearance, the less known and more humble 
mosses may claim attention. These are to be found 
almost everywhere, on the stones by the roadside, as 
soft cushions in the shade of the forest, clothing the 
base of trees in the lowlands, and forming the greater 
part of the peat swamps. Their structure is so minute 
that it cannot be studied without a microscope, and 
yields in fascination to no branch of botanical study. 
The lichens, too, are now abundant. They differ 
from the mosses in that their nutrition is derived from 
the atmosphere. It is found that they will not grow in 
a flourishing condition in the immediate neighborhood 
of large cities where the air is filled with smoke or dele- 
terious gases; so that their presence in a fully developed 
condition is an indication of the purity of the atmos- 
phere. Lichens, unlike mosses, have been applied to 
many uses, but their use is naturally diminishing as 
civilization and, especially, the science of chemistry 
have advanced. They are of slow and, frequently, of 
very long growth. They are of various colors, green, 
white, yellow, brown and black being very common. 
Some hang from the stems and limbs of trees in thread- 
like forms, and produce the shaggy and venerable ap- 
pearance characteristic of the aged tree in the forest. 
Some cling so closely to the surface of the rocks that 
the severest storms cannot detach them. They spend 
