LICHENS. 179 
been subjected to the various baths of the pro- 
fessed dyer. 
The most useful and best known of our native 
dye-lichens is the rock-moss or cudbear, Fig. 16 
(Lecanora tartarea), so called after-a Mr. Cuthbert 
who first brought it into use. It grows in the form 
of a tartareous granular crust, of a dirty-grey col- 
our, spreading in indefinite patches over the sur- 
faces of mountain rocks, and often enveloping the 
stems and leaves of mosses and other small plants. 
It varies in thickness from a scarce perceptible 
film to a solid mass an inch in diameter, is covered 
with large irregular shields of a pale flesh colour, 
and may be easily identified, even without the aid 
of its characteristic fructification, by a peculiar 
pungent alkaline smell, which is very disagreeable, 
especially when the plant is moistened. In Thors- 
havn, in the Faroe Islands, it is so plentiful from 
the sea-level up to the tops of the hills, that at a 
distance it makes the stones appear as if covered 
with lime. In the Highland districts, many an 
industrious peasant used to earn a comfortable 
living, by collecting this lichen with an iron hoop 
from the moorland rocks, and sending it to the 
Glasgow market. The value of this lichen in 
Scotland is said at one time to have averaged £10 
per ton. Hooker states that at Fort-Augustus, in 
1807, a person could gain 14s, per week by gather- 
