144 FIRST FORMS OF VEGETATION. 
duced on the north side of trees, that the Ameri- 
can backwoods-man, and the Norwegian wood- 
cutter, whose faculties of observation have been 
keenly educated by nature herself, often employ 
them as a rude but safe compass to guide them 
through the intricacies and tangled labyrinths of 
the primeval forests. 
Such are some of the most obvious purposes 
which these humble plants serve in the economy 
of nature; let us now direct our attention to a 
few of the uses to which man has applied them. 
This is the only point of importance connected 
with them in the estimation of many, especially 
of those who gauge the works of the Almighty by 
a dry utilitarian law, and see no beauty or in- 
terest in any object, except in so far as they can 
find some real or manifest utility in its existence. 
Judged by this standard, and weighed in the bal- 
ance with pounds, shillings, and pence, the lichens 
will not be found wanting. On account of the 
large quantity of starchy matter which they con- 
tain, they often considerably contribute to, and 
sometimes even entirely form, the diet of man 
and animals in those dreary inhospitable regions 
where the wintry rigour, or the scorching heat of 
the climate, forbid all other kinds of vegetation to 
grow. Every one is familiar with the fact that 
the reindeer-moss (Cladonia rangiferina, Fig. 10) 
