LICHENOLOGY OF ICELAND 245 
slight competition to which the lichens are subjected. It must, 
however, be remembered that the cold mountain heights in Iceland 
appear to be less rich in lichens, than are the more low-lying parts, 
and are remarkably poor when the fact is considered that the com- 
petition on the part of other plants is only slight, or altogether 
wanting; so that one is led to the conclusion that the climate, as 
such, is not favourable. 
