LICHENS. 127 
of comminuted schist on the summits of the 
highest Highland mountains, forming patches of 
the most beautiful and vivid green, varied, when 
the under-side of the lobes is curled up, by 
reticulations of a very rich orange-saffron colour. 
This species is not found at a lower elevation 
than 4000 feet ; hence it is unknown in England, 
Ireland, and Wales, whose highest mountains fall 
considerably short of this altitude. I have 
gathered it on Cairngorm, Ben Macdhui, and Ben 
Lawers. In this last locality, which is well 
known to botanists as exhibiting a perfect garden 
of rare and beautiful Alpine plants, it grows in 
greater abundance, I believe, than in any other 
spot in the Highlands. It occupies the whole 
ridge of rugged and splintered rocks, marked by 
the tear and wear of elemental wars during 
countless ages, which runs along the summit of 
the hill. The surface of these rocks is covered 
with masses of sharp abraded stones, interspersed 
with meagre tufts of grass and moss; and among 
these the saffron Solorina luxuriates in large 
patches. With what delight have I seen this 
beautiful lichen, beaming out on me from its 
dreary and desolate home, in the blustering days 
of early April, when the snow was falling thick 
around, and the howling wind sweeping by with 
unobstructed keenness! With fingers almost 
