LICHENS. 13 



arbutus and candleberry myrtles, beneath which the earth 

 is profusely carpeted with a beautiful heath, known to the 

 natives by the name of Texo, and forming a striking con- 

 trast to the vast forests of dark and sombre pines, which 

 surround them as a girdle. 



Grasses and lichens constitute the fourth and fifth zones, 

 among which heaps of pumice-stone and masses of lava, 

 hurled from the summit of the mountain, are seen in all 

 directions. Tufts of flowering broom, however, present 

 occasional patches of verdure ; and two herbaceous plants, 

 the figwort and a gigantic kind of violet, advance even to 

 the Malpays. To these succeed a turf scorched by the 

 beams of an African sun, where the humble Cladonia 

 paschalis overspreads a burning soil, and athwart which, 

 wreaths of smoke and flame often hurry in their headlong 

 course, when the herdsman has unwarily set fire to some 

 patch of arid vegetation. Higher up, innumerable lichens 

 labour unceasingly at the decomposition of scorified matter ; 

 and thus, by a continual combination of organic forces, by 



