THE VOYAGE OF THE BEAGLE 251 



and wet was every part, that not even the fungi, mosses, or 

 ferns could flourish. In the valleys it was scarcely possible 

 to crawl along, they were so completely barricaded by great 

 mouldering trunks, which had fallen down in every direction. 

 When passing over these natural bridges, one's course was 

 often arrested by sinking knee deep into the rotten wood ; at 

 other times, when attempting to lean against a firm tree, one 

 was startled by finding a mass of decayed matter ready to 

 fall at the slightest touch. We at last found ourselves among 

 the stunted trees, and then soon reached the bare ridge, which 

 conducted us to the summit. Here was a view characteristic 

 of Tierra del Fuego; irregular chains of hills, mottled with 

 patches of snow, deep yellowish-green valleys, and arms of 

 the sea intersecting the land in many directions. The strong 

 wind was piercingly cold, and the atmosphere rather hazy, so 

 that we did not stay long on the top of the mountain. Our 

 descent was not quite so laborious as our ascent; for the 

 weight of the body forced a passage, and all the slips and 

 falls were in the right direction. 



I have already mentioned the sombre and dull character of 

 the evergreen forests, 8 in which two or three species of trees 

 grow, to the exclusion of all others. Above the forest land, 

 there are many dwarf alpine plants, which all spring from the 

 mass of peat, and help to compose it: these plants are very 

 remarkable from their close alliance with the species growing 

 on the mountains of Europe, though so many thousand miles 

 distant. The central part of Tierra del Fuego, where the 

 clay-slate formation occurs, is most favourable to the growth 

 of trees ; on the outer coast the poorer granitic soil, and a 

 situation more exposed to the violent winds, do not allow of 

 their attaining any great size. Near Port Famine I have seen 

 more large trees than anywhere else : I measured a Winter's 

 Bark which was four feet six inches in girth, and several of 

 the beech were as much as thirteen feet. Captain King also 



Captain Fitz Roy informs me that in April (our October), the leaves 

 Of those trees which grow near the base of the mountains, change colour, 

 but not those on the more elevated parts. I remember having read some 

 observations, showing that in England the leaves fall earlier in a warm 

 and fine autumn than in a late and cold one. The change in the colour 

 being here retarded in the more elevated, and therefore colder situations, 

 must be owing to the same general law of vegetation. The trees of Tierra 

 del Fuego during no part of the year entirely shed their leaves. 



