250 
TIERRA DEL FUEGO 
CHAP. 
of snow, deep yellowish-green valleys, and arms of the sea inter¬ 
secting 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, 1 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 mentions a beech 
which was seven feet in diameter seventeen feet above the roots. 
There is one vegetable production deserving notice from 
its importance as an article of food to the Fuegians. It is a 
globular, bright yellow fungus, which grows in vast numbers 
on the beech-trees. When young it is elastic and turgid, with 
a smooth surface ; but when mature, it shrinks, becomes tougher, 
and has its entire surface deeply pitted or honeycombed, as 
represented in the accompanying woodcut. This fungus 
belongs to a new and curious genus; 2 I found a second 
1 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. 
2 Described from my specimens and notes by the Rev. J. M. Berkeley, in the 
Linnean Transactions (vol. xix. p. 37), under the name of Cyttaria Darwinii : the 
Chilian species is the C. Berteroii. This genus is allied to Bulgaria. 
