252 CHARLES DARWIN 



mentions a beech which was seven feet in diameter, seven- 

 teen 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 

 honey-combed, as represented in the 

 accompanying wood-cut. This fun- 

 gus belongs to a new and curious 

 genus;* I found a second species on 

 another species of beech in Chile: 

 and Dr. Hooker informs me, that 

 just lately a third species has been 

 discovered on a third species of 



beech in Van Dieman's Land. How singular is this relation- 

 ship between parasitical fungi and the trees on which they 

 grow, in distant parts of the world ! In Tierra del Fuego 

 the fungus in its tough and mature state is collected in large 

 quantities by the women and children, and is eaten un- 

 cooked. It has a mucilaginous, slightly sweet taste, with a 

 faint smell like that of a mushroom. With the exception 

 of a few berries, chiefly of a dwarf arbutus, the natives eat 

 no vegetable food besides this fungus. In New Zealand, 

 before the introduction of the potato, the roots of the fern 

 were largely consumed; at the present time, I believe, Tierra 

 del Fuego is the only country in the world where a cryp- 

 togamic plant affords a staple article of food. 



The zoology of Tierra del Fuego, as might have been 

 expected from the nature of its climate and vegetation, is 

 very poor. Of mammalia, besides whales and seals, there is 

 one bat, a kind of mouse (Reithrodon chinchilloides), two 

 true mice, a ctenomys allied to or identical with the tucutuco, 

 two foxes (Canis Magellanicus and C. Azarae), a sea-otter, 

 the guanaco, and a deer. Most of these animals inhabit only 



* Described from my specimens and notes by the Rev. J. M. Berkeley, 

 in the Linnean Transactions (vol. xix. p. 37), under the name of Cyttana 

 Darwinii; the Chilian species is the C. Berteroii. This genus is allied to 

 Bulgaria. 



