XI 
ZOOLOGY 
251 
CYTTARIA DARWINII. 
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 Diemen’s Land. How 
singular is this relationship 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 uncooked. 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 
cryptogamic plant affords a staple article of food. 
The zoology of Tierra del Fuego, as might have been ex¬ 
pected 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 the drier 
eastern parts of the country ; and the deer has never been seen 
south of the Strait of Magellan. Observing the general corre¬ 
spondence of the cliffs of soft sandstone, mud, and shingle, 
on the opposite sides of the Strait, and on some intervening 
islands, one is strongly tempted to believe that the land was 
once joined, and thus allowed animals so delicate and helpless 
as the tucutuco and Reithrodon to pass over. The correspond¬ 
ence of the cliffs is far from proving any junction ; because 
such cliffs generally are formed by the intersection of sloping 
deposits, which, before the elevation of the land, had been 
accumulated near the then existing shores. It is, however, a 
remarkable coincidence, that in the two large islands cut off 
by the Beagle Channel from the rest of Tierra del Fuego, one 
has cliffs composed of matter that may be called stratified 
alluvium, which front similar ones on the opposite side of the 
