succeed to perfection; and even in this continent, at the Rio Negro,
under nearly the same parallel with Valdivia, sweet potatoes
(convolvulus) are cultivated; and grapes, figs, olives, oranges, water
and musk melons, produce abundant fruit. Although the humid and
equable climate of Chiloe, and of the coast northward and southward of
it, is so unfavourable to our fruits, yet the native forests, from lat.
45 to 38 degs., almost rival in luxuriance those of the glowing
intertropical regions. Stately trees of many kinds, with smooth and
highly coloured barks, are loaded by parasitical monocotyledonous
plants; large and elegant ferns are numerous, and arborescent grasses
entwine the trees into one entangled mass to the height of thirty or
forty feet above the ground. Palm-trees grow in lat 37 degs.; an
arborescent grass, very like a bamboo, in 40 degs.; and another closely
allied kind, of great length, but not erect, flourishes even as far
south as 45 degs. S.
An equable climate, evidently due to the large area of sea compared
with the land, seems to extend over the greater part of the southern
hemisphere; and, as a consequence, the vegetation partakes of a
semi-tropical character. Tree-ferns thrive luxuriantly in Van Diemen's
Land (lat. 45 degs.), and I measured one trunk no less than six feet in
circumference. An arborescent fern was found by Forster in New Zealand
in 46 degs., where orchideous plants are parasitical on the trees. In
the Auckland Islands, ferns, according to Dr. Dieffenbach [10] have
trunks so thick and high that they may be almost called tree-ferns; and
in these islands, and even as far south as lat. 55 degs. in the
Macquarrie Islands, parrots abound.
On the Height of the Snow-line, and on the Descent of the Glaciers in
South America.--For the detailed authorities for the following table, I
must refer to the former edition:--
Height in feet
Latitude of Snow-line Observer
----------------------------------------------------------------
Equatorial region; mean result 15,748 Humboldt. Bolivia,
lat. 16 to 18 degs. S. 17,000 Pentland. Central Chile,
lat. 33 degs. S. 14,500 - 15,000 Gillies, and
the Author.
Chiloe, lat. 41 to 43 degs. S. 6,000 Officers of the
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