animals have become extinct, so may we suppose that the species of
plants have likewise been changed.
These remarks, I may be permitted to add, directly bear on the case of
the Siberian animals preserved in ice. The firm conviction of the
necessity of a vegetation possessing a character of tropical
luxuriance, to support such large animals, and the impossibility of
reconciling this with the proximity of perpetual congelation, was one
chief cause of the several theories of sudden revolutions of climate,
and of overwhelming catastrophes, which were invented to account for
their entombment. I am far from supposing that the climate has not
changed since the period when those animals lived, which now lie buried
in the ice. At present I only wish to show, that as far as _quantity_
of food _alone_ is concerned, the ancient rhinoceroses might have
roamed over the _steppes_ of central Siberia (the northern parts
probably being under water) even in their present condition, as well as
the living rhinoceroses and elephants over the _Karros_ of Southern
Africa.
I will now give an account of the habits of some of the more
interesting birds which are common on the wild plains of Northern
Patagonia: and first for the largest, or South American ostrich. The
ordinary habits of the ostrich are familiar to every one. They live on
vegetable matter, such as roots and grass; but at Bahia Blanca I have
repeatedly seen three or four come down at low water to the extensive
mud-banks which are then dry, for the sake, as the Gauchos say, of
feeding on small fish. Although the ostrich in its habits is so shy,
wary, and solitary, and although so fleet in its pace, it is caught
without much difficulty by the Indian or Gaucho armed with the bolas.
When several horsemen appear in a semicircle, it becomes confounded,
and does not know which way to escape. They generally prefer running
against the wind; yet at the first start they expand their wings, and
like a vessel make all sail. On one fine hot day I saw several
ostriches enter a bed of tall rushes, where they squatted concealed,
till quite closely approached. It is not generally known that ostriches
readily take to the water. Mr. King informs me that at the Bay of San
Blas, and at Port Valdes in Patagonia, he saw these birds swimming
several times from island to island. They ran into the water both when
driven down to a point, and likewise of their own accord when not
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