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 mudbanks 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.