1833.] RIO TERCERO. 127 



broken masses, covered with cacti and mimosa-trees.. The real 

 grandeur, however, of an immense river like this, is derived 

 from reflecting how important a means of communication and 

 commerce it forms between one nation and another ; to what a 

 distance it travels ; and from how vast a territory it drains the 

 great body of fresh water which flows past your feet. 



For many leagues north and south of San Nicolas and Roza- 

 rio, the country is really level. Scarcely anything which travel- 

 lers have written about its extreme flatness, can be considered as 

 exaggeration. Yet I could never find a spot where, by slowly 

 turning round, objects were not seen at greater distances in some 

 directions than in others ; and this manifestly proves inequality 

 in the plain. At sea, a person's eye being six feet above the 

 surface of the water, his horizon is two miles and four-fifths dis- 

 tant. In like manner, the more level the plain, the more nearly 

 does the horizon approach within these narrow limits ; and this, 

 in my opinion, entirely destroys that grandeur which one would 

 have imagined that a vast level plain would have possessed. 



October 1st. We started by moonlight and arrived at the 

 Rio Tercero by sunrise. This river is also called the Saladillo, 

 and it deserves the name, for the water is brackish. I stayed 

 here the greater part of the day, searching for fossil bones. 

 Besides a perfect tooth of the Toxodon, and many scattered 

 bones, 1 found two immense skeletons near each other, projecting 

 in bold relief from the perpendicular cliff of the Parana. They 

 were, however, so completely decayed, that I could only bring 

 away small fragments of one of the great molar teeth ; but these 

 are sufficient to show that the remains belonged to a Mastodon, 

 probably to the same species with that, which formerly must have 

 .nhabited the Cordillera in Upper Peru in such great numbers. 

 The men who took me in the canoe, said they had long known 

 of these skeletons, and had often wondered how they had got 

 there : the necessity of a theory being felt, they came to the 

 conclusion that, like the bizcacha, the mastodon was formerly a 

 burrowing animal ! In the evening we rode another stage, and 

 crossed the Monge, another brackish stream, bearing the dregs 

 of the washings of the Pampas. 



October 2nd. We passed through Corunda, which, from the 

 luxuriance of its gardens, was one of the prettiest villages I saw, 



