134 
RIO TERCERO 
CHAP. 
sidered 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 distant. 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 ist .—We started by moonlight and arrived at the 
TOXODON PLATENSIS. FOUND AT SALADILLO. 
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, I found two immense skeletons near each other, project¬ 
ing 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 inhabited the Cordillera in Upper Peru in 
such great numbers. The men who took me in the canoe said 
