ISLANDS IN THE PARANA. 171 



lias seen the carcasses of upwards of a thousand 

 wild horses thus destroyed. I noticed that the 

 smaller streams in the Pampas were paved with a 

 breccia of bones, but this probably is the effect of 

 a gi'adual increase rather than of the destruction 

 at any one period. Subsequently to the drought 

 of 1827 to '32, a very rainy season followed, which 

 caused great floods. Hence it is almost certain 

 that some thousands of the skeletons were buried 

 by the deposits of die very next year. What 

 would be the opinion of a geologist, viewing such 

 an enormous collection of bones, of all kinds of ani- 

 mals and of all ages, thus embedded in one thick 

 earthy mass ] Would he not attribute it to a flood 

 having swept over the surface of the land, rather 

 than to the common order of things 1* 



October \2th. — I had intended to push my ex- 

 cursion further, but not being quite well, I was 

 compelled to return by a balandra, or one-masted 

 vessel of about a hundred tons' burden, which 

 was bound to Buenos Ayres. As the weather was 

 not fair, we luoored early in the day to a branch 

 of a tree on one of the islands. The Parana is full 

 of islands, which undergo a constant round of de- 

 cay and renovation. In the memory of the master 

 several large ones had disappeared, and others 

 again had been formed and protected by vegeta- 

 tion. They are composed of muddy sand, without 

 even the smallest pebble, and were then about four 

 feet above the level of the river ; but during the 

 periodical floods they are inundated. They all 

 present one character : numerous willows and a 

 few other trees are bound together by a gi-eat 



* These droughts, to a certain degree, seem to be almost peri- 

 odical ; I was told the dates of several others, and the intervals 

 were about fifteen years. 



