146 CHARLES DARWIN 



mained. San Pedro is situated in the middle of the finest 

 country; and even now abounds again with animals; yet, 

 during the latter part of the " gran seco," live cattle were 

 brought in vessels for the consumption of the inhabitants. 

 The animals roamed from their estancias, and, wandering 

 far southward, were mingled together in such multitudes, 

 that a government commission was sent from Buenos Ayres 

 to settle the disputes of the owners. Sir Woodbine Parish 

 informed me of another and very curious source of dispute ; 

 the ground being so long dry, such quantities of dust were 

 blown about, that in this open country the landmarks be- 

 came obliterated, and people could not tell the limits of their 

 estates. 



I was informed by an eye-witness that the cattle in herds 

 of thousands rushed into the Parana, and being exhausted 

 by hunger they were unable to crawl up the muddy banks, 

 and thus were drowned. The arm of the river which runs 

 by San Pedro was so full of putrid carcasses, that the master 

 of a vessel told me that the smell rendered it quite impass- 

 able. Without doubt several hundred thousand animals 

 thus perished in the river: their bodies when putrid were 

 seen floating down the stream; and many in all probability 

 were deposited in the estuary of the Plata. All the small 

 rivers became highly saline, and this caused the death of 

 vast numbers in particular spots ; for when an animal drinks 

 of such water it does not recover. Azara describes* the 

 fury of the wild horses on a similar occasion, rushing into 

 the marshes, those which arrived first being overwhelmed 

 and crushed by those which followed. He adds that more 

 than once he has seen the carcasses of upwards of a thou- 

 sand 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 gradual increase, rather 

 than of the destruction at any one period. Subsequently 

 to the drought of 1827 to 1832, 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 the very next year. What would be the opinion of a 

 geologist, viewing such an enormous collection of bones, of 



9 Travels, vol. i. p. 374. 



