CHAP. Ill] CAYMANS AND PIRANHAS 83 



of them was Commander da Cunha (of the BrazUian 

 Navy), a capital sportsman and delightful companion. 

 They found a deepish pond a hundred yards or so long, 

 and thirty or forty across. It was tenanted by the 

 smaU caymans and by capybaras— the largest known 

 rodent, a huge aquatic guinea-pig, the size of a small 

 sheep. It also swarmed with piranhas, the ravenous 

 fish of which I have so often spoken. Undoubtedly 

 the caymans were subsisting largely on these piranhas. 

 But the tables were readily turned if any caymans were 

 injured. When a capybara was shot and sank in the 

 water, the piranhas at once attacked it, and had eaten 

 half the carcass ten minutes later. But much more 

 extraordinary was the fact that when a cayman about 

 five feet long was wounded, the piranhas attacked and 

 tore it, and actually drove it out on the bank to face its 

 human foes. The fish first attacked the wound ; then, 

 as the blood maddened them, they attacked all the soft 

 parts, their terrible teeth cutting out chunks of tough 

 hide and flesh. Evidently they did not molest either 

 cayman or capybara while it was unwounded, but blood 

 excited them to frenzy. Their habits are in some ways 

 inexplicable. We saw men frequently bathing un- 

 molested ; but there are places where this is never safe, 

 and in any place if a school of the fish appear swimmers 

 are in danger ; and a wounded man or beast is in deadly 

 peril if piranhas are in the neighbourhood. Ordinarily 

 it appears that an unwounded man is attacked only by 

 accident. Such accidents are rare, but they happen 

 with sufficient frequency to justify much caution in 

 entering water where piranhas abound. 



We frequently came across ponds tenanted by 

 numbers of capybaras. The huge, pig-like rodents are 

 said to be shy elsewhere. Here they were tame. The 



