206 IN THE WILDS OF SOUTH AMERICA 



I threw dead or stunned individuals of their species into 

 the midst of the frenzied mob, but, strange to relate, they 

 floated on the surface of the water untouched. Unplucked 

 birds were not molested, either. A struggle in the water 

 seems to attract the fish, but I must admit that their be- 

 havior is very erratic. While washing my hands in the 

 edge of the stream one day a piranha snapped a piece out 

 of a finger; a few days later a man in passing over the river 

 on a bridge dropped his purse into the water in almost the 

 exact spot where I fished, and where the piranhas were 

 most abundant; he stripped, waded out very slowly and 

 cautiously so as not to create a disturbance, and felt about 

 with his toes for the lost article; although the water was 

 over four feet deep and he remained in it fully fifteen min- 

 utes, he remained untouched. 



It is in the dark swamps dotting the chaco like low, 

 glossy islands that the precious quebracho-trees grow. It 

 was also from these same swamps that clouds of ravenous 

 mosquitoes issued with the first signs of failing daylight, 

 and drove us to the refuge of our net-covered hammocks. 

 There we sweltered through the long hours of the night, 

 listening to the angry buzzing of our outwitted assailants, 

 which was not unlike the sound produced by a swarm of 

 enraged bees. I could distinguish a number of different 

 pitches and qualities in the music, blending harmoniously 

 in one general chorus. The varying size of the insects, 

 which ranged from individuals nearly an inch long to the 

 small infection-bearing Anopheles, doubtless accounts for 

 the different tones produced by the vibrations of the wings. 

 Brockets were seen occasionally; they left the forest morn- 

 ing and night to feed. In the tall pampas-grass cavies 

 abounded. They came out into the opening beside the 

 railroad just before sunrise and ran about, or sat motion- 

 less, when they resembled clods of earth or shadows. Oce- 

 lots had worn well-defined paths through the fields in 

 their nightly raids on the cavy community. In the trees 

 we found black howlers, night-monkeys, and giant weasels 



