240 THE KIVER OF DOUBT [chap, viii 



leaf. The head, coloured like the leaf, projected in 

 front. 



We were still in the Brazilian highlands. The forest 

 did not teem with life. It was generally rather silent ; 

 we did not hear such a chorus of birds and mammals as 

 we had occasionally heard even on our overland journey, 

 when more than once we had been awakened at dawn 

 by the howling, screaming, yelping, and chattering of 

 monkeys, toucans, macaws, parrots, and parakeets. 

 There were, however, from time to time, queer sounds 

 from the forest, and after nightfall different kinds of 

 frogs and insects uttered strange cries and calls. In 

 volume and frequency these seemed to increase until 

 midnight. Then they died away and before dawn every- 

 thing was silent. 



At this camp the carregadores ants completely 

 devoured the doctor's undershirt, and ate holes in 

 his mosquito-net ; and they also ate the strap of Lyra's 

 gun-case. The little stingless bees, of many kinds, 

 swarmed in such multitudes, and were so persevering, 

 that we had to wear our head-nets when we wrote or 

 skinned specimens. 



The following day was almost without rain. It was 

 delightful to drift and paddle slowly down the beautiful 

 tropical river. Until mid-afternoon the current was not 

 very fast, and the broad, deep, placid stream bent and 

 curved in every direction, although the general course 

 was north-west. The country was flat, and more of the 

 land was under than above water. Continually we found 

 ourselves travelling between stretches of marshy forest 

 where for miles the water stood or ran among the trees. 

 Once we passed a hillock. We saw brilliantly coloured 

 parakeets and trogons. At last the slow current 

 quickened. Faster it went, and faster, until it began 



