THE RIO DA DUVIDA 175 



a very early start I could not write at all. At night 

 there were no mosquitoes. In the daytime gnats and 

 sand-flies and horse-flies sometimes bothered us a little, 

 but not much. Small, stingless bees lit on us in numbers 

 and crawled over the skin, making a slight tickling ; but 

 we did not mind them until they became very numerous. 

 There was a good deal of rain, but not enough to cause 

 any serious annoyance. 



Colonel Rondon and Lieutenant Lyra held many 

 discussions as to whither the Rio da Duvida flowed, and 

 where its mouth might be. Its provisional name — 

 " River of Doubt " — was given it precisely because of 

 this ignorance concerning it ; an ignorance which it was 

 one of the purposes of our trip to dispel. It might go 

 into the Gy-Parana, in which case its course must be 

 very short ; it might flow into the Madeira low down, 

 in which case its course would be very long ; or, which 

 was unlikely, it might flow into the Tapajos. There was 

 another river, the headwaters of which Colonel Rondon 

 had come across, whose course was equally doubtful, 

 although in its case there was rather more probability 

 of its flowing into the Juruena, by which name the 

 Tapajos is known for its upper half. To this unknown 

 river Colonel Rondon had given the name Ananas, 

 because when he came across it he found a deserted 

 Indian field with pineapples, which the hungry explorers 

 ate greedily. Among the things the Colonel and I 

 hoped to accomplish on the trip was to do a little work 

 in clearing up one or the other of these two doubtful 

 geographical points, and thereby to push a little forward 

 the knowledge of this region. Originally, as described 

 in the first chapter, my trip was undertaken primarily 

 in the interest of the American Museum of Natural 

 History of New York, to add to our knowledge of the 



