226 THROUGH THE BRAZILIAN WILDERNESS 



It was not always easy to recognize what pasturage 

 the mules would accept as good. One afternoon we pitched 

 camp by a tiny rivulet, in the midst of the scrubby upland 

 forest; a camp, by the way, where the piums, the small, 

 biting flies, were a torment during the hours of daylight, 

 while after dark their places were more than taken by 

 the diminutive gnats which the Brazilians expressively 

 term "polvora," or powder, and which get through the 

 smallest meshes of a mosquito-net. The feed was so 

 scanty, and the cover so dense, at this spot that I thought 

 we would have great difficulty in gathering the mules next 

 morning. But we did not. A few hours later, in the 

 afternoon, we camped by a beautiful open meadow; on 

 one side ran a rapid brook, with a waterfall eight feet 

 high, under which we bathed and swam. Here the feed 

 looked so good that we all expressed pleasure. But the 

 mules did not like it, and after nightfall they hiked back on 

 the trail, and it was a long and arduous work to gather 

 them next morning. 



I have touched above on the insect pests. Men un- 

 used to the South American wilderness speak with awe 

 of the danger therein from jaguars, crocodiles, and poison- 

 ous snakes. In reality, the danger from these sources is 

 trivial, much less than the danger of being run down by 

 an automobile at home. But at times the torment of in- 

 sect plagues can hardly be exaggerated. There are many 

 different species of mosquitoes, some of them bearers of 

 disease. There are many different kinds of small, biting 

 flies and gnats, loosely grouped together under various 

 titles. The ones more especially called piums by my com- 

 panions were somewhat like our northern black flies. They 



