THE START 7 



sundered by a stretch of high land, which toward the east 

 broadens out into the central plateau of Brazil. Geologi- 

 cally this is a very ancient region, having appeared above 

 the waters before the dawning of the age of reptiles, or, 

 indeed, of any true land vertebrates on the globe. This 

 plateau is a region partly of healthy, rather dry and sandy, 

 open prairie, partly of forest. The great and low-lying 

 basin of the Paraguay, which borders it on the south, is 

 one of the largest, and the still greater basin of the Ama- 

 zon, which borders it on the north, is the very largest of 

 all the river basins of the earth. 



In these basins, but especially in the basin of the Am- 

 azon, and thence in most places northward to the Carib- 

 bean Sea, lie the most extensive stretches of tropical forest 

 to be found anywhere. The forests of tropical West Africa, 

 and of portions of the Farther-Indian region, are the only 

 ones that can be compared with them. Much difficulty 

 has been experienced in exploring these forests, because 

 under the torrential rains and steaming heat the rank 

 growth of vegetation becomes almost impenetrable, and 

 the streams difficult of navigation; while white men suffer 

 much from the terrible insect scourges and the deadly 

 diseases which modern science has discovered to be due 

 very largely to insect bites. The fauna and flora, however, 

 are of great interest. The American museum was particu- 

 larly anxious to obtain collections from the divide between 

 the headwaters of the Paraguay and the Amazon, and 

 from the southern affluents of the Amazon. Our purpose 

 was to ascend the Paraguay as nearly as possible to the 

 head of navigation, thence cross to the sources of one of 

 the affluents of the Amazon, and if possible descend it in 



