293 AMAZONIA AND LA PLATA. 



observations made in the years 1887-88, on the hitherto unpublished documents 

 of the Boundary Commission of 1871-73, and on the maps prepared by Mouchez 

 and Toeppen. An excellent reprint of this map accompanies Mr. E. G. Raven- 

 stein's English edition of Bourgade's work on Paraguay.* 



Physical Features. 



Paraguay, forming geographically a southern extension of Matto Grosso, is 

 traversed by a chain of heights which continue southwards to the watershed of 

 the Parexi plateau. About the sources of the Apa, this divide between the Para- 

 guay and Parana affluents is commonly known as the Sierra Amambay. One of 

 its ridges, which, by arresting the Parana waters, gives rise to the Guayra Falls, 

 takes the name of the Sierra Mbaracayu (Maracaju), These crests, forming the 

 political frontier towards Brazil, are nowhere high enough to prevent hunters and 

 yerhati'vo^i (yerba maté gatherers) from passing from one slojDe to the other. They 

 were crossed by Sandalio Sosa and by Bourgade to the east of the sources of the 

 Jujuy, and although not yet measured, the summits of the Amambay and Maracaju 

 ridges would appear to fall below 3,500 feet. The expression CordUlem de /os 

 Montes, that is, " Forest Range," locally applied to them, shows that the chief 

 obstacle to the exploration of the country is due not so much to these ridges them- 

 selves as to the dense tangle of vegetation covering their slopes. 



South of the Maracaju bifurcation the divide is continued in the interior, not 

 by a regular chain, but bj' a succession of heights and rising-grounds, hyperboli- 

 cally called " sierras " and " Cordilleras." Here and there the horizon is limited 

 or indicated by a few lomas ("hills"), or rern'tos, isolated eminences, and a last 

 ridge striking across the bed of the Parana forms the Apipe rapids below Villa 

 Encarnacion. But the whole region between the parallel of the Guayra Falls on 

 the Parana and San Pedro on the Paraguay (24° S. latitude) continues to incline 

 gentl}'- in the direction of the south. Towards the south-west corner near the 

 confluence of the two mainstre:im3 the elevated plateau falls abruptly in cliffs 

 and bluffs limited by the shores of an ancient sea, which is now represented by 

 lagoons, morasses, and grassy tracts scarcely rising above the fluvial level. 



Sandstones prevail in most of the hilly ranges, while the plains are formed of 

 argillaceous beds and sandy stones belonging to the tertiary epoch. In some 

 districts are seen volcanic cones, such as the Cerro Tacumbu just below Asuncion, 

 and farther east the Sierra d'Acay (2,000 feet) near the sources of the Mbuarapey 

 affluent of the Tibicuarv. Earthquakes are often felt, and numerous mineral 

 springs rise in the neighbourhood. 



Vast spaces are covered with a red earth, which in some places is several 

 yards thick, and which is deeply ravined near the running waters. Some of the 

 fertile tracts about Asuncion belong to this formation, wliich contains numerous 

 well-preserved shells constantly washed up by the rains. As in S. Paulo, this red 



* Farafitiau, the Land and People, &,i'., by Dr. E. de BouTgade La Danlye, English Editiou, edited by 

 E. G. Ravenstein. 1892. 



