e usual 



84 IN THE COLORADO VALLEY, [chap. 



several hours. The idea is evidently taken from the 

 method of drying hides. My interview passed away without 

 a smile, and I obtained a passport and order for the govern- 

 ment post-horses, and this he gave me in the most obliging 

 and ready manner. 



In the morning we started for Bahia Blanca, which we 

 reached in two days. Leaving the regular encampment, we 

 passed by the toldos of the Indians. These are round like 

 ovens, and covered with hides ; by the mouth of each, a 

 tapering chuzo was stuck in the ground. The toldos were 

 divided into separate groups, which belonged to the different 

 caciques' tribes, and the groups were again divided into 

 smaller ones, according to the relationship of the owners. 

 For several miles we travelled along the valley of the 

 Colorado. The alluvial plains on the side appeared fertile, 

 and it is supposed that they are well adapted to the growth 

 of corn. Turning northward from the river, we soon 

 entered on a country differing from the plains south of the 

 river. The land still continued dry and sterile ; but it 

 supported many different kinds of plants, and the grass, 

 though brown and withered, was more abundant, as the 

 thorny bushes were less so. These latter in a short space 

 entirely disappeared, and the plains were left without a 

 thicket to cover their nakedness. This change in the 

 vegetation marks the commencement of the grand calcareo- 

 argillaceous deposit, which forms the wide extent of the 

 Pampas, and covers the granitic rocks of Banda Oriental. 

 From the Strait of Magellan to the Colorado, a distance 

 of about eight hundred miles, the face of the country is 

 everywhere composed of shingle : the pebbles are chiefly of 

 porphyry, and probably owe their origin to the rocks of 

 the Cordillera. North of the Colorado this bed thins out, 

 and the pebbles become exceedingly small, and here the 

 characteristic vegetation of Patagonia ceases. 



Having ridden about twenty-five miles, we came to a 

 broad belt of sand-dunes, which stretches, as far as the 

 eye can reach, to the east and west. The sand-hillocks 

 resting on the clay allow small pools of water to collect, 

 and thus afford in this dry country an invaluable supply 

 of fresh water. The great advantage arising from depres- 

 sions and elevations of the soil is not often brought home 

 to the mind. The two miserable springs in the long passage 

 between the Rio Negro and Colorado were caused, by 

 trifling inequalities in the plain ; without them not a drop 



