FARABEE— THE SOUTH AMERICAN INDIAN. 283 



long and varied experience had made him wise. Yet he was con- 

 tinually on the march. Crowded into the neck of the Isthmus of 

 Panama he pushed on through and found another continent which, 

 like the one he was leaving, lent itself to a north-south migration 

 with the routes well marked. The Orinoco, the great branches of 

 the Amazon and the La Plata together with the Andes and the coast 

 all offered direct lines of travel, but they all led to hard conditions. 

 The mountains were too high, the forests too dense, the south too 

 cold and the tropics too hot to make a strong appeal. But there 

 was no possibility of retreat until the farthest corner had been 

 reached and turned. By the time of the Discovery he had overrun 

 the whole continent and a return migration was in progress across 

 the isthmus and through the ^^'est Indies. 



When the first migration entered the continent the people wxre 

 deflected by the mountains to the two coasts. Those who continued 

 down the west coast, forced to compete with the rank jungle growth 

 for supremacy in a humid debilitating climate, were unable to estab- 

 lish themselves and develop a high culture. So they moved on to 

 the interior plateaus where they found more congenial conditions 

 and where they left evidence of an advanced culture. 



Those who made their way to the coast south of the equator 

 must have been surprised to step out of the jungle into an immense 

 desert country, the most arid in the world, stretching away for 

 nearly 2,000 miles as a narrow fringe along the sea. Here they 

 found fertile valleys, watered by the innumerable small rivers and 

 streams which, fed by the melting of the perpetual snows of the 

 mountain tops, made their way to the sea or lost themselves in the 

 desert. These valleys separated by trackless sands offered both 

 food and security. The sea made no call. There were few pro- 

 tected harbors along the great stretch of coast ; no outlying islands 

 to be inhabited and no timber for canoes. They became an agri- 

 cultural people living in villages and using the rivers for irrigating 

 purposes. Irrigation guaranteed regular crops and hence a constant 

 food supply. It also developed inventiveness and cooperation.. 

 Their common dependence upon the same water supply developed 

 social organization and a strong government. As these different 

 valleys had the same products there was very little commerce 



