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THE NATIONAL GEOGRAPHIC MAGAZINE 



growth of bunch grass, were once culti- 

 vated (see illustration, page 511). 



In one place just below Urcos a nar- 

 row strip between broken precipitous 

 rocks is covered with short transverse 

 ridges like a stairway. 



The areas that have been farmed in 

 this way are very extensive, much more 

 so than the lands that are still cultivated 

 in the valleys below. A few of these 

 high slopes are still cultivated, but most 

 of them have been abandoned. Where 

 the lands are now used by the Indians, 

 the same system of transverse ridges is 

 employed. The larger ridges at intervals 

 have the effect of preventing, or at least 

 impeding, erosion. These ridges are not 

 cultivated, but are left in grass, and thus 

 serve to let the water run down the slopes 

 without allowing it to cut channels, 

 thereby having the function of spillways 

 or "drops" in irrigation systems. 



EVEN THE GLACIERS RETREATED BEFORE 

 THEIR INDUSTRY 



Riding for many hours, or even for 

 days, through valleys where all of the 

 upper slopes show signs of having been 

 cultivated in former times, and very few 

 are cultivated now. eventually gives one 

 an almost oppressive feeling of the past 

 that has vanished long since, and yet is 

 so ever-present that the eye can scarcely 

 avoid it, even when one looks up to the 

 glaciers and the eternal snows. The peo- 

 ple who grew potatoes on the high slopes 

 must have stood in their day against the 

 same icy background. Indeed, their agri- 

 cultural activities may have driven the 

 very glaciers back, by gradually clearing 

 the mountain slopes and exposing them 

 to the sun, just as the}" narrowed and 

 straightened the river torrents by hem- 

 ming them in with successive walls of 

 rock. 



That the glaciers formerly extended 

 much farther down is shown by the posi- 

 tions of the moraines. There can be little 

 doubt that the whole aspect of the coun- 

 try has been altered profoundlv during 

 the very long period of intensive agricul- 

 tural occupation. Biologically speaking, 

 there is every reason to believe that most 

 of tlie cultivated lands had a forest cov- 

 ering originally, and thai the present state 



of denudation is largely artificial. Rem- 

 nants of a native forest flora are still to 

 be found in places too rocky and broken 

 to be cultivated, even by the strenuous 

 methods of the ancients.* 



A RECLAMATION AGRICULTURE 



From the facts already stated, it is ap- 

 parent that the ancient agriculture of the 

 interior valleys of Peru was to a very 

 large extent a reclamation agriculture — 

 that is, an agriculture involving com- 

 munity organization and planning in ad- 

 vance. Only a very small part of the 

 land that was used was naturally adapted 

 to the raising of crops. Much of it was 

 too dry to grow crops without irrigation,, 

 and even more of it was so steep or so 

 rocky that the surface had to be terraced 

 or otherwise reformed in order to make 

 it suitable for cultivation. 



Of the four forms of reclamation that 

 were so extensively employed in ancient 

 Peru not one has been used, or even seri- 

 ously considered, in the United States. 

 Nowhere do we cultivate steep lands like 

 the higher slopes of the Peruvian valleys, 

 or build stone walls to support narrow 

 terraces, or place artificial soil on broad 

 terraces in valley bottoms. In a few 

 places we are beginning to straighten and 

 confine our rivers to make more land 

 along the banks, but chiefly with the ob- 

 ject of preventing floods or reclaiming 

 broad, level lands by drainage, not with 

 the idea of building new lands in the 

 rocky beds of torrents, as in Peru. 



COOPERATION FOR THE COMMON GOOD 



Primitive the ancient Peruvians were 

 in many ways, as their modern Quichua 

 descendants still are ; but with respect to 

 agriculture and some of the attendant 

 arts a very high state of development 

 must have been attained and at a remote 

 period. Otherwise it would have been 

 impossible to occupy and reclaim many 

 of the places that evidently were centers 

 of population in ancient times. 



Many localities must have been treated 

 as reclamation projects from the very 



* For a more detailed treatment of these 

 matter-, ^.e "Agriculture and Native Vegeta- 

 tion in Peru". Journal of the Washington 

 Academy of Sciences, Vol. VI, pp. 284-293. 



