(iKNKRAl. 1 I I.I.I) or WORK 49 



l)r()})al)l\' tlic correct one. is that it is wliollv sedentary like 

 the chiys and gravels. What would seem more reasonahle 

 to an iingeolo<4ical observer is the theory that this series of 

 iiTeat successive sand dunes is a relic of ancient seashores, 

 althouiih close search yields no trace of seashell or coral. 

 And this we may note as the first of a host of deceptions 

 practiced upon us by the tropical elements and animals — 

 these dunes of the finest of white sand deej) hidden within 

 these niiyhty forests, whose grains have never danced at 

 the roar of ])ounding breakers nor felt the slitherin*^- rush 

 of salt water. Here the white sand lies beneath the ebony 

 mold of the jungle, undistur})ed except when fiung into the 

 li<»ht by the wrenched-up roots of a falling- tree, or when 

 scratched up by armadillos, or patiently borne to the sur- 

 face, grain after grain by indefatigable ants. 



So this particular region, although so near the Atlan- 

 tic coast and so distant from the Andes, in ages past began 

 as volcanic or igneous upthrusts of rock, and not by the 

 gradual accumulation of sediment brought down by rivers 

 and held in tenin-e by the clutching fingers of mangroves 

 and courida. But that time of mineral dominance is long- 

 past, and today we find the underlying structure, whatever 

 it is, clothed with running water and with vegetation, in the 

 shelter of which animal life teems, while mankind has merely 

 begun to paddle painfully along the rivers, and to follow 

 narrow trails — molewise — through the jungle. 



