﻿14 
  SOUTH 
  AMERICAN 
  INDIANS 
  [B. 
  A. 
  B. 
  Bull. 
  143 
  

  

  The 
  distinctive 
  feature 
  of 
  the 
  Peruvian 
  Andes 
  (James, 
  1942, 
  p. 
  

   145) 
  is 
  a 
  high 
  level 
  surface 
  with 
  gentle 
  slopes, 
  generally 
  between 
  10,000 
  

   and 
  15,000 
  feet 
  (about 
  3,000 
  to 
  4,500 
  m.) 
  in 
  altitude. 
  Much 
  of 
  this 
  

   territory 
  is 
  either 
  too 
  high 
  for 
  agriculture 
  or 
  has 
  been 
  badly 
  denuded 
  

   by 
  erosion. 
  Above 
  this 
  high 
  level 
  surface 
  rise 
  the 
  rugged 
  peaks 
  of 
  the 
  

   Andes, 
  many 
  of 
  them 
  permanently 
  snow-covered. 
  In 
  Peru, 
  unlike 
  

   Colombia 
  and 
  Ecuador, 
  the 
  Andes 
  are 
  not 
  arranged 
  in 
  parallel 
  ranges; 
  

   rather 
  they 
  are 
  composed 
  of 
  a 
  number 
  of 
  discontinuous 
  chains, 
  which 
  

   generally 
  run 
  diagonally 
  in 
  a 
  northwest-southeast 
  direction. 
  North 
  

   of 
  Cajamarca, 
  rainfall 
  is 
  more 
  or 
  less 
  continuous 
  throughout 
  the 
  

   year, 
  and 
  the 
  surfaces 
  are 
  characteristic 
  paramos. 
  The 
  central 
  and 
  

   southern 
  region, 
  however, 
  has 
  distinct 
  dry 
  and 
  rainy 
  seasons, 
  produc- 
  

   ing 
  typical 
  punas. 
  The 
  continental 
  water 
  divide 
  is 
  close 
  to 
  the 
  Pa- 
  

   cific 
  Coast 
  in 
  many 
  places, 
  so 
  that 
  in 
  the 
  Peruvian 
  Andes 
  are 
  the 
  head- 
  

   waters 
  of 
  rivers 
  which 
  flow 
  to 
  the 
  Amazon 
  and, 
  ultimately, 
  to 
  the 
  

   Atlantic. 
  Three 
  major 
  river 
  systems 
  drain 
  these 
  Highlands, 
  namely, 
  

   the 
  Rio 
  Marafi6n 
  in 
  the 
  north, 
  the 
  Rio 
  Huallaga 
  in 
  the 
  center, 
  

   and 
  the 
  Rio 
  Ucayali 
  in 
  the 
  south. 
  These 
  rivers 
  and 
  their 
  numerous 
  

   tributaries 
  originate 
  in 
  the 
  high 
  mountains, 
  cut 
  their 
  way 
  slowly 
  

   across 
  the 
  rolling 
  high 
  level 
  surface, 
  and 
  then 
  rush 
  downward 
  through 
  

   deep 
  canyons 
  to 
  the 
  eastern 
  plains. 
  Along 
  the 
  rivers 
  are 
  innumer- 
  

   able 
  pockets 
  of 
  flat 
  lands 
  where 
  agriculture 
  is 
  possible, 
  so 
  that 
  an 
  

   analysis 
  of 
  the 
  best 
  regions 
  of 
  habitation 
  is 
  exceedingly 
  difficult 
  to 
  

   make. 
  Romero 
  (1939, 
  p. 
  110) 
  lists 
  22 
  principal 
  valleys 
  in 
  the 
  moun- 
  

   tains, 
  and 
  this 
  number 
  could 
  easily 
  be 
  doubled 
  in 
  terms 
  of 
  the 
  princi- 
  

   pal 
  habitation 
  areas 
  of 
  Indian 
  culture, 
  past 
  and 
  present. 
  However, 
  

   some 
  of 
  the 
  outstanding 
  centers 
  of 
  population 
  concentration 
  can 
  be 
  

   mentioned. 
  

  

  In 
  the 
  north, 
  the 
  contemporary 
  town 
  of 
  Cajamarca, 
  located 
  in 
  a 
  

   high 
  intermont 
  basin, 
  is 
  a 
  focal 
  center 
  of 
  concentrated 
  population 
  

   for 
  a 
  region 
  which 
  includes 
  many 
  small 
  units 
  along 
  the 
  tributaries 
  

   of 
  the 
  Rio 
  MaraMn. 
  The 
  Maraii6n 
  itself 
  has 
  numerous 
  small 
  

   clusters 
  of 
  population 
  from 
  its 
  headwaters 
  at 
  Huanuco 
  on 
  down, 
  

   and 
  might 
  be 
  considered 
  a 
  secondary 
  center. 
  

  

  Another 
  important 
  center 
  in 
  the 
  north 
  is 
  the 
  Callejdn 
  de 
  Huaylas, 
  

   actually 
  the 
  upper 
  extension 
  of 
  the 
  Rio 
  Santa. 
  The 
  Santa 
  originates 
  

   in 
  a 
  high 
  marsh 
  and 
  flows 
  northward, 
  flanked 
  on 
  both 
  sides 
  by 
  moun- 
  

   tains. 
  Intensive 
  agriculture 
  has 
  long 
  been 
  practiced 
  in 
  this 
  wide 
  

   and 
  fertile 
  Highland 
  valley. 
  

  

  An 
  important 
  center 
  is 
  in 
  the 
  central 
  Highlands 
  behind 
  Lima 
  in 
  the 
  

   flat 
  valley 
  of 
  the 
  Rio 
  Mantaro. 
  The 
  largest 
  basin 
  is 
  that 
  of 
  Huan- 
  

   cayo, 
  some 
  40 
  miles 
  (64 
  km.) 
  long 
  by 
  10 
  to 
  12 
  miles 
  (16 
  to 
  19 
  km.) 
  

   wide 
  and 
  about 
  11,000 
  feet 
  (3,300 
  m.) 
  in 
  altitude. 
  

  

  The 
  Cuzco 
  region 
  is 
  one 
  of 
  the 
  largest 
  centers 
  of 
  population. 
  Here 
  

   the 
  three 
  basins 
  of 
  Cuzco, 
  Urubamba, 
  and 
  Anta 
  have 
  an 
  average 
  ele- 
  

  

  