﻿Ill] 
  Shreveport 
  Area 
  : 
  Uplands 
  193 
  

  

  their 
  aprons 
  ; 
  when 
  the 
  dinner 
  horn 
  sounded 
  they 
  dropped 
  the 
  

   dirt 
  where 
  they 
  stood 
  and 
  hurried 
  away 
  to 
  a 
  dinner 
  from 
  which 
  

   they 
  never 
  returned. 
  

  

  Some 
  of 
  the 
  theories 
  which 
  have 
  been 
  advanced 
  by 
  more 
  cul- 
  

   tured 
  people 
  are 
  but 
  a 
  step 
  removed 
  from 
  these. 
  Others 
  show 
  

   considerable 
  thought. 
  The 
  following 
  theories 
  have 
  been 
  

   advanced 
  by 
  scientists 
  : 
  

  

  1. 
  Ant-hill 
  theory. 
  

  

  2. 
  Wind 
  theory. 
  

  

  3. 
  Water 
  volcano 
  theory. 
  

  

  4. 
  Pressure 
  theory. 
  

  

  5. 
  Gas 
  theory. 
  

  

  6. 
  Indian 
  garden-mound 
  theory. 
  

  

  7. 
  Current 
  theory. 
  

  

  8. 
  Slow 
  erosion 
  theory. 
  

  

  The 
  ant-hill 
  theory 
  was 
  suggested 
  by 
  Hilgard 
  in 
  his 
  Supple- 
  

   mentary 
  and 
  Final 
  Report 
  of 
  a 
  Geological 
  Reconnaissance 
  of 
  

   the 
  State 
  of 
  Louisiana 
  p. 
  11; 
  it 
  holds 
  that 
  the 
  mounds 
  were 
  

   made 
  by 
  a 
  large 
  species 
  of 
  ant, 
  which 
  for 
  some 
  reason 
  was 
  

   entirely 
  destroyed 
  after 
  the 
  formation 
  of 
  the 
  mounds. 
  This 
  

   theory 
  seems 
  to 
  greatly 
  tax 
  the 
  ants' 
  abilities. 
  A 
  similar 
  theory 
  

   sometimes 
  heard 
  among 
  the 
  people 
  of 
  the 
  country, 
  is 
  that 
  the 
  

   mounds 
  were 
  made 
  by 
  some 
  burrowing 
  animal. 
  

  

  Clendenin 
  suggests 
  * 
  that 
  the 
  wind 
  theory 
  was 
  suggested 
  by 
  

   emigrants 
  from 
  the 
  prairie 
  regions 
  of 
  the 
  northwest, 
  who 
  had 
  

   seen 
  little 
  mounds 
  of 
  sand 
  or 
  dust 
  form 
  behind 
  little 
  obstructions 
  

   during 
  a 
  wind 
  storm. 
  

  

  Thomassy 
  conceived 
  the 
  idea 
  that 
  these 
  mounds 
  were 
  formed 
  

   by 
  springs 
  or 
  "aqueous 
  volcanoes." 
  f 
  

  

  So 
  far 
  as 
  we 
  know, 
  the 
  pressure 
  theory, 
  which 
  was 
  advanced 
  J 
  

   to 
  account 
  for 
  mud 
  lumps, 
  has 
  not 
  been 
  directly 
  applied 
  to 
  the 
  

   similar 
  phenomena, 
  the 
  mounds. 
  It 
  holds 
  that 
  over 
  a 
  semifluid 
  

   layer 
  of 
  quicksand 
  there 
  has 
  been 
  deposited 
  a 
  thick 
  layer 
  of 
  

   tenaceous 
  clay. 
  The 
  weight 
  of 
  the 
  upper 
  claj^ 
  in 
  places 
  bulges 
  

  

  *Bull. 
  La. 
  State 
  Expt. 
  Stations 
  : 
  Geol. 
  and 
  Agr. 
  part 
  III, 
  p. 
  180. 
  

   f 
  Geologie 
  Pratique 
  de 
  la 
  Louisiane, 
  Chap. 
  VIII, 
  New 
  Orleans, 
  i860. 
  

   i; 
  Lyell. 
  Principles 
  of 
  Geology, 
  loth 
  ed.. 
  1868, 
  vol. 
  i, 
  p. 
  449. 
  Hilgard. 
  

   A. 
  J. 
  S. 
  3d 
  series, 
  vol. 
  i, 
  1871, 
  p. 
  425. 
  

  

  