﻿PALEONTOLOGY 
  WELLER 
  315 
  

  

  or 
  absorbing 
  them 
  into 
  their 
  own 
  social 
  organization. 
  Geologically 
  

   speaking, 
  the 
  change 
  from 
  the 
  old 
  order 
  to 
  the 
  new, 
  in 
  each 
  case, 
  

   was 
  essentially 
  instantaneous. 
  As 
  soon 
  as 
  the 
  pathway 
  was 
  estab- 
  

   lished 
  the 
  change 
  was 
  complete. 
  The 
  few 
  centuries 
  which 
  have 
  been 
  

   required 
  to 
  transform 
  America 
  from 
  the 
  Stone 
  Age 
  culture 
  of 
  the 
  

   Indians 
  to 
  the 
  age 
  of 
  skyscrapers, 
  railroads, 
  automobiles, 
  and 
  radio 
  

   are 
  absolutely 
  negligible 
  in 
  geological 
  history. 
  The 
  change 
  has 
  been 
  

   as 
  abrupt 
  as 
  the 
  sudden 
  change 
  of 
  fauna 
  in 
  passing 
  from 
  one 
  sedi- 
  

   mentary 
  bed 
  to 
  another 
  conformably 
  overlying 
  it 
  in 
  which 
  the 
  

   paleontological 
  record 
  is 
  almost 
  totally 
  different. 
  

  

  Other 
  analogies 
  between 
  human 
  history 
  and 
  the 
  paleontological 
  

   record 
  are 
  not 
  wanting. 
  In 
  late 
  Devonian 
  time 
  a 
  series 
  of 
  faunal 
  

   migrations 
  from 
  the 
  Eurasian 
  Province 
  into 
  North 
  America 
  are 
  

   recognized. 
  First 
  came 
  the 
  Cuboides 
  fauna 
  already 
  mentioned, 
  which 
  

   is 
  typically 
  represented 
  in 
  the 
  Tully 
  limestone 
  of 
  New 
  York. 
  A 
  little 
  

   later 
  came 
  the 
  Intumescens 
  fauna 
  of 
  the 
  Portage 
  beds, 
  and 
  this 
  in 
  

   turn 
  was 
  followed 
  by 
  the 
  Spirifer 
  disjunctus 
  fauna 
  of 
  the 
  Chemung 
  

   formation. 
  This 
  succession 
  of 
  waves 
  of 
  migration 
  of 
  long 
  extinct 
  

   marine 
  life 
  may 
  be 
  compared 
  with 
  the 
  successive 
  waves 
  of 
  migration 
  

   of 
  the 
  uncultured 
  tribes 
  of 
  northern 
  Europe 
  into 
  the 
  confines 
  of 
  the 
  

   Roman 
  Empire 
  to 
  the 
  south. 
  The 
  causes 
  of 
  these 
  two 
  series 
  of 
  

   migrations, 
  one 
  of 
  the 
  more 
  primitive 
  life 
  of 
  Devonian 
  time, 
  the 
  

   other 
  of 
  human 
  races, 
  was 
  essentially 
  the 
  same 
  — 
  first, 
  the 
  discovery 
  

   in 
  each 
  case 
  of 
  the 
  pathway 
  along 
  which 
  the 
  migration 
  could 
  take 
  

   place, 
  and, 
  second, 
  the 
  crowding 
  of 
  the 
  develoj)ing 
  life 
  in 
  the 
  original 
  

   home 
  province. 
  

  

  Without 
  doubt, 
  the 
  most 
  notable 
  development 
  in 
  human 
  history 
  

   during 
  the 
  last 
  500 
  years 
  has 
  been 
  the 
  discovery 
  and 
  occupation 
  of 
  

   America 
  by 
  the 
  white 
  races 
  of 
  Europe. 
  The 
  difference 
  in 
  cultural 
  

   development 
  between 
  the 
  immigrant 
  race 
  and 
  the 
  aboriginal 
  Amer- 
  

   icans 
  was 
  so 
  great 
  that 
  all 
  opposition 
  to 
  the 
  newcomers 
  was 
  essen- 
  

   tially 
  negligible. 
  The 
  more 
  or 
  less 
  crowded 
  peoples 
  of 
  Europe 
  were 
  

   set 
  free 
  into 
  an 
  essentially 
  unoccupied 
  territory 
  of 
  vast 
  extent, 
  in 
  

   which 
  opportunity 
  was 
  afforded 
  for 
  expansional 
  development 
  on 
  a 
  

   far 
  grander 
  scale 
  than 
  during 
  any 
  similar 
  event 
  in 
  all 
  recorded 
  

   human 
  history. 
  This 
  opportunity 
  for 
  expansional 
  social 
  evolution 
  

   is 
  doubtless 
  the 
  primary 
  cause 
  for 
  the 
  rapid 
  development 
  in 
  science 
  

   and 
  invention 
  which 
  has 
  made 
  the 
  last 
  few 
  centuries 
  so 
  notable. 
  

  

  Similar 
  expansional 
  evolutions 
  have 
  taken 
  place 
  among 
  both 
  

   marine 
  and 
  land 
  faunas 
  of 
  the 
  past. 
  During 
  periods 
  of 
  rising 
  sea 
  

   level 
  relative 
  to 
  the 
  land 
  surface 
  great 
  areas 
  of 
  the 
  lower 
  portions 
  of 
  

   continental 
  surfaces 
  have 
  become 
  submerged 
  and 
  transformed 
  into 
  

   the 
  bottoms 
  of 
  more 
  or 
  less 
  widely 
  extended 
  shallow 
  seas. 
  In 
  such 
  

   situations 
  the 
  life 
  of 
  the 
  shallow 
  seas 
  adjacent 
  to 
  the 
  expansions 
  has 
  

   been 
  freed 
  from 
  its 
  more 
  severe 
  struggle 
  for 
  existence 
  and 
  has 
  been 
  

  

  