﻿542 
  PE0P. 
  C. 
  LAPWOETH 
  ON 
  THE 
  GIEVAN 
  SUCCESSION. 
  

  

  dimensions 
  as 
  are 
  there 
  developed, 
  the 
  change 
  of 
  life-type 
  seems 
  to 
  

   have 
  been 
  strictly 
  dependent 
  upon 
  the 
  progress 
  of 
  geological 
  time, 
  

   the 
  successive 
  fossil 
  assemblages 
  differing 
  in 
  facies 
  among 
  them- 
  

   selves 
  in 
  proportion 
  to 
  the 
  geological 
  interval 
  which 
  separates 
  them. 
  

   These 
  discoveries 
  have 
  thrown 
  a 
  new 
  light 
  upon 
  the 
  magnificent 
  

   results 
  long 
  since 
  obtained 
  by 
  Barrande 
  in 
  Europe, 
  and 
  by 
  Hall 
  and 
  

   his 
  brother 
  geologists 
  in 
  America, 
  and 
  have 
  led 
  some 
  of 
  the 
  more 
  

   sanguine 
  students 
  of 
  British 
  Geology 
  to 
  hope 
  that, 
  not 
  only 
  would 
  

   the 
  grand 
  rock-systems 
  of 
  Lower 
  Palaeozoic 
  age 
  on 
  this 
  side 
  of 
  the 
  

   Atlantic 
  admit 
  of 
  a 
  rude 
  parallelism 
  in 
  areas 
  now 
  widely 
  separated 
  

   geographically, 
  but 
  that 
  even 
  their 
  formations, 
  subformations, 
  and 
  

   more 
  important 
  zones 
  of 
  life 
  might 
  in 
  time 
  be 
  synchronized 
  with 
  

   average 
  accuracy, 
  and 
  an 
  ascending 
  geological 
  scale 
  be 
  thus 
  con- 
  

   structed 
  comparable 
  with 
  that 
  which 
  has 
  proved 
  so 
  valuable 
  in 
  

   correlating 
  the 
  Mesozoic 
  strata 
  of 
  Britain 
  and 
  the 
  continent. 
  

  

  The 
  further 
  discovery 
  that 
  organisms 
  of 
  such 
  a 
  lowly 
  type 
  as 
  the 
  

   Graptolites 
  followed 
  the 
  same 
  law 
  of 
  slow 
  development, 
  specific 
  

   culmination, 
  and 
  extinction 
  as 
  that 
  long 
  acknowledged 
  to 
  be 
  cha- 
  

   racteristic 
  of 
  the 
  life-periods 
  of 
  the 
  higher 
  groups 
  of 
  animals, 
  has 
  

   added 
  great 
  force 
  to 
  these 
  views. 
  It 
  has 
  allowed 
  us 
  to 
  unravel 
  

   with 
  comparative 
  ease 
  the 
  ascending 
  sequence 
  in 
  one 
  of 
  the 
  most 
  

   complicated 
  districts 
  among 
  the 
  contorted 
  strata 
  of 
  the 
  Southern 
  

   Uplands 
  and 
  has 
  shaken 
  the 
  fashionable 
  and 
  mystifying 
  doctrine 
  of 
  

   Colonies, 
  as 
  interpreted 
  by 
  British 
  geologists, 
  to 
  its 
  foundations. 
  The 
  

   host 
  of 
  proofs 
  which 
  the 
  detailed 
  study 
  of 
  these 
  fossils 
  has 
  disclosed 
  

   that 
  the 
  supposed 
  extended 
  range 
  and 
  confused 
  intermingling 
  of 
  

   their 
  species 
  does 
  not 
  actually 
  exist, 
  but 
  is 
  due, 
  primarily, 
  to 
  

   defective 
  stratigraphy, 
  has 
  led 
  myself 
  and 
  others 
  to 
  suspect 
  that 
  the 
  

   species 
  of 
  the 
  remaining 
  groups 
  of 
  Lower 
  Palaeozoic 
  fossils 
  will 
  

   ultimately 
  be 
  found 
  to 
  have 
  a 
  similar 
  restricted 
  range 
  in 
  geological 
  

   time, 
  and, 
  as 
  a 
  consequence, 
  an 
  equivalent 
  value 
  as 
  indices 
  of 
  the 
  

   systematic 
  place 
  of 
  their 
  containing 
  stratum, 
  and 
  that 
  palaeontological 
  

   evidences 
  are 
  destined 
  soon 
  to 
  regain 
  their 
  ancient 
  place 
  in 
  the 
  

   regard 
  of 
  the 
  working 
  geologist 
  among 
  the 
  older 
  sedimentary 
  rocks. 
  

   The 
  new 
  interest 
  and 
  illumination 
  thus 
  cast 
  upon 
  the 
  study 
  of 
  the 
  

   Lower 
  Palaeozoic 
  rocks 
  are, 
  it 
  is 
  hoped, 
  certain 
  to 
  lead 
  to 
  the 
  

   working 
  out 
  of 
  these 
  ancient 
  strata 
  upon 
  a 
  new 
  and 
  more 
  minute 
  

   plan, 
  with 
  the 
  result 
  of 
  the 
  discovery 
  of 
  a 
  host 
  of 
  correspondencies 
  

   at 
  present 
  unsuspected 
  between 
  British 
  and 
  foreign 
  Lower 
  Palaeozoic 
  

   sediments, 
  and 
  the 
  gradual 
  development 
  of 
  a 
  detailed 
  scheme 
  of 
  

   classification 
  of 
  widely 
  extended 
  application. 
  

  

  Now, 
  not 
  only 
  are 
  these 
  Lower 
  Palaeozoic 
  rocks 
  of 
  Carrick 
  of 
  all- 
  

   absorbing 
  interest 
  to 
  the 
  palaeontologist 
  and 
  geologist 
  from 
  their 
  

   highly 
  fossiliferous 
  nature 
  and 
  their 
  enigmatical 
  stratigraphy, 
  but 
  

   they 
  afford 
  all 
  the 
  elements 
  necessary 
  for 
  a 
  crucial 
  test 
  of 
  these 
  

   special 
  opinions. 
  If 
  the 
  asserted 
  heterogeneous 
  intermixture 
  of 
  

   fossil 
  assemblages 
  of 
  all 
  types, 
  elsewhere 
  characteristic 
  of 
  distinct 
  

   horizons, 
  were 
  actually 
  found 
  to 
  obtain 
  amongst 
  them, 
  palaeon- 
  

   tology 
  might 
  well 
  abandon 
  her 
  claim 
  to 
  be 
  the 
  unfailing 
  handmaid 
  

   of 
  stratigraphy 
  among 
  the 
  more 
  ancient 
  formations. 
  If, 
  on 
  the 
  

  

  