﻿V°l« 
  53-] 
  ANNIVERSARY 
  ADDRESS 
  OF 
  THE 
  PRESIDENT. 
  Xci 
  

  

  confine 
  ray 
  remarks, 
  with 
  one 
  or 
  two 
  exceptions, 
  to 
  the 
  researches 
  

   which 
  have 
  been 
  carried 
  on 
  in 
  the 
  British 
  Isles, 
  and 
  in 
  areas 
  with 
  

   which 
  I 
  am 
  more 
  or 
  less 
  familiar. 
  It 
  will, 
  of 
  course, 
  be 
  understood 
  

   that 
  important 
  advances 
  have 
  also 
  been 
  made 
  during 
  the 
  same 
  time 
  

   in 
  many 
  other 
  countries 
  in 
  Europe 
  and 
  in 
  America 
  ; 
  and, 
  as 
  bearing 
  

   on 
  the 
  biological 
  history, 
  the 
  discoveries 
  made 
  by 
  the 
  Scandinavian, 
  

   Russian, 
  and 
  American 
  geologists 
  have 
  been 
  of 
  the 
  highest 
  value. 
  

  

  Summary. 
  

  

  From 
  the 
  scattered 
  details 
  which 
  I 
  have 
  thus 
  imperfectly 
  laid 
  

   before 
  you, 
  it 
  may 
  be 
  well 
  to 
  sum 
  up 
  the 
  main 
  results 
  which 
  have 
  

   been 
  obtained. 
  It 
  has 
  been 
  seen 
  that 
  very 
  different 
  views 
  are 
  now 
  

   held 
  in 
  regard 
  to 
  the 
  origin 
  of 
  many 
  of 
  the 
  pre-Cambrian 
  rocks 
  from 
  

   those 
  which 
  prevailed 
  from 
  20 
  to 
  30 
  years 
  ago. 
  Then 
  all 
  the 
  crys- 
  

   talline 
  schists 
  and 
  gneisses, 
  and 
  many 
  also 
  of 
  the 
  granitic 
  rocks, 
  were 
  

   looked 
  upon 
  as 
  metamorphosed 
  sediments. 
  Gradually, 
  and 
  mainly 
  

   owing 
  to 
  the 
  careful 
  microscopical 
  work 
  which 
  has 
  been 
  carried 
  on 
  

   by 
  so 
  many 
  eminent 
  petrologists 
  in 
  this 
  and 
  other 
  countries, 
  we 
  have 
  

   been 
  led 
  to 
  recognize 
  that 
  a 
  very 
  large 
  proportion 
  of 
  the 
  crystalline 
  

   rocks 
  previously 
  supposed 
  to 
  have 
  been 
  sediments 
  are 
  igneous 
  

   rocks 
  which 
  have 
  been 
  crushed, 
  cleaved, 
  and 
  have 
  suffered 
  other 
  

   changes 
  from 
  chemical 
  and 
  mechanical 
  influences. 
  It 
  has 
  been 
  

   shown 
  also 
  that 
  very 
  large 
  and 
  unexpected 
  proportions 
  of 
  the 
  pre- 
  

   Cambrian 
  rocks 
  were 
  built 
  up 
  from 
  materials 
  derived 
  from 
  volcanic 
  

   outbursts, 
  and 
  that 
  this 
  was 
  particularly 
  the 
  case 
  in 
  the 
  British 
  

   areas. 
  As 
  a 
  consequence, 
  few 
  of 
  the 
  sediments 
  are 
  such 
  as 
  could 
  

   have 
  been 
  deposited 
  in 
  marine 
  areas 
  favourable 
  to 
  organic 
  life, 
  or 
  

   such 
  as 
  would 
  be 
  likely 
  to 
  retain 
  very 
  definite 
  evidence 
  of 
  its 
  

   existence. 
  Still 
  the 
  very 
  earliest 
  of 
  the 
  Cambrian 
  rocks, 
  or 
  those 
  

   sediments 
  which 
  were 
  deposited 
  in 
  a 
  fairly 
  tranquil 
  sea, 
  following 
  

   the 
  great 
  physical 
  changes 
  which 
  took 
  place 
  at 
  the 
  close 
  of 
  the 
  

   pre-Cambrian 
  era, 
  contain 
  ample 
  evidence 
  that 
  the 
  sea 
  which 
  was 
  

   gradually 
  encroaching 
  on 
  the 
  pre-Cambrian 
  land 
  on 
  both 
  sides 
  of 
  

   the 
  Atlantic 
  teemed 
  with 
  life, 
  in 
  which 
  probably 
  all 
  the 
  orders 
  of 
  

   the 
  Invertebrata 
  were 
  represented. 
  

  

  These 
  discoveries 
  have 
  undoubtedly 
  added 
  most 
  important 
  

   evidence 
  in 
  support 
  of 
  the 
  theory 
  of 
  the 
  gradual 
  evolution 
  of 
  

   organic 
  life, 
  and 
  lead 
  us 
  to 
  speak 
  very 
  hopefully 
  of 
  finding 
  yet 
  

   earlier 
  traces 
  of 
  the 
  life-history 
  of 
  our 
  globe. 
  The 
  readiness 
  with 
  

   which 
  suitable 
  forms 
  tenanted 
  all 
  the 
  areas 
  as 
  they 
  were 
  covered 
  

   by 
  the 
  sea 
  shows 
  that 
  there 
  was 
  abundance 
  of 
  life 
  near 
  at 
  hand 
  in 
  

   the 
  adjoining 
  submerged 
  areas, 
  and 
  that 
  the 
  changes 
  then 
  taking 
  

  

  