﻿PLIOCENE 
  PERIOD 
  Iff 
  EXGLAXD. 
  /CO 
  

  

  annual 
  precipitation 
  of 
  snow 
  only 
  equal 
  to 
  12 
  inches 
  of 
  rain. 
  Cold 
  

   merely, 
  though 
  as 
  great, 
  and 
  even 
  greater, 
  than 
  that 
  of 
  South 
  

   Greenland, 
  is 
  not 
  prohibitive 
  of 
  tree-growth, 
  as 
  we 
  see 
  by 
  the 
  limit 
  

   of 
  forests 
  in 
  Siberia, 
  which 
  reaches 
  10° 
  of 
  latitude 
  to 
  the 
  north 
  of 
  

   South 
  Greenland. 
  The 
  presence 
  of 
  trees, 
  we 
  may 
  thus 
  infer, 
  is 
  only 
  

   regulated 
  by 
  their 
  ability 
  to 
  ripen 
  their 
  seeds. 
  This 
  the 
  summer 
  

   of 
  even 
  South 
  Greenland 
  is 
  adverse 
  to, 
  while 
  from 
  the 
  high 
  latitude 
  

   of 
  Spitsbergen 
  the 
  summer 
  there, 
  we 
  may 
  infer, 
  is, 
  under 
  existing 
  

   conditions, 
  too 
  short 
  to 
  allow 
  it. 
  The 
  greater 
  length 
  of 
  the 
  summer, 
  

   however, 
  in 
  England 
  during 
  the 
  great 
  glaciation, 
  which 
  the 
  lower 
  

   latitude 
  must 
  have 
  involved, 
  may 
  have 
  been 
  as 
  favourable 
  to 
  the 
  

   ripening 
  of 
  the 
  seeds 
  of 
  the 
  most 
  northern 
  kinds 
  of 
  tree 
  as 
  that 
  of 
  

   Siberia 
  now 
  is, 
  though, 
  in 
  consequence 
  of 
  the 
  low 
  range 
  of 
  the 
  land 
  

   and 
  dryness 
  of 
  the 
  climate, 
  ice-fields 
  do 
  not 
  occur 
  in 
  Siberia. 
  The 
  

   presence 
  of 
  arboreal 
  remains 
  in 
  the 
  Hoxne 
  bed, 
  mentioned 
  by 
  Prof. 
  

   Prestwich, 
  seems 
  to 
  me 
  explicable 
  only 
  by 
  trees 
  having 
  sprung 
  up 
  

   on 
  the 
  moraine 
  of 
  chalky 
  clay 
  as 
  the 
  plateaux 
  covered 
  with 
  it 
  

   became 
  exposed 
  by 
  the 
  diminution 
  of 
  the 
  ice 
  issuing 
  in 
  that 
  direc- 
  

   tion, 
  which, 
  before 
  its 
  complete 
  recession 
  from 
  the 
  sea 
  in 
  East 
  

   Anglia, 
  became 
  sufficient 
  only 
  to 
  fill 
  the 
  valleys 
  in 
  the 
  parts 
  nearest 
  

   to 
  its 
  issue 
  there. 
  

  

  As 
  to 
  the 
  second 
  point, 
  it 
  seems 
  to 
  me 
  that 
  inasmuch 
  as 
  the 
  Hip- 
  

   popotamus 
  appears 
  actually 
  to 
  have 
  inhabited 
  England 
  during 
  the 
  

   Bed 
  Crag, 
  its 
  habits 
  were 
  not 
  inconsistent 
  with 
  the 
  freezing 
  of 
  

   rivers 
  in 
  winter. 
  As 
  some 
  Bears 
  hibernate, 
  and 
  as 
  the 
  habits 
  of 
  the 
  

   Polar 
  Bear 
  are 
  unlike 
  those 
  of 
  other 
  Bears, 
  it 
  is 
  quite 
  as 
  reasonable 
  

   to 
  infer 
  that 
  the 
  Xewer 
  Pliocene 
  Hippopotamus 
  of 
  Europe 
  had, 
  in 
  

   respect 
  to 
  frozen 
  rivers, 
  habits 
  differing 
  from 
  those 
  of 
  its 
  living 
  

   African 
  congener, 
  as 
  it 
  is 
  to 
  assign 
  to 
  it 
  the 
  habit 
  of 
  migration, 
  which 
  

   is 
  equally 
  foreign 
  to 
  the 
  living 
  animal. 
  To 
  suppose 
  that 
  the 
  Hip- 
  

   popotamus 
  migrated 
  a 
  thousand 
  miles 
  or 
  more 
  every 
  summer 
  dming 
  

   the 
  Glacial 
  period 
  appears 
  to 
  me, 
  when 
  its 
  habits 
  and 
  powers 
  are 
  

   duly 
  considered, 
  improbable 
  ; 
  and 
  since 
  from 
  the 
  presence 
  in 
  the 
  

   base 
  of 
  the 
  Bed 
  Crag 
  of 
  large 
  tabular 
  masses 
  of 
  unworn 
  flint, 
  many 
  

   miles 
  from 
  the 
  nearest 
  chalk, 
  we 
  cannot 
  doubt 
  that 
  the 
  rivers, 
  and 
  

   even 
  parts 
  of 
  the 
  estuaries, 
  were 
  at 
  that 
  time 
  frozen, 
  the 
  Hippo- 
  

   potamus, 
  if 
  it 
  lived 
  at 
  that 
  time, 
  must 
  have 
  subsisted 
  under 
  those 
  

   conditions. 
  The 
  remains 
  of 
  it 
  found 
  in 
  those 
  freshwater 
  deposits 
  

   on 
  the 
  Xorth 
  Xorfolk 
  coast 
  beneath 
  the 
  sands 
  hi 
  and 
  Till, 
  which 
  

   I 
  regard 
  as 
  of 
  the 
  age 
  of 
  the 
  Bed 
  Crag 
  (and 
  which 
  would 
  hardly 
  be 
  

   referred 
  by 
  any 
  one 
  to 
  a 
  time 
  when 
  a 
  still 
  milder 
  climate 
  than 
  that 
  

   of 
  the 
  Upper 
  Crag 
  prevailed), 
  seem 
  to 
  me 
  to 
  prove 
  that 
  it 
  did 
  live 
  

   where 
  the 
  rivers 
  were 
  thus 
  frozen 
  in 
  winter, 
  and 
  that 
  its 
  habits 
  

   must 
  somehow 
  have 
  been 
  conformable 
  to 
  those 
  conditions. 
  There 
  

   is 
  nothing 
  yet 
  made 
  known, 
  however, 
  so 
  far 
  as 
  T 
  can 
  make 
  out, 
  

   which 
  points 
  at 
  all 
  to 
  its 
  having 
  inhabited 
  England 
  during 
  any 
  part 
  

   of 
  the 
  great 
  glaciation, 
  none 
  of 
  the 
  freshwater 
  formations 
  which 
  

   appear 
  to 
  me 
  to 
  belong 
  to 
  the 
  wane 
  of 
  this 
  glaciation, 
  such 
  as 
  those 
  

   of 
  Hoxne, 
  Mildenhall, 
  Brandon, 
  Copford, 
  &c, 
  having, 
  so 
  far 
  as 
  I 
  

   know, 
  yielded 
  its 
  remains. 
  It 
  is 
  the 
  presence 
  of 
  its 
  remains 
  (gene- 
  

  

  