﻿1875.] 
  Sea-bottom 
  procured 
  by 
  H.M.S. 
  ' 
  Challenger.' 
  235 
  

  

  believe 
  it 
  will 
  prove 
  that 
  the 
  truth 
  lies 
  between 
  two 
  extreme 
  views. 
  

   That 
  the 
  Globigerince 
  live 
  on 
  the 
  bottom 
  only 
  is 
  a 
  position 
  clearly 
  no 
  longer 
  

   tenable 
  ; 
  but 
  that 
  they 
  live 
  and 
  multiply 
  in 
  the 
  upper 
  waters 
  only, 
  and 
  

   only 
  sink 
  to 
  the 
  bottom 
  after 
  death, 
  seems 
  to 
  me 
  a 
  position 
  no 
  more 
  

   tenable 
  than 
  the 
  preceding 
  : 
  and 
  I 
  shall 
  now 
  adduce 
  the 
  evidence 
  which 
  

   appears 
  to 
  me 
  at 
  present 
  to 
  justify 
  the 
  conclusion 
  (I 
  refrain 
  from 
  express- 
  

   ing 
  myself 
  more 
  positively, 
  because 
  I 
  consider 
  the 
  question 
  still 
  open 
  to 
  

   investigation), 
  that 
  whilst 
  the 
  Globigerince 
  are 
  pelagic 
  in 
  an 
  earlier 
  stage 
  of 
  

   their 
  lives, 
  frequenting 
  the 
  upper 
  stratum 
  of 
  the 
  ocean, 
  they 
  sink 
  to 
  

   the 
  bottom 
  ivhilst 
  still 
  living, 
  in 
  consequence 
  of 
  the 
  increasing 
  thickness 
  

   of 
  their 
  calcareous 
  shells, 
  and 
  not 
  only 
  continue 
  to 
  live 
  on 
  the 
  sea-bed, 
  

   but 
  probably 
  multiply 
  there 
  — 
  perhaps 
  there 
  exclusively. 
  

  

  That 
  there 
  is 
  no 
  a 
  priori 
  improbability 
  in 
  their 
  doing 
  so, 
  is 
  proved 
  by 
  

   the 
  abundant 
  evidence 
  in 
  my 
  possession 
  of 
  the 
  existence 
  of 
  Eoramini- 
  

   feral 
  life 
  at 
  abyssal 
  depths. 
  The 
  collections 
  made 
  during 
  the 
  ' 
  Porcupine 
  ' 
  

   Expeditions 
  of 
  1869 
  and 
  1870 
  yielded 
  a 
  large 
  number 
  of 
  those 
  Arenace- 
  

   ous 
  types 
  which 
  construct 
  their 
  " 
  tests 
  " 
  by 
  the 
  cementation 
  of 
  sand- 
  

   grains 
  only 
  to 
  be 
  obtained 
  on 
  the 
  bottom 
  ; 
  and 
  these 
  were 
  almost 
  the 
  

   only 
  Foraruinifera, 
  except 
  Globigerince 
  and 
  Orbulince, 
  which 
  came 
  up 
  in 
  

   the 
  2435 
  fathoms 
  dredging. 
  Again, 
  many 
  Foraminifera, 
  both 
  arenace- 
  

   ous 
  and 
  shelly, 
  were 
  brought 
  up 
  from 
  great 
  depths, 
  attached 
  to 
  shells, 
  

   stones, 
  &c, 
  that 
  must 
  have 
  lain 
  at 
  the 
  bottom. 
  Further, 
  among 
  the 
  

   " 
  vitreous 
  " 
  Foraminifera, 
  the 
  most 
  common 
  deep-sea 
  types, 
  except 
  those 
  

   of 
  the 
  Grlobigerine 
  family, 
  were 
  Cristellarians 
  with 
  shells 
  so 
  thick 
  and 
  

   massive 
  as 
  to 
  be 
  (it 
  may 
  be 
  safely 
  affirmed) 
  incapable 
  of 
  being 
  floated 
  

   by 
  the 
  animals 
  which 
  form 
  them 
  ; 
  while 
  among 
  the 
  " 
  porcellanous 
  " 
  Fora- 
  

   minifera, 
  the 
  Biloculince 
  and 
  Triloculince 
  were 
  equally 
  distinguished 
  by 
  a 
  

   massiveness.of 
  shell, 
  which 
  seemed 
  to 
  forbid 
  the 
  idea 
  that 
  they 
  could 
  have 
  

   floated 
  subsequently 
  to 
  that 
  stage 
  of 
  their 
  lives 
  in 
  which 
  this 
  massive- 
  

   ness 
  had 
  been 
  acquired. 
  

  

  Of 
  the 
  existence 
  of 
  living 
  Globigerince 
  in 
  great 
  numbers 
  in 
  the 
  stratum 
  

   of 
  water 
  immediately 
  above 
  the 
  bottom, 
  at 
  from 
  500 
  to 
  750 
  fathoms 
  

   depth, 
  I 
  am 
  able 
  to 
  speak 
  with 
  great 
  positiveness. 
  It 
  several 
  times 
  hap- 
  

   pened, 
  during 
  the 
  Third 
  Cruise 
  of 
  the 
  ' 
  Porcupine 
  ' 
  in 
  1869, 
  that 
  the 
  

   water 
  brought 
  up 
  by 
  the 
  water-bottle 
  from 
  immediately 
  above 
  the 
  Glo- 
  

   bigerina-ooze 
  was 
  quite 
  turbid 
  ; 
  and 
  this 
  turbidity 
  was 
  found 
  (by 
  filtra- 
  

   tion) 
  to 
  depend, 
  not 
  upon 
  the 
  suspension 
  of 
  amorphous 
  particles 
  diffused 
  

   through 
  the 
  water, 
  but 
  upon 
  the 
  presence 
  of 
  multitudes 
  of 
  young 
  Globi- 
  

   gerince, 
  which 
  were 
  retained 
  upon 
  the 
  filter, 
  the 
  water 
  passing 
  through 
  it 
  

   quite 
  clear. 
  The 
  thin 
  shells 
  of 
  these 
  specimens, 
  exhibiting 
  very 
  distinct 
  

   pseudopodial 
  orifices, 
  contrasted 
  strongly 
  with 
  the 
  larger 
  and 
  thicker 
  

   shells 
  of 
  the 
  specimens 
  brought 
  up 
  by 
  the 
  sounding-apparatus 
  from 
  the 
  

   bottom 
  immediately 
  beneath, 
  in 
  which 
  the 
  shells 
  are 
  thick 
  and 
  those 
  

   orifices 
  obscure. 
  It 
  is 
  obvious 
  that 
  if 
  this 
  extraordinary 
  abundance 
  of 
  

   Grlobigerine 
  life 
  in 
  the 
  bottom-water 
  was 
  the 
  result 
  of 
  subsidence 
  from 
  

  

  u2 
  

  

  