﻿THE 
  CRITERIA 
  OF 
  LIVINGNESS 
  103 
  

  

  istics 
  of 
  living 
  creatures. 
  Hence 
  this 
  inquiry 
  into 
  the 
  criteria 
  

   of 
  livingness. 
  The 
  bearing 
  of 
  this 
  on 
  modern 
  Natural 
  The- 
  

   ology 
  is 
  that 
  an 
  easy-going 
  concept 
  of 
  ' 
  organism 
  ' 
  is 
  a 
  dead 
  

   fly 
  that 
  may 
  spoil 
  many 
  an 
  ointment. 
  

  

  SUMMARY. 
  

  

  If 
  we 
  are 
  to 
  reach 
  a 
  coherent 
  view 
  of 
  Nature, 
  such 
  as 
  could 
  be 
  

   included 
  in 
  a 
  philosophy, 
  we 
  must 
  arrive 
  at 
  some 
  definition 
  of 
  the 
  

   characteristics 
  which 
  mark 
  off 
  living 
  organisms 
  from 
  their 
  not-living 
  

   surroundings. 
  In 
  the 
  present 
  state 
  of 
  science 
  this 
  definition 
  cannot 
  

   be 
  more 
  than 
  tentative, 
  but 
  it 
  must 
  be 
  continually 
  attempted. 
  

  

  Living 
  may 
  be 
  described 
  as 
  a 
  twofold 
  relation 
  of 
  action 
  and 
  re- 
  

   action 
  between 
  organisms 
  and 
  their 
  environment, 
  and 
  living 
  crea- 
  

   tures 
  are 
  always 
  active 
  towards 
  two 
  main 
  results, 
  self 
  -maintenance 
  

   and 
  the 
  continuance 
  of 
  their 
  race. 
  But 
  the 
  difficult 
  question 
  is: 
  

   What 
  are 
  the 
  insignia 
  of 
  living 
  creatures? 
  

  

  The 
  first 
  is 
  the 
  power 
  of 
  persisting 
  in 
  a 
  complex 
  specific 
  metabo- 
  

   lism, 
  and 
  in 
  a 
  corresponding 
  specific 
  organisation, 
  (a) 
  The 
  essential 
  

   metabolism 
  of 
  life 
  has 
  to 
  do 
  with 
  the 
  up-building 
  and 
  down-break- 
  

   ing 
  of 
  protein 
  substances 
  in 
  a 
  colloid 
  state, 
  (b) 
  Each 
  living 
  

   creature 
  has 
  its 
  own 
  chemical 
  individuality 
  and 
  its 
  own 
  specific 
  

   microscopic 
  and 
  ultra-microscopic 
  architecture, 
  (c) 
  Part 
  of 
  the 
  

   secret 
  of 
  life 
  is 
  a 
  correlation 
  of 
  chemical 
  processes 
  so 
  that 
  in 
  

   spite 
  of 
  ceaseless 
  change 
  the 
  organism 
  persists 
  in 
  its 
  integrity 
  

   for 
  days 
  or 
  years 
  or 
  centuries. 
  It 
  is 
  always 
  burning 
  away; 
  but 
  

   it 
  is 
  not 
  consumed. 
  

  

  Secondly 
  there 
  are 
  the 
  capacities 
  of 
  (a) 
  growth, 
  of 
  (b) 
  re- 
  

   production, 
  and 
  of 
  (c) 
  development 
  a 
  triad 
  of 
  qualities. 
  (a) 
  

   Organic 
  growth, 
  an 
  increase 
  in 
  the 
  amount 
  of 
  organised 
  living- 
  

   matter, 
  is 
  at 
  the 
  expense 
  of 
  materials 
  different 
  from 
  those 
  which 
  

   compose 
  'the 
  growing 
  substance; 
  it 
  implies 
  active 
  assimilation 
  

   rather 
  than 
  passive 
  accretion; 
  it 
  is 
  very 
  definitely 
  a 
  regulated 
  

   process. 
  (b) 
  The 
  power 
  of 
  spontaneous 
  division 
  leading 
  on, 
  

   directly 
  or 
  indirectly, 
  to 
  the 
  origin 
  of 
  new 
  individualities 
  is 
  

   one 
  of 
  the 
  momentous 
  distinctions 
  between 
  the 
  living 
  and 
  the 
  

   not-living, 
  (c) 
  Development 
  is 
  the 
  actualisation 
  of 
  the 
  intrinsic 
  

   manifoldness 
  of 
  the 
  liberated 
  fragment, 
  sample, 
  or 
  cell, 
  and 
  may 
  

   be 
  brought 
  into 
  line 
  with 
  the 
  process 
  of 
  repairing 
  the 
  specific 
  

   organisation. 
  

  

  