﻿90 
  THE 
  CRITERIA 
  OF 
  LIVINGNESS 
  

  

  hausted 
  tube 
  for 
  a 
  year 
  ; 
  submitted 
  tbem 
  to 
  the 
  temperature 
  

   of 
  liquid 
  air 
  (- 
  -190) 
  for 
  three 
  weeks, 
  and 
  of 
  liquid 
  hydro- 
  

   gen 
  (- 
  -250) 
  for 
  three 
  days; 
  and 
  then 
  put 
  them 
  on 
  moist 
  

   cotton 
  wool, 
  where 
  they 
  germinated. 
  We 
  are 
  forced 
  by 
  such 
  

   experiments 
  to 
  realise 
  that 
  life 
  is 
  not 
  an 
  entity 
  but 
  a 
  relation 
  

   between 
  organism 
  and 
  environment, 
  but 
  we 
  must 
  have 
  more 
  

   facts 
  before 
  we 
  deal 
  effectively 
  with 
  the 
  difficulties 
  which 
  

   the 
  facts 
  raise. 
  Does 
  the 
  process 
  of 
  living 
  suffer 
  complete 
  

   interruption, 
  and 
  recommence 
  when 
  water 
  soaks 
  in, 
  and 
  

   oxygen 
  after 
  it, 
  as 
  Becquerel 
  seems 
  to 
  think 
  ; 
  or 
  does 
  the 
  

   metabolism 
  sink 
  to 
  a 
  minimum, 
  like 
  the 
  combustion 
  of 
  a 
  

   sleeping 
  fire 
  ? 
  Very 
  interesting, 
  in 
  this 
  connection, 
  is 
  Pro- 
  

   fessor 
  Waller's 
  observation 
  that 
  as 
  long 
  as 
  a 
  tissue 
  is 
  living, 
  

   or 
  an 
  egg 
  capable 
  of 
  development, 
  or 
  a 
  seed 
  able 
  to 
  germinate, 
  

   there 
  is 
  a 
  particular 
  electrical 
  reaction 
  the 
  l 
  blaze 
  ' 
  reaction 
  

   which 
  disappears 
  when 
  living 
  has 
  irrecoverably 
  ceased. 
  

  

  (5) 
  The 
  criterion 
  of 
  an 
  organism 
  to 
  which 
  we 
  have 
  given 
  

   prominence 
  is 
  that 
  of 
  persistence, 
  which 
  is 
  obviously 
  relative. 
  

   Some 
  organisms 
  can 
  keep 
  agoing 
  for 
  a 
  hundred 
  years, 
  some 
  

   for 
  only 
  a 
  hundred 
  days, 
  and 
  some 
  for 
  only 
  a 
  hundred 
  hours. 
  

   The 
  question 
  arises 
  as 
  to 
  the 
  limit. 
  Is 
  it 
  possible 
  that 
  there 
  

   were 
  primeval 
  organisms 
  which 
  lived 
  for 
  only 
  a 
  hundred 
  

   seconds 
  ? 
  If 
  so, 
  how 
  would 
  these 
  hypothetical 
  creatures 
  

   differ 
  from 
  the 
  pill 
  of 
  potassium 
  which 
  flares 
  itself 
  out, 
  

   rushing 
  about 
  on 
  the 
  surface 
  of 
  the 
  basin 
  of 
  water 
  on 
  which 
  

   it 
  has 
  been 
  thrown? 
  The 
  answer 
  must 
  be, 
  that 
  it 
  is 
  not 
  

   the 
  length 
  of 
  life 
  that 
  counts 
  ; 
  the 
  criterion 
  is 
  whether, 
  

   alongside 
  of 
  disruptive 
  processes 
  associated 
  with 
  protein 
  sub- 
  

   stances, 
  there 
  were 
  also 
  correlated 
  constructive 
  processes, 
  

   making 
  for 
  repair 
  and 
  self-maintenance. 
  Some 
  Infusorians 
  

   divide 
  more 
  than 
  once 
  every 
  day, 
  some 
  Bacteria 
  divide 
  more 
  

   than 
  once 
  every 
  hour, 
  and 
  these 
  may 
  be 
  near 
  the 
  limit 
  of 
  

  

  