﻿THE 
  CRITERIA 
  OF 
  LIVINGNESS 
  89 
  

  

  cannot 
  operate 
  except 
  under 
  certain 
  conditions, 
  it 
  is 
  an 
  ex- 
  

   traordinary 
  fact 
  that 
  some 
  creatures 
  can 
  be 
  re-made 
  even 
  

   after 
  mincing. 
  If 
  a 
  sponge 
  be 
  minced 
  up 
  and 
  forced 
  through 
  

   a 
  cloth 
  filter, 
  little 
  drops 
  of 
  the 
  debris, 
  placed 
  in 
  appropriate 
  

   environment, 
  will 
  at 
  once 
  proceed 
  to 
  build 
  themselves 
  up 
  

   into 
  new 
  sponges. 
  The 
  characteristic 
  metabolism 
  is 
  retained, 
  

   re-differentiation 
  sets 
  in, 
  the 
  tiny 
  mass 
  begins 
  to 
  feed 
  and 
  

   grow, 
  the 
  normal 
  organisation 
  is 
  restored, 
  the 
  sponge 
  is 
  once 
  

   more 
  a 
  going 
  concern. 
  The 
  restoration 
  of 
  the 
  sponge 
  from 
  

   a 
  drop 
  of 
  debris 
  is 
  as 
  different 
  from 
  the 
  re-building 
  of 
  a 
  

   crystal 
  from 
  a 
  fragment, 
  as 
  the 
  highly 
  differentiated 
  sponge 
  

   from 
  the 
  very 
  homogeneous 
  crystal, 
  or 
  as 
  the 
  intensely 
  meta- 
  

   bolic 
  living 
  sponge 
  from 
  the 
  self-contained, 
  though 
  certainly 
  

   not 
  inert, 
  crystal. 
  

  

  (4) 
  If 
  living 
  implies 
  persistent 
  metabolism, 
  we 
  must 
  

   admit 
  a 
  saving-clause 
  to 
  the 
  effect 
  that 
  the 
  metabolism 
  may 
  

   sink 
  at 
  times 
  to 
  a 
  minimum. 
  Further 
  investigation 
  will 
  

   make 
  things 
  clearer, 
  but 
  there 
  is 
  difficulty 
  at 
  present 
  in 
  

   regard 
  to 
  the 
  familiar 
  facts 
  that 
  dried 
  seeds 
  may 
  retain 
  their 
  

   power 
  of 
  germinating 
  for 
  as 
  long 
  as 
  a 
  man 
  lives, 
  or 
  that 
  

   desiccated 
  animals 
  and 
  germs 
  of 
  animals 
  (as 
  in 
  the 
  case 
  

   of 
  some 
  thread-worms, 
  rotifers, 
  bear-animalcules, 
  and 
  small 
  

   crustaceans) 
  may 
  remain 
  in 
  a 
  state 
  of 
  so-called 
  suspended 
  

   animation 
  for, 
  it 
  may 
  be, 
  a 
  dozen 
  years. 
  Small 
  Nematode 
  

   worms 
  have 
  been 
  known 
  to 
  revive 
  after 
  being 
  fourteen 
  years 
  

   dry 
  alive 
  rather 
  than 
  living. 
  It 
  has 
  not 
  been 
  satisfactorily 
  

   proved 
  that 
  mummy 
  wheat 
  germinates, 
  but 
  Becquerel 
  got 
  

   seedlings 
  from 
  seeds 
  which 
  had 
  lain 
  for 
  eighty-seven 
  years 
  

   in 
  a 
  herbarium 
  a 
  Jiortus 
  siccus 
  indeed. 
  

  

  Becquerel 
  took 
  seeds 
  of 
  wheat, 
  mustard, 
  and 
  lucerne, 
  and 
  

   perforated 
  their 
  air-tight 
  seed 
  coats 
  ; 
  dried 
  them 
  in 
  a 
  vacuum 
  

   at 
  40 
  C. 
  for 
  six 
  months; 
  sealed 
  them 
  up 
  in 
  an 
  almost 
  ex- 
  

  

  