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  ORGANISM 
  AND 
  MECHANISM 
  

  

  threads 
  composing 
  the 
  skeleton 
  of 
  the 
  common 
  hath 
  sponge, 
  

   large 
  numbers 
  of 
  secretory 
  cells 
  called 
  i 
  spongohlasts 
  ' 
  group 
  

   themselves 
  in 
  double 
  file 
  every 
  here 
  and 
  there 
  through- 
  

   out 
  the 
  middle 
  stratum 
  of 
  the 
  sponge, 
  as 
  if 
  some 
  unseen 
  

   captain 
  marshalled 
  them. 
  Up 
  the 
  middle 
  of 
  the 
  double 
  file 
  

   the 
  spongin 
  is 
  secreted, 
  made 
  at 
  the 
  expense 
  of 
  the 
  living 
  

   matter 
  of 
  the 
  spongoblasts, 
  and 
  the 
  many 
  individual 
  contri- 
  

   butions 
  coalesce 
  into 
  a 
  spongin-fibre. 
  

  

  In 
  his 
  Science 
  and 
  Philosophy 
  of 
  the 
  Organism 
  (1908), 
  

   Driesch 
  has 
  with 
  unexampled 
  thoroughness 
  and 
  subtlety 
  

   tested 
  the 
  possibilities 
  of 
  mechanistic 
  description 
  with 
  

   particular 
  reference 
  to 
  the 
  facts 
  of 
  development. 
  He 
  reaches 
  

   a 
  conclusion 
  of 
  the 
  first 
  importance 
  : 
  " 
  ISTo 
  kind 
  of 
  causality 
  

   based 
  upon 
  the 
  constellations 
  of 
  single 
  physical 
  and 
  chemical 
  

   acts 
  can 
  account 
  for 
  organic 
  individual 
  development; 
  this 
  

   development 
  is 
  not 
  to 
  be 
  explained 
  by 
  any 
  hypothesis 
  about 
  

   configuration 
  of 
  physical 
  and 
  chemical 
  agents. 
  . 
  . 
  . 
  Life, 
  

   at 
  least 
  morphogenesis, 
  is 
  not 
  a 
  specialised 
  arrangement 
  

   of 
  inorganic 
  events; 
  biology, 
  therefore, 
  is 
  not 
  applied 
  

   physics 
  and 
  chemistry; 
  life 
  is 
  something 
  apart, 
  and 
  bi- 
  

   ology 
  is 
  an 
  independent 
  science." 
  But 
  what, 
  it 
  may 
  be 
  said, 
  

   of 
  the 
  science 
  of 
  * 
  developmental 
  mechanics 
  ' 
  and 
  of 
  the 
  

   lengthening 
  row 
  of 
  volumes 
  entitled 
  Arcliiv 
  fur 
  Entwick- 
  

   lungsmechanikf 
  The 
  first 
  answer 
  is, 
  that, 
  after 
  all, 
  the 
  

   developing 
  embryo 
  is 
  a 
  material 
  system, 
  and 
  must 
  exhibit 
  

   chemical 
  and 
  physical 
  means. 
  Development 
  shows 
  a 
  continu- 
  

   ous 
  action 
  and 
  reaction 
  between 
  an 
  implicit 
  organisation 
  and 
  

   the 
  environing 
  conditions, 
  and 
  ' 
  developmental 
  mechanics 
  ' 
  

   so-called 
  is 
  in 
  great 
  part 
  concerned 
  with 
  discovering 
  the 
  

   correlation 
  between 
  steps 
  in 
  development 
  and 
  their 
  ap- 
  

   propriate 
  external 
  stimulation 
  and 
  nurture. 
  These 
  cor- 
  

   relations 
  are 
  of 
  great 
  interest, 
  but 
  as 
  our 
  knowledge 
  of 
  them 
  

  

  