﻿FOURTH 
  REPORT 
  OF 
  THE 
  DIRECTOR 
  IOX>7 
  149 
  

  

  social 
  and 
  apparently 
  harmless 
  or 
  even 
  mutually 
  advantageous 
  to 
  

   the 
  participants, 
  it 
  is 
  probable 
  that 
  the 
  outcome 
  is 
  infallibly 
  del- 
  

   eterious. 
  

  

  The 
  glass 
  rope 
  sponge 
  (Hyalonema) 
  has 
  its 
  coil 
  of 
  rope, 
  by 
  which 
  

   it 
  anchors 
  itself 
  to 
  the 
  sea 
  bottom, 
  incrusted 
  and 
  shielded 
  by 
  a 
  coral 
  

   (Polythoa) 
  , 
  which 
  spreads 
  like 
  a 
  thin 
  wrap 
  of 
  felt 
  all 
  about 
  it, 
  while 
  its 
  

   ally 
  the 
  Venus 
  Flowerbasket 
  (Euplectella) 
  imprisons 
  a 
  crab 
  in 
  its 
  in- 
  

   terior 
  behind 
  the 
  bars 
  it 
  throws 
  across 
  its 
  aperture 
  but 
  feeds 
  it 
  with 
  

   ever 
  changing 
  water 
  currents 
  ; 
  worms 
  and 
  anthozoan 
  corals 
  grow 
  to 
  

   gether, 
  with 
  the 
  tubes 
  of 
  the 
  former 
  surrounded 
  by 
  the 
  cells 
  of 
  the 
  

   latter, 
  both 
  sweeping 
  the 
  water 
  currents 
  together 
  for 
  food 
  which 
  

   may 
  go 
  to 
  either 
  mouth; 
  dead 
  snail 
  shells 
  in 
  which 
  hermit 
  crabs 
  

   have 
  taken 
  residence 
  are 
  often 
  beset 
  with 
  sea 
  anemones 
  (Sagartia 
  

   and 
  Adamsia) 
  whose 
  stinging 
  cells 
  may 
  scare 
  away 
  the 
  enemies 
  of 
  

   the 
  crab, 
  while 
  the 
  crab 
  favors 
  the 
  fixed 
  anemones 
  by 
  moving 
  his 
  

   establishment 
  from 
  place 
  to 
  place, 
  thus 
  to 
  new 
  feeding 
  grounds. 
  

  

  All 
  these 
  conditions 
  seem 
  on 
  the 
  surface 
  entirely 
  harmless 
  or 
  

   positively 
  advantageous 
  to 
  all 
  parties 
  involved; 
  that 
  is 
  advan- 
  

   tageous 
  in 
  the 
  sense 
  that 
  they 
  make 
  life 
  easier, 
  less 
  arduous, 
  dis- 
  

   courage 
  activity 
  and 
  perfect 
  adaptation. 
  Perfect 
  adaptation, 
  

   however, 
  advantageous 
  to 
  the 
  individual 
  concerned, 
  is 
  the 
  very 
  

   expression 
  of 
  degeneration 
  in 
  symbiotic 
  life. 
  Throughout 
  nature 
  

   complete 
  adaptation 
  makes 
  for 
  stability 
  and 
  long 
  life, 
  incomplete 
  

   adaptation 
  for 
  the 
  restless 
  activity 
  which 
  leads 
  to 
  progress. 
  

  

  The 
  general 
  effect 
  then 
  of 
  all 
  symbiotic 
  conditions 
  is 
  degenera- 
  

   tive. 
  They 
  themselves 
  arise 
  from 
  degenerate 
  tendencies 
  and 
  

   could 
  not 
  exist 
  save 
  that 
  degeneration 
  had 
  already 
  set 
  in. 
  They 
  

   are 
  expressions 
  of 
  this 
  condition 
  and 
  serve 
  to 
  confirm 
  and 
  transmit 
  

   this 
  tendency. 
  The 
  fact 
  is 
  tremendously 
  evident 
  that 
  even 
  the 
  

   most 
  innocent 
  of 
  symbiotic, 
  dependent 
  or 
  attached 
  conditions 
  of 
  

   growth 
  is 
  the 
  leaven 
  of 
  progressive 
  degeneracy. 
  

  

  It 
  is 
  well 
  known 
  that 
  the 
  critical 
  methods 
  of 
  morphology 
  and 
  

   embryology 
  have 
  been 
  requisite 
  to 
  determine 
  the 
  original 
  ancestral 
  

   independence 
  of 
  the 
  most 
  debased 
  of 
  parasites. 
  While 
  the 
  doctors 
  

   of 
  the 
  middle 
  ages 
  wondered 
  over 
  the 
  barnacles 
  and 
  pictured 
  them 
  

   as 
  growing 
  on 
  trees, 
  dropping 
  thence 
  to 
  the 
  ground 
  transformed 
  

   into 
  geese, 
  their 
  real 
  nature 
  as 
  debased 
  crustaceans 
  was 
  not 
  un- 
  

   folded 
  till 
  the 
  life 
  history 
  of 
  the 
  creatures 
  showed 
  that 
  their 
  early 
  

   stages 
  were 
  free 
  and 
  predatory, 
  and 
  the 
  adult 
  condition 
  one 
  of 
  

   extreme 
  adaptation 
  by 
  progressive 
  loss 
  of 
  functions 
  and 
  organs. 
  

   Thus 
  the 
  parasitic 
  and 
  dependent 
  habit 
  is 
  always 
  preceded 
  by 
  a 
  

  

  