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  PROCEEDINGS 
  OF 
  THE 
  CALIFORNIA 
  

  

  reach 
  the 
  simplest 
  expression 
  in 
  the 
  microscopic 
  cell 
  or 
  microscopic 
  spherule 
  of 
  

   protoplasm. 
  The 
  equation 
  of 
  life 
  is 
  reduced 
  to 
  its 
  simplest 
  terms, 
  and 
  then, 
  

   only, 
  we 
  begin 
  to 
  find 
  the 
  value 
  of 
  the 
  unknown 
  quantity. 
  This 
  series 
  I 
  will 
  call 
  

   the 
  natural 
  Iriitory 
  scries. 
  Again, 
  nature 
  prepares 
  for 
  us 
  another 
  series 
  of 
  ex- 
  

   periments. 
  Commencing 
  with 
  the 
  mature 
  condition 
  of 
  the 
  higher 
  animals, 
  and 
  

   going 
  backwards 
  along 
  the 
  line 
  of 
  individual 
  history 
  through 
  the 
  stages 
  of 
  em- 
  

   bryo, 
  egg 
  and 
  germ, 
  we 
  find 
  again 
  the 
  phenomena 
  of 
  life 
  become 
  simpler 
  and 
  

   simpler, 
  until 
  we 
  again 
  reach 
  the 
  simplest 
  condition 
  in 
  the 
  microscopic 
  cell. 
  

   This, 
  I 
  will 
  call 
  the 
  embryonic 
  series. 
  Again, 
  that 
  there 
  might 
  be 
  no 
  excuse 
  for 
  

   man's 
  ignorance 
  of 
  the 
  laws 
  of 
  life, 
  nature 
  prepares 
  still 
  another 
  series 
  of 
  ex- 
  

   periments. 
  Commencing 
  with 
  the 
  fauna 
  and 
  flora 
  of 
  the 
  present 
  time, 
  and 
  go- 
  

   ing 
  back 
  along 
  the 
  track 
  of 
  geological 
  history, 
  through 
  Tertiary, 
  Secondary, 
  

   Palaezoic 
  and 
  Eozoic, 
  to 
  the 
  very 
  dawn 
  of 
  life, 
  we 
  find 
  a 
  series 
  of 
  organic 
  forms 
  

   becoming 
  simpler 
  and 
  simpler, 
  until 
  we 
  again 
  reach 
  the 
  simplest 
  terra 
  in 
  the 
  

   lowest 
  conceivable 
  forms 
  of 
  life. 
  This 
  I 
  will 
  call 
  the 
  geological 
  or 
  palsontolog- 
  

   ical, 
  or 
  evolution 
  series. 
  

  

  Now 
  it 
  has 
  been 
  by 
  extensive 
  comparison 
  in 
  each 
  of 
  these 
  series 
  up 
  and 
  

   down, 
  and 
  by 
  extensive 
  comparison 
  of 
  the 
  three 
  series 
  with 
  each 
  other, 
  that 
  

   our 
  knowledge 
  of 
  organisms 
  has 
  gradually 
  become 
  scientific 
  ; 
  that 
  mere 
  accu- 
  

   mulation 
  of 
  facts 
  and 
  phenomena 
  has 
  grown 
  with 
  science 
  ; 
  that 
  a 
  mere 
  heap 
  of 
  

   useless 
  rubbish 
  has 
  been 
  changed 
  into 
  a 
  beautiful 
  edifice. 
  This 
  is 
  what 
  is 
  

   called 
  the 
  method 
  of 
  comparison 
  — 
  the 
  great 
  method 
  used 
  in 
  the 
  science 
  of 
  life. 
  

   Yes, 
  anatomy 
  only 
  becomes 
  scientific 
  through 
  comparative 
  anatomy. 
  Physi- 
  

   ology 
  only 
  becomes 
  scientific 
  through 
  comparative 
  physiology 
  ; 
  and 
  I 
  may 
  add, 
  

   psychology 
  will 
  never 
  become 
  scientific 
  except 
  through 
  compar.j/iye 
  psychology. 
  

  

  So 
  much 
  I 
  have 
  said 
  to 
  show 
  you 
  the 
  nature 
  and 
  power 
  of 
  scientific 
  methods 
  

   and 
  especially 
  of 
  that 
  method 
  — 
  the 
  method 
  of 
  comparison 
  — 
  upon 
  which 
  rests 
  

   the 
  whole 
  fabric 
  of 
  the 
  science 
  of 
  organisms. 
  Now 
  what 
  has 
  Agassiz 
  done 
  in 
  

   perfecting 
  this 
  method 
  ? 
  I 
  will 
  attempt 
  to 
  explain. 
  

  

  We 
  have 
  seen 
  that 
  this 
  method 
  consists 
  of 
  three 
  subordinate 
  methods 
  which 
  

   lead 
  to 
  similar 
  results, 
  viz 
  : 
  comparison 
  in 
  the 
  three 
  series, 
  the 
  natural 
  history 
  

   series, 
  the 
  embryonic 
  series, 
  and 
  the 
  geological 
  series. 
  Now 
  Cuvier 
  and 
  his 
  co- 
  

   laborers 
  introduced 
  and 
  perfected 
  comparison 
  in 
  the 
  natural 
  history 
  series 
  and 
  

   thus 
  laid 
  the 
  foundation 
  of 
  scientific 
  zoology 
  ; 
  but 
  Agassiz 
  and 
  Von 
  Baer 
  and 
  

   their 
  co-laborers 
  extended 
  the 
  method 
  of 
  comparison 
  into 
  the 
  embryonic 
  and 
  

   geological 
  series, 
  and 
  also 
  into 
  the 
  relation 
  of 
  the 
  three 
  series 
  to 
  each 
  other 
  ; 
  

   and 
  thus 
  greatly 
  perfected 
  the 
  method 
  and 
  increased 
  its 
  power. 
  Others, 
  no 
  doubt 
  

   many 
  others, 
  assisted 
  in 
  the 
  great 
  work, 
  but 
  Agassiz 
  was 
  unquestionably 
  the 
  

   leader 
  in 
  the 
  movement. 
  For 
  forty 
  years 
  Agassiz 
  worked 
  incessantly, 
  enthusi- 
  

   astically 
  — 
  even 
  to 
  the 
  breaking 
  down 
  of 
  his 
  strong 
  physical 
  constitution 
  and 
  

   the 
  sacrifice 
  of 
  his 
  life 
  — 
  on 
  the 
  ideas 
  and 
  the 
  methods 
  conceived 
  in 
  his 
  youth. 
  

   Is 
  not 
  this 
  a 
  great 
  life 
  ? 
  

  

  Finally, 
  let 
  us 
  glance 
  at 
  -some 
  of 
  the 
  results 
  of 
  Agassiz' 
  method. 
  The 
  direct 
  

   result 
  is 
  too 
  familiar 
  and 
  obvious 
  to 
  dwell 
  on. 
  We 
  see 
  it 
  in 
  the 
  amazing 
  im- 
  

   pulse 
  given 
  to 
  Biology 
  and 
  its 
  consequent 
  great 
  and 
  ever-increasing 
  progress 
  in 
  

  

  