﻿698 
  Mutations 
  

  

  sops, 
  petals 
  of 
  Nymphaea 
  may 
  be 
  cited 
  as 
  in- 
  

   stances, 
  and 
  they 
  are 
  as 
  perfectly 
  preserved 
  as 
  

   the 
  best 
  herbarium-specimens 
  of 
  the 
  present 
  

   time. 
  The 
  petals 
  and 
  stamens 
  retain 
  their 
  orig- 
  

   inal 
  colors, 
  displaying 
  them 
  as 
  brightly 
  as 
  is 
  

   consistent 
  with 
  their 
  dry 
  state. 
  

  

  Paleontologic 
  evidence 
  points 
  to 
  the 
  same 
  

   conclusion. 
  Of 
  course 
  the 
  remains 
  are 
  incom- 
  

   plete, 
  and 
  rarely 
  adequate 
  for 
  a 
  close 
  compari- 
  

   son. 
  The 
  range 
  of 
  fluctuating 
  variability 
  should 
  

   be 
  examined 
  first, 
  but 
  the 
  test 
  of 
  elementary 
  

   species 
  given 
  by 
  their 
  constancy 
  from 
  seed 
  can- 
  

   not, 
  of 
  course, 
  be 
  applied. 
  Apart 
  from 
  these 
  

   difficulties, 
  paleontologists 
  agree 
  in 
  recognizing 
  

   the 
  very 
  great 
  age 
  of 
  large 
  numbers 
  of 
  species. 
  

   It 
  would 
  require 
  a 
  too 
  close 
  survey 
  of 
  geologic 
  

   facts 
  to 
  go 
  into 
  details 
  on 
  this 
  point. 
  Suffice 
  it 
  

   to 
  say 
  that 
  in 
  more 
  recent 
  Tertiary 
  deposits 
  

   many 
  species 
  have 
  been 
  identified 
  with 
  living 
  

   forms. 
  In 
  the 
  Miocene 
  period 
  especially, 
  the 
  

   similarity 
  of 
  the 
  types 
  of 
  phanerogamic 
  plants 
  

   with 
  their 
  present 
  offspring, 
  becomes 
  so 
  striking 
  

   that 
  in 
  a 
  large 
  number 
  of 
  cases 
  specific 
  distinc- 
  

   tions 
  rest 
  in 
  greater 
  part 
  on 
  theoretical 
  con- 
  

   ceptions 
  rather 
  than 
  on 
  real 
  facts. 
  For 
  a 
  long 
  

   time 
  the 
  idea 
  prevailed 
  that 
  the 
  same 
  species 
  

   could 
  not 
  have 
  existed 
  through 
  more 
  than 
  one 
  

   geologic 
  period. 
  Many 
  distinctions 
  founded 
  

   on 
  this 
  belief 
  have 
  since 
  had 
  to 
  be 
  abandoned. 
  

  

  