﻿Periodic 
  Mutations 
  713 
  

  

  the 
  physicists 
  are 
  harmonized 
  on 
  the 
  ground 
  of 
  

   the 
  theory 
  of 
  mutation. 
  

  

  The 
  steps 
  may 
  be 
  surmised 
  to 
  have 
  never 
  been 
  

   essentially 
  larger 
  than 
  in 
  the 
  mutations 
  now 
  

   going 
  on 
  under 
  our 
  eyes, 
  and 
  some 
  thousands 
  of 
  

   them 
  may 
  be 
  estimated 
  as 
  sufficient 
  to 
  account 
  

   for 
  the 
  entire 
  organization 
  of 
  the 
  higher 
  forms. 
  

   Granting 
  between 
  twenty 
  and 
  forty 
  millions 
  

   of 
  years 
  since 
  the 
  beginning 
  of 
  life, 
  the 
  intervals 
  

   between 
  two 
  successive 
  mutations 
  may 
  have 
  

   been 
  centuries 
  and 
  even 
  thousands 
  of 
  years. 
  As 
  

   yet 
  there 
  has 
  been 
  no 
  objection 
  cited 
  against 
  this 
  

   assumption, 
  and 
  hence 
  we 
  see 
  that 
  the 
  lack 
  of 
  

   harmony 
  between 
  the 
  demands 
  of 
  biologists 
  and 
  

   the 
  results 
  of 
  the 
  physicists 
  disappears 
  in 
  the 
  

   light 
  of 
  the 
  theory 
  of 
  mutation. 
  

  

  Summing 
  up 
  the 
  results 
  of 
  this 
  discussion, 
  we 
  

   may 
  justifiably 
  assert 
  that 
  the 
  conclusions 
  de- 
  

   rived 
  from 
  the 
  observations 
  and 
  experiments 
  

   made 
  with 
  evening-primroses 
  and 
  other 
  plants 
  

   in 
  the 
  main 
  agree 
  satisfactorily 
  with 
  the 
  in- 
  

   ferences 
  drawn 
  from 
  paleontologic, 
  geologic 
  

   and 
  systematic 
  evidence. 
  Obviously 
  these 
  ex- 
  

   periments 
  are 
  wonderfully 
  supported 
  by 
  the 
  

   whole 
  of 
  our 
  knowledge 
  concerning 
  evolution. 
  

   For 
  this 
  reason 
  the 
  laws 
  discovered 
  in 
  the 
  ex- 
  

   perimental 
  garden 
  may 
  be 
  considered 
  of 
  great 
  

   importance, 
  and 
  they 
  may 
  guide 
  us 
  in 
  our 
  fur- 
  

   ther 
  inquiries. 
  Without 
  doubt 
  many 
  minor 
  

  

  