﻿Multiplication 
  of 
  Extremes 
  757 
  

  

  the 
  manifold 
  aspects 
  of 
  this 
  intricate 
  problem. 
  

   These 
  fall 
  under 
  two 
  heads, 
  the 
  exigencies 
  of 
  

   practice, 
  and 
  the 
  physiologic 
  laws 
  of 
  varia- 
  

   bility. 
  Of 
  course, 
  only 
  the 
  latter 
  heading 
  conies 
  

   within 
  the 
  limits 
  of 
  our 
  discussion 
  which 
  in- 
  

   cludes 
  two 
  main 
  points. 
  First 
  conies 
  the 
  gen- 
  

   eral 
  law 
  of 
  fluctuation 
  that, 
  though 
  slight 
  

   deviations 
  from 
  the 
  average 
  may 
  be 
  found 
  

   by 
  thousands, 
  or 
  rather 
  in 
  nearly 
  every 
  in- 
  

   dividual, 
  larger 
  and 
  therefore 
  important 
  de- 
  

   viations 
  are 
  very 
  rare. 
  Thousands 
  of 
  seedlings 
  

   must 
  be 
  examined 
  carefully 
  in 
  order 
  to 
  find 
  one 
  

   or 
  two 
  from 
  which 
  it 
  might 
  be 
  profitable 
  to 
  

   start 
  a 
  new 
  race. 
  This 
  point 
  is 
  the 
  same 
  

   for 
  practical 
  and 
  for 
  scientific 
  investigation. 
  

   In 
  the 
  second 
  place 
  however, 
  a 
  digression 
  

   is 
  met 
  with. 
  The 
  practical 
  man 
  must 
  take 
  

   into 
  consideration 
  all 
  the 
  varying 
  qualities 
  of 
  

   his 
  improved 
  strains. 
  Some 
  of 
  them 
  must 
  be 
  

   increased 
  and 
  others 
  be 
  decreased, 
  and 
  their 
  

   common 
  dependency 
  on 
  external 
  conditions 
  

   often 
  makes 
  it 
  very 
  difficult 
  to 
  discover 
  the 
  de- 
  

   sired 
  combinations. 
  It 
  is 
  obvious, 
  however, 
  

   that 
  the 
  neglect 
  of 
  one 
  quality 
  may 
  make 
  all 
  im- 
  

   provement 
  of 
  other 
  characters 
  wholly 
  useless. 
  

   No 
  augmentation 
  of 
  sugar-percentage, 
  of 
  size 
  

   and 
  flavor 
  of 
  fruits 
  can 
  counterbalance 
  an 
  in- 
  

   crease 
  in 
  sensitiveness 
  to 
  disease, 
  and 
  so 
  it 
  is 
  

   with 
  other 
  qualities 
  also. 
  

  

  