﻿Multiplication 
  of 
  Extremes 
  751 
  

  

  Of 
  course 
  the 
  application 
  is 
  limited, 
  and 
  forage- 
  

   crops 
  and 
  the 
  greater 
  number 
  of 
  vegetables 
  will 
  

   always 
  necessarily 
  be 
  propagated 
  by 
  seed. 
  

  

  Nature 
  ordinarily 
  prefers 
  the 
  sexual 
  way. 
  

   Asexual 
  multiplications, 
  although 
  very 
  common 
  

   with 
  perennial 
  plants, 
  appear 
  not 
  to 
  offer 
  im- 
  

   portant 
  material 
  for 
  selection. 
  Hence 
  it 
  fol- 
  

   lows 
  that 
  in 
  comparing 
  the 
  work 
  of 
  nature 
  

   with 
  that 
  of 
  man, 
  the 
  results 
  of 
  selection 
  fol- 
  

   lowed 
  by 
  vegetative 
  propagation 
  should 
  always 
  

   be 
  carefully 
  excluded. 
  Our 
  large 
  bulb-flowers 
  

   and 
  delicious 
  fruits 
  have 
  nothing 
  in 
  common 
  

   with 
  natural 
  products, 
  and 
  do 
  not 
  yield 
  a 
  stand- 
  

   ard 
  by 
  which 
  to 
  judge 
  nature's 
  work. 
  

  

  It 
  is 
  very 
  difficult 
  for 
  a 
  botanist 
  to 
  give 
  a 
  sur- 
  

   vey 
  of 
  what 
  practice 
  has 
  attained 
  by 
  the 
  asexual 
  

   multiplication 
  of 
  extremes. 
  Nearly 
  all 
  of 
  the 
  

   large 
  and 
  more 
  palatable 
  fruits 
  are 
  due 
  to 
  such 
  

   efforts. 
  Some 
  flowers 
  and 
  garden-plants 
  af- 
  

   ford 
  further 
  instances. 
  By 
  far 
  the 
  greatest 
  

   majority 
  of 
  improved 
  asexual 
  varieties, 
  how- 
  

   ever, 
  are 
  not 
  the 
  result 
  of 
  pure 
  intra-specific 
  

   selection. 
  They 
  are 
  due 
  largely 
  to 
  the 
  choice 
  

   of 
  the 
  best 
  existing 
  elementary 
  species, 
  and 
  to 
  

   some 
  extent 
  to 
  crosses 
  between 
  them, 
  or 
  be- 
  

   tween 
  distinct 
  systematic 
  species. 
  In 
  practice 
  

   selection 
  and 
  hybridization 
  go 
  hand 
  in 
  hand 
  and 
  

   it 
  is 
  often 
  difficult 
  to 
  ascertain 
  what 
  part 
  of 
  

  

  