﻿190 
  INTRODUCTION 
  TO 
  BOTANY 
  

  

  habit 
  of 
  growth, 
  and 
  form 
  of 
  root, 
  stem, 
  or 
  leaf 
  (fig. 
  161). 
  

   They 
  may 
  show 
  much 
  variation 
  in 
  the 
  flowers 
  or 
  in 
  the 
  fruit 
  

   (fig. 
  160). 
  The 
  physiological 
  characters 
  of 
  the 
  seedlings 
  may 
  

   vary 
  greatly 
  ; 
  that 
  is, 
  they 
  may 
  have 
  very 
  different 
  periods 
  

   of 
  maturity 
  and 
  of 
  hardiness 
  in 
  resisting 
  drought, 
  frost, 
  or 
  

   disease. 
  If 
  any 
  of 
  the 
  characters 
  of 
  the 
  hybrid 
  are 
  highly 
  de- 
  

   sirable, 
  the 
  breeder 
  will 
  try 
  to 
  perpetuate 
  the 
  type. 
  If 
  he 
  is 
  

   dealing 
  with 
  a 
  plant 
  like 
  the 
  potato 
  or 
  the 
  bulb-bearing 
  plants, 
  

   which 
  can 
  be 
  propagated 
  by 
  planting 
  the 
  tubers, 
  bulbs, 
  or 
  simi- 
  

   lar 
  parts, 
  the 
  effort 
  to 
  introduce 
  the 
  new 
  variety 
  will 
  probably 
  

   succeed 
  ; 
  and 
  it 
  is 
  not 
  difficult 
  to 
  propagate 
  new 
  varieties 
  of 
  

   grapes 
  by 
  cuttings, 
  and 
  apples, 
  pears, 
  quinces, 
  peaches, 
  plums, 
  

   and 
  cherries 
  by 
  grafting 
  or 
  budding; 
  but 
  in 
  the 
  case 
  of 
  plants 
  

   which 
  must 
  be 
  grown 
  from 
  the 
  seed 
  the 
  perpetuation 
  of 
  hybrid 
  

   varieties 
  is 
  often 
  difficult 
  or 
  impossible. 
  Sometimes 
  the 
  seed 
  

   of 
  the 
  hybrid 
  seedling 
  cannot 
  be 
  made 
  to 
  grow, 
  and 
  some- 
  

   times 
  the 
  plants 
  will 
  not 
  come 
  true 
  from 
  the 
  seed, 
  so 
  that 
  

   the 
  promising 
  hybrid 
  variety 
  is 
  represented 
  only 
  by 
  one 
  plant, 
  

   which 
  leaves 
  no 
  descendants 
  like 
  itself. 
  Professor 
  L. 
  H. 
  Bailey, 
  

   one 
  of 
  the 
  highest 
  authorities 
  on 
  plant 
  breeding, 
  has 
  by 
  cross- 
  

   ing 
  obtained 
  about 
  a 
  thousand 
  wholly 
  new 
  types 
  of 
  pumpkins 
  

   and 
  squashes, 
  and 
  never 
  succeeded 
  in 
  perpetuating 
  a 
  single 
  one. 
  

  

  179. 
  Instances 
  of 
  successful 
  hybrids. 
  A 
  few 
  successful 
  varie- 
  

   ties 
  of 
  wheat 
  and 
  corn 
  are 
  the 
  result 
  of 
  hybridization, 
  and 
  more 
  

   may 
  be 
  expected 
  in 
  the 
  future. 
  Many 
  good 
  grapes 
  are 
  knm\ 
  n 
  

   to 
  be 
  hybrids, 
  and 
  so 
  are 
  probably 
  a 
  few 
  of 
  the 
  best, 
  like 
  the 
  

   Delaware 
  and 
  Catawba. 
  Some 
  good 
  blackberries 
  and 
  many 
  

   excellent 
  plums 
  have 
  been 
  obtained 
  by 
  hybridization. 
  Citrous 
  

   fruits 
  have 
  been 
  successfully 
  hybridized. 
  1 
  Many 
  of 
  our 
  most 
  

   ornamental 
  flowers, 
  especially 
  varieties 
  of 
  Canna, 
  Amaryllis, 
  and. 
  

   G-lnlioliix, 
  together 
  with 
  great 
  numbers 
  of 
  orchids, 
  are 
  hybrids. 
  

  

  180. 
  Some 
  rules 
  for 
  plant 
  breeding. 
  2 
  Neither 
  the 
  science 
  

   nor 
  the 
  art 
  of 
  plant 
  breeding 
  can 
  be 
  taught 
  wholly 
  from 
  

  

  1 
  See 
  Yearbook 
  of 
  tin 
  /v/oY///oi/ 
  nf 
  .!<///<(/// 
  un. 
  T.I04. 
  

  

  2 
  See 
  L.H. 
  Bailey, 
  Plant 
  -I'.ivciling, 
  Lecture 
  III. 
  The 
  Macmillan 
  Company, 
  

   New 
  York. 
  

  

  