﻿PLANT 
  BREEDING 
  193 
  

  

  5. 
  (iive 
  examples 
  of 
  plaiits 
  that 
  " 
  come 
  true 
  to 
  seed 
  " 
  and 
  of 
  others 
  

   that 
  do 
  not. 
  How 
  does 
  this 
  determine 
  the 
  mode 
  of 
  plant 
  breeding 
  

   necessary 
  in 
  each 
  case 
  ? 
  

  

  6. 
  How 
  do 
  you 
  account 
  for 
  the 
  fact 
  that 
  there 
  are 
  so 
  many 
  slight 
  

   differences 
  in 
  long-known 
  varieties 
  of 
  cultivated 
  plants, 
  as 
  Baldwin 
  

   apples, 
  Crawford 
  peaches, 
  Bartlett 
  pears? 
  

  

  7. 
  In 
  saving 
  seed 
  corn 
  of 
  a 
  valuable 
  variety, 
  what 
  can 
  you 
  do 
  to 
  

   keep 
  the 
  quality 
  up 
  to 
  the 
  highest 
  point? 
  Name 
  several 
  points 
  to 
  be 
  

   attended 
  to. 
  Send 
  to 
  your 
  state 
  agricultural 
  experiment 
  station 
  for 
  

   reports 
  upon 
  the 
  change 
  in 
  yield 
  produced 
  by 
  proper 
  selection 
  of 
  seed. 
  

  

  8. 
  Why 
  is 
  it 
  important 
  for 
  seed 
  corn 
  but 
  not 
  for 
  wheat 
  that 
  plots 
  

   of 
  different 
  varieties 
  should 
  be 
  kept 
  widely 
  separated. 
  

  

  9. 
  If 
  you 
  were 
  to 
  undertake 
  to 
  hybridize 
  the 
  following 
  plants, 
  

   which 
  would 
  be 
  the 
  easiest 
  to 
  manipulate 
  and 
  which 
  the 
  most 
  diffi- 
  

   cult 
  ? 
  Give 
  reasons. 
  Thistle 
  (fig. 
  Ill), 
  willow 
  (fig. 
  105), 
  arum 
  (fig. 
  132), 
  

   grape 
  (fig. 
  120), 
  corn 
  (figs. 
  126 
  and 
  127). 
  

  

  10. 
  If 
  you 
  succeeded 
  in 
  hybridizing 
  two 
  species 
  of 
  tulips, 
  A 
  and 
  B, 
  

   could 
  you 
  propagate 
  the 
  hybrid 
  by 
  planting 
  the 
  bulb 
  matured 
  during 
  

   that 
  season 
  ? 
  Give 
  full 
  reasons 
  for 
  your 
  answer. 
  

  

  