﻿POLLINATION" 
  AND 
  FERTILIZATION 
  

  

  143 
  

  

  maturing, 
  close 
  over 
  the 
  stigmas 
  and 
  insure 
  self-pollination. 
  

   The 
  fact 
  that 
  seeds 
  are 
  abundantly 
  produced 
  shows 
  tliat 
  

  

  the 
  pollination 
  is 
  

   effective. 
  

  

  136. 
  Corn; 
  pol- 
  

   lination 
  by 
  wind. 
  

   Indian 
  corn 
  af- 
  

   fords 
  an 
  admirable 
  

   example 
  of 
  polli- 
  

   nation 
  effected 
  by 
  

   aid 
  of 
  the 
  wind. 
  

   The 
  pollen 
  is 
  pro- 
  

   duced 
  in 
  the 
  staminate 
  flower 
  

   clusters, 
  which 
  are 
  commonly 
  

   known 
  as 
  the 
  tassel 
  (fig. 
  126), 
  

   borne 
  at 
  the 
  summit 
  of 
  the 
  

   cornstalk. 
  Each 
  cluster 
  con- 
  

   sists 
  of 
  many 
  stamens, 
  and 
  every 
  stamen 
  

   produces 
  a 
  multitude 
  of 
  dry, 
  dust-like 
  pol- 
  

   len 
  grains, 
  which 
  are 
  carried 
  for 
  long 
  dis- 
  

   tances 
  by 
  the 
  wind. 
  The 
  familiar 
  corn 
  silk, 
  

   which 
  protrudes 
  from 
  inside 
  the 
  husk 
  of 
  

   the 
  young 
  ear 
  of 
  corn, 
  is 
  composed 
  of 
  

   many 
  thread-like 
  styles 
  (one 
  from 
  each 
  

   grain 
  of 
  corn). 
  The 
  styles 
  terminate 
  in 
  a 
  

   two-forked, 
  hairy 
  stigma 
  (fig. 
  127 
  (7, 
  st). 
  

   The 
  brush-like 
  character 
  of 
  the 
  protruding 
  

   stigmas 
  makes 
  them 
  very 
  efficient 
  in 
  catch- 
  

   ing 
  flying 
  pollen 
  grains. 
  

  

  If 
  the 
  pollen 
  from 
  a 
  corn 
  plant 
  is 
  shaken 
  

   down 
  upon 
  the 
  stigmas 
  of 
  the 
  same 
  plant, 
  

   self-pollination 
  only 
  is 
  effected 
  and 
  poor 
  seed 
  results. 
  If 
  the 
  

   pollen 
  which 
  pollinates 
  an 
  ear 
  comes 
  from 
  another 
  corn 
  plant, 
  

   cross-pollination 
  is 
  effected 
  and 
  good 
  seed 
  results. 
  Figure 
  159 
  

   shows 
  the 
  difference 
  in 
  growth 
  between 
  plants 
  produced 
  in 
  

   the 
  next 
  generation 
  from 
  the 
  two 
  kinds 
  of 
  seed. 
  

  

  FIG. 
  120. 
  Part 
  of 
  a 
  

   corn 
  tassel 
  (stami- 
  

   nate 
  flower 
  cluster) 
  

  

  Z>r,abraot; 
  .sV.stamriis. 
  

   One 
  half 
  natural 
  size 
  

  

  