﻿189^. 
  J 
  BOTANICAL 
  GAZETTE. 
  265 
  

  

  all 
  these 
  structures 
  and 
  what 
  is 
  their 
  derivation. 
  It 
  has 
  long 
  

   been 
  known 
  that 
  flowers 
  and 
  fruits 
  are 
  produced 
  from 
  whorls 
  

   of 
  especially 
  developed 
  leaves. 
  Let 
  us 
  compare 
  a 
  mature 
  

   leat 
  with 
  one 
  of 
  the 
  loculi, 
  and 
  note 
  the 
  similarities 
  (figs. 
  

   5 
  and 
  6). 
  In 
  the 
  leaf 
  a 
  large 
  midvein 
  extends 
  through 
  the 
  

   whole 
  length, 
  graduall}- 
  tapering 
  trom 
  the 
  base 
  toward 
  the 
  tip. 
  

   A 
  very 
  small 
  irregular 
  marginal 
  vein 
  is 
  seen, 
  and 
  a 
  short 
  space 
  

   mward 
  from 
  the 
  marginal 
  vein 
  and 
  connected 
  withjt 
  at 
  va- 
  

   rious 
  places, 
  is 
  a 
  submarginal 
  vein. 
  A 
  hand 
  magnifier 
  is 
  

   needed 
  to 
  make 
  out 
  the 
  marginal 
  vein 
  in 
  the 
  leaf. 
  From 
  the 
  

   midvein 
  other 
  veins 
  pass 
  obliquely 
  toward 
  the 
  margin 
  ; 
  from 
  

   these 
  again 
  minute 
  branches 
  pass 
  off, 
  forming 
  a 
  close 
  net- 
  

  

  work 
  of 
  veins. 
  Now 
  

  

  Along 
  the 
  

  

  center 
  of 
  the 
  back 
  is 
  a 
  large 
  fibro-vascular 
  bundle 
  slowly 
  

   tapering 
  toward 
  the 
  tips. 
  With 
  this 
  bundle 
  many 
  others 
  are 
  

   connected, 
  which 
  form 
  a 
  network 
  over 
  the 
  back 
  of 
  the 
  locu- 
  

   Jus, 
  similar 
  to 
  the 
  network 
  of 
  veins 
  on 
  the 
  back 
  of 
  the 
  leaf. 
  

   The 
  meshes 
  formed 
  by 
  the 
  bundles 
  are 
  larger 
  toward 
  the 
  

   base 
  of 
  the 
  loculus 
  than 
  at 
  and 
  beyond 
  the 
  center. 
  It 
  will 
  be 
  

   seen 
  in 
  a 
  side 
  view 
  of 
  a 
  loculus 
  (fig. 
  7) 
  that 
  a 
  large 
  bun- 
  

   ale 
  passing 
  along 
  its 
  inner 
  angle 
  through 
  the 
  center 
  column 
  

   curves 
  about 
  the 
  end 
  of 
  the 
  loculus 
  and 
  passes 
  back 
  along 
  

   ^^e 
  upper 
  lateral 
  angle 
  to 
  the 
  end 
  from 
  which 
  it 
  started, 
  

   i 
  his 
  IS 
  the 
  bundle 
  previously 
  mentioned 
  in 
  the 
  description 
  

   ot 
  the 
  cross 
  section 
  as 
  being 
  seen 
  at 
  the 
  angle 
  between 
  any 
  

   two 
  loculi. 
  The 
  only 
  way 
  in 
  which 
  I 
  can 
  account 
  for 
  this 
  

   nbro-vascular 
  bundle 
  and 
  its 
  peculiar 
  shape, 
  is 
  that 
  it 
  is 
  formed 
  

   Y 
  the 
  marginal 
  and 
  submarginal 
  veins 
  of 
  the 
  leaf. 
  As 
  has 
  

   already 
  been 
  noticed, 
  there 
  are 
  several 
  points 
  of 
  connection 
  

   between 
  these 
  veins 
  so 
  that 
  by 
  the 
  development 
  of 
  the 
  vein 
  

   connecting 
  them, 
  at 
  or 
  below 
  the 
  place 
  where 
  the 
  style 
  drops 
  

   on, 
  the 
  required 
  curve 
  is 
  made 
  and 
  the 
  bundle 
  receives 
  its 
  

   Shape. 
  One 
  fact 
  favoring 
  this 
  supposition 
  is 
  that 
  the 
  pulp 
  

   flubs 
  are 
  not 
  attached 
  to 
  the 
  side 
  walls 
  but 
  to 
  the 
  back 
  of 
  the 
  

   ^culus. 
  The 
  great 
  development 
  of 
  the 
  space 
  between 
  the 
  

   marginal 
  and 
  submarginal 
  veins 
  of 
  the 
  leaf 
  necessary 
  to 
  form 
  

   the 
  side 
  of 
  the 
  loculus 
  would 
  not 
  be 
  favorable 
  to 
  the 
  develop- 
  

   ment 
  of 
  the 
  leaf 
  hairs 
  of 
  that 
  region. 
  Another 
  favorable 
  

   ^'^ct 
  IS 
  that 
  a 
  longitudinal 
  section 
  of 
  .a 
  fruit 
  before 
  the 
  pistil 
  

   nas 
  fallen, 
  if 
  made 
  at 
  the 
  right 
  place, 
  shows 
  the 
  bundle 
  al- 
  

   ready 
  curved 
  about 
  the 
  loculus 
  at 
  a 
  very 
  short 
  distance 
  from 
  

   ^be 
  pistil. 
  The 
  fibro-vascular 
  bundles 
  in 
  the 
  rind 
  at 
  right 
  

   ^,"gles 
  with 
  the 
  large 
  mid 
  bundles 
  probably 
  represent 
  small 
  

   '^>«s 
  passing 
  from 
  the 
  larger 
  veins 
  to 
  the 
  surface 
  of 
  the 
  leat. 
  

  

  