﻿G. 
  M, 
  Thomson. 
  — 
  Xotes 
  on 
  Cleistogamic 
  Flowers 
  of 
  the 
  Genus 
  Viola. 
  417 
  

  

  Avliile 
  still 
  ill 
  the 
  anther 
  cells, 
  may 
  be 
  seen 
  emitting 
  their 
  tubes 
  to 
  tho 
  

  

  stigma. 
  The 
  style 
  is 
  nearly 
  as 
  long 
  as 
  that 
  of 
  the 
  conspicuous 
  flowers, 
  

  

  Z,ct. 
  ^^'^ 
  ii^ 
  order 
  to 
  bring 
  the 
  stigma 
  within 
  reach 
  of 
  tho 
  

  

  pollen, 
  it 
  lies 
  coiled 
  and 
  twisted 
  on 
  the 
  summit 
  of 
  the 
  

  

  ovary. 
  In 
  some 
  of 
  the 
  flowers 
  all 
  the 
  stamens 
  were 
  

  

  reduced 
  to 
  mere 
  filaments 
  except 
  one 
  ; 
  in 
  others 
  there 
  

  

  occurs 
  one 
  stamen 
  with 
  both 
  anthers; 
  another 
  with 
  a 
  

  

  single 
  anther, 
  the 
  rest 
  being 
  represented 
  by 
  filaments 
  ; 
  

  

  while 
  others 
  again 
  had 
  the 
  rudiments 
  of 
  anthers, 
  but 
  

  

  no 
  pollen. 
  The 
  size 
  of 
  the 
  pollen 
  grains 
  varied 
  some- 
  

  

  /^ 
  ^^ 
  what 
  in 
  the 
  two 
  hinds 
  of 
  flowers. 
  In 
  the 
  large, 
  con- 
  

  

  (a) 
  \j) 
  spicuous 
  flowers, 
  the 
  grains 
  appeared 
  uniform 
  in 
  size 
  and 
  

  

  9 
  h 
  ii^ 
  shape, 
  and 
  averaged 
  about 
  ■jruir'''^^ 
  of 
  an 
  inch 
  in 
  length 
  ; 
  

  

  2, 
  a. 
  Stamens 
  from 
  iu 
  the 
  cleistogamic 
  flowers, 
  the 
  larger 
  grains 
  were 
  similar 
  

   cleistogamic 
  flowers 
  . 
  iixi.ii 
  c 
  L^ 
  ^ 
  n 
  i 
  -i 
  

  

  oiV.fiUcaulis 
  X 
  25. 
  n"! 
  shape 
  and 
  length 
  to 
  those 
  oi 
  the 
  larger 
  nowcrs, 
  whilG 
  

  

  2, 
  h. 
  Pollen 
  grains 
  the 
  majority 
  were 
  rounder 
  and 
  thicker, 
  and 
  not 
  more 
  than 
  

   from 
  the 
  same 
  X 
  , 
  ,1 
  r 
  • 
  i 
  ■ 
  i 
  ii 
  

   225 
  ttjV(J^^^ 
  °^ 
  '^^^ 
  ^^^*^^^ 
  ^^^ 
  length. 
  

  

  Viola 
  cunnin(j]iam.u, 
  Hooli. 
  f. 
  

   This 
  species, 
  as 
  a 
  rule, 
  flowers 
  earlier 
  than 
  the 
  preceding. 
  When 
  

   examined 
  by 
  me 
  during 
  the 
  month 
  of 
  January, 
  it 
  bore 
  abundance 
  of 
  cleisto- 
  

   gamic 
  flowers, 
  while 
  the 
  empty 
  valves 
  of 
  their 
  capsules 
  showed 
  that 
  the 
  

   other 
  flowers 
  had 
  already 
  ripened 
  and 
  shed 
  their 
  seed. 
  The 
  ordinary 
  

   flowers 
  are 
  very 
  similar 
  to 
  those 
  of 
  V.filicaulis, 
  and 
  are 
  produced 
  on 
  pedun- 
  

   cles 
  of 
  similar 
  length. 
  The 
  cleistogamic 
  flowers 
  are 
  produced 
  on 
  very 
  short 
  

   peduncles, 
  which 
  lengthen 
  in 
  fruit 
  to 
  h 
  or 
  f 
  of 
  an 
  inch. 
  All 
  the 
  parts 
  

   in 
  these 
  flowers 
  are 
  very 
  small. 
  The 
  sepals 
  are 
  all 
  present, 
  and 
  of 
  the 
  

   normal 
  form, 
  but 
  the 
  petals 
  are 
  wanting 
  ; 
  their 
  disappearance 
  seems 
  to 
  be 
  

   complete, 
  as 
  there 
  was 
  no 
  trace 
  of 
  their 
  presence. 
  

  

  The 
  stamens 
  are 
  very 
  feebly 
  developed. 
  Two 
  of 
  them 
  have 
  both 
  

   their 
  anthers 
  developed, 
  but 
  these 
  are 
  very 
  small 
  and 
  do 
  not 
  contain 
  

   much 
  pollen. 
  The 
  filament 
  is 
  narrow 
  below, 
  but 
  has 
  its 
  

   upper 
  part 
  extended 
  into 
  a 
  hood. 
  These 
  two 
  stamens 
  aro 
  

   placed 
  on 
  opposite 
  sides 
  of 
  the 
  pistil, 
  and 
  their 
  hoods 
  com- 
  

   pletely 
  overlap 
  and 
  enclose 
  it, 
  their 
  anthers 
  being 
  in 
  contact 
  

   with 
  the 
  short, 
  obtuse 
  stigma. 
  

  

  In 
  all 
  the 
  flowers 
  examined 
  by 
  me, 
  there 
  seemed 
  no 
  

   departure 
  from 
  this 
  type 
  of 
  structure, 
  nor 
  was 
  there 
  the 
  

   variability 
  which 
  I 
  noticed 
  in 
  the 
  cleistogamic 
  flowers 
  of 
  V, 
  

   r\ 
  fiUcaulis. 
  

  

  M 
  3.1. 
  

  

  8, 
  a. 
  Hooded 
  stamen 
  from 
  cleistogamic 
  flower 
  of 
  V. 
  cunningliaviil 
  X 
  25. 
  

   8, 
  h. 
  Eudimentary 
  stamen 
  from 
  the 
  same 
  X 
  25, 
  

  

  m 
  

  

  