﻿^^9'^-] 
  BOTANICAL 
  GAZETTE. 
  83 
  

  

  The 
  filaments 
  are 
  expanded 
  at 
  the 
  tips 
  and 
  are 
  turned 
  

   outward 
  a 
  little, 
  so 
  as 
  to 
  form 
  a 
  little 
  basket 
  in 
  which 
  the 
  

   pollen 
  is 
  received 
  when 
  discharged, 
  and 
  which 
  aids 
  in 
  

   throwing 
  the 
  pollen 
  when 
  the 
  trap 
  is 
  sprung. 
  

  

  Foerste 
  says, 
  "The 
  fact 
  that 
  the 
  tenth 
  stamen 
  is 
  free 
  is 
  a 
  

   J>rior/ 
  evidence 
  of 
  the 
  existence 
  of 
  honey." 
  Bessey 
  seems 
  to 
  

   have 
  supposed 
  that 
  nectar 
  was 
  present 
  and 
  that 
  the 
  spots 
  on 
  

   the 
  base 
  of 
  the 
  banner 
  were 
  nectar-guides. 
  But 
  the 
  stamen 
  

   tube 
  is 
  closed 
  below 
  and 
  nectar 
  is 
  wanting 
  ; 
  the 
  flower 
  be- 
  

   longs 
  with 
  such 
  flowers 
  as 
  Genista 
  tinctoria 
  and 
  Sarotham- 
  

  

  _ 
  _ 
  . 
  ^ 
  :ed 
  to 
  be 
  visited 
  only 
  by 
  pol- 
  

  

  len-collecting 
  bees, 
  and 
  which 
  permit 
  only 
  one 
  visit. 
  

  

  When 
  a 
  bee 
  lights 
  upon 
  the 
  flower 
  it 
  thrusts 
  its 
  head 
  un- 
  

   der 
  the 
  base 
  of 
  the 
  banner 
  while 
  with 
  its 
  legs 
  it 
  forces 
  one 
  or 
  

   both 
  of 
  the 
  wings 
  outward 
  and 
  downward 
  so 
  as 
  to 
  dislodge 
  

   itfrom 
  the 
  banner. 
  This 
  frees 
  the 
  keel, 
  which 
  snaps 
  down 
  

   violently. 
  The 
  column, 
  being 
  in 
  turn 
  freed 
  from 
  the 
  keel, 
  

   flies 
  up 
  and 
  hurls 
  the 
  pollen 
  against 
  the 
  ventral 
  surface 
  of 
  

   the 
  bee. 
  

  

  Desniodiuni 
  Canadense 
  DC. 
  — 
  This 
  is 
  the 
  largest 
  flowered 
  

   species, 
  and 
  can 
  onl3r 
  be 
  exploded 
  easily 
  by 
  the 
  largest 
  bees. 
  

   Consequently, 
  humble 
  bees 
  are 
  more 
  abundant 
  than 
  on 
  any 
  

   of 
  the 
  other 
  species. 
  

  

  Visitors 
  (July 
  20, 
  Aug. 
  15): 
  Afidae: 
  {i) 
  Bombussepura- 
  

   ins 
  Cr. 
  ^ 
  •. 
  (2) 
  B. 
  aincricaiiormn 
  F. 
  ? 
  ; 
  (3) 
  Melissodes 
  binia- 
  

   ^ulata 
  St. 
  Farg. 
  9 
  ; 
  (4) 
  Megachile 
  brevis 
  Say 
  9 
  , 
  rare, 
  and 
  

   only 
  open 
  the 
  flower 
  with 
  difficulty. 
  

  

  Desniodimn 
  cuspidatwn 
  T. 
  & 
  G. 
  — 
  Visitors 
  (Aug. 
  13 
  and 
  

   ^2): 
  Afidae: 
  (r) 
  Bombus 
  atnericanorwn 
  F. 
  5 
  ; 
  (2) 
  Melissodes 
  

   •bimaculata 
  St. 
  Farg. 
  $ 
  ; 
  (3) 
  Megachile 
  brevis 
  Say 
  9 
  . 
  

  

  Desiii 
  odium 
  Dilleiiii'D.xxX. 
  — 
  Visited 
  by 
  Boiiibus 
  anicrican- 
  

   oYmn 
  F. 
  $ 
  . 
  

  

  Dc^nodiuiii 
  pn/iculatuni 
  DC, 
  — 
  Visitors 
  (4 
  days, 
  Aug. 
  8- 
  

   *5ept. 
  10): 
  Afidae: 
  (i) 
  Bomhus 
  ainericaiioriim 
  F. 
  5 
  ; 
  (2) 
  

   Melissodes 
  bimaculata 
  St. 
  Farg. 
  9 
  ; 
  (3) 
  Megachile 
  brevis 
  

  

  ^ay 
  9 
  ; 
  (4) 
  ][f 
  mcndica 
  Cr. 
  9 
  ; 
  (5) 
  Galliopsis 
  audreniforniis 
  

   om. 
  9 
  . 
  

  

  Desmodium 
  sessilifolium 
  T. 
  & 
  G. 
  — 
  Visited 
  by 
  Megachile 
  

   -brevis 
  Say 
  9 
  . 
  ** 
  

  

  Desmodium 
  Marilaiuiicum 
  Boott. 
  — 
  The 
  small 
  flowers 
  of 
  

  

  ^his 
  plant 
  aiT 
  exploded 
  

  

  forynis 
  Sm. 
  Q 
  . 
  

  

  'i> 
  

  

  We 
  have 
  observed 
  that 
  the 
  Howei's 
  are 
  adapted 
  to 
  the 
  

  

  ^See 
  Muller, 
  Fertiliztion 
  of 
  Flowers. 
  

  

  