﻿72 
  Miscellaneous. 
  

  

  insects? 
  There 
  is 
  neither 
  pollen 
  nor 
  nectar 
  in 
  the 
  male 
  flowers 
  of 
  

   H. 
  hortensis. 
  They 
  conceal 
  the 
  terminal 
  hermaphrodites, 
  and 
  it 
  is 
  

   scarcely 
  probable 
  that 
  many 
  insects, 
  if 
  any, 
  visit 
  the 
  flowers. 
  In 
  the 
  

   other 
  two, 
  many 
  insects 
  visit 
  the 
  flowers 
  — 
  so 
  far 
  as 
  my 
  observations 
  

   go, 
  as 
  many 
  visit 
  the 
  H. 
  arborescens 
  without 
  the 
  attractive 
  sepals, 
  as 
  

   the 
  H. 
  quercifolia 
  that 
  makes 
  such 
  a 
  show 
  of 
  them. 
  

  

  Turning 
  to 
  the 
  minute 
  fertile 
  flowers 
  on 
  these 
  two 
  species, 
  we 
  

   are 
  struck 
  by 
  the 
  immense 
  number 
  of 
  stamens 
  and 
  the 
  enormous 
  

   number 
  of 
  pollen-grains 
  one 
  of 
  these 
  racemose 
  cymes 
  gives 
  us. 
  I 
  

   estimated 
  the 
  number 
  of 
  stamens 
  on 
  one 
  of 
  H. 
  quercifolia 
  at 
  13,000 
  ; 
  

   shaken 
  over 
  a 
  sheet 
  of 
  dark 
  paper 
  it 
  completely 
  whitens 
  it. 
  Its 
  pollen 
  

   can 
  be 
  carried 
  by 
  the 
  wind 
  everywhere, 
  why 
  should 
  it 
  develop 
  petaloid 
  

   sepals 
  to 
  attract 
  insects? 
  Both 
  species 
  have 
  the 
  odour 
  of 
  hawthorn, 
  

   but 
  in 
  addition 
  H. 
  quercifolia 
  has 
  an 
  enormous 
  yield 
  of 
  nectar, 
  which 
  

   is 
  apparently 
  not 
  abundant 
  in 
  II. 
  arborescens. 
  In 
  spite 
  of 
  all 
  the 
  

   attractions, 
  the 
  petaloid 
  sepals, 
  the 
  abundance 
  of 
  pollen, 
  the 
  delight- 
  

   ful 
  fragrance, 
  the 
  superabundance 
  of 
  nectar, 
  and 
  the 
  actual 
  visits 
  of 
  

   numerous 
  insects, 
  the 
  flowers 
  are 
  self-fertilizing. 
  The 
  outer 
  row 
  of 
  

   five 
  stamens 
  mature 
  pollen 
  simultaneously 
  with 
  the 
  expansion 
  of 
  the 
  

   petals, 
  which 
  falls 
  at 
  once 
  on 
  the 
  receptive 
  stigmas, 
  some 
  hours 
  after 
  

   the 
  inuer 
  series 
  mature, 
  and 
  ensures 
  that 
  self-fertilization 
  which 
  the 
  

   pollen 
  from 
  the 
  first 
  series 
  may 
  possibly 
  have 
  missed. 
  The 
  only 
  pos- 
  

   sible 
  aid 
  insects 
  can 
  give 
  is 
  in 
  self-fertilization. 
  

  

  It 
  is 
  broadly 
  asserted 
  that 
  we 
  owe 
  to 
  the 
  existence 
  of 
  insects 
  the 
  

   various 
  forms 
  and 
  colours 
  of 
  flowers 
  with 
  their 
  grateful 
  odours 
  and 
  

   sweet 
  secretions. 
  Here 
  we 
  have 
  illustrations 
  of 
  the 
  most 
  dissimilar 
  

   and 
  contradictory 
  variations 
  in 
  a 
  single 
  genus, 
  variations 
  which 
  

   cover 
  all 
  the 
  leading 
  points 
  called 
  for 
  by 
  the 
  insect-adaptationists, 
  

   and, 
  so 
  far 
  as 
  any 
  argument 
  in 
  common 
  use 
  goes, 
  could 
  have 
  oc- 
  

   curred 
  with 
  as 
  much 
  reason 
  if 
  not 
  a 
  single 
  insect 
  ever 
  existed. 
  The 
  

   facts 
  are 
  absolutely 
  inexplicable 
  on 
  any 
  theory 
  of 
  the 
  survival 
  of 
  the 
  

   fittest 
  in 
  the 
  struggle 
  for 
  life 
  ; 
  but 
  on 
  my 
  view 
  of 
  the 
  absolute 
  

   necessity 
  of 
  variation 
  for 
  its 
  own 
  sake 
  the 
  explanation 
  seems 
  simple 
  

   enough. 
  

  

  Variation 
  is 
  inseparable 
  from 
  even 
  the 
  closest 
  in-and-in 
  breeding. 
  

   We 
  are 
  as 
  fully 
  justified 
  in 
  saying 
  that 
  nature 
  abhors 
  a 
  perpetuity 
  

   of 
  form 
  as 
  that 
  she 
  abhors 
  in-and-in 
  breeding, 
  and 
  we 
  can 
  just 
  as 
  

   earnestly 
  claim 
  cross-fertilization 
  as 
  an 
  agent 
  in 
  bringing 
  about 
  

   variation 
  for 
  the 
  sake 
  of 
  variety 
  as 
  for 
  the 
  reasons 
  usually 
  given, 
  

   and 
  which 
  we 
  find 
  we 
  cannot 
  apply 
  with 
  consistency 
  in 
  so 
  many 
  

   cases. 
  

  

  That 
  cross-fertilization 
  aids 
  variation 
  we 
  may 
  well 
  believe 
  is 
  a 
  

   sufficient 
  reason 
  for 
  its 
  existence, 
  without 
  assuming 
  that 
  it 
  has 
  no 
  

   other 
  office 
  to 
  perform.- 
  — 
  Proc. 
  Acad. 
  Nat. 
  Sci. 
  Philacl. 
  1888, 
  p. 
  277. 
  

  

  