﻿268 
  REPORT 
  UNITED 
  STATES 
  ENTOMOLOGICAL 
  COMMISSION. 
  

  

  Development 
  of 
  the 
  wings. 
  — 
  As 
  has 
  been 
  shown 
  by 
  Weismann, 
  the 
  wings 
  

   of 
  flies 
  are 
  indicated 
  late 
  in 
  larval 
  life. 
  They 
  arise 
  from 
  minute 
  masses 
  

   of 
  indifferent 
  cells 
  called 
  *'invaginal 
  disks," 
  these 
  being 
  microscopic 
  in- 
  

   ternal 
  bodies 
  attached 
  to 
  some 
  nerve 
  or 
  tracheal 
  branch. 
  

  

  The 
  mode 
  of 
  origin 
  of 
  the 
  wings 
  may, 
  however, 
  be 
  best 
  understood 
  by 
  

   observing 
  the 
  early 
  stages 
  of 
  those 
  insects, 
  such 
  as 
  the 
  Hemiptera, 
  Ortho- 
  

   ptera, 
  andPseudoueuroptera, 
  which 
  have 
  an 
  incomi^lete 
  metamorjihosis. 
  

   If 
  the 
  student 
  will 
  examine 
  Plates 
  I-III 
  of 
  the 
  First 
  Eeport 
  of 
  the 
  

   United 
  States 
  Entomological 
  Commission, 
  j^articularly 
  Figs. 
  1, 
  2, 
  3, 
  he 
  

   will 
  see 
  that 
  the 
  wings 
  in 
  the 
  locust 
  arise 
  as 
  simple 
  expansions 
  down- 
  

   ward 
  and 
  backward 
  of 
  the 
  lateral 
  edges 
  of 
  the 
  meso- 
  and 
  metanotum. 
  

   In 
  the 
  second 
  larval 
  stage 
  this 
  change 
  begins 
  to 
  take 
  place, 
  but 
  it 
  does 
  

   not 
  become 
  marked 
  until 
  the 
  first 
  pupal 
  stage, 
  when 
  the 
  indications 
  of 
  

   veins 
  begin 
  to 
  appear, 
  and 
  the 
  lobe-like 
  expansion 
  of 
  the 
  notum 
  is 
  plaiuly 
  

   enough 
  a 
  rudimentary 
  wing. 
  This 
  mode 
  of 
  development 
  of 
  the 
  wings 
  

   in 
  Orthoptera 
  has 
  been 
  shown 
  and 
  well 
  illustrated 
  by 
  Graber,^^* 
  who 
  first 
  

   drew 
  attention 
  to 
  this 
  mode 
  of 
  development 
  of 
  the 
  wings, 
  and 
  showed 
  

   that 
  it 
  is 
  common 
  to 
  all 
  Orthoptera. 
  Ignorant 
  of 
  his 
  paper, 
  we 
  had 
  

   arrived 
  at 
  the 
  same 
  result, 
  after 
  an 
  examination 
  of 
  the 
  early 
  pupal 
  stages 
  

   of 
  the 
  cockroach, 
  as 
  well 
  as 
  the 
  locusts, 
  of 
  Termites 
  and 
  various 
  Hemi- 
  

   ptera. 
  In 
  all 
  these 
  forms 
  it 
  is 
  plainly 
  to 
  be 
  seen 
  that 
  the 
  wiugs 
  are 
  simply 
  

   expansions, 
  either 
  horizontal 
  or 
  partly 
  vertical 
  (when 
  as 
  in 
  locusts, 
  «&c., 
  

   the 
  body 
  is 
  compressed, 
  and 
  the 
  meso- 
  and 
  metanota 
  are 
  rounded 
  down- 
  

   wards), 
  of 
  the 
  hinder 
  and 
  outer 
  edge 
  of 
  the 
  meso- 
  and 
  metanotum. 
  As 
  

   will 
  be 
  seen 
  by 
  reference 
  to 
  Plates 
  I-II 
  of 
  our 
  First 
  Eeport, 
  and 
  by 
  the 
  

   accompanying 
  figures, 
  the 
  wings 
  are 
  notal 
  (tergal) 
  outgrowths 
  from 
  the 
  

   dorsal 
  arch 
  of 
  the 
  two 
  hinder 
  segments 
  of 
  the 
  thorax. 
  At 
  first, 
  as 
  seen 
  

   in 
  the 
  young 
  pupal 
  cockroach 
  (PI. 
  LXII, 
  Fig. 
  1) 
  and 
  locust, 
  the 
  rudiments 
  

   of 
  the 
  wings 
  are 
  continuous 
  with 
  the 
  notum. 
  Late 
  in 
  pupal 
  life 
  a 
  suture 
  

   and 
  a 
  hinge-joint 
  appear 
  at 
  the 
  base 
  of 
  the 
  wing, 
  and 
  thus 
  there 
  is 
  some 
  

   movement 
  of 
  the 
  wing 
  upon 
  the 
  notum 
  j 
  finally, 
  the 
  tracheae 
  are 
  well 
  

   developed 
  in 
  the 
  wings, 
  and 
  numerous 
  small 
  sclerites 
  are 
  differentiated 
  

   at 
  the 
  base 
  of 
  the 
  wing, 
  to 
  which 
  the 
  special 
  muscles 
  of 
  flight 
  are 
  at- 
  

   tached, 
  and 
  thus 
  the 
  wings, 
  after 
  the 
  last 
  pupal 
  molt, 
  have 
  the 
  power 
  

   of 
  flapping, 
  and 
  of 
  sustaining 
  the 
  insect 
  in 
  the 
  air; 
  they 
  thus 
  become 
  

   true 
  organs 
  of 
  flight. 
  

  

  It 
  is 
  to 
  be 
  observed, 
  then, 
  that 
  the 
  wings 
  in 
  all 
  ametabolous 
  and 
  hemi- 
  

   metabolous 
  insects 
  are 
  outgrowths 
  from 
  the 
  notum, 
  and 
  not 
  from 
  the 
  

   flanks 
  or 
  pleurum 
  of 
  the 
  thorax. 
  There 
  is, 
  then, 
  no 
  structure 
  in 
  any 
  

   other 
  i^art 
  of 
  the 
  body 
  with 
  which 
  they 
  are 
  homologous. 
  

  

  The 
  same 
  may 
  be 
  said 
  of 
  the 
  true 
  Neuroptera, 
  the 
  Coleoptera, 
  and 
  the 
  

   Diptera, 
  Lepidoptera, 
  and 
  Hymenoptera. 
  As 
  we 
  have 
  observed 
  in 
  the 
  

   house 
  fly,^^^ 
  the 
  wings 
  are 
  evidently 
  outgrowths 
  of 
  the 
  meso- 
  and 
  meta- 
  

  

  124 
  Zur 
  EntwickeluTigsgescbiclite 
  und 
  Eeiiroductioiisfiibigkeit 
  der 
  Ortliopteren. 
  Von 
  Vitus 
  Graber. 
  

   Sitzungsbericlite 
  d. 
  matb.-naturw. 
  Classe 
  der 
  Akad. 
  d. 
  Wissonscb., 
  Wien. 
  Ed. 
  Iv, 
  Abtbi. 
  i, 
  1867. 
  

  

  1^5 
  On 
  tbe 
  Transformations 
  of 
  tbe 
  Comraou 
  House 
  My, 
  by 
  A. 
  S. 
  Packard, 
  jr. 
  Proceedings 
  Boston 
  So- 
  

   ciety 
  of 
  Natural 
  History, 
  vol. 
  xvi, 
  1874. 
  See 
  PI. 
  3, 
  Figs. 
  12a, 
  126. 
  

  

  