﻿[20] 
  REPORT 
  UNITED 
  STATES 
  ENTOMOLOGICAL 
  COMMISSION. 
  

  

  ward, 
  resemble 
  coat-tails, 
  and 
  are 
  placed 
  under 
  the 
  distinctly 
  segmented 
  

   body. 
  The 
  antenna! 
  sbeatlis 
  pass 
  down 
  on 
  the 
  inner 
  margin 
  of 
  the 
  wings, 
  

   coming 
  from 
  the 
  vertex. 
  Between 
  the 
  antennae 
  are 
  the 
  parallelly 
  

   placed, 
  ventrally 
  appressed 
  leg 
  sheaths, 
  innermost 
  those 
  of 
  the 
  anterior, 
  

   outermost 
  those 
  of 
  the 
  posterior 
  legs, 
  the 
  tips 
  of 
  which 
  reach 
  about 
  

   to 
  the 
  sixth 
  abdominal 
  segment. 
  On 
  each 
  side 
  of 
  the 
  thorax 
  protrudes 
  

   a 
  slightly 
  curved, 
  small 
  horn 
  — 
  the 
  breathing 
  tubes 
  characteristic 
  of 
  the 
  

   gall-gnats.* 
  

  

  Immediately 
  behind 
  each 
  antenna 
  a 
  short 
  bristle 
  arises 
  from 
  a 
  small, 
  

   ronnd 
  protuberance. 
  The 
  chitinous 
  structure 
  of 
  the 
  nose-shaped 
  pro- 
  

   cess 
  between 
  the 
  bases 
  of 
  the 
  antennae 
  seems 
  to 
  be 
  of 
  some 
  service 
  in 
  

   hatching. 
  

  

  The 
  mode 
  of 
  hatching 
  I 
  never 
  observed 
  in 
  the 
  field, 
  but 
  shall 
  state 
  

   here 
  my 
  observations 
  made 
  at 
  home. 
  As 
  soon 
  as 
  the 
  pupa 
  has 
  matured 
  

   it 
  turns 
  around, 
  head 
  downward, 
  and 
  fills 
  out 
  with 
  its 
  abdomen 
  the 
  

   hitherto 
  empty 
  part 
  of 
  the 
  pupa-case. 
  Thus 
  propped, 
  it 
  raises 
  the 
  out- 
  

   wardly 
  placed 
  dorsal 
  side 
  of 
  the 
  abdomen 
  and 
  cracks 
  the 
  shell 
  ; 
  a 
  trans- 
  

   verse 
  slit 
  has 
  formed 
  usually 
  through 
  the 
  eighth 
  and 
  ninth 
  segment. 
  The 
  

   various 
  body-parts 
  are 
  yet 
  so 
  soft 
  and 
  flexible 
  that 
  they 
  can 
  thus 
  be 
  

   bent. 
  1^0 
  w, 
  as 
  the 
  insect 
  props 
  the 
  chitinous 
  frontal 
  process 
  against 
  the 
  

   shell 
  and 
  presses 
  the 
  body 
  toward 
  the 
  formed 
  slit, 
  the 
  latter 
  widens 
  and 
  

   allows 
  the 
  anterior 
  part 
  of 
  the 
  insect 
  to 
  pass 
  through. 
  After 
  a 
  short 
  

   recreation 
  from 
  the 
  great 
  work, 
  a 
  few 
  stretchings 
  and 
  jerks 
  suffice 
  to 
  

   break 
  the 
  thorax 
  of 
  the 
  shell 
  longitudinally. 
  Again 
  comes 
  a 
  short 
  

   pause: 
  head 
  and 
  thorax 
  become 
  free; 
  whereupon 
  the 
  insect 
  pulls 
  forth 
  

   the 
  antennae, 
  wings, 
  and 
  legs 
  out 
  of 
  their 
  sheaths, 
  freeing 
  itself 
  entirely. 
  

   The 
  young 
  fly 
  now 
  creeps 
  to 
  the 
  light 
  and 
  moves 
  its 
  soft, 
  stick-like 
  

   looking 
  wings 
  along 
  toward 
  each 
  other 
  with 
  great 
  rapidity 
  until 
  after 
  

   some 
  five 
  minutes 
  they 
  are 
  fully 
  stretched. 
  After 
  the 
  free 
  access 
  of 
  air 
  

   has 
  brought 
  its 
  drying 
  and 
  solidifying 
  influence 
  upon 
  the 
  external 
  mem- 
  

   branes, 
  the 
  fly 
  finally 
  submits 
  to 
  the 
  bearing 
  capacity 
  of 
  its 
  tender 
  

   wings. 
  

  

  To 
  remove 
  any 
  objections, 
  as 
  if 
  the 
  narrow 
  space 
  between 
  the 
  stalk 
  

   and 
  the 
  blade 
  would 
  not 
  allow 
  any 
  motions 
  of 
  the 
  fly, 
  I 
  add 
  that, 
  at 
  the 
  

   time 
  of 
  hatching, 
  the 
  connection 
  between 
  the 
  lower 
  blades 
  and 
  the 
  stalk 
  

   is 
  already 
  sufficiently 
  loosened 
  so 
  that 
  there 
  is 
  no 
  want 
  of 
  S])ace 
  for 
  the 
  

   escai:)e 
  of 
  the 
  fly. 
  In 
  this, 
  perhaps, 
  is 
  the 
  reason 
  why 
  the 
  female 
  sup- 
  

   plies 
  the 
  loiver 
  Leaves 
  only 
  with 
  eggs. 
  

  

  The 
  process 
  cannot 
  essentially 
  differ 
  from 
  the 
  above 
  in 
  pupae 
  lying 
  

   free 
  on 
  the 
  soil; 
  but 
  as 
  the 
  shell 
  is 
  freely 
  movable, 
  the 
  hatching 
  re- 
  

   quires 
  less 
  force 
  by 
  the 
  insect. 
  

  

  4. 
  TJie 
  perfect 
  insect. 
  

  

  From 
  the 
  17th 
  of 
  December 
  till 
  January 
  291 
  the 
  soil 
  was 
  covered 
  with 
  

   snow; 
  the 
  out-of-door 
  observations, 
  therefore, 
  had 
  to 
  be 
  discontinued 
  for 
  

   a 
  long 
  time. 
  The 
  subsequent 
  alternation 
  of 
  sunshine 
  and 
  dew 
  (during 
  

   the 
  day) 
  and 
  frost 
  (at 
  night) 
  proved 
  to 
  be 
  bad 
  for 
  our 
  crops 
  ; 
  in 
  some 
  

   districts 
  over 
  half 
  of 
  the 
  sprouts 
  were 
  killed 
  within 
  a 
  few 
  days. 
  The 
  

   sprouts 
  infested 
  with 
  larvae, 
  formerly 
  easily-recognizable 
  (owing 
  to 
  

   their 
  discolored 
  look), 
  could 
  not 
  be 
  distinguished, 
  after 
  the 
  snow 
  had 
  

   melted 
  away, 
  from 
  those 
  killed 
  by 
  frost, 
  or 
  if 
  already 
  decayed, 
  no 
  

   pseudo-chrysalids 
  were 
  found. 
  This 
  was 
  quite 
  inopportune, 
  as 
  I 
  did 
  not 
  

   collect 
  any 
  maggots 
  in 
  the 
  fore- 
  winter, 
  expecting 
  to 
  obtain 
  in 
  spring 
  ac- 
  

  

  * 
  On 
  the 
  empty 
  pupa 
  shell 
  two 
  long, 
  bristled 
  organs, 
  usually 
  spirally 
  wound 
  above, 
  which 
  appear 
  

   to 
  connect 
  with 
  the 
  tracheal 
  tubes 
  by 
  a 
  canal, 
  arise 
  out 
  of 
  the 
  thorax-slit, 
  a 
  little 
  before 
  the 
  tracheal 
  

   tubes. 
  I 
  cannot 
  see 
  for 
  what 
  use 
  they 
  are. 
  

  

  