﻿[18] 
  REPORT 
  UNITED 
  STATES 
  ENTOMOLOGICAL 
  COMMISSION. 
  

  

  of 
  transverse 
  grooves 
  ; 
  the 
  body-segments 
  were 
  but 
  partially 
  indicated 
  

   by 
  slightly 
  bluish 
  transverse 
  lines. 
  The 
  colored 
  liquid 
  concentrated 
  in 
  

   the 
  dorsal 
  vessel 
  was 
  yellowish-green 
  on 
  account 
  of 
  the 
  underlying 
  in- 
  

   testine. 
  The 
  head 
  was 
  here, 
  as 
  in 
  all 
  forms, 
  retracted. 
  The 
  maggot 
  at- 
  

   tains 
  with 
  this 
  stage 
  the 
  maximum 
  of 
  its 
  size, 
  therefore 
  taking 
  no 
  more 
  

   nourishment. 
  All 
  its 
  motions 
  and 
  bodily 
  modifications 
  henceforth 
  go 
  

   on 
  within 
  its 
  integument. 
  Therefore 
  an 
  important 
  epoch 
  in 
  the 
  life-his- 
  

   tory 
  of 
  the 
  maggot 
  is 
  herewith 
  concluded. 
  

  

  To 
  this 
  connective 
  and 
  transitory 
  form 
  belong 
  those 
  maggots 
  which 
  

   produced 
  by 
  contraction 
  in 
  the 
  direction 
  of 
  the 
  longitudinal 
  axis 
  a 
  i)ar- 
  

   tial 
  separation 
  of 
  the 
  external 
  skin, 
  also 
  those 
  which 
  were 
  no 
  more 
  in 
  

   connection 
  with 
  this 
  skin. 
  The 
  period 
  of 
  pseudo-pupation 
  begins 
  with 
  

   this 
  moment. 
  The 
  dead 
  external 
  skin, 
  excluded 
  from 
  the 
  life-functions 
  

   of 
  the 
  organism, 
  becomes 
  now 
  a 
  protecting 
  cover, 
  within 
  which 
  the 
  mag- 
  

   got 
  undergoes 
  the 
  transformation 
  into 
  the 
  real 
  puj^a 
  and 
  imago. 
  Through 
  

   this 
  still 
  white 
  cover 
  we 
  recognize 
  the 
  scarcely 
  changed 
  maggot, 
  and 
  in 
  

   the 
  latter, 
  especially 
  on 
  removing 
  the 
  external 
  shell, 
  we 
  recognize 
  the 
  

   reddish-yellow 
  or 
  red 
  dorsal 
  vessel 
  and 
  the 
  snow-white 
  adipose 
  body, 
  

   which 
  later 
  becomes 
  separated 
  according 
  to 
  the 
  segments 
  into 
  more 
  dis- 
  

   tinct 
  sections. 
  In 
  consequence 
  of 
  that 
  contraction 
  of 
  tlie 
  maggot 
  an 
  

   empty 
  space 
  is 
  produced 
  at 
  both 
  ends 
  of 
  the 
  shell. 
  The 
  shell 
  on 
  some 
  

   specimens 
  has 
  already 
  assumed 
  a 
  yellow-brown 
  color 
  and 
  denser 
  con- 
  

   sistency. 
  The 
  anterior 
  end 
  of 
  the 
  shell 
  plainly 
  exhibits 
  a 
  curvature 
  

   and 
  a 
  protuberance 
  as 
  a 
  remainder 
  of 
  the 
  retracted 
  mouth, 
  as 
  a 
  sign 
  

   that 
  the 
  mouth-parts 
  were 
  not 
  excluded 
  in 
  the 
  late 
  change. 
  T 
  owe 
  it 
  to 
  

   a 
  lucky 
  chance 
  to 
  have 
  had 
  once 
  the 
  opportunity 
  to 
  see 
  through 
  the 
  

   still 
  slightly 
  colored 
  shell 
  of 
  such 
  a 
  maggot, 
  which 
  pushed 
  the 
  front 
  part 
  

   of 
  the 
  l3od3' 
  back 
  and 
  forth, 
  not 
  only 
  the 
  head 
  with 
  the 
  palpi, 
  but 
  also 
  

   to 
  observe, 
  how 
  in 
  each 
  forward 
  push 
  the 
  mouth-parts 
  entered 
  behind 
  the 
  

   mentioned 
  protuberance. 
  The 
  position 
  of 
  the 
  head 
  therefore 
  fully 
  cor- 
  

   resj^onds 
  with 
  that 
  of 
  the 
  protuberance. 
  On 
  the 
  light-brown 
  shell 
  we 
  

   can 
  better 
  see 
  the 
  punctured 
  transverse 
  lines 
  lining 
  each 
  body-segment 
  

   than 
  later 
  in 
  the 
  dark-brown 
  pupa. 
  

  

  The 
  rye 
  sprouts 
  infected 
  by 
  our 
  gall-gnat 
  and 
  examined 
  in 
  November 
  

   and 
  December 
  have 
  taught 
  me 
  that 
  very 
  likely 
  none 
  of 
  those 
  sprouts 
  

   have 
  sufficient 
  resistance 
  to 
  attain 
  maturity, 
  therefore 
  all 
  succumb 
  to 
  

   this 
  insect; 
  further 
  on, 
  that, 
  as 
  a 
  rule, 
  the 
  full 
  growth 
  of 
  the 
  maggot 
  

   coincides 
  with 
  the 
  death 
  of 
  the 
  sprout. 
  The 
  dead 
  sprout 
  for 
  a 
  time 
  serves 
  

   as 
  a 
  protecting 
  cover, 
  but 
  after 
  its 
  decay 
  the 
  enveloped 
  maggot 
  imbeds 
  

   itselt 
  in 
  the 
  soil. 
  The 
  latter 
  supplies 
  moisture 
  for 
  the 
  preservation 
  of 
  

   the 
  maggot, 
  to 
  which 
  the 
  parchment 
  like 
  cover 
  moreover 
  yields 
  special 
  

   protection 
  against 
  the 
  drying-up 
  snn-rays. 
  

  

  Tlie 
  young 
  maggot, 
  as 
  a 
  rule, 
  places 
  itself 
  immediately 
  above 
  the 
  knot 
  

   from 
  which 
  the 
  sheath 
  of 
  that 
  leaf 
  arises 
  on 
  which 
  the 
  eggs 
  were 
  hatched. 
  

   On 
  sprouts 
  still 
  wanting 
  an 
  internoded 
  stalk,J;he 
  leaf-sheaths 
  arise 
  from 
  

   the 
  root-head, 
  therefore 
  the 
  maggots 
  occur 
  right 
  above 
  there. 
  On 
  the 
  

   other 
  hand, 
  if 
  the 
  fly 
  finds 
  already 
  a 
  developed 
  sprout, 
  it 
  never 
  deposits 
  

   the 
  eggs 
  on 
  the 
  lowest 
  leaves, 
  but 
  on 
  blade-bearing 
  ones. 
  Of 
  this 
  I 
  con- 
  

   vinced 
  myself 
  on 
  that 
  barley 
  aftergrowth 
  ; 
  the 
  maggots 
  were 
  not 
  all 
  

   the 
  way 
  down, 
  but 
  always 
  in 
  the 
  neighborhood 
  of 
  the 
  two 
  lowest 
  knots, 
  

   from 
  which 
  it 
  follows 
  that 
  the 
  plants 
  at 
  the 
  time 
  of 
  oviposition 
  of 
  the 
  fly 
  

   had 
  already 
  developed 
  a 
  stalk. 
  Therefore 
  if 
  the 
  maggots 
  occur 
  on 
  the 
  

   young 
  winter 
  sprouts 
  near 
  the 
  root, 
  we 
  should 
  nevertheless 
  expect 
  to 
  

   see 
  a 
  special 
  peculiarity 
  of 
  the 
  winter 
  generation. 
  

  

  