﻿the 
  Hessian 
  Fly. 
  335 
  

  

  leaf. 
  The 
  progress 
  of 
  the 
  young 
  larvte 
  was 
  very 
  much 
  

   accelerated 
  Avhen 
  the 
  leaf 
  was 
  moistened, 
  and 
  many 
  died 
  

   on 
  a 
  hot, 
  dry 
  day. 
  

  

  Some 
  of 
  the 
  "one-day-old 
  larvae" 
  I 
  mounted 
  in 
  fluid, 
  

   and 
  the 
  one 
  now 
  before 
  you 
  shows 
  the 
  head 
  and 
  organs 
  

   of 
  the 
  mouth 
  as 
  seen 
  from 
  above, 
  and 
  the 
  other 
  seen 
  

   from 
  the 
  side 
  (Plate 
  XVI., 
  fig. 
  1). 
  From 
  these 
  you 
  will 
  

   observe 
  that 
  the 
  mouth 
  of 
  the 
  young 
  larva 
  appears 
  to 
  

   consist 
  of 
  a 
  notched 
  semicircular 
  plate, 
  at 
  each 
  side 
  of 
  

   which 
  are 
  the 
  palpi. 
  At 
  the 
  anal 
  end 
  there 
  are 
  indi- 
  

   cations 
  of 
  suckers, 
  or 
  prehensile 
  feet. 
  

  

  Larvae 
  measured 
  Aug. 
  9th, 
  bred 
  Aug. 
  7th, 
  were 
  2 
  mm. 
  

   long. 
  On 
  Aug. 
  23rd 
  I 
  examined 
  some 
  of 
  the 
  young 
  

   barley 
  plants 
  growing 
  in 
  pots, 
  upon 
  which 
  a 
  number 
  of 
  

   eggs 
  were 
  laid 
  Aug. 
  8th 
  : 
  at 
  one 
  joint 
  I 
  found 
  three 
  

   larvse, 
  and 
  at 
  the 
  second 
  joint 
  of 
  another 
  no 
  less 
  than 
  

   nineteen 
  of 
  various 
  sizes, 
  packed 
  close 
  together. 
  

  

  On 
  Aug. 
  8th 
  eggs 
  were 
  laid 
  by 
  a 
  female, 
  and 
  hatched 
  

   on 
  the 
  12th 
  ; 
  the 
  larvae 
  full 
  grown 
  Sept. 
  6th, 
  when 
  I 
  

   noticed 
  some 
  were 
  beginning 
  to 
  change 
  colour 
  ; 
  this 
  

   gives 
  25 
  days 
  as 
  the 
  feeding-time 
  of 
  these 
  larvae 
  in 
  con- 
  

   finement. 
  

  

  A 
  good 
  deal 
  has 
  been 
  written 
  about 
  the 
  so-called 
  

   " 
  anchor-process," 
  or 
  " 
  breast-bone," 
  which 
  is 
  (according 
  

   to 
  Miss 
  Ormerod) 
  : 
  — 
  "A 
  short 
  stem 
  fixed 
  at 
  one 
  end 
  to 
  

   the 
  larva, 
  and 
  free 
  at 
  the 
  other 
  ; 
  the 
  free 
  end, 
  which 
  

   points 
  forward, 
  is 
  considerably 
  enlarged, 
  and 
  is 
  of 
  various 
  

  

  forms 
  but 
  the 
  use 
  of 
  this 
  appendage 
  does 
  not 
  

  

  appear 
  as 
  yet 
  to 
  be 
  fully 
  known 
  ; 
  but 
  from 
  my 
  own 
  

   observations 
  I 
  conjectured 
  that 
  it 
  is 
  used 
  as 
  a 
  digger 
  or 
  

   scraper, 
  and 
  it 
  may 
  be 
  that 
  the 
  reason 
  why 
  strong- 
  

   stemmed 
  wheat, 
  or 
  stems 
  containing 
  more 
  silica, 
  are 
  not 
  

   so 
  much 
  injured 
  by 
  attack 
  as 
  other 
  kinds 
  is 
  that 
  the 
  fork 
  

   is 
  not 
  strong 
  enough, 
  in 
  these 
  instances, 
  to 
  assist 
  the 
  

   excessively 
  delicate 
  mouth-parts 
  to 
  acquire 
  their 
  food 
  

   from 
  the 
  stem." 
  

  

  And 
  again, 
  in 
  our 
  one 
  " 
  Official 
  Keport," 
  which 
  was 
  

   " 
  presented 
  to 
  both 
  Houses 
  of 
  Parliament 
  by 
  command 
  

   of 
  Her 
  Majesty 
  " 
  ! 
  we 
  read, 
  at 
  p. 
  12 
  :- 
  " 
  From 
  the 
  eggs 
  

   laid 
  in 
  the 
  spring 
  comes 
  a 
  wrinkled 
  yellowish 
  maggot, 
  

   the 
  larva, 
  without 
  legs, 
  having 
  fourteen 
  joints. 
  It 
  

   is 
  close 
  upon 
  the 
  eighth 
  of 
  an 
  inch 
  in 
  length 
  when 
  

   full-grown, 
  being 
  then 
  of 
  a 
  clouded 
  white 
  hue, 
  and 
  

   showing 
  faint 
  greenish 
  lines 
  under 
  the 
  skin. 
  The 
  

  

  