﻿the 
  Hessian 
  Ply. 
  343 
  

  

  have 
  bred 
  the 
  minute 
  parasite, 
  Platijgaster 
  minutus, 
  

   which, 
  by 
  the 
  bye, 
  can 
  force 
  its 
  way 
  through 
  the 
  meshes 
  

   of 
  the 
  finest 
  book-musHn, 
  and 
  only 
  a 
  cambric 
  pocket- 
  

   handkercliief 
  tied 
  over 
  the 
  cylinder 
  will 
  keep 
  them 
  in. 
  

  

  In 
  the 
  table 
  given 
  later 
  on 
  of 
  the 
  parasites 
  bred, 
  you 
  

   will 
  notice 
  how 
  very 
  few 
  emerge 
  in 
  September 
  and 
  

   October, 
  and 
  I 
  think 
  that 
  one 
  reason 
  why 
  the 
  " 
  fall- 
  

   wheat 
  " 
  is 
  so 
  free 
  from 
  parasites 
  is 
  that 
  they 
  could 
  not 
  

   get 
  down 
  to 
  the 
  puparia, 
  which 
  are 
  close 
  to 
  the 
  roots 
  ; 
  

   but 
  I 
  have 
  repeatedly 
  watched 
  these 
  small 
  Platijgaster 
  

   minutus 
  searching 
  for 
  and 
  sounding 
  the 
  lower 
  part 
  of 
  the 
  

   stems 
  for 
  puparia, 
  and, 
  failing 
  to 
  find 
  them, 
  they 
  have 
  

   worked 
  their 
  way 
  down 
  the 
  smallest 
  space 
  between 
  the 
  

   stem 
  and 
  surrounding 
  earth, 
  and 
  no 
  doubt 
  reached 
  the 
  

   objects 
  of 
  their 
  search. 
  

  

  The 
  plants 
  of 
  " 
  fall- 
  wheat 
  " 
  sent 
  from 
  America 
  were 
  so 
  

   dried 
  up 
  and 
  brittle 
  that 
  when 
  I 
  attempted 
  to 
  search 
  for 
  

   puparia 
  their 
  position 
  could 
  not 
  be 
  accurately 
  noted 
  ; 
  

   but 
  in 
  infested 
  plants 
  of 
  a 
  similar 
  size 
  grown 
  in 
  j)ots, 
  and 
  

   on 
  which 
  the 
  eggs 
  were 
  laid 
  before 
  a 
  stem 
  was 
  formed, 
  

   I 
  found 
  the 
  puparia 
  at 
  the 
  roots, 
  and 
  in 
  some 
  instances 
  

   lying 
  in 
  the 
  old 
  husk 
  of 
  the 
  grain, 
  and 
  others 
  actually 
  

   underneath 
  the 
  crown 
  among 
  the 
  roots. 
  The 
  photograph 
  

   of 
  American 
  "fall-wheat" 
  shows 
  the 
  empty 
  pupse-cases 
  

   protruding 
  from 
  the 
  stems. 
  

  

  In 
  only 
  one 
  instance 
  have 
  I 
  found 
  puparia 
  at 
  both 
  2nd 
  

   and 
  3rd 
  joints 
  of 
  the 
  same 
  plant, 
  at 
  Stroud, 
  Oct., 
  1888. 
  

   From 
  about 
  500 
  infested 
  straws 
  gathered, 
  I 
  noticed 
  a 
  

   great 
  many 
  puparia 
  were 
  at 
  the 
  3rd 
  joint, 
  at 
  least 
  nine 
  

   inches 
  from 
  the 
  ground, 
  and 
  that 
  the 
  barley 
  at 
  each 
  side 
  

   of 
  the 
  roadway 
  through 
  the 
  fields 
  was 
  always 
  most 
  

   affected; 
  this, 
  to 
  my 
  mind, 
  was 
  the 
  result 
  of 
  the 
  

   previous 
  year's 
  scattering 
  of 
  puparia 
  from 
  the 
  waggons 
  

   at 
  the 
  time 
  of 
  carrying. 
  I 
  particularly 
  noticed 
  this 
  at 
  

   Hertford, 
  Littlehampton, 
  and 
  many 
  fields 
  around 
  Stroud, 
  

   Gloucestershire. 
  

  

  The 
  next 
  stage 
  is 
  the 
  third 
  larval, 
  or 
  rather 
  final 
  larval, 
  

   form, 
  which 
  is 
  most 
  easily 
  obtained 
  by 
  placing 
  on 
  damp 
  

   blotting-paper 
  or 
  sand 
  a 
  number 
  of 
  puparia 
  picked 
  out 
  

   from 
  " 
  screenings 
  " 
  ; 
  these 
  are 
  more 
  or 
  less 
  injured 
  by 
  

   having 
  passed 
  through 
  the 
  thresher, 
  and 
  the 
  effect 
  of 
  

   moisture 
  upon 
  a 
  fractured 
  puparium 
  is 
  most 
  striking, 
  

   causing 
  the 
  larva 
  to 
  work 
  its 
  way 
  out, 
  and, 
  when 
  entirely 
  

   free, 
  it 
  quietly 
  rests 
  in 
  some 
  cranny 
  or 
  under 
  the 
  sur- 
  

   rounding 
  puparia 
  ; 
  and 
  it 
  is 
  whilst 
  they 
  are 
  in 
  this 
  state 
  

  

  