﻿ARMY 
  WOEM: 
  HABITS 
  AND 
  NATURAL 
  HISTORY. 
  105 
  

  

  figure 
  (Plate 
  1^ 
  Fig. 
  3, 
  a). 
  It 
  is 
  in 
  reality 
  composed 
  of 
  two 
  tliin 
  layerSy 
  

   closely 
  appressed 
  except 
  at 
  the 
  upper 
  or 
  dorsal 
  portion 
  near 
  the 
  base^ 
  

   where 
  it 
  swells 
  into 
  a 
  somewhat 
  angular 
  ridge 
  outside 
  and 
  is 
  hollow 
  

   within. 
  A 
  more 
  careful 
  examination 
  will 
  show 
  that 
  the 
  upper 
  portion 
  

   is 
  irregularly 
  and 
  obliquely 
  striate 
  (Fig. 
  3, 
  d), 
  the 
  striations 
  representiug 
  

   folds 
  of 
  the 
  membrane, 
  to 
  facilitate 
  expansion; 
  and 
  that 
  the 
  hind 
  bor- 
  

   der 
  is 
  garnished 
  with 
  fine 
  hairs, 
  which 
  easily 
  rub 
  oft" 
  and 
  leave 
  the 
  edge 
  

   quite 
  sharp, 
  so 
  that 
  the 
  two 
  layers 
  form 
  a 
  blade 
  which 
  is 
  admirably 
  

   adapted 
  to 
  pressing 
  in 
  between 
  narrow 
  passages, 
  or 
  even 
  to 
  splitting 
  

   frail 
  and 
  hollow 
  stalks. 
  In 
  life 
  this 
  ovipositor 
  plays 
  on 
  the 
  two 
  sub- 
  

   joints, 
  which 
  may 
  be 
  greatly 
  extended, 
  and 
  when 
  so 
  extended 
  forms 
  a 
  

   somewhat 
  cylindrical 
  and 
  telescopic 
  tube, 
  which 
  is 
  rendered 
  very 
  firm 
  

   by 
  a 
  series 
  of 
  stout 
  muscles 
  within 
  (Fig. 
  3, 
  5). 
  The 
  valve 
  opens 
  from 
  

   top 
  to 
  bottom, 
  and 
  may 
  be 
  very 
  considerably 
  distended, 
  so 
  as 
  to 
  make 
  

   way 
  for 
  the 
  oviduct, 
  which 
  is 
  a 
  quite 
  complicated 
  structure." 
  

  

  HABITS 
  AND 
  NATURAL 
  HISTORY. 
  

  

  It 
  was 
  not 
  until 
  1855 
  that 
  the 
  first 
  step 
  towards 
  ascertaining 
  defi- 
  

   nitely 
  the 
  life-history 
  of 
  the 
  Army 
  Worm 
  was 
  made, 
  although, 
  as 
  we 
  

   have 
  already 
  showu, 
  it 
  had 
  been 
  destructive 
  at 
  intervals 
  for 
  more 
  than 
  

   a 
  hundred 
  years 
  before. 
  In 
  this 
  year 
  John 
  Kirkpatrick 
  reared 
  the 
  per- 
  

   fect 
  moth 
  from 
  the 
  destructive 
  worm, 
  and 
  described 
  both 
  pupa 
  and 
  

   adult 
  in 
  the 
  Ohio 
  Agricultural 
  Eeport 
  for 
  the 
  same 
  year. 
  Our 
  more 
  

   extended 
  knowledge 
  of 
  the 
  subject 
  dates, 
  however, 
  from 
  the 
  great 
  

   Army 
  Worm 
  year 
  of 
  1861. 
  In 
  this 
  year 
  Walsh, 
  Kirkpatrick, 
  Thomas, 
  

   and 
  Klippart 
  at 
  the 
  West, 
  and 
  Fitch 
  and 
  Packard 
  at 
  the 
  East, 
  all 
  im- 
  

   proved 
  their 
  opportunities 
  for 
  studying 
  the 
  worm. 
  To 
  Walsh 
  we 
  are 
  

   particularly 
  indebted 
  for 
  a 
  study 
  of 
  its 
  parasites, 
  though 
  his 
  views 
  of 
  

   its 
  natural 
  history 
  have 
  proved 
  singularly 
  unfortunate. 
  To 
  Fitch 
  is 
  

   due 
  the 
  credit 
  of 
  the 
  correct 
  scientific 
  naming 
  and 
  the 
  discovery 
  of 
  the 
  

   synonymy. 
  Kirkpatrick 
  first 
  described 
  the 
  most 
  important 
  of 
  all 
  the 
  

   parasites 
  — 
  Wemorcea 
  leucanice 
  — 
  and, 
  in 
  the 
  light 
  of 
  later 
  developments, 
  

   he 
  was 
  remarkably 
  correct 
  in 
  his 
  ideas 
  as 
  to 
  the 
  number 
  of 
  broods 
  and 
  

   method 
  of 
  hibernation. 
  

  

  Yet 
  up 
  to 
  1876 
  no 
  definite 
  knowledge, 
  based 
  on 
  observation 
  and 
  ex- 
  

   periment, 
  existed 
  on 
  some 
  of 
  the 
  most 
  important 
  points 
  in 
  the 
  natural 
  

   history 
  of 
  the 
  species. 
  The 
  eggs 
  and 
  the 
  mode 
  and 
  place 
  of 
  oviposition 
  

   were 
  unknown 
  ; 
  the 
  question 
  of 
  hibernation 
  and 
  of 
  the 
  number 
  of 
  an- 
  

   nual 
  generations 
  was 
  still 
  as 
  open 
  to 
  discussion 
  as 
  when 
  so 
  warmly 
  de- 
  

   bated 
  by 
  Walsh 
  and 
  others, 
  and 
  many 
  minor 
  matters 
  remained 
  unset- 
  

   tled. 
  Since 
  1876 
  we 
  have 
  been 
  able 
  to 
  replace 
  our 
  uncertainty 
  in 
  these 
  

   directions 
  by 
  positive 
  knowledge, 
  so 
  that 
  there 
  are 
  no 
  questions 
  having-^ 
  

   any 
  important 
  practical 
  bearing 
  that 
  are 
  now 
  mooted 
  in 
  respect 
  of 
  this 
  

   insect. 
  

  

  Concerning 
  the 
  Egg, 
  

  

  When 
  and 
  where 
  the 
  eggs 
  are 
  laid. 
  — 
  The 
  favorite 
  place 
  to 
  

   which 
  the 
  Army 
  Worm 
  moth 
  consigns 
  her 
  eggs, 
  in 
  wild 
  or 
  cultivated 
  

  

  