﻿XVllI 
  

  

  SOME 
  GENERAL 
  OBSERVATIONS. 
  

  

  There 
  have 
  been 
  some 
  remarkable 
  differences 
  of 
  opinion 
  in 
  regard 
  

   to 
  this 
  insect, 
  which 
  deserve 
  brief 
  attention 
  here. 
  Some 
  of 
  these 
  

   differences 
  may 
  be 
  easily 
  explained, 
  others 
  not 
  so 
  easily. 
  

  

  Dr. 
  Fitch, 
  in 
  his 
  original 
  description, 
  says, 
  "The 
  insects 
  are 
  

   wholly 
  imperceptible 
  to 
  the 
  naked 
  eye," 
  and 
  gives 
  their 
  measure- 
  

   ments 
  at 
  a 
  little 
  more 
  than 
  .01 
  of 
  an 
  inch. 
  Dr. 
  Shimer 
  also 
  says, 
  

   "The 
  insect 
  is 
  quite 
  a 
  minute 
  creature, 
  and 
  is 
  not 
  readily 
  seen 
  with- 
  

   out 
  the 
  aid 
  of 
  a 
  Ions.'" 
  Professor 
  Osborn 
  calls 
  attention 
  to 
  the 
  state- 
  

   ment 
  of 
  Dr. 
  Fitch, 
  adding 
  that 
  it 
  is 
  quite 
  an 
  easy 
  matter 
  to 
  see 
  the 
  

   eggs 
  even, 
  much 
  more, 
  then, 
  the 
  insect 
  itself, 
  with 
  the 
  unaided 
  eye. 
  

   This 
  is 
  very 
  evidently 
  true: 
  the 
  difficulty 
  in 
  seeing 
  the 
  insect 
  arises 
  

   mostly 
  from 
  the 
  protective 
  coloration. 
  

  

  Dr. 
  Fitch 
  observed 
  them 
  upon 
  the 
  white 
  pine, 
  most 
  numerous 
  upon 
  

   the 
  trunk, 
  absent 
  from 
  spots 
  where 
  the 
  direct 
  sunlight 
  fell. 
  Professor 
  

   Osborn 
  notes 
  (L^TV)) 
  that 
  they 
  infest 
  the 
  Scotch 
  pine, 
  being 
  most 
  

   numerous 
  upon 
  the 
  small 
  twigs, 
  and 
  avoid 
  the 
  white 
  pines. 
  My 
  own 
  

   observations 
  sustain 
  Dr. 
  Fitch, 
  both 
  as 
  to 
  the 
  tree 
  infested 
  and 
  the 
  

   distribution 
  thereon. 
  Though 
  the 
  Scotch 
  pines 
  grow 
  immediately 
  

   beside 
  the 
  white 
  in 
  the 
  grove 
  at 
  Urbana, 
  yet, 
  so 
  far 
  as 
  I 
  was 
  able 
  to 
  

   learn, 
  the 
  Chermes 
  were 
  not 
  found 
  at 
  all 
  upon 
  the 
  former. 
  

  

  In 
  the 
  matter 
  of 
  classification. 
  Dr. 
  Fitch 
  placed 
  the 
  apterous 
  female 
  

   among 
  the 
  Cocridii'. 
  naming 
  it 
  Coccus 
  pinicorticis. 
  Later, 
  when 
  he 
  

   discovered 
  the 
  winged 
  form, 
  but 
  without 
  recognizing 
  its 
  connection 
  

   with 
  the 
  apterous 
  female, 
  he 
  named 
  it 
  Chermes 
  pinifol 
  ice. 
  Dr. 
  Shimer 
  

   in 
  1SG9 
  pointed 
  out 
  its 
  connection 
  with 
  the 
  apterous 
  female, 
  but 
  

   meanwhile 
  Mr. 
  Walsh 
  confused 
  it 
  with 
  Aspidiotns 
  innifolici:. 
  Pro- 
  

   fessor 
  Osborn 
  confirms 
  Dr. 
  Shimer's 
  statement, 
  and 
  here 
  again 
  he 
  is, 
  

   without 
  doubt, 
  correct. 
  

  

  Dr. 
  Fitch 
  says 
  of 
  the 
  winged 
  form, 
  that 
  the 
  females 
  remain 
  seated 
  

   upon 
  the 
  pine 
  needles, 
  with 
  the 
  head 
  toward 
  the 
  base, 
  until 
  they 
  die, 
  

   covering 
  the 
  eggs. 
  No 
  such 
  habit 
  was 
  observed 
  at 
  Urbana. 
  Shortly 
  

   after 
  the 
  appearance 
  of 
  the 
  winged 
  form, 
  all 
  the 
  lice 
  disa^apeared 
  

   completely. 
  If 
  any 
  eggs 
  were 
  laid 
  upon 
  the 
  white 
  pine 
  before 
  their 
  

   disappearance, 
  I 
  failed 
  to 
  discover 
  them. 
  If 
  none 
  were 
  laid 
  upon 
  the 
  

   pines, 
  then 
  another 
  host 
  plant 
  must 
  be 
  sought. 
  Professor 
  Osborn 
  

   records 
  a 
  similarly 
  sudden 
  disappearance 
  of 
  the 
  lice, 
  June 
  10, 
  1878, 
  

   Dr. 
  Shimer 
  says 
  that 
  on 
  June 
  3, 
  1868, 
  he 
  first 
  observed 
  a 
  few 
  speci- 
  

   mens 
  of 
  the 
  winged 
  form, 
  and 
  on 
  June 
  1 
  he 
  found 
  them 
  plentifully 
  

   on 
  the 
  leaves; 
  then 
  he 
  adds: 
  "On 
  June 
  8, 
  I 
  had 
  great 
  difficulty 
  in 
  

   finding 
  one 
  perfect 
  specimen 
  of 
  the 
  winged 
  imago: 
  the 
  cold 
  rain 
  

   which 
  had 
  fallen 
  since 
  the 
  4th 
  seems 
  to 
  have 
  almost 
  entirely 
  de- 
  

   stroyed 
  them: 
  many 
  dead 
  ones, 
  with 
  their 
  wings 
  shriveled, 
  were 
  

   found 
  adhering 
  to 
  the 
  leaves. 
  From 
  the 
  8th 
  to 
  the 
  25th 
  of 
  June, 
  no 
  

   winged 
  specimens 
  could 
  be 
  found." 
  ft 
  is 
  evident 
  that 
  their 
  disap- 
  

   pearance 
  is 
  not 
  to 
  be 
  accounted 
  for 
  by 
  the 
  cold 
  rain. 
  The 
  most 
  satis- 
  

   factory 
  explanation 
  is 
  the 
  presence 
  in 
  the 
  vicinity 
  of 
  anotiier 
  host- 
  

   plant. 
  

  

  