﻿236 
  REPORT 
  UNITED 
  STATES 
  ENTOMOLOGICAL 
  COMMISSION. 
  

  

  nucleated 
  cells, 
  which 
  become 
  very 
  numerous 
  in 
  the 
  antennal 
  nerve. 
  

   The 
  nerve 
  fibers 
  are 
  stained 
  reddish 
  by 
  the 
  picrocarmine. 
  

  

  Turning 
  now 
  to 
  other 
  orthopterous 
  insects, 
  Flogel 
  mentions 
  Acrydium, 
  

   but 
  states 
  that 
  he 
  had 
  no 
  serviceable 
  preparations, 
  and 
  after 
  describing 
  

   the 
  brain 
  of 
  Forficula, 
  the 
  ear- 
  wig, 
  says 
  : 
  " 
  As 
  I 
  observe 
  in 
  Acrydium, 
  the 
  

   cells 
  and 
  fibers 
  in 
  this 
  animal 
  are 
  especially 
  large, 
  and 
  these 
  objects 
  in- 
  

   vite 
  further 
  investigation." 
  FlogePs 
  photograph 
  and 
  description 
  of 
  the 
  

   brain 
  of 
  Forficula, 
  a 
  representative 
  of 
  an 
  aberrant 
  family 
  of 
  Orthoptera, 
  

   and 
  Dieti's 
  beautiful 
  figures 
  and 
  descriptions 
  of 
  the 
  brain 
  of 
  the 
  mole- 
  

   cricket 
  (Gryllotalpa 
  vulgaris) 
  and 
  the 
  cricket 
  (Acheta 
  campestris) 
  show 
  

   that 
  the 
  orthopterous 
  brain, 
  judging 
  from 
  these 
  representative 
  forms, 
  is 
  

   constructed 
  on 
  a 
  common 
  type, 
  the 
  most 
  variable 
  part 
  being 
  the 
  calices 
  

   of 
  the 
  mushroom 
  body. 
  

  

  From 
  these 
  facts 
  we 
  should 
  judge 
  that, 
  on 
  the 
  whole, 
  the 
  locusts 
  were 
  

   as 
  highly 
  endowed 
  intellectually 
  as 
  any 
  other 
  insects, 
  with 
  the 
  excep- 
  

   tion 
  of 
  the 
  ants, 
  bees, 
  or 
  wasps, 
  i. 
  e., 
  the 
  social 
  species; 
  while 
  in 
  a 
  num- 
  

   ber 
  of 
  insects 
  the 
  brain 
  is 
  less 
  developed 
  than 
  in 
  the 
  locust. 
  It 
  would 
  

   thus 
  appear 
  that, 
  as 
  in 
  the 
  vertebrates, 
  there 
  are 
  different 
  grades 
  of 
  

   brain-development, 
  considerable 
  extremes 
  existing 
  in 
  the 
  same 
  sub-class 
  

   of 
  insects, 
  as 
  in 
  the 
  same 
  sub-class 
  of 
  mammals. 
  

  

  The 
  brain 
  of 
  the 
  bee 
  and 
  ant, 
  as 
  shown 
  by 
  Dujardin 
  and 
  demonstrated 
  

   by 
  Dietl 
  and 
  Flogel, 
  is 
  constructed 
  on 
  a 
  higher, 
  more 
  complicated 
  type 
  

   than 
  in 
  the 
  other 
  winged 
  insects, 
  owing 
  to 
  the 
  much 
  greater 
  complexity 
  

   of 
  the 
  folds 
  of 
  the 
  calices 
  or 
  folded 
  disk-like 
  bodies 
  capping 
  the 
  double 
  

   stalk 
  of 
  this 
  organ. 
  

  

  STRUCTURE 
  OF 
  THE 
  BRAIN 
  IN 
  THE 
  EMBRYO 
  LOCUST. 
  

  

  Much 
  light 
  may 
  be 
  thrown 
  upon 
  the 
  structure 
  of 
  different 
  parts 
  of 
  the 
  

   adult 
  brain 
  if 
  we 
  can 
  trace 
  their 
  origin 
  in 
  the 
  embryo, 
  or 
  in 
  the 
  larval 
  

   and 
  pupal 
  conditions. 
  Hence, 
  we 
  have, 
  with 
  what 
  material 
  we 
  could 
  

   obtain, 
  made 
  a 
  series 
  of 
  sections 
  of 
  the 
  embryo 
  and 
  different 
  stages 
  of 
  

   the 
  larva 
  and 
  pupa, 
  with 
  some 
  results 
  of 
  considerable 
  interest 
  and 
  im- 
  

   portance. 
  No 
  one 
  has 
  yet 
  examined 
  the 
  brain 
  of 
  the 
  embryo 
  insect. 
  The 
  

   only 
  observer 
  who 
  has 
  studied 
  the 
  brain 
  of 
  the 
  larva, 
  as 
  compared 
  with 
  

   the 
  adult, 
  has 
  been 
  Flogel. 
  Speaking 
  of 
  the 
  cockroach, 
  he 
  says 
  : 
  

  

  Of 
  especial 
  interest 
  would 
  be 
  an 
  investigation 
  of 
  the 
  development 
  of 
  the 
  separate 
  

   parts 
  of 
  the 
  brain. 
  The 
  difficulty 
  of 
  making 
  preparations 
  of 
  small 
  heads 
  has 
  been 
  such 
  

   that 
  no 
  particular 
  results 
  have 
  been 
  reached. 
  Still, 
  I 
  can 
  say 
  this 
  much, 
  that 
  in 
  small 
  

   creatures 
  7-8 
  mm 
  in 
  length 
  all 
  the 
  parts 
  are 
  present, 
  only 
  of 
  a 
  finer 
  aud 
  more 
  delicate 
  

   structure 
  than 
  in 
  the 
  large 
  adult 
  25 
  mm 
  in 
  length. 
  

  

  He 
  says 
  that 
  in 
  the 
  Hymenoptera 
  he 
  has 
  discovered 
  much 
  concern- 
  

   ing 
  the 
  development 
  of 
  the 
  parts 
  of 
  the 
  brain; 
  that 
  in 
  bee 
  larvae 
  the 
  

   calices 
  are 
  present, 
  though 
  very 
  small 
  and 
  with 
  thin 
  walls. 
  The 
  peduncle 
  

   and 
  trabecula 
  have 
  reached 
  their 
  ultimate 
  proportions 
  more 
  nearly 
  

   than 
  the 
  cauli 
  cuius, 
  which 
  is 
  still 
  very 
  thiu. 
  In 
  the 
  larval 
  ants 
  the 
  cen- 
  

   tral 
  body 
  and 
  entire 
  mushroom 
  bodies 
  are 
  present, 
  though 
  an 
  early 
  larval 
  

  

  