﻿234 
  REPORT 
  UNITED 
  STATES 
  ENTOMOLOGICAL 
  COMMISSION. 
  

  

  Hymenoptera, 
  where 
  it 
  is 
  well 
  developed. 
  We 
  have 
  been 
  unable 
  to 
  find 
  

   it 
  as 
  yet 
  in 
  the 
  brain 
  of 
  myriopods 
  or 
  of 
  the 
  spider. 
  In 
  the 
  locust 
  each 
  

   body 
  is 
  more 
  or 
  less 
  rounded 
  and 
  rudely 
  saucer-like 
  rather 
  than 
  cup- 
  

   like, 
  with 
  the 
  rim 
  very 
  thick 
  ; 
  the 
  hollow 
  of 
  the 
  cup, 
  if 
  it 
  be 
  hollow, 
  is 
  

   small 
  in 
  proportion 
  to 
  the 
  thickness 
  of 
  the 
  saucer-like 
  cup. 
  The 
  diam- 
  

   eter 
  of 
  a 
  calyx 
  is 
  about 
  ■$%-$. 
  The 
  anterior 
  edge 
  reaches 
  to 
  the 
  front 
  

   edge 
  of 
  each 
  hemisphere 
  of 
  the 
  brain, 
  but 
  does 
  not 
  extend 
  to 
  the 
  back 
  

   part 
  of 
  the 
  brain. 
  The 
  relations 
  in 
  a 
  vertical, 
  i. 
  e., 
  longitudinal 
  section 
  

   of 
  the 
  'mushroom 
  body 
  to 
  the 
  rest 
  of 
  the 
  brain 
  are 
  seen 
  in 
  (PI. 
  X, 
  Fig. 
  

   8 
  a). 
  It 
  thus 
  appears 
  that 
  the 
  double 
  stalk 
  is 
  situated 
  near 
  the 
  center 
  

   of 
  the 
  brain, 
  and 
  that 
  the 
  cap 
  projects 
  far 
  forward, 
  but 
  posteriorly 
  does 
  

   not 
  extend 
  behind 
  the 
  antennal 
  lobes 
  or 
  the 
  commissures. 
  In 
  section 
  18 
  

   (Fig. 
  4) 
  the 
  calices 
  are 
  seen 
  to 
  be 
  double, 
  the 
  outer 
  (o. 
  cat.) 
  attached 
  to 
  

   the 
  cauliculus 
  (can.) 
  and 
  the 
  inner 
  arising 
  from 
  the 
  peduncle. 
  Fig. 
  8 
  a 
  

   gives 
  an 
  idea 
  of 
  the 
  two 
  calices 
  and 
  their 
  mode 
  of 
  attachment 
  to 
  the 
  

   stalk. 
  The 
  peduncle 
  (if 
  we 
  interpret 
  that 
  division 
  of 
  the 
  stalk 
  aright) 
  

   subdivides, 
  sending 
  a 
  thick 
  bundle 
  of 
  fibers 
  to 
  each 
  calyx, 
  ending 
  ab- 
  

   ruptly 
  in 
  the 
  hollow 
  of 
  the 
  calyx. 
  The 
  substance 
  of 
  the 
  calices 
  is 
  finely 
  

   granular, 
  with 
  some 
  coarse 
  granules, 
  and 
  apparently 
  short 
  scattered 
  

   irregular 
  fibers. 
  The 
  structure 
  of 
  the 
  calices 
  of 
  the 
  locust 
  appears 
  to 
  

   be 
  more 
  homogeneous 
  than 
  that 
  of 
  the 
  cockroach, 
  judging 
  by 
  our 
  sec- 
  

   tions 
  of 
  the 
  latter. 
  Owing 
  to 
  different 
  treatment 
  by 
  reagents 
  the 
  dark 
  

   masses 
  described 
  by 
  Newton 
  as 
  existing 
  in 
  the 
  cockroach 
  were 
  not 
  so 
  

   clearly 
  shown 
  in 
  my 
  sections 
  (ygoo 
  mcn 
  thick) 
  as 
  in 
  those 
  made 
  by 
  Mr. 
  

   Newton. 
  The 
  substance 
  of 
  the 
  calices 
  when 
  examined 
  under 
  a 
  power 
  

   of 
  725 
  diameters 
  is 
  much 
  the 
  same 
  both 
  in 
  the 
  cockroach 
  and 
  the 
  locust, 
  

   the 
  dark 
  bodies 
  not 
  appearing 
  in 
  either. 
  The 
  form 
  of 
  the 
  calices 
  is 
  very 
  

   different 
  in 
  the 
  cockroach, 
  the 
  calices 
  being 
  truly 
  cup-like, 
  the 
  disk 
  being 
  

   deeply 
  folded, 
  and 
  the 
  edges 
  of 
  each 
  cup 
  being 
  thin 
  compared 
  with 
  those 
  

   of 
  the 
  locust. 
  

  

  The 
  optic 
  lobes. 
  — 
  As 
  seen 
  in 
  section 
  19 
  (PI. 
  XI, 
  Fig. 
  1 
  op. 
  I.) 
  these 
  

   bodies 
  are 
  larger 
  than 
  the 
  antennal 
  lobes, 
  and 
  consist 
  of 
  numerous 
  

   irregular 
  small 
  bundles 
  of 
  fibers 
  besides 
  those 
  composing 
  the 
  optic 
  

   nerve, 
  the 
  interspaces 
  being 
  filled 
  with 
  fine 
  granular 
  nerve 
  substance. 
  

   The 
  optic 
  nerve 
  is 
  much 
  larger 
  at 
  the 
  outer 
  edge 
  of 
  the 
  lobe 
  before 
  pass- 
  

   ing 
  into 
  the 
  optic 
  ganglion, 
  the 
  fibers 
  still 
  being 
  immersed 
  in 
  the 
  finely 
  

   granular 
  nervous 
  substance. 
  

  

  The 
  optic 
  ganglion. 
  — 
  This 
  is 
  situated 
  at 
  the 
  back 
  of 
  the 
  brain, 
  and 
  is 
  

   a 
  large 
  rounded 
  mass 
  of 
  white 
  fine 
  granular 
  nervous 
  matter, 
  enveloped 
  

   in 
  very 
  numerous 
  but 
  small 
  ganglion 
  cells, 
  which 
  stain 
  dark 
  red 
  by 
  car- 
  

   mine, 
  the 
  granular 
  matter 
  remaining 
  unstained 
  by 
  the 
  picrocarmine. 
  

   The 
  granular 
  or 
  white 
  portion 
  is 
  subdivided 
  into 
  three 
  rudely 
  lens- 
  

   shaped 
  masses 
  (see 
  PI. 
  XV, 
  Fig. 
  1), 
  the 
  one 
  nearest 
  the 
  eye 
  being 
  much 
  

   the 
  largest. 
  The 
  structure 
  of 
  the 
  optic 
  ganglion 
  is 
  substantially 
  as 
  

   described 
  by 
  Newton, 
  as 
  seen 
  in 
  his 
  description 
  and 
  our 
  preparations. 
  

   A 
  farther 
  description 
  is 
  reserved 
  for 
  our 
  account 
  of 
  the 
  eye, 
  which 
  we 
  

   hope 
  to 
  give 
  in 
  the 
  next 
  report. 
  

  

  