﻿THE 
  BRAIX 
  OF 
  THE 
  LOCUST. 
  

  

  223 
  

  

  CHAPTER 
  XL 
  

  

  ps 
  — 
  

  

  THE 
  BRAIX 
  OF 
  THE 
  LOCUST. 
  

  

  In 
  order 
  to 
  appreciate 
  the 
  habits, 
  migratory, 
  reproductive, 
  &c, 
  of 
  the 
  

   locust, 
  aud 
  to 
  learn 
  something 
  of 
  its 
  general 
  

   intelligence 
  as 
  an 
  insect 
  and 
  as 
  compared 
  oc 
  

   with 
  other 
  insects, 
  it 
  is 
  necessary 
  for 
  us 
  to 
  sp 
  

   study 
  with 
  a 
  good 
  deal 
  of 
  care 
  the 
  organ 
  of 
  ™ 
  

   the 
  locust's 
  mind, 
  i. 
  e., 
  its 
  nervous 
  system, 
  

   comprising 
  its 
  nervous 
  centers 
  and 
  the 
  nerves 
  y 
  

   arising 
  from 
  them. 
  The 
  present 
  chapter 
  

   will 
  be 
  devoted 
  to 
  a 
  study 
  of 
  the 
  brain. 
  

  

  The 
  nervous 
  system 
  in 
  general. 
  — 
  The 
  ner- 
  

   vous 
  system 
  of 
  the 
  locust 
  has 
  been 
  described 
  

   in 
  a 
  general 
  way 
  in 
  the 
  First 
  Annual 
  Eeport 
  

   of 
  the 
  Commission 
  (p. 
  264, 
  Figs. 
  14, 
  15). 
  It 
  

   consists 
  of 
  a 
  series 
  of 
  nerve 
  centers 
  or 
  ganglia, 
  

   connected 
  by 
  nervous 
  cords 
  called 
  commis- 
  

   sures. 
  There 
  are 
  ten 
  of 
  these 
  ganglia 
  in 
  the 
  

   locust, 
  i. 
  e. 
  } 
  two 
  in 
  the 
  head, 
  the 
  first 
  and 
  

   largest 
  of 
  which 
  is 
  called 
  the 
  u 
  brain 
  v 
  ] 
  there 
  

   are 
  three 
  ganglia 
  in 
  the 
  thorax, 
  and 
  five 
  in 
  

   the 
  hind-body 
  or 
  abdomen. 
  The 
  brain 
  is 
  

   situated 
  in 
  the 
  upper 
  part 
  of 
  the 
  head, 
  rest- 
  

   ing 
  upon 
  the 
  gullet 
  or 
  oesophagus, 
  whence 
  its 
  

   true 
  name 
  siq)raoeso2)hageal 
  ganglion. 
  (Plate 
  

   IX. 
  Fig. 
  1.) 
  The 
  succeeding 
  nerve-center 
  is 
  

   situated 
  in 
  the 
  lower 
  part 
  of 
  the 
  head, 
  be- 
  

   hind 
  the 
  mouth 
  and 
  under 
  the 
  oesophagus, 
  

   hence 
  it 
  is 
  called 
  the 
  suboesopliageal 
  ganglion. 
  

   (Plate 
  IX, 
  Fig. 
  5.) 
  The 
  supra 
  oesophageal 
  

   ganglion 
  is 
  larger 
  than 
  the 
  succeeding 
  ones, 
  

   and 
  is 
  compressed 
  from 
  before 
  and 
  behind, 
  

   its 
  height 
  being 
  much 
  greater 
  than 
  its 
  

   length, 
  while 
  the 
  other 
  ganglia 
  are 
  more 
  or 
  

   less 
  lens-shaped 
  and 
  flattened 
  vertically, 
  be- 
  

   ing 
  broader 
  than 
  thick. 
  The 
  brain 
  really 
  is 
  

   ii 
  double 
  ganglion, 
  being 
  composed 
  of 
  two 
  

   hemispheres, 
  each 
  hemisphere 
  being 
  a 
  single 
  

   ganglion 
  or 
  nerve-center 
  ; 
  all 
  the 
  succeeding 
  

   ganglia 
  are 
  also 
  double 
  ganglia 
  ; 
  but 
  for 
  con- 
  

   venitnce 
  we 
  will 
  call 
  the 
  "brain" 
  and 
  each 
  

   of 
  the 
  succeeding 
  nerve-centers 
  a 
  ganglion. 
  

   Each 
  side 
  of 
  the 
  brain 
  contracts, 
  and 
  then 
  

   swells 
  out 
  into 
  a 
  rounded 
  portion 
  next 
  to 
  

   the 
  eye, 
  called 
  the 
  optic 
  ganglion. 
  From 
  this 
  optic 
  ganglion 
  the 
  optic 
  

  

  4 
  — 
  

  

  Fig. 
  

  

  