﻿THE 
  BRAIN 
  OF 
  THE 
  LOCUST. 
  225 
  

  

  bairson 
  tin 
  1 
  crust 
  of 
  the 
  insect, 
  or 
  from 
  the 
  antennae, 
  or 
  the 
  eyes 
  or 
  ears, 
  

  

  and 
  end 
  in 
  separate 
  masses 
  or 
  lobes, 
  which 
  are 
  modified 
  ganglia, 
  snch 
  

   ganglia 
  are 
  regarded 
  as 
  u 
  sensory 
  ganglia," 
  and 
  the 
  nerves 
  leading 
  in 
  

  

  from 
  them 
  are 
  ealled 
  ingoing 
  or 
  "afferent 
  nerves." 
  while 
  the 
  ganglia 
  

   which 
  give 
  rise 
  to 
  the 
  outgoing 
  or 
  •• 
  efferent" 
  nerves, 
  i. 
  0., 
  those 
  going 
  to 
  

   the 
  muscles 
  of 
  the 
  wings, 
  legs, 
  &C, 
  are 
  called 
  " 
  motor 
  ganglia." 
  as 
  

   stated 
  by 
  Bastiau, 
  in 
  his 
  popular 
  and 
  excellent 
  work 
  •• 
  The 
  Brain 
  as 
  an 
  

   Organ 
  of 
  Mind." 
  As 
  to 
  the 
  term 
  ganglion 
  we 
  quote 
  as 
  follows 
  from 
  

   Bastian 
  : 
  

  

  Two 
  or 
  more 
  sensory 
  ganglia, 
  or 
  two 
  or 
  more 
  motor 
  ganglia, 
  may 
  grow 
  together 
  into 
  

   a 
  single 
  mass; 
  or, 
  what 
  is 
  equally 
  common, 
  a 
  sensory 
  and 
  its 
  corresponding 
  motor 
  

   ganglion, 
  or 
  two 
  or 
  more 
  pairs 
  of 
  these, 
  may 
  fuse 
  into 
  a 
  single 
  larger 
  nodule, 
  which 
  

   may 
  be 
  called 
  a 
  " 
  nerve-center." 
  The 
  term 
  ganglia 
  is, 
  however, 
  commonly 
  applied 
  

   to 
  any 
  round, 
  ovoid 
  nodnle 
  containing 
  nerve-cells, 
  whatever 
  its 
  size 
  or 
  degree 
  of 
  in- 
  

   ternal 
  complexity. 
  Many 
  ganglia 
  in 
  the 
  lower 
  animals, 
  which 
  are 
  typically 
  deserv- 
  

   ing 
  of 
  the 
  name 
  as 
  regards 
  mere 
  form 
  and 
  separateness, 
  are 
  also, 
  by 
  reason 
  of 
  their 
  

   compound 
  nature, 
  true 
  nerve-centers. 
  The 
  two 
  terms 
  are, 
  therefore, 
  to 
  a 
  considerable 
  

   extent, 
  interchangeable. 
  

  

  Referring 
  the 
  reader 
  to 
  Bastian's 
  book, 
  or 
  to 
  the 
  text-books 
  on 
  physi- 
  

   ology 
  by 
  Huxley, 
  Foster, 
  or 
  Dalton, 
  for 
  information 
  regarding 
  the 
  

   structure 
  and 
  physiology 
  of 
  the 
  nervous 
  system 
  in 
  general, 
  we 
  will 
  pro- 
  

   ceed 
  to 
  describe 
  that 
  of 
  the 
  locust. 
  It 
  should 
  be 
  borne 
  in 
  mind, 
  how- 
  

   ever, 
  that 
  the 
  subcesophageal 
  ganglion, 
  or 
  " 
  brain," 
  of 
  the 
  insect 
  is 
  much, 
  

   more 
  complex 
  than 
  any 
  other 
  ganglion, 
  consisting 
  more 
  exclusively 
  both 
  

   of 
  sensory 
  as 
  well 
  as 
  motor 
  ganglia 
  and 
  their 
  nerves. 
  But 
  it 
  should 
  

   also 
  be 
  borne 
  in 
  mind 
  that 
  the 
  subcesophageal 
  ganglion 
  also 
  receives 
  

   nerves 
  of 
  special 
  sense, 
  situated 
  possibly 
  on 
  the 
  palpi 
  and 
  possibly 
  on 
  the 
  

   tongue, 
  at 
  least 
  the 
  latter 
  is 
  the 
  case 
  with 
  the 
  bee 
  ; 
  hence, 
  this 
  ganglion 
  is 
  

   probably 
  complex, 
  consisting 
  of 
  sensory 
  and 
  motor 
  ganglia. 
  The 
  third 
  

   thoracic 
  ganglion 
  is 
  also, 
  without 
  doubt, 
  a 
  complex 
  one, 
  as 
  in 
  the 
  locusts 
  

   the 
  auditory 
  nerves 
  pass 
  into 
  it 
  from 
  the 
  ears, 
  which 
  are 
  situated 
  at 
  the 
  

   base 
  of 
  the 
  abdomen. 
  But 
  in 
  the 
  green 
  grasshoppers, 
  such 
  as 
  the 
  katy- 
  

   dids 
  and 
  their 
  allies, 
  whose 
  ears 
  are 
  situated 
  in 
  their 
  fore-legs, 
  the 
  first 
  

   thoracic 
  ganglion 
  is 
  a 
  complex 
  one. 
  In 
  the 
  cockroach 
  and 
  in 
  the 
  Leptis 
  

   (Ohrysopila), 
  a 
  common 
  fly, 
  the 
  caudal 
  appendages 
  bear 
  what 
  are 
  prob- 
  

   ably 
  olfactory 
  organs, 
  and 
  as 
  these 
  parts 
  are 
  undoubtedly 
  supplied 
  from 
  

   the 
  last 
  abdominal 
  ganglion, 
  this 
  is 
  probably 
  composed 
  of 
  sensory 
  and 
  

   motor 
  ganglia 
  ; 
  so 
  that 
  we 
  have 
  in 
  the 
  ganglionated 
  cord 
  of 
  insects 
  a 
  

   series 
  of 
  brains, 
  as 
  it 
  were, 
  running 
  from 
  head 
  to 
  tail, 
  and 
  thus 
  in 
  a 
  still 
  

   stronger 
  sense 
  than 
  in 
  vertebrates 
  the 
  entire 
  nervous 
  system, 
  and 
  not 
  

   the 
  brain 
  alone, 
  is 
  the 
  organ 
  of 
  the 
  mind, 
  or 
  psychological 
  endowment, 
  

   of 
  the 
  insect. 
  

  

  AYe 
  will 
  now 
  proceed 
  to 
  examine 
  the 
  brain 
  of 
  the 
  adult 
  C«lo_ptemis 
  

   spretus, 
  and 
  compare 
  it 
  with 
  that 
  of 
  other 
  insects 
  ; 
  then 
  study 
  its 
  devel- 
  

   opment 
  in 
  the 
  embryo, 
  and 
  finally 
  examine 
  the 
  changes 
  it 
  undergoes 
  in 
  

   15 
  L 
  

  

  