﻿STUUCTURE 
  AND 
  CLASSIFICATION 
  OF 
  THE 
  ARACHNIDA. 
  237 
  

  

  head 
  to 
  the 
  eud 
  of 
  the 
  sting, 
  and 
  occur 
  in 
  tropical 
  India 
  and 
  

   Africa. 
  Between 
  200 
  and 
  300 
  species 
  are 
  known. 
  The 
  

   scorpions 
  use 
  their 
  large 
  chela? 
  for 
  seizing 
  prey 
  and 
  for 
  fight- 
  

   ing 
  with 
  one 
  another. 
  They 
  never 
  use 
  the 
  sting 
  when 
  (as 
  

   frequently 
  happens) 
  they 
  attack 
  another 
  scorpion, 
  because, 
  

   as 
  was 
  ascertained 
  by 
  A. 
  G. 
  Bourne 
  (24), 
  the 
  poison 
  exuded 
  

   by 
  the 
  sting- 
  has 
  no 
  injurious 
  effect 
  on 
  another 
  scorpion 
  nor 
  

   on 
  the 
  scorpion 
  itself. 
  The 
  stories 
  of 
  a 
  scorpion 
  stinging 
  

   itself 
  to 
  death 
  when 
  placed 
  in 
  a 
  circle 
  of 
  burning 
  coals 
  are 
  

   due 
  to 
  erroneous 
  observation. 
  When 
  placed 
  in 
  such 
  a 
  

   position 
  the 
  scorpion 
  faints 
  and 
  becomes 
  inert. 
  It 
  is 
  found 
  

   (Bourne, 
  24) 
  that 
  some 
  species 
  of 
  scorpion 
  faint 
  at 
  a 
  tempera- 
  

   ture 
  of 
  40° 
  Cent. 
  They 
  recover 
  on 
  being 
  removed 
  to 
  cooler 
  

   conditions. 
  A 
  scorpion, 
  having 
  seized 
  its 
  prey 
  (usually 
  a 
  

   large 
  insect, 
  or 
  small 
  reptile 
  or 
  mammal) 
  with 
  the 
  large 
  

   chelae, 
  brings 
  its 
  tail 
  over 
  its 
  head, 
  and 
  deliberately 
  punctures 
  

   the 
  struggling 
  victim 
  twice 
  with 
  its 
  sting 
  (Fig. 
  52). 
  The 
  

   poison 
  of 
  the 
  sting 
  is 
  similar 
  to 
  snake 
  poison 
  (Calmette), 
  and 
  

   rapidly 
  paralyses 
  animals 
  which 
  are 
  not 
  immune 
  to 
  it. 
  It 
  is 
  

   probably 
  only 
  sickly 
  adults 
  or 
  young 
  children 
  of 
  the 
  human 
  

   race 
  who 
  can 
  be 
  actually 
  killed 
  by 
  a 
  scor])ion's 
  sting. 
  When 
  

   the 
  scorpion 
  has 
  paralysed 
  its 
  prey 
  in 
  this 
  way 
  the 
  two 
  short 
  

   chelicerse 
  are 
  brought 
  into 
  play 
  (Fig. 
  58). 
  By 
  the 
  crushing- 
  

   action 
  of 
  their 
  pincers, 
  and 
  an 
  alternate 
  backward 
  and 
  for- 
  

   ward 
  movement, 
  they 
  bring 
  the 
  soft 
  blood-holding 
  tissues 
  of 
  

   the 
  victim 
  close 
  to 
  the 
  minute 
  pin-hole 
  aperture 
  which 
  is 
  the 
  

   scorpion's 
  mouth. 
  The 
  muscles 
  acting 
  on 
  the 
  bulb-like 
  

   pharynx 
  now 
  set 
  up 
  a 
  pumping 
  action 
  (see 
  Huxley 
  [26] 
  ) 
  ; 
  and 
  

   the 
  juices 
  — 
  but 
  no 
  solid 
  mattei', 
  excepting 
  such 
  as 
  is 
  reduced 
  

   to 
  powder 
  — 
  are 
  sucked 
  into 
  the 
  scorpion's 
  alimentary 
  canal. 
  

   A 
  scorpion 
  appears 
  to 
  prefer 
  for 
  its 
  food 
  another 
  scorpion, 
  

   and 
  will 
  suck 
  out 
  the 
  juices 
  of 
  an 
  individual 
  as 
  large 
  as 
  itself. 
  

   When 
  this 
  has 
  taken 
  place 
  the 
  gorged 
  scorpion 
  becomes 
  dis- 
  

   tended 
  and 
  tense 
  in 
  the 
  mesosomatic 
  region. 
  It 
  is 
  certain 
  

   that 
  the 
  absorbed 
  juices 
  do 
  not 
  occupy 
  the 
  alimentary 
  canal 
  

   alone, 
  but 
  pass 
  also 
  into 
  its 
  cascal 
  off-sets, 
  which 
  are 
  the 
  

   ducts 
  of 
  the 
  gastric 
  glands 
  (see 
  Fig. 
  33). 
  

  

  