﻿GENEALOGY 
  OF 
  INSECTS. 
  

   GENEALOGY 
  OF 
  THE 
  INSECTS 
  (HEXAPODA). 
  

  

  X. 
  Hymenoptera. 
  

  

  IX. 
  Lepidoptera- 
  

  

  295 
  

  

  Vm. 
  DiPTERA. 
  

  

  YII. 
  COLEOPTERA. 
  

  

  Trichoptera. 
  / 
  

  

  \ 
  PanorpidBB, 
  i^ 
  

  

  \ 
  HemerobiidsB. 
  

  

  1. 
  Platyptera. 
  

  

  Termiti^. 
  

  

  I 
  

   V. 
  Hemiptera. 
  Embidae. 
  

  

  . 
  Ephemerina. 
  

   Psocidfe. 
  

  

  I 
  

   Perlina. 
  /2. 
  Odonata, 
  

  

  -Sialidae. 
  

  

  lY. 
  PSEUDONEUROPTERA. 
  

  

  VI. 
  Neuropteua. 
  

  

  in. 
  Orthoptera, 
  

  

  n. 
  Dermatop'A'bra 
  

  

  Metabola. 
  

  

  A 
  metabola. 
  

  

  I. 
  Thysanura. 
  

   (Campodea.) 
  

  

  GENEALOGY 
  OF 
  THE 
  HEX 
  APOD 
  A. 
  

  

  I. 
  Thysanura. 
  — 
  This 
  order 
  once 
  comprised 
  some 
  lost 
  types 
  nearly 
  re- 
  

   sembling 
  Lepisma, 
  Campodea, 
  and 
  Japyx, 
  and 
  more 
  especially 
  Scolopen- 
  

   drella, 
  tlie 
  probable 
  stem-form 
  of 
  the 
  Hexapoda. 
  In 
  other 
  words, 
  from 
  a 
  

   hypothetical 
  form 
  resembling 
  Campodea 
  or 
  Scolopendrella, 
  it 
  is 
  not 
  difii- 
  

   cult 
  to 
  suppose 
  that 
  all 
  or 
  at 
  least 
  the 
  majority 
  of 
  Hexapoda 
  took 
  their 
  

   origin. 
  It 
  is 
  possible 
  that 
  by 
  a 
  few 
  intermediate 
  steps 
  now 
  lost, 
  Forh- 
  

   cula 
  may 
  have 
  descended 
  from 
  the 
  Thysanuran 
  Japyx 
  ; 
  this 
  is 
  suggested 
  

   by 
  the 
  form 
  of 
  the 
  body, 
  the 
  head 
  with 
  its 
  Y-shaped 
  suture, 
  and 
  the 
  ab- 
  

   domen 
  with 
  its 
  forceps, 
  so 
  like 
  that 
  of 
  Japyx. 
  The 
  genus 
  Lepisma 
  is 
  a 
  

   rather 
  more 
  specialized 
  form 
  than 
  CaTmpodea, 
  and 
  Machilis 
  is 
  still 
  more 
  

   so, 
  as 
  proved 
  by 
  its 
  mouth 
  parts 
  and 
  the 
  presence 
  of 
  compound 
  eyes. 
  

   Scolopendrella, 
  with 
  its 
  abdominal 
  true 
  legs, 
  comes 
  nearer 
  to 
  our 
  hypo- 
  

   thetical 
  form 
  than 
  even 
  Campodea. 
  The 
  group 
  of 
  Poduridw 
  (Collem- 
  

   bola) 
  is 
  most 
  probably 
  a 
  series 
  of 
  degradational 
  forms, 
  originally 
  sprung 
  

   from 
  a 
  higher, 
  more 
  generalized, 
  Catnpodea-like 
  ancestor. 
  

  

  II. 
  Dermatoptera. 
  — 
  This 
  order, 
  represented 
  by 
  but 
  one 
  family, 
  differs, 
  

   as 
  already 
  stated, 
  from 
  the 
  Orthoptera, 
  with 
  which 
  it 
  is 
  usually 
  classi- 
  

  

  