﻿HOW 
  INSECTS 
  FLY 
  SNODGKASS 
  

  

  411 
  

  

  tion 
  of 
  the 
  first 
  median 
  plate 
  (m) 
  on 
  the 
  second 
  axillary 
  {2 
  Ax), 
  and 
  

   the 
  consequent 
  inward 
  swing 
  of 
  the 
  posterior 
  end 
  of 
  the 
  plica 
  basalis 
  

   (bf) 
  between 
  the 
  two 
  median 
  plates 
  (m, 
  m') 
  turns 
  both 
  the 
  medio- 
  

  

  FiGURE 
  22.— 
  Diagrams 
  illustrating 
  the 
  flexion 
  of 
  a 
  wing. 
  A, 
  The 
  extended 
  wing, 
  

   showing 
  folds 
  and 
  regions 
  named 
  on 
  Figure 
  14; 
  B, 
  the 
  partly 
  flexed 
  wing, 
  showing 
  

   the 
  basal 
  folding 
  along 
  the 
  pUca 
  basalis 
  (bf), 
  and 
  the 
  jugal 
  region 
  lapped 
  beneath 
  

   the 
  vannu 
  along 
  the 
  jugal 
  fold; 
  C, 
  a 
  fully 
  flexed 
  wing 
  in 
  which 
  the 
  entire 
  axillary 
  

   region 
  is 
  turned 
  vertically 
  on 
  its 
  base 
  (a-6); 
  the 
  vannus 
  is 
  elevated 
  by 
  the 
  apex 
  (c) 
  

   of 
  the 
  axillary 
  region 
  and 
  turned 
  horizontally 
  against 
  the 
  body; 
  the 
  remigium, 
  

   turned 
  posteriorly 
  on 
  the 
  point 
  d 
  (see 
  flg. 
  12), 
  slopes 
  downward 
  and 
  laterally 
  on 
  

   the 
  flexure 
  at 
  the 
  vannal 
  fold 
  

  

  cubital 
  and 
  vannal 
  areas 
  of 
  the 
  wing 
  posteriorly. 
  The 
  costo-radial 
  

   area 
  necessarily 
  follows, 
  turning 
  posteriorly 
  on 
  the 
  hinge 
  of 
  the 
  radius 
  

   (d) 
  with 
  the 
  second 
  axillary, 
  and 
  on 
  that 
  of 
  the 
  subcosta 
  (e) 
  with 
  the 
  

  

  