﻿STRUCTURE 
  OF 
  THE 
  GASTRIC 
  CCECA. 
  215 
  

  

  whose 
  observations 
  are 
  also 
  cited 
  by 
  Leydig 
  on 
  p. 
  337 
  of 
  his 
  "Band- 
  

   buck.' 
  1 
  Sirodot 
  305 
  repeats 
  the 
  old 
  and 
  incorrect 
  statement, 
  while 
  Griiber 
  306 
  

   expressly 
  states 
  that 
  their 
  structure 
  is 
  not 
  the 
  same 
  as 
  that 
  of 
  the 
  stom- 
  

   ach, 
  and 
  that 
  they 
  are 
  not 
  " 
  einfache 
  Aussackungen 
  des 
  Chylusmagens." 
  

   More 
  recently 
  M. 
  F. 
  Plateau 
  30 
  " 
  has 
  again 
  called 
  attention 
  to 
  the 
  incorrect- 
  

   ness 
  of 
  the 
  old 
  view. 
  

  

  In 
  fact, 
  a 
  single 
  transverse 
  section 
  of 
  one 
  of 
  the 
  diverticula 
  (Fig. 
  37) 
  

   demonstrates 
  at 
  once 
  that 
  its 
  structure 
  is 
  entirely 
  different 
  from 
  that 
  of 
  

   the 
  stomach. 
  Its 
  inner 
  surface 
  is 
  thrown 
  up 
  into 
  longitudinal 
  folds, 
  

   generally 
  twelve 
  in 
  number. 
  These 
  folds 
  shine 
  through 
  the 
  outer 
  walls, 
  

   and 
  are, 
  accordingly, 
  indicated 
  in 
  the 
  drawings 
  of 
  Dufour, 
  Griiber, 
  and 
  

   others. 
  The 
  whole 
  diverticulum 
  has 
  an 
  external 
  muscular 
  envelope, 
  out- 
  

   side 
  of 
  which 
  are 
  a 
  few 
  isolated 
  longitudinal 
  muscular 
  bands. 
  The 
  

   folds 
  within 
  are 
  formed 
  mainly 
  by 
  the 
  high 
  cylindrical 
  epithelium, 
  which 
  

   lines 
  the 
  whole 
  interior 
  of 
  the 
  cavity. 
  The 
  shape 
  of 
  the 
  folds 
  will 
  be 
  

   more 
  comprehensible 
  from 
  the 
  Fig. 
  37 
  than 
  from 
  any 
  description 
  I 
  

   can 
  give. 
  They 
  are 
  not 
  all 
  of 
  the 
  same 
  height, 
  but 
  they 
  form 
  two 
  op- 
  

   posite 
  groups, 
  the 
  folds 
  in 
  the 
  center 
  of 
  each 
  group 
  being 
  the 
  highest. 
  

   On 
  either 
  side 
  and 
  between 
  the 
  two 
  groups 
  there 
  are 
  smaller 
  folds. 
  

   TVhatever 
  the 
  height 
  of 
  the 
  folds, 
  however, 
  they 
  all 
  have 
  the 
  same 
  gen- 
  

   eral 
  histological 
  character, 
  which 
  is 
  indicated 
  by 
  Fig. 
  38. 
  The 
  cells 
  

   are 
  large 
  and 
  cylindrical, 
  slightly 
  granular, 
  those 
  near 
  the 
  top 
  of 
  each 
  

   fold 
  being 
  slightly 
  pigmented 
  with 
  brownish 
  matter 
  that 
  obscures 
  their 
  

   definition. 
  The 
  nuclei 
  are 
  large, 
  oval, 
  coarsely 
  granular, 
  and 
  lie 
  in 
  the 
  

   middle 
  or 
  lower 
  parts 
  of 
  the 
  cells. 
  The 
  cells 
  are 
  protected 
  by 
  a 
  delicate 
  

   but 
  very 
  distinct 
  cuticula, 
  in 
  which 
  I 
  can 
  detect 
  no 
  pore-canals, 
  though 
  

   it 
  otherwise 
  resembles 
  the 
  cuticula 
  in 
  the 
  ventriculus. 
  In 
  the 
  center 
  of 
  

   each 
  fold 
  there 
  runs 
  up 
  a 
  thin 
  partition 
  of 
  fibrous 
  tissue 
  (Fig. 
  38, 
  conn), 
  

   which 
  separates 
  the 
  epithelium 
  of 
  the 
  two 
  sides, 
  and 
  is 
  itself 
  an 
  off- 
  

   shoot 
  of 
  the 
  connective 
  tissue, 
  tunica 
  propria, 
  that 
  intervenes 
  between 
  

   the 
  muscles, 
  mice., 
  and 
  the 
  epithelial 
  layer. 
  The 
  tracheae 
  ramify 
  through- 
  

   out 
  all 
  the 
  layers 
  outside 
  the 
  epithelium 
  ; 
  one 
  of 
  the 
  main 
  trunks 
  run- 
  

   ning 
  to 
  the 
  wall 
  is 
  shown 
  at 
  Tr. 
  (Fig. 
  37). 
  It 
  sometimes 
  looked 
  as 
  if 
  

   there 
  were 
  glandular 
  follicles 
  in 
  the 
  bottom 
  of 
  the 
  spaces 
  between 
  the 
  

   folds, 
  but 
  of 
  this 
  I 
  could 
  not 
  make 
  sure. 
  

  

  Towards 
  the 
  tips 
  of 
  the 
  diverticula 
  the 
  folds 
  decrease 
  in 
  height 
  as 
  the 
  

   diameter 
  of 
  sacks 
  diminishes, 
  until 
  finally 
  they 
  disappear 
  almost 
  com- 
  

   pletely. 
  

  

  Gastro-ileal 
  folds. 
  — 
  I 
  have 
  now 
  to 
  speak 
  of 
  some 
  very 
  curious 
  and 
  

   striking 
  formations 
  which 
  seem 
  to 
  have 
  escaped 
  notice 
  until 
  now, 
  for 
  I 
  

   find 
  no 
  description 
  of 
  them 
  in 
  any 
  of 
  the 
  works 
  on 
  insect 
  anatomy 
  which 
  

  

  **i. 
  «., 
  p. 
  157. 
  

  

  306 
  V. 
  Graber: 
  Zur 
  naberen 
  Kenntniss 
  des 
  Proventriculus 
  und 
  der 
  Appendices 
  ventriculares 
  bei 
  den 
  

   Grillen 
  und 
  Laubheuschrecken. 
  Sitzber. 
  Wien. 
  Akad. 
  (1869), 
  lix, 
  p. 
  33. 
  

  

  307 
  F. 
  Plateau 
  : 
  Recberches 
  sur 
  les 
  Pbenomenes 
  de 
  la 
  Digestion 
  chez 
  les 
  Insectes. 
  M6moires 
  Acad. 
  

   Roy. 
  B-elg. 
  Q875), 
  tome 
  xli. 
  p. 
  7j. 
  

  

  