﻿EPITHELIAL 
  ISLETS 
  OF 
  THE 
  PANCREAS 
  IN 
  TELEOSTEI. 
  405 
  

  

  jiy.c. 
  Pyloric 
  Cfeca. 
  re. 
  Kele 
  mirabile. 
  sm. 
  is. 
  Small 
  islet 
  in 
  Ammodytes. 
  

   ip. 
  Spleen, 
  d. 
  Slomacli. 
  v. 
  Vein. 
  

  

  PLATE 
  26. 
  

  

  Dissection 
  of 
  Zens 
  faber 
  to 
  show 
  relation 
  of 
  principal 
  islet 
  to 
  other 
  organs. 
  

  

  PLATE 
  27. 
  

   Abdominal 
  viscera 
  of 
  Loph 
  ins 
  piscatorius, 
  showinpj 
  general 
  distribution 
  

   of 
  the 
  islets. 
  The 
  principal, 
  which 
  is 
  always 
  the 
  largest, 
  is 
  seen 
  directly 
  

   anterior 
  to 
  the 
  spleen. 
  

  

  PLATE 
  28. 
  

  

  Fig. 
  3. 
  — 
  Principal 
  islet 
  in 
  Syngnathus 
  acus. 
  x 
  about 
  50 
  times. 
  

  

  Pig. 
  4.— 
  Litercsecal 
  islet 
  from 
  Zeus 
  faber. 
  X 
  350. 
  The 
  centre 
  portion 
  

   throughout 
  the 
  series 
  stained 
  more 
  darkly 
  than 
  the 
  rest 
  of 
  the 
  islet. 
  Note 
  

   the 
  absence 
  of 
  a 
  capsule. 
  

  

  Fig, 
  5, 
  — 
  Principal 
  islet 
  from 
  Anarrhichas 
  lupus. 
  Here 
  there 
  is 
  a 
  

   slight 
  penetration 
  of 
  its 
  tissue 
  by 
  pancreas. 
  The 
  full 
  thickness 
  of 
  the 
  latter 
  

   tissue 
  in 
  the 
  proximity 
  of 
  the 
  islet 
  is 
  shown. 
  X 
  72 
  times. 
  

  

  Pig. 
  6. 
  — 
  Islet 
  from 
  Ammodytes 
  tobianus. 
  X 
  350. 
  This 
  islet 
  shows 
  

   well 
  the 
  relation 
  to 
  pancreas 
  wherever 
  the 
  latter 
  is 
  at 
  all 
  massive. 
  Dark 
  and 
  

   light 
  cells 
  are 
  well 
  contrasted. 
  Capillaries 
  are 
  extremely 
  abundant, 
  but 
  it 
  

   should 
  be 
  noted 
  that 
  in 
  this 
  fish 
  a 
  similar 
  appearance, 
  in 
  this 
  respect, 
  is 
  seen 
  

   in 
  other 
  organs, 
  e. 
  g. 
  the 
  liver. 
  Besides 
  the 
  main 
  islet, 
  which 
  in 
  this 
  section 
  

   appears 
  in 
  two 
  portions, 
  there 
  is 
  a 
  very 
  small 
  one 
  to 
  the 
  right 
  near 
  a 
  large 
  

   vein. 
  A 
  large 
  pancreatic 
  duct 
  is 
  present. 
  

  

  Pig. 
  7. 
  — 
  Dark 
  and 
  light 
  cells 
  from 
  the 
  section 
  in 
  fig. 
  6. 
  X 
  810. 
  The 
  

   nuclei 
  («.) 
  in 
  the 
  light 
  cells 
  appear 
  slmiliar 
  to 
  those 
  seen 
  by 
  Diamare 
  also, 
  and 
  

   described 
  by 
  him 
  as 
  " 
  contort!." 
  

  

  Pig. 
  8. 
  — 
  Pyloric 
  islet 
  from 
  Pleuronectes 
  platessa. 
  x 
  50. 
  It 
  

   shows 
  areas 
  of 
  dark 
  and 
  light 
  cells, 
  and 
  also 
  a 
  considerable 
  amount 
  of 
  penetra- 
  

   tion 
  of 
  pancreas. 
  

  

  Fig. 
  9. 
  — 
  Portion 
  of 
  the 
  principal 
  islet 
  of 
  Pleuronectes, 
  showing 
  

   different 
  appearances 
  of 
  the 
  dark 
  and 
  light 
  cells, 
  x 
  810. 
  

  

  Fig. 
  10. 
  — 
  Rete 
  mirabile 
  from 
  capsule 
  of 
  Lophius. 
  x 
  810. 
  

  

  Fig. 
  11. 
  — 
  Principal 
  islet 
  from 
  Zoarces 
  viviparus. 
  x 
  72. 
  

  

  Fig. 
  12,— 
  (a) 
  Dark 
  and 
  (b) 
  light 
  cells 
  from 
  islet 
  in 
  fig. 
  11. 
  X 
  810. 
  

  

  Fig. 
  13. 
  — 
  Portion 
  of 
  islet 
  from 
  Onos 
  mustela. 
  x 
  810. 
  Showing 
  the 
  

   contrast 
  between 
  the 
  two 
  types 
  of 
  cell 
  in 
  this 
  species. 
  

  

  