﻿EPITHELIAL 
  ISLETS 
  OP 
  THE 
  PANCREAS 
  IN 
  TELEOSTEI. 
  SSo 
  

  

  but 
  some 
  are 
  of 
  fairly 
  large 
  size; 
  they 
  are 
  circular, 
  elliptical, 
  

   or 
  irregular 
  in 
  outline. 
  They 
  do 
  not 
  possess 
  a 
  special 
  

   limiting 
  capsule, 
  but 
  are 
  surrounded 
  by 
  the 
  ordinary 
  con- 
  

   nective 
  tissue 
  of 
  the 
  pancreatic 
  alveoli. 
  

  

  Gadus 
  a3glefiuus. 
  — 
  The 
  islets 
  here 
  occupy 
  the 
  same 
  

   position 
  as 
  in 
  the 
  preceding 
  species. 
  Their 
  relations 
  to 
  the 
  

   zymogenous 
  elements 
  are 
  also 
  similar, 
  

  

  Cyclogaster 
  Montagui. 
  — 
  Four 
  specimens 
  of 
  this 
  small 
  

   species 
  were 
  examined, 
  and 
  in 
  a 
  position 
  corresponding 
  to 
  

   that 
  of 
  the 
  principal, 
  an 
  islet 
  was 
  in 
  each 
  case 
  found. 
  It 
  is, 
  

   of 
  course, 
  very 
  minute, 
  but 
  may 
  be 
  found 
  on 
  the 
  right 
  side 
  

   of 
  the 
  fish 
  slightly 
  anterior 
  to 
  the 
  spleen 
  and 
  near 
  to 
  the 
  

   pyloric 
  c^ca. 
  

  

  Zoarces 
  viviparus. 
  — 
  In 
  this 
  species 
  the 
  principal 
  islet 
  

   occupies 
  a 
  position 
  similar 
  to 
  that 
  in 
  Pholis 
  gunnellus 
  

   within 
  the 
  triangular 
  area 
  already 
  referred 
  to, 
  which 
  is 
  

   slightly 
  larger 
  than 
  in 
  the 
  related 
  genus; 
  the 
  islet 
  has 
  a 
  

   variable 
  position, 
  lying 
  in 
  some 
  cases 
  close 
  to 
  the 
  hepatic 
  

   artery 
  and 
  in 
  others 
  lower 
  down 
  in 
  the 
  angle 
  between 
  the 
  

   mesenteric 
  artery 
  and 
  the 
  portal 
  vein. 
  There 
  are 
  present, 
  in 
  

   some 
  instances 
  at 
  least, 
  one 
  or 
  two 
  smaller 
  islets 
  nearer 
  

   the 
  gut 
  and 
  within 
  the 
  area 
  bounded 
  by 
  the 
  vessels 
  already 
  

   named. 
  

  

  The 
  pancreas 
  is 
  of 
  the 
  commonest 
  type, 
  viz. 
  diffuse, 
  and 
  is 
  

   sometimes 
  greatly 
  obscured 
  by 
  the 
  presence 
  of 
  fatty 
  tissue. 
  

   Hence, 
  although 
  the 
  islets 
  are 
  definitely 
  separated 
  from 
  the 
  

   zymogenous 
  elements 
  by 
  a 
  firm 
  capsule, 
  they 
  may 
  be 
  more 
  or 
  

   less 
  concealed 
  by 
  this 
  tissue, 
  and 
  not 
  so 
  readily 
  observed 
  as 
  

   in 
  other 
  instances. 
  They 
  are 
  ovoid 
  or 
  spherical, 
  and 
  in 
  

   medium 
  sized 
  adults 
  the 
  larger 
  is 
  about 
  2 
  mm. 
  in 
  length. 
  

   The 
  capsule 
  is 
  usually 
  pigmented. 
  

  

  Onos 
  must 
  el 
  a. 
  — 
  Islets 
  exist 
  within 
  the 
  pancreatic 
  tissue 
  

   which 
  is 
  found 
  alongside 
  the 
  pyloric 
  cseca. 
  I 
  noted 
  in 
  

   particular 
  a 
  large 
  example 
  of 
  elongated 
  irregular 
  outline. 
  

   The 
  islets 
  are 
  in 
  close 
  relation 
  to 
  the 
  ordinary 
  pancreatic 
  

   tissue, 
  and 
  do 
  not 
  have 
  any 
  special 
  limiting 
  capsule. 
  

  

  Ammodytes 
  t 
  obi 
  anus. 
  — 
  The 
  pancreas 
  here 
  is 
  of 
  the 
  

  

  