﻿EPITHELIAL 
  ISLETS 
  OF 
  THE 
  PANCREAS 
  IN 
  TELEOSTEl. 
  401 
  

  

  Diamare 
  has^ 
  as 
  the 
  result 
  of 
  similar 
  experiments, 
  failed 
  to 
  

   find 
  any 
  appearance 
  which 
  might 
  be 
  taken 
  as 
  representing 
  

   transitional 
  forms, 
  and 
  his 
  histological 
  methods 
  and 
  results 
  

   seem 
  beyond 
  reproach. 
  Laguesse, 
  who 
  held 
  the 
  opinion 
  that 
  

   throughout 
  life 
  there 
  was 
  a 
  repeated 
  transformation 
  of 
  islet 
  

   tissue 
  into 
  zymogenous 
  and 
  vice 
  versa, 
  has 
  (according 
  to 
  

   Pearce), 
  in 
  deference 
  to 
  Diamare's 
  work, 
  in 
  large 
  measui-e 
  

   abandoned 
  this 
  view. 
  I 
  have 
  never 
  observed 
  any 
  appear- 
  

   ances 
  which 
  might 
  be 
  regarded 
  as 
  transitional, 
  but 
  in 
  any 
  

   case 
  the 
  facts 
  already 
  adduced 
  are 
  entirely 
  opposed 
  to 
  such 
  

   interdependence 
  as 
  is 
  here 
  described. 
  It 
  is, 
  indeed, 
  quite 
  

   possible 
  that 
  under 
  such 
  unnatural 
  conditions 
  as 
  those 
  of 
  the 
  

   experiments 
  of 
  Lewaschew 
  or 
  Statkewitsch 
  the 
  pancreatic 
  

   lobuli 
  underwent 
  degeneration, 
  or 
  possibly 
  reverted 
  to 
  the 
  

   condition 
  of 
  the 
  cellular 
  '^ 
  processes" 
  of 
  Pearce, 
  which, 
  

   although 
  distinct 
  in 
  appearance 
  from 
  the 
  islets, 
  might 
  well 
  be 
  

   mistaken 
  for 
  transitional 
  forms. 
  

  

  The 
  fact 
  is 
  not 
  without 
  interest 
  that 
  hitherto 
  observers 
  

   have 
  failed 
  to 
  find 
  anything 
  like 
  epithelial 
  blood-islets 
  within 
  

   the 
  pancreas 
  in 
  elasmobranchs. 
  It 
  is 
  possible, 
  assuming 
  that 
  

   they 
  do 
  not 
  exist 
  within 
  this 
  organ, 
  that 
  their 
  function 
  is 
  

   carried 
  out 
  by 
  certain 
  of 
  the 
  other 
  ductless 
  glands 
  in 
  these 
  

   fishes. 
  In 
  elasmobranchs 
  both 
  interrenal 
  and 
  supra-renal 
  

   glands 
  exist, 
  while 
  in 
  teleosts 
  adrenals, 
  regarded 
  as 
  corre- 
  

   sponding 
  to 
  the 
  interi'enals, 
  are 
  the 
  only 
  forms. 
  May 
  not 
  one 
  

   or 
  other 
  of 
  the 
  glands 
  in 
  the 
  former 
  group 
  carry 
  on 
  the 
  

   function 
  of 
  the 
  missing 
  "islets^' 
  ? 
  

  

  The 
  Function 
  of 
  the 
  Islets. 
  

  

  Amongst 
  the 
  later 
  investigators 
  there 
  appears 
  to 
  be 
  agree- 
  

   ment 
  concerning 
  the 
  functional 
  nature 
  of 
  these 
  bodies. 
  They 
  

   are 
  regarded 
  as 
  blood-glands 
  with 
  internal 
  secretion. 
  This 
  is 
  

   the 
  opinion 
  of 
  Laguesse, 
  who 
  until 
  recently 
  held 
  the 
  some- 
  

   what 
  peculiar 
  view 
  that 
  they 
  are 
  alternately 
  " 
  endocrine 
  

   islets'' 
  and 
  " 
  esocrine 
  glands/' 
  the 
  change 
  being 
  repeated 
  

   during 
  life. 
  Other 
  investigators, 
  e. 
  g. 
  Dogiel 
  (2), 
  have 
  held 
  

  

  