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  JOHN 
  RENNJE, 
  

  

  genera, 
  e.g. 
  Lophius, 
  Pholis, 
  Zoarces, 
  Syngnathus, 
  

   the 
  "islet" 
  tissue 
  has 
  no 
  more 
  intimate 
  relation 
  to 
  pancreas 
  

   than 
  to 
  other 
  neighbouring 
  organs. 
  Diamare, 
  indeed, 
  points 
  

   out 
  that 
  the 
  "islets'^ 
  are 
  glands 
  of 
  a 
  more 
  primitive 
  type 
  

   than 
  the 
  pancreas, 
  which 
  represents 
  an 
  advance 
  in 
  the 
  evolu- 
  

   tion 
  of 
  organs. 
  What 
  he 
  fails 
  to 
  appreciate 
  is 
  the 
  fact 
  that 
  

   the 
  more 
  highly 
  developed 
  organ, 
  in 
  its 
  most 
  primitive 
  

   state, 
  is 
  distinct 
  from 
  the 
  still 
  more 
  primitive 
  internal 
  

   secreting 
  gland. 
  The 
  compact 
  pancreas, 
  I 
  consider, 
  is 
  a 
  

   further 
  development, 
  in 
  which 
  the 
  association 
  of 
  the 
  two 
  

   tissues 
  is 
  strengthened, 
  so 
  that 
  they 
  become 
  virtually 
  one 
  

   organ, 
  although 
  there 
  is 
  no 
  evidence 
  but 
  that 
  they 
  are 
  still 
  of 
  

   independent 
  function. 
  This 
  association 
  is 
  due 
  to 
  the 
  fact 
  that 
  

   they 
  arise 
  from 
  the 
  same 
  embryonic 
  tissue. 
  The 
  results 
  of 
  

   Pearce 
  (14) 
  on 
  the 
  development 
  of 
  the 
  islands 
  in 
  the 
  human 
  

   embryo 
  are 
  of 
  interest, 
  and 
  their 
  bearing 
  on 
  this 
  point 
  worth 
  

   quoting. 
  He 
  does 
  not 
  agree 
  with 
  Laguesse 
  and 
  Renaut 
  that 
  

   the 
  islands 
  arise 
  from 
  "peculiar 
  cells 
  with 
  rich 
  eosinophilic 
  

   protoplasm, 
  comparable 
  to 
  the 
  parietal 
  or 
  oxyntic 
  cells 
  of 
  the 
  

   gastric 
  tubules." 
  He 
  finds 
  that 
  the 
  pancreas 
  develops 
  as 
  

   branching 
  glandular 
  processes, 
  which 
  become 
  tubular 
  later. 
  

   The 
  islets 
  develop 
  as 
  side 
  branches 
  of 
  these 
  processes 
  , 
  and, 
  

   from 
  a 
  careful 
  study 
  of 
  the 
  paper, 
  I 
  consider 
  it 
  clearly 
  

   brought 
  out 
  that 
  the 
  island 
  is 
  formed 
  from 
  the 
  '' 
  branching- 
  

   glandular 
  process 
  " 
  before 
  the 
  remainder 
  of 
  it 
  is 
  trans- 
  

   formed 
  into 
  acini. 
  Thus 
  the 
  interesting 
  point 
  seems 
  to 
  

   be 
  established 
  that 
  "island" 
  is 
  an 
  earlier 
  formation 
  than 
  

   acinus; 
  that 
  is, 
  the 
  phylogenetic 
  order 
  is 
  paralleled 
  in 
  

   ontogeny. 
  

  

  Certain 
  observers, 
  investigating 
  the 
  pancreas 
  of 
  mammals, 
  

   have 
  concluded 
  that 
  the 
  islets 
  exhibit 
  transitional 
  forms 
  indi- 
  

   cating 
  a 
  change 
  of 
  islet 
  tissue 
  into 
  gland 
  lobuli. 
  Lewaschew 
  

   (11) 
  claimed 
  that 
  irritation 
  caused 
  the 
  groups 
  to 
  become 
  

   more 
  numerous 
  and 
  larger, 
  and 
  that 
  various 
  transitions 
  

   became 
  apparent. 
  Statkewitsch 
  (16) 
  asserted 
  that 
  some 
  of 
  

   the 
  lobuli 
  of 
  the 
  pancreas 
  underwent 
  such 
  changes 
  during 
  

   fasting 
  that 
  they 
  assumed 
  the 
  islet 
  form. 
  On 
  the 
  other 
  hand. 
  

  

  