﻿MATURATION, 
  KTL'., 
  OF 
  THE 
  E(4G 
  OF 
  THE 
  AXOLOTf,. 
  4()3 
  

  

  As 
  the 
  process 
  takes 
  place 
  much 
  less 
  rapidly 
  here 
  than 
  in 
  

   other 
  cases 
  the 
  formation 
  and 
  structure 
  of 
  the 
  aster 
  may 
  be 
  

   very 
  readily 
  observed. 
  The 
  drop 
  spreads 
  out 
  in 
  the 
  thickness 
  

   of 
  the 
  film 
  ; 
  radial 
  processes 
  are 
  then 
  given 
  off 
  from 
  its 
  

   circumference^ 
  which 
  as 
  they 
  grow 
  out 
  branch 
  repeatedly 
  and 
  

   anastomose 
  with 
  one 
  another. 
  In 
  this 
  way 
  tracts 
  of 
  egg-yolk 
  

   left 
  in 
  between 
  the 
  excurrent 
  radii 
  may 
  be 
  cut 
  off 
  and 
  isolated 
  

   from 
  one 
  another. 
  Where 
  the 
  radii 
  leave 
  the 
  central 
  drop, 
  

   and 
  where 
  their 
  branches 
  leave 
  the 
  radii, 
  they 
  are 
  frequently 
  

   exceedingly 
  narrow 
  ; 
  in 
  their 
  formation 
  the 
  contained 
  liquid 
  

   first 
  pierces 
  a 
  small 
  aperture 
  in 
  the 
  surface 
  (or 
  surface 
  mem- 
  

   brane) 
  between 
  itself 
  and 
  the 
  yolk, 
  and 
  then 
  expands 
  on 
  the 
  

   outer 
  side. 
  The 
  intervening 
  portions 
  of 
  yolk 
  are 
  naturally 
  

   thickened 
  here 
  and 
  often 
  fuse 
  with 
  one 
  another, 
  pieces 
  of 
  the 
  

   excurrent 
  radii 
  being 
  thus 
  cut 
  off 
  in 
  their 
  turn. 
  In 
  this 
  way 
  

   the 
  Avhole 
  aster 
  comes 
  to 
  have 
  the 
  appearance 
  of 
  a 
  sj'stem 
  of 
  

   radially 
  elongated 
  alveoli, 
  more 
  or 
  less 
  completely 
  sej^arated 
  

   from 
  one 
  another 
  by 
  thin 
  intervening 
  lamellge. 
  When 
  two 
  such 
  

   asters 
  are 
  formed 
  close 
  together 
  and 
  simultaneously, 
  a 
  spindle 
  

   results 
  with 
  a 
  plane 
  equatorial 
  plate 
  where 
  the 
  opposing 
  radii 
  

   meet 
  (fig. 
  D.). 
  The 
  aster 
  is 
  frequently 
  made 
  up 
  of 
  concentric 
  

   zones 
  ; 
  this 
  is 
  due 
  to 
  the 
  radii 
  branching, 
  and 
  rebranching 
  at 
  

   equal 
  distances 
  from 
  the 
  centre. 
  

  

  Lastly, 
  asters 
  of 
  the 
  same 
  type 
  were 
  made 
  with 
  many 
  of 
  

   the 
  above-mentioned 
  reagents 
  in 
  mixtures 
  of 
  gum 
  and 
  gela- 
  

   tin 
  and 
  of 
  gum 
  and 
  albumen. 
  

  

  My 
  next 
  efforts 
  were 
  directed 
  towards 
  producing 
  these 
  

   outgrowths 
  in 
  the 
  bulk 
  of 
  the 
  colloid, 
  and 
  here 
  I 
  have 
  been 
  

   less 
  successful. 
  

  

  The 
  following 
  experiments 
  were 
  tried 
  : 
  — 
  A 
  small 
  drop 
  of 
  

   dried 
  gum 
  saturated 
  with 
  potassium 
  carbonate 
  was 
  supported 
  

   on 
  a 
  needle-point 
  in 
  a 
  vessel 
  of 
  filtered 
  albumen. 
  Tubular 
  

   processes 
  were 
  given 
  off 
  in 
  all 
  directions, 
  but 
  soon 
  turned 
  

   down 
  and 
  sank 
  to 
  the 
  bottom. 
  In 
  albumen, 
  however, 
  which 
  

   has 
  become 
  highly 
  viscid 
  by 
  desiccation, 
  the 
  tubes 
  which 
  are 
  

   given 
  off 
  retain 
  their 
  original 
  direction. 
  

  

  A 
  drop 
  of 
  picric 
  acid 
  was 
  placed 
  in 
  a 
  \ 
  per 
  cent, 
  cold 
  solu- 
  

  

  