﻿478 
  J. 
  \V. 
  JENKINSON. 
  

  

  EXPLANATION 
  OF 
  PLATES 
  29—33, 
  

  

  Illustrating 
  Mr. 
  J. 
  W. 
  Jenkinson's 
  paper 
  on 
  " 
  Observations 
  on 
  

   the 
  Maturation 
  and 
  Fertilisation 
  of 
  the 
  Egg 
  of 
  the 
  Axolotl." 
  

  

  All 
  the 
  figures 
  were 
  drawn 
  with 
  the 
  aid 
  of 
  Zeiss' 
  camera 
  liicida 
  ; 
  comp. 
  

   oc. 
  6, 
  achr. 
  obj. 
  2nim. 
  magn. 
  750 
  x. 
  

  

  Figs. 
  1—14. 
  Maturation. 
  

  

  Fig. 
  1. 
  — 
  Metaphase 
  of 
  first 
  polar 
  spindle. 
  At 
  the 
  outer 
  end 
  may 
  be 
  seen 
  

   some 
  astral 
  rays. 
  The 
  inner 
  end 
  is 
  bi-polar. 
  

  

  Fig. 
  2. 
  — 
  Telophase 
  of 
  first 
  polar 
  spindle. 
  The 
  chromosomes 
  have 
  united 
  

   into 
  an 
  annular 
  skein. 
  The 
  surface 
  of 
  the 
  egg 
  is 
  raised 
  up 
  into 
  a 
  flat 
  disc; 
  

   the 
  beginning 
  of 
  the 
  first 
  polar 
  body. 
  

  

  Fig. 
  3. 
  — 
  Formation 
  of 
  the 
  first 
  polar 
  body. 
  This 
  is 
  still 
  united 
  to 
  the 
  

   egg 
  by 
  a 
  narrow 
  stalk 
  in 
  which 
  Z 
  wischen-korper 
  are 
  seen. 
  The 
  chromo- 
  

   somes 
  are 
  again 
  distinct. 
  

  

  Fig. 
  4. 
  — 
  The 
  first 
  polar 
  body 
  is 
  completely 
  separated. 
  The 
  chromosomes 
  

   in 
  it 
  have 
  divided 
  longitudinally, 
  the 
  chromosomes 
  of 
  each 
  pair 
  being 
  united 
  by 
  

   their 
  apices. 
  In 
  the 
  egg 
  the 
  chromosomes 
  have 
  also 
  divided, 
  and 
  lie 
  in 
  a 
  

   tangentially 
  elongated 
  striated 
  clear 
  area, 
  the 
  first 
  sign 
  of 
  the 
  second 
  polar 
  

   spindle. 
  

  

  Fig. 
  5. 
  — 
  Metaphase 
  of 
  the 
  second 
  polar 
  spindle 
  from 
  a 
  freshly 
  laid 
  egg 
  

   preserved 
  in 
  aceto-corrosive. 
  Note 
  the 
  fibie-bundles 
  attached 
  to 
  the 
  apices 
  

   of 
  the 
  chromosomes. 
  The 
  latter 
  are 
  paired 
  and 
  lie 
  in 
  the 
  equator. 
  The 
  

   outer 
  spindle 
  pole 
  is 
  slightly 
  depressed. 
  

  

  Fig. 
  5 
  a. 
  — 
  The 
  same, 
  cut 
  across. 
  The 
  apices 
  of 
  the 
  chromosomes 
  point 
  

   towards 
  the 
  spindle 
  axis. 
  

  

  Fig. 
  6 
  a. 
  — 
  The 
  same, 
  but 
  form 
  an 
  oviducal 
  egg 
  preserved 
  in 
  picro-acetic. 
  

   The 
  chromosomes, 
  scattered 
  irregularly 
  over 
  the 
  spindles, 
  are 
  beginning 
  to 
  

   diverge 
  by 
  their 
  apices. 
  Note 
  the 
  "Zugfasern" 
  and 
  the 
  " 
  Verbindungs- 
  

   faden." 
  The 
  outer 
  spindle 
  pole 
  projects 
  above 
  the 
  surface. 
  

  

  Fig. 
  6 
  b. 
  — 
  The 
  same 
  as 
  the 
  last, 
  but 
  preserved 
  in 
  chromo-acetic. 
  

  

  Fig. 
  7 
  «. 
  — 
  Late 
  anaphase 
  of 
  the 
  second 
  polar 
  spindle. 
  There 
  are 
  no 
  

   "Zugfasern" 
  to 
  be 
  seen. 
  Note 
  the 
  outer 
  fibres 
  diverging 
  into 
  the 
  equatorial 
  

   plane. 
  

  

  Fig, 
  7 
  b. 
  — 
  The 
  same 
  as 
  last, 
  but 
  a 
  little 
  later 
  ; 
  the 
  first 
  stage 
  in 
  the 
  for- 
  

   mation 
  of 
  the 
  second 
  polar 
  body. 
  

  

  