﻿MATUIJATION, 
  ETC., 
  OF 
  THE 
  KGG 
  OP 
  THE 
  AXOLOTL. 
  409 
  

  

  I 
  have 
  preserved 
  the 
  eggs 
  in 
  two 
  mixtures 
  : 
  chromic 
  

   (I 
  per 
  cent.) 
  ninety-five 
  parts, 
  glacial 
  acetic 
  five 
  parts, 
  and 
  

   corrosive 
  sublimate, 
  with 
  5 
  per 
  cent, 
  to 
  10 
  per 
  cent, 
  acetic 
  

   acid 
  added. 
  I 
  tried 
  a 
  picro- 
  corrosive 
  mixture 
  but 
  found 
  it 
  

   useless. 
  

  

  The 
  aceto-corrosive 
  eggs 
  have 
  been 
  stained 
  in 
  borax- 
  

   carmine, 
  followed 
  by 
  picro-indigo-carmine, 
  and 
  iron-hfema- 
  

   toxylin 
  ; 
  those 
  preserved 
  in 
  chromic 
  and 
  acetic 
  in 
  gentian- 
  

   violet, 
  followed 
  b}^ 
  eosin 
  or 
  orange, 
  and 
  in 
  iron-bsematoxylin. 
  

   I 
  have 
  often 
  unmounted 
  preparations 
  first 
  stained 
  in 
  carmine 
  

   or 
  gentian 
  and 
  re-stained 
  them 
  in 
  iron-li£ematoxylin. 
  

  

  The 
  cutting 
  of 
  the 
  eggs 
  is 
  a 
  most 
  formidable 
  task, 
  as 
  any 
  

   one 
  who 
  is 
  acquainted 
  with 
  what 
  Fick 
  calls 
  ''die 
  scliwierige 
  

   Technik 
  der 
  Amphibieneier-Untersuchung 
  ^' 
  will 
  understand. 
  

   Even 
  with 
  the 
  very 
  briefest 
  sojourn 
  in 
  the 
  water-bath 
  the 
  

   eggs 
  become 
  so 
  brittle 
  that 
  it 
  is 
  impossible 
  to 
  cut 
  them 
  into 
  

   continuous 
  ribbons 
  of 
  unbroken 
  sections. 
  They 
  must 
  be 
  cut 
  

   on 
  a 
  Jung 
  microtome 
  with 
  the 
  knife 
  oblique, 
  and 
  the 
  block 
  

   must 
  be 
  painted 
  before 
  each 
  section 
  is 
  cut 
  with 
  a 
  mixture 
  of 
  

   gum 
  mastic 
  and 
  collodion 
  dissolved 
  in 
  ether 
  and 
  absolute 
  

   alcohol. 
  The 
  thickness 
  of 
  the 
  sections 
  Avas 
  always 
  7'5 
  fx. 
  

   The 
  eggs 
  were 
  oriented 
  by 
  being 
  placed, 
  in 
  a 
  known 
  position, 
  

   in 
  a 
  square 
  hole 
  cut 
  in 
  an 
  oblong 
  slip 
  of 
  liver, 
  and 
  cemented 
  

   down 
  with 
  albumen, 
  which 
  is 
  then 
  coagulated 
  with 
  alcohol. 
  

   The 
  liver, 
  with 
  the 
  egg, 
  can 
  of 
  course 
  be 
  cut 
  in 
  any 
  desired 
  

   plane. 
  

  

  I 
  have 
  ventured 
  to 
  add 
  to 
  the 
  descriptive 
  part 
  of 
  this 
  

   paper, 
  not 
  only 
  a 
  critique 
  of 
  current 
  theories 
  of 
  fertilization, 
  but 
  

   also 
  an 
  account 
  of 
  a 
  few 
  experiments 
  I 
  have 
  made 
  in 
  the 
  hope 
  

   of 
  throwing 
  some 
  light 
  on 
  the 
  nature 
  of 
  the 
  physical 
  processes 
  

   involved. 
  In 
  making 
  these 
  experiments 
  I 
  have 
  had 
  the 
  

   advantage 
  of 
  the 
  counsel 
  and 
  help 
  of 
  my 
  friend 
  Dr. 
  Ramsden, 
  

   of 
  Pembroke 
  College; 
  I 
  am 
  under 
  the 
  greatest 
  obligation 
  to 
  

   him 
  for 
  the 
  assistance 
  he 
  has 
  so 
  generously 
  afforded 
  me. 
  

  

  I 
  must 
  not 
  conclude 
  this 
  introductory 
  chapter 
  without 
  

   attempting 
  to 
  define 
  my 
  attitude 
  to 
  the 
  criticism 
  which 
  the 
  

   botanist 
  Alfred 
  Fischer 
  published 
  two 
  or 
  three 
  years 
  ago 
  

  

  