﻿The 
  Relation 
  of 
  Spermatozoa 
  to 
  Certain 
  Electrolytes. 
  

  

  155 
  

  

  «0 
  

  

  1 
  

  

  NaOH 
  

  

  •v 
  NaOH 
  

  

  IT 
  

  

  ft) 
  

  

  Maximum 
  Positive 
  Charge 
  

  

  soe/ectric 
  Point 
  

  

  HCl 
  

  

  fa-is 
  

  

  Ce' 
  

  

  Normal 
  Negative 
  Charge 
  

  

  Diagram 
  illustrating 
  effect 
  of 
  Polarising 
  Ions 
  on 
  Surface 
  Charge 
  and 
  Precipitation 
  

  

  of 
  Spermatozoa. 
  

  

  Note 
  on 
  Experimental 
  Hybridisation. 
  

  

  In 
  a 
  previous 
  paper 
  (Gray 
  (7)) 
  it 
  was 
  suggested 
  that 
  the 
  action 
  of 
  various 
  

   electrolytes 
  upon 
  the 
  eggs 
  of 
  echinoderms 
  was 
  to 
  be 
  found 
  in 
  the 
  action 
  of 
  

   these 
  substances 
  on 
  the 
  surface 
  charge 
  of 
  the 
  eggs, 
  and 
  that 
  this 
  charge 
  

   played 
  a 
  fundamental 
  role 
  in 
  the 
  physiological 
  activity 
  of 
  the 
  egg. 
  In 
  the 
  

   present 
  paper 
  evidence 
  is 
  brought 
  forward 
  to 
  show 
  that 
  the 
  surface 
  charge 
  on 
  

   the 
  spermatozoa 
  is 
  of 
  fundamental 
  importance 
  to 
  their 
  activity, 
  and 
  that 
  this 
  

   <charge 
  depends 
  upon 
  the 
  nature 
  of 
  the 
  solutions 
  with 
  which 
  the 
  spermatozoa 
  

   aFe 
  in 
  contact. 
  Now, 
  just 
  as 
  the 
  particles 
  of 
  different 
  colloids 
  (or 
  membranes 
  

   of 
  different 
  composition) 
  possess 
  different 
  charges 
  when 
  in 
  contact 
  with 
  the 
  

   same 
  solution, 
  so 
  the 
  eggs 
  and 
  spermatozoa 
  of 
  different 
  species 
  may 
  have 
  

   -different 
  surface 
  charges 
  when 
  in 
  sea 
  water 
  of 
  the 
  same 
  composition. 
  If, 
  

   therefore, 
  the 
  possibility 
  of 
  fertilisation 
  of 
  the 
  egg 
  depends 
  partly 
  on 
  the 
  

  

  