﻿The 
  Biological 
  Significance 
  of 
  Anaphylaxis. 
  131 
  

  

  anaphylaxis 
  can 
  be 
  transmitted 
  to 
  a 
  normal 
  animal 
  by 
  serum 
  from 
  one 
  which 
  

   is 
  itself 
  anaphylactic. 
  It 
  is 
  found, 
  however, 
  that 
  serum 
  from 
  an 
  immunized 
  

   animal 
  is 
  even 
  more 
  effective 
  in 
  thus 
  rendering 
  a 
  normal 
  one 
  passively 
  

   anaphylactic, 
  and 
  that 
  its 
  efficiency, 
  measured 
  by 
  the 
  reciprocal 
  of 
  the 
  volume 
  

   required 
  to 
  communicate 
  a 
  given 
  intensity 
  of 
  anaphylaxis, 
  is 
  closely 
  parallel 
  

   to 
  the 
  intensity 
  of 
  its 
  precipitating 
  quality. 
  

  

  There 
  is 
  another 
  feature 
  of 
  this 
  production 
  of 
  passive 
  anaphylaxis 
  in 
  the 
  

   guinea-pig 
  which 
  is 
  highly 
  suggestive. 
  When 
  serum 
  from 
  an 
  anaphylactic 
  

   or 
  immune 
  animal 
  is 
  injected 
  into 
  a 
  normal 
  guinea-pig, 
  even 
  when 
  the 
  injec- 
  

   tion 
  is 
  made 
  into 
  a 
  vein, 
  no 
  trace 
  of 
  the 
  transmitted 
  sensitiveness 
  can 
  be 
  

   detected 
  for 
  a 
  period 
  of 
  some 
  hours, 
  and 
  it 
  is 
  not 
  fully 
  developed 
  until 
  a 
  day 
  

   or 
  so 
  after 
  the 
  injection. 
  By 
  a 
  series 
  of 
  ingenious 
  experiments 
  the 
  late 
  

   Eichard 
  Weil,* 
  of 
  New 
  York, 
  was 
  able 
  to 
  follow 
  the 
  fate 
  of 
  the 
  antibody 
  

   after 
  such 
  transference 
  to 
  the 
  normal 
  guinea-pig, 
  and 
  to 
  show 
  that 
  the 
  

   passive 
  anaphylaxis 
  did 
  not 
  begin 
  to 
  appear 
  until 
  the 
  antibody 
  began 
  to 
  

   leave 
  the 
  blood, 
  and 
  that 
  most 
  of 
  the 
  antibody 
  had 
  disappeared 
  from 
  the 
  

   circulation 
  by 
  the 
  time 
  the 
  sensitiveness 
  was 
  fully 
  developed. 
  When 
  the 
  

   animal 
  had 
  thus 
  been 
  rendered 
  sensitive, 
  a 
  further 
  large 
  injection 
  of 
  the 
  

   immune 
  serum 
  protected 
  the 
  animal 
  for 
  the 
  time 
  being 
  against 
  the 
  otherwise 
  

   fatal 
  effect 
  of 
  an 
  injection 
  of 
  the 
  antigen. 
  

  

  All 
  this 
  evidence 
  seems 
  to 
  point 
  clearly 
  in 
  one 
  direction. 
  It 
  strongly 
  

   suggests 
  that 
  the 
  so-called 
  anaphylactic 
  antibody 
  and 
  the 
  precipitin 
  of 
  the 
  

   immune 
  serum 
  are 
  either 
  identical 
  or 
  very 
  closely 
  similar 
  ; 
  that 
  the 
  remark- 
  

   able 
  difference 
  in 
  physiological 
  response 
  to 
  the 
  antigen, 
  between 
  the 
  anaphy- 
  

   lactic 
  and 
  the 
  immune 
  animal, 
  depends 
  on 
  the 
  different 
  distribution 
  of 
  the 
  

   antibody 
  between 
  the 
  blood 
  and 
  the 
  cells 
  of 
  the 
  vital 
  organs 
  ; 
  that 
  the 
  

   antigen 
  acts 
  as 
  a 
  poison 
  to 
  the 
  anaphylactic 
  animal 
  because 
  its 
  reaction 
  with 
  the 
  

   antibody 
  takes 
  place 
  in 
  the 
  cells 
  ; 
  but 
  that 
  an 
  excess 
  of 
  antibody 
  in 
  the 
  blood 
  

   protects 
  the 
  cells, 
  by 
  removing 
  the 
  antigen 
  from 
  the 
  sphere 
  of 
  action 
  before 
  

   it 
  reaches 
  them, 
  and 
  thereby 
  renders 
  the 
  animal 
  immune. 
  This 
  is 
  the 
  con- 
  

   ception 
  of 
  anaphylaxis 
  and 
  its 
  relation 
  to 
  immunity 
  which 
  I 
  shall 
  endeavour 
  

   to 
  commend 
  to 
  you 
  with 
  the 
  aid 
  of 
  some 
  experimental 
  results 
  of 
  my 
  own 
  

   work. 
  It 
  was 
  one 
  of 
  the 
  earliest 
  to 
  be 
  put 
  forward, 
  being 
  known 
  in 
  the 
  

   language 
  of 
  the 
  side-chain 
  theory 
  as 
  the 
  theory 
  of 
  " 
  sessile 
  receptors." 
  It 
  

   must 
  be 
  admitted 
  that 
  the 
  evidence 
  in 
  its 
  support 
  has 
  been 
  obtained 
  almost 
  

   entirely 
  by 
  experiments 
  on 
  the 
  guinea-pig, 
  and 
  that 
  there 
  is 
  reason 
  for 
  

   hesitation 
  in 
  applying 
  it 
  to 
  species 
  in 
  which 
  anaphylaxis 
  has 
  as 
  yet 
  been 
  

   less 
  thoroughly 
  investigated. 
  Experiments 
  on 
  the 
  guinea-pig, 
  however, 
  

  

  * 
  ' 
  Journ. 
  Med. 
  Res.,' 
  vol. 
  27, 
  p. 
  525 
  (1913) 
  ; 
  vol. 
  29, 
  p. 
  233 
  (1913). 
  

  

  