﻿The 
  Biological 
  Significance 
  of 
  Anaphylaxis. 
  135 
  

  

  guinea-pig 
  in 
  a 
  manner 
  much 
  more 
  closely 
  resembling 
  the 
  anaphylactic 
  shock. 
  

   It 
  may 
  freely 
  be 
  admitted 
  that 
  a 
  full 
  understanding 
  of 
  the 
  nature 
  of 
  the 
  

   changes 
  in 
  serum, 
  which 
  give 
  it 
  the 
  power 
  of 
  inducing 
  these 
  symptoms, 
  

   might 
  throw 
  a 
  great 
  deal 
  of 
  light 
  on 
  our 
  problem. 
  

  

  The 
  weakness 
  of 
  all 
  this 
  evidence, 
  however, 
  seems 
  to 
  me 
  to 
  lie 
  in 
  the 
  

   lack 
  of 
  clear 
  connection 
  with 
  the 
  conditions 
  of 
  the 
  true 
  anaphylactic 
  

   reaction. 
  Much 
  of 
  the 
  work 
  seems 
  to 
  have 
  proceeded 
  on 
  the 
  unconscious 
  

   assumption 
  that 
  the 
  symptom 
  complex 
  was 
  in 
  itself 
  characteristic, 
  and 
  

   that 
  the 
  appearance 
  of 
  this 
  type 
  of 
  toxicity 
  was 
  sufficient 
  warrant 
  for 
  

   classing 
  the 
  phenomenon 
  as 
  anaphylactic. 
  We 
  have 
  seen 
  that 
  the 
  

   symptoms 
  are 
  not 
  characteristic 
  ; 
  the 
  essential 
  feature 
  of 
  anaphylaxis 
  is 
  

   that 
  they 
  are 
  produced 
  by 
  a 
  substance 
  which 
  normally 
  has 
  no 
  such 
  effect. 
  

   If 
  it 
  could 
  be 
  proved 
  that 
  the 
  injection 
  of 
  the 
  antigen 
  into 
  the 
  anaphylactic 
  

   animal 
  produced 
  a 
  toxicity 
  of 
  the 
  blood, 
  similar 
  to 
  that 
  imparted 
  to 
  the 
  

   serum 
  by 
  these 
  various 
  .procedures 
  in 
  vitro, 
  the 
  evidence 
  would 
  be 
  strong. 
  

   But 
  it 
  is 
  just 
  here 
  that 
  it 
  fails. 
  If 
  the 
  enhancement 
  of 
  the 
  toxicity 
  of 
  

   serum 
  in 
  vitro, 
  by 
  these 
  various 
  substances, 
  really 
  reproduces 
  a 
  process 
  

   occurring 
  in 
  the 
  blood 
  in 
  the 
  anaphylactic 
  shock, 
  they 
  should 
  be 
  even 
  

   more 
  effective 
  when 
  injected 
  into 
  the 
  living 
  blood-stream. 
  -Experience 
  

   shows, 
  however, 
  that 
  sols 
  of 
  agar 
  and 
  starch 
  can 
  usually 
  be 
  injected 
  with 
  

   impunity 
  into 
  a 
  guinea-pig's 
  circulation. 
  Further, 
  if 
  the 
  appearance 
  of 
  

   toxicity 
  in 
  the 
  serum 
  when 
  treated 
  with 
  these 
  reagents, 
  reproduces 
  the 
  effect 
  

   of 
  the 
  union 
  of 
  antigen 
  and 
  antibody 
  in 
  the 
  blood, 
  the 
  most 
  uniformly 
  

   successful 
  method 
  of 
  evoking 
  the 
  toxicity 
  should 
  be 
  to 
  mix 
  serum 
  from 
  

   an 
  anaphylactic 
  animal 
  with 
  the 
  corresponding 
  antigen. 
  This 
  has 
  been 
  

   tried 
  a 
  large 
  number 
  of 
  times, 
  and 
  I 
  think 
  it 
  is 
  a 
  fair 
  summary 
  of 
  the 
  

   results 
  to 
  say 
  that, 
  though 
  successes 
  have 
  been 
  recorded* 
  and 
  emphasized, 
  

   the 
  usual 
  outcome 
  has 
  been 
  complete 
  failure. 
  The 
  fact 
  that 
  recourse 
  is 
  

   had 
  to 
  such 
  artificial 
  procedures 
  for 
  preparing 
  the 
  so-called 
  " 
  anaphylatoxin 
  " 
  

   is 
  sufficient 
  indication 
  of 
  the 
  failure 
  of 
  the 
  natural 
  and 
  obvious 
  method. 
  

   The 
  rarity 
  with 
  which 
  the 
  anaphylactic 
  serum 
  is 
  rendered 
  toxic 
  by 
  contact 
  

   with 
  the 
  antigen 
  is 
  in 
  striking 
  contrast 
  with 
  the 
  regularity 
  with 
  which 
  

   the 
  toxicity 
  is 
  acquired 
  by 
  contact 
  with 
  agar, 
  starch 
  or 
  coagulated 
  protein, 
  

   which 
  have 
  no 
  power 
  of 
  producing 
  the 
  anaphylactic 
  shock 
  in 
  vivo. 
  Still 
  

   more 
  difficult 
  is 
  it 
  to 
  reconcile 
  these 
  theories 
  of 
  the 
  anaphylactic 
  phenomenon 
  

   with 
  the 
  fact, 
  already 
  mentioned, 
  that 
  injection 
  of 
  the 
  antigen 
  simultaneously 
  

   with 
  or 
  soon 
  after 
  the 
  antibody 
  is 
  uniformly 
  without 
  effect, 
  at 
  any 
  rate 
  

   in 
  guinea-pigs, 
  to 
  the 
  phenomena 
  in 
  which 
  species 
  these 
  theories 
  have 
  

  

  * 
  Eichet, 
  Vaughan, 
  loc. 
  cit., 
  Anderson 
  and 
  Frost, 
  'Hyg. 
  Lab. 
  Bull.,' 
  No. 
  64, 
  

   Washington, 
  1910. 
  

  

  