﻿146 
  The 
  Biological 
  Significance 
  of 
  Anaphylaxis. 
  

  

  analogy. 
  Dakin 
  and 
  Dudley's 
  results 
  seem 
  to 
  constitute 
  a 
  first 
  step 
  towards- 
  

   explanation 
  of 
  what 
  was 
  hitherto 
  a 
  completely 
  mysterious 
  difference. 
  

   They 
  may 
  even 
  represent 
  a 
  first 
  step, 
  though 
  a 
  very 
  short 
  one, 
  towards 
  a 
  

   recognition 
  of 
  the 
  chemical 
  differences 
  which 
  underly 
  the 
  characteristics 
  of 
  

   the 
  species, 
  of 
  the 
  variety, 
  and 
  even 
  of 
  the 
  individual. 
  If 
  a 
  study 
  of 
  anaphy- 
  

   laxis 
  can 
  assist 
  progress 
  towards 
  a 
  solution 
  of 
  this 
  ultimate 
  biological 
  mystery, 
  

   it 
  will 
  not 
  be 
  difficult 
  to 
  justify 
  a 
  claim 
  for 
  its 
  general 
  biological 
  significance. 
  

  

  There 
  are 
  problems 
  of 
  a 
  more 
  purely 
  physiological 
  nature, 
  to 
  the 
  solution 
  

   of 
  which 
  I 
  believe 
  that 
  a 
  study 
  of 
  anaphylaxis 
  may 
  contribute. 
  We 
  have 
  

   seen 
  that 
  the 
  resemblance 
  between 
  the 
  anaphylactic 
  shock 
  and 
  the 
  effects 
  of 
  

   certain 
  poisons 
  has 
  led 
  to 
  attempts 
  to 
  explain 
  the 
  former 
  in 
  terms 
  of 
  the 
  

   latter, 
  by 
  assuming 
  that 
  a 
  liberation 
  of 
  poisons 
  of 
  this 
  type 
  is 
  the 
  immediate 
  

   cause 
  of 
  the 
  shock. 
  This 
  attitude 
  has 
  always 
  seemed 
  to 
  me 
  illogical 
  ; 
  it 
  

   involves 
  the 
  assumption 
  that 
  more 
  is 
  known 
  concerning 
  the 
  mode 
  of 
  action 
  of 
  

   the 
  poisons 
  than 
  of 
  the 
  antigen 
  on 
  the 
  anaphylactic 
  animal. 
  I 
  believe 
  the 
  

   reverse 
  to 
  be 
  the 
  case. 
  If, 
  on 
  the 
  evidence 
  as 
  it 
  stands, 
  one 
  phenomenon 
  is 
  

   to 
  be 
  interpreted 
  by 
  what 
  is 
  known 
  of 
  the 
  other, 
  it 
  is 
  the 
  anaphylactic 
  

   reaction 
  which 
  must 
  furnish 
  the 
  key 
  to 
  the 
  action 
  of 
  poisons 
  producing 
  the 
  

   same 
  type 
  of 
  effect, 
  concerning 
  which 
  our 
  ignorance 
  is 
  otherwise 
  complete. 
  

   Much 
  has 
  been 
  written 
  concerning 
  the 
  action 
  of 
  poisons 
  and 
  their 
  pre- 
  

   ferential 
  action 
  on 
  certain 
  types 
  of 
  cell. 
  Receptive 
  substances 
  are 
  postulated, 
  

   on 
  which 
  the 
  sensitiveness 
  of 
  the 
  cell 
  depends. 
  In 
  the 
  case 
  of 
  the 
  

   anaphylactic 
  cell 
  alone, 
  we 
  are 
  able 
  to 
  obtain 
  a 
  " 
  receptive 
  substance," 
  the 
  

   antibody, 
  apart 
  from 
  the 
  cell, 
  and 
  to 
  study 
  in 
  the 
  test-tube 
  the 
  nature 
  of 
  its 
  

   reaction 
  with 
  the 
  " 
  drug," 
  the 
  specific 
  antigen. 
  We 
  are 
  entitled, 
  I 
  think, 
  to 
  

   suppose 
  that, 
  when 
  antigen 
  meets 
  antibody 
  in 
  the 
  specifically 
  sensitive 
  cell, 
  

   the 
  immediate 
  effect 
  is 
  a 
  change 
  in 
  the 
  state 
  of 
  dispersion 
  of 
  the 
  colloids 
  

   entering 
  into 
  its 
  structure. 
  It 
  appears 
  to 
  me 
  to 
  be 
  at 
  least 
  a 
  legitimate 
  

   working 
  hypothesis 
  to 
  suppose 
  that 
  certain 
  poisonous 
  substances 
  produce 
  

   similar 
  symptoms 
  because 
  they 
  also 
  bring 
  about 
  a 
  change 
  of 
  this 
  type. 
  We 
  

   should 
  still 
  have 
  to 
  explain 
  why 
  such 
  a 
  change, 
  occurring 
  in 
  a 
  plain 
  muscle 
  

   cell, 
  caused 
  it 
  to 
  contract 
  : 
  occurring 
  in 
  an 
  endothelial 
  cell, 
  caused 
  it 
  to 
  

   become 
  lax 
  and 
  permeable. 
  That 
  explanation 
  would 
  involve 
  a 
  knowledge 
  of 
  

   the 
  physiological 
  processes 
  of 
  these 
  cells 
  which 
  is 
  not 
  yet 
  available. 
  On 
  the 
  

   other 
  hand, 
  a 
  knowledge 
  of 
  the 
  nature 
  of 
  the 
  reaction 
  underlying 
  the 
  

   anaphylactic 
  phenomena 
  may 
  itself 
  contribute 
  to 
  an 
  understanding 
  of 
  the 
  

   intimate 
  nature 
  of 
  the 
  changes 
  which 
  give 
  rise 
  to 
  contraction 
  and 
  maintain 
  

   tonus 
  in 
  plain 
  muscle 
  — 
  phenomena 
  which 
  still 
  await 
  their 
  due 
  share 
  in 
  that 
  

   investigation 
  of 
  the 
  nature 
  of 
  muscular 
  motion, 
  for 
  the 
  promotion 
  of 
  which 
  

   the 
  Croonian 
  Lecture 
  was 
  founded. 
  

  

  