﻿394 
  PROFESSOR 
  ALISON'S 
  DEFENCE 
  

  

  salivary 
  glands, 
  of 
  the 
  testes, 
  even 
  of 
  the 
  liver, 
  of 
  which 
  the 
  organisation 
  is 
  the 
  

   most 
  uniform, 
  and 
  likewise 
  of 
  the 
  kidneys." 
  " 
  It 
  would 
  be 
  interesting 
  also," 
  he 
  

   adds, 
  " 
  to 
  compare 
  the 
  secreting 
  organs 
  with 
  then 
  secreted 
  fluids, 
  and 
  observe 
  

   whether 
  the 
  organs 
  that 
  have 
  a 
  similar 
  structure 
  afford 
  similar 
  products. 
  But 
  

   experience 
  will 
  sanction 
  no 
  such 
  theory. 
  Nothing, 
  for 
  example, 
  can 
  be 
  more 
  

   various 
  than 
  the 
  matter 
  furnished 
  by 
  ' 
  crypts' 
  in 
  different 
  animals, 
  from 
  a 
  simple 
  

   mucus 
  to 
  the 
  most 
  odoriferous 
  compounds." 
  " 
  The 
  simplest 
  secreting 
  organs," 
  he 
  

   observes 
  elsewhere, 
  " 
  are 
  in 
  insects, 
  where 
  they 
  are 
  merely 
  tubes 
  which 
  float 
  in 
  the 
  

   general 
  nourishing 
  fluid, 
  which 
  is 
  in 
  contact 
  with 
  their 
  outer 
  surface, 
  while 
  their 
  

   inner 
  surface 
  contains 
  the 
  secreted 
  fluid. 
  Secretion 
  there 
  can 
  be 
  only 
  a 
  kind 
  of 
  

   filtration 
  ; 
  but 
  how 
  different 
  from 
  that 
  which 
  can 
  take 
  place 
  where 
  there 
  is 
  no 
  

   life, 
  through 
  ' 
  an 
  inorganic 
  solid 
  ! 
  ' 
  ' 
  (Legons 
  sur 
  VAnat. 
  Comp. 
  Lect. 
  xxx., 
  Art. 
  1.) 
  

   But 
  farther, 
  not 
  only 
  is 
  the 
  complex 
  vascular 
  structure 
  and 
  the 
  varying 
  pres- 
  

   sure 
  from 
  contracting 
  solids, 
  which 
  was 
  regarded 
  by 
  Murray 
  as 
  the 
  main 
  cause 
  

   of 
  the 
  formation 
  of 
  new 
  compounds 
  out 
  of 
  the 
  blood, 
  shewn 
  by 
  the 
  examination 
  

   of 
  other 
  animals, 
  to 
  be 
  quite 
  unnecessary 
  for 
  that 
  purpose 
  ; 
  but 
  we 
  now 
  know, 
  

   that 
  where 
  these 
  conditions 
  exist, 
  that 
  formation 
  is 
  never 
  effected 
  — 
  the 
  most 
  com- 
  

   pound 
  fluids 
  of 
  the 
  animal 
  economy, 
  which 
  appear 
  in 
  the 
  different 
  glands, 
  being 
  

   really 
  not 
  formed 
  there, 
  but 
  in 
  the 
  course 
  of 
  circulation, 
  and 
  appearing 
  in 
  the 
  

   blood 
  or 
  in 
  other 
  parts 
  of 
  the 
  body 
  when 
  the 
  organs 
  where 
  they 
  usually 
  appear 
  

   have 
  been 
  extirpated, 
  or 
  rendered 
  useless 
  by 
  disease 
  ; 
  that 
  is, 
  when 
  the 
  cause 
  to 
  

   which 
  their 
  origin 
  is 
  here 
  ascribed 
  has 
  been 
  absolutely 
  withdrawn. 
  

  

  The 
  mere 
  selection 
  and 
  attraction 
  out 
  of 
  the 
  blood 
  at 
  different 
  places, 
  of 
  dif- 
  

   ferent 
  compounds 
  already 
  existing 
  and 
  circulating 
  in 
  it, 
  is 
  certainly 
  the 
  chief, 
  and, 
  

   according 
  to 
  many, 
  and 
  particularly 
  according 
  to 
  Dr 
  Daubeny 
  himself, 
  the 
  sole 
  

   office, 
  performed 
  by 
  any 
  parts 
  of 
  animals 
  by 
  which 
  any 
  new 
  organic 
  products 
  are 
  

   exhibited 
  ; 
  and 
  the 
  office 
  of 
  forming 
  those 
  organic 
  compounds, 
  the 
  origin 
  of 
  which 
  

   is 
  the 
  great 
  chemical 
  change 
  effected 
  by 
  living 
  beings, 
  is 
  performed 
  by 
  no 
  organ 
  

   capable 
  of 
  exerting 
  a 
  varying 
  power 
  of 
  contraction 
  and 
  pressure, 
  but 
  simply 
  by 
  

   the 
  cells 
  of 
  vegetables, 
  where 
  the 
  fluid 
  introduced 
  from 
  without 
  is 
  usually 
  not 
  con- 
  

   veyed 
  in 
  vessels 
  at 
  all, 
  and 
  is 
  clearly 
  not 
  subjected 
  to 
  any 
  such 
  pressure 
  from 
  

   contracting 
  solids, 
  as 
  is 
  exerted 
  on 
  the 
  blood 
  in 
  most 
  animals 
  ; 
  nor 
  to 
  any 
  such 
  

   peculiar 
  cause 
  of 
  movement 
  as 
  can 
  be 
  ascribed 
  to 
  the 
  living 
  property 
  of 
  contrac- 
  

   tility, 
  the 
  only 
  one 
  which 
  Dr 
  Daubeny 
  admits 
  to 
  be 
  strictly 
  vital. 
  

  

  I 
  have 
  formerly 
  stated, 
  and 
  notwithstanding 
  the 
  opposition 
  of 
  Dr 
  Daubeny 
  

   and 
  others, 
  still 
  think, 
  that 
  the 
  judgment 
  of 
  various 
  authors 
  on 
  the 
  respective 
  

   offices 
  of 
  vegetables 
  and 
  animals 
  as 
  to 
  vital 
  affinities, 
  — 
  the 
  supposition 
  that 
  no 
  

   organic 
  compound 
  can 
  be 
  formed 
  in 
  animals, 
  and 
  that 
  their 
  office 
  is 
  merely 
  the 
  

   selection 
  and 
  appropriation 
  of 
  the 
  compounds 
  formed 
  in 
  vegetables, 
  and 
  after- 
  

   wards 
  the 
  destructive 
  assimilation 
  by 
  which 
  these 
  are 
  restored, 
  through 
  the 
  excre- 
  

   tions, 
  to 
  the 
  inorganic 
  world, 
  is 
  too 
  hasty. 
  It 
  appears 
  from 
  the 
  experiments 
  of 
  

  

  