﻿208 
  ANNUAL 
  REPORT 
  SMITHSONIAN 
  INSTITUTION, 
  1929 
  

  

  have 
  been 
  the 
  case 
  in 
  the 
  past 
  we 
  have 
  now, 
  by 
  the 
  progress 
  of 
  our 
  

   knowledge 
  reached 
  a 
  dividing 
  line 
  which 
  really 
  marks 
  a 
  difference 
  in 
  

   kind 
  ; 
  that 
  there 
  have 
  been 
  brought 
  to 
  light 
  in 
  the 
  realm 
  of 
  biology 
  

   phenomena 
  of 
  such 
  a 
  nature 
  that 
  they 
  are 
  not 
  explainable 
  by 
  ordinary 
  

   chemical 
  or 
  physical 
  principles; 
  that 
  it 
  is 
  necessary 
  to 
  assume 
  a 
  

   principle 
  peculiar 
  to 
  living 
  matter 
  (in 
  other 
  words, 
  a 
  "vital 
  force") 
  

   to 
  explain 
  them. 
  Let 
  us 
  select 
  what 
  is 
  perhaps 
  an 
  extreme 
  case 
  

   in 
  illustration. 
  

  

  Food 
  taken 
  into 
  the 
  stomach 
  of 
  man 
  and 
  other 
  animals 
  is 
  digested 
  

   by 
  means 
  of 
  the 
  gastric 
  juice. 
  Some 
  of 
  this 
  food 
  is 
  meat 
  (all 
  of 
  it 
  in 
  

   the 
  case 
  of 
  certain 
  animals), 
  muscular 
  tissue 
  like 
  that 
  of 
  the 
  stomach 
  

   itself. 
  The 
  question 
  naturally 
  arises 
  why 
  the 
  gastric 
  juice 
  does 
  not 
  

   digest 
  also 
  the 
  wall 
  of 
  the 
  stomach. 
  Is 
  it 
  not 
  like 
  trying 
  to 
  dissolve 
  a 
  

   piece 
  of 
  zinc 
  in 
  acid 
  contained 
  in 
  a 
  zinc 
  vessel? 
  

  

  It 
  is 
  not 
  easy 
  to 
  answer 
  this 
  question. 
  It 
  can 
  not 
  be 
  due 
  in 
  any 
  way 
  

   to 
  mastication, 
  for 
  if 
  a 
  piece 
  of 
  meat 
  is 
  swallowed 
  without 
  chewing, 
  the 
  

   stomach 
  will 
  eventually 
  digest 
  it. 
  It 
  can 
  not 
  be 
  argued 
  that 
  cooking 
  

   accounts 
  for 
  the 
  difference, 
  for 
  this 
  is 
  an 
  art 
  practiced 
  by 
  man 
  alone, 
  

   and 
  is 
  a 
  comparatively 
  late 
  acquisition 
  on 
  his 
  part. 
  And 
  in 
  the 
  face 
  

   of 
  the 
  use 
  of 
  tripe 
  as 
  an 
  article 
  of 
  food 
  it 
  can 
  not 
  be 
  that 
  the 
  stomach 
  

   contains 
  a 
  protective 
  substance 
  which 
  other 
  muscular 
  tissue 
  does 
  not 
  

   possess. 
  

  

  There 
  seems 
  to 
  be 
  no 
  difference 
  between 
  the 
  stomach 
  and 
  the 
  food 
  

   other 
  than 
  that 
  the 
  stomach 
  is 
  alive 
  and 
  the 
  food 
  dead, 
  whatever 
  this 
  

   may 
  mean; 
  and 
  even 
  this 
  explanation 
  is 
  hard 
  pushed 
  by 
  the 
  fact 
  that 
  

   the 
  food 
  of 
  carnivorous 
  animals 
  under 
  natural 
  conditions 
  usually 
  

   reaches 
  the 
  stomach 
  of 
  the 
  captor 
  in 
  a 
  very 
  short 
  time 
  after 
  the 
  death 
  

   of 
  the 
  prey, 
  an 
  interval 
  measurable 
  almost 
  in 
  seconds. 
  

  

  By 
  considerations 
  such 
  as 
  these 
  the 
  controversy 
  between 
  the 
  vitalist 
  

   and 
  the 
  mechanist 
  is 
  kept 
  alive. 
  The 
  vitalist 
  maintains 
  that 
  between 
  

   the 
  phenomena 
  of 
  the 
  living 
  and 
  the 
  nonliving 
  there 
  is 
  a 
  difference 
  in 
  

   kind, 
  not 
  merely 
  in 
  degree. 
  Just 
  what 
  this 
  difference 
  may 
  be 
  he 
  is 
  not 
  

   prepared 
  to 
  say, 
  but 
  he 
  maintains 
  its 
  existence. 
  The 
  mechanist, 
  

   on 
  the 
  other 
  hand, 
  says 
  that 
  exactly 
  the 
  same 
  arguments 
  have 
  been 
  

   advanced 
  in 
  the 
  past 
  in 
  connection 
  with 
  problems 
  that 
  seemed 
  just 
  as 
  

   insoluble, 
  and 
  that 
  these 
  arguments 
  have 
  finally 
  been 
  disposed 
  of 
  by 
  

   the 
  progress 
  of 
  our 
  knowledge. 
  Differences 
  in 
  kind, 
  once 
  regarded 
  as 
  

   numerous 
  in 
  Nature, 
  have 
  slowly 
  and 
  steadily 
  been 
  resolved 
  into 
  

   differences 
  in 
  degree. 
  Sharp 
  lines 
  of 
  demarcation 
  have 
  been 
  wiped 
  out 
  

   until 
  the 
  line 
  between 
  the 
  living 
  and 
  the 
  nonliving 
  is 
  perhaps 
  the 
  only 
  

   one 
  left. 
  Such 
  diverse 
  phenomena 
  as 
  those 
  of 
  electricity 
  and 
  light 
  

   have 
  been 
  found 
  to 
  be 
  closely 
  akin; 
  man 
  himself 
  has 
  been 
  shown 
  to 
  be 
  

   one 
  with 
  the 
  rest 
  of 
  animated 
  Nature 
  ; 
  and 
  if 
  the 
  past 
  is 
  any 
  guide 
  to 
  

   the 
  future, 
  it 
  seems 
  that 
  even 
  this 
  last 
  sharp 
  line 
  will 
  some 
  day 
  dis- 
  

   appear 
  also. 
  

  

  